WorldWideScience

Sample records for atmospheric cherenkov telescopes

  1. CELESTE: an atmospheric Cherenkov telescope for high energy gamma astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Pare, E.; Balauge, B.; Bazer-Bachi, R.; Bergeret, H.; Berny, F.; Briand, N.; Bruel, P.; Cerutti, M.; Collon, J.; Cordier, A.; Cornebise, P.; Debiais, G.; Dezalay, J.-P.; Dumora, D.; Durand, E.; Eschstruth, P.; Espigat, P.; Fabre, B.; Fleury, P.; Gilly, J.; Gouillaud, J.-C.; Gregory, C.; Herault, N.; Holder, J.; Hrabovsky, M.; Incerti, S.; Jouenne, A.; Kalt, L.; LeGallou, R.; Lott, B.; Lodygensky, O.; Manigot, P.; Manseri, H.; Manitaz, H.; Martin, M.; Morano, R.; Morineaud, G.; Muenz, F.; Musquere, A.; Naurois, M. de; Neveu, J.; Noppe, J.-M.; Olive, J.-F.; Palatka, M.; Perez, A.; Quebert, J.; Rebii, A.; Reposeur, T. E-mail: reposeur@in2p3.fr; Rob, L.; Roy, P.; Sans, J.-L.; Sako, T.; Schovanek, P.; Smith, D.A.; Snabre, P.; Villard, G

    2002-09-01

    CELESTE is an atmospheric Cherenkov telescope based on the sampling method which makes use of the de-commissioned THEMIS solar electrical plant in the French Pyrenees. A large (2000 m{sup 2}) mirror surface area from 40 independent heliostats followed by a secondary optic, a trigger system using analog summing techniques and signal digitization with 1 GHz flash ADCs make possible the detection of cosmic {gamma}-rays down to 30 GeV. This paper provides a detailed technical description of the CELESTE installation.

  2. Upgraded cameras for the HESS imaging atmospheric Cherenkov telescopes

    Science.gov (United States)

    Giavitto, Gianluca; Ashton, Terry; Balzer, Arnim; Berge, David; Brun, Francois; Chaminade, Thomas; Delagnes, Eric; Fontaine, Gérard; Füßling, Matthias; Giebels, Berrie; Glicenstein, Jean-François; Gräber, Tobias; Hinton, James; Jahnke, Albert; Klepser, Stefan; Kossatz, Marko; Kretzschmann, Axel; Lefranc, Valentin; Leich, Holger; Lüdecke, Hartmut; Lypova, Iryna; Manigot, Pascal; Marandon, Vincent; Moulin, Emmanuel; de Naurois, Mathieu; Nayman, Patrick; Penno, Marek; Ross, Duncan; Salek, David; Schade, Markus; Schwab, Thomas; Simoni, Rachel; Stegmann, Christian; Steppa, Constantin; Thornhill, Julian; Toussnel, François

    2016-08-01

    The High Energy Stereoscopic System (H.E.S.S.) is an array of five imaging atmospheric Cherenkov telescopes, sensitive to cosmic gamma rays of energies between 30 GeV and several tens of TeV. Four of them started operations in 2003 and their photomultiplier tube (PMT) cameras are currently undergoing a major upgrade, with the goals of improving the overall performance of the array and reducing the failure rate of the ageing systems. With the exception of the 960 PMTs, all components inside the camera have been replaced: these include the readout and trigger electronics, the power, ventilation and pneumatic systems and the control and data acquisition software. New designs and technical solutions have been introduced: the readout makes use of the NECTAr analog memory chip, which samples and stores the PMT signals and was developed for the Cherenkov Telescope Array (CTA). The control of all hardware subsystems is carried out by an FPGA coupled to an embedded ARM computer, a modular design which has proven to be very fast and reliable. The new camera software is based on modern C++ libraries such as Apache Thrift, ØMQ and Protocol buffers, offering very good performance, robustness, flexibility and ease of development. The first camera was upgraded in 2015, the other three cameras are foreseen to follow in fall 2016. We describe the design, the performance, the results of the tests and the lessons learned from the first upgraded H.E.S.S. camera.

  3. A site evaluation campaign for a ground based atmospheric Cherenkov telescope in Romania

    Science.gov (United States)

    Radu, Aurelian Andrei; Angelescu, Tatiana; Curtef, Valentin; Delia, Florin; Felea, Daniel; Goia, Ioana; Haşegan, Dumitru; Lucaschi, Bogdan; Manea, Ancuta; Popa, Vlad; Raliţă, Ioan; Văcăreanu, Radu

    2012-07-01

    Around the world, several scientific projects share the interest of a global network of small Cherenkov telescopes for monitoring observations of the brightest blazars—the DWARF network. A small, ground based, imaging atmospheric Cherenkov telescope of last generation is intended to be installed and operated in Romania as a component of the DWARF network. To prepare the construction of the observatory, two support projects have been initiated. Within the framework of these projects, we have assessed a number of possible sites where to settle the observatory. In this paper we submit a brief report on the general characteristics of the best four sites selected after the local infrastructure, the nearby facilities and the social impact criteria have been applied.

  4. Front-end electronics and data acquisition system for imaging atmospheric Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Y.T., E-mail: chenytao@ynu.edu.cn [Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, 91406 Orsay Cedex (France); Yunnan University, 650091 Kunming (China); La Taille, C. de [OMEGA (UMS 3605) - IN2P3/CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Suomijärvi, T. [Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, 91406 Orsay Cedex (France); Cao, Z. [Institute of High Energy Physics, 100049 Beijing (China); Deligny, O. [Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, 91406 Orsay Cedex (France); Dulucq, F. [OMEGA (UMS 3605) - IN2P3/CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Ge, M.M. [Yunnan University, 650091 Kunming (China); Lhenry-Yvon, I. [Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, 91406 Orsay Cedex (France); Martin-Chassard, G. [OMEGA (UMS 3605) - IN2P3/CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France); Nguyen Trung, T.; Wanlin, E. [Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, 91406 Orsay Cedex (France); Xiao, G.; Yin, L.Q. [Institute of High Energy Physics, 100049 Beijing (China); Yun Ky, B. [Institut de Physique Nucléaire, IN2P3-CNRS, Université Paris-Sud, 91406 Orsay Cedex (France); Zhang, L. [Yunnan University, 650091 Kunming (China); Zhang, H.Y. [Tsinghua University, 100084 Beijing (China); Zhang, S.S.; Zhu, Z. [Institute of High Energy Physics, 100049 Beijing (China)

    2015-09-21

    In this paper, a front-end electronics based on an application-specific integrated circuit (ASIC) is presented for the future imaging atmospheric Cherenkov telescopes (IACTs). To achieve this purpose, a 16-channel ASIC chip, PARISROC 2 (Photomultiplier ARray Integrated in SiGe ReadOut Chip) is used in the analog signal processing and digitization. The digitized results are sent to the server by a user-defined User Datagram Protocol/Internet Protocol (UDP/IP) hardcore engine through Ethernet that is managed by a FPGA. A prototype electronics fulfilling the requirements of the Wide Field of View Cherenkov Telescope Array (WFCTA) of the Large High Altitude Air Shower Observatory (LHAASO) project has been designed, fabricated and tested to prove the concept of the design. A detailed description of the development with the results of the test measurements are presented. By using a new input structure and a new configuration of the ASIC, the dynamic range of the circuit is extended. A highly precise-time calibrating algorithm is also proposed, verified and optimized for the mass production. The test results suggest that the proposed electronics design fulfills the general specification of the future IACTs.

  5. Gamma/hadron segregation for a ground based imaging atmospheric Cherenkov telescope using machine learning methods: Random Forest leads

    Science.gov (United States)

    Sharma, Mradul; Nayak, Jitadeepa; Krishna Koul, Maharaj; Bose, Smarajit; Mitra, Abhas

    2014-11-01

    A detailed case study of γ-hadron segregation for a ground based atmospheric Cherenkov telescope is presented. We have evaluated and compared various supervised machine learning methods such as the Random Forest method, Artificial Neural Network, Linear Discriminant method, Naive Bayes Classifiers, Support Vector Machines as well as the conventional dynamic supercut method by simulating triggering events with the Monte Carlo method and applied the results to a Cherenkov telescope. It is demonstrated that the Random Forest method is the most sensitive machine learning method for γ-hadron segregation.

  6. Exploring physics of rotation powered pulsars with sub-10 GeV imaging atmospheric Cherenkov telescopes

    Science.gov (United States)

    Aharonian, F. A.; Bogovalov, S. V.

    2003-02-01

    We discuss the potential of future sub-10 GeV threshold imaging atmospheric Cherenkov telescope arrays for exploring the physics of rotation powered pulsars and their interactions with the ambient medium through relativistic winds and termination shocks. One such telescope is the high-altitude concept called '5@5' recently suggested by Aharonian [APh 5 (2001) 335]. 5@5, with its enormous detection area exceeding 10 4 m 2 at the threshold energy of about 5 GeV, combines two distinct features of the current satellite-borne (large photon fluxes at GeV energies) and ground-based (large detection areas at TeV energies) γ-ray astronomies. Such an instrument would allow comprehensive studies of temporal and spectral characteristics of γ-ray pulsars in the crucial 5 to 30 GeV energy interval. An equally important topic in the program of pulsar studies by 5@5 would be the search for GeV γ-radiation from other radio pulsars at a few mVela level. Finally, the searches for pulsed radiation components in the spectra of a large fraction of unidentified EGRET sources (suspected to be pulsars) without invoking information from lower (radio, optical, X-ray) frequency domains, seems to be another important issue, because the periodic signals at lower energies could be significantly suppressed in many cases. The detection rate of γ-rays from 'standard' EGRET sources by 5@5 is expected to exceed ten events per one second. This should provide an adequate photon statistics for the search for periodic signals at the flux level of 3 mVela within the observation time of 3 h or so (a time resolution below which any change of a signal's phase can be ignored). The spectral coverage by 5@5 and its flux sensitivity are nicely suited for studying other aspects of pulsar physics and astrophysics, in particular for detecting unshocked relativistic pulsar winds, as well as for quantifying characteristics of pulsar driven synchrotron nebulae through the inverse Compton radiation at energies

  7. FACT. Bokeh alignment for Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Sebastian Achim [ETH Zurich (Switzerland); Buss, Jens [TU Dortmund (Germany)

    2016-07-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) need fast and large imaging optics to map the faint Cherenkov light emitted in cosmic ray air showers onto their image sensors. Segmented reflectors are inexpensive, lightweight and offer good image quality. However, alignment of the mirror facets remains a challenge. A good alignment is crucial in IACT observations to separate gamma rays from hadronic cosmic rays. We present a simple, yet extendable method, to align segmented reflectors using their Bokeh. Bokeh alignment does not need a star or good weather nights but can be done anytime, even during the day. Bokeh alignment optimizes the facet orientations by comparing the segmented reflector's Bokeh to a predefined template. The Bokeh is observed using the out of focus image of a nearby point like light source in a distance of about ten times the focal lengths. We introduce Bokeh alignment on segmented reflectors and present its use on the First Geiger-mode Avalanche Cherenkov Telescope (FACT) on Canary Island La Palma, as well as on the Cherenkov Telescope Array (CTA) Medium Size Telescope (MST) prototype in Berlin Adlershof.

  8. TARGET 5: A new multi-channel digitizer with triggering capabilities for gamma-ray atmospheric Cherenkov telescopes

    Science.gov (United States)

    Albert, A.; Funk, S.; Katagiri, H.; Kawashima, T.; Murphy, M.; Okumura, A.; Quagliani, R.; Sapozhnikov, L.; Shigenaka, A.; Tajima, H.; Tibaldo, L.; Vandenbroucke, J.; Varner, G.; Wu, T.

    2017-06-01

    TARGET 5 is a new application-specific integrated circuit (ASIC) of the TARGET family, designed for the readout of signals from photosensors in the cameras of imaging atmospheric Cherenkov telescopes (IACTs) for ground-based gamma-ray astronomy. TARGET 5 combines sampling and digitization on 16 signal channels with the formation of trigger signals based on the analog sum of groups of four channels. We describe the ASIC architecture and performance. TARGET 5 improves over the performance of the first-generation TARGET ASIC, achieving: tunable sampling frequency from 1 GSa/s; a dynamic range on the data path of 1.2 V with effective dynamic range of 11 bits and DC noise of ∼0.6 mV; 3-dB bandwidth of 500 MHz; crosstalk between adjacent channels 100 p.e. (assuming 4 mV per p.e.); and minimum stable trigger threshold of 20 mV (5 p.e.) with trigger noise of 5 mV (1.2 p.e.), which is mostly limited by interference between trigger and sampling operations. TARGET 5 is the first ASIC of the TARGET family used in an IACT prototype, providing one development path for readout electronics in the forthcoming Cherenkov Telescope Array (CTA).

  9. Rare Events searches with Cherenkov Telescopes

    Directory of Open Access Journals (Sweden)

    Doro Michele

    2017-01-01

    Full Text Available Ground-based Imaging Cherenkov Telescope Arrays observe the Cherenkov radiation emitted in extended atmospheric showers generated by cosmic gamma rays in the TeV regime. The rate of these events is normally overwhelmed by 2–3 orders of magnitude more abundant cosmic rays induced showers. A large fraction of these “back-ground” events is vetoed at the on-line trigger level, but a substantial fraction still goes through data acquisition system and is saved for the off-line reconstruction. What kind of information those events carry, normally rejected in the analysis? Is there the possibility that an exotic signature is hidden in those data? In the contribution, some science cases, and the problems related to the event reconstruction for the current and future generation of these telescopes will be discussed.

  10. Camera Development for the Cherenkov Telescope Array

    Science.gov (United States)

    Moncada, Roberto Jose

    2017-01-01

    With the Cherenkov Telescope Array (CTA), the very-high-energy gamma-ray universe, between 30 GeV and 300 TeV, will be probed at an unprecedented resolution, allowing deeper studies of known gamma-ray emitters and the possible discovery of new ones. This exciting project could also confirm the particle nature of dark matter by looking for the gamma rays produced by self-annihilating weakly interacting massive particles (WIMPs). The telescopes will use the imaging atmospheric Cherenkov technique (IACT) to record Cherenkov photons that are produced by the gamma-ray induced extensive air shower. One telescope design features dual-mirror Schwarzschild-Couder (SC) optics that allows the light to be finely focused on the high-resolution silicon photomultipliers of the camera modules starting from a 9.5-meter primary mirror. Each camera module will consist of a focal plane module and front-end electronics, and will have four TeV Array Readout with GSa/s Sampling and Event Trigger (TARGET) chips, giving them 64 parallel input channels. The TARGET chip has a self-trigger functionality for readout that can be used in higher logic across camera modules as well as across individual telescopes, which will each have 177 camera modules. There will be two sites, one in the northern and the other in the southern hemisphere, for full sky coverage, each spanning at least one square kilometer. A prototype SC telescope is currently under construction at the Fred Lawrence Whipple Observatory in Arizona. This work was supported by the National Science Foundation's REU program through NSF award AST-1560016.

  11. Volcanoes muon imaging using Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Catalano, O. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Del Santo, M., E-mail: melania@ifc.inaf.it [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Mineo, T.; Cusumano, G.; Maccarone, M.C. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, via U. La Malfa 153, I-90146 Palermo (Italy); Pareschi, G. [INAF Osservatorio Astronomico di Brera, Via E. Bianchi 46, I-23807, Merate (Italy)

    2016-01-21

    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting of the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energy. Our new approach offers the advantage of a negligible background and an improved spatial resolution. To test the feasibility of our new method, we have carried out simulations with a toy-model based on the geometrical parameters of ASTRI SST-2M, i.e. the imaging atmospheric Cherenkov telescope currently under installation onto the Etna volcano. Comparing the results of our simulations with previous experiments based on particle detectors, we gain at least a factor of 10 in sensitivity. The result of this study shows that we resolve an empty cylinder with a radius of about 100 m located inside a volcano in less than 4 days, which implies a limit on the magma velocity of 5 m/h.

  12. Design Concepts for the Cherenkov Telescope Array

    OpenAIRE

    Actis, M.; Agnetta, G.; Aharonian, F.; Akhperjanian, A.; Aleksić, J.; Aliu, E.; ALLAN, D.; Allekotte, I.; Antico, F.; Antonelli, L. A.; Antoranz, P.; Aravantinos, A.; Arlen, T.; Arnaldi, H.; Artmann, S.

    2010-01-01

    Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV to 10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will con...

  13. Performance of the Reflector of the CANGAROO-III Imaging Atmospheric Cherenkov Telescope

    Science.gov (United States)

    Ohnishi, M.; Kawachi, A.; Mori, M.; Asahara, A.; Bicknell, G. V.; Clay, R. W.; Doi, Y.; Edwards, P. G.; Enomoto, R.; Gunji, S.; Hara, S.; Hara, T.; Hattori, T.; Itoh, C.; Kabuki, S.; Kajino, F.; Katagiri, H.; Kifune, T.; Ksenofontov, L. T.; Kurihara, T.; Kurosaka, R.; Kushida, J.; Matsubara, Y.; Miyashita, Y.; Mizumoto, Y.; Moro, H.; Muraishi, H.; Muraki, Y.; Naito, T.; Nakase, T.; Nishida, D.; Nishijima, K.; Okumura, K.; Patterson, J. R.; Protheore, R. J.; Sakamoto, N.; Sakurazawa, K.; Swaby, D. L.; Tanimori, T.; Tanimura, H.; Thornton, G.; Tokanai, F.; Tsuchiya, K.; Uchida, T.; Watanabe, S.; Yamaoka, T.; Yanagita, S.; Yoshida, T.; Yoshikoshi, T.

    2003-07-01

    The second 10m-diameter telescope of the CANGAROO-I I I project was completed in December 2002. The reflector is a tessellated parab oloid which consists of 114 spherical mirror segments with a f/d ratio of 0.8. In order to obtain light-weight, durable segments, we have been working on development of FRP (Fib er Reinforced Plastic) composite mirrors since 1995. These segments are all equipp ed with a remote-control alignment system and their optical axes were aligned using bright stars as standard light sources.

  14. Mirror position determination for the alignment of Cherenkov Telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Adam, J. [TU Dortmund, Experimental Physics 5 Otto-Hahn-Str. 4, 44221 Dortmund (Germany); Ahnen, M.L. [ETH Zurich, Institute for Particle Physics Otto-Stern-Weg 5, 8093 Zurich (Switzerland); Baack, D. [TU Dortmund, Experimental Physics 5 Otto-Hahn-Str. 4, 44221 Dortmund (Germany); Balbo, M. [University of Geneva, ISDC Data Center for Astrophysics Chemin Ecogia 16, 1290 Versoix (Switzerland); Bergmann, M. [Universität Würzburg, Institute for Theoretical Physics and Astrophysics Emil-Fischer-Str. 31, 97074 Würzburg (Germany); Biland, A. [ETH Zurich, Institute for Particle Physics Otto-Stern-Weg 5, 8093 Zurich (Switzerland); Blank, M. [Universität Würzburg, Institute for Theoretical Physics and Astrophysics Emil-Fischer-Str. 31, 97074 Würzburg (Germany); Bretz, T. [ETH Zurich, Institute for Particle Physics Otto-Stern-Weg 5, 8093 Zurich (Switzerland); RWTH Aachen (Germany); Bruegge, K.A.; Buss, J. [TU Dortmund, Experimental Physics 5 Otto-Hahn-Str. 4, 44221 Dortmund (Germany); Dmytriiev, A. [University of Geneva, ISDC Data Center for Astrophysics Chemin Ecogia 16, 1290 Versoix (Switzerland); Domke, M. [TU Dortmund, Experimental Physics 5 Otto-Hahn-Str. 4, 44221 Dortmund (Germany); Dorner, D. [Universität Würzburg, Institute for Theoretical Physics and Astrophysics Emil-Fischer-Str. 31, 97074 Würzburg (Germany); FAU Erlangen (Germany); Einecke, S. [TU Dortmund, Experimental Physics 5 Otto-Hahn-Str. 4, 44221 Dortmund (Germany); Hempfling, C. [Universität Würzburg, Institute for Theoretical Physics and Astrophysics Emil-Fischer-Str. 31, 97074 Würzburg (Germany); and others

    2017-07-11

    Imaging Atmospheric Cherenkov Telescopes (IACTs) need imaging optics with large apertures to map the faint Cherenkov light emitted in extensive air showers onto their image sensors. Segmented reflectors fulfill these needs using mass produced and light weight mirror facets. However, as the overall image is the sum of the individual mirror facet images, alignment is important. Here we present a method to determine the mirror facet positions on a segmented reflector in a very direct way. Our method reconstructs the mirror facet positions from photographs and a laser distance meter measurement which goes from the center of the image sensor plane to the center of each mirror facet. We use our method to both align the mirror facet positions and to feed the measured positions into our IACT simulation. We demonstrate our implementation on the 4 m First Geiger-mode Avalanche Cherenkov Telescope (FACT).

  15. Muon imaging of volcanoes with Cherenkov telescopes

    Science.gov (United States)

    Carbone, Daniele; Catalano, Osvaldo; Cusumano, Giancarlo; Del Santo, Melania; La Parola, Valentina; La Rosa, Giovanni; Maccarone, Maria Concetta; Mineo, Teresa; Pareschi, Giovanni; Sottile, Giuseppe; Zuccarello, Luciano

    2017-04-01

    The quantitative understanding of the inner structure of a volcano is a key feature to model the processes leading to paroxysmal activity and, hence, to mitigate volcanic hazards. To pursue this aim, different geophysical techniques are utilized, that are sensitive to different properties of the rocks (elastic, electrical, density). In most cases, these techniques do not allow to achieve the spatial resolution needed to characterize the shallowest part of the plumbing system and may require dense measurements in active zones, implying a high level of risk. Volcano imaging through cosmic-ray muons is a promising technique that allows to overcome the above shortcomings. Muons constantly bombard the Earth's surface and can travel through large thicknesses of rock, with an energy loss depending on the amount of crossed matter. By measuring the absorption of muons through a solid body, one can deduce the density distribution inside the target. To date, muon imaging of volcanic structures has been mainly achieved with scintillation detectors. They are sensitive to noise sourced from (i) the accidental coincidence of vertical EM shower particles, (ii) the fake tracks initiated from horizontal high-energy electrons and low-energy muons (not crossing the target) and (iii) the flux of upward going muons. A possible alternative to scintillation detectors is given by Cherenkov telescopes. They exploit the Cherenkov light emitted when charged particles (like muons) travel through a dielectric medium, with velocity higher than the speed of light. Cherenkov detectors are not significantly affected by the above noise sources. Furthermore, contrarily to scintillator-based detectors, Cherenkov telescopes permit a measurement of the energy spectrum of the incident muon flux at the installation site, an issue that is indeed relevant for deducing the density distribution inside the target. In 2014, a prototype Cherenkov telescope was installed at the Astrophysical Observatory of Serra

  16. FACT. Normalized and asynchronous mirror alignment for Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Sebastian Achim [ETH Zurich (Switzerland); Buss, Jens [TU Dortmund (Germany)

    2016-07-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) need fast and large imaging optics to map the faint Cherenkov light emitted in cosmic ray air showers onto their image sensors. Segmented reflectors are inexpensive, lightweight and offer good image quality. However, alignment of the mirror facets remains a challenge. A good alignment is crucial in IACT observations to separate gamma rays from hadronic cosmic rays. We present a star tracking alignment method which is not restricted to clear nights. It normalizes the mirror facet reflections to be independent of the reference star or the cloud coverage. It records asynchronously of the telescope drive which makes the method easy to integrate in existing telescopes. It can be combined with remote facet actuation, but it does not need one to work. Furthermore, it can reconstruct all individual mirror facet point spread functions. We present the method and alignment results on the First Geiger-mode Photo Diode Avalanche Cherenkov Telescope (FACT) on the Canary Island of La Palma, Spain.

  17. Cherenkov Telescope Array: the next-generation gamma ray observatory

    Science.gov (United States)

    Ebr, Jan

    2017-08-01

    The Cherenkov Telescope Array (CTA) is a project to build the next generation ground-based observatory for gamma-ray astronomy at very-high energies in the range from 20 GeV to 300 TeV, which will both surpass the sensitivity of existing instruments in their energy domains and extend the limits of the observed energy spectrum. It will probe some of the most energetic processes in the Universe and provide insight into topics such as the acceleration of charged cosmic rays and their role in galaxy evolution, processes in relativistic jets, wind and explosions and the nature and distribution of dark matter. The CTA Observatory will consist of more than a hundred imaging atmospheric Cherenkov telescopes (IACT) of three different size classes, installed at two premier astronomical locations, one in each hemisphere. It is foreseen that the telescopes will use a variety of optical designs including parabolic primary mirrors, variations of the Davies-Cotton design and two-mirror setups such as the Schwarzschild-Couder telescope, and several camera designs, using both photomultiplier tubes (PMTs) and silicon photomultipliers (SiPMs) for detection of the nanosecond-scale Cherenkov flashes. Each telescope will feature a precise but lightweight and agile mount, allowing even the largest telescopes to change targets within 20 seconds, with systems of sensors and actuators actively controlling the shape of the reflecting surfaces. As an integral part, the Observatory will feature extensive calibration facilities, closely monitoring both the detectors themselves and the surrounding atmosphere. Several telescope prototypes already exist and the installation works at the northern site have started.

  18. PyFACT: Python and FITS analysis for Cherenkov telescopes

    Science.gov (United States)

    Raue, Martin; Deil, Christoph

    2012-12-01

    Ground-based very-high energy (VHE; E>100 GeV) gamma-ray astronomy is growing from being conducted by small teams in closed collaborations into a full-fledged branch of astronomy with open observatories. This is best illustrated by the number of known sources: it increased by one order of magnitude in the past ten years, from 10 in the year 2000 to more than 100 in 2010. It is expected that this trend will continue with the next-generation instrument Cherenkov Telescope Array (CTA). This transformation has a profound impact on the data format and analysis of Imaging Atmospheric Cherenkov Telescopes (IACTs). Up to now, IACT data analysis was an internal task performed by specialists with no public access to the data or software. In the future, a large community of VHE astronomers from different scientific topics should be enabled to work with the data. Ease of use, compatibility, and integration with existing astronomy standards and tools will be key. In this contribution, a collection of Python tools for the analysis of data in FITS format (PyFACT; Python and FITS Analysis for Cherenkov Telescopes) is presented, which connects with existing tools like xspec, sherpa, and ds9. The package is available as open source (https://github.com/mraue/pyfact, comments and contributions welcome). Advantages of the chosen ansatz are discussed and implications for future observatories and data archival are presented.

  19. Construction of a Schwarzschild-Couder telescope as a candidate for the Cherenkov Telescope Array: status of the optical system

    OpenAIRE

    Rousselle, J.; Byrum, K.; Cameron, R.; Connaughton, V.; Errando, M.; Guarino, V.; Humensky, T.; Jenke, P.; Kieda, D.; Mukherjee, R.; Nieto, D.; Okumura, A.; Petrashyk, A; Vassiliev, V.

    2015-01-01

    We present the design and the status of procurement of the optical system of the prototype Schwarzschild-Couder telescope (pSCT), for which construction is scheduled to begin in fall at the Fred Lawrence Whipple Observatory in southern Arizona, USA. The Schwarzschild-Couder telescope is a candidate for the medium-sized telescopes of the Cherenkov Telescope Array, which utilizes imaging atmospheric Cherenkov techniques to observe gamma rays in the energy range of 60Gev-60TeV. The pSCT novel ap...

  20. Prototyping the graphical user interface for the operator of the Cherenkov Telescope Array

    Science.gov (United States)

    Sadeh, I.; Oya, I.; Schwarz, J.; Pietriga, E.

    2016-07-01

    The Cherenkov Telescope Array (CTA) is a planned gamma-ray observatory. CTA will incorporate about 100 imaging atmospheric Cherenkov telescopes (IACTs) at a Southern site, and about 20 in the North. Previous IACT experiments have used up to five telescopes. Subsequently, the design of a graphical user interface (GUI) for the operator of CTA involves new challenges. We present a GUI prototype, the concept for which is being developed in collaboration with experts from the field of Human-Computer Interaction (HCI). The prototype is based on Web technology; it incorporates a Python web server, Web Sockets and graphics generated with the d3.js Javascript library.

  1. NECTAr: New electronics for the Cherenkov Telescope Array

    Energy Technology Data Exchange (ETDEWEB)

    Vorobiov, S., E-mail: vorobiov@lpta.in2p3.f [LPTA, Universite Montpellier II and IN2P3/CNRS, Montpellier (France); Bolmont, J.; Corona, P. [LPNHE, Universite Paris VI and IN2P3/CNRS, Paris (France); Delagnes, E. [IRFU/DSM/CEA, Saclay, Gif-sur-Yvette (France); Feinstein, F. [LPTA, Universite Montpellier II and IN2P3/CNRS, Montpellier (France); Gascon, D. [ICC-UB, Universitat Barcelona, Barcelona (Spain); Glicenstein, J.-F. [IRFU/DSM/CEA, Saclay, Gif-sur-Yvette (France); Naumann, C.L.; Nayman, P. [LPNHE, Universite Paris VI and IN2P3/CNRS, Paris (France); Sanuy, A. [ICC-UB, Universitat Barcelona, Barcelona (Spain); Toussenel, F.; Vincent, P. [LPNHE, Universite Paris VI and IN2P3/CNRS, Paris (France)

    2011-05-21

    The European astroparticle physics community aims to design and build the next generation array of Imaging Atmospheric Cherenkov Telescopes (IACTs), that will benefit from the experience of the existing H.E.S.S. and MAGIC detectors, and further expand the very-high energy astronomy domain. In order to gain an order of magnitude in sensitivity in the 10 GeV to >100TeV range, the Cherenkov Telescope Array (CTA) will employ 50-100 mirrors of various sizes equipped with 1000-4000 channels per camera, to be compared with the 6000 channels of the final H.E.S.S. array. A 3-year program, started in 2009, aims to build and test a demonstrator module of a generic CTA camera. We present here the NECTAr design of front-end electronics for the CTA, adapted to the trigger and data acquisition of a large IACTs array, with simple production and maintenance. Cost and camera performances are optimized by maximizing integration of the front-end electronics (amplifiers, fast analog samplers, ADCs) in an ASIC, achieving several GS/s and a few {mu}s readout dead-time. We present preliminary results and extrapolated performances from Monte Carlo simulations.

  2. Development of the optical system for the SST-1M telescope of the Cherenkov Telescope Array observatory

    CERN Document Server

    Ostrowski, Michael; Błocki, J.; Bogacz, L.; Bulik, T.; Cadoux, F.; Christov, A.; Curyło, M.; della Volpe, D.; Dyrda, M.; Favre, Y.; Frankowski, A.; Grudnik, Ł.; Grudzińska, M.; Heller, M.; Idźkowski, B.; Jamrozy, M.; Janiak, M.; Kasperek, J.; Lalik, K.; Lyard, E.; Mach, E.; Mandat, D.; Marszałek, A.; Michałowski, J.; Moderski, R.; Montaruli, T.; Neronov, A.; Niemiec, J.; Paśko, P.; Pech, M.; Porcelli, A.; Prandini, E.; Pueschel, E.; Rajda, P.; Rameez, M.; Schioppa, E. jr; Schovanek, P.; Skowron, K.; Sliusar, V.; Sowiński, M.; Stawarz, Ł.; Stodulska, M.; Stodulski, M.; Toscano, S.; Troyano Pujadas, I.; Walter, R.; Wiȩcek, M.; Zagdański, A.; Ziȩtara, K.; Żychowski, P.; Barciński, T.; Karczewski, M.; Kukliński, J. Nicolau; Płatos, Ł.; Rataj, M.; Wawer, P.; Wawrzaszek, R.

    2016-01-01

    The prototype of a Davies-Cotton small size telescope (SST-1M) has been designed and developed by a consortium of Polish and Swiss institutions and proposed for the Cherenkov Telescope Array (CTA) observatory. The main purpose of the optical system is to focus the Cherenkov light emitted by extensive air showers in the atmosphere onto the focal plane detectors. The main component of the system is a dish consisting of 18 hexagonal mirrors with a total effective collection area of 6.47 m2 (including the shadowing and estimated mirror reflectivity). Such a solution was chosen taking into account the analysis of the Cherenkov light propagation and based on optical simulations. The proper curvature and stability of the dish is ensured by the mirror alignment system and the isostatic interface to the telescope structure. Here we present the design of the optical subsystem together with the performance measurements of its components.

  3. On-site mirror facet condensation measurements for the Cherenkov Telescope Array

    Energy Technology Data Exchange (ETDEWEB)

    Dipold, J., E-mail: jessica.dipold@gmail.com [Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP (Brazil); Medina, M.C. [Instituto Argentino de Radioastronomía, CCT La Plata-CONICET (Argentina); García, B. [Instituto en Tecnologías de Detección y Astropartículas, CNEA, CONICET, UNSAM (Argentina); Universidad Tecnológica Nacional, FR-Mendoza (Argentina); Rasztocky, E. [Instituto Argentino de Radioastronomía, CCT La Plata-CONICET (Argentina); Mancilla, A.; Maya, J. [Instituto en Tecnologías de Detección y Astropartículas, CNEA, CONICET, UNSAM (Argentina); Larrarte, J.J. [Instituto Argentino de Radioastronomía, CCT La Plata-CONICET (Argentina); Souza, V. de [Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP (Brazil)

    2016-09-11

    The Imaging Atmospheric Cherenkov Technique (IACT) has provided very important discoveries in Very High Energy (VHE) γ-ray astronomy for the last two decades, being exploited mainly by experiments such as H.E.S.S., MAGIC and VERITAS. The same technique will be used by the next generation of γ-ray telescopes, Cherenkov Telescope Array – CTA, which is conceived to be an Observatory composed by two arrays strategically placed in both hemispheres, one in the Northern and one in the Southern. Each site will consist of several tens of Cherenkov telescopes of different sizes and will be equipped with about 10000 m{sup 2} of reflective surface. Because of its large size, the reflector of a Cherenkov telescope is composed of many individual mirror facets. Cherenkov telescopes operate without any protective system from weather conditions therefore it is important to understand how the reflective surfaces behave under different environmental conditions. This paper describes a study of the behavior of the mirrors in the presence of water vapor condensation. The operational time of a telescope is reduced by the presence of condensation on the mirror surface, therefore, to control and to monitor the formation of condensation is an important issue for IACT observatories. We developed a method based on pictures of the mirrors to identify the areas with water vapor condensation. The method is presented here and we use it to estimate the time and area two mirrors had condensation when exposed to the environmental conditions in the Argentinean site. The study presented here shows important guidelines in the selection procedure of mirror technologies and shows an innovative monitoring tool to be used in future Cherenkov telescopes.

  4. Active optics system of the ASTRI SST-2M prototype for the Cherenkov Telescope Array

    Science.gov (United States)

    Gardiol, Daniele; Capobianco, Gerardo; Fantinel, Daniela; Giro, Enrico; Lessio, Luigi; Loreggia, Davide; Rodeghiero, Gabriele; Russo, Federico; Volpicelli, Antonio C.

    2014-07-01

    ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) SST-2M is an end-to-end prototype of Small Size class of Telescope for the Cherenkov Telescope Array. It will apply a dual mirror configuration to Imaging Atmospheric Cherenkov Telescopes. The 18 segments composing the primary mirror (diameter 4.3 m) are equipped with an active optics system enabling optical re-alignment during telescope slew. The secondary mirror (diameter 1.8 m) can be moved along three degrees of freedom to perform focus and tilt corrections. We describe the kinematic model used to predict the system performance as well as the hardware and software design solution that will be implemented for optics control.

  5. Design and operation of FACT - the first G-APD Cherenkov telescope

    Science.gov (United States)

    Anderhub, H.; Backes, M.; Biland, A.; Boccone, V.; Braun, I.; Bretz, T.; Buß, J.; Cadoux, F.; Commichau, V.; Djambazov, L.; Dorner, D.; Einecke, S.; Eisenacher, D.; Gendotti, A.; Grimm, O.; von Gunten, H.; Haller, C.; Hildebrand, D.; Horisberger, U.; Huber, B.; Kim, K.-S.; Knoetig, M. L.; Köhne, J.-H.; Krähenbühl, T.; Krumm, B.; Lee, M.; Lorenz, E.; Lustermann, W.; Lyard, E.; Mannheim, K.; Meharga, M.; Meier, K.; Montaruli, T.; Neise, D.; Nessi-Tedaldi, F.; Overkemping, A.-K.; Paravac, A.; Pauss, F.; Renker, D.; Rhode, W.; Ribordy, M.; Röser, U.; Stucki, J.-P.; Schneider, J.; Steinbring, T.; Temme, F.; Thaele, J.; Tobler, S.; Viertel, G.; Vogler, P.; Walter, R.; Warda, K.; Weitzel, Q.; Zänglein, M.

    2013-06-01

    The First G-APD Cherenkov Telescope (FACT) is designed to detect cosmic gamma-rays with energies from several hundred GeV up to about 10 TeV using the Imaging Atmospheric Cherenkov Technique. In contrast to former or existing telescopes, the camera of the FACT telescope is comprised of solid-state Geiger-mode Avalanche Photodiodes (G-APD) instead of photomultiplier tubes for photo detection. It is the first full-scale device of its kind employing this new technology. The telescope is operated at the Observatorio del Roque de los Muchachos (La Palma, Canary Islands, Spain) since fall 2011. This paper describes in detail the design, construction and operation of the system, including hardware and software aspects. Technical experiences gained after one year of operation are discussed and conclusions with regard to future projects are drawn.

  6. A versatile digital camera trigger for telescopes in the Cherenkov Telescope Array

    Science.gov (United States)

    Schwanke, U.; Shayduk, M.; Sulanke, K.-H.; Vorobiov, S.; Wischnewski, R.

    2015-05-01

    This paper describes the concept of an FPGA-based digital camera trigger for imaging atmospheric Cherenkov telescopes, developed for the future Cherenkov Telescope Array (CTA). The proposed camera trigger is designed to select images initiated by the Cherenkov emission of extended air showers from very-high energy (VHE, E > 20 GeV) photons and charged particles while suppressing signatures from background light. The trigger comprises three stages. A first stage employs programmable discriminators to digitize the signals arriving from the camera channels (pixels). At the second stage, a grid of low-cost FPGAs is used to process the digitized signals for camera regions with 37 pixels. At the third stage, trigger conditions found independently in any of the overlapping 37-pixel regions are combined into a global camera trigger by few central FPGAs. Trigger prototype boards based on Xilinx FPGAs have been designed, built and tested and were shown to function properly. Using these components a full camera trigger with a power consumption and price per channel of about 0.5 W and 19 €, respectively, can be built. With the described design the camera trigger algorithm can take advantage of pixel information in both the space and the time domain allowing, for example, the creation of triggers sensitive to the time-gradient of a shower image; the time information could also be exploited to online adjust the time window of the acquisition system for pixel data. Combining the results of the parallel execution of different trigger algorithms (optimized, for example, for the lowest and highest energies, respectively) on each FPGA can result in a better response over all photons energies (as demonstrated by Monte Carlo simulation in this work).

  7. Operating performance of the gamma-ray Cherenkov telescope: An end-to-end Schwarzschild–Couder telescope prototype for the Cherenkov Telescope Array

    Energy Technology Data Exchange (ETDEWEB)

    Dournaux, J.L., E-mail: jean-laurent.dournaux@obspm.fr [GEPI, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Paris Cité, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); De Franco, A. [Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Laporte, P. [GEPI, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Paris Cité, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); White, R. [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Greenshaw, T. [University of Liverpool, Oliver Lodge Laboratory, P.O. Box 147, Oxford Street, Liverpool L69 3BX (United Kingdom); Sol, H. [LUTH, Observatoire de Paris, PSL Research University, CNRS, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); Abchiche, A. [CNRS, Division technique DT-INSU, 1 Place Aristide Briand, 92190 Meudon (France); Allan, D. [Department of Physics and Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE (United Kingdom); Amans, J.P. [GEPI, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Paris Cité, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); Armstrong, T.P. [Department of Physics and Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE (United Kingdom); Balzer, A.; Berge, D. [GRAPPA, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Boisson, C. [LUTH, Observatoire de Paris, PSL Research University, CNRS, Université Paris Diderot, Place J. Janssen, 92190 Meudon (France); and others

    2017-02-11

    The Cherenkov Telescope Array (CTA) consortium aims to build the next-generation ground-based very-high-energy gamma-ray observatory. The array will feature different sizes of telescopes allowing it to cover a wide gamma-ray energy band from about 20 GeV to above 100 TeV. The highest energies, above 5 TeV, will be covered by a large number of Small-Sized Telescopes (SSTs) with a field-of-view of around 9°. The Gamma-ray Cherenkov Telescope (GCT), based on Schwarzschild–Couder dual-mirror optics, is one of the three proposed SST designs. The GCT is described in this contribution and the first images of Cherenkov showers obtained using the telescope and its camera are presented. These were obtained in November 2015 in Meudon, France.

  8. Development of a SiPM Camera for a Schwarzschild-Couder Cherenkov Telescope for the Cherenkov Telescope Array

    CERN Document Server

    Otte, A N; Dickinson, H.; Funk, S.; Jogler, T.; Johnson, C.A.; Karn, P.; Meagher, K.; Naoya, H.; Nguyen, T.; Okumura, A.; Santander, M.; Sapozhnikov, L.; Stier, A.; Tajima, H.; Tibaldo, L.; Vandenbroucke, J.; Wakely, S.; Weinstein, A.; Williams, D.A.

    2015-01-01

    We present the development of a novel 11328 pixel silicon photomultiplier (SiPM) camera for use with a ground-based Cherenkov telescope with Schwarzschild-Couder optics as a possible medium-sized telescope for the Cherenkov Telescope Array (CTA). The finely pixelated camera samples air-shower images with more than twice the optical resolution of cameras that are used in current Cherenkov telescopes. Advantages of the higher resolution will be a better event reconstruction yielding improved background suppression and angular resolution of the reconstructed gamma-ray events, which is crucial in morphology studies of, for example, Galactic particle accelerators and the search for gamma-ray halos around extragalactic sources. Packing such a large number of pixels into an area of only half a square meter and having a fast readout directly attached to the back of the sensors is a challenging task. For the prototype camera development, SiPMs from Hamamatsu with through silicon via (TSV) technology are used. We give ...

  9. The Cherenkov Telescope Array: Exploring the Very-high-energy Sky from ESO's Paranal Site

    Science.gov (United States)

    Hofmann, W.

    2017-06-01

    The Cherenkov Telescope Array (CTA) is a next-generation observatory for ground-based very-high-energy gamma-ray astronomy, using the imaging atmospheric Cherenkov technique to detect and reconstruct gamma-ray induced air showers. The CTA project is planning to deploy 19 telescopes on its northern La Palma site, and 99 telescopes on its southern site at Paranal, covering the 20 GeV to 300 TeV energy domain and offering vastly improved performance compared to currently operating Cherenkov telescopes. The combination of three different telescope sizes (23-, 12- and 4-metre) allows cost-effective coverage of the wide energy range. CTA will be operated as a user facility, dividing observation time between a guest observer programme and large Key Science Projects (KSPs), and the data will be made public after a one-year proprietary period. The history of the project, the implementation of the arrays, and some of the major science goals and KSPs, are briefly summarised.

  10. Search for annihilating Dark Matter towards dwarf galaxies with the Cherenkov Telescope Array

    Directory of Open Access Journals (Sweden)

    Morselli Aldo

    2017-01-01

    Full Text Available The standard model of cosmology indicates that approximately 27% of the energy density of the Universe is in the form of dark matter. The nature of dark matter is an open question in modern physics. Indirect dark matter searches with imaging atmospheric Cherenkov telescopes are playing a crucial role in constraining the nature of the dark matter particle through the study of their potential annihilation that could produce very high energy gamma rays from different astrophysical structures. The Cherenkov Telescope Array will provide an unprecedented sensitivity over a range of dark matter mass from ~100 GeV to ~30 TeV. In this contribution we review the status of indirect dark matter searches at dwarf spheroidal galaxies.

  11. Pre-selecting muon events in the camera server of the ASTRI telescopes for the Cherenkov Telescope Array

    Science.gov (United States)

    Maccarone, Maria C.; Mineo, Teresa; Capalbi, Milvia; Conforti, Vito; Coffaro, Martina

    2016-08-01

    The Cherenkov Telescope Array (CTA) represents the next generation of ground based observatories for very high energy gamma ray astronomy. The CTA will consist of two arrays at two different sites, one in the northern and one in the southern hemisphere. The current CTA design foresees, in the southern site, the installation of many tens of imaging atmospheric Cherenkov telescopes of three different classes, namely large, medium, and small, so defined in relation to their mirror area; the northern hemisphere array would consist of few tens of the two larger telescope types. The telescopes will be equipped with cameras composed either of photomultipliers or silicon photomultipliers, and with different trigger and read-out electronics. In such a scenario, several different methods will be used for the telescopes' calibration. Nevertheless, the optical throughput of any CTA telescope, independently of its type, can be calibrated analyzing the characteristic image produced by local atmospheric highly energetic muons that induce the emission of Cherenkov light which is imaged as a ring onto the focal plane if their impact point is relatively close to the telescope optical axis. Large sized telescopes would be able to detect useful muon events under stereo coincidence and such stereo muon events will be directly addressed to the central CTA array data acquisition pipeline to be analyzed. For the medium and small sized telescopes, due to their smaller mirror area and large inter-telescope distance, the stereo coincidence rate will tend to zero; nevertheless, muon events will be detected by single telescopes that must therefore be able to identify them as possible useful calibration candidates, even if no stereo coincidence is available. This is the case for the ASTRI telescopes, proposed as pre-production units of the small size array of the CTA, which are able to detect muon events during regular data taking without requiring any dedicated trigger. We present two fast

  12. Testing light concentrators prototypes for the Cherenkov Telescope Array

    Science.gov (United States)

    Hénault, François; Petrucci, Pierre-Olivier; Jocou, Laurent; Arezki, Brahim; Magnard, Yves; Khélifi, Bruno; Manigot, Pascal; Olive, Jean-François; Jean, Pierre; Punch, Michael

    2017-09-01

    With more than 30 Medium-Size Telescopes (MST) located in both North and South hemispheres, the Cherenkov Telescope Array (CTA) shall be the largest cosmic gamma ray detector ever built. Each MST focal plane consists in an array of some 1800 photomultipliers equipped with their own light concentrating optics in order to maximizing the amount of Cherenkov radiation collected by the telescope and to block stray light originating from ground environment. Within the CTA Consortium, the Institut de Planétologie et d'Astrophysique de Grenoble (IPAG) is in charge of designing, subcontracting the realization to industry, and testing the MST light concentrators. Two different optical solutions were pre-selected, respectively based on CPCs (Winston cones) and non-imaging concentrating lenses. Prototypes were manufactured by different industrial companies and tested in our laboratory on a test bench specifically built for the project. After shortly describing both optical designs, this communication is essentially focused at experimental results. Each type of concentrator has been submitted to extensive performance measurements, including radiometric efficiency at different wavelengths, rejection curves, and qualitative shape error test. The final selected concentrator is the CPC, although non-imaging lenses exhibit interesting properties in terms of radiometric performance.

  13. INFN Camera demonstrator for the Cherenkov Telescope Array

    CERN Document Server

    Ambrosi, G; Aramo, C.; Bertucci, B.; Bissaldi, E.; Bitossi, M.; Brasolin, S.; Busetto, G.; Carosi, R.; Catalanotti, S.; Ciocci, M.A.; Consoletti, R.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Lotto, B.; de Palma, F.; Desiante, R.; Di Girolamo, T.; Di Giulio, C.; Doro, M.; D'Urso, D.; Ferraro, G.; Ferrarotto, F.; Gargano, F.; Giglietto, N.; Giordano, F.; Giraudo, G.; Iacovacci, M.; Ionica, M.; Iori, M.; Longo, F.; Mariotti, M.; Mastroianni, S.; Minuti, M.; Morselli, A.; Paoletti, R.; Pauletta, G.; Rando, R.; Fernandez, G. Rodriguez; Rugliancich, A.; Simone, D.; Stella, C.; Tonachini, A.; Vallania, P.; Valore, L.; Vagelli, V.; Verzi, V.; Vigorito, C.

    2015-01-01

    The Cherenkov Telescope Array is a world-wide project for a new generation of ground-based Cherenkov telescopes of the Imaging class with the aim of exploring the highest energy region of the electromagnetic spectrum. With two planned arrays, one for each hemisphere, it will guarantee a good sky coverage in the energy range from a few tens of GeV to hundreds of TeV, with improved angular resolution and a sensitivity in the TeV energy region better by one order of magnitude than the currently operating arrays. In order to cover this wide energy range, three different telescope types are envisaged, with different mirror sizes and focal plane features. In particular, for the highest energies a possible design is a dual-mirror Schwarzschild-Couder optical scheme, with a compact focal plane. A silicon photomultiplier (SiPM) based camera is being proposed as a solution to match the dimensions of the pixel (angular size of ~ 0.17 degrees). INFN is developing a camera demonstrator made by 9 Photo Sensor Modules (PSMs...

  14. The next generation Cherenkov Telescope Array observatory: CTA

    Energy Technology Data Exchange (ETDEWEB)

    Vercellone, S., E-mail: stefano@ifc.inaf.it

    2014-12-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to the very high-energy gamma-ray astrophysics in the energy range 30 GeV–100 TeV, which will improve by about one order of magnitude the sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS). In order to achieve such improved performance, for both the northern and southern CTA sites, four units of 23 m diameter Large Size Telescopes (LSTs) will be deployed close to the centre of the array with telescopes separated by about 100 m. A larger number (about 25 units) of 12 m Medium Size Telescopes (MSTs, separated by about 150 m), will cover a larger area. The southern site will also include up to 24 Schwarzschild–Couder dual-mirror medium-size Telescopes (SCTs) with the primary mirror diameter of 9.5 m. Above a few TeV, the Cherenkov light intensity is such that showers can be detected even well outside the light pool by telescopes significantly smaller than the MSTs. To achieve the required sensitivity at high energies, a huge area on the ground needs to be covered by Small Size Telescopes (SSTs) with a field of view of about 10° and an angular resolution of about 0.2°, making the dual-mirror configuration very effective. The SST sub-array will be composed of 50–70 telescopes with a mirror area of about 5–10 m{sup 2} and about 300 m spacing, distributed across an area of about 10 km{sup 2}. In this presentation we will focus on the innovative solution for the optical design of the medium and small size telescopes based on a dual-mirror configuration. This layout will allow us to reduce the dimension and the weight of the camera at the focal plane of the telescope, to adopt Silicon-based photo-multipliers as light detectors thanks to the reduced plate-scale, and to have an optimal imaging resolution on a wide field of view.

  15. Prototyping hexagonal light concentrators using high-reflectance specular films for the Large-Sized Telescopes of the Cherenkov Telescope Array

    Science.gov (United States)

    Okumura, A.; Dang, T. V.; Ono, S.; Tanaka, S.; Hayashida, M.; Hinton, J.; Katagiri, H.; Noda, K.; Teshima, M.; Yamamoto, T.; Yoshida, T.

    2017-12-01

    We have developed a prototype hexagonal light concentrator for the Large-Sized Telescopes of the Cherenkov Telescope Array. To maximize the photodetection efficiency of the focal-plane camera pixels for atmospheric Cherenkov photons and to lower the energy threshold, a specular film with a very high reflectance of 92–99% has been developed to cover the inner surfaces of the light concentrators. The prototype has a relative anode sensitivity (which can be roughly regarded as collection efficiency) of about 95 to 105% at the most important angles of incidence. The design, simulation, production procedure, and performance measurements of the light-concentrator prototype are reported.

  16. The On-Site Analysis of the Cherenkov Telescope Array

    CERN Document Server

    Bulgarelli, Andrea; Zoli, Andrea; Aboudan, Alessio; Rodríguez-Vázquez, Juan José; De Cesare, Giovanni; De Rosa, Adriano; Maier, Gernot; Lyard, Etienne; Bastieri, Denis; Lombardi, Saverio; Tosti, Gino; Bergamaschi, Sonia; Beneventano, Domenico; Lamanna, Giovanni; Jacquemier, Jean; Kosack, Karl; Antonelli, Lucio Angelo; Boisson, Catherine; Borkowski, Jerzy; Buson, Sara; Carosi, Alessandro; Conforti, Vito; Colomé, Pep; Reyes, Raquel de los; Dumm, Jon; Evans, Phil; Fortson, Lucy; Fuessling, Matthias; Gotz, Diego; Graciani, Ricardo; Gianotti, Fulvio; Grandi, Paola; Hinton, Jim; Humensky, Brian; Inoue, Susumu; Knödlseder, Jürgen; Flour, Thierry Le; Lindemann, Rico; Malaguti, Giuseppe; Markoff, Sera; Marisaldi, Martino; Neyroud, Nadine; Nicastro, Luciano; Ohm, Stefan; Osborne, Julian; Oya, Igor; Rodriguez, Jerome; Rosen, Simon; Ribo, Marc; Tacchini, Alessandro; Schüssler, Fabian; Stolarczyk, Thierry; Torresi, Eleonora; Testa, Vincenzo; Wegner, Peter

    2015-01-01

    The Cherenkov Telescope Array (CTA) observatory will be one of the largest ground-based very high-energy gamma-ray observatories. The On-Site Analysis will be the first CTA scientific analysis of data acquired from the array of telescopes, in both northern and southern sites. The On-Site Analysis will have two pipelines: the Level-A pipeline (also known as Real-Time Analysis, RTA) and the level-B one. The RTA performs data quality monitoring and must be able to issue automated alerts on variable and transient astrophysical sources within 30 seconds from the last acquired Cherenkov event that contributes to the alert, with a sensitivity not worse than the one achieved by the final pipeline by more than a factor of 3. The Level-B Analysis has a better sensitivity (not be worse than the final one by a factor of 2) and the results should be available within 10 hours from the acquisition of the data: for this reason this analysis could be performed at the end of an observation or next morning. The latency (in part...

  17. First optical validation of a Schwarzschild Couder telescope: the ASTRI SST-2M Cherenkov telescope

    Science.gov (United States)

    Giro, E.; Canestrari, R.; Sironi, G.; Antolini, E.; Conconi, P.; Fermino, C. E.; Gargano, C.; Rodeghiero, G.; Russo, F.; Scuderi, S.; Tosti, G.; Vassiliev, V.; Pareschi, G.

    2017-12-01

    Context. The Cherenkov Telescope Array (CTA) represents the most advanced facility designed for Cherenkov Astronomy. ASTRI SST-2M has been developed as a demonstrator for the Small Size Telescope in the context of the upcoming CTA. Its main innovation consists in the optical layout which implements the Schwarzschild-Couder configuration and is fully validated for the first time. The ASTRI SST-2M optical system represents the first qualified example of a two-mirror telescope for Cherenkov Astronomy. This configuration permits us to (i) maintain high optical quality across a large field of view; (ii) demagnify the plate scale; and (iii) exploit new technological solutions for focal plane sensors. Aims: The goal of the paper is to present the optical qualification of the ASTRI SST-2M telescope. The qualification has been obtained measuring the point spread function (PSF) sizes generated in the focal plane at various distances from the optical axis. These values have been compared with the performances expected by design. Methods: After an introduction on Gamma-ray Astronomy from the ground, the optical design of ASTRI SST-2M and how it has been implemented is discussed. Moreover, the description of the set-up used to qualify the telescope over the full field of view is shown. Results: We report the results of the first-light optical qualification. The required specification of a flat PSF of 10 arcmin in a large field of view ( 10°) has been demonstrated. These results validate the design specifications, opening a new scenario for Cherenkov Gamma-ray Astronomy and, in particular, for the detection of high-energy (5-300 TeV) gamma rays and wide-field observations with CTA.

  18. New electronics for the Cherenkov Telescope Array (NECTAr)

    Energy Technology Data Exchange (ETDEWEB)

    Naumann, C.L., E-mail: christopher.naumann@lpnhe.in2p3.fr [LPNHE, IN2P3/CNRS Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Paris (France); Delagnes, E. [IRFU, CEA/DSM, Saclay, Gif-sur-Yvette (France); Bolmont, J.; Corona, P. [LPNHE, IN2P3/CNRS Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Paris (France); Dzahini, D. [LPSC, Universite Joseph Fourier, INPG and IN2P3/CNRS, Grenoble (France); Feinstein, F. [LUPM, Universite Montpellier II and IN2P3/CNRS, Montpellier (France); Gascon, D. [ICC-UB, Universitat Barcelona (Spain); Glicenstein, J.-F.; Guilloux, F. [IRFU, CEA/DSM, Saclay, Gif-sur-Yvette (France); Nayman, P. [LPNHE, IN2P3/CNRS Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Paris (France); Rarbi, F. [LPSC, Universite Joseph Fourier, INPG and IN2P3/CNRS, Grenoble (France); Sanuy, A. [ICC-UB, Universitat Barcelona (Spain); Tavernet, J.-P.; Toussenel, F.; Vincent, P. [LPNHE, IN2P3/CNRS Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Paris (France); Vorobiov, S. [LUPM, Universite Montpellier II and IN2P3/CNRS, Montpellier (France); DESY Zeuthen, Platanenallee 6, 15738 Zeuthen (Germany)

    2012-12-11

    The international CTA consortium has recently entered into its preparatory phase towards the construction of the next-generation Cherenkov Telescope Array CTA. This experiment will be a successor, and based on the return of experience from the three major current-generation arrays H.E.S.S., MAGIC and VERITAS, and aims to significantly improve upon the sensitivity as well as the energy range of its highly successful predecessors. Construction is planned to begin by 2013, and when finished, CTA will be able to explore the highest-energy gamma ray sky in unprecedented detail. To achieve this increase in sensitivity and energy range, CTA will employ the order of 100 telescopes of three different sizes on two sites, with around 1000-4000 channels per camera, depending on the telescope size. To equip and reliably operate the order of 100000 channels of photodetectors (compared to 6000 of the H.E.S.S. array), a new kind of flexible and powerful yet inexpensive front-end hardware will be required. One possible solution is pursued by the NECTAr (New Electronics for the Cherenkov Telescope Array) project. Its main feature is the integration of as much as possible of the front-end electronics (amplifiers, fast analogue samplers, memory and ADCs) into a single ASIC, which will allow very fast readout performances while significantly reducing the cost and the power consumption per channel. Also included is a low-cost FPGA for digital treatment and online data processing, as well as an Ethernet connection. Other priorities of NECTAr are the modularity of the system, a high degree of flexibility in the trigger system as well as the possibility of flexible readout modes to optimise the signal-to-noise ratio while at the same time allowing a significant reduction of data rates, both of which could improve the sensitivity of CTA compared to current detection systems. This paper gives an overview over the development work for the Nectar system, with particular focus on its main

  19. The Alignment System for a Medium-Sized Schwarzschild-Couder Telescope Prototype for the Cherenkov Telescope Array

    Science.gov (United States)

    Ribeiro, Deivid; Humensky, Brian; Nieto, Daniel; V Vassiliev Group in UCLA division of Astronomy and Astrophysics, P Kaaret Group at Iowa University Department of Physics and Astronomy, CTA Consortium

    2016-01-01

    The Cherenkov Telescope Array (CTA) is an international project for a next-generation ground-based gamma-ray observatory. CTA, conceived as an array of tens of imaging atmospheric Cherenkov telescopes, comprising small, medium and large-size telescopes, is aiming to improve on the sensitivity of current-generation experiments by an order of magnitude and provide energy coverage from 20 GeV to more than 300 TeV. The Schwarzschild-Couder design is a candidate 9-m diameter medium-sized telescope featuring a novel aplanatic two-mirror optical design capable of a wide field of view with significantly improved imaging resolution as compared to the traditional Davies-Cotton optical design. Achieving this imaging resolution imposes strict mirror alignment requirements that necessitate a sophisticated alignment system. This system uses a collection of position sensors between panels to determine the relative position of adjacent panels; each panel is mounted on a Stewart platform to allow motion control with six degrees of freedom, facilitating the alignment of the optical surface for the segmented primary and secondary mirrors. Alignments of the primary and secondary mirrors and the camera focal plane with respect to each other are performed utilizing a set of CCD cameras which image LEDs placed on the mirror panels to measure relative translation, and custom-built auto-collimators to measure relative tilt between the primary and secondary mirrors along the optical axis of the telescope. In this contribution we present the status of the development of the SC optical alignment system, soon to be materialized in a full-scale prototype SC medium-size telescope (pSCT) at the Fred Lawrence Whipple Observatory in southern Arizona.

  20. Intensity Interferometry with Cherenkov Telescope Arrays: Prospects for submilliarcsecond optical imaging

    Science.gov (United States)

    Dravins, D.

    2014-04-01

    Intensity interferometry measures the second-order coherence of light. Very rapid (nanosecond) fluctuations are correlated between separate telescopes, without any optical connection. This makes the method insensitive to atmospheric turbulence and optical imperfections, permitting observations over long baselines, and at short wavelengths. The required large telescopes are becoming available as those primarily erected to study gamma rays: the planned Cherenkov Telescope Array (https://www.cta-observatory.org/) envisions many tens of telescopes distributed over a few square km. Digital signal handling enables very many baselines to be simultaneously synthesized between many pairs of telescopes, while stars may be tracked across the sky with electronic time delays, synthesizing an optical interferometer in software. Simulations indicate limiting magnitudes around m(v)=8, reaching a resolution of 30 microarcseconds in the violet. Since intensity interferometry provides only the modulus (not phase) of any spatial frequency component of the source image, image reconstruction requires phase retrieval techniques. As shown in simulations, full two-dimensional images can be retrieved, provided there is an extensive coverage of the (u,v)-plane, such as will be available once the number of telescopes reaches numbers on the order of ten.

  1. SST-GATE telescope: an innovative dual-mirror prototype for the Cherenkov Telescope Array

    Science.gov (United States)

    Dumas, Delphine; Huet, Jean-Michel; Dournaux, Jean-Laurent; Laporte, Philippe; Amans, Jean-Philippe; Fasola, Gilles; Zech, Andreas; Rulten, Cameron; Sol, Hélène; Blake, Simon; Schmoll, Jurgen

    2014-07-01

    The Observatoire de Paris is involved in the Cherenkov Telescope Array (CTA) project by designing and constructing on the site of Meudon a Small Size Telescope prototype, named SST-GATE, in collaboration with the CHEC team (Compact High Energy Camera) which is providing the camera. The telescope structure is based on the Schwarzschild- Couder optical design which has never been adopted before in the design of a ground-based telescope. This concept allows a larger field of view and cheaper and smaller telescope and camera design with improved performance compared to the Davies-Cotton design traditionally used in very high energy gamma-ray telescopes. The SST-GATE telescope has been designed with the prime objectives of being light, versatile and simple to assemble with a minimal maintenance cost. This papers aims at reviewing the SST-GATE telescope structure from mechanics to optics along with the control command architecture; several innovative developments implemented within the design are discussed. Updates of the project status and perspectives are made.

  2. On the prospects of cross-calibrating the Cherenkov Telescope Array with an airborne calibration platform

    Science.gov (United States)

    Brown, Anthony M.

    2018-01-01

    Recent advances in unmanned aerial vehicle (UAV) technology have made UAVs an attractive possibility as an airborne calibration platform for astronomical facilities. This is especially true for arrays of telescopes spread over a large area such as the Cherenkov Telescope Array (CTA). In this paper, the feasibility of using UAVs to calibrate CTA is investigated. Assuming a UAV at 1km altitude above CTA, operating on astronomically clear nights with stratified, low atmospheric dust content, appropriate thermal protection for the calibration light source and an onboard photodiode to monitor its absolute light intensity, inter-calibration of CTA's telescopes of the same size class is found to be achievable with a 6 - 8 % uncertainty. For cross-calibration of different telescope size classes, a systematic uncertainty of 8 - 10 % is found to be achievable. Importantly, equipping the UAV with a multi-wavelength calibration light source affords us the ability to monitor the wavelength-dependent degradation of CTA telescopes' optical system, allowing us to not only maintain this 6 - 10 % uncertainty after the first few years of telescope deployment, but also to accurately account for the effect of multi-wavelength degradation on the cross-calibration of CTA by other techniques, namely with images of air showers and local muons. A UAV-based system thus provides CTA with several independent and complementary methods of cross-calibrating the optical throughput of individual telescopes. Furthermore, housing environmental sensors on the UAV system allows us to not only minimise the systematic uncertainty associated with the atmospheric transmission of the calibration signal, it also allows us to map the dust content above CTA as well as monitor the temperature, humidity and pressure profiles of the first kilometre of atmosphere above CTA with each UAV flight.

  3. Prototype of a production system for Cherenkov Telescope Array with DIRAC

    CERN Document Server

    Arrabito, L; Haupt, A; Graciani Diaz, R; Stagni, F; Tsaregorodtsev, A

    2015-01-01

    The Cherenkov Telescope Array (CTA) — an array of many tens of Imaging Atmospheric Cherenkov Telescopes deployed on an unprecedented scale — is the next generation instrument in the field of very high energy gamma-ray astronomy. CTA will operate as an open observatory providing data products to the scientific community. An average data stream of about 10 GB/s for about 1000 hours of observation per year, thus producing several PB/year, is expected. Large CPU time is required for data-processing as well for massive Monte Carlo simulations needed for detector calibration purposes. The current CTA computing model is based on a distributed infrastructure for the archive and the data off-line processing. In order to manage the off-line data-processing in a distributed environment, CTA has evaluated the DIRAC (Distributed Infrastructure with Remote Agent Control) system, which is a general framework for the management of tasks over distributed heterogeneous computing environments. In particular, a production sy...

  4. Redshift measurement of Fermi blazars for the Cherenkov telescope array

    Science.gov (United States)

    Pita, S.; Goldoni, P.; Boisson, C.; Cotter, G.; Lefaucheur, J.; Lenain, J.-P.; Lindfors, E.; Williams, D. A.

    2017-01-01

    Blazars are active galactic nuclei, and the most numerous High Energy (HE) and Very High Energy (VHE) γ-ray emitters. Their optical emission is often dominated by non-thermal, and, in the case of BL Lacs, featureless continuum radiation. This makes the determination of their redshift extremely difficult. Indeed, as of today only about 50% of γ-ray blazars have a measured spectroscopic redshift. The knowledge of redshift is fundamental because it allows the precise modeling of the VHE emission and also of its interaction with the extragalactic background light (EBL). The beginning of the Cherenkov Telescope Array (CTA) operations in the near future will allow the detection of several hundreds of new blazars. Using the Fermi catalogue of sources above 50 GeV (2FHL), we performed simulations which indicate that a significant fraction of the 2FHL blazars detectable by CTA will not have a measured redshift. As a matter of fact, the organization of observing campaigns to measure the redshift of these blazars has been recognized as a necessary support for the AGN Key Science Project of CTA. We are planning such an observing campaign. In order to optimize our chances of success, we will perform preliminary deep imaging observations aimed at detecting or setting upper limits to the host galaxy. We will then take spectra of the candidates with the brightest host galaxies. Taking advantage of the recent success of an X-shooter GTO observing campaign, these observations will be different with respect to previous ones due to the use of higher resolution spectrographs and of 8 meter class telescopes. We are starting to submit proposals for these observations. In this paper we briefly describe how candidates are selected and the corresponding observation program.

  5. The Cherenkov Telescope Array production system for Monte Carlo simulations and analysis

    Science.gov (United States)

    Arrabito, L.; Bernloehr, K.; Bregeon, J.; Cumani, P.; Hassan, T.; Haupt, A.; Maier, G.; Moralejo, A.; Neyroud, N.; pre="for the"> CTA Consortium, DIRAC Consortium,

    2017-10-01

    The Cherenkov Telescope Array (CTA), an array of many tens of Imaging Atmospheric Cherenkov Telescopes deployed on an unprecedented scale, is the next-generation instrument in the field of very high energy gamma-ray astronomy. An average data stream of about 0.9 GB/s for about 1300 hours of observation per year is expected, therefore resulting in 4 PB of raw data per year and a total of 27 PB/year, including archive and data processing. The start of CTA operation is foreseen in 2018 and it will last about 30 years. The installation of the first telescopes in the two selected locations (Paranal, Chile and La Palma, Spain) will start in 2017. In order to select the best site candidate to host CTA telescopes (in the Northern and in the Southern hemispheres), massive Monte Carlo simulations have been performed since 2012. Once the two sites have been selected, we have started new Monte Carlo simulations to determine the optimal array layout with respect to the obtained sensitivity. Taking into account that CTA may be finally composed of 7 different telescope types coming in 3 different sizes, many different combinations of telescope position and multiplicity as a function of the telescope type have been proposed. This last Monte Carlo campaign represented a huge computational effort, since several hundreds of telescope positions have been simulated, while for future instrument response function simulations, only the operating telescopes will be considered. In particular, during the last 18 months, about 2 PB of Monte Carlo data have been produced and processed with different analysis chains, with a corresponding overall CPU consumption of about 125 M HS06 hours. In these proceedings, we describe the employed computing model, based on the use of grid resources, as well as the production system setup, which relies on the DIRAC interware. Finally, we present the envisaged evolutions of the CTA production system for the off-line data processing during CTA operations and

  6. Status of the large-size telescope prototyping for the Cherenkov Telescope Array

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, Robert [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany); Excellence Cluster ' ' Universe' ' , Technische Universitaet Muenchen, 85747 Garching b. Muenchen (Germany); Teshima, Masahiro [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany); Institute for Cosmic Ray Research, University of Tokyo (Japan); Schweizer, Thomas; Mirzoyan, Razmik; Wetteskind, Holger; Jablonski, Christopher; Reimann, Olaf [Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany); Lorenz, Eckart [ETH Zuerich, CH-8093 Zuerich (Switzerland); Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany)

    2011-07-01

    The Cherenkov Telescope Array (CTA) observatory aims at increasing the sensitivity of ground-based gamma-ray (GeV/TeV energies) observatories by a factor >10 compared to current facilities, to extend the accessible gamma-ray energies from a few tens of GeV to a hundred TeV, and to improve on other parameters like the energy and angular resolution. Sensitivity at the lowest possible energies is important for a variety of key physics goals, like the observation of distant active galactic nuclei or gamma-ray bursts, but also for measuring pulsar cutoffs. For this aim, CTA will incorporate a number of central large-size telescopes (LSTs of 23 m diameter). In this presentation, design considerations and the status of the LST prototyping are reported.

  7. Atmospheric Monitoring at the Site of the MAGIC Telescopes

    Directory of Open Access Journals (Sweden)

    Will Martin

    2017-01-01

    Full Text Available The MAGIC telescopes in La Palma, Canary Islands, measure the Cherenkov light emitted by gamma ray-induced extended air showers in the atmosphere. The good knowledge of the atmospheric parameters is important, both for the correct and safe operations of the telescopes, but also for subsequent data analysis. A weather station measures the state variables of the atmosphere, temperature, humidity and wind, an elastic Lidar system and an infrared pyrometer determine the optical transmission of the atmosphere. Using an AllSky camera, the cloud cover can be estimated. The measured values are completed by data from global atmospheric models based on numeric weather forecasts.

  8. The engineering prototype of the wide-field Cherenkov telescope for the Yakutsk array

    Science.gov (United States)

    Ivanov, A. A.; Knurenko, S. P.; Krasilnikov, A. D.; Ksenofontov, I. V.; Petrov, Z. E.; Pravdin, M. I.; Timofeev, L. V.; Sleptsov, I. Ye

    2013-02-01

    The Yakutsk array group is developing the wide FOV Cherenkov telescopes to be operated in coincidence with the surface detectors of the array under modernization. Currently the engineering prototype of the reflecting telescope with front-end electronics is designed and assembled to prove the feasibility of the concept. In this report the status and parameters of the engineering prototype are presented.

  9. The Cherenkov Telescope Array Observatory: top level use cases

    Science.gov (United States)

    Bulgarelli, A.; Kosack, K.; Hinton, J.; Tosti, G.; Schwanke, U.; Schwarz, J.; Colomé, P.; Conforti, V.; Khelifi, B.; Goullon, J.; Ong, R.; Markoff, S.; Contreras, J. L.; Lucarelli, F.; Antonelli, L. A.; Bigongiari, C.; Boisson, C.; Bosnjak, Z.; Brau-Nogué, S.; Carosi, A.; Chen, A.; Cotter, G.; Covino, S.; Daniel, M.; De Cesare, G.; de Ona Wilhelmi, E.; Della Volpe, M.; Di Pierro, F.; Fioretti, V.; Füßling, M.; Garczarczyk, M.; Gaug, M.; Glicenstein, J. F.; Goldoni, P.; Götz, D.; Grandi, P.; Heller, M.; Hermann, G.; Inoue, S.; Knödlseder, J.; Lenain, J.-P.; Lindfors, E.; Lombardi, S.; Luque-Escamilla, P.; Maier, G.; Marisaldi, M.; Mundell, C.; Neyroud, N.; Noda, K.; O'Brien, P.; Petrucci, P. O.; Martí Ribas, J.; Ribó, M.; Rodriguez, J.; Romano, P.; Schmid, J.; Serre, N.; Sol, H.; Schussler, F.; Stamerra, A.; Stolarczyk, T.; Vandenbrouck, J.; Vercellone, S.; Vergani, S.; Zech, A.; Zoli, A.

    2016-08-01

    Today the scientific community is facing an increasing complexity of the scientific projects, from both a technological and a management point of view. The reason for this is in the advance of science itself, where new experiments with unprecedented levels of accuracy, precision and coverage (time and spatial) are realised. Astronomy is one of the fields of the physical sciences where a strong interaction between the scientists, the instrument and software developers is necessary to achieve the goals of any Big Science Project. The Cherenkov Telescope Array (CTA) will be the largest ground-based very high-energy gamma-ray observatory of the next decades. To achieve the full potential of the CTA Observatory, the system must be put into place to enable users to operate the telescopes productively. The software will cover all stages of the CTA system, from the preparation of the observing proposals to the final data reduction, and must also fit into the overall system. Scientists, engineers, operators and others will use the system to operate the Observatory, hence they should be involved in the design process from the beginning. We have organised a workgroup and a workflow for the definition of the CTA Top Level Use Cases in the context of the Requirement Management activities of the CTA Observatory. Scientists, instrument and software developers are collaborating and sharing information to provide a common and general understanding of the Observatory from a functional point of view. Scientists that will use the CTA Observatory will provide mainly Science Driven Use Cases, whereas software engineers will subsequently provide more detailed Use Cases, comments and feedbacks. The main purposes are to define observing modes and strategies, and to provide a framework for the flow down of the Use Cases and requirements to check missing requirements and the already developed Use-Case models at CTA sub-system level. Use Cases will also provide the basis for the definition of

  10. Design of a 7m Davies-Cotton Cherenkov telescope mount for the high energy section of the Cherenkov Telescope Array

    Science.gov (United States)

    Rovero, A. C.; Ringegni, P.; Vallejo, G.; Supanitsky, A. D.; Actis, M.; Botani, A.; Ochoa, I.; Hughes, G.

    2013-08-01

    The Cherenkov Telescope Array is the next generation ground-based observatory for the study of very-high-energy gamma-rays. It will provide an order of magnitude more sensitivity and greater angular resolution than present systems as well as an increased energy range (20 GeV to 300 TeV). For the high energy portion of this range, a relatively large area has to be covered by the array. For this, the construction of ˜7 m diameter Cherenkov telescopes is an option under study. We have proposed an innovative design of a Davies-Cotton mount for such a telescope, within Cherenkov Telescope Array specifications, and evaluated its mechanical and optical performance. The mount is a reticulated-type structure with steel tubes and tensioned wires, designed in three main parts to be assembled on site. In this work we show the structural characteristics of the mount and the optical aberrations at the focal plane for three options of mirror facet size caused by mount deformations due to wind and gravity.

  11. A major electronics upgrade for the H.E.S.S. Cherenkov telescopes 1-4

    CERN Document Server

    Giavitto, G; Balzer, A.; Berge, D.; Brun, F.; Chaminade, T.; Delagnes, E.; Fontaine, G.; Füßling, M.; Giebels, B.; Glicenstein, J.F.; Gräber, T.; Hinton, J.A.; Jahnke, A.; Klepser, S.; Kossatz, M.; Kretzschmann, A.; Lefranc, V.; Leich, H.; Lüdecke, H.; Manigot, P.; Marandon, V.; Moulin, E.; de, M.; Nayman, P.; Penno, M.; Ross, D.; Salek, D.; Schade, M.; Schwab, T.; Simoni, R.; Stegmann, C.; Thornhill, J.; Toussenel, F.

    2015-01-01

    The High Energy Stereoscopic System (H.E.S.S.) is an array of imaging atmospheric Cherenkov telescopes (IACTs) located in the Khomas Highland in Namibia. It consists of four 12-m telescopes (CT1-4), which started operations in 2003, and a 28-m diameter one (CT5), which was brought online in 2012. It is the only IACT system featuring telescopes of different sizes, which provides sensitivity for gamma rays across a very wide energy range, from ~30 GeV up to ~100 TeV. Since the camera electronics of CT1-4 are much older than the one of CT5, an upgrade is being carried out; first deployment was in 2015, full operation is planned for 2016. The goals of this upgrade are threefold: reducing the dead time of the cameras, improving the overall performance of the array and reducing the system failure rate related to aging. Upon completion, the upgrade will assure the continuous operation of H.E.S.S. at its full sensitivity until and possibly beyond the advent of CTA. In the design of the new components, several CTA con...

  12. Towards a network of atmospheric Cherenkov detectors 7

    Energy Technology Data Exchange (ETDEWEB)

    Robin, M. [Ecole Polytechnique, 91 - Palaiseau (France); Weekes, T.C. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States); Mori, M. [Tokyo Univ., Institute for Cosmic Ray Research (Japan); Mariotti, M. [Padova Univ., INFN (Italy); Hofmann, W.; Aharonian, F. [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Sinitsyna, V. [P.N. Lebedev Physical Institute, Moscow (Russian Federation); Smith, D. [Centre d' Etudes Nucleaires de Bordeaux Gradignan, 33 - Gradignan (France); Marleau, P. [California Univ., Davis, CA (United States); Sinnis, G. [Los Alamos National Lab., NM (United States); Volk, H. [Max-Planck-Institut fur Kernphysik (Germany); Jager, O. de [South Africa Univ., North-West (South Africa); Harding, A. [NASA Goddard Space Flight Center (United States); Coppi, P. [Yale Univ., New Haven, CT (United States); Dermer, C. [Naval Research Laboratory (United States); Goldwurm, A.; Paul, J. [CEA Saclay, Dept. d' Astrophysique, de Physique des Particules de Physique Nucleaire et de l' Instrumentation Associee, 91- Gif sur Yvette (France); Puhlhofer, G. [Landessternwarte Heidelberg (Germany); Bernardini, E. [DESy-Zeuthen (Germany); Swordy, S. [Chicago Univ., IL (United States); Yoshikoshi, T. [Tokyo Univ., Tanashi (Japan). Inst. for Cosmic Ray Research; Teshima, M. [Max-Planck-Institute for Physics, Munich (Germany); Punch, M. [Astrophysique et Cosmologie (APC), College de France, 75 - Paris (France)

    2005-07-01

    This document gathers the papers and transparencies presented at the conference. The main part of the conference was organized into 6 sessions: 1) the review of present experiments (Veritas, Cangaroo-3, Magic, Hess-1, Shalon, Cactus, Cygnus-X-3...), 2) calibration and analysis techniques in VHE (very high energy) astrophysics, 3) multi-wavelength observations and phenomenology of sources, 4) the future of ground-based VHE astronomy, 5) developments in instrumentation for Cherenkov telescopes, and 6) the evolution of the field and its link with mainstream astrophysics.

  13. The image camera of the 17 m diameter air Cherenkov telescope MAGIC

    CERN Document Server

    Ostankov, A P

    2001-01-01

    The image camera of the 17 m diameter MAGIC telescope, an air Cherenkov telescope currently under construction to be installed at the Canary island La Palma, is described. The main goal of the experiment is to cover the unexplored energy window from approx 10 to approx 300 GeV in gamma-ray astrophysics. In its first phase with a classical PMT camera the MAGIC telescope is expected to reach an energy threshold of approx 30 GeV. The operational conditions, the special characteristics of the developed PMTs and their use with light concentrators, the fast signal transfer scheme using analog optical links, the trigger and DAQ organization as well as image reconstruction strategy are described. The different paths being explored towards future camera improvements, in particular the constraints in using silicon avalanche photodiodes and GaAsP hybrid photodetectors in air Cherenkov telescopes are discussed.

  14. Gamma-ray burst science in the era of the Cherenkov Telescope Array

    NARCIS (Netherlands)

    Inoue, S.; Granof, J.; O'Brien, P.T.; Asano, K.; Bouvier, A.; Carosi, A.; Connaughton, V.; Garczarczyk, M.; Gilmore, R.; Hinton, J.; Inoue, Y.; Kakuwa, J.; Markoff, S.; Murase, K.; Osborne, J.P.; Nepomuk Otte, A.; Starling, R.; Tajima, H.; Teshima, M.; Toma, K.; Wagner, S.; Wijers, R.A.M.J.; Williams, D.A.; Yamamoto, T.; Yamazaki, R.

    2013-01-01

    We outline the science prospects for gamma-ray bursts (GRBs) with the Cherenkov Telescope Array (CTA), the next-generation ground-based gamma-ray observatory operating at energies above few tens of GeV. With its low energy threshold, large effective area and rapid slewing capabilities, CTA will be

  15. Prospects for the detection of high-energy (E > 25 GeV) Fermi pulsars with the Cherenkov Telescope Array

    Science.gov (United States)

    Burtovoi, A.; Saito, T. Y.; Zampieri, L.; Hassan, T.

    2017-10-01

    Around 160 gamma-ray pulsars were discovered by the Fermi-Large Area Telescope (LAT) since 2008. The most energetic of them, 12 objects with emission above 25 GeV, are suitable candidates for the detection with the current and future Imaging Atmospheric Cherenkov Telescopes above few tens of GeV. We perform an analysis of the Fermi-LAT data of these high-energy pulsars in order to determine if such objects can be detected with the Cherenkov Telescope Array (CTA). Our goal is to forecast the significance of their point source detection with CTA. We analyse 5 yr of the Fermi-LAT data fitting the spectra of each pulsar at energies E > 10 GeV with a power-law function. Assuming no spectral cut-off, we extrapolate the resulting spectra to the very high energy range (VHE, E > 0.1 TeV) and simulate CTA observations of all 12 pulsars with the ctools software package. Using different analysis tools, individual CTA sensitivity curves are independently calculated for each pulsar and cross-checked with the ctools results. Our simulations result in significant CTA detections of up to eight pulsars in 50 h. Observations of the most energetic Fermi pulsars with CTA will shed light on the nature of the high-energy emission of pulsars, clarifying whether the VHE emission detected in the Crab pulsar spectrum is present also in other gamma-ray pulsars.

  16. Prototype of a production system for Cherenkov Telescope Array with DIRAC

    Science.gov (United States)

    Arrabito, L.; Bregeon, J.; Haupt, A.; Graciani Diaz, R.; Stagni, F.; Tsaregorodtsev, A.

    2015-12-01

    The Cherenkov Telescope Array (CTA) — an array of many tens of Imaging Atmospheric Cherenkov Telescopes deployed on an unprecedented scale — is the next generation instrument in the field of very high energy gamma-ray astronomy. CTA will operate as an open observatory providing data products to the scientific community. An average data stream of about 10 GB/s for about 1000 hours of observation per year, thus producing several PB/year, is expected. Large CPU time is required for data-processing as well for massive Monte Carlo simulations needed for detector calibration purposes. The current CTA computing model is based on a distributed infrastructure for the archive and the data off-line processing. In order to manage the off-line data-processing in a distributed environment, CTA has evaluated the DIRAC (Distributed Infrastructure with Remote Agent Control) system, which is a general framework for the management of tasks over distributed heterogeneous computing environments. In particular, a production system prototype has been developed, based on the two main DIRAC components, i.e. the Workload Management and Data Management Systems. After three years of successful exploitation of this prototype, for simulations and analysis, we proved that DIRAC provides suitable functionalities needed for the CTA data processing. Based on these results, the CTA development plan aims to achieve an operational production system, based on the DIRAC Workload Management System, to be ready for the start of CTA operation phase in 2017-2018. One more important challenge consists of the development of a fully automatized execution of the CTA workflows. For this purpose, we have identified a third DIRAC component, the so-called Transformation System, which offers very interesting functionalities to achieve this automatisation. The Transformation System is a ’data-driven’ system, allowing to automatically trigger data-processing and data management operations according to pre

  17. Feasibility of utilizing Cherenkov Telescope Array gamma-ray telescopes as free-space optical communication ground stations.

    Science.gov (United States)

    Carrasco-Casado, Alberto; Vilera, Mariafernanda; Vergaz, Ricardo; Cabrero, Juan Francisco

    2013-04-10

    The signals that will be received on Earth from deep-space probes in future implementations of free-space optical communication will be extremely weak, and new ground stations will have to be developed in order to support these links. This paper addresses the feasibility of using the technology developed in the gamma-ray telescopes that will make up the Cherenkov Telescope Array (CTA) observatory in the implementation of a new kind of ground station. Among the main advantages that these telescopes provide are the much larger apertures needed to overcome the power limitation that ground-based gamma-ray astronomy and optical communication both have. Also, the large number of big telescopes that will be built for CTA will make it possible to reduce costs by economy-scale production, enabling optical communications in the large telescopes that will be needed for future deep-space links.

  18. Perspectives with the GCT end-to-end prototype of the small-sized telescope proposed for the Cherenkov telescope array

    Science.gov (United States)

    Costantini, H.; Dournaux, J.-L.; Ernenwein, J.-P.; Laporte, P.; Sol, H.

    2017-01-01

    In the framework of the Cherenkov Telescope Array (CTA), the GCT (Gamma-ray Cherenkov Telescope) team is building a dual-mirror telescope as one of the proposed prototypes for the CTA small size class of telescopes. The telescope is based on a Schwarzschild-Couder (SC) optical design, an innovative solution for ground-based Cherenkov astronomy, which allows a compact telescope structure, a lightweight large Field of View (FoV) camera and enables good angular resolution across the entire FoV. We review the different mechanical and optical components of the telescope. In order to characterise them, the Paris prototype will be operated during several weeks in 2016. In this framework, an estimate of the expected performance of this prototype has been made, based on Monte Carlo simulations. In particular the observability of the Crab Nebula in the context of high Night Sky Background (NSB) is presented.

  19. Towards the development of a SiPM-based camera for the Cherenkov Telescope Array

    Directory of Open Access Journals (Sweden)

    Ambrosi G.

    2017-01-01

    Full Text Available The Italian National Institute for Nuclear Physics (INFN is involved in the development of a prototype for a camera based on Silicon Photomultipliers (SiPMs for the Cherenkov Telescope Array (CTA, a new generation of telescopes for ground-based gamma-ray astronomy. In this framework, an R&D program within the ‘Progetto Premiale TElescopi CHErenkov made in Italy (TECHE.it’ for the development of SiPMs suitable for Cherenkov light detection in the Near-Ultraviolet (NUV has been carried out. The developed device is a NUV High-Density (NUV-HD SiPM based on a micro cell of 30 μm × 30 μm and an area of 6 mm × 6 mm, produced by Fondazione Bruno Kessler (FBK. A full characterization of the single NUV-HD SiPM will be presented. A matrix of 8 × 8 single NUV-HD SiPMs will be part of the focal plane of the Schwarzschild- Couder Telescope prototype (pSCT for CTA. An update on recent tests on the detectors arranged in this matrix configuration and on the front-end electronics will be given.

  20. Sensitivity of the Cherenkov Telescope Array to the detection of a dark matter signal in comparison to direct detection and collider experiments

    Science.gov (United States)

    Balázs, Csaba; Conrad, Jan; Farmer, Ben; Jacques, Thomas; Li, Tong; Meyer, Manuel; Queiroz, Farinaldo S.; Sánchez-Conde, Miguel A.

    2017-10-01

    Imaging atmospheric Cherenkov telescopes (IACTs) that are sensitive to potential γ -ray signals from dark matter (DM) annihilation above ˜50 GeV will soon be superseded by the Cherenkov Telescope Array (CTA). CTA will have a point source sensitivity an order of magnitude better than currently operating IACTs and will cover a broad energy range between 20 GeV and 300 TeV. Using effective field theory and simplified models to calculate γ -ray spectra resulting from DM annihilation, we compare the prospects to constrain such models with CTA observations of the Galactic center with current and near-future measurements at the Large Hadron Collider (LHC) and direct detection experiments. For DM annihilations via vector or pseudoscalar couplings, CTA observations will be able to probe DM models out of reach of the LHC, and, if DM is coupled to standard fermions by a pseudoscalar particle, beyond the limits of current direct detection experiments.

  1. Mount control system of the ASTRI SST-2M prototype for the Cherenkov Telescope Array

    Science.gov (United States)

    Antolini, Elisa; Tosti, Gino; Tanci, Claudio; Bagaglia, Marco; Canestrari, Rodolfo; Cascone, Enrico; Gambini, Giorgio; Nucciarelli, Giuliano; Pareschi, Giovanni; Scuderi, Salvo; Stringhetti, Luca; Busatta, Andrea; Giacomel, Stefano; Marchiori, Gianpietro; Manfrin, Cristiana; Marcuzzi, Enrico; Di Michele, Daniele; Grigolon, Carlo; Guarise, Paolo

    2016-08-01

    The ASTRI SST-2M telescope is an end-to-end prototype proposed for the Small Size class of Telescopes (SST) of the future Cherenkov Telescope Array (CTA). The prototype is installed in Italy at the INAF observing station located at Serra La Nave on Mount Etna (Sicily) and it was inaugurated in September 2014. This paper presents the software and hardware architecture and development of the system dedicated to the control of the mount, health, safety and monitoring systems of the ASTRI SST-2M telescope prototype. The mount control system installed on the ASTRI SST-2M telescope prototype makes use of standard and widely deployed industrial hardware and software. State of the art of the control and automation industries was selected in order to fulfill the mount related functional and safety requirements with assembly compactness, high reliability, and reduced maintenance. The software package was implemented with the Beckhoff TwinCAT version 3 environment for the software Programmable Logical Controller (PLC), while the control electronics have been chosen in order to maximize the homogeneity and the real time performance of the system. The integration with the high level controller (Telescope Control System) has been carried out by choosing the open platform communications Unified Architecture (UA) protocol, supporting rich data model while offering compatibility with the PLC platform. In this contribution we show how the ASTRI approach for the design and implementation of the mount control system has made the ASTRI SST-2M prototype a standalone intelligent machine, able to fulfill requirements and easy to be integrated in an array configuration such as the future ASTRI mini-array proposed to be installed at the southern site of the Cherenkov Telescope Array (CTA).

  2. Prospects for Gamma-Ray Burst detection by the Cherenkov Telescope Array

    Directory of Open Access Journals (Sweden)

    Bissaldi E.

    2017-01-01

    Full Text Available The Large Area Telescope (LAT on the Fermi satellite is expected to publish a catalogue with more than 100 Gamma-Ray Bursts (GRBs detected above 100 MeV thanks to a new detection algorithm and a new event reconstruction. This work aims at revising the prospects for GRB alerts with the Cherenkov Telescope Array (CTA based on the new LAT results. We start considering the simulation of the observations with the full CTA of two extremely bright events, the long GRB 130427A and the short GRB 090510, then we investigate how these GRBs would be observed by a particular configuration of the array with the telescopes pointing to different directions in what is called the “coupled divergent mode”.

  3. Techniques and results for the calibration of the MST prototype for the Cherenkov telescope array

    Science.gov (United States)

    Oakes, L.; Garczarczyk, M.; Kaphle, S.; Mayer, M.; Schlenstedt, S.; Schwanke, U.

    2017-01-01

    The next generation instrument for ground-based gamma-ray astronomy will be the Cherenkov Telescope Array (CTA), consisting of approximately 100 telescopes in three sizes, built on two sites with one each in the Northern and Southern Hemi-spheres. Up to 40 of these will be Medium Size Telescopes (MSTs) which will dominate sensitivity in the core energy range. Since 2012, a full size mechanical prototype for the modified 12 m Davies-Cotton design MST has been in operation in Berlin. This document describes the techniques which have been implemented to calibrate and optimise the mechanical and optical performance of the prototype, and gives the results of over three years of observations and measurements. Pointing calibration techniques will be discussed, along with the development of a bending model, and calibration of the CCD cameras used for pointing measurements. Additionally alignment of mirror segments using the Bokeh method is shown.

  4. Nature of the low-energy, γ-like background for the Cherenkov Telescope Array

    Science.gov (United States)

    Sitarek, Julian; Sobczyńska, Dorota; Szanecki, Michał; Adamczyk, Katarzyna; Cumani, Paolo; Moralejo, Abelardo

    2018-01-01

    The upcoming Cherenkov Telescope Array (CTA) project is expected to provide unprecedented sensitivity in the low-energy ( ≲ 100 GeV) range for Cherenkov telescopes. Most of the remaining background in this energy range results from misidentified hadron showers. In order to fully exploit the potential of the telescope systems it is worthwhile to look for ways to further improve the available analysis methods for γ/hadron separation. We study the composition of the background for the planned CTA-North array by identifying events composed mostly of a single electromagnetic subcascade or double subcascade from a π0 (or another neutral meson) decay. We apply the standard simulation chain and state-of-the-art analysis chain of CTA to evaluate the potential of the standard analysis to reject such events. Simulations show a dominant role of such single subcascade background for CTA up to energies ∼ 70 GeV. We show that a natural way of rejection of such events stems from a shifted location of the shower maximum, and that the standard stereo reconstruction method used by CTA already exploits most of expected separation.

  5. CHEC: a Compact High Energy Camera for the Cherenkov Telescope Array

    Science.gov (United States)

    White, R.

    2017-12-01

    The Cherenkov Telescope Array will provide unprecedented sensitivity and angular resolution to gamma rays across orders of magnitude in energy. Above 1 TeV up to around 300 TeV an array of Small-Sized Telescopes (SSTs) will cover several kilometres on the ground. The Compact High-Energy Camera (CHEC) is a proposed option for the camera of the SSTs. CHEC contains 2048 pixels of physical size about 6 mm×6 mm, leading to a field of view of over 8 degrees. Electronics based on custom ASICs (TARGET) and FPGAs sample incoming signals at a gigasample per second and provide a flexible triggering scheme. Waveforms for every pixel in every event are read out without loss at over 600 events per second. A telescope prototype in Meudon, Paris, saw first Cherenkov light from air showers in late 2015, using the first CHEC prototype. Research and development for CHEC is currently focussed on taking advantage of the latest generation of silicon photomultipliers (SiPMs).

  6. Readout electronics for the Wide Field of view Cherenkov/Fluorescence Telescope Array

    Science.gov (United States)

    Zhang, J.; Zhang, S.; Zhang, Y.; Zhou, R.; Bai, L.; Zhang, J.; Huang, J.; Yang, C.; Cao, Z.

    2015-08-01

    The aim of the Large High Altitude Air Shower Observatory (LHAASO), supported by IHEP of the Chinese Academy of Sciences, is a multipurpose project with a complex detectors array for high energy gamma ray and cosmic ray detection. The Wide Field of view Cherenkov Telescope Array (WFCTA), as one of the components of the LHAASO project, aim to tag each primary particle that causes an air shower. The WFCTA is a portable telescope array used to detect cosmic ray spectra. The design of the readout electronics of the WFCTA is described in this paper Sixteen photomultiplier tubes (PMTs), together with their readout electronics are integrated into a single sub-cluster. To maintain good resolution and linearity over a wide dynamic range, a dual-gain amplification configuration on an analog board is used The digital board contains two 16channel 14-bit, 50 Msps analog-to-digital converters (ADC) and its power consumption, noise level, and relative deviation are all tested.

  7. First data from IceAct, an imaging air Cherenkov telescope with SiPMs at the South Pole

    Energy Technology Data Exchange (ETDEWEB)

    Auffenberg, Jan; Bretz, Thomas; Hansmann, Bengt; Hansmann, Tim; Hebbeker, Thomas; Kemp, Julian; Middendorf, Lukas; Niggemann, Tim; Raedel, Leif; Schaufel, Merlin; Schumacher, Johannes; Stahlberg, Martin; Werhan, Ansgar; Wiebusch, Christopher [RWTH Aachen University (Germany)

    2016-07-01

    IceCube-Gen2 is planned to extend the IceCube Neutrino Observatory at the geographic South Pole. For neutrino astronomy, a large background-free sample of well-reconstructed astrophysical neutrinos is essential. The main background for this signal are muons and neutrinos which are produced in cosmic-ray air showers in the Earth's atmosphere. The coincident detection of these air showers by the surface detector IceTop has been proven to be a powerful veto for atmospheric neutrinos and muons in the field of view of the Southern Hemisphere. This motivates a large extension of IceTop to more efficiently detect cosmic rays, IceVeto. Part of these extension plans is an array of imaging air Cherenkov telescopes, IceAct. A first IceAct prototype is consisting of an SiPM camera and lens optics optimized for harsh environments. Compared to IceTop stations, these telescopes potentially lower the detection threshold for air showers at the cost of a lower duty cycle. We present first data, taken during the commissioning of an IceAct prototype in December 2015 at the South Pole.

  8. The telescope control of the ASTRI SST-2M prototype for the Cherenkov telescope Array: hardware and software design architecture

    Science.gov (United States)

    Antolini, Elisa; Cascone, Enrico; Schwarz, Joseph; Stringhetti, Luca; Tanci, Claudio; Tosti, Gino; Aisa, Damiano; Aisa, Simone; Bagaglia, Marco; Busatta, Andrea; Campeggi, Carlo; Cefala, Marco; Farnesini, Lucio; Giacomel, Stefano; Marchiori, Gianpiero; Marcuzzi, Enrico; Nucciarelli, Giuliano; Piluso, Antonfranco

    2014-07-01

    ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is a flagship project of the Italian Ministry of Research and led by the Italian National Institute of Astrophysics (INAF). One of its aims is to develop, within the Cherenkov Telescope Array (CTA) framework, an end-to-end small-sized telescope prototype in a dual-mirror configuration (SST-2M) in order to investigate the energy range E ~ 1-100 TeV. A long-term goal of the ASTRI program is the production of an ASTRI/CTA mini-array composed of seven SST-2M telescopes. The prototype, named ASTRI SST-2M, is seen as a standalone system that needs only network and power connections to work. The software system that is being developed to control the prototype is the base for the Mini-Array Software System (MASS), which has the task to make possible the operation of both the ASTRI SST-2M prototype and the ASTRI/CTA mini-array. The scope of this contribution is to give an overview of the hardware and software architecture adopted for the ASTRI SST- 2M prototype, showing how to apply state of the art industrial technologies to telescope control and monitoring systems.

  9. Dark Matter Searches with Cherenkov Telescopes: Nearby Dwarf Galaxies or Local Galaxy Clusters?

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Conde, Miguel A.; /KIPAC, Menlo Park /SLAC /IAC, La Laguna /Laguna U., Tenerife; Cannoni, Mirco; /Huelva U.; Zandanel, Fabio; /IAA, Granada; Gomez, Mario E.; /Huelva U.; Prada, Francisco; /IAA, Granada

    2012-06-06

    In this paper, we compare dwarf galaxies and galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies (Draco, Ursa Minor, Wilman 1 and Segue 1) and local galaxy clusters (Perseus, Coma, Ophiuchus, Virgo, Fornax, NGC 5813 and NGC 5846), and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman 1 appears as the best candidate in the sample. However, its mass modeling is still rather uncertain, so probably other candidates with less uncertainties and quite similar fluxes, namely Ursa Minor and Segue 1, might be better options. As for galaxy clusters, Virgo represents the one with the highest flux. However, its large spatial extension can be a serious handicap for IACT observations and posterior data analysis. Yet, other local galaxy cluster candidates with more moderate emission regions, such as Perseus, may represent good alternatives. After comparing dwarfs and clusters, we found that the former exhibit annihilation flux profiles that, at the center, are roughly one order of magnitude higher than those of clusters, although galaxy clusters can yield similar, or even higher, integrated fluxes for the whole object once substructure is taken into account. Even when any of these objects are strictly point-like according to the properties of their annihilation signals, we conclude that dwarf galaxies are best suited for observational strategies based on the search of point-like sources, while galaxy clusters represent best targets for analyses that can deal with rather extended emissions. Finally, we study the detection prospects for present and future IACTs in the framework of the constrained minimal supersymmetric standard model. We

  10. Silicon Photomultipliers and front-end electronics performance for Cherenkov Telescope Array camera development

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosi, G. [INFN – Sezione di Perugia, Perugia (Italy); Bissaldi, E.; Giglietto, N.; Giordano, F. [Dipartimento Interateneo di Fisica, Università e Politecnico di Bari, Bari (Italy); INFN – Sezione di Bari, Bari (Italy); Ionica, M. [INFN – Sezione di Perugia, Perugia (Italy); Paoletti, R. [Università di Siena, Siena (Italy); INFN – Sezione di Pisa, Pisa (Italy); Rando, R. [Università di Padova, Padova (Italy); INFN – Sezione di Padova, Padova (Italy); Simone, D., E-mail: daniela.simone@ba.infn.it [INFN – Sezione di Bari, Bari (Italy); Vagelli, V. [INFN – Sezione di Perugia, Perugia (Italy)

    2017-02-11

    In the last few years a number of efforts have been undertaken to develop new technology related to Silicon Photomultipliers (SiPMs). These photosensors consist of an array of identical Avalanche Photodiodes operating in Geiger mode and connected in parallel to a single output. The Italian Institute of Nuclear Physics (INFN) is involved in the R&D program Progetto Premiale Telescopi CHErenkov made in Italy (TECHE.it) to develop photosensors for a SiPM based camera that will be part of the Cherenkov Telescope Array (CTA) observatory. In this framework tests are ongoing on innovative devices suitable to detect Cherenkov light in the blue and near-UV wavelength region, the so-called Near Ultra-Violet Silicon Photomultipliers (NUV SiPMs). The tests on photosensors produced by Fondazione Bruno Kessler (FBK) are revealing promising performance: low operating voltage, capability to detect very low intensity light down to a single photon and high Photo Detection Efficiency (PDE) in the range 390–410 nm. In particular the developed device is a High Density NUV-SiPM (NUV-HD SiPM) based on a micro-cell of 30 μm×30 μm and 6 mm×6 mm area. Tests on this detector in single-cell configuration and in a matrix arrangement have been done. At the same time front-end electronics based on the waveform sampling technique optimized for the new NUV-HD SIPMs is under study and development.

  11. Reaching the lowest energy threshold of ground-based Cherenkov telescopes with MAGIC-stereo: A goal achieved

    Science.gov (United States)

    Doro, Michele; MAGIC Collaboration

    2012-11-01

    The MAGIC telescopes have been designed primarily to reach the lowest possible energy threshold with the ground-based Imaging Atmospheric Cherenkov technique, in order to fill the gap between MeV-GeV gamma-ray satellite experiments and TeV ground-based installations. With the construction of a second MAGIC telescope and the subsequent use of the stereoscopic operation mode, this goal has already been largely achieved. Astrophysical spectra of some active galactic nuclei and pulsar wind nebulae, for example, are now completely sampled in the high energy peak from MeV to TeV. Frequently, this was achieved in multi-wavelength campaigns covering many orders of magnitude in energy and permitting a deeper insight into the target physics. In addition, the sensitivity at low energies allows us to perform studies of pulsars, gamma-ray burst and other fundamental physics topics. In this review, the improvement due to the stereoscopic upgrade will be briefly presented and discussed. The importance of low energy studies in astrophysics and fundamental physics searches will be exposed together with a selection of the most recent and sometimes conspicuous results obtained with the MAGIC-stereo experiment.

  12. Prototyping a 10Gigabit-Ethernet Event-Builder for a Cherenkov Telescope Array

    CERN Multimedia

    CERN. Geneva

    2012-01-01

    We present the prototyping of a 10Gigabit-Ethernet based UDP data acquisition (DAQ) system that has been conceived in the context of the Array and Control group of CTA (Cherenkov Telescope Array). The CTA consortium plans to build the next generation ground-based gamma-ray instrument, with approximately 100 telescopes of at least three different sizes installed on two sites. The genuine camera dataflow amounts to 1.2 GByte/s per camera. We have conceived and built a prototype of a front-end event builder DAQ able to receive and compute such a data rate, allowing a more sustainable level for the central data logging of the site by data reduction. We took into account characteristics and constraints of several camera electronics projects in CTA, thus keeping a generic approach to all front-end types. The big number of telescopes and the remoteness of the array sites imply that any front-end element must be robust and self-healing to a large extent. The main difficulty is to combine very high performances with a...

  13. Aplanatic telescopes based on Schwarzschild optical configuration: from grazing incidence Wolter-like x-ray optics to Cherenkov two-mirror normal incidence telescopes

    Science.gov (United States)

    Sironi, Giorgia

    2017-09-01

    At the beginning of XX century Karl Schwarzschild defined a method to design large-field aplanatic telescopes based on the use of two aspheric mirrors. The approach was then refined by Couder (1926) who, in order to correct for the astigmatic aberration, introduced a curvature of the focal plane. By the way, the realization of normal-incidence telescopes implementing the Schwarzschild aplanatic configuration has been historically limited by the lack of technological solutions to manufacture and test aspheric mirrors. On the other hand, the Schwarzschild solution was recovered for the realization of coma-free X-ray grazing incidence optics. Wolter-like grazing incidence systems are indeed free of spherical aberration, but still suffer from coma and higher order aberrations degrading the imaging capability for off-axis sources. The application of the Schwarzschild's solution to X-ray optics allowed Wolter to define an optical system that exactly obeys the Abbe sine condition, eliminating coma completely. Therefore these systems are named Wolter-Schwarzschild telescopes and have been used to implement wide-field X-ray telescopes like the ROSAT WFC and the SOHO X-ray telescope. Starting from this approach, a new class of X-ray optical system was proposed by Burrows, Burg and Giacconi assuming polynomials numerically optimized to get a flat field of view response and applied by Conconi to the wide field x-ray telescope (WFXT) design. The Schwarzschild-Couder solution has been recently re-discovered for the application to normal-incidence Cherenkov telescopes, thanks to the suggestion by Vassiliev and collaborators. The Italian Institute for Astrophysics (INAF) realized the first Cherenkov telescope based on the polynomial variation of the Schwarzschild configuration (the so-called ASTRI telescope). Its optical qualification was successfully completed in 2016, demonstrating the suitability of the Schwarzschild-like configuration for the Cherenkov astronomy requirements

  14. The ASTRI SST-2M prototype for the next generation of Cherenkov telescopes: a single framework approach from requirement analysis to integration and verification strategy definition

    Science.gov (United States)

    Fiorini, Mauro; La Palombara, Nicola; Stringhetti, Luca; Canestrari, Rodolfo; Catalano, Osvaldo; Giro, Enrico; Leto, Giuseppe; Maccarone, Maria Concetta; Pareschi, Giovanni; Tosti, Gino; Vercellone, Stefano

    2014-08-01

    ASTRI is a flagship project of the Italian Ministry of Education, University and Research, which aims to develop an endto- end prototype of one of the three types of telescopes to be part of the Cherenkov Telescope Array (CTA), an observatory which will be the main representative of the next generation of Imaging Atmospheric Cherenkov Telescopes. The ASTRI project, led by the Italian National Institute of Astrophysics (INAF), has proposed an original design for the Small Size Telescope, which is aimed to explore the uppermost end of the Very High Energy domain up to about few hundreds of TeV with unprecedented sensitivity, angular resolution and imaging quality. It is characterized by challenging and innovative technological solutions which will be adopted for the first time in a Cherenkov telescope: a dual-mirror Schwarzschild-Couder configuration, a modular, light and compact camera based on silicon photomultipliers, and a front-end electronic based on a specifically designed ASIC. The end-to-end project is also including all the data-analysis software and the data archive. In this paper we describe the process followed to derive the ASTRI specifications from the CTA general requirements, a process which had to take into proper account the impact on the telescope design of the different types of the CTA requirements (performance, environment, reliability-availability-maintenance, etc.). We also describe the strategy adopted to perform the specification verification, which will be based on different methods (inspection, analysis, certification, and test) in order to demonstrate the telescope compliance with the CTA requirements. Finally we describe the integration planning of the prototype assemblies (structure, mirrors, camera, control software, auxiliary items) and the test planning of the end-to-end telescope. The approach followed by the ASTRI project is to have all the information needed to report the verification process along all project stages in a single

  15. The ASTRI SST-2M telescope prototype for the Cherenkov Telescope Array: camera DAQ software architecture

    Science.gov (United States)

    Conforti, Vito; Trifoglio, Massimo; Bulgarelli, Andrea; Gianotti, Fulvio; Fioretti, Valentina; Tacchini, Alessandro; Zoli, Andrea; Malaguti, Giuseppe; Capalbi, Milvia; Catalano, Osvaldo

    2014-07-01

    ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is a Flagship Project financed by the Italian Ministry of Education, University and Research, and led by INAF, the Italian National Institute of Astrophysics. Within this framework, INAF is currently developing an end-to-end prototype of a Small Size dual-mirror Telescope. In a second phase the ASTRI project foresees the installation of the first elements of the array at CTA southern site, a mini-array of 7 telescopes. The ASTRI Camera DAQ Software is aimed at the Camera data acquisition, storage and display during Camera development as well as during commissioning and operations on the ASTRI SST-2M telescope prototype that will operate at the INAF observing station located at Serra La Nave on the Mount Etna (Sicily). The Camera DAQ configuration and operations will be sequenced either through local operator commands or through remote commands received from the Instrument Controller System that commands and controls the Camera. The Camera DAQ software will acquire data packets through a direct one-way socket connection with the Camera Back End Electronics. In near real time, the data will be stored in both raw and FITS format. The DAQ Quick Look component will allow the operator to display in near real time the Camera data packets. We are developing the DAQ software adopting the iterative and incremental model in order to maximize the software reuse and to implement a system which is easily adaptable to changes. This contribution presents the Camera DAQ Software architecture with particular emphasis on its potential reuse for the ASTRI/CTA mini-array.

  16. A prototype for the real-time analysis of the Cherenkov Telescope Array

    Science.gov (United States)

    Bulgarelli, Andrea; Fioretti, Valentina; Zoli, Andrea; Aboudan, Alessio; Rodríguez-Vázquez, Juan José; Maier, Gernot; Lyard, Etienne; Bastieri, Denis; Lombardi, Saverio; Tosti, Gino; De Rosa, Adriano; Bergamaschi, Sonia; Interlandi, Matteo; Beneventano, Domenico; Lamanna, Giovanni; Jacquemier, Jean; Kosack, Karl; Antonelli, Lucio Angelo; Boisson, Catherine; Burkowski, Jerzy; Buson, Sara; Carosi, Alessandro; Conforti, Vito; Contreras, Jose Luis; De Cesare, Giovanni; de los Reyes, Raquel; Dumm, Jon; Evans, Phil; Fortson, Lucy; Fuessling, Matthias; Graciani, Ricardo; Gianotti, Fulvio; Grandi, Paola; Hinton, Jim; Humensky, Brian; Knödlseder, Jürgen; Malaguti, Giuseppe; Marisaldi, Martino; Neyroud, Nadine; Nicastro, Luciano; Ohm, Stefan; Osborne, Julian; Rosen, Simon; Tacchini, Alessandro; Torresi, Eleonora; Testa, Vincenzo; Trifoglio, Massimo; Weinstein, Amanda

    2014-07-01

    The Cherenkov Telescope Array (CTA) observatory will be one of the biggest ground-based very-high-energy (VHE) γ- ray observatory. CTA will achieve a factor of 10 improvement in sensitivity from some tens of GeV to beyond 100 TeV with respect to existing telescopes. The CTA observatory will be capable of issuing alerts on variable and transient sources to maximize the scientific return. To capture these phenomena during their evolution and for effective communication to the astrophysical community, speed is crucial. This requires a system with a reliable automated trigger that can issue alerts immediately upon detection of γ-ray flares. This will be accomplished by means of a Real-Time Analysis (RTA) pipeline, a key system of the CTA observatory. The latency and sensitivity requirements of the alarm system impose a challenge because of the anticipated large data rate, between 0.5 and 8 GB/s. As a consequence, substantial efforts toward the optimization of highthroughput computing service are envisioned. For these reasons our working group has started the development of a prototype of the Real-Time Analysis pipeline. The main goals of this prototype are to test: (i) a set of frameworks and design patterns useful for the inter-process communication between software processes running on memory; (ii) the sustainability of the foreseen CTA data rate in terms of data throughput with different hardware (e.g. accelerators) and software configurations, (iii) the reuse of nonreal- time algorithms or how much we need to simplify algorithms to be compliant with CTA requirements, (iv) interface issues between the different CTA systems. In this work we focus on goals (i) and (ii).

  17. Development of the quality control system of the readout electronics for the large size telescope of the Cherenkov Telescope Array observatory

    Energy Technology Data Exchange (ETDEWEB)

    Konno, Y.; Kubo, H.; Masuda, S. [Department of Physics, Graduate School of Science, Kyoto University, Kyoto (Japan); Paoletti, R.; Poulios, S. [SFTA Department, Physics Section, University of Siena and INFN, Siena (Italy); Rugliancich, A., E-mail: andrea.rugliancich@pi.infn.it [SFTA Department, Physics Section, University of Siena and INFN, Siena (Italy); Saito, T. [Department of Physics, Graduate School of Science, Kyoto University, Kyoto (Japan)

    2016-07-11

    The Cherenkov Telescope Array (CTA) is the next generation VHE γ-ray observatory which will improve the currently available sensitivity by a factor of 10 in the range 100 GeV to 10 TeV. The array consists of different types of telescopes, called large size telescope (LST), medium size telescope (MST) and small size telescope (SST). A LST prototype is currently being built and will be installed at the Observatorio Roque de los Muchachos, island of La Palma, Canary islands, Spain. The readout system for the LST prototype has been designed and around 300 readout boards will be produced in the coming months. In this note we describe an automated quality control system able to measure basic performance parameters and quickly identify faulty boards. - Highlights: • The Dragon Board is part of the DAQ of the LST Cherenkov telescope prototype. • We developed an automated quality control system for the Dragon Board. • We check pedestal, linearity, pulse shape and crosstalk values. • The quality control test can be performed on the production line.

  18. Front-end and slow control electronics for large area SiPMs used for the single mirror Small Size Telescope (SST-1M) of the Cherenkov Telescope Array (CTA)

    Science.gov (United States)

    Aguilar, J. A.; Bilnik, W.; Borkowski, J.; Cadoux, F.; Christov, A.; della Volpe, D.; Favre, Y.; Heller, M.; Kasperek, J.; Lyard, E.; Marszalek, A.; Moderski, R.; Montaruli, T.; Porcelli, A.; Prandini, E.; Rajda, P.; Rameez, M.; Schioppa, E., Jr.; Troyano Pujadas, I.; Zietara, K.; Blocki, J.; Bogacz, L.; Bulik, T.; Curyło, M.; Dyrda, M.; Frankowski, A.; Grudniki, Ł.; Grudzinska, M.; Idźkowski, B.; Jamrozy, M.; Janiak, M.; Lalik, K.; Mach, E.; Mandat, D.; Michalowski, J.; Neronov, A.; Niemiec, J.; Ostrowski, M.; Paśko, P.; Pech, M.; Schovanek, P.; Seweryn, K.; Skowron, K.; Sliusar, V.; Sowinski, M.; Stawarz, Ł.; Stodulska, M.; Stodulski, M.; Toscano, S.; Walter, R.; Wiecek, M.; Zagdański, A.; Żychowski, P.

    2016-07-01

    The single mirror Small Size Telescope (SST-1M) project proposes a design among others for the smallest type of telescopes (SST), that will compose the south observatory of the Cherenkov Telescope Array (CTA). The SST camera collecting the Cherenkov light resulting from very high energy gamma-ray interactions in the atmosphere proposes to use Silicon PhotoMultipliers (SiPM). The SST-1M design has led to the use of unique pixel shape and size that required a dedicated development by the University of Geneva and Hamamatsu. An active surface of 94 mm2 and a resulting total capacitance of 3.4 nF combined with the stringent requirements of the CTA project on timing and charge resolution have led the University of Geneva to develop a custom preamplifier stage and slow-control system. The design and performance of the tailor made preamplifier stage and of the slow control electronics will be briefly described. The bias circuit of the sensor contains a resistor meant to prevent the sensor from drawing high current. However this resistor also introduces a voltage drop at the sensor input impacting the stability of its operation. A model has been developed in order to derive the parameters needed to account for it at the data analysis level. A solution based on the SST-1M front-end and digital readout is proposed to compensate for the voltage drop at the sensor cathode.

  19. The ASTRI mini-array within the future Cherenkov Telescope Array

    Science.gov (United States)

    Vercellone, Stefano

    2016-07-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to very high-energy gamma-ray astrophysics in the energy range from a few tens of GeV to above 100 TeV, which will yield about an order of magnitude improvement in sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS). Within this framework, the Italian National Institute for Astrophysics is leading the ASTRI project, whose main goals are the design and installation on Mt. Etna (Sicily) of an end-to-end dual-mirror prototype of the CTA small size telescope (SST) and the installation at the CTA Southern site of a dual-mirror SST mini-array composed of nine units with a relative distance of about 300 m. The innovative dual-mirror Schwarzschild-Couder optical solution adopted for the ASTRI Project allows us to substantially reduce the telescope plate-scale and, therefore, to adopt silicon photo-multipliers as light detectors. The ASTRI mini-array is a wider international effort. The mini-array, sensitive in the energy range 1-100 TeV and beyond with an angular resolution of a few arcmin and an energy resolution of about 10-15%, is well suited to study relatively bright sources (a few × 10-12 erg cm-2 s-1 at 10 TeV) at very high energy. Prominent sources such as extreme blazars, nearby well-known BL Lac objects, Galactic pulsar wind nebulae, supernovae remnants, micro-quasars, and the Galactic Center can be observed in a previously unexplored energy range. The ASTRI mini-array will extend the current IACTs sensitivity well above a few tens of TeV and, at the same time, will allow us to compare our results on a few selected targets with those of current (HAWC) and future high-altitude extensive air-shower detectors.

  20. The ASTRI mini-array within the future Cherenkov Telescope Array

    Directory of Open Access Journals (Sweden)

    Vercellone Stefano

    2016-01-01

    Full Text Available The Cherenkov Telescope Array (CTA is a large collaborative effort aimed at the design and operation of an observatory dedicated to very high-energy gamma-ray astrophysics in the energy range from a few tens of GeV to above 100 TeV, which will yield about an order of magnitude improvement in sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS. Within this framework, the Italian National Institute for Astrophysics is leading the ASTRI project, whose main goals are the design and installation on Mt. Etna (Sicily of an end-to-end dual-mirror prototype of the CTA small size telescope (SST and the installation at the CTA Southern site of a dual-mirror SST mini-array composed of nine units with a relative distance of about 300 m. The innovative dual-mirror Schwarzschild-Couder optical solution adopted for the ASTRI Project allows us to substantially reduce the telescope plate-scale and, therefore, to adopt silicon photo-multipliers as light detectors. The ASTRI mini-array is a wider international effort. The mini-array, sensitive in the energy range 1–100 TeV and beyond with an angular resolution of a few arcmin and an energy resolution of about 10–15%, is well suited to study relatively bright sources (a few × 10−12 erg cm−2 s−1 at 10 TeV at very high energy. Prominent sources such as extreme blazars, nearby well-known BL Lac objects, Galactic pulsar wind nebulae, supernovae remnants, micro-quasars, and the Galactic Center can be observed in a previously unexplored energy range. The ASTRI mini-array will extend the current IACTs sensitivity well above a few tens of TeV and, at the same time, will allow us to compare our results on a few selected targets with those of current (HAWC and future high-altitude extensive air-shower detectors.

  1. Performance characteristics of large aperture, ten-cell atmospheric pressure isobutane Cherenkov counters

    Science.gov (United States)

    Hylen, J.; Ming Ma, Z.; Jawahery, A.; Maruyama, T.; Milburn, R. H.

    1981-06-01

    Two large-aperture, 10-cell atmospheric-pressure isobutane Cherenkov counters were designed and constructed for a SLAC streamer-chamber experiment. The rejection efficiencies for a 9 GeV/ cπ- were measured to be 99.84% ⋍ 0.006% and 99.717% ± 0.008% for the two counters. The design details and performance characteristics are discussed.

  2. Time calibration with atmospheric muon tracks in the ANTARES neutrino telescope

    CERN Document Server

    Adrián-Martínez, S.; André, M.; Anton, G.; Ardid, M.; Aubert, J.-J.; Baret, B.; Barrios-Martí, J.; Basa, S.; Bertin, V.; Biagi, S.; Bogazzi, C.; Bormuth, R.; Bou-Cabo, M.; Bouwhuis, M.C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carr, J.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Coyle, P.; Creusot, A.; Dekeyser, I.; Deschamps, A.; De Bonis, G.; Distefano, C.; Donzaud, C.; Dornic, D.; Drouhin, D.; Dumas, A.; Eberl, T.; Elsässer, D.; Enzenhöfer, A.; Fehn, K.; Felis, I.; Fermani, P.; Flaminio, V.; Folger, F.; Fusco, L.A.; Galatà, S.; Gay, P.; Geißelsöder, S.; Geyer, K.; Giordano, V.; Gleixner, A.; Gracia-Ruiz, R.; Gómez-González, J.P.; Graf, K.; van Haren, H.; Heijboer, A.J.; Hello, Y.; Hernández-Rey, J.J.; Herrero, A.; Hößl, J.; Hofestädt, J.; Hugon, C.; James, C.W.; de Jong, M.; Kadler, M.; Kalekin, O.; Katz, U.; Kießling, D.; Kooijman, P.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lambard, G.; Lattuada, D.; Lefèvre, D.; Leonora, E.; Loucatos, S.; Mangano, S.; Marcelin, M.; Margiotta, A.; Marinelli, A.; Martínez-Mora, J.A.; Martini, S.; Mathieu, A.; Michael, T.; Migliozzi, P.; Moussa, A.; Mueller, C.; Neff, M.; Nezri, E.; Păvălaş, G.E.; Pellegrino, C.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Riccobene, G.; Richter, R.; Roensch, K.; Rostovtsev, A.; Saldaña, M.; Samtleben, D.F.E.; Sánchez-Losa, A.; Sanguineti, M.; Sapienza, P.; Schmid, J.; Schnabel, J.; Schulte, S.; Schüssler, F.; Seitz, T.; Sieger, C.; Spurio, M.; Steijger, J.J.M.; Stolarczyk, Th.; Taiuti, M.; Tamburini, C.; Trovato, A.; Tselengidou, M.; Tönnis, C.; Turpin, D.; Vallage, B.; Vallée, C.; Van Elewyck, V.; Visser, E.; Vivolo, D.; Wagner, S.; Wilms, J.; Zornoza, J.D.; Zúñiga, J.

    The ANTARES experiment consists of an array of photomultipliers distributed along 12 lines and located deep underwater in the Mediterranean Sea. It searches for astrophysical neutrinos collecting the Cherenkov light induced by the charged particles, mainly muons, produced in neutrino interactions around the detector. Since at energies of $\\sim$10 TeV the muon and the incident neutrino are almost collinear, it is possible to use the ANTARES detector as a neutrino telescope and identify a source of neutrinos in the sky starting from a precise reconstruction of the muon trajectory. To get this result, the arrival times of the Cherenkov photons must be accurately measured. A to perform time calibrations with the precision required to have optimal performances of the instrument is described. The reconstructed tracks of the atmospheric muons in the ANTARES detector are used to determine the relative time offsets between photomultipliers. Currently, this method is used to obtain the time calibration constants for ph...

  3. Experimental study of the atmospheric neutrino backgrounds for proton decay to positron and neutral pion searches in water Cherenkov detectors

    CERN Document Server

    Mine, S; Andringa, S; Aoki, S; Argyriades, J; Asakura, K; Ashie, R; Berghaus, F; Berns, H; Bhang, H; Blondel, A; Borghi, S; Bouchez, J; Burguet-Castell, J; Casper, D; Catala, J; Cavata, C; Cervera-Villanueva, Anselmo; Chen, S M; Cho, K O; Choi, J H; Dore, U; Espinal, X; Fechner, M; Fernández, E; Fujii, Y; Fukuda, Y; Gomez-Cadenas, J; Gran, R; Hara, T; Hasegawa, M; Hasegawa, T; Hayato, Y; Helmer, R L; Hiraide, K; Hosaka, J; Ichikawa, A K; Iinuma, M; Ikeda, A; Ishida, T; Ishihara, K; Ishii, T; Ishitsuka, M; Itow, Y; Iwashita, T; Jang, H I; Jeon, E J; Jeong, I S; Joo, K K; Jover, G; Jung, C K; Kajita, T; Kameda, J; Kaneyuki, K; Kato, I; Kearns, E; Kim, C O; Khabibullin, M; Khotjantsev, A; Kielczewska, D; Kim, J Y; Kim, S B; Kitching, P; Kobayashi, K; Kobayashi, T; Konaka, A; Koshio, Y; Kropp, W; Kudenko, Yu; Kuno, Y; Kurimoto, Y; Kutter, T; Learned, J; Likhoded, S; Lim, I T; Loverre, P F; Ludovici, L; Maesaka, H; Mallet, J; Mariani, C; Matsuno, S; Matveev, V; McConnel, K; McGrew, C; Mikheyev, S; Minamino, A; Mineev, O; Mitsuda, C; Miura, M; Moriguchi, Y; Moriyama, S; Nakadaira, T; Nakahata, M; Nakamura, K; Nakano, I; Nakaya, T; Nakayama, S; Namba, T; Nambu, R; Nawang, S; Nishikawa, K; Nitta, K; Nova, F; Novella, P; Obayashi, Y; Okada, A; Okumura, K; Oser, S M; Oyama, Y; Pac, M Y; Pierre, F; Rodríguez, A; Saji, C; Sakuda, M; Sánchez, F; Scholberg, K; Schroeter, R; Sekiguchi, M; Shiozawa, M; Shiraishi, K; Sitjes, G; Smy, M; Sobel, H; Sorel, M; Stone, J; Sulak, L; Suzuki, A; Suzuki, Y; Tada, M; Takahashi, T; Takenaga, Y; Takeuchi, Y; Taki, K; Takubo, Y; Tamura, N; Tanaka, M; Terri, R; T'Jampens, S; Tornero-Lopez, A; Totsuka, Y; Vagins, M; Whitehead, L; Walter, C W; Wang, W; Wilkes, R J; Yamada, S; Yamada, Y; Yamamoto, S; Yanagisawa, C; Yershov, N; Yokoyama, H; Yokoyama, M; Yoo, J; Yoshida, M; Zalipska, J

    2008-01-01

    The atmospheric neutrino background for proton decay to positron and neutral pion in ring imaging water Cherenkov detectors is studied with an artificial accelerator neutrino beam for the first time. In total, about 314,000 neutrino events corresponding to about 10 megaton-years of atmospheric neutrino interactions were collected by a 1,000 ton water Cherenkov detector (KT). The KT charged-current single neutral pion production data are well reproduced by simulation programs of neutrino and secondary hadronic interactions used in the Super-Kamiokande (SK) proton decay search. The obtained proton to positron and neutral pion background rate by the KT data for SK from the atmospheric neutrinos whose energies are below 3 GeV is about two per megaton-year. This result is also relevant to possible future, megaton-scale water Cherenkov detectors.

  4. The control, monitor, and alarm system for the ICT equipment of the ASTRI SST-2M telescope prototype for the Cherenkov Telescope Array

    Science.gov (United States)

    Gianotti, Fulvio; Fioretti, Valentina; Tanci, Claudio; Conforti, Vito; Tacchini, Alessandro; Leto, Giuseppe; Gallozzi, Stefano; Bulgarelli, Andrea; Trifoglio, Massimo; Malaguti, Giuseppe; Zoli, Andrea

    2014-07-01

    ASTRI is an Italian flagship project whose first goal is the realization of an end-to-end telescope prototype, named ASTRI SST-2M, for the Cherenkov Telescope Array (CTA). The prototype will be installed in Italy during Fall 2014. A second goal will be the realization of the ASTRI/CTA mini-array which will be composed of seven SST-2M telescopes placed at the CTA Southern Site. The Information and Communication Technology (ICT) equipment necessary to drive the infrastructure for the ASTRI SST-2M prototype is being designed as a complete and stand-alone computer center. The design goal is to obtain basic ICT equipment that might be scaled, with a low level of redundancy, for the ASTRI/CTA mini-array, taking into account the necessary control, monitor and alarm system requirements. The ICT equipment envisaged at the Serra La Nave observing station in Italy, where the ASTRI SST-2M telescope prototype will operate, includes computers, servers and workstations, network devices, an uninterruptable power supply system, and air conditioning systems. Suitable hardware and software tools will allow the parameters related to the behavior and health of each item of equipment to be controlled and monitored. This paper presents the proposed architecture and technical solutions that integrate the ICT equipment in the framework of the Observatory Control System package of the ASTRI/CTA Mini- Array Software System, MASS, to allow their local and remote control and monitoring. An end-toend test case using an Internet Protocol thermometer is reported in detail.

  5. Prospects for Cherenkov Telescope Array Observations of the Young Supernova Remnant RX J1713.7-3946

    Science.gov (United States)

    Acero, F.; Aloisio, R.; Amans, J.; Amato, E.; Antonelli, L. A.; Aramo, C.; Armstrong, T.; Arqueros, F.; Asano, K.; Ashley, M.; Backes, M.; Balazs, C.; Balzer, A.; Bamba, A.; Barkov, M.; Barrio, J. A.; Benbow, W.; Bernlöhr, K.; Beshley, V.; Bigongiari, C.; Biland, A.; Bilinsky, A.; Bissaldi, E.; Biteau, J.; Blanch, O.; Blasi, P.; Blazek, J.; Boisson, C.; Bonanno, G.; Bonardi, A.; Bonavolontà, C.; Bonnoli, G.; Braiding, C.; Brau-Nogué, S.; Bregeon, J.; Brown, A. M.; Bugaev, V.; Bulgarelli, A.; Bulik, T.; Burton, M.; Burtovoi, A.; Busetto, G.; Böttcher, M.; Cameron, R.; Capalbi, M.; Caproni, A.; Caraveo, P.; Carosi, R.; Cascone, E.; Cerruti, M.; Chaty, S.; Chen, A.; Chen, X.; Chernyakova, M.; Chikawa, M.; Chudoba, J.; Cohen-Tanugi, J.; Colafrancesco, S.; Conforti, V.; Contreras, J. L.; Costa, A.; Cotter, G.; Covino, S.; Covone, G.; Cumani, P.; Cusumano, G.; D'Ammando, F.; D'Urso, D.; Daniel, M.; Dazzi, F.; De Angelis, A.; De Cesare, G.; De Franco, A.; De Frondat, F.; de Gouveia Dal Pino, E. M.; De Lisio, C.; de los Reyes Lopez, R.; De Lotto, B.; de Naurois, M.; De Palma, F.; Del Santo, M.; Delgado, C.; della Volpe, D.; Di Girolamo, T.; Di Giulio, C.; Di Pierro, F.; Di Venere, L.; Doro, M.; Dournaux, J.; Dumas, D.; Dwarkadas, V.; Díaz, C.; Ebr, J.; Egberts, K.; Einecke, S.; Elsässer, D.; Eschbach, S.; Falceta-Goncalves, D.; Fasola, G.; Fedorova, E.; Fernández-Barral, A.; Ferrand, G.; Fesquet, M.; Fiandrini, E.; Fiasson, A.; Filipovíc, M. D.; Fioretti, V.; Font, L.; Fontaine, G.; Franco, F. J.; Freixas Coromina, L.; Fujita, Y.; Fukui, Y.; Funk, S.; Förster, A.; Gadola, A.; Garcia López, R.; Garczarczyk, M.; Giglietto, N.; Giordano, F.; Giuliani, A.; Glicenstein, J.; Gnatyk, R.; Goldoni, P.; Grabarczyk, T.; Graciani, R.; Graham, J.; Grandi, P.; Granot, J.; Green, A. J.; Griffiths, S.; Gunji, S.; Hakobyan, H.; Hara, S.; Hassan, T.; Hayashida, M.; Heller, M.; Helo, J. C.; Hinton, J.; Hnatyk, B.; Huet, J.; Huetten, M.; Humensky, T. B.; Hussein, M.; Hörandel, J.; Ikeno, Y.; Inada, T.; Inome, Y.; Inoue, S.; Inoue, T.; Inoue, Y.; Ioka, K.; Iori, M.; Jacquemier, J.; Janecek, P.; Jankowsky, D.; Jung, I.; Kaaret, P.; Katagiri, H.; Kimeswenger, S.; Kimura, S.; Knödlseder, J.; Koch, B.; Kocot, J.; Kohri, K.; Komin, N.; Konno, Y.; Kosack, K.; Koyama, S.; Kraus, M.; Kubo, H.; Kukec Mezek, G.; Kushida, J.; La Palombara, N.; Lalik, K.; Lamanna, G.; Landt, H.; Lapington, J.; Laporte, P.; Lee, S.; Lees, J.; Lefaucheur, J.; Lenain, J.-P.; Leto, G.; Lindfors, E.; Lohse, T.; Lombardi, S.; Longo, F.; Lopez, M.; Lucarelli, F.; Luque-Escamilla, P. L.; López-Coto, R.; Maccarone, M. C.; Maier, G.; Malaguti, G.; Mandat, D.; Maneva, G.; Mangano, S.; Marcowith, A.; Martí, J.; Martínez, M.; Martínez, G.; Masuda, S.; Maurin, G.; Maxted, N.; Melioli, C.; Mineo, T.; Mirabal, N.; Mizuno, T.; Moderski, R.; Mohammed, M.; Montaruli, T.; Moralejo, A.; Mori, K.; Morlino, G.; Morselli, A.; Moulin, E.; Mukherjee, R.; Mundell, C.; Muraishi, H.; Murase, K.; Nagataki, S.; Nagayoshi, T.; Naito, T.; Nakajima, D.; Nakamori, T.; Nemmen, R.; Niemiec, J.; Nieto, D.; Nievas-Rosillo, M.; Nikołajuk, M.; Nishijima, K.; Noda, K.; Nogues, L.; Nosek, D.; Novosyadlyj, B.; Nozaki, S.; Ohira, Y.; Ohishi, M.; Ohm, S.; Okumura, A.; Ong, R. A.; Orito, R.; Orlati, A.; Ostrowski, M.; Oya, I.; Padovani, M.; Palacio, J.; Palatka, M.; Paredes, J. M.; Pavy, S.; Pe'er, A.; Persic, M.; Petrucci, P.; Petruk, O.; Pisarski, A.; Pohl, M.; Porcelli, A.; Prandini, E.; Prast, J.; Principe, G.; Prouza, M.; Pueschel, E.; Pühlhofer, G.; Quirrenbach, A.; Rameez, M.; Reimer, O.; Renaud, M.; Ribó, M.; Rico, J.; Rizi, V.; Rodriguez, J.; Rodriguez Fernandez, G.; Rodríguez Vázquez, J. J.; Romano, P.; Romeo, G.; Rosado, J.; Rousselle, J.; Rowell, G.; Rudak, B.; Sadeh, I.; Safi-Harb, S.; Saito, T.; Sakaki, N.; Sanchez, D.; Sangiorgi, P.; Sano, H.; Santander, M.; Sarkar, S.; Sawada, M.; Schioppa, E. J.; Schoorlemmer, H.; Schovanek, P.; Schussler, F.; Sergijenko, O.; Servillat, M.; Shalchi, A.; Shellard, R. C.; Siejkowski, H.; Sillanpää, A.; Simone, D.; Sliusar, V.; Sol, H.; Stanič, S.; Starling, R.; Stawarz, Ł.; Stefanik, S.; Stephan, M.; Stolarczyk, T.; Szanecki, M.; Szepieniec, T.; Tagliaferri, G.; Tajima, H.; Takahashi, M.; Takeda, J.; Tanaka, M.; Tanaka, S.; Tejedor, L. A.; Telezhinsky, I.; Temnikov, P.; Terada, Y.; Tescaro, D.; Teshima, M.; Testa, V.; Thoudam, S.; Tokanai, F.; Torres, D. F.; Torresi, E.; Tosti, G.; Townsley, C.; Travnicek, P.; Trichard, C.; Trifoglio, M.; Tsujimoto, S.; Vagelli, V.; Vallania, P.; Valore, L.; van Driel, W.; van Eldik, C.; Vandenbroucke, J.; Vassiliev, V.; Vecchi, M.; Vercellone, S.; Vergani, S.; Vigorito, C.; Vorobiov, S.; Vrastil, M.; Vázquez Acosta, M. L.; Wagner, S. J.; Wagner, R.; Wakely, S. P.; Walter, R.; Ward, J. E.; Watson, J. J.; Weinstein, A.; White, M.; White, R.; Wierzcholska, A.; Wilcox, P.; Williams, D. A.; Wischnewski, R.; Wojcik, P.; Yamamoto, T.; Yamamoto, H.; Yamazaki, R.; Yanagita, S.; Yang, L.; Yoshida, T.; Yoshida, M.; Yoshiike, S.; Yoshikoshi, T.; Zacharias, M.; Zampieri, L.; Zanin, R.; Zavrtanik, M.; Zavrtanik, D.; Zdziarski, A.; Zech, A.; Zechlin, H.; Zhdanov, V.; Ziegler, A.; Zorn, J.

    2017-05-01

    We perform simulations for future Cherenkov Telescope Array (CTA) observations of RX J1713.7-3946, a young supernova remnant (SNR) and one of the brightest sources ever discovered in very high energy (VHE) gamma rays. Special attention is paid to exploring possible spatial (anti)correlations of gamma rays with emission at other wavelengths, in particular X-rays and CO/H i emission. We present a series of simulated images of RX J1713.7-3946 for CTA based on a set of observationally motivated models for the gamma-ray emission. In these models, VHE gamma rays produced by high-energy electrons are assumed to trace the nonthermal X-ray emission observed by XMM-Newton, whereas those originating from relativistic protons delineate the local gas distributions. The local atomic and molecular gas distributions are deduced by the NANTEN team from CO and H i observations. Our primary goal is to show how one can distinguish the emission mechanism(s) of the gamma rays (i.e., hadronic versus leptonic, or a mixture of the two) through information provided by their spatial distribution, spectra, and time variation. This work is the first attempt to quantitatively evaluate the capabilities of CTA to achieve various proposed scientific goals by observing this important cosmic particle accelerator.

  6. Prospects for Cherenkov Telescope Array Observations of the Young Supernova Remnant RX J1713.7−3946

    Energy Technology Data Exchange (ETDEWEB)

    Acero, F. [CEA/IRFU/SAp, CEA Saclay, Bat 709, Orme des Merisiers, F-91191 Gif-sur-Yvette (France); Aloisio, R.; Amato, E. [Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, I-50125 Firenze (Italy); Amans, J. [LUTH and GEPI, Observatoire de Paris, CNRS, PSL Research University, 5 place Jules Janssen, F-92190, Meudon (France); Antonelli, L. A. [INAF—Osservatorio Astronomico di Roma, Via di Frascati 33, I-00040, Monteporzio Catone (Italy); Aramo, C. [INFN Sezione di Napoli, Via Cintia, ed. G, I-80126 Napoli (Italy); Armstrong, T. [Department of Physics and Centre for Advanced Instrumentation, Durham University, South Road, Durham DH1 3LE (United Kingdom); Arqueros, F.; Barrio, J. A. [Grupo de Altas Energías, Universidad Complutense de Madrid., Av Complutense s/n, E-28040 Madrid (Spain); Asano, K. [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5, Kashi-wanoha, Kashiwa, Chiba 277-8582 (Japan); Ashley, M. [School of Physics, University of New South Wales, Sydney NSW 2052 (Australia); Backes, M. [University of Namibia, Department of Physics, 340 Mandume Ndemufayo Ave., Pioneerspark Windhoek (Namibia); Balazs, C. [School of Physics and Astronomy, Monash University, Melbourne, Victoria 3800 (Australia); Balzer, A. [Astronomical Institute Anton Pannekoek, University of Amsterdam, Science Park 904 1098 XH Amsterdam (Netherlands); Bamba, A. [Department of Physics, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Barkov, M. [Riken, Institute of Physical and Chemical Research, 2-1 Hirosawa, Wako, Saitama, 351-0198 (Japan); Benbow, W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02180 (United States); Bernlöhr, K., E-mail: sano@a.phys.nagoya-u.ac.jp, E-mail: nakamori@sci.kj.yamagata-u.ac.jp [Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); and others

    2017-05-10

    We perform simulations for future Cherenkov Telescope Array (CTA) observations of RX J1713.7−3946, a young supernova remnant (SNR) and one of the brightest sources ever discovered in very high energy (VHE) gamma rays. Special attention is paid to exploring possible spatial (anti)correlations of gamma rays with emission at other wavelengths, in particular X-rays and CO/H i emission. We present a series of simulated images of RX J1713.7−3946 for CTA based on a set of observationally motivated models for the gamma-ray emission. In these models, VHE gamma rays produced by high-energy electrons are assumed to trace the nonthermal X-ray emission observed by XMM-Newton , whereas those originating from relativistic protons delineate the local gas distributions. The local atomic and molecular gas distributions are deduced by the NANTEN team from CO and H i observations. Our primary goal is to show how one can distinguish the emission mechanism(s) of the gamma rays (i.e., hadronic versus leptonic, or a mixture of the two) through information provided by their spatial distribution, spectra, and time variation. This work is the first attempt to quantitatively evaluate the capabilities of CTA to achieve various proposed scientific goals by observing this important cosmic particle accelerator.

  7. Kinematic reconstruction of atmospheric neutrino events in a large water Cherenkov detector with proton identification

    CERN Document Server

    Fechner, M

    2009-01-01

    We report the development of a proton identification method for the Super-Kamiokande detector. This new tool is applied to the search for events with a single proton track, a high purity neutral current sample of interest for sterile neutrino searches. After selection using a neural network, we observe 38 events in the combined SK-I and SK-II data corresponding to 2285.1 days of exposure, with an estimated signal to background ratio of 1.6 to 1. Proton identification was also applied to a direct search for charged-current quasi-elastic (CCQE) events, obtaining a high precision sample of fully kinematically reconstructed atmospheric neutrinos, which has not been previously reported in water Cherenkov detectors. The CCQE fraction of this sample is 55%, and its neutrino (as opposed to anti-neutrino) fraction is 91.7+/-3%. We selected 78 mu-like and 47 e-like events in the SK-I and SK-II data set. With this data, a clear zenith angle distortion of the neutrino direction itself is reported in a sub-GeV sample of m...

  8. Wideband pulse amplifier with 8 GHz GBW product in a 0.35 {mu}m CMOS technology for the integrated camera of the Cherenkov Telescope Array

    Energy Technology Data Exchange (ETDEWEB)

    Gascon, D; Sanuy, A; Ribo, M [Dept. AM i Dept.ECM, Institut de Ciencies del Cosmos (ICC), Universitat de Barcelona, Marti i Franques 1, E08028, Barcelona (Spain); Delagnes, E; Glicenstein, J-F [IRFU/DSM/CEA, CE-Saclay, Bat. 141 SEN Saclay, F-91191, Gif-sur-Yvette (France); Sieiro, X [Departament d' Electronica, Universitat de Barcelona, Marti i Franques 1, E08028, Barcelona (Spain); Feinstein, F; Vorobiov, S [LPTA, Universite Montpellier II and IN2P3/CNRS, Montpellier (France); Nayman, P; Toussenel, F; Tavernet, J-P; Vincent, P, E-mail: gascon@ecm.ub.es [LPNHE, Universite Paris VI and IN2P3/CNRS, Paris (France)

    2010-12-15

    A fully differential wideband amplifier for the camera of the Cherenkov Telescope Array (CTA) is presented. This amplifier would be part of a new ASIC, developed by the NECTAr collaboration, performing the digitization at 1 GS/s with a dynamic range of 16 bits. Input amplifiers must have a voltage gain up to 20 V/V and a bandwidth of 400 MHz. Being impossible to design a fully differential operational amplifier with an 8 GHz GBW product in a 0.35{mu}m CMOS technology, an alternative implementation based on HF linearised transconductors is explored. Test results show that the required GBW product is achieved, with a linearity error smaller than 1% for a differential output voltage range up to 1 Vpp, and smaller than 3% for 2 Vpp.

  9. An atmosphere monitoring system for the Sardinia radio telescope

    Science.gov (United States)

    Buffa, F.; Bolli, P.; Sanna, G.; Serra, G.

    2017-01-01

    The Sardinia radio telescope (SRT) is a new facility managed by the Italian National Institute for Astrophysics (INAF). SRT will detect the extremely faint radio wave signals emitted by astronomical objects in a wide frequency range from decimeter to millimeter wavelengths. Especially at high frequencies (>10 GHz), specific weather conditions and interactions between signal and atmospheric constituents (mainly water and oxygen molecules) affect the radio astronomic observation reducing the antenna performances. Thus, modern ground-based telescopes are usually equipped with systems able to examine in real-time several atmospheric parameters (opacity, integrated water vapor, etc.), and in some cases to forecast the weather conditions (wind, rain, snow, etc.), in order to ensure the antenna safety and support the schedule of the telescope observations. Here, we describe the atmosphere monitoring system (AMS) realized with the aim to improve the SRT operative efficiency. It consists of a network of different sensors such as radiometers, radiosondes, weather stations, GPS and some well-established weather models. After a validation of the scheme, we successfully tested the AMS in two real practical scenarios, comparing the AMS outcomes with those of independent techniques. In the first one we were able to detect an incoming storm front applying different techniques (GPS, radiometer and the weather forecast model), while in the last one we modeled the SRT antenna system temperature at 22 GHz processing the AMS data set.

  10. Time calibration with atmospheric muon tracks in the ANTARES neutrino telescope

    OpenAIRE

    Adrián Martínez, Silvia; Albert, A.; André, M.; Anton, G.; Ardid Ramírez, Miguel; Aubert, J.-J.; Baret, B.; Barrios Martí, J.; Basa, S.; Bertin, V.; Bou Cabo, Manuel; FELIS ENGUIX, IVÁN; Herrero Debón, Alicia; Martínez Mora, Juan Antonio; Saldaña-Coscollar, María

    2016-01-01

    The ANTARES experiment consists of an array of photomultipliers distributed along 12 lines and located deep underwater in the Mediterranean Sea. It searches for astrophysical neutrinos collecting the Cherenkov light induced by the charged particles, mainly muons, produced in neutrino interactions around the detector. Since at energies of ∼10 TeV the muon and the incident neutrino are almost collinear, it is possible to use the ANTARES detector as a neutrino telescope and identify a sour...

  11. Long term performance evaluation of the TACTIC imaging telescope ...

    Indian Academy of Sciences (India)

    The TeV atmospheric Cherenkov telescope with imaging camera (TACTIC) -ray telescope has been in operation at Mt. Abu, India since 2001 to study TeV -ray emission from celestial sources. During the last 10 years, apart from consistently detecting a steady signal from the Crab Nebula above ∼1.2 TeV energy, at a ...

  12. Caracterización de un sistema de telescopios Cherenkov para la detección de rayos gamma de energías del TeV desde el CASLEO

    Science.gov (United States)

    Melo, D.; Yelós, L. D.; Garcia, B.; Rovero, A. C.

    2017-10-01

    Gamma-ray astronomy opened the universe of the more energetic electromagnetic radiation using ground and orbiting instruments, which provide information for the understanding of sources of different types. Ground-based telescope arrays use Cherenkov light produced by the charged particles from extensive air showers generated in the Earth's atmosphere to identify gamma rays. This imposes a minimum energy threshold on the gamma rays to be detected. Towards the high-energy end of the spectrum, however, the amount of Cherenkov radiation produced by a gamma-ray photon guarantees its detectability, the limiting factor being the low flux of the sources. For this reason, the detection strategy consists in using arrays of small telescopes. In this work, we investigate the feasibility of detecting gamma-ray cascades using Cherenkov telescopes, in the range of 100 GeV to 2 TeV, at the CASLEO site, characterizing the response of a system of three Cherenkov telescopes.

  13. Design, optimization and characterization of the light concentrators of the single-mirror small size telescopes of the Cherenkov Telescope Array

    Science.gov (United States)

    Aguilar, J. A.; Basili, A.; Boccone, V.; Cadoux, F.; Christov, A.; della Volpe, D.; Montaruli, T.; Płatos, Ł.; Rameez, M.

    2015-01-01

    The focal-plane cameras of γ -ray telescopes frequently use light concentrators in front of the light sensors. The purpose of these concentrators is to increase the effective area of the camera as well as to reduce the stray light coming at large incident angles. These light concentrators are usually based on the Winston cone design. In this contribution we present the design of a hexagonal hollow light concentrator with a lateral profile optimized using a cubic Bézier function to achieve a higher collection efficiency in the angular region of interest. The design presented here is optimized for a Davies-Cotton telescope with a primary mirror of about 4 m in diameter and a focal length of 5.6 m. The described concentrators are part of an innovative camera made up of silicon-photomultiplier sensors, although a similar approach can be used for other sizes of single-mirror telescopes with different camera sensors, including photomultipliers. The challenge of our approach is to achieve a cost-effective design suitable for standard industrial production of both the plastic concentrator substrate and the reflective coating. At the same time we maximize the optical performance. In this paper we also describe the optical set-up to measure the absolute collection efficiency of the light concentrators and demonstrate our good understanding of the measured data using a professional ray-tracing simulation.

  14. Characterizing Exoplanet Atmospheres with the James Webb Space Telescope

    Science.gov (United States)

    Greene, Tom

    2017-01-01

    The James Webb Space Telescope (JWST) will have numerous modes for acquiring photometry and spectra of stars, planets, galaxies, and other astronomical objects over wavelengths of 0.6 - 28 microns. Several of these modes are well-suited for observing atomic and molecular features in the atmospheres of transiting or spatially resolved exoplanets. I will present basic information on JWST capabilities, highlight modes that are well-suited for observing exoplanets, and give examples of what may be learned from JWST observations. This will include simulated spectra and expected retrieved chemical abundance, composition, equilibrium, and thermal information and uncertainties. JWST Cycle 1 general observer proposals are expected to be due in March 2018 with launch in October 2018, and the greater scientific community is encouraged to propose investigations to study exoplanet atmospheres and other topics.

  15. Cherenkov radiation threshold in random inhomogeneous media

    CERN Document Server

    Grichine, V M

    2009-01-01

    Cherenkov radiation in media with random inhomogeneities like aerogel or Earth atmosphere is discussed. The spectral-angular distribution of Cherenkov photons emitted by relativistic charged particle and averaged over the dielectric permittivity fluctuations shows angular broadening similarly to the case of media with the photon absorption. The broadening results in the smoothing of Cherenkov threshold, and therefore media with strong photon scattering have more extended dependence of Cherenkov light output on the particle speed. It can be potentially used for the particle identification

  16. Polarization properties of receiving telescopes in atmospheric remote sensing polarization lidars.

    Science.gov (United States)

    Luo, Jing; Liu, Dong; Huang, Zihao; Wang, Binyu; Bai, Jian; Cheng, Zhongtao; Zhang, Yupeng; Tang, Peijun; Yang, Liming; Su, Lin

    2017-08-20

    A receiving telescope is an indispensable component in an atmospheric remote sensing polarization lidar. In order to achieve accurate atmospheric depolarization measurements, it is necessary to study the polarization properties of receiving telescopes, which are embodied by their Mueller matrices. In this paper, the Mueller matrices of receiving telescopes are obtained by ray tracing with space vectors. The relationship between the measurement errors of the atmospheric depolarization parameter and the elements of the Mueller matrix of receiving telescopes is derived. The polarization properties of receiving telescopes in terms of orientation, field of view, and F number are analyzed, respectively. By comparing two common receiving telescopes in linear and circular polarization lidars, it is found that the measurement errors caused by the Newton telescopes in circular polarization lidars are significantly greater than those in linear polarization lidars, while the performances of the Cassegrain telescopes in the two lidars are almost identical. What is more, the measurement errors caused by the Cassegrain telescopes are much less than the counterparts caused by the Newton telescopes. According to the comparison results, the optimal telescopes are respectively presented for polarization lidars working in different polarization states and laser wavelengths.

  17. The Cherenkov Surface Detector of the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Billoir, Pierre, E-mail: billoir@lpnhe.in2p3.fr [LPNHE, CNRS/IN2P3 and Univ. P. and M. Curie and Univ. D. Diderot, 4 place Jussieu 75272 Paris Cedex 05 (France); Observatorio Pierre Auger, av. San Martín Norte, 304 5613, Malargüe (Argentina)

    2014-12-01

    The Pierre Auger Observatory detects the atmospheric showers induced by cosmic rays of ultra-high energy (UHE). It is the first one to use the hybrid technique. A set of telescopes observes the fluorescence of the nitrogen molecules on clear moonless nights, giving access to the longitudinal profile of the shower. These telescopes surround a giant array of 1600 water Cherenkov tanks (covering more than 3000 km{sup 2}), which works continuously and samples the particles reaching the ground (mainly muons, photons and electrons/positrons); the light produced within the water is recorded into FADC (Fast Analog to Digital Convertes) traces. A subsample of hybrid events provides a cross calibration of the two components. We describe the structure of the Cherenkov detectors, their sensitivity to different particles and the information they can give on the direction of origin, the energy and the nature of the primary UHE object; we discuss also their discrimination power for rare events (UHE photons or neutrinos). To cope with the variability of weather conditions and the limitations of the communication system, the procedures for trigger and real time calibration have been shared between local processors and a central acquisition system. The overall system has been working almost continuously for 10 years, while being progressively completed and increased by the creation of a dense “infill” subarray. - Highlights: • The water Cherenkov technique is used in the Surface Detector of the Pierre Auger Observatory. • Cross-calibrated with the Fluorescence Detector, it provides a measurement of the primary energy. • The spectrum of the UHE cosmic rays exhibits clearly an “ankle” and a cutoff. • The muon observed muon content of the atmospheric showers is larger than expected from the models. • Stringent limits on the flux of UHE neutrinos and photons are obtained.

  18. Modelling atmospheric turbulence effects on ground-based telescope systems

    Energy Technology Data Exchange (ETDEWEB)

    Bradford, L.W.; Flatte, S.M. [California Univ., Santa Cruz, CA (United States). Dept. of Physics; Max, C.E. [Lawrence Livermore National Lab., CA (United States)

    1993-09-30

    Questions still exist concerning the appropriate model for turbulence- induced phase fluctuations seen in ground-based telescopes. Bester et al. used a particular observable (slope of the Allan variance) with an infrared interferometer in an attempt to distinguish models. The authors have calculated that observable for Kolmogorov and {open_quotes}random walk{close_quotes} models with a variety of outer scales and altitude-dependent turbulence and wind velocity. The authors have found that clear distinction between models requires good data on the vertical distribution of wind and turbulence. Furthermore, measurements at time separations of order 60 s are necessary to distinguish the {open_quotes}random walk{close_quotes} model from the Kolmogorov model.

  19. Strategy implementation for the CTA Atmospheric monitoring program

    Directory of Open Access Journals (Sweden)

    Doro Michele

    2015-01-01

    Full Text Available The Cherenkov Telescope Array (CTA is the next generation facility of Imaging Atmospheric Cherenkov Telescopes. It reaches unprecedented sensitivity and energy resolution in very-high-energy gamma-ray astronomy. CTA detects Cherenkov light emitted within an atmospheric shower of particles initiated by cosmic-gamma rays or cosmic rays entering the Earth's atmosphere. From the combination of images the Cherenkov light produces in the telescopes, one is able to infer the primary particle energy and direction. A correct energy estimation can be thus performed only if the local atmosphere is well characterized. The atmosphere not only affects the shower development itself, but also the Cherenkov photon transmission from the emission point in the particle shower, at about 10–20 km above the ground, to the detector. Cherenkov light on the ground is peaked in the UV-blue region, and therefore molecular and aerosol extinction phenomena are important. The goal of CTA is to control systematics in energy reconstruction to better than 10%. For this reason, a careful and continuous monitoring and characterization of the atmosphere is required. In addition, CTA will be operated as an observatory, with data made public along with appropriate analysis tools. High-level data quality can only be ensured if the atmospheric properties are consistently and continuously taken into account. In this contribution, we concentrate on discussing the implementation strategy for the various atmospheric monitoring instruments currently under discussion in CTA. These includes Raman lidars and ceilometers, stellar photometers and others available both from commercial providers and public research centers.

  20. CHERENKOV RADIATION DETECTOR

    African Journals Online (AJOL)

    ES Obe

    1981-03-01

    Mar 1, 1981 ... Most of Radiation detectors based on the Cherenkov Effect are essentially very bulky and expensive for schools and colleges. An inexpensive yet very compact radiation detector is designed, built and tested. It is used to measure the Cherenkov angles for natural radioactivity from sources as. Cs137.

  1. Measurement of the Muon Atmospheric Production Depth with the Water Cherenkov Detectors of the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Molina Bueno, Laura [Univ. of Granada (Spain)

    2015-09-01

    Ultra-high-energy cosmic rays (UHECR) are particles of uncertain origin and composition, with energies above 1 EeV (1018 eV or 0.16 J). The measured flux of UHECR is a steeply decreasing function of energy. The largest and most sensitive apparatus built to date to record and study cosmic ray Extensive Air Showers (EAS) is the Pierre Auger Observatory. The Pierre Auger Observatory has produced the largest and finest amount of data ever collected for UHECR. A broad physics program is being carried out covering all relevant topics of the field. Among them, one of the most interesting is the problem related to the estimation of the mass composition of cosmic rays in this energy range. Currently the best measurements of mass are those obtained by studying the longitudinal development of the electromagnetic part of the EAS with the Fluorescence Detector. However, the collected statistics is small, specially at energies above several tens of EeV. Although less precise, the volume of data gathered with the Surface Detector is nearly a factor ten larger than the fluorescence data. So new ways to study composition with data collected at the ground are under investigation. The subject of this thesis follows one of those new lines of research. Using preferentially the time information associated with the muons that reach the ground, we try to build observables related to the composition of the primaries that initiated the EAS. A simple phenomenological model relates the arrival times with the depths in the atmosphere where muons are produced. The experimental confirmation that the distributions of muon production depths (MPD) correlate with the mass of the primary particle has opened the way to a variety of studies, of which this thesis is a continuation, with the aim of enlarging and improving its range of applicability. We revisit the phenomenological model which is at the root of the analysis and discuss a new way to improve some aspects of the model. We carry

  2. Instrumentation for the observation of atmospheric parameters, relevant for IACTs, for site-search and correction of the energy spectra

    Energy Technology Data Exchange (ETDEWEB)

    Fruck, Christian; Hose, Juergen; Engelhardt, Toni; Mirzoyan, Razmik; Schweizer, Thomas; Teshima, Masahiro [Max Plank Institut fuer Physik, Muenchen (Germany)

    2010-07-01

    The atmospheric conditions have impact on the measured data by imaging atmospheric Cherenkov telescopes (IACT). Cherenkov light from air showers traverses 5-25 km distance in the atmosphere before reaching the telescopes. This light becomes attenuated because of absorption by oxigen and ozone as well as because of the Rayleigh and the Mie scatterings. The latter is the variable component in the atmosphere that depends on the momentary distribution of aerosols, their size and types and distribution heights. We have developed a micro-LIDAR system for parametrising these losses and plan to locate it next to the MAGIC telescopes for simultaneous operation. This shall allow us to improve the energy resolution of the telescopes for the data taken at non-ideal weather conditions. Also, we are working on developing diverse instrumentation for paramerising the atmosphere and for the searching proper sites for the CTA project. In our presentation we plan to report about the above-mentioned activities.

  3. A Major Upgrade of the H.E.S.S. Cherenkov Cameras

    Science.gov (United States)

    Lypova, Iryna; Giavitto, Gianluca; Ashton, Terry; Balzer, Arnim; Berge, David; Brun, Francois; Chaminade, Thomas; Delagnes, Eric; Fontaine, Gerard; Füßling, Matthias; Giebels, Berrie; Glicenstein, Jean-Francois; Gräber, Tobias; Hinton, Jim; Jahnke, Albert; Klepser, Stefan; Kossatz, Marko; Kretzschmann, Axel; Lefranc, Valentin; Leich, Holger; Lüdecke, Hartmut; Manigot, Pascal; Marandon, Vincent; Moulin, Emmanuel; de Naurois, Mathieu; Nayman, Patrick; Ohm, Stefan; Penno, Marek; Ross, Duncan; Salek, David; Schade, Markus; Schwab, Thomas; Simoni, Rachel; Stegmann, Christian; Steppa, Constantin; Thornhill, Julian; Toussnel, Francois

    2017-03-01

    The High Energy Stereoscopic System (H.E.S.S.) is an array of imaging atmospheric Cherenkov telescopes (IACTs) located in Namibia. It was built to detect Very High Energy (VHE, >100 GeV) cosmic gamma rays, and consists of four 12 m diameter Cherenkov telescopes (CT1-4), built in 2003, and a larger 28 m telescope (CT5), built in 2012. The larger mirror surface of CT5 permits to lower the energy threshold of the array down to 30 GeV. The cameras of CT1-4 are currently undergoing an extensive upgrade, with the goals of reducing their failure rate, reducing their readout dead time and improving the overall performance of the array. The entire camera electronics has been renewed from ground-up, as well as the power, ventilation and pneumatics systems, and the control and data acquisition software. Technical solutions forseen for the next-generation Cherenkov Telescope Array (CTA) observatory have been introduced, most notably the readout is based on the NECTAr analog memory chip. The camera control subsystems and the control software framework also pursue an innovative design, increasing the camera performance, robustness and flexibility. The CT1 camera has been upgraded in July 2015 and is currently taking data; CT2-4 will upgraded in Fall 2016. Together they will assure continuous operation of H.E.S.S at its full sensitivity until and possibly beyond the advent of CTA. This contribution describes the design, the testing and the in-lab and on-site performance of all components of the newly upgraded H.E.S.S. camera.

  4. A Major Upgrade of the H.E.S.S. Cherenkov Cameras

    Directory of Open Access Journals (Sweden)

    Lypova Iryna

    2017-01-01

    Full Text Available The High Energy Stereoscopic System (H.E.S.S. is an array of imaging atmospheric Cherenkov telescopes (IACTs located in Namibia. It was built to detect Very High Energy (VHE, >100 GeV cosmic gamma rays, and consists of four 12 m diameter Cherenkov telescopes (CT1-4, built in 2003, and a larger 28 m telescope (CT5, built in 2012. The larger mirror surface of CT5 permits to lower the energy threshold of the array down to 30 GeV. The cameras of CT1-4 are currently undergoing an extensive upgrade, with the goals of reducing their failure rate, reducing their readout dead time and improving the overall performance of the array. The entire camera electronics has been renewed from ground-up, as well as the power, ventilation and pneumatics systems, and the control and data acquisition software. Technical solutions forseen for the next-generation Cherenkov Telescope Array (CTA observatory have been introduced, most notably the readout is based on the NECTAr analog memory chip. The camera control subsystems and the control software framework also pursue an innovative design, increasing the camera performance, robustness and flexibility. The CT1 camera has been upgraded in July 2015 and is currently taking data; CT2-4 will upgraded in Fall 2016. Together they will assure continuous operation of H.E.S.S at its full sensitivity until and possibly beyond the advent of CTA. This contribution describes the design, the testing and the in-lab and on-site performance of all components of the newly upgraded H.E.S.S. camera.

  5. Diseño de montura Davies-Cotton de telescopio Cherenkov de 6m de diámetro para el proyecto CTA

    Science.gov (United States)

    Actis, M.; Ringegni, P.; Antico, F.; Bottani, A.; Vallejo, G.; Ochoa, I.; Marconi, D.; Supanitsky, A. D.; Rovero, A. C.

    For the next generation of ground-based instruments for the observation of gamma-rays, the construction of 6 m diameter Cherenkov telescopes is foreseen. We have proposed a design of Davies-Cotton mount for such a telescope, within Cherenkov Telescope Array specifications, and evaluated its mechanical and optical performance. FULL TEXT IN SPANISH

  6. Atmospheric MUons from PArametric formulas: a fast GEnerator for neutrino telescopes (MUPAGE)

    Science.gov (United States)

    Carminati, G.; Bazzotti, M.; Margiotta, A.; Spurio, M.

    2008-12-01

    Neutrino telescopes will open, in the next years, new opportunities in observational high energy astrophysics. In these detectors, atmospheric muons from primary cosmic ray interactions in the atmosphere play an important role, because they provide the most abundant source of events for calibration and test. On the other side, they represent the major background source. In this paper a fast Monte Carlo generator (called MUPAGE) of bundles of atmospheric muons for underwater/ice neutrino telescopes is presented. MUPAGE is based on parametric formulas [Y. Becherini, A. Margiotta, M. Sioli, M. Spurio, Astrop. Phys. 25 (2006) 1] obtained from a full Monte Carlo simulation of cosmic ray showers generating muons in bundle, which are propagated down to 5 km w.e. It produces the event kinematics on the surface of a user-defined cylinder, surrounding the virtual detector. The multiplicity of the muons in the bundle, the muon lateral distribution and energy spectrum are simulated according to a specific model of primary cosmic ray flux, with constraints from measurements of the muon flux with underground experiments. As an example of application, the result of the generation of events on a cylindrical surface of ˜1.4 km2 at a depth of 2450 m of water is presented. Catalogue identifier: AEBT_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEBT_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 3534 No. of bytes in distributed program, including test data, etc.: 61 383 Distribution format: tar.gz Programming language: C++ Computer: Pentium M, 2.0 GHz; 2x Intel Xeon Quad Core, 2.33 GHz Operating system: Scientific Linux 3.x; Scientific Linux 4.x; Slackware 12.0.0 RAM: 50 MB Word size: 32 bits Classification: 1.1, 11.3 External routines: The ROOT system (http

  7. Coherent Cherenkov radiation from cosmic-ray-induced air showers.

    Science.gov (United States)

    de Vries, K D; van den Berg, A M; Scholten, O; Werner, K

    2011-08-05

    Very energetic cosmic rays entering the atmosphere of Earth will create a plasma cloud moving with almost the speed of light. The magnetic field of Earth induces an electric current in this cloud which is responsible for the emission of coherent electromagnetic radiation. We propose to search for a new effect: Because of the index of refraction of air, this radiation is collimated in a Cherenkov cone. To express the difference from usual Cherenkov radiation, i.e., the emission from a fast-moving electric charge, we call this magnetically induced Cherenkov radiation. We indicate its signature and possible experimental verification.

  8. Sharpening stellar images: real-time phase correction has permitted a ground-based telescope to overcome atmospheric distortion

    Energy Technology Data Exchange (ETDEWEB)

    Buffington, A.; Crawford, F.S.; Pollaine, S.M.; Orth, C.D.; Muller, R.A.

    1978-05-05

    Atmospherically induced phase perturbations have for years limited the resolution of large optical astronomical telescopes. A prototype telescope system with six movable elements has successfully corrected these phase perturbations. This use of real-time image sharpening has restored stellar images to the diffraction limit (in one dimension) for 30-centimeter telescope. The double-star image presented indicates that the bulk of the atmospherically induced wave-front phase change occurred within 2 kilometers of the telescope. This implies that, at least for conditions similar to those of our measurement, real-time correction can be accomplished simultaneously for a region at least several arc seconds in angular size. With the present apparatus the technique should be practical for objects as dim as fifth magnitude, and with improvements the technique holds the promise of active image restoration for objects as dim as ninth magnitude.

  9. CHERENKOV RADIATION DETECTOR

    African Journals Online (AJOL)

    ES Obe

    1981-03-01

    Mar 1, 1981 ... magnetic field. S(λ) = the response of a photo multiplier to an equi-energy spectrum. t(λ) = transmission characteristics c(λ) = Cherenkov spectrum energy distribution ζ. = optical efficiency for codecting light at the cathode ... operator applied to the vector potential A leads to an inhomogeneous equation:.

  10. CHARACTERIZING THE ATMOSPHERES OF TRANSITING PLANETS WITH A DEDICATED SPACE TELESCOPE

    Energy Technology Data Exchange (ETDEWEB)

    Tessenyi, M.; Tinetti, G.; Swinyard, B.; Aylward, A.; Tennyson, J. [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Ollivier, M. [Institut d' Astrophysique Spatiale, Universite de Paris-Sud and CNRS (UMR 8617), IAS UMR8617, Orsay F-91405 (France); Beaulieu, J. P. [Institut d' Astrophysique de Paris, CNRS, UMR7095, Universite Paris VI, 98bis Boulevard Arago, Paris (France); Coude du Foresto, V.; Encrenaz, T. [Observatoire de Paris, LESIA, Meudon (France); Micela, G. [INAF-Osservatorio Astronomico di Palermo, Piazza del Parlamento 1, 90134 Palermo (Italy); Ribas, I. [Institut de Ciencies de l' Espai (CSIC-IEEC), Campus UAB, 08193 Bellaterra (Spain); Swain, M. R.; Vasisht, G.; Deroo, P. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109-8099 (United States); Sozzetti, A. [INAF-Osservatorio Astronomico di Torino, Strada Osservatorio 20, 10025 Pino Torinese (Italy)

    2012-02-10

    Exoplanetary science is one of the fastest evolving fields of today's astronomical research, continuously yielding unexpected and surprising results. Ground-based planet-hunting surveys, together with dedicated space missions such as Kepler and CoRoT, are delivering an ever-increasing number of exoplanets, over 690, and ESA's Gaia mission will escalate the exoplanetary census into the several thousands. The next logical step is the characterization of these new worlds. What is their nature? Why are they as they are? Use of the Hubble Space Telescope and Spitzer Space Telescope to probe the atmospheres of transiting hot, gaseous exoplanets has opened perspectives unimaginable even just 10 years ago, demonstrating that it is indeed possible with current technology to address the ambitious goal of characterizing the atmospheres of these alien worlds. However, these successful measurements have also shown the difficulty of understanding the physics and chemistry of these exotic environments when having to rely on a limited number of observations performed on a handful of objects. To progress substantially in this field, a dedicated facility for exoplanet characterization, able to observe a statistically significant number of planets over time and a broad spectral range will be essential. Additionally, the instrument design (e.g., detector performances, photometric stability) will be tailored to optimize the extraction of the astrophysical signal. In this paper, we analyze the performance and tradeoffs of a 1.2/1.4 m space telescope for exoplanet transit spectroscopy from the visible to the mid-IR. We present the signal-to-noise ratio as a function of integration time and stellar magnitude/spectral type for the acquisition of spectra of planetary atmospheres for a variety of scenarios: hot, warm, and temperate planets orbiting stars ranging in spectral type from hot F- to cooler M-dwarfs. Our results include key examples of known planets (e.g., HD 189733b, GJ

  11. Measurement of Atmospheric Neutrino Oscillations with Very Large Volume Neutrino Telescopes

    Directory of Open Access Journals (Sweden)

    J. P. Yáñez

    2015-01-01

    Full Text Available Neutrino oscillations have been probed during the last few decades using multiple neutrino sources and experimental set-ups. In the recent years, very large volume neutrino telescopes have started contributing to the field. First ANTARES and then IceCube have relied on large and sparsely instrumented volumes to observe atmospheric neutrinos for combinations of baselines and energies inaccessible to other experiments. Using this advantage, the latest result from IceCube starts approaching the precision of other established technologies and is paving the way for future detectors, such as ORCA and PINGU. These new projects seek to provide better measurements of neutrino oscillation parameters and eventually determine the neutrino mass ordering. The results from running experiments and the potential from proposed projects are discussed in this review, emphasizing the experimental challenges involved in the measurements.

  12. Large Binocular Telescope view of the atmosphere of GJ1214b

    Science.gov (United States)

    Nascimbeni, V.; Mallonn, M.; Scandariato, G.; Pagano, I.; Piotto, G.; Micela, G.; Messina, S.; Leto, G.; Strassmeier, K. G.; Bisogni, S.; Speziali, R.

    2015-07-01

    The atmospheric composition and vertical structure of the super-Earth GJ1214b has been a subject of debate since its discovery in 2009. Recent studies have indicated that high-altitude clouds might mask the lower layers. However, some data points that were gathered at different times and facilities do not fit this picture, probably because of a combination of stellar activity and systematic errors. We observed two transits of GJ1214b with the Large Binocular Camera, the dual-channel camera at the Large Binocular Telescope. For the first time, we simultaneously measured the relative planetary radius k = Rp/R⋆ at blue and red optical wavelengths (B + R), thus constraining the Rayleigh scattering on GJ1214b after correcting for stellar activity effects. To the same purpose, a long-term photometric follow-up of the host star was carried out with WiFSIP at STELLA, revealing a rotational period that is significantly longer than previously reported. Our new unbiased estimates of k yield a flat transmission spectrum extending to shorter wavelengths, thus confirming the cloudy atmosphere scenario for GJ1214b. Based on data acquired using the Large Binocular Telescope (LBT). The LBT is an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are the University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; the Ohio State University; and the Research Corporation, on behalf of the University of Notre Dame, University of Minnesota and University of Virginia. Partly based on STELLA WiFSIP data (Strassmeier et al. 2004).The data of the light curves are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/579/A113

  13. Search for Primordial Black Holes with the Whipple Atmospheric Cerenkov Telescope

    Science.gov (United States)

    Linton, Eric

    2005-04-01

    Stephen Hawking's prediction that black holes should radiate like black bodies has several important consequences, including the possibility for the detection of small (˜10^15 g) black holes created in the very early universe. The detection of such primordial black holes (PBHs) would not only validate Hawking's theory, but would provide useful insights into the history of the early universe. A search through 5.5 years of archival data from the Whipple Atmospheric Cerenkov Telescope was made for TeV gamma-ray bursts on 1 s, 3 s, and 5 s timescales. Based on a null result, an upper-limit on the evaporation rate of PBHs of 2.69 x10^6 pc-3 yr^- 1 (99% CL) was made, assuming the Standard Model of particle physics. When combined with the results of an earlier search through Whipple data, this limit was lowered to 1.33 x10^6 pc-3 yr-1, which is nearly a factor of 2 better than the previous limit at this energy range.

  14. Mega-ton water Cherenkov detectors for particle and astro-particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Kajita, Takaaki [Research Center for Cosmic Neutrinos, Institute for Cosmic Ray Research, Univ. of Tokyo, Kashiwa-no-ha 5-1-5, Kashiwa, Chiba 277-8582 (Japan)

    2006-05-15

    Physics potential of mega-ton-class water Cherenkov detectors is discussed. Especially, emphasis is made on the non-accelerator physics topics, including atmospheric neutrinos, solar neutrinos, supernova neutrinos and proton decays.

  15. Prototype of a silicon photomultiplier upgrade for the MAGIC telescopes camera

    Energy Technology Data Exchange (ETDEWEB)

    Hahn, Alexander; Mazin, Daniel; Bangale, Priyadarshini; Dettlaff, Antonios; Fink, David; Grundner, Felix; Haberer, Werner; Maier, Roland; Mirzoyan, Razmik; Podkladkin, Sergey; Teshima, Masahiro; Wetteskind, Holger [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany)

    2015-07-01

    The MAGIC collaboration operates two 17 m diameter Imaging Atmospheric Cherenkov Telescopes on the Canary Island La Palma. Each of the two telescopes is currently equipped with 1039 photomultiplier tubes (PMTs). Due to the advances in the development of Silicon Photomultipliers (SiPMs), they are becoming a widely used alternative to PMTs in many research fields including Cherenkov astronomy. Within the Otto-Hahn group at the MPI for physics we are developing a SiPM based detector module for a possible upgrade of the MAGIC cameras and also for future experiments as, e.g., the Cherenkov Telescope Array (CTA). SiPMs have a smaller detector size that the 1-inch diameter PMTs used in MAGIC and we, therefore, make use of a matrix of SiPMs to cover the same area. We optimized the light concentrator (Winston cone) for the angular acceptance of the SiPMs using ray tracing simulations and developed an analog summation circuit to sum up and amplify the SiPM signals. We will present the results of the simulations as well as a schematic structure of the detector and compare our SiPM module with the established PMT modules.

  16. DELPHI Barrel Ring Imaging Cherenkov Detector

    CERN Multimedia

    DELPHI was one of the four experiments installed at the LEP particle accelerator from 1989 - 2000. This is a piece of the Barrel Ring Imaging Cherenkov detector which was used to identify particles in DELPHI.It measured the Cherenkov light emitted when particles travelled faster than the speed of light through the material of the detector. The photo shows the complete Cherenkov detector.

  17. Measurement of the atmospheric nu (mu) energy spectrum from 100 GeV to 200 TeV with the ANTARES telescope

    NARCIS (Netherlands)

    Adrian-Martinez, S.; Albert, A.; Al Samarai, I.; Andre, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Astraatmadja, T.; Aubert, J. -J.; Baret, B.; Barrios-Marti, J.; Basa, S.; Bertin, V.; Biagi, S.; Bigongiari, C.; Bogazzi, C.; Bouhou, B.; Bouwhuis, M.C.; Bruijn, R.; Brunner, J.; Busto, J.; Capone, A.; Caramete, L.; Carloganu, C.; Carr, J.; Cecchini, S.; Charif, Z.; Charvis, Ph.; Chiarusi, T.; Circella, M.; Classen, F.; Core, L.; Costantini, H.; Coyle, P.; Creusot, A.; Curtil, C.; Dekeyser, I.; Deschamps, A.; De Bonis, G.; Decowski, M. P.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drouhin, D.; Dumas, A.; Eberl, T.; Emanuele, U.; Enzenhoefer, A.; Ernenwein, J. -P.; Escoffier, S.; Fehn, K.; Fermani, P.; Flaminio, V.; Folger, F.; Fritsch, U.; Fusco, L. A.; Galata, S.; Gay, P.; Geisselsoeder, S.; Geyer, K.; Giacomelli, G.; Giordano, V.; Gleixner, A.; Gomez-Gonzalez, J. P.; Graf, K.; Guillard, G.; van Haren, H.; Heijboer, A. J.; Hello, Y.; Hernandez-Rey, J. J.; Herold, B.; Hoessl, J.; James, C. W.; de Jong, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U.; Kooijman, P.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lambard, E.; Lambard, G.; Larosa, G.; Lattuada, D.; Lefevre, D.; Leonora, E.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Martini, S.; Michael, T.; Montaruli, T.; Morganti, M.; Motz, H.; Mueller, C.; Neff, M.; Nezri, E.; Palioselitis, D.; Pavalas, G. E.; Perrina, C.; Piattelli, P.; Popa, V.; Pradier, T.; Racca, C.; Richter, R.; Riviere, C.; Robert, A.; Roensch, K.; Rostovtsev, A.; Samtleben, D. F. E.; Sanguineti, M.; Sapienza, P.; Schmid, J.; Schnabel, J.; Schulte, S.; Schuessler, F.; Seitz, T.; Shanidze, R.; Sieger, C.; Simeone, F.; Spies, A.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Sanchez-Losa, A.; Taiuti, M.; Tamburini, C.; Tayalati, Y.; Trovato, A.; Vallage, B.; Vallee, C.; Van Elewyck, V.; Vernin, P.; Visser, E.; Wagner, S.; Wilms, J.; de Wolf, E.; Yatkin, K.; Yepes, H.; Zornoza, J. D.; Zuniga, J.

    2013-01-01

    Atmospheric neutrinos are produced during cascades initiated by the interaction of primary cosmic rays with air nuclei. In this paper, a measurement of the atmospheric energy spectrum in the energy range 0.1-200 TeV is presented, using data collected by the ANTARES underwater neutrino telescope from

  18. Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters

    NARCIS (Netherlands)

    Cenarro, A. J.; Peletier, R. F.; Sanchez-Blazquez, P.; Selam, S. O.; Toloba, E.; Cardiel, N.; Falcon-Barroso, J.; Gorgas, J.; Jimenez-Vicente, J.; Vazdekis, A.

    2007-01-01

    We present a homogeneous set of stellar atmospheric parameters (T-eff, log g, [Fe/H]) for MILES, a new spectral stellar library covering the range lambda lambda 3525-7500 angstrom at 2.3 angstrom (FWHM) spectral resolution. The library consists of 985 stars spanning a large range in atmospheric

  19. Tunable femtosecond Cherenkov fiber laser

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Svane, Ask Sebastian; Lægsgaard, Jesper

    2014-01-01

    We demonstrate electrically-tunable femtosecond Cherenkov fiber laser output at the visible range. Using an all-fiber, self-starting femtosecond Yb-doped fiber laser as the pump source and nonlinear photonic crystal fiber link as the wave-conversion medium, ultrafast, milliwatt-level, tunable...

  20. DELPHI's Ring Imaging Cherenkov Chamber

    CERN Multimedia

    1989-01-01

    The hundreds of mirrors around this Ring Imaging Cherenkov Chamber reflect cones of light created by fast moving particles to a detector. The velocity of a particle can be measured by the size of the ring produced on the detector. DELPHI, which ran from 1989 to 2000 on the LEP accelerator, was primarily concerned with particle identification.

  1. Characteristics of ground-based adaptive telescope determined by atmospheric turbulence

    Science.gov (United States)

    Lukin, Vladimir P.

    1996-08-01

    Numerical simulation on a computer is one of the main methods used for studying the possibilities of adaptive correction of turbulent distortions of imaging forming in the atmosphere. The problem of compensation for atmospheric distortions of a wave front has been studied sufficiently long. The first papers on this subject were published in the mid-1960's. At that time, however, the engineering base gives no way for designing the efficient devices for compensating for atmospheric distortions. In recent years much progress has been reached in developing wave front distortion meters and correctors and then fitting the optical facilities operating under atmospheric distortions with these devices. In this connection an increased interest of researchers is observed to the theoretical works concerning with selection of an optical design and configuration of the wave front corrections.

  2. Atmospheric characterization of five hot Jupiters with the wide field Camera 3 on the Hubble space telescope

    Energy Technology Data Exchange (ETDEWEB)

    Ranjan, Sukrit; Charbonneau, David [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Désert, Jean-Michel [Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States); Madhusudhan, Nikku [Yale Center for Astronomy and Astrophysics, Yale University, New Haven, CT 06511 (United States); Deming, Drake; Wilkins, Ashlee [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Mandell, Avi M., E-mail: sranjan@cfa.harvard.edu [NASA' s Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-04-20

    We probe the structure and composition of the atmospheres of five hot Jupiter exoplanets using the Hubble Space Telescope Wide Field Camera 3 (WFC3) instrument. We use the G141 grism (1.1-1.7 μm) to study TrES-2b, TrES-4b, and CoRoT-1b in transit; TrES-3b in secondary eclipse; and WASP-4b in both. This wavelength region includes a predicted absorption feature from water at 1.4 μm, which we expect to be nondegenerate with the other molecules that are likely to be abundant for hydrocarbon-poor (e.g., solar composition) hot Jupiter atmospheres. We divide our wavelength regions into 10 bins. For each bin we produce a spectrophotometric light curve spanning the time of transit or eclipse. We correct these light curves for instrumental systematics without reference to an instrument model. For our transmission spectra, our mean 1σ precision per bin corresponds to variations of 2.1, 2.8, and 3.0 atmospheric scale heights for TrES-2b, TrES-4b, and CoRoT-1b, respectively. We find featureless spectra for these three planets. We are unable to extract a robust transmission spectrum for WASP-4b. For our dayside emission spectra, our mean 1σ precision per bin corresponds to a planet-to-star flux ratio of 1.5 × 10{sup –4} and 2.1 × 10{sup –4} for WASP-4b and TrES-3b, respectively. We combine these estimates with previous broadband measurements and conclude that for both planets isothermal atmospheres are disfavored. We find no signs of features due to water. We confirm that WFC3 is suitable for studies of transiting exoplanets, but in staring mode multivisit campaigns are necessary to place strong constraints on water abundance.

  3. Atmospheric Characterization of Five Hot Jupiters with the Wide Field Camera 3 on the Hubble Space Telescope

    Science.gov (United States)

    Ranjan, Sukrit; Charbonneau, David; Desert, Jean-Michel; Madhusudhan, Nikku; Deming, Drake; Wilkins, Ashlee; Mandell, Avi M.

    2014-01-01

    We probe the structure and composition of the atmospheres of five hot Jupiter exoplanets using the Hubble Space Telescope Wide Field Camera 3 (WFC3) instrument. We use the G141 grism (1.1-1.7 micrometers) to study TrES-2b, TrES-4b, and CoRoT-1b in transit; TrES-3b in secondary eclipse; and WASP-4b in both. This wavelength region includes a predicted absorption feature from water at 1.4 micrometers, which we expect to be nondegenerate with the other molecules that are likely to be abundant for hydrocarbon-poor (e.g., solar composition) hot Jupiter atmospheres. We divide our wavelength regions into 10 bins. For each bin we produce a spectrophotometric light curve spanning the time of transit or eclipse. We correct these light curves for instrumental systematics without reference to an instrument model. For our transmission spectra, our mean 1s precision per bin corresponds to variations of 2.1, 2.8, and 3.0 atmospheric scale heights for TrES-2b, TrES-4b, and CoRoT-1b, respectively. We find featureless spectra for these three planets. We are unable to extract a robust transmission spectrum for WASP-4b. For our dayside emission spectra, our mean 1 sigma precision per bin corresponds to a planet-to-star flux ratio of 1.5 x 10(exp -4) and 2.1 x 10(exp -4) for WASP-4b and TrES-3b, respectively. We combine these estimates with previous broadband measurements and conclude that for both planets isothermal atmospheres are disfavored. We find no signs of features due to water. We confirm that WFC3 is suitable for studies of transiting exoplanets, but in staring mode multivisit campaigns are necessary to place strong constraints on water abundance.

  4. Cherenkov particle identification in FOCUS

    CERN Document Server

    Link, J M; Alimonti, G; Anjos, J C; Arena, V; Bediaga, I; Bianco, S; Boca, G; Bonomi, G; Boschini, M; Butler, J N; Carrillo, S; Casimiro, E; Cawlfield, C; Cheung, H W K; Cho, K; Chung, Y S; Cinquini, L; Cuautle, E; Cumalat, J P; D'Angelo, P; Di Corato, M; Dini, P; Engh, D; Fabbri, Franco Luigi; Gaines, I; Garbincius, P H; Gardner, R; Garren, L A; Giammarchi, M; Gianini, G; Gottschalk, E; Göbel, C; Handler, T; Hernández, H; Hosack, M; Inzani, P; Johns, W E; Kang, J S; Kasper, P H; Kim, D Y; Ko, B R; Kreymer, A E; Kryemadhi, A; Kutschke, R; Kwak, J W; Lee, K B; Leveraro, F; Liguori, G; Magnin, J; Malvezzi, S; Massafferri, A; Menasce, D; Merlo, M M; Mezzadri, M; Milazzo, L; Miranda, J M D; Mitchell, R; Montiel, E; Moroni, L; Méndez, H; Méndez, L; Nehring, M S; O'Reilly, B; Olaya, D; Pantea, D; Paris, A; Park, H; Park, K S; Pedrini, D; Pepe, I M; Pontoglio, C; Prelz, F; Quinones, J; Rahimi, A; Ramírez, J E; Ratti, S P; Reis, A C D; Reyes, M; Riccardi, C; Rivera, C; Rovere, M; Sala, S; Sarwar, S; Segoni, I; Sheaff, M; Sheldon, P D; Stenson, K; Sánchez-Hernández, A; Uribe, C; Vaandering, E W; Vitulo, P; Vázquez, F; Webster, M; Wilson, J R; Wiss, J; Xiong, W; Yager, P M; Zallo, A; Zhang, Y

    2002-01-01

    We describe the algorithm used to identify charged tracks in the fixed-target charm-photoproduction experiment FOCUS. We begin by describing the new algorithm and contrast this approach with that used in our preceding experiment - E687. We next illustrate the algorithm's performance using physics signals. Finally, we briefly describe some of the methods used to monitor the quantum efficiency and noise of the Cherenkov cells.

  5. Ellerman bombs observed with the new vacuum solar telescope and the atmospheric imaging assembly onboard the solar dynamics observatory

    Science.gov (United States)

    Chen, Yajie; Tian, Hui; Xu, Zhi; Xiang, Yongyuan; Fang, Yuliang; Yang, Zihao

    2017-12-01

    Ellerman bombs (EBs) are believed to be small-scale reconnection events occurring around the temperature minimum region in the solar atmosphere. They are often identified as significant enhancements in the extended Hα wings without obvious signatures in the Hα core. Here we explore the possibility of using the 1700 Å images taken by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) to study EBs. From the Hα wing images obtained with the New Vacuum Solar Telescope (NVST) on 2015 May 2, we have identified 145 EBs and 51% of them clearly correspond to the bright points (BPs) in the AIA 1700 Å images. If we resize the NVST images using a linear interpolation to make the pixel sizes of the AIA and NVST images the same, some previously identified EBs disappear and about 71% of the remaining EBs are associated with BPs. Meanwhile, 66% of the compact brightenings in the AIA 1700 Å images can be identified as EBs in the Hα wings. The intensity enhancements of the EBs in the Hα wing images reveal a linear correlation with those of the BPs in the AIA 1700 Å images. Our study suggests that a significant fraction of EBs can be observed with the AIA 1700 Å filter, which is promising for large-sample statistical study of EBs as the seeing-free and full-disk SDO/AIA data are routinely available.

  6. Progress in Cherenkov femtosecond fiber lasers

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Svane, Ask Sebastian; Lægsgaard, Jesper

    2016-01-01

    We review the recent developments in the field of ultrafast Cherenkov fiber lasers. Two essential properties of such laser systems—broad wavelength tunability and high efficiency of Cherenkov radiation wavelength conversion are discussed. The exceptional performance of the Cherenkov fiber laser...... Cherenkov laser with all-fiber architecture is presented and discussed. Operating in the visible range, it delivers 100–200 fs wavelength-tunable pulses with multimilliwatt output power and exceptionally low noise figure an order of magnitude lower than the traditional wavelength tunable supercontinuumbased...

  7. The reflective surface of the MAGIC telescope

    Science.gov (United States)

    Doro, M.; Bastieri, D.; Biland, A.; Dazzi, F.; Font, L.; Garczarczyk, M.; Ghigo, M.; Giro, E.; Goebel, F.; Kosyra, R.; Lorenz, E.; Mariotti, M.; Mirzoyan, R.; Peruzzo, L.; Pareschi, G.; Zapatero, J.

    2008-09-01

    The atmospheric Cherenkov telescope MAGIC for ground-based gamma-ray astronomy is operating since late 2003 on the Canary island of La Palma. Its 17 m diameter mirror is composed of 964 square all-aluminum mirrors of ˜0.5m side, making up a parabola of 236 m2 area. Each mirror is composed of a sandwich of two thin aluminum layers interspaced by a honeycomb structure that ensures rigidity, high temperature conductivity and low weight. The surface of each raw blank is diamond milled to provide high reflectivity and a slightly different focal length to fit the overall parabolic shape of the reflector. We report about the stability and performance of the surface exposed to the atmosphere for over 3 years. For the construction of the clone of the first telescope, dubbed MAGIC II, major improvements of the design and performance of the reflective surface were required. Given the good experience with aluminum mirrors, a similar assembly was tested, but the area was increased to 1 m2, which allowed to skip the inter-alignment of four mirrors within a panel and to reduce substantially the weight. The increased rigidity of the mirror unit resulted in an improved focussing quality. In addition, a second class of mirrors will be installed in the outermost part of the reflector, namely glass mirrors obtained by cold-slumping replica technique. Details on the construction of both type MAGIC II new mirrors and the 17 m reflector will be presented.

  8. Imaging rings in ring imaging Cherenkov counters

    Energy Technology Data Exchange (ETDEWEB)

    Ratcliff, Blair N

    2002-11-25

    The general concepts used to form images in Ring Imaging Cherenkov (RICH) counters are described and their performance properties compared. Particular attention is paid to issues associated with imaging in the time dimension, especially in Detectors of Internally Reflected Cherenkov light (DIRCs).

  9. Cherenkov Radiation Detector | Obinabo | Nigerian Journal of ...

    African Journals Online (AJOL)

    Most of Radiation detectors based on the Cherenkov Effect are essentially very bulky and expensive for schools and colleges. An inexpensive yet very compact radiation detector is designed, built and tested. It is used to measure the Cherenkov angles for natural radioactivity from sources as Cs137 p32 with energies 0.51 ...

  10. Neptune long-lived atmospheric features in 2013-2015 from small (28-cm) to large (10-m) telescopes

    Science.gov (United States)

    Hueso, R.; de Pater, I.; Simon, A.; Sánchez-Lavega, A.; Delcroix, M.; Wong, M. H.; Tollefson, J. W.; Baranec, C.; de Kleer, K.; Luszcz-Cook, S. H.; Orton, G. S.; Hammel, H. B.; Gómez-Forrellad, J. M.; Ordonez-Etxeberria, I.; Sromovsky, L.; Fry, P.; Colas, F.; Rojas, J. F.; Pérez-Hoyos, S.; Gorczynski, P.; Guarro, J.; Kivits, W.; Miles, P.; Millika, D.; Nicholas, P.; Sussenbach, J.; Wesley, A.; Sayanagi, K.; Ammons, S. M.; Gates, E. L.; Gavel, D.; Victor Garcia, E.; Law, N. M.; Mendikoa, I.; Riddle, R.

    2017-10-01

    Since 2013, observations of Neptune with small telescopes (28-50 cm) have resulted in several detections of long-lived bright atmospheric features that have also been observed by large telescopes such as Keck II or Hubble. The combination of both types of images allows the study of the long-term evolution of major cloud systems in the planet. In 2013 and 2014 two bright features were present on the planet at southern mid-latitudes. These may have merged in late 2014, possibly leading to the formation of a single bright feature observed during 2015 at the same latitude. This cloud system was first observed in January 2015 and nearly continuously from July to December 2015 in observations with telescopes in the 2-10-m class and in images from amateur astronomers. These images show the bright spot as a compact feature at -40.1 ± 1.6° planetographic latitude well resolved from a nearby bright zonal band that extended from -42° to -20°. The size of this system depends on wavelength and varies from a longitudinal extension of 8000 ± 900 km and latitudinal extension of 6500 ± 900 km in Keck II images in H and Ks bands to 5100 ± 1400 km in longitude and 4500 ± 1400 km in latitude in HST images in 657 nm. Over July to September 2015 the structure drifted westward in longitude at a rate of 24.48 ± 0.03°/day or -94 ± 3 m/s. This is about 30 m/s slower than the zonal winds measured at the time of the Voyager 2 flyby. Tracking its motion from July to November 2015 suggests a longitudinal oscillation of 16° in amplitude with a 90-day period, typical of dark spots on Neptune and similar to the Great Red Spot oscillation in Jupiter. The limited time covered by high-resolution observations only covers one full oscillation and other interpretations of the changing motions could be possible. HST images in September 2015 show the presence of a dark spot at short wavelengths located in the southern flank (planetographic latitude -47.0°) of the bright compact cloud observed

  11. Caracterización y automatización mecánica de los telescopios Cherenkov de CASLEO

    Science.gov (United States)

    Leal, N.; Yelós, L. D.; Mancilla, A.; Maya, J.; Feres, L.; Lazarte, F.; García, B.

    2017-10-01

    A new automation system for the Cherenkov Telescopes at CASLEO is designed. Two rotation speeds are proposed: a fast speed for positioning and parking and a slow speed for tracking. The wind speed at El Leoncito site is used as a design parameter. In this work we present the first tests with the new setup which shows a correct performance at fast speeds.

  12. Large Water Cherenkov Detectors - Technical Issues -

    CERN Document Server

    Aihara, H

    2010-01-01

    We address technical issues and challenges to construct a one-megaton scale water Cherenkov detector for neutrino detection. Studies presented here are mostly based on preliminary work for Hyper Kamiokande project.

  13. All-fiber femtosecond Cherenkov radiation source

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe

    2012-01-01

    An all-fiber femtosecond source of spectrally isolated Cherenkov radiation is reported, to the best of our knowledge, for the first time. Using a monolithic, self-starting femtosecond Yb-doped fiber laser as the pump source and the combination of photonic crystal fibers as the wave-conversion med......An all-fiber femtosecond source of spectrally isolated Cherenkov radiation is reported, to the best of our knowledge, for the first time. Using a monolithic, self-starting femtosecond Yb-doped fiber laser as the pump source and the combination of photonic crystal fibers as the wave......-conversion medium, we demonstrate milliwatt-level, stable, and tunable Cherenkov radiation at visible wavelengths 580–630 nm, with pulse duration of sub-160-fs, and the 3 dB spectral bandwidth not exceeding 36 nm. Such an all-fiber Cherenkov radiation source is promising for practical applications in biophotonics...

  14. Cherenkov Radiation from e+e- Pairs and Its Effect on nu e InducedShowers

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Sourav K.; Klein, Spencer R.; Jackson, J. David

    2005-06-08

    We calculate the Cherenkov radiation from an e{sup +}e{sup -} pair at small separations, as occurs shortly after a pair conversion. The radiation is reduced (compared to that from two independent particles) when the pair separation is smaller than the wavelength of the emitted light. We estimate the reduction in light in large electromagnetic showers, and discuss the implications for detectors that observe Cherenkov radiation from showers in the Earth's atmosphere, as well as in oceans and Antarctic ice.

  15. Template analysis for the MAGIC telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, Uta [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: MAGIC-Collaboration

    2016-07-01

    The MAGIC telescopes are two 17-m-diameter Imaging Air Cherenkov Telescopes located on the Canary island of La Palma. They record the Cherenkov light from air showers induced by very high energy photons. The current data analysis uses a parametrization of the two shower images (including Hillas parameters) to determine the characteristics of the primary particle. I am implementing an advanced analysis method that compares shower images on a pixel basis with template images based on Monte Carlo simulations. To reduce the simulation effort the templates contain only pure shower images that are convolved with the telescope response later in the analysis. The primary particle parameters are reconstructed by maximizing the likelihood of the template. By using all the information available in the shower images, the performance of MAGIC is expected to improve. In this presentation I will explain the general idea of a template-based analysis and show the first results of the implementation.

  16. TARGET: A multi-channel digitizer chip for very-high-energy gamma-ray telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Bechtol, K.; Funk, S.; /Stanford U., HEPL /KIPAC, Menlo Park; Okumura, A.; /JAXA, Sagamihara /Stanford U., HEPL /KIPAC, Menlo Park; Ruckman, L.; /Hawaii U.; Simons, A.; Tajima, H.; Vandenbroucke, J.; /Stanford U., HEPL /KIPAC, Menlo Park; Varner, G.; /Hawaii U.

    2011-08-11

    The next-generation very-high-energy (VHE) gamma-ray observatory, the Cherenkov Telescope Array, will feature dozens of imaging atmospheric Cherenkov telescopes (IACTs), each with thousands of pixels of photosensors. To be affordable and reliable, reading out such a mega-channel array requires event recording technology that is highly integrated and modular, with a low cost per channel. We present the design and performance of a chip targeted to this application: the TeV Array Readout with GSa/s sampling and Event Trigger (TARGET). This application-specific integrated circuit (ASIC) has 16 parallel input channels, a 4096-sample buffer for each channel, adjustable input termination, self-trigger functionality, and tight window-selected readout. We report the performance of TARGET in terms of sampling frequency, power consumption, dynamic range, current-mode gain, analog bandwidth, and cross talk. The large number of channels per chip allows a low cost per channel ($10 to $20 including front-end and back-end electronics but not including photosensors) to be achieved with a TARGET-based IACT readout system. In addition to basic performance parameters of the TARGET chip itself, we present a camera module prototype as well as a second-generation chip (TARGET 2), both of which have been produced.

  17. Particle Identification in Cherenkov Detectors using Convolutional Neural Networks

    CERN Document Server

    Theodore, Tomalty

    2016-01-01

    Cherenkov detectors are used for charged particle identification. When a charged particle moves through a medium faster than light can propagate in that medium, Cherenkov radiation is released in the shape of a cone in the direction of movement. The interior of the Cherenkov detector is instrumented with PMTs to detect this Cherenkov light. Particles, then, can be identified by the shapes of the images on the detector walls.

  18. Cherenkov TOF PET with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Dolenec, R., E-mail: rok.dolenec@ijs.si [Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor (Slovenia); Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana (Slovenia); Korpar, S. [Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor (Slovenia); Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Križan, P. [Faculty of Mathematics and Physics, University of Ljubljana, Ljubljana (Slovenia); Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia); Pestotnik, R. [Jožef Stefan Institute, Jamova cesta 39, SI-1000 Ljubljana (Slovenia)

    2015-12-21

    As previously demonstrated, an excellent timing resolution below 100 ps FWHM is possible in time-of-flight positron emission tomography (TOF PET) if the detection method is based on the principle of detecting photons of Cherenkov light, produced in a suitable material and detected by microchannel plate photomultipliers (MCP PMTs). In this work, the silicon photomultipliers (SiPMs) were tested for the first time as the photodetectors in Cherenkov TOF PET. The high photon detection efficiency (PDE) of SiPMs led to a large improvement in detection efficiency. On the other hand, the time response of currently available SiPMs is not as good as that of MCP PMTs. The SiPM dark counts introduce a new source of random coincidences in Cherenkov method, which would be overwhelming with present SiPM technology at room temperature. When the apparatus was cooled, its performance significantly improved.

  19. A Cherenkov Detector for Monitoring ATLAS Luminosity

    CERN Document Server

    Sbrizzi, A; The ATLAS collaboration

    2010-01-01

    LUCID (LUminosity Cherenkov Integrating Detector) is the monitor of the luminosity delivered by the LHC accelerator to the ATLAS experiment. The detector is made of two symmetric arms deployed at about 17 m from the ATLAS interaction point. Each arm consists of an aluminum vessel containing 20 tubes, 15 mm diameter and 1500 mm length, and a Cherenkov gaseous radiator (C4F10) at about 1.1 bar absolute. The light generated by charged particles above the Cherenkov threshold is collected by photomultiplier tubes (PMT) directly placed at the tubes end. Thanks to an intrinsically fast response and to its custom readout electronics, LUCID estimates the number of interactions per LHC bunch crossing and provides an interaction trigger to the ATLAS experiment. The relevant details of the detector design and the expexted performance based on Monte Carlo simulations are presented, together with the first results obtained with pp collisions produced by LHC.

  20. Measurement of the atmospheric {nu}{sub {mu}} energy spectrum from 100 GeV to 200 TeV with the ANTARES telescope

    Energy Technology Data Exchange (ETDEWEB)

    Adrian-Martinez, S.; Ardid, M.; Larosa, G.; Martinez-Mora, J.A. [Universitat Politecnica de Valencia, Institut d' Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Gandia (Spain); Albert, A.; Drouhin, D.; Racca, C. [GRPHE - Institut universitaire de technologie de Colmar, 34 rue du Grillenbreit, BP 50568, Colmar (France); Al Samarai, I.; Aubert, J.J.; Bertin, V.; Brunner, J.; Busto, J.; Carr, J.; Charif, Z.; Core, L.; Costantini, H.; Coyle, P.; Curtil, C.; Dornic, D.; Ernenwein, J.P.; Escoffier, S.; Lambard, E.; Riviere, C.; Vallee, C.; Yatkin, K. [Aix-Marseille Universite, CPPM, CNRS/IN2P3, Marseille (France); Andre, M. [Technical University of Catalonia, Laboratory of Applied Bioacoustics, Vilanova i la Geltru, Barcelona (Spain); Anghinolfi, M.; Sanguineti, M. [INFN - Sezione di Genova, Genova (Italy); Anton, G.; Classen, F.; Eberl, T.; Enzenhoefer, A.; Fehn, K.; Folger, F.; Fritsch, U.; Geisselsoeder, S.; Geyer, K.; Gleixner, A.; Graf, K.; Herold, B.; Hoessl, J.; James, C.W.; Kalekin, O.; Kappes, A.; Katz, U.; Lahmann, R.; Motz, H.; Neff, M.; Richter, R.; Roensch, K.; Schmid, J.; Schnabel, J.; Seitz, T.; Shanidze, R.; Sieger, C.; Spies, A.; Wagner, S. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erlangen (Germany); Anvar, S.; Louis, F. [CEA Saclay, Direction des Sciences de la Matiere - Institut de recherche sur les lois fondamentales de l' Univers - Service d' Electronique des Detecteurs et d' Informatique, Gif-sur-Yvette Cedex (France); Astraatmadja, T.; Bogazzi, C.; Bouwhuis, M.C.; Heijboer, A.J.; Jong, M. de; Michael, T.; Palioselitis, D.; Schulte, S.; Steijger, J.J.M.; Visser, E. [Nikhef, Amsterdam (Netherlands); Baret, B.; Bouhou, B.; Creusot, A.; Galata, S.; Kouchner, A.; Elewyck, V. van [Universite Paris Diderot, APC, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Paris (France); Barrios-Marti, J.; Bigongiari, C.; Emanuele, U.; Gomez-Gonzalez, J.P.; Hernandez-Rey, J.J.; Lambard, G.; Mangano, S.; Sanchez-Losa, A.; Yepes, H.; Zornoza, J.D.; Zuniga, J. [CSIC - Universitat de Valencia, IFIC - Instituto de Fisica Corpuscular, Edificios Investigacion de Paterna, Valencia (Spain); Basa, S.; Marcelin, M.; Nezri, E. [Pole de l' Etoile Site de Chateau-Gombert, LAM - Laboratoire d' Astrophysique de Marseille, Marseille Cedex 13 (France); Biagi, S.; Fusco, L.A.; Giacomelli, G.; Margiotta, A.; Spurio, M. [INFN - Sezione di Bologna, Bologna (Italy); Dipartimento di Fisica dell' Universita, Bologna (Italy); Bruijn, R.; Decowski, M.P.; Wolf, E. de [Nikhef, Amsterdam (Netherlands); Universiteit van Amsterdam, Instituut voor Hoge-Energie Fysica, XG Amsterdam (Netherlands); Capone, A.; De Bonis, G.; Fermani, P.; Perrina, C.; Simeone, F. [INFN - Sezione di Roma, Roma (Italy); Dipartimento di Fisica dell' Universita La Sapienza, Roma (Italy); Caramete, L.; Pavalas, G.E.; Popa, V. [Institute for Space Sciences, Bucharest (Romania); Carloganu, C.; Dumas, A.; Gay, P.; Guillard, G. [Clermont Universite, Universite Blaise Pascal, CNRS/IN2P3, Laboratoire de Physique Corpusculaire, BP 10448, Clermont-Ferrand (France); Cecchini, S.; Chiarusi, T. [INFN - Sezione di Bologna, Bologna (Italy); Charvis, P.; Deschamps, A.; Hello, Y. [Universite Nice Sophia-Antipolis, Geoazur, CNRS/INSU, IRD, Observatoire de la Cote d' Azur, Sophia Antipolis (France); Circella, M. [INFN - Sezione di Bari, Bari (Italy); Dekeyser, I.; Lefevre, D.; Martini, S.; Robert, A.; Tamburini, C. [Aix-Marseille University, Mediterranean Institute of Oceanography (MIO), Marseille Cedex 9 (France); Universite du Sud Toulon-Var, CNRS-INSU/IRD UM 110, La Garde Cedex (France); Distefano, C.; Lattuada, D.; Piattelli, P.; Sapienza, P.; Trovato, A. [INFN - Laboratori Nazionali del Sud (LNS), Catania (Italy); Donzaud, C. [Universite Paris Diderot, APC, CNRS/IN2P3, CEA/IRFU, Observatoire de Paris, Paris (France); Univ Paris-Sud, Orsay Cedex (France); Dorosti, Q.; Loehner, H. [University of Groningen, Kernfysisch Versneller Instituut (KVI), Groningen (Netherlands); Flaminio, V. [INFN - Sezione di Pisa, Pisa (Italy); Dipartimento di Fisica dell' Universita, Pisa (Italy); Giordano, V. [INFN - Sezione di Catania, Catania (Italy); Haren, H. van [Royal Netherlands Institute for Sea Research (NIOZ), ' t Horntje (Texel) (Netherlands); Kadler, M. [Universitaet Wuerzburg, Institut fuer Theoretische Physik und Astrophysik, Wuerzburg (Germany); Kooijman, P. [Nikhef, Amsterdam (Netherlands); Universiteit Utrecht, Faculteit Betawetenschappen, Utrecht (Netherlands); Universiteit van Amsterdam, Instituut voor Hoge-Energie Fysica, XG Amsterdam (Netherlands); Kreykenbohm, I.; Mueller, C.; Wilms, J. [Universitaet Erlangen-Nuernberg, Dr. Remeis-Sternwarte and ECAP, Bamberg (Germany); Kulikovskiy, V. [INFN - Sezione di Genova, Genova (Italy); Moscow State University, Skobeltsyn Institute of Nuclear Physics, Moscow (Russian Federation); Leonora, E.; Lo Presti, D. [INFN - Sezione di Catania, Catania (Italy); Dipartimento di Fisica ed Astronomia dell' Universita, Catania (IT); Loucatos, S.; Schuessler, F.; Stolarczyk, T.; Vallage, B.; Vernin, P. [CEA Saclay, Direction des Sciences de la Matiere, Institut de recherche sur les lois fondamentales de l' Univers, Service de Physique des Particules, Gif-sur-Yvette Cedex (FR); Montaruli, T. [INFN - Sezione di Bari, Bari (IT); Universite de Geneve, Departement de Physique Nucleaire et Corpusculaire, Geneva (CH); Morganti, M. [INFN - Sezione di Pisa, Pisa (IT); Pradier, T. [Universite de Strasbourg et CNRS/IN2P3, IPHC-Institut Pluridisciplinaire Hubert Curien, 23 rue du Loess, BP 28, Strasbourg Cedex 2 (FR); Rostovtsev, A. [ITEP - Institute for Theoretical and Experimental Physics, Moscow (RU); Samtleben, D.F.E. [Nikhef, Amsterdam (NL); Universiteit Leiden, Leids Instituut voor Onderzoek in Natuurkunde, Leiden (NL); Taiuti, M. [INFN - Sezione di Genova, Genova (IT); Dipartimento di Fisica dell' Universita, Genova (IT); Tayalati, Y. [University Mohammed I, Laboratory of Physics of Matter and Radiations, B.P. 717, Oujda (MA)

    2013-10-15

    Atmospheric neutrinos are produced during cascades initiated by the interaction of primary cosmic rays with air nuclei. In this paper, a measurement of the atmospheric {nu}{sub {mu}} + anti {nu}{sub {mu}} energy spectrum in the energy range 0.1-200 TeV is presented, using data collected by the ANTARES underwater neutrino telescope from 2008 to 2011. Overall, the measured flux is {proportional_to}25 % higher than predicted by the conventional neutrino flux, and compatible with the measurements reported in ice. The flux is compatible with a single power-law dependence with spectral index {gamma}{sub meas}=3.58{+-}0.12. With the present statistics the contribution of prompt neutrinos cannot be established. (orig.)

  1. The Cherenkov Radiation for Non-Trivial Systems; La Radiacion Cherenkov en Sistemas No Triviales

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A.

    2002-07-01

    The charge pathways and the dielectric properties of the medium are two essential aspects to be considered in the study of the emission of Cherenkov radiation. We described the evolution of the Cherenkov wavefront when the charges follow circular or helical pathways. Also we derive expressions for the refractive Index in different transparent media (solid, liquid or gas), focusing our attention on optically active plasmas. The optical analogies between the plasma and the birefringent crystals is studied in detail. Finally, we list some examples of plasmas, which can be considered emitters of Cherenkov radiation. (Author) 52 refs.

  2. All-fiber femtosecond Cherenkov source

    Directory of Open Access Journals (Sweden)

    Tu H.

    2013-03-01

    Full Text Available An all-fiber femtosecond Cherenkov radiation source is demonstrated for the first time, to the best of our knowledge. Using a stable monolithic femtosecond Ybdoped fiber laser as the pump source, and the combination of photonic crystal fibers as the wave-conversion medium, we have generated tunable Cherenkov radiation at visible wavelengths 580 – 630 nm, with pulse duration of sub-160 fs, and the 3 dB spectral bandwidth not exceeding 36 nm. Such femtosecond source can find applications in practical biophotonics such as bio-imaging and microscopy.

  3. Muon Telescope (MuTe): A first study using Geant4

    Science.gov (United States)

    Asorey, H.; Balaguera-Rojas, A.; Calderon-Ardila, R.; Núñez, L. A.; Sanabria-Gómez, J. D.; Súarez-Durán, M.; Tapia, A.

    2017-07-01

    Muon tomography is based on recording the difference of absorption of muons by matter, as ordinary radiography does for using X-rays. The interaction of cosmic rays with the atmosphere produces extensive air showers which provides an abundant source for atmospheric muons, benefiting various applications of muon tomography, particularly the study of the inner structure of volcanoes. The MuTe (for Muon Telescope) is a hybrid detector composed of scintillation bars and a water Cherenkov detector designed to measure cosmic muon flux crossing volcanic edifices. This detector consists of two scintillator plates (1.44 m2 with 30 x 30 pixels), with a maximum distance of 2.0m of separation. In this work we report the first simulation of the MuTe using GEANT4 -set of simulation tools, based in C++ - that provides information about the interaction between radiation and matter. This computational tool allows us to know the energy deposited by the muons and modeling the response of the scintillators and the water cherenkov detector to the passage of radiation which is crucial to compare to our data analysis.

  4. Modeling The Atmosphere In The Era Of Big Data From Extremely Wide Field-Of-View Telescopes

    Science.gov (United States)

    Gonzalez Quiles, Junellie; Nordin, Jakob

    2018-01-01

    Surveys like the Sloan Digital Sky Survey (SDSS), Pan-STARRS and the Palomar Transient Factory Survey (PTF) receive large amounts of data, which need to be processed and calibrated in order to correct for various factors. One of the limiting factors in obtaining high quality data is the atmosphere, and it is therefore essential to find the appropriate calibration for the atmospheric extinction. It is to be expected that a physical atmospheric model, compared to a photometric calibration used currently by PTF, is more effective in calibrating for the atmospheric extinction due to its ability to account for rapid atmospheric fluctuation and objects of different colors. We focused on creating tools to model the atmospheric extinction for the upcoming Zwicky Transient Factory Survey (ZTF). In order to model the atmosphere, we created a program that combines input data and catalogue values, and efficiently handles them. Then, using PTF data and the SDSS catalogue, we created several models to fit the data, and tested the quality of the fits by chi-square minimization. This will allow us to optimize atmospheric extinction for the upcoming ZTF in the near future.

  5. All-fiber femtosecond Cherenkov source

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe Visbech

    2013-01-01

    An all-fiber femtosecond Cherenkov radiation source is demonstrated for the first time, to the best of our knowledge. Using a stable monolithic femtosecond Ybdoped fiber laser as the pump source, and the combination of photonic crystal fibers as the wave-conversion medium, we have generated tunable...

  6. LHCb ring imaging Cherenkov detector mirrors

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    In a large dark room, men in white move around an immense structure some 7 m high, 10 m wide and nearly 2.5 m deep. Apparently effortlessly, they are installing the two large high-precision spherical mirrors. These mirrors will focus Cherenkov light, created by the charged particles that will traverse this detector, onto the photon detectors.

  7. Energy Reconstruction Methods in the IceCube Neutrino Telescope

    DEFF Research Database (Denmark)

    Aartsen, M.G.; Abbasi, R.; Ackermann, M.

    2014-01-01

    Accurate measurement of neutrino energies is essential to many of the scientific goals of large-volume neutrino telescopes. The fundamental observable in such detectors is the Cherenkov light produced by the transit through a medium of charged particles created in neutrino interactions. The amoun...

  8. The positioning system of the ANTARES Neutrino Telescope

    NARCIS (Netherlands)

    Adrian-Martinez, S.; Ageron, M.; Aguilar, J. A.; Al Samarai, I.; Albert, A.; Andre, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Jesus, A. C. Assis; Astraatmadja, T.; Aubert, J. -J.; Baret, B.; Basa, S.; Bertin, V.; Biagi, S.; Bigi, A.; Bigongiari, C.; Bogazzi, C.; Bou-Cabo, M.; Bouhou, B.; Bouwhuis, M. C.; Brunner, J.; Busto, J.; Camarena, F.; Capone, A.; Carloganu, C.; Carminati, G.; Carr, J.; Cecchini, S.; Charif, Z.; Charvis, Ph.; Chiarusi, T.; Circella, M.; Coniglione, R.; Costantini, H.; Coyle, P.; Curtil, C.; De Bonis, G.; Decowski, M. P.; Dekeyser, I.; Deschamps, A.; Distefano, C.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drouhin, D.; Eberl, T.; Emanuele, U.; Enzenhoefer, A.; Ernenwein, J. -P.; Escoffier, S.; Fermani, P.; Ferri, M.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J. -L.; Galata, S.; Gay, P.; Giacomelli, G.; Giordano, V.; Gomez-Gonzalez, J. P.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartman, J.; Heijboer, A. J.; Hello, Y.; Hernandez-Rey, J. J.; Herold, B.; Hoessl, J.; Hsu, C. C.; de Jong, M.; Kadler, M.; Kalekin, O.; Kappes, A.; Katz, U.; Kavatsyuk, O.; Keller, P.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kreykenbohm, I.; Kulikovskiy, V.; Lahmann, R.; Lamare, P.; Larosa, G.; Lattuada, D.; Lefevre, D.; Le Van Suu, A.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Meli, A.; Montaruli, T.; Moscoso, L.; Motz, H.; Neff, M.; Nezri, E.; Niess, V.; Palioselitis, D.; Pavalas, G. E.; Payet, K.; Payre, P.; Petrovic, J.; Piattelli, P.; Picot-Clemente, N.; Popa, V.; Pradier, T.; Presani, E.; Racca, C.; Real, D.; Reed, C.; Riccobene, G.; Richardt, C.; Richter, R.; Riviere, C.; Robert, A.; Roensch, K.; Rostovtsev, A.; Ruiz-Rivas, J.; Rujoiu, M.; Russo, G. V.; Salesa, F.; Samtleben, D. F. E.; Schoeck, F.; Schuller, J. -P.; Schuessler, F.; Seitz, T.; Shanidze, R.; Simeone, F.; Spies, A.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th.; Sanchez-Losa, A.; Taiuti, M.; Tamburini, C.; Toscano, S.; Vallage, B.; Van Elewyck, V.; Vannoni, G.; Vecchi, M.; Vernin, P.; Wagner, S.; Wijnker, G.; Wilms, J.; de Wolf, E.; Yepes, H.; Zaborov, D.; Zornoza, J. D.; Zuniga, J.

    The ANTARES neutrino telescope, located 40km off the coast of Toulon in the Mediterranean Sea at a mooring depth of about 2475m, consists of twelve detection lines equipped typically with 25 storeys. Every storey carries three optical modules that detect Cherenkov light induced by charged secondary

  9. On Cherenkov light production by irradiated nuclear fuel rods

    Science.gov (United States)

    Branger, E.; Grape, S.; Jacobsson Svärd, S.; Jansson, P.; Andersson Sundén, E.

    2017-06-01

    Safeguards verification of irradiated nuclear fuel assemblies in wet storage is frequently done by measuring the Cherenkov light in the surrounding water produced due to radioactive decays of fission products in the fuel. This paper accounts for the physical processes behind the Cherenkov light production caused by a single fuel rod in wet storage, and simulations are presented that investigate to what extent various properties of the rod affect the Cherenkov light production. The results show that the fuel properties have a noticeable effect on the Cherenkov light production, and thus that the prediction models for Cherenkov light production which are used in the safeguards verifications could potentially be improved by considering these properties. It is concluded that the dominating source of the Cherenkov light is gamma-ray interactions with electrons in the surrounding water. Electrons created from beta decay may also exit the fuel and produce Cherenkov light, and e.g. Y-90 was identified as a possible contributor to significant levels of the measurable Cherenkov light in long-cooled fuel. The results also show that the cylindrical, elongated fuel rod geometry results in a non-isotropic Cherenkov light production, and the light component parallel to the rod's axis exhibits a dependence on gamma-ray energy that differs from the total intensity, which is of importance since the typical safeguards measurement situation observes the vertical light component. It is also concluded that the radial distributions of the radiation sources in a fuel rod will affect the Cherenkov light production.

  10. The mechanism of Vavilov-Cherenkov radiation

    Science.gov (United States)

    Kobzev, A. P.

    2010-05-01

    The mechanism of generation of Vavilov-Cherenkov radiation is discussed in this article. The developers of the theory of the Vavilov-Cherenkov effect, I.E. Tamm and I.M. Frank, attributed this effect to their discovery of a new mechanism of radiation when a charged particle moves uniformly and rectilinearly in the medium. As such a mechanism presupposes the violation of the laws of conservation of energy and momentum, they proposed the abolition of these laws to account for the Vavilov-Cherenkov radiation mechanism. This idea has received a considerably wide acceptance in the creation of other theories, for example, transition radiation theory. In this paper, the radiation mechanism for the charge constant motion is demonstrated to be incorrect, because it contradicts not only the laws of conservation of energy and momentum, but also the very definitions of uniform and rectilinear motion (Newton's First Law). A consistent explanation of the Vavilov-Cherenkov radiation microscopic mechanism that does not contradict the basic laws is proposed. It is shown that the radiation arises from the interaction of the moving charge with bound charges that are spaced fairly far away from its trajectory. The Vavilov-Cherenkov radiation mechanism bears a slowing down character, but it differs fundamentally from bremsstrahlung, primarily because the Vavilov-Cherenkov radiation onset results from a two-stage process. First, the moving particle polarizes the medium; then, the already polarized atoms radiate coherently, provided that the particle velocity exceeds the phase speed of light in the medium. If the particle velocity is less than the phase speed of light in the medium, the polarized atoms return energy to the outgoing particle. In this case, radiation is not observed. Special attention is given to the relatively constant particle velocity as the condition of the coherent composition of waves. However, its motion cannot be designated as a uniform and rectilinear one in the

  11. Space Telescope.

    Science.gov (United States)

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    This pamphlet describes the Space Telescope, an unmanned multi-purpose telescope observatory planned for launch into orbit by the Space Shuttle in the 1980s. The unique capabilities of this telescope are detailed, the major elements of the telescope are described, and its proposed mission operations are outlined. (CS)

  12. Alternative particle identification techniques to Cherenkov detectors

    Energy Technology Data Exchange (ETDEWEB)

    Harnew, Neville, E-mail: n.harnew@physics.ox.ac.uk

    2014-12-01

    Alternative particle identification methods to Cherenkov techniques are reviewed. Particular focus is given to recent advances in Transition Radiation Detectors (TRDs), improvements in dE/dx ionization loss by cluster counting, and Time of Flight (ToF) techniques. In each case several state of the art detectors are highlighted. For advances in ToF techniques, the status of fast photon detectors and electronics developments is summarized.

  13. Cherenkov Detectors for Precision Parity Experiments

    Science.gov (United States)

    Kutz, Tyler; Prex Collaboration; Moller Collaboration

    2017-09-01

    Fused silica Cherenkov detectors are ideal for measuring high-rate fluxes of charged particles. The parity program at Jefferson Lab relies on these detectors to measure cross section asymmetries, some of which are predicted to be on the order of tens of parts per billion. Given the required precision of such experiments, it is important that the resolution of these detectors is minimized. Detectors must be optimized while conforming to the physics and engineering constraints of a specific experiment. Two upcoming JLab experiments that will utilize Cherenkov detectors are the Lead (Pb) Radius EXperiment (PREX) and Measurement Of a Lepton-Lepton Electroweak Reaction (MOLLER). PREX will constrain the neutron equation of state by measuring the neutron skin thickness of 208Pb. MOLLER will test the Standard Model by providing the most precise low-energy measurement of the weak mixing angle. Several detector prototypes have been designed, tested, and simulated to meet the demands of PREX and MOLLER. Presented here is a summary of ongoing work to design state-of-the-art Cherenkov detectors for precision parity experiments.

  14. Proposal for Cherenkov Time of Flight Technique with Picosecond Resolution

    Energy Technology Data Exchange (ETDEWEB)

    S. Majewski; A. Margaryan; L. Tang

    2005-08-05

    A new particle identification device for Jlab 12 GeV program is proposed. It is based on the measurement of time information obtained by means of a new photon detector and time measuring concept. The expected time measurement precision for the Cherenkov time-of-flight detector is about or less than 10 picosecond for Cherenkov radiators with lengths less than 50 cm.

  15. Current status of the ANTARES neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Naumann-Godo, M. [Physics Institute 4, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany)

    2007-10-15

    The ANTARES collaboration is currently installing a neutrino telescope in the Mediterranean Sea close to the French coast at Toulon. The complete detector will consist of 900 photomultipliers arranged on 12 detector lines in 2500 m depth, thus instrumenting a volume of 0.01 km{sup 3} sea water as target material. The incident neutrinos are detected by collecting the Cherenkov light from charged secondary particles, which are emitted by neutrino interactions with the sea water or the rock of the sea bed beneath. By reconstructing the Cherenkov cone and therewith the direction of the incident neutrinos with high accuracy, the principal objective of ANTARES is the search for point sources of high-energy cosmic neutrinos and dark matter. In this presentation, emphasis will be placed on the operation of the detector in the hostile deep sea environment and on the status of the project. Results of the first complete detector line will be shown.

  16. Cherenkov detector for beam quality measurement

    Science.gov (United States)

    Orfanelli, S.; CMS Collaboration

    2016-07-01

    A new detector to measure the machine induced background at larger radii has been developed and installed in the CMS experiment at the LHC. It consists of forty modules, each comprising a quartz bar read out by a photomultiplier tube. Since Cherenkov radiation is emitted in a forward cone around the charged particle trajectory, these detectors can distinguish between the arrival directions of the machine induced background and the collision products. The back-end electronics consists of a uTCA readout with excellent time resolution. The installation in the CMS is described and first commissioning measurements with the LHC beams in Run II are presented.

  17. Test of aerogel as Cherenkov radiator

    CERN Document Server

    Alemi, M; Calvi, M; Matteuzzi, C; Negri, P; Paganoni, M; Liko, D; Neufeld, N; Chesi, Enrico Guido; Joram, C; Séguinot, Jacques; Ypsilantis, Thomas

    2001-01-01

    Two different stacks of aerogel were tested in a pion/proton beam of momentum between 3 and 10 GeV/c. The optical characteristics of the aerogel samples were different: one sample was hygroscopic while the other was hydrophobic. Two HPD tubes were used as photodetectors, and different thicknesses of the stacks were used, in order to determine the photoelectron yield, the Cherenkov angle and its precision. Pion/proton separation has been demonstrated at momenta up to 10 GeV/c.

  18. The Ring Imaging Cherenkov Detectors for LHCb

    CERN Document Server

    Papanestis, Antonis

    2005-01-01

    The success of the LHCb experiment depends heavily on particle identification over the momentum 2-100 GeV/c. To meet this challenge, LHCb uses a Ring Imaging Cherenkov (RICH) system composed of two detectors with three radiators. RICH1 has both aerogel and gas (C$_4$F$_{10}$) radiators, while RICH2 has only a gas (CF$_4$) radiator. The design of RICH1 is almost complete, whereas RICH2 has been constructed and installed (Nov 2005). Novel Hybrid Photon Detectors (HPDs) have been developed in collaboration with industry to detect the Cherenkov photons. A silicon pixel detector bump-bonded to a readout chip is encapsulated in a vacuum tube. A bi-alkali photocathode is deposited on the inside of the quartz entrance window to convert photons in the range 200-600 nm. The pixel chip is manufactured in 0.25 $\\mu$m deep-submicron radiation-tolerant technology and consists of 1024 logical pixels, each pixel having an area of 0.5 mm x 05. Mm. Photo-electrons are accelerated by a 20kV potential, resulting in a signal of ...

  19. The Potential of Spaced-based High-Energy Neutrino Measurements via the Airshower Cherenkov Signal

    Science.gov (United States)

    Krizmanic, John F.; Mitchell, John W.

    2011-01-01

    Future space-based experiments, such as (Orbiting Wide-angle Light Collectors (OWL) and JEM-EUSO, view large atmospheric and terrestrial neutrino targets. With energy thresholds slightly above 10(exp 19) eV for observing airshowers via air fluorescence, the potential for observing the cosmogenic neutrino flux associated with the GZK effect is limited. However, the forward Cherenkov signal associated with the airshower can be observed at much lower energies. A simulation was developed to determine the Cherenkov signal strength and spatial extent at low-Earth orbit for upward-moving airshowers. A model of tau neutrino interactions in the Earth was employed to determine the event rate of interactions that yielded a tau lepton which would induce an upward-moving airshower observable by a space-based instrument. The effect of neutrino attenuation by the Earth forces the viewing of the Earth's limb to observe the vT-induced Cherenkov airshower signal at above the OWL Cherenkov energy threshold of approximately 10(exp 16.5) eV for limb-viewed events. Furthermore, the neutrino attenuation limits the effective terrestrial neutrino target area to approximately 3 x 10(exp 5) square km at 10(exp 17) eV, for an orbit of 1000 km and an instrumental full Field-of-View of 45 deg. This translates into an observable cosmogenic neutrino event rate of approx. l/year based upon two different models of the cosmogenic neutrino flux, assuming neutrino oscillations and a 10% duty cycle for observation.

  20. The Timepix3 Telescope for LHCb Upgrade RD 1 measurements

    CERN Document Server

    Saunders, Daniel Martin

    2016-01-01

    The Timepix3 telescope is a high rate, data driven beam telescope created for LHCb upgrade studies, such as sensor performance for prototypes of the vertex locator (VELO) upgrade. When testing VELO prototypes the readout is identical to the telescope, and additionally, a simple way to integrate triggers from other detectors is also provided, allowing tracks to be synchronised offline with other devices under test. Examples of LHCb upgrade detectors which have been qualified with the Timepix3 telescope are the Upstream Tracker (UT), Scintillating Fibres (SciFi), Ring Imaging CHerenkov (RICH), and Time Of internally Reflected CHerenkov light (TORCH). The telescope was installed in the SPS North hall at CERN. It consists of 8 planes with 300 μ m p-on-n silicon sensors read out by Timepix3 ASICs. Tracks measured with the telescope have excellent temporal ( ∼ 1 ns) and spatial resolution ( 2 μ m). The telescope has been operated with a rate of tracks written to disk up to 5 MHz - limited only by conditions at ...

  1. On the electromagnetic energy resolution of Cherenkov-fiber calorimeters

    CERN Document Server

    Lundin, M; Dellacasa, G; DeSalvo, R; Gallio, M; Gorodetzky, P; Helleboid, J M; Johnson, K F; Juillot, P; Lazic, D; Musso, A; Vercellin, Ermanno; White, S

    1996-01-01

    Electromagnetic calorimeters which sample the Cherenkov radiation of shower particles in optical fibers operate in a markedly different manner from calorimeters which rely on the dE/dx of shower particles. The well-understood physics of electromagnetic shower development is applied to the case of Cherenkov-fiber calorimetry (also known as quartz fiber calorimetry) and the results of systematically performed studies are considered in detail to derive an understanding of the critical parameters involved in energy measurement using such calorimeters. A quantitative parameterization of Cherenkov-fiber calorimetry electromagnetic energy resolution is proposed and compared with existing experimental results.

  2. Tachyonic Cherenkov emission from Jupiter's radio electrons

    Energy Technology Data Exchange (ETDEWEB)

    Tomaschitz, Roman, E-mail: tom@geminga.org

    2013-12-17

    Tachyonic Cherenkov radiation from inertial relativistic electrons in the Jovian radiation belts is studied. The tachyonic modes are coupled to a frequency-dependent permeability tensor and admit a negative mass-square, rendering them superluminal and dispersive. The superluminal radiation field can be cast into Maxwellian form, using 3D field strengths and inductions, and the spectral densities of tachyonic Cherenkov radiation are derived. The negative mass-square gives rise to a longitudinal flux component. A spectral fit to Jupiter's radio spectrum, inferred from ground-based observations and the Cassini 2001 fly-by, is performed with tachyonic Cherenkov flux densities averaged over a thermal electron population.

  3. NESTOR - Neutrino Extended Submarine Telescope with Oceanographic Research

    CERN Document Server

    2002-01-01

    {\\bf NESTOR} is a deep-sea neutrino telescope that is being deployed in the Mediterranean off the south-west coast of the Peleponnese in Greece. Neutrinos, when they interact in the earth below or in the seawater around the detector, produce muons that can be observed by the Cherenkov radiation, which they emit. At an operating depth of 4000 metres, the detector is effectively shielded from muons produced in atmospheric interactions. {\\bf The site:} A major feature of the Ionian Sea floor is the Hellenic Trench, the deepest in the Mediterranean, which in places exceeds 5000 meters. It runs close to the western coast of the Peleponnese and is protected on its western side by the submarine Eastern Mediterranean Ridge. It is far from big city pollution or the effluent of major river systems flowing into the Mediterranean and is protected from deep-water perturbations.\\\\ The NESTOR site is located on a broad plateau some 8 $\\times$ 9 kilometres in area on the eastern side of the Hellenic Trench at a mean depth of...

  4. Aerogel Cherenkov Counters of the KEDR Detector

    CERN Document Server

    Ovtin, I V; Barnyakov, M Y; Bobrovnikov, V S; Buzykaev, A R; Danilyuk, A F; Katcin, A A; Kononov, S A; Kravchenko, E A; Kuyanov, I A; Onuchin, A P; Rodiakin, V A

    2017-01-01

    The particle identification system of the KEDR detector is based on aerogel threshold Cherenkov counters called ASHIPH counters. The system consists of 160 counters arranged in two layers. An event reconstruction program for the ASHIPH system was developed. The position of each counter relative to the tracking system was determined using cosmic muons and Bhabha events. The geometric efficiency of the ASHIPH system was verified with Bhabha events. The efficiency of relativistic particle detection was measured with cosmic muons. A π/K separation of 4δ in the momentum range 0.95 −1.45 GeV/c was confirmed. A simulation program for the ASHIPH counters has been developed.

  5. Why Space Telescopes Are Amazing

    Science.gov (United States)

    Rigby, Jane R.

    2012-01-01

    One of humanity's best ideas has been to put telescopes in space. The dark stillness of space allows telescopes to perform much better than they can on even the darkest and clearest of Earth's mountaintops. In addition, from space we can detect colors of light, like X-rays and gamma rays, that are blocked by the Earth's atmosphere I'll talk about NASA's team of great observatories: the Hubble Space Telescope, Spitzer Space Telescope, and Chandra X-ray Observatory} and how they've worked together to answer key questions: When did the stars form? Is there really dark matter? Is the universe really expanding ever faster and faster?

  6. Trends in the development of large area photon detectors for Cherenkov light imaging applications

    CERN Document Server

    Nappi, E

    2003-01-01

    Since the successful operations of hi-tech devices at OMEGA, DELPHI and SLD, the technique of Cherenkov light imaging has gone through an impressive and fruitful evolution driven by the conception of novel large area photon detectors. The well-assessed potentialities of thin CsI films, employed as reflective photoconverters in gas counters operated at atmospheric pressure, will be compared with the promising features of hybrid and multianode vacuum photomultipliers. Recently proposed single-photon gaseous detectors based on GEMs will also be reviewed.

  7. Solar panels as air Cherenkov detectors for extremely high energy cosmic rays

    CERN Document Server

    Cecchini, S; Esposti, L D; Giacomelli, G; Guerra, M; Lax, I; Mandrioli, G; Parretta, A; Sarno, A; Schioppo, R; Sorel, M; Spurio, M

    2000-01-01

    Increasing interest towards the observation of the highest energy cosmic rayshas motivated the development of new detection techniques. The properties ofthe Cherenkov photon pulse emitted in the atmosphere by these very rareparticles indicate low-cost semiconductor detectors as good candidates fortheir optical read-out. The aim of this paper is to evaluate the viability of solar panels for thispurpose. The experimental framework resulting from measurements performed withsuitably-designed solar cells and large conventional photovoltaic areas ispresented. A discussion on the obtained and achievable sensitivities follows.

  8. Cherenkov wakefield excitation by relativistic electron beams in plasma channels

    Science.gov (United States)

    Wang, Tianhong; Khudik, Vladimir; Shvets, Gennday

    2017-10-01

    We report on our theoretical investigations of Cherenkov radiation excited by relativistic electron bunches propagating in plasma channels and in polaritonic channels. Two surface plasmons (SPs) modes of the radiation are analyzed: the longitudinal (accelerating) and the transverse (deflecting) ones. Both form Cherenkov cones that are different in the magnitude of the cone angle and the central frequency. We show that the Cherenkov field profile change dramatically depending on the driver velocity and the channel size, and the longitudinal mode forms a reversed Cherenkov radiation cone due to the negative group velocity for sufficiently small air gaps. In addition, we find that when the channel surface is corrugated, a strong deflecting wake is excited by a relativistic electron bunch. A trailing electron bunch experiencing this wake is forced to undergo betatron oscillations and thus to emit radiation. Numerical simulation showed that intense x-ray radiation can be generated.

  9. Constraint on ghost-free bigravity from gravitational Cherenkov radiation

    CERN Document Server

    Kimura, Rampei; Yamamoto, Kazuhiro; Yamashita, Yasuho

    2016-01-01

    We investigate gravitational Cherenkov radiation in a healthy branch of background solutions in the ghost-free bigravity model. In this model, because of the modification of dispersion relations, each polarization mode can possess subluminal phase velocities, and the gravitational Cherenkov radiation could be potentially emitted from a relativistic particle. In the present paper, we derive conditions for the process of the gravitational Cherenkov radiation to occur and estimate the energy emission rate for each polarization mode. We found that the gravitational Cherenkov radiation emitted even from an ultrahigh energy cosmic ray is sufficiently suppressed for the graviton's effective mass less than $100\\,{\\rm eV}$, and the bigravity model with dark matter coupled to the hidden metric is therefore consistent with observations of high energy cosmic rays.

  10. Cherenkov and scintillation light separation in organic liquid scintillators

    Science.gov (United States)

    Caravaca, J.; Descamps, F. B.; Land, B. J.; Yeh, M.; Orebi Gann, G. D.

    2017-12-01

    The CHErenkov/Scintillation Separation experiment (CHESS) has been used to demonstrate the separation of Cherenkov and scintillation light in both linear alkylbenzene (LAB) and LAB with 2 g/L of PPO as a fluor (LAB/PPO). This is the first successful demonstration of Cherenkov light detection from the more challenging LAB/PPO cocktail and improves on previous results for LAB. A time resolution of 338± 12 ps FWHM results in an efficiency for identifying Cherenkov photons in LAB/PPO of 70 ± 3 % and 63± 8% for time- and charge-based separation, respectively, with scintillation contamination of 36± 5% and 38± 4%. LAB/PPO data is consistent with a rise time of τ _r=0.72± 0.33 ns.

  11. TORCH: Time of Flight Identification with Cherenkov Radiation

    CERN Document Server

    Charles, M J

    2011-01-01

    TORCH is a time-of-flight detector concept using Cherenkov light to provide charged particle identification up to 10 GeV/c. The concept and design are described and performance in simulation is quantified.

  12. Vavilov-Cherenkov and Synchrotron Radiation Foundations and Applications

    CERN Document Server

    Afanasiev, G. N

    2005-01-01

    The theory of the Vavilov-Cherenkov radiation observed by Cherenkov in 1934 was created by Tamm, Frank and Ginsburg who associated the observed blue light with the uniform charge motion of a charge at a velocity greater than the velocity of light in the medium. On the other hand, Vavilov, Cherenkov's teacher, attributed the observed blue light to the deceleration of electrons. This has given rise to the appearance of papers in which the radiation of a charge uniformly moving in a finite space interval was related to the Bremsstrahlung arising at the end points of the motion interval. This monograph is intended for students of the third year and higher, for postgraduates, for professional scientists (both experimentalists and theoreticians) dealing with Vavilov-Cherenkov and synchrotron radiation. An acquaintance with the three volumes of the Landau and Lifshitz course (Quantum Mechanics, Classical Field Theory and Macroscopic Electrodynamics) is sufficient for understanding the text.

  13. SNAP telescope

    Energy Technology Data Exchange (ETDEWEB)

    Lampton, Michael L.; Akerlof, C.W.; Aldering, G.; Amanullah, R.; Astier, P.; Barrelet, E.; Bebek, C.; Bergstrom, L.; Bercovitz, J.; Bernstein, G.; Bester, M.; Bonissent, A.; Bower, C.; Carithers Jr., W.C.; Commins, E.D.; Day, C.; Deustua, S.E.; DiGennaro, R.; Ealet, A.; Ellis,R.S.; Eriksson, M.; Fruchter, A.; Genat, J.-F.; Goldhaber, G.; Goobar,A.; Groom, D.; Harris, S.E.; Harvey, P.R.; Heetderks, H.D.; Holland,S.E.; Huterer, D.; Karcher, A.; Kim, A.G.; Kolbe, W.; Krieger, B.; Lafever, R.; Lamoureux, J.; Levi, M.E.; Levin, D.S.; Linder, E.V.; Loken,S.C.; Malina, R.; Massey, R.; McKay, T.; McKee, S.P.; Miquel, R.; Mortsell, E.; Mostek, N.; Mufson, S.; Musser, J.; Nugent, P.; Oluseyi,H.; Pain, R.; Palaio, N.; Pankow, D.; Perlmutter, S.; Pratt, R.; Prieto,E.; Refregier, A.; Rhodes, J.; Robinson, K.; Roe, N.; Sholl, M.; Schubnell, M.; Smadja, G.; Smoot, G.; Spadafora, A.; Tarle, G.; Tomasch,A.; von der Lippe, H.; Vincent, R.; Walder, J.-P.; Wang, G.; Wang, G.

    2002-07-29

    The SuperNova/Acceleration Probe (SNAP) mission will require a two-meter class telescope delivering diffraction limited images spanning a one degree field in the visible and near infrared wavelength regime. This requirement, equivalent to nearly one billion pixel resolution, places stringent demands on its optical system in terms of field flatness, image quality, and freedom from chromatic aberration. We discuss the advantages of annular-field three-mirror anastigmat (TMA) telescopes for applications such as SNAP, and describe the features of the specific optical configuration that we have baselined for the SNAP mission. We discuss the mechanical design and choice of materials for the telescope. Then we present detailed ray traces and diffraction calculations for our baseline optical design. We briefly discuss stray light and tolerance issues, and present a preliminary wavefront error budget for the SNAP Telescope. We conclude by describing some of tasks to be carried out during the upcoming SNAP research and development phase.

  14. Space Telescopes

    Science.gov (United States)

    Rigby, Jane R.

    2011-01-01

    The science of astronomy depends on modern-day temples called telescopes. Astronomers make pilgrimages to remote mountaintops where these large, intricate, precise machines gather light that rains down from the Universe. Bit, since Earth is a bright, turbulent planet, our finest telescopes are those that have been launched into the dark stillness of space. These space telescopes, named after heroes of astronomy (Hubble, Chandra, Spitzer, Herschel), are some of the best ideas our species has ever had. They show us, over 13 billion years of cosmic history, how galaxies and quasars evolve. They study planets orbiting other stars. They've helped us determine that 95% of the Universe is of unknown composition. In short, they tell us about our place in the Universe. The next step in this journey is the James Webb Space Telescope, being built by NASA, Europe, and Canada for a 2018 launch; Webb will reveal the first galaxies that ever formed.

  15. Sensitivity of the High Altitude Water Cherenkov Experiment to observe Gamma-Ray Bursts

    Science.gov (United States)

    González, M. M.

    Ground based telescopes have marginally observed very high energy emission (>100GeV) from gamma-ray bursts(GRB). For instance, Milagrito observed GRB970417a with a significance of 3.7 sigmas over the background. Milagro have not yet observed TeV emission from a GRB with its triggered and untriggered searches or GeV emission with a triggered search using its scalers. These results suggest the need of new observatories with higher sensitivity to transient sources. The HAWC (High Altitute Water Cherenkov) observatory is proposed as a combination of the Milagro tecnology with a very high altitude (>4000m over see level) site. The expected HAWC sensitivity for GRBs is at least >10 times the Milagro sensitivity. In this work HAWC sensitivity for GRBs is discussed for different detector configurations such as altitude, distance between PMTs, depth under water of PMTs, number of PMTs required for a trigger, etc.

  16. Space Telescopes

    Science.gov (United States)

    2010-01-01

    Proc 6317:OT1–OT9 Serlemitsos PJ, Jahota L, Soong Y (plus 14 authors) (1995) The X-ray telescope on board ASCA. Pub Astron Soc Jap 47:105–114...Serlemitsos PJ, Soong Y, Chan K-W (plus 31 authors) (2007) The X-ray telescope on board Suzaku. Pub Astron Soc Jap 59:9–21 Shimizu T (2004) Solar-B solar

  17. Status, performance and scientific highlights from the MAGIC telescope system

    Energy Technology Data Exchange (ETDEWEB)

    Doert, Marlene [Technische Universitaet Dortmund (Germany); Ruhr-Universitaet Bochum (Germany); Collaboration: MAGIC-Collaboration

    2015-07-01

    The MAGIC telescopes are a system of two 17 m Imaging Air Cherenkov Telescopes, which are located at 2200 m above sea level at the Roque de Los Muchachos Observatory on the Canary Island of La Palma. In this presentation, we report on recent scientific highlights gained from MAGIC observations in the galactic and the extragalactic regime. We also present the current status and performance of the MAGIC system after major hardware upgrades in the years 2011 to 2014 and give an overview of future plans.

  18. The South Pole Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Ruhl, J.E.; Ade, P.A.R.; Carlstrom, J.E.; Cho, H.M.; Crawford,T.; Dobbs, M.; Greer, C.H.; Halverson, N.W.; Holzapfel, W.L.; Lanting,T.M.; Lee, A.T.; Leitch, E.M.; Leong, J.; Lu, W.; Lueker, M.; Mehl, J.; Meyer, S.S.; Mohr, J.J.; Padin, S.; Plagge, T.; Pryke, C.; Runyan, M.C.; Schwan, D.; Sharp, M.K.; Spieler, H.; Staniszewski, Z.; Stark, A.A.

    2004-11-04

    A new 10 meter diameter telescope is being constructed for deployment at the NSF South Pole research station. The telescope is designed for conducting large-area millimeter and sub-millimeter wave surveys of faint, low contrast emission, as required to map primary and secondary anisotropies in the cosmic microwave background. To achieve the required sensitivity and resolution, the telescope design employs an off-axis primary with a 10 m diameter clear aperture. The full aperture and the associated optics will have a combined surface accuracy of better than 20 microns rms to allow precision operation in the submillimeter atmospheric windows. The telescope will be surrounded with a large reflecting ground screen to reduce sensitivity to thermal emission from the ground and local interference. The optics of the telescope will support a square degree field of view at 2mm wavelength and will feed a new 1000-element micro-lithographed planar bolometric array with superconducting transition-edge sensors and frequency-multiplexed readouts. The first key project will be to conduct a survey over 4000 degrees for galaxy clusters using the Sunyaev-Zeldovich Effect. This survey should find many thousands of clusters with a mass selection criteria that is remarkably uniform with redshift. Armed with redshifts obtained from optical and infrared follow-up observations, it is expected that the survey will enable significant constraints to be placed on the equation of state of the dark energy.

  19. The ring imaging Cherenkov detector of DELPHI

    Energy Technology Data Exchange (ETDEWEB)

    Adam, W.; Anassontzis, E.G.; Albrecht, E.; Ambec, I.; Apeldoorn, G. van; Arnoud, Y.; Aubret, C.; Augustinus, A.; Baillon, P.; Barnoux, C.; Battaglia, M.; Berggren, M.; Bloch, D.; Botner, O.; Bourdarios, C.; Bruemmer, N.; Brunet, J.M.; Budziak, A.P.; Buys, A.; Caloba, L.P.; Carecchio, P.; Carrie, P.; Cavalli, P.; Cereseto, R.; Cerutti, G.; Chevry, M.; Christophel, E.; Dahl-Jensen, E.; D' Almagne, B.; Dam, P.; Dam, P. van; Damgaard, G.; Davenport, M.; Dolbeau, J.; Dracos, M.; Dris, M.; Koning, N. de; De la Vega, A.S.; Dimitriou, N.; Eek, L.O.; Ekeloef, T.; Erikson, J.; Engel, J.P.; Evers, G.; Fassouliotis, D.; Filippas, T.A.; Florek, A.; Florek, B.; Fokitis, E.; Fontanelli, F.; Fontenille, A.; Fraissard, D.; Galuszka, K.; Garcia, J.; Gaumann, E.; Gazis, E.; Goret, B.; Gracco, V.; Guglielmi, L.; Hahn, F.; Haider, S.; Hallgren, A.; Hao, W.; Henkes, T.; Honore, P.F.; Huet, K.; Ioannou, P.; Johansson, H.; Juillot, P.; Kalkanis, G.; Karvelas, E.; Katsanevas, S.; Katsoufis, E.; Kindblom, P.; Kj

    1994-04-01

    The ring imaging Cherenkov detector system in the DELPHI experiment at the Large Electron-Positron storage ring at CERN, is designed to do particle identification over most of the solid angle in the momentum range from [approx] 2 GeV/c to [approx] 40 GeV/c. Two radiator media are used to cover the momentum range; (i) a 1 cm layer of liquid C[sub 6]F[sub 14], and (ii) a volume filled with gaseous C[sub 5]F[sub 12] or C[sub 4]F[sub 10]. Photosensitive time projection chambers record the conversion points of the ultraviolet photons produced in both radiator systems. The total active area is [approx] 30 m[sup 2] in the barrel region and [approx] 8 m[sup 2] in the two endcaps. The design of the detector systems is described in this paper. We will also report performance figures and compare them to simulation studies. (orig.)

  20. Experiment to demonstrate separation of Cherenkov and scintillation signals

    Science.gov (United States)

    Caravaca, J.; Descamps, F. B.; Land, B. J.; Wallig, J.; Yeh, M.; Orebi Gann, G. D.

    2017-05-01

    The ability to separately identify the Cherenkov and scintillation light components produced in scintillating mediums holds the potential for a major breakthrough in neutrino detection technology, allowing development of a large, low-threshold, directional detector with a broad physics program. The CHESS (CHErenkov/Scintillation Separation) experiment employs an innovative detector design with an array of small, fast photomultiplier tubes and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillating medium based on photon hit time and detected photoelectron density. This paper describes the physical properties and calibration of CHESS along with first results. The ability to reconstruct Cherenkov rings is demonstrated in a water target, and a time precision of 338 ±12 ps FWHM is achieved. Monte Carlo-based predictions for the ring imaging sensitivity with a liquid scintillator target predict an efficiency for identifying Cherenkov hits of 94 ±1 % and 81 ±1 % in pure linear alkyl benzene (LAB) and LAB loaded with 2 g/L of a fluor, PPO, respectively, with a scintillation contamination of 12 ±1 % and 26 ±1 % .

  1. CLASSiC: Cherenkov light detection with silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

    Adriani, Oscar [Physics Dept., University of Florence, Via Sansone 1, 50019, Sesto Fiorentino (Italy); INFN dep. of Florence, Via Bruno Rossi 1, 50019 Sesto Fiorentino (Italy); Albergo, Sebastiano [Physics Dept., University of Catania, Via Santa Sofia 64, 95123 Catania (Italy); INFN dep. of Catania, Via Santa Sofia 64, 95123 Catania (Italy); D' Alessandro, Raffaello [Physics Dept., University of Florence, Via Sansone 1, 50019, Sesto Fiorentino (Italy); INFN dep. of Florence, Via Bruno Rossi 1, 50019 Sesto Fiorentino (Italy); Lenzi, Piergiulio [INFN dep. of Florence, Via Bruno Rossi 1, 50019 Sesto Fiorentino (Italy); Sciuto, Antonella [CNR-IMM, VIII Strada 5, Zona Industriale, Catania (Italy); INFN dep. of Catania, Via Santa Sofia 64, 95123 Catania (Italy); Starodubtsev, Oleksandr [INFN dep. of Florence, Via Bruno Rossi 1, 50019 Sesto Fiorentino (Italy); Tricomi, Alessia [Physics Dept., University of Catania, Via Santa Sofia 64, 95123 Catania (Italy); INFN dep. of Catania, Via Santa Sofia 64, 95123 Catania (Italy)

    2017-02-11

    We present the CLASSiC R&D for the development of a silicon carbide (SiC) based avalanche photodiode for the detection of Cherenkov light. SiC is a wide-bandgap semiconductor material, which can be used to make photodetectors that are insensitive to visible light. A SiC based light detection device has a peak sensitivity in the deep UV, making it ideal for Cherenkov light. Moreover, the visible blindness allows such a device to disentangle Cherenkov light and scintillation light in all those materials that scintillate above 400 nm. Within CLASSiC, we aim at developing a device with single photon sensitivity, having in mind two main applications. One is the use of the SiC APD in a new generation ToF PET scanner concept, using the Cherenov light emitted by the electrons following 511 keV gamma ray absorption as a time-stamp. Cherenkov is intrinsically faster than scintillation and could provide an unprecedentedly precise time-stamp. The second application concerns the use of SiC APD in a dual readout crystal based hadronic calorimeter, where the Cherenkov component is used to measure the electromagnetic fraction on an event by event basis. We will report on our progress towards the realization of the SiC APD devices, the strategies that are being pursued toward the realization of these devices and the preliminary results on prototypes in terms of spectral response, quantum efficiency, noise figures and multiplication.

  2. Cherenkov Radiation Control via Self-accelerating Wave-packets.

    Science.gov (United States)

    Hu, Yi; Li, Zhili; Wetzel, Benjamin; Morandotti, Roberto; Chen, Zhigang; Xu, Jingjun

    2017-08-18

    Cherenkov radiation is a ubiquitous phenomenon in nature. It describes electromagnetic radiation from a charged particle moving in a medium with a uniform velocity larger than the phase velocity of light in the same medium. Such a picture is typically adopted in the investigation of traditional Cherenkov radiation as well as its counterparts in different branches of physics, including nonlinear optics, spintronics and plasmonics. In these cases, the radiation emitted spreads along a "cone", making it impractical for most applications. Here, we employ a self-accelerating optical pump wave-packet to demonstrate controlled shaping of one type of generalized Cherenkov radiation - dispersive waves in optical fibers. We show that, by tuning the parameters of the wave-packet, the emitted waves can be judiciously compressed and focused at desired locations, paving the way to such control in any physical system.

  3. On the reconstruction of Cherenkov rings from aerogel radiators

    CERN Document Server

    Cunha, J P D; Lopes, M I

    2000-01-01

    An event reconstruction algorithm to analyze Cherenkov rings in a Ring Imaging Cherenkov (RICH) detector is considered and the results of a Monte Carlo simulation are discussed. It is demonstrated that aerogel radiators can be used in RICH detectors despite the Rayleigh scattering of light if filtered by a pattern recognition program. The velocity of the particle radiating Cherenkov light, beta, is determined by a fit to the photon hit pattern, assuming prior momentum measurement by a tracking system. The charge of the particle, z, is obtained from the collected light. The results show that, for the geometries considered, velocity resolutions sigma subbeta/beta approx =1x10 sup - sup 3 and charge resolutions sigma sub Z /Z approx =10% can be achieved for 5 GeV/c protons and a 2 cm thick aerogel radiator.

  4. The Cherenkov correlated timing detector beam test results from quartz and acrylic bars

    CERN Document Server

    Sugaya, Y; Yoshimura, Y; Kanda, S; Olsen, S; Ueno, K; Varner, G S; Bergfeld, T; Bialek, J J; Lorenc, J; Palmer, M; Rudnick, G; Selen, M; Auran, T; Boyer, V; Honscheid, K; Tamura, N; Yoshimura, K; Lü, C; Marlow, D R; Mindas, C R; Prebys, E J; Asai, M; Kimura, A; Hayashi, S

    1995-01-01

    Several prototypes of a Cherenkov Correlated Timing (CCT) Detector have been tested at the KEK-PS test beam line. We describe the results for Cherenkov light yields and timing characteristics from quartz and acrylic bar prototypes. A Cherenkov angle resolution is found to be 15 mrad at a propagation distance of 100 cm with a 2 cm thick quartz bar prototype.

  5. New air Cherenkov light detectors to study mass composition of cosmic rays with energies above knee region

    Energy Technology Data Exchange (ETDEWEB)

    Tsunesada, Yoshiki, E-mail: tsunesada@cr.phys.titech.ac.jp [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Katsuya, Ryoichi, E-mail: katsuya@cr.phys.titech.ac.jp [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Mitsumori, Yu; Nakayama, Keisuke; Kakimoto, Fumio; Tokuno, Hisao [Graduate School of Science and Engineering, Tokyo Institute of Technology, Meguro, Tokyo 152-8550 Japan (Japan); Tajima, Norio [RIKEN, Wako, Saitama 351-0198 (Japan); Miranda, Pedro; Salinas, Juan; Tavera, Wilfredo [Instituto de Investigaciones Físicas, Universidad Mayor de San Andrés, La Paz (Bolivia, Plurinational State of)

    2014-11-01

    We have installed a hybrid detection system for air showers generated by cosmic rays with energies greater than 3×10{sup 15}eV at Mount Chacaltaya (5200 m above the sea level), in order to study the mass composition of cosmic rays above the knee region. This detection system comprises an air shower array with 49 scintillation counters in an area of 500 m×650 m, and seven new Cherenkov light detectors installed in a radial direction from the center of the air shower array with a separation of 50 m. It is known that the longitudinal development of a particle cascade in the atmosphere strongly depends on the type of the primary nucleus, and an air shower initiated by a heavier nucleus develops faster than that by a lighter primary of the same energy, because of the differences in the interaction cross-section and the energy per nucleon. This can be measured by detecting the Cherenkov radiation emitted from charged particles in air showers at higher altitudes. In this paper we describe the design and performance of our new non-imaging Cherenkov light detectors at Mount Chacaltaya that are operated in conjunction with the air shower array. The arrival directions and energies of air showers are determined by the shower array, and information about the primary masses is obtained from the Cherenkov light data including the time profiles and lateral distributions. The detector consists of photomultiplier tube (PMT), high-speed ADCs, other control modules, and data storage device. The Cherenkov light signals from an air shower are typically 10–100 ns long, and the waveforms are digitized with a sampling frequency of 1 GHz and recorded in situ without long-distance analog signal transfers. All the Cherenkov light detectors record their time-series data by receiving a triggering signal transmitted from the trigger module of the air shower array, which is fired by a coincidence of shower signals in four neighboring scintillation counters. The optical characteristics of the

  6. Cherenkov Radiation from Jets in Heavy-ion Collisions

    Energy Technology Data Exchange (ETDEWEB)

    Koch, Volker; Majumder, Abhijit; Wang, Xin-Nian

    2005-07-26

    The possibility of Cherenkov-like gluon bremsstrahlung in dense matter is studied. We point out that the occurrence of Cherenkov radiation in dense matter is sensitive to the presence of partonic bound states. This is illustrated by a calculation of the dispersion relation of a massless particle in a simple model in which it couples to two different massive resonance states. We further argue that detailed spectroscopy of jet correlations can directly probe the index of refraction of this matter, which in turn will provide information about the mass scale of these partonic bound states.

  7. Use of silica aerogel for Cherenkov radiation counter

    CERN Document Server

    Bourdinaud, M; Thévenin, J C

    1976-01-01

    The Cherenkov light collection from silica aerogel has been studied in two types of counters. In the first counter a mirror was used to collect the light and in the latter a diffusing box surrounded the aerogel sample. The optical characteristics of the aerogel (refractive index 1.06) and the diffusion coefficients of different diffusing materials have been measured. It is thus possible to build Cherenkov counters with silica aerogel for a high energy physics experiment at the CERN Intersecting Storage Rings. (4 refs).

  8. A new air-Cherenkov array at the South Pole

    CERN Document Server

    Dickinson, J E; Hart, S P; Hill, G C; Hinton, J A; Lloyd-Evans, J; Potter, D; Pryke, C L; Rochester, K; Schwarz, R; Watson, A A

    2000-01-01

    VULCAN comprises a 9 element array of air-Cherenkov radiation detectors established at the South Pole. VULCAN operates in coincidence with the air-shower array SPASE-2 and the two Antarctic Muon And Neutrino Detector Arrays, AMANDA A and B, supplementing the data gathered by these instruments with a measurement of the lateral distribution of air-Cherenkov light from extensive air-showers. An overview of the aims and methods of the whole coincidence experiment (SPASE-2, VULCAN and AMANDA) can be found in an accompanying paper (Dickinson et al., Nucl. Instr. and Meth. A (1999), to be published).

  9. Light-weight spherical mirrors for Cherenkov detectors

    CERN Document Server

    Cisbani, E; Colilli, S; Crateri, R; Cusanno, F; De Leo, R; Fratoni, R; Frullani, S; Garibaldi, F; Giuliani, F; Gricia, M; Iodice, M; Iommi, R; Lagamba, L; Lucentini, M; Mostarda, A; Nappi, E; Pierangeli, L; Santavenere, F; Urciuoli, G M; Vernin, P

    2003-01-01

    Light-weight spherical mirrors have been appositely designed and built for the gas threshold Cherenkov detectors of the two Hall A spectrometers. The mirrors are made of a 1 mm thick aluminized plexiglass sheet, reinforced by a rigid backing consisting of a phenolic honeycomb sandwiched between two carbon fiber mats epoxy glued. The produced mirrors have a thickness equivalent to 0.55% of radiation length, and an optical slope error of about 5.5 mrad. These characteristics make these mirrors suitable for the implementation in Cherenkov threshold detectors. Ways to improve the mirror features are also discussed in view of their possible employment in RICH detectors.

  10. Atmospheric Sciences Meet Astronomy: Mutual Benefits from two Different Approaches

    Science.gov (United States)

    Kausch, Wolfgang; Noll, Stefan; Kimeswenger, Stefan; Kondrak, Matthias; Unterguggenberger, Stefanie; Przybilla, Norbert; Lakićević, Maša; Zeilinger, Werner

    2016-04-01

    ENVISAT (MIPAS instrument), Aura (MLS), and TIMED (SABER), and modelled data from the Global Data Assimilation System (GDAS), and the ERA/MACC reanalysis from the European Centre for Medium-Range Weather Forecasts (ECMWF). In this presentation we give an overview on our methods to link these various data, the impact/application of these data on atmospheric sciences and observations with classical and future astro-particle Cherenkov telescopes, and present recent results.

  11. Primary gamma ray selection in a hybrid timing/imaging Cherenkov array

    Directory of Open Access Journals (Sweden)

    Postnikov E.B.

    2017-01-01

    Full Text Available This work is a methodical study on hybrid reconstruction techniques for hybrid imaging/timing Cherenkov observations. This type of hybrid array is to be realized at the gamma-observatory TAIGA intended for very high energy gamma-ray astronomy (> 30 TeV. It aims at combining the cost-effective timing-array technique with imaging telescopes. Hybrid operation of both of these techniques can lead to a relatively cheap way of development of a large area array. The joint approach of gamma event selection was investigated on both types of simulated data: the image parameters from the telescopes, and the shower parameters reconstructed from the timing array. The optimal set of imaging parameters and shower parameters to be combined is revealed. The cosmic ray background suppression factor depending on distance and energy is calculated. The optimal selection technique leads to cosmic ray background suppression of about 2 orders of magnitude on distances up to 450 m for energies greater than 50 TeV.

  12. Long term biological developments in water Cherenkov detector media

    Energy Technology Data Exchange (ETDEWEB)

    Venturini, M. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Filevich, A., E-mail: filevich@tandar.cnea.gov.ar [Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Pizarro, R.; Ibanez, J. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Bauleo, P. [Fort Collins, CO (United States); Rodriguez Martino, J. [Pierre Auger Observatory, Malarguee, Mendoza (Argentina)

    2011-12-11

    Fourteen years ago, studies on bacteria growing in clean water were made in order to assess the hazard imposed by a possible expansion of bacteria population in the water tanks of the Pierre Auger Observatory Cherenkov detectors. In 1999 TANGO Array, a reduced-size unitary cell, composed of four water Cherenkov detectors, was constructed at the TANDAR campus of the Atomic Energy Commission, in Buenos Aires, to be used as a working model of the proposed surface array. TANGO Array ran for one year observing energy, intensity, and arrival directions of cosmic rays at sea level. Nine years after it was decommissioned, the water tanks configuring the Cherenkov detectors are still kept closed. In May 2009 water and liner samples from these tanks were collected to determine eventual long term bacteria growth in the internal detector environment, which is very similar to those of the detectors installed in the Malarguee Site. In the present note we report the results of the bacteriological study performed on the samples obtained from the TANGO Array detector tanks. Cultivable, long time surviving, bacterial species were identified, both in the water mass and on the liner surface, and the light transmission in water at the relevant Cherenkov wavelength was studied. An upper limit of possible interferences caused by bacteria is estimated.

  13. Optical Cherenkov radiation in ultrafast cascaded second-harmonic generation

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Zhou, Binbin

    2010-01-01

    We show through theory and numerics that when few-cycle femtosecond solitons are generated through cascaded (phase-mismatched) second-harmonic generation, these broadband solitons can emit optical Cherenkov radiation in the form of linear dispersive waves located in the red part of the spectrum. ...

  14. Extension of Cherenkov Light LDF Parametrization for Tunka and ...

    Indian Academy of Sciences (India)

    The Cherenkov light Lateral Distribution Function (LDF) from particles initiated Extensive Air Showers (EAS) with ultrahigh energies ( > 1016 eV) was simulated using CORSIKA program for configuration of Tunka and Yakutsk EAS arrays for different primary particles (p, Fe and O2) and different zenith angles.

  15. Extension of Cherenkov Light LDF Parametrization for Tunka and ...

    Indian Academy of Sciences (India)

    by depending on the Breit–Wigner function, sets of approximating functions were constructed for different primary particles and different zenith angles. The extrap- olation of the Cherenkov light lateral distribution function parametrization of the obtained data with CORSIKA program for the energies, E > 1016 eV is obtained.

  16. Cherenkov luminescence measurements with digital silicon photomultipliers: a feasibility study

    Energy Technology Data Exchange (ETDEWEB)

    Ciarrocchi, Esther; Belcari, Nicola; Guerra, Alberto Del [Department of Physics, University of Pisa, Pisa (Italy); INFN, section of Pisa, Pisa (Italy); Cherry, Simon R. [Department of Biomedical Engineering, University of California, Davis, CA (United States); Lehnert, Adrienne; Hunter, William C. J.; McDougald, Wendy; Miyaoka, Robert S.; Kinahan, Paul E. [Department of Radiology, University of Washington, Seattle, WA (United States)

    2015-11-16

    A feasibility study was done to assess the capability of digital silicon photomultipliers to measure the Cherenkov luminescence emitted by a β source. Cherenkov luminescence imaging (CLI) is possible with a charge coupled device (CCD) based technology, but a stand-alone technique for quantitative activity measurements based on Cherenkov luminescence has not yet been developed. Silicon photomultipliers (SiPMs) are photon counting devices with a fast impulse response and can potentially be used to quantify β-emitting radiotracer distributions by CLI. In this study, a Philips digital photon counting (PDPC) silicon photomultiplier detector was evaluated for measuring Cherenkov luminescence. The PDPC detector is a matrix of avalanche photodiodes, which were read one at a time in a dark count map (DCM) measurement mode (much like a CCD). This reduces the device active area but allows the information from a single avalanche photodiode to be preserved, which is not possible with analog SiPMs. An algorithm to reject the noisiest photodiodes and to correct the measured count rate for the dark current was developed. The results show that, in DCM mode and at (10–13) °C, the PDPC has a dynamic response to different levels of Cherenkov luminescence emitted by a β source and transmitted through an opaque medium. This suggests the potential for this approach to provide quantitative activity measurements. Interestingly, the potential use of the PDPC in DCM mode for direct imaging of Cherenkov luminescence, as a opposed to a scalar measurement device, was also apparent. We showed that a PDPC tile in DCM mode is able to detect and image a β source through its Cherenkov radiation emission. The detector’s dynamic response to different levels of radiation suggests its potential quantitative capabilities, and the DCM mode allows imaging with a better spatial resolution than the conventional event-triggered mode. Finally, the same acquisition procedure and data processing could

  17. Proxy magnetometry with the Dutch Open Telescope

    NARCIS (Netherlands)

    Rutten, R.J.; Hammerschlag, R.H.; Sütterlin, P.; Bettonvil, F.C.M.

    1999-01-01

    Superb movies from the Dutch Open Telescope (DOT) on La Palma have proven the validity of the open concept of this innovative telescope for high-resolution imaging of the solar atmosphere. A five- camera speckle-burst registration system is being installed that should permit consistent and

  18. Solar Magnetometry with the dutch open telescope

    NARCIS (Netherlands)

    Rutten, R.J.; Hammerschlag, R.H.; Sütterlin, P.; Bettonvil, F.C.M.; Zalm, E.B.J. van der

    2001-01-01

    The Dutch Open Telescope (DOT) has become op- erational at the Roque de los Muchachos Observa- tory on La Palma. The rst image sequences taken with this innovative telescope demonstrate its capa- bility for tomographic high-resolution imaging of the magnetic topology of the solar atmosphere up

  19. Hubble Space Telescope observations of Europa in and out of eclipse

    Science.gov (United States)

    Sparks, W.B.; McGrath, M.; Hand, K.; Ford, H.C.; Geissler, P.; Hough, J.H.; Turner, E.L.; Chyba, C.F.; Carlson, R.; Turnbull, M.

    2010-01-01

    Europa is a prime target for astrobiology and has been prioritized as the next target for a National Aeronautics and Space Administration flagship mission. It is important, therefore, that we advance our understanding of Europa, its ocean and physical environment as much as possible. Here, we describe observations of Europa obtained during its orbital eclipse by Jupiter using the Hubble Space Telescope. We obtained Advanced Camera for Surveys Solar Blind Channel far ultraviolet low-resolution spectra that show oxygen line emission both in and out of eclipse. We also used the Wide-Field and Planetary Camera-2 and searched for broad-band optical emission from fluorescence of the surface material, arising from the very high level of incident energetic particle radiation on ices and potentially organic substances. The high-energy particle radiation at the surface of Europa is extremely intense and is responsible for the production of a tenuous oxygen atmosphere and associated FUV line emission. Approximately 50% of the oxygen emission lasts at least a few hours into the eclipse. We discuss the detection limits of the optical emission, which allow us to estimate the fraction of incident energy reradiated at optical wavelengths, through electron-excited emission, Cherenkov radiation in the ice and fluorescent processes. ?? 2010 Cambridge University Press.

  20. Holographic telescope

    Science.gov (United States)

    Odhner, Jefferson E.

    2016-07-01

    Holographic optical elements (HOEs) work on the principal of diffraction and can in some cases replace conventional optical elements that work on the principal of refraction. An HOE can be thinner, lighter, can have more functionality, and can be lower cost than conventional optics. An HOE can serve as a beam splitter, spectral filter, mirror, and lens all at the same time. For a single wavelength system, an HOE can be an ideal solution but they have not been widely accepted for multispectral systems because they suffer from severe chromatic aberration. A refractive optical system also suffers from chromatic aberration but it is generally not as severe. To color correct a conventional refractive optical system, a flint glass and a crown glass are placed together such that the color dispersion of the flint and the crown cancel each other out making an achromatic lens (achromat) and the wavelengths all focus to the same point. The color dispersion of refractive lenses and holographic lenses are opposite from each other. In a diffractive optical system, long wavelengths focus closer (remember for HOEs: RBM "red bends more") than nominal focus while shorter wavelengths focus further out. In a refractive optical system, it is just the opposite. For this reason, diffractives can be incorporated into a refractive system to do the color correction and often cut down on the number of optical elements used [1.]. Color correction can also be achieved with an all-diffractive system by combining a holographic optical element with its conjugate. In this way the color dispersion of the first holographic optical element can be cancelled by the color dispersion of the second holographic optic. It is this technique that will be exploited in this paper to design a telescope made entirely of holographic optical elements. This telescope could be more portable (for field operations) the same technique could be used to make optics light enough for incorporation into a UAV.

  1. Optical Properties of the DIRC Fused Silica Cherenkov Radiator

    Energy Technology Data Exchange (ETDEWEB)

    Schwiening, Jochen

    2003-04-30

    The DIRC is a new type of Cherenkov detector that is successfully operating as the hadronic particle identification system for the BABAR experiment at SLAC. The fused silica bars that serve as the DIRC's Cherenkov radiators must transmit the light over long optical pathlengths with a large number of internal reflections. This imposes a number of stringent and novel requirements on the bar properties. This note summarizes a large amount of R&D that was performed both to develop specifications and production methods and to determine whether commercially produced bars could meet the requirements. One of the major outcomes of this R&D work is an understanding of methods to select radiation hard and optically uniform fused silica material. Others include measurement of the wavelength dependency of the internal reflection coefficient, and its sensitivity to surface contaminants, development of radiator support methods, and selection of good optical glue.

  2. Modeling coherent cherenkov radio emissions from high energy electromagnetic showers.

    Energy Technology Data Exchange (ETDEWEB)

    Schoessow, P.

    1998-04-24

    A technique currently under study for the detection of ultrahigh energy cosmic ray neutrinos involves the measurement of radio emissions from the electromagnetic shower generated by the neutrino in a large volume of naturally occurring dielectric such as the Antarctic ice cap or salt domes. The formation of an electron excess in the shower leads to the emission of coherent Cherenkov radiation, an effect similar to the generation of wakefields in dielectric loaded structures. We have used the finite difference time domain (FDTD) wakefield code ARRAKIS to model coherent Cherenkov radiation fields from high energy showers; we present as an example calculations of expected signals in a proof of principle experiment proposed for the Fermilab Main Injector.

  3. Performance test of wavelength-shifting acrylic plastic Cherenkov detector

    CERN Document Server

    Beckford, B; de la Puente, A; Fuji, Y; Futatsukawa, K; Hashimoto, O; Kaneta, M; Kanda, H; Koike, T; Maeda, K; Matsumura, A; Nakamura, S N; Okayasu, Y; Perez, N; Reinhold, J; Shirotori, K; Tamura, H; Tang, L; Tsukada, K

    2010-01-01

    The collection efficiency for Cherenkov light incident on a wavelength shifting plate (WLS) has been determined during a beam test at the Proton Synchrotron facility located in the National Laboratory for High Energy Physics (KEK), Tsukuba, Japan. The experiment was conducted in order to determine the detector's response to photoelectrons converted from photons produced by a fused silica radiator; this allows for an approximation of the detector's quality. The yield of the photoelectrons was measured as a function of the momentum of the incident hadron beam. The yield is proportional to sin2{\\theta}c, where {\\theta}c is the opening angle of the Cherenkov light created. Based on estimations and results from similarly conducted tests, where the collection efficiency was roughly 39%, the experimental result was expected to be around 40% for internally produced light from the WLS. The results of the experiment determined the photon collection response efficiency of the WLS to be roughly 62% for photons created in...

  4. Detection of Cherenkov light emission in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

    Antonello, M.; Arneodo, F.; Badertscher, A.; Baiboussinov, B.; Baldo Ceolin, M.; Battistoni, G.; Bekman, B.; Benetti, P.; Bernardini, E.; Bischofberger, M.; Borio di Tigliole, A.; Brunetti, R.; Bueno, A.; Calligarich, E.; Campanelli, M.; Carpanese, C.; Cavalli, D.; Cavanna, F. E-mail: flavio.cavanna@aquila.infn.it; Cennini, P.; Centro, S.; Cesana, A.; Chen, C.; Chen, D.; Chen, D.B.; Chen, Y.; Cieslik, C.; Cline, D.; Dai, Z.; De Vecchi, C.; Dabrowska, A.; Dolfini, R.; Felcini, M.; Ferrari, A.; Ferri, F.; Ge, Y.; Gibin, D.; Gigli Berzolari, A.; Gil-Botella, I.; Graczyk, K.; Grandi, L.; Guglielmi, A.; He, K.; Holeczek, J.; Huang, X.; Juszczak, C.; Kielczewska, D.; Kisiel, J.; Kozlowski, T.; Laffranchi, M.; Lagoda, J.; Li, Z.; Lu, F.; Ma, J.; Markiewicz, M.; Matthey, C.; Mauri, F.; Mazza, D.; Meng, G.; Messina, M.; Montanari, C.; Muraro, S.; Navas-Concha, S.; Nurzia, G.; Otwinowski, S.; Ouyang, Q.; Palamara, O.; Pascoli, D.; Periale, L.; Piano Mortari, G.B.; Piazzoli, A.; Picchi, P.; Pietropaolo, F.; Polchlopek, W.; Rancati, T.; Rappoldi, A.; Raselli, G.L.; Rico, J.; Rondio, E.; Rossella, M.; Rubbia, A.; Rubbia, C.; Sala, P.; Scannicchio, D.; Segreto, E.; Seo, Y.; Sergiampietri, F.; Sobczyk, J.; Stepaniak, J.; Szarska, M.; Szeptycka, M.; Terrani, M.; Ventura, S.; Vignoli, C.; Wang, H.; Woo, J.; Xu, G.; Xu, Z.; Zalewska, A.; Zalipska, J.; Zhang, C.; Zhang, Q.; Zhen, S.; Zipper, W

    2004-01-11

    Detection of Cherenkov light emission in liquid argon has been obtained with an ICARUS prototype, during a dedicated test run at the Gran Sasso Laboratory external facility. Ionizing tracks from cosmic ray muons crossing the detector active volume have been collected in coincidence with visible light signals from a photo-multiplier (PMT) immersed in liquid argon. A 3D reconstruction of the tracks has been performed exploiting the ICARUS imaging capability. The angular distributions of the tracks triggered by the PMT signals show an evident directionality. By means of a detailed Monte Carlo simulation we show that the geometrical characteristics of the events are compatible with the hypothesis of Cherenkov light emission as the main source of the PMT signals.

  5. Terahertz Cherenkov radiation from ultrafast magnetization in terbium gallium garnet

    Science.gov (United States)

    Gorelov, S. D.; Mashkovich, E. A.; Tsarev, M. V.; Bakunov, M. I.

    2013-12-01

    We report an experimental observation of terahertz Cherenkov radiation from a moving magnetic moment produced in terbium gallium garnet by a circularly polarized femtosecond laser pulse via the inverse Faraday effect. Contrary to some existing theoretical predictions, the polarity of the observed radiation unambiguously demonstrates the paramagnetic, rather than diamagnetic, nature of the ultrafast inverse Faraday effect. From measurements of the radiation field, the Verdet constant in the subpicosecond regime is ˜3-10 times smaller than its table quasistatic value.

  6. Hartmann test of the COMPASS RICH-1 optical telescopes

    CERN Document Server

    Polak, J; Alekseev, M; Angerer, H; Apollonio, M; Birsa, R; Bordalo, P; Bradamante, F; Bressan, A; Busso, L; Chiosso, V M; Ciliberti, P; Colantoni, M L; Costa, S; Dibiase, N; Dafni, T; Dalla Torre, S; Diaz, V; Duic, V; Delagnes, E; Deschamps, H; Eyrich, W; Faso, D; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Gerassimov, S; Giorgi, M; Gobbo, B; Hagemann, R; von Harrach, D; Heinsius, F H; Joosten, R; Ketzer, B; Königsmann, K; Kolosov, V N; Konorov, I; Kramer, D; Kunne, F; Levorato, S; Maggiora, A; Magnon, A; Mann, A; Martin, A; Rebourgeard, P; Mutter, A; Nähle, O; Neyret, D; Nerling, F; Pagano, P; Paul, S; Panebianco, S; Panzieri, D; Pesaro, G; Pizzolotto, C; Menon, G; Rocco, E; Robinet, F; Schiavon, P; Schill, C; Schoenmeier, P; Silva, L; Slunecka, M; Steiger, L; Sozzi, F; Sulc, M; Svec, M; Tessarotto, F; Teufel, A; Wollny, H

    2008-01-01

    The central region of COMPASS RICH-1 has been equipped with a new photon detection system based on MultiAnode PhotoMultiplier Tubes (MAPMT). The Cherenkov photons are focused by an array of 576 fused silica telescopes onto 576 MAPMTs. The quality and positioning of all optical components have been tested by Hartmann method. The validation procedures are described. The quality of the optical concentrators was checked and alignment corrections were made. The upgraded detector showed excellent performances during 2006 data taking.

  7. Status and recent results of the MAGIC telescope system

    Energy Technology Data Exchange (ETDEWEB)

    Fruck, Christian [Max-Planck-Institut fuer Physik, Muenchen (Germany); Collaboration: MAGIC-Collaboration

    2016-07-01

    MAGIC is an instrument for pointed ground-based observations of the gamma-ray sky in the 50 GeV to 80 TeV regime. The two 17 m diameter Imaging Air Cherenkov Telescopes are located on 2200 m a.s.l. at the Roque de los Muchachos Observatory on the Canary island La Palma. We will report the status and recent technical developments of the instrument, highlight the most important scientific results obtained with observations of Galactic and extragalactic objects, and will summarize future plans.

  8. Characterization of Multianode Photomultiplier Tubes for a Cherenkov Detector

    Science.gov (United States)

    Benninghoff, Morgen; Turisini, Matteo; Kim, Andrey; Benmokhtar, Fatiha; Kubarovsky, Valery; Duquesne University Collaboration; Jefferson Lab Collaboration

    2017-09-01

    In the Fall of 2017, Jefferson Lab's CLAS12 (CEBAF Large Acceptance Spectrometer) detector is expecting the addition of a RICH (ring imaging Cherenkov) detector which will allow enhanced particle identification in the momentum range of 3 to 8 GeV/c. RICH detectors measure the velocity of charged particles through the detection of produced Cherenkov radiation and the reconstruction of the angle of emission. The emitted Cherenkov photons are detected by a triangular-shaped grid of 391 multianode photomultiplier tubes (MAPMTs) made by Hamamatsu. The custom readout electronics consist of MAROC (multianode read out chip) boards controlled by FPGA (Field Programmable Gate Array) boards, and adapters used to connect the MAROC boards and MAPMTs. The focus of this project is the characterization of the MAPMTs with the new front end electronics. To perform these tests, a black box setup with a picosecond diode laser was constructed with low and high voltage supplies. A highly automated procedure was developed to acquire data at different combinations of high voltage values, light intensities and readout electronics settings. Future work involves using the collected data in calibration procedures and analyzing that data to resolve the best location for each MAPMT. SULI, NSF.

  9. Hubble Space Telescope-Illustration

    Science.gov (United States)

    1989-01-01

    This illustration depicts a side view of the Hubble Space Telescope (HST). The HST is the product of a partnership between NASA, European Space Agency Contractors, and the international community of astronomers. It is named after Edwin P. Hubble, an American Astronomer who discovered the expanding nature of the universe and was the first to realize the true nature of galaxies. The purpose of the HST, the most complex and sensitive optical telescope ever made, is to study the cosmos from a low-Earth orbit. By placing the telescope in space, astronomers are able to collect data that is free of the Earth's atmosphere. The HST detects objects 25 times fainter than the dimmest objects seen from Earth and provides astronomers with an observable universe 250 times larger than visible from ground-based telescopes, perhaps as far away as 14 billion light-years. The HST views galaxies, stars, planets, comets, possibly other solar systems, and even unusual phenomena such as quasars, with 10 times the clarity of ground-based telescopes. The major elements of the HST are the Optical Telescope Assembly (OTA), the Support System Module (SSM), and the Scientific Instruments (SI). The HST is approximately the size of a railroad car, with two cylinders joined together and wrapped in a silvery reflective heat shield blanket. Wing-like solar arrays extend horizontally from each side of these cylinders, and dish-shaped anternas extend above and below the body of the telescope. The HST was deployed from the Space Shuttle Discovery (STS-31 mission) into Earth orbit in April 1990. The Marshall Space Flight Center had responsibility for design, development, and construction of the HST. The Perkin-Elmer Corporation, in Danbury, Connecticut, developed the optical system and guidance sensors. The Lockheed Missile and Space Company of Sunnyvale, California produced the protective outer shroud and spacecraft systems, and assembled and tested the finished telescope.

  10. Applications of Cherenkov Light Emission for Dosimetry in Radiation Therapy

    Science.gov (United States)

    Glaser, Adam Kenneth

    Since its discovery in the 1930's, the Cherenkov effect has been paramount in the development of high-energy physics research. It results in light emission from charged particles traveling faster than the local speed of light in a dielectric medium. The ability of this emitted light to describe a charged particle's trajectory, energy, velocity, and mass has allowed scientists to study subatomic particles, detect neutrinos, and explore the properties of interstellar matter. However, only recently has the phenomenon been considered in the practical context of medical physics and radiation therapy dosimetry, where Cherenkov light is induced by clinical x-ray photon, electron, and proton beams. To investigate the relationship between this phenomenon and dose deposition, a Monte Carlo plug-in was developed within the Geant4 architecture for medically-oriented simulations (GAMOS) to simulate radiation-induced optical emission in biological media. Using this simulation framework, it was determined that Cherenkov light emission may be well suited for radiation dosimetry of clinically used x-ray photon beams. To advance this application, several novel techniques were implemented to realize the maximum potential of the signal, such as time-gating for maximizing the signal to noise ratio (SNR) and Cherenkov-excited fluorescence for generating isotropic light release in water. Proof of concept experiments were conducted in water tanks to demonstrate the feasibility of the proposed method for two-dimensional (2D) projection imaging, three-dimensional (3D) parallel beam tomography, large field of view 3D cone beam tomography, and video-rate dynamic imaging of treatment plans for a number of common radiotherapy applications. The proposed dosimetry method was found to have a number of unique advantages, including but not limited to its non-invasive nature, water-equivalence, speed, high-resolution, ability to provide full 3D data, and potential to yield data in-vivo. Based on

  11. SOAR Telescope Progress Report

    Science.gov (United States)

    Sebring, T.; Cecil, G.; Krabbendam, V.

    1999-12-01

    The 4.3m SOAR telescope is fully funded and under construction. A partnership between the country of Brazil, NOAO, Michigan State University, and the University of North Carolina at Chapel Hill, SOAR is being designed for high-quality imaging and imaging spectroscopy in the optical and near-IR over a field of view up to 12' diameter. US astronomers outside MSU and UNC will access 30% of the observing time through the standard NOAO TAC process. The telescope is being designed to support remote and synoptic observations. First light is scheduled for July 2002 at Cerro Pachon in Chile, a site with median seeing of 2/3" at 500 nm. The telescope will be operated by CTIO. Corning Inc. has fused the mirror blanks from boules of ULE glass. RSI in Richardson, Texas and Raytheon Optical Systems Inc. in Danbury, Conn. are designing and will fabricate the mount and active optics systems, respectively. The mount supports an instrument payload in excess of 5000 kg, at 2 Nasmyth locations and 3 bent Cass. ports. The mount and facility building have space for a laser to generate an artificial AO guide star. LabVIEW running under the Linux OS on compactPCI hardware has been adopted to control all telescope, detector, and instrument systems. The primary mirror is 10 cm thick and will be mounted on 120 electro-mechanical actuators to maintain its ideal optical figure at all elevations. The position of the light-weighted secondary mirror is adjusted to maintain collimation through use of a Shack-Hartmann wavefront sensor. The tertiary mirror feeds instruments and also jitters at up to 50 Hz to compensate for telescope shake and atmosphere wavefront tilt. The dome is a steel framework, with fiberglass panels. Air in the observing volume will be exchanged with that outside every few minutes by using large fans under computer control. All systems will be assembled and checked at the manufacturer's facility, then shipped to Chile. A short integration period is planned, and limited science

  12. Testing the emission models of blazar jets with the MAGIC telescopes

    OpenAIRE

    Becerra-González, J.; Stamerra, A.; Saito, K.; Mazin, D.; Tavecchio, F.; Maraschi, L.; Prandini, E.; Sitarek, J.; Berger, K.; Collaboration, for the MAGIC

    2011-01-01

    The MAGIC telescopes discovered very high energy (VHE, E>100 GeV) gamma-ray emission coming from the distant Flat Spectrum Radio Quasar (FSRQ) PKS 1222+21 (4C +21.35, z=0.432). It is the second most distant VHE gamma-ray source, with well measured redshift, detected until now. The observation was performed on 2010 June 17 (MJD 55364.9) using the two 17 m diameter imaging Cherenkov telescopes on La Palma (Canary Islands, Spain). The MAGIC detection coincides with high energy MeV/GeV gamma-ray ...

  13. Deep space telescopes

    CERN Multimedia

    CERN. Geneva

    2006-01-01

    The short series of seminars will address results and aims of current and future space astrophysics as the cultural framework for the development of deep space telescopes. It will then present such new tools, as they are currently available to, or imagined by, the scientific community, in the context of the science plans of ESA and of all major world space agencies. Ground-based astronomy, in the 400 years since Galileo’s telescope, has given us a profound phenomenological comprehension of our Universe, but has traditionally been limited to the narrow band(s) to which our terrestrial atmosphere is transparent. Celestial objects, however, do not care about our limitations, and distribute most of the information about their physics throughout the complete electromagnetic spectrum. Such information is there for the taking, from millimiter wavelengths to gamma rays. Forty years astronomy from space, covering now most of the e.m. spectrum, have thus given us a better understanding of our physical Universe then t...

  14. Glasses for Detection of Penetrating Radiation via the Cherenkov Effect

    Science.gov (United States)

    2015-07-01

    aware that...as  integrated  charge  per  pulse  in  a   PMT ,  above   what  would  be  produced  by  the  prompt  active...Absolute  counting  measurements  of  low   energy  gamma-­‐ray  sources  with  Cherenkov  glass  detectors  having  a   PMT

  15. THGEM based photon detector for Cherenkov imaging applications

    CERN Document Server

    Alexeev, M; Bradamante, F; Bressan, A; Chiosso, M; Ciliberti, P; Croci, G; Colantoni, M L; Dalla Torre, S; Duarte Pinto, S; Denisov, O; Diaz, V; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Giacomini, G; Giorgi, M; Gobbo, B; Heinsius, F H; Herrmann, F; Jahodova, V; Königsmann, K; Lauser, L; Levorato, S; Maggiora, A; Martin, A; Menon, G; Nerling, F; Panzieri, D; Pesaro, G; Polak, J; Rocco, E; Ropelewski, L; Sauli, F; Sbrizzai, G; Schiavon, P; Schill, C; Schopferer, S; Slunecka, M; Sozzi, F; Steiger, L; Sulc, M; Takekawa, S; Tessarotto, F; Wollny, H

    2010-01-01

    We are developing a single photon detector for Cherenkov imaging counters. This detector is based on the use of THGEM electron multipliers in a multilayer design. The major goals of our project are ion feedback suppression down to a few per cent, large gain, fast response, insensitivity to magnetic fields, and a large detector size. We report about the project status and perspectives. In particular, we present a systematic study of the THGEM response as a function of geometrical parameters, production techniques and the gas mixture composition. The first figures obtained from measuring the response of a CsI coated THGEM to single photons are presented.

  16. SU-F-T-684: Analysis of Cherenkov Excitation in Tissue and the Feasibility of Cherenkov Excited Photodynamic Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Saunders, Sara L; Andreozzi, Jacqueline M; Pogue, Brian W [Dartmouth College, Hanover, NH (United States); Glaser, Adam K [University of Washington, Seattle, WA (United States)

    2016-06-15

    Purpose: The irradiation of photodynamic agents with radiotherapy beams has been demonstrated to enhance tumor killing in various studies, and one proposed mechanism is the optical fluence of Cherenkov emission activating the photosensitizer. This mechanism is explored in Monte Carlo simulations of fluence as well as laboratory measurements of fluence and radical oxygen species. Methods: Simulations were completed using GAMOS/GEANT4 with a 6 MV photon beam in tissue. The effects of blood vessel diameter, blood oxygen saturation, and beam size were examined, recording spectral fluence. Experiments were carried out in solutions of photosensitizer and phantoms. Results: Cherenkov produced by a 100×100um{sup 2} 6 MV beam resulted in fluence of less than 1 nJ/cm{sup 2}/Gy per 1 nm wavelength. At this microscopic level, differences in absorption of blood and water in the tissue affected the fluence spectrum, but variation in blood oxygenation had little effect. Light in tissue resulting from larger (10mm ×10mm) 6 MV beams had greater fluence due to light transport and elastic scattering of optical photons, but this transport process also resulted in higher absorption shifts. Therefore, the spectrum produced by a microscopic beam was weighted more heavily in UV/blue wavelengths than the spectrum at the macroscopic level. At the macroscopic level, the total fluence available for absorption by Verteporfin (BPD) in tissue approached uJ/cm{sup 2} for a high radiation dose, indicating that photodynamic activation seems unlikely. Tissue phantom confirmation of these light levels supported this observation, and photosensitization measurements with a radical oxygen species reporter are ongoing. Conclusion: Simulations demonstrated that fluence produced by Cherenkov in tissue by 6 MV photon beams at typical radiotherapy doses appears insufficient to activate photosensitizers to the level required for threshold effects, yet this disagrees with published biological experiments

  17. Toward the construction of a medium size prototype Schwarzschild-Couder telescope for CTA

    Science.gov (United States)

    Rousselle, J.; Byrum, K.; Cameron, R.; Connaughton, V.; Errando, M.; Griffiths, S.; Guarino, V.; Humensky, T. B.; Jenke, P.; Kaaret, P.; Kieda, D.; Limon, M.; Mognet, I.; Mukherjee, R.; Nieto, D.; Okumura, A.; Peck, A.; Petrashyk, A.; Ribeiro, D.; Stevenson, B.; Vassiliev, V.; Yu, P.

    2015-09-01

    The construction of a prototype Schwarzschild-Couder telescope (pSCT) started in early June 2015 at the Fred Lawrence Whipple Observatory in Southern Arizona, as a candidate medium-sized telescope for the Cherenkov Telescope Array (CTA). Compared to current Davies-Cotton telescopes, this novel instrument with an aplanatic two-mirror optical system will offer a wider field-of-view and improved angular resolution. In addition, the reduced plate scale of the camera allows the use of highly-integrated photon detectors such as silicon photo multipliers. As part of CTA, this design has the potential to greatly improve the performance of the next generation ground-based observatory for very high-energy (E>60 GeV) gamma-ray astronomy. In this contribution we present the design and performance of both optical and alignment systems of the pSCT.

  18. Particle Identification Using a Ring Imaging Cherenkov Counter

    Science.gov (United States)

    Goodwill, Justin; Benmokhtar, Fatiha; Kim, Andrey; RICH Collaboration

    2017-09-01

    The construction of the Ring Imaging Cherenkov Counter (RICH) at Jefferson Lab aims to significantly enhance the particle identification capabilities of Hall B's CLAS12 spectrometer, particularly with respect to the separation of pions, kaons, and protons in the 3-8 GeV/c momentum range. The RICH functions by detecting a ring of Cherenkov radiation emitted by particles going faster than the speed of light in an aerogel radiator using a vast array of 8×8 multi-anode photomultiplier tubes (MAPMTs). More specifically, using a time-to-digital converter (TDC), each pixel in the 8×8 grid of the MAPMTs will measure whether or not there is a photon hit and will subsequently time-stamp it. My work in this project consisted of implementing parts of the RICH geometry in Geant4 Monte-Carlo (GEMC) simulation software. With the output from the simulation of particles passing through the detector, I built a graphical user interface (GUI) monitoring system that can display the TDC data on the RICH detector. Based on the output of the GEMC simulations, this GUI will show the location and number of hits for each pixel. Once the actual detector is constructed, the monitoring system will be used to record the hits on the detector. I would like to acknowledge SULI and NSF for the funding of this project.

  19. Workshop on Non-Imaging Cherenkov at High Energy

    CERN Document Server

    2013-01-01

    The non-Imaging Cherenkov air shower measurement technique holds great promise in furthering our understanding the Knee-to-Ankle region of the cosmic ray spectrum. In particular, this technique offers a unique way to determine the evolution of the cosmic ray nuclear composition, and an example is given by the recent spectrum results of the Tunka Collaboration. With this in mind, we are organizing a workshop, to be held at the University of Utah, to bring together the various practitioners of this cosmic ray measurement technique to share simulations, analyses, detector designs, and past experimental results amongst the community. The workshop will also be in support of our effort, NICHE, to extend the reach of the TA/TALE detector systems down to the Knee. We anticipate that the workshop will result in a white paper on the scientific importance of these high-energy cosmic ray measurements and on using the Cherenkov technique to accomplish them. Our goal is to have contributions from members of the previous ge...

  20. Cherenkov and parametric (quasi-Cherenkov) radiation from relativistic charged particles moving in crystals formed by metallic wires

    CERN Document Server

    Baryshevsky, Vladimir

    2016-01-01

    Until recently, the interaction of electromagnetic waves with crystals built from parallel metallic wires (wire media) was analyzed in the approximation of isotropic scattering of the electromagnetic wave by a single wire. However, if the wires are thick (kR~1), electromagnetic wave scattering by a wire is anisotropic, i.e., the scattering amplitude depends on the scattering angle. In this work, we derive the equations that describe diffraction of electromagnetic waves and spontaneous emission of charged particles in wire media, and take into account the angular dependence of scattering amplitude. Numerical solutions of these equations show that the radiation intensity increases as the wire radius is increased and achieves its maximal value in the range kR~1. The case when the condition kR~1 is fulfilled in the THz frequency range is considered in detail. The calculations show that the instantaneous power of Cherenkov and parametric (quasi-Cherenkov) radiations from electron bunches in the crystal can be tens...

  1. Probing Cherenkov and Scintillation Light Separation for Next-Generation Neutrino Detectors

    Science.gov (United States)

    Caravaca, J.; Descamps, F. B.; Land, B. J.; Orebi Gann, G. D.; Wallig, J.; Yeh, M.

    2017-09-01

    The ability to separate Cherenkov and scintillation signals in liquid scintillator detectors would enable outstanding background rejection for next-generation neutrino experiments. Reconstruction of directional information, ring imaging, and sub-Cherenkov threshold detection all have the potential to substantially improve particle and event identification. The Cherenkov-Scintillation Separation (CHESS) experiment uses an array of small, fast photomultipliers (PMTs) and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in a scintillation medium based on photon hit times and detected charge. This setup has been used to characterize the ability to detect Cherenkov light in a range of target media. We show results with pure organic scintillator (LAB) and the prospects with scintillators with a secondary fluor (LAB/PPO). There are future plans to deploy the newly developed water-based liquid scintillator, a medium with a higher Cherenkov/Scintillation light yield ratio than conventional pure liquid scintillators, enhancing the visibility of the less abundant Cherenkov light in the presence of scintillation light. These results can inform the development of future large-scale detectors, such as the proposed Theia experiment, or other large detectors at underground laboratories such as the far-site of the new Long Baseline Neutrino Facility at the Sanford Underground Research Facility. CHESS detector calibrations and commissioning will be discussed, and the latest results will be presented.

  2. Cherenkov angle and charge reconstruction with the RICH detector of the AMS experiment

    CERN Document Server

    Barão, F; Borges, J; Gonçalves, P; Pimenta, M; Pérez, I

    2003-01-01

    The Alpha Magnetic Spectrometer experiment to be installed on the International Space Station will be equipped with a proximity focusing Ring Imaging Cherenkov (RICH) detector, for measurements of particle electric charge and velocity. In this note, two possible methods for reconstructing the Cherenkov angle and the electric charge with the RICH are discussed. A Likelihood method for the Cherenkov angle reconstruction was applied leading to a velocity determination for protons with a resolution of around 0.1%. The existence of a large fraction of background photons which can vary from event to event implied a charge reconstruction method based on an overall efficiency estimation on an event-by-event basis.

  3. Quenching the scintillation in CF{sub 4} Cherenkov gas radiator

    Energy Technology Data Exchange (ETDEWEB)

    Blake, T. [Department of Physics, University of Warwick, Coventry (United Kingdom); D' Ambrosio, C. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Easo, S. [STFC Rutherford Appleton Laboratory, Didcot (United Kingdom); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Eisenhardt, S. [School of Physics and Astronomy, University of Edinburgh, Edinburgh (United Kingdom); Fitzpatrick, C. [Ecole Polytechnique Fédérale de Lausanne (EPFL), Lausanne (Switzerland); Forty, R.; Frei, C. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Gibson, V. [Cavendish Laboratory, University of Cambridge, Cambridge (United Kingdom); Gys, T. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Harnew, N.; Hunt, P. [Department of Physics, University of Oxford, Oxford (United Kingdom); Jones, C.R. [Cavendish Laboratory, University of Cambridge, Cambridge (United Kingdom); Lambert, R.W. [Nikhef National Institute for Subatomic Physics and VU University Amsterdam, Amsterdam (Netherlands); Matteuzzi, C. [Sezione INFN di Milano Bicocca, Milano (Italy); Muheim, F. [School of Physics and Astronomy, University of Edinburgh, Edinburgh (United Kingdom); Papanestis, A., E-mail: antonis.papanestis@stfc.ac.uk [STFC Rutherford Appleton Laboratory, Didcot (United Kingdom); European Organization for Nuclear Research (CERN), Geneva (Switzerland); Perego, D.L. [Sezione INFN di Milano Bicocca, Milano (Italy); Università di Milano Bicocca, Milano (Italy); Piedigrossi, D. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Plackett, R. [Imperial College London, London (United Kingdom); Powell, A. [Department of Physics, University of Oxford, Oxford (United Kingdom); and others

    2015-08-11

    CF{sub 4} is used as a Cherenkov gas radiator in one of the Ring Imaging Cherenkov detectors at the LHCb experiment at the CERN Large Hadron Collider. CF{sub 4} is well known to have a high scintillation photon yield in the near and far VUV, UV and in the visible wavelength range. A large flux of scintillation photons in our photon detection acceptance between 200 and 800 nm could compromise the particle identification efficiency. We will show that this scintillation photon emission system can be effectively quenched, consistent with radiationless transitions, with no significant impact on the photons resulting from Cherenkov radiation.

  4. Observation of the black widow B1957+20 millisecond pulsar binary system with the MAGIC telescopes

    Science.gov (United States)

    Ahnen, M. L.; Ansoldi, S.; Antonelli, L. A.; Arcaro, C.; Babić, A.; Banerjee, B.; Bangale, P.; Barres de Almeida, U.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Berti, A.; Biasuzzi, B.; Biland, A.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carosi, R.; Carosi, A.; Chatterjee, A.; Colin, P.; Colombo, E.; Contreras, J. L.; Cortina, J.; Covino, S.; Cumani, P.; da Vela, P.; Dazzi, F.; de Angelis, A.; de Lotto, B.; De Oña Wilhelmi, E.; Di Pierro, F.; Doert, M.; Domínguez, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher Glawion, D.; Elsaesser, D.; Engelkemeier, M.; Fallah Ramazani, V.; Fernández-Barral, A.; Fidalgo, D.; Fonseca, M. V.; Font, L.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Gaug, M.; Giammaria, P.; Godinović, N.; Gora, D.; Gozzini, S. R.; Griffiths, S.; Guberman, D.; Hadasch, D.; Hahn, A.; Hassan, T.; Hayashida, M.; Herrera, J.; Hose, J.; Hrupec, D.; Hughes, G.; Ishio, K.; Konno, Y.; Kubo, H.; Kushida, J.; Kuveždić, D.; Lelas, D.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; Majumdar, P.; Makariev, M.; Maneva, G.; Manganaro, M.; Mannheim, K.; Maraschi, L.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Mirzoyan, R.; Moralejo, A.; Moreno, V.; Moretti, E.; Neustroev, V.; Niedzwiecki, A.; Nievas Rosillo, M.; Nilsson, K.; Nishijima, K.; Noda, K.; Nogués, L.; Paiano, S.; Palacio, J.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Pedaletti, G.; Peresano, M.; Perri, L.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Garcia, J. R.; Reichardt, I.; Rhode, W.; Ribó, M.; Rico, J.; Saito, T.; Satalecka, K.; Schroeder, S.; Schweizer, T.; Sillanpää, A.; Sitarek, J.; Šnidarić, I.; Sobczynska, D.; Stamerra, A.; Strzys, M.; Surić, T.; Takalo, L.; Tavecchio, F.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Torres, D. F.; Torres-Albà, N.; Treves, A.; Vanzo, G.; Vazquez Acosta, M.; Vovk, I.; Ward, J. E.; Will, M.; Wu, M. H.; Zarić, D.; MAGIC Collaboration; Cognard, I.; Guillemot, L.

    2017-10-01

    B1957+20 is a millisecond pulsar located in a black-widow-type compact binary system with a low-mass stellar companion. The interaction of the pulsar wind with the companion star wind and/or the interstellar plasma is expected to create plausible conditions for acceleration of electrons to TeV energies and subsequent production of very high-energy γ-rays in the inverse Compton process. We performed extensive observations with the Major Atmospheric Gamma Imaging Cherenkov Telescopes (MAGIC) telescopes of B1957+20. We interpret results in the framework of a few different models, namely emission from the vicinity of the millisecond pulsar, the interaction of the pulsar and stellar companion wind region or bow shock nebula. No significant steady very high-energy γ-ray emission was found. We derived a 95 per cent confidence level upper limit of 3.0 × 10-12 cm-2 s-1 on the average γ-ray emission from the binary system above 200 GeV. The upper limits obtained with the MAGIC constrain, for the first time, different models of the high-energy emission in B1957+20. In particular, in the inner mixed wind nebula model with mono-energetic injection of electrons, the acceleration efficiency of electrons is constrained to be below ˜2-10 per cent of the pulsar spin-down power. For the pulsar emission, the obtained upper limits for each emission peak are well above the exponential cut-off fits to the Fermi-LAT data, extrapolated to energies above 50 GeV. The MAGIC upper limits can rule out a simple power-law tail extension through the sub-TeV energy range for the main peak seen at radio frequencies.

  5. ATST telescope mount: telescope of machine tool

    Science.gov (United States)

    Jeffers, Paul; Stolz, Günter; Bonomi, Giovanni; Dreyer, Oliver; Kärcher, Hans

    2012-09-01

    The Advanced Technology Solar Telescope (ATST) will be the largest solar telescope in the world, and will be able to provide the sharpest views ever taken of the solar surface. The telescope has a 4m aperture primary mirror, however due to the off axis nature of the optical layout, the telescope mount has proportions similar to an 8 meter class telescope. The technology normally used in this class of telescope is well understood in the telescope community and has been successfully implemented in numerous projects. The world of large machine tools has developed in a separate realm with similar levels of performance requirement but different boundary conditions. In addition the competitive nature of private industry has encouraged development and usage of more cost effective solutions both in initial capital cost and thru-life operating cost. Telescope mounts move relatively slowly with requirements for high stability under external environmental influences such as wind buffeting. Large machine tools operate under high speed requirements coupled with high application of force through the machine but with little or no external environmental influences. The benefits of these parallel development paths and the ATST system requirements are being combined in the ATST Telescope Mount Assembly (TMA). The process of balancing the system requirements with new technologies is based on the experience of the ATST project team, Ingersoll Machine Tools who are the main contractor for the TMA and MT Mechatronics who are their design subcontractors. This paper highlights a number of these proven technologies from the commercially driven machine tool world that are being introduced to the TMA design. Also the challenges of integrating and ensuring that the differences in application requirements are accounted for in the design are discussed.

  6. Selective Filtration of Gadolinium Trichloride for Use in Neutron Detection in Large Water Cherenkov Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vagins, Mark R.

    2013-04-10

    Water Cherenkov detectors have been used for many years as inexpensive, effective detectors for neutrino interactions and nucleon decay searches. While many important measurements have been made with these detectors a major drawback has been their inability to detect the absorption of thermal neutrons. We believe an inexpensive, effective technique could be developed to overcome this situation via the addition to water of a solute with a large neutron cross section and energetic gamma daughters which would make neutrons detectable. Gadolinium seems an excellent candidate especially since in recent years it has become very inexpensive, now less than $8 per kilogram in the form of commercially-available gadolinium trichloride, GdCl{sub 3}. This non-toxic, non-reactive substance is highly soluble in water. Neutron capture on gadolinium yields a gamma cascade which would be easily seen in detectors like Super-Kamiokande. We have been investigating the use of GdCl{sub 3} as a possible upgrade for the Super-Kamiokande detector with a view toward improving its performance as a detector for atmospheric neutrinos, supernova neutrinos, wrong-sign solar neutrinos, reactor neutrinos, proton decay, and also as a target for the coming T2K long-baseline neutrino experiment. This focused study of selective water filtration and GdCl{sub 3} extraction techniques, conducted at UC Irvine, followed up on highly promising benchtop-scale and kiloton-scale work previously carried out with the assistance of 2003 and 2005 Advanced Detector Research Program grants.

  7. The HERMES dual-radiator ring imaging Cherenkov detector

    CERN Document Server

    Akopov, N; Bailey, K; Bernreuther, S; Bianchi, N; Capitani, G P; Carter, P; Cisbani, E; De Leo, R; De Sanctis, E; De Schepper, D; Dzhordzhadze, V; Filippone, B W; Frullani, S; Garibaldi, F; Hansen, J O; Hommez, B; Iodice, M; Jackson, H E; Jung, P; Kaiser, R; Kanesaka, J; Kowalczyk, R; Lagamba, L; Maas, A; Muccifora, V; Nappi, E; Negodaeva, K; Nowak, Wolf-Dieter; O'Connor, T; O'Neill, T G; Potterveld, D H; Ryckbosch, D; Sakemi, Y; Sato, F; Schwind, A; Shibata, T A; Suetsugu, K; Thomas, E; Tytgat, M; Urciuoli, G M; Van De Kerckhove, K; Van De Vyver, R; Yoneyama, S; Zhang, L F; Zohrabyan, H G

    2002-01-01

    The construction and use of a dual radiator Ring Imaging Cherenkov (RICH) detector is described. This instrument was developed for the HERMES experiment at DESY which emphasises measurements of semi-inclusive deep-inelastic scattering. It provides particle identification for pions, kaons, and protons in the momentum range from 2 to 15 GeV, which is essential to these studies. The instrument uses two radiators, C sub 4 F sub 1 sub 0 , a heavy fluorocarbon gas, and a wall of silica aerogel tiles. The use of aerogel in a RICH detector has only recently become possible with the development of clear, large, homogeneous and hydrophobic aerogel. A lightweight mirror was constructed using a newly perfected technique to make resin-coated carbon-fiber surfaces of optical quality. The photon detector consists of 1934 photomultiplier tubes (PMT) for each detector half, held in a soft steel matrix to provide shielding against the residual field of the main spectrometer magnet.

  8. Signal Temporal Profile of a Water Cherenkov Detector

    Science.gov (United States)

    Salazar, H.; Martinez, O.; Cotzomi, J.; Moreno, E.; Villaseñor, L.

    2003-07-01

    The suggested existence of temporal structure in the signals of extensive air showers (EAS) for energies greater than 1017 eV at core distances of about 500 m, and its correlation with important parameters of EASs has stimulated us to study this structure for showers with lower energies in an Auger water Cherenkov detector(WCD). Preliminary analysis of experimental data on the widths of signals in a WCD and their correlation with other parameters of the signal are presented. The detector was triggered by the EAS-BUAP array which operates in the region of 1014 - 1016 eV. The distance of the WCD to the EAS core is larger than 30 m.

  9. SST-GATE: an innovative telescope for very high energy astronomy

    Science.gov (United States)

    Laporte, Philippe; Dournaux, Jean-Laurent; Sol, Hélène; Blake, Simon; Boisson, Catherine; Chadwick, Paula; Dumas, Delphine; Fasola, Gilles; de Frondat, Fatima; Greenshaw, Tim; Hervet, Olivier; Hinton, James; Horville, David; Huet, Jean-Michel; Jégouzo, Isabelle; Schmoll, Jürgen; White, Richard; Zech, Andreas

    2012-09-01

    The Cherenkov Telescope Array (CTA) is an international collaboration that aims to create the world's largest (ever) Very High Energy gamma-ray telescope array, consisting of more than 100 telescopes covering an area of several square kilometers to observe the electromagnetic showers generated by incoming cosmic gamma-rays with very high energies (from a few tens of GeV up to over 100 TeV). Observing such sources requires - amongst many other things - a large FoV (Field of View). In the framework of CTA, SST-GATE (Small Size Telescope - GAmma-ray Telescope Elements) aims to investigate and to build one of the two first CTA prototypes based on the Schwarzschild-Couder (SC) optical design that delivers a FoV close to 10 degrees in diameter. To achieve the required performance per unit cost, many improvements in mirror manufacturing and in other technologies are required. We present in this paper the current status of our project. After a brief introduction of the very high energy context, we present the opto-mechanical design, discuss the technological tradeoffs and explain the electronics philosophy that will ensure the telescopes cost is minimised without limiting its capabilities. We then describe the software nedeed to operate the telescope and conclude by presenting the expected telescope performance and some management considerations.

  10. Extremely frequency-widened terahertz wave generation using Cherenkov-type radiation

    National Research Council Canada - National Science Library

    Koji Suizu; Kaoru Koketsu; Takayuki Shibuya; Toshihiro Tsutsui; Takuya Akiba; Kodo Kawase

    2009-01-01

    .... The fact limits efficient and wide tunable THz-wave generation. Here, we show that Cherenkov radiation with waveguide structure is an effective strategy for achieving efficient and extremely wide tunable THz-wave source...

  11. Research on mutual influence of Cherenkov-type probes within the ISTTOK tokamak chamber

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L., E-mail: lech.jakubowski@ncbj.gov.pl [National Centre for Nuclear Research (NCBJ), 05-400 Otwock (Poland); Plyusnin, V.V. [Association Euratom/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Malinowski, K.; Sadowski, M.J.; Zebrowski, J.; Rabinski, M. [National Centre for Nuclear Research (NCBJ), 05-400 Otwock (Poland); Fernandes, H.; Silva, C.; Figueiredo, H. [Association Euratom/IST, Instituto de Plasmas e Fusão Nuclear, Instituto Superior Técnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Jakubowski, M.J. [National Centre for Nuclear Research (NCBJ), 05-400 Otwock (Poland)

    2014-12-11

    The paper describes an influence of a Cherenkov-type probe, which is used for measurements of fast electron streams inside the ISTTOK chamber, on other probes and behaviour of a plasma ring. The reported study shows that such a probe situated near the plasma column has a strong influence on signals from another Cherenkov probe, and can cause a considerable reduction of electron-induced signals. This effect does not depend on positions of the probes in relation to the limiter. Measurements of hard X-ray (HXR) emission show that the deeply immersed Cherenkov probe can also influence on the limiter . Under specific experimental conditions such a Cherenkov probe can play the role of a new limiter and change the plasma configuration.

  12. Silica aerogel threshold Cherenkov counters for the JLab Hall A spectrometers: improvements and proposed modifications

    CERN Document Server

    Lagamba, L; Colilli, S; Crateri, R; De Leo, R; Frullani, S; Garibaldi, F; Giuliani, F; Gricia, M; Iodice, M; Iommi, R; Leone, A; Lucentini, M; Mostarda, A; Nappi, E; Perrino, R; Pierangeli, L; Santavenere, F; Urciuoli, G M

    2001-01-01

    Recently approved experiments at Jefferson Lab Hall A require a clean kaon identification in a large electron, pion, and proton background environment. To this end, improved performance is required of the silica aerogel threshold Cherenkov counters installed in the focal plane of the two Hall A spectrometers. In this paper we propose two strategies to improve the performance of the Cherenkov counters which presently use a hydrophilic aerogel radiator, and convey Cherenkov photons towards the photomultipliers by means of mirrors with a parabolic shape in one direction and flat in the other. The first strategy is aerogel baking. In the second strategy we propose a modification of the counter geometry by replacing the mirrors with a planar diffusing surface and by displacing in a different way the photomultipliers. Tests at CERN with a 5 GeV/c multiparticle beam revealed that both the strategies are able to increase significantly the number of the detected Cherenkov photons and, therefore, the detector performan...

  13. Maximizng the sensitivity of a low threshold VHE gamma ray telescope by the use of neural nets and other methods

    Energy Technology Data Exchange (ETDEWEB)

    Kertzman, M.P. (Department of Physics and Astronomy, DePauw University Greencastle, Indiana 46135 (USA)); Sembroski, G.H. (Department of Physcis, Purdue University West Lafayette, Indiana 47907 (USA))

    1991-04-05

    Detailed 3-dimensional Monte-Carlo computer simulations of the Cherenkov photons produced by VHE (10 GeV to 10 TeV) gamma ray and proton induced air shower cascades are used to calculate the sensitivity and threshold of a ground-based, single-mount, multi-mirror, single photo-electron sensitive gamma ray telescope. Such a telescope is designed to have the lowest possible energy threshold for gamma ray induced air showers for a given light collection area. The sensitivity and energy threshold of this design are determined for various triggering configurations, and the sources and properties of background triggers are investigated. In particular, it is found that up to 40% of the background triggers are due to single muons produced by proton induced showers with primary energies in the 25 to 75 GeV range. Two methods for increasing the sensitivity of such a telescope by discrimination against the single muon induced triggers are investigated. The first uses small outrider telescopes triggering in coincidence with the main telescope. The second uses software implemented neural nets trained to identify muon induced triggers by use of the temporal shape of the Cherenkov light pulse.

  14. Academic Training: Deep Space Telescopes

    CERN Multimedia

    Françoise Benz

    2006-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 20, 21, 22, 23, 24 February from 11:00 to 12:00 - Council Chamber on 20, 21, 23, 24 February, TH Auditorium, bldg 4 - 3-006, on 22 February Deep Space Telescopes G. BIGNAMI / CNRS, Toulouse, F & Univ. di Pavia, I The short series of seminars will address results and aims of current and future space astrophysics as the cultural framework for the development of deep space telescopes. It will then present such new tools, as they are currently available to, or imagined by, the scientific community, in the context of the science plans of ESA and of all major world space agencies. Ground-based astronomy, in the 400 years since Galileo's telescope, has given us a profound phenomenological comprehension of our Universe, but has traditionally been limited to the narrow band(s) to which our terrestrial atmosphere is transparent. Celestial objects, however, do not care about our limitations, and distribute most of the information about their physics thro...

  15. SU-F-J-56: The Connection Between Cherenkov Light Emission and Radiation Absorbed Dose in Proton Irradiated Phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Darafsheh, A; Kassaee, A; Finlay, J [University of Pennsylvania, Philadelphia, PA (United States); Taleei, R [UT Southwestern Medical Center, Dallas, TX (United States)

    2016-06-15

    Purpose: Range verification in proton therapy is of great importance. Cherenkov light follows the photon and electron energy deposition in water phantom. The purpose of this study is to investigate the connection between Cherenkov light generation and radiation absorbed dose in a water phantom irradiated with proton beams. Methods: Monte Carlo simulation was performed by employing FLUKA Monte Carlo code to stochastically simulate radiation transport, ionizing radiation dose deposition, and Cherenkov radiation in water phantoms. The simulations were performed for proton beams with energies in the range 50–600 MeV to cover a wide range of proton energies. Results: The mechanism of Cherenkov light production depends on the initial energy of protons. For proton energy with 50–400 MeV energy that is below the threshold (∼483 MeV in water) for Cherenkov light production directly from incident protons, Cherenkov light is produced mainly from the secondary electrons liberated as a result of columbic interactions with the incident protons. For proton beams with energy above 500 MeV, in the initial depth that incident protons have higher energy than the Cherenkov light production threshold, the light has higher intensity. As the slowing down process results in lower energy protons in larger depths in the water phantom, there is a knee point in the Cherenkov light curve vs. depth due to switching the Cherenkov light production mechanism from primary protons to secondary electrons. At the end of the depth dose curve the Cherenkov light intensity does not follow the dose peak because of the lack of high energy protons to produce Cherenkov light either directly or through secondary electrons. Conclusion: In contrast to photon and electron beams, Cherenkov light generation induced by proton beams does not follow the proton energy deposition specially close to the end of the proton range near the Bragg peak.

  16. WIMP search and a Cherenkov detector prototype for ILC polarimetry

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, Christoph

    2011-10-15

    The planned International Linear Collider (ILC) will be an essential experiment to precisely determine the properties and structure of physics at the TeV scale. An important feature of the ILC is the possibility to use polarized electrons and positrons. In part 1 of this thesis, a model independent search for Weakly Interacting Massive Particles (WIMPs) at ILC is presented. The signal channel under study is direct WIMP pair production with associated Initial State Radiation (ISR), e{sup +}e{sup -} {yields} {chi}{chi}{gamma}, where the WIMPs leave the detector without any further interaction, and only the emitted photon is detected. From the energy spectrum of the detected photons the coupling structure, cross sections, masses and the quantum number of the dominant partial wave in the production process can be inferred. The analysis includes the dominant SM, as well as machine-induced backgrounds, and is performed using a full simulation of the ILD detector concept. For an integrated luminosity of L=500 fb{sup -1}, the signal cross sections can be measured to a precision of 3%, dominated by systematic uncertainties on the polarization measurement of the initial electrons and positrons. Masses can be measured to a precision of up to 2% by a comparison of the data photon spectrum to parametrized template spectra. In part 2 of this thesis, a Cherenkov detector prototype for Compton polarimetry at ILC is presented. For the polarization measurement a systematic uncertainty of {delta} P/P = 0.25% or better is envisioned. To achieve this goal, the Cherenkov detector has to be precisely aligned with the fan of Compton scattered electrons and its signal response needs to be highly linear. For the detector prototype data driven alignment strategies have been developed by comparing data recorded at the Elsa accelerator in Bonn, Germany, with detailed Geant4 simulations. With the use of multi-anode photomultipliers, data driven alignment strategies promise to provide the

  17. Vacuum Cherenkov radiation for Lorentz-violating fermions

    Science.gov (United States)

    Schreck, M.

    2017-11-01

    The current work focuses on the process of vacuum Cherenkov radiation for Lorentz-violating fermions that are described by the minimal standard-model extension (SME). To date, most considerations of this important hypothetical process have been restricted to Lorentz-violating photons, as the necessary theoretical tools for the SME fermion sector have not been available. With their development in a very recent paper, we are now in a position to compute the decay rates based on a modified Dirac theory. Two realizations of the Cherenkov process are studied. In the first scenario, the spin projection of the incoming fermion is assumed to be conserved, and in the second, the spin projection is allowed to flip. The first type of process is shown to be still forbidden for the dimensionful a and b coefficients where there are strong indications that it is energetically disallowed for the H coefficients, as well. However, it is rendered possible for the dimensionless c , d , e , f , and g coefficients. For large initial fermion energies, the decay rates for the c and d coefficients were found to grow linearly with momentum and to be linearly suppressed by the smallness of the Lorentz-violating coefficient where for the e , f , and g coefficients this suppression is even quadratic. The decay rates vanish in the vicinity of the threshold, as expected. The decay including a fermion spin-flip plays a role for the spin-nondegenerate operators and it was found to occur for the dimensionful b and H coefficients as well as for the dimensionless d and g . The characteristics of this process differ much from the properties of the spin-conserving one, e.g., there is no threshold. Based on experimental data of ultra-high-energy cosmic rays, new constraints on Lorentz violation in the quark sector are obtained from the thresholds. However, it does not seem to be possible to derive bounds from the spin-flip decays. This work reveals the usefulness of the quantum field theoretic methods

  18. VSiPMT for underwater neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Barbarino, Giancarlo [Università di Napoli Federico II, Dipartimento di Scienze Fisiche, via Cintia 80126 Napoli (Italy); Asmundis, Riccardo de [Istituto Nazionale di fisica Nucleare, sezione di Napoli, Complesso di Monte S. Angelo Ed. 6, via Cintia 80126 Napoli (Italy); De Rosa, Gianfranca [Università di Napoli Federico II, Dipartimento di Scienze Fisiche, via Cintia 80126 Napoli (Italy); Maximiliano Mollo, Carlos [Istituto Nazionale di fisica Nucleare, sezione di Napoli, Complesso di Monte S. Angelo Ed. 6, via Cintia 80126 Napoli (Italy); Vivolo, Daniele, E-mail: vivolo@na.infn.it [Università di Napoli Federico II, Dipartimento di Scienze Fisiche, via Cintia 80126 Napoli (Italy); Istituto Nazionale di fisica Nucleare, sezione di Napoli, Complesso di Monte S. Angelo Ed. 6, via Cintia 80126 Napoli (Italy)

    2013-10-11

    Underwater neutrino telescopes are nowadays considered among the most important aims in the field of astroparticle physics. Their structure consists of a cubic-kilometer three-dimensional array of photosensitive devices aimed at the detection of the Cherenkov light emitted by charged particles produced by high energy neutrino interactions with the Earth. To date, a crucial role in this kind of experiments has been played by PhotoMultiplier Tubes (PMTs), however they suffer from many drawbacks such as linearity-to-gain relationship and difficulty in single photon counting. The next generation of experiments will require further improvements in photon detectors performances, therefore alternatives to PMTs are currently under study. In particular the most promising development in this field is represented by the rapidly emerging CMOS p-n Geiger-mode avalanche photodiode technology (G-APD or SiPM), that will allow the detection of high-speed single photons with high gain and linearity. In order to overcome the limit of small sensitive surfaces we suggest an innovative design for a modern hybrid, high gain, silicon based Vacuum Silicon Photomultiplier Tube (VSiPMT) based on the combination of a SiPM with a hemispherical vacuum glass PMT standard envelope. In this work we describe the full SiPM characterization realized by our group and we present the results of our Geant4-based simulations of electron backscattering over the SiPM surface.

  19. Camera calibration strategy of the SST-1M prototype of the Cherenokov Telescope Array

    CERN Document Server

    Prandini, E; Lyard, E.; Schioppa, E. jr.; Neronov, A.; Bilnik, W.; Błocki, J.; Bogacz, L.; Bulik, T.; Cadoux, F.; Christov, A.; Curyło, M.; della Volpe, D.; Dyrda, M.; Favre, Y.; Frankowski, A.; Grudnik, Ł.; Grudzińska, M.; Idźkowski, B.; Jamrozy, M.; Janiak, M.; Kasperek, J.; Lalik, K.; Mach, E.; Mandat, D.; Marszałek, A.; Michałowski, J.; Moderski, R.; Montaruli, T.; Niemiec, J.; Ostrowski, M.; Paśko, P.; Pech, M.; Porcelli, A.; Rameez, M.; Rajda, P.; Schovanek, P.; Seweryn, K.; Skowron, K.; Sliusar, V.; Sowiński, M.; Stawarz, Ł.; Stodulska, M.; Stodulski, M.; Toscano, S.; Pujadas, I. Troyano; Walter, R.; Więcek, M.; Zagdański, A.; Ziętara, K.; Żychowski, P.

    2015-01-01

    The SST-1M telescope is one of the prototypes under construction proposed to be part of the future Cherenkov Telescope Array. It uses a standard Davis-Cotton design for the optics and telescope structure, with a dish diameter of 4 meters and a large field-of-view of 9 degrees. The innovative camera design is composed of a photo-detection plane with 1296 pixels including entrance window, light concentrators, Silicon Photomultipliers (SiPMs), and pre-amplifier stages together with a fully digital readout and trigger electronics, DigiCam. In this contribution we give a general description of the analysis chain designed for the SST-1M prototype. In particular we focus on the calibration strategy used to convert the SiPM signals registered by DigiCam to the quantities needed for Cherenkov image analysis. The calibration is based on an online feedback system to stabilize the gain of the SiPMs, as well as dedicated events (dark count, pedestal, and light flasher events) to be taken during the normal operation of the...

  20. Optical telescopes for COMPASS RICH1 up-grade

    CERN Document Server

    Sulc, M; Alekseev, M; Angerer, H; Appolonio, M; Birsa, R; Bordalo, P; Bradamante, F; Bressan, A; Busso, L; Chiosso, V M; Ciliberti, P; Colantoni, M L; Costa, S; Dibiase, N; Dafni, T; Dalla Torre, S; Diaz, V; Duic, V; Delagnes, E; Deschamps, H; Eyrich, W; Faso, D; Ferrero, A; Finger, M; Finger, M Jr; Fischer, H; Gerassimov, S; Giorgi, M; Gobbo, B; Hagemann, R; von Harrach, D; Heinsius, F H; Joosten, R; Ketzer, B; Königsmann, K; Kolosov, V N; Konorov, I; Kramer, D; Kunne, F; Levorato, S; Maggiora, A; Magnon, A; Mann, A; Martin, A; Menon, G; Mutter, A; Nähle, O; Neyret, D; Nerling, F; Pagano, P; Paul, S; Panebianco, S; Panzieri, D; Pesaro, G; Pizzolotto, C; Polak, J; Rebourgeard, P; Rocco, E; Robinet, F; Schiavon, P; Schill, C; Schoenmeier, P; Silva, L; Slunecka, M; Steiger, L; Sozzi, F; Svec, M; Tessarotto, F; Teufel, A; Wollny, H

    2006-01-01

    The central photon detection area of the Ring Imaging Cherenkov detector at COMPASS, a particle physics experiment at CERN SPS dedicated to hadron physics, has been upgraded from the previous system formed by wire chambers with CsI layers to a very fast UV extended multi anode photo multiplier tube array (MAPMT), including 576 tubes. The active area covered by the MAPMTs is 7.3 times smaller than the one previously equipped with CsI photocathodes, so 576 optical concentrators transforming the image from the old system focal plane to the new photocathode plane were needed. The telescope system formed by two fused silica lenses was designed, produced and assembled. The first prismatic plano-convex field lens is placed in the focal plane of the RICH mirrors. The second condenser lens is off centered and tilted and has one aspherical surface. All lenses have antireflection coating.

  1. Development of Ring Imaging Cherenkov Detectors for LHCb

    CERN Document Server

    Bellunato, T; Matteuzzi, C

    2003-01-01

    The work described in this thesis has been carried out in the framework of the development program of the Ring Imaging Cherenkov (RICH) detectors of the LHCb experiment. LHCb will operate at the Large Hadron Collider at CERN, and it will perform a wide range of measurements in the b-hadrons realm. The extensive study of CP violation and rare decays in the b-hadron system are the main goals of the experiment. An introduction to CP violation in hadronic interactions is given in chapter 1. The high b-b bar production cross section at the LHC energy will provide an unprecedented amount of data which will give LHCb a unique opportunity for precision tests on a large set of physics channels as well as a promising discovery potential for sources of CP violation arising from physics beyond the Standard Model. The experiment is designed in such a way to optimally match the kinematic structure of events where a pair of b quarks is produced in the collision between to 7 GeV protons. Chapter 2 is devoted to an overview o...

  2. TORCH - a Cherenkov-based time-of-flight detector

    CERN Document Server

    van Dijk, M W U; Cowie, E N; Cussans, D; D' Ambrosio, C; Forty, R; Frei, C; Gys, T; Piedigrossi, D; Castillo Garcia, L; Fopma, J; Gao, R; Harnew, N; Keri, T

    2014-01-01

    TORCH is an innovative high-precision time-of-flight system to provide particle identification in the difficult intermediate momentum region up to 10 GeV/c. It is also suitable for large-area applications. The detector provides a time-of-flight measurement from the imaging of Cherenkov photons emitted in a 1 cm thick quartz radiator. The photons propagate by total internal reflection to the edge of the quartz plate, where they are focused onto an array of photon detectors at the periphery. A time-of-flight resolution of about 10–15 ps per incident charged particle needs to be achieved for a three sigma kaon–pion separation up to 10 GeV/c momentum for the TORCH located 9.5 m from the interaction point. Given ∼ 30 detected photons per incident charged particle, this requires measuring the time-of-arrival of individual photons to about 70 ps. This paper will describe the design of a TORCH prototype involving a number of ground-breaking and challenging techniques.

  3. Development of a gaseous photon detector for Cherenkov imaging applications

    CERN Document Server

    Rocco, Elena; Dalla Torre, Silvia

    2010-01-01

    This thesis is dedicated to the R&D activity aiming at a novel micro pattern gaseous photon detector based on the THick Gas Electron Multiplier (THGEM). The goal application of the novel photon detector is the detection of single photon in Ring Imaging CHerenkov (RICH) counters. The THGEM principle is derived from the Gas Electron Multiplier (GEM) one, even if the material, the production technology and the size scale are different: a THGEM is a Circuit Printed Board (PCB) coated with thin copper layers on both faces, with holes obtained by drilling. Part of the THGEM features are similar to those of the GEMs, but a number of characteristics aspects result substantially different: in fact, if the geometrical parameters can be scaled from the GEM ones, the parameters related to the electrons multiplication, which is a microscopic physical phenomenon, do not. This is why, before starting the photon detector development, we have performed a systematic study of the THGEM multiplier. A photon detector is forme...

  4. Athermal laser launch telescopes

    NARCIS (Netherlands)

    Kamphues, F.G.; Henselmans, R.; Rijnveld, N.; Lemmen, M.H.J.; Doelman, N.J.; Nijkerk, M.D.

    2011-01-01

    ESO has developed a concept for a compact laser guide star unit for use in future Adaptive Optics (AO) systems. A small powerful laser is combined with a telescope that launches the beam, creating a single modular unit that can be mounted directly on a large telescope. This approach solves several

  5. Japanese radio telescopes

    Science.gov (United States)

    Kawaguchi, Noriyuki

    Japanese principal radio telescopes available for Very Long Baseline Interferometry (VLBI) observations are overviewed, and their characteristics and performances are summarized. Three fixed stations, Usuda, Nobeyama, and Kashima, and one 5-m mobile station use a hydrogen master-frequency standard, while other stations use an ultrastable X'tal oscillator locked to a cesium frequency standard. The 64-m telescope in Usuda developed for tracking satellites of deep-space missions is outlined, as well as the Kashima 34-m telescope covering a frequency range from 300 MHz to 49 GHz with 11 receivers. Attention is given to the Nobeyama 45-m telescope as a major telescope in Japan working in an international mm-VLBI network.

  6. Observing the Sun with Coronado telescopes telescopes

    CERN Document Server

    Pugh, Philip

    2007-01-01

    The Sun provides amateur astronomers with one of the few opportunities for daytime astronomy. In order to see the major features of our nearest star, special telescopes that have a very narrow visible bandwidth are essential. The bandwidth has to be as narrow as 1 A- 10-10 m (1 Angstrom) and centred on the absorption line of neutral hydrogen. This makes many major features of the Suna (TM)s chromosphere visible to the observer. Such narrow-band "Fabry-Perot etalon filters" are high technology, and until the introduction of the Coronado range of solar telescopes, were too expensive for amateur use. The entry-level Coronado telescope, the PST (Personal Solar Telescope) costs under 500. Solar prominences (vast columns of plasma, best seen at the edge of the solar disk), filaments, flares, sunspots, plage and active regions are all visible and can be imaged to produce spectacular solar photographs. Philip Pugh has assembled a team of contributors who show just how much solar work can be done with Coronado telesco...

  7. Application of a stochastic TDCR model based on Geant4 for Cherenkov primary measurements.

    Science.gov (United States)

    Bobin, C; Thiam, C; Bouchard, J; Jaubert, F

    2010-12-01

    Cherenkov measurements can be advantageously carried out using a counting instrumentation dedicated to liquid scintillation. In the case of radionuclide measurements, the interest of this technique is largely described in the literature. For instance, it is generally quoted that the possibility to measure directly the activity of aqueous solutions makes the sample preparation easier. Based on a three-photomultipliers apparatus, the Triple to Double Coincidence Ratio (TDCR) method is implemented in National Metrology Institutes for liquid scintillation measurements. Knowing the decay scheme associated with the radionuclide to be standardized, a free parameter model of light emission is constructed to determine the counter detection efficiency using the experimental TDCR value. Contrary to liquid scintillation, Cherenkov emission is characterized by a directional behavior. Instead of using an additional free parameter to take this effect into account, a stochastic modeling based on the Monte Carlo code Geant4 is proposed in order to extend the TDCR method to Cherenkov counting. The purpose of this model is to simulate the different optical processes of Cherenkov photons leading to the production of photoelectrons in the three-photomultipliers counter. The validation of this stochastic approach of the TDCR method for Cherenkov counting is carried out in the case of (90)Y activity measurements. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Application of a stochastic TDCR model based on Geant4 for Cherenkov primary measurements

    Energy Technology Data Exchange (ETDEWEB)

    Bobin, C., E-mail: christophe.bobin@cea.f [CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), F-91191 Gif-sur-Yvette Cedex (France); Thiam, C.; Bouchard, J.; Jaubert, F. [CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), F-91191 Gif-sur-Yvette Cedex (France)

    2010-12-15

    Cherenkov measurements can be advantageously carried out using a counting instrumentation dedicated to liquid scintillation. In the case of radionuclide measurements, the interest of this technique is largely described in the literature. For instance, it is generally quoted that the possibility to measure directly the activity of aqueous solutions makes the sample preparation easier. Based on a three-photomultipliers apparatus, the Triple to Double Coincidence Ratio (TDCR) method is implemented in National Metrology Institutes for liquid scintillation measurements. Knowing the decay scheme associated with the radionuclide to be standardized, a free parameter model of light emission is constructed to determine the counter detection efficiency using the experimental TDCR value. Contrary to liquid scintillation, Cherenkov emission is characterized by a directional behavior. Instead of using an additional free parameter to take this effect into account, a stochastic modeling based on the Monte Carlo code Geant4 is proposed in order to extend the TDCR method to Cherenkov counting. The purpose of this model is to simulate the different optical processes of Cherenkov photons leading to the production of photoelectrons in the three-photomultipliers counter. The validation of this stochastic approach of the TDCR method for Cherenkov counting is carried out in the case of {sup 90}Y activity measurements.

  9. Observation of oscillations of atmospheric neutrinos with the IceCube Neutrino Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Euler, Sebastian

    2014-02-04

    Neutrino oscillations have become one of the most important research topics in particle physics since their discovery 15 years ago. In the past, the study of neutrino oscillations has been largely the domain of dedicated experiments, but in the last year also the large-volume neutrino telescopes ANTARES and IceCube reported their results on the oscillations of atmospheric muon neutrinos and thus joined the community of experiments studying neutrino oscillations. The precision of their results is not yet competitive, but their sheer size and the consequently enormous statistics give rise to the expectation of a competitive measurement in the future. This thesis describes an analysis that was done on IceCube data taken with the nearly complete detector in the years 2010/2011. IceCube is the world's largest neutrino detector, located at the geographic South Pole, where it uses the Antarctic ice sheet as its detection medium. It detects neutrinos interacting within or close to the instrumented volume by observing the Cherenkov light which is emitted by secondary particles produced in these interactions. An array of optical sensors deployed within a cubic kilometer of ice detects the Cherenkov light and makes it possible to reconstruct the energy and direction of the initial neutrino. Unfortunately, IceCube detects not only neutrinos: the desired neutrino signal is buried in a huge background of atmospheric muons, produced in air showers induced by cosmic rays. This background has to be rejected first. The analysis presented here employs an event selection that is based on the idea of using the outer layers of IceCube as an active veto against the background of atmospheric muons and achieves the necessary background rejection of more than 6 orders of magnitude while keeping a high-statistics sample of several thousands of muon neutrinos. In contrast to the earlier IceCube analysis, which used only the zenith angle, it then performs a 2-dimensional likelihood fit on

  10. Measurements of the atmospheric neutrino flux by Super-Kamiokande: energy spectra, geomagnetic effects, and solar modulation

    CERN Document Server

    Richard, E; Abe, K; Haga, Y; Hayato, Y; Ikeda, M; Iyogi, K; Kameda, J; Kishimoto, Y; Miura, M; Moriyama, S; Nakahata, M; Nakajima, T; Nakano, Y; Nakayama, S; Orii, A; Sekiya, H; Shiozawa, M; Takeda, A; Tanaka, H; Tomura, T; Wendell, R A; Akutsu, R; Irvine, T; Kajita, T; Kaneyuki, K; Nishimura, Y; Labarga, L; Fernandez, P; Gustafson, J; Kachulis, C; Kearns, E; Raaf, J L; Stone, J L; Sulak, L R; Berkman, S; Nantais, C M; Tanaka, H A; Tobayama, S; Goldhaber, M; Kropp, W R; Mine, S; Weatherly, P; Smy, M B; Sobel, H W; Takhistov, V; Ganezer, K S; Hartfiel, B L; Hill, J; Hong, N; Kim, J Y; Lim, I T; Park, R G; Himmel, A; Li, Z; OSullivan, E; Scholberg, K; Walter, C W; Wongjirad, T; Ishizuka, T; Tasaka, S; Jang, J S; Learned, J G; Matsuno, S; Smith, S N; Friend, M; Hasegawa, T; Ishida, T; Ishii, T; Kobayashi, T; Nakadaira, T; Nakamura, K; Oyama, Y; Sakashita, K; Sekiguchi, T; Tsukamoto, T; Suzuki, A T; Takeuchi, Y; Yano, T; Cao, S V; Hiraki, T; Hirota, S; Huang, K; Kikawa, T; Minamino, A; Nakaya, T; Suzuki, K; Fukuda, Y; Choi, K; Itow, Y; Suzuki, T; Mijakowski, P; Frankiewicz, K; Hignight, J; Imber, J; Jung, C K; Li, X; Palomino, J L; Wilking, M J; Yanagisawa, C; Fukuda, D; Ishino, H; Kayano, T; Kibayashi, A; Koshio, Y; Mori, T; Sakuda, M; Xu, C; Kuno, Y; Tacik, R; Kim, S B; Okazawa, H; Choi, Y; Nishijima, K; Koshiba, M; Totsuka, Y; Suda, Y; Yokoyama, M; Bronner, C; Hartz, M; Martens, K; Marti, Ll; Suzuki, Y; Vagins, M R; Martin, J F; Konaka, A; Chen, S; Zhang, Y; Wilkes, R J

    2015-01-01

    A comprehensive study on the atmospheric neutrino flux in the energy region from sub-GeV up to several TeV using the Super-Kamiokande water Cherenkov detector is presented in this paper. The energy and azimuthal spectra of the atmospheric ${\

  11. Gemini telescope structure design

    Science.gov (United States)

    Raybould, Keith; Gillett, Paul E.; Hatton, Peter; Pentland, Gordon; Sheehan, Mike; Warner, Mark

    1994-06-01

    The Gemini project is an international collaboration to design, fabricate, and assemble two 8 M telescopes, one on Mauna Kea in Hawaii, the other on Cerro Pachon in Chile. The telescopes will be national facilities designed to meet the Gemini Science Requirements (GSR), a document developed by the Gemini Science Committee (GSC) and the national project scientists. The Gemini telescope group, based on Tucson, has developed a telescope structure to meet the GSR. This paper describes the science requirements that have technically driven the design, and the features that have been incorporated to meet these requirements. This is followed by a brief description of the telescope design. Finally, analyses that have been performed and development programs that have been undertaken are described briefly. Only the designs that have been performed by the Gemini Telescope Structure, Building and Enclosure Group are presented here; control, optical systems, acquisition and guiding, active and adaptive optics, Cassegrain rotator and instrumentation issues are designed and managed by others and will not be discussed here, except for a brief description of the telescope configurations to aid subsequent discussions.

  12. Comparación del funcionamiento entre PMT y SiPM para la detección de Cherenkov atmosférico en el Complejo Astronómico El Leoncito

    Science.gov (United States)

    Yelós, L. D.; Suarez, F.; García, B.

    2017-10-01

    Most recent discoveries in gamma ray astronomy with energies around 50 GeV to 30 TeV, were achieved with ground Cherenkov Telescopes, traditionally composed of a parabolic mirror and a single or an array of photo multiplier tubes (PMTs) in their focus. The same detectors (or similar) are used in most astrophysics experiments. Recently, a new detector, the silicon photo-multiplier (SiPM), is progressively replacing the PMTs due to their technical advantages. However some limitations in their functioning make them more complex to use than PMTs and forces their characterization for each project. This work describes the characterization of SiPM from SensL (model MicroFC-SMA-30035) and a PMT from Hamamatsu (model R1463), both detectors are possible options to be used in an array of three Cherenkov telescopes at CASLEO. Additionally, we include the results of the operation of both detectors under controlled laboratory conditions that simulate expected conditions at field. Laboratory test were run in a darkbox with a data acquisition system, a personalized data analyze system with ROOT libraries, temperature control and monitoring, polarization control, a controlled light source, and humidity monitoring.

  13. Telescopic vision contact lens

    Science.gov (United States)

    Tremblay, Eric J.; Beer, R. Dirk; Arianpour, Ashkan; Ford, Joseph E.

    2011-03-01

    We present the concept, optical design, and first proof of principle experimental results for a telescopic contact lens intended to become a visual aid for age-related macular degeneration (AMD), providing magnification to the user without surgery or external head-mounted optics. Our contact lens optical system can provide a combination of telescopic and non-magnified vision through two independent optical paths through the contact lens. The magnified optical path incorporates a telescopic arrangement of positive and negative annular concentric reflectors to achieve 2.8x - 3x magnification on the eye, while light passing through a central clear aperture provides unmagnified vision.

  14. Hubble Space Telescope

    Science.gov (United States)

    1990-01-01

    An overview of the mission of the Hubble Space Telescope, a joint project between NASA and the European Space Agency which will be used to study deep space, as well as our solar system is presented. The video contains animations depicting the Hubble Space Telescope in orbit, as well as footage of scientists at the Space Telescope Science Institute making real time observations. The images Hubble acquires will be downloaded into a database that contains images of over 19,000,000 celestial objects called the Star Catalog.

  15. Ritchey-Chretien Telescope

    Science.gov (United States)

    Rosin, S.; Amon, M. (Inventor)

    1973-01-01

    A Ritchey-Chretien telescope is described which was designed to respond to images located off the optical axis by using two transparent flat plates positioned in the ray path of the image. The flat plates have a tilt angle relative to the ray path to compensate for astigmatism introduced by the telescope. The tilt angle of the plates is directly proportional to the off axis angle of the image. The plates have opposite inclination angles relative to the ray paths. A detector which is responsive to the optical image as transmitted through the plates is positioned approximately on the sagittal focus of the telescope.

  16. Solar Rejection Filter for Large Telescopes

    Science.gov (United States)

    Hemmati, Hamid; Lesh, James

    2009-01-01

    front aperture filter is integrated with the telescope dome, it will reject heat from the dome and will significantly reduce dome temperature regulation requirements and costs. Also, the filter will protect the telescope optics from dust and other contaminants in the atmosphere. It will be simpler to clean or replace this filter than the telescope primary mirror. It may be necessary to paint the support grid with a highly reflective material to avoid overheating.

  17. Measurement of high-energy electrons by means of a Cherenkov detector in ISTTOK tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L., E-mail: lech.Jjakubowski@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Plyusnin, V.V. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049 - 001 Lisboa (Portugal); Malinowski, K.; Sadowski, M.J.; Rabinski, M. [Andrzej Soltan Institute for Nuclear Studies (IPJ), 05-400 Otwock-Swierk (Poland); Fernandes, H.; Silva, C.; Duarte, P. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049 - 001 Lisboa (Portugal)

    2010-10-15

    The paper concerns detectors of the Cherenkov radiation which can be used to measure high-energy electrons escaping from short-living plasma. Such detectors have high temporal (about 1 ns) and spatial (about 1 mm) resolution. The paper describes a Cherenkov-type detector which was designed, manufactured and installed in the ISTTOK tokamak in order to measure fast runaway electrons. The radiator of that detector was made of an aluminium nitride (AlN) tablet with a light-tight filter on its front surface. Cherenkov signals from the radiator were transmitted through an optical cable to a fast photomultiplier. It made possible to perform direct measurements of the runaway electrons of energy above 80 keV. The measured energy values and spatial characteristics of the recorded electrons appeared to be consistent with results of numerical modelling of the runaway electron generation process in the ISTTOK tokamak.

  18. Neutrino superluminality without Cherenkov-like processes in Finslerian special relativity

    Science.gov (United States)

    Chang, Zhe; Li, Xin; Wang, Sai

    2012-04-01

    Recently, Cohen and Glashow [A.G. Cohen, S.L. Glashow, Phys. Rev. Lett. 107 (2011) 181803] pointed out that the superluminal neutrinos reported by the OPERA would lose their energy rapidly via the Cherenkov-like process. The Cherenkov-like process for the superluminal particles would be forbidden if the principle of special relativity holds in any frame instead violated with a preferred frame. We have proposed that the Finslerian special relativity could account for the data of the neutrino superluminality (arxiv:arXiv:1110.6673 [hep-ph]). The Finslerian special relativity preserves the principle of special relativity and involves a preferred direction while consists with the causality. In this Letter, we prove that the energy-momentum conservation is preserved and the energy-momentum is well defined in Finslerian special relativity. The Cherenkov-like process is forbidden in the Finslerian special relativity. Thus, the superluminal neutrinos would not lose energy in their distant propagation.

  19. Silica aerogel Cherenkov counter for the KEK B-factory experiment

    CERN Document Server

    Sumiyoshi, T; Enomoto, R; Iijima, T; Suda, R; Leonidopoulos, C; Marlow, D R; Prebys, E; Kawabata, R; Kawai, H; Ooba, T; Nanao, M; Suzuki, K; Ogawa, S; Murakami, A; Khan, M H R

    1999-01-01

    Low-refractive-index silica aerogel is a convenient radiator for threshold-type Cherenkov counters, which are used for particle identification in high-energy physics experiments. For the BELLE detector at the KEK B-Factory we have produced about 2 m sup 3 of hydrophobic silica aerogels of n=1.01-1.03 using a new production method. The particle identification capability of the aerogel Cherenkov counters was tested and 3 sigma pion/proton separation has been achieved at 3.5 GeV/c. Radiation hardness of the aerogels was confirmed up to 9.8 Mrad. The Aerogel Cherenkov counter system (ACC) was successfully installed in the BELLE just before this conference.

  20. Goddard Robotic Telescope (GRT)

    Data.gov (United States)

    National Aeronautics and Space Administration — Since it is not possible to predict when a Gamma-Ray Burst (GRB) occurs, the follow-up ground telescopes must be distributed as uniform as possible all over the...

  1. LISA Telescope Sensitivity Analysis

    Science.gov (United States)

    Waluschka, Eugene; Krebs, Carolyn (Technical Monitor)

    2002-01-01

    The Laser Interferometer Space Antenna (LISA) for the detection of Gravitational Waves is a very long baseline interferometer which will measure the changes in the distance of a five million kilometer arm to picometer accuracies. As with any optical system, even one with such very large separations between the transmitting and receiving, telescopes, a sensitivity analysis should be performed to see how, in this case, the far field phase varies when the telescope parameters change as a result of small temperature changes.

  2. Analytical Solution for the Stopping Power of the Cherenkov Radiation in a Uniaxial Nanowire Material

    Directory of Open Access Journals (Sweden)

    Tiago A. Morgado

    2015-06-01

    Full Text Available We derive closed analytical formulae for the power emitted by moving charged particles in a uniaxial wire medium by means of an eigenfunction expansion. Our analytical expressions demonstrate that, in the absence of material dispersion, the stopping power of the uniaxial wire medium is proportional to the charge velocity, and that there is no velocity threshold for the Cherenkov emission. It is shown that the eigenfunction expansion formalism can be extended to the case of dispersive lossless media. Furthermore, in the presence of material dispersion, the optimal charge velocity that maximizes the emitted Cherenkov power may be less than the speed of light in a vacuum.

  3. Quality Assurance of Pixel Hybrid Photon Detectors for the LHCb Ring Imaging Cherenkov Counters

    CERN Document Server

    Carson, Laurence

    Pion/kaon discrimination in the LHCb experiment will be provided by two Ring Imaging Cherenkov (RICH) counters. These use arrays of 484 Hybrid Photon Detectors (HPDs) to detect the Cherenkov photons emitted by charged particles traversing the RICH. The results from comprehensive quality assurance tests on the 550 HPDs manufactured for LHCb are described. Leakage currents, dead channel probabilities, dark count rates and ion feedback rates are reported. Furthermore, measurements carried out on a sample of tubes to determine the efficiency of the HPD pixel chip by measuring the summed analogue response from the backplane of the silicon sensor are described.

  4. Measuring the attenuation length of water in the CHIPS-M water Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Amat, F.; Bizouard, P. [Aix Marseille University Saint-Jerome, 13013 Marseille (France); Bryant, J. [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); Carroll, T.J.; Rijck, S. De [Department of Physics, University of Texas at Austin, Austin, TX 78712 (United States); Germani, S. [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); Joyce, T. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Kriesten, B. [Department of Physics, College of William & Mary, Williamsburg, VA 23187 (United States); Marshak, M.; Meier, J. [School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455 (United States); Nelson, J.K. [Department of Physics, College of William & Mary, Williamsburg, VA 23187 (United States); Perch, A.J.; Pfützner, M.M. [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); Salazar, R. [Department of Physics, University of Texas at Austin, Austin, TX 78712 (United States); Thomas, J., E-mail: jennifer.thomas@ucl.ac.uk [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Trokan-Tenorio, J. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Vahle, P. [Department of Physics, College of William & Mary, Williamsburg, VA 23187 (United States); Wade, R. [Avenir Consulting, Abingdon, Oxfordshire (United Kingdom); Wendt, C. [Department of Physics, University of Wisconsin, Madison, WI 53706 (United States); Whitehead, L.H. [Department of Physics and Astronomy, UCL, Gower St, London WC1E 6BT (United Kingdom); and others

    2017-02-01

    The water at the proposed site of the CHIPS water Cherenkov detector has been studied to measure its attenuation length for Cherenkov light as a function of filtering time. A scaled model of the CHIPS detector filled with water from the Wentworth 2W pit, proposed site of the CHIPS deployment, in conjunction with a 3.2 m vertical column filled with this water, was used to study the transmission of 405 nm laser light. Results consistent with attenuation lengths of up to 100 m were observed for this wavelength with filtration and UV sterilization alone.

  5. Eclipse telescope design factors

    Science.gov (United States)

    Hull, Tony; Trauger, John T.; Macenka, Steven A.; Moody, Dwight; Olarte, Guillermo; Sepulveda, Cesar; Tsuha, Walter; Cohen, David

    2003-02-01

    Very high contrast imagery, required for exoplanet image acquisition, imposes significantly different criteria upon telescope architecture than do the requirements imposed upon most spaceborne telescopes. For the Eclipse Mission, the fundamental figure-of-merit is a stellar contrast, or brightness reduction ratio, reaching a factor of 10-9 or better at star-planet distances as close as the 4th Airy ring. Factors necessary to achieve such contrast ratios are both irrelevant and largely ignored in contemporary telescope design. Although contemporary telescoeps now meet Hubble Space Telescope performance at substantially lower mass and cost than HST, control of mid-spatial-frequency (MSF) errors, crucial to coronagraphy, has not been emphasized. Accordingly, roughness at MSF has advanced little since HST. Fortunately, HST primary mirror smoothness would nearly satisfy Eclipse requirements, although other aspects of HST are undesirable for stellar coronagraphy. Conversely, the narrow field required for Eclipse eases other drivers of traditional telescope design. A systematic approach to telescope definition, with primary and sub-tier figures-of-merit, will be discussed in the context of the Eclipse Mission.

  6. Adaptive Optics for Large Telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Olivier, S

    2008-06-27

    The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments.

  7. Telescopes in education

    Science.gov (United States)

    Yessayian, Rick

    Imagine sitting in your classroom with your students and controlling a Research Grade 24 inch telescope. You control where it points, you control the duration of the exposure of a high grade CCD camera, and you control all of this within your school day, on a camera half way around the globe, in real time. You can hear the telescope moving, talk to the operator sitting atop historic Mt. Wilson Observatory in California. You might be looking at comets, asteroids, galaxies, nebulas or a host of other interesting celestial objects. Perhaps you have students that are up to a real challenge -- doing real science! Students in our program have contributed the discovery of a new variable star, to the Pluto Express project, to the search for supernovas, and the collection of images of intersecting galaxies. These are among the many possible projects you might choose from. The age and ability of your students are taken into account when you choose your project. Students from Kindergarten through Grade 12 have participated in this free program. A new robotic telescope was added at Mount Wilson in 1999. The telescope is a Celestron 14" SCT mounted on a Bisque Paramount GT-1100 with an Apogee AP-7 CCD camera (512X512 pixels). In the Spring of 2001, we duplicated the 14" robotic telescope configuration and placed it at the Las Campanas Observatory, Chile (operated by the Carnegie Observatories). I installed the system in late September, 2001, and we began testing. The system requires one more upgrade and some hardware adjustments, which I will complete in June, 2002. We duplicated another 14" robotic telescope, and sent it to Brisbane Australia in January, 2002. The grand opening of the telescope will be in August 2002.

  8. Hubble Space Telescope: The Telescope, the Observations & the Servicing Mission

    Science.gov (United States)

    1999-11-01

    Hubble's success is the advantage of being in orbit, beyond the Earth's atmosphere. From there it enjoys a crystal-clear view of the universe - without clouds and atmospheric disturbances to blur its vision. European astronomer Guido De Marchi from ESO in Munich has been using Hubble since the early days of the project. He explains: "HST can see the faintest and smallest details and lets us study the stars with great accuracy, even where they are packed together - just as with those in the centre of our Galaxy". Dieter Reimers from Hamburg Observatory adds: "HST has capabilities to see ultraviolet light, which is not possible from the ground due to the blocking effect of the atmosphere. And this is really vital to our work, the main aim of which is to discover the chemical composition of the Universe." The Servicing Missions In the early plans for telescope operations, maintenance visits were to have been made every 2.5 years. And every five years HST should have been transported back to the ground for thorough overhaul. This plan has changed somewhat over time and a servicing scheme, which includes Space Shuttle Servicing Missions every three years, was decided upon. The two first Servicing Missions, in December 1993 (STS-61) and February 1997 (STS-82) respectively, were very successful. In the first three years of operations HST did not meet expectations because its primary mirror was 2 microns too flat at the edge. The first Servicing Mission in 1993 (on which the European astronaut Claude Nicollier flew) dealt with this problem by installing a new instrument with corrective optics (COSTAR - Corrective Optics Space Telescope Axial Replacement). With this pair of "glasses" HST's golden age began. The images were as sharp as originally hoped and astonishing new results started to emerge on a regular basis. The first Servicing Mission also replaced the solar panels and installed a new camera (Wide Field and Planetary Camera 2 - WFPC2). The High-Speed Photometer (HSP) was

  9. Whipple Telescope observations of the Crab Nebula with a Pattern Selection Trigger

    Science.gov (United States)

    Bradbury, Stella

    For imaging Cherenkov telescopes the single pixel trigger rate is heavily influenced by fluctuating night sky brightness. The random trigger rate of an N pixel coincidence quickly escalates with decreasing energy threshold. To keep the data rate to a manageable level, by further requiring that N signals are adjacent, we developed CAMAC Pattern Selection Trigger modules, in which the pixel fire pattern is compared with the contents of a delay memory pre-programmed with allowed patterns of 2, 3 or 4 pixels. This system has been used as a next neighbour trigger for the 331 pixel camera of the Whipple 10m telescope, to acquire data at a 20% lower discriminator threshold than that sustainable with a simple multiplicity trigger. We discuss the performance of the trigger modules and present the results of our analysis of data recorded on the Crab Nebula at this reduced threshold.

  10. Measurement of neutrino oscillations in atmospheric neutrinos with the IceCube DeepCore detector

    Energy Technology Data Exchange (ETDEWEB)

    Yanez Garza, Juan Pablo

    2014-06-02

    The study of neutrino oscillations is an active field of research. During the last couple of decades many experiments have measured the effects of oscillations, pushing the field from the discovery stage towards an era of precision and deeper understanding of the phenomenon. The IceCube Neutrino Observatory, with its low energy subarray, DeepCore, has the possibility of contributing to this field. IceCube is a 1 km{sup 3} ice Cherenkov neutrino telescope buried deep in the Antarctic glacier. DeepCore, a region of denser instrumentation in the lower center of IceCube, permits the detection of neutrinos with energies as low as 10 GeV. Every year, thousands of atmospheric neutrinos around these energies leave a strong signature in DeepCore. Due to their energy and the distance they travel before being detected, these neutrinos can be used to measure the phenomenon of oscillations. This work starts with a study of the potential of IceCube DeepCore to measure neutrino oscillations in different channels, from which the disappearance of ν{sub μ} is chosen to move forward. It continues by describing a novel method for identifying Cherenkov photons that traveled without being scattered until detected direct photons. These photons are used to reconstruct the incoming zenith angle of muon neutrinos. The total energy of the interacting neutrino is also estimated. In data taken in 343 days during 2011-2012, 1487 neutrino candidates with an energy between 7 GeV and 100 GeV are found inside the DeepCore volume. Compared to the expectation from the atmospheric neutrino flux without oscillations, this corresponds to a deficit of about 500 muon neutrino events. The oscillation parameters that describe the data best are sin{sup 2}(2θ{sub 23})=1(>0.94 at 68 % C.L.) and vertical stroke Δm{sup 2}{sub 32} vertical stroke =2.4{sub -0.4}{sup +0.6}.10{sup -3} eV{sup 2}, which are in agreement with the results reported by other experiments. The simulation follows the data closely

  11. Robotic and Survey Telescopes

    Science.gov (United States)

    Woźniak, Przemysław

    Robotic telescopes are revolutionizing the way astronomers collect their dataand conduct sky surveys. This chapter begins with a discussion of principles thatguide the process of designing, constructing, and operating telescopes andobservatories that offer a varying degree of automation, from instruments remotelycontrolled by observers to fully autonomous systems requiring no humansupervision during their normal operations. Emphasis is placed on designtrade-offs involved in building end-to-end systems intended for a wide range ofscience applications. The second part of the chapter contains descriptions ofseveral projects and instruments, both existing and currently under development.It is an attempt to provide a representative selection of actual systems thatillustrates state of the art in technology, as well as important ideas and milestonesin the development of the field. The list of presented instruments spans the fullrange in size starting from small all-sky monitors, through midrange robotic andsurvey telescopes, and finishing with large robotic instruments and surveys.Explosive growth of telescope networking is enabling entirely new modesof interaction between the survey and follow-up observing. Increasingimportance of standardized communication protocols and software is stressed.These developments are driven by the fusion of robotic telescope hardware,massive storage and databases, real-time knowledge extraction, and datacross-correlation on a global scale. The chapter concludes with examplesof major science results enabled by these new technologies and futureprospects.

  12. The Travelling Telescope

    Science.gov (United States)

    Murabona Oduori, Susan

    2015-08-01

    The telescope has been around for more than 400 years, and through good use of it scientists have made many astonishing discoveries and begun to understand our place in the universe. Most people, however, have never looked through one. Yet it is a great tool for cool science and observation especially in a continent and country with beautifully dark skies. The Travelling Telescope project aims to invite people outside under the stars to learn about those curious lights in the sky.The Travelling Telescope aims to promote science learning to a wide range of Kenyan schools in various locations exchanging knowledge about the sky through direct observations of celestial bodies using state of the art telescopes. In addition to direct observing we also teach science using various hands-on activities and astronomy software, ideal for explaining concepts which are hard to understand, and for a better grasp of the sights visible through the telescope. We are dedicated to promoting science using astronomy especially in schools, targeting children from as young as 3 years to the youth, teachers, their parents and members of the public. Our presentation focuses on the OAD funded project in rural coastal Kenya.

  13. Radio Telescope Reflectors

    Science.gov (United States)

    Baars, Jacob W. M.; Kärcher, Hans J.

    2017-11-01

    This book demonstrates how progress in radio astronomy is intimately linked to the development of reflector antennas of increasing size and precision. The authors describe the design and construction of major radio telescopes as those in Dwingeloo, Jodrell Bank, Parkes, Effelsberg and Green Bank since 1950 up to the present as well as millimeter wavelength telescopes as the 30m MRT of IRAM in Spain, the 50m LMT in Mexico and the ALMA submillimeter instrument. The advances in methods of structural design and coping with environmental influences (wind, temperature, gravity) as well as application of new materials are explained in a non-mathematical, descriptive and graphical way along with the story of the telescopes. Emphasis is placed on the interplay between astronomical and electromagnetic requirements and structural, mechanical and control solutions. A chapter on management aspects of large telescope projects closes the book. The authors address a readership with interest in the progress of engineering solutions applied to the development of radio telescope reflectors and ground station antennas for satellite communication and space research. The book will also be of interest to historians of science and engineering with an inclination to astronomy.

  14. Low-Noise Operation of All-Fiber Femtosecond Cherenkov Laser

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Villanueva Ibáñez, Guillermo Eduardo; Lægsgaard, Jesper

    2013-01-01

    We investigate the noise properties of a femtosecond all-fiber Cherenkov radiation source with emission wavelength around 600 nm, based on an Yb-fiber laser and a highly-nonlinear photonic crystal fiber. A relative intensity noise as low as - 103 dBc/Hz, corresponding to 2.48 % pulse-to-pulse flu...

  15. Study of the Planacon XP85012 photomultiplier characteristics for its use in a Cherenkov detector

    Science.gov (United States)

    Grigoryev, V. A.; Kaplin, V. A.; Karavicheva, T. L.; Kurepin, A. B.; Maklyaev, E. F.; Melikyan, Yu A.; Serebryakov, D. V.; Trzaska, W. H.; Tykmanov, E. M.

    2016-02-01

    Main properties of the multi-anode microchannel plate photomultiplier to be used in a Cherenkov detector are discussed. The laboratory test results obtained using irradiation of the MCP-PMT photocathode by picosecond optical laser pulses with different intensities (from single photon regime to the PMT saturation conditions) are presented.

  16. Gas breakdown limit and maximum acceleration gradient for inverse Cherenkov laser accelerator

    CERN Document Server

    Liu, Y; Cline, D

    1999-01-01

    Laser intensity thresholds for CO sub 2 laser-induced gas breakdown, such as tunneling, multiphoton, and cascade ionization have been estimated for the inverse Cherenkov accelerator experiment at the Brookhaven Accelerator Test Facility. The gas breakdown is dominated by cascade ionization and the maximum acceleration gradient is up to 300 MeV/m for a 3 ps CO sub 2 laser.

  17. Electrostatic design of the barrel CRID (Cherenkov Ring Imaging Detector) and associated measurements

    Energy Technology Data Exchange (ETDEWEB)

    Abe, K.; Hasegawa, K.; Suekane, F.; Yuta, H. (Tohoku Univ., Sendai (Japan). Dept. of Physics); Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.W.G.S.; Muller, D.; Nagamine, T.; Pavel, T.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Toge, N.; Va' Vra, J. Williams, H. (Stanford Linear Accelerator Center, Menlo Park, CA (US

    1990-04-01

    We report on the electrostatic design and related measurements of the barrel Cherenkov Ring Imaging Detector for the Stanford Large Detector experiment at the Stanford Linear Accelerator Center Linear Collider. We include test results of photon feedback in TMAE-laden gas, distortion measurements in the drift boxes and corona measurements. 13 refs., 21 figs.

  18. Cherenkov-light detectors for LHCb an application for hybrid photodetectors

    CERN Document Server

    Websdale, David M

    1997-01-01

    The Ring Imaging Cherenkov detectors proposed for the CERN LHC-B experiment will need photon detectors with challenging specifications. Single photon sensitivity, millimetre precision and timing resolution adequate to resolve the LHC bunch-crossing period of 25ns are required. The Hybrid Photodetector offers a promising solution

  19. Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Ullaland, O

    2011-01-01

    Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors in 'Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors 3.3.1 Introduction 3.3.2 Time of Flight Measurements 3.3.2.1 Scintillator hodoscopes 3.3.2.2 Parallel plate ToF detectors 3.3.3 Cherenkov Radiation 3.3.3.1 ...

  20. Large acceptance forward Cherenkov detector for the BRAHMS experiment at RHIC

    Science.gov (United States)

    Budick, B.; Beavis, D.; Chasman, C.

    2010-09-01

    A multi-element detector based on Cherenkov radiation in plastic and on photomultiplier tubes has been constructed that is particularly useful in collider experiments. The detector covers the pseudorapidity interval 3.23Monte Carlo simulations describe the pulse height response of the detector well, as does an analytic expression that has been developed. The detector performed well in the RHIC experiment BRAHMS.

  1. Space telescopes capturing the rays of the electromagnetic spectrum

    CERN Document Server

    English, Neil

    2017-01-01

    Space telescopes are among humankind’s greatest scientific achievements of the last fifty years. This book describes the instruments themselves and what they were designed to discover about the Solar System and distant stars. Exactly how these telescopes were built and launched and the data they provided is explored. Only certain kinds of radiation can penetrate our planet's atmosphere, which limits what we can observe. But with space telescopes all this changed. We now have the means to "see" beyond Earth using ultraviolet, microwave, and infrared rays, X-rays and gamma rays. In this book we meet the pioneers and the telescopes that were built around their ideas. This book looks at space telescopes not simply chronologically but also in order of the electromagnetic spectrum, making it possible to understand better why they were made.

  2. Telescopes and Techniques

    CERN Document Server

    Kitchin, C R

    2013-01-01

    Telescopes and Techniques has proved itself in its first two editions, having become probably one of the most widely used astronomy texts, both for amateur astronomers and astronomy and astrophysics undergraduates. Both earlier editions of the book were widely used for introductory practical astronomy courses in many universities. In this Third Edition the author guides the reader through the mathematics, physics and practical techniques needed to use today's telescopes (from the smaller models to the larger instruments installed in many colleges) and how to find objects in the sky. Most of the physics and engineering involved is described fully and requires little prior knowledge or experience. Both visual and electronic imaging techniques are covered, together with an introduction to how data (measurements) should be processed and analyzed. A simple introduction to radio telescopes is also included. Brief coverage of the more advanced topics of photometry and spectroscopy are included, but mainly to enable ...

  3. Corot telescope (COROTEL)

    Science.gov (United States)

    Viard, Thierry; Mathieu, Jean-Claude; Fer, Yann; Bouzou, Nathalie; Spalinger, Etienne; Chataigner, Bruno; Bodin, Pierre; Magnan, Alain; Baglin, Annie

    2017-11-01

    COROTEL is the telescope of the COROT Satellite which aims at measuring stellar flux variations very accurately. To perform this mission, COROTEL has to be very well protected against straylight (from Sun and Earth) and must be very stable with time. Thanks to its high experience in this field, Alcatel Alenia Space has proposed, manufactured and tested an original telescope concept associated with a high baffling performance. Since its delivery to LAM (Laboratoire d'Astrophysique de Marseille, CNRS) the telescope has passed successfully the qualification tests at instrument level performed by CNES. Now, the instrument is mounted on a Proteus platform and should be launched end of 2006. The satellite should bring to scientific community for the first time precious data coming from stars and their possible companions.

  4. Configurable Aperture Space Telescope

    Science.gov (United States)

    Ennico, Kimberly; Vassigh, Kenny; Bendek, Selman; Young, Zion W; Lynch, Dana H.

    2015-01-01

    In December 2014, we were awarded Center Innovation Fund to evaluate an optical and mechanical concept for a novel implementation of a segmented telescope based on modular, interconnected small sats (satlets). The concept is called CAST, a Configurable Aperture Space Telescope. With a current TRL is 2 we will aim to reach TLR 3 in Sept 2015 by demonstrating a 2x2 mirror system to validate our optical model and error budget, provide strawman mechanical architecture and structural damping analyses, and derive future satlet-based observatory performance requirements. CAST provides an alternative access to visible andor UV wavelength space telescope with 1-meter or larger aperture for NASA SMD Astrophysics and Planetary Science community after the retirement of HST.

  5. Comparison of prediction models for Cherenkov light emissions from nuclear fuel assemblies

    Science.gov (United States)

    Branger, E.; Grape, S.; Jacobsson Svärd, S.; Jansson, P.; Andersson Sundén, E.

    2017-06-01

    The Digital Cherenkov Viewing Device (DCVD) [1] is a tool used by nuclear safeguards inspectors to verify irradiated nuclear fuel assemblies in wet storage based on the Cherenkov light produced by the assembly. Verifying that no rods have been substituted in the fuel, so-called partial-defect verification, is done by comparing the intensity measured with a DCVD with a predicted intensity, based on operator fuel declaration. The prediction model currently used by inspectors is based on simulations of Cherenkov light production in a BWR 8x8 geometry. This work investigates prediction models based on simulated Cherenkov light production in a BWR 8x8 and a PWR 17x17 assembly, as well as a simplified model based on a single rod in water. Cherenkov light caused by both fission product gamma and beta decays was considered. The simulations reveal that there are systematic differences between the model used by safeguards inspectors and the models described in this publication, most noticeably with respect to the fuel assembly cooling time. Consequently, if the intensity predictions are based on another fuel type than the fuel type being measured, a systematic bias in intensity with respect to burnup and cooling time is introduced. While a simplified model may be accurate enough for a set of fuel assemblies with nearly identical cooling times, the prediction models may differ systematically by up to 18 % for fuels with more varied cooling times. Accordingly, these investigations indicate that the currently used model may need to be exchanged with a set of more detailed, fuel-type specific models, in order minimize the model dependent systematic deviations.

  6. Fast, Large-Area, Wide-Bandgap UV Photodetector for Cherenkov Light Detection

    Science.gov (United States)

    Wrbanek, John D.; Wrbanek, Susan Y.

    2013-01-01

    Due to limited resources available for power and space for payloads, miniaturizing and integrating instrumentation is a high priority for addressing the challenges of manned and unmanned deep space missions to high Earth orbit (HEO), near Earth objects (NEOs), Lunar and Martian orbits and surfaces, and outer planetary systems, as well as improvements to high-altitude aircraft safety. New, robust, and compact detectors allow future instrumentation packages more options in satisfying specific mission goals. A solid-state ultraviolet (UV) detector was developed with a theoretical fast response time and large detection area intended for application to Cherenkov detectors. The detector is based on the wide-bandgap semiconductor zinc oxide (ZnO), which in a bridge circuit can detect small, fast pulses of UV light like those required for Cherenkov detectors. The goal is to replace the role of photomultiplier tubes in Cherenkov detectors with these solid-state devices, saving on size, weight, and required power. For improving detection geometry, a spherical detector to measure high atomic number and energy (HZE) ions from any direction has been patented as part of a larger space radiation detector system. The detector will require the development of solid-state UV photodetectors fast enough (2 ns response time or better) to detect the shockwave of Cherenkov light emitted as the ions pass through a quartz, sapphire, or acrylic ball. The detector must be small enough to fit in the detector system structure, but have an active area large enough to capture enough Cherenkov light from the sphere. The detector is fabricated on bulk single-crystal undoped ZnO. Inter - digitated finger electrodes and contact pads are patterned via photolithography, and formed by sputtered metal of silver, platinum, or other high-conductivity metal.

  7. Construction of the Advanced Technology Solar Telescope

    Science.gov (United States)

    Rimmele, T. R.; Keil, S.; McMullin, J.; Knölker, M.; Kuhn, J. R.; Goode, P. R.; Rosner, R.; Casini, R.; Lin, H.; Tritschler, A.; Wöger, F.; ATST Team

    2012-12-01

    The 4m Advance Technology Solar Telescope (ATST) will be the most powerful solar telescope and the world's leading ground-based resource for studying solar magnetism that controls the solar wind, flares, coronal mass ejections and variability in the Sun's output. The project has entered its construction phase. Major subsystems have been contracted. As its highest priority science driver ATST shall provide high resolution and high sensitivity observations of the dynamic solar magnetic fields throughout the solar atmosphere, including the corona at infrared wavelengths. With its 4m aperture, ATST will resolve features at 0.″03 at visible wavelengths and obtain 0.″1 resolution at the magnetically highly sensitive near infrared wavelengths. A high order adaptive optics system delivers a corrected beam to the initial set of state-of-the-art, facility class instrumentation located in the Coudé laboratory facility. The initial set of first generation instruments consists of five facility class instruments, including imagers and spectro-polarimeters. The high polarimetric sensitivity and accuracy required for measurements of the illusive solar magnetic fields place strong constraints on the polarization analysis and calibration. Development and construction of a four-meter solar telescope presents many technical challenges, including thermal control of the enclosure, telescope structure and optics and wavefront control. A brief overview of the science goals and observational requirements of the ATST will be given, followed by a summary of the design status of the telescope and its instrumentation, including design status of major subsystems, such as the telescope mount assembly, enclosure, mirror assemblies, and wavefront correction

  8. Measurement of the Atmospheric $\

    CERN Document Server

    Aartsen, M G; Abdou, Y; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Altmann, D; Andeen, K; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Baum, V; Bay, R; Beattie, K; Beatty, J J; Bechet, S; Tjus, J Becker; Becker, K -H; Bell, M; Benabderrahmane, M L; BenZvi, S; Berdermann, J; Berghaus, P; Berley, D; Bernardini, E; Bertrand, D; Besson, D Z; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohaichuk, S; Bohm, C; Bose1, D; Boser, S; Botner, O; Brayeur, L; Brown, A M; Bruijn, R; Brunner, J; Buitink, S; Carson, M; Casey, J; Casier, M; Chirkin, D; Christy, B; Clark, K; Clevermann, F; Cohen, S; Cowen, D F; Silva, A H Cruz; Danninger, M; Daughhetee, J; Davis, J C; De Clercq, C; De Ridder, S; Descamps, F; Desiati, P; de Vries-Uiterweerd, G; DeYoung, T; Diaz-Velez, J C; Dreyer, J; Dumm, J P; Dunkman, M; Eagan, R; Eberhardt, B; Eisch, J; Ellsworth, R W; Engdegard, O; Euler, S; Evenson, P A; Fadiran, O; Fazely, A R; Fedynitch, A; Feintzeig, J; Feusels, T; Filimonov, K; Finley, C; Fischer-Wasels, T; Flis, S; Franckowiak, A; Franke, R; Frantzen, K; Fuchs, T; Gaisser, T K; Gallagher, J; Gerhardt, L; Gladstone, L; Glusenkamp, T; Goldschmidt, A; Golup, G; Goodman, J A; Gora, D; Grant, D; Gross, A; Grullon, S; Gurtner, M; Ha, C; Ismail, A Haj; Hallgren, A; Halzen, F; Hanson, K; Heereman, D; Heimann, P; Heinen, D; Helbing, K; Hellauer, R; Hickford, S; Hill, G C; Hoffman, K D; Hoffmann, R; Homeier, A; Hoshina, K; Huelsnitz, W; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jacobi, E; Jacobsen, J; Japaridze, G S; Jlelati, O; Kappes, A; Karg, T; Karle, A; Kiryluk, J; Kislat, F; Klas, J; Klein, S R; Kohne, J -H; Kohnen, G; Kolanoski, H; Kopke, L; Kopper, C; Kopper, S; Koskinen, D J; Kowalski, M; Krasberg, M; Kroll, G; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Landsman, H; Larson, M J; Lauer, R; Lesiak-Bzdak, M; Lunemann, J; Madsen, J; Maruyama, R; Mase, K; Matis, H S; McNally, F; Meagher, K; Merck, M; Meszaros, P; Meures, T; Miarecki, S; Middell, E; Milke, N; Miller, J; Mohrmann, L; Montaruli, T; Morse, R; Nahnhauer, R; Naumann, U; Nowicki, S C; Nygren, D R; Obertacke, A; Odrowski, S; Olivas, A; Olivo, M; O'Murchadha, A; Panknin, S; Paul, L; Pepper, J A; Heros, C Perez de los; Pieloth, D; Pirk, N; Posselt, J; Price, P B; Przybylski, G T; Radel, L; Rawlins, K; Redl, P; Resconi, E; Rhode, W; Ribordy, M; Richman, M; Riedel, B; Rodrigues, J P; Rott, C; Ruhe, T; Ruzybayev, B; Ryckbosch, D; Saba, S M; Salameh, T; Sander, H -G; Santander, M; Sarkar, S; Schatto, K; Scheel, M; Scheriau, F; Schmidt, T; Schmitz, M; Schoenen, S; Schoneberg, S; Schonherr, L; Schonwald, A; Schukraft, A; Schulte, L; Schulz, O; Seckel, D; Seo, S H; Sestayo, Y; Seunarine, S; Sheremata, C; Smith, M W E; Soiron, M; Soldin, D; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stasik, A; Stezelberger, T; Stokstad, R G; Stoss, A; Strahler, E A; Strom, R; Sullivan, G W; Taavola, H; Taboada, I; Tamburro, A; Ter-Antonyan, S; Tilav, S; Toale, P A; Toscano, S; Usner, M; van der Drift, D; van Eijndhoven, N; Van Overloop, A; van Santen, J; Vehring, M; Voge1, M; Vraeghe, M; Walck, C; Waldenmaier, T; Wallraff, M; Walter, M; Wasserman, R; Weaver, Ch; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, C; Xu, D L; Xu, X W; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Ziemann, J; Zierke, S; Zilles, A; Zoll, M

    2012-01-01

    We report the first observation in a high energy neutrino telescope of cascades induced by atmospheric electron neutrinos and by neutral current interactions of atmospheric neutrinos of all flavors. Using data recorded during the first year of operation of IceCube's DeepCore low energy extension, a sample of 1029 events is observed in 281 days of data. The number of observed cascades is $N_{\\rm cascade} = 496 \\pm 66 (stat.) \\pm 88(syst.)$ and the rest of the sample consists of residual backgrounds due to atmospheric muons and charged current interactions of atmospheric muon neutrinos. The flux of the atmospheric electron neutrinos is determined in the energy range between approximately 80 GeV and 6 TeV and is consistent with models of atmospheric neutrinos.

  9. The Liverpool Telescope

    Science.gov (United States)

    Smith, Robert J.; Bates, S. D.; Clay, Neil R.; Fraser, Stephen N.; Marchant, J. M.; Mottram, C. J.; Steele, I. A.; Tomlinson, M. D.

    2011-03-01

    The Liverpool Telescope (LT) is a fully robotic 2m optical telescope at a world-class observatory site. It runs autonomously without direct human control either on site or remotely. It is not operated primarily for a single science project, but rather is a common-user facility, time allocated by an open, peer-review process and conducting a variety of optical and IR imaging, spectroscopic and polarimetric programs. This paper describes some of aspects of the site infrastructure and instrument suite designed specifically to support robust and reliable unsupervised operations. Aside from the telescope hardware, the other aspect of robotic operations is the mechanisms whereby users interact with the telescope and its automated scheduler. We describe how these have been implemented for the LT. Observing routinely since 2004, the LT has demonstrated it is possible to operate a large, common-user robotic observatory. Making the most of the flexibility afforded by fully robotic operations, development continues in collaboration with both observers and other observatories to develop observing modes to enable new science across the broad discipline of time-domain astrophysics.

  10. Exploring Galileo's Telescope

    Science.gov (United States)

    Straulino, Samuele; Terzuoli, Alessandra

    2010-01-01

    In the first months of 2009, the International Year of Astronomy, the authors developed an educational project for middle-level students connected with the first astronomical discoveries that Galileo Galilei (1564-1642) made 400 years ago. The project included the construction of a basic telescope and the observation of the Moon. The project, if…

  11. Taiwan Automated Telescope Network

    Directory of Open Access Journals (Sweden)

    Dean-Yi Chou

    2010-01-01

    can be operated either interactively or fully automatically. In the interactive mode, it can be controlled through the Internet. In the fully automatic mode, the telescope operates with preset parameters without any human care, including taking dark frames and flat frames. The network can also be used for studies that require continuous observations for selected objects.

  12. Upgrade of the MAGIC Telescope with a Multiplexed Fiber-Optic 2 GSamples/s FADC Data Acquisition system

    CERN Document Server

    Goebel, Florian; Carmona, Emiliano; Galante, Nicola; Jogler, Tobias; Mirzoyan, Razmik; Coarasa, Jose Antonio; Teshima, Masahiro

    2007-01-01

    In February 2007 the MAGIC Air Cherenkov Telescope for gamma ray astronomy was fully upgraded with a fast 2 GSamples/s digitization system. The upgraded readout system uses a novel fiber-optic multiplexing technique. It consists of 10-bit 2 GSamples/s FADCs to digitize 16 channels consecutively and optical fibers to delay the analog signals. A distributed data acquisition system using GBit Ethernet and FiberChannel technology allows to read out the 100 kByte events with a continuous rate of up to 1 kHz.

  13. Giant Magellan Telescope: overview

    Science.gov (United States)

    Johns, Matt; McCarthy, Patrick; Raybould, Keith; Bouchez, Antonin; Farahani, Arash; Filgueira, Jose; Jacoby, George; Shectman, Steve; Sheehan, Michael

    2012-09-01

    The Giant Magellan Telescope (GMT) is a 25-meter optical/infrared extremely large telescope that is being built by an international consortium of universities and research institutions. It will be located at the Las Campanas Observatory, Chile. The GMT primary mirror consists of seven 8.4-m borosilicate honeycomb mirror segments made at the Steward Observatory Mirror Lab (SOML). Six identical off-axis segments and one on-axis segment are arranged on a single nearly-paraboloidal parent surface having an overall focal ratio of f/0.7. The fabrication, testing and verification procedures required to produce the closely-matched off-axis mirror segments were developed during the production of the first mirror. Production of the second and third off-axis segments is underway. GMT incorporates a seven-segment Gregorian adaptive secondary to implement three modes of adaptive-optics operation: natural-guide star AO, laser-tomography AO, and ground-layer AO. A wide-field corrector/ADC is available for use in seeing-limited mode over a 20-arcmin diameter field of view. Up to seven instruments can be mounted simultaneously on the telescope in a large Gregorian Instrument Rotator. Conceptual design studies were completed for six AO and seeing-limited instruments, plus a multi-object fiber feed, and a roadmap for phased deployment of the GMT instrument suite is being developed. The partner institutions have made firm commitments for approximately 45% of the funds required to build the telescope. Project Office efforts are currently focused on advancing the telescope and enclosure design in preparation for subsystem- and system-level preliminary design reviews which are scheduled to be completed in the first half of 2013.

  14. Coherent Cherenkov Radiation from Cosmic-Ray-Induced Air Showers

    NARCIS (Netherlands)

    de Vries, K. D.; van den Berg, A. M.; Scholten, O.; Werner, K.

    2011-01-01

    Very energetic cosmic rays entering the atmosphere of Earth will create a plasma cloud moving with almost the speed of light. The magnetic field of Earth induces an electric current in this cloud which is responsible for the emission of coherent electromagnetic radiation. We propose to search for a

  15. HabEx space telescope optical system

    Science.gov (United States)

    Martin, Stefan; Rud, Mayer; Scowen, Paul; Stern, Daniel; Nissen, Joel; Krist, John

    2017-09-01

    The HabEx study is defining a concept for a new space telescope with the primary mission of detecting and characterizing planetary systems around nearby stars. The telescope is designed specifically to operate with both a high contrast coronagraph and a starshade, enabling the direct optical detection of exoplanets as close as 70 mas from their star. The telescope will be equipped with cameras for exoplanetary system imaging and with spectrometers capable of characterizing exoplanet atmospheres. Gases such as oxygen, carbon dioxide, water vapor and methane have spectral lines in the visible and near infrared part of the spectrum and may indicate biological activity. In addition to the study of exoplanets, HabEx enables general astrophysics with two dedicated instruments. One instrument is a camera enabling imaging on a 3 arc minute field of view in two bands stretching from the UV to the near infrared. The same instrument can also be operated as a multi-object spectrograph, with resolution of 2000. A second instrument will be a high resolution UV spectrograph operating from 120 nm with up to 60,0000 resolution. We discuss the preliminary designs of the telescope and the optical instruments for the observatory.

  16. Optical Space Telescope Assembly Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Optical Space Telescope Assembly (OSTA) task is to demonstrate the technology readiness of assembling large space telescopes on orbit in 2015. This task is an...

  17. Development of a diagnostic technique based on Cherenkov effect for measurements of fast electrons in fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Plyusnin, V. V.; Duarte, P.; Fernandes, H.; Silva, C. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Universidade Tecnica de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Jakubowski, L.; Zebrowski, J.; Malinowski, K.; Rabinski, M.; Sadowski, M. J. [National Centre for Nuclear Research (NCBJ), 7 Andrzeja Soltana Str., 05-400 Otwock (Poland)

    2012-08-15

    A diagnostic technique based on the Cherenkov effect is proposed for detection and characterization of fast (super-thermal and runaway) electrons in fusion devices. The detectors of Cherenkov radiation have been specially designed for measurements in the ISTTOK tokamak. Properties of several materials have been studied to determine the most appropriate one to be used as a radiator of Cherenkov emission in the detector. This technique has enabled the detection of energetic electrons (70 keV and higher) and the determination of their spatial and temporal variations in the ISTTOK discharges. Measurement of hard x-ray emission has also been carried out in experiments for validation of the measuring capabilities of the Cherenkov-type detector and a high correlation was found between the data of both diagnostics. A reasonable agreement was found between experimental data and the results of numerical modeling of the runaway electron generation in ISTTOK.

  18. Uzaybimer Radio Telescope Control System

    Science.gov (United States)

    Balbay, R.; Öz, G. K.; Arslan, Ö.; Özeren, F. F.; Küçük, İ.

    2016-12-01

    A 13 meters former NATO radar is being converted into a radio telescope. The radio telescope is controlled by a system which has been developed at UZAYBİMER. The Telescope Control System(TCS) has been designed using modern industrial systems. TCS has been developed in LabView platform in which works Windows embedded OS. The position feedback used on radio telescopes is an industrial EtherCAT standard. ASCOM library is used for astronomical calculations.

  19. Galileo's wondrous telescope

    Science.gov (United States)

    Cartlidge, Edwin

    2008-06-01

    If you need reminding of just how wrong the great and the good can be, take a trip to the Museum of the History of Science in Florence, Italy. The museum is staging an exhibition entitled "Galileo's telescope - the instrument that changed the world" to mark the 400th anniversary this year of Galileo Galilei's revolutionary astronomical discoveries, which were made possible by the invention of the telescope. At the start of the 17th century, astronomers assumed that all the planets and the stars in the heavens had been identified and that there was nothing new for them to discover, as the exhibition's curator, Giorgio Strano, points out. "No-one could have imagined what wondrous new things were about to be revealed by an instrument created by inserting two eyeglass lenses into the ends of a tube," he adds.

  20. The Bionic Telescope

    Science.gov (United States)

    Woolf, Neville

    2009-05-01

    Four hundred years after children in a spectacle makers workshop accidentally discovered the telescope, the development of this device has been a continuous replacement of the ``natural'' by the deliberate. The human eye is gone. The lens is gone. The tube is gone. The dome is on the verge of going. The size of the optics are ceasing to be set by transportation limits. Adaptive optics are preferred to stable optics. We deliberately break the Lagrange invariant. We focus on lasers instead of stars, and natural observing environments are being replaced by adaptive environments. The goals for the new ground based telescope encompass the oldest and newest ideas, to find signs of life elsewhere, and to find how all the universe developed.

  1. Calibrating the Athena telescope

    Science.gov (United States)

    de Bruijne, J.; Guainazzi, M.; den Herder, J.; Bavdaz, M.; Burwitz, V.; Ferrando, P.; Lumb, D.; Natalucci, L.; Pajot, F.; Pareschi, G.

    2017-10-01

    Athena is ESA's upcoming X-ray mission, currently set for launch in 2028. With two nationally-funded, state-of-the-art instruments (a high-resolution spectrograph named X-IFU and a wide-field imager named WFI), and a telescope collecting area of 1.4-2 m^2 at 1 keV, the calibration of the spacecraft is a challenge in itself. This poster presents the current (spring 2017) plan of how to calibrate the Athena telescope. It is based on a hybrid approach, using bulk manufacturing and integration data as well as dedicated calibration measurements combined with a refined software model to simulate the full response of the optics.

  2. Everyday Radio Telescope

    CERN Document Server

    Mandal, Pranshu; Kumar, Pratik; Yelikar, Anjali; Soni, Kanchan; T, Vineeth Krishna

    2016-01-01

    We have developed an affordable, portable college level radio telescope for amateur radio astronomy which can be used to provide hands-on experience with the fundamentals of a radio telescope and an insight into the realm of radio astronomy. With our set-up one can measure brightness temperature and flux of the Sun at 11.2 GHz and calculate the beam width of the antenna. The set-up uses commercially available satellite television receiving system and parabolic dish antenna. We report the detection of point sources like Saturn and extended sources like the galactic arm of the Milky way. We have also developed python pipeline, which are available for free download, for data acquisition and visualization.

  3. Atmospheric trident production for probing new physics

    Directory of Open Access Journals (Sweden)

    Shao-Feng Ge

    2017-09-01

    Full Text Available We propose to use atmospheric neutrinos as a powerful probe of new physics beyond the Standard Model via neutrino trident production. The final state with double muon tracks simultaneously produced from the same vertex is a distinctive signal at large Cherenkov detectors. We calculate the expected event numbers of trident production in the Standard Model. To illustrate the potential of this process to probe new physics we obtain the sensitivity on new vector/scalar bosons with coupling to muon and tau neutrinos.

  4. [Galileo and his telescope].

    Science.gov (United States)

    Strebel, Christoph

    2006-01-01

    Galileo's publication of observations made with his newly reinvented telescope provoked a fierce debate. In April 1610 Martinus Horky, a young Bohemian astronomer, had an opportunity to make his own observations with Galileo's telescope in the presence of Antonio Magini and other astronomers. Horky and the other witnesses denied the adequacy of Galileo's telescope and therefore the bona fides of his discoveries. Kepler conjectured Horky as well as all his witnesses to be myopic. But Kepler's objection could not stop the publication of Horky's Peregrinatio contra nuncium sidereum (Modena, 1610), the first printed refutation of Galileo's Sidereus nuncius. In his treatise, Horky adresses four questions: 1) Do the four newly observed heavenly bodies actually exist? Horky denies their existence on various grounds: a) God, as every astronomer teaches, has created only seven moveable heavenly bodies and astronomical knowledge originates in God, too. b) Heavenly bodies are either stars or planets. Galileo's moveable heavenly bodies fit into neither category. c) If they do exist, why have they not already been observed by other scholars? Horky concludes that there are no such heavenly bodies. 2) What are these phenomena? They are purely artefactual, and produced by Galileo's telescope. 3) How are they like? Galileo's "stars" are so small as to be almost invisible. Galileo claims that he has measured their distances from each other. This however is impossible due to their diminutive size and other observational problems. Hence, Galileo's claim is a further proof that he is a fraud. 4) Why are they? For Galileo they are a chance to earn money but for astronomers like Horky they are a reason to offer thanks and honour to God. Horky's treatise was favourably received by the enemies of Galileo. But Kepler's critique was devastating. After calling on Kepler in Prague, Horky had to revoke the contents of his book.

  5. The aerogel threshold Cherenkov detector for the high momentum spectrometer in Hall C at Jefferson lab

    Energy Technology Data Exchange (ETDEWEB)

    Razmik Asaturyan; Rolf Ent; Howard Fenker; David Gaskell; Garth Huber; Mark Jones; David Mack; Hamlet Mkrtchyan; Bert Metzger; Nadia Novikoff; Vardan Tadevosyan; William Vulcan; Stephen Wood

    2004-11-09

    We describe a new aerogel threshold Cherenkov detector installed in the HMS spectrometer in Hall C at Jefferson Lab. The Hall C experimental program in 2003 required an improved particle identification system for better identification of {pi}/K/p, which was achieved by installing an additional threshold Cherenkov counter. Two types of aerogel with n = 1.03 and n = 1.015 allow one to reach {approx}10{sup -3} proton and 10{sup -2} kaon rejection in the 1-5 GeV/c momentum range with pion detection efficiency better than 99% (97%). The detector response shows no significant position dependence due to a diffuse light collection technique. The diffusion box was equipped with 16 Photonis XP4572 PMT's. The mean number of photoelectrons in saturation was {approx}16 and {approx}8, respectively. Moderate particle identification is feasible near threshold.

  6. Influence of thermal fluctuations on Cherenkov radiation from fluxons in dissipative Josephson systems

    DEFF Research Database (Denmark)

    Antonov, A. A.; Pankratov, A. L.; Yulin, A. V.

    2000-01-01

    The nonlinear dynamics of fluxons in Josephson systems with dispersion and thermal fluctuations is analyzed using the "quasiparticle" approach to investigate the influence of noise on the Cherenkov radiation effect. Analytical expressions for the stationary amplitude of the emitted radiation...... and its spectral distribution have been obtained in an annular geometry. It is demonstrated that noise reduces the amplitude of the radiated wave and broadens its spectrum. The effect of the radiated wave on the fluxon dynamics leads to a considerably smaller linewidth than observed in the usual flux flow...... oscillator. A resonant behavior of both the mean amplitude and the linewidth as functions of bias current is found. The obtained results enable an optimization of the main parameters (power, tunability, and linewidth) of practical mm- and sub-mm wave Cherenkov flux flow oscillators....

  7. Analog Cherenkov detectors used in laser spectroscopy experiments on antiprotonic helium

    CERN Document Server

    Hori, Masaki; Hayano, R S; Yamazaki, T

    2003-01-01

    We describe some acrylic Cherenkov detectors read out by gateable fine-mesh photomultipliers, used in laser spectroscopy experiments of metastable antiprotonic helium (pbarHe+) atoms carried out at the LEAR and AD facilities at CERN. The atoms were produced by stopping pulsed antiproton beams in a helium target. Charged particles emerging from the antiproton annihilations produced Cherenkov light in the detector, the time envelope of which consisted of a strong flash from the promptly-annihilating antiprotons, followed by a much longer but less intense tail from the delayed annihilations of the metastable atoms. The photomultiplier was turned off during the initial light flash by reversing the electric potential on its dynodes, thus allowing only the delayed annihilations to be recorded as an analog pulse. The atoms were irradiated with a laser pulse tuned to the characteristic wavelength whic simulated antiproton transitions from a metastable state to a state with a short lifetime against annihilation. The r...

  8. Study on single-channel signals of water Cherenkov detector array for the LHAASO project

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.C., E-mail: lihuicai@ihep.ac.cn [University of Nankai, Tianjin 300071 (China); Yao, Z.G.; Chen, M.J. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Yu, C.X. [University of Nankai, Tianjin 300071 (China); Zha, M.; Wu, H.R.; Gao, B.; Wang, X.J. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Liu, J.Y.; Liao, W.Y. [University of Nankai, Tianjin 300071 (China); Huang, D.Z. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China)

    2017-05-11

    The Large High Altitude Air Shower Observatory (LHAASO) is planned to be built at Daocheng, Sichuan Province, China. The water Cherenkov detector array (WCDA), with an area of 78,000 m{sup 2} and capacity of 350,000 tons of purified water, is one of the major components of the LHAASO project. A 9-cell detector prototype array has been built at the Yangbajing site, Tibet, China to comprehensively understand the water Cherenkov technique and investigate the engineering issues of WCDA. In this paper, the rate and charge distribution of single-channel signals are evaluated using a full detail Monte Carlo simulation. The results are discussed and compared with the results obtained with prototype array.

  9. Design and fabrication of a window for the gas Cherenkov detector 3

    Energy Technology Data Exchange (ETDEWEB)

    Fatherley, V. E., E-mail: vef@lanl.gov; Bingham, D. A.; Cartelli, M. D.; Griego, J. R.; Herrmann, H. W.; Lopez, F. E.; Oertel, J. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); DiDomizio, R. A.; Pollack, M. J. [EnvirOptics, Inc., Colmar, Pennsylvania 18915 (United States)

    2016-11-15

    The gas Cherenkov detector 3 was designed at Los Alamos National Laboratory for use in inertial confinement fusion experiments at both the Omega Laser Facility and the National Ignition Facility. This instrument uses a low-Z gamma-to-electron convertor plate and high pressure gas to convert MeV gammas into UV/visible Cherenkov photons for fast optical detection. This is a follow-on diagnostic from previous versions, with two notable differences: the pressure of the gas is four times higher, and it allows the use of fluorinated gas, requiring metal seals. These changes force significant changes in the window component, having a unique set of requirements and footprint limitations. The selected solution for this component, a sapphire window brazed into a stainless steel flange housing, is described.

  10. The quest for a third generation of gaseous photon detectors for Cherenkov imaging counters

    CERN Document Server

    Alexeev, M

    2009-01-01

    RICH (Ring Imaging CHerenkov) counters for PID in the high momentum domain and in large acceptance experiments require photon detectors covering extended surface (several square meters) and able to accept Cherenkov photons in a wide angular range. An ideal approach is represented by gaseous photon detectors, which allow covering wide surfaces at affordable costs. The first generation of these detectors was based on the use of organic vapors. The second generation consists of CsI photocathodes and open geometry gaseous detectors (MWPC). In spite of the success of this approach, some limits of the technique arise from the bombardment of the photocathodes by the ions generated in the amplification process and by the photon feedback. A third generation of gaseous photon detectors using closed geometry, as those possible with multistage arrangements of micropattern gaseous detectors, can overcome the observed limitations. We have started an R&D programme to develop a Thick-GEM-based photon detector and we repo...

  11. CHerenkov detectors In mine PitS (CHIPS) Letter of Intent to FNAL

    Energy Technology Data Exchange (ETDEWEB)

    Adamson, P. [Fermi National Accelerator Laboratory (FNAL), Batavia, IL (United States); Austin, J. [Univ. of Minnesota, Duluth, MN (United States); Cao, S. V. [Univ. of Texas, Austin, TX (United States); Coelho, J. A. B. [Tufts Univ., Medford, MA (United States); Davies, G. S. [Iowa State Univ., Ames, IA (United States); Evans, J. J. [Univ. of Manchester (United Kingdom); Guzowski, P. [Univ. of Manchester (United Kingdom); Habig, A. [Univ. of Minnesota, Duluth, MN (United States); Holin, A. [Univ. College London, London (United Kingdom); Huang, J. [Univ. of Texas, Austin, TX (United States); Johnson, R. [Univ. of Cincinnati, OH (United States); St. John, J. [Univ. of Cincinnati, OH (United States); Kreymer, A. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Kordosky, M. [College of William and Mary, Williamsburg, VA (United States); Lang, K. [Univ. of Texas, Austin, TX (United States); Marshak, M. L. [Univ. of Minnesota, Minneapolis, MN (United States); Mehdiyev, R. [Univ. of Texas, Austin, TX (United States); Meier, J. [Univ. of Minnesota, Minneapolis, MN (United States); Miller, W. [Univ. of Minnesota, Minneapolis, MN (United States); Naples, D. [Univ. of Pittsburgh, PA (United States); Nelson, J. K. [College of William and Mary, Williamsburg, VA (United States); Nichol, R. J. [Univ. College London, London (United Kingdom); Patterson, R. B. [California Inst. of Technology (CalTech), Pasadena, CA (United States); Paolone, V. [Univ. of Pittsburgh, PA (United States); Pawloski, G. [Univ. of Minnesota, Minneapolis, MN (United States); Perch, A. [Univ. College London, London (United Kingdom); Pfutzner, M. [Univ. College London, London (United Kingdom); Proga, M. [Univ. of Texas, Austin, TX (United States); Qian, X. [Brookhaven National Lab. (BNL), Upton, NY (United States); Radovic, A. [Univ. College London, London (United Kingdom); Sanchez, M. C. [Iowa State Univ., Ames, IA (United States); Schreiner, S. [Univ. of Minnesota, Minneapolis, MN (United States); Soldner-Rembold, S. [Univ. of Manchester (United Kingdom); Sousa, A. [Univ. of Cincinnati, OH (United States); Thomas, J. [Univ. College London, London (United Kingdom); Vahle, P. [College of William and Mary, Williamsburg, VA (United States); Wendt, C. [Univ. of Wisconsin, Madison, WI (United States); Whitehead, L. H. [Univ. College London, London (United Kingdom); Wojcicki, S. [Stanford Univ., CA (United States)

    2013-12-30

    This Letter of Intent outlines a proposal to build a large, yet cost-effective, 100 kton fiducial mass water Cherenkov detector that will initially run in the NuMI beam line. The CHIPS detector (CHerenkov detector In Mine PitS) will be deployed in a flooded mine pit, removing the necessity and expense of a substantial external structure capable of supporting a large detector mass. There are a number of mine pits in northern Minnesota along the NuMI beam that could be used to deploy such a detector. In particular, the Wentworth Pit 2W is at the ideal off-axis angle to contribute to the measurement of the CP violating phase. The detector is designed so that it can be moved to a mine pit in the LBNE beam line once that becomes operational.

  12. Water resistant rhodium plated reflectors for use in the DIRC BaBar Cherenkov detector

    CERN Document Server

    Benkebil, M; Plaszczynski, S; Schune, M H; Wormser, G

    2000-01-01

    Early simulation studies showed that reflectors mounted on the photomultipliers would be useful for the DIRC BaBar Cherenkov detector, showing a gain between 20% and 30% in the number of Cherenkov photons. The proof of principle for these reflectors has been obtained during the beam test of a large-scale prototype of the DIRC detector. An extensive R and D has been conducted in order to test different metallization procedures. Indeed, the challenge was to find a metallization technique which can resist the pure de-ionized water (>15 M OMEGA) up to 10 yr. The chosen technology was rhodium plated reflectors. During the first BaBar cosmic run, the measured performance confirmed the results of the simulation, the prototype-II and the R and D.

  13. Rapid screening of 90Sr activity in water and milk samples using Cherenkov radiation.

    Science.gov (United States)

    Stamoulis, K C; Ioannides, K G; Karamanis, D T; Patiris, D C

    2007-01-01

    A method for screening 90Sr in milk samples is proposed. This method is based on a liquid scintillation technique taking advantage of Cherenkov radiation, which is produced in a liquid medium and then detected by the photomultipliers of a Liquid Scintillation Counter (LSC). Twenty millilitres of water and milk samples spiked with various concentrations of 90Sr/90Y in equilibrium were added in plastic vials and then were measured with an LSC (TriCarb 3170 TR/SL). The derived efficiencies were 49% for water samples and 14% for milk samples. The detection limit was 470 mBq L(-1)(90)Sr for water, without any pretreatment. Milk contains potassium, which also produces Cherenkov radiation due to the presence of 40K. For this reason, the interference of 40K in the measurements of 90Sr in milk samples was also investigated. The detection limit for milk was 1.7 Bq L(-1)90Sr.

  14. LPM Interference and Cherenkov-like Gluon Bremsstrahlung in DenseMatter

    Energy Technology Data Exchange (ETDEWEB)

    Majumder, Abhijit; Wang, Xin-Nian

    2005-07-26

    Gluon bremsstrahlung induced by multiple parton scattering in a finite dense medium has a unique angular distribution with respect to the initial parton direction. A dead-cone structure with an opening angle; theta2{sub 0}; approx 2(1-z)/(zLE) for gluons with fractional energy z arises from the Landau-Pomeran chuck-Migdal (LPM) interference. In a medium where the gluon's dielectric constant is; epsilon>1, the LPM interference pattern is shown to become Cherenkov-like with an increased opening angle determined by the dielectric constant$/cos2/theta{sub c}=z+(1-z)//epsilon$. For a large dielectric constant/epsilon; gg 1+2/z2LE, the corresponding total radiative parton energy loss is about twice that from normal gluon bremsstrahlung. Implications of this Cherenkov-like gluon bremsstrahlung to the jet correlation pattern in high-energy heavy-ion collisions is discussed.

  15. Performance study of the fast timing Cherenkov detector based on a microchannel plate PMT

    OpenAIRE

    Finogeev, D. A.; Grigoriev, V A; Kaplin, V A; Karavichev, O. V.; Karavicheva, T. L.; Konevskikh, A. S.; Kurepin, A.B.; Kurepin, A N; Loginov, V. A.; Mayevskaya, A. I.; Melikyan, Yu. A.; Morozov, I. V.; Serebryakov, D. V.; Shabanov, A. I.; Slupecki, Maciej

    2017-01-01

    Prototype of the fast timing Cherenkov detector, applicable in high-energy collider experiments, has been developed basing on the modified Planacon XP85012 MCP-PMT and fused silica radiators. We present the reasons and description of the MCP-PMT modification, timing and amplitude characteristics of the prototype including the summary of the detector's response on particle hits at oblique angles and MCP-PMT performance at high illumination rates.

  16. Picosecond Cherenkov detectors for high-energy heavy ion experiments at LHEP/JINR

    Energy Technology Data Exchange (ETDEWEB)

    Yurevich, V.I., E-mail: yurevich@jinr.ru [Joint Institute for Nuclear Research, Joliot-Curie 6, 141980 Dubna (Russian Federation); Batenkov, O.I. [Radium Institute, 2nd Murinskiy 28, 194021 St. Petersburg (Russian Federation)

    2016-07-11

    The modular Cherenkov detectors based on MCP-PMTs are developed for study Au+Au collisions in MPD and BM@N experiments with beams of Nuclotron and future collider NICA in Dubna. The aim of the detector is fast and effective triggering nucleus–nucleus collisions and generation of start signal for TOF detectors. The detector performance is studied with MC simulation and test measurements with a beam of Nuclotron.

  17. Picosecond Cherenkov detectors for high-energy heavy ion experiments at LHEP/JINR

    Science.gov (United States)

    Yurevich, V. I.; Batenkov, O. I.

    2016-07-01

    The modular Cherenkov detectors based on MCP-PMTs are developed for study Au+Au collisions in MPD and BM@N experiments with beams of Nuclotron and future collider NICA in Dubna. The aim of the detector is fast and effective triggering nucleus-nucleus collisions and generation of start signal for TOF detectors. The detector performance is studied with MC simulation and test measurements with a beam of Nuclotron.

  18. Performance study of the fast timing Cherenkov detector based on a microchannel plate PMT

    Science.gov (United States)

    Finogeev, D. A.; Grigoriev, V. A.; Kaplin, V. A.; Karavichev, O. V.; Karavicheva, T. L.; Konevskikh, A. S.; Kurepin, A. B.; Kurepin, A. N.; Loginov, V. A.; Mayevskaya, A. I.; Melikyan, Yu A.; Morozov, I. V.; Serebryakov, D. V.; Shabanov, A. I.; Slupecki, M.; Tikhonov, A. A.; Trzaska, W. H.

    2017-01-01

    Prototype of the fast timing Cherenkov detector, applicable in high-energy collider experiments, has been developed basing on the modified Planacon XP85012 MCP-PMT and fused silica radiators. We present the reasons and description of the MCP-PMT modification, timing and amplitude characteristics of the prototype including the summary of the detector’s response on particle hits at oblique angles and MCP-PMT performance at high illumination rates.

  19. Development of a research reactor power measurement system using Cherenkov radiation

    Energy Technology Data Exchange (ETDEWEB)

    Salles, Brício M.; Mesquita, Amir Z., E-mail: briciomares@hotmail.com, E-mail: amir@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-11-01

    Nuclear research reactors are usually located in open pools, to allow visibility to the core and bluish luminosity of Cherenkov radiation. Usually the thermal power released in these reactors is monitored by chambers that measure the neutron flux, as it is proportional to the power. There are other methods used for power measurement, such as monitoring the core temperature and the energy balance in the heat exchanger. The brightness of Cherenkov's radiation is caused by the emission of visible electromagnetic radiation (in the blue band) by charged particles that pass through an insulating medium (water in nuclear research reactors) at a speed higher than that of light in this medium. This effect was characterized by Pavel Cherenkov, which earned him the Nobel Prize for Physics in 1958. The project's objective is to develop an innovative and alternative method for monitoring the power of nuclear research reactors. It will be performed by analyzing and monitoring the intensity of luminosity generated by Cherenkov radiation in the reactor core. This method will be valid for powers up to 250 kW, since above that value the luminosity saturates, as determined by previous studies. The reactor that will be used to test the method is the TRIGA, located at Nuclear Technology Development Center (CDTN), which currently has a maximum operating power of 250 kW. This project complies with International Atomic Energy Agency (IAEA) recommendations on reactor safety. It will give more redundancy and diversification in this measure and will not interfere with its operation. (author)

  20. The AMS02 Cherenkov imager prototype In-beam tests with high-energy ions

    CERN Document Server

    Buénerd, Michel

    2005-01-01

    A prototype of the AMS Cherenkov imager has been tested at CERN with 20 and per nucleon ion obtained by fragmentation of a primary beam of Pb and In ions, respectively. Data have been collected with single low-intensity beam settings, over the range of nuclear charges 2

  1. Cherenkov-cyclotron instability in a metamaterial loaded waveguide for high power generation

    Science.gov (United States)

    Lu, Xueying; Shapiro, Michael; Temkin, Richard

    2017-10-01

    This work presents the analytical theory for an S-band high power microwave experiment at MIT utilizing a metamaterial (MTM) structure. A 490 kV, 84 A electron beam travels through a rectangular waveguide loaded with two MTM plates in a DC magnetic field B0. The excited waveguide mode is deflecting with a transverse E field on beam axis. Microsecond long megawatt level microwave pulses were generated under a low B0 in the Cherenkov-cyclotron type of interaction. A linear theory has been developed to explain the high power generation due to the Cherenkov-cyclotron instability. The simplified model is a planar waveguide filled with a double negative dispersive medium, and in the mode being studied, the longitudinal E field has an antisymmetric pattern in the direction perpendicular to the MTM plates. We have proved that the Cherenkov-cyclotron instability can happen with a zero initial transverse beam velocity when B0 is below a threshold. Also this instability is a unique feature of the left-handed MTM, since it requires a propagating mode below the cut-off frequency. The minimum beam current to start the instability is calculated, and the scaling law different from that of the traditional backward wave oscillators operated by longitudinal bunching will be discussed. This research was supported by the Air Force Office of Scientific Research within the Multidisciplinary University Research Initiative under Grant No. FA9550-12-1-0489 through the University of New Mexico.

  2. Cherenkov radiation imaging of beta emitters: in vitro and in vivo results

    Energy Technology Data Exchange (ETDEWEB)

    Spinelli, Antonello E., E-mail: spinelli.antonello@hsr.it [Medical Physics Department, S. Raffaele Scientific Institute, Via Olgettina N. 60, Milan (Italy); Boschi, Federico [Department of Morphological-Biomedical Sciences, University of Verona, Strada Le Grazie N. 8, Verona (Italy); D' Ambrosio, Daniela [Medical Physics Department, S. Orsola-Malpighi University Hospital, via Massarenti N. 9, Bologna (Italy); Calderan, Laura [Department of Morphological-Biomedical Sciences, University of Verona, Strada Le Grazie N. 8, Verona (Italy); Marengo, Mario [Medical Physics Department, S. Orsola-Malpighi University Hospital, via Massarenti N. 9, Bologna (Italy); Fenzi, Alberto [Department of Morphological-Biomedical Sciences, University of Verona, Strada Le Grazie N. 8, Verona (Italy); Menegazzi, Marta [Department of Life and Reproduction Sciences, University of Verona, Strada Le Grazie N. 8, Verona (Italy); Sbarbati, Andrea [Department of Morphological-Biomedical Sciences, University of Verona, Strada Le Grazie N. 8, Verona (Italy); Del Vecchio, Antonella; Calandrino, Riccardo [Medical Physics Department, S. Raffaele Scientific Institute, Via Olgettina N. 60, Milan (Italy)

    2011-08-21

    The main purpose of this work was to investigate both in vitro and in vivo Cherenkov radiation (CR) emission coming from {sup 18}F and {sup 32}P. The main difference between {sup 18}F and {sup 32}P is mainly the number of the emitted light photons, more precisely the same activity of {sup 32}P emits more CR photons with respect to {sup 18}F. In vitro results obtained by comparing beta counter measurements with photons average radiance showed that Cherenkov luminescence imaging (CLI) allows quantitative tracer activity measurements. In order to investigate in vivo the CLI approach, we studied an experimental xenograft tumor model of mammary carcinoma (BB1 tumor cells). Cherenkov in vivo dynamic whole body images of tumor bearing mice were acquired and the tumor tissue time activity curves reflected the well-known physiological accumulation of {sup 18}F-FDG in malignant tissues with respect to normal tissues. The results presented here show that it is possible to use conventional optical imaging devices for in vitro or in vivo study of beta emitters.

  3. Aerogel Cherenkov detector for characterizing the intense flash x-ray source, Cygnus, spectrum

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Y., E-mail: yhkim@lanl.gov; Herrmann, H. W.; McEvoy, A. M.; Young, C. S.; Hamilton, C. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Schwellenbach, D. D.; Malone, R. M.; Kaufman, M. I.; Smith, A. S. [National Security Technologies, LLC, Los Alamos, New Mexico 87544 (United States)

    2016-11-15

    An aerogel Cherenkov detector is proposed to measure the X-ray energy spectrum from the Cygnus—intense flash X-ray source operated at the Nevada National Security Site. An array of aerogels set at a variety of thresholds between 1 and 3 MeV will be adequate to map out the bremsstrahlung X-ray production of the Cygnus, where the maximum energy of the spectrum is normally around 2.5 MeV. In addition to the Cherenkov radiation from aerogels, one possible competing light-production mechanism is optical transition radiation (OTR), which may be significant in aerogels due to the large number of transitions from SiO{sub 2} clusters to vacuum voids. To examine whether OTR is a problem, four aerogel samples were tested using a mono-energetic electron beam (varied in the range of 1–3 MeV) at NSTec Los Alamos Operations. It was demonstrated that aerogels can be used as a Cherenkov medium, where the rate of the light production is about two orders magnitude higher when the electron beam energy is above threshold.

  4. R and D on high momentum particle identification with a pressurized Cherenkov radiator

    Energy Technology Data Exchange (ETDEWEB)

    Agócs, A.G. [Wigner RCP of the HAS, Budapest (Hungary); Barile, F. [INFN Sezione di Bari and Universit´a degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); Barnaföldi, G.G. [Wigner RCP of the HAS, Budapest (Hungary); Bellwied, R. [University of Houston, Houston (United States); Bencédi, G.; Bencze, G.; Berényi, D.; Boldizsár, L. [Wigner RCP of the HAS, Budapest (Hungary); Chattopadhyay, S. [Saha Institute of Nuclear Physics, Kolkata (India); Chinellato, D.D. [University of Houston, Houston (United States); Cindolo, F. [University of Salerno, Salerno (Italy); Cossyleon, K. [Chicago State University, Chicago, IL (United States); Das, D.; Das, K.; Das-Bose, L. [Saha Institute of Nuclear Physics, Kolkata (India); De Cataldo, G.; Di Bari, D. [INFN Sezione di Bari and Universit´a degli Studi di Bari, Dipartimento Interateneo di Fisica M. Merlin, Bari (Italy); Di Mauro, A. [CERN, CH1211 Geneva 23 (Switzerland); Futó, E. [Wigner RCP of the HAS, Budapest (Hungary); Garcia-Solis, E. [Chicago State University, Chicago, IL (United States); and others

    2014-12-01

    We report on the R and D results for a Very High Momentum Particle Identification (VHMPID) detector, which was proposed to extend the charged hadron track-by-track identification in the momentum range from 5 to 25 GeV/c in the ALICE experiment at CERN. It is a RICH detector with focusing geometry using pressurized perfluorobutane (C{sub 4}F{sub 8}O) as a Cherenkov radiator. A MWPC with a CsI photocathode was investigated as the baseline option for the photon detector. The results of beam tests performed on RICH prototypes using both liquid C{sub 6}F{sub 14} radiator (in proximity focusing geometry for reference measurements) and pressurized C{sub 4}F{sub 8}O gaseous radiator will be shown in this paper. In addition, we present studies of a CsI based gaseous photon detector equipped with a MWPC having an adjustable anode–cathode gap, aiming at the optimization of the chamber layout and performance in the detection of single photoelectrons. - Highlights: • Pressurized and heated C{sub 4}F{sub 8}O was used as Cherenkov radiator gas. • A Cherenkov angle resolution of 1.5 mrad was achieved. • The separation of electrons, pions, and kaons in a large momentum range is shown.

  5. Performance study of wavelength shifting acrylic plastic for Cherenkov light detection

    Energy Technology Data Exchange (ETDEWEB)

    Beckford, B., E-mail: beckford@aps.org [American Physical Society, One Physics Ellipse, College Park, MD 20740 (United States); De la Puente, A. [TRIUMF Laboratory, 4004 Wesbrook Mall, Vancouver, BC, Canada V6T 2A3 (Canada); Fujii, Y.; Hashimoto, O.; Kaneta, M.; Kanda, H.; Maeda, K.; Matsumura, A.; Nakamura, S.N. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan); Perez, N.; Reinhold, J. [Department of Physics, Florida International University, Miami, FL 33199 (United States); Tang, L. [Department of Physics, Hampton University, Hampton, VA 23668 (United States); Tsukada, K. [Department of Physics, Tohoku University, Sendai 980-8578 (Japan)

    2014-01-21

    The collection efficiency for Cherenkov light incident on a wavelength shifting plate (WLS) has been determined during a beam test at the Proton Synchrotron facility located in the National Laboratory for High Energy Physics (KEK), Tsukuba, Japan. The experiment was conducted in order to determine the detector's response to photoelectrons converted from photons produced by a fused silica radiator; this allows for an approximation of the detector's quality. The yield of the photoelectrons produced through internally generated Cherenkov light as well as light incident from the radiator was measured as a function of the momentum of the incident hadron beam. The yield is proportional to sin{sup 2}θ{sub c}, where θ{sub c} is the opening angle of the Cherenkov light created. Based on estimations and results from similar conducted tests, where the collection efficiency was roughly 39%, the experimental result was expected to be around 40% for internally produced light from the WLS. The results of the experiment determined the photon collection response efficiency of the WLS to be roughly 62% for photons created in a fused silica radiator and 41% for light created in the WLS.

  6. LUCID A Cherenkov Tube Based Detector for Monitoring the ATLAS Experiment Luminosity

    CERN Document Server

    Sbrizzi, A

    2007-01-01

    The LUCID (LUminosity Cherenkov Integrating Detector) apparatus is composed by two symmetric arms deployed at about 17 m from the ATLAS interaction point. The purpose of this detector, which will be installed in january 2008, is to monitor the luminosity delivered by the LHC machine to the ATLAS experiment. An absolute luminosity calibration is needed and it will be provided by a Roman Pot type detector with the two arms placed at about 240 m from the interaction point. Each arm of the LUCID detector is based on an aluminum vessel containing 20 Cherenkov tubes, 15 mm diameter and 1500 mm length, filled with C4F10 radiator gas at 1.5 bar. The Cherenkov light generated by charged particles above the threshold is collected by photomultiplier tubes (PMT) directly placed at the tubes end. The challenging aspect of this detector is its readout in an environment characterized by the high dose of radiation (about 0.7 Mrad/year at 10^33cm^2 s^-1) it must withstand. In order to fulfill these radiation hardness requirem...

  7. Development of a Cherenkov-type diagnostic system to study runaway electrons within the COMPASS tokamak

    Science.gov (United States)

    Rabinski, M.; Jakubowski, L.; Malinowski, K.; Sadowski, M. J.; Zebrowski, J.; Jakubowski, M. J.; Mirowski, R.; Weinzettl, V.; Ficker, O.; Mlynar, J.; Panek, R.; Paprok, R.; Vlainic, M.

    2017-10-01

    Direct measurements of fast electrons, which are produced in high-temperature plasma and escape from tokamak-type facilities, are of particular interest for ITER and future fusion devices, where intense runaway electrons (RE) can significantly damage the first wall components. Therefore, the runaway control and mitigation based on credible measuring methods should be developed already in present devices. A team from the National Centre for Nuclear Research (NCBJ), Poland, developed special probes equipped with Cherenkov-type detectors for measurements of the fast electrons within edge plasmas of tokamaks. Studies of the fast runaway electrons were extensively carried out at the COMPASS tokamak at the Institute of Plasma Physics (IPP) in Prague during experimental campaigns in 2014–2016. In order to investigate an electron-beam energy distribution a three-channel probe equipped with the Cherenkov-type detectors sensitive to electrons of different energies has been constructed. The measurements performed by means of these detectors showed that the first fast electron peak appears usually in the current ramp-up phase, even before the hard X-rays (HXR) pulse. Some electron signals can also be observed during subsequent HXR emissions. However, the most distinct electron peaks in all energy channels appear mainly during the plasma disruption. A correlation of Cherenkov signals with the MHD activity was also studied.

  8. First observation of Cherenkov rings with a large area CsI-TGEM-based RICH prototype

    CERN Document Server

    Peskov, V; Di Mauro, A; Martinengo, P; Mayani, D; Molnar, L; Nappi, E; Paic, G; Smirnov, N; Anand, H; Shukla, I

    2012-01-01

    We have built a RICH detector prototype consisting of a liquid C6F14 radiator and six triple Thick Gaseous Electron Multipliers (TGEMs), each of them having an active area of 10x10 cm2. One triple TGEM has been placed behind the liquid radiator in order to detect the beam particles, whereas the other five have been positioned around the central one at a distance to collect the Cherenkov photons. The upstream electrode of each of the TGEM stacks has been coated with a 0.4 micron thick CsI layer. In this paper, we will present the results from a series of laboratory tests with this prototype carried out using UV light, 6 keV photons from 55Fe and electrons from 90Sr as well as recent results of tests with a beam of charged pions where for the first time Cherenkov Ring images have been successfully recorded with TGEM photodetectors. The achieved results prove the feasibility of building a large area Cherenkov detector consisting of a matrix of TGEMs.

  9. Check of the accuracy of the relativity theory with atmospheric muon neutrinos from the AMANDA data of the years 2000 to 2003; Ueberpruefung der Genauigkeit der Relativitaetstheorie mit atmosphaerischen Myonneutrinos aus den AMANDA-Daten der Jahre 2000 bis 2003

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, J.C.

    2006-11-08

    Atmospheric neutrinos allow one to test the principles of the Theory of Relativity in particular Lorentz invariance and the equivalence principle. Small deviations from these principles could lead, according to some theories, to detectable neutrino oscillations. Such oscillation effects are analysed in this thesis, using the data collected by the AMANDA detector. The neutrino telescope AMANDA is located at the South Pole and embedded in the Antarctic ice shield at a depth between 1500 m and 2000 m. AMANDA detects muon neutrinos via the Cherenkov light of neutrino induced muons allowing the reconstruction of the original neutrino direction. From the data of the years 2000 to 2003, which contain about seven billion recorded events and which mainly consist of the background of atmospheric muons, a sample of 3401 neutrino induced events has been selected. No indication for alternative oscillation effects has been found. For maximal mixing angles, a lower limit for parameters which violate Lorentz invariance or the equivalence principle could be set to {delta}{beta}(2 vertical stroke {phi} vertical stroke {delta}{gamma}){<=}5.15.10{sup -27}. (orig)

  10. Revisiting the Effectiveness of Large Optical Telescopes

    Directory of Open Access Journals (Sweden)

    V. V. Sychev

    2015-01-01

    Full Text Available To create large-size optical telescopes, various design concepts have been used. Each concept inevitably faced the challenge to optimize technical characteristics and parameters of the telescope. There was always a question: what concept to choose, how to estimate efficiency of such telescopes and by what criteria and how to estimate expediency of this or that project of the large-size telescope. It is, obviously, insufficient to make a resolution-based estimation. An estimate by the angular field size is inappropriate too. Well, it may be also an estimate by the stellar magnitude. All these criteria are related to each other. Improvement of one of these parameters inevitably leads to deterioration of the others. Obviously, the certain generalized criterion considering all parameters and features of the design concept of the large-size telescope is necessary here. As such can serve the criterion of informational content of the telescope.The article offers a complex criterion allowing not only to estimate efficiency of large-size optical telescopes, but also to compare their conceptual and technological level among themselves in terms of obtaining information.The article suggests a new term, i.e. the informational content invariant to characterize informative capacities of the chosen concept and of the realizing technology. It will allow us to avoid unjustified complications of technical solutions, wrong accents in designing and excess material inputs when developing the project.The informational content criterion-based analysis of the existing projects of large-size telescopes has been convincingly shown that, conceptually, there are three best telescopes, namely: GSMT, CELT, and ACT-25. And, in terms of informational content, the АCТ-25 is 10 times more than GSMT and CELT, and the existing Keck-telescope exceeds by 30 times. Hence, it is hard to escape a conclusion that it is more favourable to implement one ACT-25, than to do 10 GSMT or CELT

  11. The Origins Space Telescope (OST)

    Science.gov (United States)

    Staguhn, Johannes

    2018-01-01

    The Origins Space Telescope is the mission concept for the Far-Infrared Surveyor, one of the four science and technology definition studies to be submitted by NASA Headquarters to the 2020 Astronomy and Astrophysics Decadal survey. The observatory will provide orders of magnitude improvements in sensitivity over prior missions, in particular for spectroscopy, enabling breakthrough science across astrophysics. The observatory will cover a wavelength range between 5 μm and 600 μm in order to enable the study of the formation of proto-planetary disks, detection of bio-signatures from extra-solar planet's atmospheres, characterization of the first galaxies in the universe, and many more. The five instruments that are currently studied are two imaging far-infrared spectrometers using incoherent detectors, providing up to R 10^5 spectral resolution, one far-infrared infrared heterodyne instrument for even higher spectral resolving powers, one far-infrared continuum imager and polarimeter, plus a mid-infrared coronagraph with imaging and spectroscopy mode. I will describe the scientific and technical capabilities of the observatory with focus on the expected synergies with AtLAST.

  12. BGO as a hybrid scintillator / Cherenkov radiator for cost-effective time-of-flight PET

    Science.gov (United States)

    Brunner, S. E.; Schaart, D. R.

    2017-06-01

    Due to detector developments in the last decade, the time-of-flight (TOF) method is now commonly used to improve the quality of positron emission tomography (PET) images. Clinical TOF-PET systems based on L(Y)SO:Ce crystals and silicon photomultipliers (SiPMs) with coincidence resolving times (CRT) between 325 ps and 400 ps FWHM have recently been developed. Before the introduction of L(Y)SO:Ce, BGO was used in many PET systems. In addition to a lower price, BGO offers a superior attenuation coefficient and a higher photoelectric fraction than L(Y)SO:Ce. However, BGO is generally considered an inferior TOF-PET scintillator. In recent years, TOF-PET detectors based on the Cherenkov effect have been proposed. However, the low Cherenkov photon yield in the order of  ˜10 photons per event complicates energy discrimination-a severe disadvantage in clinical PET. The optical characteristics of BGO, in particular its high transparency down to 310 nm and its high refractive index of  ˜2.15, are expected to make it a good Cherenkov radiator. Here, we study the feasibility of combining event timing based on Cherenkov emission with energy discrimination based on scintillation in BGO, as a potential approach towards a cost-effective TOF-PET detector. Rise time measurements were performed using a time-correlated single photon counting (TCSPC) setup implemented on a digital photon counter (DPC) array, revealing a prompt luminescent component likely to be due to Cherenkov emission. Coincidence timing measurements were performed using BGO crystals with a cross-section of 3 mm  ×  3 mm and five different lengths between 3 mm and 20 mm, coupled to DPC arrays. Non-Gaussian coincidence spectra with a FWHM of 200 ps were obtained with the 27 mm3 BGO cubes, while FWHM values as good as 330 ps were achieved with the 20 mm long crystals. The FWHM value was found to improve with decreasing temperature, while the FWTM value showed the opposite trend.

  13. The Planck Telescope reflectors

    Science.gov (United States)

    Stute, Thomas

    2004-09-01

    The mechanical division of EADS-Astrium GmbH, Friedrichshafen is currently engaged with the development, manufacturing and testing of the advanced dimensionally stable composite reflectors for the ESA satellite borne telescope Planck. The objective of the ESA mission Planck is to analyse the first light that filled the universe, the cosmic microwave background radiation. Under contract of the Danish Space Research Institute and ESA EADS-Astrium GmbH is developing the all CFRP primary and secondary reflectors for the 1.5-metre telescope which is the main instrument of the Planck satellite. The operational frequency ranges from to 25 GHz to 1000 GHz. The demanding high contour accuracy and surface roughness requirements are met. The design provides the extreme dimensional stability required by the cryogenic operational environment at around 40 K. The elliptical off-axis reflectors display a classical lightweight sandwich design with CFRP core and facesheets. Isostatic mounts provide the interfaces to the telescope structure. Protected VDA provides the reflecting surface. The manufacturing is performed at the Friedrichshafen premises of EADS-Space Transportation GmbH, the former Dornier composite workshops. Advanced manufacturing technologies like true angle lay-up by CNC fibre placement and filament winding are utilized. The protected coating is applied at the CAHA facilities at the Calar Alto Observatory, Spain. The exhaustive environmental testing is performed at the facilities of IABG, Munich (mechanical testing) and for the cryo-optical tests at CSL Liege. The project is in advanced state with both Qualification Models being under environmental testing. The flight models will be delivered in 2004. The paper gives an overview over the requirements and the main structural features how these requirements are met. Special production aspects and available test results are reported.

  14. Is Your Telescope Tweeting?

    Science.gov (United States)

    Atkinson, Nancy

    2009-05-01

    Half of the world's population today was born after the Apollo Moon landings. The best way to reach this generation and get them excited about today's space exploration and astronomy news and events is through online social media, which are technologies that allow anyone to communicate with everyone. Twitter is a growing popular social media tool that uses short, 140 character "Tweets" to quickly and concisely convey updates on what you "are doing." With the right combination of information, personality and fun, telescopes and spacecraft are using Twitter for public outreach, providing important status updates while making the public feel like they are part of the mission.

  15. Medium-resolution isaac newton telescope library of empirical spectra

    NARCIS (Netherlands)

    Sanchez-Blazquez, P.; Peletier, R. F.; Jimenez-Vicente, J.; Cardiel, N.; Cenarro, A. J.; Falcon-Barroso, J.; Gorgas, J.; Selam, S.; Vazdekis, A.

    2006-01-01

    A new stellar library developed for stellar population synthesis modelling is presented. The library consists of 985 stars spanning a large range in atmospheric parameters. The spectra were obtained at the 2.5-m Isaac Newton Telescope and cover the range lambda lambda 3525-7500 angstrom at 2.3

  16. Proposal of a new generation of Laser Beacon for time calibration in the KM3NeT neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Real, Diego [IFIC, Instituto de Física Corpuscular, CSIC-Universidad de Valencia, C/Catedrático José Beltrán, 2. 46980 Paterna (Spain); Collaboration: KM3NeT Collaboration

    2014-11-18

    The KM3NeT collaboration aims at the construction of a multi-km3 high-energy neutrino telescope in the Mediterranean Sea consisting of a matrix of pressure resistant glass spheres holding each a set (31) of small area photomultipliers. The main motivation of the telescope is to observe cosmic neutrinos through the Cherenkov light induced in sea water by charged particles produced in neutrino interactions with the surrounding medium. A relative time calibration between photomultipliers of the order of 1 ns is required to achieve an optimal performance. To this end, several time calibration subsystems have been developed. In this article, the proposal of a last generation Laser Beacon, to be used in KM3NeT and developed to measure and monitor the relative time offsets between photomultipliers, is presented.

  17. Polaris Tracking Telescope

    Science.gov (United States)

    Ritchie, Justin; Castelaz, M.; Cline, D. J.

    2009-01-01

    Pisgah Astronomical Research Institute (PARI) in Rosman, NC has been imaging 5 degrees of the sky surrounding Polaris since 2004 using a wide-angle lens and CCD camera. The images are used for differential photometry and to measure the variation in brightness of the Polaris itself. To enhance the quality of the measurements of Polaris a special robotic telescope mount was built to accommodate a narrow field-of-view telescope that focuses on Polaris alone. The movement of Polaris is a circle about 1 degree in radius every 24 hours which is 1 arcsecond every 8 seconds of clock time. The design team had to consider that the polar axis is on a 19-year cycle due to the changing lunar gravitational attractions upon the earth's equatorial bulge. There are several components to this effect. The lunar component amplitude is +/-9 arcseconds towards the ecliptic pole with a period of 18.6 years. The solar component is +/- 1.2 arcseconds over 0.5 years; there is a 'fortnightly nutation' of +/- 0.1 arcseconds per 5 days; there is also a seasonal variation caused by the movement of airm asses of +/- 0.18 arcseconds per year. Utilizing two CCD cameras, the SBIG STV and the SBIG ST7 we can capture the image of Polaris by following the path of the star in the sky with linear actuators set to the coordinates of its circular path.

  18. Magellan Telescopes operations 2008

    Science.gov (United States)

    Osip, David J.; Phillips, Mark M.; Palunas, Povilas; Perez, Frank; Leroy, M.

    2008-07-01

    The twin 6.5m Magellan Telescopes have been in routine operations at the Las Campanas Observatory in the Chilean Andes since 2001 and 2002 respectively. The telescopes are owned and operated by Carnegie for the benefit of the Magellan consortium members (Carnegie Institution of Washington, Harvard University, the University of Arizona, Massachusetts Institute of Technology, and the University of Michigan). This paper provides an up to date review of the scientific, technical, and administrative structure of the 'Magellan Model' for observatory operations. With a modest operations budget and a reasonably small staff, the observatory is operated in the "classical" mode, wherein the visiting observer is a key member of the operations team. Under this model, all instrumentation is supplied entirely by the consortium members and the various instrument teams continue to play a critical support role beyond initial deployment and commissioning activities. Here, we present a critical analysis of the Magellan operations model and suggest lessons learned and changes implemented as we continue to evolve an organizational structure that can efficiently deliver a high scientific return for the investment of the partners.

  19. Origins Space Telescope

    Science.gov (United States)

    Cooray, Asantha; Origins Space Telescope Study Team

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. This presentation will provide a summary of the OST STDT, our completed first mission concept and an introduction to the second concept that will be studied at the study center in 2018. This presentation will also summarize key science drivers and the key study milestones between 2018 and 2020.

  20. Measurements and elimination of Cherenkov light in fiber-optic scintillating detector for electron beam therapy dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Bongsoo; Jang, Kyoung Won; Cho, Dong Hyun; Yoo, Wook Jae; Tack, Gye-Rae; Chung, Soon-Cheol [School of Biomedical Engineering, College of Biomedical and Health Science, Konkuk University, Chungju 380-701 (Korea, Republic of); Kim, Sin [Department of Nuclear and Energy Engineering, Applied Radiological Science Research Institute, Cheju National University, Cheju 690-756 (Korea, Republic of)], E-mail: sinkim@cheju.ac.kr; Cho, Hyosung [Basic Atomic Energy Research Institute and Department of Radiological Science, Yonsei University, Wonju 220-710 (Korea, Republic of)

    2007-08-21

    In this study, a miniature fiber-optic radiation detector has been developed using a water-equivalent organic scintillator for electron beam therapy dosimetry. Usually, two kinds of light signals such as fluorescent and Cherenkov lights are generated in a fiber-optic radiation detector when a high-energy electron beam is irradiated. The fluorescent light signal is produced in the scintillator and is transmitted through a plastic optical fiber to a remote light-measuring device such as a PMT or a photodiode. The Cherenkov light could be also produced in the plastic optical fiber itself and be detected by a light-measuring device. Therefore, it could cause problems or limit the accuracy of the detection of a fluorescent light signal that is proportional to dose. The objectives of this study are to measure, characterize and eliminate Cherenkov light generated in a plastic optical fiber used as a component of a fiber-optic radiation detector and to detect a real fluorescent light signal from the scintillator. In this study, the intensity of Cherenkov light is measured and characterized as a function of the incident angle of an electron beam from a LINAC, as a function of the electron beam energy, and as a function of electron beam size. Also, a subtraction method using a background optical fiber without a scintillator and an optical discrimination method using optical filters are investigated to remove Cherenkov light.

  1. Advanced Technology Solar Telescope Construction: Progress Report

    Science.gov (United States)

    Rimmele, Thomas R.; McMullin, J.; Keil, S.; Goode, P.; Knoelker, M.; Kuhn, J.; Rosner, R.; ATST Team

    2012-05-01

    The 4m Advance Technology Solar Telescope (ATST) on Haleakala will be the most powerful solar telescope and the world’s leading ground-based resource for studying solar magnetism that controls the solar wind, flares, coronal mass ejections and variability in the Sun’s output. The ATST will provide high resolution and high sensitivity observations of the dynamic solar magnetic fields throughout the solar atmosphere, including the corona at infrared wavelengths. With its 4 m aperture, ATST will resolve magnetic features at their intrinsic scales. A high order adaptive optics system delivers a corrected beam to the initial set of five state-of-the-art, facility class instrumentation located in the coude laboratory facility. Photopheric and chromospheric magnetometry is part of the key mission of four of these instruments. Coronal magnetometry and spectroscopy will be performed by two of these instruments at infrared wavelengths. The ATST project has transitioned from design and development to its construction phase. Site construction is expected to begin in April 2012. The project has awarded design and fabrication contracts for major telescope subsystems. A robust instrument program has been established and all instruments have passed preliminary design reviews or critical design reviews. A brief overview of the science goals and observational requirements of the ATST will be given, followed by a summary of the project status of the telescope and discussion of the approach to integrating instruments into the facility. The National Science Foundation (NSF) through the National Solar Observatory (NSO) funds the ATST Project. The NSO is operated under a cooperative agreement between the Association of Universities for Research in Astronomy, Inc. (AURA) and NSF.

  2. Galileo Italian National Telescope and its instrumentation

    Science.gov (United States)

    Barbieri, Cesare

    1997-03-01

    This paper gives an overview of the present status of the Telescopio Nazionale Galileo (TNG), a 3.5 m, active-optics telescope for the Italian community, whose initial characteristics were derived from those of the ESO NTT. For a more detailed description see e.g. in Barbieri et al. (1994). Its site is the Observatorio del Roque de los Muchachos, in the Canary Island of La Palma, on the West side of the mountain, at an altitude of about 2360 m. Construction and erection activities, started in 1993, are nearing completion. The telescope structure has been installed inside the rotating dome. The three main mirrors have also been transported to the mountain and aluminized in the WHT plant. They will shortly be installed in the telescope. Three major subsystems still undergo intensive activity in Italy, namely testing of the M2 and M3 units, testing of the operational version of the control hardware and software, and construction of the two rotator adapters for the Nasmyth foci. First light instruments are also being built. Arm A of the telescope is reserved for the imaging section, composed by a visual camera, a near-IR camera, plus a common adaptive optics module. On the other arm B, a faint object spectrograph with long slit, atmospheric dispersion corrector, multiobject and imaging capabilities, will be mounted. A fixed high resolution spectrograph with optical derotation is also being designed. Attention has already been given to the archive of the data. It is planned to have first light before the end of 1996, and to start regular scientific operations after an adequate period of debugging and commissioning.

  3. The University of Durham Mark 3 very high energy gamma ray telescope

    Science.gov (United States)

    Chadwick, P. M.; Dipper, N. A.; Dowthwaite, J. C.; Kirkman, I. W.; Mccomb, T. J.; Orford, K. J.; Turver, K. E.

    1985-01-01

    A new very high energy gamma-ray telescope employing the atmospheric Cerenkov light technique and currently nearing completion is described. The telescope is designed to have capability as both a wide angle instrument (4 degree field of view) for sky survey work and as a narrow field of view instrument (1.35 degrees) for conventional drift-scanning and tracking modes of operation. The telescope consists of two 10 sq. m. mirrors operated in fast coincidence with multiple phototube assemblies at the prime focus of each mirror. The design philosophy of the instrument is discussed and comparisons of its performance with our previous telescopes are made.

  4. The metagenomic telescope.

    Directory of Open Access Journals (Sweden)

    Balázs Szalkai

    Full Text Available Next generation sequencing technologies led to the discovery of numerous new microbe species in diverse environmental samples. Some of the new species contain genes never encountered before. Some of these genes encode proteins with novel functions, and some of these genes encode proteins that perform some well-known function in a novel way. A tool, named the Metagenomic Telescope, is described here that applies artificial intelligence methods, and seems to be capable of identifying new protein functions even in the well-studied model organisms. As a proof-of-principle demonstration of the Metagenomic Telescope, we considered DNA repair enzymes in the present work. First we identified proteins in DNA repair in well-known organisms (i.e., proteins in base excision repair, nucleotide excision repair, mismatch repair and DNA break repair; next we applied multiple alignments and then built hidden Markov profiles for each protein separately, across well-researched organisms; next, using public depositories of metagenomes, originating from extreme environments, we identified DNA repair genes in the samples. While the phylogenetic classification of the metagenomic samples are not typically available, we hypothesized that some very special DNA repair strategies need to be applied in bacteria and Archaea living in those extreme circumstances. It is a difficult task to evaluate the results obtained from mostly unknown species; therefore we applied again the hidden Markov profiling: for the identified DNA repair genes in the extreme metagenomes, we prepared new hidden Markov profiles (for each genes separately, subsequent to a cluster analysis; and we searched for similarities to those profiles in model organisms. We have found well known DNA repair proteins, numerous proteins with unknown functions, and also proteins with known, but different functions in the model organisms.

  5. ALMA Telescope Reaches New Heights

    Science.gov (United States)

    2009-09-01

    ball at a distance of nine miles, and to keep their smooth reflecting surfaces accurate to less than the thickness of a human hair. Once the transporter reached the high plateau it carried the antenna to a concrete pad -- a docking station with connections for power and fiber optics -- and positioned it with an accuracy of a small fraction of an inch. The transporter is guided by a laser steering system and, just like some cars, also has ultrasonic collision detectors. These sensors ensure the safety of the state-of-the-art antennas as the transporter drives them across what will soon be a rather crowded plateau. Ultimately, ALMA will have at least 66 antennas distributed over about 200 pads, spread over distances of up to 11.5 miles and operating as a single, giant telescope. Even when ALMA is fully operational, the transporters will be used to move the antennas between pads to reconfigure the telescope for different kinds of observations. This first ALMA antenna at the high site will soon be joined by others, and the ALMA team looks forward to making their first observations from the Chajnantor plateau. They plan to link three antennas by early 2010, and to make the first scientific observations with ALMA in the second half of 2011. ALMA will help astronomers answer important questions about our cosmic origins. The telescope will observe the Universe using light with millimeter and submillimeter wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, and from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born, or remote galaxies towards the edge of the observable universe. The Universe is relatively unexplored at submillimeter wavelengths, as the telescopes need extremely dry atmospheric conditions, such as those at Chajnantor, and advanced detector technology. The Atacama Large Millimeter/submillimeter Array

  6. Infrared up-conversion telescope

    DEFF Research Database (Denmark)

    2014-01-01

    There is presented to an up-conversion infrared telescope (110) arranged for imaging an associated scene (130), wherein the up-conversion infrared telescope (110) comprises a non-linear crystal (120) arranged for up-conversion of infrared electromagnetic radiation, and wherein a first optical...

  7. Kashima 34-m Radio Telescope

    Science.gov (United States)

    Sekido, Mamoru; Kawai, Eiji

    2013-01-01

    The Kashima 34-m radio telescope has been continuously operated and maintained by the National Institute of Information and Communications Technology (NICT) as a facility of the Kashima Space Technology Center (KSTC) in Japan. This brief report summarizes the status of this telescope, the staff, and activities during 2012.

  8. The Advanced Technology Solar Telescope: Science Drivers and Construction Status

    Science.gov (United States)

    Rimmele, Thomas; Berger, Thomas; McMullin, Joseph; Keil, Stephen; Goode, Phil; Knoelker, Michael; Kuhn, Jeff; Rosner, Robert; Casini, Roberto; Lin, Haosheng; Woeger, Friedrich; von der Luehe, Oskar; Tritschler, Alexandra; Atst Team

    2013-04-01

    The 4-meter Advance Technology Solar Telescope (ATST) currently under construction on the 3000 meter peak of Haleakala on Maui, Hawaii will be the world's most powerful solar telescope and the leading ground-based resource for studying solar magnetism. The solar atmosphere is permeated by a 'magnetic carpet' that constantly reweaves itself to control solar irradiance and its effects on Earth's climate, the solar wind, and space weather phenomena such as flares and coronal mass ejections. Precise measurement of solar magnetic fields requires a large-aperture solar telescope capable of resolving a few tens of kilometers on the solar surface. With its 4 meter aperture, the ATST will for the first time resolve magnetic structure at the intrinsic scales of plasma convection and turbulence. The ATST's ability to perform accurate and precise spectroscopic and polarimetric measurements of magnetic fields in all layers of the solar atmosphere, including accurate mapping of the elusive coronal magnetic fields, will be transformative in advancing our understanding of the magnetic solar atmosphere. The ATST will utilize the Sun as an important astro- and plasma-physics "laboratory" demonstrating key aspects of omnipresent cosmic magnetic fields. The ATST construction effort is led by the US National Solar Observatory. State-of-the-art instrumentation will be constructed by US and international partner institutions. The technical challenges the ATST is facing are numerous and include the design of the off-axis main telescope, the development of a high order adaptive optics system that delivers a corrected beam to the instrument laboratory, effective handling of the solar heat load on optical and structural elements, and minimizing scattered light to enable observations of the faint corona. The ATST project has transitioned from design and development to its construction phase. The project has awarded design and fabrication contracts for major telescope subsystems. Site

  9. Design of Cherenkov bars for the optical part of the time-of-flight detector in Geant4.

    Science.gov (United States)

    Nozka, L; Brandt, A; Rijssenbeek, M; Sykora, T; Hoffman, T; Griffiths, J; Steffens, J; Hamal, P; Chytka, L; Hrabovsky, M

    2014-11-17

    We present the results of studies devoted to the development and optimization of the optical part of a high precision time-of-flight (TOF) detector for the Large Hadron Collider (LHC). This work was motivated by a proposal to use such a detector in conjunction with a silicon detector to tag and measure protons from interactions of the type p + p → p + X + p, where the two outgoing protons are scattered in the very forward directions. The fast timing detector uses fused silica (quartz) bars that emit Cherenkov radiation as a relativistic particle passes through and the emitted Cherenkov photons are detected by, for instance, a micro-channel plate multi-anode Photomultiplier Tube (MCP-PMT). Several possible designs are implemented in Geant4 and studied for timing optimization as a function of the arrival time, and the number of Cherenkov photons reaching the photo-sensor.

  10. The CTA medium size telescope prototype, a test bench for the array control software

    Energy Technology Data Exchange (ETDEWEB)

    Birsin, Emrah; Oya, Igor; Schwanke, Ullrich [Institut fuer Physik, Humboldt-Universitaet zu Berlin (Germany); Behera, Bagmeet; Koeppel, Hendryk; Melkumyan, David; Schmidt, Torsten; Wegner, Peter; Wiesand, Stephan; Winde, Michael [Deutsches Elektronen-Synchrotron, DESY, Zeuthen (Germany)

    2012-07-01

    CTA (Cherenkov Telescope Array) will be the largest ground-based gamma-ray observatory ever built. Two arrays are foreseen to be build, one in the Southern and one in the Northern hemisphere. A prototype for the Medium Size Telescope (MST) type (diameter: 12 m) will be installed in Berlin in early 2012. This MST prototype will be composed of the mechanical structure, drive system and mirror facets with an active mirror control system. The stability of the mechanical structure will be investigated with CCD cameras and a weather station. Furthermore the ALMA Common Software (ACS) distributed control framework will used as readout and control system for the MST, allowing to evaluate the software with the future use for the whole CTA array in mind. The design of the control software is following the concepts and tools under evaluation within the CTA consortium, like the use of a UML based code generation framework for ACS component modeling, and the use of OPC Unified Architecture (OPC UA) for hardware access. In this contribution the progress in the implementation of the control system for this CTA prototype telescope is described.

  11. Recognition of Cherenkov Ring Patterns with the HMPID-RICH Detector in ALICE at LHC

    CERN Document Server

    Di Bari, D

    1999-01-01

    A high momentum particle identification detector (HMPID) covering about 50f the ALICE central barrel region has been designed and prototyped.The detector consists of seven RICH modules with a proximity focusing geometry, covering 12m2. The very large density of hits on the detector (80÷90 part/m2 in the extreme cases) makes the recognition of the Cherenkov photon patterns a complex and crucial task. A study of the pattern recognition based on the Hough transformation in terms of particle identification efficiency and particle contamination will be presented.

  12. Recognition of Cherenkov ring patterns with the HMPID-RICH detector in ALICE at LHC

    CERN Document Server

    Cozza, D; De Cataldo, G; Di Bari, D; Di Mauro, A; Elia, D; Franco, A; Goret, B; Martinengo, P; Nappi, E; Paic, G; Piuz, François; Posa, F; Williams, T D

    1999-01-01

    A high momentum particle identification detector (HMPID) covering about 5% of the ALICE central barrel region has been designed and prototyped. The detector consists of seven RICH modules with a proximity focusing geometry, covering 12 m/sup 2/. The very large density of hits on the detector (80/90 part/m/sup 2/ in the extreme cases) makes the recognition of the Cherenkov photon patterns a complex and crucial task. A study of the pattern recognition strategy based on the Hough transformation in terms of particle identification efficiency and particle contamination will be presented. (7 refs).

  13. Very high voltage power supply system for the ring imaging Cherenkov detectors of the LHCb experiment

    CERN Document Server

    Fontanellia, F; Gracco, V; Gys, T; Jost, B; Minì, G; Neufeld, N; Petrolini, A; Piedigrossi, D; Sannino, M

    2009-01-01

    A modular power supply system is described, for use in the Ring Imaging Cherenkov Detectors of the LHCb experiment. The main characteristics of the supply are very good time stability and voltage resolution, full programmability, floating supplies, self protection and remote control. The choice of a commercial HV module with standard control inputs allows easy customisation to adapt our design to different requirements. The realisation shown here supplies voltages up to 20 kV with a maximum current of 0.5 mA and up to 32 channels on a single crate.

  14. Vacuum Cherenkov radiation and photon decay rates from generic Lorentz Invariance Violation

    Science.gov (United States)

    Martínez-Huerta, H.; Pérez-Lorenzana, A.

    2016-10-01

    Among the most studied approaches to introduce the breaking of Lorentz symmetry, the generic approach is one of the most frequently used for phenomenology, it converges on the modification of the free particle dispersion relation. Using this approach in the photon sector, we have calculated the squared probability amplitude for vacuum Cherenkov radiation and photon decay by correcting the QED coupling at tree level and first order in LIV parameters. For the lower order energy correction we calculate the emission and decay rate for each process.

  15. The monitoring system for the aerogel Cherenkov counter of the BELLE detector

    CERN Document Server

    Khan, M H R; Sumiyoshi, T; Kuniya, T; Adachi, I; Enomoto, R; Hattori, H; Iijima, T; Kaneda, K; Kawabata, R; Ooba, T; Suda, R; Suzuki, K; Watanabe, M

    1998-01-01

    We report on a design and performances of a monitoring system developed for the aerogel Cherenkov counters (ACC) of the BELLE detector. The system consists of blue LEDs, a diffuser box, and optical distributors which distribute the LED light to the ACC modules. The employed LED (NSPB series) has been observed to have high reliability on the long term stability and the temprature dependence. The diffuser box is employed to reduce the intrinsic non-uniformity of the LED light intensity. The overall performances of the present monitoring system on uniformity and intensity of the light output have been found to satisfy all the requirements for the monitoring.

  16. Tip tilt corection for astronomical telescopes using adaptive control

    Energy Technology Data Exchange (ETDEWEB)

    Watson, J.

    1997-04-17

    The greatest hindrance to modern astronomy is the effect of the Earth`s atmosphere on incoming light. The fundamental, or lowest mode of disturbance is tip and tilt.. This mode causes the focused image of a distant point source to move about in a plane (X-Y motion) as viewed form a telescope objective. Tip-tilt correction systems can be used to correct for these disturbances in real time. We propose a novel application of adaptive control to address some unique problems inherent with tip-tilt correction systems for astronomical telescopes.

  17. The Efficient Discrimination Of Electron And Pi-zero Events In A Water Cherenkov Detector And The Application To Neutrino Oscillation Experiments

    CERN Document Server

    Barszczak, T

    2005-01-01

    Super-Kamiokande, a large water Cherenkov detector, observed atmospheric neutrinos produced by interactions of cosmic rays in the atmosphere. By observing zenith angle and energy of the particles produced by the neutrinos in single ring events in Super-Kamiokande, it became apparent that the muon neutrino (νμ) undergoes oscillations. During the oscillations, ν μ changes into another kind of neutrino, which can be either the tau neutrino (ντ) or a sterile neutrino (ν s). In addition, a small component of νe is possible but not considered here. With the standard single ring analysis, using two-flavor oscillations without matter effects, it was hard to discriminate between these two possibilities because, while νs doesn't interact at all and ν τ does, interactions of ντ don't produce a significant single ring signal. Due to the large mass of the taon (τ), charged current interactions of ντ are sup...

  18. Optical Cherenkov radiation by cascaded nonlinear interaction: an efficient source of few-cycle energetic near- to mid-IR pulses

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Zhou, Binbin

    2011-01-01

    When ultrafast noncritical cascaded second-harmonic generation of energetic femtosecond pulses occur in a bulk lithium niobate crystal optical Cherenkov waves are formed in the near- to mid-IR. Numerical simulations show that the few-cycle solitons radiate Cherenkov (dispersive) waves in the λ = ...... efficiency is up to 25%. Thus, optical Cherenkov waves formed with cascaded nonlinearities could become an efficient source of energetic near- to mid-IR few-cycle pulses.......When ultrafast noncritical cascaded second-harmonic generation of energetic femtosecond pulses occur in a bulk lithium niobate crystal optical Cherenkov waves are formed in the near- to mid-IR. Numerical simulations show that the few-cycle solitons radiate Cherenkov (dispersive) waves in the λ = 2...

  19. Staging atmospheres

    DEFF Research Database (Denmark)

    Bille, Mikkel; Bjerregaard, Peter; Sørensen, Tim Flohr

    2015-01-01

    The article introduces the special issue on staging atmospheres by surveying the philosophical, political and anthropological literature on atmosphere, and explores the relationship between atmosphere, material culture, subjectivity and affect. Atmosphere seems to occupy one of the classic...

  20. Particle Identification with Cherenkov detectors in the 2011 CALICE Tungsten Analog Hadronic Calorimeter Test Beam at the CERN SPS

    CERN Document Server

    Dannheim, D; Klempt, W; Lucaci Timoce, A; van der Kraaij, E

    2013-01-01

    In 2011 the CALICE Tungsten Analog Hadronic Calorimeter prototype (W-AHCAL) was exposed to mixed beams of electrons, pions, kaons and protons with momenta from 10 to 300 GeV in the CERN SPS H8 beam line. The selection of pion, kaon and proton samples is based on the information obtained from two Cherenkov threshold counters. This note presents the strategy for the particle identification, as well as the calibration, operation and analysis of the Cherenkov counters. Efficiency and sample-purity estimates are given for the data selected for the W-AHCAL data analysis.

  1. Space Telescope Systems Description Handbook

    Science.gov (United States)

    Carter, R. E.

    1985-01-01

    The objective of the Space Telescope Project is to orbit a high quality optical 2.4-meter telescope system by the Space Shuttle for use by the astronomical community in conjunction with NASA. The scientific objectives of the Space Telescope are to determine the constitution, physical characteristics, and dynamics of celestial bodies; the nature of processes which occur in the extreme physical conditions existing in stellar objects; the history and evolution of the universe; and whether the laws of nature are universal in the space-time continuum. Like ground-based telescopes, the Space Telescope was designed as a general-purpose instrument, capable of utilizing a wide variety of scientific instruments at its focal plane. This multi-purpose characteristic will allow the Space Telescope to be effectively used as a national facility, capable of supporting the astronomical needs for an international user community and hence making contributions to man's needs. By using the Space Shuttle to provide scientific instrument upgrading and subsystems maintenance, the useful and effective operational lifetime of the Space Telescope will be extended to a decade or more.

  2. San Pedro Martir Telescope: Mexican design endeavor

    Science.gov (United States)

    Toledo-Ramirez, Gengis K.; Bringas-Rico, Vicente; Reyes, Noe; Uribe, Jorge; Lopez, Aldo; Tovar, Carlos; Caballero, Xochitl; Del-Llano, Luis; Martinez, Cesar; Macias, Eduardo; Lee, William; Carramiñana, Alberto; Richer, Michael; González, Jesús; Sanchez, Beatriz; Lucero, Diana; Manuel, Rogelio; Segura, Jose; Rubio, Saul; Gonzalez, German; Hernandez, Obed; García, Mary; Lazaro, Jose; Rosales-Ortega, Fabian; Herrera, Joel; Sierra, Gerardo; Serrano, Hazael

    2016-08-01

    The Telescopio San Pedro Martir (TSPM) is a new ground-based optical telescope project, with a 6.5 meters honeycomb primary mirror, to be built in the Observatorio Astronomico Nacional on the Sierra San Pedro Martir (OAN-SPM) located in Baja California, Mexico. The OAN-SPM has an altitude of 2830 meters above sea level; it is among the best location for astronomical observation in the world. It is located 1830 m higher than the atmospheric inversion layer with 70% of photometric nights, 80% of spectroscopic nights and a sky brightness up to 22 mag/arcsec2. The TSPM will be suitable for general science projects intended to improve the knowledge of the universe established on the Official Mexican Program for Science, Technology and Innovation 2014-2018. The telescope efforts are headed by two Mexican institutions in name of the Mexican astronomical community: the Universidad Nacional Autonoma de Mexico and the Instituto Nacional de Astrofisica, Optica y Electronica. The telescope has been financially supported mainly by the Consejo Nacional de Ciencia y Tecnologia (CONACYT). It is under development by Mexican scientists and engineers from the Center for Engineering and Industrial Development. This development is supported by a Mexican-American scientific cooperation, through a partnership with the University of Arizona (UA), and the Smithsonian Astrophysical Observatory (SAO). M3 Engineering and Technology Corporation in charge of enclosure and building design. The TSPM will be designed to allow flexibility and possible upgrades in order to maximize resources. Its optical and mechanical designs are based upon those of the Magellan and MMT telescopes. The TSPM primary mirror and its cell will be provided by the INAOE and UA. The telescope will be optimized from the near ultraviolet to the near infrared wavelength range (0.35-2.5 m), but will allow observations up to 26μm. The TSPM will initially offer a f/5 Cassegrain focal station. Later, four folded Cassegrain and

  3. Detection of magnetic monopoles in the future neutrino telescope Antares and characterization of the photomultiplier pulse treatment; Etude de la detection de monopoles magnetiques au sein du futur telescope a neutrinos antares et caracterisation des performances du traitement des impulsions des photomultiplicateurs

    Energy Technology Data Exchange (ETDEWEB)

    Ricol, J.St

    2002-10-01

    Grand unified theories (GUT) involve phase transitions in the early universe, that could create topological defects, like magnetic monopoles. Monopoles main characteristics are shown and in particular energy losses and flux limits. High energy neutrino telescopes offer a new opportunity for magnetic monopole search. The study of the photomultiplier pulse treatment by the Antares detector front-end electronics indicates that this one is well adapted to the telescope needs. The pulses detailed analysis has allowed to obtain a time measurement precision lower than 0.6 ns and electronic noise and saturation have no relevant effect on the telescope performances. Relativistic monopoles generate a large amount of light, that leads to an effective area for the Antares detector of about 0.06 km{sup 2} for velocities {beta}{sub mon} = 0.6 and 0.35 km{sup 2} for velocities {beta}{sub mon} {approx} 1. Monopole track are well reconstructed and the velocity determination is made with an error lower than few percents, which represents a decisive result for the background rejection, caused by high energy muons with a velocity {beta}{sub {mu}} {approx} 1. The very dispersive light emission of monopoles below the Cherenkov limit, 0.6 {approx}< {beta}{sub mon} {<=} 0.74, via the delta-rays produced by ionisation, does not allow an accurate expecting signal and the bad reconstructed muons rejection must be improved. Above the Cherenkov limit, {beta}{sub mon} {>=} 0.8, bad reconstructed events can be rejected from the Cherenkov emission parametrisation. A magnetic monopole signal can then clearly be distinguished from background. (author)

  4. Multi-anode photon-multiplier readout electronics for the LHCb ring imaging Cherenkov detectors

    CERN Document Server

    Smale, N J

    2004-01-01

    A readout system for the Ring Imaging CHerenkov (RICH) detectors of the LHCb experiment has been developed. Two detector technologies for the measurement of Cherenkov photons are considered, the Multi-Anode Photo-Multiplier Tube (MAPMT) and the Hybrid Photon Detector (HPD), both of which meet the RICH requirements. The properties of the MAPMT are evaluated using a controlled single-photon source; a pixel-to-pixel gain variation of ~3 and a typical signal to noise of ~20 is measured. The relative tube efficiency is found to be reduced by ~26 % due to the detailed focusing structure of the MAPMT device. A radiation hard application-specific integrated circuit (ASIC) chip, the Beetle1.2MA0, has been developed to capture and store signals from a pair of MAPMTs. The Beetle1.2MA0 is built on the architecture of the Beetle family that was designed for silicon strip detectors, the difference being a modified front-end amplifier. The 128 input-channels of the Beetle1.2MA0 have a charge-sensitive pre-amplifier followed...

  5. Reconstructing the direction of reactor antineutrinos via electron scattering in Gd-doped water Cherenkov detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hellfeld, D., E-mail: dhellfeld@berkeley.edu [Department of Nuclear Engineering, University of California, Berkeley, Berkeley, CA 94720 (United States); Bernstein, A. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Dazeley, S., E-mail: dazeley2@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Marianno, C. [Department of Nuclear Engineering, Texas A& M University, College Station, TX 77843 (United States)

    2017-01-01

    The potential of elastic antineutrino-electron scattering in a Gd-doped water Cherenkov detector to determine the direction of a nuclear reactor antineutrino flux was investigated using the recently proposed WATCHMAN antineutrino experiment as a baseline model. The expected scattering rate was determined assuming a 13-km standoff from a 3.758-GWt light water nuclear reactor and the detector response was modeled using a Geant4-based simulation package. Background was estimated via independent simulations and by scaling published measurements from similar detectors. Background contributions were estimated for solar neutrinos, misidentified reactor-based inverse beta decay interactions, cosmogenic radionuclides, water-borne radon, and gamma rays from the photomultiplier tubes (PMTs), detector walls, and surrounding rock. We show that with the use of low background PMTs and sufficient fiducialization, water-borne radon and cosmogenic radionuclides pose the largest threats to sensitivity. Directional sensitivity was then analyzed as a function of radon contamination, detector depth, and detector size. The results provide a list of experimental conditions that, if satisfied in practice, would enable antineutrino directional reconstruction at 3σ significance in large Gd-doped water Cherenkov detectors with greater than 10-km standoff from a nuclear reactor.

  6. Reconstructing the direction of reactor antineutrinos via electron scattering in Gd-doped water Cherenkov detectors

    Energy Technology Data Exchange (ETDEWEB)

    Hellfeld, D. [Univ. of California, Berkeley, CA (United States). Dept. of Nuclear Engineering; Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Dazeley, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Marianno, C. [Texas A & M Univ., College Station, TX (United States). Dept. of Nuclear Engineering

    2017-01-01

    The potential of elastic antineutrino-electron scattering (ν¯e + e → ν¯e + e) in a Gd-doped water Cherenkov detector to determine the direction of a nuclear reactor antineutrino flux was investigated using the recently proposed WATCHMAN antineutrino experiment as a baseline model. The expected scattering rate was determined assuming a 13 km standoff from a 3.758 GWt light water nuclear reactor. Background was estimated via independent simulations and by appropriately scaling published measurements from similar detectors. Many potential backgrounds were considered, including solar neutrinos, misidentified reactor-based inverse beta decay interactions, cosmogenic radionuclide and water-borne radon decays, and gamma rays from the photomultiplier tubes, detector walls, and surrounding rock. The detector response was modeled using a GEANT4-based simulation package. The results indicate that with the use of low radioactivity PMTs and sufficient fiducialization, water-borne radon and cosmogenic radionuclides pose the largest threats to sensitivity. The directional sensitivity was then analyzed as a function of radon contamination, detector depth, and detector size. Lastly, the results provide a list of theoretical conditions that, if satisfied in practice, would enable nuclear reactor antineutrino directionality in a Gd-doped water Cherenkov detector approximately 10 km from a large power reactor.

  7. Prism-coupled Cherenkov phase-matched terahertz wave generation using a DAST crystal.

    Science.gov (United States)

    Suizu, Koji; Shibuya, Takayuki; Uchida, Hirohisa; Kawase, Kodo

    2010-02-15

    Terahertz (THz) wave generation based on nonlinear frequency conversion is a promising method for realizing a tunable monochromatic high-power THz-wave source. Unfortunately, many nonlinear crystals have strong absorption in the THz frequency region. This limits efficient and widely tunable THz-wave generation. The Cherenkov phase-matching method is one of the most promising techniques for overcoming these problems. Here, we propose a prism-coupled Cherenkov phase-matching (PCC-PM) method, in which a prism with a suitable refractive index at THz frequencies is coupled to a nonlinear crystal. This has the following advantages. Many crystals can be used as THz-wave emitters; the phase-matching condition inside the crystal does not have to be observed; the absorption of the crystal does not prevent efficient generation of radiation; and pump sources with arbitrary wavelengths can be employed. Here we demonstrate PCC-PM THz-wave generation using the organic crystal 4-dimethylamino-N-metyl-4-stilbazolium tosylate (DAST) and a Si prism coupler. We obtain THz-wave radiation with tunability of approximately 0.1 to 10 THz and with no deep absorption features resulting from the absorption spectrum of the crystal. The obtained spectra did not depend on the pump wavelength in the range 1300 to 1450 nm. This simple technique shows promise for generating THz radiation using a wide variety of nonlinear crystals.

  8. The ring imaging Cherenkov detector of the NA62 experiment at CERN

    Energy Technology Data Exchange (ETDEWEB)

    Cenci, P., E-mail: patrizia.cenci@pg.infn.it [INFN Perugia, Via A. Pascoli, 06123 Perugia (Italy); Anzivino, G. [Physics Department of the University, Via A. Pascoli, 06123 Perugia (Italy); Bucci, F. [INFN Florence, Via G. Sansone 1, 50019 Sesto Fiorentino (Florence) (Italy); Cassese, A. [Physics Department of the University, Via G. Sansone 1, 50019 Sesto Fiorentino (Florence) (Italy); Ciaranfi, R. [INFN Florence, Via G. Sansone 1, 50019 Sesto Fiorentino (Florence) (Italy); Collazuol, G. [Physics Department of the University, INFN Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy); Duk, V. [INFN Perugia, Via A. Pascoli, 06123 Perugia (Italy); Iacopini, E. [Physics Department of the University, Via G. Sansone 1, 50019 Sesto Fiorentino (Florence) (Italy); Lamanna, G. [CERN, Meyrin, Geneve 23 (Switzerland); Lami, S.; Lenti, M. [INFN Florence, Via G. Sansone 1, 50019 Sesto Fiorentino (Florence) (Italy); Pepe, M. [INFN Perugia, Via A. Pascoli, 06123 Perugia (Italy); Piandani, R. [Physics Department of the University, Via A. Pascoli, 06123 Perugia (Italy); Piccini, M. [INFN Perugia, Via A. Pascoli, 06123 Perugia (Italy); Sergi, A. [CERN, Meyrin, Geneve 23 (Switzerland); Sozzi, M.S. [Physics Department of the University, INFN Pisa, Largo Pontecorvo 3, 56127 Pisa (Italy)

    2013-12-21

    A Ring Imaging Cherenkov (RICH) detector is the key element for particle identification in the NA62 experiment at CERN. Its purposes are to distinguish pions from muons in the momentum range from 15 GeV/c to 35 GeV/c with a muon suppression factor at the 0.5% level, to measure the particle arrival time with better than 100 ps resolution and to provide the reference time and a fast signal for the trigger system. This paper describes the updated detector design, the present status of the construction, the final results of a prototype beam test and a possible application of Graphics Processing Units in the NA62 trigger system based on RICH information. -- Highlights: •The updated design and the construction status of the NA62 RICH are described. •As NA62 requires, the RICH can distinguish μ from p at the 0.5% level. •The time resolution is below 100 ps and the Cherenkov angle one is below 80μrad. •The RICH is a fundamental element of the new three-level NA62 trigger system. •GPUs can successfully manage RICH information both at L0 and L1 trigger levels.

  9. Separation of cosmic-ray components in a single water Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, H. [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla Pue. 72570 (Mexico); Villasenor, L. [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla Pue. 72570 (Mexico)]. E-mail: villasen@ifm.umich.mx

    2005-11-11

    We describe the use of a water Cherenkov detector to study in detail the signals associated to secondary cosmic rays. In particular we describe a direct way to identify some of the components of secondary cosmic rays. It consists of a polyethylene tank of 1.54 m of diameter filled with water up to a height of 1.2 with one 8'' phototube looking downwards in the center of the tank at the level of the water. By collecting data using three different types of triggers, namely, vertical non-central muons, vertical central muons and arbitrary muons, we show the existence of very strong correlations among the voltage amplitudes, charge depositions, and rise times from 10% to 90% for isolated electrons, isolated muons and extended air showers using a single detector. The simple technique described also allows a clear identification of the muon interaction with the PMT glass envelope. We discuss a way in which our results can be used, in conjunction with a classification scheme such as neural networks, to form artificial signals for extensive air showers with the purpose to estimate the muon/EM ratio of air showers measured with large ground arrays of water Cherenkov detectors such as in the case of the Pierre Auger Observatory.

  10. Development of new photon detection device for Cherenkov and fluorescence radiation

    Directory of Open Access Journals (Sweden)

    Tinti A.

    2013-06-01

    Full Text Available Recent progress on the development of a new solid state detector allowed the use of finely pixelled photocathodes obtained from silicon semiconductors. SiPM detectors seem to be an ideal tool for the detection of Cherenkov and fluorescence light in spite of their not yet resolved criticism for operating temperature and intrinsic noise. The main disadvantage of SiPM in this case is the poor sensitivity in the wavelength range 300-400 nm, where the Cherenkov light and fluorescence radiation are generated. We report on the possibility to realize a new kind of pixelled photodetector based on the use of silicon substrate with carbon nanotube compounds, more sensitive to the near UV radiation. Also if at the very beginning, the development of such detector appears very promising and useful for astroparticle physics, both in the ground based arrays and in the space experiments. The detectors are ready to be operated in conditions of measurements without signal amplification.

  11. Southern Fireworks above ESO Telescopes

    Science.gov (United States)

    1999-05-01

    atmosphere are also indicated. A VLT spectrum with the multi-mode FORS1 instrument was obtained a little later and showed a number of absorption lines , e.g. from ionized Aluminium, Chromium and neutral Magnesium. They do not arise in the optical counterpart itself - the gas there is so hot and turbulent that any spectral lines will be extremely broad and hence extremely difficult to identify - but from interstellar gas in a galaxy 'hosting' the GRB source, or from intergalactic clouds along the line of sight. It is possible to measure the distance to this intervening material from the redshift of the lines; astronomers Vreeswijk, Galama and Rol found z = 1.619 ± 0.002 [4]. This allows to establish a lower limit for the distance of the explosion and also its total power. The numbers turn out to be truly enormous. The burst occurred at an epoch corresponding to about one half of the present age of the Universe (at a distance of about 7,000 million light-years [5]), and the total energy of the explosion in gamma-rays must be higher than 1.4 10 53 erg , assuming a spherical emission. This energy corresponds to the entire optical energy emitted by the Milky Way in more than 30 years; yet the gamma-ray burst took less than 100 seconds. Since the optical afterglows of gamma-ray bursts are faint, and their flux decays quite rapidly in time, the combination of large telescopes and fast response through suitable observing programs are crucial and, as demonstrated here, ESO's VLT is ideally suited to this goal! The lightcurve Combining results from a multitude of telescopes has provided most useful information. Interestingly, a "break" was observed in the light curve (the way the light of the optical counterpart fades) of the afterglow. Some 1.5 - 2 days after the explosion, the brightness began to decrease more rapidly; this is well documented with the CCD images from the Danish 1.5-m telescope at La Silla and the corresponding diagrams are available on a dedicated webpage at http

  12. The James Webb Space Telescope

    Science.gov (United States)

    Mather, John C.

    2004-01-01

    The James Webb Space Telescope (JWST) will extend the discoveries of the Hubble Space Telescope (HST) and the Spitzer Space Telescope (SST) by deploying a large cooled infrared telescope around the Sun-Earth Lagrange point L2. With a 6 m aperture and three instruments covering the wavelength range from 0.6 to 28 microns, it will provide sensitivities orders of magnitude better than any other facilities. It is intended to observe the light from the first galaxies and the first supernovae, the assembly of galaxies, and the formation and evolution of stars and planetary systems. In this talk I will review the scientific objectives and the ability of the system to meet them. I will close with a summary of possible future IR space missions, ranging from the far IR to planet-finding coronagraphs and interferometers

  13. Large aperture Fresnel telescopes/011

    Energy Technology Data Exchange (ETDEWEB)

    Hyde, R.A., LLNL

    1998-07-16

    At Livermore we`ve spent the last two years examining an alternative approach towards very large aperture (VLA) telescopes, one based upon transmissive Fresnel lenses rather than on mirrors. Fresnel lenses are attractive for VLA telescopes because they are launchable (lightweight, packagable, and deployable) and because they virtually eliminate the traditional, very tight, surface shape requirements faced by reflecting telescopes. Their (potentially severe) optical drawback, a very narrow spectral bandwidth, can be eliminated by use of a second (much smaller) chromatically-correcting Fresnel element. This enables Fresnel VLA telescopes to provide either single band ({Delta}{lambda}/{lambda} {approximately} 0.1), multiple band, or continuous spectral coverage. Building and fielding such large Fresnel lenses will present a significant challenge, but one which appears, with effort, to be solvable.

  14. The origins of the telescope

    OpenAIRE

    van Helden, A.; Dupré, S.; van Gent, R.; Zuidervaart, H.J.

    2011-01-01

    The origins of the telescope have been debated since the instrument’s appearance in the Hague in 1608. Civic and national pride has led local dignitaries, popular writers, and scholars to present sharply divergent histories over the years, crediting a variety of people and places with the invention. Drawing on newly discovered documents, re-examined records, and tests of early lenses and telescopes, this fascinating study proposes a new and convincing account of the origins of the instrument ...

  15. The Large Binocular Telescope Project

    Science.gov (United States)

    Hill, J. M.

    1994-12-01

    The Large Binocular Telescope (LBT) Project has evolved from concepts first proposed in 1985. The present partners involved in the design and construction of this 2 x 8.4 meter binocular telescope are the University of Arizona, Italy represented by the Osservatorio Astronomico di Arcetri and the Research Corporation based in Tucson. These three partners have committed sufficient funds to build the enclosure and the telescope populated with a single 8.4 meter optical train --- approximately 40 million dollars (1989). Based on this commitment, design and construction activities are now moving forward. Additional partners are being sought. The next mirror to be cast at the Steward Observatory Mirror Lab in late fall 1995 will be the first borosilicate honeycomb primary for LBT. The baseline optical configuration of LBT includes wide field Cassegrain secondaries with optical foci above the primaries to provide a corrected one degree field at F/4. The infrared F/15 secondaries are a Gregorian design to allow maximum flexibility for adaptive optics. The F/15 secondaries are undersized to provide a low thermal background focal plane which is unvignetted over a 4 arcminute diameter field-of-view. The interferometric focus combining the light from the two 8.4 meter primaries will reimage two folded Gregorian focal planes to a central location. The telescope elevation structure accommodates swing arms which allow rapid interchange of the various secondary and tertiary mirrors. Maximum stiffness and minimal thermal disturbance continue to be important drivers for the detailed design of the telescope. The telescope structure accommodates installation of a vacuum bell jar for aluminizing the primary mirrors in-situ on the telescope. The detailed design of the telescope structure will be completed in 1995 by ADS Italia (Lecco) and European Industrial Engineering (Mestre). The final enclosure design is now in progress at M3 Engineering (Tucson) and ADS Italia. Construction

  16. Standardization of 68Ge/68Ga using the 4πβ-γ coincidence method based on Cherenkov counting.

    Science.gov (United States)

    Bobin, C; Thiam, C; Bouchard, J

    2017-06-29

    In the framework of an international BIPM comparison (Bureau International des Poids et Mesures), the activity standardization of 68Ge in a solution of 68Ge/68Ga in equilibrium provided by NIST was carried out at LNHB. This exercise was organized to meet the growing interest in 68Ga as a radiopharmaceutical in nuclear medicine services (e.g. as a surrogate of 18F for PET imaging). Due to the volatility of germanium, the activity standardization of 68Ge was investigated at LNHB by means of 4πβ-γ coincidence counting based on Cherenkov measurements. This technique was applied to take advantage of the Cherenkov threshold (~ 260keV in aqueous solutions) in order to prevent counting from electron-capture events associated with 68Ge disintegrations. Cherenkov counting was performed using glass and polyethylene vials and the resulting activity concentrations were compared with 4πβ-γ coincidence measurements based on liquid scintillation. The efficiency-extrapolation curve obtained with Cherenkov measurements in glass vials was compared to Monte Carlo simulations based on the Geant4 code. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Demonstration Telescopes Using "Dollar Optics"

    Science.gov (United States)

    Ross, Paul

    2008-05-01

    I propose a poster that illustrates the use of "dollar optics” for experimentation and for the creation of demonstration telescopes. Handling a variety of lenses and mirrors provides an opportunity for discovering practical optics. Some part of this path of exploration must have been traveled by Galileo as he experimented with spectacle lenses. "Dollar optics” include reading glasses (positive meniscus lenses), convex and concave mirrors, Fresnel sheets, magnifying lenses, and eye loupes. Unwanted distance spectacles (negative meniscus lenses) are available at second-hand stores. Galileo telescopes, "long” 17th century telescopes, and useful demonstration models of Newtonian reflectors can be made with "dollar” optics. The poster will illustrate practical information about "dollar optics” and telescopes: magnification, focal length, and "diopters” disassembling spectacles; creating cheap mounts for spectacle lenses; the importance of optical axes and alignment; eyepieces; and focusing. (A table would be useful with the poster to set out a hands-on display of "dollar optic” telescopes.) Educators, experimenters, and those concerned with astronomy outreach might be interested in this poster. Working with "dollar optics” requires facility with simple tools, interest in planning projects, patience, imagination, and the willingness to invest some time and effort. "Dollar optics” may help to foster creativity and hands-on enthusiasm - as did Galileo's work with simple lenses 400 years ago. "Oh! When will there be an end put to the new observations and discoveries of this admirable instrument?” - Galileo Galilei as quoted by Henry C. King, The History of the Telescope.

  18. WE-AB-303-04: A Tissue Model of Cherenkov Emission From the Skin Surface During Megavoltage X-Ray Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, A. N.; Loyalka, S. K. [University of Missouri, Columbia, MO (United States); Izaguirre, E. W. [University of Missouri, Columbia, MO (United States); Baylor Scott & White Health, Temple, TX (United States)

    2015-06-15

    Purpose: To develop a tissue model of Cherenkov radiation emitted from the skin surface during external beam radiotherapy. Imaging Cherenkov radiation emitted from human skin allows visualization of the beam position and potentially surface dose estimates, and our goal is to characterize the optical properties of these emissions. Methods: We developed a Monte Carlo model of Cherenkov radiation generated in a semi-infinite tissue slab by megavoltage x-ray beams with optical transmission properties determined by a two-layered skin model. We separate the skin into a dermal and an epidermal layer in our model, where distinct molecular absorbers modify the Cherenkov intensity spectrum in each layer while we approximate the scattering properties with Mie and Rayleigh scattering from the highly structured molecular organization found in human skin. Results: We report on the estimated distributions of the Cherenkov wavelength spectrum, emission angles, and surface distribution for the modeled irradiated skin surface. The expected intensity distribution of Cherenkov radiation emitted from skin shows a distinct intensity peak around 475 nm, the blue region of the visible spectrum, between a pair of optical absorption bands in hemoglobin and a broad plateau beginning near 600 nm and extending to at least 700 nm where melanin and hemoglobin absorption are both low. We also find that the Cherenkov intensity decreases with increasing angle from the surface normal, the majority being emitted within 20 degrees of the surface normal. Conclusion: Our estimate of the spectral distribution of Cherenkov radiation emitted from skin indicates an advantage to using imaging devices with long wavelength spectral responsivity. We also expect the most efficient imaging to be near the surface normal where the intensity is greatest; although for contoured surfaces, the relative intensity across the surface may appear to vary due to decreasing Cherenkov intensity with increased angle from the

  19. Using ISS to develop telescope technology

    Science.gov (United States)

    Saenz-Otero, Alvar; Miller, David W.

    2005-08-01

    Future space telescope missions concepts have introduced new technologies such as precision formation flight, optical metrology, and segmented mirrors. These new technologies require demonstration and validation prior to deployment in final missions such as the James Webb Space Telescope, Terrestrial Planet Finder, and Darwin. Ground based demonstrations do not provide the precision necessary to obtain a high level of confidence in the technology; precursor free flyer space missions suffer from the same problems as the final missions. Therefore, this paper proposes the use of the International Space Station as an intermediate research environment where these technologies can be developed, demonstrated, and validated. The ISS provides special resources, such as human presence, communications, power, and a benign atmosphere which directly reduce the major challenges of space technology maturation: risk, complexity, cost, remote operations, and visibility. Successful design of experiments for use aboard the space station, by enabling iterative research and supporting multiple scientists, can further reduce the effects of these challenges of space technology maturation. This paper presents results of five previous MIT Space Systems Laboratory experiments aboard the Space Shuttle, MIR, and the ISS to illustrate successful technology maturation aboard these facilities.

  20. Results from the ANTARES neutrino telescope

    Directory of Open Access Journals (Sweden)

    Spurio M.

    2016-01-01

    Full Text Available ANTARES is the largest neutrino telescope in the Northern hemisphere, running in its final configuration since 2008. After the discovery of a cosmic neutrino diffuse flux by the IceCube detector, the search for its origin has become a key mission in high-energy astrophysics. The ANTARES sensitivity is large enough to constrain the origin of the IceCube excess from regions extended up to 0.2 sr in the Southern sky. The Southern sky has been studied searching for point-like objects, for extended regions of emission (as the Galactic plane and for signal from transient objects selected through multimessenger observations. Upper limits are presented assuming different spectral indexes for the energy spectrum of neutrino sources. In addition, ANTARES provides results on studies of the sky in combination with different multimessenger experiments, on atmospheric neutrinos, on the searches for rare particles in the cosmic radiation (such as magnetic monopoles and nuclearites, and on Earth and Sea science. Particularly relevant are the searches for Dark Matter: the limits obtained for the spin-dependent WIMP-nucleon cross section overcome that of existing direct-detection experiments. The recent results, widely discussed in dedicated presentations during the 7th edition of the Very Large Volume Neutrino Telescope Workshop (VLVνT-2015, are highlighted in this paper.

  1. The design and performance of a prototype water Cherenkov optical time-projection chamber

    Science.gov (United States)

    Oberla, Eric; Frisch, Henry J.

    2016-04-01

    A first experimental test of tracking relativistic charged particles by 'drifting' Cherenkov photons in a water-based optical time-projection chamber (OTPC) has been performed at the Fermilab Test Beam Facility. The prototype OTPC detector consists of a 77 cm long, 28 cm diameter, 40 kg cylindrical water mass instrumented with a combination of commercial 5.1 × 5.1cm2 micro-channel plate photo-multipliers (MCP-PMT) and 6.7 × 6.7cm2 mirrors. Five MCP-PMTs are installed in two columns along the OTPC cylinder in a small-angle stereo configuration. A mirror is mounted opposite each MCP-PMT on the inner surface of the detector cylinder, effectively increasing the photo-detection efficiency and providing a time-resolved image of the Cherenkov light on the opposing wall. Each MCP-PMT is coupled to an anode readout consisting of thirty 50 Ω microstrips. A 180-channel data acquisition system digitizes the MCP-PMT signals on one end of the microstrips using the PSEC4 waveform sampling-and-digitizing chip operating at a sampling rate of 10.24 Gigasamples-per-second. The single-ended microstrip readout determines the time and position of a photon arrival at the face of the MCP-PMT by recording both the direct signal and the pulse reflected from the unterminated far end of the strip. The detector was installed on the Fermilab MCenter secondary beam-line behind a steel absorber where the primary flux is multi-GeV muons. Approximately 80 Cherenkov photons are detected for a through-going muon track in a total event duration of 2 ns. By measuring the time-of-arrival and the position of individual photons at the surface of the detector to ≤ 100 ps and a few mm, respectively, we have measured a spatial resolution of 15 mm for each MCP-PMT track segment, and, from linear fits over the entire track length of 40 cm, an angular resolution on the track direction of 60 mrad.

  2. The servo control system of KDUST telescope

    Science.gov (United States)

    Jian, Zhang; Du, Fujia

    2014-07-01

    The KDUST telescope would be installed in Antarctic Dome A, where is extremely cold, high, dry, but have a very stable, calm atmosphere for astronomical observation. According to project requirement, the position following error should be less than 1''. To achieve project target, a direct drive method is used in the project. Normal PID control algorithm is used in controller. It can meet the target in the room temperature. But the following error increased too significantly in the cryogenic environment. In this paper, the expert PID algorithm is applied to control system. The control parameter can be adjusted by amplitude and variation of following error. Experiment proved that expert PID has an obvious advantage in both start-up and tracking process under different temperature. Moreover expert PID also can improve the stability of whole system.

  3. Recent results from the ANTARES deep sea neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, Paschal

    2013-02-15

    The ANTARES deep sea neutrino telescope has acquired over four years of high quality data. This data has been used to measure the oscillation parameters of atmospheric neutrinos and also to search for neutrinos of a nonterrestrial origin. Competitive upper limits on the fluxes of neutrinos from dark matter annihilation in the Sun, a variety of Galactic and extra-galactic sources, both steady and transient, are presented.

  4. 110th anniversary of the birth of P A Cherenkov (Scientific session of the Physical Sciences Division of the Russian Academy of Sciences, 17 December 2014)

    Science.gov (United States)

    2015-05-01

    A scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) was held on 17 December 2014 at the conference hall of the Lebedev Physical Institute, RAS, devoted to the 110th anniversary of the birth of Academician P A Cherenkov. The agenda posted on the website of the Physical Sciences Division RAS http://www.gpad.ac.ru comprised the following reports: (1) Bashmakov Yu A (Lebedev Physical Institute, RAS, Moscow) "Prehistory of discovery"; (2) Kadmensky S G (Voronezh State University, Voronezh) "Cherenkov radiation as a serendipity phenomenon"; (3) Denisov S P (Russian Federation State Scientific Center 'Institute for High Energy Physics' of National Research Center 'Kurchatov Institute', Protvino, Moscow region) "Use of Cherenkov counters in accelerator experiments"; (4) Petrukhin A A (National Research Nuclear University 'MEPhI', Moscow) "Cherenkov NEVOD water detector"; (5) Dremin I M (Lebedev Physical Institute, RAS, Moscow) "Cherenkov radiation from gluons in a nuclear medium"; (6) Domogatsky G V (Institute for Nuclear Research, RAS, Moscow) "Cherenkov detectors for high-energy neutrino astrophysics"; (7) Kravchenko E A (Budker Institute of Nuclear Physics, SB RAS, Novosibirsk) "Cherenkov detectors with aerogel radiators"; (8) Malinovski E I (Institute for Nuclear Research, RAS, Moscow) "Cherenkov total absorption spectrometers for high-energy electrons and photons"; (9) Maltseva Yu I (Budker Institute of Nuclear Physics, SB RAS, Novosibirsk) "Distributed beam loss monitor based on the Cherenkov effect in an optical fiber". Papers based on oral reports 1-4, 6-9 are presented below. Some aspects of report 5 can be found in the review by I M Dremin and A V Leonidov published in 2010 in Physics-Uspekhi (Vol. 53, p. 1123). • Cherenkov radiation: from discovery to RICH, Yu A Bashmakov Physics-Uspekhi, 2015, Volume 58, Number 5, Pages 467-471 • Cherenkov radiation as a serendipitous phenomenon, S G Kadmensky Physics

  5. James Webb Space Telescope Optical Telescope Element Mirror Coatings

    Science.gov (United States)

    Keski-Kuha, Ritva A.; Bowers, Charles W.; Quijada, Manuel A.; Heaney, James B.; Gallagher, Benjamin; McKay, Andrew; Stevenson, Ian

    2012-01-01

    James Webb Space Telescope (JWST) Optical Telescope Element (OTE) mirror coating program has been completed. The science goals of the JWST mission require a uniform, low stress, durable optical coating with high reflectivity over the JWST spectral region. The coating has to be environmentally stable, radiation resistant and compatible with the cryogenic operating environment. The large size, 1.52 m point to point, light weight, beryllium primary mirror (PM) segments and flawless coating process during the flight mirror coating program that consisted coating of 21 flight mirrors were among many technical challenges. This paper provides an overview of the JWST telescope mirror coating program. The paper summarizes the coating development program and performance of the flight mirrors.

  6. Advances in vacuum ultraviolet detection with multistep gaseous detectors and application to Cherenkov ring imaging

    CERN Document Server

    Breskin, Amos; Charpak, Georges; Peisert, Anna; Policarpo, Armando; Sauli, Fabio

    1981-01-01

    The multistep avalanche chamber permits an efficient detection of VUV photons. In a two-step proportional mode charges higher than 1 pC are obtained from single electrons. By using as the final localization step a spark chamber viewed by a TV digitizer it is easy to have imaging of complex patterns. This is applied to Cherenkov ring imaging and (K, pi ) separation with 3 sigma up to 320 GeV is envisaged. The properties of various photoionizable vapours have been studied. By combining a scintillation xenon chamber with a photoionization wire chamber, a resolution of 8.3% (FWHM) has been obtained for 5.9 keV X- rays using tetrakis(dimethylamine)-ethylene vapour. (15 refs).

  7. Strangeonium spectroscopy at 11 GeV/c and Cherenkov Ring Imaging at the SLD

    Energy Technology Data Exchange (ETDEWEB)

    Bienz, T.L.

    1990-07-01

    This thesis is divided into two sections, which describe portions of the data acquisition system and online software for the Cherenkov Ring Imaging Detector (CRID) for the SLD, and analyses of several low cross section strangeonium channels in data from the LASS spectrometer. The CRID section includes a description of the data acquisition system, determination of the preamplifier gain, and development of an online pulse finding algorithm based on deconvolution. Deconvolution uses knowledge of the preamplifier impulse response to aid in pulse finding. The algorithm is fast and shows good single pulse resolution and excellent double pulse resolution in preliminary tests. The strangeonium analyses are based on data from a 4.1 event/nanobarn exposure of the LASS spectrometer in K{sup {minus}}p interactions at 11 GeV/c, and include studies of {Lambda}{eta}{pi}{sup {plus}}{pi}{sup {minus}}, {Lambda}{Kappa}*{Kappa}*, and {Lambda}{phi}{phi}.

  8. Cherenkov radiation effects on counting efficiency in extremely quenched liquid scintillation samples

    Energy Technology Data Exchange (ETDEWEB)

    Grau Carles, A. (Instituto de Investigacion Basica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain)); Grau Malonda, A. (Instituto de Investigacion Basica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain)); Rodriguez Barquero, L. (Instituto de Investigacion Basica, Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas, Madrid (Spain))

    1993-10-01

    The CIEMAT/NIST tracer method has successfully standardized nuclides with diverse quench values and decay schemes in liquid scintillation counting. However, the counting efficiency is computed inaccurately for extremely quenched samples. This article shows that when samples are extremely quenched, the counting efficiency in high-energy beta-ray nuclides depends principally on the Cherenkov effect. A new technique is described for quench determination, which makes the measurement of counting efficiency possible when scintillation counting approaches zero. A new efficiency computation model for pure beta-ray nuclides is also described. The results of the model are tested experimentally for [sup 89]Sr, [sup 90]Y, [sup 36]Cl and [sup 204]Tl nuclides with independence of the quench level. (orig.)

  9. Liner radius fluctuations in a high-gain Cherenkov free-electron laser

    Directory of Open Access Journals (Sweden)

    I. de la Fuente

    2007-02-01

    Full Text Available Phase shifts in the propagating electromagnetic field of a Cherenkov free-electron laser (CFEL can affect its gain. The phase velocity of an electromagnetic wave varies, for example, when the lined waveguide is inhomogeneous along its length. In this paper, we study quantitatively the saturated power of a particular CFEL at both weak and strong electron-beam pumping when the inner radius of the liner contains fluctuations along the waveguide. We show that the gain bandwidth of the CFEL is substantially broadened when the CFEL is pumped with a high-current beam. We also show that the design of a CFEL needs to include optimization with respect to sensitivity to liner fluctuations, especially for weakly pumped CFELs, that is, CFELs that use a low-current electron-beam density. This optimization can be relaxed for more strongly pumped CFELs.

  10. Large acceptance forward Cherenkov detector for the BRAHMS experiment at RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Budick, B., E-mail: bb2@nyu.ed [New York University, New York, NY 10003 (United States); Beavis, D., E-mail: beavis@bnl.go [Brookhaven National Laboratory, Upton, NY 11973 (United States); Chasman, C., E-mail: chasman@bnl.go [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2010-09-21

    A multi-element detector based on Cherenkov radiation in plastic and on photomultiplier tubes has been constructed that is particularly useful in collider experiments. The detector covers the pseudorapidity interval 3.23<{eta}<5.25 with large acceptance for the products of proton-proton and heavy ion collisions. The detector's primary purposes are determining the vertex of the interaction, providing a minimum bias trigger, finding the start time for time of flight (and other timing applications), and monitoring the luminosity. Monte Carlo simulations describe the pulse height response of the detector well, as does an analytic expression that has been developed. The detector performed well in the RHIC experiment BRAHMS.

  11. Greenland Telescope (GLT Project

    Directory of Open Access Journals (Sweden)

    Nakamura M.

    2013-12-01

    Full Text Available The GLT project is deploying a new submillimeter (submm VLBI station in Greenland. Our primary scientific goal is to image a shadow of the supermassive black hole (SMBH of six billion solar masses in M87 at the center of the Virgo cluster of galaxies. The expected SMBH shadow size of 40-50 μas requires superbly high angular resolution, suggesting that the submm VLBI would be the only way to obtain the shadow image. The Summit station in Greenland enables us to establish baselines longer than 9,000 km with ALMA in Chile and SMA in Hawaii as well as providing a unique u–v coverage for imaging M87. Our VLBI network will achieve a superior angular resolution of about 20 μas at 350 GHz, corresponding to ∼ 2.5 times of the Schwarzschild radius of the supermassive black hole in M87. We have been monitoring the atmospheric opacity at 230 GHz since August. 2011; we have confirmed the value on site during the winter season is comparable to the ALMA site thanks to high altitude of 3,200 m and low temperature of −50°C. We will report current status and future plan of the GLT project towards our expected first light on 2015–2016.

  12. Trick or Treat and Telescopes

    Science.gov (United States)

    Buratti, Bonnie J.; Meinke, Bonnie K.; Schmude, Richard W.

    2017-10-01

    Based on an activity that DPS member Richard Schmude Jr. has been doing for years, with over 5000 children reached, DPS initiated in 2016 a pilot program entitled “Trick-or-Treat and Telescopes.” DPS encouraged its members to put out their telescopes during trick-or-treat time on Halloween, in their own lawns or in a neighbor’s lawn with better viewing (or more traffic). The program will be continued in 2017. This year should offer good viewing with a waxing gibbous moon and Saturn visible. The program was also advertised though the Night Sky Network, a consortium of astronomy clubs. The following website gives advice and connections to resources.https://dps.aas.org/education/trick-or-treat-and-telescopes acknowledged.

  13. Characterization benches for neutrino telescope Optical Modules at the APC laboratory

    Directory of Open Access Journals (Sweden)

    Avgitas Theodore

    2016-01-01

    Full Text Available As has been demonstrated by the first generation of neutrino telescopes Antares and IceCube, precise knowledge of the photon detection efficiency of optical modules is of fundamental importance for the understanding of the instrument and accurate event reconstruction. Dedicated test benches have been developed to measure all related quantities for the Digital Optical Modules of the KM3NeT neutrino telescope being currently deployed in the Mediterranean sea. The first bench is a black box with robotic arms equipped with a calibrated single photon source or laser which enable a precise mapping of the detection efficiency at arbitrary incident angles as well as precise measurements of the time delays induced by the photodetection chain. These measurement can be incorporated and compared to full GEANT MonteCarlo simulations of the optical modules. The second bench is a 2 m×2 m ×2 m water tank equipped with muon hodoscopes on top and bottom. It enables to study and measure the angular dependence of the DOM's detection efficiency of the Cherenkov light produced in water by relativistic muons, thus reproducing in situ detection conditions. We describe these two benches and present their first results and status.

  14. A balloon-borne telescope developed for remote sensing of planets from the polar stratosphere

    OpenAIRE

    Taguchi, Makoto; Shoji, Yasuhiro; Sakamoto, Yuji; Yoshida, Kazuya; Takahashi, Yukihiro; Teraguchi, Tomoko; Ohnishi, Tomoya; Battazo, Steve; Sato, Takao; Hoshino, Naoya; 田口, 真; 莊司, 泰弘; 坂本, 裕二; 吉田, 和哉; 高橋, 幸弘

    2010-01-01

    A long-term continuous observation is essential for studies of time-dependent phenomena of the planetary atmospheres and plasmas. A balloon-borne telescope system has been developed for remote sensing of the planets from the polar stratosphere. In this system, a Schmidt-Cassegrain telescope with a 300-mm clear aperture is mounted on a gondola whose attitude is controlled by control moment gyros, an active decoupling motor, and attitude sensors. The gondola can float in the stratosphere for pe...

  15. LISA telescope spacer design investigations

    Science.gov (United States)

    Sanjuan, Josep; Mueller, Guido; Livas, Jeffrey; Preston, Alix; Arsenovic, Petar; Castellucci, Kevin; Generie, Joseph; Howard, Joseph; Stebbins, Robin

    The Laser Interferometer Space Antenna (LISA) is a space-based gravitational wave observa-tory with the goal of observing Gravitational Waves (GWs) from astronomical sources in a frequency range from 30 µHz to 0.1 Hz. The detection of GWs at such low frequency requires measurements of distances at the pico-meter level between bodies separated by 5 million kilo-meters. The LISA mission consists of three identical spacecraft (SC) separated by 5 × 106 km forming an equilateral triangle. Each SC contains two optical assemblies and two vacuum en-closures housing one proof mass (PM) in geodesic (free fall) motion each. The two assemblies on one SC are each pointing towards an identical assembly on each of the other two SC to form a non-equal arm interferometer. The measurement of the GW strain is done by measuring the change in the length of the optical path between the PMs of one arm relative to the other arms caused by the pass of a GW. An important element of the Interferometric Measurement System (IMS) is the telescope which, on one hand, gathers the light coming from the far SC (˜100 pW) and, on the other hand, expands and collimates the small outgoing beam ( 1 W) and sends it to the far SC. Due to the very demanding sensitivity requirements care must be taken in the design and validation of the telescope not to degrade the IMS performance. For instance, the diameter of the telescope sets the the shot noise of the IMS and depends critically on the diameter of the primary and the divergence angle of the outgoing beam. As the telescope is rather fast telescope, the divergence angle is a critical function of the overall separation between the primary and secondary. Any long term changes of the distance of more than a a few micro-meter would be detrimental to the LISA mission. Similarly challenging are the requirements on the in-band path-length noise for the telescope which has to be kept below 1 pm Hz-1/2 in the LISA band. Different configurations (on-axis/off axis

  16. The Large Space Telescope program.

    Science.gov (United States)

    O'Dell, C. R.

    1972-01-01

    The 1980's should see the establishment of the first major observatory in space. This observatory will contain a long-lifetime reflecting telescope of about 120 inches clear aperture. Advantages of an orbiting telescope include the elimination of astronomical seeing effects and improvements in resolving power. The small images and darker sky will permit low-dispersion spectrographs to avoid more of the contaminating background. The crispness of the images also has potential for very efficient high-dispersion spectroscopy. A further advantage lies in the accessibility of all the sky and nearly around-the-clock observing.

  17. Superconductor lunar telescopes --Abstract only

    Science.gov (United States)

    Chen, P. C.; Pitts, R.; Shore, S.; Oliversen, R.; Stolarik, J.; Segal, K.; Hojaji, H.

    1994-01-01

    We propose a new type of telescope designed specifically for the lunar environment of high vacuum and low temperature. Large area UV-Visible-IR telescope arrays can be built with ultra-light-weight replica optics. High T(sub c) superconductors provide support, steering, and positioning. Advantages of this approach are light-weight payload compatible with existing launch vehicles, configurable large area optical arrays, no excavation or heavy construction, and frictionless electronically controlled mechanisms. We have built a prototype and will be demonstarting some of its working characteristics.

  18. Atmospheric Change on Pluto

    Science.gov (United States)

    Person, Michael

    2013-10-01

    We propose to use SOFIA with HIPO and FLITECAM (FLIPO) to measure the parameters of Pluto's atmosphere (temperature, pressure, possible particulate haze) by observing a stellar occultation by Pluto on 15 November 2014. Due to its highly elliptical orbit and seasonally variable obliquity, Pluto's atmosphere is predicted to condense onto its surface within the next ~10 years and possibly within the next few years and thus frequent observations are critical. Detection of the occultation central flash will allow measurement of the structure of Pluto's lower atmosphere and atmospheric oblateness. We will use FLIPO to measure the refracted starlight contemporaneously at visible and infrared wavelengths; this approach is needed to differentiate between two competing explanations for the deficiency in the observed light refracted from Pluto's lower atmosphere (strong thermal gradients versus variable particulate extinction). Only an airborne platform such as SOFIA has the flexibility to place a large telescope in the center of the shadow path of this brief event while at the same time nearly eliminating the possibility of missing time-critical observations due to unfortunate weather systems. Occultation predictions will be updated throughout the period preceding the observations with the goal of achieving sufficient prediction accuracy at the event time to place SOFIA directly in the path of Pluto's central flash. This SOFIA observation will be combined with our ongoing ground-based observing program whose goal is to measure the temporal variability of Pluto's atmosphere in response to its changing seasonal obliquity (and resulting ice migration) and recession from the sun. For the NASA New Horizons mission to Pluto and the Kuiper Belt, this Pluto occultation event represents the last chance, prior to the spacecraft closest approach to the Pluto/Charon system (July 2015), to provide input to the mission for encounter planning, as well as context and supporting atmospheric

  19. Atmospheric aerosol monitoring at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Cester, R.; Chiosso, M.; Chirin, J.; Clay, R.; Dawson, B.; Fick, B.; Filipcic, A.; Garcia, B.; Grillo, A.; Horvat, M.; Iarlori, M.; Malek, M.; Matthews, J.; Matthews,; Melo, D.; Meyhandan, R.; Mostafa, M.; Mussa, R.; Prouza, M.; Raefert, B.; Rizi, V.

    2005-07-01

    For a ground based cosmic-ray observatory the atmosphere is an integral part of the detector. Air fluorescence detectors (FDs) are particularly sensitive to the presence of aerosols in the atmosphere. These aerosols, consisting mainly of clouds and dust, can strongly affect the propagation of fluorescence and Cherenkov light from cosmic-ray induced extensive air showers. The Pierre Auger Observatory has a comprehensive program to monitor the aerosols within the atmospheric volume of the detector. In this paper the aerosol parameters that affect FD reconstruction will be discussed. The aerosol monitoring systems that have been deployed at the Pierre Auger Observatory will be briefly described along with some measurements from these systems.

  20. The origins of the telescope

    NARCIS (Netherlands)

    van Helden, A.|info:eu-repo/dai/nl/072210524; Dupré, S.|info:eu-repo/dai/nl/23478055X; van Gent, R.; Zuidervaart, H.J.

    2011-01-01

    The origins of the telescope have been debated since the instrument’s appearance in the Hague in 1608. Civic and national pride has led local dignitaries, popular writers, and scholars to present sharply divergent histories over the years, crediting a variety of people and places with the invention.

  1. Monster telescope hunts blue planets

    CERN Multimedia

    Leake, J

    2003-01-01

    BRITAIN is to back a project to build the world's biggest telescope - so powerful that it could see life-bearing planets in other solar systems. It will need the largest mirror ever built at about 100 metres in diameter (1/2 page).

  2. Lightning detection in planetary atmospheres

    Science.gov (United States)

    Aplin, Karen L.; Fischer, Georg

    2017-02-01

    Lightning in planetary atmospheres is now a well-established concept. Here we discuss the available detection techniques for, and observations of, planetary lightning by spacecraft, planetary landers and, increasingly, sophisticated terrestrial radio telescopes. Future space missions carrying lightning-related instrumentation are also summarised, specifically the European ExoMars mission and Japanese Akatsuki mission to Venus, which could both yield lightning observations in 2016.

  3. Lightning detection in planetary atmospheres

    OpenAIRE

    Aplin, Karen L; Fischer, Georg

    2016-01-01

    Lightning in planetary atmospheres is now a well-established concept. Here we discuss the available detection techniques for, and observations of, planetary lightning by spacecraft, planetary landers and, increasingly, sophisticated terrestrial radio telescopes. Future space missions carrying lightning-related instrumentation are also summarised, specifically the European ExoMars mission and Japanese Akatsuki mission to Venus, which could both yield lightning observations in 2016.

  4. Overdenture dengan Pegangan Telescopic Crown

    Directory of Open Access Journals (Sweden)

    Pambudi Santoso

    2014-06-01

    Full Text Available Kaitan presisi merupakan alat retensi mekanis yang menghubungkan antara satu atau lebih pegangan gigi tiruan, yang bertujuan untuk menambah retensi dan/atau stabilisasi. Kaitan presisi dapat digunakan secara luas pada gigi tiruan cekat, gigi tiruan sebagian lepasan, overdenture, implant untuk retensi overdenture, dan protesa maksilo fasial. Overdenture dengan kaitan presisi dapat membantu dalam pembagian beban kunyah, meminimalkan trauma pada gigi pegangan dan jaringan lunak, meminimalkan resorbsi tulang, dan meningkatkan estetik dan pengucapan suara. Salah satu jenis dari kaitan presisi adalah telescopic crown, terdiri dari 2 macam mahkota, yaitu mahkota primer yang melekat secara permanen pada gigi penyangga, dan mahkota sekunder yang melekat pada gigi tiruan. Tujuan pemaparan kasus ini adalah untuk memberikan informasi tentang rehabilitasi pasien edentulous sebagian rahang atas dengan telescopic crown..  Pasien wanita berusia 45 tahun datang ke klinik prostodonsia RSGM Prof.Soedomo dengan keluhan ingin dibuatkan gigi tiruan. Pasien kehilangan gigi 11 12 15 16 17 21 22 24 25 26 dan 27 yang diindikasikan untuk pembuatan overdenture gigi tiruan sebagian lepasan (GTS kerangka logam dengan pegangan telescopic crown pada gigi 13 dan 14 dengan sistem parallel-sided crown. Tahap-tahap pembuatan telescopic crown yaitu mencetak model study dengan catatan gigit pendahuluan. Perawatan saluran dilakukan pada akar gigi 13, dilanjutkan pemasangan pasak fiber serta rewalling dinding bukal. Gigi 13 dan 14 dilakukan preparasi mahkota penuh, dilanjutkan dengan pencetakan model kerja untuk coping primer dan kerangka logam dengan metode double impression. Coping primer disementasi pada gigi penyangga, dilanjutkan pasang coba coping sekunder beserta kerangka logam. Selanjutnya dilakukan pencatatan gigit, pencetakan model kerja, penyusunan gigi dan pasang coba penyusunan gigi pada pasien. Prosedur dilanjutkan dengan proses di laboratorium, serta insersi pada

  5. A search for the analogue to Cherenkov radiation by high energy neutrinos at superluminal speeds in ICARUS

    CERN Document Server

    Antonello, M.; Baibussinov, B.; Baldo Ceolin, M.; Benetti, P.; Calligarich, E.; Canci, N.; Carbonara, F.; Centro, S.; Cesana, A.; Cieslik, K.; Cline, D.B.; Cocco, A.G.; Dabrowska, A.; Dequal, D.; Dermenev, A.; Dolfini, R.; Farnese, C.; Fava, A.; Ferrari, A.; Fiorillo, G.; Gibin, D.; Gigli Berzolari, A.; Gninenko, S.; Guglielmi, A.; Haranczyk, M.; Holeczek, J.; Ivashkin, A.; Kisiel, J.; Kochanek, I.; Lagoda, J.; Mania, S.; Mannocchi, G.; Menegolli, A.; Meng, G.; Montanari, C.; Otwinowski, S.; Periale, L.; Piazzoli, A.; Picchi, P.; Pietropaolo, F.; Plonski, P.; Rappoldi, A.; Raselli, G.L.; Rossella, M.; Rubbia, C.; Sala, P.R.; Scantamburlo, E.; Scaramelli, A.; Segreto, E.; Sergiampietri, F.; Stefan, D.; Stepaniak, J.; Sulej, R.; Szarska, M.; Terrani, M.; Varanini, F.; Ventura, S.; Vignoli, C.; Wang, H.; Yang, X.; Zalewska, A.; Zaremba, K.; Cohen, A.

    2012-01-01

    The OPERA collaboration [1] has claimed evidence of superluminal propagation between CERN and the LNGS with . We find that the neutrino energy distribution of the ICARUS events in LAr agrees with the expectations from the Monte Carlo predictions from an unaffected energy distribution of beam from CERN. Our results therefore refute a superluminal interpretation of the OPERA result according to the Cohen and Glashow prediction [2] for a weak currents analog to Cherenkov radiation. In particular no events with a superluminal Cherenkov like e+e- pair or gamma emission have been directly observed inside the fiducial volume of the "bubble chamber like" ICARUS TPC-LAr detector, setting much stricter limits to the value of delta comparable with the one due to the observations from the SN1987A.

  6. Planning the 8-meter Chinese Giant Solar Telescope

    Science.gov (United States)

    Beckers, Jacques M.; Liu, Z.; Deng, Y.; Ji, H.

    2013-07-01

    The Chinese Giant Solar Telescope (CGST) will be a diffraction limited solar telescope optimized for the near-infrared (NIR) spectral region (0.8 - 2.5 microns). Its diffraction limit will be reached by the incorporation of Multi-Conjugate Adaptive Optics (MCAO) enhanced by image restoration techniques to achieve uniform (u.v) plane coverage over the angular spatial frequency region allowed by its 8-meter aperture. Thus it will complement the imaging capabilities of 4-meter telescopes being planned elsewhere which are optimized for the visible (VIS) spectral region (300 - 1000 nm) In the NIR spectral regions the CGST will have access to unique spectral features which will improve the diagnostics of the solar atmosphere. These include the CaII lines near 860 nm , the HeI lines near 1083 nm, the 1074 nm FeXIII coronal lines, the large Zeeman-split FeI line at 1548 nm, and (v) the H- continuum absorption minimum at 1.6 micron. Especially in sunspot umbrae the simultaneous observation of continua and lines across the NIR spectral range will cover a substantial depth range in the solar atmosphere. Of course the mid- and far- infrared regions are also available for unequalled high-angular resolution solar observations, for example, in the Hydrogen Bracket lines, CO molecular bands, and the MgI emission line at 12.3 microns. The CGST is a so-called ring telescope in which the light is captured by a 1 meter wide segmented ring or by a ring of 7 smaller off-axis aperture telescopes. The open central area of the telescope is large. The advantages of such a ring configuration is that (a) it covers all the spatial frequencies out to those corresponding to its outer diameter, (b) its circular symmetry makes it polarization neutral, (c) its large central hole helps thermal control, and (d) it provides ample space for the MCAO system and instrumentation in the Gregorian focus. Even though optimized for the NIR, we expect to use the CGST also at visible wavelengths in the so

  7. NEAT: A Microarcsec Astrometric Telescope

    Science.gov (United States)

    Shao, M.; Nemati, B.; Zhai, C.; Goullioud, R.

    2011-01-01

    NEAT, Nearby Exo-Earth Astrometric Telescope is a medium-small telescope (is) approximately 1m in diameter that is designed to make ultra precise (is) less than 1 uas (microarcsec) astrometric measurements of nearby stars in a (is) approximately 1hr observation. Four major error sources prevent normal space telescopes from obtaining accuracies close to 1 uas. Even with a small 1m telescope, photon noise is usually not a problem for the bright nearby target stars. But in general, the reference stars are much fainter. Typically a field of view of (is) approximately 0.5 deg dia is needed to obtain enough bright reference stars. The NEAT concept uses a very simple but unusual design to avoid optically induced astrometric errors. The third source of error is the accuracy and stability of the focal plane. A 1uas error over a (is) approximately 2000 arcsec field of view implies the focal plane is accurate or at least stable to 5 parts in 10(exp 10) over the lifetime of the mission ( (is) approximately 5yrs). The 4th class of error has to do with our knowledge of the PSF and how that PSF is sampled by an imperfect detector. A Nyquist sampled focal plane would have (is) greater than 2 pixels per lambda/D, and centroiding to 1uas means centroiding to 10-5 pixels. This paper describes the mission concept, and an overview of the technology needed to perform 1uas astrometry with a small telescope, and how we overcome problems 1 and 2. A companion paper will describe the technical progress we've made in solving problems 3 and 4.

  8. Construction of the Advanced Technology Solar Telescope - A Progress Report.

    Science.gov (United States)

    Rimmele, T. R.; Keil, S.; McMullin, J.; Goode, P. R.; Knoelker, M.; Kuhn, J. R.; Rosner, R.; ATST Team

    2012-12-01

    The 4m Advance Technology Solar Telescope (ATST) will be the most powerful solar telescope and the world's leading ground-based resource for studying solar magnetism that controls the solar wind, flares, coronal mass ejections and variability in the Sun's output. The ATST will provide high resolution and high sensitivity observations of the dynamic solar magnetic fields throughout the solar atmosphere, including the corona at infrared wavelengths. With its 4 m aperture, ATST will resolve magnetic features at their intrinsic scales. A high order adaptive optics system delivers a corrected beam to the initial set of five state-of-the-art, facility class instrumentation located in the coude laboratory facility. Photopheric and chromospheric magnetometry is part of the key mission of four of these instruments. Coronal magnetometry and spectroscopy will be performed by two of these instruments at infrared wavelengths. The ATST project has transitioned from design and development to its construction phase. Site construction is expected to begin in the first half of 2012. The project has awarded design and fabrication contracts for major telescope subsystems. A robust instrument program has been established and all instruments have passed preliminary design reviews or critical design reviews. A brief summary of the science goals and observational requirements of the ATST will be given, followed by a summary of the project status of the telescope and discussion of the approach to integrating instruments into the facility.

  9. Overview and status of the Giant Magellan Telescope project

    Science.gov (United States)

    Bernstein, Rebecca A.; McCarthy, Patrick J.; Raybould, Keith; Bigelow, Bruce C.; Bouchez, Atonin H.; Filgueira, José M.; Jacoby, George; Johns, Matt; Sawyer, David; Shectman, Stephen; Sheehan, Michael

    2014-07-01

    The Giant Magellan Telescope (GMT) is a 25.4-m diameter, optical/infrared telescope that is being built by an international consortium of universities and research institutions as one of the next generation of Extremely Large Telescopes. The primary mirror of GMT consists of seven 8.4 m borosilicate honeycomb mirror segments that are optically conjugate to seven corresponding segments in the Gregorian secondary mirror. Fabrication is complete for one primary mirror segment and is underway for the next two. The final focal ratio of the telescope is f/8.2, so that the focal plane has an image scale of 1.02 arcsec/mm. GMT will be commissioned using a fast-steering secondary mirror assembly comprised of conventional, rigid segments to provide seeing-limited observations. A secondary mirror with fully adaptive segments will be used in standard operation to additionally enable ground-layer and diffraction-limited adaptive optics. In the seeing limited mode, GMT will provide a 10 arcmin field of view without field correction. A 20 arcmin field of view will be obtained using a wide-field corrector and atmospheric dispersion compensator. The project has recently completed a series of sub-system and system-level preliminary design reviews and is currently preparing to move into the construction phase. This paper summarizes the technical development of the GMT sub-systems and the current status of the GMT project.

  10. Radio Telescopes Will Add to Cassini-Huygens Discoveries

    Science.gov (United States)

    2004-12-01

    When the European Space Agency's Huygens spacecraft makes its plunge into the atmosphere of Saturn's moon Titan on January 14, radio telescopes of the National Science Foundation's National Radio Astronomy Observatory (NRAO) will help international teams of scientists extract the maximum possible amount of irreplaceable information from an experiment unique in human history. Huygens is the 700-pound probe that has accompanied the larger Cassini spacecraft on a mission to thoroughly explore Saturn, its rings and its numerous moons. The Green Bank Telescope The Robert C. Byrd Green Bank Telescope CREDIT: NRAO/AUI/NSF (Click on image for GBT gallery) The Robert C. Byrd Green Bank Telescope (GBT) in West Virginia and eight of the ten telescopes of the continent-wide Very Long Baseline Array (VLBA), located at Pie Town and Los Alamos, NM, Fort Davis, TX, North Liberty, IA, Kitt Peak, AZ, Brewster, WA, Owens Valley, CA, and Mauna Kea, HI, will directly receive the faint signal from Huygens during its descent. Along with other radio telescopes in Australia, Japan, and China, the NRAO facilities will add significantly to the information about Titan and its atmosphere that will be gained from the Huygens mission. A European-led team will use the radio telescopes to make extremely precise measurements of the probe's position during its descent, while a U.S.-led team will concentrate on gathering measurements of the probe's descent speed and the direction of its motion. The radio-telescope measurements will provide data vital to gaining a full understanding of the winds that Huygens encounters in Titan's atmosphere. Currently, scientists know little about Titan's winds. Data from the Voyager I spacecraft's 1980 flyby indicated that east-west winds may reach 225 mph or more. North-south winds and possible vertical winds, while probably much weaker, may still be significant. There are competing theoretical models of Titan's winds, and the overall picture is best summarized as

  11. Art concept of the Hubble Space Telescope

    Science.gov (United States)

    1986-01-01

    Art concept of the Hubble Space Telescope in orbit above the earth with a Space Shuttle approaching and an astronaut performing an extravehicular activity (EVA) (30462); Art concept of the Hubble Space Telescope with the interior design exposed (30463).

  12. Cherenkov radiation conversion and collection considerations for a gamma bang time/reaction history diagnostic for the NIF.

    Science.gov (United States)

    Herrmann, Hans W; Mack, Joseph M; Young, Carlton S; Malone, Robert M; Stoeffl, Wolfgang; Horsfield, Colin J

    2008-10-01

    Bang time and reaction history measurements are fundamental components of diagnosing inertial confinement fusion (ICF) implosions and will be essential contributors to diagnosing attempts at ignition on the National Ignition Facility (NIF). Fusion gammas provide a direct measure of fusion interaction rate without being compromised by Doppler spreading. Gamma-based gas Cherenkov detectors that convert fusion gamma rays to optical Cherenkov photons for collection by fast recording systems have been developed and fielded at Omega. These systems have established their usefulness in illuminating ICF physics in several experimental campaigns. Bang time precision better than 25 ps has been demonstrated, well below the 50 ps accuracy requirement defined by the NIF system design requirements. A comprehensive, validated numerical study of candidate systems is providing essential information needed to make a down selection based on optimization of sensitivity, bandwidth, dynamic range, cost, and NIF logistics. This paper presents basic design considerations arising from the two-step conversion process from gamma rays to relativistic electrons to UV/visible Cherenkov radiation.

  13. Monte Carlo simulation of the Cherenkov radiation emitted by TeO{sub 2} crystal when crossed by cosmic muons

    Energy Technology Data Exchange (ETDEWEB)

    Casali, N., E-mail: nicola.casali@gmail.com [Dipartimento di Scienze Fisiche e Chimiche, Università degli studi dell' Aquila, Coppito (AQ) (Italy); Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso, Assergi (AQ) (Italy); Bellini, F. [Sapienza Università di roma, P.le A. Moro 2, Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, Roma (Italy); Dafinei, I. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, Roma (Italy); Marafini, M. [Museo Storico della Fisisca e Centro Studi e Ricerche “Enrico Fermi“, Piazza del Viminale 1, Roma (Italy); Morganti, S.; Orio, F.; Pinci, D.; Vignati, M.; Voena, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, Roma (Italy)

    2013-12-21

    TeO{sub 2} crystals are currently used as bolometric detectors in experiments searching for the neutrinoless double beta decay of {sup 130}Te. The extreme rarity of the studied signal forces the experiments to reach an ultra low background level. The main background source is represented by α particles emitted by radioactive contaminants placed in the materials that compose and surround the detector. Recent measurements show that a particle discrimination in TeO{sub 2} bolometers detecting the light emitted by β/γ particles is possible, opening the possibility to make large improvements in the performance of experiments based on this kind of materials. In order to understand the nature of this light emission a measurement at room temperature with TeO{sub 2} crystals was performed. According to these results, the detected light was compatible with the Cherenkov emission, even though the scintillation hypothesis could not be discarded. In this work a Monte Carlo (MC) simulation of the Cherenkov radiation emitted by TeO{sub 2} crystal when crossed by cosmic muons was performed. The data from MC and the room temperature measurement are perfectly compatible and prove that the Cherenkov light is the only component of the light yield of TeO{sub 2} crystals.

  14. Simulation of Cherenkov photons emitted in photomultiplier windows induced by Compton diffusion using the Monte Carlo code GEANT4

    Energy Technology Data Exchange (ETDEWEB)

    Thiam, C. [CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), F-91191 Gif-sur-Yvette Cedex (France); Bobin, C., E-mail: christophe.bobin@cea.f [CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), F-91191 Gif-sur-Yvette Cedex (France); Bouchard, J. [CEA, LIST, Laboratoire National Henri Becquerel (LNE-LNHB), F-91191 Gif-sur-Yvette Cedex (France)

    2010-07-15

    The implementation of the TDCR method (Triple to Double Coincidence Ratio) is based on a liquid scintillation system which comprises three photomultipliers; at LNHB, this counter can also be used in the {beta}-channel of a 4{pi}(LS){beta}-{gamma} coincidence counting equipment. It is generally considered that the {gamma}-sensitivity of the liquid scintillation detector comes from the interaction of the {gamma}-photons in the scintillation cocktail but when introducing solid {gamma}-ray emitting sources instead of the scintillation vial, light emitted by the surrounding of the counter is observed. The explanation proposed in this article is that this effect comes from the emission of Cherenkov photons induced by Compton diffusion in the photomultiplier windows. In order to support this assertion, the creation and the propagation of Cherenkov photons inside the TDCR counter is simulated using the Monte Carlo code GEANT4. Stochastic calculations of double coincidences confirm the hypothesis of Cherenkov light produced in the photomultiplier windows.

  15. The Next Generation Space Telescope

    Science.gov (United States)

    Bely, Pierre-Yves (Editor); Burrows,, Christopher J. (Editor); Illingworth,, Garth D.

    1989-01-01

    In Space Science in the Twenty-First Century, the Space Science Board of the National Research Council identified high-resolution-interferometry and high-throughput instruments as the imperative new initiatives for NASA in astronomy for the two decades spanning 1995 to 2015. In the optical range, the study recommended an 8 to 16-meter space telescope, destined to be the successor of the Hubble Space Telescope (HST), and to complement the ground-based 8 to 10-meter-class telescopes presently under construction. It might seem too early to start planning for a successor to HST. In fact, we are late. The lead time for such major missions is typically 25 years, and HST has been in the making even longer with its inception dating back to the early 1960s. The maturity of space technology and a more substantial technological base may lead to a shorter time scale for the development of the Next Generation Space Telescope (NGST). Optimistically, one could therefore anticipate that NGST be flown as early as 2010. On the other hand, the planned lifetime of HST is 15 years. So, even under the best circumstances, there will be a five year gap between the end of HST and the start of NGST. The purpose of this first workshop dedicated to NGST was to survey its scientific potential and technical challenges. The three-day meeting brought together 130 astronomers and engineers from government, industry and universities. Participants explored the technologies needed for building and operating the observatory, reviewed the current status and future prospects for astronomical instrumentation, and discussed the launch and space support capabilities likely to be available in the next decade. To focus discussion, the invited speakers were asked to base their presentations on two nominal concepts, a 10-meter telescope in space in high earth orbit, and a 16-meter telescope on the moon. The workshop closed with a panel discussion focused mainly on the scientific case, siting, and the

  16. CFRP lightweight structures for extremely large telescopes

    DEFF Research Database (Denmark)

    Jessen, Niels Christian; Nørgaard-Nielsen, Hans Ulrik; Schroll, J.

    2008-01-01

    Telescope structures are traditionally built out of steel. To improve the possibility of realizing the ambitious extremely large telescopes, materials with a higher specific stiffness and a lower coefficient of thermal expansion are needed. An important possibility is Carbon Fibre Reinforced Plas...... Plastic (CFRP). The advantages of using CFRP for the secondary mirror support structure of the European overwhelmingly large telescope are discussed....

  17. The Hubble Space Telescope: Problems and Solutions.

    Science.gov (United States)

    Villard, Ray

    1990-01-01

    Presented is the best understanding of the flaw discovered in the optics of the Hubble Space Telescope and the possible solutions to the problems. The spherical aberration in the telescope's mirror and its effect on the quality of the telescope's imaging ability is discussed. (CW)

  18. The Principles of Astronomical Telescope Design

    CERN Document Server

    Cheng, Jingquan

    2009-01-01

    Presents a summary of the author's twenty five years of experience in telescope design. This work provides a general introduction to various aspects of telescope design. It discusses the theory behind telescope design. It covers Radio, Infrared, Optical, X-Ray and Gamma-Ray wavelengths

  19. New Solar System Researches expected by a New Telescope Project at Mt. Haleakala, Hawaii

    Science.gov (United States)

    Kagitani, Masato; Okano, S.; Kasaba, Y.; Kuhn, J.; Berdyugina, S.

    2009-09-01

    We Tohoku University starts the project for the new ground-based telescope dedicated to planets and exoplanets, in collaboration with the Institute for Astronomy of University of Hawaii(IfA/UH) and ETH Zurich. The summit of Mt. Haleakala in Maui, Hawaii is one of the best sites with clear skies, good seeing, and low humidity conditions as well as good accessibility despite its high altitude (elv. 3,000m). Haleakala High Altitude Observatory is operated by IfA/UH, and we have been making observation of planets there since 2000. Currently, our observation facility consists of a 40cm telescope. We have been making observations of faint atmospheric and plasma features around bright planets, Io plasma torus, Mercury and Lunar sodium tail, and so on. Atmospheric escapes from Mars and Venus, the exoplanets close to mother stars are also possible future important topics. When we try to observe those faint emissions surrounding the bright objects, intense scattered light causes a serious problem. The new telescope shall avoid the diffraction due to a spider structure that holds a secondary mirror and to minimize the scattered light from mirror surfaces as far as possible. Such telescope with a wide dynamic range dedicated to planetary and exoplanetary sciences does not exist yet. The project, called PLANETS (Poralized Light from Atmospheres of Nearby Extra Terrestrial Planets), develops a new telescope (tentatively named as JHET; Japan Hawaii Europe Telescope) which consists of an off-axis primary mirror with a diameter of 1.8m, and Gregorian optics on an equatorial mount. State-of-art adaptive optics and masking technologies will also be adopted to eliminate the scattering light. This telescope will enables us to do spectro-polarimetric observations and faint plasma and atmospheres around the bright bodies. We will introduce the progress of our ground-based observations and the future plan involving the wide area of the international communities.

  20. Focusing Telescopes in Nuclear Astrophysics

    CERN Document Server

    Ballmoos, Peter von

    2007-01-01

    This volume is the first of its kind on focusing gamma-ray telescopes. Forty-eight refereed papers provide a comprehensive overview of the scientific potential and technical challenges of this nascent tool for nuclear astrophysics. The book features articles dealing with pivotal technologies such as grazing incident mirrors, multilayer coatings, Laue- and Fresnel-lenses - and even an optic using the curvature of space-time. The volume also presents an overview of detectors matching the ambitious objectives of gamma ray optics, and facilities for operating such systems on the ground and in space. The extraordinary scientific potential of focusing gamma-ray telescopes for the study of the most powerful sources and the most violent events in the Universe is emphasized in a series of introductory articles. Practicing professionals, and students interested in experimental high-energy astrophysics, will find this book a useful reference

  1. Atmospheric Dispositifs

    DEFF Research Database (Denmark)

    Wieczorek, Izabela

    2015-01-01

    Through the coupling of dispositif with atmosphere this paper engages in a discussion of the atmospherics as both a form of knowledge and a material practice. In doing so the objective is to provide an inventory of tools and methodologies deployed in the construction of atmosphere understood......, the conceptual foundations and protocols for the production of atmosphere in architecture might be found beneath the surface of contemporary debates. In this context, the notion of atmospheric dispositif – illustrated through an oeuvre of the German architect Werner Ruhnau and its theoretical and historical...

  2. Diffractive X-ray Telescopes

    OpenAIRE

    Skinner, Gerald K

    2010-01-01

    Diffractive X-ray telescopes using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution several orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted space- time in the immediate vicinity of the super...

  3. The NASA Spitzer Space Telescope.

    Science.gov (United States)

    Gehrz, R D; Roellig, T L; Werner, M W; Fazio, G G; Houck, J R; Low, F J; Rieke, G H; Soifer, B T; Levine, D A; Romana, E A

    2007-01-01

    The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.

  4. Building the Green Bank Telescope

    Science.gov (United States)

    Kellermann, Kenneth I.

    2017-01-01

    In a previous presentation, I reported on how the freak collapse of the NRAO 300-ft transit radio telescope led to the inclusion of $75 million for a new radio telescope in the 1989 Congressional Emergency Supplemental Appropriations Act. But, this was only the beginning. NRAO was faced with challenging specifications and an unworkable schedule, but there was no design and no project team. Only one bid was even close to the Congressional appropriation. In an attempt to meet the unrealistic antenna delivery date, the contractor started construction of the foundation and fabrication of antenna members before the design was finished, leading to retrofits, redesign, and multiple delays. The antenna contractor was twice sold to other companies leading to further delays and cost escalation. In order to recoup their mounting losses, the new owners sued NRAO for $29 million for claimed design changes, and NRAO countersued demanding to be reimbursed for added project management costs and lost scientific data resulting from the seven-year delay in the completion of the telescope. Legal fees and a small net award in favor of the contractor left NRAO and the NSF with a nine million dollar bill which NSF handled by an innovative accounting adjustment.

  5. The NASA Spitzer Space Telescope

    Science.gov (United States)

    Gehrz, R. D.; Roellig, T. L.; Werner, M. W.; Fazio, G. G.; Houck, J. R.; Low, F. J.; Rieke, G. H.; Soifer, B. T.; Levine, D. A.; Romana, E. A.

    2007-01-01

    The National Aeronautics and Space Administration's Spitzer Space Telescope (formerly the Space Infrared Telescope Facility) is the fourth and final facility in the Great Observatories Program, joining Hubble Space Telescope (1990), the Compton Gamma-Ray Observatory (1991-2000), and the Chandra X-Ray Observatory (1999). Spitzer, with a sensitivity that is almost three orders of magnitude greater than that of any previous ground-based and space-based infrared observatory, is expected to revolutionize our understanding of the creation of the universe, the formation and evolution of primitive galaxies, the origin of stars and planets, and the chemical evolution of the universe. This review presents a brief overview of the scientific objectives and history of infrared astronomy. We discuss Spitzer's expected role in infrared astronomy for the new millennium. We describe pertinent details of the design, construction, launch, in-orbit checkout, and operations of the observatory and summarize some science highlights from the first two and a half years of Spitzer operations. More information about Spitzer can be found at http://spitzer.caltech.edu/.

  6. Pixel hybrid photon detectors for the ring imaging Cherenkov detectors of LHCb

    CERN Document Server

    Somerville, L

    2005-01-01

    A Pixel Hybrid Photon Detector (pixel HPD) has been developed for the LHCb Ring Imaging Cherenkov (RICH) detectors. The pixel HPD is a vacuum tube with a multi-alkali photocathode, high-voltage cross- focused electron optics and an anode consisting of a silicon pixel detector bump-bonded to a CMOS readout chip; the readout chip is thus fully encapsulated in the device. The pixel HPD fulfils the stringent requirements for the RICH detectors of LHCb, combining single photon sensitivity, high signal-to-noise ratio and fast readout with an ~8cm diameter active area and an effective pixel size of 2.5mm 2.5mm at the photocathode. The performance and characteristics of two prototype pixel HPDs have been studied in laboratory measurements and in recent beam tests. The results of all measurements agree with expectations and fulfil the LHCb RICH requirements. In readiness for production of the ~500pixel HPDs for the RICH detectors, a test programme was designed and implemented to ensure component quality control at eac...

  7. R&D on high momentum particle identification with a pressurized Cherenkov radiator

    Science.gov (United States)

    Agócs, A. G.; Barile, F.; Barnafo¨ldi, G. G.; Bellwied, R.; Bencédi, G.; Bencze, G.; Berényi, D.; Boldizsár, L.; Chattopadhyay, S.; Chinellato, D. D.; Cindolo, F.; Cossyleon, K.; Das, D.; Das, K.; Das-Bose, L.; De Cataldo, G.; Di Bari, D.; Di Mauro, A.; Futó, E.; Garcia-Solis, E.; Hamar, G.; Harton, A.; Jayarathna, S. P.; Jimenez, R. T.; Kim, D. W.; Kim, J. S.; Knospe, A.; Lévai, P.; Markert, C.; Martinengo, P.; Molnar, L.; Nappi, E.; Oláh, L.; Paić, G.; Pastore, C.; Patino, M. E.; Peskov, V.; Pinsky, L.; Piuz, F.; Piyarathna, D. B.; Pochybová, S.; Sgura, I.; Sinha, T.; Song, J.; Timmins, A.; Van Beelen, J. B.; Varga, D.; Volpe, G.; Weber, M.; Xaplanteris, L.; Yi, J.; Yoo, I.-K.

    2014-12-01

    We report on the R&D results for a Very High Momentum Particle Identification (VHMPID) detector, which was proposed to extend the charged hadron track-by-track identification in the momentum range from 5 to 25 GeV/c in the ALICE experiment at CERN. It is a RICH detector with focusing geometry using pressurized perfluorobutane (C4F8O) as a Cherenkov radiator. A MWPC with a CsI photocathode was investigated as the baseline option for the photon detector. The results of beam tests performed on RICH prototypes using both liquid C6F14 radiator (in proximity focusing geometry for reference measurements) and pressurized C4F8O gaseous radiator will be shown in this paper. In addition, we present studies of a CsI based gaseous photon detector equipped with a MWPC having an adjustable anode-cathode gap, aiming at the optimization of the chamber layout and performance in the detection of single photoelectrons.

  8. Elastic Cherenkov effects in transversely isotropic soft materials-I: Theoretical analysis, simulations and inverse method

    Science.gov (United States)

    Li, Guo-Yang; Zheng, Yang; Liu, Yanlin; Destrade, Michel; Cao, Yanping

    2016-11-01

    A body force concentrated at a point and moving at a high speed can induce shear-wave Mach cones in dusty-plasma crystals or soft materials, as observed experimentally and named the elastic Cherenkov effect (ECE). The ECE in soft materials forms the basis of the supersonic shear imaging (SSI) technique, an ultrasound-based dynamic elastography method applied in clinics in recent years. Previous studies on the ECE in soft materials have focused on isotropic material models. In this paper, we investigate the existence and key features of the ECE in anisotropic soft media, by using both theoretical analysis and finite element (FE) simulations, and we apply the results to the non-invasive and non-destructive characterization of biological soft tissues. We also theoretically study the characteristics of the shear waves induced in a deformed hyperelastic anisotropic soft material by a source moving with high speed, considering that contact between the ultrasound probe and the soft tissue may lead to finite deformation. On the basis of our theoretical analysis and numerical simulations, we propose an inverse approach to infer both the anisotropic and hyperelastic parameters of incompressible transversely isotropic (TI) soft materials. Finally, we investigate the properties of the solutions to the inverse problem by deriving the condition numbers in analytical form and performing numerical experiments. In Part II of the paper, both ex vivo and in vivo experiments are conducted to demonstrate the applicability of the inverse method in practical use.

  9. Cosmic Ray Astrophysics using The High Altitude Water Cherenkov (HAWC Observatory in México

    Directory of Open Access Journals (Sweden)

    de la Fuente Eduardo

    2017-01-01

    Full Text Available The High-Altitude Water Cherenkov (HAWC TeV gamma–ray Observatory in México is ready to search and study gamma-ray emission regions, extremely high-energy cosmic-ray sources, and to identify transient phenomena. With a better Gamma/Hadron rejection method than other similar experiments, it will play a key role in triggering multi–wavelength and multi–messenger studies of active galaxies (AGN, gamma-ray bursts (GRB, supernova remnants (SNR, pulsar wind nebulae (PWN, Galactic Plane Sources, and Cosmic Ray Anisotropies. It has an instantaneous field-of-view of ∼2 str, equivalent to 15% of the whole sky and continuous operation (24 hours per day. The results obtained by HAWC–111 (111 detectors in operation were presented on the proceedings of the International Cosmic Ray Conference 2015 and in [1]. The results obtained by HAWC–300 (full operation are now under analysis and will be published in forthcoming papers starting in 2017 (see preliminary results on http://www.hawc-observatory.org/news/. Here we present the HAWC contributions on cosmic ray astrophysics via anisotropies studies, summarizing the HAWC detector and its upgrading by the installation of “outriggers”.

  10. Cosmic Ray Astrophysics using The High Altitude Water Cherenkov (HAWC) Observatory in México

    Science.gov (United States)

    de la Fuente, Eduardo; Díaz-Vélez, Juan Carlos; Almada, Alberto Hernández; Nigoche-Netro, Alberto

    2017-06-01

    The High-Altitude Water Cherenkov (HAWC) TeV gamma-ray Observatory in México is ready to search and study gamma-ray emission regions, extremely high-energy cosmic-ray sources, and to identify transient phenomena. With a better Gamma/Hadron rejection method than other similar experiments, it will play a key role in triggering multi-wavelength and multi-messenger studies of active galaxies (AGN), gamma-ray bursts (GRB), supernova remnants (SNR), pulsar wind nebulae (PWN), Galactic Plane Sources, and Cosmic Ray Anisotropies. It has an instantaneous field-of-view of ˜2 str, equivalent to 15% of the whole sky and continuous operation (24 hours per day). The results obtained by HAWC-111 (111 detectors in operation) were presented on the proceedings of the International Cosmic Ray Conference 2015 and in [1]. The results obtained by HAWC-300 (full operation) are now under analysis and will be published in forthcoming papers starting in 2017 (see preliminary results on http://www.hawc-observatory.org/news/). Here we present the HAWC contributions on cosmic ray astrophysics via anisotropies studies, summarizing the HAWC detector and its upgrading by the installation of "outriggers".

  11. Next generation gamma-ray Cherenkov detectors for the National Ignition Facility

    Science.gov (United States)

    Herrmann, H. W.; Kim, Y. H.; McEvoy, A. M.; Zylstra, A. B.; Young, C. S.; Lopez, F. E.; Griego, J. R.; Fatherley, V. E.; Oertel, J. A.; Stoeffl, W.; Khater, H.; Hernandez, J. E.; Carpenter, A.; Rubery, M. S.; Horsfield, C. J.; Gales, S.; Leatherland, A.; Hilsabeck, T.; Kilkenny, J. D.; Malone, R. M.; Hares, J. D.; Milnes, J.; Shmayda, W. T.; Stoeckl, C.; Batha, S. H.

    2016-11-01

    The newest generation of Gas Cherenkov Detector (GCD-3) employed in Inertial Confinement Fusion experiments at the Omega Laser Facility has provided improved performance over previous generations. Comparison of reaction histories measured using two different deuterium-tritium fusion products, namely gamma rays using GCD and neutrons using Neutron Temporal Diagnostic (NTD), have provided added credibility to both techniques. GCD-3 is now being brought to the National Ignition Facility (NIF) to supplement the existing Gamma Reaction History (GRH-6m) located 6 m from target chamber center (TCC). Initially it will be located in a reentrant well located 3.9 m from TCC. Data from GCD-3 will inform the design of a heavily-shielded "Super" GCD to be located as close as 20 cm from TCC. It will also provide a test-bed for faster optical detectors, potentially lowering the temporal resolution from the current ˜100 ps state-of-the-art photomultiplier tubes (PMT) to ˜10 ps Pulse Dilation PMT technology currently under development.

  12. Implementation of the next-generation Gas Cherenkov Detector at the National Ignition Facility

    Science.gov (United States)

    Carrera, J. A.; Herrmann, H. W.; Khater, H. Y.; Carpenter, A. C.; Beeman, B. V.; Hernandez, J. E.; Sitaraman, S.; Lopez, F. E.; Zylstra, A. B.; Griego, J. R.; Kim, Y. H.; Gales, S. A.; Horsfield, C. J.; Milnes, J. S.; Hares, J. D.

    2017-08-01

    The newest Gas Cherenkov Detector (GCD-3) diagnostic has completed its Phase I commissioning/milestone at the National Ignition Facility (NIF). GCD-3 was fielded for several years at the Omega Laser Facility in its initial configuration, before being moved to the NIF. Installation at the NIF involved optimization of GCD-3 for the higher background environment and designing a new insertion carrier assembly. GCD-3 serves as the initial phase towards the implementation of the "Super GCD" (SGCD) at the NIF. During this phase of development GCD-3 took measurements from a re-entrant well, 3.9 meters from target chamber center (TCC). Plans to insert GCD-3 within 20 cm of TCC with a Target and Diagnostic Manipulator (TANDM) will be discussed. Data was collected using a Photomultiplier Tube (PMT) in combination with a Mach-Zehnder based recording system. These measurements were used to aid in shielding analysis, validate MCNP models, and fuel design efforts for the SGCD. Findings from the initial data will be covered extensively, including an in-depth look into sources of background and possible mitigation strategies. Ongoing development of phase two, the addition of an ultra-high bandwidth Pulse Dilatation Photomultiplier Tube (PD-PMT), will also be presented.

  13. Study and Search for Main Reason of Lung Cancers Based on Cherenkov Radiation in Environmental Radiation

    Science.gov (United States)

    Ito, Hiroshi; Emoto, Yusaku; Fujihara, Kento; Kawai, Hideyuki; Kimura, Shota; Kodama, Satoshi; Mizuno, Takahiro

    2018-01-01

    The number of lung-cancer-related death is highest among all cancers in the world, and it is increasing in Japan where population aging in progressing. The main reason for the lung cancer of non-smokers is regarded to be environmental pollution or exposure of the lung to radon in the nature. The risk of lung cancer was estimated to increase by 8 to 13% per every 100 Bq m-3 concentration of radon in the air. We observed beta rays with maximum energy of 3.27 MeV emitted from 214Bi as one of the progenies based on a detection of Cherenkov radiation. The surface radioactivity concentration of 214Bi on the sample was measured; the relation between the concentration and exposure time for the sample at the room air is researched. The behavior of the radon progenies in the air is discussed by a research for the progenies attaching on the sample after the radon decay. The inhalation of the radon progenies is not clear. Thus, to understand the behavior of progenies in the air make to clear the causal relation between the radon concentration and lung cancers.

  14. The water Cherenkov detector array for studies of cosmic rays at the University of Puebla

    Energy Technology Data Exchange (ETDEWEB)

    Cotzomi, J. [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla Pue. 72570 (Mexico); Moreno, E. [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla Pue. 72570 (Mexico); Murrieta, T. [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla Pue. 72570 (Mexico); Palma, B. [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla Pue. 72570 (Mexico); Perez, E. [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla Pue. 72570 (Mexico); Salazar, H. [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla Pue. 72570 (Mexico)]. E-mail: hsalazar@fcfm.buap.mx; Villasenor, L. [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla Pue. 72570 (Mexico)

    2005-11-11

    We describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla (19{sup -}bar N, 90{sup -}bar W, 800g/cm{sup 2}) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1PeV, i.e., around the knee of the cosmic ray spectrum. The array consists of 3 water Cherenkov detectors of 1.86m{sup 2} cross-section and 12 liquid scintillator detectors of 1m{sup 2} distributed in a square grid with a detector spacing of 20m over an area of 4000m{sup 2}. We discuss the calibration and stability of the array for both sets of detectors and report on preliminary measurements and reconstruction of the lateral distributions for the electromagnetic (EM) and muonic components of extensive air showers. We also discuss how the hybrid character of the array can be used to measure mass composition of the primary cosmic rays by estimating the relative contents of muons with respect to the EM component of extensive air showers. This facility is also used to train students interested in the field of cosmic rays.

  15. Maui Analysis of Upper Atmospheric Injections

    Science.gov (United States)

    Dressler, Rainer A.

    2008-01-01

    Maui Analysis of Upper Atmospheric Injections (MAUI) will observe the Space Shuttle engine exhaust plumes from the Maui Space Surveillance Site in Hawaii. The observations will occur when the Space Shuttle fires its engines at night or twilight. A telescope and all-sky imagers will take images and data while the Space Shuttle flies over the Maui site. The images will be analyzed to better understand the interaction between the spacecraft plume and the upper atmosphere of Earth.

  16. Ground-based observations of exoplanet atmospheres

    NARCIS (Netherlands)

    Mooij, Ernst Johan Walter de

    2011-01-01

    This thesis focuses on the properties of exoplanet atmospheres. The results for ground-based near-infrared secondary eclipse observations of three different exoplanets, TrES-3b, HAT-P-1b and WASP-33b, are presented which have been obtained with ground-based telescopes as part of the GROUSE project.

  17. Articulating Atmospheres

    DEFF Research Database (Denmark)

    Kinch, Sofie

    2011-01-01

    This paper presents an architectural approach to designing computational interfaces by articulating the notion of atmosphere in the field of interaction design. It draws upon the concept of kinesthetic interaction and a philosophical notion on atmosphere emphasizing the importance of bodily exper......” implications and qualities of the approach are identified through concrete examples of a design case, which also investigates the qualities and implications of addressing atmospheres both as design concern and user experience.......This paper presents an architectural approach to designing computational interfaces by articulating the notion of atmosphere in the field of interaction design. It draws upon the concept of kinesthetic interaction and a philosophical notion on atmosphere emphasizing the importance of bodily...... experience in space, presented as middle ground experience. In the field of HCI, middle ground experiences complete the unarticulated spectrum between designing for foreground of attention or background awareness. When “Articulating Atmospheres through Middle Ground Experiences in Interaction Design...

  18. Eastern Anatolia Observatory (DAG): Recent developments and a prospective observing site for robotic telescopes

    Science.gov (United States)

    Yesilyaprak, C.; Yerli, S. K.; Keskin, O.

    2016-12-01

    This document (Eastern Anatolia Observatory (DAG) is the new observatory of Turkey with the optical and near-infrared largest telescope (4 m class) and its robust observing site infrastructure. This national project consists of three phases with DAG (Telescope, Enclosure, Buildings and Infrastructures), FPI (Focal Plane Instruments and Adaptive Optics) and MCP (Mirror Coating Plant) and is supported by the Ministry of Development of Turkey. The tenders of telescope and enclosure have been made and almost all the infrastructure (roads, geological and atmospherical surveys, electricity, fiber optics, cable car, water, generator, etc.) of DAG site (Erzurum/Turkey, 3,170 m altitude) have been completed. This poster is about the recent developments of DAG and about the future possible collaborations for various robotic telescopes which can be set up in DAG site.

  19. On the feasibility of photon-limited tip-tilt correction in very small telescopes

    Science.gov (United States)

    Popowicz, A.; Orlov, V. G.

    2017-10-01

    The resolution of astronomical images taken from the ground is severely degraded by the atmosphere. One of the simplest methods for overcoming this problem is tip-tilt (TT) correction. This method is especially valuable for small telescopes, as it enables them to reach their diffraction limit. Unfortunately, the method requires a bright guide star to asses the blurring of astronomical images. In this study we show how various factors influence the feasibility of tip-tilt correction in very small telescopes (≤ 1 m). We evaluate the effect of: (1) the intensity of the guide star, (2) seeing conditions, (3) telescope size and (4) sky background. The results are obtained from data simulated using the Random Wave Vector method. The dependencies presented in this paper can be used to predict the sky coverage of small telescopes with TT correction for a wide range of observational conditions.

  20. Atmospheric electricity

    CERN Document Server

    Chalmers, J Alan

    1957-01-01

    Atmospheric Electricity brings together numerous studies on various aspects of atmospheric electricity. This book is composed of 13 chapters that cover the main problems in the field, including the maintenance of the negative charge on the earth and the origin of the charges in thunderstorms. After a brief overview of the historical developments of atmospheric electricity, this book goes on dealing with the general principles, results, methods, and the MKS system of the field. The succeeding chapters are devoted to some aspects of electricity in the atmosphere, such as the occurrence and d

  1. Atmospheric Neutrinos

    Directory of Open Access Journals (Sweden)

    Takaaki Kajita

    2012-01-01

    Full Text Available Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron-neutrinos and muon-neutrinos are produced mainly by the decay chain of charged pions to muons to electrons. Atmospheric neutrino experiments observed zenith angle and energy-dependent deficit of muon-neutrino events. It was found that neutrino oscillations between muon-neutrinos and tau-neutrinos explain these data well. This paper discusses atmospheric neutrino experiments and the neutrino oscillation studies with these neutrinos.

  2. Stereo-scopy of {gamma}-ray air showers with the H.E.S.S. telescopes: first images of the supernova remnants at TeV; Stereoscopie de gerbes de {gamma} avec les telescopes H.E.S.S.: premieres images de vestiges de supernovae au TeV

    Energy Technology Data Exchange (ETDEWEB)

    Lemoine-Goumard, Marianne [Ecole Polytechnique, 91128 Palaiseau Cedex (France)

    2006-05-15

    The H.E.S.S. (High Energy Stereoscopic System) experiment in gamma-ray Astronomy consists of four imaging atmospheric Cherenkov telescopes devoted to the observation of the gamma-ray sky in the energy domain above 100 GeV and extending up to several tens of TeV. This thesis presents a new reconstruction method of gamma-ray induced air showers which takes full advantage of the stereo-scopy and of the fine-grain imaging of the H.E.S.S. cameras. This new method provides an angular resolution better than 0.1 angle, an energy resolution of about 15% at zenith and a very efficient hadronic rejection based on a cut on the lateral spread of the electromagnetic shower which does not depend on simulations. A new background subtraction method, well adapted to the study of extended sources, was also developed. No assumption, either on the distribution of gamma-rays in the field of view, or on the distribution of hadrons are necessary. It provides two sky maps obtained from a maximum likelihood fit: one for {gamma}-rays and the other for hadrons. These two analysis methods were applied to the study of the shell-type supernova remnants RX J1713.7-3946 and RX J0852.0-4622 (Vela Junior), allowing for the first time to resolve their morphology in the gamma-ray domain. The study of these sources should answer the question: 'can shell-type supernova remnants accelerate cosmic-rays up to the knee (5 x 10{sup 15} eV)?'. A morphological and spectral study of these sources combined with a comparison of a simple model of emission processes (from electrons and protons accelerated in supernova remnants) provides some constraints on the parameters of the leptonic process. Nevertheless, this scenario cannot be excluded. The different results obtained are discussed and compared with a third shell-type supernova remnant observed by H.E.S.S. but not detected: SN 1006. (author)

  3. Radio Telescopes "Save the Day," Produce Data on Titan's Winds

    Science.gov (United States)

    2005-02-01

    In what some scientists termed "a surprising, almost miraculous turnabout," radio telescopes, including major facilities of the National Science Foundation's National Radio Astronomy Observatory (NRAO), have provided data needed to measure the winds encountered by the Huygens spacecraft as it descended through the atmosphere of Saturn's moon Titan last month -- measurements feared lost because of a communication error between Huygens and its "mother ship" Cassini. The Green Bank Telescope The Robert C. Byrd Green Bank Telescope CREDIT: NRAO/AUI/NSF (Click on image for GBT gallery) A global network of radio telescopes, including the NRAO's Robert C. Byrd Green Bank Telescope (GBT) in West Virginia and eight of the ten antennas of the Very Long Baseline Array (VLBA), recorded the radio signal from Huygens during its descent on January 14. Measurements of the frequency shift caused by the craft's motion, called Doppler shift, are giving planetary scientists their first direct information about Titan's winds. "When we began working with our international partners on this project, we thought our telescopes would be adding to the wind data produced by the two spacecraft themselves. Now, with the ground-based telescopes providing the only information about Titan's winds, we are extremely proud that our facilities are making such a key contribution to our understanding of this fascinating planetary body," said Dr. Fred K.Y. Lo, Director of the National Radio Astronomy Observatory (NRAO). Early analysis of the radio-telescope data shows that Titan's wind flows from west to east, in the direction of the moon's rotation, at all altitudes. The highest wind speed, nearly 270 mph, was measured at an altitude of about 75 miles. Winds are weak near Titan's surface and increase in speed slowly up to an altitude of about 37 miles, where the spacecraft encountered highly-variable winds that scientists think indicate a region of vertical wind shear. The ground-based Doppler

  4. The Space Telescope Looks for Black Holes v V V V V v

    Indian Academy of Sciences (India)

    for Black Holes. Monsters Lurk at the Centres of. Many Galaxies. R Nityananda. Significant progress is now being made in many areas of astronomy through observations with HST (short for the Hubble. Space Telescope). Orbiting above the. Earth's turbulent atmosphere, it produces images nearly ten times sharper than its.

  5. The ANTARES Deep-Sea Neutrino Telescope: Status and First Results

    OpenAIRE

    Coyle, Paschal

    2010-01-01

    Various aspects of the construction, operation and calibration of the recently completed deep-sea ANTARES neutrino telescope are described. Some first results obtained with a partial five line configuration are presented, including depth dependence of the atmospheric muon rate, the search for point-like cosmic neutrino sources and the search for dark matter annihilation in the Sun.

  6. Measurement of charged hadron spectra at the Z{sup 0} with Cherenkov ring imaging

    Energy Technology Data Exchange (ETDEWEB)

    Pavel, Tomas Josef [Stanford Univ., CA (United States)

    1997-08-01

    This dissertation attempts to probe hadronization, the process by which the fundamental quarks described by quantum chromodynamics produce the jets of hadrons that the author observed in experiments. The measurements are made using e+e- collisions at the SLAC Linear Collider (SLC), operating at the Z0 resonance with the SLC Large Detector (SLD), and the unique capabilities of the SLC/SLD facility are exploited. First, the spectra of charged hadrons (π±, K±, and p/$\\bar{p}$) are measured. This is accomplished with the SLD Cherenkov Ring Imaging Detector (CRID), one of a first generation of devices that have been developed for efficient particle identification over a wide momentum range. The use of the CRID is central to this dissertation, and its design and performance are described in detail here. The measured spectra agree with other measurements at the Z0 and extend the momentum coverage. Next, the excellent spatial resolution of the SLD tracking systems, along with the small and stable beam spots of the SLC, is employed to identify jets produced from heavy b or c quarks and to separate them from the remaining light-quark (uds) jets. This removes the effects of heavy quark fragmentation and decays of heavy-quark hadrons from the study of hadronization. The first measurements of particle spectra in light-quark jets are then presented. Finally, the highly-polarized incident electron beam of the SLC, together with the electroweak asymmetries of the quarks, is exploited to separate quark and antiquark jets. Significant differences in quark-antiquark production of protons and of kaons are observed at high momenta. This signal suggests a leading particle effect, where the particles containing the primary quark of a jet are more likely to populate the high-momentum phase space than are other hadrons.

  7. First beam test of a liquid Cherenkov detector prototype for a future TOF measurements at the Super-FRS

    Science.gov (United States)

    Kuzminchuk-Feuerstein, Natalia; Ferber, Nadine; Rozhkova, Elena; Kaufeld, Ingo; Voss, Bernd

    2017-09-01

    In order to separate and identify fragmentation products with the Super-Fragment Separator (SuperFRS) at FAIR a high resolving power detector system is required for position and Time-Of-Flight (TOF) measurements. The TOF detector is used to measure the velocity of the particles and hence, in conjunction with their momentum or energy, to determine their mass and hence their identity. Aiming to develop a system with a precision down to about 50 ps in time and resistant to a high radiation rate of relativistic heavy ions of up to 107 per spill (at the second focal plane), we have shown a conceptual design for a Cherenkov detector envisioned for the future TOF measurements employing Iodine Naphthalene (C10H7I) as a fluid radiator. The application of a liquid radiator allows the circulation of the active material and therefore to greatly reduce the effects of the degradation of the optical performance expected after exposure to the high ion rates at the Super-FRS. The prototype of a TOF-Cherenkov detector was designed, constructed and its key-properties have been investigated in measurements with heavy ions at CaveC at GSI. These measurements were performed with nickel ions at 300-1500 MeV/u and ion-beam intensities of up to 4 × 106 ions/spill of 8 s. As a first result a maximum detection efficiency of 70% and a timing resolution of 267 ps (σ) was achieved. We report the first attempt of time measurements with a Cherenkov detector based on a liquid radiator. Further optimization is required.

  8. A search for the analogue to Cherenkov radiation by high energy neutrinos at superluminal speeds in ICARUS

    Science.gov (United States)

    ICARUS Collaboration; Antonello, M.; Aprili, P.; Baibussinov, B.; Baldo Ceolin, M.; Benetti, P.; Calligarich, E.; Canci, N.; Carbonara, F.; Centro, S.; Cesana, A.; Cieslik, K.; Cline, D. B.; Cocco, A. G.; Dabrowska, A.; Dequal, D.; Dermenev, A.; Dolfini, R.; Farnese, C.; Fava, A.; Ferrari, A.; Fiorillo, G.; Gibin, D.; Gigli Berzolari, A.; Gninenko, S.; Guglielmi, A.; Haranczyk, M.; Holeczek, J.; Ivashkin, A.; Kisiel, J.; Kochanek, I.; Lagoda, J.; Mania, S.; Mannocchi, G.; Menegolli, A.; Meng, G.; Montanari, C.; Otwinowski, S.; Periale, L.; Piazzoli, A.; Picchi, P.; Pietropaolo, F.; Plonski, P.; Rappoldi, A.; Raselli, G. L.; Rossella, M.; Rubbia, C.; Sala, P. R.; Scantamburlo, E.; Scaramelli, A.; Segreto, E.; Sergiampietri, F.; Stefan, D.; Stepaniak, J.; Sulej, R.; Szarska, M.; Terrani, M.; Varanini, F.; Ventura, S.; Vignoli, C.; Wang, H.; Yang, X.; Zalewska, A.; Zaremba, K.; Cohen, A.

    2012-05-01

    The OPERA Collaboration (2011) [1] has reported evidence of superluminal νμ propagation between CERN and the LNGS. Cohen and Glashow (2011) [2] argued that such neutrinos should lose energy by producing photons and e+e- pairs, through Z0 mediated processes analogous to Cherenkov radiation. In terms of the parameter δ≡(vν2-vc2)/vc2, the OPERA result corresponds to δ≈5ṡ10-5. For this value (note that (vν-vc)/vc≈δ2≈2.5ṡ10-5) of δ, a very significant deformation of the neutrino energy spectrum and an abundant production of photons and e+e- pairs should be observed at LNGS. We present an analysis based on the 2010 and part of the 2011 data sets from the ICARUS experiment, located at Gran Sasso National Laboratory and using the same neutrino beam from CERN. We find that the rates and deposited energy distributions of neutrino events in ICARUS agree with the expectations for an unperturbed spectrum of the CERN neutrino beam, as also reported by OPERA. Our results therefore refute a superluminal interpretation of the OPERA result according to the Cohen and Glashow (2011) prediction [2] for a weak current analog to Cherenkov radiation. In a dedicated search, no superluminal Cherenkov-like e+e- pair or γ emission event has been directly observed inside the fiducial volume of the "bubble chamber-like" ICARUS TPC-LAr detector, setting the much stricter limit of δ<2.5ṡ10-8 at the 90% confidence level, comparable with the one due to the observations from the SN1987a (M.J. Longo, 1987 [4]). The observations of high energy neutrino events by Super-Kamiokande and IceCube are also pointing to a much stricter limit on δ.

  9. Urban atmospheres.

    Science.gov (United States)

    Gandy, Matthew

    2017-07-01

    What is an urban atmosphere? How can we differentiate an 'atmosphere' from other facets of urban consciousness and experience? This essay explores some of the wider cultural, political, and philosophical connotations of atmospheres as a focal point for critical reflections on space and subjectivity. The idea of an 'affective atmosphere' as a distinctive kind of mood or shared corporeal phenomenon is considered in relation to recent developments in phenomenology, extended conceptions of agency, and new understandings of materialism. The essay draws in particular on the changing characteristics of air and light to reflect on different forms of sensory experience and their wider cultural and political connotations. The argument highlights some of the tensions and anomalies that permeate contemporary understandings of urban atmospheres.

  10. Merz telescopes a global heritage worth preserving

    CERN Document Server

    2017-01-01

    This book comprises a fascinating collection of contributions on the Merz telescopes in Italy that collectively offer the first survey on historical large refracting telescopes in the country, drawing on original documents and photographs. It opens with a general introduction on the importance of Merz telescopes in the history of astronomy and analyses of the local and international contexts in which the telescopes were made. After examination of an example of the interaction between the maker and the astronomer in the construction and maintenance of these refractors, the history of the Merz telescopes at the main Italian observatories in the nineteenth century is described in detail. Expert testimony is also provided on how these telescopes were successfully used until the second half of the twentieth century for research purposes, thus proving their excellent optical qualities.

  11. Performance of a hybrid photon detector prototype with electrostatic cross-focussing and integrated silicon Pixel readout for Cherenkov ring detection

    CERN Document Server

    Alemi, M; Bibby, J H; Campbell, M; Duane, A; Easo, S; Gys, Thierry; Halley, A W; Piedigrossi, D; Puertolas, D; Rosso, E; Simmons, B; Snoeys, W; Websdale, David M; Wotton, S A; Wyllie, Ken H

    1999-01-01

    We report on the first test beam performance of a hybrid photon detector prototype, using binary readout electronics, intended for use in the ring imaging Cherenkov detectors of the LHCb experiment at the CERN Large Hadron Collider. The photon detector is based on a cross-focussed image intensifier tube geometry. The anode consists of a silicon pixel array bump-bonded to a binary readout chip with matching pixel electronics. The detector has been installed in a quarter-scale prototype vessel of the LHCb ring imaging Cherenkov system. Focussed ring images produced by 120 GeV/c negative pions traversing an air radiator have been recorded. The observed light yield and Cherenkov angle resolution are discussed.

  12. ANTARES: An Undersea Neutrino telescope

    CERN Multimedia

    2002-01-01

    The ANTARES (Astronomy with a Neutrino Telescope and ${Abyss}$ environmental RESearch) deep-sea neutrino telescope is designed to search for neutrinos of astrophysical origin. Neutrinos are unique probes of the high energy universe; being neutral they are not deflected by magnetic fields and interacting weakly they can readily escape from the densest regions of the universe. Potential sources of neutrino are galactic (e.g supernova remnants, micro-quasars) and extra-galactic (e.g active galactic nuclei, gamma-ray bursters). Annihilation of dark matter particles in the Sun or Galactic Centre is another well motivated potential source of extra terrestrial neutrinos. The ANTARES detector is located 40 km off the coast of Toulon (France) at a depth of 2475m in the Mediterranean Sea. Being located in the Northern hemisphere it studies the Southern sky and in particular has the Galactic Centre in its field of view. Since 2006, the detector has operated continuously in a partial configuration. The detector was compl...

  13. Advances in telescope mirror cleaning

    Science.gov (United States)

    Blanken, Maarten F.; Chopping, Alan K.; Dee, Kevin M.

    2004-09-01

    Metrology and cleaning techniques for telescope mirrors are generally well established. CO2 cleaning and water washing are mainly used. Water washing has proven to be the best method of removing oil and water stains and restoring the aluminium to nearly fresh values. The risk of water getting to unwanted places such as electronics or other optics prevents this method from being employed more often. Recently the Isaac Newton Group introduced a new cleaning technique for their telescope mirrors, which reduces the risks discussed above. This technique uses water vapour instead of water to wash the mirror. The advantage of this method is that the amount of water needed is drastically reduced. In addition the pressure of the vapour will blow away any large dust particles on the mirror and the temperature shock between the vapour and the mirror will help to de-bond the dust particles. Adding a soapy solution will help to clean oil and watermarks of the mirror. This paper describes the vapour cleaning method, tests that have been done and the overall findings.

  14. Telescoping phenomenon in pathological gambling

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian Lawrence; Mooney, Marc E

    2012-01-01

    The course of pathological gambling (PG) in women has been described as having a later age of initiation but a shorter time to problematic gambling ("telescoped"). This study examined evidence for telescoping and its relationship with comorbidities. Seventy-one treatment-seeking individuals with PG...... underwent a diagnostic interview to examine gambling behaviors, age at initiation of gambling, and time from initiation to meeting criteria for PG. The women had a higher mean age at gambling initiation compared with that of the men (mean [SD] age, 31.3 [13.0] years, compared with 22.4 [7.9] years; p = 0.......0003) and a significantly shorter time from initiation of gambling to meeting the criteria for PG (8.33 [8.7] years compared with 11.97 [9.1] years; p = 0.0476) after controlling for demographic and clinical variables. This study presents evidence for a gender-specific course of PG unrelated to psychiatric comorbidities...

  15. Large aperture diffractive space telescope

    Science.gov (United States)

    Hyde, Roderick A.

    2001-01-01

    A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

  16. Origins Space Telescope: Study Plan

    Science.gov (United States)

    Nayyeri, Hooshang; Cooray, Asantha; Origins Space Telescope Study Team

    2018-01-01

    The Origins Space Telescope (OST) is the mission concept for the Far-Infrared Surveyor, a study in development by NASA in preparation for the 2020 Astronomy and Astrophysics Decadal Survey. Origins is planned to be a large aperture, actively-cooled telescope covering a wide span of the mid- to far-infrared spectrum. Its spectrographs will enable 3D surveys of the sky that will discover and characterize the most distant galaxies, Milky-Way, exoplanets, and the outer reaches of our Solar system. Origins will enable flagship-quality general observing programs led by the astronomical community in the 2030s. The Science and Technology Definition Team (STDT) would like to hear your science needs and ideas for this mission. The team can be contacted at firsurveyor_info@lists.ipac.caltech.edu. This presentation will provide a summary of the OST STDT, the OST Study Team based at NASA Goddard Space Flight Center, study partners, and the advisory panel to the study. This presentation will also summarize recent activities, including the process used to reach a decision on the mission architecture, the identification of key science drivers, and the key study milestones between 2017 and 2020.

  17. Cherenkov emission of terahertz surface plasmon polaritons from a superluminal optical spot on a structured metal surface.

    Science.gov (United States)

    Bakunov, M I; Tsarev, M V; Hangyo, M

    2009-05-25

    We propose to launch terahertz surface plasmon polaritons on a structured metal surface by using a femtosecond laser pulse obliquely incident on a strip of an electro-optic material deposited on the surface. The laser pulse creates a nonlinear polarization that moves along the strip with a superluminal velocity and emits surface terahertz waves via the Cherenkov radiation mechanism. We calculate the radiated fields and frequency distribution of the radiated energy for a grooved perfect-conductor surface with a GaAs strip illuminated by Ti:sapphire laser. This technique can be used to perform surface terahertz spectroscopy.

  18. Parametric analysis of cherenkov light LDF from EAS for high energy gamma rays and nuclei: Ways of practical application

    Directory of Open Access Journals (Sweden)

    Elshoukrofy A.Sh.M.

    2017-01-01

    Full Text Available In this paper we propose a ‘knee-like’ approximation of the lateral distribution of the Cherenkov light from extensive air showers in the energy range 30–3000 TeV and study a possibility of its practical application in high energy ground-based gamma-ray astronomy experiments (in particular, in TAIGA-HiSCORE. The approximation has a very good accuracy for individual showers and can be easily simplified for practical application in the HiSCORE wide angle timing array in the condition of a limited number of triggered stations.

  19. MO-FG-303-02: BEST IN PHYSICS (THERAPY): Cherenkov Emission Dosimetry: Feasibility for Electron Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Zlateva, Y; El Naqa, I [McGill University, Montreal, QC (Canada)

    2015-06-15

    Purpose: To investigate from first principles, corroborated by Monte Carlo simulations and experimental measurements, the feasibility of developing a relative Cherenkov emission (CE) dosimetry protocol for electron beam radiotherapy. Methods: Monte Carlo (MC) simulations of mono-energetic electrons incident on water were carried out in Geant4. Percent depth Cherenkov emission (PDCE) and dose (PDD) distributions were scored for incidence energies of 4, 6, 9, 12, 15, and 18 MeV. PDCE-to-PDD analytical conversion models were developed from least-squares data fits generated for PDD as a function of PDCE at the same depth and at different depths. Experimental techniques for validation of these models are examined. Results: Same-depth PDD versus PDCE data fits indicate that although the relationship is linear to first order (correlation r > 0.9 for all energies), it is much more accurately approximated by separate linear and quadratic models for the build-up and drop-off regions, respectively (r > 0.999), which is theoretically underpinned. To understand the source of this relationship and its basis for developing robust conversion models, an approximate quadratic first-principles model was derived and found in agreement with MC/measured data (20% deviation at worst). Conversely, data fits of PDD versus different-depth PDCE unveiled a depth-invariant effective point of measurement of 1.5–2.1 mm downstream with 4–18 MeV incidence, respectively (r > 0.999 in the drop-off region). We present an analytical first-principles justification for this shift. This method led to errors of <1% in drop-off region PDD (<2% for PDD<20% with 4 MeV incidence) and <0.2 mm in practical range prediction. Conclusion: We present robust quantitative prediction models, derived from first-principles and supported by simulation and measurement, for relative dose from Cherenkov emission by high-energy electrons. This constitutes a major step towards development of protocols for routine clinical

  20. Use of water-Cherenkov detectors to detect Gamma Ray Bursts at the Large Aperture GRB Observatory (LAGO)

    Energy Technology Data Exchange (ETDEWEB)

    Allard, D. [APC, CNRS et Universite Paris 7 (France); Allekotte, I. [Centro Atomico Bariloche, Instituto Balseiro (Argentina); Alvarez, C. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Asorey, H. [Centro Atomico Bariloche, Instituto Balseiro (Argentina); Barros, H. [Laboratorio de Fisica Nuclear, Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of); Bertou, X. [Centro Atomico Bariloche, Instituto Balseiro (Argentina)], E-mail: bertou@cab.cnea.gov.ar; Burgoa, O. [Instituto de Investigaciones Fisicas, UMSA (Bolivia); Gomez Berisso, M. [Centro Atomico Bariloche, Instituto Balseiro (Argentina); Martinez, O. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Miranda Loza, P. [Instituto de Investigaciones Fisicas, UMSA (Bolivia); Murrieta, T.; Perez, G. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Rivera, H. [Instituto de Investigaciones Fisicas, UMSA (Bolivia); Rovero, A. [Instituto de Astronomia y Fisica del Espacio (Argentina); Saavedra, O. [Dipartimento di Fisica Generale and INFN, Torino (Italy); Salazar, H. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Tello, J.C. [Laboratorio de Fisica Nuclear, Universidad Simon Bolivar, Caracas (Venezuela, Bolivarian Republic of); Ticona Peralda, R.; Velarde, A. [Instituto de Investigaciones Fisicas, UMSA (Bolivia); Villasenor, L. [Facultad de Ciencias Fisico-Matematicas de la BUAP (Mexico); Instituto de Fisica y Matematicas, Universidad de Michoacan (Mexico)

    2008-09-21

    The Large Aperture GRB Observatory (LAGO) project aims at the detection of high energy photons from Gamma Ray Bursts (GRB) using the single particle technique in ground-based water-Cherenkov detectors (WCD). To reach a reasonable sensitivity, high altitude mountain sites have been selected in Mexico (Sierra Negra, 4550 m a.s.l.), Bolivia (Chacaltaya, 5300 m a.s.l.) and Venezuela (Merida, 4765 m a.s.l.). We report on detector calibration and operation at high altitude, search for bursts in 4 months of preliminary data, as well as search for signal at ground level when satellites report a burst.

  1. Design of Galilean-type telescope systems.

    Science.gov (United States)

    Menchaca, C; Malacara, D

    1988-09-01

    In this paper we present the design of three Galilean-type telescope systems with magnifications of 2.2x, 4x, and 5x. These systems are free of the large weight and length as well as the reduced field of view, which are frequent undesirable properties of Galilean telescopes. These designs have a moderate field of view and a short length, with reasonably good aberration correction, and may be used as binocular telescopes or magnifiers with a large working distance.

  2. Development of adaptive optics elements for solar telescope

    Science.gov (United States)

    Lukin, V. P.; Grigor'ev, V. M.; Antoshkin, L. V.; Botugina, N. N.; Kovadlo, P. G.; Konyaev, P. A.; Kopulov, E. A.; Skomorovsky, V. I.; Trifonov, V. D.; Chuprakov, S. A.

    2012-07-01

    The devices and components of adaptive optical system ANGARA, which is developed for image correction in the Big solar vacuum telescope (BSVT) at Baykal astrophysical observatory are described. It is shown that the use of modernized adaptive system on BSVT not only reduces the turbulent atmospheric distortions of image, but also gives a possibility to improve the telescope developing new methods of solar observations. A high precision Shack-Hartmann wavefront (WF) sensor has been developed on the basis of a low-aperture off-axis diffraction lens array. The device is capable of measuring WF slopes at array sub-apertures of size 640X640 μm with an error not exceeding 4.80 arc.sec. Also the modification of this sensor for adaptive system of solar telescope using extended scenes as tracking objects, such as sunspot, pores, solar granulation and limb, is presented. The software package developed for the proposed WF sensors includes three algorithms of local WF slopes estimation (modified centroids, normalized cross-correlation and fast Fourier-demodulation), as well as three methods of WF reconstruction (modal Zernike polynomials expansion, deformable mirror response functions expansion and phase unwrapping), that can be selected during operation with accordance to the application.

  3. Trading order for degree in creative telescoping

    Science.gov (United States)

    Chen, Shaoshi; Kauers, Manuel

    2012-01-01

    We analyze the differential equations produced by the method of creative telescoping applied to a hyperexponential term in two variables. We show that equations of low order have high degree, and that higher order equations have lower degree. More precisely, we derive degree bounding formulas which allow to estimate the degree of the output equations from creative telescoping as a function of the order. As an application, we show how the knowledge of these formulas can be used to improve, at least in principle, the performance of creative telescoping implementations, and we deduce bounds on the asymptotic complexity of creative telescoping for hyperexponential terms. PMID:26538804

  4. eSTAR: a distributed telescope network

    Science.gov (United States)

    Steele, Iain A.; Naylor, Tim; Allan, Alisdair; Etherton, Jason; Mottram, C. J.

    2002-11-01

    The e-STAR (e-Science Telescopes for Astronomical Research) project uses GRID techniques to develop the software infrastructure for a global network of robotic telescopes. The basic architecture is based around Intelligent Agents which request data from Discovery Nodes that may be telescopes or databases. Communication is based on a development of the XML RTML language secured using the Globus I/O library, with status serving provided via LDAP. We describe the system architecture and protocols devised to give a distributed approach to telescope scheduling, as well as giving details of the implementation of prototype Intelligent Agent and Discovery Node systems.

  5. The Trigger and Data Acquisition System for the KM3NeT-Italy neutrino telescope

    Science.gov (United States)

    Chiarusi, T.; Favaro, M.; Giacomini, F.; Manzali, M.; Margiotta, A.; Pellegrino, C.

    2017-10-01

    KM3NeT-Italy is an INFN project that will develop the central part of a submarine cubic-kilometer neutrino telescope in the Ionian Sea, at about 80 km from the Sicilian coast (Italy). It will use hundreds of distributed optical modules to measure the Cherenkov light emitted by high-energy muons, whose signal-to-noise ratio is quite disfavoured. In this contribution the Trigger and Data Acquisition System (TriDAS) developed for the KM3NeT-Italy detector is presented. The “all data to shore” approach is adopted to reduce the complexity of the submarine detector: at the shore station the TriDAS collects, processes and filters all the data coming from the detector, storing triggered events to a permanent storage for subsequent analysis. Due to the large optical background in the sea from 40K decays and bioluminescence, the throughput from the sea can range up to 30 Gbps. This puts strong constraints on the performances of the TriDAS processes and the related network infrastructure.

  6. Atmospheric Infancy

    DEFF Research Database (Denmark)

    Roald, Tone; Pedersen, Ida Egmose; Levin, Kasper

    2017-01-01

    In this article we establish intersubjective meaning-making in infancy as atmospheric. Through qualitative descriptions of five mother–infant dyads in a video-recorded, experimental setting when the infant is 4, 7, 10, and 13 months, we discovered atmospheric appearances with a developmental...... pattern of atmospheric variations. These appearances, we argue, are contextual and intersubjective monologues. The monologues are similar to what Daniel Stern describes with his concept of “vitality affects,” but they arise as a unified force that envelops the mother and child. As such, we present a new...

  7. An afocal telescope configuration for the ESA Ariel mission

    Science.gov (United States)

    Da Deppo, V.; Middleton, K.; Focardi, M.; Morgante, G.; Pace, E.; Claudi, R.; Micela, G.

    2017-09-01

    ARIEL (Atmospheric Remote-sensing Infrared Exoplanet Large-survey) is one of the three candidates for the next ESA medium-class science mission (M4) expected to be launched in 2026. This mission will be devoted to observing spectroscopically in the infrared (IR) a large population of known transiting planets in the neighborhood of the Solar System, opening a new discovery space in the field of extrasolar planets and enabling the understanding of the physics and chemistry of these far away worlds. ARIEL is based on a 1-m class telescope ahead of two spectrometer channels covering the band 1.95 to 7.8 microns. In addition there are four photometric channels: two wide band, also used as fine guidance sensors, and two narrow band. During its 3.5 years of operations from L2 orbit, ARIEL will continuously observe exoplanets transiting their host star. The ARIEL optical design is conceived as a fore-module common afocal telescope that will feed the spectrometer and photometric channels. The telescope optical design is composed of an off-axis portion of a two-mirror classic Cassegrain coupled to a tertiary off-axis paraboloidal mirror. The telescope and optical bench operating temperatures, as well as those of some subsystems, will be monitored and fine tuned/stabilised mainly by means of a thermal control subsystem (TCU-Telescope Control Unit) working in closed-loop feedback and hosted by the main Payload electronics unit, the Instrument Control Unit (ICU). Another important function of the TCU will be to monitor the telescope and optical bench thermistors when the Payload decontamination heaters will be switched on (when operating the instrument in Decontamination Mode) during the Commissioning Phase and cyclically, if required. Then the thermistors data will be sent by the ICU to the On Board Computer by means of a proper formatted telemetry. The latter (OBC) will be in charge of switching on and off the decontamination heaters on the basis of the thermistors readout

  8. Planetary polarisation measurements with small telescopes

    Science.gov (United States)

    Masding, Philip; Rossi, Loic; Miles, Phil

    2017-04-01

    image as a function of the angle of the polariser. The coefficients of the multivariate fit are used to calculate the polarisation and its direction (the phase angle of the curve). Statistical analysis of the results gives a one standard deviation confidence interval for the polarisation. Initial results for Jupiter show the strong polarisation at the poles and variation in the belts and zones. The confidence interval is typically less than 1 percent. Analysis of the results is at an early stage but has the potential to help our understanding of the structure and composition of planetary atmospheres. In addition the involvement of amateur astronomers allows for plenty of available telescope time and the potential for long term monitoring of possible variations in polarisation patterns.

  9. Diffractive X-Ray Telescopes

    Science.gov (United States)

    Skinner, Gerald K.

    2010-01-01

    Diffractive X-ray telescopes, using zone plates, phase Fresnel lenses, or related optical elements have the potential to provide astronomers with true imaging capability with resolution many orders of magnitude better than available in any other waveband. Lenses that would be relatively easy to fabricate could have an angular resolution of the order of micro-arc-seconds or even better, that would allow, for example, imaging of the distorted spacetime in the immediate vicinity of the super-massive black holes in the center of active galaxies. What then is precluding their immediate adoption? Extremely long focal lengths, very limited bandwidth, and difficulty stabilizing the image are the main problems. The history, and status of the development of such lenses is reviewed here and the prospects for managing the challenges that they present are discussed.

  10. Space Telescope Science Institute Symposium

    CERN Document Server

    Unsolved Problems in Stellar Evolution

    2000-01-01

    This timely volume reviews recent progress in our understanding of all aspects of stellar structure and evolution, with special emphasis on currently unsolved problems. It covers every stage in the life of a star, from birth to death, as well as the fundamental processes that affect stellar evolution. Each chapter is written by a leading world expert, based on presentations at an international conference held at the Space Telescope Science Institute. A complete understanding of stellar evolution is important in its own right, constituting a vital piece in the more general puzzle of understanding how galaxies form and evolve. This volume presents the most comprehensive and up-to-date survey available of this crucial topic in astrophysics.

  11. Can Radio Telescopes Find Axions?

    Science.gov (United States)

    Kohler, Susanna

    2017-08-01

    axions. Now scientists Katharine Kelley and Peter Quinn at ICRAR, University of Western Australia, have explored how we might use next-generation radio telescopes to search for photons that were created by axions interacting with the magnetic fields of our galaxy.Hope for Next-Gen TelescopesPotential axion coupling strengths vs. mass (click for a closer look). The axion mass is thought to lie between a eV and a meV; two theoretical models are shown with dashed lines. The plot shows the sensitivity of the upcoming SKA and its precursors, ASKAP and MEERKAT. [KelleyQuinn 2017]By using a simple galactic halo model and reasonable assumptions for the central galactic magnetic field even taking into account the time dependence of the field Kelley and Quinn estimate the radio-frequency power density that we would observe at Earth from axions being converted to photons within the Milky Ways magnetic field.The authors then compare this signature to the detection capabilities of upcoming radio telescope arrays. They show that the upcoming Square Kilometer Array and its precursors should have the capability to detect signs of axions across large parts of parameter space.Kelley and Quinn conclude that theres good cause for optimism about future radio telescopes ability to detect axions. And if we did succeed in making a detection, it would be a triumph for both particle physics and astrophysics, finally providing an explanation for the universes dark matter.CitationKatharine Kelley and P. J. Quinn 2017 ApJL 845 L4. doi:10.3847/2041-8213/aa808d

  12. SLAC Cosmic Ray Telescope Facility

    Energy Technology Data Exchange (ETDEWEB)

    Va' vra, J.

    2010-02-15

    SLAC does not have a test beam for the HEP detector development at present. We have therefore created a cosmic ray telescope (CRT) facility, which is presently being used to test the FDIRC prototype. We have used it in the past to debug this prototype with the original SLAC electronics before going to the ESA test beam. Presently, it is used to test a new waveform digitizing electronics developed by the University of Hawaii, and we are also planning to incorporate the new Orsay TDC/ADC electronics. As a next step, we plan to put in a full size DIRC bar box with a new focusing optics, and test it together with a final SuberB electronics. The CRT is located in building 121 at SLAC. We anticipate more users to join in the future. This purpose of this note is to provide an introductory manual for newcomers.

  13. The Mini-EUSO telescope on the ISS

    Science.gov (United States)

    Scotti, Valentina; Osteria, Giuseppe

    2017-02-01

    The Mini-EUSO project aims to perform observations of the UV-light night emission from Earth. The UV background produced in atmosphere is a key measurement for any experiment aiming at the observation of Extreme Energy Cosmic Rays (EECR) from space, the most energetic component of the cosmic radiation. The Mini-EUSO instrument will be placed within the International Space Station (ISS) in the Russian Module and measures through a UV transparent window. The instrument comprises a compact telescope with a large field of view, based on an optical system employing two Fresnel lenses for increased light collection. The light is focused onto an array of photo-multipliers and the resulting signal is converted into digital, processed and stored via the electronics subsystems on-board. The instrument is designed and built by the members of the JEM-EUSO collaboration. JEM-EUSO is a wide-angle refractive UV telescope being proposed for attachment to the ISS, which has been designed to address basic problems of fundamental physics and high-energy astrophysics investigating the nature of cosmic rays with energies above 1020 eV. Mini-EUSO will be able to study beside EECRs a wide range of scientific phenomena including atmospheric physics, strange quark matter and bioluminescence. The mission is approved by the Italian Space Agency and the Russian Space Agency. Scientific, technical and programmatic aspects of this project will be described.

  14. The Mini-EUSO telescope on the ISS

    Energy Technology Data Exchange (ETDEWEB)

    Scotti, Valentina, E-mail: scottiv@na.infn.it; Osteria, Giuseppe

    2017-02-11

    The Mini-EUSO project aims to perform observations of the UV-light night emission from Earth. The UV background produced in atmosphere is a key measurement for any experiment aiming at the observation of Extreme Energy Cosmic Rays (EECR) from space, the most energetic component of the cosmic radiation. The Mini-EUSO instrument will be placed within the International Space Station (ISS) in the Russian Module and measures through a UV transparent window. The instrument comprises a compact telescope with a large field of view, based on an optical system employing two Fresnel lenses for increased light collection. The light is focused onto an array of photo-multipliers and the resulting signal is converted into digital, processed and stored via the electronics subsystems on-board. The instrument is designed and built by the members of the JEM-EUSO collaboration. JEM-EUSO is a wide-angle refractive UV telescope being proposed for attachment to the ISS, which has been designed to address basic problems of fundamental physics and high-energy astrophysics investigating the nature of cosmic rays with energies above 10{sup 20} eV. Mini-EUSO will be able to study beside EECRs a wide range of scientific phenomena including atmospheric physics, strange quark matter and bioluminescence. The mission is approved by the Italian Space Agency and the Russian Space Agency. Scientific, technical and programmatic aspects of this project will be described.

  15. Spitzer Space Telescope Mid-IR Light Curves of Neptune

    Science.gov (United States)

    Stauffer, John; Marley, Mark S.; Gizis, John E.; Rebull, Luisa; Carey, Sean J.; Krick, Jessica; Ingalls, James G.; Lowrance, Patrick; Glaccum, William; Kirkpatrick, J. Davy; hide

    2016-01-01

    We have used the Spitzer Space Telescope in 2016 February to obtain high cadence, high signal-to-noise, 17 hr duration light curves of Neptune at 3.6 and 4.5 microns. The light curve duration was chosen to correspond to the rotation period of Neptune. Both light curves are slowly varying with time, with full amplitudes of 1.1 mag at 3.6 microns and 0.6 mag at 4.5 microns. We have also extracted sparsely sampled 18 hr light curves of Neptune at W1 (3.4 microns) and W2 (4.6 microns) from the Wide-field Infrared Survey Explorer (WISE)/NEOWISE archive at six epochs in 2010-2015. These light curves all show similar shapes and amplitudes compared to the Spitzer light curves but with considerable variation from epoch to epoch. These amplitudes are much larger than those observed with Kepler/K2 in the visible (amplitude approximately 0.02 mag) or at 845 nm with the Hubble Space Telescope (HST) in 2015 and at 763 nm in 2016 (amplitude approximately 0.2 mag). We interpret the Spitzer and WISE light curves as arising entirely from reflected solar photons, from higher levels in Neptune's atmosphere than for K2. Methane gas is the dominant opacity source in Neptune's atmosphere, and methane absorption bands are present in the HST 763 and 845 nm, WISE W1, and Spitzer 3.6 micron filters.

  16. An afocal telescope configuration for the ESA ARIEL mission

    Science.gov (United States)

    Da Deppo, Vania; Focardi, Mauro; Middleton, Kevin; Morgante, Gianluca; Pascale, Enzo; Grella, Samuele; Pace, Emanuele; Claudi, Riccardo; Amiaux, Jérôme; Colomé Ferrer, Josep; Hunt, Thomas; Rataj, Miroslaw; Sierra-Roig, Carles; Ficai Veltroni, Iacopo; Eccleston, Paul; Micela, Giuseppina; Tinetti, Giovanna

    2017-12-01

    Atmospheric Remote-Sensing Infrared Exoplanet Large Survey (ARIEL) is a candidate as an M4 ESA mission to launch in 2026. During its 3.5 years of scientific operations, ARIEL will observe spectroscopically in the infrared (IR) a large population of known transiting planets in the neighbourhood of the solar system. ARIEL aims to give a breakthrough in the observation of exoplanet atmospheres and understanding of the physics and chemistry of these far-away worlds. ARIEL is based on a 1 m class telescope feeding a collimated beam into two separate instrument modules: a spectrometer module covering the waveband between 1.95 and 7.8 μm and a combined fine guidance system/visible photometer/NIR spectrometer. The telescope configuration is a classic Cassegrain layout used with an eccentric pupil and coupled to a tertiary off-axis paraboloidal mirror. To constrain the thermo-mechanically induced optical aberrations, the primary mirror (M1) temperature will be monitored and finely tuned using an active thermal control system based on thermistors and heaters. They will be switched on and off to maintain the M1 temperature within ± 1 K by the telescope control unit (TCU). The TCU is a payload electronics subsystem also responsible for the thermal control of the spectrometer module detectors as well as the secondary mirror mechanism and IR calibration source management. The TCU, being a slave subsystem of the instrument control unit, will collect the housekeeping data from the monitored subsystems and will forward them to the master unit. The latter will run the application software, devoted to the main spectrometer management and to the scientific data on-board processing.

  17. An afocal telescope configuration for the ESA ARIEL mission

    Science.gov (United States)

    Da Deppo, Vania; Focardi, Mauro; Middleton, Kevin; Morgante, Gianluca; Pascale, Enzo; Grella, Samuele; Pace, Emanuele; Claudi, Riccardo; Amiaux, Jérôme; Colomé Ferrer, Josep; Hunt, Thomas; Rataj, Miroslaw; Sierra-Roig, Carles; Ficai Veltroni, Iacopo; Eccleston, Paul; Micela, Giuseppina; Tinetti, Giovanna

    2017-11-01

    Atmospheric Remote-Sensing Infrared Exoplanet Large Survey (ARIEL) is a candidate as an M4 ESA mission to launch in 2026. During its 3.5 years of scientific operations, ARIEL will observe spectroscopically in the infrared (IR) a large population of known transiting planets in the neighbourhood of the solar system. ARIEL aims to give a breakthrough in the observation of exoplanet atmospheres and understanding of the physics and chemistry of these far-away worlds. ARIEL is based on a 1 m class telescope feeding a collimated beam into two separate instrument modules: a spectrometer module covering the waveband between 1.95 and 7.8 μm and a combined fine guidance system/visible photometer/NIR spectrometer. The telescope configuration is a classic Cassegrain layout used with an eccentric pupil and coupled to a tertiary off-axis paraboloidal mirror. To constrain the thermo-mechanically induced optical aberrations, the primary mirror (M1) temperature will be monitored and finely tuned using an active thermal control system based on thermistors and heaters. They will be switched on and off to maintain the M1 temperature within ± 1 K by the telescope control unit (TCU). The TCU is a payload electronics subsystem also responsible for the thermal control of the spectrometer module detectors as well as the secondary mirror mechanism and IR calibration source management. The TCU, being a slave subsystem of the instrument control unit, will collect the housekeeping data from the monitored subsystems and will forward them to the master unit. The latter will run the application software, devoted to the main spectrometer management and to the scientific data on-board processing.

  18. A radionuclide calibrator based on Cherenkov counting for activity measurements of high-energy pure β¯-emitters.

    Science.gov (United States)

    Bobin, C; Thiam, C; Chauvenet, B

    2017-01-01

    Due to their stability and reproducibility, re-entrant pressurized ionization chambers (also called radionuclide calibrators) are widely used for activity measurements in nuclear medicine services as well as in national metrology institutes to maintain reference standards. Generally, these secondary instruments yield accurate activity measurements for γ-emitting radionuclides. Ionization chambers are easy to use and thus well-adapted to guarantee the metrological traceability between national metrology institutes and end-users. However, the reproducibility of calibration factors can be significantly impaired when measuring high-energy pure β¯-emitters such as radiopharmaceuticals based on 90Y. This is because the bremsstrahlung emission contributing to the instrument response is strongly dependent on the geometry of the components surrounding the radioactive solution. The present article describes a new design based on pulse counting to address this problem. It takes advantage of Cherenkov emission resulting from Compton scattering in transparent materials. The interest of Cherenkov counting is to obtain a low-sensitivity detector that enables direct measurements of high-activity solutions (at least up to 10 GBq for 90Y-microspheres in aqueous suspensions used in nuclear medicine). A simple design based on a geometry close to an ionization chamber used at LNHB (Vinten 671 type) is described. The feasibility in terms of detection efficiencies (lower than 10-4 for 90Y solutions) of the new radionuclide calibrator is investigated by Monte Carlo calculations using the Geant4 code. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Improvement of optical properties and radiation hardness of NaBi(WO sub 4) sub 2 Cherenkov crystals

    CERN Document Server

    Zadneprovski, B I; Polyansky, E V; Devitsin, E G; Kozlov, V A; Potashov, S Yu; Terkulov, A R

    2002-01-01

    On the basis of the data on melt evaporation while growing NaBi(WO sub 4) sub 2 Cherenkov crystals, the formation of nonstoichiometry and most probable types of dot defects of the crystals have been considered. The influence of melt nonstoichiometry and doping with Sc on optical transmission and radiation hardness of the crystals has been experimentally investigated. The surplus of WO sub 3 has been established to increase optical transmission and radiation hardness and lack of Bi sub 2 O sub 3 in the melt to reduce radiation hardness. Sc doping is shifting the absorption edge to UV region by 30-35 nm and is increasing radiation hardness of the crystals about three-fold. Analytical estimations give the increase of the number of Cherenkov photons by a factor of 1.3, which leads to an improvement of the energy resolution of a calorimeter based on NaBi(WO sub 4) sub 2 :Sc crystals compared with undoped NaBi(WO sub 4) sub 2 of approximately 15%.

  20. Challenges of arbitrary waveform signal detection by Silicon Photomultipliers as readout for Cherenkov fibre based beam loss monitoring systems

    CERN Document Server

    Vinogradov, Sergey; Nebot del Busto, Eduardo; Kastriotou, Maria; Welsch, Carsten P

    2016-01-01

    Silicon Photomultipliers (SiPMs) are well recognised as very competitive photodetectors due to their exceptional photon number and time resolution, room-temperature low-voltage operation, insensitivity to magnetic fields, compactness, and robustness. Detection of weak light pulses of nanosecond time scale appears to be the best area for SiPM applications because in this case most of the SiPM drawbacks have a rather limited effect on its performance. In contrast to the more typical scintillation and Cherenkov detection applications, which demand information on the number of photons and/or the arrival time of the light pulse only, beam loss monitoring (BLM) systems utilising Cherenkov fibres with photodetector readout have to precisely reconstruct the temporal profile of the light pulse. This is a rather challenging task for any photon detector especially taking into account the high dynamic range of incident signals (100K – 1M) from a few photons to a few percents of destructive losses in a beam line and pre...

  1. ANTARES : The first undersea neutrino telescope

    NARCIS (Netherlands)

    Ageron, M.; Aguilar, J. A.; Al Samarai, I.; Albert, A.; Ameli, F.; Andre, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Arnaud, K.; Aslanides, E.; Jesus, A. C. Assis; Astraatmadja, T.; Aubert, J. -J.; Auer, R.; Barbarito, E.; Baret, B.; Basa, S.; Bazzotti, M.; Becherini, Y.; Beltramelli, J.; Bersani, A.; Bertin, V.; Beurthey, S.; Biagi, S.; Bigongiari, C.; Billault, M.; Blaes, R.; Bogazzi, C.; de Botton, N.; Bou-Cabo, M.; Boudahef, B.; Bouwhuis, M. C.; Brown, A. M.; Brunner, J.; Busto, J.; Caillat, L.; Calzas, A.; Camarena, F.; Capone, A.; Caponetto, L.; Carloganu, C.; Carminati, G.; Carmona, E.; Carr, J.; Carton, P. H.; Cassano, B.; Castorina, E.; Cecchini, S.; Ceres, A.; Chaleil, Th; Charvis, Ph; Chauchot, P.; Chiarusi, T.; Circella, M.; Compere, C.; Coniglione, R.; Coppolani, X.; Cosquer, A.; Costantini, H.; Cottini, N.; Coyle, P.; Cuneo, S.; Curtil, C.; D'Amato, C.; Damy, G.; van Dantzig, R.; De Bonis, G.; Decock, G.; Decowski, M. P.; Dekeyser, I.; Delagnes, E.; Desages-Ardellier, F.; Deschamps, A.; Destelle, J. -J.; Di Maria, F.; Dinkespiler, B.; Distefano, C.; Dominique, J. -L.; Donzaud, C.; Dornic, D.; Dorosti, Q.; Drogou, J. -F.; Drouhin, D.; Druillole, F.; Durand, D.; Durand, R.; Eberl, T.; Emanuele, U.; Engelen, J. J.; Ernenwein, J. -P.; Escoffier, S.; Falchini, E.; Favard, S.; Fehr, F.; Feinstein, F.; Ferri, M.; Ferry, S.; Fiorello, C.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J. -L.; Galata, S.; Galeotti, S.; Gay, P.; Gensolen, F.; Giacomelli, G.; Gojak, C.; Gomez-Gonzalez, J. P.; Goret, Ph.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartmann, B.; Heijboer, A. J.; Heine, E.; Hello, Y.; Henry, S.; Hernandez-Rey, J. J.; Herold, B.; Hoessl, J.; Hogenbirk, J.; Hsu, C. C.; Hubbard, J. R.; Jaquet, M.; Jaspers, M.; de Jong, M.; Jourde, D.; Kadler, M.; Kalantar-Nayestanaki, N.; Kalekin, O.; Kappes, A.; Karg, T.; Karkar, S.; Karolak, M.; Katz, U.; Keller, P.; Kestener, P.; Kok, E.; Kok, H.; Kooijman, P.; Kopper, C.; Kouchner, A.; Kretschmer, W.; Kruijer, A.; Kuch, S.; Kulikovskiy, V.; Lachartre, D.; Lafoux, H.; Lagier, P.; Lahmann, R.; Lahonde-Hamdoun, C.; Lamare, P.; Lambard, G.; Languillat, J-C; Larosa, G.; Lavalle, J.; Le Guen, Y.; Le Provost, H.; LeVanSuu, A.; Lefevre, D.; Legou, T.; Lelaizant, G.; Leveque, C.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Louis, F.; Lucarelli, F.; Lyashuk, V.; Magnier, P.; Mangano, S.; Marcel, A.; Marcelin, M.; Margiotta, A.; Martinez-Mora, J. A.; Masullo, R.; Mazeas, F.; Mazure, A.; Meli, A.; Melissas, M.; Migneco, E.; Mongelli, M.; Montaruli, T.; Morganti, M.; Moscoso, L.; Motz, H.; Musumeci, M.; Naumann, C.; Naumann-Godo, M.; Neff, M.; Niess, V.; Nooren, G. J. L.; Oberski, J. E. J.; Olivetto, C.; Palanque-Delabrouille, N.; Patioselitis, D.; Papaleo, R.; Pavalas, G. E.; Payet, K.; Payre, P.; Peek, H.; Petrovic, J.; Piattelli, P.; Picot-Clemente, N.; Picq, C.; Piret, Y.; Poinsignon, J.; Popa, V.; Pradier, T.; Presani, E.; Prono, G.; Racca, C.; Raia, G.; van Randwijk, J.; Real, D.; Reed, C.; Rethore, F.; Rewiersma, P.; Riccobene, G.; Richardt, C.; Richter, R.; Ricol, J. S.; Rigaud, V.; Roca, V.; Roensch, K.; Rolin, J. -F.; Rostovtsev, A.; Rottura, A.; Roux, J.; Rujoiu, M.; Ruppi, M.; Russo, G. V.; Salesa, F.; Salomon, K.; Sapienza, P.; Schmitt, F.; Schoeck, F.; Schuller, J. -P.; Schuessler, F.; Sciliberto, D.; Shanidze, R.; Shirokov, E.; Simeone, F.; Sottoriva, A.; Spies, A.; Spona, T.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th; Streeb, K.; Sulak, L.; Taiuti, M.; Tamburini, C.; Tao, C.; Tasca, L.; Terreni, G.; Tezier, D.; Toscano, S.; Urbano, F.; Valdy, P.; Vallage, B.; Van Elewyck, V.; Vannoni, G.; Vecchi, M.; Venekamp, G.; Verlaat, B.; Vernin, P.; Virique, E.; de Vries, G.; Wijnker, G.; Wobbe, G.; de Wolf, E.; Yakovenko, Y.; Yepes, H.; Zaborov, D.; Zaccone, H.; Zornoza, J. D.; Zuniga, J.; van Wijk, R.

    2011-01-01

    The ANTARES Neutrino Telescope was completed in May 2008 and is the first operational Neutrino Telescope in the Mediterranean Sea. The main purpose of the detector is to perform neutrino astronomy and the apparatus also offers facilities for marine and Earth sciences. This paper describes the

  2. Reverse Galilean telescopic spectacles in unilateral aphakia.

    Science.gov (United States)

    Krefman, R A

    1981-09-01

    Minimizing aniseikonia in unilateral aphakia is often a difficult task. A case is presented in which a patient preferred a reverse Galilean telescopic spectacle of his own design to a contact lens. The design of the spectacles and the patient's visual performance with them are described. A reverse Galilean telescopic spectacle should not be excluded from the therapeutic alternatives in unilateral aphakia.

  3. Herschel SPIRE FTS telescope model correction

    Science.gov (United States)

    Hopwood, Rosalind; Fulton, Trevor; Polehampton, Edward T.; Valtchanov, Ivan; Benielli, Dominique; Imhof, Peter; Lim, Tanya; Lu, Nanyao; Marchili, Nicola; Pearson, Chris P.; Swinyard, Bruce M.

    2014-07-01

    Emission from the Herschel telescope is the dominant source of radiation for the majority of SPIRE Fourier transform spectrometer (FTS) observations, despite the exceptionally low emissivity of the primary and secondary mirrors. Accurate modelling and removal of the telescope contribution is, therefore, an important and challenging aspect of FTS calibration and data reduction pipeline. A dust-contaminated telescope model with time invariant mirror emissivity was adopted before the Herschel launch. However, measured FTS spectra show a clear evolution of the telescope contribution over the mission and strong need for a correction to the standard telescope model in order to reduce residual background (of up to 7 Jy) in the final data products. Systematic changes in observations of dark sky, taken over the course of the mission, provide a measure of the evolution between observed telescope emission and the telescope model. These dark sky observations have been used to derive a time dependent correction to the telescope emissivity that reduces the systematic error in the continuum of the final FTS spectra to ˜0.35 Jy.

  4. Simulation and Track Reconstruction for Beam Telescopes

    CERN Document Server

    Maqbool, Salman

    2017-01-01

    Beam telescopes are an important tool to test new detectors under development in a particle beam. To test these novel detectors and determine their properties, the particle tracks need to be reconstructed from the known detectors in the telescope. Based on the reconstructed track, its predicted position on the Device under Test (DUT) are compared with the actual hits on the DUT. Several methods exist for track reconstruction, but most of them do not account for the effects of multiple scattering. General Broken Lines is one such algorithm which incorporates these effects during reconstruction. The aim of this project was to simulate the beam telescope and extend the track reconstruction framework for the FE-I4 telescope, which takes these effects into account. Section 1 introduces the problem, while section 2 focuses on beam telescopes. This is followed by the Allpix2 simulation framework in Section 3. And finally, Section 4 introduces the Proteus track reconstruction framework along with the General Broken ...

  5. Remote secure observing for the Faulkes Telescopes

    Science.gov (United States)

    Smith, Robert J.; Steele, Iain A.; Marchant, Jonathan M.; Fraser, Stephen N.; Mucke-Herzberg, Dorothea

    2004-09-01

    Since the Faulkes Telescopes are to be used by a wide variety of audiences, both powerful engineering level and simple graphical interfaces exist giving complete remote and robotic control of the telescope over the internet. Security is extremely important to protect the health of both humans and equipment. Data integrity must also be carefully guarded for images being delivered directly into the classroom. The adopted network architecture is described along with the variety of security and intrusion detection software. We use a combination of SSL, proxies, IPSec, and both Linux iptables and Cisco IOS firewalls to ensure only authenticated and safe commands are sent to the telescopes. With an eye to a possible future global network of robotic telescopes, the system implemented is capable of scaling linearly to any moderate (of order ten) number of telescopes.

  6. Design of the STAR-X Telescope

    Science.gov (United States)

    Saha, Timo T.; Zhang, William W.; McClelland, Ryan S.

    2017-01-01

    Top-level science goals of the Survey and Time-domain Astrophysical Research eXplorer (STAR-X) include: investigations of most violent explosions in the universe, study of growth of black holes across cosmic time and mass scale, and measure how structure formation heats majority of baryons in the universe. To meet these goals, the field-of-view of the telescope should be about 1 square-degree, the angular resolution should be 5 arc-seconds or below across large part of the field-of-view. The on-axis effective area at 1 KeV should be about 2,000 sq cm. Payload cost and launch considerations limit the outer diameter, focal length, and mass to 1.3 meters, 5 meters, and 250 kilograms, respectively. Telescope design is based on a segmented meta-shell approach we have developed at Goddard Space Flight Center for the STAR-X telescope. The telescope shells are divided into 30-degree segments. Individual telescopes and meta-shells are nested inside each other to meet the effective area requirements in 0.5 - 6.0 KeV range. We consider Wolter-Schwarzschild, and Modified-Wolter-Schwarzschild telescope designs as basic building blocks of the nested STAR-X telescope. These designs offer an excellent resolution over a large field of views. Nested telescopes are vulnerable to stray light problems. We have designed a multi-component baffle system to eliminate direct and single-reflection light paths inside the telescopes. Large number of internal and external baffle vane structures are required to prevent stray rays from reaching the focal plane. We have developed a simple ray-trace based tool to determine the dimensions and locations of the baffles. In this paper, we present the results of our trade studies, baffle design studies, and optical performance analyses of the STAR-X telescope.

  7. Atmospheric neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Kajita, Takaaki [Research Center for Cosmic Neutrinos, Institute for Cosmic Ray Research, University of Tokyo, Kashiwa-no-ha 5-1-5, Kashiwa, Chiba 277-8582 (Japan)

    2004-12-01

    Neutrino oscillation was discovered through the study of atmospheric neutrinos. Atmospheric neutrinos are produced as decay products in hadronic showers resulting from collisions of cosmic rays with nuclei in the atmosphere. Electron neutrinos and muon neutrinos are produced mainly by the decay chain of charged pions to muons and electrons. Depending on the energy of the neutrinos, atmospheric neutrinos are observed as fully contained events, partially contained events and upward-going muon events. The energy range covered by these events is from a few hundred MeV to >1 TeV. Data from various experiments showed zenith angle- and energy-dependent deficit of {nu}{sub {mu}} events, while {nu}{sub e} events did not show any such effect. It was also shown that the {nu}{sub {mu}} survival probability obeys the sinusoidal function as predicted by neutrino oscillations. Two-flavour {nu}{sub {mu}} {r_reversible} {nu}{sub {tau}} oscillations, with sin{sup 2} 2{theta} > 0.90 and {delta}m{sup 2} in the region of 1.9 x 10{sup -3} to 3.0 x 10{sup -3} eV{sup 2}, explain all these data. Various detailed studies using high statistics atmospheric neutrino data excluded the alternative hypotheses that were proposed to explain the {nu}{sub {mu}} deficit.

  8. Strange meson spectroscopy in K[omega] and K[phi] at 11 GeV/c and Cherenkov ring imaging at SLD

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Youngjoon.

    1993-01-01

    This thesis consists of two independent parts; development of Cherenkov Ring Imaging Detector (CRID) system and analysis of high-statistics data of strange meson reactions from the LASS spectrometer. Part 1: The CRID system is devoted to charged particle identification in the SLAC Large Detector (SLD) to study e[sup +]e[sup [minus

  9. Study of electron beams within ISTTOK tokamak by means of a multi-channel Cherenkov detector; their correlation with hard X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L., E-mail: Lech.Jakubowski@ipj.gov.p [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Malinowski, K.; Sadowski, M.J.; Zebrowski, J. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Plyusnin, V.V. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Rabinski, M. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland); Fernandes, H.; Silva, C.; Duarte, P. [Association Euratom/IST, Instituto de Plasmas e Fusao Nuclear, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Jakubowski, M.J. [Andrzej Soltan Institute for Nuclear Studies, 05-400 Otwock-Swierk (Poland)

    2010-11-11

    The paper describes experimental studies of electron beams emitted from a plasma torus within the ISTTOK tokamak, which were performed by means of a new four-channel detector of the Cherenkov type. A range of electron energy was estimated. There were also measured hard X-rays, and their correlation with the fast run-away electron beams was investigated experimentally.

  10. The experimental cascade curves of EAS at E sub 0 10(17) eV obtained by the method of detection of Cherenkov pulse shape

    Science.gov (United States)

    Fomin, Y. A.; Kalmykov, G. B.; Khristiansen, M. V.; Motova, M. V.; Nechin, Y. A.; Prosin, V. V.; Zhukov, V. Y.; Efimov, N. N.; Grigoriev, V. M.; Nikiforova, E. S.

    1985-01-01

    The individual cascade curves of EAS with E sub 0 10 to the 17th power eV/I to 3/ were studied by detection of EAS Cherenkov light pulses. The scintillators located at the center of the Yakutsk EAS array within a 500-m radius circle were used to select the showers and to determine the main EAS parameters. The individual cascade curves N(t) were obtained using the EAS Cherenkov light pulses satisfying the following requirements: (1) the signal-to-noise ratio fm/delta sub n 15, (2) the EAS axis-detector distance tau sub 350 m, (3) the zenith angle theta 30 deg, (4) the probability for EAS to be detected by scintillators W 0.8. Condition (1) arises from the desire to reduce the amplitude distortion of Cherenkov pulses due to noise and determines the range of EAS sizes, N(t). The resolution times of the Cherenkov pulse shape detectors are tau sub 0 approx. 23 ns which results in distortion of a pulse during the process of the detection. The distortion of pulses due to the finiteness of tau sub 0 value was estimated. It is shown that the rise time of pulse becomes greater as tau sub 0.5/tau sub 0 ratio decreases.

  11. The control system of the 12-m medium-size telescope prototype: a test-ground for the CTA array control

    Science.gov (United States)

    Oya, I.; Anguner, E. A.; Behera, B.; Birsin, E.; Fuessling, M.; Lindemann, R.; Melkumyan, D.; Schlenstedt, S.; Schmidt, T.; Schwanke, U.; Sternberger, R.; Wegner, P.; Wiesand, S.

    2014-07-01

    The Cherenkov Telescope Array (CTA) will be the next generation ground-based very-high energy -ray observatory. CTA will consist of two arrays: one in the Northern hemisphere composed of about 20 telescopes, and the other one in the Southern hemisphere composed of about 100 telescopes, both arrays containing telescopes of different sizes and types and in addition numerous auxiliary devices. In order to provide a test-ground for the CTA array control, the steering software of the 12-m medium size telescope (MST) prototype deployed in Berlin has been implemented using the tools and design concepts under consideration to be used for the control of the CTA array. The prototype control system is implemented based on the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) control middleware, with components implemented in Java, C++ and Python. The interfacing to the hardware is standardized via the Object Linking and Embedding for Process Control Unified Architecture (OPC UA). In order to access the OPC UA servers from the ACS framework in a common way, a library has been developed that allows to tie the OPC UA server nodes, methods and events to the equivalents in ACS components. The front-end of the archive system is able to identify the deployed components and to perform the sampling of the monitoring points of each component following time and value change triggers according to the selected configurations. The back-end of the archive system of the prototype is composed by two different databases: MySQL and MongoDB. MySQL has been selected as storage of the system configurations, while MongoDB is used to have an efficient storage of device monitoring data, CCD images, logging and alarm information. In this contribution, the details and conclusions on the implementation of the control software of the MST prototype are presented.

  12. Atmospheric thermodynamics

    CERN Document Server

    Iribarne, J V

    1973-01-01

    The thermodynamics of the atmosphere is the subject of several chapters in most textbooks on dynamic meteorology, but there is no work in English to give the subject a specific and more extensive treatment. In writing the present textbook, we have tried to fill this rather remarkable gap in the literature related to atmospheric sciences. Our aim has been to provide students of meteorology with a book that can playa role similar to the textbooks on chemical thermodynamics for the chemists. This implies a previous knowledge of general thermodynamics, such as students acquire in general physics courses; therefore, although the basic principles are reviewed (in the first four chapters), they are only briefly discussed, and emphasis is laid on those topics that will be useful in later chapters, through their application to atmospheric problems. No attempt has been made to introduce the thermodynamics of irreversible processes; on the other hand, consideration of heterogeneous and open homogeneous systems permits a...

  13. Hundred metre virtual telescope captures unique detailed colour image

    Science.gov (United States)

    2009-02-01

    A team of French astronomers has captured one of the sharpest colour images ever made. They observed the star T Leporis, which appears, on the sky, as small as a two-storey house on the Moon [1]. The image was taken with ESO's Very Large Telescope Interferometer (VLTI), emulating a virtual telescope about 100 metres across and reveals a spherical molecular shell around an aged star. ESO PR Photo 06a/09 The star T Leporis as seen with VLTI ESO PR Photo 06b/09 The star T Leporis to scale ESO PR Photo 06c/09 A virtual 100-metre telescope ESO PR Photo 06d/09 The orbit of Theta1 Orionis C ESO PR Video 06a/09 Zoom-in onto T Leporis "This is one of the first images made using near-infrared interferometry," says lead author Jean-Baptiste Le Bouquin. Interferometry is a technique that combines the light from several telescopes, resulting in a vision as sharp as that of a giant telescope with a diameter equal to the largest separation between the telescopes used. Achieving this requires the VLTI system components to be positioned to an accuracy of a fraction of a micrometre over about 100 metres and maintained so throughout the observations -- a formidable technical challenge. When doing interferometry, astronomers must often content themselves with fringes, the characteristic pattern of dark and bright lines produced when two beams of light combine, from which they can model the physical properties of the object studied. But, if an object is observed on several runs with different combinations and configurations of telescopes, it is possible to put these results together to reconstruct an image of the object. This is what has now been done with ESO's VLTI, using the 1.8-metre Auxiliary Telescopes. "We were able to construct an amazing image, and reveal the onion-like structure of the atmosphere of a giant star at a late stage of its life for the first time," says Antoine Mérand, member of the team. "Numerical models and indirect data have allowed us to imagine the

  14. Parametric cost models for space telescopes

    Science.gov (United States)

    Stahl, H. Philip; Henrichs, Todd; Dollinger, Courtnay

    2017-11-01

    Multivariable parametric cost models for space telescopes provide several benefits to designers and space system project managers. They identify major architectural cost drivers and allow high-level design trades. They enable cost-benefit analysis for technology development investment. And, they provide a basis for estimating total project cost. A survey of historical models found that there is no definitive space telescope cost model. In fact, published models vary greatly [1]. Thus, there is a need for parametric space telescopes cost models. An effort is underway to develop single variable [2] and multi-variable [3] parametric space telescope cost models based on the latest available data and applying rigorous analytical techniques. Specific cost estimating relationships (CERs) have been developed which show that aperture diameter is the primary cost driver for large space telescopes; technology development as a function of time reduces cost at the rate of 50% per 17 years; it costs less per square meter of collecting aperture to build a large telescope than a small telescope; and increasing mass reduces cost.

  15. The earliest telescope preserved in Japan

    Science.gov (United States)

    Nakamura, Tsuko

    2008-11-01

    This paper describes the antique telescope owned by one of Japan's major feudal warlords, Tokugawa Yoshinao. As he died in 1650, this means that this telescope was produced in or before that year. Our recent investigation of the telescope revealed that it is of Schyrlean type, consisting of four convex lenses, so that it gives erect images with a measured magnifying power of 3.9 (± 0.2-0.3). This also implies that Yoshinao's telescope could be one of the earliest Schyrlean telescopes ever. The design, fabrication technique, and the surface decoration of the telescopic tube and caps all suggest that it is not a Western make at all, but was produced probably under the guidance of a Chinese Jesuit missionary or by the Chinese, in Suzhou or Hangzhou in Zhejiang province, China, or in Nagasaki. Following descriptions in the Japanese and Chinese historical literature, we also discuss the possibility that production of Schyrlean-type telescopes started independently in the Far East nearly simultaneously with the publication of Oculus Enoch et Eliae by Anton Maria Schyrle in 1645.

  16. Parametric Cost Models for Space Telescopes

    Science.gov (United States)

    Stahl, H. Philip; Henrichs, Todd; Dollinger, Courtney

    2010-01-01

    Multivariable parametric cost models for space telescopes provide several benefits to designers and space system project managers. They identify major architectural cost drivers and allow high-level design trades. They enable cost-benefit analysis for technology development investment. And, they provide a basis for estimating total project cost. A survey of historical models found that there is no definitive space telescope cost model. In fact, published models vary greatly [1]. Thus, there is a need for parametric space telescopes cost models. An effort is underway to develop single variable [2] and multi-variable [3] parametric space telescope cost models based on the latest available data and applying rigorous analytical techniques. Specific cost estimating relationships (CERs) have been developed which show that aperture diameter is the primary cost driver for large space telescopes; technology development as a function of time reduces cost at the rate of 50% per 17 years; it costs less per square meter of collecting aperture to build a large telescope than a small telescope; and increasing mass reduces cost.

  17. HUBBLE SPACE TELESCOPE CAPTURES FIRST DIRECT IMAGE OF A STAR

    Science.gov (United States)

    2002-01-01

    This is the first direct image of a star other than the Sun, made with NASA's Hubble Space Telescope. Called Alpha Orionis, or Betelgeuse, it is a red supergiant star marking the shoulder of the winter constellation Orion the Hunter (diagram at right). The Hubble image reveals a huge ultraviolet atmosphere with a mysterious hot spot on the stellar behemoth's surface. The enormous bright spot, more than ten times the diameter of Earth, is at least 2,000 Kelvin degrees hotter than the surface of the star. The image suggests that a totally new physical phenomenon may be affecting the atmospheres of some stars. Follow-up observations will be needed to help astronomers understand whether the spot is linked to oscillations previously detected in the giant star, or whether it moves systematically across the star's surface under the grip of powerful magnetic fields. The observations were made by Andrea Dupree of the Harvard- Smithsonian Center for Astrophysics in Cambridge, MA, and Ronald Gilliland of the Space Telescope Science Institute in Baltimore, MD, who announced their discovery today at the 187th meeting of the American Astronomical Society in San Antonio, Texas. The image was taken in ultraviolet light with the Faint Object Camera on March 3, 1995. Hubble can resolve the star even though the apparent size is 20,000 times smaller than the width of the full Moon -- roughly equivalent to being able to resolve a car's headlights at a distance of 6,000 miles. Betelgeuse is so huge that, if it replaced the Sun at the center of our Solar System, its outer atmosphere would extend past the orbit of Jupiter (scale at lower left). Credit: Andrea Dupree (Harvard-Smithsonian CfA), Ronald Gilliland (STScI), NASA and ESA Image files in GIF and JPEG format and captions may be accessed on Internet via anonymous ftp from oposite.stsci.edu in /pubinfo.

  18. Buried plastic scintillator muon telescope

    Science.gov (United States)

    Sanchez, F.; Medina-Tanco, G.A.; D'Olivo, J.C.; Paic, G.; Patino Salazar, M.E.; Nahmad-Achar, E.; Valdes Galicia, J.F.; Sandoval, A.; Alfaro Molina, R.; Salazar Ibarguen, H.; Diozcora Vargas Trevino, M.A.; Vergara Limon, S.; Villasenor, L.M.

    Muon telescopes can have several applications, ranging from astrophysical to solar-terrestrial interaction studies, and fundamental particle physics. We show the design parameters, characterization and end-to-end simulations of a detector composed by a set of three parallel dual-layer scintillator planes, buried at fix depths ranging from 0.30 m to 3 m. Each layer is 4 m2 and is composed by 50 rectangular pixels of 4cm x 2 m, oriented at a 90 deg angle with respect to its companion layer. The scintillators are MINOS extruded polystyrene strips with two Bicron wavelength shifting fibers mounted on machined grooves. Scintillation light is collected by multi-anode PMTs of 64 pixels, accommodating two fibers per pixel. The front-end electronics has a time resolution of 7.5 nsec. Any strip signal above threshold opens a GPS-tagged 2 micro-seconds data collection window. All data, including signal and background, are saved to hard disk. Separation of extensive air shower signals from secondary cosmic-ray background muons and electrons is done offline using the GPS-tagged threefold coincidence signal from surface water cerenkov detectors located nearby in a triangular array. Cosmic-ray showers above 6 PeV are selected. The data acquisition system is designed to keep both, background and signals from extensive air showers for a detailed offline data.

  19. LAST: Laser Array Space Telescope

    Science.gov (United States)

    Madajian, Jonathan A.; Cohen, Alexander; Hwang, Rebecca; Bishman, Chase; Reyes, Rachel; Bautista, Miguel; Tsukamoto, Ryan; Pon, Brandon; Vanmali, Dylan; Xu, Xu; Rommelfanger, Nicholas; Ho, Ian; Lin, Lucas; Prazak, Michael; Ruehl, Patrick; Brashears, Travis; Rupert, Nic; Lubin, Philip

    2016-09-01

    A phased array operates by modulating the phases of several signals, allowing electronic control over the locations that these signals interfere constructively or destructively, allowing the beam to be steered. A space-based laser phased array, called the Directed Energy System for Targeting of Asteroids and exploRation (DE-STAR) has previously been posited by our group for a number of uses, from planetary defense to relativistic propulsion of small probes. Here we propose using the same basic system topology as a receiver rather than a transmitter. All of the components in the system, excluding the laser, are bidirectional. Rather than each elements transmitting laser light, they would instead receive light, which will then be combined to create an interference pattern that can be imaged onto a focal plane. The Laser Array Space Telescope (LAST) uses most of the same components and metrology as DE-STAR and could thus be integrated into a singular system, allowing both transmit and receive modes. This paper discusses the possible applications of this system from laser communications to astrophysics.

  20. A search for the analogue to Cherenkov radiation by high energy neutrinos at superluminal speeds in ICARUS

    Energy Technology Data Exchange (ETDEWEB)

    Antonello, M.; Aprili, P. [Laboratori Nazionali del Gran Sasso dell' INFN, Assergi (AQ) (Italy); Baibussinov, B.; Baldo Ceolin, M. [Dipartimento di Fisica e INFN, Universita di Padova, Via Marzolo 8, I-35131 Padova (Italy); Benetti, P.; Calligarich, E. [Dipartimento di Fisica Nucleare e Teorica e INFN, Universita di Pavia, Via Bassi 6, I-27100 Pavia (Italy); Canci, N. [Laboratori Nazionali del Gran Sasso dell' INFN, Assergi (AQ) (Italy); Carbonara, F. [Dipartimento di Scienze Fisiche, INFN e Universita Federico II, Napoli (Italy); Centro, S. [Dipartimento di Fisica e INFN, Universita di Padova, Via Marzolo 8, I-35131 Padova (Italy); Cesana, A. [INFN, Sezione di Milano e Politecnico, Via Celoria 16, I-20133 Milano (Italy); Cieslik, K. [The Henryk Niewodniczanski, Institute of Nuclear Physics, Polish Academy of Science, Krakow (Poland); Cline, D.B. [Department of Physics and Astronomy, University of California, Los Angeles, CA (United States); Cocco, A.G. [Dipartimento di Scienze Fisiche, INFN e Universita Federico II, Napoli (Italy); Dabrowska, A. [The Henryk Niewodniczanski, Institute of Nuclear Physics, Polish Academy of Science, Krakow (Poland); Dequal, D. [Dipartimento di Fisica e INFN, Universita di Padova, Via Marzolo 8, I-35131 Padova (Italy); Dermenev, A. [INR RAS, prospekt 60-letiya Oktyabrya 7a, Moscow 117312 (Russian Federation); Dolfini, R. [Dipartimento di Fisica Nucleare e Teorica e INFN, Universita di Pavia, Via Bassi 6, I-27100 Pavia (Italy); Farnese, C.; Fava, A. [Dipartimento di Fisica e INFN, Universita di Padova, Via Marzolo 8, I-35131 Padova (Italy); Ferrari, A., E-mail: alfredo.ferrari@cern.ch [CERN, CH-1211 Geneve 23 (Switzerland); and others

    2012-05-15

    The OPERA Collaboration (2011) has reported evidence of superluminal {nu}{sub {mu}} propagation between CERN and the LNGS. Cohen and Glashow (2011) argued that such neutrinos should lose energy by producing photons and e{sup +}e{sup -} pairs, through Z{sup 0} mediated processes analogous to Cherenkov radiation. In terms of the parameter {delta}{identical_to}(v{sub {nu}}{sup 2}-v{sub c}{sup 2})/v{sub c}{sup 2}, the OPERA result corresponds to {delta}=5 Dot-Operator 10{sup -5}. For this value (note that (v{sub {nu}}-v{sub c})/v{sub c}={delta})/2 =2.5 Dot-Operator 10{sup -5}) of {delta}, a very significant deformation of the neutrino energy spectrum and an abundant production of photons and e{sup +}e{sup -} pairs should be observed at LNGS. We present an analysis based on the 2010 and part of the 2011 data sets from the ICARUS experiment, located at Gran Sasso National Laboratory and using the same neutrino beam from CERN. We find that the rates and deposited energy distributions of neutrino events in ICARUS agree with the expectations for an unperturbed spectrum of the CERN neutrino beam, as also reported by OPERA. Our results therefore refute a superluminal interpretation of the OPERA result according to the Cohen and Glashow (2011) prediction for a weak current analog to Cherenkov radiation. In a dedicated search, no superluminal Cherenkov-like e{sup +}e{sup -} pair or {gamma} emission event has been directly observed inside the fiducial volume of the 'bubble chamber-like' ICARUS TPC-LAr detector, setting the much stricter limit of {delta}<2.5 Dot-Operator 10{sup -8} at the 90% confidence level, comparable with the one due to the observations from the SN1987a (M.J. Longo, 1987 ). The observations of high energy neutrino events by Super-Kamiokande and IceCube are also pointing to a much stricter limit on {delta}.