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Sample records for atmospheric cherenkov telescopes

  1. Performance of the STACEE Atmospheric Cherenkov Telescope

    CERN Document Server

    Williams, D A; Boone, L M; Chantell, M C; Conner, Z; Covault, C E; Dragovan, M; Fortin, P; Gingrich, D M; Gregorich, D T; Hanna, D S; Mohanty, G B; Mukherjee, R; Ong, R A; Oser, S M; Ragan, K; Scalzo, R A; Schütte, D R; Theoret, C G; Tümer, T O; Vincent, F; Zweerink, J A

    2000-01-01

    The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is located at the National Solar Thermal Test Facility of Sandia National Laboratories in Albuquerque, New Mexico, USA. The field of solar tracking mirrors (heliostats) around a central receiver tower is used to direct Cherenkov light from atmospheric showers onto secondary mirrors on the tower, which in turn image the light onto cameras of photomultiplier tubes. The STACEE Collaboration has previously reported a detection of the Crab Nebula with approximately 7 standard deviation significance, using 32 heliostats (STACEE-32). This result demonstrates both the viability of the technique and the suitability of the site. We are in the process of completing an upgrade to 48 heliostats (STACEE-48) en route to an eventual configuration using 64 heliostats (STACEE-64) in early 2001. In this paper, we summarize the results obtained on the sensitivity of STACEE-32 and our expectations for STACEE-48 and STACEE-64.

  2. The Atmospheric Monitoring Strategy for the Cherenkov Telescope Array

    CERN Document Server

    Daniel, M K

    2015-01-01

    The Imaging Atmospheric Cherenkov Technique (IACT) is unusual in astronomy as the atmosphere actually forms an intrinsic part of the detector system, with telescopes indirectly detecting very high energy particles by the generation and transport of Cherenkov photons deep within the atmosphere. This means that accurate measurement, characterisation and monitoring of the atmosphere is at the very heart of successfully operating an IACT system. The Cherenkov Telescope Array (CTA) will be the next generation IACT observatory with an ambitious aim to improve the sensitivity of an order of magnitude over current facilities, along with corresponding improvements in angular and energy resolution and extended energy coverage, through an array of Large (23m), Medium (12m) and Small (4m) sized telescopes spread over an area of order ~km$^2$. Whole sky coverage will be achieved by operating at two sites: one in the northern hemisphere and one in the southern hemisphere. This proceedings will cover the characterisation of...

  3. Wavelet Imaging Cleaning Method for Atmospheric Cherenkov Telescopes

    OpenAIRE

    Lessard, R. W.; Cayón, L.; Sembroski, G.H.; Gaidos, J. A.

    2001-01-01

    We present a new method of image cleaning for imaging atmospheric Cherenkov telescopes. The method is based on the utilization of wavelets to identify noise pixels in images of gamma-ray and hadronic induced air showers. This method selects more signal pixels with Cherenkov photons than traditional image processing techniques. In addition, the method is equally efficient at rejecting pixels with noise alone. The inclusion of more signal pixels in an image of an air shower allows for a more ac...

  4. Calibration of an atmospheric Cherenkov telescope using muon ring images

    International Nuclear Information System (INIS)

    Theoretical and experimental studies have been made of the Chernkov light images from single muons recorded by the atmospheric Cherenkov imaging telescopes which are commonly used in TeV gamma-ray astronomy. In particular, the Cherenkov ring images from single muons have been used to calibrate the Whipple Observatory 10 meter imaging telescope. This approach tests the total throughput of the telescope and uses an atmospheric Chernkov light signal that matches the shower signal. We discusss the geometrical and physical factors Chernkov rings and match the measured images with predicted rings. The preliminary estimate of the absolute calibration of the Whipple telescope is in agreement with that obtained by other methods but the uncertainty is reduced

  5. The TACTIC atmospheric Cherenkov Imaging telescope

    CERN Document Server

    Koul, R; Kaul, S K; Kaul, S R; Kumar, N; Yadav, K K; Bhatt, N; Venugopal, K; Goyal, H C; Kothari, M; Chandra, P; Rannot, R C; Dhar, V K; Koul, M K; Kaul, R K; Kotwal, S; Chanchalani, K; Thoudam, S; Chouhan, N; Sharma, M; Bhattacharya, S; Sahayanathan, S

    2007-01-01

    The TACTIC $\\gamma$-ray telescope, equipped with a light collector of area $\\sim$9.5m$^2$ and a medium resolution imaging camera of 349-pixels, has been in operation at Mt.Abu, India since 2001. This paper describes the main features of its various subsystems and its overall performance with regard to (a) tracking accuracy of its 2-axes drive system, (b) spot size of the light collector, (c) back-end signal processing electronics and topological trigger generation scheme, (d) data acquisition and control system and (e) relative and absolute gain calibration methodology. Using a trigger field of view of 11$\\times$11 pixels ($\\sim$ 3.4$^\\circ nsiderable scope for the TACTIC telescope to monitor similar TeV $\\gamma$-ray emission activity from other active galactic nuclei on a long term basis.

  6. Calibration of the Sensitivity of Imaging Atmospheric Cherenkov Telescopes using a Reference Light Source

    OpenAIRE

    Frass, A.; Koehler, C.; Hermann, G.; Hess, M.; Hofmann, W.

    1997-01-01

    The sensitivity of an Imaging Atmospheric Cherenkov telescope is calibrated by shining, from a distant pulsed monochromatic light source, a defined photon flux onto the mirror. The light pulse is captured and reconstructed by the telescope in an identical fashion as real Cherenkov light. The intensity of the calibration light pulse is monitored via a calibrated sensor at the telescope; in order to account for the lower sensitivity of this sensor compared to the Cherenkov telescope, an attenua...

  7. Early attempts at atmospheric simulations for the Cherenkov Telescope Array

    CERN Document Server

    Rulten, Cameron B

    2014-01-01

    The Cherenkov Telescope Array (CTA) will be the world's first observatory for detecting gamma-rays from astrophysical phenomena and is now in its prototyping phase with construction expected to begin in 2015/16. In this work we present the results from early attempts at detailed simulation studies performed to assess the need for atmospheric monitoring. This will include discussion of some lidar analysis methods with a view to determining a range resolved atmospheric transmission profile. We find that under increased aerosol density levels, simulated gamma-ray astronomy data is systematically shifted leading to softer spectra. With lidar data we show that it is possible to fit atmospheric transmission models needed for generating lookup tables, which are used to infer the energy of a gamma-ray event, thus making it possible to correct affected data that would otherwise be considered unusable.

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

    Czech Academy of Sciences Publication Activity Database

    Paré, E.; Balauge, B.; Bazer-Bachi, R.; Bergeret, H.; Berny, F.; Briand, N.; Bruel, P.; Cerutti, M.; Collon, J.; Cordier, A.; Cornbise, 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.; Hérault, N.; Holder, J.; Hrabovský, Miroslav; Incerti, S.; Jouenne, A.; Kalt, L.; LeGallou, R.; Lott, B.; Manigot, P.; Neveu, J.; Olive, J. F.; Palatka, Miroslav; Perez, A.; Rebii, A.; Rob, L.; Sans, J. L.; Schovánek, Petr; Villard, G.

    2002-01-01

    Roč. 490, - (2002), s. 71-89. ISSN 0168-9002 R&D Projects: GA MŠk LN00A006 Institutional research plan: CEZ:AV0Z1010920 Keywords : gamma-ray astronopy * atmospheric Cherenkov detector Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.167, year: 2002

  9. Large size SiPM matrix for Imaging Atmospheric Cherenkov Telescopes applications

    Science.gov (United States)

    Ambrosi, G.; Corti, D.; Ionica, M.; Manea, C.; Mariotti, M.; Rando, R.; Reichardt, I.; Schultz, C.

    2016-07-01

    SiPM photo detectors are nowadays commonly used in many applications. For large size telescopes like MAGIC or the future Large Size Telescope (LST) of the Cherenkov Telescope Array (CTA) project, a pixel size of some square centimeters is needed. An analog amplifier and sum stage was built and characterized. A large and compact SiPM matrix prototype, with the associated focusing optics, was assembled into a monolithic light detector with an active area of 3 cm2. The performance of the electronics is tailored for Imaging Atmospheric Cherenkov Telescopes (IACT) applications, with fast signal and adequate signal-to-noise (S/N) ratio.

  10. Towards a full Atmospheric Calibration system for the Cherenkov Telescope Array

    CERN Document Server

    Doro, M; Blanch, O; Font, LL; Garrido, D; Lopez-Oramas, A

    2013-01-01

    The current generation of Cherenkov telescopes is mainly limited in their gamma-ray energy and flux reconstruction by uncertainties in the determination of atmospheric parameters. The Cherenkov Telescope Array (CTA) aims to provide high-precision data extending the duty cycle as much as possible. To reach this goal, it is necessary to continuously and precisely monitor the atmosphere by means of remote-sensing devices, which are able to provide altitude-resolved and wavelength-dependent extinction factors, sensitive up to the tropopause and higher. Raman LIDARs are currently the best suited technology to achieve this goal with one single instrument. However, the synergy with other instruments like radiometers, solar and stellar photometers, all-sky cameras, and possibly radio-sondes is desirable in order to provide more precise and accurate results, and allows for weather forecasts and now-casts. In this contribution, we will discuss the need and features of such multifaceted atmospheric calibration systems.

  11. Simulation of Imaging Atmospheric Cherenkov Telescopes with CORSIKA and sim_telarray

    OpenAIRE

    Bernlohr, Konrad

    2008-01-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) have resulted in a breakthrough in very-high energy (VHE) gamma-ray astrophysics. While early IACT installations faced the problem of detecting any sources at all, current instruments are able to see many sources, often over more than two orders of magnitude in energy. As instruments and analysis methods have matured, the requirements for calibration and modelling of physical and instrumental effects have increased. In this article, a set of Mo...

  12. The Cherenkov Telescope Array

    OpenAIRE

    Bigongiari, Ciro

    2016-01-01

    The Cherenkov Telescope Array (CTA) is planned to be the next generation ground based observatory for very high energy (VHE) gamma-ray astronomy. Gamma-rays provide a powerful insight into the non-thermal universe and hopefully a unique probe for new physics. Imaging Cherenkov telescopes have already discovered more than 170 VHE gamma-ray emitters providing plentiful of valuable data and clearly demonstrating the power of this technique. In spite of the impressive results there are indication...

  13. Optimal strategies for observation of active galactic nuclei variability with Imaging Atmospheric Cherenkov Telescopes

    CERN Document Server

    Giomi, Matteo; Maier, Gernot

    2016-01-01

    Variable emission is one of the defining characteristic of active galactic nuclei (AGN). While providing precious information on the nature and physics of the sources, variability is often challenging to observe with time- and field-of-view-limited astronomical observatories such as Imaging Atmospheric Cherenkov Telescopes (IACTs). In this work, we address two questions relevant for the observation of sources characterized by AGN-like variability: what is the most time-efficient way to detect such sources, and what is the observational bias that can be introduced by the choice of the observing strategy when conducting blind surveys of the sky. Different observing strategies are evaluated using simulated light curves and realistic instrument response functions of the Cherenkov Telescope Array (CTA), a future gamma-ray observatory. We show that strategies that makes use of very small observing windows, spread over large periods of time, allows for a faster detection of the source, and are less influenced by the...

  14. The Topo-trigger: a new concept of stereo trigger system for imaging atmospheric Cherenkov telescopes

    CERN Document Server

    López-Coto, Rubén; Paoletti, Riccardo; Bigas, Oscar Blanch; Cortina, Juan

    2016-01-01

    Imaging atmospheric Cherenkov telescopes (IACTs) such as the Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes endeavor to reach the lowest possible energy threshold. In doing so the trigger system is a key element. Reducing the trigger threshold is hampered by the rapid increase of accidental triggers generated by ambient light, the so-called Night Sky Background (NSB). In this paper we present a topological trigger, dubbed Topo-trigger, which rejects events on the basis of their relative orientation in the telescope cameras. We have simulated and tested the trigger selection algorithm in the MAGIC telescopes. The algorithm was tested using MonteCarlo simulations and shows a rejection of 85% of the accidental stereo triggers while preserving 99 % of the gamma rays. A full implementation of this trigger system would achieve an increase in collection area between 10 and 20% at the energy threshold. The analysis energy threshold of the instrument is expected to decrease by ?8 %. The selection alg...

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

    International Nuclear Information System (INIS)

    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

  16. 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.

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

    Science.gov (United States)

    Chen, Y. T.; de La Taille, C.; Suomijärvi, T.; Cao, Z.; Deligny, O.; Dulucq, F.; Ge, M. M.; Lhenry-Yvon, I.; Martin-Chassard, G.; Nguyen Trung, T.; Wanlin, E.; Xiao, G.; Yin, L. Q.; Yun Ky, B.; Zhang, L.; Zhang, H. Y.; Zhang, S. S.; Zhu, Z.

    2015-09-01

    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.

  18. Optimal strategies for observation of active galactic nuclei variability with Imaging Atmospheric Cherenkov Telescopes

    Science.gov (United States)

    Giomi, Matteo; Gerard, Lucie; Maier, Gernot

    2016-07-01

    Variable emission is one of the defining characteristic of active galactic nuclei (AGN). While providing precious information on the nature and physics of the sources, variability is often challenging to observe with time- and field-of-view-limited astronomical observatories such as Imaging Atmospheric Cherenkov Telescopes (IACTs). In this work, we address two questions relevant for the observation of sources characterized by AGN-like variability: what is the most time-efficient way to detect such sources, and what is the observational bias that can be introduced by the choice of the observing strategy when conducting blind surveys of the sky. Different observing strategies are evaluated using simulated light curves and realistic instrument response functions of the Cherenkov Telescope Array (CTA), a future gamma-ray observatory. We show that strategies that makes use of very small observing windows, spread over large periods of time, allows for a faster detection of the source, and are less influenced by the variability properties of the sources, as compared to strategies that concentrate the observing time in a small number of large observing windows. Although derived using CTA as an example, our conclusions are conceptually valid for any IACTs facility, and in general, to all observatories with small field of view and limited duty cycle.

  19. GAW - An Imaging Atmospheric Cherenkov Telescope with Large Field of View

    CERN Document Server

    Cusumano, G; Alberdi, A; Alvarez, M; Assis, P; Biondo, B; Bocchino, F; Brogueira, P; Caballero, J A; Carvajal, M; Castro-Tirado, A J; Catalano, O; Celi, F; Delgado, C; Di Cocco, G; Dominguez, A; Navas, J M Espino; Santo, M C Espirito; Gallardo, M I; García, J E; Giarrusso, S; Gómez, M; Gómez, J L; Gonçalves, P; Guerriero, M; La Barbera, A; La Rosa, G; Lozano, M; Maccarone, M C; Mangano, A; Martel, I; Massaro, E; Mineo, T; Moles, M; Pérez-Bernal, F; Peres-Torres, M A; Pimenta, M; Pina, A; Prada, F; Quesada, J M; Quintana, J M; Quintero, J R; Rodríguez, J; Russo, F; Sacco, B; Sanchez-Conde, M A; Segreto, A; Tome', B; Postigo, A de Ugarte; Vallania, P

    2007-01-01

    GAW, acronym for Gamma Air Watch, is a Research and Development experiment in the TeV range, whose main goal is to explore the feasibility of large field of view Imaging Atmospheric Cherenkov Telescopes. GAW is an array of three relatively small telescopes (2.13 m diameter) which differs from the existing and presently planned projects in two main features: the adoption of a refractive optics system as light collector and the use of single photoelectron counting as detector working mode. The optics system allows to achieve a large field of view (24x24 squared degrees) suitable for surveys of large sky regions. The single photoelectron counting mode in comparison with the charge integration mode improves the sensitivity by permitting also the reconstruction of events with a small number of collected Cherenkov photons. GAW, which is a collaboration effort of Research Institutes in Italy, Portugal and Spain, will be erected in the Calar Alto Observatory (Sierra de Los Filabres - Andalucia, Spain), at 2150 m a.s....

  20. Real-time atmospheric monitoring for the Cherenkov Telescope Array using a wide-field optical telescope

    CERN Document Server

    Ebr, Jan; Prouza, Michael; Blazek, Jiri

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next generation of ground-based very high energy gamma-ray instruments and is planned to be built on two sites (one in each hemisphere) in the coming years, with full array operation foreseen to begin 2020. The goal of performing high precision gamma-ray energy measurements while maximizing the use of observation time demands detailed and fast information about atmospheric conditions. Besides LIDARs designed to monitor clouds and aerosol content of the atmosphere in the pointing direction of the CTA telescopes, we propose to use the "FRAM" (F(/Ph)otometric Robotic Atmospheric Monitor) device, which is a small robotic astronomical telescope with a large field of view and a sensitive CCD camera that together ensure precise atmospheric characterization over the complete field-of-view of the CTA. FRAM will use stellar photometry to measure atmospheric extinction across the field of view of the CTA without interfering with the observation (unlike laser-based methods). Thi...

  1. Typical atmospheric aerosol behavior at the Cherenkov Telescope Array candidate sites in Argentina

    CERN Document Server

    Piacentini, Rubén D; Micheletti, María I; Salum, Graciela M; Maya, Javier; Mancilla, Alexis; García, Beatriz

    2013-01-01

    Aerosols from natural and antropogenic sources are one of the atmospheric components that have the largest spacial-temporal variability, depending on the type (land or ocean) surface, human activity and climatic conditions (mainly temperature and wind). Since Cherenkov photons generated by the incidence of a primary ultraenergetic cosmic gamma photon have a spectral intensity distribution concentrated in the UV and visible ranges [Hillas AM. Space Science Reviews, 75, 17-30, 1996], it is important to know the aerosol concentration and its contribution to atmospheric radiative transfer. We present results of this concentration measured in typical rather calm (not windy) days at San Antonio de los Cobres (SAC) and El Leoncito/CASLEO proposed Argentinean Andes range sites for the placement of the Cherenkov Telescope Array (CTA). In both places, the aerosol concentration has a peak in the 2.5-5.0$\\mu$m range of the mean aerosol diameter and a very low mean total concentration of 0.097$\\mu$g/m$^3$ (0.365$\\mu$g/m$^...

  2. Supernova remnants and pulsar wind nebulae with Imaging Atmospheric Cherenkov Telescopes (IACTs)

    Science.gov (United States)

    Eger, Peter

    2015-08-01

    The observation of very-high-energy (VHE, E > 100 GeV) gamma rays is an excellent tool to study the most energetic and violent environments in the Galaxy. This energy range is only accessible with ground-based instruments such as Imaging Atmospheric Cherenkov Telescopes (IACTs) that reconstruct the energy and direction of the primary gamma ray by observing the Cherenkov light from the induced extended air showers in Earths atmosphere. The main goals of Galactic VHE gamma-ray science are the identification of individual sources of cosmic rays (CRs), such as supernova remnants (SNRs), and the study of other extreme astrophysical objects at the highest energies, such as gamma-ray binaries and pulsar wind nebulae (PWNe). One of the main challenges is the discrimination between leptonic and hadronic gamma-ray production channels. To that end, the gamma-ray signal from each individual source needs to be brought into context with the multi-wavelength environment of the astrophysical object in question, particularly with observations tracing the density of the surrounding interstellar medium, or synchrotron radiation from relativistic electrons. In this review presented at the European Cosmic Ray Symposium 2014 (ECRS2014), the most recent developments in the field of Galactic VHE gamma-ray science are highlighted, with particular emphasis on SNRs and PWNe.

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

    International Nuclear Information System (INIS)

    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. (research papers)

  4. The upgraded MAGIC Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Tescaro, D., E-mail: dtescaro@iac.es [Instituto de Astrofísica de Canarias (IAC), E-38205 La Laguna, Tenerife (Spain); Universidad de La Laguna (ULL), Dept. Astrofísica, E-38206 La Laguna, Tenerife (Spain)

    2014-12-01

    The MAGIC Cherenkov telescopes underwent a major upgrade in 2011 and 2012. A new 1039-pixel camera and a larger area digital trigger system were installed in MAGIC-I, making it essentially identical to the newer MAGIC-II telescope. The readout systems of both telescopes were also upgraded, with fully programmable receiver boards and DRS4-chip-based digitization systems. The upgrade eased the operation and maintenance of the telescopes and also improved significantly their performance. The system has now an integral sensitivity as good as 0.6% of the Crab Nebula flux (for E>400GeV), with an effective analysis threshold at 70 GeV. This allows MAGIC to secure one of the leading roles among the current major ground-based Imaging Atmospheric Cherenkov telescopes for the next 5–10 years. - Highlights: • In 2011 and 2012 the MAGIC telescopes underwent a two-stage major upgrade. • The new camera of MAGIC-I allows us to exploit a 1.4 larger trigger area. • The novel DRS4-based readout systems allow a cost-effective ultra-fast digitization. • The upgrade greatly improved the maintainability of the system. • MAGIC has now an optimal integral sensitivity of 0.6% of the Crab Nebula flux.

  5. The upgraded MAGIC Cherenkov telescopes

    International Nuclear Information System (INIS)

    The MAGIC Cherenkov telescopes underwent a major upgrade in 2011 and 2012. A new 1039-pixel camera and a larger area digital trigger system were installed in MAGIC-I, making it essentially identical to the newer MAGIC-II telescope. The readout systems of both telescopes were also upgraded, with fully programmable receiver boards and DRS4-chip-based digitization systems. The upgrade eased the operation and maintenance of the telescopes and also improved significantly their performance. The system has now an integral sensitivity as good as 0.6% of the Crab Nebula flux (for E>400GeV), with an effective analysis threshold at 70 GeV. This allows MAGIC to secure one of the leading roles among the current major ground-based Imaging Atmospheric Cherenkov telescopes for the next 5–10 years. - Highlights: • In 2011 and 2012 the MAGIC telescopes underwent a two-stage major upgrade. • The new camera of MAGIC-I allows us to exploit a 1.4 larger trigger area. • The novel DRS4-based readout systems allow a cost-effective ultra-fast digitization. • The upgrade greatly improved the maintainability of the system. • MAGIC has now an optimal integral sensitivity of 0.6% of the Crab Nebula flux

  6. The structure of an Imaging Atmospheric Cherenkov Telescope with novel photon detectors for ground-based gamma-ray astronomy

    International Nuclear Information System (INIS)

    Very high energy gamma-ray astronomy is a rapidly expanding field of research. Observations are nearly all carried out with so-called Imaging Atmospheric Cherenkov Telescopes all using Photomultipliers as light sensors up to now. A test telescope using Geiger-mode avalanche photodiodes (G-APD) for the first time is under construction. The former HEGRA CT3 telescope mount on the Canary island La Palma is being refurbished for the First G-APD Cherenkov Telescope (FACT). Here, we describe the mirror system, its detailed construction, focal length distribution, spectral reflectivity and point spread function for all hexagonal aluminum facets. In October 2010, the mirrors were pre-aligned on site using a laser alignment setup, and first tracking tests of the new drive system were conducted.

  7. The Cherenkov Telescope Array

    CERN Document Server

    Bigongiari, Ciro

    2016-01-01

    The Cherenkov Telescope Array (CTA) is planned to be the next generation ground based observatory for very high energy (VHE) gamma-ray astronomy. Gamma-rays provide a powerful insight into the non-thermal universe and hopefully a unique probe for new physics. Imaging Cherenkov telescopes have already discovered more than 170 VHE gamma-ray emitters providing plentiful of valuable data and clearly demonstrating the power of this technique. In spite of the impressive results there are indications that the known sources represent only the tip of the iceberg. A major step in sensitivity is needed to increase the number of detected sources, observe short time-scale variability and improve morphological studies of extended sources. An extended energy coverage is advisable to observe far-away extragalactic objects and improve spectral analysis. CTA aims to increase the sensitivity by an order of magnitude compared to current facilities, to extend the accessible gamma-ray energies from a few tens of GeV to a hundred o...

  8. Probing the Pulsar Origin of the Anomalous Positron Fraction with AMS-02 and Atmospheric Cherenkov Telescopes

    CERN Document Server

    Linden, Tim

    2013-01-01

    Recent observations by PAMELA, Fermi-LAT, and AMS-02 have conclusively indicated a rise in the cosmic-ray positron fraction above 10 GeV, a feature which is impossible to mimic under the paradigm of secondary positron production with self-consistent Galactic cosmic-ray propagation models. A leading explanation for the rising positron fraction is an additional source of electron-positron pairs, for example one or more mature, energetic, and relatively nearby pulsars. We point out that any one of two well-known nearby pulsars, Geminga and Monogem, can satisfactorily provide enough positrons to reproduce AMS-02 observations. A smoking-gun signature of this scenario is an anisotropy in the arrival direction of the cosmic-ray electrons and positrons, which may be detectable by existing, or future, telescopes. The predicted anisotropy level is, at present, consistent with limits from Fermi-LAT and AMS-02. We argue that the large collecting area of Atmospheric Cherenkov Telescopes (ACTs) makes them optimal tools for...

  9. An astroclimatological study of candidate sites to host an imaging atmospheric Cherenkov telescope in Romania

    CERN Document Server

    Radu, A A; Curtef, V; Felea, D; Hasegan, D; Lucaschi, B; Manea, A; Popa, V; Ralita, I

    2011-01-01

    We come out in this paper with an astroclimatological study of meteorological data on relative humidity, dew point temperature, air temperature, wind speed, barometric air pressure, and sky cloudiness recorded at four Romanian locations (Baisoara, Rosia Montana, Semenic, Ceahlau) and Nordic Optical Telescope (NOT) located at Observatorio del Roque de Los Muchachos, in the Canary Islands. Long term trends of microclimates have been compared in order to identify the site-to-site variations. We have performed this analysis as part of a site testing campaign aimed at finding the best location for the establishment of a small Cherenkov telescope in Romania. The conditions at the Romanian sites have been compared to those of the Canary Islands considered as a reference. A statistical approach has been used for data analysis. Monthly and annual samples have been extracted from series of raw data for nighttime, daytime and entire day intervals. Percentage distributions of meteorological parameters, whose values excee...

  10. Schwarzschild-Couder Telescope for the Cherenkov Telescope Array

    OpenAIRE

    Meagher, Kevin J.

    2014-01-01

    The Cherenkov Telescope Array (CTA) is the next major ground-based observatory for gamma-ray astronomy. With CTA gamma-ray sources will be studied in the very-high energy gamma-ray range of a few tens of GeV to 100 TeV with up to ten times better sensitivity than available with current generation instruments. We discuss the proposed US contribution to CTA that comprises imaging atmospheric Cherenkov telescope with Schwarzschild-Couder (SC) optics. Key features of the SC telescope are a wide f...

  11. A new analysis strategy for detection of faint gamma-ray sources with Imaging Atmospheric Cherenkov Telescopes

    CERN Document Server

    Becherini, Yvonne; Marandon, Vincent; Punch, Michael; Pita, Santiago; 10.1016/j.astropartphys.2011.03.005

    2011-01-01

    A new background rejection strategy for gamma-ray astrophysics with stereoscopic Imaging Atmospheric Cherenkov Telescopes (IACT), based on Monte Carlo (MC) simulations and real background data from the H.E.S.S. [High Energy Stereoscopic System, see [1].] experiment, is described. The analysis is based on a multivariate combination of both previously-known and newly-derived discriminant variables using the physical shower properties, as well as its multiple images, for a total of eight variables. Two of these new variables are defined thanks to a new energy evaluation procedure, which is also presented here. The method allows an enhanced sensitivity with the current generation of ground-based Cherenkov telescopes to be achieved, and at the same time its main features of rapidity and flexibility allow an easy generalization to any type of IACT. The robustness against Night Sky Background (NSB) variations of this approach is tested with MC simulated events. The overall consistency of the analysis chain has been ...

  12. MACHETE: A transit Imaging Atmospheric Cherenkov Telescope to survey half of the Very High Energy $\\gamma$-ray sky

    CERN Document Server

    Cortina, J; Moralejo, A

    2015-01-01

    Current Imaging Atmospheric Cherenkov Telescopes for Very High Energy $\\gamma$-ray astrophysics are pointing instruments with a Field of View up to a few tens of sq deg. We propose to build an array of two non-steerable (drift) telescopes. Each of the telescopes would have a camera with a FOV of 5$\\times$60 sq deg oriented along the meridian. About half of the sky drifts through this FOV in a year. We have performed a Montecarlo simulation to estimate the performance of this instrument. We expect it to survey this half of the sky with an integral flux sensitivity of $\\sim$0.77\\% of the steady flux of the Crab Nebula in 5 years, an analysis energy threshold of $\\sim$150 GeV and an angular resolution of $\\sim$0.1$^{\\circ}$. For astronomical objects that transit over the telescope for a specific night, we can achieve an integral sensitivity of 12\\% of the Crab Nebula flux in a night, making it a very powerful tool to trigger further observations of variable sources using steerable IACTs or instruments at other w...

  13. MACHETE: A transit imaging atmospheric Cherenkov telescope to survey half of the very high energy γ-ray sky

    Science.gov (United States)

    Cortina, J.; López-Coto, R.; Moralejo, A.

    2016-01-01

    Current imaging atmospheric Cherenkov telescopes for very high energy γ-ray astrophysics are pointing instruments with a field of view up to a few tens of sq deg. We propose to build an array of two non-steerable (drift) telescopes. Each of the telescopes would have a camera with a FOV of 5 × 60 sq deg oriented along the meridian. About half of the sky drifts through this FOV in a year. We have performed a Monte Carlo simulation to estimate the performance of this instrument. We expect it to survey this half of the sky with an integral flux sensitivity of ˜0.77% of the steady flux of the Crab Nebula in 5 years, an analysis energy threshold of ˜150 GeV and an angular resolution of ˜0.1°. For astronomical objects that transit over the telescope for a specific night, we can achieve an integral sensitivity of 12% of the Crab Nebula flux in a night, making it a very powerful tool to trigger further observations of variable sources using steerable IACTs or instruments at other wavelengths.

  14. Volcanoes muon imaging using Cherenkov telescopes

    CERN Document Server

    Catalano, Osvaldo; Mineo, Teresa; Cusumano, Giancarlo; Maccarone, Maria Concetta; Pareschi, Giovanni

    2015-01-01

    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 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 energ...

  15. GETFOCOS for imaging atmospheric Cherenkov telescopes - A GEant4 tool for optimization and characterization of an optical system

    Energy Technology Data Exchange (ETDEWEB)

    Arruda, L., E-mail: luisa@lip.pt [LIP - Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Lisbon (Portugal); Assis, P.; Barao, F.; Pereira, R.; Pimenta, M.; Tome, B. [LIP - Laboratorio de Instrumentacao e Fisica Experimental de Particulas, Lisbon (Portugal)

    2011-12-11

    The aim of this article is to introduce a dedicated simulation package, named GETFOCOS, that combines Geant4 and ray-tracing algorithms that can be used on the characterization of the optics of a generic Imaging Atmospheric Cherenkov telescope as well as on the optimization of its focal plane geometry. The image spot size is evaluated for both cases in a large field-of-view observation scenario. This tool allows to perform fast but precise tests for different optical options. The specific case of a Fresnel lens, inspired by the concept developed for the GAW experiment, is analysed. However, this intends to be an universal and relevant tool for any kind of optical system. A complete characterization of the optics is presented together with a study for the optimization of the focal plane shape.

  16. Novel Photo Multiplier Tubes for the Cherenkov Telescope Array Project

    OpenAIRE

    Toyama, Takeshi; Mirzoyan, Razmik; Dickinson, Hugh; Fruck, Christian; Hose, Jürgen; Kellermann, Hanna; Knötig, Max; Lorenz, Eckart; Menzel, Uta; Nakajima, Daisuke; Orito, Reiko; Paneque, David; Schweizer, Thomas; Teshima, Masahiro; Yamamoto, Tokonatsu

    2013-01-01

    Currently the standard light sensors for imaging atmospheric Cherenkov telescopes are the classical photo multiplier tubes that are using bialkali photo cathodes. About eight years ago we initiated an improvement program with the Photo Multiplier Tube (PMT) manufacturers Hamamatsu (Japan), Electron Tubes Enterprises (England) and Photonis (France) for the needs of imaging atmospheric Cherenkov telescopes. As a result, after about 40 years of stagnation of the peak Quantum Efficiency (QE) on t...

  17. How to focus a Cherenkov telescope

    OpenAIRE

    Hofmann, Werner

    2001-01-01

    Cherenkov telescopes image the Cherenkov emission from air showers. A priori, it is not obvious if the `best' images are achieved by measuring Cherenkov photon angles, i.e. focusing the telescope at infinity, or by considering the air shower as an object to be imaged, in which case one might focus the telescope on the central region of the shower. The issue is addressed using shower simulations.

  18. Calibration of the Cherenkov Telescope Array

    CERN Document Server

    Gaug, Markus; Berge, David; Reyes, Raquel de los; Doro, Michele; Foerster, Andreas; Maccarone, Maria Concetta; Parsons, Dan; van Eldik, Christopher

    2015-01-01

    The construction of the Cherenkov Telescope Array is expected to start soon. We will present the baseline methods and their extensions currently foreseen to calibrate the observatory. These are bound to achieve the strong requirements on allowed systematic uncertainties for the reconstructed gamma-ray energy and flux scales, as well as on the pointing resolution, and on the overall duty cycle of the observatory. Onsite calibration activities are designed to include a robust and efficient calibration of the telescope cameras, and various methods and instruments to achieve calibration of the overall optical throughput of each telescope, leading to both inter-telescope calibration and an absolute calibration of the entire observatory. One important aspect of the onsite calibration is a correct understanding of the atmosphere above the telescopes, which constitutes the calorimeter of this detection technique. It is planned to be constantly monitored with state-of-the-art instruments to obtain a full molecular and...

  19. The Formation of Condensation on Cherenkov Telescope Mirrors

    CERN Document Server

    Chadwick, P M; Dyrda, M; Förster, A; Michalowski, J; Niemiec, J; Schultz, C; Stodulski, M

    2013-01-01

    The mirrors of imaging atmospheric Cherenkov telescopes are different from those of conventional astronomical telescopes in several ways, not least in that they are exposed to the elements. One of the issues which may arise is condensation forming on the mirrors during observing under certain atmospheric conditions, which has important consequences for the operation of the telescopes. This contribution discusses why telescope mirrors suffer condensation and describes the atmospheric conditions and mirror designs which are likely to be problematic.

  20. Cherenkov Telescope Array Data Management

    CERN Document Server

    Lamanna, G; Contreras, J L; Knödlseder, J; Kosack, K; Neyroud, N; Aboudan, A; Arrabito, L; Barbier, C; Bastieri, D; Boisson, C; Brau-Nogué, S; Bregeon, J; Bulgarelli, A; Carosi, A; Costa, A; De Cesare, G; Reyes, R de los; Fioretti, V; Gallozzi, S; Jacquemier, J; Khelifi, B; Kocot, J; Lombardi, S; Lucarelli, F; Lyard, E; Maier, G; Massimino, P; Osborne, J P; Perri, M; Rico, J; Sanchez, D A; Satalecka, K; Siejkowski, H; Stolarczyk, T; Szepieniec, T; Testa, V; Walter, R; Ward, J E; Zoli, A

    2015-01-01

    Very High Energy gamma-ray astronomy with the Cherenkov Telescope Array (CTA) is evolving towards the model of a public observatory. Handling, processing and archiving the large amount of data generated by the CTA instruments and delivering scientific products are some of the challenges in designing the CTA Data Management. The participation of scientists from within CTA Consortium and from the greater worldwide scientific community necessitates a sophisticated scientific analysis system capable of providing unified and efficient user access to data, software and computing resources. Data Management is designed to respond to three main issues: (i) the treatment and flow of data from remote telescopes; (ii) "big-data" archiving and processing; (iii) and open data access. In this communication the overall technical design of the CTA Data Management, current major developments and prototypes are presented.

  1. Bokeh Mirror Alignment for Cherenkov Telescopes

    CERN Document Server

    Ahnen, M L; Balbo, M; Bergmann, M; Biland, A; Blank, M; Bretz, T; Bruegge, K A; Buss, J; Domke, M; Dorner, D; Einecke, S; Hempfling, C; Hildebrand, D; Hughes, G; Lustermann, W; Mannheim, K; Mueller, S A; Neise, D; Neronov, A; Noethe, M; Overkemping, A -K; Paravac, A; Pauss, F; Rhode, W; Shukla, A; Temme, F; Thaele, J; Toscano, S; Vogler, P; Walter, R; Wilbert, A

    2016-01-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) need imaging optics with large apertures and high image intensities to map the faint Cherenkov light emitted from cosmic ray air showers onto their image sensors. Segmented reflectors fulfill these needs, and composed from mass production mirror facets they are inexpensive and lightweight. However, as the overall image is a superposition of the individual facet images, alignment remains a challenge. Here we present a simple, yet extendable method, to align a segmented reflector using its Bokeh. Bokeh alignment does not need a star or good weather nights but can be done even during daytime. Bokeh alignment optimizes the facet orientations by comparing the segmented reflectors Bokeh to a predefined template. The optimal Bokeh template is highly constricted by the reflector's aperture and is easy accessible. The Bokeh is observed using the out of focus image of a near by point like light source in a distance of about 10 focal lengths. We introduce Bokeh alignment ...

  2. Volcanoes muon imaging using Cherenkov telescopes

    Science.gov (United States)

    Catalano, O.; Del Santo, M.; Mineo, T.; Cusumano, G.; Maccarone, M. C.; Pareschi, G.

    2016-01-01

    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.

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

    CERN Document Server

    Albert, A; Kawashima, T; Murphy, M; Okumura, A; Quagliani, R; Sapozhnikov, L; Tajima, H; Tibaldo, L; Vandenbroucke, J; Wu, T

    2016-01-01

    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. {\\rev We describe the ASIC architecture and performance.} TARGET~5 improves over the performance of the first-generation TARGET ASIC, achieving: tunable sampling frequency from {\\rev $1$~GSa/s}}; a dynamic range on the data path of 1.2 V with {\\mod effective dynamic range of 11}~bits and DC noise of ${\\sim}0.6$~mV; 3-dB bandwidth of 500 MHz; {\\rev 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.), {\\rev which is} mostly limited by {\\mod interference between trigger and sampling operations}. {\\mod TAR...

  4. The small size telescope projects for the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    The small size telescopes (SSTs), spread over an area of several square km, dominate the CTA sensitivity in the photon energy range from a few TeV to over 100 TeV, enabling for the detailed exploration of the very high energy gamma-ray sky. The proposed telescopes are innovative designs providing a wide field of view. Two of them, the ASTRI (Astrophysics con Specchi a Tecnologia Replicante Italiana) and the GCT (Gamma-ray Cherenkov Telescope) telescopes, are based on dual mirror Schwarzschild-Couder optics, with primary mirror diameters of 4 m. The third, SST-1M, is a Davies-Cotton design with a 4 m diameter mirror. Progress with the construction and testing of prototypes of these telescopes is presented. The SST cameras use silicon photomultipliers, with preamplifier and readout/trigger electronics designed to optimize the performance of these sensors for (atmospheric) Cherenkov light. The status of the camera developments is discussed. The SST sub-array will consist of about 70 telescopes at the CTA souther...

  5. Effect of stars in the field of view of the VHE gamma-ray atmospheric Cherenkov telescope

    International Nuclear Information System (INIS)

    Very high energy gamma-ray astronomy in the energy range above 100 GeV has made dramatic progress through the development of imaging atmospheric Cherenkov telescopes (lACTs). The technique has been pivotal in the establishing the existence of a number of discrete gamma-ray sources. Normally due to the presence of stars in the field of view (FOV), a number of photomultiplier tubes (pmts) in the camera has to be turned off. This may have the effect of distorting some images that happens to be in that part of the camera. This may in turn affect the gamma-ray sensitivity of the telescope. The present study aims to shade some light on this possible effect. Experimental data on the extragalactic gamma-ray source Mrk 421 measured using the 10-m Whipple IACT were used for this purpose because of its relative dark FOV compared with other sources; e.g. the Crab nebula. To simulate the presence of star(s) in the FOV, the analysis program selects randomly a number of clusters of pmts to be turned off in the software. The pmts in each cluster have to be adjacent to each other (neighbors) and the selected clusters have to be separated from each other. The significance of the detected signal and the gamma-ray rate were then determined and compared with the original results. Clusters of 2, 3 and 4 pmts were used. The number of clusters was increased up to 12 clusters at various distances from the center of the FOV

  6. ALTAI: computational code for the simulations of TeV air showers as observed with the ground-based imaging atmospheric Cherenkov telescopes

    International Nuclear Information System (INIS)

    Ground-based atmospheric Cherenkov telescopes are proven to be effective instruments for observations of very high-energy (VHE) γ-radiation from celestial objects. For effective use of such technique one needs detailed Monte Carlo simulations of γ-ray- and proton/nuclei-induced air showers in the Earth atmosphere. Here we discuss in detail the algorithms used in the numerical code ALTAI developed particularly for the simulations of Cherenkov light emission from air showers of energy below 50 TeV. The specific scheme of sampling the charged particle transport in the atmosphere allows the performance of very fast and accurate simulations used for interpretation of the VHE γ-ray observations

  7. Searching for tau neutrinos with Cherenkov telescopes

    OpenAIRE

    Gora, D.; Bernardini, E.; Kappes, A.

    2015-01-01

    Cherenkov telescopes have the capability of detecting high energy tau neutrinos in the energy range of 1--1000 PeV by searching for very inclined showers. If a tau lepton, produced by a tau neutrino, escapes from the Earth or a mountain, it will decay and initiate a shower in the air which can be detected by an air shower fluorescence or Cherenkov telescope. In this paper, we present detailed Monte Carlo simulations of corresponding event rates for the VERITAS and two proposed Cherenkov Teles...

  8. Layout design studies for medium-sized telescopes within the Cherenkov Telescope Array

    CERN Document Server

    Hassan, T; Nieto, D; Wood, M

    2015-01-01

    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. In this study we explore how the medium-sized telescopes layout design and composition impacts the overall CTA performance by analyzing Monte Carlo simulations including Davies-Cotton and Schwarzschild-Couder medium-sized telescopes.

  9. Construction of a Medium-Sized Schwarzschild-Couder Telescope for the Cherenkov Telescope Array: Implementation of the Cherenkov-Camera Data Acquisition System

    OpenAIRE

    Santander, M.; Buckley, J.; Humensky, B.; Mukherjee, R.; Consortium, for the CTA

    2015-01-01

    A medium-sized Schwarzchild-Couder Telescope (SCT) is being developed as a possible extension for the Cherenkov Telescope Array (CTA). The Cherenkov camera of the telescope is designed to have 11328 silicon photomultiplier pixels capable of capturing high-resolution images of air showers in the atmosphere. The combination of the large number of pixels and the high trigger rate (> 5 kHz) expected for this telescope results in a multi-Gbps data throughput. This sets challenging requirements on ...

  10. The History of Ground-Based Very High Energy Gamma-Ray Astrophysics with the Atmospheric Air Cherenkov Telescope Technique

    International Nuclear Information System (INIS)

    In the recent two decades the ground-based technique of imaging atmosphericescopes has established itself as a powerful new discipline in science. As of today some ∼ 150 sources of gamma rays of very different types, of both galactic and extragalactic origin, have been discovered due to this technique. The study of these sources is providing clues to many basic questions in astrophysics, astro-particle physics, physics of cosmic rays and cosmology. The current generation of telescopes, despite the young age of the technique, offers a solid performance. The technique is still maturing, leading to the next generation large instrument known under the name Cherenkov Telescope Array. The latter's sensitivity will be an order of magnitude higher than that of the currently best instruments VERITAS, H.E.S.S. and MAGIC. This article is devoted to outlining the milestones in a long history that step-by-step have given shape to this technique and have brought about today's successful source marathon

  11. The History of Ground-Based Very High Energy Gamma-Ray Astrophysics with the Atmospheric Air Cherenkov Telescope Technique

    Energy Technology Data Exchange (ETDEWEB)

    Mirzoyan, Razmik

    2013-06-15

    In the recent two decades the ground-based technique of imaging atmosphericescopes has established itself as a powerful new discipline in science. As of today some ∼ 150 sources of gamma rays of very different types, of both galactic and extragalactic origin, have been discovered due to this technique. The study of these sources is providing clues to many basic questions in astrophysics, astro-particle physics, physics of cosmic rays and cosmology. The current generation of telescopes, despite the young age of the technique, offers a solid performance. The technique is still maturing, leading to the next generation large instrument known under the name Cherenkov Telescope Array. The latter's sensitivity will be an order of magnitude higher than that of the currently best instruments VERITAS, H.E.S.S. and MAGIC. This article is devoted to outlining the milestones in a long history that step-by-step have given shape to this technique and have brought about today's successful source marathon.

  12. Searching for tau neutrinos with Cherenkov telescopes

    CERN Document Server

    Gora, D; Kappes, A

    2014-01-01

    Cherenkov telescopes have the capability of detecting high energy tau neutrinos in the energy range of 1--1000 PeV by searching for very inclined showers. If a tau lepton, produced by a tau neutrino, escapes from the Earth or a mountain, it will decay and initiate a shower in the air which can be detected by an air shower fluorescence or Cherenkov telescope. In this paper, we present detailed Monte Carlo simulations of corresponding event rates for the VERITAS and two proposed Cherenkov Telescope Array sites: Meteor Crater and Yavapai Ranch, which use representative AGN neutrino flux models and take into account topographic conditions of the detector sites. The calculated neutrino sensitivities depend on the observation time and the shape of the energy spectrum, but in some cases are comparable or even better than corresponding neutrino sensitivities of the IceCube detector. For VERITAS and the considered Cherenkov Telescope Array sites the expected neutrino sensitivities are up to factor 3 higher than for th...

  13. Fundamental and exotic physics with Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    De Angelis, A., E-mail: alessandro.de.angelis@cern.c [Dipartimento di Fisica dell' Universita di Udine and INFN, Udine (Italy); De Lotto, B. [Dipartimento di Fisica dell' Universita di Udine and INFN, Udine (Italy); Roncadelli, M. [INFN Pavia (Italy)

    2011-02-21

    The detection of high-energy {gamma} rays from astrophysical sources, using the Fermi/LAT detector and in the very-high-energy limit the Cherenkov telescopes MAGIC, H.E.S.S. and VERITAS, can provide tests of fundamental physics with unprecedented sensitivity, and possibly allows to probe new and exotic scenarios.

  14. Silicon Photomultiplier Research and Development Studies for the Large Size Telescope of the Cherenkov Telescope Array

    OpenAIRE

    Rando, Riccardo; Corti, Daniele; Dazzi, Francesco; de Angelis, Alessandro; Dettlaff, Antonios; Dorner, Daniela; Fink, David; Fouque, Nadia; Grundner, Felix; Haberer, Werner; Hahn, Alexander; Hermel, Richard; Korpar, Samo; Mezek, Gašper Kukec; Maier, Ronald

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the the next generation facility of imaging atmospheric Cherenkov telescopes; two sites will cover both hemispheres. CTA will reach unprecedented sensitivity, energy and angular resolution in very-high-energy gamma-ray astronomy. Each CTA array will include four Large Size Telescopes (LSTs), designed to cover the low-energy range of the CTA sensitivity ($\\sim$20 GeV to 200 GeV). In the baseline LST design, the focal-plane camera will be instrumented with...

  15. SST-GATE: A dual mirror telescope for the Cherenkov Telescope Array

    OpenAIRE

    Zech, A.; Amans, J.-P.; Blake, S; Boisson, C.; Costille, C.; De-Frondat, F.; Dournaux, J. -L.; Dumas, D.; Fasola, G.; T. Greenshaw; Hervet, O.; Huet, J. -M.; Laporte, P.; Rulten, C.; Savoie, D.

    2013-01-01

    The Cherenkov Telescope Array (CTA) will be the world's first open observatory for very high energy gamma-rays. Around a hundred telescopes of different sizes will be used to detect the Cherenkov light that results from gamma-ray induced air showers in the atmosphere. Amongst them, a large number of Small Size Telescopes (SST), with a diameter of about 4 m, will assure an unprecedented coverage of the high energy end of the electromagnetic spectrum (above ~1TeV to beyond 100 TeV) and will ope...

  16. Mirror Development for the Cherenkov Telescope Array

    CERN Document Server

    Förster, A; Baba, H; Bähr, J; Bonardi, A; Bonnoli, G; Brun, P; Canestrari, R; Chadwick, P; Chikawa, M; Carton, P -H; De Souza, V; Dipold, J; Doro, M; Durand, D; Dyrda, M; Giro, E; Glicenstein, J -F; Hanabata, Y; Hayashida, M; Hrabovski, M; Jeanney, C; Kagaya, M; Katagiri, H; Lessio, L; MANDAT, D; Mariotti, M; Medina, C; Michałowski, J; Micolon, P; Nakajima, D; Niemiec, J; Nozato, A; Palatka, M; Pareschi, G; Pech, M; Peyaud, B; Pühlhofer, G; Rataj, M; Rodeghiero, G; Rojas, G; Rousselle, J; Sakonaka, R; Schovanek, P; Seweryn, K; Schultz, C; Shu, S; Stinzing, F; Stodulski, M; Teshima, M; Travniczek, P; Van Eldik, C; Vassiliev, V; Wiśniewski, Ł; Wörnlein, A; Yoshida, T

    2013-01-01

    The Cherenkov Telescope Array (CTA) is a planned observatory for very-high energy gamma-ray astronomy. It will consist of several tens of telescopes of different sizes, with a total mirror area of up to 10,000 square meters. Most mirrors of current installations are either polished glass mirrors or diamond-turned aluminium mirrors, both labour intensive technologies. For CTA, several new technologies for a fast and cost-efficient production of light-weight and reliable mirror substrates have been developed and industrial pre-production has started for most of them. In addition, new or improved aluminium-based and dielectric surface coatings have been developed to increase the reflectance over the lifetime of the mirrors compared to those of current Cherenkov telescope instruments.

  17. Roughness tolerances for Cherenkov telescope mirrors

    Science.gov (United States)

    Tayabaly, K.; Spiga, D.; Canestrari, R.; Bonnoli, G.; Lavagna, M.; Pareschi, G.

    2015-09-01

    The Cherenkov Telescope Array (CTA) is a forthcoming international ground-based observatory for very high-energy gamma rays. Its goal is to reach sensitivity five to ten times better than existing Cherenkov telescopes such as VERITAS, H.E.S.S. or MAGIC and extend the range of observation to energies down to few tens of GeV and beyond 100 TeV. To achieve this goal, an array of about 100 telescopes is required, meaning a total reflective surface of several thousands of square meters. Thence, the optimal technology used for CTA mirrors' manufacture should be both low-cost (~1000 euros/m2) and allow high optical performances over the 300-550 nm wavelength range. More exactly, a reflectivity higher than 85% and a PSF (Point Spread Function) diameter smaller than 1 mrad. Surface roughness can significantly contribute to PSF broadening and limit telescope performances. Fortunately, manufacturing techniques for mirrors are now available to keep the optical scattering well below the geometrically-predictable effect of figure errors. This paper determines first order surface finish tolerances based on a surface microroughness characterization campaign, using Phase Shift Interferometry. That allows us to compute the roughness contribution to Cherenkov telescope PSF. This study is performed for diverse mirror candidates (MAGIC-I and II, ASTRI, MST) varying in manufacture technologies, selected coating materials and taking into account the degradation over time due to environmental hazards.

  18. The ARCADE Raman Lidar System for the Cherenkov Telescope Array

    CERN Document Server

    Valore, Laura; Doro, Michele; Iarlori, Marco; Rizi, Vincenzo; Tonachini, Aurelio Siro; Vallania, Piero

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next generation of ground-based very high energy gamma-ray instruments; the facility will be organized in two arrays, one for each hemisphere. The atmospheric calibration of the CTA telescopes is a critical task. The atmosphere affects the measured Cherenkov yield in several ways: the air-shower development itself, the variation of the Cherenkov angle with altitude, the loss of photons due to scattering and absorption of Cherenkov light out of the camera field-of-view and the scattering of photons into the camera. In this scenario, aerosols are the most variable atmospheric component in time and space and therefore need a continuous monitoring. Lidars are among the most used instruments in atmospheric physics to measure the aerosol attenuation profiles of light. The ARCADE Lidar system is a very compact and portable Raman Lidar system that has been built within the FIRB 2010 grant and is currently taking data in Lamar, Colorado. The ARCADE Lidar is proposed to operat...

  19. Acceleration of atmospheric Cherenkov telescope signal processing to real-time speed with the Auto-Pipe design system

    International Nuclear Information System (INIS)

    The imaging atmospheric Cherenkov technique for high-energy gamma-ray astronomy is emerging as an important new technique for studying the high energy universe. Current experiments have data rates of ∼20TB/year and duty cycles of about 10%. In the future, more sensitive experiments may produce up to 1000 TB/year. The data analysis task for these experiments requires keeping up with this data rate in close to real-time. Such data analysis is a classic example of a streaming application with very high performance requirements. This class of application often benefits greatly from the use of non-traditional approaches for computation including using special purpose hardware (FPGAs and ASICs), or sophisticated parallel processing techniques. However, designing, debugging, and deploying to these architectures is difficult and thus they are not widely used by the astrophysics community. This paper presents the Auto-Pipe design toolset that has been developed to address many of the difficulties in taking advantage of complex streaming computer architectures for such applications. Auto-Pipe incorporates a high-level coordination language, functional and performance simulation tools, and the ability to deploy applications to sophisticated architectures. Using the Auto-Pipe toolset, we have implemented the front-end portion of an imaging Cherenkov data analysis application, suitable for real-time or offline analysis. The application operates on data from the VERITAS experiment, and shows how Auto-Pipe can greatly ease performance optimization and application deployment of a wide variety of platforms. We demonstrate a performance improvement over a traditional software approach of 32x using an FPGA solution and 3.6x using a multiprocessor based solution

  20. Monte Carlo Studies of medium-size telescope designs for the Cherenkov Telescope Array

    CERN Document Server

    Wood, M; Dumm, J; Funk, S

    2015-01-01

    We present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parameters including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters repre...

  1. Normalized and Asynchronous Mirror Alignment for Cherenkov Telescopes

    CERN Document Server

    Ahnen, M L; Balbo, M; Bergmann, M; Biland, A; Blank, M; Bretz, T; Bruegge, K A; Buss, J; Domke, M; Dorner, D; Einecke, S; Hempfling, C; Hildebrand, D; Hughes, G; Lustermann, W; Mannheim, K; Mueller, S A; Neise, D; Neronov, A; Noethe, M; Overkemping, A -K; Paravac, A; Pauss, F; Rhode, W; Shukla, A; Temme, F; Thaele, J; Toscano, S; Vogler, P; Walter, R; Wilbert, A

    2016-01-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) need imaging optics with large apertures and high image intensities to map the faint Cherenkov light emitted from cosmic ray air showers onto their image sensors. Segmented reflectors fulfill these needs, and as they are composed from mass production mirror facets they are inexpensive and lightweight. However, as the overall image is a superposition of the individual facet images, alignment is a challenge. Here we present a computer vision based star tracking alignment method, which also works for limited or changing star light visibility. Our method normalizes the mirror facet reflection intensities to become independent of the reference star's intensity or the cloud coverage. Using two CCD cameras, our method records the mirror facet orientations asynchronously of the telescope drive system, and thus makes the method easy to integrate into existing telescopes. It can be combined with remote facet actuation, but does not require one to work. Furthermore, it ca...

  2. A Monte Carlo template-based analysis for very high definition imaging atmospheric Cherenkov telescopes as applied to the VERITAS telescope array

    CERN Document Server

    ,

    2015-01-01

    We present a sophisticated likelihood reconstruction algorithm for shower-image analysis of imaging Cherenkov telescopes. The reconstruction algorithm is based on the comparison of the camera pixel amplitudes with the predictions from a Monte Carlo based model. Shower parameters are determined by a maximisation of a likelihood function. Maximisation of the likelihood as a function of shower fit parameters is performed using a numerical non-linear optimisation technique. A related reconstruction technique has already been developed by the CAT and the H.E.S.S. experiments, and provides a more precise direction and energy reconstruction of the photon induced shower compared to the second moment of the camera image analysis. Examples are shown of the performance of the analysis on simulated gamma-ray data from the VERITAS array.

  3. On the potential of atmospheric Cherenkov telescope arrays for resolving TeV gamma-ray sources in the Galactic Plane

    CERN Document Server

    Ambrogi, Lucia; Aharonian, Felix

    2016-01-01

    The potential of an array of imaging atmospheric Cherenkov telescopes to detect gamma-ray sources in complex regions has been investigated. The basic characteristics of the gamma-ray instrument have been parametrized using simple analytic representations. In addition to the ideal (Gaussian form) point spread function (PSF), the impact of more realistic non-Gaussian PSFs with tails has been considered. Simulations of isolated point-like and extended sources have been used as a benchmark to test and understand the response of the instrument. The capability of the instrument to resolve multiple sources has been analyzed and the corresponding instrument sensitivities calculated. The results are of particular interest for weak gamma-ray emitters located in crowded regions of the Galactic plane, where the chance of clustering of two or more gamma-ray sources within 1 degree is high.

  4. ctools: Cherenkov Telescope Science Analysis Software

    Science.gov (United States)

    Knödlseder, Jürgen; Mayer, Michael; Deil, Christoph; Buehler, Rolf; Bregeon, Johan; Martin, Pierrick

    2016-01-01

    ctools provides tools for the scientific analysis of Cherenkov Telescope Array (CTA) data. Analysis of data from existing Imaging Air Cherenkov Telescopes (such as H.E.S.S., MAGIC or VERITAS) is also supported, provided that the data and response functions are available in the format defined for CTA. ctools comprises a set of ftools-like binary executables with a command-line interface allowing for interactive step-wise data analysis. A Python module allows control of all executables, and the creation of shell or Python scripts and pipelines is supported. ctools provides cscripts, which are Python scripts complementing the binary executables. Extensions of the ctools package by user defined binary executables or Python scripts is supported. ctools are based on GammaLib (ascl:1110.007).

  5. The cross-talk problem in SiPMs and their use as light sensors for imaging atmospheric Cherenkov telescopes

    International Nuclear Information System (INIS)

    One of the major drawbacks of a SiPM is due to the so-called cross-talk effect. Often, one single photon in a chain reaction can generate more photons and thus can fire more than one micro-cell of a SiPM. This can be considered as a noise in the signal multiplication process and this degrades the signal/noise ratio. In self-trigger schemes this noise can be so high that it can make operating them difficult at low threshold settings. For the past few years, we have dwelt on this effect aiming to suppress it at the design stage. One can use (a) trenches around the micro-cells for suppressing the direct photon 'communication' channel and (b) the so-called double p-n junction for suppressing photon-induced charge 'communication' in neighbor pixels. The low cross-talk is mandatory, for example, for producing SiPM-based light sensor modules for the Imaging Atmospheric Cherenkov Technique projects for ground-based gamma-ray astrophysics. We produced and tested a few modules consisting of 4 SiPMs, each with a size of 5 mmx5 mm of custom production type. We report here on the main parameters of these units.

  6. Novel Photo Multiplier Tubes for the Cherenkov Telescope Array Project

    CERN Document Server

    Toyama, Takeshi; Dickinson, Hugh; Fruck, Christian; Hose, Jürgen; Kellermann, Hanna; Knötig, Max; Lorenz, Eckart; Menzel, Uta; Nakajima, Daisuke; Orito, Reiko; Paneque, David; Schweizer, Thomas; Teshima, Masahiro; Yamamoto, Tokonatsu

    2013-01-01

    Currently the standard light sensors for imaging atmospheric Cherenkov telescopes are the classical photo multiplier tubes that are using bialkali photo cathodes. About eight years ago we initiated an improvement program with the Photo Multiplier Tube (PMT) manufacturers Hamamatsu (Japan), Electron Tubes Enterprises (England) and Photonis (France) for the needs of imaging atmospheric Cherenkov telescopes. As a result, after about 40 years of stagnation of the peak Quantum Efficiency (QE) on the level of 25-27%, new PMTs appeared with a peak QE of 35%. These have got the name super-bialkali. The second significant upgrade has happened very recently, as a result of a dedicated improvement program for the candidate PMT for Cherenkov Telescope Array. The latter is going to be the next generation major instrument in the field of very high energy gamma astrophysics and will consist of over 100 telescopes of three different sizes of 23m, 12m and 4-7m, located both in southern and northern hemispheres. Now PMTs with ...

  7. Photosensor Characterization for the Cherenkov Telescope Array: Silicon Photomultiplier versus Multi-Anode Photomultiplier Tube

    OpenAIRE

    Bouvier, Aurelien; Gebremedhin, Lloyd; Johnson, Caitlin; Kuznetsov, Andrey; Williams, David; Otte, Nepomuk; Strausbaugh, Robert; Hidaka, Naoya; Tajima, Hiroyasu; Hinton, Jim; White, Richard; Errando, Manel; Mukherjee, Reshmi

    2013-01-01

    Photomultiplier tube technology has been the photodetector of choice for the technique of imaging atmospheric Cherenkov telescopes since its birth more than 50 years ago. Recently, new types of photosensors are being contemplated for the next generation Cherenkov Telescope Array. It is envisioned that the array will be partly composed of telescopes using a Schwarzschild-Couder two mirror design never built before which has significantly improved optics. The camera of this novel optical design...

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

    OpenAIRE

    Sadeh, Iftach; Oya, Igor; Schwarz, Joseph; Pietriga, Emmanuel

    2016-01-01

    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-Comput...

  9. Ultra High Energy Cosmic Rays and Atmospheric Monitoring of Air-Fluorescence and Air-Cherenkov Telescopes Via High Spectral Resolution Lidar

    International Nuclear Information System (INIS)

    In this work, we give first a review of Ultra High Energy Cosmic Rays (UHECR), with consideration to their origins, composition, acceleration mechanism and an introduction to present and future experiments for such studies. We describe the role of troposphere as a medium responsible for the production of Extensive Air Showers focusing in the characteristics of 3 components: electromagnetic, hadronic and muonic and we explain the production of air-fluorescence and Cherenkov radiation, as well as corresponding simulation codes. We discuss the origins of the needed correction of the overall UHECR signal recorded by EAS telescopes due to scattering of air-Cherenkov and air-fluorescence radiation by molecular and aerosol particulates of the atmosphere. Therefore we explain the necessity of using advanced and at the same time reasonable cost LIDARS for quantification of aerosol to molecular scattering ratio. On the experimental side, we present a prototype of High Spectral Resolution Lidar (HSRL) in bi static mode with laser emitter at 532 nm and telescope receiver hosting two Fabry-Perot etalons, needed for the molecular and aerosol channels, respectively. We present experimental results on the characterization of each of the two channels and an algorithm for extraction of the aerosol to molecular scattering ratio. Finally, we give some preliminary report on our plans on using, as alternative to Fabry-Perot etalons, Atomic and Molecular Absorption Filters. In this way, the atomic vapor version of the HSRL replaces the temperature and mechanically sensitive Fabryperot with a robust and stable atomic or molecular absorption filter.

  10. Photo multiplier tubes candidates for the Cherenkov telescope array project

    International Nuclear Information System (INIS)

    Photo Multiplier Tubes (PMTs) are the most wide spread detectors for fast low-level light signals. They are commonly used as standard light sensors for camera systems in imaging atmospheric Cherenkov telescopes. Years ago, an improvement program for the PMT candidates for the Cherenkov Telescope Array (CTA) project was initialized with the companies Hamamatsu Photonics K.K. (Japan) and Electron Tubes Enterprises Ltd. (England). CTA is the next generation of imaging atmospheric Cherenkov telescopes for high energy gamma ray astrophysics. Therefore, we need PMTs with outstanding good parameters concerning quantum efficiency, pulse width, after-pulsing and transit time spread. The currently available ''super-bialkali'' PMTs show a peak Quantum Efficiency of 40% and have an enhanced collection efficiency of up to 95-98% for wavelengths≥400 nm. The pulse width averages around 3ns at a gain of 40000. Also, the after-pulsing for a set threshold level of ≥4 photo electrons is reduced down to 0,02%. We report on the measurement results of PMT R-12292-100 from Hamamatsu as the final version and the intermediate version PMT D569/3SA from Electron Tubes Enterprises as candidate PMTs for the CTA project.

  11. Schwarzschild-Couder telescope for the Cherenkov Telescope Array: Development of the Optical System

    CERN Document Server

    Rousselle, Julien; Errando, Manel; Humensky, Brian; Mukherjee, Reshmi; Nieto, Daniel; Okumura, Akira; Vassiliev, Vladimir

    2013-01-01

    The CTA (Cherenkov Telescope Array) is the next generation ground-based experiment for very high-energy (VHE) gamma-ray observations. It will integrate several tens of imaging atmospheric Cherenkov telescopes (IACTs) with different apertures into a single astronomical instrument. The US part of the CTA collaboration has proposed and is developing a novel IACT design with a Schwarzschild-Couder (SC) aplanatic two mirror optical system. In comparison with the traditional single mirror Davies-Cotton IACT the SC telescope, by design, can accommodate a wide field-of-view, with significantly improved imaging resolution. In addition, the reduced plate scale of an SC telescope makes it compatible with highly integrated cameras assembled from silicon photo multipliers. In this submission we report on the status of the development of the SC optical system, which is part of the effort to construct a full-scale prototype telescope of this type at the Fred Lawrence Whipple Observatory in southern Arizona.

  12. A medium sized telescope prototype for the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    The CTA (Cherenkov Telescope Array) is a proposed next generation instrument to observe very high energy (VHE) gamma-rays at ground level. The array will consist of 3 sizes of telescope covering a wide photon energy range: small (4m diameter) telescopes sensitive to the highest energy photons, medium sized telescopes (12 m) operating in the mid energy range, and a small number of large telescopes (24 m) with high sensitivity to low energy photons. Current Cherenkov Telescope experiments consist of up to 5 telescopes; CTA will be made up of an order of magnitude more, which will greatly enhance the number of photons that can be detected as well as increasing the number of views of each cascade, bringing significantly improved angular resolution and background suppression. The observatory is currently in the planning and development phase. A prototype CTA medium sized telescope (MST) is being built in Adlershof (Berlin). This talk focuses on plans for CTA and the design and construction of the MST prototype, as well as its operation, instrumentation and early measurement results.

  13. A Medium Sized Schwarzschild-Couder Cherenkov Telescope Mechanical Design Proposed for the Cherenkov Telescope Array

    CERN Document Server

    Byrum, K; Benbow, W; Cameron, R; Criswell, S; Errando, M; Guarino, V; Kaaret, P; Kieda, D; Mukherjee, R; Naumann, D; Nieto, D; Northrop, R; Okumura, A; Roache, E; Rousselle, J; Schlenstedt, S; Sternberger, R; Vassiliev, V; Wakely, S; Zhao, H

    2015-01-01

    The Cherenkov Telescope Array (CTA) is an international next-generation ground-based gamma-ray observatory. CTA will be implemented as southern and northern hemisphere arrays of tens of small, medium and large-sized imaging Cherenkov telescopes with the goal of improving the sensitivity over the current-generation experiments by an order of magnitude. CTA will provide energy coverage from ~20 GeV to more than 300 TeV. The Schwarzschild-Couder (SC) medium size (9.5m) telescopes will feature a novel aplanatic two-mirror optical design capable of accommodating a wide field-of-view with significantly improved angular resolution as compared to the traditional Davies-Cotton optical design. A full-scale prototype SC medium size telescope structure has been designed and will be constructed at the Fred Lawrence Whipple Observatory in southern Arizona during the fall of 2015. concentrate on the novel features of the design.

  14. The Cherenkov Telescope Array For Very High-Energy Astrophysics

    Science.gov (United States)

    Kaaret, Philip

    2015-08-01

    The field of very high energy (VHE) astrophysics had been revolutionized by the results from ground-based gamma-ray telescopes, including the current imaging atmospheric Cherenkov telescope (IACT) arrays: HESS, MAGIC and VERITAS. A worldwide consortium of scientists from 29 countries has formed to propose the Cherenkov Telescope Array (CTA) that will capitalize on the power of this technique to greatly expand the scientific reach of ground-based gamma-ray telescopes. CTA science will include key topics such as the origin of cosmic rays and cosmic particle acceleration, understanding extreme environments in regions close to neutron stars and black holes, and exploring physics frontiers through, e.g., the search for WIMP dark matter, axion-like particles and Lorentz invariance violation. CTA is envisioned to consist of two large arrays of Cherenkov telescopes, one in the southern hemisphere and one in the north. Each array will contain telescopes of different sizes to provide a balance between cost and array performance over an energy range from below 100 GeV to above 100 TeV. Compared to the existing IACT arrays, CTA will have substantially better angular resolution and energy resolution, will cover a much wider energy range, and will have up to an order of magnitude better sensitivity. CTA will also be operated as an open observatory and high-level CTA data will be placed into the public domain; these aspects will enable broad participation in CTA science from the worldwide scientific community to fully capitalize on CTA's potential. This talk will: 1) review the scientific motivation and capabilities of CTA, 2) provide an overview of the technical design and the status of prototype development, and 3) summarize the current status of the project in terms of its proposed organization and timeline. The plans for access to CTA data and opportunities to propose for CTA observing time will be highlighed.Presented on behalf of the CTA Consortium.

  15. Upgrading and testing the 3D reconstruction of gamma-ray air showers as observed with an array of Imaging Atmospheric Cherenkov telescopes

    CERN Document Server

    Naumann-Godó, M; Degrange, B

    2009-01-01

    Stereoscopic arrays of Imaging Atmospheric Cherenkov Telescopes allow to reconstruct gamma-ray-induced showers in 3 dimensions, which offers several advantages: direct access to the shower parameters in space and straightforward calorimetric measurement of the incident energy. In addition, correlations between the different images of the same shower are taken into account. An analysis method based on a simple 3D-model of electromagnetic showers was recently implemented in the framework of the H.E.S.S. experiment. In the present article, the method is completed by an additional quality criterion, which reduces the background contamination by a factor of about 2 in the case of extended sources, while keeping gamma-ray efficiency at a high level. On the other hand, the dramatic flares of the blazar PKS 2155-304 in July 2006, which provided H.E.S.S. data with an almost pure gamma-ray sample, offered the unique opportunity of a precision test of the 3D-reconstruction method as well as of the H.E.S.S. simulations u...

  16. Development of a mid-sized Schwarzschild-Couder Telescope for the Cherenkov Telescope Array

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, Robert A.

    2012-06-28

    The Cherenkov Telescope Array (CTA) is a ground-based observatory for very high-energy (10 GeV to 100 TeV) gamma rays, planned for operation starting in 2018. It will be an array of dozens of optical telescopes, known as Atmospheric Cherenkov Telescopes (ACTs), of 8 m to 24 m diameter, deployed over an area of more than 1 square km, to detect flashes of Cherenkov light from showers initiated in the Earth's atmosphere by gamma rays. CTA will have improved angular resolution, a wider energy range, larger fields of view and an order of magnitude improvement in sensitivity over current ACT arrays such as H.E.S.S., MAGIC and VERITAS. Several institutions have proposed a research and development program to eventually contribute 36 medium-sized telescopes (9 m to 12 m diameter) to CTA to enhance and optimize its science performance. The program aims to construct a prototype of an innovative, Schwarzschild-Couder telescope (SCT) design that will allow much smaller and less expensive cameras and much larger fields of view than conventional Davies-Cotton designs, and will also include design and testing of camera electronics for the necessary advances in performance, reliability and cost. We report on the progress of the mid-sized SCT development program.

  17. Observer Access to the Cherenkov Telescope Array

    CERN Document Server

    Knödlseder, Jürgen; Boisson, Catherine; Brau-Nogué, Sylvie; Deil, Christoph; Khélifi, Bruno; Mayer, Michael; Walter, Roland

    2015-01-01

    The Cherenkov Telescope Array (CTA), a ground-based facility for very-high-energy (VHE) gamma-ray astronomy, will operate as an open observatory, serving a wide scientific community to explore and to study the non-thermal universe. Open community access is a novelty in this domain, putting a challenge on the implementation of services that make VHE gamma-ray astronomy as accessible as any other waveband. We present here the design of the CTA Observer Access system that comprises support of scientific users, dissemination of data and software, tools for scientific analysis, and the system to submit observing proposals. We outline the scientific user workflows and provide the status of the current developments.

  18. Influence of aerosols from biomass burning on the spectral analysis of Cherenkov telescopes

    CERN Document Server

    Reyes, R de los; Bernloehr, K; Krueger, P; Deil, C; Gast, H; Kosack, K; Marandon, V

    2013-01-01

    During the last decade, imaging atmospheric Cherenkov telescopes (IACTs) have proven themselves as astronomical detectors in the very-high-energy (VHE; E>0.1 TeV) regime. The IACT technique observes the VHE photons indirectly, using the Earth's atmosphere as a calorimeter. Much of the calibration of Cherenkov telescope experiments is done using Monte Carlo simulations of the air shower development, Cherenkov radiation and detector, assuming certain models for the atmospheric conditions. Any deviation of the real conditions during observations from the assumed atmospheric model will result in a wrong reconstruction of the primary gamma-ray energy and the resulting source spectra. During eight years of observations, the High Energy Stereoscopic System (H.E.S.S.) has experienced periodic natural as well as anthropogenic variations of the atmospheric transparency due to aerosols created by biomass burning. In order to identify data that have been taken under such long-term reductions in atmospheric transparency, ...

  19. Sites in Argentina for the Cherenkov Telescope Array Project

    CERN Document Server

    Allekotte, Ingo; Etchegoyen, Alberto; García, Beatriz; Mancilla, Alexis; Maya, Javier; Ravignani, Diego; Rovero, Adrián

    2013-01-01

    The Cherenkov Telescope Array (CTA) Project will consist of two arrays of atmospheric Cherenkov telescopes to study high-energy gamma radiation in the range of a few tens of GeV to beyond 100 TeV. To achieve full-sky coverage, the construction of one array in each terrestrial hemisphere is considered. Suitable candidate sites are being explored and characterized. The candidate sites in the Southern Hemisphere include two locations in Argentina, one in San Antonio de los Cobres (Salta Province, Lat. 24:02:42 S, Long. 66:14:06 W, at 3600 m.a.s.l) and another one in El Leoncito (San Juan Province, Lat. 31:41:49 S, Long. 69:16:21 W, at 2600 m.a.s.l). Here we describe the two sites and the instrumentation that has been deployed to characterize them. We summarize the geographic, atmospheric and climatic data that have been collected for both of them.

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

    CERN Document Server

    Sadeh, Iftach; Schwarz, Joseph; Pietriga, Emmanuel

    2016-01-01

    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. 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. Monte Carlo studies of medium-size telescope designs for the Cherenkov Telescope Array

    Science.gov (United States)

    Wood, M.; Jogler, T.; Dumm, J.; Funk, S.

    2016-01-01

    We present studies for optimizing the next generation of ground-based imaging atmospheric Cherenkov telescopes (IACTs). Results focus on mid-sized telescopes (MSTs) for CTA, detecting very high energy gamma rays in the energy range from a few hundred GeV to a few tens of TeV. We describe a novel, flexible detector Monte Carlo package, FAST (FAst Simulation for imaging air cherenkov Telescopes), that we use to simulate different array and telescope designs. The simulation is somewhat simplified to allow for efficient exploration over a large telescope design parameter space. We investigate a wide range of telescope performance parameters including optical resolution, camera pixel size, and light collection area. In order to ensure a comparison of the arrays at their maximum sensitivity, we analyze the simulations with the most sensitive techniques used in the field, such as maximum likelihood template reconstruction and boosted decision trees for background rejection. Choosing telescope design parameters representative of the proposed Davies-Cotton (DC) and Schwarzchild-Couder (SC) MST designs, we compare the performance of the arrays by examining the gamma-ray angular resolution and differential point-source sensitivity. We further investigate the array performance under a wide range of conditions, determining the impact of the number of telescopes, telescope separation, night sky background, and geomagnetic field. We find a 30-40% improvement in the gamma-ray angular resolution at all energies when comparing arrays with an equal number of SC and DC telescopes, significantly enhancing point-source sensitivity in the MST energy range. We attribute the increase in point-source sensitivity to the improved optical point-spread function and smaller pixel size of the SC telescope design.

  2. NECTAr: New electronics for the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    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 μs readout dead-time. We present preliminary results and extrapolated performances from Monte Carlo simulations.

  3. Open-structure composite mirrors for the Cherenkov Telescope Array

    CERN Document Server

    Dyrda, Michal; Niemiec, Jacek; Stodulski, Marek

    2013-01-01

    The Cherenkov Telescope Array (CTA) Observatory for high-energy gamma-ray astronomy will comprise several tens of imaging atmospheric Cherenkov telescopes (IACTs) of different size with a total reflective area of about 10,000 m$^2$. Here we present a new technology for the production of IACT mirrors that has been developed in the Institute of Nuclear Physics PAS in Krakow, Poland. An open-structure composite mirror consists of a rigid flat sandwich support structure and cast-in-mould spherical epoxy resin layer. To this layer a thin glass sheet complete with optical coating is cold-slumped to provide the spherical reflective layer of the mirror. The main components of the sandwich support structure are two flat float glass panels inter spaced with V-shape aluminum spacers of equal length. The sandwich support structure is open, thus enabling good cooling and ventilation of the mirror. A special arrangement of the aluminum spacers also prohibits water being trapped inside. The open-structure technology thus re...

  4. Construction of a Medium-Sized Schwarzschild-Couder Telescope for the Cherenkov Telescope Array: Implementation of the Cherenkov-Camera Data Acquisition System

    CERN Document Server

    Santander, M; Humensky, B; Mukherjee, R

    2015-01-01

    A medium-sized Schwarzchild-Couder Telescope (SCT) is being developed as a possible extension for the Cherenkov Telescope Array (CTA). The Cherenkov camera of the telescope is designed to have 11328 silicon photomultiplier pixels capable of capturing high-resolution images of air showers in the atmosphere. The combination of the large number of pixels and the high trigger rate (> 5 kHz) expected for this telescope results in a multi-Gbps data throughput. This sets challenging requirements on the design and performance of a data acquisition system for processing and storing this data. A prototype SCT (pSCT) with a partial camera containing 1600 pixels, covering a field of view of 2.5 x 2.5 square degrees, is being assembled at the F.L. Whipple Observatory. We present the design and current status of the SCT data acquisition system.

  5. An outdoor test facility for the Cherenkov Telescope Array mirrors

    CERN Document Server

    Medina, M C; Maya, J; Mancilla, A; Larrarte, J J; Rasztocky, E; Benitez, M; Dipold, J; Platino, M

    2013-01-01

    The Cherenkov Telescopes Array (CTA) is planned to be an Observatory for very high energy gamma ray astronomy and will consist of several tens of telescopes which account for a reflective surface of more than 10000 m$^2$. The mirrors of these telescopes will be formed by a set of facets. Different technological solutions, for a fast and cost efficient production of light-weight mirror facets are under test inside the CTA Consortium. Most of them involve composite structures whose behavior under real observing conditions is not yet fully tested. An outdoor test facility has been built in one of the candidate sites for CTA, in Argentina (San Antonio de los Cobres [SAC], 3600m a.s.l) in order to monitor the optical and mechanical properties of these facets exposed to the local atmospheric conditions for a given period of time. In this work we present the preliminary results of the first Middle Size Telescope (MST) mirror-monitoring campaign, started in 2013.

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

    CERN Document Server

    Seweryn, K; Błocki, J.; Bogacz, L.; Bulik, T.; Cadoux, F.; Christov, A.; Chruślińska, M.; 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.; Ostrowski, M.; Paśko, P.; Pech, M.; Porcelli, A.; Prandini, E.; Pueschel, E.; Rajda, P.; Rameez, M.; Rozwadowski, P.; Schioppa, E. jr; Schovanek, P.; Skowron, K.; Sliusar, V.; Sowiński, M.; Stawarz, Ł.; Stodulska, M.; Stodulski, M.; Toscano, S.; Pujadas, I. Troyano; 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.

    2015-01-01

    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.

  7. The GCT camera for the Cherenkov Telescope Array

    CERN Document Server

    Brown, Anthony M; Allan, D; Amans, J P; Armstrong, T P; Balzer, A; Berge, D; Boisson, C; Bousquet, J -J; Bryan, M; Buchholtz, G; Chadwick, P M; Costantini, H; Cotter, G; Daniel, M K; De Franco, A; De Frondat, F; Dournaux, J -L; Dumas, D; Fasola, G; Funk, S; Gironnet, J; Graham, J A; Greenshaw, T; Hervet, O; Hidaka, N; Hinton, J A; Huet, J -M; Jegouzo, I; Jogler, T; Kraus, M; Lapington, J S; Laporte, P; Lefaucheur, J; Markoff, S; Melse, T; Mohrmann, L; Molyneux, P; Nolan, S J; Okumura, A; Osborne, J P; Parsons, R D; Rosen, S; Ross, D; Rowell, G; Sato, Y; Sayede, F; Schmoll, J; Schoorlemmer, H; Servillat, M; Sol, H; Stamatescu, V; Stephan, M; Stuik, R; Sykes, J; Tajima, H; Thornhill, J; Tibaldo, L; Trichard, C; Vink, J; Watson, J J; White, R; Yamane, N; Zech, A; Zink, A; Zorn, J

    2016-01-01

    The Gamma-ray Cherenkov Telescope (GCT) is proposed for the Small-Sized Telescope component of the Cherenkov Telescope Array (CTA). GCT's dual-mirror Schwarzschild-Couder (SC) optical system allows the use of a compact camera with small form-factor photosensors. The GCT camera is ~0.4 m in diameter and has 2048 pixels; each pixel has a ~0.2 degree angular size, resulting in a wide field-of-view. The design of the GCT camera is high performance at low cost, with the camera housing 32 front-end electronics modules providing full waveform information for all of the camera's 2048 pixels. The first GCT camera prototype, CHEC-M, was commissioned during 2015, culminating in the first Cherenkov images recorded by a SC telescope and the first light of a CTA prototype. In this contribution we give a detailed description of the GCT camera and present preliminary results from CHEC-M's commissioning.

  8. The first GCT camera for the Cherenkov Telescope Array

    CERN Document Server

    De Franco, A.; Allan, D.; Armstrong, T.; Ashton, T.; Balzer, A.; Berge, D.; Bose, R.; Brown, A.M.; Buckley, J.; Chadwick, P.M.; Cooke, P.; Cotter, G.; Daniel, M.K.; Funk, S.; Greenshaw, T.; Hinton, J.; Kraus, M.; Lapington, J.; Molyneux, P.; Moore, P.; Nolan, S.; Okumura, A.; Ross, D.; Rulten, C.; Schmoll, J.; Schoorlemmer, H.; Stephan, M.; Sutcliffe, P.; Tajima, H.; Thornhill, J.; Tibaldo, L.; Varner, G.; Watson, J.; Zink, A.

    2015-01-01

    The Gamma Cherenkov Telescope (GCT) is proposed to be part of the Small Size Telescope (SST) array of the Cherenkov Telescope Array (CTA). The GCT dual-mirror optical design allows the use of a compact camera of diameter roughly 0.4 m. The curved focal plane is equipped with 2048 pixels of ~0.2{\\deg} angular size, resulting in a field of view of ~9{\\deg}. The GCT camera is designed to record the flashes of Cherenkov light from electromagnetic cascades, which last only a few tens of nanoseconds. Modules based on custom ASICs provide the required fast electronics, facilitating sampling and digitisation as well as first level of triggering. The first GCT camera prototype is currently being commissioned in the UK. On-telescope tests are planned later this year. Here we give a detailed description of the camera prototype and present recent progress with testing and commissioning.

  9. Status of the Cherenkov Telescope Array's Large Size Telescopes

    CERN Document Server

    Cortina, J

    2015-01-01

    The Cherenkov Telescope Array (CTA) observatory, will be deployed over two sites in the two hemispheres. Both sites will be equipped with four Large Size Telescopes (LSTs), which are crucial to achieve the science goals of CTA in the 20-200 GeV energy range. Each LST is equipped with a primary tessellated mirror dish of 23 m diameter, supported by a structure made mainly of carbon fibre reinforced plastic tubes and aluminum joints. This solution guarantees light weight (around 100 tons), essential for fast repositioning to any position in the sky in <20 seconds. The camera is composed of 1855 PMTs and embeds the control, readout and trigger electronics. The detailed design is now complete and production of the first LST, which will serve as a prototype for the remaining seven, is well underway. In 2016 the first LST will be installed at the Roque de los Muchachos Observatory on the Canary island of La Palma (Spain). In this talk we will outline the technical solutions adopted to fulfill the design requirem...

  10. Status of the technologies for the production of the Cherenkov Telescope Array (CTA) mirrors

    CERN Document Server

    Pareschi, G; Baba, H; Bähr, J; Bonardi, A; Bonnoli, G; Brun, P; Canestrari, R; Chadwick, P; Chikawa, M; Carton, P -H; de Souza, V; Dipold, J; Doro, M; Durand, D; Dyrda, M; Förster, A; Garczarczyk, M; Giro, E; Glicenstein, J -F; Hanabata, Y; Hayashida, M; Hrabovski, M; Jeanney, C; Kagaya, M; Katagiri, H; Lessio, L; Mandat, D; Mariotti, M; Medina, C; Michałowski, J; Micolon, P; Nakajima, D; Niemiec, J; Nozato, A; Palatka, M; Pech, M; Peyaud, B; Pühlhofer, G; Rataj, M; Rodeghiero, G; Rojas, G; Rousselle, J; Sakonaka, R; Schovanek, P; Seweryn, K; Schultz, C; Shu, S; Stinzing, F; Stodulski, M; Teshima, M; Travniczek, P; van Eldik, C; Vassiliev, V; Wiśniewski, Ł; Wörnlein, A; Yoshida, T

    2013-01-01

    The Cherenkov Telescope Array (CTA) is the next generation very high-energy gamma-ray observatory, with at least 10 times higher sensitivity than current instruments. CTA will comprise several tens of Imaging Atmospheric Cherenkov Telescopes (IACTs) operated in array-mode and divided into three size classes: large, medium and small telescopes. The total reflective surface could be up to 10,000 m2 requiring unprecedented technological efforts. The properties of the reflector directly influence the telescope performance and thus constitute a fundamental ingredient to improve and maintain the sensitivity. The R&D status of lightweight, reliable and cost-effective mirror facets for the CTA telescope reflectors for the different classes of telescopes is reviewed in this paper.

  11. A facility to evaluate the focusing performance of mirrors for Cherenkov Telescopes

    CERN Document Server

    Canestrari, Rodolfo; Bonnoli, Giacomo; Farisato, Giancarlo; Lessio, Luigi; Rodeghiero, Gabriele; Spiga, Rossella; Toso, Giorgio; Pareschi, Giovanni

    2015-01-01

    With the advent of the imaging atmospheric Cherenkov technique in late 1980's, ground-based observations of Very High-Energy gamma rays came into reality. Since the first source detected at TeV energies in 1989 by Whipple, the number of high energy gamma-ray sources has rapidly grown up to more than 150 thanks to the second generation experiments like MAGIC, H.E.S.S. and VERITAS. The Cherenkov Telescope Array observatory is the next generation of Imaging Atmospheric Cherenkov Telescopes, with at least 10 times higher sensitivity than current instruments. Cherenkov Telescopes have to be equipped with optical dishes of large diameter -- in general based on segmented mirrors -- with typical angular resolution of a few arc-minutes. To evaluate the mirror's quality specific metrological systems are required that possibly take into account the environmental conditions in which typically Cherenkov telescopes operate (in open air without dome protection). For this purpose a new facility for the characterization of mi...

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

    CERN Document Server

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

    2015-01-01

    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 wi...

  13. Test bench for front end electronic of the GCT camera for the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    The Gamma Cherenkov Telescope (GCT) is a design proposed to be part of the Small Sized Telescope (SST) array of the Cherenkov Telescope Array (CTA). The GCT camera is designed to record the flashes of atmospheric Cherenkov light from gamma and cosmic ray initiated cascades, which last only a few tens of nanoseconds. The camera thus needs very fast and compact electronics, addressed by the TARGET modules, based on homonymous ASICs which provide digitation at 1 GSample/s and the first level of trigger on the analog output of the photosensors. In this paper we describe a test bench lab set up to evaluate the performance and functionality of the camera' s front end electronics with an added educational value

  14. Stellar intensity interferometry: Optimizing air Cherenkov telescope array layouts

    CERN Document Server

    Jensen, Hannes; LeBohec, Stephan; Nuñez, Paul D; 10.1117/12.856412

    2010-01-01

    Kilometric-scale optical imagers seem feasible to realize by intensity interferometry, using telescopes primarily erected for measuring Cherenkov light induced by gamma rays. Planned arrays envision 50--100 telescopes, distributed over some 1--4 km$^2$. Although array layouts and telescope sizes will primarily be chosen for gamma-ray observations, also their interferometric performance may be optimized. Observations of stellar objects were numerically simulated for different array geometries, yielding signal-to-noise ratios for different Fourier components of the source images in the interferometric $(u,v)$-plane. Simulations were made for layouts actually proposed for future Cherenkov telescope arrays, and for subsets with only a fraction of the telescopes. All large arrays provide dense sampling of the $(u,v)$-plane due to the sheer number of telescopes, irrespective of their geographic orientation or stellar coordinates. However, for improved coverage of the $(u,v)$-plane and a wider variety of baselines (...

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

    Science.gov (United States)

    Dipold, J.; Medina, M. C.; García, B.; Rasztocky, E.; Mancilla, A.; Maya, J.; Larrarte, J. J.; de Souza, V.

    2016-09-01

    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 m2 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.

  16. GAW (Gamma Air Watch): a novel imaging Cherenkov telescope

    OpenAIRE

    Cusumano, G.; Agnetta, G.; B. Biondo; Catalano, O.; Giarrusso, S.; Gugliotta, G.; La Fata, L.; Maccarone, M. C.; Mangano, A.; Mineo, T.; Russo, F; Sacco, B.

    2001-01-01

    GAW (Gamma Air Watch) is a new imaging Cherenkov telescope designed for observation of very high-energy gamma-ray sources. GAW will be equipped with a 3 meter diameter Fresnel lens as light collector and with an array of 300 multi-anode photomultipliers at the focal plane. The pixel size will be 4 arcmin wide for a total field of view of 10.5 degrees. Whith respect to the planned imaging Cherenkov telescopes (CANGAROO III, HESS, MAGIC, VERITAS) GAW follows a different approach for what concer...

  17. SST-GATE: A dual mirror telescope for the Cherenkov Telescope Array

    CERN Document Server

    Zech, A; Blake, S; Boisson, C; Costille, C; De-Frondat, F; Dournaux, J -L; Dumas, D; Fasola, G; Greenshaw, T; Hervet, O; Huet, J -M; Laporte, P; Rulten, C; Savoie, D; Sayede, F; Schmoll, J

    2013-01-01

    The Cherenkov Telescope Array (CTA) will be the world's first open observatory for very high energy gamma-rays. Around a hundred telescopes of different sizes will be used to detect the Cherenkov light that results from gamma-ray induced air showers in the atmosphere. Amongst them, a large number of Small Size Telescopes (SST), with a diameter of about 4 m, will assure an unprecedented coverage of the high energy end of the electromagnetic spectrum (above ~1TeV to beyond 100 TeV) and will open up a new window on the non-thermal sky. Several concepts for the SST design are currently being investigated with the aim of combining a large field of view (~9 degrees) with a good resolution of the shower images, as well as minimizing costs. These include a Davies-Cotton configuration with a Geiger-mode avalanche photodiode (GAPD) based camera, as pioneered by FACT, and a novel and as yet untested design based on the Schwarzschild-Couder configuration, which uses a secondary mirror to reduce the plate-scale and to all...

  18. Silicon Photomultiplier Research and Development Studies for the Large Size Telescope of the Cherenkov Telescope Array

    CERN Document Server

    Rando, Riccardo; Dazzi, Francesco; De Angelis, Alessandro; Dettlaff, Antonios; Dorner, Daniela; Fink, David; Fouque, Nadia; Grundner, Felix; Haberer, Werner; Hahn, Alexander; Hermel, Richard; Korpar, Samo; Mezek, Gašper Kukec; Maier, Ronald; Manea, Christian; Mariotti, Mosè; Mazin, Daniel; Mehrez, Fatima; Mirzoyan, Razmik; Podkladkin, Sergey; Reichardt, Ignasi; Rhode, Wolfgang; Rosier, Sylvie; Schultz, Cornelia; Stella, Carlo; Teshima, Masahiro; Wetteskind, Holger; Zavrtanik, Marko

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the the next generation facility of imaging atmospheric Cherenkov telescopes; two sites will cover both hemispheres. CTA will reach unprecedented sensitivity, energy and angular resolution in very-high-energy gamma-ray astronomy. Each CTA array will include four Large Size Telescopes (LSTs), designed to cover the low-energy range of the CTA sensitivity ($\\sim$20 GeV to 200 GeV). In the baseline LST design, the focal-plane camera will be instrumented with 265 photodetector clusters; each will include seven photomultiplier tubes (PMTs), with an entrance window of 1.5 inches in diameter. The PMT design is based on mature and reliable technology. Recently, silicon photomultipliers (SiPMs) are emerging as a competitor. Currently, SiPMs have advantages (e.g. lower operating voltage and tolerance to high illumination levels) and disadvantages (e.g. higher capacitance and cross talk rates), but this technology is still young and rapidly evolving. SiPM technology has a strong pot...

  19. GAW (Gamma Air Watch) a novel imaging Cherenkov telescope

    CERN Document Server

    Cusumano, G; Biondo, B; Catalano, O; Giarrusso, S; Gugliotta, G; La Fata, L; Maccarone, M C; Mangano, A; Mineo, T; Russo, F; Sacco, B

    2001-01-01

    GAW (Gamma Air Watch) is a new imaging Cherenkov telescope designed for observation of very high-energy gamma-ray sources. GAW will be equipped with a 3 meter diameter Fresnel lens as light collector and with an array of 300 multi-anode photomultipliers at the focal plane. The pixel size will be 4 arcmin wide for a total field of view of 10.5 degrees. Whith respect to the planned imaging Cherenkov telescopes (CANGAROO III, HESS, MAGIC, VERITAS) GAW follows a different approach for what concerns both the optical system and the detection working mode: the Cherenkov light collector is a single acrylic flat Fresnel lens (instead of mirrors) that allows to achieve wide field of view; the photomultipliers operate in single photoelectron counting mode (instead of charge integration). The single photoelectron counting mode allows to reach a low energy threshold of ~200 GeV, in spite of the relatively small dimension of the GAW optic system.

  20. Design and Operation of FACT -- The First G-APD Cherenkov Telescope

    CERN Document Server

    Anderhub, H; 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; K"ohne, J H; Kr"ahenb"uhl, 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; R"oser, U; Stucki, J -P; Schneider, J; Steinbring, T; Temme, F; Thaele, J; Tobler, S; Viertel, G; Vogler, P; Walter, R; Warda, K; Weitzel, Q; Z"anglein, M

    2013-01-01

    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.

  1. Photosensor Characterization for the Cherenkov Telescope Array: Silicon Photomultiplier versus Multi-Anode Photomultiplier Tube

    CERN Document Server

    Bouvier, Aurelien; Johnson, Caitlin; Kuznetsov, Andrey; Williams, David; Otte, Nepomuk; Strausbaugh, Robert; Hidaka, Naoya; Tajima, Hiroyasu; Hinton, Jim; White, Richard; Errando, Manel; Mukherjee, Reshmi

    2013-01-01

    Photomultiplier tube technology has been the photodetector of choice for the technique of imaging atmospheric Cherenkov telescopes since its birth more than 50 years ago. Recently, new types of photosensors are being contemplated for the next generation Cherenkov Telescope Array. It is envisioned that the array will be partly composed of telescopes using a Schwarzschild-Couder two mirror design never built before which has significantly improved optics. The camera of this novel optical design has a small plate scale which enables the use of compact photosensors. We present an extensive and detailed study of the two most promising devices being considered for this telescope design: the silicon photomultiplier and the multi-anode photomultiplier tube. We evaluated their most critical performance characteristics for imaging gamma-ray showers, and we present our results in a cohesive manner to clearly evaluate the advantages and disadvantages that both types of device have to offer in the context of GeV-TeV gamma...

  2. On the Use of Cherenkov Telescopes for Outer Solar System Body Occultations

    CERN Document Server

    Lacki, Brian C

    2014-01-01

    Imaging Atmosphere Cherenkov Telescopes (IACT) are arrays of very large optical telescopes that are well-suited for rapid photometry of bright sources. I investigate their potential in observing stellar occultations by small objects in the outer Solar System, Transjovian Objects (TJOs). These occultations cast diffraction patterns on the Earth. Current IACT arrays are capable of detecting objects smaller than 100 meters in radius in the Kuiper Belt and 1 km radius out to 5000 AU. The future Cherenkov Telescope Array (CTA) will have even greater capabilities. Because the arrays include several telescopes, they can potentially measure the speeds of TJOs without degeneracies, and the sizes of the TJOs and background stars. I estimate the achievable precision using a Fisher matrix analysis. With CTA, the precisions of these parameter estimations will be as good as a few percent. I consider how often IACTs can observe occultations by members of different TJO populations, including Centaurs, Kuiper Belt Objects (KB...

  3. Monte Carlo studies of the VERITAS array of Cherenkov telescopes

    CERN Document Server

    Maier, G

    2007-01-01

    VERITAS is a system of four imaging Cherenkov telescopes located at the Fred Lawrence Whipple Observatory in southern Arizona. We present here results of detailed Monte Carlo simulations of the array response to extensive air showers. Cherenkov image and shower parameter distributions are calculated and show good agreement with distributions obtained from observations of background cosmic rays and high-energy gamma-rays. Cosmic-ray and gamma-ray rates are accurately predicted by the simulations. The energy threshold of the 3-telescope system is about 150 GeV after gamma-hadron separation cuts; the detection rate after gamma-selection cuts for the Crab Nebula is 7.5 gamma's/min. The three-telescope system is able to detect a source with a flux equivalent to 10% of the Crab Nebula flux in 1.2 h of observations (5 sigma detection).

  4. Status of the First G-APD Cherenkov Telescope (FACT)

    International Nuclear Information System (INIS)

    Full text: In the past years, the second generation of imaging air-Cherenkov telescopes has proven its power detecting weak sources with high sensitivity and low energy threshold. The goal to further improve the sensitivity and lower the energy threshold requires a robust and highly efficient sensor technology. A promising detector technology are silicon based photon detectors, namely Geiger-mode avalanche photo-diodes (G-APDs). They promise robustness and easy manageability compared photo-multiplier tubes so far in use. To prove the applicability of this technology for Cherenkov telescopes, one of the former HEGRA telescopes was revived and will be equipped with a camera using G-APDs as photo sensors. Since G-APDs are comparably small, solid light guides are used to significantly increase the light collection area of each sensor. With this technologies, the First G-APD Cherenkov Telescopes (FACT) promises an increase in sensitivity and decrease in energy threshold, compared with a classical photo-multiplier based camera. As of today (March 2011), the components of the camera are produced or in production and the camera assembly has been started. Once extensive tests will have been conducted, the camera will be installed at the telescope site. The current status and measurement of the commissioning are presented. (author)

  5. Prospects for Measuring the Positron Excess with the Cherenkov Telescope Array

    CERN Document Server

    Vandenbroucke, Justin; Wood, Matthew; Colin, Pierre

    2015-01-01

    The excess of positrons in cosmic rays above $\\sim$10 GeV has been a puzzle since it was discovered. Possible interpretations of the excess have been suggested, including acceleration in a local supernova remnant or annihilation of dark matter particles. To discriminate between these scenarios, the positron fraction must be measured at higher energies. One technique to perform this measurement is using the Earth-Moon spectrometer: observing the deflection of positron and electron moon shadows by the Earth's magnetic field. The measurement has been attempted by previous imaging atmospheric Cherenkov telescopes without success. The Cherenkov Telescope Array (CTA) will have unprecedented sensitivity and background rejection that could make this measurement successful for the first time. In addition, the possibility of using silicon photomultipliers in some of the CTA telescopes could greatly increase the feasibility of making observations near the moon. Estimates of the capabilities of CTA to measure the positro...

  6. Design of light concentrators for Cherenkov telescope observatories

    CERN Document Server

    Hénault, F; jocou, L; Khélifi, B; Manigot, P; Hormigos, S; Knodlseder, J; Olive, J F; Jean, P; Punch, M

    2013-01-01

    The Cherenkov Telescope Array (CTA) will be the largest cosmic gamma ray detector ever built in the world. It will be installed at two different sites in the North and South hemispheres and should be operational for about 30 years. In order to cover the desired energy range, the CTA is composed of typically 50-100 collecting telescopes of various sizes (from 6 to 24-m diameters). Most of them are equipped with a focal plane camera consisting of 1500 to 2000 Photomultipliers (PM) equipped with light concentrating optics, whose double function is to maximize the amount of Cherenkov light detected by the photo-sensors, and to block any stray light originating from the terrestrial environment. Two different optical solutions have been designed, respectively based on a Compound Parabolic Concentrator (CPC), and on a purely dioptric concentrating lens. In this communication are described the technical specifications, optical designs and performance of the different solutions envisioned for all these light concentra...

  7. The next generation Cherenkov Telescope Array observatory: CTA

    CERN Document Server

    Vercellone, Stefano

    2014-01-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to the VHE 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 23m diameter Large Size Telescopes (LSTs) will be deployed close to the centre of the array with telescopes separated by about 100m. A larger number (about 25 units) of 12m Medium Size Telescopes (MSTs, separated by about 150m), 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 9.5m. 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 a...

  8. An Innovative Workspace for The Cherenkov Telescope Array

    OpenAIRE

    Costa, Alessandro; Sciacca, Eva; Becciani, Ugo; Massimino, Piero; Riggi, Simone; Sanchez, David; Vitello, Fabio

    2016-01-01

    The Cherenkov Telescope Array (CTA) is an initiative to build the next generation, ground-based gamma-ray observatories. We present a prototype workspace developed at INAF that aims at providing innovative solutions for the CTA community. The workspace leverages open source technologies providing web access to a set of tools widely used by the CTA community. Two different user interaction models, connected to an authentication and authorization infrastructure, have been implemented in this wo...

  9. 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 ...

  10. Simultaneous operation and control of about 100 telescopes for the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    The Cherenkov Telescope Array (CTA) project is an initiative to build the next generation ground-based very high energy (VHE) gamma-ray instrument. Compared to current imaging atmospheric Cherenkov telescope experiments CTA will extend the energy range and improve the angular resolution while increasing the sensitivity up to a factor of 10. With about 100 separate telescopes it will be operated as an observatory open to a wide astrophysics and particle physics community, providing a deep insight into the non-thermal high-energy universe. The CTA Array Control system (ACTL) is responsible for several essential control tasks supporting the evaluation and selection of proposals, as well as the preparation, scheduling, and finally the execution of observations with the array. A possible basic distributed software framework for ACTL being considered is the ALMA Common Software (ACS). The ACS framework follows a container component model and contains a high level abstraction layer to integrate different types of device. To achieve a low-level consolidation of connecting control hardware, OPC UA (OPen Connectivity-Unified Architecture) client functionality is integrated directly into ACS, thus allowing interaction with other OPC UA capable hardware. The CTA Data Acquisition System comprises the data readout of all cameras and the transfer of the data to a camera server farm, thereby using standard hardware and software technologies. CTA array control is also covering conceptions for a possible array trigger system and the corresponding clock distribution. The design of the CTA observations scheduler is introducing new algorithmic technologies to achieve the required flexibility.

  11. Expected performance of the ASTRI mini-array in the framework of the Cherenkov Telescope Array

    Science.gov (United States)

    Di Pierro, F.; Bigongiari, C.; Stamerra, A.; Vallania, P.; ASTRI Collaboration; CTA Consortium, the

    2016-05-01

    The Cherenkov Telescope Array (CTA) Observatory is a world-wide project for the ground-based study of the sources of the highest energy photons. By adopting telescopes of three different size categories it will cover the wide energy range from tens of GeV up to hundreds of TeV, limited only by the source physical properties and the gamma absorption by the extragalactic background light. The full sky coverage will be assured by two arrays, one in each hemisphere. An array of small size telescopes (SSTs), covering the highest energy region (3-100 TeV), the region most flux limited for current imaging atmospheric Cherenkov telescopes, is planned to be deployed at the southern CTA site in the first phase of the CTA project. The ASTRI collaboration has developed a prototype of a dual mirror SST equipped with a SiPM-based focal plane (ASTRI SST-2M) and has proposed to install a mini-array of nine of such telescopes at the CTA southern site (the ASTRI mini-array). In order to study the expected performance and the scientific capabilities of different telescope configurations, full Monte Carlo (MC) simulations of the shower development in the atmosphere for both gammas and hadronic background have been performed, followed by detailed simulations of the telescopes. In this work the expected performance of the ASTRI mini-array in terms of sensitivity, angular and energy resolution are presented and discussed.

  12. The Photodetector Plane of the 4m Davies Cotton Small Size Telescope for the Cherenkov Telescope Array

    CERN Document Server

    Boccone, V; Basili, A; Christov, A; della Volpe, M; Montaruli, T

    2013-01-01

    Photomultipliers (PMTs) are currently adopted for the photodetector plane of Imaging Atmospheric Cherenkov Telescopes (IACTs). Even though PMT quantum efficiency has improved impressively in the recent years, one of the main limitation for their application in the gamma-astronomy field - the impossibility to operate with moon light - still remains. As a matter of fact, the light excess would lead to significant and faster camera ageing. Solid state detectors, in particular Geiger-mode avalanche photo-diodes (G-APDs) represent a valuable alternative solution to overcome this limitation as demonstrated in the field by the FACT experiment (The First G- APD Cherenkov Telescope). They can be regarded as a more promising long term approach, which can be easily adopted for the new generation of cameras and for the Cherenkov Telescope Array (CTA). We describe here the Photo-Detector Plane (PDP) of the camera for the 4 m Davies Cotton CTA Small Size Telescopes, for which large area G-APD coupled to non-imaging light c...

  13. Large Size Telescope camera support structures for the Cherenkov Telescope Array

    OpenAIRE

    Deleglise, G.; Geffroy, N.; Lamanna, G.; Consortium, for The Cherenkov Telescope Array

    2013-01-01

    The design of the camera support structures for the Cherenkov Telescope Array (CTA) Large Size Telescopes (LSTs) is based on an elliptical arch geometry reinforced along its orthogonal projection by two symmetric sets of stabilizing ropes. The main requirements in terms of minimal camera displacement, minimal weight, minimal shadowing on the telescope mirror, maximal strength of the structures and fast dynamical stabilization have led to the application of Carbon Fibre Plastic Reinforced (CFP...

  14. Status of the Cherenkov Telescope Array Project

    CERN Document Server

    de Almeida, Ulisses Barres

    2016-01-01

    Gamma-ray astronomy holds a great potential for Astrophysics, Particle Physics and Cosmology. The CTA is an inter- national initiative to build the next generation of ground-based gamma-ray observatories, which will represent a factor of 5-10 times improvement in the sensitivity of observations in the range 100 GeV - 10 TeV, as well as an extension of the observational capabilities down to energies below 100 GeV and beyond 100 TeV. The array will consist of two telescope networks (one in the Northern Hemisphere and another in the South) so to achieve a full-sky coverage, and will be com- posed by a hybrid system of 4 different telescope types. It will operate as an observatory, granting open access to the community through calls for submission of proposals competing for observation time. The CTA will give us access to the non-thermal and high-energy universe at an unprecedented level, and will be one of the main instruments for high-energy astrophysics and astroparticle physics of the next 30 years. CTA has n...

  15. Detection of tau neutrinos by Imaging Air Cherenkov Telescopes

    CERN Document Server

    Gora, Dariusz

    2016-01-01

    This paper investigates the potential to detect tau neutrinos in the energy range of 1-1000 PeV searching for very inclined showers with imaging Cherenkov telescopes. A neutrino induced tau lepton escaping from the Earth may decay and initiate an air shower which can be detected by a fluorescence or Cherenkov telescope. We present here a study of the detection potential of Earth-skimming neutrinos taking into account neutrino interactions in the Earth crust, local matter distributions at various detector sites, the development of tau-induced showers in air and the detection of Cherenkov photons with IACTs. We analyzed simulated shower images on the camera focal plane and implemented generic reconstruction chains based on Hillas parameters. We find that present IACTs can distinguish air showers induced by tau neutrinos from the background of hadronic showers in the PeV-EeV energy range. We present the neutrino trigger efficiency obtained for a few configurations being considered for the next-generation Cherenk...

  16. Detection of tau neutrinos by Imaging Air Cherenkov Telescopes

    CERN Document Server

    Gora, Dariusz

    2015-01-01

    This paper investigates the potential to detect tau neutrinos in the energy range of 1-1000 PeV searching for very inclined showers with imaging Cherenkov telescopes. A neutrino induced tau lepton escaping from the Earth may decay and initiate an air shower which can be detected by a fluorescence or Cherenkov telescope. We present here a study of the detection potential of Earth-skimming neutrinos taking into account neutrino interactions in the Earth crust, local matter distributions at various detector sites, the development of tau-induced showers in air and the detection of Cherenkov photons with IACTs. We analysed simulated shower images on the camera focal plane and implemented generic reconstruction chains based on Hillas parameters. We find that present IACTs can distinguish air showers induced by tau neutrinos from the background of hadronic showers in the PeV-EeV energy range. We present the neutrino trigger efficiency obtained for a few configurations being considered for the next-generation Cherenk...

  17. Simulation of the ASTRI two-mirrors small-size telescope prototype for the Cherenkov Telescope Array

    Science.gov (United States)

    Bigongiari, C.; Cusumano, G.; Di Pierro, F.; La Parola, V.; Stamerra, A.; Vallania, P.; ASTRI Collaboration; CTA Consortium, the

    2016-05-01

    The Cherenkov Telescope Array (CTA) is a world-wide project to build a new generation ground-based gamma-ray instrument operating in the energy range from some tens of GeV to above 100 TeV. To ensure full sky coverage CTA will consist of two arrays of Imaging Atmospheric Cherenkov Telescopes (IACTs), one in the southern hemisphere and another one in the northern hemisphere. CTA has just completed the design phase and it is entering in the pre-production one that includes the development of telescope precursor mini-arrays. ASTRI is an ongoing project, to develop and install at the southern CTA site one of such mini-arrays composed by nine dual-mirror small size telescopes equipped with an innovative camera based on silicon photomultiplier sensors. The end-to-end telescope prototype, named ASTRI SST-2M, has been recently inaugurated at the Serra La Nave observing station, on Mount Etna, Italy. ASTRI SST-2M expected performance has been carefully studied using a full Monte Carlo simulation of the shower development in the atmosphere and detector response. Simulated data have been analyzed using the traditional Hillas moment analysis to obtain the expected angular and energy resolution. Simulation results, together with the comparison with the available experimental measurements, are shown.

  18. Monte Carlo Performance Studies of Candidate Sites for the Cherenkov Telescope Array

    CERN Document Server

    Maier, G; Bernlöhr, K; Bregeon, J; Di Pierro, F; Hassan, T; Jogler, T; Hinton, J; Moralejo, A; Wood, M

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next-generation gamma-ray observatory with sensitivity in the energy range from 20 GeV to beyond 300 TeV. CTA is proposed to consist of two arrays of 40-100 imaging atmospheric Cherenkov telescopes, with one site located in each of the Northern and Southern Hemispheres. The evaluation process for the candidate sites for CTA is supported by detailed Monte Carlo simulations, which take different attributes like site altitude and geomagnetic field configuration into account. In this contribution we present the comparison of the sensitivity and performance of the different CTA site candidates for the measurement of very-high energy gamma rays.

  19. Sensitivity of the space-based CHerenkov from Astrophysical Neutrinos Telescope (CHANT)

    CERN Document Server

    Neronov, A; Anchordoqui, L A; Adams, J; Olinto, A V

    2016-01-01

    Neutrinos with energies in the PeV to EeV range produce upgoing extensive air showers when they interact underground close enough to the surface of the Earth. We study the possibility for detection of such showers with a system of very wide field-of-view imaging atmospheric Cherenkov telescopes, named CHANT for CHerenkov from Astrophysical Neutrinos Telescope, pointing down to a strip below the Earth's horizon from space. We find that CHANT provides sufficient sensitivity for the study of the astrophysical neutrino flux in a wide energy range, from 10~PeV to 10~EeV. A space-based CHANT system can discover and study in detail the cosmogenic neutrino flux originating from interactions of ultra-high-energy cosmic rays in the intergalactic medium.

  20. The development of simulation and atmospheric shower reconstruction tools for the study of future Cherenkov Imaging telescopes; Developpement d'outils de simulation et de reconstruction de gerbes de particules pour l'astronomie gamma avec les futurs imageurs Tcherenkov

    Energy Technology Data Exchange (ETDEWEB)

    Sajjad, S.

    2007-09-15

    The future of ground based gamma-ray astronomy lies in large arrays of Imaging Atmospheric Cherenkov Telescopes with better capabilities: lower energy threshold, higher sensitivity, better resolution and background rejection. The design of IACT systems and the optimisation of their parameters requires an understanding of the atmospheric showers as well as dedicated tools for the simulation of telescope systems and the evaluation of their performance. The first part of this dissertation deals with atmospheric showers, the various properties of the Cherenkov light they emit and their simulation. The second part presents the tools we have developed for the simulation of imaging atmospheric Cherenkov telescopes and the characteristics of the shower images obtained by them. The third part of this thesis contains a presentation of the tools developed for the reconstruction of the source position in the sky, core position on the ground and energy of the gamma-rays as well as ideas for gamma-hadron separation. In the end, we use these tools to study two large arrays of telescopes at two altitudes and evaluate their performance for gamma-ray detection. (author)

  1. A Compact High Energy Camera for the Cherenkov Telescope Array

    CERN Document Server

    Daniel, M K; Berge, D; Buckley, J; Chadwick, P M; Cotter, G; Funk, S; Greenshaw, T; Hidaka, N; Hinton, J; Lapington, J; Markoff, S; Moore, P; Nolan, S; Ohm, S; Okumura, A; Ross, D; Sapozhnikov, L; Schmoll, J; Sutcliffe, P; Sykes, J; Tajima, H; Varner, G S; Vandenbroucke, J; Vink, J; Williams, D

    2013-01-01

    The Compact High Energy Camera (CHEC) is a camera-development project involving UK, US, Japanese and Dutch institutes for the dual-mirror Small-Sized Telescopes (SST-2M) of the Cherenkov Telescope Array (CTA). Two CHEC prototypes, based on different photosensors are funded and will be assembled and tested in the UK over the next ~18 months. CHEC is designed to record flashes of Cherenkov light lasting from a few to a hundred nanoseconds, with typical RMS image width and length of ~0.2 x 1.0 degrees, and has a 9 degree field of view. The physical camera geometry is dictated by the telescope optics: a curved focal surface with radius of curvature 1m and diameter ~35cm is required. CHEC is designed to work with both the ASTRI and GATE SST-2M telescope structures and will include an internal LED flasher system for calibration. The first CHEC prototype will be based on multi-anode photomultipliers (MAPMs) and the second on silicon photomultipliers (SiPMs or MPPCs). The first prototype will soon be installed on the...

  2. Large zenith-angle observations with the CAT Cherenkov imaging telescope

    OpenAIRE

    collaboration, G. Mohanty for the CAT

    1999-01-01

    We present here results from large zenith-angle observations with the CAT atmospheric Cherenkov imaging telescope, based on data taken on the Crab Nebula and on the blazar Mk501 from 1996 onwards. From Monte Carlo simulations, the threshold energy of the telescope is expected to vary from about 250 GeV at zenith to about 2 TeV at a zenith angle of 60 degrees. The lower source-fluxes due to the increased threshold energy are partly compensated for by an increase in the effective collection are...

  3. Status of the Cherenkov telescope array project

    Science.gov (United States)

    Barres de Almeida, Ulisses

    2015-12-01

    Gamma-ray astronomy holds a great potential for Astrophysics, Particle Physics and Cosmology. The CTA is an international initiative to build the next generation of ground-based gamma-ray observatories, which will represent a factor of 5-10× improvement in the sensitivity of observations in the range 100 GeV - 10 TeV, as well as an extension of the observational capabilities down to energies below 100 GeV and beyond 100 TeV. The array will consist of two telescope networks (one in the Northern Hemisphere and another in the South) so to achieve a full-sky coverage, and will be composed by a hybrid system of 4 different telescope types. It will operate as an observatory, granting open access to the community through calls for submission of proposals competing for observation time. The CTA will give us access to the non-thermal and high-energy universe at an unprecedented level, and will be one of the main instruments for high-energy astrophysics and astroparticle physics of the next 30 years. CTA has now entered its prototyping phase with the first, stand-alone instruments being built. Brazil is an active member of the CTA consortium, and the project is represented in Latin America also by Argentina, Mexico and Chile. In the next few months the consortium will define the site for installation of CTA South, which might come to be hosted in the Chilean Andes, with important impact for the high-energy community in Latin America. In this talk we will present the basic concepts of the CTA and the detailed project of the observatory. Emphasis will be put on its scientific potential and on the Latin-American involvement in the preparation and construction of the observatory, whose first seed, the ASTRI mini-array, is currently being constructed in Sicily, in a cooperation between Italy, Brazil and South Africa. ASTRI should be installed on the final CTA site in 2016, whereas the full CTA array is expected to be operational by the end of the decade.

  4. The SST-1M camera for the Cherenkov Telescope Array

    CERN Document Server

    Schioppa, E J; Christov, A.; della Volpe, D.; Favre, Y.; Heller, M.; Montaruli, T.; Porcelli, A.; Rameez, M.; Pujadas, I. Troyano; Bilnik, W.; Blocki, J.; Bogacz, L.; Bulik, T.; Curylo, M.; Dyrda, M.; Frankowski, A.; Grudniki, L.; Grudzinska, M.; Idzkowski, B.; Jamrozy, M.; Janiak, M.; Kasperek, J.; Lalik, K.; Lyard, E.; Mach, E.; Mandat, D.; Marszalek, A.; Michaowski, J.; Moderski, R.; Neronov, A.; Niemiec, J.; Ostrowski, M.; Pasko, P.; Pech, M.; Prandini, E.; Rajda, P.; Schovanek, P.; Seweryn, K.; Skowron, K.; Sliusar, V.; Sowinski, M.; Stawarz, L.; Stodulska, M.; Stodulski, M.; Toscano, S.; Walter, R.; Wiecek, M.; Zagdanski, A.; Zietara, K.; Zychowski, P.

    2015-01-01

    The prototype camera of the single-mirror Small Size Telescopes (SST-1M) proposed for the Cherenkov Telescope Array (CTA) project has been designed to be very compact and to deliver high performance over thirty years of operation. The camera is composed of an hexagonal photo-detection plane made of custom designed large area hexagonal silicon photomultipliers and a high throughput, highly configurable, fully digital readout and trigger system (DigiCam). The camera will be installed on the telescope structure at the H. Niewodnicza{\\'n}ski institute of Nuclear Physics in Krakow in fall 2015. In this contribution, we review the steps that led to the development of the innovative photo-detection plane and readout electronics, and we describe the test and calibration strategy adopted.

  5. 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...

  6. The Camera Calibration Strategy of the Cherenkov Telescope Array

    CERN Document Server

    Daniel, M K; Majumdar, P

    2015-01-01

    The Cherenkov Telescope Array (CTA) will be the next generation ground based observatory in very high energy gamma ray astronomy. The facility will achieve a wide energy coverage, starting from a threshold of a few tens of GeV up to hundreds of TeV by utilising several classes of telescopes, each optimised for different regions of the gamma-ray spectrum. The required energy resolution of better than 10-15% over most of the energy range and a goal of 5% systematic uncertainty on the measurement of the Cherenkov light intensity at the position of each telescope means that a very precise evaluation of the entire system will need to be made. The composite nature of the array means multiple camera technologies will be employed so multiple calibration systems and procedures will be necessary to meet the performance requirements. Additional constraints will come from the need to minimise observing time losses and that the observatory is foreseen to operate for tens of years, so both short and long term systematic ch...

  7. FACT -- Operation of the First G-APD Cherenkov Telescope

    CERN Document Server

    Bretz, T; Buß, J; Commichau, V; Djambazov, L; Dorner, D; Einecke, S; Eisenacher, D; Freiwald, J; Grimm, O; von Gunten, H; Haller, C; Hempfling, C; Hildebrand, D; Hughes, G; Horisberger, U; Knoetig, M L; Krähenbühl, T; Lustermann, W; Lyard, E; Mannheim, K; Meier, K; Mueller, S; Neise, D; Overkemping, A -K; Paravac, A; Pauss, F; Rhode, W; Röser, U; Stucki, J -P; Steinbring, T; Temme, F; Thaele, J; Vogler, P; Walter, R; Weitzel, Q

    2014-01-01

    Since more than two years, the First G-APD Cherenkov Telescope (FACT) is operating successfully at the Canary Island of La Palma. Apart from its purpose to serve as a monitoring facility for the brightest TeV blazars, it was built as a major step to establish solid state photon counters as detectors in Cherenkov astronomy. The camera of the First G-APD Cherenkov Telesope comprises 1440 Geiger-mode avalanche photo diodes (G-APD aka. MPPC or SiPM) for photon detection. Since properties as the gain of G-APDs depend on temperature and the applied voltage, a real-time feedback system has been developed and implemented. To correct for the change introduced by temperature, several sensors have been placed close to the photon detectors. Their read out is used to calculate a corresponding voltage offset. In addition to temperature changes, changing current introduces a voltage drop in the supporting resistor network. To correct changes in the voltage drop introduced by varying photon flux from the night-sky background...

  8. The next generation Cherenkov Telescope Array observatory: CTA

    International Nuclear Information System (INIS)

    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 m2 and about 300 m spacing, distributed across an area of about 10 km2. 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

  9. 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...

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

    CERN Document Server

    Rousselle, J; Cameron, R; Connaughton, V; Errando, M; Guarino, V; Humensky, T B; 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 aplanatic optical system is made of two segmented aspheric mirrors. The primary mirror has 48 mirror panels with an aperture of 9.6 m, while the secondary, made of 24 panels, has an diameter of 5.4 m. The resulting point spread function (PSF) is required to be better than 4 arcmin within a field of view of 6.4 degrees (80% of the field of view), which corresponds to a physical size of 6.4 mm on the focal plane. This goal represents a challenge for the inexpensive fabrication of aspheric mirror panels and for the precise ali...

  11. Prototype of the SST-1M Telescope Structure for the Cherenkov Telescope Array

    CERN Document Server

    Niemiec, J; Błocki, J; Bogacz, L; Borkowski, J; 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; Ostrowski, M; Paśko, P; Pech, M; Porcelli, A; Prandini, E; Rajda, P; Rameez, M; Schioppa, E jr; Schovanek, P; Seweryn, K; Skowron, K; Sliusar, V; Sowiński, M; Stawarz, Ł; Stodulska, M; Stodulski, M; Pujadas, I Troyano; Toscano, S; Walter, R; Wiȩcek, M; Zagdański, A; Ziȩtara, K

    2015-01-01

    A single-mirror small-size (SST-1M) Davies-Cotton telescope with a dish diameter of 4 m has been built by a consortium of Polish and Swiss institutions as a prototype for one of the proposed small-size telescopes for the southern observatory of the Cherenkov Telescope Array (CTA). The design represents a very simple, reliable, and cheap solution. The mechanical structure prototype with its drive system is now being tested at the Institute of Nuclear Physics PAS in Krakow. Here we present the design of the prototype and results of the performance tests of the structure and the drive and control system.

  12. On the use of Cherenkov Telescopes for outer Solar system body occultations

    Science.gov (United States)

    Lacki, Brian C.

    2014-12-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) are arrays of very large optical telescopes that are well-suited for rapid photometry of bright sources. I investigate their potential in observing stellar occultations by small objects in the outer Solar system, Transjovian Objects (TJOs). These occultations cast diffraction patterns on the Earth. Current IACT arrays are capable of detecting objects smaller than 100 m in radius in the Kuiper Belt and 1 km radius out to 5000 au. The future Cherenkov Telescope Array (CTA) will have even greater capabilities. Because the arrays include several telescopes, they can potentially measure the speeds of TJOs without degeneracies, and the sizes of the TJOs and background stars. I estimate the achievable precision using a Fisher matrix analysis. With CTA, the precisions of these parameter estimations will be as good as a few per cent. I consider how often detectable occultations occur by members of different TJO populations, including Centaurs, Kuiper Belt Objects (KBOs), Oort Cloud objects, and satellites and Trojans of Uranus and Neptune. The great sensitivity of IACT arrays means that they likely detect KBO occultations once every O(10) hours when looking near the ecliptic. IACTs can also set useful limits on many other TJO populations.

  13. Status and Plans for the Array Control and Data Acquisition System of the Cherenkov Telescope Array

    CERN Document Server

    Oya, I; Schwanke, U; Wegner, P; Balzer, A; Berge, D; Borkowski, J; Camprecios, J; Colonges, S; Colome, J; Champion, C; Conforti, V; Gianotti, F; Flour, T Le; Lindemann, R; Lyard, E; Mayer, M; Melkumyan, D; Punch, M; Tanci, C; Schmidt, T; Schwarz, J; Tosti, G; Verma, K; Weinstein, A; Wiesand, S; Wischnewski, R

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next-generation atmospheric Cherenkov gamma-ray observatory. CTA will consist of two installations, one in the northern, and the other in the southern hemisphere, containing tens of telescopes of different sizes. The CTA performance requirements and the inherent complexity associated with the operation, control and monitoring of such a large distributed multi-telescope array leads to new challenges in the field of the gamma-ray astronomy. The ACTL (array control and data acquisition) system will consist of the hardware and software that is necessary to control and monitor the CTA arrays, as well as to time-stamp, read-out, filter and store -at aggregated rates of few GB/s- the scientific data. The ACTL system must be flexible enough to permit the simultaneous automatic operation of multiple sub-arrays of telescopes with a minimum personnel effort on site. One of the challenges of the system is to provide a reliable integration of the control of a large and heterogene...

  14. Improved energy resolution for VHE gamma-ray astronomy with systems of Cherenkov telescopes

    CERN Document Server

    Hofmann, W; Konopelko, A K; Krawczynski, H

    2000-01-01

    We present analysis techniques to improve the energy resolution of stereoscopic systems of imaging atmospheric Cherenkov telescopes, using the HEGRA telescope system as an example. The techniques include (i) the determination of the height of the shower maximum, which is then taken into account in the energy determination, and (ii) the determination of the location of the shower core with the additional constraint that the direction of the gamma rays is known a priori. This constraint can be applied for gamma-ray point sources, and results in a significant improvement in the localization of the shower core, which translates into better energy resolution. Combining both techniques, the HEGRA telescopes reach an energy resolution between 9% and 12%, over the entire energy range from 1 TeV to almost 100 TeV. Options for further improvements of the energy resolution are discussed.

  15. Stellar intensity interferometry over kilometer baselines: Laboratory simulation of observations with the Cherenkov Telescope Array

    CERN Document Server

    Dravins, Dainis

    2014-01-01

    A long-held astronomical vision is to realize diffraction-limited optical aperture synthesis over kilometer baselines. This will enable imaging of stellar surfaces and their environments, show their evolution over time, and reveal interactions of stellar winds and gas flows in binary star systems. An opportunity is now opening up with the large telescope arrays primarily erected for measuring Cherenkov light in air induced by gamma rays. With suitable software, such telescopes could be electronically connected and used also for intensity interferometry. With no optical connection between the telescopes, the error budget is set by the electronic time resolution of a few nanoseconds. Corresponding light-travel distances are on the order of one meter, making the method practically insensitive to atmospheric turbulence or optical imperfections, permitting both very long baselines and observing at short optical wavelengths. Theoretical modeling has shown how stellar surface images can be retrieved from such observ...

  16. Construction of prototype two-mirror Schwartzchild-Couder Imaging Air Cherenkov Telescope (IACT) for VHE gamma-ray astronomy

    Science.gov (United States)

    Kieda, David; CTA-US Collaboration Collaboration

    2016-03-01

    Next generation ground-based VHE gamma-ray observatories such as the Cherenkov Telescope Array (CTA) will employ an array of different sized IACTs distributed across square kilometer areas. During 2015-2016, the CTA-US collaboration is constructing a prototype 9.6 m primary diameter Schwartzchild-Couder IACT (SCT) at the FL Whipple Observatory, Amado, AZ USA. The two-mirror SCT design provides 8 degree field of view with 0.067 degree pixel size. The SCT uses a high resolution (11,328 pixel) Silicon PhotoMultiplier (SiPM) camera to record atmospheric Cherenkov light images generated by gamma-ray and cosmic ray primaries. Incorporation of SCT telescopes into a CTA-type observatory can provide superior angular resolution (30 % improvement) and point source sensitivity (30-50 %). In this talk, I will describe the capabilities of the SCT telescope, and the construction and commissioning of the prototype SCT telescope during 2016.

  17. Data compression for the First G-APD Cherenkov Telescope

    CERN Document Server

    Ahnen, M L; Bergmann, M; Biland, A; Bretz, T; Buß, J; Dorner, D; Einecke, S; Freiwald, J; Hempfling, C; Hildebrand, D; Hughes, G; Lustermann, W; Lyard, E; Mannheim, K; Meier, K; Mueller, S; Neise, D; Neronov, A; Overkemping, A -K; Paravac, A; Pauss, F; Rhode, W; Steinbring, T; Temme, F; Thaele, J; Toscano, S; Vogler, P; Walter, R; Wilbert, A

    2015-01-01

    The First Geiger-mode Avalanche photodiode (G-APD) Cherenkov Telescope (FACT) has been operating on the Canary island of La Palma since October 2011. Operations were automated so that the system can be operated remotely. Manual interaction is required only when the observation schedule is modified due to weather conditions or in case of unexpected events such as a mechanical failure. Automatic operations enabled high data taking efficiency, which resulted in up to two terabytes of FITS files being recorded nightly and transferred from La Palma to the FACT archive at ISDC in Switzerland. Since long term storage of hundreds of terabytes of observations data is costly, data compression is mandatory. This paper discusses the design choices that were made to increase the compression ratio and speed of writing of the data with respect to existing compression algorithms. Following a more detailed motivation, the FACT compression algorithm along with the associated I/O layer is discussed. Eventually, the performances...

  18. An Innovative Workspace for The Cherenkov Telescope Array

    CERN Document Server

    Costa, Alessandro; Becchini, Ugo; Massimino, Piero; Riggi, Simone; Sanchez, David; Vitello, Fabio

    2016-01-01

    The Cherenkov Telescope Array (CTA) is an initiative to build the next generation, ground-based gamma-ray observatories. We present a prototype workspace developed at INAF that aims at providing innovative solutions for the CTA community. The workspace leverages open source technologies providing web access to a set of tools widely used by the CTA community. Two different user interaction models, connected to an authentication and authorization infrastructure, have been implemented in this workspace. The first one is a workflow management system accessed via a science gateway (based on the Liferay platform) and the second one is an interactive virtual desktop environment. The integrated workflow system allows to run applications used in astronomy and physics researches into distributed computing infrastructures (ranging from clusters to grids and clouds). The interactive desktop environment allows to use many software packages without any installation on local desktops exploiting their native graphical user i...

  19. Data model issues in the Cherenkov Telescope Array project

    CERN Document Server

    Contreras, J L; Bernlöhr, K; Boisson, C; Bregeon, J; Bulgarelli, A; de Cesare, G; Reyes, R de los; Fioretti, V; Kosack, K; Lavalley, C; Lyard, E; Marx, R; Rico, J; Sanguillot, M; Servillat, M; Walter, R; Ward, J E

    2015-01-01

    The planned Cherenkov Telescope Array (CTA), a future ground-based Very-High-Energy (VHE) gamma-ray observatory, will be the largest project of its kind. It aims to provide an order of magnitude increase in sensitivity compared to currently operating VHE experiments and open access to guest observers. These features, together with the thirty years lifetime planned for the installation, impose severe constraints on the data model currently being developed for the project. In this contribution we analyze the challenges faced by the CTA data model development and present the requirements imposed to face them. While the full data model is still not completed we show the organization of the work, status of the design, and an overview of the prototyping efforts carried out so far. We also show examples of specific aspects of the data model currently under development.

  20. Single-Mirror Small-Size Telescope structure for the Cherenkov Telescope Array

    CERN Document Server

    Niemiec, Jacek; Dyrda, Michał; Kochański, Wojciech; Ludwin, Jaromir; Stodulski, Marek; Ziółkowski, Paweł

    2013-01-01

    A single-mirror small-size (1M-SST) Davies-Cotton telescope has been proposed for the southern observatory of the Cherenkov Telescope Array (CTA) by a consortium of scientific institutions from Poland, Switzerland, and Germany. The telescope has a 4 m diameter reflector and will be equipped with a fully digital camera based on Geiger avalanche photodiodes (APDs). Such a design is particularly interesting for CTA because it represents a very simple, reliable, and cheap solution for a SST. Here we present the design and the characteristics of the mechanical structure of the 1M-SST telescope and its drive system. We also discuss the results of a finite element method analysis in order to demonstrate the conformance of the design with the CTA specifications and scientific objectives. In addition, we report on the current status of the construction of a prototype telescope structure at the Institute of Nuclear Physics PAS in Krakow.

  1. The Instrument Response Function Format for the Cherenkov Telescope Array

    CERN Document Server

    Ward, John E

    2015-01-01

    The Cherenkov Telescope Array (CTA) is a future ground-based observatory (with two locations, in the Northern and Southern Hemispheres) that will be used in the study of the very-high-energy gamma-ray sky. CTA observations will be proposed by external users or initiated by the observatory, with the resulting measurements being processed by the CTA observatory and the reduced data made accessible to the corresponding proposer. Instrument Response Functions (IRFs) will also be provided to convert the quantities measured by the array(s) into relevant science products (i.e. spectra, sky maps, light curves). As the response of the telescopes depend on many correlated observational and physical quantities (e.g. gamma-ray arrival direction, energy, telescope orientation, background light, weather conditions etc.) the CTA IRFs could grow into increasingly larger and larger file sizes, which can become unwieldy or impractical for use in specific observation cases. To this end, a customized IRF format (complying with t...

  2. 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.

  3. Reflecting on Cherenkov reflections

    OpenAIRE

    Fargion, D.; Gaug, M.; Oliva, P.

    2007-01-01

    Magic Telescope may observe and reveal at horizons lights from air-shower Cherenkov reflections. The ground, the sea, the cloudy sky (below the mountain) may reflect PeVs-EeV UHECR Cherenkov lights observable by MAGIC telescopes. Even rarest UHE neutrino skimming the atmosphere or skimming the Earth may induce upward-horizontal airshowers: a new Neutrino Astronomy. These fluorescence signals or the Cherenkov reflections in upper cloudy sky may flash in correlated BL-Lac or GRB shining at oppo...

  4. NectarCAM : a camera for the medium size telescopes of the Cherenkov Telescope Array

    OpenAIRE

    Glicenstein, J-F.; Abril, O.; Barrio, J-A.; Blanch Bigas, O.; Bolmont, J.; Bouyjou, F.; Brun, P.; Chabanne, E.; Champion, C.; Colonges, S.; Corona, P.; Delagnes, E.; Delgado, C.; Ginzov, C. Diaz; Durand, D

    2015-01-01

    NectarCAM is a camera proposed for the medium-sized telescopes of the Cherenkov Telescope Array (CTA) covering the central energy range of ~100 GeV to ~30 TeV. It has a modular design and is based on the NECTAr chip, at the heart of which is a GHz sampling Switched Capacitor Array and a 12-bit Analog to Digital converter. The camera will be equipped with 265 7-photomultiplier modules, covering a field of view of 8 degrees. Each module includes the photomultiplier bases, high voltage supply, p...

  5. Analogue sum ASIC for L1 trigger decision in Cherenkov Telescope cameras

    International Nuclear Information System (INIS)

    The Cherenkov Telescope Array (CTA) project [1] aims to build the largest ground-based gamma-ray observatory based on an array of Imaging Atmospheric Cherenkov Telescopes (IACTs). The CTA will implement a multi-level trigger system to distinguish between gamma ray-like induced showers and background images induced by night sky background (NSB) light [2]. The trigger system is based on coincident detections among pixels (level 0 trigger), clusters of pixels (level 1) or telescopes. In this article, the first version of the application specific integrated circuit (ASIC) for Level 1 trigger system is presented, capable of working with different Level 0 strategies and different trigger region sizes. In addition, it complies with all the requirements specified by the CTA project, specially the most critical ones as regards noise, bandwidth, dynamic range and power consumption. All these features make the presented system very suitable for use in the CTA cameras and improve the features of discrete components prototypes of the L1 trigger circuit in terms of compactness, noise, performance and power consumption

  6. Developments of a new mirror technology for the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    The Cherenkov Telescope Array (CTA) observatory for very high-energy gamma rays will consist of about a hundred of imaging atmospheric Cherenkov telescopes (IACTs) of different size with a total reflective area of about 10,000 m$^2$. Here we present a novel technology for the production of IACT mirrors that has been developed in the Institute of Nuclear Physics PAS in Krakow, Poland. The mirrors are made by cold-slumping of the front reflecting aluminium-coated panel and the rear panel interspaced with aluminium spacers. Each panel is built of two glass panels laminated with a layer of a fibreglass tissue in between for reinforcement of the structure against mechanical damage. The mirror structure is open and does not require a perfect sealing needed in closed-type designs. It prohibits water to be trapped inside and enables a proper ventilation of the mirror. Full-size hexagonal prototype mirrors produced for the medium-sized CTA telescopes will be presented together with the results of recent comprehensive ...

  7. From MAGIC to CTA: the INAF participation to Cherenkov Telescopes experiments for very high energy astrophysics .

    Science.gov (United States)

    Antonelli, L. A.; INAF MAGIC Collaboration

    The next decade can be considered the "golden age" of the Gamma Ray Astronomy with the two satellites for Gamma Ray Astronomy (AGILE and GLAST) in orbit. Therefore, thanks to many other X-ray experiments already in orbit (e.g. Swift, Chandra, NewtonXMM, etc.) it will be possible to image the Universe for the first time all over the electromagnetic spectrum almost contemporarily. The new generations of ground-based very high gamma-ray instruments are ready to extend the observed band also to the very high frequencies. Scientists from the Italian National Institute for Astrophysics (INAF) are involved in many, both space- and ground- based gamma ray experiments, and recently such an involvement has been largely improved in the field of the Imaging Atmospheric Cherenkov Telescopes (IACT). INAF is now member of the MAGIC collaboration and is participating to the realization of the second MAGIC telescope. MAGIC, as well other IACT experiments, is not operated as an observatory so a proper guest observer program does not exist. A consortium of European scientists (including INAF scientists) is thus now thinking to the design of a new research infrastructure: the Cherenkov Telescope Array (CTA). CTA is conceived to provide 10 times the sensitivity of current instruments, combined with increased flexibility and increased coverage from some 10 GeV to some 100 TeV. CTA will be operated as an observatory to serve a wider community of astronomer and astroparticle physicists.

  8. Expected performance of the GAW Cherenkov Telescopes Array. Simulation and Analysis

    CERN Document Server

    Maccarone, M C; Catalano, O; Cusumano, G; Santo, M C Espirito; Gonçalves, P; Moles, M; Pimenta, M; Pina, A; Sacco, B; Tome', B

    2007-01-01

    GAW is a "path-finder" experiment to test the feasibility of a new generation of Imaging Atmospheric Cherenkov telescopes that join high flux sensitivity with large field of view capability using Fresnel lens, stereoscopic observational approach, and single photon counting mode. GAW is an array of three telescopes that will be erected at the Calar Alto Observatory site (Spain, 2150 m a.s.l.). To evaluate the performance of GAW, a consistent data--set has been simulated, including a Crab-like source observation, and a proper image analysis code has been developed, as described in this contribution. The expected performance of GAW are also reported, mainly for what concerns effective area, angular resolution, Cherenkov flux as function of the core distance, ability in the gamma/proton separation, and sensitivity. The first telescope realization, foreseen within the end of this year, will allow to verify if the parameters used in the analysis are in agreement with the "real" performance of the GAW apparatus.

  9. A Prototype Data Format for the Cherenkov Telescope Array: Regions Of Interest (ROI)

    CERN Document Server

    ,

    2015-01-01

    The Cherenkov Telescope Array (CTA) is a ground-based $\\gamma$-ray observatory that will observe the full sky in the energy range from 20 GeV to 100 TeV from facilities in both hemispheres. It is proposed to consist of more than 100 telescopes and the large amount of data produced will exceed the volume of current VHE Imaging Atmospheric Cherenkov Telescopes by $\\sim$two orders of magnitude. This volume of data represents a new challenge to the community, which is looking for new data formats to transfer and store the CTA data. One of the prototypes currently under study is the ROI (Regions Of Interest) file format for camera images. It can store only those pixels of a camera image that are close to the shower, thus removing the major part of the night sky background (NSB) while keeping all pixels that might belong to the shower. Simple on-the-fly compression is used to reduce the file size even further. Here, we explain the ROI prototype in detail and present preliminary results when applied to simulations.

  10. Status of the Medium-Sized Telescope for the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    The Cherenkov Telescope Array (CTA), is an international project for the next generation ground- based observatory for gamma-ray astronomy in the energy range from 20 GeV to 300 TeV. The sensitivity in the core energy range will be dominated by up to 40 Medium-Sized Telescopes (MSTs). The MSTs, of Davies-Cotton type with a 12 m diameter reflector are currently in the prototype phase. A full-size mechanical telescope structure has been assembled in Berlin. The telescope is partially equipped with different mirror prototypes, which are currently being tested and evaluated for performances characteristics. A report concentrating on the details of the tele- scope structure, the drive assemblies and the optics of the MST prototype will be given.

  11. Kalman filter tracking in a Cherenkov neutrino telescope

    International Nuclear Information System (INIS)

    The reconstruction of tracks in underwater Cherenkov neutrino telescopes is strongly complicated due to large background counting rate originates from 40K beta decay and to the electromagnetic showers accompanying high energy muons together with the effects of light propagation in the water, in particular the photon scattering. These two effects lead to a non-linear problem with a non-Gaussian measurement noise. A method for track reconstruction based on Kalman filter approach in this situation is presented. We use Gaussian Sum Filter algorithm to take into account non-Gaussian process noise. While usual Kalman filter estimators based on linear least-square method are optimal in case all observations are Gaussian distributed, the Gaussian Sum Filter offers a better treatment of non-Gaussian process noise and/or measurement errors when these are modeled by Gaussian mixtures. As an example of the application, the results of muon track reconstruction in NEMO underwater neutrino telescope are presented as well as the comparison of its capability with other standard track reconstruction methods.

  12. Design constraints on Cherenkov telescopes with Davies-Cotton reflectors

    CERN Document Server

    Bretz, Thomas

    2013-01-01

    This paper discusses the construction of high-performance ground-based gamma-ray Cherenkov telescopes with a Davies-Cotton reflector. For the design of such telescopes, usually physics constrains the field-of-view, while the photo-sensor size is defined by limited options. Including the effect of light-concentrators in front of the photo sensor, it is demonstrated that these constraints are enough to mutually constrain all other design parameters. The dependability of the various design parameters naturally arises once a relationship between the value of the point-spread functions at the edge of the field-of-view and the pixel field-of-view is introduced. To be able to include this constraint into a system of equations, an analytical description for the point-spread function of a tessellated Davies-Cotton reflector is derived from Taylor developments and ray-tracing simulations. Including higher order terms renders the result precise on the percent level. Design curves are provided within the typical phase sp...

  13. The IFAE/UAB and LUPM Raman LIDARs for Cherenkov Telescope Array Observatory

    CERN Document Server

    López-Oramas, A; Bigas, O Blanch; Boix, J; Da Deppo, V; Doro, M; Font, L; Garrido, D; Gaug, M; Martínez, M; Vasileiadis, G

    2013-01-01

    The Cherenkov Telescope Array (CTA) is the next generation of Imaging Atmospheric Cherenkov Telescopes. It will reach a sensitivity and an energy resolution with no precendent in very high energy gamma-ray astronomy. In order to achieve this goal, the systematic uncertainties derived from the atmospheric conditions shall be reduced to the minimum. Different instruments may help account for these uncertainties. The Barcelona IFAE/UAB (acronyms for Institut de F\\'isica d'Altes Energies and Universitat Aut\\`onoma de Barcelona, respectively) and the Montpellier LUPM (Laboratoire Univers et Particules de Montpellier) groups are building Raman LIDARs, devices which can reduce the systematic uncertainties in the reconstruction of the gamma-ray energies from 20$%$ down to 5$%$. The Raman LIDARs subject of this work have coaxial 1.8 m mirrors with a Nd-YAG laser each. A liquid light-guide collects the light at the focal plane and transports it to the readout system. We are developping a monochromator with the purpose ...

  14. Monte Carlo comparison of mid-size telescope designs for the Cherenkov Telescope Array

    CERN Document Server

    Jogler, T; Dumm, J

    2012-01-01

    The Cherenkov Telescope Array (CTA) is a future very high energy gamma-ray observatory. CTA will be comprised of small-, medium- and large-size telescopes covering an energy range from tens of GeV to hundreds of TeV and will surpass existing telescopes in sensitivity by an order of magnitude. The aim of our study is to find the optimal design for the medium-size telescopes (MSTs), which will determine the sensitivity in the key energy range between a few hundred GeV to about ten TeV. To study the effect of the telescope design parameters on the array performance, we simulated arrays of 61 MSTs with 120 m spacing and a variety of telescope configurations. We investigated the influence of the primary telescope characteristics including optical resolution, pixel size, and light collection area on the total array performance with a particular emphasis on telescope configurations with imaging performance similar to the proposed Davis-Cotton (DC) and Schwarzschild-Couder (SC) MST designs. We compare the performance...

  15. Monte Carlo comparison of medium-size telescope designs for the Cherenkov Telescope Array

    CERN Document Server

    Jogler, T; Dumm, J

    2013-01-01

    The Cherenkov Telescope Array (CTA) is a future very high energy gamma-ray observatory. CTA will be comprised of small-,medium- and large-size telescopes covering an energy range from tens of GeV to hundreds of TeV and will surpass existing telescopes in sensitivity by an order of magnitude. The aim of our study is to find the optimal design for the medium-size telescopes (MSTs), which will determine the sensitivity in the key energy range between a few hundred GeV to about ten TeV. To study the effect of the telescope design parameters on the array performance, we simulated arrays of 61 MSTs with 120 m spacing and a variety of telescope configurations. We investigated the influence of the primary telescope characteristics including optical resolution, pixel size, and light collection area on the total array performance with a particular emphasis on telescope configurations with imaging performance similar to the proposed Davies-Cotton (DC) and Schwarzschild-Couder (SC) MST designs. We compare the performance...

  16. The possibilities of Cherenkov telescopes to perform cosmic-ray muon imaging of volcanoes

    Science.gov (United States)

    Carbone, Daniele; Catalano, Osvaldo; Cusumano, Giancarlo; Del Santo, Melania; Maccarone, Maria Concetta; Mineo, Teresa; Pareschi, Giovanni; Vercellone, Stefano; Zuccarello, Luciano

    2016-04-01

    atmospheric muons, that is needed to asses a reference model of the through-target integrated flux. Here we describe our plans for the production of a Cherenkov telescope with suitable characteristics for installation in the summit zone of Etna volcano.

  17. 4 m Davies-Cotton telescope for the Cherenkov Telescope Array

    CERN Document Server

    Moderski, R; Barnacka, A; Basili, A; Boccone, V; Bogacz, L; Cadoux, F; Christov, A; Della Volpe, M; Dyrda, M; Frankowski, A; Grudzińska, M; Janiak, M; Karczewski, M; Kasperek, J; Kochański, W; Korohoda, P; Kozioł, J; Lubiński, P; Ludwin, J; Lyard, E; Marszałek, A; Michałowski, J; Montaruli, T; Nicolau-Kukliński, J; Niemiec, J; Ostrowski, M; Płatos, Ł; Rajda, P J; Rameez, M; Romaszkan, W; Rupiński, M; Seweryn, K; Stodulska, M; Stodulski, M; Walter, R; Winiarski, K; Wiśniewski, Ł; Zagdański, A; Zietara, K; Ziółkowski, P; Żychowski, P

    2013-01-01

    The Cherenkov Telescope Array (CTA) is the next generation very high energy gamma-ray observatory. It will consist of three classes of telescopes, of large, medium and small sizes. The small telescopes, of 4 m diameter, will be dedicated to the observations of the highest energy gamma-rays, above several TeV. We present the technical characteristics of a single mirror, 4 m diameter, Davies-Cotton telescope for the CTA and the performance of the sub-array consisting of the telescopes of this type. The telescope will be equipped with a fully digital camera based on custom made, hexagonal Geiger-mode avalanche photodiodes. The development of cameras based on such devices is an RnD since traditionally photomultipliers are used. The photodiodes are now being characterized at various institutions of the CTA Consortium. Glass mirrors will be used, although an alternative is being considered: composite mirrors that could be adopted if they meet the project requirements. We present a design of the telescope structure,...

  18. Microsecond Time Resolution Optical Photometry using a H.E.S.S. Cherenkov Telescope

    CERN Document Server

    Deil, C; Hermann, G

    2008-01-01

    We have constructed an optical photometer with microsecond time resolution, which is currently being operated on one of the H.E.S.S. telescopes. H.E.S.S. is an array of four Cherenkov telescopes, each with a 107 m^2 mirror, located in the Khomas highland in Namibia. In its normal mode of operation H.E.S.S. observes Cherenkov light from air showers generated by very high energy gamma-rays in the upper atmosphere. Our detector consists of seven photomultipliers, one in the center to record the lightcurve from the target and six concentric photomultipliers as a veto system to reject disturbing signals e.g. from meteorites or lightning at the horizon. The data acquisition system has been designed to continuously record the signals with zero deadtime. The Crab pulsar has been observed to verify the performance of the instrument and the GPS timing system. Compact galactic targets were observed to search for flares on timescales of a few microseconds to ~ 100 milliseconds. The design and sensitivity of the instrumen...

  19. 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...

  20. Calibration of the Cherenkov Telescope Array using Cosmic Ray Electrons

    CERN Document Server

    Parsons, R D; Schoorlemmer, H

    2016-01-01

    Cosmic ray electrons represent a background for gamma-ray observations with Cherenkov telescopes, initiating air-showers which are difficult to distinguish from photon-initiated showers. This similarity, however, and the presence of cosmic ray electrons in every field observed, makes them potentially very useful for calibration purposes. Here we study the precision with which the relative energy scale and collection area/efficiency for photons can be established using electrons for a major next generation instrument such as CTA. We find that variations in collection efficiency on hour timescales can be corrected to better than 1%. Furthermore, the break in the electron spectrum at ~0.9 TeV can be used to calibrate the energy scale at the 3% level on the same timescale. For observations on the order of hours, statistical errors become negligible below a few TeV and allow for an energy scale cross-check with instruments such as CALET and AMS. Cosmic ray electrons therefore provide a powerful calibration tool, e...

  1. Probing the Inert Doublet Dark Matter Model with Cherenkov Telescopes

    CERN Document Server

    Garcia-Cely, Camilo; Ibarra, Alejandro

    2015-01-01

    We present a detailed study of the annihilation signals of the inert dark matter doublet model in its high mass regime. Concretely, we study the prospects to observe gamma-ray signals of the model in current and projected Cherenkov telescopes taking into account the Sommerfeld effect and including the contribution to the spectrum from gamma-ray lines as well as from internal bremsstrahlung. We show that present observations of the galactic center by the H.E.S.S. instrument are able exclude regions of the parameter space that give the correct dark matter relic abundance. In particular, models with the charged and the neutral components of the inert doublet nearly degenerate in mass have strong gamma-ray signals. Furthermore, for dark matter particle masses above 1 TeV, we find that the non-observation of the continuum of photons generated by the hadronization of the annihilation products typically give stronger constraints on the model parameters than the sharp spectral features associated to annihilation into...

  2. Pointing Calibration for the Cherenkov Telescope Array Medium Size Telescope Prototype

    CERN Document Server

    Oakes, Louise; Baehr, Juergen; Gruenewald, Sandra; Raeck, Tobias; Schlenstedt, Stefan; Schubert, Anja; Schwanke, Ullrich

    2013-01-01

    Pointing calibration is an offline correction applied in order to obtain the true pointing direction of a telescope. The Cherenkov Telescope Array (CTA) aims to have the precision to determine the position of point-like as well as slightly extended sources, with the goal of systematic errors less than 7 arc seconds in space angle. This poster describes the pointing calibration concept being developed for the CTA Medium Size Telescope (MST) prototype at Berlin-Adlershof, showing test results and preliminary measurements. The MST pointing calibration method uses two CCD cameras, mounted on the telescope dish, to determine the true pointing of the telescope. The "Lid CCD" is aligned to the optical axis of the telescope, calibrated with LEDs on the dummy gamma-camera lid; the "Sky CCD" is pre-aligned to the Lid CCD and the transformation between the Sky and Lid CCD camera fields of view is precisely modelled with images from special pointing runs which are also used to determine the pointing model. During source ...

  3. A conceptual design of an advanced 23-m diameter Imaging Air Cherenkov Telescope of 50 tons for ground-based gamma-ray astronomy

    International Nuclear Information System (INIS)

    The MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) Telescope has opened the field of ground-base sub-100 GeV gamma-ray astronomy. Observations with higher sensitivity in this energy region will have important consequences for the understanding of both galactic and extragalactic sources of non-thermal gamma radiation. We present a conceptual design of an advanced Imaging Air Cherenkov Telescope with a 23 m diameter reflector and a weight of 50 tons. A system photon detection efficiency of 15-17%, averaged over 300-600 nm, is aimed at to lower the energy threshold to 10-20 GeV. Prospects for a second generation camera with Geiger-mode avalanche photodiodes are also discussed. The 23-m design can serve as large-size telescope for the future Cherenkov Telescope Array project.

  4. Flasher and muon-based calibration of the GCT telescopes proposed for the Cherenkov Telescope Array

    CERN Document Server

    Brown, Anthony M; Chadwick, Paula M; Daniel, Michael; White, Richard

    2015-01-01

    The GCT is a dual-mirror Small-Sized-Telescope prototype proposed for the Cherenkov Telescope Array. Calibration of the GCT's camera is primarily achieved with LED-based flasher units capable of producing $\\sim4$ ns FWHM pulses of 400 nm light across a large dynamic range, from 0.1 up to 1000 photoelectrons. The flasher units are housed in the four corners of the camera's focal plane and illuminate it via reflection from the secondary mirror. These flasher units are adaptable to allow several calibration scenarios to be accomplished: camera flat-fielding, linearity measurements (up to and past saturation), and gain estimates from both single pe measurements and from the photon statistics at various high illumination levels. In these proceedings, the performance of the GCT flashers is described, together with ongoing simulation work to quantify the efficiency of using muon rings as an end-to-end calibration for the optical throughput of the GCT.

  5. The dual-mirror Small Size Telescope for the Cherenkov Telescope Array

    CERN Document Server

    Pareschi, G; Antonelli, L A; Bastieri, D; Bellassai, G; Belluso, M; Bigongiari, C; Billotta, S; Biondo, B; Bonanno, G; Bonnoli, G; Bruno, P; Bulgarelli, A; Canestrari, R; Capalbi, M; Caraveo, P; Carosi, A; Cascone, E; Catalano, O; Cereda, M; Conconi, P; Conforti, V; Cusumano, G; De Caprio, V; De Luca, A; Di Paola, A; Di Pierro, F; Fantinel, D; Fiorini, M; Fugazza, D; Gardiol, D; Ghigo, M; Gianotti, F; Giarrusso, S; Giro, E; Grillo, A; Impiombato, D; Incorvaia, S; La Barbera, A; La Palombara, N; La Parola, V; La Rosa, G; Lessio, L; Leto, G; Lombardi, S; Lucarelli, F; Maccarone, M C; Malaguti, G; Malaspina, G; Mangano, V; Marano, D; Martinetti, E; Millul, R; Mineo, T; MistÒ, A; Morello, C; Morlino, G; Panzera, M R; Rodeghiero, G; Romano, P; Russo, F; Sacco, B; Sartore, N; Schwarz, J; Segreto, A; Sironi, G; Sottile, G; Stamerra, A; Strazzeri, E; Stringhetti, L; Tagliaferri, G; Testa, V; Timpanaro, M C; Toso, G; Tosti, G; Trifoglio, M; Vallania, P; Vercellone, S; Zitelli, V; Amans, J P; Boisson, C; Costille, C; Dournaux, J L; Dumas, D; Fasola, G; Hervet, O; Huet, J M; Laporte, P; Rulten, C; Sol, H; Zech, A; White, R; Hinton, J; Ross, D; Sykes, J; Ohm, S; Schmoll, J; Chadwick, P; Greenshaw, T; Daniel, M; Cotter, G; Varner, G S; Funk, S; Vandenbroucke, J; Sapozhnikov, L; Buckley, J; Moore, P; Williams, D; Markoff, S; Vink, J; Berge, D; Hidaka, N; Okumura, A; Tajima, H

    2013-01-01

    In this paper, the development of the dual mirror Small Size Telescopes (SST) for the Cherenkov Telescope Array (CTA) is reviewed. Up to 70 SST, with a primary mirror diameter of 4 m, will be produced and installed at the CTA southern site. These will allow investigation of the gamma-ray sky at the highest energies accessible to CTA, in the range from about 1 TeV to 300 TeV. The telescope presented in this contribution is characterized by two major innovations: the use of a dual mirror Schwarzschild-Couder configuration and of an innovative camera using as sensors either multi-anode photomultipliers (MAPM) or silicon photomultipliers (SiPM). The reduced plate-scale of the telescope, achieved with the dual-mirror optics, allows the camera to be compact (40 cm in diameter), and low-cost. The camera, which has about 2000 pixels of size 6x6 mm^2, covers a field of view of 10{\\deg}. The dual mirror telescopes and their cameras are being developed by three consortia, ASTRI (Astrofisica con Specchi a Tecnologia Repl...

  6. Mechanical design of SST-GATE, a dual-mirror telescope for the Cherenkov Telescope Array

    Science.gov (United States)

    Dournaux, Jean-Laurent; Huet, Jean-Michel; Amans, Jean-Philippe; Dumas, Delphine; Laporte, Philippe; Sol, Hélène; Blake, Simon

    2014-07-01

    The Cherenkov Telescope Array (CTA) project aims to create the next generation Very High Energy (VHE) gamma-ray telescope array. It will be devoted to the observation of gamma rays over a wide band of energy, from a few tens of GeV to more than 100 TeV. Two sites are foreseen to view the whole sky where about 100 telescopes, composed of three different classes, related to the specific energy region to be investigated, will be installed. Among these, the Small Size class of Telescopes, SSTs, are devoted to the highest energy region, to beyond 100 TeV. Due to the large number of SSTs, their unit cost is an important parameter. At the Observatoire de Paris, we have designed a prototype of a Small Size Telescope named SST-GATE, based on the dual-mirror Schwarzschild-Couder optical formula, which has never before been implemented in the design of a telescope. Over the last two years, we developed a mechanical design for SST-GATE from the optical and preliminary mechanical designs made by the University of Durham. The integration of this telescope is currently in progress. Since the early stages of mechanical design of SST-GATE, finite element method has been used employing shape and topology optimization techniques to help design several elements of the telescope. This allowed optimization of the mechanical stiffness/mass ratio, leading to a lightweight and less expensive mechanical structure. These techniques and the resulting mechanical design are detailed in this paper. We will also describe the finite element analyses carried out to calculate the mechanical deformations and the stresses in the structure under observing and survival conditions.

  7. Cherenkov counter of extensive air showers for combined operation with the neutrino telescope NT-200

    International Nuclear Information System (INIS)

    The Baikal NT-200 neutrino telescope consists of 192 optical modules based on the Quasar-370 hybrid photodetectors. To study the angular resolution of NT-200 neutrino telescope one has developed the Cherenkov counter of extensive air showers with 1 deg angular resolution. Paper describes the electron structure of the facility made in terms of the CAMAC standard. One evaluates the measurement error for time intervals depending on the amplitude of output signals of photodetector. The counting rate of coinciding events of the Cherenkov counter for extensive air showers and of NT-200 deep-sea neutrino telescope constitutes about 0.5 min-1.Measuring of time interval between the trigger signals of the neutrino telescope and of the Cherenkov counter enables to suppress efficiently random coincidences and to obtain additional information on the muon trajectory

  8. First ground based measurement of atmospheric Cherenkov light from cosmic rays

    CERN Document Server

    Aharonian, F A; Bazer-Bachi, A R; Beilicke, M; Benbow, W; Berge, D; Bernlöhr, K; Boisson, C; Bolz, O; Borrel, V; Braun, I; Brion, E; Brown, A M; Buhler, R; Büsching, I; Carrigan, S; Chadwick, P M; Chounet, L M; Coignet, G; Cornils, R; Costamante, L; Degrange, B; Dickinson, H J; Djannati-Atai, A; O'Connor-Drury, L; Dubus, G; Egberts, K; Emmanoulopoulos, D; Espigat, P; Feinstein, F; Ferrero, E; Fiasson, A; Fontaine, G; Funk, Seb; Funk, S; Fussling, M; Gallant, Y A; Giebels, B; Glicenstein, J F; Glück, B; Goret, P; Hadjichristidis, C; Hauser, D; Hauser, M; Heinzelmann, G; Henri, G; Hermann, G; Hinton, J A; Hoffmann, A; Hofmann, W; Holleran, M; Hoppe, S; Horns, D; Jacholkowska, A; De Jager, O C; Kendziorra, E; Kerschhaggl, M; Khelifi, B; Komin, Nu; Konopelko, A; Kosack, K; Lamanna, G; Latham, I J; Le Gallou, R; Lemiere, A; Lemoine-Goumard, M; Lohse, T; Martin, J M; Martineau-Huynh, O; Marcowith, A; Masterson, C; Maurin, G; McComb, T J L; Moulin, E; De Naurois, Mathieu; Nedbal, D; Nolan, S J; Noutsos, A; Olive, J P; Orford, K J; Osborne, J L; Panter, M; Pelletier, G; Pita, S; Pühlhofer, G; Punch, M; Ranchon, S; Raubenheimer, B C; Raue, M; Rayner, S M; Reimer, A; Ripken, J; Rob, L; Rolland, L; Rosier-Lees, S; Rowell, G; Sahakian, V V; Santangelo, A; Sauge, L; Schlenker, S; Schlickeiser, R; Schroder, R; Schwanke, U; Schwarzburg, S; Schwemmer, S; Shalchi, A; Sol, H; Spangler, D; Spanier, F; Steenkamp, R; Stegmann, C; Superina, G; Tam, P H; Tavernet, J P; Terrier, R; Tluczykont, M; Van Eldik, C; Vasileiadis, G; Venter, C; Vialle, J P; Vincent, P; Völk, H J; Wagner, S J; Ward, M

    2007-01-01

    A recently proposed novel technique for the detection of cosmic rays with arrays of Imaging Atmospheric Cherenkov Telescopes is applied to data from the High Energy Stereoscopic System (H.E.S.S.). The method relies on the ground based detection of Cherenkov light emitted from the primary particle prior to its first interaction in the atmosphere. The charge of the primary particle (Z) can be estimated from the intensity of this light, since it is proportional to Z$^2$. Using H.E.S.S. data, an energy spectrum for cosmic-ray iron nuclei in the energy range 13--200 TeV is derived. The reconstructed spectrum is consistent with previous direct measurements and is one of the most precise so far in this energy range.

  9. A template method for measuring the iron spectrum in cosmic rays with Cherenkov telescopes

    CERN Document Server

    Fleischhack, Henrike

    2015-01-01

    The energy-dependent abundance of elements in cosmic rays plays an important role in understanding their acceleration and propagation. Most current results are obtained either from direct measurements by balloon- or satellite-borne detectors, or from indirect measurements by air shower detector arrays on the Earth's surface. Imaging Atmospheric Cherenkov Telescopes (IACTs), used primarily for $\\gamma$-ray astronomy, can also be used for cosmic-ray physics. They are able to measure Cherenkov light emitted both by heavy nuclei and by secondary particles produced in air showers, and are thus sensitive to the charge and energy of cosmic ray particles with energies of tens to hundreds of TeV. A template-based method, which can be used to reconstruct the charge and energy of primary particles simultaneously from images taken by IACTs, will be introduced. Heavy nuclei, such as iron, can be separated from lighter cosmic rays with this method, and thus the abundance and spectrum of these nuclei can be measured in the ...

  10. FlashCam: a fully-digital camera for the medium-sized telescopes of the Cherenkov Telescope Array

    OpenAIRE

    Pühlhofer, G.; Bauer, C.; Bernhard, S.; Capasso, M.; Diebold, S; Eisenkolb, F.; Florin, D.; Föhr, C.; S Funk; Gadola, A.; Garrecht, F.; Hermann, G.; Jung, I.; Kalekin, O.(Erlangen Centre for Astroparticle Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany); Kalkuhl, C.

    2015-01-01

    The FlashCam group is currently preparing photomultiplier-tube based cameras proposed for the medium-sized telescopes (MST) of the Cherenkov Telescope Array (CTA). The cameras are designed around the FlashCam readout concept which is the first fully-digital readout system for Cherenkov cameras, based on commercial FADCs and FPGAs as key components for the front-end electronics modules and a high performance camera server as back-end. This contribution describes the progress of the full-scale ...

  11. Observation of Optical Flashes of the Night Star Sky on the Atmospheric Cherenkov Installation Tunka-13

    OpenAIRE

    Gress, O. A.; Gress, T. I.; Pan'kov, L. V.; Parfenov, Yu. V.; Semeney, Yu. A.; Kuzmichev, L. A.

    2000-01-01

    Experiment on the study of fluctuation of night glow is conducted on the base of 13 module atmospheric Cherenkov telescope TUNKA-13.Basic task of TUNKA-13 is registration of light from Extended Air Shower (EAS) initiated by primary cosmic particles. Observation of light flashes radiating in nigght atmosphere is one more experiment which is run for TUNKA-13 to study the background condition for EAS registration. At a period from December 1997 on a May 1998 was registered 149 light flashes of r...

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

    CERN Document Server

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

    2013-01-01

    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.

  13. Towards SiPM camera for current and future generations of Cherenkov telescopes

    CERN Document Server

    Mazin, Daniel; Sitarek, Julian; Cortina, Juan; Fink, David; Hose, Jürgen; Illa, Jose Maria; Lorenz, Eckart; Martínez, Manel; Menzel, Uta; Mirzoyan, Razmik; Teshima, Masahiro

    2014-01-01

    So far the current ground-based Imaging Atmospheric Cherenkov Telescopes (IACTs) have energy thresholds in the best case in the range of ~30 to 50 GeV (H.E.S.S. II and MAGIC telescopes). Lowest energy gamma-ray showers produce low light intensity images and cannot be efficiently separated from dominating images from hadronic background. A cost effective way of improving the telescope performance at lower energies is to use novel photosensors with superior photon detection efficiency (PDE). Currently the best commercially available superbialkali photomultipliers (PMTs) have a PDE of about 30-33%, whereas the silicon photomultipliers (SiPMs, also known as MPPC, GAPD) from some manufacturers show a photon detection efficiency of about 40-45%. Using these devices can lower the energy threshold of the instrument and may improve the background rejection due to intrinsic properties of SiPMs such as a superb single photoelectron resolution. Compared to PMTs, SiPMs are more compact, fast in response, operate at low vo...

  14. 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...

  15. Prototyping of Hexagonal Light Concentrators for the Large-Sized Telescopes of the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    Reflective light concentrators with hexagonal entrance and exit apertures are frequently used at the focal plane of gamma-ray telescopes in order to reduce the size of the dead area caused by the geometries of the photodetectors, as well as to reduce the amount of stray light entering at large field angles. The focal plane of the large-sized telescopes (LSTs) of the Cherenkov Telescope Array (CTA) will also be covered by hexagonal light concentrators with an entrance diameter of 50 mm (side to side) to maximize the active area and the photon collection efficiency, enabling realization of a very low energy threshold of 20 GeV. We have developed a prototype of this LST light concentrator with an injection-molded plastic cone and a specular multilayer film. The shape of the plastic cone has been optimized with a cubic B\\'{e}zier curve and a ray-tracing simulation. We have also developed a multilayer film with very high reflectance ($\\gtrsim95$\\%) along wide wavelength and angle coverage. The current status of th...

  16. Divergent pointing with the Cherenkov Telescope Array for surveys and beyond

    CERN Document Server

    ,

    2015-01-01

    The galactic and extragalactic surveys are two of the main proposed legacy projects of the Cherenkov Telescope Array (CTA), providing an unbiased view of the Universe at energies above tens of GeV. Considering Cherenkov telescopes' limited field of view ($<10^\\circ$), the time needed for those projects is large. The many telescopes of CTA will allow taking full advantage of new pointing modes in which telescopes point slightly offset from one another. This divergent pointing mode leads to an increase of the array field of view ($\\sim 14^\\circ$ or larger) with competitive performance compared to normal pointing. We present here a study of the performance of the divergent pointing for different array configurations and number of telescopes. We briefly discuss the prospect of using divergent pointing for surveys.

  17. Construction of a medium-sized Schwarzschild-Couder telescope as a candidate for the Cherenkov Telescope Array: development of the optical alignment system

    CERN Document Server

    Nieto, D; Humensky, B; Kaaret, P; Limon, M; Mognet, I; Peck, A; Petrashyk, A; Ribeiro, D; Rousselle, J; Stevenson, B; Vassiliev, V; Yu, P

    2015-01-01

    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 (SC) medium-size candidate telescope model features a novel aplanatic two-mirror optical design capable of a wide field-of-view with significantly improved imaging resolution as compared to the traditional Davis-Cotton optics design. Achieving this imaging resolution imposes strict alignment requirements to be accomplished by a dedicated alignment system. 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 at the Fred Lawrence Whipple Observatory in southern ...

  18. Towards a network of atmospheric Cherenkov detectors 7

    International Nuclear Information System (INIS)

    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

  19. 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.

  20. The Optical System for the Large Size Telescope of the Cherenkov Telescope Array

    CERN Document Server

    Hayashida, M; Teshima, M; de Almeida, U Barres; Chikawa, M; Cho, N; Fukami, S; Gadola, A; Hanabata, Y; Horns, D; Jablonski, C; Katagiri, H; Kagaya, M; Ogino, M; Okumura, A; Saito, T; Stadler, R; Steiner, S; Straumann, U; Vollhardt, A; Wetteskind, H; Yamamoto, T; Yoshida, T

    2015-01-01

    The Large Size Telescope (LST) of the Cherenkov Telescope Array (CTA) is designed to achieve a threshold energy of 20 GeV. The LST optics is composed of one parabolic primary mirror 23 m in diameter and 28 m focal length. The reflector dish is segmented in 198 hexagonal, 1.51 m flat to flat mirrors. The total effective reflective area, taking into account the shadow of the mechanical structure, is about 368 m$^2$. The mirrors have a sandwich structure consisting of a glass sheet of 2.7 mm thickness, aluminum honeycomb of 60 mm thickness, and another glass sheet on the rear, and have a total weight about 47 kg. The mirror surface is produced using a sputtering deposition technique to apply a 5-layer coating, and the mirrors reach a reflectivity of $\\sim$94% at peak. The mirror facets are actively aligned during operations by an active mirror control system, using actuators, CMOS cameras and a reference laser. Each mirror facet carries a CMOS camera, which measures the position of the light spot of the optical ...

  1. Development of Slow Control Boards for the Large Size Telescopes of the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    The camera of the Large Size Telescopes (LSTs) of the Cherenkov Telescope Array (CTA) consists of 265 photosensor modules, each of them containing 7 photomultiplier tubes (PMTs), a slow control board (SCB), a readout board, and a trigger logic. We have developed the SCB, which is installed between the 7 PMTs and the readout board. The main task for SCBs is the controlling of the high voltages for the PMTs and the monitoring of their anode currents. In addition, the SCB provides the functionality to create test pulses that can be injected at the input of the PMT preamplifier in order to emulate a PMT signal without the need of setting a high voltage, or even without the PMT itself. The test pulses have a very similar width as the PMT pulses (less than 3 ns FWHM) and their amplitude can be adjusted in a wide dynamic range. These features allow us not only to test the functionality of the camera modules but also to fully characterize these. We report on the design and the functions of the SCB together with the r...

  2. Satellite Characterization of four candidate sites for the Cherenkov Telescope Array telescope

    CERN Document Server

    Cavazzani, S; Bulik, T; Ortolani, S

    2012-01-01

    In this paper we have evaluated the amount of available telescope time at four sites which are candidate to host the future Cherenkov Telescope Array (CTA). We use the GOES 12 data for the years 2008 and 2009. We use a homogeneous methodology presented in several previous papers to classify the nights as clear (completely cloud-free), mixed (partially cloud-covered), and covered. Additionally, for the clear nights, we have evaluated the amount of satellite stable nights which correspond to the amount of ground based photometric nights, and the clear nights corresponding to the spectroscopic nights. We have applied this model to two sites in the Northern Hemisphere (San Pedro Martir (SPM), Mexico; Izana, Canary Islands) and to two sites in the Southern Hemisphere (El Leoncito, Argentine; San Antonio de Los Cobres (SAC), Argentine). We have obtained, from the two years considered, a mean amount of cloud free nights of 68.6% at Izana, 76.0% at SPM, 70.6% at Leoncito and 70.0% at SAC. We have evaluated, among the...

  3. NectarCAM : a camera for the medium size telescopes of the Cherenkov Telescope Array

    CERN Document Server

    Glicenstein, J-F; Barrio, J-A; Blanch~Bigas, O; Bolmont, J; Bouyjou, F; Brun, P; Chabanne, E; Champion, C; Colonges, S; Corona, P; Delagnes, E; Delgado, C; Ginzov, C Diaz; Durand, D; Ernenwein, J-P; Fegan, S; Ferreira, O; Fesquet, M; Fiasson, A; Fontaine, G; Fouque, N; Gascon, D; Giebels, B; Henault, F; Hermel, R; Hoffmann, D; Horan, D; Houles, J; Jean, P; Jocou, L; Karkar, S; Knoedlseder, J; Kossakowski, R; Lamanna, G; LeFlour, T; Lenain, J-P; Leveque, A; Louis, F; Martinez, G; Moudden, Y; Moulin, E; Nayman, P; Nunio, F; Olive, J-F; Panazol, J-L; Pavy, S; Petrucci, P-O; Pierre, E; Prast, J; Punch, M; Ramon, P; Rateau, S; Ravel, T; Rosier-Lees, S; Sanuy, A; Shayduk, M; Sizun, P-Y; Sulanke, K-H; Tavernet, J-P; Tejedor~Alvarez, L-A; Toussenel, F; Vasileiadis, G; Voisin, V; Waegebert, V; Wischnewski, R

    2015-01-01

    NectarCAM is a camera proposed for the medium-sized telescopes of the Cherenkov Telescope Array (CTA) covering the central energy range of ~100 GeV to ~30 TeV. It has a modular design and is based on the NECTAr chip, at the heart of which is a GHz sampling Switched Capacitor Array and a 12-bit Analog to Digital converter. The camera will be equipped with 265 7-photomultiplier modules, covering a field of view of 8 degrees. Each module includes the photomultiplier bases, high voltage supply, pre-amplifier, trigger, readout and Ethernet transceiver. The recorded events last between a few nanoseconds and tens of nanoseconds. The camera trigger will be flexible so as to minimize the read-out dead-time of the NECTAr chips. NectarCAM is designed to sustain a data rate of more than 4 kHz with less than 5\\% dead time. The camera concept, the design and tests of the various subcomponents and results of thermal and electrical prototypes are presented. The design includes the mechanical structure, cooling of the electro...

  4. Recent developments for the testing of Cherenkov Telescope Array mirrors and actuators in T\\"ubingen

    CERN Document Server

    ,

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next generation Cherenkov telescope facility. It will consist of a large number of segmented-mirror telescopes of three different diameters, placed in two locations, one in the northern and one in the southern hemisphere, thus covering the whole sky. The total number of mirror tiles will be on the order of 10,000, corresponding to a reflective area of ~10^4 m^2. The Institute for Astronomy and Astrophysics in T\\"ubingen (IAAT) is currently developing mirror control alignment mechanics, electronics, and software optimized for the medium sized telescopes. In addition, IAAT is participating in the CTA mirror prototype testing. In this paper we present the status of the current developments, the main results of recent tests, and plans for the production phase of the mirror control system. We also briefly present the T\\"ubingen facility for mirror testing.

  5. Ground-based VHE γ ray astronomy with air Cherenkov imaging telescopes

    International Nuclear Information System (INIS)

    The history of astronomy has been one of the scientific discovery following immediately the introduction of new technology. In this report, we will review shortly the basic development of the atmospheric air Cherenkov light detection technique, particularly the imaging telescope technique, which in the last years led to the firm establishment of a new branch in experimental astronomy, namely ground-based very high-energy (VHE) γ ray astronomy. Milestones in the technology and in the analysis of imaging technique will be discussed. The design of the 17 m diameter MAGIC Telescope, being currently under construction, is based on the development of new technologies for all its major parts and sets new standards in the performance of the ground-based γ detectors. MAGIC is one of the next major steps in the development of the technique being the first instrument that will allow one to carry out measurements also in the not yet investigated energy gap i.e. between 10 and 300 GeV

  6. From MAGIC to CTA: the INAF participation to Cherenkov Telescopes experiments for Very High Energy Astrophysics

    CERN Document Server

    Antonelli, L Angelo

    2008-01-01

    The next decade can be considered the "golden age" of the Gamma Ray Astronomy with the two satellites for Gamma Ray Astronomy (AGILE and GLAST) in orbit. Therefore, thanks to many other X-ray experiments already in orbit (e.g. Swift, Chandra, NewtonXMM, etc.) it will be possible to image the Universe for the first time all over the electromagnetic spectrum almost contemporarily. The new generations of ground-based very high gamma-ray instruments are ready to extend the observed band also to the very high frequencies. Scientists from the Italian National Institute for Astrophysics (INAF) are involved in many, both space- and ground- based gamma ray experiments, and recently such an involvement has been largely improved in the field of the Imaging Atmospheric Cherenkov Telescopes (IACT). INAF is now member of the MAGIC collaboration and is participating to the realization of the second MAGIC telescope. MAGIC, as well other IACT experiments, is not operated as an observatory so a proper guest observer program do...

  7. TARGET: toward a solution for the readout electronics of the Cherenkov Telescope Array

    CERN Document Server

    Tibaldo, L; Albert, A M; Funk, S; Kawashima, T; Kraus, M; Okumura, A; Sapozhnikov, L; Tajima, H; Varner, G S; Wu, T; Zink, A

    2015-01-01

    TARGET is an application specific integrated circuit (ASIC) designed to read out signals recorded by the photosensors in cameras of very-high-energy gamma-ray telescopes exploiting the imaging of Cherenkov radiation from atmospheric showers. TARGET capabilities include sampling at a high rate (typically 1 GSample/s), digitization, and triggering on the sum of four adjacent pixels. The small size, large number of channels read out per ASIC (16), low cost per channel, and deep buffer for trigger latency (~16 $\\mu$s at 1 GSample/s) make TARGET ideally suited for the readout in systems with a large number of telescopes instrumented with compact photosensors like multi-anode or silicon photomultipliers combined with dual-mirror optics. The possible advantages of such systems are better sensitivity, a larger field of view, and improved angular resolution. The two latest generations of TARGET ASICs, TARGET 5 and TARGET 7, are soon to be used for the first time in two prototypes of small-sized and medium-sized dual-m...

  8. TeV to PeV neutrinos and gamma-rays with Mountain SHALON Mirror Cherenkov Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Sinitsyna, V.G.; Arsov, T.P.; Musin, F.I.; Nikolsky, S.I.; Sinitsyna, V.Y.; Platonov, G.F. [P.N. Lebedev Physical Institute, Leninsky prospect 53, Moscow, 119991 (Russian Federation)

    2008-01-15

    Problems in observation of extensive air showers generated by neutrinos are connected with an extremely small cross-section of inelastic collisions of neutrinos with nuclei. However, two facts allow to search for showers generated by neutrinos: (1) a hadron cascade with a primary energy of more than 10{sup 13} eV leaves a mountain ridge to the atmosphere from a depth {approx} 300 g/cm{sup 2} without any essential loss of the total energy in the hadron cascade, and (2) air Cherenkov radiation from such hadron cascades will be observed with a 7.5 km distant telescope over an area of more than 7x10{sup 5}m{sup 2}. This partially compensates for the small cross-section of inelastic neutrino collisions. Observations have been carried out since 1992 at the high mountain Tien-Shan station using the SHALON Cherenkov mirror telescope with {approx}11.2 m{sup 2} mirror area and image matrix of 144 PMT with full angle >8{sup o}. The telescope characteristics allowed to start searching for local neutrino sources with energy 10{sup 13}-10{sup 16} eV on EAS generated in the mountain-range located at some 7.5 and more kilometers from the gamma-telescope (in Russian the abbreviation SHALON means - the Extensive Air Showers from Neutrino)

  9. Stellar intensity interferometry over kilometer baselines: Laboratory simulation of observations with the Cherenkov Telescope Array

    OpenAIRE

    Dravins, Dainis; Lagadec, Tiphaine

    2014-01-01

    A long-held astronomical vision is to realize diffraction-limited optical aperture synthesis over kilometer baselines. This will enable imaging of stellar surfaces and their environments, show their evolution over time, and reveal interactions of stellar winds and gas flows in binary star systems. An opportunity is now opening up with the large telescope arrays primarily erected for measuring Cherenkov light in air induced by gamma rays. With suitable software, such telescopes could be electr...

  10. The mini-array of ASTRI SST-2M telescopes, precursors for the Cherenkov Telescope Array

    Science.gov (United States)

    Pareschi, Giovanni; Bonnoli, Giacomo; Vercellone, Stefano; ASTRI Collaboration; CTA Consortium

    2016-05-01

    In the framework of the Cherenkov Telescope Array (CTA) Observatory, the Italian National Institute of Astrophysics (INAF) has recently inaugurated in Sicily (Italy), at the Serra La Nave astronomical site on the slopes of Mount Etna, a large field of view (FoV, ~ 9.6°) dual-mirror prototype (ASTRI SST-2M) of the CTA small size class of telescopes (SST). The CTA plans to install about 70 SST in the southern site to allow the study of the gamma rays from a few TeV up to hundreds of TeV. The ASTRI SST-2M telescope prototype has been developed following an end-to-end approach, since it includes the entire system of structure, mirrors optics (primary and secondary mirrors), camera, and control/acquisition software. A remarkable performance improvement could come from the operation of the ASTRI mini-array, led by INAF in synergy with the Universidade de Sao Paulo (Brazil) and the North-West University (South Africa). The ASTRI mini-array will be composed of nine ASTRI SST-2M units and it is proposed as a precursor and initial seed of the CTA to be installed at the final CTA southern site. Apart from the assessment of a number of technological aspects related to the CTA, the ASTRI mini-array will, if compared for instance to H.E.S.S., extend the point source sensitivity up to ~ 100 TeV, also improving it above 5-10 TeV. Moreover, the unprecedented width of the FoV, with its homogeneous acceptance and angular resolution, will significantly contribute to the achievement of original results during the early CTA science phase.

  11. NICHE: Using Cherenkov radiation to extend Telescope Array to sub-PeV energies

    Science.gov (United States)

    Bergman, Douglas; Krizmanic, John; Tsunesada, Yoshiki; Abu-Zayyad, Tareq; Belz, John; Thomson, Gordon

    2016-03-01

    The Non-Imaging CHErenkov (NICHE) Array will measure the flux and nuclear composition evolution of cosmic rays (CRs) from below 1 PeV to 1 EeV. NICHE will be co-sited with the Telescope Array (TA) Low Energy (TALE) extension, and will observe events simultaneously with the TALE telescopes acting in imaging-Cherenkov mode. This will be the first hybrid-Cherenkov (simultaneous imaging and non-imaging Cherenkov) measurements of CRs in the Knee region of the CR energy spectrum. NICHE uses easily deployable detectors to measure the amplitude and time-spread of the air-shower Cherenkov signal to achieve an event-by-event measurement of Xmax and energy, each with excellent resolution. First generation detectors are under construction and will form an initial prototype array (j-NICHE) that will be deployed in Summer 2016. In this talk, the NICHE design, array performance, prototype development, and status will be discussed as well as NICHE's ability to measure the cosmic ray nuclear composition as a function of energy.

  12. GAW, Gamma Air Watch - A Large Field of View Imaging Atmospheric Cherenkov

    CERN Document Server

    Maccarone, M C; Assis, P; Biondo, B; Brogueira, P; Catalano, O; Celi, F; Costa, J; Cusumano, G; Delgado, C; Cocco, G D; Espirito-Santo, M C; Galeotti, P; Giarrusso, S; La Barbera, A; La Rosa, G; Mangano, A; Mineo, T; Moles, M; Pimenta, M; Prada, F; Russo, F; Sacco, B; Sanchez, M A; Segreto, A; Tome', B; De Postigo, A U; Vallania, P; Vigorito, C

    2005-01-01

    GAW, acronym for Gamma Air Watch, is a path-finder experiment to test the feasibility of a new generation of imaging atmospheric Cherenkov telescopes that join high flux sensitivity with large field of view capability. GAW is conceived as an array of three identical imaging telescopes disposed at the vertexes of an equilateral triangle, about 80 m side. Two main features characterize GAW with respect to all the existing and presently planned ground-based Cherenkov telescopes. The first difference concerns the optics system: GAW uses a Fresnel refractive lens (2.13 m diameter) as light collector instead of classical reflective mirror. The second main difference is the detection working mode used: the detector at the focal surface operates in single photoelectron counting mode instead of the usual charge integration one. The GAW array is planned to be located at the Calar Alto Observatory site, Spain, 2150 m a.s.l. During its first phase, only 6x6 degrees of the focal plane detector will be implemented; moving ...

  13. The ASTRI Project: a mini-array of dual-mirror small Cherenkov telescopes for CTA

    CERN Document Server

    La Palombara, N; Antonelli, L A; Bastieri, D; Bellassai, G; Belluso, M; Bigongiari, C; Billotta, S; Biondo, B; Bonanno, G; Bonnoli, G; Bruno, P; Bulgarelli, A; Canestrari, R; Capalbi, M; Caraveo, P; Carosi, A; Cascone, E; Catalano, O; Cereda, M; Conconi, P; Conforti, V; Cusumano, G; De Caprio, V; De Luca, A; Di Paola, A; Di Pierro, F; Fantinel, D; Fiorini, M; Fugazza, D; Gardiol, D; Ghigo, M; Gianotti, F; Giarrusso, S; Giro, E; Grillo, A; Impiombato, D; Incorvaia, S; La Barbera, A; La Parola, V; La Rosa, G; Lessio, L; Leto, G; Lombardi, S; Lucarelli, F; Maccarone, M C; Malaguti, G; Malaspina, G; Mangano, V; Marano, D; Martinetti, E; Millul, R; Mineo, T; Mistó, A; Morello, C; Morlino, G; Panzera, M R; Pareschi, G; Rodeghiero, G; Romano, P; Russo, F; Sacco, B; Sartore, N; Schwarz, J; Segreto, A; Sironi, G; Sottile, G; Stamerra, A; Strazzeri, E; Stringhetti, L; Tagliaferri, G; Testa, V; Timpanaro, M C; Toso, G; Tosti, G; Trifoglio, M; Vallania, P; Vercellone, S; Zitelli, V

    2013-01-01

    ASTRI is a flagship project of the Italian Ministry of Education, University and Research, which aims to develop an end-to-end prototype of the CTA small-size telescope. The proposed design is characterized by a dual-mirror Schwarzschild-Couder configuration and a camera based on Silicon photo-multipliers, two challenging but innovative technological solutions which will be adopted for the first time on a Cherenkov telescope. Here we describe the current status of the project, the expected performance and the possibility to realize a mini-array composed by a few small-size telescopes, which shall be placed at the final CTA Southern Site.

  14. FlashCam: a fully-digital camera for the medium-sized telescopes of the Cherenkov Telescope Array

    CERN Document Server

    Pühlhofer, G; Bernhard, S; Capasso, M; Diebold, S; Eisenkolb, F; Florin, D; Föhr, C; Funk, S; Gadola, A; Garrecht, F; Hermann, G; Jung, I; Kalekin, O; Kalkuhl, C; Kasperek, J; Kihm, T; Lahmann, R; Manalaysay, A; Marszalek, A; Pfeifer, M; Rajda, P J; Reimer, O; Santangelo, A; Schanz, T; Schwab, T; Steiner, S; Straumann, U; Tenzer, C; Vollhardt, A; Weitzel, Q; Werner, F; Wolf, D; Zietara, K

    2015-01-01

    The FlashCam group is currently preparing photomultiplier-tube based cameras proposed for the medium-sized telescopes (MST) of the Cherenkov Telescope Array (CTA). The cameras are designed around the FlashCam readout concept which is the first fully-digital readout system for Cherenkov cameras, based on commercial FADCs and FPGAs as key components for the front-end electronics modules and a high performance camera server as back-end. This contribution describes the progress of the full-scale FlashCam camera prototype currently under construction, as well as performance results also obtained with earlier demonstrator setups. Plans towards the production and implementation of FlashCams on site are also briefly presented.

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

    CERN Document Server

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

    2013-01-01

    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.

  16. Observation of Optical Flashes of the Night Star Sky on the Atmospheric Cherenkov Installation Tunka-13

    CERN Document Server

    Gress, O A; Pankov, L V; Parfenov, Y V; Semeney, Y A; Kuzmichev, L A; Parfenov, Yu. V.; Semeney, Yu. A.

    2000-01-01

    Experiment on the study of fluctuation of night glow is conducted on the base of 13 module atmospheric Cherenkov telescope TUNKA-13.Basic task of TUNKA-13 is registration of light from Extended Air Shower (EAS) initiated by primary cosmic particles. Observation of light flashes radiating in nigght atmosphere is one more experiment which is run for TUNKA-13 to study the background condition for EAS registration. At a period from December 1997 on a May 1998 was registered 149 light flashes of radiwting night atmosphere with duration from 16 ms to 190 seconds. General time of night observing has formed 237 hours. Coincidence of optical flashes with the gamma-bursts from the catalogue of BATSE experiment of observatories "Compton" was analysed.

  17. Comparison of Different Trigger and Readout Approaches for Cameras in the Cherenkov Telescope Array Project

    CERN Document Server

    Shayduk, M; Schwanke, U

    2013-01-01

    The Cherenkov Telescope Array (CTA) is a next-generation ground-based observatory for g -rays with energies between some ten GeV and a few hundred TeV. CTA is currently in the advanced design phase and will consist of arrays with different size of prime-focus Cherenkov telescopes, to ensure a proper energy coverage from the threshold up to the highest energies. The extension of the CTA array with double-mirror Schwarzschild- Couder telescopes is planned to improve the array angular resolution over wider field of view.We present an end-to-end Monte-Carlo comparison of trigger concepts for the different imaging cameras that will be used on the Cherenkov telescopes. The comparison comprises three alternative trigger schemes (analog, majority, flexible pattern analysis) for each camera design. The study also addresses the influence of the properties of the readout system (analog bandwidth of the electronics, length of the readout window in time) and uses an offline shower reconstruction to investigate the impact ...

  18. Dark matter searches with Cherenkov telescopes: nearby dwarf galaxies or local galaxy clusters?

    CERN Document Server

    Sanchez-Conde, Miguel A; Zandanel, F; Gomez, Mario E; Prada, F

    2011-01-01

    In the last few years, most of the attention in gamma-ray dark matter (DM) searches has been devoted to neutralino annihilations in nearby dwarf galaxies. However, massive galaxy clusters in the local Universe may constitute very good targets as well. The main aim of this work is to compare both dwarf galaxies and local 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 and galaxy clusters, 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 and, given the morphology of its annihilation signal, it is also one of the objects more readily observable by IACTs. As for galaxy clusters, Virgo represents the one with the hi...

  19. Capability of Cherenkov Telescopes to Observe Ultra-fast Optical Flares

    CERN Document Server

    Deil, C; Hermann, G; Clapson, A -C; Förster, A; Van Eldik, C; Hofmann, W

    2008-01-01

    The large optical reflector (~ 100 m^2) of a H.E.S.S. Cherenkov telescope was used to search for very fast optical transients of astrophysical origin. 43 hours of observations targeting stellar-mass black holes and neutron stars were obtained using a dedicated photometer with microsecond time resolution. The photometer consists of seven photomultiplier tube pixels: a central one to monitor the target and a surrounding ring of six pixels to veto background events. The light curves of all pixels were recorded continuously and were searched offline with a matched-filtering technique for flares with a duration of 2 us to 100 ms. As expected, many unresolved (500 us) background events originating in the earth's atmosphere were detected. In the time range 3 to 500 us the measurement is essentially background-free, with only eight events detected in 43 h; five from lightning and three presumably from a piece of space debris. The detection of flashes of brightness ~ 0.1 Jy and only 20 us duration from the space debri...

  20. Development of the photomultiplier tube readout system for the first Large-Sized Telescope of the Cherenkov Telescope Array

    OpenAIRE

    Masuda, Shu; Konno, Yusuke; Barrio, Juan Abel; Bigas, Oscar Blanch; Delgado, Carlos; Coromina, Lluís Freixas; Gunji, Shuichi; Hadasch, Daniela; Hatanaka, Kenichiro; Ikeno, Masahiro; Laguna, Jose Maria Illa; Inome, Yusuke; Ishio, Kazuma; Katagiri, Hideaki; Kubo, Hidetoshi

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next generation ground-based very high energy gamma-ray observatory. The Large-Sized Telescope (LST) of CTA targets 20 GeV -- 1 TeV gamma rays and has 1855 photomultiplier tubes (PMTs) installed in the focal plane camera. With the 23 m mirror dish, the night sky background (NSB) rate amounts to several hundreds MHz per pixel. In order to record clean images of gamma-ray showers with minimal NSB contamination, a fast sampling of the signal waveform is...

  1. Developments for coating, testing, and aligning Cherenkov Telescope Array mirrors in T\\"ubingen

    CERN Document Server

    Bonardi, A; Kendziorra, E; Pühlhofer, G

    2013-01-01

    The Cherenkov Telescope Array (CTA) is the next generation very-high energy gamma-ray air-shower Cherenkov observatory. CTA will consist of many segmented-mirror telescopes of three different diameters, placed in two arrays, one in the Northern hemisphere and one in the South, thus covering the whole sky. The total number of mirror tiles will be of the order of 10000, corresponding to a reflective area of ~10^4 m^2. The Institute for Astronomy and Astrophysics in T\\"ubingen is developing procedures to coat glass-substrate-based mirror tiles, is participating to the CTA mirror prototype testing, and is prototyping Active Mirror Control alignment mechanics, electronics and software. We will present the current status of our work and plans for future developments.

  2. Prospects for annihilating Dark Matter towards Milky Way's dwarf galaxies by the Cherenkov Telescope Array

    OpenAIRE

    Lefranc, Valentin; Panci, Paolo; Mamon, Gary A.

    2016-01-01

    We derive the large Cherenkov Telescope Array (CTA) sensitivity to dark matter (DM) annihilation in several primary channels, over a broad range of DM masses. These sensitivities are estimated when CTA is pointed towards a large sample of Milky Way's dwarf spheroidal galaxies (dSphs) with promising $J$-factors and small statistical uncertainties. This analysis neglects systematic uncertainties, which we estimate at the level of at least 1 dex. We also present sensitivities on the annihilation...

  3. Monte Carlo Simulations For The Cherenkov Telescope Array Observatory Using Pl-Grid E-Infrastructure

    Directory of Open Access Journals (Sweden)

    Anna Barnacka

    2012-01-01

    Full Text Available The paper presents Monte Carlo simulations carried out during the preparatory phase of the Cherenkov Telescope Array project. The aim of the project is to build the next generation observatory of very high energy gamma rays. During the preparatory phase there is a need to optimize and verify design concepts for various elements of the array. In this paper we describe the main components of the software being used for that purpose, their functions and requirements. Preliminary results of the optimization of the small telescope – one of the several kinds intended for the array, are presented.

  4. The ASTRI Project: a mini-array of dual-mirror small Cherenkov telescopes for CTA

    OpenAIRE

    La Palombara, N.; Agnetta, G; Antonelli, L.A.; Bastieri, D.; Bellassai, G.; Belluso, M; Bigongiari, C.; Billotta, S.; Biondo, B.; Bonanno, G.; Bonnoli, G.; Bruno, P; Bulgarelli, A.; Canestrari, R.; Capalbi, M.

    2013-01-01

    ASTRI is a flagship project of the Italian Ministry of Education, University and Research, which aims to develop an end-to-end prototype of the CTA small-size telescope. The proposed design is characterized by a dual-mirror Schwarzschild-Couder configuration and a camera based on Silicon photo-multipliers, two challenging but innovative technological solutions which will be adopted for the first time on a Cherenkov telescope. Here we describe the current status of the project, the expected pe...

  5. Using Raster Scans of Bright Stars to Measure the Relative Total Throughputs of Cherenkov Telescopes

    CERN Document Server

    Griffin, Sean

    2013-01-01

    Gamma-ray astronomy at energies in excess of 100 GeV is carried out using arrays of imaging Cherenkov telescopes. Each telescope comprises a large reflector, of order 10 m diameter, made of many mirror facets, and a camera consisting of a matrix of photomultiplier pixels. Differences in the total throughput between nominally identical telescopes, due to aging of the mirrors and PMTs and other effects, should be monitored to reduce possible systematic errors. One way to directly measure the throughput of such telescopes is to track bright stars and measure the photocurrents produced by their light falling on camera pixels. We have developed such a procedure using the four telescopes in the VERITAS array. We note the technique is general, however, and could be applied to other imaging Cherenkov experiments. For this measurement, a raster scan is performed on a single star such that its image is swept across the central pixels in the camera, thus providing a statistically robust set of measurements in a short pe...

  6. Simulating the optical performance of a small-sized telescope with secondary optics for the Cherenkov Telescope Array

    Science.gov (United States)

    Rulten, Cameron; Zech, Andreas; Okumura, Akira; Laporte, Philippe; Schmoll, Jürgen

    2016-09-01

    The Gamma-ray Cherenkov Telescope (GCT) is a small-sized telescope (SST) that represents one of three novel designs that are based on Schwarzschild-Couder optics and are proposed for use within the Cherenkov Telescope Array (CTA). The GAmma-ray Telescope Elements (GATE) program has led an effort to build a prototype of the GCT at the Paris Observatory in Meudon, France. The mechanical structure of the prototype, known as the SST-GATE prototype telescope, is now complete along with the successful installation of the camera. We present the results of extensive simulation work to determine the optical performance of the SST-GATE prototype telescope. Using the ROBAST software and assuming an ideal optical system, we find the radius of the encircled point spread function (θ80) of the SST-GATE to be ∼1.3 arcmin (∼0.02°) for an on-axis (θfield =0∘) observation and ∼3.6 arcmin (∼0.06°) for an observation at the edge of the field of view (θfield = 4 .4∘). In addition, this research highlights the shadowing that results from the stopping of light rays by various telescope components such as the support masts and trusses. It is shown that for on-axis observations the effective collection area decreases by approximately 1 m2 as a result of shadowing components other than the secondary mirror. This is a similar loss (∼11%) to that seen with the current generation of conventional Davies-Cotton (DC) Cherenkov telescopes. An extensive random tolerance analysis was also performed and it was found that certain parameters, especially the secondary mirror z-position and the tip and tilt rotations of the mirrors, are critical in order to contain θ80 within the pixel limit radius for all field angles. In addition, we have studied the impact upon the optical performance of introducing a hole in the center of the secondary mirror for use with pointing and alignment instruments. We find that a small circular area (radius collection efficiency for all field angles, but

  7. Software design for the control system for Small-Size Telescopes with single-mirror of the Cherenkov Telescope Array

    CERN Document Server

    :,; Błocki, J; Bogacz, L; Borkowski, J; 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; Rameez, M; Montaruli, T; Neronov, A; Niemiec, J; Ostrowski, M; Paśko, P; Pech, M; Porcelli, A; Prandini, E; Rajda, P; Schioppa, E jr; Schovanek, P; Seweryn, K; Skowron, K; Sliusar, V; Sowiński, M; Stawarz, Ł; Stodulska, M; Stodulski, M; Pujadas, I Troyano; Toscano, S; Walter, R; Wiȩcek, M; Zagdański, A; Ziȩtara, K; Zychowski, P

    2015-01-01

    The Small-Size Telescope with single-mirror (SST-1M) is a 4 m Davies-Cotton telescope and is among the proposed telescope designs for the Cherenkov Telescope Array (CTA). It is conceived to provide the high-energy ($>$ few TeV) coverage. The SST-1M contains proven technology for the telescope structure and innovative electronics and photosensors for the camera. Its design is meant to be simple, low-budget and easy-to-build industrially. Each device subsystem of an SST-1M telescope is made visible to CTA through a dedicated industrial standard server. The software is being developed in collaboration with the CTA Medium-Size Telescopes to ensure compatibility and uniformity of the array control. Early operations of the SST-1M prototype will be performed with a subset of the CTA central array control system based on the Alma Common Software (ACS). The triggered event data are time stamped, formatted and finally transmitted to the CTA data acquisition. The software system developed to control the devices of an SS...

  8. First results of the two square meters multilayer glass composite mirror design proposed for the Cherenkov Telescope Array developed at INFN

    CERN Document Server

    Schultz, C; Lessio, L; Mariotti, M; Rando, R

    2015-01-01

    The Cherenkov Telescope Array (CTA) is a future ground-based gamma-ray astronomy detector that will consist of more than 100 Imaging Atmospheric Cherenkov Telescopes of different sizes. The total reflective surface of roughly 10 000 m$^2$ requires unprecedented technological efforts towards a cost-efficient production of light-weight and reliable mirror substrates at high production rate. We report on a new mirror concept proposed for CTA developed by INFN, which is based on the replication from a spherical convex mold under low pressure. The mirror substrate is an open structure design made by thin glass layers at the mirror's front and rear interspaced by steel cylinders. A first series of nominal size mirrors has been produced, for which we discuss the optical properties in terms of radius of curvature and focusing power.

  9. Real-Time Analysis sensitivity evaluation of the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    The Cherenkov Telescope Array (CTA), the new generation very high-energy gamma-ray observatory, will improve the flux sensitivity of the current Cherenkov telescopes by an order of magnitude over a continuous range from about 10 GeV to above 100 TeV. With tens of telescopes distributed in the Northern and Southern hemispheres, the large effective area and field of view coupled with the fast pointing capability make CTA a crucial instrument for the detection and understanding of the physics of transient, short-timescale variability phenomena (e.g. Gamma-Ray Bursts, Active Galactic Nuclei, gamma-ray binaries, serendipitous sources). The key CTA system for the fast identification of flaring events is the Real-Time Analysis (RTA) pipeline, a science alert system that will automatically detect and generate science alerts with a maximum latency of 30 seconds with respect to the triggering event collection and ensure fast communication to/from the astrophysics community. According to the CTA design requirements, the...

  10. Development of the photomultiplier tube readout system for the first Large-Sized Telescope of the Cherenkov Telescope Array

    CERN Document Server

    Masuda, Shu; Barrio, Juan Abel; Bigas, Oscar Blanch; Delgado, Carlos; Coromina, Lluís Freixas; Gunji, Shuichi; Hadasch, Daniela; Hatanaka, Kenichiro; Ikeno, Masahiro; Laguna, Jose Maria Illa; Inome, Yusuke; Ishio, Kazuma; Katagiri, Hideaki; Kubo, Hidetoshi; Martínez, Gustavo; Mazin, Daniel; Nakajima, Daisuke; Nakamori, Takeshi; Ohoka, Hideyuki; Paoletti, Riccardo; Ritt, Stefan; Rugliancich, Andrea; Saito, Takayuki; Sulanke, Karl-Heinz; Takeda, Junki; Tanaka, Manobu; Tanigawa, Shunsuke; Tejedor, Luis Ángel; Teshima, Masahiro; Tsuchiya, Yugo; Uchida, Tomohisa; Yamamoto, Tokonatsu

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next generation ground-based very high energy gamma-ray observatory. The Large-Sized Telescope (LST) of CTA targets 20 GeV -- 1 TeV gamma rays and has 1855 photomultiplier tubes (PMTs) installed in the focal plane camera. With the 23 m mirror dish, the night sky background (NSB) rate amounts to several hundreds MHz per pixel. In order to record clean images of gamma-ray showers with minimal NSB contamination, a fast sampling of the signal waveform is required so that the signal integration time can be as short as the Cherenkov light flash duration (a few ns). We have developed a readout board which samples waveforms of seven PMTs per board at a GHz rate. Since a GHz FADC has a high power consumption, leading to large heat dissipation, we adopted the analog memory ASIC "DRS4". The sampler has 1024 capacitors per channel and can sample the waveform at a GHz rate. Four channels of a chip are cascaded to obtain deeper sampling depth with 4096 capacitors. After a trigger ...

  11. Silicon photomultiplier integration in the camera of the mid-size Schwarzschild–Couder Cherenkov telescope for CTA

    International Nuclear Information System (INIS)

    The design of the focal plane of the mid-size Schwarzschild–Couder telescope for the Cherenkov Telescope Array (CTA) is described. For the camera under development for the prototype telescope, novel Multi-Pixel Photon Counters (MPPCs) from Hamamatsu with Through Silicon Via (TSV) technology are used. The photon-detectors are integrated into an insulated environment that is actively temperature stabilized to avoid gain and photon detection efficiency fluctuations due to temperature variations

  12. Silicon photomultiplier integration in the camera of the mid-size Schwarzschild–Couder Cherenkov telescope for CTA

    Energy Technology Data Exchange (ETDEWEB)

    Otte, A.N., E-mail: nepomuk.otte@gmail.com; Meagher, K.; Nguyen, T.; Carroll, M.; Hooper, S.; McKinney, K.; Peet, S.

    2015-07-01

    The design of the focal plane of the mid-size Schwarzschild–Couder telescope for the Cherenkov Telescope Array (CTA) is described. For the camera under development for the prototype telescope, novel Multi-Pixel Photon Counters (MPPCs) from Hamamatsu with Through Silicon Via (TSV) technology are used. The photon-detectors are integrated into an insulated environment that is actively temperature stabilized to avoid gain and photon detection efficiency fluctuations due to temperature variations.

  13. Qualification and Testing of a Large Hot Slumped Secondary Mirror for Schwarzschild-Couder Imaging Air Cherenkov Telescopes

    Science.gov (United States)

    Rodeghiero, G.; Giro, E.; Canestrari, R.; Pernechele, C.; Sironi, G.; Pareschi, G.; Lessio, L.; Conconi, P.

    2016-05-01

    Dual-mirror Schwarzschild-Couder (SC) telescopes are based on highly aspherical optics, and they represent a novel design in the world of very high energy astrophysics. This work addresses the realization and the qualification of the secondary mirror for an SC telescope, named ASTRI, developed in the context of the Cherenkov Telescope Array Observatory. The discussion surveys the overall development from the early design concept to the final acceptance optical tests.

  14. A template method for measuring the iron spectrum in cosmic rays with Cherenkov telescopes

    CERN Document Server

    ,

    2015-01-01

    Understanding the sources, acceleration mechanisms, and propagation of cosmic rays is an active area of research in astro-particle physics. Measuring the spectrum and elemental composition of cosmic rays on earth can help solve this question. IACTs, while mainly used for $\\gamma$-ray astronomy and indirect searches for dark matter, can make an important contribution here. In particular, they are able to distinguish heavy nuclei in cosmic rays from protons and lighter nuclei by exploiting the direct Cherenkov light emitted by charged particles high in the atmosphere. In this paper, a method to reconstruct relevant properties of primary cosmic ray particles from the Cherenkov light emitted by the primary particles and the air showers induced by them will be presented.

  15. A Prototype for the Cherenkov Telescope Array Pipelines Framework: Modular Efficiency Simple System (MESS)

    CERN Document Server

    ,

    2015-01-01

    The Cherenkov Telescope Array (CTA) is a ground-based $\\gamma$-ray observatory that will observe the full sky in the energy range from 20 GeV to 100 TeV from facilities in both hemispheres. It is proposed to consist of more than 100 telescopes, producing large amounts of data. Apart from the storage system, there are also requirements on the software framework to allow efficient data processing, i.e. robustness, execution speed and coding efficiency. This contribution will present a plain and simple pipeline framework design prototype for CTA that builds upon well-known tools, allowing the users to focus on physics problems without learning complicated software paradigms.

  16. A facility to evaluate the focusing performance of mirrors for Cherenkov Telescopes

    Science.gov (United States)

    Canestrari, Rodolfo; Giro, Enrico; Bonnoli, Giacomo; Farisato, Giancarlo; Lessio, Luigi; Rodeghiero, Gabriele; Spiga, Rossella; Toso, Giorgio; Pareschi, Giovanni

    2016-01-01

    Cherenkov Telescopes are equipped with optical dishes of large diameter - in general based on segmented mirrors - with typical angular resolution of a few arc-minutes. To evaluate the mirror's quality specific metrological systems are required that possibly take into account the environmental conditions in which typically these telescopes operate (in open air without dome protection). For this purpose a new facility for the characterization of mirrors has been developed at the labs of the Osservatorio Astronomico di Brera of the Italian National Institute of Astrophysics. The facility allows the precise measurement of the radius of curvature and the distribution of the concentred light in terms of focused and scattered components and it works in open air. In this paper we describe the facility and report some examples of its measuring capabilities.

  17. Cooling Tests of the NectarCAM camera for the Cherenkov Telescope Array

    CERN Document Server

    Moulin, E; Durand, D; Feirreira, O; Fesquet, M; Giebels, B; Glicenstein, J -F; Loiseau, D; Louis, F; Nunio, F; Rateau, S; consortia, CTA

    2015-01-01

    The NectarCAM is a camera proposed for the medium-sized telescopes in the framework of the Cherenkov Telescope Array (CTA), the next-generation observatory for very-high-energy gamma-ray astronomy. The cameras are designed to operate in an open environment and their mechanics must provide protection for all their components under the conditions defined for the CTA observatory. In order to operate in a stable environment and ensure the best physics performance, each NectarCAM will be enclosed in a slightly overpressurized, nearly air-tight, camera body, to prevent dust and water from entering. The total power dissipation will be ~7.7 kW for a 1855-pixel camera. The largest fraction is dissipated by the readout electronics in the modules. We present the design and implementation of the cooling system together with the test bench results obtained on the NectarCAM thermal demonstrator.

  18. The Real-Time Analysis of the Cherenkov Telescope Array Observatory

    CERN Document Server

    Bulgarelli, A; Contreras, J L; Lorca, A; Aboudan, A; Rodríguez-Vázquez, J J; Lombardi, S; Maier, G; Antonelli, L A; Bastieri, D; Boisson, C; Borkowski, J; Buson, S; Carosi, A; Conforti, V; Djannati-Ataï, A; Dumm, J; Evans, P; Fortson, L; Gianotti, F; Graciani, R; Grandi, P; Hinton, J; Humensky, B; Kosack, K; Lamanna, G; Malaguti, G; Marisaldi, M; Nicastro, L; Ohm, S; Osborne, J; Rosen, S; Trifoglio, M

    2013-01-01

    The Cherenkov Telescope Array (CTA) Observatory must be capable of issuing fast alerts on variable and transient sources to maximize the scientific return. 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 large foreseen data flow rate, between 0.5 and 8 GB/s. As a consequence, substantial efforts toward the optimization of this high-throughput computing service are envisaged, with the additional constraint that the RTA should be performed on-site (as part of the auxiliary infrastructure of the telescopes). In this work, the functional design of the RTA pipeline is presented.

  19. FlashCam: a novel Cherenkov telescope camera with continuous signal digitization

    International Nuclear Information System (INIS)

    The Cherenkov Telescope Array (CTA) will be the next generation ground-based observatory for cosmic gamma rays. The FlashCam camera for its mid-size telescope introduces a new concept, with a modest sampling rate of 250 MS/s, that enables a continuous digitization as well as event buffering and trigger processing using the same front-end FPGAs. The high performance Ethernet-based readout provides a dead-time free operation for event rates up to 30 kHz corresponding to a data rate of 2.0 GByte/s sent to the camera server. We present the camera design and the current status of the project

  20. 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.

  1. The Cherenkov Telescope Array On-Site integral sensitivity: observing the Crab

    CERN Document Server

    Fioretti, Valentina; Schussler, Fabian

    2016-01-01

    The Cherenkov Telescope Array (CTA) is the future large observatory in the very high energy (VHE) domain. Operating from 20 GeV to 300 TeV, it will be composed of tens of Imaging Air Cherenkov Telescopes (IACTs) displaced in a large area of a few square kilometers in both the southern and northern hemispheres. The CTA/DATA On-Site Analysis (OSA) is the system devoted to the development of dedicated pipelines and algorithms to be used at the CTA site for the reconstruction, data quality monitoring, science monitoring and realtime science alerting during observations. The OSA integral sensitivity is computed here for the most studied source at Gamma-rays, the Crab Nebula, for a set of exposures ranging from 1000 seconds to 50 hours, using the full CTA Southern array. The reason for the Crab Nebula selection as the first example of OSA integral sensitivity is twofold: (i) this source is characterized by a broad spectrum covering the entire CTA energy range; (ii) it represents, at the time of writing, the standar...

  2. Design of a Cherenkov telescope for the measurement of PCR composition above 1 PeV

    Directory of Open Access Journals (Sweden)

    Galkin V I

    2013-06-01

    Full Text Available The problem of PCR Composition at super high energies is far from being solved.EAS Cherenkov light spatial-angular distribution (CL SAD can yield important information on the primary mass. In order to use EAS CL SAD for the study of PCR composition one needs a set of imaging telescopes with the appropriate parameters supported by a dense net of fast optical detectors capable of measuring EAS Cherenkov light pulses. On the basis of full Monte-Carlo simulations the pixel size of imaging telescopes is optimized for a specific observation level ∼4km which is typical for the Eastern Pamir mountains. Another goal to be pursued by the new detector array is the search for ultra high energy gamma ray sources and this is where the imaging technique can help a lot. A simple criterion is introduced to recognize gamma-quanta against the proton background and its performance, once again analyzed using simulated events, sets certain limits to the pixel size.

  3. 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.

  4. Monte Carlo simulations of alternative sky observation modes with the Cherenkov Telescope Array

    CERN Document Server

    Szanecki, M; Niedźwiecki, A; Sitarek, J; Bednarek, W

    2015-01-01

    We investigate possible sky survey modes with the Middle Sized Telescopes (MST, aimed at covering the energy range from $\\sim$100 GeV to 10 TeV) subsystem of the Cherenkov Telescope Array (CTA). We use the standard CTA tools, CORSIKA and sim_telarray, to simulate the development of gamma-ray showers, proton background and the telescope response. We perform simulations for the H.E.S.S.-site in Namibia, which is one of the candidate sites for the CTA experiment. We study two previously considered modes, parallel and divergent, and we propose a new, convergent mode with telescopes tilted toward the array center. For each mode we provide performance parameters crucial for choosing the most efficient survey strategy. For the non-parallel modes we study the dependence on the telescope offset angle. We show that use of both the divergent and convergent modes results in potential advantages in comparison with use of the parallel mode. The fastest source detection can be achieved in the divergent mode with larger offs...

  5. Impact of E-ELT laser light on Cherenkov Telescope Array cameras

    CERN Document Server

    Gaug, Markus

    2013-01-01

    As one of the options, the Cherenkov Telescope Array (CTA) Consortium is considering the possibility to install its Southern array in Chile, in the Atacama Desert. The envisaged site is situated about 5 km from the future European Extremely Large Telescope (E-ELT), which will operate 8 parallel DC lasers emitting at 589.2 nm, to create an artificial 6.8 magnitude star at an altitude of 90 km. The guide stars are used for the adaptive optics of the telescope. Although having the artificial stars in the field-of-view of a CTA telescope would happen rather seldom, and can be avoided by coordinated scheduling, the laser beams may cross the field-of-view of a telescope more frequently and leave spurious light tracks, hence complicating the analysis of the shower images. We derive an approximate formula to estimate the expected number of photons from molecular and aerosol scattering of the laser light beam into the field-of-view of a camera pixel. We then present several specific cases of laser influence on the CTA...

  6. The readout and control system of the mid-size telescope prototype of the Cherenkov telescope array

    International Nuclear Information System (INIS)

    The Cherenkov Telescope Array (CTA) is one of the major ground-based astronomy projects being pursued and will be the largest facility for ground-based y-ray observations ever built. 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 type and size. A prototype for the Mid-Size Telescope (MST) with a diameter of 12 m has been installed in Berlin and is currently being commissioned. This prototype is composed of a mechanical structure, a drive system and mirror facets mounted with powered actuators to enable active control. Five Charge-Coupled Device (CCD) cameras, and a wide set of sensors allow the evaluation of the performance of the instrument. The design of the control software is following concepts and tools under evaluation within the CTA consortium in order to provide a realistic test-bed for the middleware: 1) The readout and control system for the MST prototype is implemented with the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) distributed control middleware; 2) the OPen Connectivity-Unified Architecture (OPC UA) is used for hardware access; 3) the document oriented MongoDB database is used for an efficient storage of CCD images, logging and alarm information: and 4) MySQL and MongoDB databases are used for archiving the slow control monitoring data and for storing the operation configuration parameters. In this contribution, the details of the implementation of the control system for the MST prototype telescope are described.

  7. The readout and control system of the mid-size telescope prototype of the Cherenkov Telescope Array

    Science.gov (United States)

    Oya, I.; Anguner, O.; Behera, B.; Birsin, E.; Fuessling, M.; Melkumyan, D.; Schmidt, T.; Schwanke, U.; Sternberger, R.; Wegner, P.; Wiesand, S.; Cta Consortium,the

    2014-06-01

    The Cherenkov Telescope Array (CTA) is one of the major ground-based astronomy projects being pursued and will be the largest facility for ground-based y-ray observations ever built. 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 type and size. A prototype for the Mid-Size Telescope (MST) with a diameter of 12 m has been installed in Berlin and is currently being commissioned. This prototype is composed of a mechanical structure, a drive system and mirror facets mounted with powered actuators to enable active control. Five Charge-Coupled Device (CCD) cameras, and a wide set of sensors allow the evaluation of the performance of the instrument. The design of the control software is following concepts and tools under evaluation within the CTA consortium in order to provide a realistic test-bed for the middleware: 1) The readout and control system for the MST prototype is implemented with the Atacama Large Millimeter/submillimeter Array (ALMA) Common Software (ACS) distributed control middleware; 2) the OPen Connectivity-Unified Architecture (OPC UA) is used for hardware access; 3) the document oriented MongoDB database is used for an efficient storage of CCD images, logging and alarm information: and 4) MySQL and MongoDB databases are used for archiving the slow control monitoring data and for storing the operation configuration parameters. In this contribution, the details of the implementation of the control system for the MST prototype telescope are described.

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

    International Nuclear Information System (INIS)

    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

  9. Dark matter searches with Cherenkov telescopes: nearby dwarf galaxies or local galaxy clusters?

    International Nuclear Information System (INIS)

    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. 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

  11. The Atmospheric Monitoring system of the JEM-EUSO telescope

    CERN Document Server

    Toscano, S; Frías, M D Rodríguez

    2014-01-01

    The JEM-EUSO observatory on board of the International Space Station (ISS) is a proposed pioneering space mission devoted to the investigation of Ultra High Energy Cosmic Rays (UHECRs). Looking downward at the earth's atmosphere with a 60$^\\circ$ Field of View (FoV), the JEM-EUSO telescope will detect the fluorescence and Cherenkov UV emission from UHECR induced Extensive Air Showers (EAS) penetrating in the atmosphere. The capability of reconstructing the properties of the primary cosmic ray depends on the accurate measurement of the atmospheric conditions in the region of EAS development. The Atmospheric Monitoring system of JEM-EUSO will continuously monitor the atmosphere at the location of the EAS candidates and between the EAS and the JEM-EUSO telescope. With an UV LIDAR and an Infrared (IR) Camera the system will monitor the cloud cover and retrieve the cloud top altitude with an accuracy of $\\sim$ 500 m and the optical depth profile of the atmosphere with an accuracy of $\\Delta\\tau \\leq$ 0.15 and a re...

  12. Calibration and performance of the photon sensor response of FACT — the first G-APD Cherenkov telescope

    International Nuclear Information System (INIS)

    The First G-APD Cherenkov Telescope (FACT) is the first in-operation test of the performance of silicon photo detectors in Cherenkov Astronomy. For more than two years it is operated on La Palma, Canary Islands (Spain), for the purpose of long-term monitoring of astrophysical sources. For this, the performance of the photo detectors is crucial and therefore has been studied in great detail. Special care has been taken for their temperature and voltage dependence implementing a correction method to keep their properties stable. Several measurements have been carried out to monitor the performance. The measurements and their results are shown, demonstrating the stability of the gain below the percent level. The resulting stability of the whole system is discussed, nicely demonstrating that silicon photo detectors are perfectly suited for the usage in Cherenkov telescopes, especially for long-term monitoring purpose

  13. Calibration and performance of the photon sensor response of FACT -- The First G-APD Cherenkov telescope

    CERN Document Server

    Biland, A; Buß, J; Commichau, V; Djambazov, L; Dorner, D; Einecke, S; Eisenacher, D; Freiwald, J; Grimm, O; von Gunten, H; Haller, C; Hempfling, C; Hildebrand, D; Hughes, G; Horisberger, U; Knoetig, M L; Krähenbühl, T; Lustermann, W; Lyard, E; Mannheim, K; Meier, K; Mueller, S; Neise, D; Overkemping, A -K; Paravac, A; Pauss, F; Rhode, W; Röser, U; Stucki, J -P; Steinbring, T; Temme, F; Thaele, J; Vogler, P; Walter, R; Weitzel, Q

    2014-01-01

    The First G-APD Cherenkov Telescope (FACT) is the first in-operation test of the performance of silicon photo detectors in Cherenkov Astronomy. For more than two years it is operated on La Palma, Canary Islands (Spain), for the purpose of long-term monitoring of astrophysical sources. For this, the performance of the photo detectors is crucial and therefore has been studied in great detail. Special care has been taken for their temperature and voltage dependence implementing a correction method to keep their properties stable. Several measurements have been carried out to monitor the performance. The measurements and their results are shown, demonstrating the stability of the gain below the percent level. The resulting stability of the whole system is discussed, nicely demonstrating that silicon photo detectors are perfectly suited for the usage in Cherenkov telescopes, especially for long-term monitoring purpose.

  14. Studies towards an understanding of global array pointing for the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    For the proposed Cherenkov Telescope Array (CTA), a post-calibration point-source location accuracy of 3 seconds of arc is aimed for under favorable observing conditions and for gamma-ray energies exceeding 100 GeV. In this contribution, results of first studies on the location accuracy are presented. These studies are based on a toy Monte Carlo simulation of a typical CTA-South array layout, taking into account the expected trigger rates of the different CTA telescope types and the gamma-ray spectrum of the simulated source. With this simulation code it is possible to study the location accuracy as a function of arbitrary telescope mis-orientations and for typical observing patterns on the sky. Results are presented for various scenarios, including one for which all individual telescopes are randomly mis-oriented within their specified limits. The study provides solid lower limits for the expected source location accuracy of CTA, and can be easily extended to include various other important effects like atmo...

  15. Design study of an air-Cherenkov telescope for harsh environments with efficient air-shower detection at 100 TeV

    CERN Document Server

    Auffenberg, Jan; Middendorf, Lukas; Niggemann, Tim; Rädel, Leif; Schaufel, Merlin; Schoenen, Sebastian; Schumacher, Johannes; Wiebusch, Christopher

    2015-01-01

    Telescopes, designed with semi-conductor based photo sensors, have the potential to detect Cherenkov or fluorescence light emitted by cosmic-rays in the atmosphere. Such telescopes promise a high duty cycle and efficiency in remote harsh environments. Given the relatively low costs and robustness of these instruments, this technology could prove interesting especially if deployed in large numbers with existing and future extended cosmic-ray and gamma ray detectors, including the Pierre Auger observatory, HAWC, IceCube and CTA. They may have the potential to enhance the sensitivity of these instruments for the detection of high-energy gamma rays and cosmic-ray air showers. In addition, for neutrino telescopes such a technology could prove to be an efficient cosmic-ray veto on the surface. In this contribution the current motivation, design, and development of a prototype SiPM based air Cherenkov telescope is described. The results of initial sensitivity studies, and the readiness of the system for first tests,...

  16. Evaluation of Photo Multiplier Tube candidates for the Cherenkov Telescope Array

    Science.gov (United States)

    Mirzoyan, R.; Müller, D.; Hanabata, Y.; Hose, J.; Menzel, U.; Nakajima, D.; Takahashi, M.; Teshima, M.; Toyama, T.; Yamamoto, T.

    2016-07-01

    Photo Multiplier Tubes (PMTs) are the most wide spread detectors for fast, faint light signals. Six years ago, an improvement program for the PMT candidates for the Cherenkov Telescope Array (CTA) project was started with the companies Hamamatsu Photonics K.K. and Electron Tubes Enterprises Ltd. (ETE). For maximizing the performance of the CTA imaging cameras we need PMTs with outstanding good quantum efficiency, high photoelectron collection efficiency, short pulse width, very low afterpulse probability and transit time spread. We will report on the measurements of PMT R-12992-100 from Hamamatsu as their final product and the PMT D573KFLSA as one of the latest test versions from ETE as candidate PMTs for the CTA project.

  17. Gamma-Ray Burst Science in the Era of the Cherenkov Telescope Array

    CERN Document Server

    Inoue, Susumu; O'Brien, Paul T; Asano, Katsuaki; Bouvier, Aurelien; Carosi, Alessandro; Connaughton, Valerie; Garczarczyk, Markus; Gilmore, Rudy; Hinton, Jim; Inoue, Yoshiyuki; Ioka, Kunihito; Kakuwa, Jun; Markoff, Sera; Murase, Kohta; Osborne, Julian P; Otte, A Nepomuk; Starling, Rhaana; Tajima, Hiroyasu; Teshima, Masahiro; Toma, Kenji; Wagner, Stefan; Wijers, Ralph A M J; Williams, David A; Yamamoto, Tokonatsu; Yamazaki, Ryo

    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 able to measure the spectra and variability of GRBs at multi-GeV energies with unprecedented photon statistics, and thereby break new ground in elucidating the physics of GRBs, which is still poorly understood. Such measurements will also provide crucial diagnostics of ultra-high-energy cosmic ray and neutrino production in GRBs, advance observational cosmology by probing the high-redshift extragalactic background light and intergalactic magnetic fields, and contribute to fundamental physics by testing Lorentz invariance violation with high precision. Aiming to quantify these goals, we present some simulated observations of GRB spectra and light curves, together with estimates of their detection rates with CTA. Alth...

  18. Prospects On Testing Lorentz Invariance Violation With The Cherenkov Telescope Array

    CERN Document Server

    Daniel, M K; Fairbairn, M; Otte, N

    2015-01-01

    The assumption of Lorentz invariance is one of the founding principles of modern physics and violation of that would have deep consequences to our understanding of the universe. Potential signatures of such a violation could range from energy dependent dispersion introduced into a light curve to a change in the photon-photon pair production threshold that changes the expected opacity of the universe. Astronomical sources of Very High Energy (VHE) photons can be used as test beams to probe fundamental physics phenomena, however, such effects would likely be small and need to be disentangled from intrinsic source physics processes. The Cherenkov Telescope Array (CTA) will be the next generation ground based observatory of VHE photons. It will have improved flux sensitivity, a lower energy threshold (tens of GeV), broader energy coverage (nearly 5 decades) and improved energy resolution (better than 10\\% over much of the energy range) compared to current facilities in addition to excellent time resolution for sh...

  19. Contributions from the Cherenkov Telescope Array (CTA) Consortium to the ICRC 2011

    CERN Document Server

    ,

    2011-01-01

    The Cherenkov Telescope Array (CTA) is a project for the construction of a next generation VHE gamma ray observatory with full sky coverage. Its aim is improving by about one order of magnitude the sensitivity of the existing installations, covering about 5 decades in energy (from few tens of GeV to above a hundred TeV) and having enhanced angular and energy resolutions. During 2010 the project became a truly global endeavour carried out by a consortium of about 750 collaborators from Europe, Asia, Africa and the North and South Americas. Also during 2010 the CTA project completed its Design Study phase and started a Preparatory Phase that is expected to extend for three years and should lead to the starting of the construction of CTA. An overview of the CTA Consortium activities project will be given.

  20. Astroclimatic Characterization of Vallecitos: A candidate site for the Cherenkov Telescope Array at San Pedro Martir

    CERN Document Server

    Tovmassian, Gagik; Ochoa, Jose Luis; Ernenwein, Jean-Pierre; Mandat, Dusan; Pech, Miroslav; Frayn, Ilse Plauchu; Colorado, Enrique; Murillo, Jose Manuel; Cesena, Urania; Garcia, Benjamin; Lee, William H; Bulik, Tomasz; Garczarczyk, Markus; Fruck, Christian; Costantini, Heide; Cieslar, Marek; Aune, Taylor; Vincent, Stephane; Carr, John; Serre, Natalia; Janecek, Petr; Haefner, Dennis

    2016-01-01

    We conducted an 18 month long study of the weather conditions of the Vallecitos, a proposed site in Mexico to harbor the northern array of the Cherenkov Telescope Array (CTA). It is located in Sierra de San Pedro Martir (SPM) a few kilometers away from Observatorio Astron\\'omico Nacional. The study is based on data collected by the ATMOSCOPE, a multi-sensor instrument measuring the weather and sky conditions, which was commissioned and built by the CTA Consortium. Additionally, we compare the weather conditions of the optical observatory at SPM to the Vallecitos regarding temperature, humidity, and wind distributions. It appears that the excellent conditions at the optical observatory benefit from the presence of microclimate established in the Vallecitos.

  1. Sensitivity of the Cherenkov Telescope Array to the Detection of Intergalactic Magnetic Fields

    CERN Document Server

    Meyer, Manuel; Dickinson, Hugh

    2016-01-01

    Very high energy (VHE; energy $E \\gtrsim 100\\,$GeV) $\\gamma$ rays originating from extragalactic sources undergo pair production with low-energy photons of background radiation fields. These pairs can inverse-Compton scatter background photons, initiating an electromagnetic cascade. The spatial and temporal structure of this secondary $\\gamma$-ray signal is altered as the $e^+e^-$ pairs are deflected in an intergalactic magnetic field (IGMF). We investigate how VHE observations with the future Cherenkov Telescope Array (CTA) with its high angular resolution and broad energy range can potentially probe the IGMF. We identify promising sources and simulate $\\gamma$-ray spectra over a wide range of values of the IGMF strength and coherence length using the publicly available ELMAG Monte-Carlo code. Combining simulated observations in a joint likelihood approach, we find that current limits on the IGMF can be significantly improved. The projected sensitivity depends strongly on the time a source has been $\\gamma$-...

  2. All Sky Cameras for the characterization of the Cherenkov Telescope Array candidate sites

    CERN Document Server

    Mandát, Dušan; Ebr, Jan; Hrabovský, Miroslav; Prouza, Michael; Bulik, Tomasz; Allekotte, Ingomar

    2013-01-01

    The All Sky Camera (ASC) was developed as a universal device for the monitoring of the night sky quality. Eight ASCs are already installed and measure night sky parameters at eight of the candidate sites of the Cherenkov Telescope Array (CTA) gamma-ray observatory. The ACS system consists of an astronomical CCD camera, a fish eye lens, a control computer and associated electronics. The measurement is carried out during astronomical night. The images are automatically taken every 5 minutes and automatically processed using the control computer of the device. The analysis results are the cloud fraction (the percentage of the sky covered by clouds) and night sky brightness (in mag/arcsec$^{2}$)

  3. Detecting extended gamma-ray emission with the next generation Cherenkov telescopes

    CERN Document Server

    Alonso, M Fernandez; Rovero, A C

    2015-01-01

    Very high energy (VHE $>$100 GeV) gamma rays coming from blazars can produce pairs when interacting with the Extragalactic Background Light (EBL) and the Cosmic Microwave Background, generating an electromagnetic cascade. Depending on the Intergalactic Magnetic Field (IGMF) intensity, this cascade may result in an extended isotropic emission of photons around the source (halo), or in a broadening of the emission beam. The detection of these effects might lead to important constrains both on the IGMF intensity and the EBL density, quantities of great relevance in cosmological models. Using a Monte Carlo program, we simulate electromagnetic cascades for different values of the IGMF intensities and coming from a source similar to 1ES0229+200, a blazar with hard intrinsic spectrum at redshift $z=0.14$, which is an ideal distance for potentially observing the effect. We study the possible response of a generic future Cherenkov telescope using a simplified model for the sensitivity, effective area and angular resol...

  4. Second large-scale Monte Carlo study for the Cherenkov Telescope Array

    CERN Document Server

    Hassan, T; Bernlör, K; Bregeon, J; Hinton, J; Jogler, T; Maier, G; Moralejo, A; Di Pierro, F; Wood, M

    2015-01-01

    The Cherenkov Telescope Array (CTA) represents the next generation of ground based instruments for Very High Energy gamma-ray astronomy. It is expected to improve on the sensitivity of current instruments by an order of magnitude and provide energy coverage from 20 GeV to more than 200 TeV. In order to achieve these ambitious goals Monte Carlo (MC) simulations play a crucial role, guiding the design of CTA. Here, results of the second large-scale MC production are reported, providing a realistic estimation of feasible array candidates for both Northern and Sourthern Hemisphere sites performance, placing CTA capabilities into the context of the current generation of High Energy $\\gamma$-ray detectors.

  5. Characterization of the candidate site for the Cherenkov Telescope Array at the Observatorio del Teide

    CERN Document Server

    Puerto-Giménez, Irene; Barrena, Rafael; Castro, Julio; Doro, Michele; Font, Lluís; Rosillo, Miguel Nievas; Zamorano, Jaime

    2013-01-01

    The Spanish partners of the future Cherenkov Telescope Array (CTA) have selected a candidate site for the Northern installation of CTA, at 3 km from the Observatorio del Teide (OT), in the Canary Island of Tenerife. As the OT is a very well-characterized astronomical site. We focus here on differences between the publicly accessible measurements from the OT observatory and those obtained with instruments deployed at the candidate site. We find that the winds are generally softer at the candidate site, and the level of background light comparable to the Observatorio del Roque de los Muchachos (ORM) at La Palma in the B-band, while it is only slightly higher in the V-band.

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

    CERN Document Server

    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...

  7. Upper Limits from Five Years of Blazar Observations with the VERITAS Cherenkov Telescopes

    Science.gov (United States)

    Archambault, S.; Archer, A.; Benbow, W.; Bird, R.; Biteau, J.; Buchovecky, M.; Buckley, J. H.; Bugaev, V.; Byrum, K.; Cerruti, M.; Chen, X.; Ciupik, L.; Connolly, M. P.; Cui, W.; Eisch, J. D.; Errando, M.; Falcone, A.; Feng, Q.; Finley, J. P.; Fleischhack, H.; Fortin, P.; Fortson, L.; Furniss, A.; Gillanders, G. H.; Griffin, S.; Grube, J.; Gyuk, G.; Hütten, M.; Håkansson, N.; Hanna, D.; Holder, J.; Humensky, T. B.; Johnson, C. A.; Kaaret, P.; Kar, P.; Kelley-Hoskins, N.; Kertzman, M.; Kieda, D.; Krause, M.; Krennrich, F.; Kumar, S.; Lang, M. J.; Maier, G.; McArthur, S.; McCann, A.; Meagher, K.; Moriarty, P.; Mukherjee, R.; Nguyen, T.; Nieto, D.; O’Faoláin de Bhróithe, A.; Ong, R. A.; Otte, A. N.; Park, N.; Perkins, J. S.; Pichel, A.; Pohl, M.; Popkow, A.; Pueschel, E.; Quinn, J.; Ragan, K.; Reynolds, P. T.; Richards, G. T.; Roache, E.; Rovero, A. C.; Santander, M.; Sembroski, G. H.; Shahinyan, K.; Smith, A. W.; Staszak, D.; Telezhinsky, I.; Tucci, J. V.; Tyler, J.; Vincent, S.; Wakely, S. P.; Weiner, O. M.; Weinstein, A.; Williams, D. A.; Zitzer, B.; the VERITAS collaboration; Fumagalli, M.; Prochaska, J. X.

    2016-06-01

    Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) γ-ray sources. In this work, we present the analysis results of a sample of 114 undetected objects. The observations constitute a total live-time of ∼570 hr. The sample includes several unidentified Fermi-Large Area Telescope (LAT) sources (located at high Galactic latitude) as well as all the sources from the second Fermi-LAT catalog that are contained within the field of view of the VERITAS observations. We have also performed optical spectroscopy measurements in order to estimate the redshift of some of these blazars that do not have spectroscopic distance estimates. We present new optical spectra from the Kast instrument on the Shane telescope at the Lick observatory for 18 blazars included in this work, which allowed for the successful measurement or constraint on the redshift of four of them. For each of the blazars included in our sample, we provide the flux upper limit in the VERITAS energy band. We also study the properties of the significance distributions and we present the result of a stacked analysis of the data set, which shows a 4σ excess.

  8. Simulated Gamma-Ray Pulse Profile of the Crab pulsar with the Cherenkov Telescope Array

    Science.gov (United States)

    Burtovoi, A.; Zampieri, L.

    2016-04-01

    We present simulations of the very high energy (VHE) gamma-ray light curve of the Crab pulsar as observed by the Cherenkov Telescope Array (CTA). The CTA pulse profile of the Crab pulsar is simulated with the specific goal of determining the accuracy of the position of the interpulse. We fit the pulse shape obtained by the MAGIC telescope with a three-Gaussian template and rescale it to account for the different CTA instrumental and observational configurations. Simulations are performed for different configurations of CTA and for the ASTRI mini-array. The northern CTA configuration will provide an improvement of a factor of ˜3 in accuracy with an observing time comparable to that of MAGIC (73 hours). Unless the VHE spectrum above 1 TeV behaves differently from what we presently know, unreasonably long observing times are required for a significant detection of the pulsations of the Crab pulsar with the high-energy-range sub-arrays. We also found that an independent VHE timing analysis is feasible with Large Size Telescopes (LSTs). CTA will provide a significant improvement in determining the VHE pulse shape parameters necessary to constrain theoretical models of the gamma-ray emission of the Crab pulsar. One of such parameters is the shift in phase between peaks in the pulse profile at VHE and in other energy bands that, if detected, may point to different locations of the emission regions.

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

    CERN Document Server

    Vercellone, Stefano

    2015-01-01

    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 wid...

  10. Upper limits from five years of blazar observations with the VERITAS Cherenkov telescopes

    CERN Document Server

    Archambault, S; Benbow, W; Bird, R; Biteau, J; Buchovecky, M; Buckley, J H; Bugaev, V; Byrum, K; Cerruti, M; Chen, X; Ciupik, L; Connolly, M P; Cui, W; Eisch, J D; Errando, M; Falcone, A; Feng, Q; Finley, J P; Fleischhack, H; Fortin, P; Fortson, L; Furniss, A; Gillanders, G H; Griffin, S; Grube, J; Gyuk, G; Hütten, M; Hakansson, N; Hanna, D; Holder, J; Humensky, T B; Johnson, C A; Kaaret, P; Kar, P; Kelley-Hoskins, N; Kertzman, M; Kieda, D; Krause, M; Krennrich, F; Kumar, S; Lang, M J; Maier, G; McArthur, S; McCann, A; Meagher, K; Moriarty, P; Mukherjee, R; Nguyen, T; Nieto, D; De Bhróithe, A O'Faoláin; Ong, R A; Otte, A N; Park, N; Perkins, J S; Pichel, A; Pohl, M; Popkow, A; Pueschel, E; Quinn, J; Ragan, K; Reynolds, P T; Richards, G T; Roache, E; Rovero, A C; Santander, M; Sembroski, G H; Shahinyan, K; Smith, A W; Staszak, D; Telezhinsky, I; Tucci, J V; Tyler, J; Vincent, S; Wakely, S P; Weiner, O M; Weinstein, A; Williams, D A; Zitzer, B; Fumagalli, M; Prochaska, J X

    2016-01-01

    Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E>100 GeV) {\\gamma}-ray sources. In this work, we present the analysis results of a sample of 114 undetected objects. The observations constitute a total live-time of ~570 hours. The sample includes several unidentified Fermi-Large Area Telescope (LAT) sources (located at high Galactic latitude) as well as all the sources from the second Fermi-LAT catalog which are contained within the field of view of the VERITAS observations. We have also performed optical spectroscopy measurements in order to estimate the redshift of some of these blazars that do not have a spectroscopic distance estimate. We present new optical spectra from the Kast instrument on the Shane telescope at the Lick observatory for 18 blazars included in this work, which allowed for the successful measurement or constraint on the redshift of fo...

  11. The Cherenkov Telescope Array potential for the study of young supernova remnants

    Science.gov (United States)

    Acharya, B. S.; Aramo, C.; Babic, A.; Barrio, J. A.; Baushev, A.; Becker Tjus, J.; Berge, D.; Bohacova, M.; Bonardi, A.; Brown, A.; Bugaev, V.; Bulik, T.; Burton, M.; Busetto, G.; Caraveo, P.; Carosi, R.; Carr, J.; Chadwick, P.; Chudoba, J.; Conforti, V.; Connaughton, V.; Contreras, J. L.; Cotter, G.; Dazzi, F.; De Franco, A.; de la Calle, I.; de los Reyes Lopez, R.; De Lotto, B.; De Palma, F.; Di Girolamo, T.; Di Giulio, C.; Di Pierro, F.; Dournaux, J.-L.; Dwarkadas, V.; Ebr, J.; Egberts, K.; Fesquet, M.; Fleischhack, H.; Font, L.; Fontaine, G.; Förster, A.; Fuessling, M.; Garcia, B.; Garcia López, R.; Garczarczyk, M.; Gargano, F.; Garrido, D.; Gaug, M.; Giglietto, N.; Giordano, F.; Giuliani, A.; Godinovic, N.; Gonzalez, M. M.; Grabarczyk, T.; Hassan, T.; Hörandel, J.; Hrabovsky, M.; Hrupec, D.; Humensky, T. B.; Huovelin, J.; Jamrozy, M.; Janecek, P.; Kaaret, P. E.; Katz, U.; Kaufmann, S.; Khélifi, B.; Kluźniak, W.; Kocot, J.; Komin, N.; Kubo, H.; Kushida, J.; Lamanna, G.; Lee, W. H.; Lenain, J.-P.; Lohse, T.; Lombardi, S.; López-Coto, R.; López-Oramas, A.; Lucarelli, F.; Maccarone, M. C.; Maier, G.; Majumdar, P.; Malaguti, G.; Mandat, D.; Mazziotta, M. N.; Meagher, K.; Mirabal, N.; Morselli, A.; Moulin, E.; Niemiec, J.; Nievas, M.; Nishijima, K.; Nosek, D.; Nunio, F.; Ohishi, M.; Ohm, S.; Ong, R. A.; Orito, R.; Otte, N.; Palatka, M.; Pareschi, G.; Pech, M.; Persic, M.; Pohl, M.; Prouza, M.; Quirrenbach, A.; Rainó, S.; Rodriguez Fernandez, G.; Romano, P.; Rovero, A. C.; Rudak, B.; Schovanek, P.; Shayduk, M.; Siejkowski, H.; Sillanpää, A.; Stefanik, S.; Stolarczyk, T.; Szanecki, M.; Szepieniec, T.; Tejedor, L. A.; Telezhinsky, I.; Teshima, M.; Tibaldo, L.; Tibolla, O.; Tovmassian, G.; Travnicek, P.; Trzeciak, M.; Vallania, P.; van Eldik, C.; Vercellone, S.; Vigorito, C.; Wagner, S. J.; Wakely, S. P.; Weinstein, A.; Wierzcholska, A.; Wilhelm, A.; Wojcik, P.; Yoshikoshi, T.

    2015-03-01

    Supernova remnants (SNRs) are among the most important targets for γ-ray observatories. Being prominent non-thermal sources, they are very likely responsible for the acceleration of the bulk of Galactic cosmic rays (CRs). To firmly establish the SNR paradigm for the origin of cosmic rays, it should be confirmed that protons are indeed accelerated in, and released from, SNRs with the appropriate flux and spectrum. This can be done by detailed theoretical models which account for microphysics of acceleration and various radiation processes of hadrons and leptons. The current generation of Cherenkov telescopes has insufficient sensitivity to constrain theoretical models. A new facility, the Cherenkov Telescope Array (CTA), will have superior capabilities and may finally resolve this long standing issue of high-energy astrophysics. We want to assess the capabilities of CTA to reveal the physics of various types of SNRs in the initial 2000 years of their evolution. During this time, the efficiency to accelerate cosmic rays is highest. We perform time-dependent simulations of the hydrodynamics, the magnetic fields, the cosmic-ray acceleration, and the non-thermal emission for type Ia, Ic and IIP SNRs. We calculate the CTA response to the γ-ray emission from these SNRs for various ages and distances, and we perform a realistic analysis of the simulated data. We derive distance limits for the detectability and resolvability of these SNR types at several ages. We test the ability of CTA to reconstruct their morphological and spectral parameters as a function of their distance. Finally, we estimate how well CTA data will constrain the theoretical models.

  12. Design of a prototype device to calibrate the Large Size Telescope camera of the Cherenkov Telescope Array

    CERN Document Server

    Iori, M; De Persio, F; Chatterjee, A; Ferrarotto, F; Nagesh, B K; Saha, L; Singh, B B

    2015-01-01

    The Cherenkov Telescope Array is a project that aims to exploring the highest energy region of electromagnetic spectrum. Two arrays, one for each hemisphere, will cover the full sky in a range from few tens of GeV to hundreds of TeV improving the sensitivity and angular resolution of the present operating arrays. A prototype of the Large Size Telescope (LST) for the study of gamma ray astronomy above some tens of GeV will be installed at the Canary Island of La Palma in 2016. The LST camera, made by an array of photomultipliers (PMTs), requires an accurate and systematic calibration over a wide dynamic range. In this contribution, we present an optical calibration system made by a 355 nm wavelength laser with 400 ps pulse width, 1 muJ output energy, up to 4k Hz repetition rate and a set of neutral density filters to obtain a wide range of photon intensities, up to 1000 photoelectrons/PMT, to be sent to the camera plane 28 m away. The number of photons after the diffuser of the calibration box, located in the ...

  13. Simulation studies of an air Cherenkov telescope, IceACT, for future IceCube surface extensions

    Energy Technology Data Exchange (ETDEWEB)

    Hansmann, Bengt; Auffenberg, Jan; Bekman, Ilja; Kemp, Julian; Roegen, Martin; Schaufel, Merlin; Stahlberg, Martin; Wiebusch, Christopher [III. Physikalisches Institut B, RWTH Aachen, Aachen (Germany); Bretz, Thomas; Hebbeker, Thomas; Middendorf, Lukas; Niggemann, Tim; Schumacher, Johannes [III. Physikalisches Institut A, RWTH Aachen, Aachen (Germany); Collaboration: IceCube-Collaboration

    2015-07-01

    IceACT is a compact air Cherenkov telescope using silicon photomultipliers. The Fresnel lens based design has been adopted from the fluorescence telescope FAMOUS. The goal of IceACT is the efficient detection of cosmic ray induced air showers above the IceCube Neutrino Observatory at the geographic South Pole. This allows to distinguish cosmic ray induced muons and neutrinos in the southern sky from astrophysical neutrinos in the deep ice detector. This leads to an increase in low-background astrophysical neutrinos of several dozen events per year for a detection threshold of several 100 TeV cosmic ray primary energy. To determine the actual telescope performance, dedicated CORSIKA air shower simulations incorporating the full Cherenkov light information are performed.

  14. Simulation studies of an air Cherenkov telescope, IceACT, for future IceCube surface extensions

    International Nuclear Information System (INIS)

    IceACT is a compact air Cherenkov telescope using silicon photomultipliers. The Fresnel lens based design has been adopted from the fluorescence telescope FAMOUS. The goal of IceACT is the efficient detection of cosmic ray induced air showers above the IceCube Neutrino Observatory at the geographic South Pole. This allows to distinguish cosmic ray induced muons and neutrinos in the southern sky from astrophysical neutrinos in the deep ice detector. This leads to an increase in low-background astrophysical neutrinos of several dozen events per year for a detection threshold of several 100 TeV cosmic ray primary energy. To determine the actual telescope performance, dedicated CORSIKA air shower simulations incorporating the full Cherenkov light information are performed.

  15. 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

  16. Science with the ASTRI mini-array for the Cherenkov Telescope Array: blazars and fundamental physics

    Science.gov (United States)

    Bonnoli, Giacomo; Tavecchio, Fabrizio; Giuliani, Andrea; Bigongiari, Ciro; Di Pierro, Federico; Stamerra, Antonio; Pareschi, Giovanni; Vercellone, Stefano; ASTRI Collaboration; CTA Consortium

    2016-05-01

    ASTRI (“Astronomia a Specchi con Tecnologia Replicante Italiana”) is a flagship project of the Italian Ministry of Research (MIUR), devoted to the realization, operation and scientific validation of an end-to-end prototype for the Small Size Telescope (SST) envisaged to become part of the Cherenkov Telescope Array (CTA). The ASTRI SST-2M telescope prototype is characterized by a dual mirror, Schwarzschild-Couder optical design and a compact camera based on silicon photo-multipliers. It will be sensitive to multi-TeV very high energy (VHE) gamma rays up to 100 TeV, with a PSF ~ 6’ and a wide (9.6°) unaberrated optical field of view. Right after validation of the design in single-dish observations at the Serra La Nave site (Sicily, Italy) during 2015, the ASTRI collaboration will be able to start deployment, at the final CTA southern site, of the ASTRI mini-array, proposed to constitute the very first CTA precursor. Counting 9 ASTRI SST-2M telescopes, the ASTRI mini-array will overtake current IACT systems in differential sensitivity above 5 TeV, thus allowing unprecedented observations of known and predicted bright TeV emitters in this band, including some extragalactic sources such as extreme high-peaked BL Lacs with hard spectra. We exploited the ASTRI scientific simulator ASTRIsim in order to understand the feasibility of observations tackling blazar and cosmic ray physics, including discrimination of hadronic and leptonic scenarios for the VHE emission from BL Lac relativistic jets and indirect measurements of the intergalactic magnetic field and of the extragalactic background light. We selected favorable targets, outlining observation modes, exposure times, multi-wavelength coverage needed and the results expected. Moreover, the perspectives for observation of effects due to the existence of axion-like particles or to Lorentz invariance violations have been investigated.

  17. Modern middleware for the data acquisition of the Cherenkov Telescope Array

    CERN Document Server

    Lyard, Etienne; Kosack, Karl; Jacquemier, Jean; Oya, Igor; Wegner, Peter; Fuessling, Matthias; Wu, Xin

    2015-01-01

    The data acquisition system (DAQ) of the future Cherenkov Telescope Array (CTA) must be ef- ficient, modular and robust to be able to cope with the very large data rate of up to 550 Gbps coming from many telescopes with different characteristics. The use of modern middleware, namely ZeroMQ and Protocol Buffers, can help to achieve these goals while keeping the development effort to a reasonable level. Protocol Buffers are used as an on-line data for- mat, while ZeroMQ is employed to communicate between processes. The DAQ will be controlled and monitored by the Alma Common Software (ACS). Protocol Buffers from Google are a way to define high-level data structures through an in- terface description language (IDL) and a meta-compiler. ZeroMQ is a middleware that augments the capabilities of TCP/IP sockets. It does not implement very high-level features like those found in CORBA for example, but makes use of sockets easier, more robust and almost as effective as raw TCP. The use of these two middlewares enabled u...

  18. Simulated Gamma-Ray Pulse Profile of the Crab Pulsar with the Cherenkov Telescope Array

    CERN Document Server

    Burtovoi, A

    2016-01-01

    We present simulations of the very high energy (VHE) gamma-ray light curve of the Crab pulsar as observed by the Cherenkov Telescope Array (CTA). The CTA pulse profile of the Crab pulsar is simulated with the specific goal of determining the accuracy of the position of the interpulse. We fit the pulse shape obtained by the MAGIC telescope with a three-Gaussian template and rescale it to account for the different CTA instrumental and observational configurations. Simulations are performed for different configurations of CTA and for the ASTRI mini-array. The northern CTA configuration will provide an improvement of a factor of ~3 in accuracy with an observing time comparable to that of MAGIC (73 hours). Unless the VHE spectrum above 1 TeV behaves differently from what we presently know, unreasonably long observing times are required for a significant detection of the pulsations of the Crab pulsar with the high-energy-range sub-arrays. We also found that an independent VHE timing analysis is feasible with Large ...

  19. Parallel waveform extraction algorithms for the Cherenkov Telescope Array Real-Time Analysis

    CERN Document Server

    Zoli, Andrea; De Rosa, Adriano; Aboudan, Alessio; Fioretti, Valentina; De Cesare, Giovanni; Marx, Ramin

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next generation observatory for the study of very high-energy gamma rays from about 20 GeV up to 300 TeV. Thanks to the large effective area and field of view, the CTA observatory will be characterized by an unprecedented sensitivity to transient flaring gamma-ray phenomena compared to both current ground (e.g. MAGIC, VERITAS, H.E.S.S.) and space (e.g. Fermi) gamma-ray telescopes. In order to trigger the astrophysics community for follow-up observations, or being able to quickly respond to external science alerts, a fast analysis pipeline is crucial. This will be accomplished by means of a Real-Time Analysis (RTA) pipeline, a fast and automated science alert trigger system, becoming a key system of the CTA observatory. Among the CTA design key requirements to the RTA system, the most challenging is the generation of alerts within 30 seconds from the last acquired event, while obtaining a flux sensitivity not worse than the one of the final analysis by more than a fac...

  20. Measuring Atmospheric Neutrino Oscillations with Neutrino Telescopes

    OpenAIRE

    Albuquerque, Ivone F. M.; Smoot, George F.

    2001-01-01

    Neutrino telescopes with large detection volumes can demonstrate that the current indications of neutrino oscillation are correct or if a better description can be achieved with non-standard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of non-standard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest ad...

  1. Monte Carlo Studies of the GCT Telescope for the Cherenkov Telescope Array

    CERN Document Server

    Armstrong, Thomas; Rulten, Cameron; Stamatescu, Victor; Zech, Andreas

    2015-01-01

    The GCT is an innovative dual-mirror solution proposed for the small-size telescopes for CTA, capable of imaging primary cosmic gamma-rays from below a TeV to hundreds of TeV. The reduced plate scale resulting from the secondary optics allows the use of compact photosensors, including multi-anode photomultiplier tubes or silicon photomultipliers. We show preliminary results of Monte Carlo simulations using the packages CORSIKA and Sim_telarray, comparing the relative performance of each photosensor type. We also investigate the effect of the secondary optics in terms of optical performance, image resolution and camera response. With the ongoing commissioning of the prototype structure and camera, we present the preliminary expected performance of GCT.

  2. FACT-The first Cherenkov telescope using a G-APD camera for TeV gamma-ray astronomy

    International Nuclear Information System (INIS)

    Geiger-mode Avalanche Photodiodes (G-APD) bear the potential to significantly improve the sensitivity of Imaging Air Cherenkov Telescopes (IACT). We are currently building the First G-APD Cherenkov Telescope (FACT) by refurbishing an old IACT with a mirror area of 9.5 square meters and are constructing a new, fine-pixelized camera using novel G-APDs. The main goal is to evaluate the performance of a complete system by observing very high energy gamma-rays from the Crab Nebula. This is an important field test to check the feasibility of G-APD-based cameras to replace at some time the PMT-based cameras of planned future IACTs like AGIS and CTA. In this article, we present the basic design of such a camera as well as some important details.

  3. Impact of the Cherenkov Telescope Array (CTA) altitude on Dark Matter searches in the Milky Way Halo

    CERN Document Server

    Oakes, Louise; Maier, Gernot; Schwanke, Ullrich

    2013-01-01

    Observations of dwarf galaxies and of the Milky Way halo with current ground-based Cherenkov telescopes have resulted in interesting limits on the cross-section for dark matter (DM) self- annihilation for WIMP masses above some 100 GeV. The future Cherenkov Telescope Array (CTA) is expected to further explore the parameter space of dark matter candidates that are predicted in extensions of the standard model of particle physics. Due to its low energy threshold (of order of few tens of GeV) and high sensitivity, CTA will also probe lower WIMP masses than current experiments, but the actual performance in this regime will be influenced by the altitude of the observatory above sea level. Using the response of possible CTA candidate arrays to simulated photons and hadrons, we estimate how searches for a WIMP annihilation signal from the Milky Way halo will be influenced by altitude of different possible CTA sites.

  4. High Energy Gamma-Ray Observations of the Crab Nebula and Pulsar with the Solar Tower Atmospheric Cherenkov Effect Experiment

    CERN Document Server

    Oser, S; Boone, L M; Chantell, M C; Conner, Z; Covault, C E; Dragovan, M; Fortin, P; Gregorich, D T; Hanna, D S; Mukherjee, R; Ong, R A; Ragan, K; Scalzo, R A; Schuette, D R; Theoret, C G; Tumer, T O; Williams, D A; Zweerink, J A

    2015-01-01

    The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is a new ground-based atmospheric Cherenkov telescope for gamma-ray astronomy. STACEE uses the large mirror area of a solar heliostat facility to achieve a low energy threshold. A prototype experiment which uses 32 heliostat mirrors with a total mirror area of ~ 1200\\unit{m^2} has been constructed. This prototype, called STACEE-32, was used to search for high energy gamma-ray emission from the Crab Nebula and Pulsar. Observations taken between November 1998 and February 1999 yield a strong statistical excess of gamma-like events from the Crab, with a significance of $+6.75\\sigma$ in 43 hours of on-source observing time. No evidence for pulsed emission from the Crab Pulsar was found, and the upper limit on the pulsed fraction of the observed excess was E_{th}) = (2.2 \\pm 0.6 \\pm 0.2) \\times 10^{-10}\\unit{photons cm^{-2} s^{-1}}. The observed flux is in agreement with a continuation to lower energies of the power law spectrum seen at TeV energies...

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

    Science.gov (United States)

    Konno, Y.; Kubo, H.; Masuda, S.; Paoletti, R.; Poulios, S.; Rugliancich, A.; Saito, T.

    2016-07-01

    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.

  6. Night Sky Background Analysis for the Cherenkov Telescope Array using the Atmoscope instrument

    CERN Document Server

    Gaug, Markus

    2013-01-01

    The site selection group for the future Cherenkov Telescope Array (CTA) has deployed sensitive light sensors at 9 candidate sites, 5 of them in the Southern and 4 in the Northern hemisphere. The sensors are equipped with a PIN diode and a calibrated V-filter, and a blue/UV filter matching the spectral response of the photomultipliers to be employed in the CTA cameras. All sensor installations, denominated "Atmoscopes", have been cross-calibrated before deployment, and their sensitivity is monitored every two to five months. We show that a thoroughly developed model of the integral contribution of starlight to the overall light measure serves as an additional cross-calibration for each device during each night, reducing the systematic uncertainty of this measurement to less than 15%. The starlight can then be subtracted from the measurements, and the residuals compared among the different sites. We show that in most cases a decomposition into the contributions from zodiacal light, airglow and anthropogenic lig...

  7. Simulating Cherenkov Telescope Array observation of RX J1713.7-3946

    CERN Document Server

    Nakamori, T; Sano, H; Yamazaki, R; Ohira, Y; Bamba, A; Fukui, Y; Mori, K; Lee, S -H; Fujita, Y; Tajima, H; Inoue, T; Gunji, S; Hanabata, Y; Hayashida, M; Kubo, H; Kushida, J; Inoue, S; Ioka, K; Kohri, K; Murase, K; Nagataki, S; Naito, T; Okumura, A; Saito, T; Sawada, M; Tanaka, T; Terada, Y; Uchiyama, Y; Yanagita, S; Yoshida, T; Yoshikoshi, T

    2015-01-01

    We perform simulations of Cherenkov Telescope Array (CTA) observations of a young supernova remnant RX J1713.7-3946. This target is not only one of the brightest sources ever discovered in very high-energy gamma rays but also well observed in other wavebands. In X-rays, the emission is dominated by synchrotron radiation, which links directly to the existence of high-energy electrons. Radio observations of CO and HI gas have revealed a highly inhomogeneous medium surrounding the SNR, such as clumpy molecular clouds. Therefore gamma rays from hadronic interactions are naturally expected. However, the spectrum in GeV energy range measured by Fermi/LAT indicates more typical of leptonic emission from accelerated electrons. Despite lots of multi-wavelength information, the competing interpretations have led to much uncertainty in the quest of unraveling the true origin of the gamma-ray emission from RX~J1713.7--3946. CTA will achieve highest performance ever in sensitivity, angular resolution, and energy resolutio...

  8. Sensitivity of the Cherenkov Telescope Array to the Detection of Intergalactic Magnetic Fields

    Science.gov (United States)

    Meyer, Manuel; Conrad, Jan; Dickinson, Hugh

    2016-08-01

    Very high energy (VHE; energy E ≳ 100 GeV) γ-rays originating from extragalactic sources undergo pair production with low-energy photons of background radiation fields. These pairs can inverse-Compton-scatter background photons, initiating an electromagnetic cascade. The spatial and temporal structure of this secondary γ-ray signal is altered as the {e}+{e}- pairs are deflected in an intergalactic magnetic field (IGMF). We investigate how VHE observations with the future Cherenkov Telescope Array, with its high angular resolution and broad energy range, can potentially probe the IGMF. We identify promising sources and simulate γ-ray spectra over a wide range of values of the IGMF strength and coherence length using the publicly available ELMAG Monte Carlo code. Combining simulated observations in a joint likelihood approach, we find that current limits on the IGMF can be significantly improved. The projected sensitivity depends strongly on the time a source has been γ-ray active and on the emitted maximum γ-ray energy.

  9. Prospects for annihilating Dark Matter towards Milky Way's dwarf galaxies by the Cherenkov Telescope Array

    CERN Document Server

    Lefranc, Valentin; Mamon, Gary A

    2016-01-01

    We derive the large Cherenkov Telescope Array (CTA) sensitivity to dark matter (DM) annihilation in several primary channels, over a broad range of DM masses. These sensitivities are estimated when CTA is pointed towards a large sample of Milky Way's dwarf spheroidal galaxies (dSphs) with promising $J$-factors and small statistical uncertainties. This analysis neglects systematic uncertainties, which we estimate at the level of at least 1 dex. We also present sensitivities on the annihilation cross section from a combined analysis of 4 dSphs. We assess the CTA sensitivity by: $i)$ using, for each dSph, recent determination of the $J$-factor and its statistical error; $ii)$ considering the most up-to-date cosmic ray background; and $iii)$ applying a joint spatial and spectral analysis in the likelihood. We find that a joint spectral and spatial analysis improves the CTA sensitivity, in particular for primary channels with sharp features in the $\\gamma$-ray energy spectrum and for dSphs with steep $J$-factor pr...

  10. Performance of the Mechanical Structure of the SST-2M GCT Proposed for the Cherenkov Telescope Array

    CERN Document Server

    Dournaux, Jean-Laurent; Dumas, Delphine; Amans, Jean-Philippe; Fasola, Gilles; Laporte, Philippe; Bousquet, Jean-Jacques; Sol, Hélène

    2015-01-01

    The Cherenkov Telescope Array (CTA) consortium aims to create the next generation Very High Energy gamma-ray observatory. It will be devoted to the observation of gamma rays over a wide band of energy, from 20 GeV to 300 TeV. Three different classes, Large, Medium and Small Size Telescopes, are foreseen to cover the low, intermediate and high energy regions, respectively. The energy range of the Small Size Telescopes (SSTs) extends from 1 TeV to 300 TeV. Among them, the Gamma-ray Cherenkov Telescope (GCT), a telescope based on a Schwarzschild-Couder dual-mirror optical design, is one of the prototypes under construction proposed for the SST sub-array of CTA. This contribution focuses on the mechanical structure of GCT. It reports on last progress on the mechanical design and discusses this in the context of CTA specifications. Recent advances in the assembly and installation of the opto-mechanical prototype of GCT on the French site of the Paris Observatory are also described.

  11. Measuring atmospheric neutrino oscillations with neutrino telescopes

    International Nuclear Information System (INIS)

    Neutrino telescopes with large detection volumes can demonstrate whether the current indications of neutrino oscillation are correct or if a better description can be achieved with nonstandard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of nonstandard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely instrumented strings to the AMANDA II detector makes oscillation observations feasible. Such a configuration is competitive with current and proposed experiments

  12. Measuring Atmospheric Neutrino Oscillations with Neutrino Telescopes

    CERN Document Server

    Albuquerque, I F M; Albuquerque, Ivone F.M.; Smoot, George F.

    2001-01-01

    Neutrino telescopes with large detection volumes can demonstrate that the current indications of neutrino oscillation are correct or if a better description can be achieved with non-standard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of non-standard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely-instrumented strings to the AMANDA II detector makes observations feasible. Such a configuration is competitive with current and proposed experiments.

  13. Measuring atmospheric neutrino oscillations with neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, Ivone F. M.; Smoot, George F.

    2001-09-01

    Neutrino telescopes with large detection volumes can demonstrate whether the current indications of neutrino oscillation are correct or if a better description can be achieved with nonstandard alternatives. Observations of contained muons produced by atmospheric neutrinos can better constrain the allowed region for oscillations or determine the relevant parameters of nonstandard models. We analyze the possibility of neutrino telescopes measuring atmospheric neutrino oscillations. We suggest adjustments to improve this potential. An addition of four densely instrumented strings to the AMANDA II detector makes oscillation observations feasible. Such a configuration is competitive with current and proposed experiments.

  14. 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.

  15. Evolution of ground-based gamma-ray astronomy from the early days to the Cherenkov Telescope Arrays

    Science.gov (United States)

    Hillas, A. M.

    2013-03-01

    Most of what we know of cosmic gamma rays has come from spacecraft, but at energies above tens of GeV it has become possible to make observations with ground-based detectors of enormously greater collecting area. In recent years one such detector type, the cluster of imaging air Cherenkov telescopes, has reached a very productive state, whilst several alternative approaches have been explored, including converted solar power collectors and novel high-altitude particle shower detectors which promised to extend the energy range covered. Key examples of development from 1952 to 2011 are followed, noting the problems and discoveries that stimulated the current work, explaining the logic of the alternative approaches that were taken. The merits of the current major Cherenkov observatories and of other viable detectors are examined and compared, with examples of the astrophysical information they are beginning to provide. The detectors are still evolving, as we still do not understand the processes onto which the gamma rays provide a window. These include the acceleration of Galactic cosmic rays (in particular, the wide-band spectra of radiation from some individual supernova remnants are still hard to interpret), the highly relativistic and variable jets from active galactic nuclei, and aspects of the electrodynamics of pulsars. Larger groups of Cherenkov telescopes still offer the possibility of an increase in power of the technique for resolvable Galactic sources especially.

  16. Wide field-of-view Cherenkov telescope for the detection of cosmic rays in coincidence with the Yakutsk extensive air shower array

    International Nuclear Information System (INIS)

    The Yakutsk array group is developing a wide field-of-view Cherenkov telescope to be operated in coincidence with the surface detectors of the extensive air shower array. Currently, the engineering prototype of the reflecting telescope with the front-end electronics is designed, assembled, and tested to demonstrate the feasibility of the conceived instrument. The status and specifications of the prototype telescope are presented, as well as the modernization program of the already existing Cherenkov light detectors subset of the array measuring ultra-high energy cosmic rays

  17. ROBAST: Development of a ROOT-based ray-tracing library for cosmic-ray telescopes and its applications in the Cherenkov Telescope Array

    Science.gov (United States)

    Okumura, Akira; Noda, Koji; Rulten, Cameron

    2016-03-01

    We have developed a non-sequential ray-tracing simulation library, ROOT-basedsimulatorforraytracing (ROBAST), which is aimed to be widely used in optical simulations of cosmic-ray (CR) and gamma-ray telescopes. The library is written in C++, and fully utilizes the geometry library of the ROOT framework. Despite the importance of optics simulations in CR experiments, no open-source software for ray-tracing simulations that can be widely used in the community has existed. To reduce the dispensable effort needed to develop multiple ray-tracing simulators by different research groups, we have successfully used ROBAST for many years to perform optics simulations for the Cherenkov Telescope Array (CTA). Among the six proposed telescope designs for CTA, ROBAST is currently used for three telescopes: a Schwarzschild-Couder (SC) medium-sized telescope, one of SC small-sized telescopes, and a large-sized telescope (LST). ROBAST is also used for the simulation and development of hexagonal light concentrators proposed for the LST focal plane. Making full use of the ROOT geometry library with additional ROBAST classes, we are able to build the complex optics geometries typically used in CR experiments and ground-based gamma-ray telescopes. We introduce ROBAST and its features developed for CR experiments, and show several successful applications for CTA.

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

    OpenAIRE

    Blondel, Alain; Borghi, Silvia; Cervera Villanueva, Anselmo; Schroeter, Raphaël; K2K Collaboration

    2007-01-01

    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 s...

  19. The MAGIC Telescope

    OpenAIRE

    Bigongiari, Ciro

    2005-01-01

    MAGIC (Major Atmospheric Gamma Imaging Cherenkov telescope) is presently the largest ground-based gamma ray telescope. MAGIC has been taking data regularly since October 2004 at the Roque de los Muchachos Observatory on the island of La Palma. In this paper the MAGIC telescope status, its performances and some preliminary results on observed gamma ray sources are presented.

  20. Design concepts for the Cherenkov Telescope Array CTA: an advanced facility for ground-based high-energy gamma-ray astronomy

    Science.gov (United States)

    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.; Asano, K.; Asorey, H.; Bähr, J.; Bais, A.; Baixeras, C.; Bajtlik, S.; Balis, D.; Bamba, A.; Barbier, C.; Barceló, M.; Barnacka, A.; Barnstedt, J.; Barres de Almeida, U.; Barrio, J. A.; Basso, S.; Bastieri, D.; Bauer, C.; Becerra, J.; Becherini, Y.; Bechtol, K.; Becker, J.; Beckmann, V.; Bednarek, W.; Behera, B.; Beilicke, M.; Belluso, M.; Benallou, M.; Benbow, W.; Berdugo, J.; Berger, K.; Bernardino, T.; Bernlöhr, K.; Biland, A.; Billotta, S.; Bird, T.; Birsin, E.; Bissaldi, E.; Blake, S.; Blanch, O.; Bobkov, A. A.; Bogacz, L.; Bogdan, M.; Boisson, C.; Boix, J.; Bolmont, J.; Bonanno, G.; Bonardi, A.; Bonev, T.; Borkowski, J.; Botner, O.; Bottani, A.; Bourgeat, M.; Boutonnet, C.; Bouvier, A.; Brau-Nogué, S.; Braun, I.; Bretz, T.; Briggs, M. S.; Brun, P.; Brunetti, L.; Buckley, J. H.; Bugaev, V.; Bühler, R.; Bulik, T.; Busetto, G.; Buson, S.; Byrum, K.; Cailles, M.; Cameron, R.; Canestrari, R.; Cantu, S.; Carmona, E.; Carosi, A.; Carr, J.; Carton, P. H.; Casiraghi, M.; Castarede, H.; Catalano, O.; Cavazzani, S.; Cazaux, S.; Cerruti, B.; Cerruti, M.; Chadwick, P. M.; Chiang, J.; Chikawa, M.; Cieślar, M.; Ciesielska, M.; Cillis, A.; Clerc, C.; Colin, P.; Colomé, J.; Compin, M.; Conconi, P.; Connaughton, V.; Conrad, J.; Contreras, J. L.; Coppi, P.; Corlier, M.; Corona, P.; Corpace, O.; Corti, D.; Cortina, J.; Costantini, H.; Cotter, G.; Courty, B.; Couturier, S.; Covino, S.; Croston, J.; Cusumano, G.; Daniel, M. K.; Dazzi, F.; Angelis, A. De; de Cea Del Pozo, E.; de Gouveia Dal Pino, E. M.; de Jager, O.; de La Calle Pérez, I.; de La Vega, G.; de Lotto, B.; de Naurois, M.; de Oña Wilhelmi, E.; de Souza, V.; Decerprit, B.; Deil, C.; Delagnes, E.; Deleglise, G.; Delgado, C.; Dettlaff, T.; di Paolo, A.; di Pierro, F.; Díaz, C.; Dick, J.; Dickinson, H.; Digel, S. W.; Dimitrov, D.; Disset, G.; Djannati-Ataï, A.; Doert, M.; Domainko, W.; Dorner, D.; Doro, M.; Dournaux, J.-L.; Dravins, D.; Drury, L.; Dubois, F.; Dubois, R.; Dubus, G.; Dufour, C.; Durand, D.; Dyks, J.; Dyrda, M.; Edy, E.; Egberts, K.; Eleftheriadis, C.; Elles, S.; Emmanoulopoulos, D.; Enomoto, R.; Ernenwein, J.-P.; Errando, M.; Etchegoyen, A.; Falcone, A. D.; Farakos, K.; Farnier, C.; Federici, S.; Feinstein, F.; Ferenc, D.; Fillin-Martino, E.; Fink, D.; Finley, C.; Finley, J. P.; Firpo, R.; Florin, D.; Föhr, C.; Fokitis, E.; Font, Ll.; Fontaine, G.; Fontana, A.; Förster, A.; Fortson, L.; Fouque, N.; Fransson, C.; Fraser, G. W.; Fresnillo, L.; Fruck, C.; Fujita, Y.; Fukazawa, Y.; Funk, S.; Gäbele, W.; Gabici, S.; Gadola, A.; Galante, N.; Gallant, Y.; García, B.; García López, R. J.; Garrido, D.; Garrido, L.; Gascón, D.; Gasq, C.; Gaug, M.; Gaweda, J.; Geffroy, N.; Ghag, C.; Ghedina, A.; Ghigo, M.; Gianakaki, E.; Giarrusso, S.; Giavitto, G.; Giebels, B.; Giro, E.; Giubilato, P.; Glanzman, T.; Glicenstein, J.-F.; Gochna, M.; Golev, V.; Gómez Berisso, M.; González, A.; González, F.; Grañena, F.; Graciani, R.; Granot, J.; Gredig, R.; Green, A.; Greenshaw, T.; Grimm, O.; Grube, J.; Grudzińska, M.; Grygorczuk, J.; Guarino, V.; Guglielmi, L.; Guilloux, F.; Gunji, S.; Gyuk, G.; Hadasch, D.; Haefner, D.; Hagiwara, R.; Hahn, J.; Hallgren, A.; Hara, S.; Hardcastle, M. J.; Hassan, T.; Haubold, T.; Hauser, M.; Hayashida, M.; Heller, R.; Henri, G.; Hermann, G.; Herrero, A.; Hinton, J. A.; Hoffmann, D.; Hofmann, W.; Hofverberg, P.; Horns, D.; Hrupec, D.; Huan, H.; Huber, B.; Huet, J.-M.; Hughes, G.; Hultquist, K.; Humensky, T. B.; Huppert, J.-F.; Ibarra, A.; Illa, J. M.; Ingjald, J.; Inoue, Y.; Inoue, S.; Ioka, K.; Jablonski, C.; Jacholkowska, A.; Janiak, M.; Jean, P.; Jensen, H.; Jogler, T.; Jung, I.; Kaaret, P.; Kabuki, S.; Kakuwa, J.; Kalkuhl, C.; Kankanyan, R.; Kapala, M.; Karastergiou, A.; Karczewski, M.; Karkar, S.; Karlsson, N.; Kasperek, J.; Katagiri, H.; Katarzyński, K.; Kawanaka, N.; Kȩdziora, B.; Kendziorra, E.; Khélifi, B.; Kieda, D.; Kifune, T.; Kihm, T.; Klepser, S.; Kluźniak, W.; Knapp, J.; Knappy, A. R.; Kneiske, T.; Knödlseder, J.; Köck, F.; Kodani, K.; Kohri, K.; Kokkotas, K.; Komin, N.; Konopelko, A.; Kosack, K.; Kossakowski, R.; Kostka, P.; Kotuła, J.; Kowal, G.; Kozioł, J.; Krähenbühl, T.; Krause, J.; Krawczynski, H.; Krennrich, F.; Kretzschmann, A.; Kubo, H.; Kudryavtsev, V. A.; Kushida, J.; La Barbera, N.; La Parola, V.; La Rosa, G.; López, A.; Lamanna, G.; Laporte, P.; Lavalley, C.; Le Flour, T.; Le Padellec, A.; Lenain, J.-P.; Lessio, L.; Lieunard, B.; Lindfors, E.; Liolios, A.; Lohse, T.; Lombardi, S.; Lopatin, A.; Lorenz, E.; Lubiński, P.; Luz, O.; Lyard, E.; Maccarone, M. C.; Maccarone, T.; Maier, G.; Majumdar, P.; Maltezos, S.; Małkiewicz, P.; Mañá, C.; Manalaysay, A.; Maneva, G.; Mangano, A.; Manigot, P.; Marín, J.; Mariotti, M.; Markoff, S.; Martínez, G.; Martínez, M.; Mastichiadis, A.; Matsumoto, H.; Mattiazzo, S.; Mazin, D.; McComb, T. J. L.; McCubbin, N.; McHardy, I.; Medina, C.; Melkumyan, D.; Mendes, A.; Mertsch, P.; Meucci, M.; Michałowski, J.; Micolon, P.; Mineo, T.; Mirabal, N.; Mirabel, F.; Miranda, J. M.; Mirzoyan, R.; Mizuno, T.; Moal, B.; Moderski, R.; Molinari, E.; Monteiro, I.; Moralejo, A.; Morello, C.; Mori, K.; Motta, G.; Mottez, F.; Moulin, E.; Mukherjee, R.; Munar, P.; Muraishi, H.; Murase, K.; Murphy, A. Stj.; Nagataki, S.; Naito, T.; Nakamori, T.; Nakayama, K.; Naumann, C.; Naumann, D.; Nayman, P.; Nedbal, D.; Niedźwiecki, A.; Niemiec, J.; Nikolaidis, A.; Nishijima, K.; Nolan, S. J.; Nowak, N.; O'Brien, P. T.; Ochoa, I.; Ohira, Y.; Ohishi, M.; Ohka, H.; Okumura, A.; Olivetto, C.; Ong, R. A.; Orito, R.; Orr, M.; Osborne, J. P.; Ostrowski, M.; Otero, L.; Otte, A. N.; Ovcharov, E.; Oya, I.; Oziȩbło, A.; Paiano, S.; Pallota, J.; Panazol, J. L.; Paneque, D.; Panter, M.; Paoletti, R.; Papyan, G.; Paredes, J. M.; Pareschi, G.; Parsons, R. D.; Paz Arribas, M.; Pedaletti, G.; Pepato, A.; Persic, M.; Petrucci, P. O.; Peyaud, B.; Piechocki, W.; Pita, S.; Pivato, G.; Płatos, Ł.; Platzer, R.; Pogosyan, L.; Pohl, M.; Pojmański, G.; Ponz, J. D.; Potter, W.; Prandini, E.; Preece, R.; Prokoph, H.; Pühlhofer, G.; Punch, M.; Quel, E.; Quirrenbach, A.; Rajda, P.; Rando, R.; Rataj, M.; Raue, M.; Reimann, C.; Reimann, O.; Reimer, A.; Reimer, O.; Renaud, M.; Renner, S.; Reymond, J.-M.; Rhode, W.; Ribó, M.; Ribordy, M.; Rico, J.; Rieger, F.; Ringegni, P.; Ripken, J.; Ristori, P.; Rivoire, S.; Rob, L.; Rodriguez, S.; Roeser, U.; Romano, P.; Romero, G. E.; Rosier-Lees, S.; Rovero, A. C.; Roy, F.; Royer, S.; Rudak, B.; Rulten, C. B.; Ruppel, J.; Russo, F.; Ryde, F.; Sacco, B.; Saggion, A.; Sahakian, V.; Saito, K.; Saito, T.; Sakaki, N.; Salazar, E.; Salini, A.; Sánchez, F.; Sánchez Conde, M. Á.; Santangelo, A.; Santos, E. M.; Sanuy, A.; Sapozhnikov, L.; Sarkar, S.; Scalzotto, V.; Scapin, V.; Scarcioffolo, M.; Schanz, T.; Schlenstedt, S.; Schlickeiser, R.; Schmidt, T.; Schmoll, J.; Schroedter, M.; Schultz, C.; Schultze, J.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schweizer, T.; Seiradakis, J.; Selmane, S.; Seweryn, K.; Shayduk, M.; Shellard, R. C.; Shibata, T.; Sikora, M.; Silk, J.; Sillanpää, A.; Sitarek, J.; Skole, C.; Smith, N.; Sobczyńska, D.; Sofo Haro, M.; Sol, H.; Spanier, F.; Spiga, D.; Spyrou, S.; Stamatescu, V.; Stamerra, A.; Starling, R. L. C.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Steiner, S.; Stergioulas, N.; Sternberger, R.; Stinzing, F.; Stodulski, M.; Straumann, U.; Suárez, A.; Suchenek, M.; Sugawara, R.; Sulanke, K. H.; Sun, S.; Supanitsky, A. D.; Sutcliffe, P.; Szanecki, M.; Szepieniec, T.; Szostek, A.; Szymkowiak, A.; Tagliaferri, G.; Tajima, H.; Takahashi, H.; Takahashi, K.; Takalo, L.; Takami, H.; Talbot, R. G.; Tam, P. H.; Tanaka, M.; Tanimori, T.; Tavani, M.; Tavernet, J.-P.; Tchernin, C.; Tejedor, L. A.; Telezhinsky, I.; Temnikov, P.; Tenzer, C.; Terada, Y.; Terrier, R.; Teshima, M.; Testa, V.; Tibaldo, L.; Tibolla, O.; Tluczykont, M.; Todero Peixoto, C. J.; Tokanai, F.; Tokarz, M.; Toma, K.; Torres, D. F.; Tosti, G.; Totani, T.; Toussenel, F.; Vallania, P.; Vallejo, G.; van der Walt, J.; van Eldik, C.; Vandenbroucke, J.; Vankov, H.; Vasileiadis, G.; Vassiliev, V. V.; Vegas, I.; Venter, L.; Vercellone, S.; Veyssiere, C.; Vialle, J. P.; Videla, M.; Vincent, P.; Vink, J.; Vlahakis, N.; Vlahos, L.; Vogler, P.; Vollhardt, A.; Volpe, F.; von Gunten, H. P.; Vorobiov, S.; Wagner, S.; Wagner, R. M.; Wagner, B.; Wakely, S. P.; Walter, P.; Walter, R.; Warwick, R.; Wawer, P.; Wawrzaszek, R.; Webb, N.; Wegner, P.; Weinstein, A.; Weitzel, Q.; Welsing, R.; Wetteskind, H.; White, R.; Wierzcholska, A.; Wilkinson, M. I.; Williams, D. A.; Winde, M.; Wischnewski, R.; Wiśniewski, Ł.; Wolczko, A.; Wood, M.; Xiong, Q.; Yamamoto, T.; Yamaoka, K.; Yamazaki, R.; Yanagita, S.; Yoffo, B.; Yonetani, M.; Yoshida, A.; Yoshida, T.; Yoshikoshi, T.; Zabalza, V.; Zagdański, A.; Zajczyk, A.; Zdziarski, A.; Zech, A.; Ziȩtara, K.; Ziółkowski, P.; Zitelli, V.; Zychowski, P.

    2011-12-01

    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-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.

  1. Design concepts for the Cherenkov Telescope Array CTA: an advanced facility for ground-based high-energy gamma-ray astronomy

    International Nuclear Information System (INIS)

    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-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA. (authors)

  2. ROBAST: Development of a Non-Sequential Ray-Tracing Simulation Library and its Applications in the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    We have developed a non-sequential ray-tracing simulation library, ROot-BAsed Simulator for ray Tracing (ROBAST), which is aimed for wide use in optical simulations of cosmic-ray (CR) and gamma-ray telescopes. The library is written in C++ and fully utilizes the geometry library of the ROOT analysis framework. Despite the importance of optics simulations in CR experiments, no open-source software for ray-tracing simulations that can be widely used existed. To reduce the unnecessary effort demanded when different research groups develop multiple ray-tracing simulators, we have successfully used ROBAST for many years to perform optics simulations for the Cherenkov Telescope Array (CTA). Among the proposed telescope designs for CTA, ROBAST is currently being used for three telescopes: a Schwarzschild--Couder telescope, one of the Schwarzschild--Couder small-sized telescopes, and a large-sized telescope (LST). ROBAST is also used for the simulations and the development of hexagonal light concentrators that has be...

  3. Atmospheric multiple scattering of fluorescence and Cherenkov light emitted by extensive air showers

    OpenAIRE

    Pekala, J.; Homola, P.; Wilczynska, B.; Wilczynski, H.

    2009-01-01

    Atmospheric scattering of light emitted by an air shower not only attenuates direct fluorescence light from the shower, but also contributes to the observed shower light. So far only direct and singly-scattered Cherenkov photons have been taken into account in routine analyses of the observed optical image of air showers. In this paper a Monte Carlo method of evaluating the contribution of multiply scattered light to the optical air shower image is presented, as well as results of simulations...

  4. An innovative SiPM-based camera for gamma-ray astronomy with the small size telescopes of the Cherenkov Telescope Array

    Science.gov (United States)

    Schioppa, E. J.; Heller, M.; Troyano Pujadas, I.; della Volpe, D.; Favre, Y.; Montaruli, T.; Zietara, K.; Kasperek, J.; Marszalek, A.; Rajda, P.

    2016-01-01

    A prototype camera for one of the Cherenkov Telescope Array (CTA) projects for the small size telescopes, the single mirror Small Size Telescope (SST-1M), has been designed and is under construction. The camera is a hexagonal matrix of 1296 large area (95 mm2) hexagonal silicon photomultipliers. The sensors are grouped into 108 modules of 12 pixels each, hosting a preamplifier board and a slow-control board. Among its various functions, this latter implements a compensation logic that adjusts the bias voltage of each sensor as a function of temperature. The fully digital readout and trigger system, DigiCam, is based on the latest generation of FPGAs, featuring a high number of high speed I/O interfaces, allowing high data transfer rates in an extremely compact design.

  5. An innovative SiPM-based camera for gamma-ray astronomy with the small size telescopes of the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    A prototype camera for one of the Cherenkov Telescope Array (CTA) projects for the small size telescopes, the single mirror Small Size Telescope (SST-1M), has been designed and is under construction. The camera is a hexagonal matrix of 1296 large area (95 mm2) hexagonal silicon photomultipliers. The sensors are grouped into 108 modules of 12 pixels each, hosting a preamplifier board and a slow-control board. Among its various functions, this latter implements a compensation logic that adjusts the bias voltage of each sensor as a function of temperature. The fully digital readout and trigger system, DigiCam, is based on the latest generation of FPGAs, featuring a high number of high speed I/O interfaces, allowing high data transfer rates in an extremely compact design

  6. ROBAST: Development of a ROOT-Based Ray-Tracing Library for Cosmic-Ray Telescopes and its Applications in the Cherenkov Telescope Array

    CERN Document Server

    Okumura, Akira; Rulten, Cameron

    2016-01-01

    We have developed a non-sequential ray-tracing simulation library, ROOT-based simulator for ray tracing (ROBAST), which is aimed to be widely used in optical simulations of cosmic-ray (CR) and gamma-ray telescopes. The library is written in C++, and fully utilizes the geometry library of the ROOT framework. Despite the importance of optics simulations in CR experiments, no open-source software for ray-tracing simulations that can be widely used in the community has existed. To reduce the dispensable effort needed to develop multiple ray-tracing simulators by different research groups, we have successfully used ROBAST for many years to perform optics simulations for the Cherenkov Telescope Array (CTA). Among the six proposed telescope designs for CTA, ROBAST is currently used for three telescopes: a Schwarzschild-Couder (SC) medium-sized telescope, one of SC small-sized telescopes, and a large-sized telescope (LST). ROBAST is also used for the simulation and development of hexagonal light concentrators propose...

  7. Impact of aerosols and adverse atmospheric conditions on the data quality for spectral analysis of the H.E.S.S. telescopes

    CERN Document Server

    Hahn, J; Bernlöhr, K; Krüger, P; Lo, Y T E; Chadwick, P M; Daniel, M K; Deil, C; Gast, H; Kosack, K; Marandon, V

    2013-01-01

    The Earth's atmosphere is an integral part of the detector in ground-based imaging atmospheric Cherenkov telescope (IACT) experiments and has to be taken into account in the calibration. Atmospheric and hardware-related deviations from simulated conditions can result in the mis-reconstruction of primary particle energies and therefore of source spectra. During the eight years of observations with the High Energy Stereoscopic System (H.E.S.S.) in Namibia, the overall yield in Cherenkov photons has varied strongly with time due to gradual hardware aging, together with adjustments of the hardware components, and natural, as well as anthropogenic, variations of the atmospheric transparency. Here we present robust data selection criteria that minimize these effects over the full data set of the H.E.S.S. experiment and introduce the Cherenkov transparency coefficient as a new atmospheric monitoring quantity. The influence of atmospheric transparency, as quantified by this coefficient, on energy reconstruction and s...

  8. The Next Generation of Cherenkov Telescopes. A White Paper for the Italian National Institute for Astrophysics (INAF)

    OpenAIRE

    Antonelli, L.A.; P. Blasi(INAF Arcetri); Bonanno, G; Catalano, O.; Covino, S.; De Angelis, A.; De Lotto, B.; Ghigo, M.; G. Ghisellini(INAF National Institute for Astrophysics, I-23807 Merate, Italy); Israel, G.L.; La Barbera, A.; Pareschi, G.; Persic, M.; Roncadelli, M.; Sacco, B.

    2009-01-01

    Motivated by the recent challenging results from TeV astronomy, the VHE INAF community asked a group of them to write this White Paper to summarize the status and future of Cherenkov telescopes for gamma-ray astronomy and the INAF perspectives in this field. This document wants to review both the scientific topics and potential developments of the field as well as to point out both the interests and the capacities (scientific and technical) of the VHE astrophysics community in INAF. It is aim...

  9. Atmospheric monitor for Telescope Array experiment

    Directory of Open Access Journals (Sweden)

    Tsunesada Y.

    2013-06-01

    Full Text Available The atmospheric monitoring is very important for the observation of air shower by air fluorescence technique. In the Telescope Array (TA experiment, LIDAR (LIght Detection And Ranging system and CLF (Central Laser Facility system have been used for the measurement of atmospheric transparency. The LIDAR system is located in the southeast of TA site. The CLF is located in the center of the TA site. The usefulness of the CLF and LIDAR systems is demonstrated by analyzing the time variation of atmospheric transparency with the systems. The two atmospheric monitor systems are complementary. Therefore, monitoring efficiency is advanced by a new LIDAR system that was installed at CLF system. Clouds are observed with CCD camera, IR camera and eye scan visual check. In addition, we have also measured atmospheric parameters at the ground level using several weather systems.

  10. 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.

    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 $\\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...

  11. COLIBRI: partial camera readout and sliding trigger for the Cherenkov Telescope Array CTA

    International Nuclear Information System (INIS)

    Plans for the future Cherenkov telescope array CTA include replacing the monolithic camera designs used in H.E.S.S. and MAGIC-I by one that is built up from a number of identical segments. These so-called clusters will be relatively autonomous, each containing its own triggering and readout hardware. While this choice was made for reasons of flexibility and ease of manufacture and maintenance, such a concept with semi-independent sub-units lends itself quite naturally to the possibility of new, and more flexible, readout modes. In all previously-used concepts, triggering and readout of the camera is centralised, with a single camera trigger per event that starts the readout of all pixels in the camera at the same time and within the same integration time window. The limitations of such a trigger system can reduce the performance of a large array such as CTA, due to the huge amount of useless data created by night-sky background if trigger thresholds are set low enough to achieve the desired 20 GeV energy threshold, and to image losses at high energies due to the rigid readout window. In this study, an alternative concept (''COLIBRI'' = Concept for an Optimised Local Image Building and Readout Infrastructure) is presented, where only those parts of the camera which are likely to actually contain image data (usually a small percentage of the total pixels) are read out. This leads to a significant reduction of the expected data rate and the dead-times incurred in the camera. Furthermore, the quasi-independence of the individual clusters can be used to read different parts of the camera at slightly different times, thus allowing the readout to follow the slow development of the shower image across the camera field of view. This concept of flexible, partial camera readout is presented in the following, together with a description of Monte-Carlo studies performed to evaluate its performance as well as a hardware implementation proposed for CTA.

  12. DigiCam - Fully Digital Compact Read-out and Trigger Electronics for the SST-1M Telescope proposed for the Cherenkov Telescope Array

    CERN Document Server

    Rajda, P; 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; Heller, M; Idźkowski, B; Jamrozy, M; Janiak, M; Kasperek, J; Lalik, K; Lyard, E; Mach, E; Mandat, D; Marszałek, A; Michałowski, J; Moderski, R; Rameez, M; Montaruli, T; Neronov, A; Niemiec, J; Ostrowski, M; Paśko, P; Pech, M; Porcelli, A; Prandini, E; Schioppa, E jr; 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; Żychowski, P

    2015-01-01

    The SST-1M is one of three prototype small-sized telescope designs proposed for the Cherenkov Telescope Array, and is built by a consortium of Polish and Swiss institutions. The SST-1M will operate with DigiCam - an innovative, compact camera with fully digital read-out and trigger electronics. A high level of integration will be achieved by massively deploying state-of-the-art multi-gigabit transmission channels, beginning from the ADC flash converters, through the internal data and trigger signals transmission over backplanes and cables, to the camera's server link. Such an approach makes it possible to design the camera to fit the size and weight requirements of the SST-1M exactly, and provide low power consumption, high reliability and long lifetime. The structure of the digital electronics will be presented, along with main physical building blocks and the internal architecture of FPGA functional subsystems.

  13. Atmospheric multiple scattering of fluorescence and Cherenkov light emitted by extensive air showers

    CERN Document Server

    Pekala, J; Wilczynska, B; Wilczynski, H; 10.1016/j.nima.2009.03.244

    2009-01-01

    Atmospheric scattering of light emitted by an air shower not only attenuates direct fluorescence light from the shower, but also contributes to the observed shower light. So far only direct and singly-scattered Cherenkov photons have been taken into account in routine analyses of the observed optical image of air showers. In this paper a Monte Carlo method of evaluating the contribution of multiply scattered light to the optical air shower image is presented, as well as results of simulations and a parameterization of scattered light contribution to measured shower signal.

  14. Future imaging atmospheric telescopes: performance of possible array configurations for gamma photons in the GeV-TeV range

    CERN Document Server

    Sajjad, S; Vasileiadis, G

    2008-01-01

    The future of ground based gamma ray astronomy lies in large arrays of Imaging Atmospheric Cherenkov Telescopes (IACT) with better capabilities: lower energy threshold, higher sensitivity, better resolution and background rejection. Currently, designs for the next generation of IACT arrays are being explored by various groups. We have studied possible configurations with a large number of telescopes of various sizes. Here, we present the precision of source, shower core and energy reconstruction for gamma rays in the GeV-TeV range for different altitudes of observation. These results were obtained through tools that we have developed in order to simulate any type of IACT configuration and evaluate its performance.

  15. A design study of a trigger-less signal reconstruction, an active mirror control and a light collecting system in the framework of the Cherenkov Telescope Array (CTA)

    International Nuclear Information System (INIS)

    Full text: The Physics Institute at the University of Zuerich is involved in the general design study of the future Cherenkov Telescope Array (CTA). The feasibility studies include the prototyping of Active Mirror Control (AMC) devices, which are used to align the single mirror segments of a Cherenkov telescope. Together with our colleagues from the ETH Zuerich, a light collecting system for the telescope camera, composed of solid Plexiglas cones, is designed and investigated in detail. Furthermore, our efforts are dedicated to a trigger-less signal reconstruction method using cross-correlation algorithms. Detailed software-based testing has already been performed and hardware implementation is part of the future plans. This talk will present the basics and current results of the different topics. (author)

  16. Mechanics and cooling system for the camera of the Large Size Telescopes of the Cherenkov Telescope Array (CTA)

    CERN Document Server

    Delgado, Carlos; Diaz, Carlos; Hamer, Noemi; Hideyuki, Ohoka; Mirzoyan, Razmik; Teshima, Masahiro; Wetteskind, Holger

    2013-01-01

    Mechanics of the camera for the large size telescopes of CTA must protect and provide a stable environment for its instrumentation. This is achieved by a stiff support structure enclosed in an air and water tight volume. The structure is specially devised to facilitate extracting the power dissipated by the focal plane electronics while keeping its weight small enough to guarantee an optimum load on the telescope structure. A heat extraction system is designed to keep the electronics temperature within its optimal operation range, stable in time and homogeneous along the camera volume, whereas it is decoupled from the temperature in the telescope environment. In this contribution, we present the details of this system as well as its verification based in finite element analysis computations and tested prototypes. Finally, issues related to the integration of the camera mechanics and electronics will be dealt with.

  17. 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.

  18. Electro-optical characterization of MPPC detectors for the ASTRI Cherenkov telescope camera

    International Nuclear Information System (INIS)

    This work addresses a systematic and in-depth electro-optical characterization of the Multi-Pixel Photon Counter (MPPC) sensors constituting the camera detection system at the focal plane of the ASTRI telescope prototype. The paper reports the experimental results of a large set of measurements on the MPPC devices in order to provide a reliable qualification of the detector performance and evaluate its compliance with the telescope focal plane requirements. In particular, breakdown voltage, internal gain, dark count rate, cross-talk and extra-charge probability, and absolute photon detection efficiency measurements are performed on the basic sensor device unit as a function of the detector operating conditions

  19. FlashCam: A fully digital camera for the Cherenkov Telescope Array

    CERN Document Server

    Pühlhofer, G; Eisenkolb, F; Florin, D; Föhr, C; Gadola, A; Hermann, G; Kalkuhl, C; Kasperek, J; Kihm, T; Koziol, J; Manalaysay, A; Marszalek, A; Rajda, P J; Romaszkan, W; Rupinski, M; Schanz, T; Steiner, S; Straumann, U; Tenzer, C; Vollhardt, A; Weitzel, Q; Winiarski, K; Zietara, K

    2013-01-01

    FlashCam is a Cherenkov camera development project centered around a fully digital trigger and readout scheme with smart, digital signal processing, and a "horizontal" architecture for the electromechanical implementation. The fully digital approach, based on commercial FADCs and FPGAs as key components, provides the option to easily implement different types of triggers as well as digitization and readout scenarios using identical hardware, by simply changing the firmware on the FPGAs. At the same time, a large dynamic range and high resolution of low-amplitude signals in a single readout channel per pixel is achieved using compression of high amplitude signals in the preamplifier and signal processing in the FPGA. The readout of the front-end modules into a camera server is Ethernet-based using standard Ethernet switches. In its current implementation, data transfer and backend processing rates of ~3.8 GBytes/sec have been achieved. Together with the dead-time-free front end event buffering on the FPGAs, th...

  20. Anisotropy test of the axion-like particle Universe opacity effect: a case for the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    The opacity of the Universe to gamma rays is still poorly measured, in particular anomalies may have been observed. Assuming that such anomalies find their origin in conventional physics like intrinsic source spectra or the density of the extragalactic background light, they would be evenly distributed over the sky. If they exist, axion-like particles (ALPs) would have a potential effect on the opacity of the Universe to gamma rays, possibly related to the anomalies in the spectral indices of distant gamma-ray sources. Under the assumption that distant sources offer suitable environments for their production, ALPs convert back to photons in the Galactic magnetic field and their effect on the opacity is expected to depend on the position of the sources. In that case the anomaly is expected to exhibit peculiar correlations on the sky. We propose a method to test the origin of the opacity anomaly, based on angular correlations of spectral softening anomalies. Such a diagnosis requires a wide-field survey of high-energy gamma-ray sources over a broad range of energy. The future Cherenkov Telescope Array (CTA) is perfectly suited to perform such a study. It is shown that while the current sample of sources is not large enough to base conclusions on, with this method CTA will be sensitive to ALP couplings to gamma rays of the order of 3 × 10−11GeV−1 for ALP masses below 10−8 eV

  1. The sensitivity of Cherenkov telescopes to dark matter and astrophysical anisotropies in the diffuse gamma-ray background

    International Nuclear Information System (INIS)

    In this article, the capability of present (H.E.S.S., MAGIC, VERITAS) and planned (CTA) ground-based Cherenkov telescope systems for detecting angular anisotropies in the diffuse gamma-ray background is investigated. Following up on a study of the impact of instrumental characteristics (effective area, field of view, angular resolution, and background rejection efficiency), the first part examines the influence of different observational strategies, i.e. whether a single deep observation or a splitting over multiple shallow fields is preferred. In the second part, the sensitivity to anisotropies generated by self-annihilating dark matter is studied for different common dark matter models. We find that a relative contribution of ∼ 10% from dark matter annihilation to the extra-galactic diffuse gamma-ray background can be detected with planned configurations of CTA. In terms of the thermally-averaged self-annihilation cross section, the sensitivity of CTA corresponds to values below the thermal freeze-out expectation (σv) = 3 × 10−26 cm3 s−1 for dark matter particles lighter than ∼ 200 GeV. We stress the importance of constraining anisotropies from unresolved astrophysical sources with currently operating instruments already, as a novel and complementary method for investigating the properties of TeV sources

  2. Sensitivity of the Cherenkov Telescope Array to the detection of axion-like particles at high gamma-ray opacities

    International Nuclear Information System (INIS)

    Extensions of the Standard Model of particles commonly predict the existence of axion(-like) particles (ALPs) that could be detected through their coupling to photons in external magnetic fields. This coupling could lead to modifications of γ-ray spectra from extragalactic sources. Above a certain energy, the γ-ray flux should be exponentially damped due to the interaction with photons of background radiations fields. ALPs, on the other hand, propagate unimpeded over cosmological distances and a reconversion into γ-rays could lead to an additional component in the spectra. Here, we present the sensitivity of the proposed Cherenkov Telescope Array (CTA) to detect this spectral hardening. Using the full instrumental response functions of CTA, a combined likelihood analysis of four γ-ray sources shows that a significant detection of the ALP signal is possible for couplings gaγ ≳ 2 × 10−11 GeV−1 and ALP masses ma ∼< 100 neV. We discuss the dependency of these values on different model assumptions and magnetic-field scenarios and identify the best observation strategy to search for an ALP induced boost of the γ-ray flux

  3. Prospects for Gamma-Ray Bursts detection by the Cherenkov Telescope Array

    CERN Document Server

    ,

    2015-01-01

    The first Gamma-Ray Burst (GRB) catalog presented by the Fermi-Large Area Telescope (LAT) collaboration includes 28 GRBs, detected above 100 MeV over the first three years since the launch of the Fermi mission. However, more than 100 GRBs are expected to be found over a period of six years of data collection thanks to a new detection algorithm and to the development of a new LAT event reconstruction, the so-called "Pass 8." Our aim is to provide revised prospects for GRB alerts in the CTA era in light of these new LAT discoveries. We focus initially on the possibility of GRB detection with the Large Size Telescopes (LSTs). Moreover, we investigate the contribution of the Middle Size Telescopes (MSTs), which are crucial for the search of larger areas on short post trigger timescales. The study of different spectral components in the prompt and afterglow phase, and the limits on the Extragalactic background light are highlighted. Different strategies to repoint part of - or the entire array - are studied in det...

  4. Contributions to free-space optical communications: feasibility of utilizing Cherenkov telescopes as receivers and beam-wander correction in quantum communications

    CERN Document Server

    Carrasco-Casado, Alberto

    2015-01-01

    This thesis focuses on the two main applications where free-space optical communication (FSOC) can bring the most significant impact: interplanetary communications and quantum communications. Consequently, the dissertation is structured in two sections. In the first one, a novel proposal is suggested regarding to using Cherenkov telescopes as ground-station receivers. A feasibility study addresses the posibility of using the technology developed for the gamma-ray telescopes that will make up the Cherenkov Telescope Array (CTA) 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 deep-space optical communication both have. Also, the large number of big telescopes that will be built for CTA will make it possible to reduce unitary costs by economy-scale production. The second section of the thesis is framed in the field of free-space Quantum Key...

  5. Observations of the Pulsar PSR B1951+32 with the Solar Tower Atmospheric Cherenkov Effect Experiment

    CERN Document Server

    Kildea, J; Ball, J; Carson, J E; Covault, C E; Driscoll, D D; Fortin, P; Gingrich, D M; Hanna, D S; Jarvis, A; Lindner, T; Müller, C; Mukherjee, R; Ong, R A; Ragan, K; Williams, D A

    2007-01-01

    We present the analysis and results of 12.5 hours of high-energy gamma-ray observations of the EGRET-detected pulsar PSR B1951+32 using the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE). STACEE is an atmospheric Cherenkov detector, in Albuquerque, New Mexico, that detects cosmic gamma rays using the shower-front-sampling technique. STACEE's sensitivity to astrophysical sources at energies around 100 GeV allows it to investigate emission from gamma-ray pulsars with expected pulsed emission cutoffs below 100 GeV. We discuss the observations and analysis of STACEE's PSR 1951+32 data, accumulated during the 2005 and 2006 observing seasons.

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

    Science.gov (United States)

    Adrián-Martínez, S.; Albert, A.; 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.

    2016-05-01

    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 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 photomultipliers on different lines at a precision level of 0.5 ns. It has also been validated for calibrating photomultipliers on the same line, using a system of LEDs and laser light devices.

  7. LUNASKA experiments using the Australia Telescope Compact Array to search for ultrahigh energy neutrinos and develop technology for the lunar Cherenkov technique

    International Nuclear Information System (INIS)

    We describe the design, performance, sensitivity and results of our recent experiments using the Australia Telescope Compact Array (ATCA) for lunar Cherenkov observations with a very wide (600 MHz) bandwidth and nanosecond timing, including a limit on an isotropic neutrino flux. We also make a first estimate of the effects of small-scale surface roughness on the effective experimental aperture, finding that contrary to expectations, such roughness will act to increase the detectability of near-surface events over the neutrino energy-range at which our experiment is most sensitive (though distortions to the time-domain pulse profile may make identification more difficult). The aim of our 'Lunar UHE Neutrino Astrophysics using the Square Kilometre Array' (LUNASKA) project is to develop the lunar Cherenkov technique of using terrestrial radio telescope arrays for ultrahigh energy (UHE) cosmic ray (CR) and neutrino detection, and, in particular, to prepare for using the Square Kilometre Array (SKA) and its path-finders such as the Australian SKA Pathfinder (ASKAP) and the Low Frequency Array (LOFAR) for lunar Cherenkov experiments.

  8. FRAM telescope - monitoring of atmospheric extinction and variable star photometry

    Science.gov (United States)

    Jurysek, J.; Honkova, K.; Masek, M.

    2015-02-01

    The FRAM (F/(Ph)otometric Robotic Atmospheric Monitor) telescope is a part of the Pierre Auger Observatory (PAO) located near town Malargüe in Argentina. The main task of the FRAM telescope is the continuous night - time monitoring of the atmospheric extinction and its wavelength dependence. The current methodology of the measurement of a atmospheric extinction and for instrumentation properties also allows simultaneous observation of other interesting astronomical targets. The current observations of the FRAM telescope are focused on the photometry of eclipsing binaries, positional refinement of minor bodies of the Solar system and observations of optical counterparts of gamma ray bursts. In this contribution, we briefly describe the main purpose of the FRAM telescope for the PAO and we also present its current astrono mical observing program.

  9. Detection of metagalactic and galactic sources of very high-energy gamma-quanta and neutrinos with the mirror Cherenkov telescope SHALON

    International Nuclear Information System (INIS)

    Gamma-astronomy and neutrino astronomy are unique experimental possibilities to search for sources of high-energy cosmic rays (1012-1014eV). Experimental data on sources of γ-quanta with the energy >1TeV are characterized by the fact that observed metagalactic sources (active galactic nuclei), being different in power from galactic sources by the factor of 106-107, do not differ in the energy spectrum, F(>Eγ)∝Eγ-1.3+/-0.15. The power of the metagalactic sources and their unlimited number casts doubts on the assumption of a galactic origin of the observed cosmic-ray flux. It is possible to assume that the uniform cosmic-ray spectrum is formed by ''braking'' in multiple elastic or inelastic collisions with relict photons in intergalactic space. Thus, the observed distribution of protons and cosmic-ray nuclei with the spectral index 2.72+/-0.02 (=2.718..., the Napier's constant) may be a consequence of such a ''braking'' that warms up the relict photons. Problems in observation of extensive air showers generated by neutrinos are connected with an extremely small cross section of inelastic collisions of neutrinos with nuclei. However, two facts allow to search for showers generated by neutrinos: (1) a hadron cascade with the primary energy of more than 1012eV leaves a mountain ridge to the atmosphere from the depth ∼300g/cm2 without an essential loss of the total energy in the hadron cascade, and (2) air Cherenkov radiation from such hadron cascades will be observed with a 7.5km distant telescope over an area of more than 7x105m2. This partially compensates the small cross section of inelastic neutrino collisions

  10. Exploiting the time of arrival of Cherenkov photons at the 28 m H.E.S.S. telescope for background rejection: Methods and performance

    CERN Document Server

    Chalmé-Calvet, Raphaël; de Naurois, Mathieu; Tavernet, Jean-Paul

    2015-01-01

    In 2012, the High Energy Stereoscopic System (H.E.S.S.) was expanded by a fifth telescope (CT5). With an effective mirror diameter of 28m, CT5 is able to detect the Cherenkov light of very faint gamma-ray air showers, thereby significantly lowering the energy threshold of this telescope compared to the other four telescopes. Extracting as much information as possible from the recorded shower image is crucial for background rejection and to reach an energy threshold of a few tens of GeV. The camera of CT5 is conceived to register the time of the charge pulse maximum with respect to the beginning of the 16 ns integration window of each pixel. This information can be utilised to improve the event reconstruction. It also helps to reduce the background contamination at low energies. We present new techniques for background rejection based on CT5 timing information and evaluate their performance.

  11. The Knee of the Cosmic Hydrogen and Helium Spectrum below 1 PeV Measured by ARGO-YBJ and a Cherenkov Telescope of LHAASO

    CERN Document Server

    Bartoli, B; Bi, X J; Branchini, P; Budano, A; Camarri, P; Cao, Z; Cardarelli, R; Catalanotti, S; Chen, S Z; Chen, T L; Creti, P; Cui, S W; Dai, B Z; D'Amone, A; Danzengluobu,; De Mitri, I; Piazzoli, B D'Ettorre; Di Girolamo, T; Di Sciascio, G; Feng, C F; Feng, Zhaoyang; Feng, Zhenyong; Gou, Q B; Guo, Y Q; He, H H; Hu, Haibing; Hu, Hongbo; Iacovacci, M; Iuppa, R; Jia, H Y; Labaciren,; Li, H J; Liguori, G; Liu, C; Liu, J; Liu, M Y; Lu, H; Ma, L L; Ma, X H; Mancarella, G; Mari, S M; Marsella, G; Martello, D; Mastroianni, S; Montini, P; Ning, C C; Panareo, M; Perrone, L; Pistilli, P; Ruggieri, F; Salvini, P; Santonico, R; Shen, P R; Sheng, X D; Shi, F; Surdo, A; Tan, Y H; Vallania, P; Vernetto, S; Vigorito, C; Wang, H; Wu, C Y; Wu, H R; Xue, L; Yang, Q Y; Yang, X C; Yao, Z G; Yuan, A F; Zha, M; Zhang, H M; Zhang, L; Zhang, X Y; Zhang, Y; Zhao, J; Zhaxiciren,; Zhaxisangzhu,; Zhou, X X; Zhu, F R; Zhu, Q Q; Zizzi, G; Bai, Y X; Chen, M J; Chen, Y; Feng, S H; Gao, B; Gu, M H; Hou, C; Li, X X; Liu, J L; Wang, X; Xiao, G; Zhang, B K; Zhang, S S; Zhou, B; Zuo, X

    2015-01-01

    The measurement of cosmic ray energy spectra, in particular for individual species, is an essential approach in finding their origin. Locating the "knees" of the spectra is an important part of the approach and has yet to be achieved. Here we report a measurement of the mixed Hydrogen and Helium spectrum using the combination of the ARGO-YBJ experiment and of a prototype Cherenkov telescope for the LHAASO experiment. A knee feature at 640+/-87 TeV, with a clear steepening of the spectrum, is observed. This gives fundamental inputs to galactic cosmic ray acceleration models.

  12. Characterization of EASIROC as Front-End for the readout of the SiPM at the focal plane of the Cherenkov telescope ASTRI

    CERN Document Server

    Impiombato, D; Mineo, T; Belluso, M; Billotta, S; Bonanno, G; Catalano, O; Grillo, A; La Rosa, G; Marano, D; Sottile, G

    2013-01-01

    The Extended Analogue Silicon Photo-multiplier Integrated Read Out Chip, EASIROC, is a chip proposed as front-end of the camera at the focal plane of the imaging Cherenkov ASTRI SST-2M telescope prototype. This paper presents the results of the measurements performed to characterize EASIROC in order to evaluate its compliance with the ASTRI SST-2M focal plane requirements. In particular, we investigated the trigger time walk and the jitter effects as a function of the pulse amplitude. The EASIROC output signal is found to vary linearly as a function of the input pulse amplitude with very low level of electronic noise and cross-talk (<1%). Our results show that it is suitable as front-end chip for the camera prototype, although, specific modifications are necessary to adopt the device in the final version of the telescope.

  13. Exoplanet Atmospheres and Giant Ground-Based Telescopes

    CERN Document Server

    Crossfield, I J M

    2016-01-01

    The study of extrasolar planets has rapidly expanded to encompass the search for new planets, measurements of sizes and masses, models of planetary interiors, planetary demographics and occurrence frequencies, the characterization of planetary orbits and dynamics, and studies of these worlds' complex atmospheres. Our insights into exoplanets dramatically advance whenever improved tools and techniques become available, and surely the largest tools now being planned are the optical/infrared Extremely Large Telescopes (ELTs). Two themes summarize the advantages of atmospheric studies with the ELTs: high angular resolution when operating at the diffraction limit and high spectral resolution enabled by the unprecedented collecting area of these large telescopes. This brief review describes new opportunities afforded by the ELTs to study the composition, structure, dynamics, and evolution of these planets' atmospheres, while specifically focusing on some of the most compelling atmospheric science cases for four qua...

  14. Geomagnetic effects on the performance of atmospheric Cerenkov telescopes

    International Nuclear Information System (INIS)

    We have reported the results of the interaction between the geomagnetic field and the development of atmospheric electron cascades as manifested by the distortion of the atmospheric Cerenkov signal. We will summarize these effects and describe our initial attempt to remove this distortion for those cases where the cascade develops perpendicular to a strong (>0.35 G) field and so enhance the hadron rejection procedures of gamma ray telescopes

  15. Laser Atmospheric Studies with VERITAS

    CERN Document Server

    Hui, C M

    2007-01-01

    As a calibrated laser pulse propagates through the atmosphere, the amount of Rayleigh-scattered light arriving at the VERITAS telescopes can be calculated precisely. This technique was originally developed for the absolute calibration of ultra-high-energy cosmic-ray fluorescence telescopes but is also applicable to imaging atmospheric Cherenkov telescopes (IACTs). In this paper, we present two nights of laser data taken with the laser at various distances away from the VERITAS telescopes and compare it to Rayleigh scattering simulations.

  16. Characterization of a 6×6-mm2 75-μm cell MPPC suitable for the Cherenkov Telescope Array project

    Science.gov (United States)

    Romeo, G.; Bonanno, G.; Garozzo, S.; Grillo, A.; Marano, D.; Munari, M.; Timpanaro, M. C.; Catalano, O.; Giarrusso, S.; Impiombato, D.; La Rosa, G.; Sottile, G.

    2016-08-01

    This paper presents the latest characterization results of a novel Low Cross-Talk (LCT) large-area (6×6-mm2) Multi-Pixel Photon Counter (MPPC) detector manufactured by Hamamatsu, belonging to the recent LCT5 family and achieving a fill-factor enhancement and cross-talk reduction. In addition, the newly adopted resin coating is demonstrated to yield improved photon detection capabilities in the 290-350 nm spectral range, making the new LCT MPPC particularly suitable for emerging applications like Cherenkov Telescopes. For a 3×3-mm2 version of the new MPPC under test, a comparative analysis of the large pixel pitch (75-μm) detector versus the smaller pixel pitch (50-μm) detector is also undertaken. Furthermore, measurements of the 6×6-mm2 MPPC response versus the angle of incidence are provided for the characterized device.

  17. Photomultiplier tube selection for the Wide Field of view Cherenkov/fluorescence Telescope Array of the Large High Altitude Air Shower Observatory

    Science.gov (United States)

    Ge, Maomao; Zhang, Li; Chen, Yingtao; Cao, Zhen; Zhang, Shoushan; Wang, Chong; Bi, Baiyang

    2016-05-01

    For the purpose of selecting the most suitable photomultiplier tubes (PMTs) for the Wide Field of view Cherenkov/fluorescence Telescope Array (WFCTA), we have performed extensive tests on seven models of 25.4 mm PMTs: Hamamatsu R1924A and R7899, Beijing Hamamatsu CR303, CR332A and CR364, and HZC Photonics XP3102 and XP3182. A dedicated test system has been developed to measure the PMT characteristics such as single photo-electron spectrum, gain, linearity, and spatial uniformity of anode output. The XP3182 and CR364 (R7899) tubes both meet the pivotal requirement due to their superior pulse linearity. The PMT test system, techniques used for these measurements, and their results are also reported.

  18. Searches for dark matter self-annihilation signals from dwarf spheroidal galaxies and the Fornax galaxy cluster with imaging air Cherenkov telescopes

    International Nuclear Information System (INIS)

    Many astronomical observations indicate that dark matter pervades the universe and dominates the formation and dynamics of cosmic structures. Weakly interacting massive particles (WIMPs) with masses in the GeV to TeV range form a popular class of dark matter candidates. WIMP self-annihilation may lead to the production of γ-rays in the very high energy regime above 100 GeV, which is observable with imaging air Cherenkov telescopes (IACTs). For this thesis, observations of dwarf spheroidal galaxies (dSph) and the Fornax galaxy cluster with the Cherenkov telescope systems H.E.S.S., MAGIC and VERITAS were used to search for γ-ray signals of dark matter annihilations. The work consists of two parts: First, a likelihood-based statistical technique was introduced to combine published results of dSph observations with the different IACTs. The technique also accounts for uncertainties on the ''J factors'', which quantify the dark matter content of the dwarf galaxies. Secondly, H.E.S.S. observations of the Fornax cluster were analyzed. In this case, a collection of dark matter halo models was used for the J factor computation. In addition, possible signal enhancements from halo substructures were considered. None of the searches yielded a significant γ-ray signal. Therefore, the results were used to place upper limits on the thermally averaged dark matter self-annihilation cross-section left angle σν right angle. Different models for the final state of the annihilation process were considered. The cross-section limits range from left angle σν right angle UL∝10-19 cm3s-1 to left angle σν right angle UL∝10-25 cm3s-1 for dark matter particles masses between 100 GeV and 100 TeV. Some of the diverse model uncertainties causing this wide range of left angle σν right angle UL values were analyzed.

  19. FACT light collection - solid light concentrators in Cherenkov Astronomy

    International Nuclear Information System (INIS)

    Pixelized cameras of Imaging Atmospheric Cherenkov Telescopes use hollow light guides with reflective surfaces based on the Winston cone design. These cones minimize insensitive spaces between the photo sensors and shield the camera from stray background light by limiting the angular acceptance to the primary reflector area. FACT (First G-APD Cherenkov Telescope) will be the first IACT with Geiger-mode avalanche photodiodes as light sensors. Solid light concentrators complementing these sensors will be used instead of hollow Winston cones. We will present simulations and measurements of our light collector design, which was optimized for the requirements of the FACT telescope and detector, and discuss the specific differences to more traditional solutions.

  20. VERITAS The Very Energetic Radiation Imaging Telescope Array System

    CERN Document Server

    Weekes, T C; Biller, S D; Breslin, A C; Buckley, J H; Carter-Lewis, D A; Catanese, M; Cawley, M F; Dingus, B L; Fazio, G G; Fegan, D J; Finley, J; Fishman, G; Gaidos, J A; Gillanders, G H; Gorham, P W; Grindlay, J E; Hillas, A M; Huchra, J P; Kaaret, P E; Kertzman, M P; Kieda, D B; Krennrich, F; Lamb, R C; Lang, M J; Marscher, A P; Matz, S; McKay, T; Müller, D; Ong, R; Purcell, W; Rose, J; Sembroski, G H; Seward, F D; Slane, P O; Swordy, S P; Tümer, T O; Ulmer, M P; Urban, M; Wilkes, B J

    1997-01-01

    A next generation atmospheric Cherenkov observatory is described based on the Whipple Observatory $\\gamma$-ray telescope. A total of nine such imaging telescopes will be deployed in an array that will permit the maximum versatility and give high sensitivity in the 50 GeV - 50 TeV band (with maximum sensitivity from 100 GeV to 10 TeV).

  1. Measurement of Atmospheric Neutrino Oscillations with the ANTARES Neutrino Telescope

    CERN Document Server

    Adrian-Martinez, S; Albert, A; Andre, M; Anghinolfi, M; Anton, G; Anvar, S; Ardid, M; Astraatmadja, T; Aubert, J -J; Baret, B; Basa, S; Bertin, V; Biagi, S; Bigongiari, C; Bogazzi, C; Bou-Cabo, M; Bouhou, B; Bouwhuis, M C; Brunner, J; Busto, J; Capone, A; Carloganu, C; Carr, J; Cecchini, S; Charif, Z; Charvis, Ph; Chiarusi, T; Circella, M; Coniglione, R; Core, L; Costantini, H; Coyle, P; Creusot, A; 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; Fehn, K; Fermani, P; Ferri, M; Ferry, S; Flaminio, V; Folger, F; Fritsch, U; Fuda, J -L; Galata, S; Gay, P; Geyer, K; Giacomelli, G; Giordano, V; Gleixner, A; Gomez-Gonzalez, J P; Graf, K; Guillard, G; Hallewell, G; Hamal, M; van Haren, H; 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; Kooijman, P; Kopper, C; Kouchner, A; Kreykenbohm, I; Kulikovskiy, V; Lahmann, R; Lambard, G; Larosa, G; Lattuada, D; Lefevre, D; Lim, G; Presti, D Lo; Loehner, H; Loucatos, S; Louis, F; Mangano, S; Marcelin, M; Margiotta, A; Martinez-Mora, J A; Meli, A; Montaruli, T; Morganti, M; Moscoso, L; Motz, H; Neff, M; Nezri, E; Palioselitis, D; Pavalas, G E; Payet, K; Petrovic, J; Piattelli, P; Popa, V; Pradier, T; Presani, E; Racca, C; Reed, C; Riccobene, G; Richardt, C; Richter, R; Riviere, C; Robert, A; Roensch, K; Rostovtsev, A; Ruiz-Rivas, J; Rujoiu, M; Russo, G V; Samtleben, D F E; Sanchez-Losa, A; Sapienza, P; Schmid, J; Schnabel, J; Schoeck, F; Schuller, J -P; Schuessler, F; Seitz, T; Shanidze, R; Simeone, F; Spies, A; Spurio, M; Steijger, J J M; Stolarczyk, Th; Taiuti, M; Tamburini, C; Trovato, A; Vallage, B; Vallee, C; Van Elewyck, V; Vecchi, M; Vernin, P; Visser, E; Wagner, S; Wijnker, G; Wilms, J; de Wolf, E; Yepes, H; Zaborov, D; Zornoza, J D; Zuniga, J

    2012-01-01

    The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximum mixing, a mass difference of $\\Delta m_{32}^2=(3.1\\pm 0.9)\\cdot 10^{-3}$ eV$^2$ is obtained, in good agreement with the world average value.

  2. Measurement of atmospheric neutrino oscillations with the ANTARES neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Adrian-Martinez, S. [Institut d' Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Universitat Politecnica de Valencia, C/ Paranimf 1, 46730 Gandia (Spain); Al Samarai, I. [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); Albert, A. [GRPHE - Institut universitaire de technologie de Colmar, 34 rue du Grillenbreit, BP 50568, 68008 Colmar (France); Andre, M. [Technical University of Catalonia, Laboratory of Applied Bioacoustics, Rambla Exposicio, 08800 Vilanova i la Geltru, Barcelona (Spain); Anghinolfi, M. [INFN - Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Anton, G. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, 91058 Erlangen (Germany); Anvar, S. [Direction des Sciences de la Matiere, Institut de recherche sur les lois fondamentales de l' Univers, Service d' Electronique des Detecteurs et d' Informatique, CEA Saclay, 91191 Gif-sur-Yvette Cedex (France); Ardid, M. [Institut d' Investigacio per a la Gestio Integrada de les Zones Costaneres (IGIC), Universitat Politecnica de Valencia, C/ Paranimf 1, 46730 Gandia (Spain); Astraatmadja, T. [Nikhef, Science Park, Amsterdam (Netherlands); Aubert, J.-J. [CPPM, Aix-Marseille Universite, CNRS/IN2P3, Marseille (France); and others

    2012-08-14

    The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximal mixing, a mass difference of {Delta}m{sub 32}{sup 2}=(3.1{+-}0.9) Dot-Operator 10{sup -3} eV{sup 2} is obtained, in good agreement with the world average value.

  3. Measurement of atmospheric neutrino oscillations with the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    The data taken with the ANTARES neutrino telescope from 2007 to 2010, a total live time of 863 days, are used to measure the oscillation parameters of atmospheric neutrinos. Muon tracks are reconstructed with energies as low as 20 GeV. Neutrino oscillations will cause a suppression of vertical upgoing muon neutrinos of such energies crossing the Earth. The parameters determining the oscillation of atmospheric neutrinos are extracted by fitting the event rate as a function of the ratio of the estimated neutrino energy and reconstructed flight path through the Earth. Measurement contours of the oscillation parameters in a two-flavour approximation are derived. Assuming maximal mixing, a mass difference of Δm322=(3.1±0.9)⋅10-3 eV2 is obtained, in good agreement with the world average value.

  4. Knee of the cosmic hydrogen and helium spectrum below 1 PeV measured by ARGO-YBJ and a Cherenkov telescope of LHAASO

    Science.gov (United States)

    Bartoli, B.; Bernardini, P.; Bi, X. J.; Cao, Z.; Catalanotti, S.; Chen, S. Z.; Chen, T. L.; Cui, S. W.; Dai, B. Z.; D'Amone, A.; Danzengluobu; De Mitri, I.; D'Ettorre Piazzoli, B.; Di Girolamo, T.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Guo, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Iacovacci, M.; Iuppa, R.; Jia, H. Y.; Labaciren; Li, H. J.; Liu, C.; Liu, J.; Liu, M. Y.; Lu, H.; Ma, L. L.; Ma, X. H.; Mancarella, G.; Mari, S. M.; Marsella, G.; Mastroianni, S.; Montini, P.; Ning, C. C.; Perrone, L.; Pistilli, P.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xue, L.; Yang, Q. Y.; Yang, X. C.; Yao, Z. G.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhao, J.; Zhaxiciren; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; Bai, Y. X.; Chen, M. J.; Feng, S. H.; Gao, B.; Gu, M. H.; Hou, C.; Liu, J.; Liu, J. L.; Wang, X.; Xiao, G.; Zhang, B. K.; Zhang, S. S.; Zhou, B.; Zuo, X.; ARGO-YBJ Collaboration‡

    2015-11-01

    The measurement of the cosmic ray energy spectrum, in particular for individual species of nuclei, is an important tool to investigate cosmic ray production and propagation mechanisms. The determination of the "knees" in the spectra of different species remains one of the main challenges in cosmic ray physics. In fact, experimental results are still conflicting. In this paper we report a measurement of the mixed proton and helium energy spectrum, obtained with the combined data of the ARGO-YBJ experiment and a wide field of view Cherenkov telescope, a prototype of the future LHAASO experiment. By means of a multiparameter technique, we have selected a high-purity proton plus helium sample. The reconstructed energy resolution is found to be about 25% throughout the investigated energy range from 100 TeV to 3 PeV, with a systematic uncertainty in the absolute energy scale of 9.7%. The found energy spectrum can be fitted with a broken power-law function, with a break at the energy Ek =700 ±230 (stat )±70 (sys ) TeV , where the spectral index changes from -2.56 ±0.05 to -3.24 ±0.36 . The statistical significance of the observed spectral break is 4.2 standard deviations.

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

    CERN Document Server

    Aguilar, J A; Boccone, V; Cadoux, F; Christov, A; della Volpe, D; Montaruli, T; Platos, L; Rameez, M

    2014-01-01

    The focal-plane camera of $\\gamma$-ray telescopes frequently uses light concentrators in front of 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 an hexagonal hollow light concentrator with a lateral profile optimized using a cubic B\\'ezier 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 primary mirror of about 4 meters of diameter and focal length of 5.6 m. The described concentrators are part of an innovative camera made up of silicon-photomultipliers 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 des...

  6. 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.

  7. Detection of Callisto's oxygen atmosphere with the Hubble Space Telescope

    Science.gov (United States)

    Cunningham, Nathaniel J.; Spencer, John R.; Feldman, Paul D.; Strobel, Darrell F.; France, Kevin; Osterman, Steven N.

    2015-07-01

    We report the result of a search for evidence of an O2-dominated atmosphere on Callisto, using the high far-ultraviolet sensitivity of the Hubble Space Telescope Cosmic Origins Spectrograph (COS). Observations of Callisto's leading/Jupiter-facing hemisphere show, for the first time, variable-strength atomic oxygen (O I) emissions with brightness up to 4.7 ± 0.7 Rayleighs for the O I 1304 Å triplet and 1.9 ± 0.4 Rayleighs for the O I 1356 Å doublet, averaged over the 2.5 arcsec. diameter COS aperture. Because the observations were made in Earth's shadow, and are brighter than expected emission from nighttime geocoronal airglow or other plausible sources, we are confident that they originate from Callisto or its immediate vicinity. In addition, COS's limited (∼1 arcsec) spatial resolution implies a 2σ detection of excess 1356 Å emission concentrated on the disk of Callisto itself, with brightness 3.2 ± 1.6 Rayleighs. The (O I 1356 Å)/(O I 1304 Å) emission ratio from Callisto's disk favors dissociative excitation of O2, suggesting that O2 is the dominant atmospheric component rather than other possible oxygen-bearing alternatives. Photoelectrons, rather than magnetospheric electrons, are the most likely source of the dissociative excitation. This detection yields an O2 column density of ∼4 × 1015 cm-2 on the leading/Jupiter facing hemisphere, which implies that Callisto's atmosphere is collisional and is the fourth-densest satellite atmosphere in the Solar System, in addition to being the second-densest O2-rich collisional atmosphere in the Solar System, after Earth. Longitudinal variations in published densities of ionospheric electrons suggest that O2 densities in Callisto's trailing hemisphere, which we did not observe, may be an order of magnitude greater. The aperture-filling emissions imply that there is also an extended corona of predominantly O I 1304 Å emission around Callisto, with observed strength of 1-4 Rayleighs, likely due to solar

  8. Latest results on galactic sources obtained with the MAGIC telescope

    OpenAIRE

    Zanin, Roberta; collaboration, for the MAGIC

    2009-01-01

    The MAGIC telescope is the largest single-dish Imaging Atmospheric Cherenkov Telescope (IACT) with the lowest energy threshold among the current generation of IACTs as low as 25 GeV. Therefore, the MAGIC telescope is a perfect instrument to study the galactic sources especially in the context of observations with the satellite observatories Fermi and AGILE. This paper will give an overview of the MAGIC results on the galactic sources including detailed observations of binary systems, supernov...

  9. Study of atmospheric muons using a cosmic ray telescope

    Science.gov (United States)

    Abdollahi, S.; Bahmanabadi, M.; Purmohammad, D.

    2013-02-01

    The charge ratio of cosmic muons holds important information for both the atmospheric neutrino anomaly and hadronic interaction models. In this paper we measured the muon charge ratio (R_{\\mu }=N_{\\mu ^{+}}/N_{\\mu ^{-}}) in the cosmic ray flux in the momenta range 0.76-1.60 GeV/c by using a cosmic ray telescope. The delayed coincidence method is used based on the reduced mean lifetime of negative muons due to nuclear capture in matter. The systematic time-dependent effects of the muon charge ratio are considered by grouping the decay data into different time intervals. We compared the experimental data with the predictions of CORSIKA simulations using a high energy interaction model (QGSJET-II) and two low energy interaction models (UrQMD and GHEISHA) in the energy range 1011-1016 eV for primary particles. In addition, by considering the muon flux in different zenithal and azimuthal angles, the muon angular distribution is obtained as I(θ) = I(0)cos nθ with average n = 1.91 ± 0.07. Dependence of the muon flux on the azimuth angle (the East-West effect) is also observed, due to the influence of the geomagnetic field in particular on low energy muons.

  10. Detection and initial characterisation of an exoplanet atmosphere with small aperture telescopes

    Science.gov (United States)

    Bernt, I.; Müller, M.; Strassmeier, K. G.; Granzer, T.

    2013-09-01

    In the recent years atmospheres of exoplanets have been studied with space-based telescopes like the HST or large aperture ground-based telescopes like the Gran Telescopio Canarias. But as the number of suitable exoplanets is rising, comparative studies of atmospheres with a statistically meaningful amount of targets will follow, for which the observational time with large telescopes is limited and expensive. Our aim is to investigate whether it is possible to detect and initially characterise the atmosphere of an exoplanet with small aperture telescopes using chromatic variations in transit depths. We collected multi-color transits in the years 2011 to 2013 using the robotic 1.2m-telescope STELLA on Tenerife as well as the Nordic Optical Telescope and the 70cm-telescope at the Leibniz Institute for Astrophysics Potsdam. The highly inflated Hot Jupiter HAT-P-32 b was chosen as target for our pilot study for its favorable large atmospheric scale height and therefore enhanced atmospheric detectability. Models of the atmospheric spectra of HAT-P-32 b indicate that the STELLA-data can be used to distinguish between a dusty and a cloud-free atmosphere using the gradient in transit depth of the observations in the blue band and in the visible band. Here we want to present our project together with the first results of the transit depth analysis.

  11. Upgrade of the MAGIC telescopes

    CERN Document Server

    Mazin, Daniel; Garczarczyk, Markus; Giavitto, Gianluca; Sitarek, Julian

    2014-01-01

    The MAGIC telescopes are two Imaging Atmospheric Cherenkov Telescopes (IACTs) located on the Canary island of La Palma. With 17m diameter mirror dishes and ultra-fast electronics, they provide an energy threshold as low as 50 GeV for observations at low zenith angles. The first MAGIC telescope was taken in operation in 2004 whereas the second one joined in 2009. In 2011 we started a major upgrade program to improve and to unify the stereoscopic system of the two similar but at that time different telescopes. Here we report on the upgrade of the readout electronics and digital trigger of the two telescopes, the upgrade of the camera of the MAGIC I telescope as well as the commissioning of the system after this major upgrade.

  12. Studies of a software-based inter-telescope trigger scheme for CTA

    International Nuclear Information System (INIS)

    The Cherenkov Telescope Array (CTA), the next generation ground-based gamma-ray observatory, will consist of over 50 imaging atmospheric Cherenkov telescopes of different sizes, covering an area of up to several square kilometers. The development of a new inter-telescope trigger scheme is necessary to optimally utilize the potential of such an array. A flexible, cost-effective approach is a software-based 'asynchronous array trigger' where the inter-telescope trigger decision is made in software, based on the relative arrival times of the Cherenkov light at the different telescopes. To understand the requirements for an effective realization of such an array trigger, Monte-Carlo studies were conducted. The results of these studies are presented.

  13. Scintillation correction for astronomical photometry on large and extremely large telescopes with tomographic atmospheric reconstruction

    CERN Document Server

    Osborn, James

    2014-01-01

    We describe a new concept to correct for scintillation noise on high-precision photometry in large and extremely large telescopes using telemetry data from adaptive optics (AO) systems. Most wide-field AO systems designed for the current era of very large telescopes and the next generation of extremely large telescopes require several guide stars to probe the turbulent atmosphere in the volume above the telescope. These data can be used to tomographically reconstruct the atmospheric turbulence profile and phase aberrations of the wavefront in order to assist wide-field AO correction. If the wavefront aberrations and altitude of the atmospheric turbulent layers are known from this tomographic model, then the effect of the scintillation can be calculated numerically and used to normalize the photometric light curve. We show through detailed Monte Carlo simulation that for an 8 m telescope with a 16x16 AO system we can reduce the scintillation noise by an order of magnitude.

  14. Prototype tests for the CELESTE solar array gamma-ray telescope

    International Nuclear Information System (INIS)

    The CELESTE experiment will be an atmospheric Cherenkov detector designed to bridge the gap in energy sensitivity between current satellite and ground-based gamma-ray telescopes, 20-300 GeV. We present test results made at the former solar power plant, Themis, in the French Pyrenees. The tests confirm the viability of using a central tower heliostat array for Cherenkov wavefront sampling. (orig.)

  15. Prototype Tests for the CELESTE Solar Array $\\gamma$-Ray Telescope

    CERN Document Server

    Giebels, B; Bergeret, H; Cordier, A; Debiais, G; De Naurois, Mathieu; Dezalay, J P; Dumora, D; Eschstruth, P T; Espigat, P; Fabre, B; Fleury, P; Ghesquière, C; Herault, N; Malet, I; Merkel, B; Meynadier, C; Palatka, M; Paré, E; Procureur, J; Punch, M; Québert, J; Ragan, K; Rob, L; Schovanek, P; Smith, D A; Vrana, J

    1998-01-01

    The CELESTE experiment will be an Atmospheric Cherenkov detector designed to bridge the gap in energy sensitivity between current satellite and ground-based gamma-ray telescopes, 20 to 300 GeV. We present test results made at the former solar power plant, Themis, in the French Pyrenees. The tests confirm the viability of using a central tower heliostat array for Cherenkov wavefront sampling.

  16. Prototype Tests for the CELESTE Solar Array Gamma--Ray Telescope

    OpenAIRE

    Giebels, B.; Bazer-Bachi, R.; Bergeret, H.; Cordier, A.; Debiais, G.; de Naurois, M.; Dezalay, J. P.; Dumora, D.; Eschstruth, P.; Espigat, P.; Fabre, B.; Fleury, P.; Ghesquière, C.; Herault, N.; Malet, I.

    1998-01-01

    The CELESTE experiment will be an Atmospheric Cherenkov detector designed to bridge the gap in energy sensitivity between current satellite and ground-based gamma-ray telescopes, 20 to 300 GeV. We present test results made at the former solar power plant, Themis, in the French Pyrenees. The tests confirm the viability of using a central tower heliostat array for Cherenkov wavefront sampling.

  17. 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

  18. Experimental study and Monte Carlo modeling of the Cherenkov effect

    Energy Technology Data Exchange (ETDEWEB)

    Mishev, A.; Angelov, I.; Duverger, E.; Gschwind, R.; Makovicka, L. E-mail: libor.makovicka@pu-pm.univ-fcomte.fr; Stamenov, J

    2001-12-01

    Studies realised at the Institute for Nuclear Research and Nuclear Energy (INRNE) particularly in cosmic ray detection and construction of Muonic Cherenkov Telescope at the South West University 'Neofit Rilski' Blagoevgrad show the need to develop a theoretical model based on observed phenomena and to refinement of this for detection system optimisation. The Cherenkov effect was introduced in EGS4 code system. The first simulations realised in collaboration between the french and the bulgarian team were consecrated to different geometries of water tank in total reflection. An additional modeling of photons mean trajectory and the mean number of reflections in the tank were made. This simple model was compared with experimental data realised with {sup 60}Co gamma source, the telescope and the most efficient water tank. A trajectory simulation of Cherenkov photons in water tank was made. An efficiency estimation of the detector registration was calculated. The atmospheric model was introduced in EGS4 code and a comparison between CORSIKA5.62 and EGS4 codes was made.

  19. Strategy Implementation for the CTA Atmospheric Monitoring Program

    CERN Document Server

    Doro, M; Reyes, R de los; Gaug, M; Maccarone, M C

    2015-01-01

    The Cherenkov Telescope Array (CTA) is the next generation facility of Imaging Atmospheric Cherenkov Telescopes. It will reach unprecedented sensitivity and energy resolution in very-high-energy gamma-ray astronomy. CTA will detect 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 reconstr...

  20. Imaging Very High Energy Gamma-Ray Telescopes

    OpenAIRE

    Voelk, Heinrich J.; Bernloehr, Konrad

    2008-01-01

    The technique of gamma-ray astronomy at very high energies (VHE: > 100 GeV) with ground-based imaging atmospheric Cherenkov telescopes is described, the H.E.S.S. array in Namibia serving as example. Mainly a discussion of the physical principles of the atmospheric Cherenkov technique is given, emphasizing its rapid development during the last decade. The present status is illustrated by two examples: the spectral and morphological characterization in VHE gamma-rays of a shell-type supernova r...

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

    OpenAIRE

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

    2008-01-01

    Neutrino telescopes will open, in the next years, new opportunities in observational high energy astrophysics. For these experiments, 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 te...

  2. Development of Atmospheric Monitoring System at Akeno Observatory for the Telescope Array Project

    CERN Document Server

    Yamamoto, T; Chikawa, M; Hayashida, N; Kawakami, S; Minagawa, N; Morizane, Y; Sasano, M; Yasui, K

    2002-01-01

    We have developed an atmospheric monitoring system for the Telescope Array experiment at Akeno Observatory. It consists of a Nd:YAG laser with an alt-azimuth shooting system and a small light receiver. This system is installed inside an air conditioned weather-proof dome. All parts, including the dome, laser, shooter, receiver, and optical devices are fully controlled by a personal computer utilizing the Linux operating system. It is now operated as a back-scattering LIDAR System. For the Telescope Array experiment, to estimate energy reliably and to obtain the correct shower development profile, the light transmittance in the atmosphere needs to be calibrated with high accuracy. Based on observational results using this monitoring system, we consider this LIDAR to be a very powerful technique for Telescope Array experiments. The details of this system and its atmospheric monitoring technique will be discussed.

  3. Hubble Space Telescope Space Telescope Imaging Spectrograph Search for an Atmosphere on Callisto: A Jovian Unipolar Inductor

    Science.gov (United States)

    Strobel, Darrell F.; Saur, Joachim; Feldman, Paul D.; McGrath, Melissa A.

    2002-12-01

    Hubble Space Telescope observations of Callisto with the Space Telescope Imaging Spectrograph were performed at both eastern and western elongations to search for the UV emissions diagnostic of the presence of O2, CO2, and/or CO atmospheres. We report upper limits of 5×10-5 photons cm-2 s-1 or 15 R for a uniform disk the diameter of Callisto on emissions of O I λ1304, O I λ1356, C I λ1561, C II λ1335, and CO fourth positive bands. These upper limits yield upper bounds on O2, CO2, and CO atmospheres far in excess of the detected CO2 atmosphere by R. W. Carlson. Our results are interpreted in terms of a strong electrodynamic interaction with the Jovian magnetosphere, which drives ~1.5×105 A through Callisto's highly conducting (~104 mho) ionosphere and generates a highly reduced ionospheric electric field, severely retarded ionospheric convection (~0.1 km s-1), and a factor of ~1500 reduction in the net electron impact emission rate. Callisto's highly conducting ionosphere renders it the most tenable unipolar inductor of the Galilean satellites.

  4. AGN Observations with the MAGIC Telescope

    OpenAIRE

    Bigongiari, Ciro

    2006-01-01

    MAGIC is presently the imaging atmospheric Cherenkov telescope with the largest reflecting surface and the lowest energy threshold. MAGIC concluded its first year of regular observation in April 2006. During this period and the preceding commissioning phase, 25 Active Galactic Nuclei have been observed and VHE gamma-ray emission has been confirmed by 4 of them. Two more AGNs have been detected as gamma-ray sources with high statistical significance for the first time. We report in this paper ...

  5. 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.

  6. AtmoHEAD 2013 workshop / Atmospheric Monitoring for High-Energy Astroparticle Detectors

    CERN Document Server

    Bernlöhr, K; Blanch, O; Bourgeat, M; Bruno, P; Buscemi, M; Cassardo, C; Chadwick, P M; Chalme-Calvet, R; Chouza, F; Cilmo, M; Coco, M; Colombi, J; Compin, M; Daniel, M K; Reyes, R De Los; Ebr, J; D'Elia, R; Deil, C; Etchegoyen, A; Doro, M; Ferrarese, S; Fiorini, M; Font, LL; Garrido, D; Gast, H; Gaug, M; Gonzales, F; Grillo, A; Guarino, F; Hahn, J; Hrabovsky, M; Kosack, K; Krüger, P; La Rosa, G; Leto, G; Lo, Y T E; López-Oramas, A; Louedec, K; Maccarone, M C; Mandat, D; Marandon, V; Martinetti, E; Martinez, M; de Naurois, M; Neronov, A; Nolan, S J; Otero, L; Palatka, M; Pallotta, J; Pech, M; Puhlhofer, G; Prouza, M; Quel, E; Raul, D; Ristori, P; Frias, M D Rodriguez; Rivoire, S; Rulten, C B; Schovanek, P; Segreto, A; Sottile, G; Stringhetti, L; Tavernet, J -P; Tonachini, A S; Toscano, S; Travnicek, P; Valore, L; Vasileiadis, G; Vincent, S; Wada, S; Wiencke, L; Will, M

    2014-01-01

    A 3-day international workshop on atmospheric monitoring and calibration for high-energy astroparticle detectors, with a view towards next-generation facilities. The atmosphere is an integral component of many high-energy astroparticle detectors. Imaging atmospheric Cherenkov telescopes and cosmic-ray extensive air shower detectors are the two instruments driving the rapidly evolving fields of very-high- and ultra-high-energy astrophysics. In these instruments, the atmosphere is used as a giant calorimeter where cosmic rays and gamma rays deposit their energy and initiate EASs; it is also the medium through which the resulting Cherenkov light propagates. Uncertainties in real-time atmospheric conditions and in the fixed atmospheric models typically dominate all other systematic errors. With the improved sensitivity of upgraded IACTs such as H.E.S.S.-II and MAGIC-II and future facilities like the Cherenkov Telescope Array (CTA) and JEM-EUSO, statistical uncertainties are expected to be significantly reduced, l...

  7. New method for atmospheric calibration at the Pierre Auger Observatory using FRAM, a robotic astronomical telescope

    Czech Academy of Sciences Publication Activity Database

    BenZvi, S.; Boháčová, Martina; Connolly, B.; Grygar, Jiří; Hrabovský, Miroslav; Kárová, Tatiana; Mandát, Dušan; Nečesal, Petr; Nosek, D.; Nožka, Libor; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Šmída, Radomír; Trávníček, Petr; Vitale, P.; Westerhoff, S.

    Mexico : Universidad National Autonóma, 2007, s. 1-4. [International Cosmic Ray Conference /30./. Merida (MX), 03.07.2007-11.07.2007] R&D Projects: GA MŠk LA 134 Institutional research plan: CEZ:AV0Z10100502 Keywords : Pierre Auger Observatory * atmospheric calibration * FRAM * telescope Subject RIV: BF - Elementary Particles and High Energy Physics

  8. Data quality monitoring in the presence of aerosols and other adverse atmospheric conditions with H.E.S.S

    CERN Document Server

    Hahn, J; Bernlöhr, K; Krüger, P; Lo, Y T E; Chadwick, P M; Daniel, M K; Deil, C; Gast, H; Kosack, K; Marandon, V

    2015-01-01

    Cherenkov telescope experiments, such as H.E.S.S., have been very successful in astronomical observations in the very-high-energy (VHE; E $>$ 100 GeV) regime. As an integral part of the detector, such experiments use Earth's atmosphere as a calorimeter. For the calibration and energy determination, a standard model atmosphere is assumed. Deviations of the real atmosphere from the model may therefore lead to an energy misreconstruction of primary gamma rays. To guarantee satisfactory data quality with respect to difficult atmospheric conditions, several atmospheric data quality criteria are implemented in the H.E.S.S. software. These quantities are sensitive to clouds and aerosols. Here, the Cherenkov transparency coefficient will be presented. It is a new monitoring quantity that is able to measure long-term changes in the atmospheric transparency. The Cherenkov transparency coefficient derives exclusively from Cherenkov data and is quite hardware-independent. Furthermore, its positive correlation with indepe...

  9. The Cherenkov Surface Detector of the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    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 km2), 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

  10. 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.

  11. The ANTARES Neutrino Telescope

    CERN Document Server

    Perrina, Chiara

    2015-01-01

    At about 40 km off the coast of Toulon (France), anchored at 2475 m deep in the Mediterranean Sea, there is ANTARES: the first undersea neutrino telescope and the only one currently operating. The detector consists of 885 photomultiplier tubes arranged into 12 strings of 450-metres high, with the aim to detect the Cherenkov light induced by the charged superluminal interaction products of neutrinos. Its main scientific target is the search for high-energy (TeV and beyond) neutrinos from cosmic accelerators, as predicted by hadronic interaction models, and the measurement of the cosmic neutrino diffuse flux, focusing in particular on events coming from below the horizon (up-going events) in order to significantly reduce the atmospheric muons background. Thanks to the development of a strategy for the identification of neutrinos coming from above the horizon (down-going events) the field of view of the telescope will be extended.

  12. The major upgrade of the MAGIC telescopes, Part I: The hardware improvements and the commissioning of the system

    Science.gov (United States)

    Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barceló, M.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biasuzzi, B.; Biland, A.; Bitossi, M.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Cecchi, R.; Colin, P.; Colombo, E.; Contreras, J. L.; Corti, D.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; DeAngelis, A.; De Caneva, G.; De Lotto, B.; de Oña Wilhelmi, E.; Delgado Mendez, C.; Dettlaff, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Fidalgo, D.; Fink, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giavitto, G.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Haberer, W.; Hadasch, D.; Hanabata, Y.; Hayashida, M.; Herrera, J.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Illa, J. M.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lemus, J. L.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; López-Oramas, A.; Lorca, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Negrello, M.; Neustroev, V.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K.; Noda, K.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saito, T.; Saito, K.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schlammer, J.; Schmidl, S.; Schweizer, T.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamerra, A.; Steinbring, T.; Storz, J.; Strzys, M.; Takalo, L.; Takami, H.; Tavecchio, F.; Tejedor, L. A.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Vogler, P.; Wetteskind, H.; Will, M.; Zanin, R.

    2016-01-01

    The MAGIC telescopes are two Imaging Atmospheric Cherenkov Telescopes (IACTs) located on the Canary island of La Palma. The telescopes are designed to measure Cherenkov light from air showers initiated by gamma rays in the energy regime from around 50 GeV to more than 50 TeV. The two telescopes were built in 2004 and 2009, respectively, with different cameras, triggers and readout systems. In the years 2011-2012 the MAGIC collaboration undertook a major upgrade to make the stereoscopic system uniform, improving its overall performance and easing its maintenance. In particular, the camera, the receivers and the trigger of the first telescope were replaced and the readout of the two telescopes was upgraded. This paper (Part I) describes the details of the upgrade as well as the basic performance parameters of MAGIC such as raw data treatment, linearity in the electronic chain and sources of noise. In Part II, we describe the physics performance of the upgraded system.

  13. The Cherenkov Surface Detector of the Pierre Auger Observatory

    Science.gov (United States)

    Billoir, Pierre

    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 km2), 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.

  14. Characteristics and performance of the GAW experiment for a large field of view Cerenkov γ rays telescope

    International Nuclear Information System (INIS)

    The GAW project aims to test the feasibility of a new generation of Imaging Atmospheric Cherenkov Telescopes that join high flux sensitivity with Large Field of View capability. It consists of an array of 3 imaging Cherenkov telescopes each equipped with a Fresnel refractive lens of about 3.6 m2 geometrical area and an array of multi-anode photomultipliers at the focal surface operating in single photoelectron counting mode. Pointing along different North-South directions, GAW would reach a survey of 360 deg. x 60 deg. region of the sky. GAW is a collaboration effort of Research Institutes in Italy, Portugal and Spain

  15. A Novel Telescopic Boom Deployment System for Use in Upper Atmosphere Research

    OpenAIRE

    Wylie, Mark; Duffy, Paul; Vather, Dinesh; Keegan, John; Curran, Stephen

    2010-01-01

    Typical measurement probe deployment systems on sounding rockets employ hinged booms which extend the probes away from the rocket. This configuration often has a significant mass and may require a considerable amount of the rocket’s valuable payload volume. In an effort to reduce both mass and volume, the DIT Space Research Group have designed a light weight carbon fibre telescopic boom system, compatible with measurement probes commonly used in upper atmosphere research. Our design has been ...

  16. 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.

  17. The atmospheric transparency measured with a LIDAR system at the Telescope Array experiment

    CERN Document Server

    Tomida, Takayuki; Arai, Takahito; Benno, Takuya; Chikawa, Michiyuki; Doura, Koji; Fukushima, Masaki; Hiyama, Kazunori; Honda, Ken; Ikeda, Daisuke; Matthews, John N; Nakamura, Toru; Oku, Daisuke; Sagawa, Hiroyuki; Tokuno, Hisao; Tameda, Yuichiro; Thomson, Gordon B; Tsunesada, Yoshiki; Udo, Shigeharu; Ukai, Hisashi; 10.1016/j.nima.2011.07.012

    2011-01-01

    An atmospheric transparency was measured using a LIDAR with a pulsed UV laser (355nm) at the observation site of Telescope Array in Utah, USA. The measurement at night for two years in $2007\\sim 2009$ revealed that the extinction coefficient by aerosol at the ground level is $0.033^{+0.016}_{-0.012} \\rm km^{-1}$ and the vertical aerosol optical depth at 5km above the ground is $0.035^{+0.019}_{-0.013}$. A model of the altitudinal aerosol distribution was built based on these measurements for the analysis of atmospheric attenuation of the fluorescence light generated by ultra high energy cosmic rays.

  18. The atmospheric transparency measured with a LIDAR system at the Telescope Array experiment

    International Nuclear Information System (INIS)

    An atmospheric transparency was measured using a LIDAR with a pulsed UV laser (355 nm) at the observation site of Telescope Array in Utah, USA. The measurement at night for two years in 2007-2009 revealed that the extinction coefficient by aerosol at the ground level is 0.033-0.012+0.016km-1 and the vertical aerosol optical depth at 5 km above the ground is 0.035-0.013+0.019. A model of the altitudinal aerosol distribution was built based on these measurements for the analysis of atmospheric attenuation of the fluorescence light generated by ultra high energy cosmic rays.

  19. First Avalanche-photodiode camera test (FACT): A novel camera using G-APDs for the observation of very high-energy γ-rays with Cherenkov telescopes

    International Nuclear Information System (INIS)

    We present a project for a novel camera using Geiger-mode Avalanche Photodiodes (G-APDs), to be installed in a small telescope (former HEGRA CT3) on the MAGIC site in La Palma (Canary Island, Spain). This novel type of semiconductor photon detector provides several superior features compared to conventional photomultiplier tubes (PMTs). The most promising one is a much higher Photon Detection Efficiency.

  20. The Lake Baikal Neutrino Telescope NT-200: Status, results, future

    International Nuclear Information System (INIS)

    The Baikal Neutrino Telescope NT-200 has been put into operation on April 6th, 1998. We describe the parameters and structure of NT-200 and present results with various stages of the stepwise increasing detector: from NT-36 to NT-96. Results cover atmospheric muons, neutrino events, search for neutrino events from WIMPS annihilation, search for magnetic monopoles. We also give preliminary results of the combined operation of the underwater array and a Cherenkov EAS array, placed on the ice surface

  1. Observations of Extragalactic Sources with the MAGIC Telescope

    OpenAIRE

    Mazin, D.

    2007-01-01

    MAGIC is currently the world's largest single dish ground based imaging atmospheric Cherenkov telescope. During the first year of operation, more than 20 extragalactic sources have been observed and several of them detected. Here we present results of analyzed data, including discussion about spectral and temporal properties of the detected sources. In addition, we discuss implications of the measured energy spectra of distant sources for our knowledge of the extragalactic background light.

  2. Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) data processing and atmospheric temperature and trace gas retrieval

    Science.gov (United States)

    Riese, M.; Spang, R.; Preusse, P.; Ern, M.; Jarisch, M.; Offermann, D.; Grossmann, K. U.

    1999-07-01

    The Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) experiment aboard the Shuttle Pallet Satellite (SPAS) was successfully flown in early November 1994 (STS 66) and in August 1997 (STS 85). This paper focuses on the first flight of the instrument, which was part of the Atmospheric Laboratory for Application and Science 3 (ATLAS 3) mission of NASA. During a free flying period of 7 days, limb scan measurements of atmospheric infrared emissions were performed in the 4 to 71 μm wavelength region. For improved horizontal resolution, three telescopes (viewing directions) were used that sensed the atmosphere simultaneously. Atmospheric pressures, temperatures, and volume mixing ratios of various trace gases were retrieved from the radiance data by using a fast onion-peeling retrieval technique. This paper gives an overview of the data system including the raw data processing and the temperature and trace gas profile retrieval. Examples of version 1 limb radiance data (level 1 product) and version 1 mixing ratios (level 2 product) of ozone, ClONO2, and CFC-11 are given. A number of important atmospheric transport processes can already be identified in the level 1 limb radiance data. Radiance data of the lower stratosphere (18 km) indicate strong upwelling in some equatorial regions, centered around the Amazon, Congo, and Indonesia. Respective data at the date line are consistent with convection patterns associated with El Niño. Very low CFC-11 mixing ratios occur inside the South Polar vortex and cause low radiance values in a spectral region sensitive to CFC-11 emissions. These low values are a result of considerable downward transport of CFC-11 poor air that occurred during the winter months. Limb radiance profiles and retrieved mixing ratio profiles of CFC-11 indicate downward transport over ˜5 km. The accuracy of the retrieved version 1 mixing ratios is rather different for the various trace gases. In the middle atmosphere the estimated

  3. A Balloon-Borne Telescope System for Planetary Atmosphere and Plasma Studies

    Science.gov (United States)

    Taguchi, M.; Yoshida, K.; Sakamoto, Y.; Kanazawa, T.; Shoji, Y.; Sawakami, T.; Takahashi, Y.; Hoshino, N.; Sato, T.; Sakanoi, T.

    2007-12-01

    A telescope floating in the polar stratosphere can continuously monitor planets for more than 24 hours. Thin, clear and stable air of the stratosphere makes it possible to observe planets in a condition free from cloud with fine seeing and high atmospheric transmittance. Moreover, a balloon-borne telescope system is less expensive compared with a huge terrestrial telescope or a direct planetary probe mission. Targets of a balloon-borne telescope system will extend over various atmospheric and plasma phenomena on almost all the planets, i.e., a sodium tail of Mercury, lightning, airglow and aurora in the atmospheres of Venus, Jupiter and Saturn, escaping atmospheres of the Earth-type planets, satellite-induced luminous events in the Jovian atmosphere, etc. The first target is global dynamics of the Venusian atmosphere by detecting cloud motion in UV and NIR imagery. A decoupling mechanism and a pair of control moment gyros (CMGs) are mounted at the top of the gondola. The decoupling mechanism isolates the gondola from a balloon and also transfers an excess angular momentum of the CMGs to the balloon. The attitude of the gondola is stabilized at a constant sun azimuthal angle so that a solar cell panel faces to the sun. A 300 mm F30 Schmidt-Cassegrain telescope is installed at the bottom of the gondola. DC/DC converters, a PC, a high voltage power supply for a piezo-electrically moving mirror and digital video recorders are contained in a sealed cell. The azimuthal angle is detected by a sun-sensor. A PC processes sensor output to control DC motors used in the decoupling mechanism and CMGs with an accuracy in azimuthal attitude of about 0.5 deg. The two-axis gimbal mount of the telescope is controlled by the same PC, guiding an object within a field-of-view of a guide telescope. Residual tracking error is detected by a position sensitive photomultiplier tube and corrected by the two-axis moving mirror installed in the optical system. The optical path is divided into

  4. A third level trigger programmable on FPGA for the gamma/hadron separation in a Cherenkov telescope using pseudo-Zernike moments and the SVM classifier

    OpenAIRE

    Frailis, Marco; Mansutti, Oriana; Boinee, Praveen; Cabras, Giuseppe; De Angelis, Alessandro; De Lotto, Barbara; Forti, Alberto; Dell'Orso, Mauro; Paoletti, Riccardo; Scribano, Angelo; Turini, Nicola; Mariotti, Mose'; Peruzzo, Luigi; Saggion, Antonio

    2006-01-01

    We studied the application of the Pseudo-Zernike features as image parameters (instead of the Hillas parameters) for the discrimination between the images produced by atmospheric electromagnetic showers caused by gamma-rays and the ones produced by atmospheric electromagnetic showers caused by hadrons in the MAGIC Experiment. We used a Support Vector Machine as classification algorithm with the computed Pseudo-Zernike features as classification parameters. We implemented on a FPGA board a ker...

  5. 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

  6. New optics for resolution improving of Ring Imaging Cherenkov detectors

    OpenAIRE

    Steiger L.; Finger M.; Polak J.; Šulc M.; Kramer D.; Slunecka M.

    2013-01-01

    The Ring Imaging Cherenkov detector (RICH) of the COMPASS experiment at CERN is key tool for particle identification. Two reflecting spherical mirror surfaces, covering a total area of about 21 m2 hosted in the radiator vessel, provide Cherenkov radiation focusing to photon detectors. These ones are based on the use of multi-anode photo-multiplier tubes. They are coupled to individual lens telescopes, made from special fused silica aspherical lenses. Design, construction, and Hartmann te...

  7. New method for atmospheric calibration at the Pierre Auger Observatory using FRAM, a robotic astronomical telescope

    CERN Document Server

    BenZvi, Segev; Connolly, Brian; Grygar, Jiri; Hrabovsky, Miroslav; Karova, Tatiana; Mandat, Dusan; Necesal, Petr; Nosek, Dalibor; Nozka, Libor; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Ridky, Jan; Schovanek, Petr; Smida, Radomir; Travnicek, Petr; Vitale, Primo; Westerhoff, Stefan

    2007-01-01

    FRAM - F/(Ph)otometric Robotic Atmospheric Monitor is the latest addition to the atmospheric monitoring instruments of the Pierre Auger Observatory. An optical telescope equipped with CCD camera and photometer, it automatically observes a set of selected standard stars and a calibrated terrestrial source. Primarily, the wavelength dependence of the attenuation is derived and the comparison between its vertical values (for stars) and horizontal values (for the terrestrial source) is made. Further, the integral vertical aerosol optical depth can be obtained. A secondary program of the instrument, the detection of optical counterparts of gamma-ray bursts, has already proven successful. The hardware setup, software system, data taking procedures, and first analysis results are described in this paper.

  8. New method for atmospheric calibration at the Pierre Auger Observatory using FRAM, a robotic astronomical telescope

    Science.gov (United States)

    Trávníček, Petr; Benzvi, Segev; Boháčová, Martina; Connolly, Brian; Grygar, Jiří; Hrabovský, Miroslav; Kárová, Tatiana; Mandát, Dušan; Nečesal, Petr; Nosek, Dalibor; Nožka, Libor; Palatka, Miroslav; sPech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Šmída, Radomír; Vitale, Primo; Westerhoff, Stefan

    FRAM - F/(Ph)otometric Robotic Atmospheric Monitor is the latest addition to the atmospheric monitoring instruments of the Pierre Auger Observatory. An optical telescope equipped with CCD camera and photometer, it automatically observes a set of selected standard stars and a calibrated terrestrial source. Primarily, the wavelength dependence of the attenuation is derived and the comparison between its vertical values (for stars) and horizontal values (for the terrestrial source) is made. Further, the integral vertical aerosol optical depth can be obtained. A secondary program of the instrument, the detection of optical counterparts of gamma-ray bursts, has already proven successful. The hardware setup, software system, data taking procedures, and first analysis results are described in this paper.

  9. Discriminating between electron and gamma air showers using direct Cherenkov light

    International Nuclear Information System (INIS)

    Imaging Atmospheric Cherenkov Telescopes (IACTs) detect VHE gamma rays from galactic and extragalactic sources in order to probe the acceleration mechanisms involved in the most energetic and exotic sources. The reconstruction techniques currently used can distinguish most of the background of hadrons entering the atmosphere as they produce very different air showers. Showers initiated by electrons on the other hand are much harder to separate, as they also produce electromagnetic cascades. A new technique making use of direct Cherenkov (DC) light could provide a way to finally distinguish between the two. Cherenkov light emitted directly from the primary particle before it interacts results in a signal at the start of the extensive air shower image in the IACT camera. Probing the characteristics of DC light could allow direct identification of electrons and other charged primaries. This would lead to the increased sensitivity of H.E.S.S. and CTA, confirmation of the electron background contamination level and could also provide a measurement of the diffuse extragalactic background light.

  10. Stray light analysis of CRISTA - The Cryogenic Infrared Spectrometer and Telescope of the Atmosphere

    Science.gov (United States)

    Breault, Robert P.; Barthol, Peter

    1990-12-01

    The CRISTA experiment is designed to detect and analyze short term upper atmospheric waves and turbulence of the middle atmosphere. This paper presents two of the more intriguing stray light characteristics of the CRISTA instrument as revealed through a much more extensive stray light analysis. The two topics are the diffraction propagation from a series of edges, and the thermal loading characteristics of the outer baffles by the earth's radiation. The interesting parameters that play very complex roles relative to each other are: CRISTA's three different telescopes peer through a common aperture; the Center Telescope has an image plane shared by two spectrometers offset above or below the axis by 0.358 deg; the point source angles walk away from one slit but across the other; the wavelength bands vary from 4 microns to 70 microns; all of the imaging mirrors are simple spherical surfaces; the major source of stray light is the earth, which is only .5 deg from the optical axis; and the intermediate field stop is oversized.

  11. Improved sensitivity of H.E.S.S.-II through the fifth telescope focus system

    CERN Document Server

    Krayzel, F; Brunetti, L; Dubois, J -M; Fiasson, A; Journet, L; Lamanna, G; Leflour, T; Lieunard, B; Monteiro, I; Rosier-Lees, S

    2013-01-01

    The Imaging Atmospheric Cherenkov Telescope (IACT) works by imaging the very short flash of Cherenkov radiation generated by the cascade of relativistic charged particles produced when a TeV gamma ray strikes the atmosphere. This energetic air shower is initiated at an altitude of 10-30 km depending on the energy and the arrival direction of the primary gamma ray. Whether the best image of the shower is obtained by focusing the telescope at infinity and measuring the Cherenkov photon angles or focusing on the central region of the shower is a not obvious question. This is particularly true for large size IACT for which the depth of the field is much smaller. We address this issue in particular with the fifth telescope (CT5) of the High Energy Stereoscopic System (H.E.S.S.); a 28 m dish large size telescope recently entered in operation and sensitive to an energy threshold of tens of GeVs. CT5 is equipped with a focus system, its working principle and the expected effect of focusing depth on the telescope sens...

  12. Determination of the atmospheric muon flux with the neutrino telescope ANTARES

    International Nuclear Information System (INIS)

    The neutrino telescope ANTARES is a deep-sea detector located in the Mediterranean Sea. The universe is transparent to neutrinos, so their study provides a unique means of improving our knowledge of the nature of cosmic rays, their origins and their emission from the most powerful astrophysical sources in the cosmos. Neutrinos also offer the possibility of opening a new energy window (>TeV) for observation of the universe. This thesis is dedicated to the study of the main background noise of the detector, due to the passage of atmospheric muons produced by high energy cosmic rays interacting with atmospheric nuclei. The first part of this thesis focuses on the study of the detector. The different characteristics and the calibration of the detector as well as the techniques of monitoring the electronic are described. The second part of this thesis reports the various results obtained on the atmospheric muons with the five line detector. A detailed presentation of the simulations used is presented. The first difficulty of detecting atmospheric muons is due to the geometry of the detector. The second is due to the fact that the atmospheric muons often arrive in bundles and that the number of muons in these bundles is unknown at a depth of 2500 m. A first study based on simulations makes it possible to discriminate between the muons alone and the bundles of muons. A second study is dedicated to the measurement of the muon flux depending on the slant depth. The measurement is compatible with the results of other instruments when the systematic uncertainties are taken into account. (author)

  13. ANN-based energy reconstruction procedure for TACTIC gamma-ray telescope and its comparison with other conventional methods

    CERN Document Server

    Dhar, V K; Koul, M K; Rannot, R C; Yadav, K K; Chandra, P; Dubey, B P; Koul, R; 10.1016/j.nima.2009.04.012

    2009-01-01

    The energy estimation procedures employed by different groups, for determining the energy of the primary $\\gamma$-ray using a single atmospheric Cherenkov imaging telescope, include methods like polynomial fitting in SIZE and DISTANCE, general least square fitting and look-up table based interpolation. A novel energy reconstruction procedure, based on the utilization of Artificial Neural Network (ANN), has been developed for the TACTIC atmospheric Cherenkov imaging telescope. The procedure uses a 3:30:1 ANN configuration with resilient backpropagation algorithm to estimate the energy of a $\\gamma$-ray like event on the basis of its image SIZE, DISTANCE and zenith angle. The new ANN-based energy reconstruction method, apart from yielding an energy resolution of $\\sim$ 26%, which is comparable to that of other single imaging telescopes, has the added advantage that it considers zenith angle dependence as well. Details of the ANN-based energy estimation procedure along with its comparative performance with other...

  14. Physics performance of the upgraded MAGIC telescopes obtained with Crab Nebula data

    CERN Document Server

    Sitarek, Julian; Colin, Pierre; Frantzen, Katharina; Gaug, Markus; Lopez, Marcos; Lombardi, Saverio; Moralejo, Abelardo; Satalecka, Konstancja; Scapin, Valeria; Stamatescu, Victor; Zanin, Roberta; Mazin, Daniel; Tescaro, Diego

    2013-01-01

    MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located at the Canary Island of La Palma, designed to observe gamma rays with energies above 50 GeV. Recently it has undergone an upgrade of the camera, digital trigger and readout systems. The upgrade has led to an improvement in the performance of the telescopes, especially in the lower energy range. We evaluate the performance of the upgraded MAGIC telescopes using Monte Carlo simulations and a large sample of Crab Nebula data. We study differential and integral sensitivity of the system, its angular resolution as well as its energy resolution.

  15. Modelling and study of the Cherenkov effect

    Energy Technology Data Exchange (ETDEWEB)

    Mishev, A. E-mail: libor.makovicka@pu-pm.univ-fcomte.fr; Duverger, E.; Makovicka, L.; Stamenov, J

    2001-06-01

    Studies at the Institute for Nuclear Research and Nuclear Energy particularly in regard to cosmic ray detection and construction of the Muonic Cherenkov telescope at the University of Blagoevgrad indicate a need for the development of a theoretical model based on observed phenomena and a refinement of this for detection system optimisation. This was introduced in the EGS4 code system. The first simulations consecrate on a number of different geometries of the water tank in total reflection. The model was compared with experimental data involving a {sup 60}Co gamma source and the telescope. (author)

  16. 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.

  17. Calibration of the MAGIC telescope camera with a pulsed UV laser

    International Nuclear Information System (INIS)

    MAGIC, a system of two imaging atmospheric Cherenkov telescopes, is designed to observe the Cherenkov light produced by air showers initiated by cosmic gamma rays. In order to extract the measured amount of Cherenkov light precisely, it is necessary to perform a flat-fielding and calibration of the camera. We perform this calibration by means of pulsed UV laser which flashes the camera from a 17m distance. The calibration box has several useful features like, for example, a set of two rotating attenuation filters, and has been extensively checked to provide a homogenous and stable amplitude to the camera. Details of the development and performance of the newly developed calibration box are reported in this talk.

  18. The effect of the atmospheric condition on the extensive air shower analysis at the Telescope Array experiment

    International Nuclear Information System (INIS)

    The accuracies in determination of air shower parameters such as longitudinal profiles or primary energies with the fluorescence detection technique are strongly dependent on atmospheric conditions of the molecular and aerosol components. Moreover, air fluorescence photon yield depends on the atmospheric density, and the transparency of the air for fluorescence photons depends on the atmospheric conditions from EAS to FDs. In this paper, we describe the atmospheric monitoring system in the Telescope Array (TA experiment), and the impact of the atmospheric conditions in air shower reconstructions. The systematic uncertainties of the determination of the primary cosmic ray energies and of the measurement of depth of maximum development (Xmax) of EASs due to atmospheric variance are evaluated by Monte Carlo simulation.

  19. Threshold gas 32-channel Cherenkov counter of the spectrometer EXCHARM

    International Nuclear Information System (INIS)

    The Cherenkov 32-channel threshold gas counter with 420-cm air radiator at the atmospheric pressure is described. Spherical mirrors with the curvature radius of 214 cm and photomultipliers FEU-125, FEU-49B were used in the counter for collection and registration of the Cherenkov radiation. The photomultipliers inlet windows are covered with films of spectra mixers. The efficiency of charged particles registration on the plateau of threshold characteristics (β ≥ 0.99984) exceeds 97%. 6 refs., 6 figs., 1 tab

  20. Review of the solar array telescopes

    OpenAIRE

    Smith, D. A.

    2005-01-01

    For several years the only experiments sensitive to astrophysical gamma rays with energies beyond the reach of EGRET but below that the Cherenkov imaging telescopes have been the "solar towar" detectors. They use > 2000 m$^{2}$ mirror areas to sample the Cherenkov wavefront generated by

  1. 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.

  2. Hubble Space Telescope detection of oxygen in the atmosphere of exoplanet HD189733b

    CERN Document Server

    Ben-Jaffel, Lotfi; 10.1051/0004-6361/201221014

    2013-01-01

    Detecting heavy atoms in the inflated atmospheres of giant exoplanets that orbit close to their parent stars is a key factor for understanding their bulk composition, and the processes that drive their expansion and interaction with the impinging stellar wind. Here, we use archive data obtained with the Cosmic Origins Spectrograph onboard the Hubble Space Telescope to report an absorption of ~6.4+/-1.8% by neutral oxygen during the HD 189733b transit. Scaling published HI results from a simple hydrodynamic model of HD 189733b, a vertical OI column density of ~8x10^15/cm2 produces only a 3.5% attenuation, implying that non-thermal line broadening or super-solar abundances are required. We also report evidence of short-time variability in the measured stellar flux, a variability that we analyze and compare to solar flaring activity. In that frame, we find that non-statistical uncertainties in the measured fluxes are not negligible, which calls for caution when reporting transit absorptions. Despite these uncert...

  3. Muon signature in the CAT imaging telescope

    International Nuclear Information System (INIS)

    The CAT imaging telescope is sensitive to the Cherenkov light emitted in the atmosphere and thus it is sensitive to a substantial flux of hard muons (E ≥ 5 GeV). A detailed study of these events will help to both calibrate the instrument and to understand the background that they represent in the search for gamma-ray showers. Resorting to simulated events the paper illustrates the use of the muon image reconstruction methods. This consist in fitting a circle on the pixels touched in the chamber by taking into account the muon impact parameter and the dN/dφ. The fitting method contains a parameter r which is the ratio between the number of detected photoelectrons and the number expected from the ring geometry. Besides the effort devoted to the reconstruction procedures we have put into operation two muon detectors. Each of them is composed of a tightly sealed can containing two fast photomultipliers to detect the Cherenkov light locally emitted. A coincidence signal from the two fast photomultipliers indicates the passage of a particle with the threshold higher than the Cherenkov one and gives a signal which is recorded with the telescope data. One of the detectors is mounted on the imaging telescope while the other one is nearby and can be moved in order to catch different values of the ρ/R (the ratio of the distance separating the mirror center and the muon impact location to the mirror radius). Due to this data analysis we are now really able to study the amount of the collected light as well as the observed muon counting rate

  4. A method of observing cherenkov light from extensive air shower at Yakutsk EAS array

    Science.gov (United States)

    Timofeev, Lev; Anatoly, Ivanov

    2016-07-01

    Proposed a new method for measuring the cherenkov light from the extensive air shower (EAS) of cosmic rays (CR), which allows to determine not only the primary particle energy and angle of arrival, but also the parameters of the shower in the atmosphere - the maximum depth and "age". For measurements Cherenkov light produced by EAS is proposed to use a ground network of wide-angle telescopes which are separated from each other by a distance 100-300 m depending on the total number of telescopes operating in the coincidence signals, acting autonomously, or includes a detector of the charged components, radio waves, etc. as part of EAS. In a results such array could developed, energy measurement and CR angle of arrival data on the depth of the maximum and the associated mass of the primary particle generating by EAS. This is particularly important in the study of galactic cosmic ray in E> 10^14 eV, where currently there are no direct measurements of the maximum depth of the EAS.

  5. Search for very high-energy neutrinos by SHALON (Cherenkov radiation of extensive air showers observed at large zenith angles)

    Energy Technology Data Exchange (ETDEWEB)

    Sinitsyna, V.G. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Arsov, T.P. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Borisov, S.S. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Musin, F.I. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Nikolsky, S.I. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Malyshko, A.A. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Sinitsyna, V.Y. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation); Platonov, G.F. [P.N.Lebedev Physical Institute, Leninsky pr.53, Moscow (Russian Federation)

    2006-01-15

    The detection of extraterrestrial very high energy neutrinos by the atmospheric Cherenkov telescopic system SHALON is discussed. The analysis of results of observation of extensive air showers at 3338 m above sea level by means of the gamma-telescope SHALON at zenith angles 72{sup o}, 76{sup o}, 84{sup o}, 96{sup o} are presented. The observed results are compared with the data of of shower according to zenith angle. The observation has been carried out at Tien-Shan station with SHALON gamma-telescope. The SHALON telescopic system has mirror with area of 11.2m{sup 2} and 144 PMT matrix with 0.2{sup o} angular resolution, and has the largest angular acceptance in the world - > 8{sup o}. It allows to continuously control the background of cosmic ray particle emission and the atmospheric transparency with observation thus increasing observation efficiency. It is the telescope characteristics that permit to start searching for local neutrino sources with energy 10{sup 13}-10{sup 15} eV on EAS generated in mountain-range located at some 5 and more kilometers from the gamma-telescope (in Russian the SHALON abbreviation means - the Extensive Air Showers from Neutrino)

  6. Fermi large area telescope observations of the cosmic-ray induced γ-ray emission of the Earth's atmosphere

    International Nuclear Information System (INIS)

    We report on measurements of the cosmic-ray induced γ-ray emission of Earth's atmosphere by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The Large Area Telescope has observed the Earth during its commissioning phase and with a dedicated Earth limb following observation in September 2008. These measurements yielded ∼6.4x106 photons with energies >100 MeV and ∼250 hours total live time for the highest quality data selection. This allows the study of the spatial and spectral distributions of these photons with unprecedented detail. The spectrum of the emission--often referred to as Earth albedo gamma-ray emission--has a power-law shape up to 500 GeV with spectral index Γ=2.79±0.06.

  7. Selected results from the ANTARES neutrino telescope

    CERN Document Server

    Mangano, Salvatore

    2012-01-01

    The ANTARES telescope is the largest underwater neutrino telescope existing at present. It is based on the detection of Cherenkov light produced in sea water by neutrino-induced muons. The detector, consisting of a tri-dimensional array of 885 photomultipliers arranged on twelve vertical lines, is located at a depth of 2475 m in the Mediterranean Sea, 40 km off the French coast. The main goal of the experiment is to probe the Universe by means of neutrino events in an attempt to investigate the nature of high energy astrophysical sources, to contribute to the identification of cosmic ray sources, and to explore the nature of dark matter. In this contribution we will review the status of the detector, illustrate its operation and performance, and present the first results from the analysis carried out on atmospheric muons and neutrinos, as well as from the search for astrophysical neutrino sources.

  8. Determining Atmospheric Aerosol Content With An Infra-red Radiometer

    CERN Document Server

    Daniel, M K; Chadwick, P M

    2014-01-01

    The atmospheric attenuation of Cherenkov photons is dominated by two processes: Rayleigh scattering from the molecular component and Mie scattering from the aerosol component. Aerosols are expected to contribute up to 30 Wm$^{-2}$ to the emission profile of the atmosphere, equivalent to a difference of ~20C to the clear sky brightness temperature under normal conditions. Here we investigate the aerosol contribution of the measured sky brightness temperature at the H.E.S.S. site; compare it to effective changes in the telescope trigger rates; and discuss how it can be used to provide an assessment of sky clarity that is unambiguously free of telescope systematics.

  9. Determining atmospheric aerosol content with an infra-red radiometer

    CERN Document Server

    Daniel, Michael; 10.1063/1.4772360

    2012-01-01

    The attenuation of atmospheric Cherenkov photons is dominated by two processes: Rayleigh scattering from the molecular component and Mie scattering from the aerosol component. Aerosols are expected to contribute up to 30 Wm$^{-2}$ to the emission profile of the atmosphere, equivalent to a difference of $\\sim20^\\circ$C to the clear sky brightness temperature under normal conditions. Here we investigate the aerosol contribution of the measured sky brightness temperature at the H.E.S.S. site; compare it to effective changes in the telescope trigger rates; and discuss how it can be used to provide an assessment of sky clarity that is unambiguously free of telescope systematics.

  10. Statistical properties of Cherenkov and quasi-Cherenkov superradiance

    CERN Document Server

    Anishchenko, S V

    2016-01-01

    We consider the effects of shot noise and particle energy spread on statistical properties of Cherenkov and quasi-Cherenkov superradiance emitted by a relativistic electron beam. In the absence of energy spread, we have found the root-mean-square deviations of both peak radiated power and instability growth time as a function of the number of particles. It is shown that energy spread can lead to a sharp drop in the radiated power of Cherenkov and quasi-Cherenkov superradiance at high currents.

  11. Aerogel threshold Cherenkov counter

    International Nuclear Information System (INIS)

    The results of studying the SiO2 aerogel properties, used as radiator for the Cherenkov counters are presented. Brief data on the technology of preparing the aerogel samples and their optical characteristics are indicated. The formula binding the aerogel refractive index with its density with an account of light dispersion is analyzed. The results of the Cherenkov aerogel threshold counter testing on the charged particles beam within the pulse range of p = ∼ 0.4-2.5 eV/s are presented. The registration efficiency of pions with p ≥ 1 GeV/s constituted ∼ 97% and that of protons - ∼ 4% by the p ≤ 2.5 GeV/s

  12. 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...... and spectral isolated Cherenkov radiation at visible wavelengths are reported. Such a femtosecond Cherenkov laser source is promising for practical biophotonics applications....

  13. Constraints on Lorentz violation from gravitational Cherenkov radiation

    CERN Document Server

    Kostelecky, Alan

    2015-01-01

    Limits on gravitational Cherenkov radiation by cosmic rays are obtained and used to constrain coefficients for Lorentz violation in the gravity sector associated with operators of even mass dimensions, including orientation-dependent effects. We use existing data from cosmic-ray telescopes to obtain conservative two-sided constraints on 80 distinct Lorentz-violating operators of dimensions four, six, and eight, along with conservative one-sided constraints on three others. Existing limits on the nine minimal operators at dimension four are improved by factors of up to a billion, while 74 of our explicit limits represent stringent first constraints on nonminimal operators. Prospects are discussed for future analyses incorporating effects of Lorentz violation in the matter sector, the role of gravitational Cherenkov radiation by high-energy photons, data from gravitational-wave observatories, the tired-light effect, and electromagnetic Cherenkov radiation by gravitons.

  14. Characteristics of Cherenkov Radiation in Naturally Occuring Ice

    CERN Document Server

    Mikkelsen, R E; Uggerhøj, U I; Klein, S R

    2016-01-01

    We revisit the theory of Cherenkov radiation in uniaxial crystals. Historically, a number of flawed attempts have been made at explaining this radiation phenomenon and a consistent error-free description is nowhere available. We apply our calculation to a large modern day telescope - IceCube. Being located at the Antarctica, this detector makes use of the naturally occuring ice as a medium to generate Cherenkov radiation. However, due to the high pressure at the depth of the detector site, large volumes of hexagonal ice crystals are formed. We calculate how this affects the Cherenkov radiation yield and angular dependence. We conclude that the effect is small, at most about a percent, and would only be relevant in future high precision instruments like e.g. Precision IceCube Next Generation Upgrade (PINGU). For radio-Cherenkov experiments which use the presence of a clear Cherenkov cone to determine the arrival direction, any variation in emission angle will directly and linearly translate into a change in ap...

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

    International Nuclear Information System (INIS)

    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. 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.

  17. Differential measurement of atmospheric refraction with a telescope with double fields of view

    CERN Document Server

    Yu, Yong; Tang, Zheng-Hong; Luo, Hao; Zhao, Ming

    2015-01-01

    For the sake of complete theoretical research of atmospheric refraction, the atmospheric refraction under the condition of lower angles of elevation is still worthy to be analyzed and explored. In some engineering applications, the objects with larger zenith distance must be observed sometimes. Carrying out observational research of the atmospheric refraction at lower angles of elevation has an important significance. It has been considered difficult to measure the atmospheric refraction at lower angles of elevation. A new idea for determining atmospheric refraction by utilizing differential measurement with double fields of view is proposed. Taking the observational principle of HIPPARCOS satellite as a reference, a schematic prototype with double fields of view was developed. In August of 2013, experimental observations were carried out and the atmospheric refractions at lower angles of elevation can be obtained by the schematic prototype. The measured value of the atmospheric refraction at the zenith dista...

  18. Threshold gas 32-channel Cherenkov counter of the EXCHARM spectrometer

    International Nuclear Information System (INIS)

    A 32-channel threshold gas Cherenkov counter with 420 cm air radiator at atmospheric pressure is described. Spherical mirrors with curvature radius of 214 cm and FEU-125, FEU-49B photomultipliers are used in the counter for collection and detection of the Cherenkov radiation. The input windows of the photomultipliers are coated with a shifter of the light spectrum. The detection efficiency of charged particles at a plateau of the threshold characteristic (β ≥ 0,99984) exceeds 97%. The counter is a part of the identification system of the EXCHARM spectrometer. 6 refs., 6 figs., 1 tab

  19. The major upgrade of the MAGIC telescopes, Part I: The hardware improvements and the commissioning of the system

    CERN Document Server

    Aleksic, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; Barcelo, M; Barrio, J A; Gonzalez, J Becerra; Bednarek, W; Bernardini, E; Biasuzzi, B; Biland, A; Bitossi, M; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Cecchi, R; Colin, P; Colombo, E; Contreras, J L; Corti, D; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Wilhelmi, E de Ona; Mendez, C Delgado; Dettlaff, A; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Fidalgo, D; Fink, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; Galindo, D; Lopez, R J Garcia; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Giavitto, G; Godinovic, N; Munoz, A Gonzalez; Gozzini, S R; Haberer, W; Hadasch, D; Hanabata, Y; Hayashida, M; Herrera, J; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Illa, J M; Kadenius, V; Kellermann, H; Knoetig, M L; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lemus, J L; Lewandowska, N; Lindfors, E; Lombardi, S; Longo, F; Lopez, M; Lopez-Coto, R; Lopez-Oramas, A; Lorca, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martinez, M; Mazin, D; Menzel, U; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Negrello, M; Neustroev, V; Niedzwiecki, A; Nilsson, K; Nishijima, K; Noda, K; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Persic, M; Poutanen, J; Moroni, P G Prada; Prandini, E; Puljak, I; Reinthal, R; Rhode, W; Ribo, M; Rico, J; Garcia, J Rodriguez; Rugamer, S; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schlammer, J; Schmidl, S; Schweizer, T; Sillanpaa, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamerra, A; Steinbring, T; Storz, J; Strzys, M; Takalo, L; Takami, H; Tavecchio, F; Tejedor, L A; Temnikov, P; Terzic, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Vogler, P; Wetteskind, H; Will, M; Zanin, R

    2014-01-01

    The MAGIC telescopes are two Imaging Atmospheric Cherenkov Telescopes (IACTs) located on the Canary island of La Palma. The telescopes are designed to measure Cherenkov light from air showers initiated by gamma rays in the energy regime from around 50 GeV to more than 50 TeV. The two telescopes were built in 2004 and 2009, respectively, with different cameras, triggers and readout systems. In the years 2011-2012 the MAGIC collaboration undertook a major upgrade to make the stereoscopic system uniform, improving its overall performance and easing its maintenance. In particular, the camera, the receivers and the trigger of the first telescope were replaced and the readout of the two telescopes was upgraded. This paper (Part I) describes the details of the upgrade as well as the basic performance parameters of MAGIC such as raw data treatment, dead time of the system, linearity in the electronic chain and sources of noise. In Part II, we describe the physics performance of the upgraded system.

  20. Recent results from the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    The ANTARES detector, located 40 km off the French coast, is the largest deep-sea neutrino telescope in the world. It consists of an array of 885 photomultipliers detecting the Cherenkov light induced by charged leptons produced by neutrino interactions in and around the detector. The primary goal of ANTARES is to search for astrophysical neutrinos in the TeV–PeV range. This comprises generic searches for any diffuse cosmic neutrino flux as well as more specific searches for astrophysical sources such as active galactic nuclei or galactic sources. The search program also includes multi messenger analyses based on time and/or space coincidences with other cosmic probes. The ANTARES observatory is sensitive to a wide range of other phenomena, from atmospheric neutrino oscillations to dark matter annihilation or potential exotics such as nuclearites and magnetic monopoles. The most recent results are reported. (author)

  1. Recent results from the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    The ANTARES detector, located in the deep sea 40 km off the French coast, is the largest neutrino telescope in the northern hemisphere. It consists of an array of 885 photomultipliers detecting the Cherenkov light induced by charged leptons created in neutrino interactions in and around the detector. The main goal of ANTARES is to search for astrophysical neutrinos in the TeV-PeV range. This comprises searches for a diffuse cosmic neutrino flux and for fluxes from possible galactic and extragalactic sources of neutrinos. The search program also includes multi-messenger analyses based on time and/or space coincidences with other cosmic probes. The ANTARES detector is sensitive to a wide range of other phenomena, from atmospheric neutrino oscillations to dark matter annihilation or potential exotics such as nuclearites and magnetic monopoles

  2. VERITAS: Very energetic radiation imaging telescope array system

    International Nuclear Information System (INIS)

    The Very Energetic Radiation Imaging Telescope Array System (VERI-TAS) is a wide energy range (50 GeV-50 TeV) atmospheric Cherenkov detector and will start operation in 2004. The design is driven by a major scientific interest in jets of active galactic nuclei, probing the intergalactic IR fields with TeV γ-ray beams, measuring the high energy spectrum of γ-ray bursts and galactic sources of cosmic rays. Also γ-rays signatures of quantum gravity, neutralinos and primordial black holes constitute the exotic scientific motivations to built a highly versatile detector that can be operated in various modes. The technical concept and design of the seven-telescope array system is described

  3. Atmosphere Extinction at the ORM on La Palma: A 20 yr Statistical Database Gathered at the Carlsberg Meridian Telescope

    CERN Document Server

    Garcia-Gil, A; Varela, A M

    2010-01-01

    The Observatorio del Roque de los Muchachos (ORM), in the Canary Islands (Spain), was one of the candidates to host the future European Extremely Large Telescope (E-ELT) and is the site of the Gran Telescopio Canarias (GTC), the largest optical infrared facility to date. Sky transparency is a key parameter as it defines the quality of the photometry to be acquired in the astronomical observations. We present a study of the atmosphere extinction at the ORM, carried out after analysis of a database spanning more than 20 yr, to our knowledge, the longest and most complete and homogeneous in situ database available for any observatory. It is based on photometric measurements in the V band and r' band (transformed to the V -band extinction coefficient kV) using the Carlsberg Meridian Telescope (CMT). Clear seasonal variations that repeat yearly are observed. The median value of kV is 0.13 mag/airmass; the mean value has a maximum in the summer months (June- September), corresponding to the season with maximum freq...

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

    International Nuclear Information System (INIS)

    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 × 10–4 and 2.1 × 10–4 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.

  5. Silica aerogel Cherenkov counter

    International Nuclear Information System (INIS)

    A practical method for making silica aerogel Cherenkov counters has been developed at KEK, and some tests were performed to evaluate the performance of the counters. The method for making silica aerogel with refractive index between 1.01 and 1.06 is explained in detail. Chemical reaction with methanol, pressure and temperature conditions, and the structure of the autoclave are described together with the whole process. About 20 l aerogel is now produced per week at KEK. The dimensions of the aerogel module is 200 x 100 x 300 mm3. The aerogel with refractive index larger than 1.06 is produced from the aerogel with refractive index 1.06 by heating it up to about 900 deg C. The refractive index can be controlled by the temperature and duration of heating. Refractive index in relation to these conditions is listed in a table. However, the dispersion of the index is about ten times as large as that for the aerogel with lower index (<1.06). The wave length dependence of the transmission length of light for the aerogel was measured and compared with other data obtained at various laboratories. The performance of the counter was evaluated through the experiment with π beam. Average number of photoelectrons gathered is plotted in relation to momentum. It is deduced from the experiment that the saturation thickness of the aerogel is about 10 cm. Two examples of the practical use of the aerogel counter at KEK are also shortly described. (Aoki, K.)

  6. Cherenkov counter for particle identification test beam

    International Nuclear Information System (INIS)

    The Cherenkov counter used for selecting electrons of the test beam has been studied in this article. The design, manufacture, assembly and testing of the Cherenkov counter are described. And the performance of this counter is measured. The CO2 gas is used as Cherenkov radiator, the XP2020Q photomultiplier is applied for recording signals of the Cherenkov light. The (99.0±0.5)% efficiency of the electron selection has been reached

  7. Study of TeV range cosmic ray detection with Cherenkov imaging techniques

    International Nuclear Information System (INIS)

    The Monte Carlo study of cosmic ray detection in the TeV energy range has been triggered by the authors' interest in the ARTEMIS (Antimatter Research Through the Earth Moon Ion Spectrometer) proposal. The properties of cosmic ray showers detected by Cherenkov imaging in the visible domain are studied. The detection sensitivity and the accuracy of the reconstruction of the parent particle direction using Cherenkov imaging are discussed. The backbone of the study is the atmospheric shower Monte Carlo generator developed by A.M. Hillas. A comparison between nucleon and photon induced showers of Cherenkov detection is also included. (R.P.) 14 refs., 48 figs., 3 tabs

  8. Schwarzschild-Couder two-mirror telescope for ground-based gamma-ray astronomy

    CERN Document Server

    Vasilev, V V

    2007-01-01

    Schwarzschild-type aplanatic telescopes with two aspheric mirrors, configured to correct spherical and coma aberrations, are considered for application in gamma-ray astronomy utilizing the ground-based atmospheric Cherenkov technique. We use analytical descriptions for the figures of primary and secondary mirrors and, by means of numerical ray-tracing, we find telescope configurations which minimize astigmatism and maximize effective light collecting area. It is shown that unlike the traditional prime-focus Davies-Cotton design, such telescopes provide a solution for wide field of view gamma-ray observations. The designs are isochronous, can be optimized to have no vignetting across the field, and allow for significant reduction of the plate scale, making them compatible with finely-pixilated cameras, which can be constructed from modern, cost-effective image sensors such as multi-anode PMTs, SiPMs, or image intensifiers.

  9. Whole Earth Telescope observations of the hot helium atmosphere pulsating white dwarf EC 20058-5234

    CERN Document Server

    Sullivan, D J; O'Donoghue, D; Winget, D E; Kilkenny, D; Van Wyk, F; Kanaan, A; Kepler, S O; Nitta, A; Kawaler, S D; Montgomery, M H; Nather, R E; O'Brien, M S; Bischoff-Kim, A; Wood, M; Jiang, X J; Leibowitz, E M; Ibbetson, P; Zola, S; Krzesínski, J; Pajdosz, G; Vauclair, G; Dolez, N; Chevreton, M

    2008-01-01

    We present the analysis of a total of 177h of high-quality optical time-series photometry of the helium atmosphere pulsating white dwarf (DBV) EC 20058-5234. The bulk of the observations (135h) were obtained during a WET campaign (XCOV15) in July 1997 that featured coordinated observing from 4 southern observatory sites over an 8-day period. The remaining data (42h) were obtained in June 2004 at Mt John Observatory in NZ over a one-week observing period. This work significantly extends the discovery observations of this low-amplitude (few percent) pulsator by increasing the number of detected frequencies from 8 to 18, and employs a simulation procedure to confirm the reality of these frequencies to a high level of significance (1 in 1000). The nature of the observed pulsation spectrum precludes identification of unique pulsation mode properties using any clearly discernable trends. However, we have used a global modelling procedure employing genetic algorithm techniques to identify the n, l values of 8 pulsat...

  10. Experimental set-up of the LUNASKA lunar Cherenkov observations at the ATCA

    OpenAIRE

    James, C.W.; Ekers, R. D.; Philips, C. J.; Protheroe, R.J.; Roberts, P.; Robinson, R A; Alvarez-Muñiz, J.; Bray, J. D.

    2009-01-01

    This contribution describes the experimental set-up implemented by the LUNASKA project at the Australia Telescope Compact Array (ATCA) to enable the radio-telescope to be used to search for pulses of coherent Cherenkov radiation from UHE particle interactions in the Moon with an unprecedented bandwidth, and hence sensitivity. Our specialised hardware included analogue de-dispersion filters to coherently correct for the dispersion expected of a ~nanosecond pulse in the Earth's ionosphere over ...

  11. Automatic Determination of Stellar Atmospheric Parameters and Construction of Stellar Spectral Templates of the Guoshoujing Telescope (LAMOST)

    CERN Document Server

    Wu, Yue; Li, Haining; Shi, Jianrong; Prugniel, Philippe; Liang, Yanchun; Zhao, Yongheng; Zhang, Jiannan; Bai, Zhongrui; Wei, Peng; Dong, Weixiang; Zhang, Haotong; Chen, Jianjun

    2011-01-01

    A number of spectroscopic surveys have been carried out or are planned to study the origin of the Milky Way. Their exploitation requires reliable automated methods and softwares to measure the fundamental parameters of the stars. Adopting the ULySS package, we have tested the effect of different resolutions and signal-to-noise ratios (SNR) on the measurement of the stellar atmospheric parameters (effective temperature Teff, surface gravity log g, and metallicity [Fe/H]). We show that ULySS is reliable to determine these parameters with medium-resolution spectra (R~2000). Then, we applied the method to measure the parameters of 771 stars selected in the commissioning database of the Guoshoujing Telescope (GSJT). The results were compared with the SDSS/SEGUE Stellar Parameter Pipeline (SSPP), and we derived precisions of 167 K, 0.34 dex, and 0.16 dex for Teff, log g and [Fe/H] respectively. Furthermore, 120 of these stars are selected to construct the primary stellar spectra template library (Version 1.0) of GS...

  12. Automatic determination of stellar atmospheric parameters and construction of stellar spectral templates of the Guoshoujing Telescope (LAMOST)

    Institute of Scientific and Technical Information of China (English)

    Yue Wu; Peng Wei; Wei-Xiang Dong; Hao-Tong Zhang; Jian-Jun Chen; A-Li Luo; Hai-Ning Li; Jian-Rong Shi; Philippe Prugniel; Yan-Chun Liang; Yong-Heng Zhao; Jian-Nan Zhang; Zhong-Rui Bai

    2011-01-01

    A number of spectroscopic surveys have been carried out or are planned to study the origin of the Milky Way.Their exploitation requires reliable automated methods and softwares to measure the fundamental parameters of the stars.Adopting the ULySS package,we have tested the effect of different resolutions and signal-to-noise ratios (SNR) on the measurement of the stellar atmospheric parameters (effec tive temperature Teff,surface gravity log9,and metallicity [Fe/H]).We show thatULySS is reliable for determining these parameters with medium-resolution spectra (R ~2000).Then,we applied the method to measure the parameters of 771 stars selected in the commissioning database of the Guoshoujing Telescope (LAMOST).The results were compared with the SDSS/SEGUE Stellar Parameter Pipeline (SSPP),and we derived precisions of 167 K,0.34dex,and 0.16dex for Teff,log9 and [Fe/H] respectively.Furthermore,120 of these stars are selected to construct the primary stellar spectral template library (Version 1.0) of LAMOST,and will be deployed as basic ingredients for the LAMOST automated parametrization pipeline.

  13. 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.

  14. Tests and applications of Cherenkov imaging in TeV astronomy

    International Nuclear Information System (INIS)

    This dissertation is on the use of Cherenkov imaging for background reduction in TeV Astronomy. The technique of measuring the angular distribution of Cherenkov light from air showers as a means of identifying the primary particle type has been predicted to lead to a significant increase in the sensitivity for ground-based x-ray telescopes. The hardware test of imaging successfully finds the Cherenkov light patterns from local cosmic ray particles using the Whipple Observatory collaboration's air Cherenkov telescope. This shows that a Whipple type imaging detector is sensitive to subtle images and therefore suitable for such a technique. A Monte Carlo simulation test confirms the current knowledge of the angular distribution of Cherenkov light expected from, γ-ray induced air showers. The search for TeV photons from two massive X-ray binaries, 4U0115+63 and V0332+53, using both uncut and image selected data sets shows little evidence for emission from either source

  15. HARPS Observes the Earth Transiting the Sun — A Method to Study Exoplanet Atmospheres Using Precision Spectroscopy on Large Ground-based Telescopes

    Science.gov (United States)

    Yan, F.; Fosbury, R.; Petr-Gotzens, M.; Pallé, E.; Zhao, G.

    2015-09-01

    Exoplanetary transits offer the opportunity to measure the transmission of long, tangential pathlengths through their atmospheres. Since the fraction of the observed stellar light taking these paths is very small, transit photometric and spectrophotometric measurements of light curves require very high levels of measurement stability, favouring the use of intrinsically stable space telescopes. By studying the Rossiter-McLaughlin effect on the radial velocity of the transited star, pure, high-precision radial velocity measurements can be used to estimate the changes in planetary atmospheric transmission with wavelength: a promising method for future studies of small planets with very large ground-based telescopes since it removes the requirement for extreme photometric stability. This article describes a successful feasibility experiment using the HARPS instrument to measure reflected moonlight during the penumbral phases of a Lunar eclipse, effectively providing an observation of an Earth transit.

  16. Monte Carlo studies on the sensitivity of the HEGRA imaging atmospheric Cerenkov telescope system in observations of extended gamma-ray sources

    International Nuclear Information System (INIS)

    In this paper, we present the results of Monte Carlo simulations of atmospheric showers induced by diffuse γ-rays as detected by the high-energy gamma-ray astronomy (HEGRA) system of five imaging atmospheric Cerenkov telescopes (IACTs). We have investigated the sensitivity of observations on extended γ-ray emission over the entire field of view of the instrument. We discuss a technique to search for extended γ-ray sources within the field of view of the instrument. We give estimates for HEGRA sensitivity of observations on extended TeV γ-ray sources

  17. Study of hadron and gamma-ray acceptance of the MAGIC telescopes: towards an improved background estimation

    CERN Document Server

    Prandini, E; Da Vela, P; Wilhelmi, E de Ona; Colin, P; Fruck, C; Strzys, M; Vovk, Ie

    2015-01-01

    The MAGIC telescopes are an array of two imaging atmospheric Cherenkov telescopes (IACTs) studying the gamma ray sky at very high-energies (VHE; E>100 GeV). The observations are performed in stereoscopic mode, with both telescopes pointing at the same position in the sky. The MAGIC field of view (FoV) acceptance for hadrons and gamma rays has a complex shape, which depends on several parameters such as the azimuth and zenith angle of the observations. In the standard MAGIC analysis, the strategy adopted for estimating this acceptance is not optimal in the case of complex FoVs. In this contribution we present the results of systematic studies intended to characterise the acceptance for the entire FoV. These studies open the possibility to apply improved background estimation methods to the MAGIC data, useful to investigate the morphology of extended or multiple sources.

  18. Performance of the MAGIC telescopes after the major upgrade

    CERN Document Server

    Sitarek, Julian; Colin, Pierre; Mazin, Daniel

    2015-01-01

    MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located on the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a major upgrade. The main subsystems upgraded were the MAGIC-I camera and its trigger system and the readout system of both telescopes. We use observations of the Crab Nebula taken at low and medium zenith angles to assess the key performance parameters of the MAGIC stereo system. For low zenith angle observations, the standard trigger threshold of the MAGIC telescopes is about 50 GeV. The integral sensitivity for point-like sources with Crab Nebula-like spectra above 220 GeV is (0.66 +/- 0.03)% of Crab Nebula flux in 50 h of observations. The angular resolution, defined as the sigma of a 2-dimensional Gaussian distribution, at energies of a few hundred GeV is below 0.07degree, while the energy resolution is around 16%. We investigate the effect of the systematic uncertainty on the data taken with the MAGIC telescopes after the upgrade. We estimate that th...

  19. 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.

  20. Use of aerogel for imaging Cherenkov counters

    International Nuclear Information System (INIS)

    In the past, detectors using silica aerogel as a Cherenkov radiator treated this material as a diffuse source of Cherenkov photons. In this paper we report on measurements made to explore the feasibility of using aerogel for imaging Cherenkov purposes. The results of the measurements are reproduced by a detailed Monte Carlo. This allows us to identify parameters critical for the use of aerogel as a radiator in imaging detectors. We conclude that commercially available aerogel can be used for these purposes. ((orig.))

  1. The Lake Baikal telescope NT-36

    International Nuclear Information System (INIS)

    Since April 13th, 1993 the underwater Cherenkov telescope NT-36 consisting of 36 photomultipliers attached to 3 strings, is operated in lake Baikal. We describe this first stationary underwater multistring array and present results from the first months of operation. (orig.)

  2. GRANITE- A steroscopic imaging Chernkov telescope system

    International Nuclear Information System (INIS)

    A second 10 meter class imaging telescope was constructed on Mt. Hopkins, Arizona, the site of the original 10 meter Whipple Cherenkov telescope. The twin telescope system with a 140 meter base line will allow both a reduction in the energy threshold and an improvement in the rejection of the hardonic background. The new telescope started operation in December 1991. With the final completion of the first installation stage (GRANITE I) during spring 92, it is now operating simultaneously with the orginal reflector. We describe in this paper design and construction of the new instrument and demonstrate the capability of the experiment to record coincident events

  3. 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...

  4. Pulse profile digitization system for TACTIC γ-ray telescope

    International Nuclear Information System (INIS)

    The TACTIC gamma-ray telescope deploys an array of 4 elements to detect TeV (1012 eV) gamma-ray emissions from celestial sources. These gamma-rays are detected in the presence of an overwhelmingly large background of cosmic-ray events. In order to exploit the subtle differences in the pulse profiles of the gamma-ray and cosmic-ray initiated atmospheric Cherenkov events for the purpose of event segregation, we have recently incorporated a 1GS/Sec pulse profile digitizer in the data acquisition system of one of the Vertex elements of the array. The details of the digitization system and preliminary results obtained are discussed in the paper. (author)

  5. A computer-programmable delay-generator scheme for the TACTIC gamma-ray telescope

    International Nuclear Information System (INIS)

    A programmable multi-channel digital-delay generator, characterised by negligible dead-time count losses, has been developed for deployment in the high-sensitivity TeV γ-ray telescope, TACTIC. This telescope comprises an array of 4x10 m2 of light collectors, of which three are placed at the corners of an equilateral triangle of side ≥20 m and are operated in a prompt-coincidence mode with a resolving time of similar 10 ns to detect atmospheric Cherenkov events produced by very high energy γ-ray and cosmic-ray proton primaries. The delay generator helps to line up these events in real time whenever they are detected at different relative times by these elements. The basic circuit used in this scheme can be readily adapted for utilisation in several other areas, including experimental nuclear physics. ((orig.))

  6. Remote control and telescope auto-alignment system for multiangle LIDAR under development at CEILAP, Argentina

    CERN Document Server

    Pallotta, Juan; Otero, Lidia; Chouza, Fernando; Raul, Delia; Gonzalez, Francisco; Etchegoyen, Alberto; Quel, Eduardo

    2013-01-01

    At CEILAP (CITEDEF-CONICET), a multiangle LIDAR is under development to monitor aerosol extinction coefficients in the frame of the CTA (Cherenkov Telescope Array) Project. This is an initiative to build the next generation of ground-based instruments to collect very high energy gamma-ray radiation (>10 GeV). The atmospheric conditions are very important for CTA observations, and LIDARs play an important role in the measurement of the aerosol optical depth at any direction. The LIDAR being developed at CEILAP was conceived to operate in harsh environmental conditions during the shifts, and these working conditions may produce misalignments. To minimize these effects, the telescopes comprising the reception unit are controlled by a self-alignment system. This paper describes the self-alignment method and hardware automation.

  7. Optic detectors calibration for measuring ultra-high energy extensive air showers Cherenkov radiation by 532 nm laser

    Science.gov (United States)

    Knurenko, Stanislav; Petrov, Igor; Egorov, Yuri

    2015-08-01

    Calibration of a PMT matrix is crucial for the treatment of the data obtained with Cherenkov tracking detector. Furthermore, due to high variability of the aerosol abundance in the atmosphere depending on season, weather etc. A constant monitoring of the atmospheric transparency is required during the measurements. For this purpose, besides traditional methods, a station for laser atmospheric probing is used.

  8. Optic detectors calibration for measuring ultra-high energy extensive air showers Cherenkov radiation by 532 nm laser

    CERN Document Server

    Knurenko, Stanislav; Petrov, Igor

    2014-01-01

    Calibration of a PMT matrix is crucial for the treatment of the data obtained with Cherenkov tracking detector. Furthermore, due to high variability of the aerosol abundance in the atmosphere depending on season, weather etc. A constant monitoring of the atmospheric transparency is required during the measurements. For this purpose, besides traditional methods, a station for laser atmospheric probing is used.

  9. Have Cherenkov telescopes detected a new light boson?

    International Nuclear Information System (INIS)

    Recent observations by H.E.S.S. and MAGIC strongly suggest that the Universe is more transparent to very-high-energy gamma rays than previously thought. We show that this fact can be reconciled with standard blazar emission models provided that photon oscillations into a very light Axion-Like Particle occur in extragalactic magnetic fields. A quantitative estimate of this effect indeed explains the observed data and in particular the spectrum of blazar 3C279.

  10. A new analog trigger system for the Cherenkov Telescope array

    OpenAIRE

    Tejedor Álvarez, Luis Ángel

    2014-01-01

    La astronomía de rayos γ estudia las partículas más energéticas que llegan a la Tierra desde el espacio. Estos rayos γ no se generan mediante procesos térmicos en simples estrellas, sino mediante mecanismos de aceleración de partículas en objetos celestes como núcleos de galaxias activos, púlsares, supernovas, o posibles procesos de aniquilación de materia oscura. Los rayos γ procedentes de estos objetos y sus características proporcionan una valiosa información con la que los científicos tra...

  11. Note to Titan's Atmosphere in Late Southern Spring Observed with Adaptive Optics on the W.M. Keck II 10-meter Telescope

    CERN Document Server

    Roe, H G; MacIntosh, B A; Gibbard, S G; Max, C E; McKay, C P; Roe, Henry G.; Pater, Imke de; Macintosh, Bruce A.; Gibbard, Seran G.; Max, Claire E.; Kay, Chris P. Mc

    2002-01-01

    Using adaptive optics on the W.M. Keck II telescope we imaged Titan several times during 1999 to 2001 in narrowband near-infrared filters selected to probe Titan's stratosphere and upper troposphere. We observed a bright feature around the south pole, possibly a collar of haze or clouds. Further, we find that solar phase angle explains most of the observed east-west brightness asymmetry of Titan's atmosphere, although the data do not preclude the presence of a `morning fog' effect at small solar phase angle.

  12. NOTE: Titan's Atmosphere in Late Southern Spring Observed with Adaptive Optics on the W.M. Keck II 10-meter Telescope

    OpenAIRE

    Roe, Henry G.; De Pater, Imke; Macintosh, Bruce A.; Gibbard, Seran G.; Max, Claire E.; McKay, Chris P

    2002-01-01

    Using adaptive optics on the W.M. Keck II telescope we imaged Titan several times during 1999 to 2001 in narrowband near-infrared filters selected to probe Titan's stratosphere and upper troposphere. We observed a bright feature around the south pole, possibly a collar of haze or clouds. Further, we find that solar phase angle explains most of the observed east-west brightness asymmetry of Titan's atmosphere, although the data do not preclude the presence of a `morning fog' effect at small so...

  13. Status of the second phase of the MAGIC telescope

    OpenAIRE

    Goebel, Florian

    2008-01-01

    The MAGIC 17m diameter Cherenkov telescope will be upgraded with a second telescope with advanced photon detectors and ultra fast readout within the year 2007. The sensitivity of MAGIC-II, the two telescope system, will be improved by a factor of 2. In addition the energy threshold will be reduced and the energy and angular resolution will be improved. The design, status and expected performance of MAGIC-II is presented here.

  14. Status of the second phase of the MAGIC telescope

    OpenAIRE

    Goebel, Florian; collaboration, for the MAGIC

    2007-01-01

    The MAGIC 17m diameter Cherenkov telescope will be upgraded with a second telescope with advanced photon detectors and ultra fast readout within the year 2007. The sensitivity of MAGIC-II, the two telescope system, will be improved by a factor of 2. In addition the energy threshold will be reduced and the energy and angular resolution will be improved. The design, status and expected performance of MAGIC-II is presented here.

  15. Temporal signatures of the Cherenkov light induced by extensive air showers of cosmic rays detected with the Yakutsk array

    CERN Document Server

    Ivanov, A A

    2016-01-01

    We analyze temporal characteristics of signals from the wide field-of-view (WFOV) Cherenkov telescope (CT) detecting extensive air showers (EAS) of cosmic rays (CR) in coincidence with surface detectors of the Yakutsk array. Our aim is to reveal causal relationships between measured characteristics and physical properties of EAS.

  16. Physics and astrophysics with gamma-ray telescopes

    CERN Document Server

    Vandenbroucke, J

    2010-01-01

    In the past few years gamma-ray astronomy has entered a golden age. A modern suite of telescopes is now scanning the sky over both hemispheres and over six orders of magnitude in energy. At $\\sim$TeV energies, only a handful of sources were known a decade ago, but the current generation of ground-based imaging atmospheric Cherenkov telescopes (H.E.S.S., MAGIC, and VERITAS) has increased this number to nearly one hundred. With a large field of view and duty cycle, the Tibet and Milagro air shower detectors have demonstrated the promise of the direct particle detection technique for TeV gamma rays. At $\\sim$GeV energies, the Fermi Gamma-ray Space Telescope has increased the number of known sources by nearly an order of magnitude in its first year of operation. New classes of sources that were previously theorized to be gamma-ray emitters have now been confirmed observationally. Moreover, there have been surprise discoveries of GeV gamma-ray emission from source classes for which no theory predicted it was possi...

  17. Measurement of the atmospheric νμ energy spectrum from 100 GeV to 200 TeV with the ANTARES telescope

    International Nuclear Information System (INIS)

    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 νμ + anti νμ 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 ∝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 γmeas=3.58±0.12. With the present statistics the contribution of prompt neutrinos cannot be established. (orig.)

  18. 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.)

  19. A new method to calibrate ionospheric pulse dispersion for UHE cosmic ray and neutrino detection using the Lunar Cherenkov technique

    International Nuclear Information System (INIS)

    UHE particle detection using the lunar Cherenkov technique aims to detect nanosecond pulses of Cherenkov emission which are produced during UHE cosmic ray and neutrino interactions in the Moon's regolith. These pulses will reach Earth-based telescopes dispersed, and therefore reduced in amplitude, due to their propagation through the Earth's ionosphere. To maximise the received signal to noise ratio and subsequent chances of pulse detection, ionospheric dispersion must therefore be corrected, and since the high time resolution would require excessive data storage this correction must be made in real time. This requires an accurate knowledge of the dispersion characteristic which is parameterised by the instantaneous Total Electron Content (TEC) of the ionosphere. A new method to calibrate the dispersive effect of the ionosphere on lunar Cherenkov pulses has been developed for the LUNASKA lunar Cherenkov experiments. This method exploits radial symmetries in the distribution of the Moon's polarised emission to make Faraday rotation measurements in the visibility domain of synthesis array data (i.e. instantaneously). Faraday rotation measurements are then combined with geomagnetic field models to estimate the ionospheric TEC. This method of ionospheric calibration is particularly attractive for the lunar Cherenkov technique as it may be used in real time to estimate the ionospheric TEC along a line-of-sight to the Moon and using the same radio telescope.

  20. Tachyonic Cherenkov emission from Jupiter's radio electrons

    International Nuclear Information System (INIS)

    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.

  1. All-fiber femtosecond Cherenkov radiation source.

    Science.gov (United States)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe; Tu, Haohua; Boppart, Stephen A; Turchinovich, Dmitry

    2012-07-01

    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 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 such as bioimaging and microscopy. PMID:22743523

  2. Analytical application of Cherenkov radiation Pt. 4

    International Nuclear Information System (INIS)

    Cherenkov photometry can be used for measuring coloured solutions. The use of Cherenkov photometry is very advantageous, because Beer's law is true in a very wide concentration interval. It was studied how the various isotopes and the external standard can be used for Cherenkov Photometry with Cr2O72- and CrO42- in the 2-200 μg/cm3 interval. The upper measuring limits were found to be the lowest with low β energy isotopes. From among the isotopes studied the one with the highest energy can be used in the widest concentration interval. (author)

  3. Hubble Space Telescope Transmission Spectroscopy of the Exoplanet HD 189733b: High-altitude atmospheric haze in the optical and near-UV with STIS

    CERN Document Server

    Sing, D K; Aigrain, S; Charbonneau, D; Desert, J -M; Gibson, N; Gilliland, R; Hayek, W; Henry, G; Knutson, H; Etangs, A Lecavelier des; Mazeh, T; Tal-Or, L

    2011-01-01

    We present Hubble Space Telescope optical and near-ultraviolet transmission spectra of the transiting hot-Jupiter HD189733b, taken with the repaired Space Telescope Imaging Spectrograph (STIS) instrument. The resulting spectra cover the range 2900-5700 Ang and reach per-exposure signal-to-noise levels greater than 11,000 within a 500 Ang bandwidth. We used time series spectra obtained during two transit events to determine the wavelength dependance of the planetary radius and measure the exoplanet's atmospheric transmission spectrum for the first time over this wavelength range. Our measurements, in conjunction with existing HST spectra, now provides a broadband transmission spectrum covering the full optical regime. We find a planetary transmission spectrum in good agreement with that of Rayleigh scattering from a high-altitude atmospheric haze as previously found from HST ACS camera. The STIS data also shows unambiguous evidence of a large occulted stellar spot during one of our transit events, which we use...

  4. MEMPHYS: A large scale water Cherenkov detector at Frejus

    Energy Technology Data Exchange (ETDEWEB)

    Bellefon, A. de; Dolbeau, J.; Gorodetzky, P.; Katsanevas, S.; Patzak, T.; Salin, P.; Tonazzo, A. [APC Paris, Paris (France); Bouchez, J. [APC Paris, Paris (France)]|[DAPNIA-CEA Saclay (France); Busto, J. [CPP Marseille (France); Campagne, J.E. [LAL Orsay (France); Cavata, C.; Mosca, L. [DAPNIA-CEA Saclay (France); Dumarchez, J. [LPNHE Paris (France); Mezzetto, M. [INFN Padova (Italy); Volpe, C. [IPN Orsay (France)

    2006-07-15

    A water Cherenkov detector project, of megaton scale, to be installed in the Frejus underground site and dedicated to nucleon decay, neutrinos from supernovae, solar and atmospheric neutrinos, as well as neutrinos from a super-beam and/or a beta-beam coming from CERN, is presented and compared with competitor projects in Japan and in the USA. The performances of the European project are discussed, including the possibility to measure the mixing angle {theta}{sub 13} and the CP-violating phase {delta}. (authors)

  5. The Camera of the MAGIC-II Telescope

    CERN Document Server

    Hsu, C C; Fink, D; Göbel, F; Haberer, W; Hose, J; Maier, R; Mirzoyan, R; Pimpl, W; Reimann, O; Rudert, A; Sawallisch, P; Schlammer, J; Schmidl, S; Stipp, A; Teshima, M

    2007-01-01

    The MAGIC 17m diameter Cherenkov telescope will be upgraded with a second telescope within the year 2007. The camera of MAGIC-II will include several new features compared to the MAGIC-I camera. Photomultipliers with the highest available photon collection efficiency have been selected. A modular design allows easier access and flexibility to test new photodetector technologies. The camera will be uniformly equipped with 0.1 degree diamter pixels, which allows the use of an increased trigger area. Finally, the overall signal chain features a large bandwidth to retain the shape of the very fast Cherenkov signals.

  6. Cooperative quasi-Cherenkov radiation

    CERN Document Server

    Anishchenko, S V

    2014-01-01

    We study the features of cooperative parametric (quasi-Cherenkov) radiation arising when initially unmodulated electron (positron) bunches pass through a crystal (natural or artificial) under the conditions of dynamical diffraction of electromagnetic waves in the presence of shot noise. A detailed numerical analysis is given for cooperative THz radiation in artificial crystals. The radiation intensity above 200~MW$/$cm$^2$ is obtained in simulations. In two- and three-wave diffraction cases, the peak intensity of cooperative radiation emitted at small and large angles to particle velocity is investigated as a function of the particle number in an electron bunch. The peak radiation intensity appeared to increase monotonically until saturation is achieved. At saturation, the shot noise causes strong fluctuations in the intensity of cooperative parametric radiation. It is shown that the duration of radiation pulses can be much longer than the particle flight time through the crystal. This enables a thorough expe...

  7. FACT -- The G-APD revolution in Cherenkov astronomy

    CERN Document Server

    Bretz, T; Backes, M; Biland, A; Boccone, V; Braun, I; Buß, J; Cadoux, F; Commichau, V; Djambazov, L; Dorner, D; Einecke, S; Eisenacher, D; Gendotti, A; Grimm, O; von Gunten, H; Haller, C; Hempfling, 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; Müuller, S; 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

    2014-01-01

    Since two years, the FACT telescope is operating on the Canary Island of La Palma. Apart from its purpose to serve as a monitoring facility for the brightest TeV blazars, it was built as a major step to establish solid state photon counters as detectors in Cherenkov astronomy. The camera of the First G-APD Cherenkov Telesope comprises 1440 Geiger-mode avalanche photo diodes (G-APD), equipped with solid light guides to increase the effective light collection area of each sensor. Since no sense-line is available, a special challenge is to keep the applied voltage stable although the current drawn by the G-APD depends on the flux of night-sky background photons significantly varying with ambient light conditions. Methods have been developed to keep the temperature and voltage dependent response of the G-APDs stable during operation. As a cross-check, dark count spectra with high statistics have been taken under different environmental conditions. In this presentation, the project, the developed methods and the e...

  8. The HERA-B ring imaging Cherenkov counter

    Science.gov (United States)

    Ariño, I.; Bastos, J.; Broemmelsiek, D.; Carvalho, J.; Chmeissani, M.; Conde, P.; Davila, J.; Dujmić, D.; Eckmann, R.; Garrido, L.; Gascon, D.; Hamacher, T.; Gorišek, A.; Ivaniouchenkov, I.; Ispirian, M.; Karabekian, S.; Kim, M.; Korpar, S.; Križan, P.; Kupper, S.; Lau, K.; Maas, P.; McGill, J.; Miquel, R.; Murthy, N.; Peralta, D.; Pestotnik, R.; Pyrlik, J.; Ramachandran, S.; Reeves, K.; Rosen, J.; Schmidt-Parzefall, W.; Schwarz, A.; Schwitters, R. F.; Siero, X.; Starič, M.; Stanovnik, A.; Škrk, D.; Živko, T.

    2004-01-01

    The HERA-B RICH uses a radiation path length of 2.8 m in C 4F 10 gas and a large 24 m2 spherical mirror for imaging Cherenkov rings. The photon detector consists of 2240 Hamamatsu multi-anode photomultipliers with about 27 000 channels. A 2:1 reducing two-lens telescope in front of each photomultiplier tube increases the sensitive area at the expense of increased pixel size, resulting in a contribution to the resolution which roughly matches that of dispersion. The counter was completed in January of 1999, and its performance has been steady and reliable over the years it has been in operation. The design performance of the Ring Imaging Cherenkov counter was fully reached: the average number of detected photons in the RICH for a β=1 particle was found to be 33 with a single-hit resolution of 0.7 and 1 mrad in the fine and coarse granularity regions, respectively.

  9. 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...

  10. Interpretation of spin effects in Cherenkov radiation

    International Nuclear Information System (INIS)

    The Cherenkov radiation effect depends on correlation between electron polarization and photon spirality. This correlation in the given case is interpreted as interference of the charge radiation amplitudes and electron magnetic moment

  11. NICHE: The Non-Imaging CHErenkov Array

    CERN Document Server

    Bergman, Douglas

    2012-01-01

    The accurate measurement of the Cosmic Ray (CR) nuclear composition around and above the Knee (~ 10^15.5 eV) has been difficult due to uncertainties inherent to the measurement techniques and/or dependence on hadronic Monte Carlo simulation models required to interpret the data. Measurement of the Cherenkov air shower signal, calibrated with air fluorescence measurements, offers a methodology to provide an accurate measurement of the nuclear composition evolution over a large energy range. NICHE will use an array of widely-spaced, non-imaging Cherenkov counters to measure the amplitude and time-spread of the air shower Cherenkov signal to extract CR nuclear composition measurements and to cross-calibrate the Cherenkov energy and composition measurements with TA/TALE fluorescence and surface detector measurements.

  12. Spontaneous emission in Cherenkov FEL devices

    International Nuclear Information System (INIS)

    The main features of the spectral characteristics of the spontaneously emitted Cherenkov light in circular and rectangular wave-guides filled with dielectric are discussed. The characteristics of the radiation emitted by an electron beam moving near and parallel to the surface of a dielectric slab are also analysed. Finally, the relevance of these results to a possible FEL-Cherenkov operation is briefly discussed

  13. Use of silica aerogel in Cherenkov counters

    International Nuclear Information System (INIS)

    Silica aerogel has been widely used as a radiator for Cherenkov detectors. The review is devoted to the consideration of various aspects concerning aerogel: its production methods, optical and physical properties, including transparency, absorption, and scattering lengths, the number of photoelectrons and also factors affecting the accuracy of particle identification. The use of silica aerogel in various threshold Cherenkov counters as BELLE (KEK), TASSO (DESY), KEDR (VEPP-4M) is described

  14. Tests of a silica aerogel Cherenkov counter

    International Nuclear Information System (INIS)

    A Cherenkov counter with silica aerogel of refractive index 1.06 as radiator has been constructed and tested. The Cherenkov light produced in 9 cm thick silica aerogel was detected with four 5''-photomultipliers through a 162 cm long air light guide. The photoelectron yield for a 1 GeV/c pion beam was found to be 6 and uniform over a sensitive area of 40 x 30 cm2. (orig.)

  15. Measurement of the atmospheric muon flux with a 4 GeV threshold in the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    A new method for the measurement of the muon flux in the deep-sea ANTARES neutrino telescope and its dependence on the depth is presented. The method is based oil the observation of coincidence signals in adjacent storeys of the detector. This yields an energy threshold of about 4 GeV. The main sources of optical background are the decay of 40K and the bioluminescence in the sea water. The 40K background is used to calibrate the efficiency of the photo-multiplier tubes. (authors)

  16. Measurement of the atmospheric muon flux with a 4 GeV threshold in the ANTARES neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, J.A. [IFIC - Instituto de Fisica Corpuscular, Edificios Investigacion de Paterna, CSIC - Universitat de Valencia, Apdo. de Correos 22085, 46071 Valencia (Spain); Al Samarai, I. [CPPM - Centre de Physique des Particules de Marseille, CNRS/IN2P3 et Universite de la Mediterranee, 163 Avenue de Luminy, Case 902, 13288 Marseille Cedex 9 (FR); Albert, A. [GRPHE - Institut Universitaire de Technologie de Colmar, 34 Rue du Grillenbreit, BP 50568, 68008 Colmar (FR); Anghinolfi, M. [INFN - Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Anton, G. [Friedrich-Alexander-Universitaet Erlangen-Nuernberg, Erlangen Centre for Astroparticle Physics, Erwin-Rommel-Str. 1, D-91058 Erlangen (Germany); Anvar, S. [Direction des Sciences de la Matiere - Institut de Recherche sur les lois Fondamentales de l' Univers - Service d' Electronique des Detecteurs et d' Informatique, CEA Saclay, 91191 Gif-sur-Yvette Cedex (FR); Baret, B.; Donzaud, C.; Kouchner, A.; Moscoso, L.; Van Elewyck, V. [APC - Laboratoire AstroParticule et Cosmologie, UMR 7164, CNRS, Universite Paris 7 Diderot, CEA, Observatoire de Paris, 10, Rue Alice Domon et Leonie Duquet, 75205 Paris Cedex 13 (FR); Basa, S.; Marcelin, M.; Mazure, A.; Tasca, L. [Laboratoire d' Astrophysique de Marseille, Pole de l' Etoile Site de Chateau-Gombert, Marseille (FR); Carloganu, C.; Gay, P. [Lab. de Physique Corpusculaire, IN2P3-CNRS, Universite Blaise Pascal, Clermont-Ferrand (FR); Charvis, Ph.; Deschamps, A.; Hello, Y.; Pillet, R. [Geoazur - Universite de Nice Sophia-Antipolis, CNRS/INSU, IRD, Observatoire de la Cote d' Azur and Universite Pierre et Marie Curie, BP 48, F-06235 Villefranche-sur-mer (FR); Cottini, N.; Loucatos, S.; Moscoso, L.; Naumann, C.; Picq, C.; Schuller, J.P.; Stolarczyk, Th.; Vallage, B.; Vernin, P. [Direction des Sciences de la Matiere - Institut de Recherche sur les lois Fondamentales de l' Univers - Service de Physique des Particules, CEA Saclay, 91191 Gif-sur-Yvette (FR)

    2010-07-01

    A new method for the measurement of the muon flux in the deep-sea ANTARES neutrino telescope and its dependence on the depth is presented. The method is based oil the observation of coincidence signals in adjacent storeys of the detector. This yields an energy threshold of about 4 GeV. The main sources of optical background are the decay of {sup 40}K and the bioluminescence in the sea water. The {sup 40}K background is used to calibrate the efficiency of the photo-multiplier tubes. (authors)

  17. Measurement of the atmospheric muon flux with a 4 GeV threshold in the ANTARES neutrino telescope

    CERN Document Server

    Aguilar, J A

    2009-01-01

    A new method for the measurement of the muon flux in the deep-sea ANTARES neutrino telescope and its dependence on the depth is presented. The method is based on the observation of coincidence signals in adjacent storeys of the detector. This yields an energy threshold of about 4 GeV. The main sources of optical background are the decay of 40K and the bioluminescence in the sea water. The 40K background is used to calibrate the efficiency of the photo-multiplier tubes.

  18. The HERA-B Ring Imaging Cherenkov Counter

    CERN Document Server

    Arino, I

    2004-01-01

    The HERA-B RICH uses a radiation path length of 2.8 m in C_4F_10 gas and a large 24 square meters spherical mirror for imaging Cherenkov rings. The photon detector consists of 2240 Hamamatsu multi-anode photomultipliers with about 27000 channels. A 2:1 reducing two-lens telescope in front of each PMT increases the sensitive area at the expense of increased pixel size, resulting in a contribution to the resolution which roughly matches that of dispersion. The counter was completed in January of 1999, and its performance has been steady and reliable over the years it has been in operation. The design performance of the RICH was fully reached: the average number of detected photons in the RICH for a beta=1 particle was found to be 33 with a single hit resolution of 0.7 mrad and 1 mrad in the fine and coarse granularity regions, respectively.

  19. The neutrino telescope ANTARES

    Directory of Open Access Journals (Sweden)

    Gleixner Andreas

    2014-04-01

    Full Text Available The ANTARES neutrino telescope is currently the largest neutrino detector in the Northern Hemisphere. The detector consists of a three-dimensional array of 885 photomultiplier tubes, distributed along 12 lines, located at a depth of 2500 m in the Mediterranean Sea. The purpose of the experiment is the detection of high-energy cosmic neutrinos. The detection principle is based on the observation of Cherenkov-Light emitted by muons resulting from charged-current interactions of muon neutrinos in the vicinity of the detection volume. The main scientific targets of ANTARES include the search for astrophysical neutrino point sources, the measurement of the diffuse neutrino flux and the indirect search for dark matter.

  20. The ANTARES neutrino telescope

    CERN Document Server

    Zornoza, Juan de Dios

    2012-01-01

    The ANTARES collaboration completed the installation of the first neutrino detector in the sea in 2008. It consists of a three dimensional array of 885 photomultipliers to gather the Cherenkov photons induced by relativistic muons produced in charged-current interactions of high energy neutrinos close to/in the detector. The scientific scope of neutrino telescopes is very broad: the origin of cosmic rays, the origin of the TeV photons observed in many astrophysical sources or the nature of dark matter. The data collected up to now have allowed us to produce a rich output of physics results, including the map of the neutrino sky of the Southern hemisphere, search for correlations with GRBs, flaring sources, gravitational waves, limits on the flux produced by dark matter self-annihilations, etc. In this paper a review of these results is presented.

  1. In-situ verification of CANDU spent fuel by the Cherenkov technique

    International Nuclear Information System (INIS)

    Multilayered and densely stacked irradiated CANDU fuel bundles in storage ponds make direct viewing of bundles in order to observe Cherenkov glow practically impossible. Ability to defect the source of Cherenkov glow by visual observation invariably suffers from subjective judgment. In the case of CANDU-type storage geometry, the difficulty in drawing conclusions is even greater for a number of reasons including the near neighbour effect. In this paper, the first results of Cherenkov photographic procedure without the isolation of individual trays are presented in which a new model of the Hungarian underwater telescope in combination with a lightmeter for Cherenkov intensity measurements has been used. It is demonstrated by this technique that photographs of bundles with cooling time of up to 2 a provide a satisfactory record for conclusive attribute verification result for irradiated fuel bundles stacked in multilayers. A distinct glow, with a brightness of higher intensity between the rod of a bundle compared to the surroundings of the bundle, is clearly shown by the pictures. Based on the results of the glow intensity measurements, the use of this photographic method for fuel bundles with longer cooling time of up to 15 a or more would require considerably longer exposure times or more sensitive film. Possible impact on IAEA safeguards of CANDU spent fuel bays by a system, which offers simultaneous item counting and NDA attribute test capabilities in a relatively low intrusive manner, is discussed. The limitations are also considered. (author)

  2. 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)

  3. CTA telescopes as deep-space lasercom ground receivers

    CERN Document Server

    Carrasco-Casado, Alberto; Vergaz, Ricardo

    2015-01-01

    The amount of scientific data to be transmitted from deep-space probes is very limited due to RF-communications constraints. Free-space optical communication can alleviate this bottleneck, increasing data rate while reducing weight, mass and power of communication onboard equipment. Nevertheless, optimizing the power delivery from spacecraft to Earth is needed. In RF communications, the strategy has been to increase the aperture of ground terminals. Free-space optical communications can also follow it, as they share the limitation of low power received on Earth. As the cost of big telescopes increases exponentially with aperture, new ideas are required to maximize the aperture-to-cost ratio. This work explores the feasibility of using telescopes of the future Cherenkov Telescope Array as optical-communication ground stations. Ground-based gamma-ray astronomy has the same power limitation, hence Cherenkov telescopes are designed to maximize receiver's aperture with minimum cost and some relaxed requirements. B...

  4. Development of the Photomultiplier-Tube Readout System for the CTA Large Size Telescope

    OpenAIRE

    Kubo, H; Paoletti, R.; Awane, Y; Bamba, A.; Barcelo, M.; Barrio, J.A.; Blanch, O.; Boix, J; Delgado, C; Fink, D.; Gascon, D.; Gunji, S; Hagiwara, R.; Hanabata, Y.; K. Hatanaka

    2013-01-01

    We have developed a prototype of the photomultiplier tube (PMT) readout system for the Cherenkov Telescope Array (CTA) Large Size Telescope (LST). Two thousand PMTs along with their readout systems are arranged on the focal plane of each telescope, with one readout system per 7-PMT cluster. The Cherenkov light pulses generated by the air showers are detected by the PMTs and amplified in a compact, low noise and wide dynamic range gain block. The output of this block is then digitized at a sam...

  5. A novel LIDAR-based Atmospheric Calibration Method for Improving the Data Analysis of MAGIC

    CERN Document Server

    Fruck, Christian; Zanin, Roberta; Dorner, Daniela; Garrido, Daniel; Mirzoyan, Razmik; Font, Lluis

    2014-01-01

    A new method for analyzing the returns of the custom-made 'micro'-LIDAR system, which is operated along with the two MAGIC telescopes, allows to apply atmospheric corrections in the MAGIC data analysis chain. Such corrections make it possible to extend the effective observation time of MAGIC under adverse atmospheric conditions and reduce the systematic errors of energy and flux in the data analysis. LIDAR provides a range-resolved atmospheric backscatter profile from which the extinction of Cherenkov light from air shower events can be estimated. Knowledge of the extinction can allow to reconstruct the true image parameters, including energy and flux. Our final goal is to recover the source-intrinsic energy spectrum also for data affected by atmospheric extinction from aerosol layers, such as clouds.

  6. Gamma-telescope for the ''Kosmos-461'' satellite

    International Nuclear Information System (INIS)

    Design, electronic circuit, calibration procedure, and operation of γ-telescope of the ''Kosmos-461'' satellite are described. The telescope is designed to register γ-quanta in the range of 80-1000 MeV and was used to investigate spatial, spectral, and time distributions of hard atmospheric radiation. An incident γ-quantum forms an electron-positron pair in the lead converter 80 cm in diameter and 2.5 mm in thickness. Immediately after the converter is the thin (5 cm) Cherenkov radiator of organic glass that prevents particle passage through the instrument in the opposite direction. Development of the electromagnetic cascade shower born by incident quantum occurs in a conic CsJ(Tl) crystal-calorimeter of 9 cm thick. The head part of the instrument is covered with a protective anticoincidence scintillator of 2 cm thick. The form factor of the instrument is 3.6 cm2, average total weight is 22 kg, energy consumption is 1.5 W

  7. Energy Reconstruction Methods in the IceCube Neutrino Telescope

    CERN Document Server

    Aartsen, M G; Ackermann, M; Adams, J; Aguilar, J A; Ahlers, M; Altmann, D; Arguelles, C; Auffenberg, J; Bai, X; Baker, M; Barwick, S W; Baum, V; Bay, R; Beatty, J J; Tjus, J Becker; Becker, K -H; BenZvi, S; Berghaus, P; Berley, D; Bernardini, E; Bernhard, A; Besson, D Z; Binder, G; Bindig, D; Bissok, M; Blaufuss, E; Blumenthal, J; Boersma, D J; Bohm, C; Bose, D; Böser, S; Botner, O; Brayeur, L; Bretz, H -P; Brown, A M; Bruijn, R; Casey, J; Casier, M; Chirkin, D; Christov, A; Christy, B; Clark, K; Classen, L; Clevermann, F; Coenders, S; Cohen, S; Cowen, D F; Silva, A H Cruz; Danninger, M; Daughhetee, J; Davis, J C; Day, M; De Clercq, C; De Ridder, S; Desiati, P; de Vries, K D; de With, M; DeYoung, T; D\\'\\iaz-Vélez, J C; Dunkman, M; Eagan, R; Eberhardt, B; Eichmann, B; Eisch, J; 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; Frantzen, K; Fuchs, T; Gaisser, T K; Gallagher, J; Gerhardt, L; Gladstone, L; Glüsenkamp, T; Goldschmidt, A; Golup, G; Gonzalez, J G; Goodman, J A; Góra, D; Grandmont, D T; Grant, D; Gretskov, P; Groh, J C; Groß, A; Ha, C; Ismail, A Haj; Hallen, P; Hallgren, A; Halzen, F; Hanson, K; Hebecker, D; Heereman, D; Heinen, D; Helbing, K; Hellauer, R; Hickford, S; Hill, G C; Hoffman, K D; Hoffmann, R; Homeier, A; Hoshina, K; Huang, F; Huelsnitz, W; Hulth, P O; Hultqvist, K; Hussain, S; Ishihara, A; Jackson, S; Jacobi, E; Jacobsen, J; Jagielski, K; Japaridze, G S; Jero, K; Jlelati, O; Kaminsky, B; Kappes, A; Karg, T; Karle, A; Kauer, M; Kelley, J L; Kiryluk, J; Kläs, J; Klein, S R; Köhne, J -H; Kohnen, G; Kolanoski, H; Köpke, L; Kopper, C; Kopper, S; Koskinen, D J; Kowalski, M; Krasberg, M; Kriesten, A; Krings, K; Kroll, G; Kunnen, J; Kurahashi, N; Kuwabara, T; Labare, M; Landsman, H; Larson, M J; Lesiak-Bzdak, M; Leuermann, M; Leute, J; Lünemann, J; Macías, O; Madsen, J; Maggi, G; Maruyama, R; Mase, K; Matis, H S; McNally, F; Meagher, K; Merck, M; Meures, T; Miarecki, S; Middell, E; Milke, N; Miller, J; Mohrmann, L; Montaruli, T; Morse, R; Nahnhauer, R; Naumann, U; Niederhausen, H; Nowicki, S C; Nygren, D R; Obertacke, A; Odrowski, S; Olivas, A; Omairat, A; O'Murchadha, A; Paul, L; Pepper, J A; Heros, C Pérez de los; Pfendner, C; Pieloth, D; Pinat, E; Posselt, J; Price, P B; Przybylski, G T; Quinnan, M; Rädel, L; Rameez, M; Rawlins, K; Redl, P; Reimann, R; Resconi, E; Rhode, W; Ribordy, M; Richman, M; Riedel, B; Rodrigues, J P; Rott, C; Ruhe, T; Ruzybayev, B; Ryckbosch, D; Saba, S M; Sander, H -G; Santander, M; Sarkar, S; Schatto, K; Scheriau, F; Schmidt, T; Schmitz, M; Schoenen, S; Schöneberg, S; Schönwald, A; Schukraft, A; Schulte, L; Schulz, O; Seckel, D; Sestayo, Y; Seunarine, S; Shanidze, R; Sheremata, C; Smith, M W E; Soldin, D; Spiczak, G M; Spiering, C; Stamatikos, M; Stanev, T; Stanisha, N A; Stasik, A; Stezelberger, T; Stokstad, R G; Stößl, A; Strahler, E A; Ström, R; Strotjohann, N L; Sullivan, G W; Taavola, H; Taboada, I; Tamburro, A; Tepe, A; Ter-Antonyan, S; Tešić, G; Tilav, S; Toale, P A; Tobin, M N; Toscano, S; Tselengidou, M; Unger, E; Usner, M; Vallecorsa, S; van Eijndhoven, N; Van Overloop, A; van Santen, J; Vehring, M; Voge, M; Vraeghe, M; Walck, C; Waldenmaier, T; Wallraff, M; Weaver, Ch; Wellons, M; Wendt, C; Westerhoff, S; Whitehorn, N; Wiebe, K; Wiebusch, C H; Williams, D R; Wissing, H; Wolf, M; Wood, T R; Woschnagg, K; Xu, D L; Xu, X W; Yanez, J P; Yodh, G; Yoshida, S; Zarzhitsky, P; Ziemann, J; Zierke, S; Zoll, M

    2013-01-01

    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 charged particles created in neutrino interactions. The amount of light emitted is proportional to the deposited energy, which is approximately equal to the neutrino energy for $\

  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.

    2012-01-01

    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. 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.

  10. The optical module of the Baikal deep underwater neutrino telescope

    OpenAIRE

    Bagduev, R. I.

    1999-01-01

    A deep underwater Cherenkov telescope has been operating since 1993 in stages of growing size at 1.1 km depth in Lake Baikal. The key component of the telescope is the Optical Module (OM) which houses the highly sensitive phototube QUASAR-370. We describe design and parameters of the QUASAR-370, the layout of the optical module, the front-end electronics and the calibration procedures, and present selected results from the five-year operation underwater. Also, future developments with respect...

  11. A COMBINED VERY LARGE TELESCOPE AND GEMINI STUDY OF THE ATMOSPHERE OF THE DIRECTLY IMAGED PLANET, β PICTORIS b

    International Nuclear Information System (INIS)

    We analyze new/archival VLT/NaCo and Gemini/NICI high-contrast imaging of the young, self-luminous planet β Pictoris b in seven near-to-mid IR photometric filters, using advanced image processing methods to achieve high signal-to-noise, high precision measurements. While β Pic b's near-IR colors mimic those of a standard, cloudy early-to-mid L dwarf, it is overluminous in the mid-infrared compared to the field L/T dwarf sequence. Few substellar/planet-mass objects—i.e., κ And b and 1RXJ 1609B—match β Pic b's JHKsL' photometry and its 3.1 μm and 5 μm photometry are particularly difficult to reproduce. Atmosphere models adopting cloud prescriptions and large (∼60 μm) dust grains fail to reproduce the β Pic b spectrum. However, models incorporating thick clouds similar to those found for HR 8799 bcde, but also with small (a few microns) modal particle sizes, yield fits consistent with the data within the uncertainties. Assuming solar abundance models, thick clouds, and small dust particles ((a) = 4 μm), we derive atmosphere parameters of log (g) = 3.8 ± 0.2 and Teff = 1575-1650 K, an inferred mass of 7+4-3 MJ , and a luminosity of log(L/L☉) ∼–3.80 ± 0.02. The best-estimated planet radius, ≈1.65 ± 0.06 RJ , is near the upper end of allowable planet radii for hot-start models given the host star's age and likely reflects challenges constructing accurate atmospheric models. Alternatively, these radii are comfortably consistent with hot-start model predictions if β Pic b is younger than ≈7 Myr, consistent with a late formation well after its host star's birth ∼12+8-4 Myr ago

  12. A Combined Very Large Telescope and Gemini Study of the Atmosphere of the Directly Imaged Planet, Beta Pictoris b

    Science.gov (United States)

    Currie, Thayne; Burrows, Adam; Madhusudhan, Nikku; Fukagawa, Misato; Girard, Julien H.; Dawson, Rebekah; Murray-Clay, Ruth; Kenyon, Scott; Kuchner, Marc J.; Matsumura, Soko; Jayawardhana, Ray; Chambers, John; Bromley, Ben

    2013-01-01

    We analyze new/archival VLT/NaCo and Gemini/NICI high-contrast imaging of the young, self-luminous planet Beta Pictoris b in seven near-to-mid IR photometric filters, using advanced image processing methods to achieve high signal-to-noise, high precision measurements. While Beta Pic b's near-IR colors mimic those of a standard, cloudy early-to-mid L dwarf, it is overluminous in the mid-infrared compared to the field L/T dwarf sequence. Few substellar/planet-mass objects-i.e., ? And b and 1RXJ 1609B-match Beta Pic b's JHKsL photometry and its 3.1 micron and 5 micron photometry are particularly difficult to reproduce. Atmosphere models adopting cloud prescriptions and large (approx. 60 micron)dust grains fail to reproduce the Beta Pic b spectrum. However, models incorporating thick clouds similar to those found forHR8799 bcde, but also with small (a fewmicrons) modal particle sizes, yield fits consistent with the data within the uncertainties. Assuming solar abundance models, thick clouds, and small dust particles (a = 4 micron), we derive atmosphere parameters of log(g) = 3.8 +/- 0.2 and Teff = 1575-1650 K, an inferred mass of 7+4 -3 MJ, and a luminosity of log(L/L) approx. -3.80 +/- 0.02. The best-estimated planet radius, is approx. equal to 1.65 +/- 0.06 RJ, is near the upper end of allowable planet radii for hot-start models given the host star's age and likely reflects challenges constructing accurate atmospheric models. Alternatively, these radii are comfortably consistent with hot-start model predictions if Beta Pic b is younger than is approx. equal to 7 Myr, consistent with a late formation well after its host star's birth approx. 12+8 -4 Myr ago.

  13. Detection of Cherenkov light from air showers with Geiger-APDs

    CERN Document Server

    Otte, A N; Biland, A; Göbel, F; Lorenz, E; Pauss, F; Renker, D; Röser, U; Schweizer, T

    2007-01-01

    We have detected Cherenkov light from air showers with Geiger-mode APDs (G-APDs). G-APDs are novel semiconductor photon-detectors, which offer several advantages compared to conventional photomultiplier tubes in the field of ground-based gamma-ray astronomy. In a field test with the MAGIC telescope we have tested the efficiency of a G-APD / light catcher setup to detect Cherenkov light from air showers. We estimate a detection efficiency, which is 60% higher than the efficiency of a MAGIC camera pixel. Ambient temperature dark count rates of the tested G-APDs are below the rates of the night sky light background. According to these recent tests G-APDs promise a major progress in ground-based gamma-ray astronomy.

  14. SiPM and front-end electronics development for Cherenkov light detection

    CERN Document Server

    Ambrosi, G; Bissaldi, E; Ferri, A; Giordano, F; Gola, A; Ionica, M; Paoletti, R; Piemonte, C; Paternoster, G; Simone, D; Vagelli, V; Zappala, G; Zorzi, N

    2015-01-01

    The Italian Institute of Nuclear Physics (INFN) is involved in the development of a demonstrator for a SiPM-based camera for the Cherenkov Telescope Array (CTA) experiment, with a pixel size of 6$\\times$6 mm$^2$. The camera houses about two thousands electronics channels and is both light and compact. In this framework, a R&D program for the development of SiPMs suitable for Cherenkov light detection (so called NUV SiPMs) is ongoing. Different photosensors have been produced at Fondazione Bruno Kessler (FBK), with different micro-cell dimensions and fill factors, in different geometrical arrangements. At the same time, INFN is developing front-end electronics based on the waveform sampling technique optimized for the new NUV SiPM. Measurements on 1$\\times$1 mm$^2$, 3$\\times$3 mm$^2$, and 6$\\times$6 mm$^2$ NUV SiPMs coupled to the front-end electronics are presented

  15. Cherenkov TOF PET with silicon photomultipliers

    Science.gov (United States)

    Dolenec, R.; Korpar, S.; Križan, P.; Pestotnik, R.

    2015-12-01

    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.

  16. FEU-49 photomultiplier sensitivity to Cherenkov radiation

    International Nuclear Information System (INIS)

    With the aim of verifying the possibility of applying the FEU-19 photomultiplier in large installations for recording the Cherenkov radiation in water, the quantum sensitivity of four specimens of FEU-49 has been measured. The measurements are carried out at a maximum thickness of a distilled water layer equal to 4 cm. The Cherenkov radiation has been produced in water by cosmic muons. Presented are flowsheets used for measuring quantum efficiency of the FEU-49 photocathode and dispersion of its amplification coefficient. By comparing the results of measurements performed with the calculated estimates, a conclusion has been drawn on their good agreements and on suitability of FEU-49 for recording the Cherenkov radiation in water

  17. 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.

  18. 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.

  19. Measurement of the atmospheric muon flux with the ANTARES detector

    CERN Document Server

    Bazzotti, Marco

    2009-01-01

    ANTARES is a submarine neutrino telescope deployed in the Mediterranean Sea, at a depth of about 2500 m. It consists of a three-dimensional array of photomultiplier tubes that can detect the Cherenkov light induced by charged particles produced in the interactions of neutrinos with the surrounding medium. Down-going muons produced in atmospheric showers are a physical background to the neutrino detection, and are being studied. In this paper the measurement of the Depth Intensity Relation (DIR) of atmospheric muon flux is presented. The data collected in June and July 2007, when the ANTARES detector was in its 5-line configuration, are used in the analysis. The corresponding livetime is $724 h$. A deconvolution method based on a Bayesian approach was developed, which takes into account detector and reconstruction inefficiencies. Comparison with other experimental results and Monte Carlo expectations are presented and discussed.

  20. Flipping photons backward: reversed Cherenkov radiation

    Directory of Open Access Journals (Sweden)

    Hongsheng Chen

    2011-01-01

    Full Text Available Charged particles moving faster than light in a medium produce Cherenkov radiation. In traditional, positive index-of-refraction materials this radiation travels forward. Metamaterials, with negative indices of refraction, flip the radiation backward. This readily separates it from the particles, providing higher flexibility in photon manipulation and is useful for particle identification and counting. Here we review recent advances in reversed Cherenkov radiation research, including the first demonstration of backward emission. We also discuss the potential for developing new types of devices, such as ones that pierce invisibility cloaks.

  1. 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...... 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....

  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. All-fiber femtosecond Cherenkov radiation source

    OpenAIRE

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe; Tu, Haohua; Boppart, Stephen A.; Turchinovich, Dmitry

    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 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. ...

  4. All-fiber femtosecond Cherenkov source

    OpenAIRE

    Tu H.; Møller U.; Lægsgaard J.; Liu X.; Boppart S. A.; Turchinovich D.

    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 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 pra...

  5. A COMBINED VERY LARGE TELESCOPE AND GEMINI STUDY OF THE ATMOSPHERE OF THE DIRECTLY IMAGED PLANET, β PICTORIS b

    Energy Technology Data Exchange (ETDEWEB)

    Currie, Thayne; Jayawardhana, Ray [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street, Toronto, Ontario M5S 3H4 (Canada); Burrows, Adam [Department of Astrophysical Sciences, Princeton University, 4 Ivy Lane, Peyton Hall, Princeton, NJ 08544 (United States); Madhusudhan, Nikku [Department of Astronomy, Yale University, 260 Whitney Avenue, New Haven, CT 06511 (United States); Fukagawa, Misato [Osaka University, Machikaneyama 1-1, Toyonaka, Osaka 560-0043 (Japan); Girard, Julien H. [European Southern Observatory, Alonso de Cordova 3107, Vitacura, Cassilla 19001, Santiago (Chile); Dawson, Rebekah; Murray-Clay, Ruth; Kenyon, Scott [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 10, Cambridge, MA 02138 (United States); Kuchner, Marc [NASA-Goddard Space Flight Center, Exoplanets and Stellar Astrophysics Laboratory Code 667, Greenbelt, MD 20771 (United States); Matsumura, Soko [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Chambers, John [Department of Terrestrial Magnetism, Carnegie Institution of Washington, 5241 Broad Branch Road, NW Washington, DC 20015-1305 (United States); Bromley, Ben [Department of Physics, University of Utah, Salt Lake City, UT (United States)

    2013-10-10

    We analyze new/archival VLT/NaCo and Gemini/NICI high-contrast imaging of the young, self-luminous planet β Pictoris b in seven near-to-mid IR photometric filters, using advanced image processing methods to achieve high signal-to-noise, high precision measurements. While β Pic b's near-IR colors mimic those of a standard, cloudy early-to-mid L dwarf, it is overluminous in the mid-infrared compared to the field L/T dwarf sequence. Few substellar/planet-mass objects—i.e., κ And b and 1RXJ 1609B—match β Pic b's JHK{sub s}L' photometry and its 3.1 μm and 5 μm photometry are particularly difficult to reproduce. Atmosphere models adopting cloud prescriptions and large (∼60 μm) dust grains fail to reproduce the β Pic b spectrum. However, models incorporating thick clouds similar to those found for HR 8799 bcde, but also with small (a few microns) modal particle sizes, yield fits consistent with the data within the uncertainties. Assuming solar abundance models, thick clouds, and small dust particles ((a) = 4 μm), we derive atmosphere parameters of log (g) = 3.8 ± 0.2 and T{sub eff} = 1575-1650 K, an inferred mass of 7{sup +4}{sub -3} M{sub J} , and a luminosity of log(L/L{sub ☉}) ∼–3.80 ± 0.02. The best-estimated planet radius, ≈1.65 ± 0.06 R{sub J} , is near the upper end of allowable planet radii for hot-start models given the host star's age and likely reflects challenges constructing accurate atmospheric models. Alternatively, these radii are comfortably consistent with hot-start model predictions if β Pic b is younger than ≈7 Myr, consistent with a late formation well after its host star's birth ∼12{sup +8}{sub -4} Myr ago.

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

    CERN Document Server

    Krizmanic, John F

    2011-01-01

    Future space-based experiments, such as OWL and JEM-EUSO, view large atmospheric and terrestrial neutrino targets. With energy thresholds slightly above 10^19 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 nu_tau-induced Cherenkov airshower signal at above the OWL Cherenkov energy threshold of ~10^16.5 eV for limb-viewed events. Furthermore, the neutri...

  7. Progress on Cherenkov Reconstruction in MICE

    CERN Document Server

    Kaplan, Daniel M; Rajaram, Durga; Winter, Miles; Cremaldi, Lucien; Sanders, David; Summers, Don

    2016-01-01

    Two beamline Cherenkov detectors (Ckov-a,-b) support particle identification in the MICE beamline. Electrons and high-momentum muons and pions can be identified with good efficiency. We report on the Ckov-a,-b performance in detecting pions and muons with MICE Step I data and derive an upper limit on the pion contamination in the standard MICE muon beam.

  8. The PHENIX ring imaging Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Akiba, Y.; Begay, R.; Burwood-Hoy, J.; Chappell, R.B.; Crook, D.W.; Ebisu, K.; Emery, M.S.; Ferrierra, J.; Frawley, A.D.; Hamagaki, H.; Hara, H.; Hayano, R.S.; Hemmick, T.K.; Hibino, M.; Hutter, R.; Kennedy, M.; Kikuchi, J.; Matsumoto, T.; Moscone, G.G.; Nagasaka, Y.; Nishimura, S.; Oyama, K.; Sakaguchi, T.; Salomone, S.; Shigaki, K.; Tanaka, Y.; Walker, J.W.; Wintenberg, A.L.; Young, G.R

    2000-10-11

    The PHENIX experiment at RHIC is primarily a lepton and photon detector. Electron detection takes place in the two central arms of PHENIX, with the primary electron identifier in each arm being a ring imaging Cherenkov detector. This paper contains a description of the two identical RICH detectors and of their expected performance.

  9. Tachyonic Cherenkov radiation in the absorptive aether

    International Nuclear Information System (INIS)

    Dissipative tachyonic Cherenkov densities are derived and tested by performing a spectral fit to the γ-ray flux of supernova remnant (SNR) RX J1713.7 − 3946, measured over five frequency decades up to 100 TeV. The manifestly covariant formalism of tachyonic Maxwell–Proca radiation fields is developed in the spacetime aether, starting with the complex Lagrangian coupled to dispersive and dissipative permeability tensors. The spectral energy and flux densities of the radiation field are extracted by time averaging, the energy conservation law is derived, and the energy dissipation caused by the complex frequency-dependent permeabilities of the aether is quantified. The tachyonic mass-square in the field equations gives rise to transversally/longitudinally propagating flux components, with differing attenuation lengths determined by the imaginary part of the transversal/longitudinal dispersion relation. The spectral fit is performed with the classical tachyonic Cherenkov flux radiated by the shell-shocked electron plasma of SNR RX J1713.7 − 3946, exhibiting subexponential spectral decay. - Highlights: • Tachyonic Maxwell–Proca radiation fields in a dispersive and dissipative spacetime. • Transversal/longitudinal Poynting flux vector and associated spectral energy density. • Energy dissipation quantified by absorption term in the energy conservation law. • Dissipative Cherenkov densities (classical) and tachyonic attenuation lengths. • Cherenkov energy flux from the shocked electron plasma of SNR RX J1713.7 − 3946

  10. Neutrino telescopes

    CERN Document Server

    Carr, J

    2002-01-01

    This review presents the scientific objectives and status of Neutrino Telescope Projects. The science program of these projects covers: neutrino astronomy, dark matter searches and measurements of neutrino oscillations. The two neutrino telescopes in operation: AMANDA and BAIKAL will be described together with the ANTARES neutrino telescope being built in the Mediterranean. (18 refs).

  11. Detection of the Cherenkov light diffused by Sea Water with the ULTRA Experiment

    CERN Document Server

    Agnetta, G; Biondo, B; Brogueira, P; Cappa, A; Catalano, O; Chauvin, J; Staiti, G D'Ali'; Dattoli, M; Espirito-Santo, M C; Fava, L; Galeotti, P; Giarrusso, S; Gugliotta, G; La Rosa, G; Lebrun, D; Maccarone, M C; Mangano, A; Melo, L; Moreggia, S; Pimenta, M; Russo, F; Saavedra, O; Segreto, A; Silva, J C; Stassi, P; Tome', B; Vallania, P; Vigorito, C

    2007-01-01

    The study of Ultra High Energy Cosmic Rays represents one of the most challenging topic in the Cosmic Rays and in the Astroparticle Physics fields. The interaction of primary particles with atmospheric nuclei produces a huge Extensive Air Shower together with isotropic emission of UV fluorescence light and highly directional Cherenkov photons, that are reflected/diffused isotropically by the impact on the Earth's surface or on high optical depth clouds. For space-based observations, detecting the reflected Cherenkov signal in a delayed coincidence with the fluorescence light improves the accuracy of the shower reconstruction in space and in particular the measurement of the shower maximum, giving a strong signature for discriminating hadrons and neutrinos, and helping to estimate the primary chemical composition. Since the Earth's surface is mostly covered by water, the ULTRA (UV Light Transmission and Reflection in the Atmosphere)experiment has been designed to provide the diffusing properties of sea water, ...

  12. Indirect detection of dark matter with the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    The ANTANARES telescope is composed of an array of 900 photomultipliers (12 lines) that will be immersed in the Mediterranean sea at a depth of 2500 m. The photomultipliers are sensitive to the Cherenkov light emitted by high energy muons produced in the interactions of neutrinos with matter. My work consisted in the calibration of the detector, in time and charge in order to extract the crucial data for the reconstruction of the particle tracks and the ability of the detector to distinguish the atmospheric neutrinos from astrophysical neutrinos. The first part of this work is dedicated to the today understanding of the universe and of its models and of the importance of the neutrinos as the messengers of what occurs in the remote parts of the universe. The detection of neutrinos through the Cerenkov effect is detailed and the ANTANARES detector is presented. The second part deals with the study of the background radiation due to atmospheric muons and neutrinos. A simulation is the only tool to assess the background radiation level and to be able to extract the signal due to solar neutrinos. The third part shows how the solar neutrino flux might be influenced by the interaction of dark matter with baryonic matter. A Monte-Carlo simulation has allowed us to quantify this interaction and measure its impact on the number of events detected by ANTANARES. (A.C.)

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

    OpenAIRE

    Cecchini, S.; D'Antone, I; Esposti, L. Degli; 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 rays has motivated the development of new detection techniques. The properties of the Cherenkov photon pulse emitted in the atmosphere by these very rare particles indicate low-cost semiconductor detectors as good candidates for their optical read-out. The aim of this paper is to evaluate the viability of solar panels for this purpose. The experimental framework resulting from measurements performed with suitably-designe...

  14. Study of the atmospheric conditions at Cerro Armazones using astronomical data

    CERN Document Server

    Lakicevic, Masha; Noll, Stefan; Kausch, Wolfgang; Unterguggenberger, Stefanie; Kerber, Florian

    2016-01-01

    Aims: We studied the precipitable water vapour (PWV) content near Cerro Armazones and discuss the potential use of our technique of modelling the telluric absorbtion lines for the investigation of other molecular layers. The site is designated for the European Extremely Large Telescope (E-ELT) and the nearby planned site for the Cherenkov Telescope Array (CTA). Methods: Spectroscopic data from the Bochum Echelle Spectroscopic Observer (BESO) instrument were investigated by using line-by-line radiative transfer model (LBLRTM) radiative transfer models for the Earths atmosphere with the telluric absorption correction tool molecfit. All observations from the archive in the period from December 2008 to the end of 2014 were investigated. The dataset completely covers the El Nino event registered in the period 2009-2010. Models of the 3D Global Data Assimilation System (GDAS) were used for further comparison. Moreover, for those days with coincidence of data from a similar study with VLT/X-shooter and microwave rad...

  15. TRANSMISSION SPECTRA OF TRANSITING PLANET ATMOSPHERES: MODEL VALIDATION AND SIMULATIONS OF THE HOT NEPTUNE GJ 436b FOR THE JAMES WEBB SPACE TELESCOPE

    International Nuclear Information System (INIS)

    We explore the transmission spectrum of the Neptune-class exoplanet GJ 436b, including the possibility that its atmospheric opacity is dominated by a variety of nonequilibrium chemical products. We also validate our transmission code by demonstrating close agreement with analytic models that use only Rayleigh scattering or water vapor opacity. We find broad disagreement with radius variations predicted by another published model. For GJ 436b, the relative coolness of the planet's atmosphere, along with its implied high metallicity, may make it dissimilar in character compared to 'hot Jupiters'. Some recent observational and modeling efforts suggest low relative abundances of H2O and CH4 present in GJ 436b's atmosphere, compared to calculations from equilibrium chemistry. We include these characteristics in our models and examine the effects of absorption from methane-derived higher-order hydrocarbons. To our knowledge, the effects of these nonequilibrium chemical products on the spectra of close-in giant planets have not previously been investigated. Significant absorption from HCN and C2H2 is found throughout the infrared, while C2H4 and C2H6 are less easily seen. We perform detailed simulations of James Webb Space Telescope observations, including all likely noise sources, and find that we will be able to constrain chemical abundance regimes from this planet's transmission spectrum. For instance, the width of the features at 1.5, 3.3, and 7 μm indicates the amount of HCN versus C2H2 present. The NIRSpec prism mode will be useful due to its large spectral range and the relatively large number of photo-electrons recorded per spectral resolution element. However, extremely bright host stars like GJ 436 may be better observed with a higher spectroscopic resolution mode in order to avoid detector saturation. We find that observations with the MIRI low-resolution spectrograph should also have high signal-to-noise in the 5-10 μm range due to the brightness of the star

  16. The major upgrade of the MAGIC telescopes, Part II: A performance study using observations of the Crab Nebula

    Science.gov (United States)

    Aleksić, J.; Ansoldi, S.; Antonelli, L. A.; Antoranz, P.; Babic, A.; Bangale, P.; Barceló, M.; Barrio, J. A.; Becerra González, J.; Bednarek, W.; Bernardini, E.; Biasuzzi, B.; Biland, A.; Bitossi, M.; Blanch, O.; Bonnefoy, S.; Bonnoli, G.; Borracci, F.; Bretz, T.; Carmona, E.; Carosi, A.; Cecchi, R.; Colin, P.; Colombo, E.; Contreras, J. L.; Corti, D.; Cortina, J.; Covino, S.; Da Vela, P.; Dazzi, F.; De Angelis, A.; De Caneva, G.; De Lotto, B.; de Oña Wilhelmi, E.; Delgado Mendez, C.; Dettlaff, A.; Dominis Prester, D.; Dorner, D.; Doro, M.; Einecke, S.; Eisenacher, D.; Elsaesser, D.; Fidalgo, D.; Fink, D.; Fonseca, M. V.; Font, L.; Frantzen, K.; Fruck, C.; Galindo, D.; García López, R. J.; Garczarczyk, M.; Garrido Terrats, D.; Gaug, M.; Giavitto, G.; Godinović, N.; González Muñoz, A.; Gozzini, S. R.; Haberer, W.; Hadasch, D.; Hanabata, Y.; Hayashida, M.; Herrera, J.; Hildebrand, D.; Hose, J.; Hrupec, D.; Idec, W.; Illa, J. M.; Kadenius, V.; Kellermann, H.; Knoetig, M. L.; Kodani, K.; Konno, Y.; Krause, J.; Kubo, H.; Kushida, J.; La Barbera, A.; Lelas, D.; Lemus, J. L.; Lewandowska, N.; Lindfors, E.; Lombardi, S.; Longo, F.; López, M.; López-Coto, R.; López-Oramas, A.; Lorca, A.; Lorenz, E.; Lozano, I.; Makariev, M.; Mallot, K.; Maneva, G.; Mankuzhiyil, N.; Mannheim, K.; Maraschi, L.; Marcote, B.; Mariotti, M.; Martínez, M.; Mazin, D.; Menzel, U.; Miranda, J. M.; Mirzoyan, R.; Moralejo, A.; Munar-Adrover, P.; Nakajima, D.; Negrello, M.; Neustroev, V.; Niedzwiecki, A.; Nilsson, K.; Nishijima, K.; Noda, K.; Orito, R.; Overkemping, A.; Paiano, S.; Palatiello, M.; Paneque, D.; Paoletti, R.; Paredes, J. M.; Paredes-Fortuny, X.; Persic, M.; Poutanen, J.; Prada Moroni, P. G.; Prandini, E.; Puljak, I.; Reinthal, R.; Rhode, W.; Ribó, M.; Rico, J.; Rodriguez Garcia, J.; Rügamer, S.; Saito, T.; Saito, K.; Satalecka, K.; Scalzotto, V.; Scapin, V.; Schultz, C.; Schlammer, J.; Schmidl, S.; Schweizer, T.; Shore, S. N.; Sillanpää, A.; Sitarek, J.; Snidaric, I.; Sobczynska, D.; Spanier, F.; Stamerra, A.; Steinbring, T.; Storz, J.; Strzys, M.; Takalo, L.; Takami, H.; Tavecchio, F.; Tejedor, L. A.; Temnikov, P.; Terzić, T.; Tescaro, D.; Teshima, M.; Thaele, J.; Tibolla, O.; Torres, D. F.; Toyama, T.; Treves, A.; Vogler, P.; Wetteskind, H.; Will, M.; Zanin, R.

    2016-01-01

    MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a series of upgrades, involving the exchange of the MAGIC-I camera and its trigger system, as well as the upgrade of the readout system of both telescopes. We use observations of the Crab Nebula taken at low and medium zenith angles to assess the key performance parameters of the MAGIC stereo system. For low zenith angle observations, the standard trigger threshold of the MAGIC telescopes is ∼ 50 GeV. The integral sensitivity for point-like sources with Crab Nebula-like spectrum above 220 GeV is (0.66 ± 0.03)% of Crab Nebula flux in 50 h of observations. The angular resolution, defined as the σ of a 2-dimensional Gaussian distribution, at those energies is ≲ 0.07°, while the energy resolution is 16%. We also re-evaluate the effect of the systematic uncertainty on the data taken with the MAGIC telescopes after the upgrade. We estimate that the systematic uncertainties can be divided in the following components: < 15% in energy scale, 11%-18% in flux normalization and ± 0.15 for the energy spectrum power-law slope.

  17. The major upgrade of the MAGIC telescopes, Part II: The achieved physics performance using the Crab Nebula observations

    CERN Document Server

    Aleksic, J; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; Barcelo, M; Barrio, J A; Gonzalez, J Becerra; Bednarek, W; Bernardini, E; Biasuzzi, B; Biland, A; Bitossi, M; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Cecchi, R; Colin, P; Colombo, E; Contreras, J L; Corti, D; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; Wilhelmi, E de Ona; Mendez, C Delgado; Dettlaff, A; Prester, D Dominis; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Fidalgo, D; Fink, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; Galindo, D; Lopez, R J Garcia; Garczarczyk, M; Terrats, D Garrido; Gaug, M; Giavitto, G; Godinovic, N; Munoz, A Gonzalez; Gozzini, S R; Haberer, W; Hadasch, D; Hanabata, Y; Hayashida, M; Herrera, J; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Illa, J M; Kadenius, V; Kellermann, H; Knoetig, M L; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lemus, J L; Lewandowska, N; Lindfors, E; Lombardi, S; Longo, F; Lopez, M; Lopez-Coto, R; Lopez-Oramas, A; Lorca, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martinez, M; Mazin, D; Menzel, U; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Negrello, M; Neustroev, V; Niedzwiecki, A; Nilsson, K; Nishijima, K; Noda, K; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Persic, M; Poutanen, J; Moroni, P G Prada; Prandini, E; Puljak, I; Reinthal, R; Rhode, W; Ribo, M; Rico, J; Garcia, J Rodriguez; Rugamer, S; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schlammer, J; Schmidl, S; Schweizer, T; Shore, S N; Sillanpaa, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamerra, A; Steinbring, T; Storz, J; Strzys, M; Takalo, L; Takami, H; Tavecchio, F; Tejedor, L A; Temnikov, P; Terzic, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Vogler, P; Wetteskind, H; Will, M; Zanin, R; IFAE,; UAB, Campus; Bellaterra, E-08193; Spain,; di Udine, Universita; Trieste, INFN; Udine, I-33100; Italy,; Astrophysics, INAF National Institute for; Rome, I-00136; di Siena, Universita; Pisa, INFN; Siena, I-53100; Institute, Rudjer Boskovic; Rijeka, University of; Split, University of; Zagreb, HR-10000; Croatia,; Physik, Max-Planck-Institut fur; Munchen, D-80805; Germany,; Complutense, Universidad; Madrid, E-28040; de Canarias, Inst de Astrofisica; La Laguna, E-38200; Tenerife,; Lodz, University of; Lodz, PL-90236; Poland,; Elektronen-Synchrotron, Deutsches; Zeuthen, D-15738; Zurich, ETH; Zurich, CH-8093; Switzerland,; Wurzburg, Universitat; Wurzburg, D-97074; Energeticas, Centro de Investigaciones; Tecnologicas, Medioambientales y; Sciences, Institute of Space; Barcelona, E-08193; di Padova, Universita; INFN,; Padova, I-35131; Dortmund, Technische Universitat; Dortmund, D-44221; Radiacions, Unitat de Fisica de les; de Fisica, Departament; CERES-IEEC,; de Barcelona, Universitat Autonoma; de Barcelona, Universitat; ICC,; IEEC-UB,; Barcelona, E-08028; Physics, Division of; Astronomy,; University, Kyoto; Japan,; Observatory, Tuorla; Turku, University of; Physics, Department of; Oulu, University of; Finland,; Research, Inst for Nucl; Energy, Nucl; Sofia, BG-1784; Bulgaria,; di Pisa, Universita; Pisa, I-56126; ICREA,; Insubria, Universita dell; Bicocca, INFN Milano; Como,; Como, I-22100; Observatory, European Gravitational; Macerata, I-56021 S Stefano a; Siena, INFN; at, now; :,; Center, NASA Goddard Space Flight; Greenbelt,; 20771, MD; USA,; Physics, Department of; Astronomy, Department of; Maryland, University of; Park, College; 20742, MD; de Lausanne, now at Ecole polytechnique federale; Lausanne,; Teilchenphysik, Now at Institut fur Astro- und; Innsbruck, Leopold-Franzens- Universitat; Innsbruck, A-6020; Austria,; deceased,; ESO, now at Finnish Centre for Astronomy with; Turku,; Division, now at Astrophysics Science; Centre, Bhabha Atomic Research; 400085, Mumbai; India,; INAF-Trieste, also at

    2014-01-01

    MAGIC is a system of two Imaging Atmospheric Cherenkov Telescopes located in the Canary island of La Palma, Spain. During summer 2011 and 2012 it underwent a series of upgrades, involving the exchange of the MAGIC-I camera and its trigger system, as well as the upgrade of the readout system of both telescopes. We use observations of the Crab Nebula taken at low and medium zenith angles to assess the key performance parameters of the MAGIC stereo system. For low zenith observations the trigger threshold of the MAGIC telescopes is about 50GeV. The integral sensitivity for sources with Crab Nebula-like spectrum above 220GeV is (0.66+/-0.03)% of Crab Nebula flux in 50 h of observations. The angular resolution at those energies is < 0.07 degree, while the energy resolution is 16%. We also re-evaluate the effect of the systematic uncertainty on the data taken with the MAGIC telescopes after the upgrade. We estimate that the systematic uncertainties can be divided in following components: < 15% in energy scale...

  18. A new solution for mirror coating in $\\gamma$-ray Cherenkov Astronomy

    OpenAIRE

    Bonardi, Antonio; Pühlhofer, Gerd; Hermanutz, Stephan; Santangelo, Andrea

    2014-01-01

    In the $\\gamma$-ray Cherenkov Astronomy framework mirror coating plays a crucial role in defining the light response of the telescope. We carried out a study for new mirror coating solutions with both a numerical simulation software and a vacuum chamber for small sample production. In this article, we present a new mirror coating solution consisting of a 28-layer interferometric SiO$_{2}$-TiO$_{2}$-HfO$_{2}$ design deposited on a glass substrate, whose average reflectance is above $90\\%$ for ...

  19. A new solution for mirror coating in $\\gamma$-ray Cherenkov Astronomy

    CERN Document Server

    Bonardi, Antonio; Hermanutz, Stephan; Santangelo, Andrea

    2014-01-01

    In the $\\gamma$-ray Cherenkov Astronomy framework mirror coating plays a crucial role in defining the light response of the telescope. We carried out a study for new mirror coating solutions with both a numerical simulation software and a vacuum chamber for small sample production. In this article, we present a new mirror coating solution consisting of a 28-layer interferometric SiO$_{2}$-TiO$_{2}$-HfO$_{2}$ design deposited on a glass substrate, whose average reflectance is above $90\\%$ for normally incident light in the wavelength range between 300 and 550 nm.

  20. The optical module of the Baikal Deep underwater neutrino telescope

    CERN Document Server

    Bagduev, R I; Belolaptikov, I A; Bezrukov, L B; Budnev, N M; Borisovets, B A; Domogatsky, G V; Donskych, L A; Doroshenko, A A; Garus, A A; Golikov, A V; Gluchovskoj, B M; Heller, R; Kabikov, V B; Khripunova, M P; Klabukov, A M; Klimushin, S I; Koshechkin, A P; Kuzmichov, L A; Lisovski, G V; Lubsandorzhiev, B K; Mikolajski, T; Osipova, E A; Pokhil, P G; Pokolev, P A; Putilov, P A; Spiering, C; Stepanenko, Z I; Streicher, O; Thon, T; Vorobev, A A; Wischnewski, R

    1999-01-01

    A deep underwater Cherenkov telescope has been operating since 1993 in stages of growing size at 1.1 km depth in Lake Baikal. The key component of the telescope is the Optical Module (OM) which houses the highly sensitive phototube QUASAR-370. We describe design and parameters of the QUASAR-370, the layout of the optical module, the front-end electronics and the calibration procedures, and present selected results from the five-year operation underwater. Also, future developments with respect to a telescope consisting from several thousand OMs are discussed.