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Sample records for celeste cherenkov telescope

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

    CERN Document Server

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

    2002-01-01

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

  2. 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

  3. FACT. Bokeh alignment for Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  4. Calibration strategies for the Cherenkov Telescope Array

    NARCIS (Netherlands)

    Gaug, M.; Berge, D.; Daniel, M.; Doro, M.; Förster, A.; Hofmann, W.; Maccarone, M.C.; Parsons, D.; de los Reyes Lopez, R.; van Eldik, C.

    2014-01-01

    The Central Calibration Facilities workpackage of the Cherenkov Telescope Array (CTA) observatory for very high energy gamma ray astronomy defines the overall calibration strategy of the array, develops dedicated hardware and software for the overall array calibration and coordinates the calibration

  5. Muon imaging of volcanoes with Cherenkov telescopes

    Science.gov (United States)

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

    2017-04-01

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

  6. An effective model for fermion dark matter. Indirect detection of supersymmetric dark matter in astronomy with the CELESTE Telescope; Modele effectif de matiere noire fermionique. Detection indirecte de matiere noir supersymetrique en astronomie avec le Telescope CELESTE

    Energy Technology Data Exchange (ETDEWEB)

    Lavalle, Julien [Ecole Doctorale des Sciences Fondamentales, Universite Blaise Pascal, Aubiere (France)

    2004-07-01

    The purpose of this thesis is to discuss both phenomenological and experimental aspects of Dark Matter, related to its indirect detection with gamma-ray astronomy. In the MSSM framework, neutralinos arise as natural candidates to non-baryonic and Cold Dark Matter, whose gravitational effects manifest in the Universe at different scales. As they are Majorana particles, they may in principle annihilate in high density regions, as the centres of galaxies, and produce gamma rays. Nevertheless, the expected fluxes are basically low compared to experimental sensitivities. After estimating gamma fluxes from M31 and Draco galaxies in the MSSM scheme, we first generalize the MSSM couplings by studying an effective Lagrangian. We show that the only constraint of imposing a relic abundance compatible with recent measurements obviously deplete significantly the gamma ray production, but also that predictions in this effective approach are more optimistic for indirect detection than the MSSM. In a second part, we present the indirect searches for Dark Matter performed with the CELESTE Cherenkov telescope towards the galaxy M31. We propose a statistical method to reconstruct spectra, mandatory to discriminate classical and exotic spectra. The M31 data analysis enables the extraction of an upper limit on the gamma ray flux, which is the first worldwide for a galaxy in the energy range 50-500 GeV, and whose astrophysical interest goes beyond indirect searches for Dark Matter. (author)

  7. Basic model of fermion dark matter. Indirect detection of supersymmetric dark matter in {gamma} astronomy with the CELESTE telescope; Modele effectif de matiere noire fermionique. Detection indirecte de matiere noire supersymetrique en astronomie {gamma} avec le telescope CELESTE

    Energy Technology Data Exchange (ETDEWEB)

    Lavalle, J

    2004-10-15

    The purpose of this thesis is to discuss both phenomenological and experimental aspects of Dark Matter, related to its indirect detection with gamma-ray astronomy. In the MSSM (Minimal Supersymmetric Standard Model) framework, neutralinos arise as natural candidates to non-baryonic and Cold Dark Matter, whose gravitational effects manifest in the Universe at different scales. As they are Majorana particles, they may in principle annihilate in high density regions, as the centres of galaxies, and produce gamma rays. Nevertheless, the expected fluxes are basically low compared to experimental sensitivities. After estimating gamma fluxes from M31 and Draco galaxies in the MSSM scheme, we first generalize the MSSM couplings by studying an effective Lagrangian. We show that the only constraint of imposing a relic abundance compatible with recent measurements obviously deplete significantly the gamma ray production, but also that predictions in this effective approach are more optimistic for indirect detection than the MSSM. In a second part, we present the indirect searches for Dark Matter performed with the CELESTE Cherenkov telescope towards the galaxy M31. We propose a statistical method to reconstruct spectra, mandatory to discriminate classical and exotic spectra. The M31 data analysis enables the extraction of an upper limit on the gamma ray flux, which is the first worldwide for a galaxy in the energy range 50-500 GeV, and whose astrophysical interest goes beyond indirect searches for Dark Matter. (author)

  8. Volcanoes muon imaging using Cherenkov telescopes

    International Nuclear Information System (INIS)

    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.

  9. Volcanoes muon imaging using Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-21

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

  10. An effective model for fermion dark matter. Indirect detection of supersymmetric dark matter in astronomy with the CELESTE Telescope

    International Nuclear Information System (INIS)

    Lavalle, Julien

    2004-01-01

    The purpose of this thesis is to discuss both phenomenological and experimental aspects of Dark Matter, related to its indirect detection with gamma-ray astronomy. In the MSSM framework, neutralinos arise as natural candidates to non-baryonic and Cold Dark Matter, whose gravitational effects manifest in the Universe at different scales. As they are Majorana particles, they may in principle annihilate in high density regions, as the centres of galaxies, and produce gamma rays. Nevertheless, the expected fluxes are basically low compared to experimental sensitivities. After estimating gamma fluxes from M31 and Draco galaxies in the MSSM scheme, we first generalize the MSSM couplings by studying an effective Lagrangian. We show that the only constraint of imposing a relic abundance compatible with recent measurements obviously deplete significantly the gamma ray production, but also that predictions in this effective approach are more optimistic for indirect detection than the MSSM. In a second part, we present the indirect searches for Dark Matter performed with the CELESTE Cherenkov telescope towards the galaxy M31. We propose a statistical method to reconstruct spectra, mandatory to discriminate classical and exotic spectra. The M31 data analysis enables the extraction of an upper limit on the gamma ray flux, which is the first worldwide for a galaxy in the energy range 50-500 GeV, and whose astrophysical interest goes beyond indirect searches for Dark Matter. (author)

  11. Basic model of fermion dark matter. Indirect detection of supersymmetric dark matter in γ astronomy with the CELESTE telescope

    International Nuclear Information System (INIS)

    Lavalle, J.

    2004-10-01

    The purpose of this thesis is to discuss both phenomenological and experimental aspects of Dark Matter, related to its indirect detection with gamma-ray astronomy. In the MSSM (Minimal Supersymmetric Standard Model) framework, neutralinos arise as natural candidates to non-baryonic and Cold Dark Matter, whose gravitational effects manifest in the Universe at different scales. As they are Majorana particles, they may in principle annihilate in high density regions, as the centres of galaxies, and produce gamma rays. Nevertheless, the expected fluxes are basically low compared to experimental sensitivities. After estimating gamma fluxes from M31 and Draco galaxies in the MSSM scheme, we first generalize the MSSM couplings by studying an effective Lagrangian. We show that the only constraint of imposing a relic abundance compatible with recent measurements obviously deplete significantly the gamma ray production, but also that predictions in this effective approach are more optimistic for indirect detection than the MSSM. In a second part, we present the indirect searches for Dark Matter performed with the CELESTE Cherenkov telescope towards the galaxy M31. We propose a statistical method to reconstruct spectra, mandatory to discriminate classical and exotic spectra. The M31 data analysis enables the extraction of an upper limit on the gamma ray flux, which is the first worldwide for a galaxy in the energy range 50-500 GeV, and whose astrophysical interest goes beyond indirect searches for Dark Matter. (author)

  12. Calibration strategies for the Cherenkov Telescope Array

    Science.gov (United States)

    Gaug, Markus; Berge, David; Daniel, Michael; Doro, Michele; Förster, Andreas; Hofmann, Werner; Maccarone, Maria C.; Parsons, Dan; de los Reyes Lopez, Raquel; van Eldik, Christopher

    2014-08-01

    The Central Calibration Facilities workpackage of the Cherenkov Telescope Array (CTA) observatory for very high energy gamma ray astronomy defines the overall calibration strategy of the array, develops dedicated hardware and software for the overall array calibration and coordinates the calibration efforts of the different telescopes. The latter include LED-based light pulsers, and various methods and instruments to achieve a calibration of the overall optical throughput. On the array level, methods for the inter-telescope calibration and the absolute calibration of the entire observatory are being developed. Additionally, the atmosphere above the telescopes, used as a calorimeter, will be monitored constantly with state-of-the-art instruments to obtain a full molecular and aerosol profile up to the stratosphere. The aim is to provide a maximal uncertainty of 10% on the reconstructed energy-scale, obtained through various independent methods. Different types of LIDAR in combination with all-sky-cameras will provide the observatory with an online, intelligent scheduling system, which, if the sky is partially covered by clouds, gives preference to sources observable under good atmospheric conditions. Wide-field optical telescopes and Raman Lidars will provide online information about the height-resolved atmospheric extinction, throughout the field-of-view of the cameras, allowing for the correction of the reconstructed energy of each gamma-ray event. The aim is to maximize the duty cycle of the observatory, in terms of usable data, while reducing the dead time introduced by calibration activities to an absolute minimum.

  13. The TACTIC atmospheric Cherenkov imaging telescope

    International Nuclear Information System (INIS)

    Koul, R.; Tickoo, A.K.; 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.; Bhattacharyya, S.; Sahayanathan, S.

    2007-01-01

    The TACTIC (TeV Atomospheric Cherenkov Telescope with Imaging Camera) γ-ray telescope, equipped with a light collector of area ∼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 two-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 11x11 pixels (∼3.4 a tx3.4 a t), the telescope records a cosmic ray event rate of ∼2.5Hz at a typical zenith angle of 15 a t. Monte Carlo simulation results are also presented in the paper for comparing the expected performance of the telescope with actual observational results. The consistent detection of a steady signal from the Crab Nebula above ∼1.2TeV energy, at a sensitivity level of ∼5.0σ in ∼25h, along with excellent matching of its energy spectrum with that obtained by other groups, reassures that the performance of the TACTIC telescope is quite stable and reliable. Furthermore, encouraged by the detection of strong γ-ray signals from Mrk 501 (during 1997 and 2006 observations) and Mrk 421 (during 2001 and 2005-2006 observations), we believe that there is considerable scope for the TACTIC telescope to monitor similar TeV γ-ray emission activity from other active galactic nuclei on a long-term basis

  14. 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.

  15. Looking inside volcanoes with the Imaging Atmospheric Cherenkov Telescopes

    Science.gov (United States)

    Del Santo, M.; Catalano, O.; Cusumano, G.; La Parola, V.; La Rosa, G.; Maccarone, M. C.; Mineo, T.; Sottile, G.; Carbone, D.; Zuccarello, L.; Pareschi, G.; Vercellone, S.

    2017-12-01

    Cherenkov light is emitted when charged particles travel through a dielectric medium with velocity higher than the speed of light in the medium. The ground-based Imaging Atmospheric Cherenkov Telescopes (IACT), dedicated to the very-high energy γ-ray Astrophysics, are based on the detection of the Cherenkov light produced by relativistic charged particles in a shower induced by TeV photons interacting with the Earth atmosphere. Usually, an IACT consists of a large segmented mirror which reflects the Cherenkov light onto an array of sensors, placed at the focal plane, equipped by fast electronics. Cherenkov light from muons is imaged by an IACT as a ring, when muon hits the mirror, or as an arc when the impact point is outside the mirror. The Cherenkov ring pattern contains information necessary to assess both direction and energy of the incident muon. Taking advantage of the muon detection capability of IACTs, we present a new application of the Cherenkov technique that can be used to perform the muon radiography of volcanoes. The quantitative understanding of the inner structure of a volcano is a key-point to monitor the stages of the volcano activity, to forecast the next eruptive style and, eventually, to mitigate volcanic hazards. Muon radiography shares the same principle as X-ray radiography: muons are attenuated by higher density regions inside the target so that, by measuring the differential attenuation of the muon flux along different directions, it is possible to determine the density distribution of the interior of a volcano. To date, muon imaging of volcanic structures has been mainly achieved with detectors made up of scintillator planes. The advantage of using Cherenkov telescopes is that they are negligibly affected by background noise and allow a consistently improved spatial resolution when compared to the majority of the current detectors.

  16. Mirror position determination for the alignment of Cherenkov Telescopes

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-07-11

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

  17. The GCT camera for the Cherenkov Telescope Array

    Science.gov (United States)

    Lapington, J. S.; Abchiche, A.; Allan, D.; Amans, J.-P.; Armstrong, T. P.; Balzer, A.; Berge, D.; Boisson, C.; Bousquet, J.-J.; Bose, R.; Brown, A. M.; Bryan, M.; Buchholtz, G.; Buckley, J.; Chadwick, P. M.; Costantini, H.; Cotter, G.; Daniel, M. K.; De Franco, A.; De Frondat, F.; Dournaux, J.-L.; Dumas, D.; Ernenwein, J.-P.; Fasola, G.; Funk, S.; Gironnet, J.; Graham, J. A.; Greenshaw, T.; Hervet, O.; Hidaka, N.; Hinton, J. A.; Huet, J.-M.; Jankowsky, D.; Jegouzo, I.; Jogler, T.; Kawashima, T.; Kraus, M.; Laporte, P.; Leach, S.; Lefaucheur, J.; Markoff, S.; Melse, T.; Minaya, I. A.; Mohrmann, L.; Molyneux, P.; Moore, P.; Nolan, S. J.; Okumura, A.; Osborne, J. P.; Parsons, R. D.; Rosen, S.; Ross, D.; Rowell, G.; Rulten, C. B.; 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.; Varner, G.; Vink, J.; Watson, J. J.; White, R.; Yamane, N.; Zech, A.; Zink, A.; Zorn, J.; CTA Consortium

    2017-12-01

    The Gamma Cherenkov Telescope (GCT) is one of the designs proposed for the Small Sized Telescope (SST) section of the Cherenkov Telescope Array (CTA). The GCT uses dual-mirror optics, resulting in a compact telescope with good image quality and a large field of view with a smaller, more economical, camera than is achievable with conventional single mirror solutions. The photon counting 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 GCT optics require that the camera detectors follow a convex surface with a radius of curvature of 1 m and a diameter of 35 cm, which is approximated by tiling the focal plane with 32 modules. The first camera prototype is equipped with multi-anode photomultipliers, each comprising an 8×8 array of 6×6 mm2 pixels to provide the required angular scale, adding up to 2048 pixels in total. Detector signals are shaped, amplified and digitised by electronics based on custom ASICs that provide digitisation at 1 GSample/s. The camera is self-triggering, retaining images where the focal plane light distribution matches predefined spatial and temporal criteria. The electronics are housed in the liquid-cooled, sealed camera enclosure. LED flashers at the corners of the focal plane provide a calibration source via reflection from the secondary mirror. The first GCT camera prototype underwent preliminary laboratory tests last year. In November 2015, the camera was installed on a prototype GCT telescope (SST-GATE) in Paris and was used to successfully record the first Cherenkov light of any CTA prototype, and the first Cherenkov light seen with such a dual-mirror optical system. A second full-camera prototype based on Silicon Photomultipliers is under construction. Up to 35 GCTs are envisaged for CTA.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-02-11

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

  20. Wavelet imaging cleaning method for atmospheric Cherenkov telescopes

    Science.gov (United States)

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

    2002-07-01

    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 accurate reconstruction, especially at lower gamma-ray energies that produce low levels of light. We present the results of Monte Carlo simulations of gamma-ray and hadronic air showers which show improved angular resolution using this cleaning procedure. Data from the Whipple Observatory's 10-m telescope are utilized to show the efficacy of the method for extracting a gamma-ray signal from the background of hadronic generated images.

  1. 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 ...

  2. The Atmospheric Monitoring Strategy for the Cherenkov Telescope Array

    Science.gov (United States)

    Daniel, M. K.; CTA Consortium

    2015-04-01

    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 (23 m), Medium (12 m) and Small (4 m) sized telescopes spread over an area of order ~km2. 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 the candidate sites and the atmospheric calibration strategy. CTA will utilise a suite of instrumentation and analysis techniques for atmospheric modelling and monitoring regarding pointing forecasts, intelligent pointing selection for the observatory operations and for offline data correction.

  3. 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.

  4. Ground-based gamma-ray astronomy with Cherenkov telescopes

    International Nuclear Information System (INIS)

    Hinton, Jim

    2009-01-01

    Very high-energy (>100 GeV) γ-ray astronomy is emerging as an important discipline in both high-energy astrophysics and astro-particle physics. This field is currently dominated by imaging atmospheric-Cherenkov telescopes (IACTs) and arrays of these telescopes. Such arrays have achieved the best angular resolution and energy flux sensitivity in the γ-ray domain and are still far from the fundamental limits of the technique. Here, I will summarize some key aspects of this technique and go on to review the current status of the major instruments and to highlight selected recent results.

  5. The first telescope of the HEGRA air Cherenkov imaging telescope array

    International Nuclear Information System (INIS)

    Mirzoyan, R.; Kankanian, R.; Krennrich, F.; Mueller, N.; Sander, H.; Sawallisch, P.; Aharonian, F.; Akhperjanian, A.; Beglarian, A.; Fernandez, J.; Fonseca, V.; Grewe, W.; Heusler, A.; Konopelko, A.K.; Lorenz, E.; Merck, M.; Plyasheshnikov, A.V.; Renker, D.; Samorski, M.; Sauerland, K.; Smarsch, E.; Stamm, W.; Ulrich, M.; Wiedner, C.A.; Wirth, H.

    1994-01-01

    In search of VHE γ ray emission from cosmic point sources a system of imaging Cherenkov telescopes is constructed at present on the Canarian island of La Palma; the first telescope has been operational since 1992. The Cherenkov light from air shower particles is collected by a 5 m 2 reflector. The camera at the focus contains 37 photomultipliers which sample the images of the Cherenkov flashes. The subsequent image analysis allows the discrimination of γ ray induced events from the much more abundant charged cosmic ray induced showers. The telescope has an effective energy threshold for γ showers of about 1.5 TeV. During the first year of operation a signal from the Crab nebula was detected. ((orig.))

  6. NECTAR: New electronics for the Cherenkov Telescope Array

    Science.gov (United States)

    Naumann, Christopher Lindsay; Bolmont, J.; Corona, P.; Delagnes, E.; Dzahini, D.; Feinstein, F.; Gascon, D.; Glicenstein, J.-F.; Nayman, P.; Rarbi, F.; Ribo, M.; Sanuy, A.; Siero, X.; Tavernet, J.-P.; Toussenel, F.; Vincent, P.; Vorobiov, S.

    2012-12-01

    The international CTA consortium is currently in the preparatory phase for the development of the next-generation Cherenkov Telescope Array (CTA [1]), based on the return of experience from the three major current-generation arrays H.E.S.S., MAGIC and VERITAS. To achieve an unprecedented sensitivity and energy range for TeV gamma rays, a new kind of flexible and powerful yet inexpensive front-end hardware will be required for the order of 105 channels of photodetectors in up to 100 telescopes. One possible solution is the NECTAr (New Electronics for the Cherenkov Telescope Array) system, based on the integration of as much as possible of the front-end electronics (amplifiers, fast analogue samplers, memory and ADCs) into a single ASIC for very fast readout performance and a significant reduction of the cost and the lower consumption per channel, while offering a high degree of flexibility both for the triggering and the readout of the telescope. The current status of its development is presented, along with newest results from measurements and simulation studies.

  7. 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...

  8. Pattern recognition trigger electronics for an imaging atmospheric Cherenkov telescope

    International Nuclear Information System (INIS)

    Bradbury, S.M.; Rose, H.J.

    2002-01-01

    For imaging atmospheric Cherenkov telescopes, which aim to detect electromagnetic air showers with cameras consisting of several hundred photomultiplier pixels, the single pixel trigger rate is dominated by fluctuations in night sky brightness and by ion feedback in the photomultipliers. Pattern recognition trigger electronics may be used to reject night sky background images, thus reducing the data rate to a manageable level. The trigger system described here detects patterns of 2, 3 or 4 adjacent pixel signals within a 331 pixel camera and gives a positive trigger decision in 65 ns. The candidate pixel pattern is compared with the contents of a pre-programmed memory. With the trigger decision timing controlled by a fixed delay the time-jitter inherent in the use of programmable gate arrays is avoided. This system is now in routine operation at the Whipple 10 m Telescope

  9. Gamma ray astronomy with atmospheric Cherenkov telescopes: the future

    International Nuclear Information System (INIS)

    Krennrich, Frank

    2009-01-01

    Atmospheric Cherenkov telescopes have been key to the recent discoveries in teraelectronvolt (TeV) γ-ray astronomy. The detection of TeV γ rays from more than 90 galactic and extragalactic sources provides a wealth of data for probing physical phenomena that pertain to some of the big questions in astrophysics. These include the understanding of the origin of cosmic rays, unveiling the connection between relativistic jets and black holes, shedding light on dark matter and its relation to supersymmetric particles and estimating the brightness of cosmological diffuse radiation fields in the optical/infrared waveband. While these recent advances were made with instruments designed in the 1990s, the present paper is concerned with a next generation of imaging atmospheric Cherenkov telescopes (IACTs) that are currently in the conceptual planning stage. We discuss the basic ideas, the required technology and expected performance of a ≥1 square-kilometer array, which is poised to yield the most dramatic step yet to come in TeV astronomy.

  10. NECTAr: New electronics for the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    Vorobiov, S.; Bolmont, J.; Corona, P.; Delagnes, E.; Feinstein, F.; Gascon, D.; Glicenstein, J.-F.; Naumann, C.L.; Nayman, P.; Sanuy, A.; Toussenel, F.; Vincent, P.

    2011-01-01

    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.

  11. NECTAr: New electronics for the Cherenkov Telescope Array

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-05-21

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

  12. 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...

  13. 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.

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

    Science.gov (United States)

    Naumann, C. L.; Delagnes, E.; Bolmont, J.; Corona, P.; Dzahini, D.; Feinstein, F.; Gascón, D.; Glicenstein, J.-F.; Guilloux, F.; Nayman, P.; Rarbi, F.; Sanuy, A.; Tavernet, J.-P.; Toussenel, F.; Vincent, P.; Vorobiov, S.

    2012-12-01

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

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

    International Nuclear Information System (INIS)

    Naumann, C.L.; Delagnes, E.; Bolmont, J.; Corona, P.; Dzahini, D.; Feinstein, F.; Gascón, D.; Glicenstein, J.-F.; Guilloux, F.; Nayman, P.; Rarbi, F.; Sanuy, A.; Tavernet, J.-P.; Toussenel, F.; Vincent, P.; Vorobiov, S.

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-12-11

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

  17. Time and charge calibration of Cherenkov telescope data acquired by Domino Ring Sampler 4 chips

    Energy Technology Data Exchange (ETDEWEB)

    Hoerbe, Mario; Doert, Marlene [Ruhr-Universitaet Bochum (Germany); Bruegge, Kai; Buss, Jens; Bockermann, Christian; Egorov, Alexej [TU Dortmund (Germany)

    2016-07-01

    Very-high-energy gamma-ray astronomy aims to give an insight into the most energetic phenomena in our Universe. Earthbound Cherenkov telescopes can measure Cherenkov light emitted by atmospheric particle showers which are produced by incoming cosmic particles at high energies. Current Cherenkov telescopes, e.g. operated in the FACT and the MAGIC experiments, utilize Domino Ring Sampler 4 (DRS4) chips for recording signals at high speed coming from the telescopes' cameras. DRS4 chips will also be used in the cameras of the Large-Size telescopes of the projected Cherenkov Telescope Array (CTA). We aim at developing a software solution for the calibration of DRS4 data based on the streams-framework, a software tool for streaming analysis which has been developed within the Collaborative Research Center SFB 876. The objectives and the current status of the project are presented.

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

    Science.gov (United States)

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

    2017-01-01

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

  19. 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.

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

    Science.gov (United States)

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

    2016-08-01

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

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

    CERN Document Server

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

    2016-01-01

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

  2. A G-APD based Camera for Imaging Atmospheric Cherenkov Telescopes

    International Nuclear Information System (INIS)

    Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, S.; Commichau, V.; Dorner, D.; Gendotti, A.; Grimm, O.; Gunten, H. von; Hildebrand, D.; Horisberger, U.; Koehne, J.-H.; Kraehenbuehl, T.; Kranich, D.; Lorenz, E.; Lustermann, W.; Mannheim, K.

    2011-01-01

    Imaging Atmospheric Cherenkov Telescopes (IACT) for Gamma-ray astronomy are presently using photomultiplier tubes as photo sensors. Geiger-mode avalanche photodiodes (G-APD) promise an improvement in sensitivity and, important for this application, ease of construction, operation and ruggedness. G-APDs have proven many of their features in the laboratory, but a qualified assessment of their performance in an IACT camera is best undertaken with a prototype. This paper describes the design and construction of a full-scale camera based on G-APDs realized within the FACT project (First G-APD Cherenkov Telescope).

  3. Information and Communications Technology (ICT) Infrastructure for the ASTRI SST-2M telescope prototype for the Cherenkov Telescope Array

    Science.gov (United States)

    Gianotti, F.; Tacchini, A.; Leto, G.; Martinetti, E.; Bruno, P.; Bellassai, G.; Conforti, V.; Gallozzi, S.; Mastropietro, M.; Tanci, C.; Malaguti, G.; Trifoglio, M.

    2016-08-01

    The Cherenkov Telescope Array (CTA) represents the next generation of ground-based observatories for very high energy gamma-ray astronomy. The CTA will consist of two arrays at two different sites, one in the northern and one in the southern hemisphere. The current CTA design foresees, in the southern site, the installation of many tens of imaging atmospheric Cherenkov telescopes of three different classes, namely large, medium and small, so defined in relation to their mirror area; the northern hemisphere array would consist of few tens of the two larger telescope types. The Italian National Institute for Astrophysics (INAF) is developing the Cherenkov Small Size Telescope ASTRI SST- 2M end-to-end prototype telescope within the framework of the International Cherenkov Telescope Array (CTA) project. The ASTRI prototype has been installed at the INAF observing station located in Serra La Nave on Mt. Etna, Italy. Furthermore a mini-array, composed of nine of ASTRI telescopes, has been proposed to be installed at the Southern CTA site. Among the several different infrastructures belonging the ASTRI project, the Information and Communication Technology (ICT) equipment is dedicated to operations of computing and data storage, as well as the control of the entire telescope, and it is designed to achieve the maximum efficiency for all performance requirements. Thus a complete and stand-alone computer centre has been designed and implemented. The goal is to obtain optimal ICT equipment, with an adequate level of redundancy, that might be scaled up for the ASTRI mini-array, taking into account the necessary control, monitor and alarm system requirements. In this contribution we present the ICT equipment currently installed at the Serra La Nave observing station where the ASTRI SST-2M prototype will be operated. The computer centre and the control room are described with particular emphasis on the Local Area Network scheme, the computing and data storage system, and the

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

    CERN Document Server

    Ostankov, A P

    2001-01-01

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

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

    Science.gov (United States)

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

    2016-08-01

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

  6. On the possiblity of using vertically pointing Central Laser Facilities to calibrate the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    Gaug, Markus

    2014-01-01

    A Central Laser Facility is a system composed of a laser placed at a certain distance from a light-detector array, emitting fast light pulses, typically in the vertical direction, with the aim to calibrate that array. During calibration runs, all detectors are pointed towards the same portion of the laser beam at a given altitude. Central Laser Facilities are used for various currently operating ultra-high-energy cosmic ray and imaging atmospheric Cherenkov telescope arrays. In view of the future Cherenkov Telescope Array, a similar device could provide a fast calibration of the whole installation at different wavelengths. The relative precision (i.e. each individual telescope with respect to the rest of the array is expected) to be better than 5%, while an absolute calibration should reach a precisions of 6–11%, if certain design requirements are met. Additionally, a preciser monitoring of the sensitivity of each telescope can be made on time-scales of days to years

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

    Directory of Open Access Journals (Sweden)

    Bissaldi E.

    2017-01-01

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

  8. Simulated gamma-ray pulse profile of the Crab pulsar with the Cherenkov Telescope Array

    Science.gov (United States)

    Burtovoi, A.; Zampieri, L.

    2016-07-01

    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 Major Atmospheric Gamma-Ray Imaging Cherenkov (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 (Astrofisica con Specchi a Tecnologia Replicante Italiana) 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 h). 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. 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. Performance of a fast low noise front-end preamplifier for the MAGIC imaging Cherenkov telescope

    International Nuclear Information System (INIS)

    Blanch, O.; Blanchot, G.; Bosman, M.

    1999-01-01

    The observation of high energy cosmic gamma rays with an energy threshold of 15 GeV using the proposed MAGIC ground based air imaging Cherenkov telescope requires the development of new low noise fast preamplifiers for the camera photosensors. The speed and noise performance of a transimpedance preamplifier that resolves the multi photoelectron peaks from a hybrid photomultiplier with a peaking time below 7 ns is presented. The new front-end circuit is designed with RF low noise bipolar transistors and provides fast output pulses that allow for fast trigger settings

  10. Using Deep Learning for Gamma Ray Source Detection at the First G-APD Cherenkov Telescope (FACT)

    Science.gov (United States)

    Bieker, Jacob

    2018-06-01

    Finding gamma-ray sources is of paramount importance for Imaging Air Cherenkov Telescopes (IACT). This study looks at using deep neural networks on data from the First G-APD Cherenkov Telescope (FACT) as a proof-of-concept of finding gamma-ray sources with deep learning for the upcoming Cherenkov Telescope Array (CTA). In this study, FACT’s individual photon level observation data from the last 5 years was used with convolutional neural networks to determine if one or more sources were present. The neural networks used various architectures to determine which architectures were most successful in finding sources. Neural networks offer a promising method for finding faint and extended gamma-ray sources for IACTs. With further improvement and modifications, they offer a compelling method for source detection for the next generation of IACTs.

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

    Science.gov (United States)

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

    2017-10-01

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

  12. 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...

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

    International Nuclear Information System (INIS)

    Chen, Y.T.; La Taille, C. de; 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.

    2015-01-01

    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

  14. Studies on a silicon-photomultiplier-based camera for Imaging Atmospheric Cherenkov Telescopes

    Science.gov (United States)

    Arcaro, C.; Corti, D.; De Angelis, A.; Doro, M.; Manea, C.; Mariotti, M.; Rando, R.; Reichardt, I.; Tescaro, D.

    2017-12-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) represent a class of instruments which are dedicated to the ground-based observation of cosmic VHE gamma ray emission based on the detection of the Cherenkov radiation produced in the interaction of gamma rays with the Earth atmosphere. One of the key elements of such instruments is a pixelized focal-plane camera consisting of photodetectors. To date, photomultiplier tubes (PMTs) have been the common choice given their high photon detection efficiency (PDE) and fast time response. Recently, silicon photomultipliers (SiPMs) are emerging as an alternative. This rapidly evolving technology has strong potential to become superior to that based on PMTs in terms of PDE, which would further improve the sensitivity of IACTs, and see a price reduction per square millimeter of detector area. We are working to develop a SiPM-based module for the focal-plane cameras of the MAGIC telescopes to probe this technology for IACTs with large focal plane cameras of an area of few square meters. We will describe the solutions we are exploring in order to balance a competitive performance with a minimal impact on the overall MAGIC camera design using ray tracing simulations. We further present a comparative study of the overall light throughput based on Monte Carlo simulations and considering the properties of the major hardware elements of an IACT.

  15. 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.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  17. CTA-A project for a new generation of Cherenkov telescopes

    International Nuclear Information System (INIS)

    Doro, Michele

    2011-01-01

    Gamma-rays provide a powerful insight into the non-thermal universe and perhaps a unique probe for new physics beyond the standard model. Current experiments are already giving results in the physics of acceleration of cosmic rays in supernova remnants, pulsar and active galactic nuclei with a 100 sources detected at very-high-energies so far. Despite its relatively recent appearance, very high-energy gamma-ray astronomy has proven to have reached a mature technology with fast assembling, relatively cheap and reliable telescopes. The goal of future installation is to increase the sensitivity by a factor 10 compared to current installations, and enlarge the energy domain from few 10s of GeV to a 100 TeV. Gamma-ray spectra of astrophysical origin are rather soft thus hardly one single size telescope can cover more than 1.5 decades in energy, therefore an array of telescopes of 2-3 different sizes is required. Hereafter, we present design considerations for a Cherenkov Telescope Array (CTA), a project for a new generation of highly automated telescopes for gamma-ray astronomy. The status of the project, technical solutions and an insight in the involved physics will be presented.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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.

  19. 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.

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

    Science.gov (United States)

    Brown, Anthony M.

    2018-01-01

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

  1. NECTAr0, a new high speed digitizer ASIC for the Cherenkov telescope array

    International Nuclear Information System (INIS)

    Delagnes, E.; Glicenstein, J.F.; Guilloux, F.; Bolmont, J.; Corona, P.; Naumann, C.L.; Nayman, P.; Tavemet, J.P.; Toussenel, F.; Vincent, P.; Dzahini, D.; Rarbi, F.; Feinstein, F.; Vorobiov, S.; Gascon, D.; Sanuy, A.

    2011-01-01

    H.E.S.S. and MAGIC experiments have demonstrated the high level of maturity of Imaging Atmospheric Cherenkov Telescopes (IACTs) dedicated to very-high-energy gamma ray astronomy domain. The astro-particle physics community is preparing the next generation of instruments, with sensitivity improved by an order of magnitude in the 10 GeV to 100 TeV range. To reach this goal, the Cherenkov Telescope Array (CTA) will consist in an array of 50-100 dishes of various sizes and various spacing, each equipped with a camera, made of few thousands fast photo-detectors and its associated front-end electronics. The total number of electronics channels will be larger than 100,000 to be compared to the total of 6,000 channels of the 5-telescopes H.E.S.S.-I H.E.S.S.-II array. To decrease the overall CTA cost, a consequent effort should be done to lower the cost of the electronics while keeping performance at least as good as the one demonstrated on the current experiments and simplifying its maintenance. This will be allowed by mass production, use of standardized modules and integration of front-end functions in ASICs. The 3-year NECTAr program started in 2009 addresses these two topics. Its final aim is to develop and test a demonstrator module of a generic CTA camera. The paper is mainly focused on one of the main components of this module, the NECTAr ASIC which samples the photo-detector signal in a circular analog memory at several GSPS and digitizes it over 12 bits after having received an external trigger. (authors)

  2. The ASTRI SST-2M prototype for the Cherenkov Telescope Array: prototype technologies goals and strategies for the future SST

    Science.gov (United States)

    Marchiori, Gianpietro; Busatta, Andrea; Giacomel, Stefano; Folla, Ivan; Valsecchi, Marco; Canestrari, Rodolfo; Bonnoli, Giacomo; Cascone, Enrico; Conconi, Paolo; Fiorini, Mauro; Giro, Enrico; La Palombara, Nicola; Pareschi, Giovanni; Perri, Luca; Rodeghiero, Gabriele; Sironi, Giorgia; Stringhetti, Luca; Toso, Giorgio; Tosti, Gino; Pellicciari, Carlo

    2014-07-01

    The Cherenkov Telescope Array (CTA) observatory will represent the next generation of Imaging Atmospheric Cherenkov Telescope. Using a combination of large-, medium-, and small-scale telescopes (LST, MST, SST, respectively), it will explore the Very High Energy domain from a few tens of GeVup to about few hundreds of TeV with unprecedented sensitivity, angular resolution and imaging quality. In this framework, the Italian ASTRI program, led by the Italian National Institute of Astrophysics (INAF) developed a 4-meter class telescope, which will adopt an aplanatic, wide-field, double-reflection optical layout in a Schwarzschild- Couder configuration. Within this program INAF assigned to the consortium between Galbiati Group and EIE Group the construction, assembly and tests activities of the prototype named ASTRI SST-2M. On the basis of the lesson learnt from the prototype, other telescopes will be produced, starting from a re-design phase, in order to optimize performances and the overall costs and production schedule for the CTA-SST telescope. This paper will firstly give an overview of the concept for the SST prototype mount structure. In this contest, the technologies adopted for the design, manufacturing and tests of the entire system will be presented. Moreover, a specific focus on the challenges of the prototype and the strategies associated with it will be provided, in order to outline the near future performance goals for this type of Cherenkov telescopes employed for Gamma ray science.

  3. UPPER LIMITS FROM FIVE YEARS OF BLAZAR OBSERVATIONS WITH THE VERITAS CHERENKOV TELESCOPES

    Energy Technology Data Exchange (ETDEWEB)

    Archambault, S. [Physics Department, McGill University, Montreal, QC H3A 2T8 (Canada); Archer, A.; Buckley, J. H.; Bugaev, V. [Department of Physics, Washington University, St. Louis, MO 63130 (United States); Benbow, W.; Cerruti, M. [Fred Lawrence Whipple Observatory, Harvard-Smithsonian Center for Astrophysics, Amado, AZ 85645 (United States); Bird, R. [School of Physics, University College Dublin, Belfield, Dublin 4 (Ireland); Biteau, J. [Santa Cruz Institute for Particle Physics and Department of Physics, University of California, Santa Cruz, CA 95064 (United States); Buchovecky, M. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Byrum, K. [Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Chen, X. [Institute of Physics and Astronomy, University of Potsdam, D-14476 Potsdam-Golm (Germany); Ciupik, L. [Astronomy Department, Adler Planetarium and Astronomy Museum, Chicago, IL 60605 (United States); Connolly, M. P. [School of Physics, National University of Ireland Galway, University Road, Galway (Ireland); Cui, W.; Feng, Q.; Finley, J. P. [Department of Physics and Astronomy, Purdue University, West Lafayette, IN 47907 (United States); Eisch, J. D. [Department of Physics and Astronomy, Iowa State University, Ames, IA 50011 (United States); Errando, M. [Department of Physics and Astronomy, Barnard College, Columbia University, NY 10027 (United States); Falcone, A. [Department of Astronomy and Astrophysics, 525 Davey Lab, Pennsylvania State University, University Park, PA 16802 (United States); Fleischhack, H., E-mail: wystan.benbow@cfa.harvard.edu, E-mail: matteo.cerruti@lpnhe.in2p3.fr, E-mail: caajohns@ucsc.edu [DESY, Platanenallee 6, D-15738 Zeuthen (Germany); Collaboration: VERITAS collaboration; and others

    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 4 σ excess.

  4. 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...

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

    CERN Multimedia

    CERN. Geneva

    2012-01-01

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

  6. UPPER LIMITS FROM FIVE YEARS OF BLAZAR OBSERVATIONS WITH THE VERITAS CHERENKOV TELESCOPES

    International Nuclear Information System (INIS)

    Archambault, S.; Archer, A.; Buckley, J. H.; Bugaev, V.; Benbow, W.; Cerruti, M.; Bird, R.; Biteau, J.; Buchovecky, M.; Byrum, K.; Chen, X.; Ciupik, L.; Connolly, M. P.; Cui, W.; Feng, Q.; Finley, J. P.; Eisch, J. D.; Errando, M.; Falcone, A.; Fleischhack, H.

    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) 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 4 σ excess.

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

    Science.gov (United States)

    Sironi, Giorgia

    2017-09-01

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

  8. A generalized ray-tracing procedure for an atmospheric Cherenkov imaging telescope and optical characteristics of the TACTIC light collector

    International Nuclear Information System (INIS)

    Tickoo, A.K.; Suthar, R.L.; Koul, R.; Sapru, M.L.; Kumar, N.; Kaul, C.L.; Yadav, K.K.; Thoudam, S.; Kaul, S.K.; Venugopal, K.; Kothari, M.; Goyal, H.C.; Chandra, P.; Dhar, V.K.; Rannot, R.C.; Koul, M.K.; Kaul, S.R.

    2005-01-01

    A generalized ray-tracing procedure has been developed, which facilitates the design of a multimirror-based light collector used in atmospheric Cherenkov telescopes. This procedure has been employed to study the optical characteristics of the 3.5 m diameter light collector of the TACTIC Imaging telescope. Comparison of the measured point-spread function of the light collector with the simulated performance of ideal Davies-Cotton and paraboloid designs has been made to determine an optimum arrangement of the 34 spherical mirror facets used in the telescope to obtain the best possible point-spread function. A description of the ray-tracing subroutine used for processing CORSIKA-generated Cherenkov data, required for carrying out Monte-Carlo simulation studies, is also discussed in the paper

  9. 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.

  10. 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.

  11. Characterization and commissioning of the SST-1M camera for the Cherenkov Telescope Array

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar, J.A. [Université Libre Bruxelles, Faculté des Sciences, Avenue Franklin Roosevelt 50, 1050 Brussels (Belgium); DPNC - Université de Genéve, 24 Quai Ernest Ansermet, Genéve (Switzerland); Department of Information Technologies, Jagiellonian University, ul. prof. Stanisława Łojasiewicza 11, 30–348 Kraków (Poland); Bilnik, W. [AGH University of Science and Technology, al.Mickiewicza 30, Kraków (Poland); Department of Information Technologies, Jagiellonian University, ul. prof. Stanisława Łojasiewicza 11, 30–348 Kraków (Poland); Błocki, J. [Instytut Fizyki Jadrowej im. H. Niewodniczańskiego Polskiej Akademii Nauk, ul. Radzikowskiego 152, 31–342 Kraków (Poland); Department of Information Technologies, Jagiellonian University, ul. prof. Stanisława Łojasiewicza 11, 30–348 Kraków (Poland); Bogacz, L. [Astronomical Observatory, Jagiellonian University, ul. Orla 171, 30–244 Kraków (Poland); Department of Information Technologies, Jagiellonian University, ul. prof. Stanisława Łojasiewicza 11, 30–348 Kraków (Poland); and others

    2017-02-11

    The Cherenkov Telescope Array (CTA), the next generation very high energy gamma-rays observatory, will consist of three types of telescopes: large (LST), medium (MST) and small (SST) size telescopes. The SSTs are dedicated to the observation of gamma-rays with energy between a few TeV and a few hundreds of TeV. The SST array is expected to have 70 telescopes of different designs. The single-mirror small size telescope (SST-1 M) is one of the proposed telescope designs under consideration for the SST array. It will be equipped with a 4 m diameter segmented mirror dish and with an innovative camera based on silicon photomultipliers (SiPMs). The challenge is not only to build a telescope with exceptional performance but to do it foreseeing its mass production. To address both of these challenges, the camera adopts innovative solutions both for the optical system and readout. The Photo-Detection Plane (PDP) of the camera is composed of 1296 pixels, each made of a hollow, hexagonal light guide coupled to a hexagonal SiPM designed by the University of Geneva and Hamamatsu. As no commercial ASIC would satisfy the CTA requirements when coupled to such a large sensor, dedicated preamplifier electronics have been designed. The readout electronics also use an innovative approach in gamma-ray astronomy by adopting a fully digital approach. All signals coming from the PDP are digitized in a 250 MHz Fast ADC and stored in ring buffers waiting for a trigger decision to send them to the pre-processing server where calibration and higher level triggers will decide whether the data are stored. The latest generation of FPGAs is used to achieve high data rates and also to exploit all the flexibility of the system. As an example each event can be flagged according to its trigger pattern. All of these features have been demonstrated in laboratory measurements on realistic elements and the results of these measurements will be presented in this contribution.

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

    International Nuclear Information System (INIS)

    Mirzoyan, R.

    2000-01-01

    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

  13. Gamma astronomy above 30 GeV. A new method for identifying cosmic gamma rays from the ground based detector Celeste; Astronomie gamma au-dessus de 30 GeV. Une nouvelle methode d'identification des rayons gamma cosmiques a partir du sol avec le detecteur CELESTE

    Energy Technology Data Exchange (ETDEWEB)

    Manseri, H

    2004-03-15

    Celeste is an atmospheric Cherenkov telescope based on the reconversion of the Themis solar facility, located in the Eastern Pyrenees. The mirrors, named heliostats, recover the Cherenkov light emitted by the electromagnetic shower created by gamma-rays in the atmosphere. The Celeste experiment was designed during the 90's to cover the 30-300 GeV energy range and to fill the gap between satellites and imaging atmospheric Cherenkov telescopes. In 2000, we attained our goal with the detection of the Crab Nebula and those of the active galactic nucleus Markarian 421. This thesis presents the work accomplished since then to improve the sensitivity of our instrument by studying the detector and by developing a new analysis. Despite the very bad weather conditions, a new detection of the Crab Nebula is presented here which validates the principle of the new analysis. This manuscript ends with the study of the data sample taken on two Active Galactic Nuclei, the blazars Markarian 421 and 1ES1426+428. (author)

  14. The development of simulation and atmospheric shower reconstruction tools for the study of future Cherenkov Imaging telescopes

    International Nuclear Information System (INIS)

    Sajjad, S.

    2007-09-01

    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)

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

    International Nuclear Information System (INIS)

    Arrabito, L; Bregeon, J; 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 system prototype has been developed, based on the two main DIRAC components, i.e. the Workload Management and Data Management Systems. After three years of successful exploitation of this prototype, for simulations and analysis, we proved that DIRAC provides suitable functionalities needed for the CTA data processing. Based on these results, the CTA development plan aims to achieve an operational production system, based on the DIRAC Workload Management System, to be ready for the start of CTA operation phase in 2017-2018. One more important challenge consists of the development of a fully automatized execution of the CTA workflows. For this purpose, we have identified a third DIRAC component, the so-called Transformation System, which offers very interesting functionalities to achieve this automatisation. The Transformation System is a ’data-driven’ system, allowing to automatically trigger data-processing and data management operations according to pre

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

    International Nuclear Information System (INIS)

    Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, S.; Commichau, V.; Domke, M.; Dorner, D.; Gendotti, A.; Grimm, O.; Gunten, H. von; Hildebrand, D.; Horisberger, U.; Koehne, J.-H.; Kraehenbuehl, T.; Kranich, D.; Krumm, B.; Lorenz, E.

    2011-01-01

    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.

  17. 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.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-11

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

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

    Directory of Open Access Journals (Sweden)

    Vercellone Stefano

    2016-01-01

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

  20. FACT - Status and experience from five years of operation of the first G-APD Cherenkov Telescope

    Science.gov (United States)

    Neise, D.; Adam, J.; Ahnen, M. L.; Baack, D.; Balbo, M.; Bergmann, M.; Biland, A.; Blank, M.; Bretz, T.; Brügge, K. A.; Buss, J.; Dmytriiev, A.; Dorner, D.; Einecke, S.; Hempfling, C.; Hildebrand, D.; Hughes, G.; Linhoff, L.; Mannheim, K.; Müller, S.; Neronov, A.; Nöthe, M.; Paravac, A.; Pauss, F.; Rhode, W.; Shukla, A.; Temme, F.; Thaele, J.; Walter, R.

    2017-12-01

    The First G-APD Cherenkov Telescope (FACT) demonstrates the usability of novel Geiger-mode operated Avalanche Photo Diodes (G-APD, often called SiPM) for Imaging Atmospheric Cherenkov Telescopes (IACT). The camera consists of 1440 pixels with dedicated electronics operating at 2 Giga samples per second. It is installed on the refurbished HEGRA telescope with a mirror area of ≈ 9.5m2 on the Canary Island La Palma. FACT is taking data almost every night since the camera was installed in October 2011. It was possible to improve the data taking efficiency to very high values due to the very stable and reliable operation. This also allows to operate FACT remotely without any need for operators on site. Even remote human intervention became less and less frequent over the years, allowing operation to become mostly automatic. FACT is monitoring the long-term behavior of some very-high energy variable extra-galactic sources with unparalleled sampling density as well as testing the behavior of the sensors under severe weather conditions. Due to the long exposure of FACT's G-APDs under strong moonlight conditions it was possible to evaluate the aging effects of G-APDs due to collected charge. No indication of aging was found. No external calibration device is needed to operate FACT since the properties of the sensors themselves allow for a high precision self-calibration of the camera.

  1. Electronics for the camera of the First G-APD Cherenkov Telescope (FACT) for ground based gamma-ray astronomy

    International Nuclear Information System (INIS)

    Anderhub, H; Biland, A; Boller, A; Braun, I; Commichau, V; Djambazov, L; Dorner, D; Gendotti, A; Grimm, O; Gunten, H P von; Hildebrand, D; Horisberger, U; Huber, B; Kim, K-S; Krähenbühl, T; Backes, M; Köhne, J-H; Krumm, B; Bretz, T; Farnier, C

    2012-01-01

    Within the FACT project, we construct a new type of camera based on Geiger-mode avalanche photodiodes (G-APDs). Compared to photomultipliers, G-APDs are more robust, need a lower operation voltage and have the potential of higher photon-detection efficiency and lower cost, but were never fully tested in the harsh environments of Cherenkov telescopes. The FACT camera consists of 1440 G-APD pixels and readout channels, based on the DRS4 (Domino Ring Sampler) analog pipeline chip and commercial Ethernet components. Preamplifiers, trigger system, digitization, slow control and power converters are integrated into the camera.

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

    Energy Technology Data Exchange (ETDEWEB)

    Sánchez-Conde, Miguel A. [SLAC National Laboratory and Kavli Institute for Particle Astrophysics and Cosmology, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Cannoni, Mirco; Gómez, Mario E. [Dpto. Física Aplicada, Facultad de Ciencias Experimentales, Universidad de Huelva, 21071 Huelva (Spain); Zandanel, Fabio; Prada, Francisco, E-mail: masc@stanford.edu, E-mail: mirco.cannoni@dfa.uhu.es, E-mail: fabio@iaa.es, E-mail: mario.gomez@dfa.uhu.es, E-mail: fprada@iaa.es [Instituto de Astrofísica de Andalucía (CSIC), E-18008, Granada (Spain)

    2011-12-01

    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

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

    International Nuclear Information System (INIS)

    Naumann, C L; Tejedor, L A; Martínez, G

    2013-01-01

    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.

  4. 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

  5. 5@5 - A 5 GeV Energy Threshold Array of Imaging Atmospheric Cherenkov Telescopes at 5 km Altitude

    Science.gov (United States)

    Aharonian, F. A.; Konopelko, A. K.; Voelk, H. J.; Quintana, H.

    2000-10-01

    We discuss the concept and the performance of 5@5 - a stereoscopic array of several large imaging atmospheric Cherenkov telescopes installed at a very high mountain elevation of about 5 km a.s.l. or more - for the study of the gamma-ray sky at energies from several GeV to 100 GeV. With its capability to detect the ``standard'' EGRET sources with spectra extending up to 10 GeV in exposure times from 1 to 103 seconds, such a detector may serve as an ideal "Gamma-Ray Timing Explorer" for the study of transient non-thermal phenomena like gamma-radiation from AGN jets, synchrotron flares of microquasars, the high energy (GeV) counterparts of Gamma Ray Bursts, etc. Such an instrument would also allow detailed studies of the spectral characteristics of persistent gamma-ray sources like pulsars, supernova remnants, plerions, radiogalaxies, etc, in the energy region between 10 GeV and 100 GeV, where the capabilities of both the current space-based and ground-based gamma-ray projects are quite limited. The existing technological achievements in the design and construction of multi (1000) pixel, high resolution imagers, as well as of large, 20 m diameter class multi-mirror dishes with rather modest optical requirements, would allow the construction of the "5@5" in a foreseeable future. The Llano de Chajnantor (or the neighboring Cerro Toco) in the Atacama desert of Northern Chile seems an ideal site for such a ``post - CANGAROO/H.E.S.S./MAGIC/VERITAS'' era ground-based gamma-ray detector. The large flat area of that site, which was recently chosen for the installation of one of the most powerful future astronomical instruments - the Atacama Large Millimeter Array (ALMA) - could accomodate also an additional Cherenkov telescope array which requires a relatively compact area with a radius of about 100 m.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  7. 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.

  8. 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.

  9. Prospects for PWNe and SNRs science with the ASTRI mini-array of pre-production small-sized telescopes of the Cherenkov telescope array

    Science.gov (United States)

    Burtovoi, A.; Zampieri, L.; Giuliani, A.; Bigongiari, C.; Di Pierro, F.; Stamerra, A.

    2017-01-01

    The development and construction of the Cherenkov Telescope Array (CTA) opens up new opportunities for the study of very high energy (VHE, E > 100 GeV) sources. As a part of CTA, the ASTRI project, led by INAF, has one of the main goals to develop one of the mini-arrays of CTA pre-production telescopes, proposed to be installed at the CTA southern site. Thanks to the innovative dual-mirror optical design of its small-sized telescopes, the ASTRI mini-array will be characterized by a large field of view, an excellent angular resolution and a good sensitivity up to energies of several tens of TeV. Pulsar wind nebulae, along with Supernova Remnants, are among the most abundant sources that will be identified and investigated, with the ultimate goal to move significantly closer to an understanding of the origin of cosmic rays (CR). As part of the ongoing effort to investigate the scientific capabilities for both CTA as a whole and the ASTRI mini-array, we performed simulations of the Vela X region. We simulated its extended VHE γ-ray emission using the results of the detailed H.E.S.S. analysis of this source. We estimated the resolving capabilities of the diffuse emission and the detection significance of the pulsar with both CTA as a whole and the ASTRI mini-array. Moreover with these instruments it will be possible to observe the high-energy end of SNRs spectrum, searching for particles with energies near the cosmic-rays "knee" (E ˜ 1015 eV). We simulated a set of ASTRI mini-array observations for one young and an evolved SNRs in order to test the capabilities of this instrument to discover and study PeVatrons on the Galactic plane.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-10

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

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

    International Nuclear Information System (INIS)

    Badran, H.M.

    2004-01-01

    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

  12. Searching for gamma-ray counterparts to gravitational waves from merging binary neutron stars with the Cherenkov Telescope Array

    Science.gov (United States)

    Patricelli, B.; Stamerra, A.; Razzano, M.; Pian, E.; Cella, G.

    2018-05-01

    The merger of binary neutron star (BNS) systems are predicted to be progenitors of short gamma-ray bursts (GRBs); the definitive probe of this association came with the recent detection of gravitational waves (GWs) from a BNS merger by Advanced LIGO and Advanced Virgo (GW170817), in coincidence with the short GRB 170817A observed by Fermi-GBM and INTEGRAL. Short GRBs are also expected to emit very-high energy (VHE, > 10S0 GeV) photons and VHE electromagnetic (EM) upper limits have been set with observations performed by ground-based gamma-ray detectors and during the intense EM follow-up campaign associated with GW170817/GRB 170817A. In the next years, the searches for VHE EM counterparts will become more effective thanks to the Cherenkov Telescope Array (CTA): this instrument will be fundamental for the EM follow-up of transient GW events at VHE, owing to its unprecedented sensitivity, rapid response (few tens of seconds) and capability to monitor large sky areas via survey-mode operation. We present a comprehensive study on the prospects for joint GW and VHE EM observations of merging BNSs with Advanced LIGO, Advanced Virgo and CTA, based on detailed simulations of the multi-messenger emission and detection. We propose a new observational strategy optimized on the prior assumptions about the EM emission. The method can be further generalized to include other electromagnetic emission models. According to this study CTA will cover most of the region of the GW skymap for the intermediate and most energetic on-axis GRBs associated to the GW event. We estimate the expected joint GW and VHE EM detection rates and we found this rate goes from 0.08 up to 0.5 events per year for the most energetic EM sources.

  13. Cherenkov water detector NEVOD

    Science.gov (United States)

    Petrukhin, A. A.

    2015-05-01

    A unique multipurpose Cherenkov water detector, the NEVOD facility, uses quasispherical measuring modules to explore all the basic components of cosmic rays on Earth's surface, including neutrinos. Currently, the experimental complex includes the Cherenkov water detector, a calibration telescope system, and a coordinate detector. This paper traces the basic development stages of NEVOD, examines research directions, presents the results obtained, including the search for the solution to the 'muon puzzle', and discusses possible future development prospects.

  14. Characterization of EASIROC as front-end for the readout of the SiPM at the focal plane of the Cherenkov telescope ASTRI

    International Nuclear Information System (INIS)

    Impiombato, D.; Giarrusso, S.; 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

  15. Software design and code generation for the engineering graphical user interface of the ASTRI SST-2M prototype for the Cherenkov Telescope Array

    Science.gov (United States)

    Tanci, Claudio; Tosti, Gino; Antolini, Elisa; Gambini, Giorgio F.; Bruno, Pietro; Canestrari, Rodolfo; Conforti, Vito; Lombardi, Saverio; Russo, Federico; Sangiorgi, Pierluca; Scuderi, Salvatore

    2016-08-01

    ASTRI is an on-going project developed in the framework of the Cherenkov Telescope Array (CTA). An end- to-end prototype of a dual-mirror small-size telescope (SST-2M) has been installed at the INAF observing station on Mt. Etna, Italy. The next step is the development of the ASTRI mini-array composed of nine ASTRI SST-2M telescopes proposed to be installed at the CTA southern site. The ASTRI mini-array is a collaborative and international effort carried on by Italy, Brazil and South-Africa and led by the Italian National Institute of Astrophysics, INAF. To control the ASTRI telescopes, a specific ASTRI Mini-Array Software System (MASS) was designed using a scalable and distributed architecture to monitor all the hardware devices for the telescopes. Using code generation we built automatically from the ASTRI Interface Control Documents a set of communication libraries and extensive Graphical User Interfaces that provide full access to the capabilities offered by the telescope hardware subsystems for testing and maintenance. Leveraging these generated libraries and components we then implemented a human designed, integrated, Engineering GUI for MASS to perform the verification of the whole prototype and test shared services such as the alarms, configurations, control systems, and scientific on-line outcomes. In our experience the use of code generation dramatically reduced the amount of effort in development, integration and testing of the more basic software components and resulted in a fast software release life cycle. This approach could be valuable for the whole CTA project, characterized by a large diversity of hardware components.

  16. Method of separation of air showers initiated by γ-quanta and protons using Cherenkov light angular characteristics in combination and angular resolution estimate for an array of several optical telescopes

    International Nuclear Information System (INIS)

    Anokhina, A.M.; Galkin, V.I.; Ivanenko, I.P.; Roganova, T.M.

    1990-01-01

    Computer simulation of optical characteristics of air showers was carried out. On the basis of multidimensional analysis of Cherenkov light angular distribution possibility is considered to distinguish γ-showers from proton showers. Also an estimate for angular resolution is given for an array of five optical telescopes situated at Mt.Aragats. 7 refs.; 10 figs.; 11 tabs

  17. Study of the photon flux from the night sky at La Palma and Namibia, in the wavelength region relevant for imaging atmospheric Cherenkov telescopes

    International Nuclear Information System (INIS)

    Preuss, S.; Hermann, G.; Hofmann, W.; Kohnle, A.

    2002-01-01

    The level of the night-sky background light at La Palma and Namibia was determined, with emphasis on the wavelength region and solid angle coverage relevant for the operation of imaging atmospheric Cherenkov telescopes. The dependence of the night-sky background light both on celestial coordinates (alt,az) and on galactic coordinates (b,l) was measured, with an angular resolution of about 1 deg. Average light levels near the zenith are similar in both locations -2.2x10 12 -2.6x10 12 photons sr -1 s -1 m -2 for 300 nm<λ<650 nm. With increasing zenith angle the level of background light increases at La Palma, whereas a constant level is measured in Namibia. Near the center of the Milky Way, background light levels are increased by a factor up to 4 and more. Also the level of light backscattered from the ground has been studied

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

  19. Wideband pulse amplifier with 8 GHz GBW product in a 0.35 μm CMOS technology for the integrated camera of the Cherenkov Telescope Array

    International Nuclear Information System (INIS)

    Gascon, D; Sanuy, A; Ribo, M; Delagnes, E; Glicenstein, J-F; Sieiro, X; Feinstein, F; Vorobiov, S; Nayman, P; Toussenel, F; Tavernet, J-P; Vincent, P

    2010-01-01

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

  20. Characterization of a 6×6-mm{sup 2} 75-μm cell MPPC suitable for the Cherenkov Telescope Array project

    Energy Technology Data Exchange (ETDEWEB)

    Romeo, G., E-mail: giuseppe.romeo@oact.inaf.it [INAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy); Bonanno, G.; Garozzo, S.; Grillo, A.; Marano, D.; Munari, M.; Timpanaro, M.C. [INAF, Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95123 Catania (Italy); Catalano, O.; Giarrusso, S.; Impiombato, D.; La Rosa, G.; Sottile, G. [INAF, Istituto di Astrofisica Spaziale e Fisica cosmica di Palermo, Via U. La Malfa 153, I-90146 Palermo (Italy)

    2016-08-01

    This paper presents the latest characterization results of a novel Low Cross-Talk (LCT) large-area (6×6-mm{sup 2}) 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-mm{sup 2} 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-mm{sup 2} MPPC response versus the angle of incidence are provided for the characterized device.

  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)

    Allekotte, I.; Arnaldi, H.; Asorey, H.; Gomez Berisso, M.; Sofo Haro, M.; Cillis, A.; Rovero, A.C.; Supanitsky, A.D.; Actis, M.; Antico, F.; Bottani, A.; Ochoa, I.; Ringegni, P.; Vallejo, G.; De La Vega, G.; Etchegoyen, A.; Videla, M.; Gonzalez, F.; Pallota, J.; Quel, E.; Ristori, P.; Romero, G.E.; Suarez, A.; Papyan, G.; Pogosyan, L.; Sahakian, V.; Bissaldi, E.; Egberts, K.; Reimer, A.; Reimer, O.; Shellard, R.C.; Santos, E.M.; De Gouveia Dal Pino, E.M.; Kowal, G.; De Souza, V.; Todero Peixoto, C.J.; Maneva, G.; Temnikov, P.; Vankov, H.; Golev, V.; Ovcharov, E.; Bonev, T.; Dimitrov, D.; Hrupec, D.; Nedbal, D.; Rob, L.; Sillanpaa, A.; Takalo, L.; Beckmann, V.; Benallou, M.; Boutonnet, C.; Corlier, M.; Courty, B.; Djannati-Atai, A.; Dufour, C.; Gabici, S.; Guglielmi, L.; Olivetto, C.; Pita, S.; Punch, M.; Selmane, S.; Terrier, R.; Yoffo, B.; Brun, P.; Carton, P.H.; Cazaux, S.; Corpace, O.; Delagnes, E.; Disset, G.; Durand, D.; Glicenstein, J.F.; Guilloux, F.; Kosack, K.; Medina, C.; Micolon, P.; Mirabel, F.; Moulin, E.; Peyaud, B.; Reymond, J.M.; Veyssiere, C.

    2011-01-01

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

    Opitz, Bjoern Helmut Bastian

    2014-06-01

    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 cm 3 s -1 to left angle σν right angle UL ∝10 -25 cm 3 s -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.

  3. Real-time data acquisition and control system for the 349-pixel TACTIC atmospheric Cherenkov imaging telescope

    Energy Technology Data Exchange (ETDEWEB)

    Yadav, K.K.; Koul, R.; Kanda, A.; Kaul, S.R.; Tickoo, A.K. E-mail: aktickoo@apsara.barc.ernet.in; Rannot, R.C.; Chandra, P.; Bhatt, N.; Chouhan, N.; Venugopal, K.; Kothari, M.; Goyal, H.C.; Dhar, V.K.; Kaul, S.K

    2004-07-21

    An interrupt-based multinode data acquisition and control system has been developed for the imaging element of the TACTIC {gamma}-ray telescope. The system which has been designed around a 3-node network of PCs running the QNX real-time operating system, provides single-point control with elaborate GUI facilities for operating the multi-pixel camera of the telescope. In addition to acquiring data from the 349-pixel photomultiplier tube based imaging camera in real time, the system also provides continuous monitoring and control of several vital parameters of the telescope for ensuring the quality of the data. The paper describes the salient features of the hardware and software of the data acquisition and control system of the telescope.

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

    International Nuclear Information System (INIS)

    Buzhan, P.; Dolgoshein, B.; Ilyin, A.; Kaplin, V.; Klemin, S.; Mirzoyan, R.; Popova, E.; Teshima, M.

    2009-01-01

    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.

  5. Astroclimatic characterization of Vallecitos: a candidate site for the Cherenkov Telescope Array at San Pedro Mártir

    Czech Academy of Sciences Publication Activity Database

    Tovmassian, G.; Hernandez, M.-S.; Ochoa, J.L.; Ernenwein, J.-P.; Mandát, D.; Pech, M.; Frayn, I.P.; Colorado, E.; Murillo, J.M.; Ceseña, U.; Garcia, B.; Lee, W.H.; Bulik, T.; Garczarczyk, M.; Fruck, C.; Costantini, H.; Cieslar, M.; Aune, T.; Vincent, S.; Carr, J.; Serre, N.; Janeček, Petr; Haefner, D.

    2016-01-01

    Roč. 128, č. 961 (2016), 1-13, č. článku 035004. ISSN 0004-6280 R&D Projects: GA MŠk LG14019; GA MŠk LE13012; GA MŠk LM2015046 Institutional support: RVO:68378271 Keywords : high energy gama rays * Cherencov telescopes * site characterization Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.446, year: 2016

  6. Cherenkov radiation

    International Nuclear Information System (INIS)

    Hubert, P.

    1955-01-01

    When the radioactivity has been discovered, it was observed by researchers that different materials as mineral salts or solutions were emitting a weak light when submitted to radioactivity beams. At the beginning it has been thought that it was fluorescent light. In 1934, Cherenkov, a russian physicist, worked on the luminescence of uranyl salts solutions caused by gamma radiation and observed a very weak light was emitted by pure liquid. After further studies, he concluded that this phenomena was different from fluorescence. Since then, it has been called Cherenkov effect. This blue light emission is produced when charged particles are going through a transparent medium with an upper velocity than light velocity. This can happen only in medium with large refractive index as water or glass. It also presents its different properties discovered afterwards. The different applications of the Cherenkov radiation are discussed as counting techniques for radiation detectors or comic ray detectors. (M.P.)

  7. Measurement of the gamma ray flux between 50 and 350 GeV from the Mrk 501 Blazar with the experiment CELESTE

    International Nuclear Information System (INIS)

    Brion, E.

    2005-10-01

    The blazar Mrk 501 has a non-thermal emission spectrum with 2 components. The first one, located between radio waves and X-rays, is due to the synchrotron emission of the magnetized jet, while the second one, emitted in the high energy gamma-ray domain, is still not fully understood. Until 1999, this last domain had only been covered between 100 MeV and 4 GeV as well as above 300 GeV. This energy gap was filled by the creation of the CELESTE experiment, recording Cherenkov emission produced by gamma-rays between 50 and 350 GeV penetrating the atmosphere. Mrk 501, which has a variable emission, was observed in 2000 and 2001, and was detected in 2000. A flux has been calculated which constrains the high energy emission models, presented in this thesis. Crab nebula flux measurements validate the method since this source is the standard candle for atmospheric Cherenkov telescopes. Analysis cuts for Mrk 501 are determined using data from the blazar Mrk 421, which has nearly the same declination as Mrk 501. Finally, improved detector simulations were used to calculate the effective area of the instrument, taking the atmosphere quality into account, yielding the flux for Mrk 501 during observations taken between April and June 2000. This flux was compared with a synchrotron self-Compton emission model and with data taken in X-rays. It shows that Mrk 501 was slightly more active during this period compared to the remainder of the year and to the year 2001. A flux upper limit is calculated for other measurements. This is the first measurement in the energy range 50 - 350 GeV (this range represents the limits in energy for which the trigger rate, that is the convolution between the source spectrum and the effective area of the instrument, is higher than 20% of the trigger maximum). It helps to constrain the position of the inverse Compton emission maximum and tends to favor, in this particular case, X- and gamma-ray emission processes from 2 different electron populations

  8. The Cherenkov Bremsstrahlung

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1995-01-01

    The vanishing of the 'retardation factor' leads to a significant growth of the intensity of the electromagnetic field 'velocity part' of the moving charge. The Cherenkov radiation is its physical consequence. The same reason also conditions the growth of another term: the 'acceleration part' of the field which gives rise to the 'Cherenkov Bremsstrahlung'. 4 refs

  9. El Sistema de Referencia Celeste convencional de la IAU

    Science.gov (United States)

    Arias, E. F.

    La Unión Astronómica Internacional (IAU) recomendó la adopción de un nuevo sistema de referencia celeste baricéntrico cuyo plano fundamental y origen de ascensiones rectas estén próximos, respectivamente, al ecuador y equinoccio dinámicos J2000.0. El nuevo sistema de referencia estará materializado por las posiciones J2000.0 de radiofuentes extragalácticas determinadas con la técnica de interferometría de larga línea de base (VLBI). El Working Group on Reference Frames de la IAU (WGRF) decidió adoptar (Grasse, 1995) al sistema de referencia celeste extragaláctico del Servicio Internacional de la Rotación Terrestre (IERS) como futuro sistema de referencia celeste convencional bajo el nombre International Celestial Reference System (ICRS) y encomendó su mantenimiento futuro al IERS. El marco de referencia que materializará al ICRS contiene posiciones precisas J2000.0 de más de 600 radiofuentes extragalácticas. Las coordenadas fueron ajustadas en una única solución VLBI en la cual se incluyeron todas las observaciones realizadas hasta octubre de 1995 con la técnica de adquisición de datos VLBI Mark III. Para minimizar los errores sistemáticos que pueden afectar la calidad del marco de referencia se introdujeron mejoras sustanciales en la modelización y en la selección de datos. Un subconjunto de objetos del marco de referencia se utilizó para referir las posiciones estelares determinadas con el satélite astrométrico Hipparcos al ICRS.

  10. CHERENKOV RADIATION DETECTOR

    African Journals Online (AJOL)

    ES Obe

    1981-03-01

    Mar 1, 1981 ... to measure the Cherenkov angles for natural radioactivity from sources as. Cs137 ... at 435 Mev in their proton-proton ..... (ii) Use is made of Table 5A Jelley ..... charge and rest mass in units of electron rest mass is shown in the table ... Proton e+. 1836. 322. Neutron. 0. 1839. 325. Alpha e2+. 7344. 1600.

  11. 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....

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

    Energy Technology Data Exchange (ETDEWEB)

    Braun, Isabel [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Collaboration: FACT-Collaboration

    2011-07-01

    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.

  13. Cherenkov radiation in vacuum. 1

    International Nuclear Information System (INIS)

    Kozik, B.

    1985-01-01

    After discussing some historical aspects of the Cherenkov effect from electrodynamic and quantum theoretical points of view a methodically clear and simple theory of the Cherenkov effect is presented in which an arbitrary shaped rigid charge distribution is considered and which is based only on essential knowledge of Fourier transformations and cylindric functions. The Cherenkov effect is derived as a consequence of the structure of the potentials and the influence of the geometric shape of the charge distribution on the spectral distribution of the radiation intensity is taken into account in a general form. The educational value of such a representation of the Cherenkov effect in textbooks is emphasized

  14. Status of the MAGIC telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Colin, Pierre; Carmona, Emiliano; Schweizer, Thomas; Sitarek, Julian [Max-Planck-Institut fuer Physik, Werner-Heisenberg Institut, Muenchen (Germany)

    2010-07-01

    MAGIC is a system of two 17-m Cherenkov telescopes located on La Palma (Canary islands),sensitive to gamma-rays above 30 GeV. It has been recently upgraded by a second telescope which strongly improves the sensitivity, particularly at low energy. Here we present the status of the MAGIC telescopes and an overview of the recent results obtained in single or stereoscopic mode. We also discuss the real performance of the new stereoscopic system based on Crab Nebula observations.

  15. Commissioning and first tests of the MAGIC telescope

    Science.gov (United States)

    Baixeras, C.; Bastieri, D.; Bigongiari, C.; Blanch, O.; Blanchot, G.; Bock, R.; Bretz, T.; Chilingarian, A.; Coarasa, J. A.; Colombo, E.; Contreras, J. C.; Corti, D.; Cortina, J.; Domingo, C.; Domingo, E.; Ferenc, D.; Fernández, E.; Flix, J.; Fonseca, V.; Font, L.; Galante, N.; Gaug, M.; Garczarczyk, M.; Gebauer, J.; Giller, M.; Goebel, F.; Hengstebeck, T.; Jacone, P.; de Jager, O. C.; Kalekin, O.; Kestel, M.; Kneiske, T.; Laille, A.; López, M.; López, J.; Lorenz, E.; Mannheim, K.; Mariotti, M.; Martínez, M.; Mase, K.; Merck, M.; Meucci, M.; Miralles, L.; Mirzoyan, R.; Moralejo, A.; Wilhelmi, E. Oña; Orduña, R.; Paneque, D.; Paoletti, R.; Pascoli, D.; Pavel, N.; Pegna, R.; Peruzzo, L.; Piccioli, A.; Roberts, A.; Reyes, R.; Saggion, A.; Sánchez, A.; Sartori, P.; Scalzotto, V.; Schweizer, T.; Sillanpaa, A.; Sobczynska, D.; Stamerra, A.; Stepanian, A.; Stiehler, R.; Takalo, L.; Teshima, M.; Tonello, N.; Torres, A.; Turini, N.; Vitale, V.; Volkov, S.; Wagner, R. M.; Wibig, T.; Wittek, W.

    2004-02-01

    Major Atmospheric Gamma Imaging Cherenkov telescope is starting its operations with a set of engineering runs to tune the telescope subsystem elements to be ready for the first physics campaign. Many technical improvements have been developed and implemented in several elements of the telescope to reach the lowest energy threshold ever obtained by an Imaging Atmospheric Cherenkov Telescope. A general description of the telescope is presented. The commissioning of the telescope's elements is described and the expected performances are reviewed with the final detector set-up.

  16. Measurement of the crab flux above 60 GeV with the celeste Cerenkov telescope

    Czech Academy of Sciences Publication Activity Database

    Naurois De, M.; Holder, J.; Bazer-Bachi, R.; Bergeret, H.; Bruel, P.; Cordier, A.; Debais, G.; Dezalay, J. P.; Dumora, D.; Durand, E.; Eschstruth, P.; Espigat, P.; Fabre, B.; Fleury, P.; Hérault, N.; Hrabovský, Miroslav; Incerti, S.; Le Gallou, R.; Moenz, F.; Musquére, A.; Olive, J. F.; Paré, E.; Québert, J.; Rannot, R. C.; Reposeur, T.; Rob, L.; Roy, P.; Sako, T.; Schovánek, Petr; Smith, D. A.; Snabre, P.; Volte, A.

    2002-01-01

    Roč. 566, - (2002), s. 343-357 ISSN 0004-637X R&D Projects: GA ČR GA202/97/1181 Institutional research plan: CEZ:AV0Z1010920 Keywords : gamma ray: observations * ISM:individual (Crab Nebula) * pulsar :individual (Crab Pulsar ) * supernova remnants Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 6.187, year: 2002

  17. Measurement of the blazar Mrk421 flux above 60 GeV with the CELESTE experiment

    International Nuclear Information System (INIS)

    Le Gallou, R.

    2001-11-01

    The CELESTE experiment is based on an ancient solar plant that has been turned into a detector able to detect the particle showers triggered by the interactions of high energy cosmic photons with the earth atmosphere nuclei. The purpose of the CELESTE experiment is to study the emissions of photons by cosmic objects like supernovae remnants, pulsars or active cores of galaxies such as blazars. Blazars are very interesting objects to study because they allow us to investigate matter that is in extreme conditions and to probe a very far past. The aim of this work has been to develop methods for the analysis of the data collected by CELESTE and to validate them. A specific effort has been achieved for the selection of efficient hadronic rejection criteria in order to optimize the sensitivity of the detector. The physics of the detector is detailed from the particle showers to the data analysis. The detector acceptance has been assessed through Monte-Carlo simulations that have been shown that the detection threshold is 30 GeV at the triggering point and 60 GeV after the analysis cuts. The validation tests have been performed on the Crab nebula that is a standard in gamma astronomy for its stability and intensity. CELESTE has been operating since November 1999 in a satisfactory way and has accumulated data on 4 blazars among them Mrk421. Several bursts have been detected on Mrk421 and an average photon flux has been determined. A correlation has been deduced from the activity detected by CELESTE and the activities in the TeV and X ranges which agrees with the simulations

  18. Cherenkov radiation; La radiation Cerenkov

    Energy Technology Data Exchange (ETDEWEB)

    Hubert, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    When the radioactivity has been discovered, it was observed by researchers that different materials as mineral salts or solutions were emitting a weak light when submitted to radioactivity beams. At the beginning it has been thought that it was fluorescent light. In 1934, Cherenkov, a russian physicist, worked on the luminescence of uranyl salts solutions caused by gamma radiation and observed a very weak light was emitted by pure liquid. After further studies, he concluded that this phenomena was different from fluorescence. Since then, it has been called Cherenkov effect. This blue light emission is produced when charged particles are going through a transparent medium with an upper velocity than light velocity. This can happen only in medium with large refractive index as water or glass. It also presents its different properties discovered afterwards. The different applications of the Cherenkov radiation are discussed as counting techniques for radiation detectors or comic ray detectors. (M.P.)

  19. G-APDs in Cherenkov astronomy: The FACT camera

    International Nuclear Information System (INIS)

    Krähenbühl, T.; Anderhub, H.; Backes, M.; Biland, A.; Boller, A.; Braun, I.; Bretz, T.; Commichau, V.; Djambazov, L.; Dorner, D.; Farnier, C.; Gendotti, A.; Grimm, O.; Gunten, H. von; Hildebrand, D.; Horisberger, U.; Huber, B.; Kim, K.-S.; Köhne, J.-H.; Krumm, B.

    2012-01-01

    Geiger-mode avalanche photodiodes (G-APD, SiPM) are a much discussed alternative to photomultiplier tubes in Cherenkov astronomy. The First G-APD Cherenkov Telescope (FACT) collaboration builds a camera based on a hexagonal array of 1440 G-APDs and has now finalized its construction phase. A light-collecting solid PMMA cone is glued to each G-APD to eliminate dead space between the G-APDs by increasing the active area, and to restrict the light collection angle of the sensor to the reflector area in order to reduce the amount of background light. The processing of the signals is integrated in the camera and includes the digitization using the domino ring sampling chip DRS4.

  20. Discovery of high energy electrons in the radiation belt by devices with gas Cherenkov counters

    International Nuclear Information System (INIS)

    Kirillov-Ugryumov, V.G.; Galper, A.M.; Dmitrenko, V.V.

    1986-01-01

    A detailed study of the trapped electrons was undertaken with Bulgary-1300 satellite, the orbit altitude and the inclination being proportional900 km and 81 0 , respectively. The instrument axis in this case was perpendicular to the orbit plane. A scintillation-Cherenkov telescope, Electron, with parameters similar to that of Elena was used. (orig./HSI)

  1. Towards a network of atmospheric Cherenkov detectors 7

    International Nuclear Information System (INIS)

    Robin, M.; Weekes, T.C.; Mori, M.; Mariotti, M.; Hofmann, W.; Aharonian, F.; Sinitsyna, V.; Smith, D.; Marleau, P.; Sinnis, G.; Volk, H.; Jager, O. de; Harding, A.; Coppi, P.; Dermer, C.; Goldwurm, A.; Paul, J.; Puhlhofer, G.; Bernardini, E.; Swordy, S.; Yoshikoshi, T.; Punch, M.

    2005-01-01

    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

  2. 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.

  3. The Tunka-133 EAS Cherenkov light array: Status of 2011

    International Nuclear Information System (INIS)

    Berezhnev, S.F.; Besson, D.; Budnev, N.M.; Chiavassa, A.; Chvalaev, O.A.; Gress, O.A.; Dyachok, A.N.; Epimakhov, S.N.; Haungs, A.; Karpov, N.I.; Kalmykov, N.N.; Konstantinov, E.N.; Korobchenko, A.V.; Korosteleva, E.E.; Kozhin, V.A.; Kuzmichev, L.A.; Lubsandorzhiev, B.K.; Lubsandorzhiev, N.B.; Mirgazov, R.R.; Panasyuk, M.I.

    2012-01-01

    A new EAS Cherenkov light array, Tunka-133, with ∼1km 2 geometrical area has been installed at the Tunka Valley (50 km from Lake Baikal) in 2009. The array permits a detailed study of cosmic ray energy spectrum and mass composition in the energy range 10 16 –10 18 eV with a uniform method. We describe the array construction, DAQ and methods of the array calibration. The method of energy reconstruction and absolute calibration of measurements are discussed. The analysis of spatial and time structure of EAS Cherenkov light allows to estimate the depth of the EAS maximum X max . The results on the all particles energy spectrum and the mean depth of the EAS maximum X max vs. primary energy derived from the data of two winter seasons (2009–2011) are presented. Preliminary results of joint operation of the Cherenkov array with antennas for the detection of EAS radio signals are shown. Plans for future upgrades – deployment of remote clusters, radioantennas and a scintillator detector network and a prototype of the HiSCORE gamma-telescope – are discussed.

  4. Progress in Cherenkov femtosecond fiber lasers

    DEFF Research Database (Denmark)

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

    2016-01-01

    systems are highlighted—dependent on the realization scheme, the Cherenkov lasers can generate the femtosecond output tunable across the entire visible and even the UV range, and for certain designs more than 40% conversion efficiency from the pump to Cherenkov signal can be achieved. The femtosecond......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...

  5. 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.

  6. Deployment of a Pair of 3 M telescopes in Utah

    Energy Technology Data Exchange (ETDEWEB)

    Finnegan, G; Adams, B; Butler, K; Cardoza, J; Colin, P; Hui, C M; Kieda, D; Kirkwood, D; Kress, D; Kress, M; LeBohec, S; McGuire, C; Newbold, M; Nunez, P; Pham, K [University of Utah, Department of Physics, Salt Lake City, Utah 84112 (United States)

    2008-12-24

    Two 3 m telescopes are being installed in Grantsville Utah. They are intended for the testing of various approaches to the implementation of intensity interferometry using Cherenkov Telescopes in large arrays as receivers as well as for the testing of novel technology cameras and electronics for ground based gamma-ray astronomy.

  7. 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.

  8. GRANITE- A steroscopic imaging Chernkov telescope system

    International Nuclear Information System (INIS)

    Shubnell, M.; Akerlof, C.W.; Cawley, M.F.; Chantell, M.; Fegan, D.J.; Fennell, S.; O'Flaherty, K.S.; Freeman, S.; Frishman, D.; Gaidos, J.A.; Hagan, J.; Harris, K.; Hillas, A.M.; Kerrick, A.D.; Lamb, R.C.; Lappin, T.; Lawrence, M.A.; Levy, H.; Lewis, D.A.; Meyer, D.I.; Mohanty, G.; Punch, M.; Reynolds, P.T.; Rovero, A.C.; Sembroski, G.; Weaverdyck, C.; Weekes, T.C.; Whitaker, T.; Wilson, C.

    1993-01-01

    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

  9. Generation and propagation of synchro - Cherenkov radiation

    International Nuclear Information System (INIS)

    Heintzmann, H.; Novello, M.; Schruefer, E.

    1981-01-01

    Particles moving along the magnetic field lines emit under favorable conditions Cherenkov radiation in a cold, rarefied plasma. A peculiar phenomenon occurs for curved magnetic fields: in for example a toroidal magnetic field the radiation spirals inward and approaches a resonance. Both the generation and the study of the propagation of these Cherenkov modes appear to be within reach of present technology. (Author) [pt

  10. Aerogel as Cherenkov radiator for RICH detectors

    International Nuclear Information System (INIS)

    Bellunato, T.; Braem, A.; Buzykaev, A.R.; Calvi, M.; Chesi, E.; Danilyuk, A.F.; Easo, S.; Hansen, C.; Jolly, S.; Joram, C.; Kravchenko, E.A.; Liko, D.; Matteuzzi, C.; Musy, M.; Negri, P.; Neufeld, N.; Onuchin, A.P.; Seguinot, J.; Weilhammer, P.; Wotton, S.

    2003-01-01

    We present here the results obtained using silica aerogel as Cherenkov radiator for the separation and identification of particles in the momentum range from 6 to 10 GeV/c. Photoelectron yield and Cherenkov ring resolution were studied under different experimental conditions and compared to the simulation

  11. All-fiber femtosecond Cherenkov radiation source

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe

    2012-01-01

    -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...

  12. A large area plastic Cherenkov detector

    International Nuclear Information System (INIS)

    Bernabei, R.; Bidoli, V.; Zorzi, G. de; Biagio, A. di

    1978-01-01

    A large area Cherenkov counter has been built up using as a radiator a sheet of Pilot 425 plastic, (180x20)cm 2 x2.5 cm. Experimental tests performed with a pion beam in order to measure the average number of photoelectrons collected by photomultipliers and the scintillation to Cherenkov light ratio. (Auth.)

  13. Charged particle identification: Cherenkov counters at ISABELLE

    International Nuclear Information System (INIS)

    Etkin, A.; Kostoulas, I.; Leith, D.W.G.S.; Thun, R.

    1977-01-01

    A brief summary is given of a study of Cherenkov counters for ISABELLE. The study was certainy not exhaustive and was meant primarily to suggest future detector development. A substantial research effort is needed in order to insure that Cherenkov counters utilizing photoionization are fully exploited

  14. Template analysis for the MAGIC telescopes

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  15. Performance of aerogel as Cherenkov radiator

    International Nuclear Information System (INIS)

    Bellunato, T.; Calvi, M.; Matteuzzi, C.; Musy, M.; Negri, P.; Braem, A.; Chesi, E.; Hansen, C.; Liko, D.; Joram, C.; Neufeld, N.; Seguinot, J.; Weilhammer, P.; Buzykaev, A.R.; Kravchenko, E.A.; Onuchin, A.P.; Danilyuk, A.F.; Easo, S.; Wotton, S.; Jolly, S.

    2004-01-01

    Aerogel with index of refraction around 1.03 has been studied as Cherenkov radiator in a test at CERN PS using a π - and a mixed π + /p beam of momenta between 6 and 10 GeV/c. The Cherenkov photons were detected by means of four large HPD tubes designed and constructed at CERN. Results on the photoelectron yield, the Cherenkov angle and its resolution, and the π/p separation are obtained. The performances measured demonstrate that a RICH with aerogel is a viable detector for experiments with high multiplicity of particles in the final state

  16. The use of an ultra-violet camera in the atmospheric Cherenkov technique

    International Nuclear Information System (INIS)

    Urban, M.; Fleury, P.; Kerrick, A.D.; Pare, E.; Vacanti, G.

    1996-01-01

    The atmospheric Cherenkov technique for gamma ray astronomy is shown to be feasible using an ultraviolet (UV) camera on moon-lit-nights. The Whipple telescope has been used as the reflector and the CRab Nebula as the standard gamma ray beam. Our energy threshold is 1.2 TeV which is compared to 0.4 TeV in the visible. (orig.)

  17. Large Water Cherenkov Detectors - Technical Issues -

    CERN Document Server

    Aihara, H

    2010-01-01

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

  18. Spontaneous emission in Cherenkov FEL devices

    International Nuclear Information System (INIS)

    Ciocci, F.; Dattoli, G.; Doria, A.; Schettini, G.; Torre, A.; Walsh, J.E.

    1987-01-01

    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

  19. Asymmetric Cherenkov acoustic reverse in topological insulators

    Science.gov (United States)

    Smirnov, Sergey

    2014-09-01

    A general phenomenon of the Cherenkov radiation known in optics or acoustics of conventional materials is a formation of a forward cone of, respectively, photons or phonons emitted by a particle accelerated above the speed of light or sound in those materials. Here we suggest three-dimensional topological insulators as a unique platform to fundamentally explore and practically exploit the acoustic aspect of the Cherenkov effect. We demonstrate that by applying an in-plane magnetic field to a surface of a three-dimensional topological insulator one may suppress the forward Cherenkov sound up to zero at a critical magnetic field. Above the critical field the Cherenkov sound acquires pure backward nature with the polar distribution differing from the forward one generated below the critical field. Potential applications of this asymmetric Cherenkov reverse are in the design of low energy electronic devices such as acoustic ratchets or, in general, in low power design of electronic circuits with a magnetic field control of the direction and magnitude of the Cherenkov dissipation.

  20. Astronomía gamma con telescopios Cherenkov: hacia un observatorio astronómico abierto a la comunidad

    Science.gov (United States)

    Rovero, A. C.

    Gamma-ray astronomy is opening the way to a universe far more energetic than anyone could have imagined half a century ago. The understanding of the processes of nature which carry a large portion of the energy in the universe, has astrophysical and cosmological implications. The next gen- eration of Cherenkov telescopes, an order of magnitude more sensitive and with higher resolution than the current systems, will mean a significant step forward for ground-based gamma-ray astronomy. This paper presents the current status of this field as well as the next generation of telescopes in this energy range, which are being designed for the first international observa- tory open to the astronomical community. The Cherenkov Telescope Array project and the Argentine sites proposed for the southern observatory are described in this paper. FULL TEXT IN SPANISH

  1. Relevamiento total del hemisferio sur celeste en la frecuencia de 1420 MHz

    Science.gov (United States)

    Bava, J. A.; Colomb, F. R.; Hurrel, E.; Larrarte, J. J.; Sanz, A. J.; Testori, J. C.; Reich, P.; Reich, W.; Wielebinski, R.

    En el presente artículo se describe el relevamiento del cielo en el Hemisferio Sur Celeste en la frecuencia de 1420 MHz para declinaciones δde 30 metros de diámetro del IAR. Este relevamiento posee igual sensibilidad (3xr.m.s=50 mK) que el realizado en el Hemisferio Norte con el radiotelescopio de 25 metros de Stockert de la Universidad de Bonn, operado por el Max-Planck Institute für Radioastronomie ( Reich W., 1982, A&ASS 48, 219; Reich P. and Reich W., 1986, A&ASS 63, 205). Con los datos obtenidos por ambos radiotelescopios se posee una base de datos de todo el cielo en esta frecuencia. En esta publicación presentamos los detalles del sistema receptor, técnicas de observación y reducción de datos, calibración y discusión de los errores en los resultados.

  2. La divinidad celeste/solar en el panteón céltico peninsular

    Directory of Open Access Journals (Sweden)

    Rubén Abad Lara

    2008-01-01

    Full Text Available En la Hispania prerromana existió una divinidad suprema con carácter celeste y solar de tipo similar a la que se rindió culto en el resto de la Europa indoeuropea. El análisis de algunas piezas del arte celtibérico, nos revela que esa divinidad principal era representada bajo la forma de un jinete a caballo con lanza. La iconografía muestra que ese dios, uno de cuyos nombres pudo ser Lugus, tomó parte de numerosos mitos que le relacionaban con la guerra, la fertilidad y el mundo funerarioIn preroman Spain there was a supreme divinity with solar and heavenly roles, very similar to the divinities worshiped in the rest of the indoeuropean Europe. The analysis of some celtiberian pieces of art, revealed to us that this principal divinity was depicted in the form of a horseman on his horse and holding a spear. The iconography shows that this God, one of his names could be Lugus, took part in many myths which linked him to war, fertility and the funerary world.

  3. 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.

  4. 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.

  5. Analysis of Cherenkov counter efficiencies for E691

    International Nuclear Information System (INIS)

    Cremaldi, L.; Elliott, J.; Gibney, M.; Nauenberg, U.

    1985-01-01

    A program is outlined which simulates Cherenkov counters. The program can compute the effect of the magnetic field on the efficiencies of Cherenkov counters. It also tells what cone to mirror distance gives the highest collection efficiency and at which target position should the laser be placed to represent the direction of the actual Cherenkov light the mirror sees

  6. Beam test of Cherenkov counter prototype for ZDF setup

    International Nuclear Information System (INIS)

    Kacharava, A.K.; Macharashvili, G.G.; Nioradze, M.S.; Komarov, V.I.; Sopov, V.S.; Chernyshev, V.P.

    1995-01-01

    We describe a Cherenkov counter of total internal reflection for particle separation in the momentum range where all types of particles radiate Cherenkov light. The Cherenkov counter prototype with the lucite radiator was tested on the secondary beam of the ITEP (Moscow) accelerator. Dependence of the photomultiplier pulse height on the particle entrance angle was clearly observed. 4 refs., 4 figs

  7. 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.

  8. γ astrophysics above 10-30 GeV with the MAGIC telescope

    International Nuclear Information System (INIS)

    Mirzoyan, Razmick

    1999-01-01

    The project on the 17 m oe telescope, dubbed MAGIC (Major Atmospheric Gamma Imaging Cherenkov Telescope), is dedicated for γ astrophysics in the energy range from 10-30 GeV till 50-100 TeV. MAGIC will for the first time allow to explore with very high sensitivity the energy range 10-300 GeV and to bridge the existing energy gap between satellite and ground-based air Cherenkov measurements. We believe MAGIC will serve as a prototype for future multi-telescope γ ray observatories

  9. Sobre o uso das séries de Puiseux em mecanica celeste

    Science.gov (United States)

    Miloni, O. I.

    2003-08-01

    Neste trabalho é apresentada uma demonstração do uso dos diferentes desenvolvimentos em séries para as equações de perturbação em Mecânica Celeste no marco Hamiltoniano. Em trabalhos clássicos como os de Poincaré (Poincaré, 1893) por exemplo, já esta planteado o uso de potências não inteiras no pequeno parâmetro, o que evidencia a não analiticidade das funções quando uma ressonância ocorre. Nestes trabalhos os desenvolvimentos são na raíz quadrada da massa de Júpiter (o pequeno parâmetro). Mais recentemente (Ferraz-Mello, 1985) outros tipos de desenvolvimentos foram aplicados modificando substancialmente as ordens de grandeza e a velocidade de convergência das séries. Com esta abordagem, os desenvolvimentos foram expressados em termos da raíz cúbica do pequeno parâmetro. Neste trabalho apresentamos um enfoque geral, onde os diferentes tipos de desenvolvimentos em séries de Puiseux (Valiron, 1950) são obtidos a partir da aplicação de Teorema de Preparação de Weierstrass (Goursat, 1916) considerando a equação de Hamilton-Jacobi como uma equação algébrica. Os resultados são aplicados ao problema restrito dos três corpos em ressonância de primeira ordem e, dependendo da grandeza da excentricidade do asteróide em relação à de Júpiter, obtemos os diferentes desenvolvimentos, em raíz quadrada ou raíz cúbica da massa de Júpiter.

  10. The positioning system of the ANTARES Neutrino Telescope

    NARCIS (Netherlands)

    Adrián-Martínez, S.; Kooijman, P.|info:eu-repo/dai/nl/068449542; Zúñiga, J.

    2012-01-01

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

  11. The positioning system of the ANTARES Neutrino Telescope

    NARCIS (Netherlands)

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

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

  12. 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.A.; 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, P.; 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.; Enzenhofer, 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.; Hossl, 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.; Schock, F.; Schuller, J.P.; Schussler, F.; Seitz, T.; Shanidze, R.; Simeone, F.; Spies, A.; Spurio, M.; Steijger, J.J.M.; Stolarczyk, T.; 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

  13. Reconstruction of the characteristics of gamma showers and contribution to the data analysis of the experiment Celeste

    International Nuclear Information System (INIS)

    Herault, N.

    2000-04-01

    The detection of high energy gamma radiation is an important tool for the study of violent events occurring somewhere in the galaxies and produced by pulsars or active nuclei. Since the beginning of the nineties, a new technology is used: the ground-based detection of Cerenkov light emitted by the air shower issuing from very high energy gamma radiation. Celeste (Cerenkov low energy sampling and timing experiment) is the last of a series of experiments: Asgat, Themistocle and Cat, that have been performed on the site of the decommissioned solar plant Themis. Alike Asgat and Themistocle, Celeste is based on the same method of parting the light wave front but uses the important 54 m 2 surface mirrors of the ancient solar plant to collect it. The processing of the different accurate moments at which the Cerenkov light has reached each mirror allows the reconstruction of the tail of the shower. This installation is expected to collect more Cerenkov light and to allow physicists to reach the 30 to 300 GeV energy range that has been till now largely unexplored in gamma astronomy. The first chapter is dedicated to the various methods for detecting gamma radiation, either satellite on-board experiments or ground-based detection systems. The second chapter presents the experiment Celeste and explains how this experiment could bring new information about astrophysical concerns. The third chapter deals with the detailed technical description of the installation, especially the optical and electronic systems. The fourth chapter is dedicated to the reconstruction of gamma showers, the determination of their direction is a delicate problem. The fifth chapter presents the characteristics of the background noise coming from hadronic showers. The sixth chapter is dedicated to the calibration of the detector and it gives its first preliminary results. (A.C.)

  14. The MAGIC gamma-ray telescope: status and first results

    International Nuclear Information System (INIS)

    Fernandez, Enrique

    2006-01-01

    MAGIC, a 17 m diameter Cherenkov telescope for gamma ray astronomy, has recently been commissioned at the Roque de los Muchachos site in the Island of La Palma, of the Canary Islands. The telescope was proposed in 1998 with the goal of lowering the threshold of observation of gamma rays by ground detectors to 20-30 GeV energies. This paper describes its main design features, its physics objectives and its first operations

  15. An experimental study on cyclotron-Cherenkov radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, C Y; Masuzaki, M; Yoshida, H; Toyosugi, N; Kamada, K; Ando, R [Kanazawa Univ. (Japan). Department of Physics

    1997-12-31

    Dielectric-loaded cylindrical waveguide configurations with an injected electron beam in which the growth rate of the cyclotron-Cherenkov instability surpasses that of the Cherenkov instability were sought by numerical treatment, and one configuration of this kind was found. This configuration consists of a metallic core and an outer metallic cylinder with a dielectric liner on the inner surface. Based on the calculations, an experimental device was designed and assembled to investigate experimentally radiation due to the cyclotron-Cherenkov instability. Beam propagation in the dielectric-loaded coaxial waveguide and microwave radiation due to the cyclotron-Cherenkov instability and the Cherenkov instability were studied. (author). 6 figs., 10 refs.

  16. Scattering of Light by Colloidal Aluminosilicate Particles Produces the Unusual Sky-Blue Color of R?o Celeste (Tenorio Volcano Complex, Costa Rica)

    OpenAIRE

    Castell?n, Erick; Mart?nez, Mar?a; Madrigal-Carballo, Sergio; Arias, Mar?a Laura; Vargas, William E.; Chavarr?a, Max

    2013-01-01

    Río Celeste (Sky-Blue River) in Tenorio National Park (Costa Rica), a river that derives from the confluence and mixing of two colorless streams--Río Buenavista (Buenavista River) and Quebrada Agria (Sour Creek)--is renowned in Costa Rica because it presents an atypical intense sky-blue color. Although various explanations have been proposed for this unusual hue of Río Celeste, no exhaustive tests have been undertaken; the reasons hence remain unclear. To understand this color phenomenon, we ...

  17. An anti-Cherenkov photomultiplier tube

    International Nuclear Information System (INIS)

    Selove, W.; Cormell, L.R.; Dris, M.; Kononenko, W.; Robinson, B.; Yost, B.T.

    1982-01-01

    We have designed a special photomultiplier tube (PMT), with very much reduced sensitivity to Cherenkov light produced in the end window. These PMTs have been produced for us by EMI, and have been used in a modular calorimeter array. The design eliminates a 'hot-spot' problem which was of intolerable magnitude in our application. (orig.)

  18. The nonlinear CWFA [Cherenkov Wakefield Accelerator

    International Nuclear Information System (INIS)

    Schoessow, P.

    1989-01-01

    The possible use of nonlinear media to enhance the performance of the Cherenkov Wakefield Accelerator (CWFA) is considered. Numerical experiments have been performed using a new wakefield code which demonstrate larger gradients and transformer ratios in the nonlinear CWFA than are obtained in the linear case. 7 refs., 3 figs

  19. Cherenkov ring imaging using a television digitizer

    International Nuclear Information System (INIS)

    Charpak, G.; Peisert, A.; Sauli, F.; Cavestro, A.; Vascon, M.; Zanella, G.

    1981-01-01

    A Cherenkov ring imaging device using as photon detector a multistep spark chamber coupled to a television digitizer is described. Results of a test run using triethylamine as photo-ionizing vapour are presented, as well as preliminary results obtained with a new vapour having an extremely low ionization potential. (orig.)

  20. Reflectivity around the gold L-edges of X-ray reector of the soft X-ray telescope onboard ASTRO-H

    DEFF Research Database (Denmark)

    Maeda, Yoshitomo; Kikuchi, Naomichi; Kurashima, Sho

    2017-01-01

    We report the atomic scattering factor in the 11.2-15.4 keV for the ASTRO-H Soft X-ray Telescope (SXT)9 obtained in the ground based measurements. The large effective area of the SXT covers above 10 keV. In fact, the flight data show the spectra of the celestical objects in the hard X-ray band. I...

  1. Possible GRB Observation with the MAGIC Telescope

    Science.gov (United States)

    Bastieri, D.; Bigongiari, C.; Mariotti, M.; Peruzzo, L.; Saggion, A.

    2001-08-01

    The MAGIC Telescope, with its reflecting parabolic dish of 17 m of diameter and its careful design of a robust, lightweight, alto-azimuthal mount, is an ideal detector for GRB phenomena. The telescope is an air Cherenkov telescope that, even in the first phase, equipped with standard PMTs, can reach an energy threshold below 30 GeV. The threshold is going to drop well below 10 GeV in the envisaged second phase, when chamber PMTs will be substituted by high quantum efficiency APDs. The telescope can promptly respond to GRB alerts coming, for instance, from GCN, and can reposition itself in less than 30 seconds, 20 seconds being the time to turn half a round for the azimuth bearing. In this report, the effective area of the detector as a function of energy and zenith angle is taken into account, in order to evaluate the expected yearly occurrence and the response to different kinds of GRBs.

  2. On Cherenkov light production by irradiated nuclear fuel rods

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  3. Development of aerogel Cherenkov detectors at Novosibirsk

    International Nuclear Information System (INIS)

    Barnyakov, A.Yu.; Barnyakov, M.Yu.; Baehr, J.; Bellunato, T.; Beloborodov, K.I.; Bobrovnikov, V.S.; Buzykaev, A.R.; Calvi, M.; Danilyuk, A.F.; Djordjadze, V.; Golubev, V.B.; Kononov, S.A.; Kravchenko, E.A.; Lipka, D.; Matteuzzi, C.; Musy, M.; Onuchin, A.P.; Perego, D.; Rodiakin, V.A.; Savinov, G.A.; Serednyakov, S.I.; Shamov, A.G.; Stephan, F.; Tayursky, V.A.; Vorobiov, A.I.

    2005-01-01

    The development of aerogel Cherenkov counters with the light collection using a wavelength shifter is described. 80 counters of this type are working in the KEDR detector. A project of similar counters for the SND detector based on 'heavy' aerogel with n=1.13 has been developed. Aerogel with a refractive index of 1.006-1.13 and dimensions of blocks up to 200x200x50mm 3 is produced by the Novosibirsk group for use in Cherenkov counters of different types. The Novosibirsk group is participating in the development of LHCb RICH as well as a beam diagnostics for a photo-injector test facility at DESY-Zeuthen. Recently we started development of RICH based on focusing aerogel (FARICH) for the endcap of the SuperBaBar. For the first time in the world the focusing aerogel with layers of different refractive indices has been produced

  4. Photon detection in ring imaging Cherenkov counters

    International Nuclear Information System (INIS)

    Jansen, H.

    1988-01-01

    One of the parts of DELPHI (a detector at the CERN LEP) is the barrel-RICH which uses Cherenkov radiation to determine the velocity of charged particles; together with the measured momentum this information yields the mass of each particle. The performance of the photon detector, which determines to a large extent the analyzing power of the barrel-RICH, is studied. 98 refs.; 40 figs.; 6 tabs

  5. High-Energy Astrophysics with the High Altitude Water Cherenkov (HAWC) Observatory

    Science.gov (United States)

    Pretz, John; HAWC Collaboration

    2013-04-01

    The High Altitude Water Cherenkov (HAWC) observatory, under construction at Sierra Negra in the state of Puebla, Mexico, consists of a 22500 square meter area of water Cherenkov detectors: water tanks instrumented with light-sensitive photomultiplier tubes. The experiment is used to detect energetic secondary particles reaching the ground when a 50 GeV to 100 TeV cosmic ray or gamma ray interacts in the atmosphere above the experiment. By timing the arrival of particles on the ground, the direction of the original primary particle may be resolved with an error of between 1.0 (50 GeV) and 0.1 (10 TeV) degrees. Gamma-ray primaries may be distinguished from cosmic ray background by identifying the penetrating particles characteristic of a hadronic particle shower. The instrument is 10% complete and is performing as expected, with 30% of the channels anticipated by the summer of 2013. HAWC will complement existing Imaging Atmospheric Cherenkov Telescopes and space-based gamma-ray telescopes with its extreme high-energy sensitivity and its large field-of-view. The observatory will be used to study particle acceleration in Pulsar Wind Nebulae, Supernova Remnants, Active Galactic Nuclei and Gamma-ray Bursts. Additionally, the instrument can be used to probe dark matter annihilation in halo and sub-halos of the galaxy. We will present the sensitivity of the HAWC instrument in the context of the main science objectives. We will also present the status of the deployment including first data from the instrument and prospects for the future.

  6. On the fine structure of the Vavilov-Cherenkov radiation

    International Nuclear Information System (INIS)

    Afanas'ev, G.N.; Kartavenko, V.G.; Zrelov, V.P.

    2003-01-01

    The aim of this paper is to study the fine structure of the Cherenkov rings. We analyze Zrelov's experiments in which the Cherenkov radiation was detected without using the special focusing devices. The broad Cherenkov ring was observed in the plane perpendicular to the motion axis. Using the exact and approximate formulae, we investigate how a charge uniformly moving in a medium radiates in a finite space interval. The formulae obtained describe the radiation intensity in the whole space interval, inside and outside the Cherenkov ring. In the plane perpendicular to the motion axis, the radiation fills mainly the finite ring. Its width, proportional to the motion interval, and the energy released in this ring do not depend on the position of the observation plane. Outside the Cherenkov ring, the radiation intensity suddenly drops. Inside it, the radiation intensity exhibits small oscillations which are due to the interference of the Vavilov-Cherenkov radiation and bremsstrahlung. The increase in the radiation intensity at the ends of the Cherenkov ring is associated with the shock waves arising at the beginning and the end of the charge motion and at the moments when the charge velocity coincides with the light velocity in a medium. For the chosen motion interval, the well-known Tamm formula does not describe the radiation intensity inside the Cherenkov ring for any position of the observation plane. Outside the Cherenkov ring, the Tamm formula is valid only at very large observation distances. Theoretical calculations are in satisfactory agreement with experimental data. Thus, the combined experimental and theoretical study of the unfocused Cherenkov rings allows one to obtain information on the physical processes accompanying the Cherenkov radiation (bremsstrahlung, transition of the light velocity barrier, etc.)

  7. The Timepix3 Telescope for LHCb Upgrade RD 1 measurements

    CERN Document Server

    Saunders, Daniel Martin

    2016-01-01

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

  8. Parametric Cherenkov radiation (development of idea)

    International Nuclear Information System (INIS)

    Buts, V.A.

    2004-01-01

    Some physical results of researches about charged particles radiation in mediums with a periodic heterogeneity and in periodic potential are reported. The development of ideas Parametric Cherenkov Radiation has shown, that in mediums, which have even a weak degree of a periodic heterogeneity of an permittivity or potential, the nonrelativistic oscillators can radiated as relativistic. They effectively radiate the high numbers of harmonics. In particular, in the carried out experiments the ultra-violet radiation was excited at action on a crystal of intensive ten-centimetric radiation. These results give the reasons to hope for making of nonrelativistic lasers on free electrons

  9. Test of aerogel as Cherenkov radiator

    CERN Document Server

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

    2001-01-01

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

  10. Measurement of radionuclides in the environment via Cherenkov radiation

    International Nuclear Information System (INIS)

    Ross, H.H.

    1987-01-01

    The author has developed an alternate approach to the measurement of some beta-emitting nuclides that utilizes the luminescence generated by the Cherenkov process. The luminescence, now known as Cherenkov radiation, was shown to be generated when a charged particle passes through a transparent medium at a speed that exceeds the phase velocity of light in the same medium. Cherenkov emission is different from most other luminescence processes in that it is a purely physical phenomenon. One consequence of this is that Cherenkov systems are free of chemical quenching effects. Conventional methods of analysis for environmental levels of beta-emitting radionuclides are often tedious, time-consuming, and expensive. The Cherenkov method is fast, requires very little operator attention, and is much less expensive to perform

  11. Application of Cherenkov light observation to reactor measurements (2). Design and trial fabrication of Cherenkov light estimation system

    International Nuclear Information System (INIS)

    Yamamoto, Keiichi; Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Hayashi, Takayasu; Kosuge, Fumiaki; Sano, Tadafumi

    2015-11-01

    Development of the reactor measurement system was started to obtain the real-time in-core nuclear and thermal information, where the quantitative measurement of brightness of Cherenkov light was investigated. This report summarized the results of design and trial fabrication of the Cherenkov light estimation system from thermal power evaluation from Cherenkov light image emitted from the fuel elements. The developed Cherenkov light estimation system was verified with the Cherenkov light image emitted from the fuels in the core of Kyoto University Research Reactor (KUR). From the results, the thermal power of the fuel elements evaluated from the brightness of the Cherenkov light observed by a CCD camera was almost the same as that of thermal power calculated from SRAC code. On the other hand, the evaluation values of some fuel elements were different from the calculation values. This, it is necessary to improve the observation method of Cherenkov light in the reactor and the evaluation method of the brightness of Cherenkov light. (author)

  12. Extragalactic observations with the MAGIC telescopes

    International Nuclear Information System (INIS)

    Shore, S.N.

    2014-01-01

    The MAGIC imaging atmospheric Cherenkov telescopes, both as a single detector and now used in stereo mode, have been observing a variety of active galaxies and galactic clusters for almost a decade. This review provides a brief summary of some of the most recent results for blazars observed in the energy range > 50 GeV to tens of TeV. The very high energy emission observed with MAGIC is essential for disentangling the various contributions and timescales to the observed spectra and variability. (author)

  13. A Cherenkov-emission Microwave Source*

    Science.gov (United States)

    Lai, C. H.; Yoshii, J.; Katsouleas, T.; Hairapetian1, G.; Joshi, C.; Mori, W.

    1996-11-01

    In an unmagnetized plasma, there is no Cherenkov emission because the phase velocity vf of light is greater than c. In a magnetized plasma, the situation is completely changed. There is a rich variety of plasma modes with phase velocities vf 2 c which can couple to a fast particle. In the magnetized plasma, a fast particle, a particle beam, or even a short laser pulse excites a Cherenkov wake that has both electrostatic and electromagnetic components. Preliminary simulations indicate that at the vacuum/plasma boundary, the wake couples to a vacuum microwave with an amplitude equal to the electromagnetic component in the plasma. For a weakly magnetized plasma, the amplitude of the out-coupled radiation is approximately wc/wp times the amplitude of the wake excited in the plasma by the beam, and the frequency is approximately wp. Since plasma wakes as high as a few GeV/m are produced in current experiments, the potential for a high-power (i.e., GWatt) coherent microwave to THz source exists. In this talk, a brief overview of the scaling laws will be presented, followed by 1-D and 2-D PIC simulations. Prospects for a tuneable microwave source experiment based on this mechanism at the UCLA plasma wakefield accelerator facility will be discussed. *Work supported by AFOSR Grant #F4 96200-95-0248 and DOE Grant # DE-FG03-92ER40745. 1Now at Hughes Research Laboratories, Malibu, CA 90265

  14. Development of aerogel Cherenkov counters at Novosibirsk

    International Nuclear Information System (INIS)

    Barnyakov, A.Yu.; Barnyakov, M.Yu.; Baehr, J.; Bellunato, T.; Beloborodov, K.I.; Bobrovnikov, V.S.; Buzykaev, A.R.; Calvi, M.; Danilyuk, A.F.; Djordjadze, V.; Golubev, V.B.; Kononov, S.A.; Kravchenko, E.A.; Lipka, D.; Matteuzzi, C.; Musy, M.; Onuchin, A.P.; Perego, D.; Rodiakin, V.A.; Savinov, G.A.; Serednyakov, S.I.; Shamov, A.G.; Stephan, F.; Tayursky, V.A.; Vorobiov, A.I.

    2006-01-01

    The work on aerogel Cherenkov counters was started in Novosibirsk in 1986. Production of aerogels with refractive indices of 1.006-1.13 and thicknesses of blocks up to 50mm was developed. The light absorption length at 400nm is 5-7m, the scattering length is 4-5cm. By these parameters, the Novosibirsk aerogel is one of the best in the world. The ASHIPH Cherenkov counters with light collection on wavelength shifters have been developed. The ASHIPH system of the KEDR detector contains 1000l of aerogel. The π/K separation is 4.5σ. A project of ASHIPH counters for the SND detector has been developed. Aerogel RICH for LHCb gives a possibility to identify hadrons in the momentum range of 2-10GeV/c. The Novosibirsk group is developing an aerogel RICH for the endcap for the SuperBaBar project. Calculations performed by a group of physicists from Novosibirsk and DESY-Zeuthen have shown that aerogel radiators enable to achieve time resolution up to 20fs

  15. Evaluation of the optical cross talk level in the SiPMs adopted in ASTRI SST-2M Cherenkov Camera using EASIROC front-end electronics

    International Nuclear Information System (INIS)

    Impiombato, D; Giarrusso, S; Mineo, T; Agnetta, G; Biondo, B; Catalano, O; Gargano, C; Rosa, G La; Russo, F; Sottile, G; Belluso, M; Billotta, S; Bonanno, G; Garozzo, S; Marano, D; Romeo, G

    2014-01-01

    ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana), is a flagship project of the Italian Ministry of Education, University and Research whose main goal is the design and construction of an end-to-end prototype of the Small Size of Telescopes of the Cherenkov Telescope Array. The prototype, named ASTRI SST-2M, will adopt a wide field dual mirror optical system in a Schwarzschild-Couder configuration to explore the VHE range of the electromagnetic spectrum. The camera at the focal plane is based on Silicon Photo-Multipliers detectors which is an innovative solution for the detection astronomical Cherenkov light. This contribution reports some preliminary results on the evaluation of the optical cross talk level among the SiPM pixels foreseen for the ASTRI SST-2M camera

  16. Cherenkov Water Detectors in Particle Physics and Cosmic Rays

    Science.gov (United States)

    Petrukhin, A. A.; Yashin, I. I.

    2017-12-01

    Among various types of Cherenkov detectors (solid, liquid and gaseous) created for different studies, the most impressive development was gained by water detectors: from the first detector with a volume of several liters in which the Cherenkov radiation was discovered, to the IceCube detector with a volume of one cubic kilometer. The review of the development of Cherenkov water detectors for various purposes and having different locations - ground-based, underground and underwater-is presented in the paper. The prospects of their further development are also discussed.

  17. Quenching the scintillation in CF4 Cherenkov gas radiator

    International Nuclear Information System (INIS)

    Blake, T.; D'Ambrosio, C.; Easo, S.; Eisenhardt, S.; Fitzpatrick, C.; Forty, R.; Frei, C.; Gibson, V.; Gys, T.; Harnew, N.; Hunt, P.; Jones, C.R.; Lambert, R.W.; Matteuzzi, C.; Muheim, F.; Papanestis, A.; Perego, D.L.; Piedigrossi, D.; Plackett, R.; Powell, A.

    2015-01-01

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

  18. The Cherenkov Radiation for Non-Trivial Systems

    International Nuclear Information System (INIS)

    Grau Carles, A.

    2002-01-01

    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. DIRC, the internally reflecting ring imaging Cherenkov detector for BABAR

    International Nuclear Information System (INIS)

    Adam, I.; Aston, D.

    1997-11-01

    The DIRC is a new type of Cherenkov imaging device that will be used for the first time in the BABAR detector at the asymmetric B-factory, PEP-II. It is based on total internal reflection and uses long, rectangular bars made from synthetic fused silica as Cherenkov radiator and light guide. The principles of the DIRC ring imaging Cherenkov technique are explained and results from the prototype program are presented. Its choice for the BABAR detector particle identification system is motivated, followed by a discussion of the quartz radiator properties and the detector design

  20. A multiplicity trigger for a Cherenkov detector

    International Nuclear Information System (INIS)

    Jonsson, P.

    1984-05-01

    The Multiplicity Trigger (MT) is a device for deciding if, in a given time window, the number of wires that are hit in a multi wire proportional chamber (MWPC) is within given limits. The MT is designed for a Cherenkov detector, using a MWPC with 155 sense wires. It has ten inputs with sixteen channels on each, for 160 ECL input signals from the MWPC. With the MT, it is possible to decide if the number of hits is greater than n out of 160, where n is called the multiplicity. Here, 2 < n < 30, with an accuracy of +- 1. The time window can be adjusted from 0.7 to 4 μs. The MT has four separate NIM outputs, to make it possible to have four different values of n at the same time. The propagation delay from input to output is at the most 100 ns. (author)

  1. Aerogel Cherenkov Counters of the KEDR Detector

    CERN Document Server

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

    2017-01-01

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

  2. Cherenkov particle identifier for relativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, J P; Olson, D L; Baumgartner, M; Girard, J G; Lindstrom, P J; Greiner, D E; Symons, T J.M.; Crawford, H J

    1985-12-01

    A total internal reflection Cherenkov detector is described. A figure of merit of 84Z/sup 2/sin/sup 2/theta photoelectrons/cm has been measured and the application of the device to charge and velocity measurements of relativistic heavy ions has been tested. We have achieved a charge resolution of ..delta..Zsub(rms)=0.15e for Z=20 with a 3 mm thick glass detector and a velocity resolution of ..delta beta..sub(rms)=2x10/sup -4/ at ..beta..=0.93 and Z=26 with a 6 mm thick fused silica detector. Combining charge and velocity measurements with a magnetic rigidity selection, we have achieved an isotopic mass resolution of ..delta..Msub(rms)=0.1 u with a 2 mm thick fused silica detector for 20

  3. Cherenkov particle identifier for relativistic heavy ions

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, J P; Olson, D L; Baumgartner, M; Girard, J G; Lindstrom, P J; Greiner, D E; Symons, T J.M.; Crawford, H J

    1985-12-01

    A total internal reflection Cherenkov detector is described. A figure of merit of 84Z/sup 2/sin/sup 2/theta photoelectrons/cm has been measured and the application of the device to charge and velocity measurements of relativistic heavy ions has been tested. We have achieved a charge resolution of ..delta..Zsub(rms)=0.15e for Z=20 with a 3 mm thick glass detector and a velocity resolution of ..delta beta..sub(rms)=2 x 10/sup -4/ at ..beta..=0.93 and Z=26 with a 6 mm thick fused silica detector. Combining charge and velocity measurements with a magnetic rigidity selection, we have achieved an isotopic mass resolution of ..delta..Msub(rms)=0.1 u with a 2 mm thick fused silica detector for 20 < A < 40.

  4. Cherenkov-like emission of Z bosons

    Science.gov (United States)

    Colladay, D.; Noordmans, J. P.; Potting, R.

    2017-07-01

    We study CPT and Lorentz violation in the electroweak gauge sector of the Standard Model in the context of the Standard-Model Extension (SME). In particular, we show that any non-zero value of a certain relevant Lorentz violation parameter that is thus far unbounded by experiment would imply that for sufficiently large energies one of the helicity modes of the Z boson should propagate with spacelike four-momentum and become stable against decay in vacuum. In this scenario, Cherenkov-like radiation of Z bosons by ultra-high-energy cosmic-ray protons becomes possible. We deduce a bound on the Lorentz violation parameter from the observational data on ultra-high energy cosmic rays.

  5. Melqart-Herakles matando al Toro Celeste en una placa ebúrnea de Medellín

    Directory of Open Access Journals (Sweden)

    Almagro-Gorbea, Martín

    2002-12-01

    Full Text Available An ivory plaque found in the Tartessian necropolis from Medellin (Badajoz, Spain, dated about 600 B.C., shows a hero with a Phygian helmet killing a bull. The iconography of this scene can be interpreted a Phoenician-Tartessian myth of «Melqart killing de Heaven's Bull», which could be a precedent of the well-known Greek myth of «Herakles and the Cretan Bull». This ivory plaque is interesting not only for classical iconography but also to show the deep relation between the Phoenician and the Tartessian mythology.En la necrópolis tartésica orientalizante de Medellín ha aparecido una placa con una escena de tauromaquia fechada hacia el 600 a.C. con un personaje con gorro frigio que apuntilla a un toro. Su análisis iconográfico permite interpretarla como un posible mito de «Melqart dando muerte al Toro Celeste», probable precedente del mito griego de Heracles y el Toro de Creta. Además de su interés para la mitología clásica, este marfil confirma la profunda interrelación entre la mitología y las creencias tartésicas y fenicias.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

  7. Atmospheric Monitoring at the Site of the MAGIC Telescopes

    Directory of Open Access Journals (Sweden)

    Will Martin

    2017-01-01

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

  8. Effect of wavelength shifters on water Cherenkov detectors

    Energy Technology Data Exchange (ETDEWEB)

    Badino, G; Galeotti, P; Periale, L; Saavedra, O; Turtelli, A [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica; Turin Univ. (Italy). Ist. di Fisica Generale)

    1981-06-15

    We report the results of a test showing that concentrations of approx. equal to 2 mg/l of wavelength shifter in water give almost the maximum efficiency of detection without losing the directionality of Cherenkov light.

  9. The Cherenkov correlated timing detector: materials, geometry and timing constraints

    International Nuclear Information System (INIS)

    Aronstein, D.; Bergfeld, T.; Horton, D.; Palmer, M.; Selen, M.; Thayer, G.; Boyer, V.; Honscheid, K.; Kichimi, H.; Sugaya, Y.; Yamaguchi, H.; Yoshimura, Y.; Kanda, S.; Olsen, S.; Ueno, K.; Tamura, N.; Yoshimura, K.; Lu, C.; Marlow, D.; Mindas, C.; Prebys, E.; Pomianowski, P.

    1996-01-01

    The key parameters of Cherenkov correlated timing (CCT) detectors are discussed. Measurements of radiator geometry, optical properties of radiator and coupling materials, and photon detector timing performance are presented. (orig.)

  10. Cherenkov and scintillation light separation in organic liquid scintillators

    Energy Technology Data Exchange (ETDEWEB)

    Caravaca, J.; Descamps, F.B.; Land, B.J.; Orebi Gann, G.D. [University of California, Berkeley, CA (United States); Lawrence Berkeley National Laboratory, Berkeley, CA (United States); Yeh, M. [Brookhaven National Laboratory, Upton, NY (United States)

    2017-12-15

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

  11. Performance of a prototype water Cherenkov detector for LHAASO project

    International Nuclear Information System (INIS)

    An, Q.; Bai, Y.X.; Bi, X.J.; Cao, Z.; Cao, Zhe; Chang, J.F.; Chen, G.; Chen, L.H.; Chen, M.J.; Chen, T.L.; Chen, Y.T.; Cui, S.W.; Dai, B.Z.; Danzengluobu; Feng, C.F.; Gao, B.; Gu, M.H.; Hao, X.J.; He, H.H.; Hu, H.B.

    2011-01-01

    A large high-altitude air shower observatory is to be built at Yang-Ba-Jing, Tibet, China. One of its main purposes is to survey the northern sky for very-high-energy (above 100 GeV) gamma ray sources via its ground-based water Cherenkov detector array. To gain full knowledge of water Cherenkov technique in detecting air showers, a prototype water Cherenkov detector is built at the Institute of High Energy Physics, Beijing. The performance of the prototype water Cherenkov detector is studied by measuring its response to cosmic muons. The results are compared with those from a full Monte Carlo simulation to provide a series of information regarding the prototype detector in guiding electronics design and detector optimization.

  12. Cherenkov and scintillation light separation in organic liquid scintillators

    International Nuclear Information System (INIS)

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

    2017-01-01

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

  13. Vavilov-Cherenkov and Synchrotron Radiation Foundations and Applications

    CERN Document Server

    Afanasiev, G. N

    2005-01-01

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

  14. Optical fiber Cherenkov detector for beam current monitoring

    International Nuclear Information System (INIS)

    Pishchulin, I.V.; Solov'ev, N.G.; Romashkin, O.B.

    1991-01-01

    The results obtained in calculation of an optical fiber Cherenkov detector for accelerated beam current monitoring are presented. The technique of beam parameters monitoring is based on Cherenkov radiation excitation by accelerated electrons in the optical fiber. The formulas for calculations of optical power and time dependence of Cherenkov radiation pulse are given. The detector sensitivity and time resolution dependence on the fiber material characteristics are investigated. Parameters of a 10μm one-mode quartz optical fiber detector for the free electron laser photoinjector are calculated. The structure of a monitoring system with the optical fiber Cherenkov detector is considered. Possible applications of this technique are discussed and some recommendations are given

  15. Conceptual history of the Vavilov-Cherenkov radiation

    International Nuclear Information System (INIS)

    Frank, I.M.

    1984-01-01

    The evolution of ideas on the nature of the Vavilov-Cherenkov radiation is discussed. The period between Vavilov's ideas, advanced in 1934, and the formulation of a quantitative theory of the phenomenon in 1937 is surveyed

  16. Color quench correction for low level Cherenkov counting.

    Science.gov (United States)

    Tsroya, S; Pelled, O; German, U; Marco, R; Katorza, E; Alfassi, Z B

    2009-05-01

    The Cherenkov counting efficiency varies strongly with color quenching, thus correction curves must be used to obtain correct results. The external (152)Eu source of a Quantulus 1220 liquid scintillation counting (LSC) system was used to obtain a quench indicative parameter based on spectra area ratio. A color quench correction curve for aqueous samples containing (90)Sr/(90)Y was prepared. The main advantage of this method over the common spectra indicators is its usefulness also for low level Cherenkov counting.

  17. On the kinematics of the two-photon Cherenkov effect

    International Nuclear Information System (INIS)

    Afanas'ev, G.N.; Stepanovskij, Yu.P.

    2003-01-01

    We study the kinematics of the two-photon Cherenkov effect. In the general case, the emission angles of two photons satisfy certain inequalities and the corresponding radiation intensities are rather diffused. In special cases, when the above inequalities reduce to equalities, the emission angles of two photons are fixed and the corresponding radiation intensities should have sharp maxima at these angles. This makes easier the experimental study of the two-photon Cherenkov effect

  18. Studies of runaway electrons via Cherenkov effect in tokamaks

    Science.gov (United States)

    Zebrowski, J.; Jakubowski, L.; Rabinski, M.; Sadowski, M. J.; Jakubowski, M. J.; Kwiatkowski, R.; Malinowski, K.; Mirowski, R.; Mlynar, J.; Ficker, O.; Weinzettl, V.; Causa, F.; COMPASS; FTU Teams

    2018-01-01

    The paper concerns measurements of runaway electrons (REs) which are generated during discharges in tokamaks. The control of REs is an important task in experimental studies within the ITER-physics program. The NCBJ team proposed to study REs by means of Cherenkov-type detectors several years ago. The Cherenkov radiation, induced by REs in appropriate radiators, makes it possible to identify fast electron beams and to determine their spatial- and temporal-characteristics. The results of recent experimental studies of REs, performed in two tokamaks - COMPASS in Prague and FTU in Frascati, are summarized and discussed in this paper. Examples of the electron-induced signals, as recorded at different experimental conditions and scenarios, are presented. Measurements performed with a three-channel Cherenkov-probe in COMPASS showed that the first fast electron peaks can be observed already during the current ramp-up phase. A strong dependence of RE-signals on the radial position of the Cherenkov probe was observed. The most distinct electron peaks were recorded during the plasma disruption. The Cherenkov signals confirmed the appearance of post-disruptive RE beams in circular-plasma discharges with massive Ar-puffing. During experiments at FTU a clear correlation between the Cherenkov detector signals and the rotation of magnetic islands was identified.

  19. Application of Cherenkov light observation to reactor measurements (1). Estimation of reactor power from Cherenkov light intensity

    International Nuclear Information System (INIS)

    Yamamoto, Keiichi; Takeuchi, Tomoaki; Kimura, Nobuaki; Ohtsuka, Noriaki; Tsuchiya, Kunihiko; Sano, Tadafumi; Nakajima, Ken; Homma, Ryohei; Kosuge, Fumiaki

    2015-01-01

    Development of the reactor measurement system was started to obtain the real-time in-core nuclear and thermal information, where the quantitative measurement of brightness of Cherenkov light was investigated. The system would be applied as a monitoring system in severe accidents and for the advanced operation management technology in existing LWRs. The calculation and the observation were performed to obtain the quantity of the Cherenkov light caused by the gamma and beta rays emitted from the fuels in the core of Kyoto University Research Reactor. The results indicate that the real-time reactor power can be estimated from the brightness of the Cherenkov light observed by a CCD camera. This method can also work for the estimation of the burn-up of spent fuels at commercial reactors. Since the observed brightness value of the Cherenkov light was influenced by the camera position, the optical observation method should be improved to achieve high accuracy observation. (author)

  20. An innovative telescope control system architecture for SST-GATE telescopes at the CTA Observatory

    Science.gov (United States)

    Fasola, Gilles; Mignot, Shan; Laporte, Philippe; Abchiche, Abdel; Buchholtz, Gilles; Jégouzo, Isabelle

    2014-07-01

    SST-GATE (Small Size Telescope - GAmma-ray Telescope Elements) is a 4-metre telescope designed as a prototype for the Small Size Telescopes (SST) of the Cherenkov Telescope Array (CTA), a major facility for the very high energy gamma-ray astronomy of the next three decades. In this 100-telescope array there will be 70 SSTs, involving a design with an industrial view aiming at long-term service, low maintenance effort and reduced costs. More than a prototype, SST-GATE is also a fully functional telescope that shall be usable by scientists and students at the Observatoire de Meudon for 30 years. The Telescope Control System (TCS) is designed to work either as an element of a large array driven by an array controller or in a stand-alone mode with a remote workstation. Hence it is built to be autonomous with versatile interfacing; as an example, pointing and tracking —the main functions of the telescope— are managed onboard, including astronomical transformations, geometrical transformations (e.g. telescope bending model) and drive control. The core hardware is a CompactRIO (cRIO) featuring a real-time operating system and an FPGA. In this paper, we present an overview of the current status of the TCS. We especially focus on three items: the pointing computation implemented in the FPGA of the cRIO —using CORDIC algorithms— since it enables an optimisation of the hardware resources; data flow management based on OPCUA with its specific implementation on the cRIO; and the use of an EtherCAT field-bus for its ability to provide real-time data exchanges with the sensors and actuators distributed throughout the telescope.

  1. Estimation of primary cosmic ray characteristics with the help of EAS Cherenkov light

    International Nuclear Information System (INIS)

    Aleksandrov, L.; Brankova, M.; Kirov, I.; Mishev, A.; Stamenov, J.; Ushev, S.; Mavrodiev, S.

    1999-01-01

    A new method of estimating primary cosmic ray characteristics based on the registration and analysis of EAS Cherenkov light is proposed. The nature, energy and arrival direction of primaries are obtained as a solution of a nonlinear inverse problem. The applied mathematical model is created by analyzing 'Hotovo' telescope experimental data. The behaviour of model parameters is studied using CORSIKA code for the primary energy interval 30 GeV-3 TeV. This method could be applied successfully for a different kind of detector displacements of EAS arrays. Moreover, it is shown that the shower parameter estimation could be obtained more effectively and precisely in the case of detectors displacement according to a Spiral

  2. Roles of crustacean hyperglycaemic hormone in ionic and metabolic homeostasis in the Christmas Island blue crab, Discoplax celeste.

    Science.gov (United States)

    Turner, Lucy M; Webster, Simon G; Morris, Stephen

    2013-04-01

    There is a growing body of evidence implicating the involvement of crustacean hyperglycaemic hormone (CHH) in ionic homeostasis in decapod crustaceans. However, little is known regarding hormonally influenced osmoregulatory processes in terrestrial decapods. As many terrestrial decapods experience opposing seasonal demands upon ionoregulatory physiologies, we reasoned that these would make interesting models in which to study the effect of CHH upon these phenomena. In particular, those (tropical) species that also undergo seasonal migrations might be especially informative, as we know relatively little regarding the nature of CHHs in terrestrial decapods, and hormonally mediated responses to seasonal changes in metabolic demands might also be superimposed or otherwise integrated with those associated with ionic homeostasis. Using Discoplax celeste as a model crab that experiences seasonal extremes in water availability, and exhibits diurnal and migratory activity patterns, we identified two CHHs in the sinus gland. We biochemically characterised (cDNA cloning) one CHH and functionally characterised (in terms of dose-dependent hyperglycaemic responses and glucose-dependent negative feedback loops) both CHHs. Whole-animal in situ branchial chamber (22)NaCl perfusion experiments showed that injection of both CHHs increased gill Na(+) uptake in a seasonally dependent manner, and (51)Cr-EDTA clearance experiments demonstrated that CHH increased urine production by the antennal gland. Seasonal and salinity-dependent differences in haemolymph CHH titre further implicated CHH in osmoregulatory processes. Intriguingly, CHH appeared to have no effect on gill Na(+)/K(+)-ATPase or V-ATPase activity, suggesting unknown mechanisms of this hormone's action on Na(+) transport across gill epithelia.

  3. Prevalence and correlates of 'agua celeste' use among female sex workers who inject drugs in Ciudad Juarez, Mexico.

    Science.gov (United States)

    Morris, Meghan D; Case, Patricia; Robertson, Angela M; Lozada, Remedios; Vera, Alicia; Clapp, John D; Medina-Mora, Maria Elena; Strathdee, Steffanie A

    2011-09-01

    Agua celeste, or "heavenly water", is the street name for a sky-blue colored solvent reportedly inhaled or ingested to produce an intoxicating effect. Study aims were to (1) describe prevalence of agua celestse (AC) use, and (2) identify correlates of lifetime and recent use of AC use among female sex workers who also inject drugs (FSW-IDUs) in northern Mexico. Between 2008 and 2010, baseline data from FSW-IDUs≥18 years old living in Tijuana or Ciudad Juarez participating in a longitudinal behavioral intervention were analyzed using logistic regression. Among 623 FSW-IDUs (307 from Tijuana and 316 from Ciudad Juarez (CJ)), 166 (26%) reported ever using AC, all of whom lived in CJ. Among the CJ sample, lifetime prevalence of AC use was 53%, median age of first use was 16 years (IQR: 14-23), and 10% reported it as their first abused substance. Ever using AC was independently associated with ever being physically abused and younger age, and was marginally associated with initiating injection drug use and regular sex work at age eighteen or younger. Among those ever using AC, 70/166 (42.2%) reported using it within the last 6 months, which was independently associated with using drugs with clients before or during sex, being on the street more than 8h per day, and younger age. We observed considerable geographic variation in the use of AC in northern Mexico. Future studies exploring factors influencing use, its precise formulation(s), and its potential health effects are needed to guide prevention and treatment. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Scattering of light by colloidal aluminosilicate particles produces the unusual sky-blue color of Río Celeste (Tenorio volcano complex, Costa Rica.

    Directory of Open Access Journals (Sweden)

    Erick Castellón

    Full Text Available Río Celeste (Sky-Blue River in Tenorio National Park (Costa Rica, a river that derives from the confluence and mixing of two colorless streams--Río Buenavista (Buenavista River and Quebrada Agria (Sour Creek--is renowned in Costa Rica because it presents an atypical intense sky-blue color. Although various explanations have been proposed for this unusual hue of Río Celeste, no exhaustive tests have been undertaken; the reasons hence remain unclear. To understand this color phenomenon, we examined the physico-chemical properties of Río Celeste and of the two streams from which it is derived. Chemical analysis of those streams with ion-exchange chromatography (IC and inductively coupled plasma atomic emission spectroscopy (ICP-OES made us discard the hypothesis that the origin of the hue is due to colored chemical species. Our tests revealed that the origin of this coloration phenomenon is physical, due to suspended aluminosilicate particles (with diameters distributed around 566 nm according to a lognormal distribution that produce Mie scattering. The color originates after mixing of two colorless streams because of the enlargement (by aggregation of suspended aluminosilicate particles in the Río Buenavista stream due to a decrease of pH on mixing with the acidic Quebrada Agria. We postulate a chemical mechanism for this process, supported by experimental evidence of dynamic light scattering (DLS, zeta potential measurements, X-ray diffraction and scanning electron microscopy (SEM with energy-dispersive spectra (EDS. Theoretical modeling of the Mie scattering yielded a strong coincidence between the observed color and the simulated one.

  5. CLASSiC: Cherenkov light detection with silicon carbide

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-02-11

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

  6. Neutrino Telescope

    International Nuclear Information System (INIS)

    Coelin Baldo, Milla

    2009-01-01

    The present volume contains the proceedings of the 13. International Workshop on 'Neutrino Telescope', 17. of the series 'Un altro modo di guardare il cielo', held in Venice at the 'Istituto Veneto di Scienze, Lettere ed Arti' from March 10 to March 13, 2009. This series started in Venice 21 years ago, in 1988, motivated by the growing interest in the exciting field of the neutrino physics and astrophysics, with the aim to bring together experimentalists and theorists and encourage discussion on the most recent results and to chart the direction of future researchers.

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

    Science.gov (United States)

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

    2017-08-18

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

  8. The performance of silicon photomultipliers in Cherenkov TOF PET

    International Nuclear Information System (INIS)

    Dolenec, Rok; Korpar, Samo; Krizan, Peter; Pestotink, Rok

    2015-01-01

    In time-of-flight positron emission tomography (TOF PET) one of the main factors limiting the time resolution is the time evolution of the scintillation process. This can be avoided by using exclusively the Cherenkov light produced in a suitable material. Sub 100 ps FWHM timing has already been experimentally demonstrated but with a drawback of relatively low detection efficiency due to the photodetectors used. In this work silicon photomultipliers (SiPMs) are considered as a photodetector in Cherenkov TOF PET. The detection efficiency can be significantly improved by using SiPMs, however, at room temperature the SiPM dark counts introduce a significant source of fake coincidences. SiPM samples from different producers were tested in a simple back-to-back setup in combination with lead fluoride Cherenkov radiators. Results for coincidence timing, detection efficiency and effects of dark counts at different temperatures and SiPM overvoltages are presented.

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  10. High speed decision electronics combined to a beam Cherenkov counter

    International Nuclear Information System (INIS)

    Sghaier, H.

    1993-01-01

    The Hypolit detector for identification of particles in high energy physics using the Cherenkov radiation, is based on an intensifier tube coupled to photomultipliers via a fiber-optic matrix. Cherenkov photons are focused into a ring; particle identification consists in calculating the ring radius. A fast and high level electronic system is associated to Hypolit. Besides deriving the radius, it allows a background rejection and achieves a momentum correction. This on line tagging contributes to build the WA89 trigger. Tuning is controlled with a micro-computer which makes the access to the heart of the system friendly-user

  11. Light-weight spherical mirrors for Cherenkov detectors

    CERN Document Server

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

    2003-01-01

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

  12. Theoretical study of Cherenkov radiation emission in anisotropic uniaxial crystals

    Energy Technology Data Exchange (ETDEWEB)

    Delbart, A; Derre, J

    1996-04-01

    A theoretical review of the Cherenkov radiation emission in uniaxial crystals is presented. The formalism of C. Muzicar in terms of energetic properties of the emitted waves are corrected. This formalism is used to simulate the Cherenkov radiation emission in a strongly birefringent sodium nitrate crystal (NaNO{sub 3}) and to investigate the consequences of the slight anisotropy of sapphire (Al{sub 2}O{sub 3}) on the design of the Optical Trigger. (author). 12 refs. Submitted to Physical Review, D (US).

  13. Characteristics of a gamma telescope on the ''Kosmos-561'' satellite

    International Nuclear Information System (INIS)

    Bokov, V.L.; Kruglov, E.M.

    1981-01-01

    The results of calculations of gamma telescope characteristics intended for investigating cosmic γ radiation at E>=100 MeV in the ''Cosmos 561'' artificial Earth satellite, using the Monte Carlo method, are presented. The gamma spectrometer contains a lead converter, scintillation deteectors of polysterene, a unit of spark chambers and a Cherenkov detector of lead glass. The dependence of the device effective area and angular resolution on γ quanta energy is calculated. The relative radiation pattern of the device is given. The given integral characteristics of the gamma telescope for a γ quanta flux with an exponential spectrum are the following: the effective geometrical factor and effective device area depending on the spectrum index. The calibration gamma telescope curve is plotted according to the electron mean free path distribution [ru

  14. Recent results on galactic sources with MAGIC telescope

    International Nuclear Information System (INIS)

    De los Reyes, R.

    2009-01-01

    Located at the Canary island of La Palma, the single-dish MAGIC telescope currently has the lowest energy threshold achieved by any Cherenkov telescope, which can be as low as 25 GeV. In the last two years, the MAGIC telescope has detected a significant amount of galactic sources that emit at very high energies (up to several TeV). Here we present the most recent results that have yielded important scientific highlights in astrophysics, which include the first detection of gamma-ray emission from a pulsar, an X-ray binary system and a stellar-mass black hole. We also make a review of the latest results of the MAGIC observations on galactic sources, which will include also γ-ray unidentified sources (TeV J2032+4130), the Galactic Centre, X-ray binaries (LSI +61 303), pulsars (Crab pulsar) and SNRs (IC443).

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

    Directory of Open Access Journals (Sweden)

    Postnikov E.B.

    2017-01-01

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

  16. Cherenkov detectors and a new effective-mass spectrometer method

    Czech Academy of Sciences Publication Activity Database

    Hladký, Jan

    2006-01-01

    Roč. 75, - (2006), s. 854-855 ISSN 0969-806X Institutional research plan: CEZ:AV0Z10100502 Keywords : Cherenkov radiation * spectrometer * effective mass method Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 0.868, year: 2006

  17. Lunar imaging and ionospheric calibration for the Lunar Cherenkov technique

    NARCIS (Netherlands)

    McFadden, R.; Scholten, O.; Mevius, M.

    2013-01-01

    The Lunar Cherenkov technique is a promising method for UHE neutrino and cosmic ray detection which aims to detect nanosecond radio pulses produced during particle interactions in the Lunar regolith. For low frequency experiments, such as NuMoon, the frequency dependent dispersive effect of the

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

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... The Cherenkov light Lateral Distribution Function (LDF) from particles initiated Extensive Air Showers (EAS) with ultrahigh energies ( > 1016 eV) was simulated using CORSIKA program for configuration of Tunka and Yakutsk EAS arrays for different primary particles (p, Fe and O2) and different zenith ...

  19. Muon-track studies in a water Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Etchegoyen, A. [Departamento de Fisica, Comision Nacional de Energia Atomica, Avenida del Libertador 8250 (1429) Buenos Aires (Argentina)]. E-mail: etchegoy@tandar.cnea.gov.ar; Bauleo, P. [Departamento de Fisica, Comision Nacional de Energia Atomica, Avenida del Libertador 8250 (1429) Buenos Aires (Argentina); Bertou, X. [Enrico Fermfi Institute, University of Chicago, 5640 S. Ellis, Chicago, IL 60637 (United States); Bonifazi, C.B. [Departamento de Fisica, Comision Nacional de Energia Atomica, Avenida del Libertador 8250 (1429) Buenos Aires (Argentina); Filevich, A. [Departamento de Fisica, Comision Nacional de Energia Atomica, Avenida del Libertador 8250 (1429) Buenos Aires (Argentina); Medina, M.C. [Departamento de Fisica, Comision Nacional de Energia Atomica, Avenida del Libertador 8250 (1429) Buenos Aires (Argentina); Melo, D.G. [Departamento de Fisica, Comision Nacional de Energia Atomica, Avenida del Libertador 8250 (1429) Buenos Aires (Argentina); Rovero, A.C. [Instituto de Astronomia y Fisica del Espacio, CC 67, Suc. 28 (1428) Buenos Aires (Argentina); Supanitsky, A.D. [Departamento de Fisica, Comision Nacional de Energia Atomica, Avenida del Libertador 8250 (1429) Buenos Aires (Argentina); Tamashiro, A. [Departamento de Fisica, Comision Nacional de Energia Atomica, Avenida del Libertador 8250 (1429) Buenos Aires (Argentina)

    2005-06-21

    Background muons may be used in cosmic ray experiments to understand the response of a given detector system and to lay the basis for the further theoretical and simulation work needed in the analysis of air showers. Experiments were performed using a water Cherenkov detector at the Tandar Laboratory. Monte Carlo and semi-analytical calculations were compared to the data.

  20. First observation of Cherenkov ring images using hybrid photon detectors

    International Nuclear Information System (INIS)

    Albrecht, E.; Wilkinson, G.; Bibby, J.H.; Giles, R.; Harnew, N.; Smale, N.; Brook, N.H.; Halley, A.W.; O'Shea, V.; French, M.; Gibson, V.; Wotton, S.A.; Schomaker, R.

    1998-01-01

    A ring-imaging Cherenkov detector, equipped with hybrid photon detectors, has been operated in a charged-particle beam. Focussed ring images from various particle types were detected using silica aerogel, air and C 4 F 10 gas radiators. The detector, a prototype for the CERN LHC-B experiment, is described and first observations are reported. (orig.)

  1. First observation of Cherenkov ring images using hybrid photon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, E.; Wilkinson, G. [European Organization for Nuclear Research, Geneva (Switzerland). Div. Particle Physics Experiments; Barber, G.; Duane, A.; John, M.; Miller, D.G.; Websdale, D. [Imperial College of Science Technology and Medicine, Blackett Laboratory, Prince Consort Road, London SW7 2AZ (United Kingdom); Bibby, J.H.; Giles, R.; Harnew, N.; Smale, N. [University of Oxford, Department of Nuclear Physics, Keble Road, Oxford OX1 3RH (United Kingdom); Brook, N.H.; Halley, A.W.; O`Shea, V. [University of Glasgow, Department of Physics, Glasgow G12 8QQ (United Kingdom); French, M. [Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX (United Kingdom); Gibson, V.; Wotton, S.A. [University of Cambridge, Cavendish Laboratory, Madingley Road, Cambridge CB3 0HE (United Kingdom); Schomaker, R. [Delft Electronic Products BV, 9300 AB Roden (Netherlands)

    1998-07-11

    A ring-imaging Cherenkov detector, equipped with hybrid photon detectors, has been operated in a charged-particle beam. Focussed ring images from various particle types were detected using silica aerogel, air and C{sub 4}F{sub 10} gas radiators. The detector, a prototype for the CERN LHC-B experiment, is described and first observations are reported. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-11-16

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

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

    International Nuclear Information System (INIS)

    Ciarrocchi, Esther; Belcari, Nicola; Guerra, Alberto Del; Cherry, Simon R.; Lehnert, Adrienne; Hunter, William C. J.; McDougald, Wendy; Miyaoka, Robert S.; Kinahan, Paul E.

    2015-01-01

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

  4. Technical Note: On maximizing Cherenkov emissions from medical linear accelerators.

    Science.gov (United States)

    Shrock, Zachary; Yoon, Suk W; Gunasingha, Rathnayaka; Oldham, Mark; Adamson, Justus

    2018-04-19

    Cherenkov light during MV radiotherapy has recently found imaging and therapeutic applications but is challenged by relatively low fluence. Our purpose is to investigate the feasibility of increasing Cherenkov light production during MV radiotherapy by increasing photon energy and applying specialized beam-hardening filtration. GAMOS 5.0.0, a GEANT4-based framework for Monte Carlo simulations, was used to model standard clinical linear accelerator primary photon beams. The photon source was incident upon a 17.8 cm 3 cubic water phantom with a 94 cm source to surface distance. Dose and Cherenkov production was determined at depths of 3-9 cm. Filtration was simulated 15 cm below the photon beam source. Filter materials included aluminum, iron, and copper with thicknesses of 2-20 cm. Histories used depended on the level of attenuation from the filter, ranging from 100 million to 2 billion. Comparing average dose per history also allowed for evaluation of dose-rate reduction for different filters. Overall, increasing photon beam energy is more effective at improving Cherenkov production per unit dose than is filtration, with a standard 18 MV beam yielding 3.3-4.0× more photons than 6 MV. Introducing an aluminum filter into an unfiltered 2400 cGy/min 10 MV beam increases the Cherenkov production by 1.6-1.7×, while maintaining a clinical dose rate of 300 cGy/min, compared to increases of ~1.5× for iron and copper. Aluminum was also more effective than the standard flattening filter, with the increase over the unfiltered beam being 1.4-1.5× (maintaining 600 cGy/min dose rate) vs 1.3-1.4× for the standard flattening filter. Applying a 10 cm aluminum filter to a standard 18 MV, photon beam increased the Cherenkov production per unit dose to 3.9-4.3× beyond that of 6 MV (vs 3.3-4.0× for 18 MV with no aluminum filter). Through a combination of increasing photon energy and applying specialized beam-hardening filtration, the amount of Cherenkov photons per

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

    CERN Document Server

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

    2008-01-01

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

  6. Status and recent results of the MAGIC telescope system

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-01

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

  7. The Advanced Gamma-ray Imaging System (AGIS): Next-generation Cherenkov telescopes array.

    Science.gov (United States)

    Vassiliev, Vladimir; AGIS Collaboration

    2010-03-01

    AGIS is a concept for a next-generation ground-based gamma-ray observatory in the energy range from 50 GeV to 200 TeV. AGIS is being designed to have significantly improved sensitivity, angular resolution, and reliability of operation relative to the present generation instruments such as VERITAS and H.E.S.S. The novel technologies of AGIS are expected to enable great advances in the understanding of the populations and physics of sources of high-energy gamma rays in the Milky Way (e.g. SNR, X-ray binaries, dense molecular clouds) and outside the Galaxy (e.g. AGN, GRBs, galaxy clusters, and star-forming galaxies). AGIS will complement and extend the results now being obtained in the GeV range with the Fermi mission providing wide energy coverage, superior angular resolution, and sensitivity to variability on short time scales. AGIS will be a key instrument for identifying and characterizing Fermi LAT sources. In this submission we outline the status of the development of AGIS project, design concept, and principal technologies. As illustrations of the scientific capabilities of AGIS, we review its potential to indirectly search for dark matter and measure cosmological magnetic fields.

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

    Czech Academy of Sciences Publication Activity Database

    Acharya, B.S.; Aramo, C.; Babic, A.; Boháčová, Martina; Chudoba, Jiří; Ebr, Jan; Hrabovský, Miroslav; Janeček, Petr; Mandát, Dušan; Palatka, Miroslav; Pech, Miroslav; Prouza, Michael; Řídký, Jan; Schovánek, Petr; Trávníček, Petr

    2015-01-01

    Roč. 62, Mar (2015), s. 152-164 ISSN 0927-6505 R&D Projects: GA MŠk(CZ) 7AMB12AR013; GA MŠk LE13012; GA MŠk LG14019 Institutional support: RVO:68378271 Keywords : acceleration of particles * gamma rays: general * ISM: supernova remnants * radiation mechanisms: non-termal Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.425, year: 2015

  9. Characterization and commissioning of the SST-1M camera for the Cherenkov Telescope Array

    Czech Academy of Sciences Publication Activity Database

    Aguilar, J.A.; Bilnik, W.; Blocki, J.; Bogacz, L.; Borkowski, J.; Bulik, T.; Cadoux, F.; Christov, A.; Curylo, M.; della Volpe, D.; Dyrda, M.; Favre, Y.; Frankowski, A.; Grudnik, L.; Grudzinska, M.; Heller, M.; Idzkowski, B.; Jamrozy, M.; Janiak, M.; Kasperek, J.; Lalik, K.; Lyard, E.; Mach, E.; Mandát, Dušan; Marszalek, A.; Medina Miranda, L. D.; Michałowski, J.; Moderski, R.; Montaruli, T.; Neronov, A.; Niemiec, J.; Ostrowski, M.; Pasko, P.; Pech, Miroslav; Porcelli, A.; Prandini, E.; Rajda, P.; Rameez, M.; Schioppa, E.; Schovánek, Petr; Seweryn, K.; Skowron, K.; Sliusar, V.; Sowinski, M.; Stawarz, L.; Stodulska, M.; Stodulski, M.; Toscano, S.; Troyano Pujadas, I.; Walter, R.; Wiecek, M.; Zagdanski, A.; Zietara, K.; Zychowski, P.

    2017-01-01

    Roč. 845, Feb (2017), s. 350-354 ISSN 0168-9002 Institutional support: RVO:68378271 Keywords : SiPM * G-APD * CTA * SST-1 M * Gamma-ray Astronomy * FPGA * PhotoDetection * high-speed electronics * ADC Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 1.362, year: 2016

  10. Dark matter substructure modelling and sensitivity of the Cherenkov Telescope Array to Galactic dark halos

    Energy Technology Data Exchange (ETDEWEB)

    Huetten, M. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Humboldt Univ. Berlin (Germany); Combet, C.; Maurin, D. [Grenoble-Alpes Univ., CNRS/IN2P3, Grenoble (France). LPSC; Maier, G. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2016-07-15

    Hierarchical structure formation leads to a clumpy distribution of dark matter in the Milky Way. These clumps are possible targets to search for dark matter annihilation with present and future γ-ray instruments. Many uncertainties exist on the clump distribution, leading to disputed conclusions about the expected number of detectable clumps and the ensuing limits that can be obtained from non-detection. In this paper, we use the CLUMPY code to simulate thousands of skymaps for several clump distributions. This allows us to statistically assess the typical properties (mass, distance, angular size, luminosity) of the detectable clumps. Varying parameters of the clump distributions allows us to identify the key quantities to which the number of detectable clumps is the most sensitive. Focusing our analysis on two extreme clump configurations, yet consistent with results from numerical simulations, we revisit and compare various calculations made for the Fermi-LAT instrument, in terms of number of dark clumps expected and the angular power spectrum for the Galactic signal. We then focus on the prospects of detecting dark clumps with the future CTA instrument, for which we make a detailed sensitivity analysis using open-source CTA software. Based on a realistic scenario for the foreseen CTA extragalactic survey, and accounting for a post-trial sensitivity in the survey, we show that we obtain competitive and complementary limits to those based on long observation of a single bright dwarf spheroidal galaxy.

  11. Dark matter substructure modelling and sensitivity of the Cherenkov Telescope Array to Galactic dark halos

    International Nuclear Information System (INIS)

    Huetten, M.; Combet, C.; Maurin, D.

    2016-07-01

    Hierarchical structure formation leads to a clumpy distribution of dark matter in the Milky Way. These clumps are possible targets to search for dark matter annihilation with present and future γ-ray instruments. Many uncertainties exist on the clump distribution, leading to disputed conclusions about the expected number of detectable clumps and the ensuing limits that can be obtained from non-detection. In this paper, we use the CLUMPY code to simulate thousands of skymaps for several clump distributions. This allows us to statistically assess the typical properties (mass, distance, angular size, luminosity) of the detectable clumps. Varying parameters of the clump distributions allows us to identify the key quantities to which the number of detectable clumps is the most sensitive. Focusing our analysis on two extreme clump configurations, yet consistent with results from numerical simulations, we revisit and compare various calculations made for the Fermi-LAT instrument, in terms of number of dark clumps expected and the angular power spectrum for the Galactic signal. We then focus on the prospects of detecting dark clumps with the future CTA instrument, for which we make a detailed sensitivity analysis using open-source CTA software. Based on a realistic scenario for the foreseen CTA extragalactic survey, and accounting for a post-trial sensitivity in the survey, we show that we obtain competitive and complementary limits to those based on long observation of a single bright dwarf spheroidal galaxy.

  12. El ecoturismo: quimera o realidad de desarrollo en la Reserva de la Biosfera Ría Celestún, México

    Directory of Open Access Journals (Sweden)

    Manuel Jesús Pinkus Rendón

    2015-01-01

    Full Text Available El ecoturismo es una alternativa que puede incidir positivamente en la conservación de los recursos naturales y en la economía de las comunidades. En este trabajo se reflexiona sobre el impacto del ecoturismo en comunidades ubicadas en la Reserva de la Biosfera Ría Celestún, Península de Yucatán. Se realizaron entrevistas semiestructuradas a los prestadores de servicios y se observaron diferencias en la percepción de la conservación de los recursos naturales dependiendo de la capacitación recibida. Se advirtió una falta de coordinación entre las autoridades que influía negativamente en el manejo sustentable de la reserva y en las cooperativas turísticas.

  13. Poincaré, creador de los métodos todavía modernos en las ecuaciones diferenciales y en la mecánica celeste

    Directory of Open Access Journals (Sweden)

    Delshams i Valdés, Amadeu

    2004-08-01

    Full Text Available Con motivo del sesquicentenario del nacimiento de Henri Poincaré, resulta impresionante comprobar la influencia actual de su obra, así como el gran adelanto de sus métodos e ideas respecto a las de los científicos coetáneos. En esta conferencia se repasan algunas de sus contribuciones principales a las ecuaciones diferenciales y ala mecánica celeste, y se discute el papel central que tuvo en éstas su memoria sobre el problema de tres cuerpos presentada en 1889 a un concurso para conmemorar el sexagésimo aniversario del Rey Óscar II de Suecia y Noruega.…

  14. Teorí­as de primer y segundo orden sobre el potencial de ciertas figuras de equilibrio de cuerpos celestes

    Science.gov (United States)

    Gumbau, Manuel Forner

    2010-11-01

    Uno de los problemas que aborda la Mecánica Celeste es la determinación de las figuras de equilibrio de los cuerpos celestes. Para investigar su solución mediante métodos directos, se precisa evaluar el potencial generado por su autogravitación, el generado por su fuerza centrí­fuga y el generado por la fuerza de atracción entre los cuerpos. Los métodos clásicos de Finlay y Kopal que afrontan estos problemas, para determinar el potencial autogravitatorio en las configuraciones de equilibrio, emplean desarrollos en serie de los potenciales interior y exterior del potencial autogravitatorio. Estos métodos incurren en el error de suponer la convergencia en capas donde resulta cuestionable dicha convergencia para estos desarrollos en serie. En este trabajo se han elaborado unos algoritmos que contemplan toda la casuí&stica y que permiten una manipulación efic iente del producto de polinomios de Legendre, del producto de funciones asociada s de Legendre y del producto de armónicos esféricos como combinacióon lineal de ellos mismos, respectivamente. Se han obtenido, para primer y segundo orden en las amplitudes, los desarrollos correctos para los potencial es interior y exterior del potencial autogravitatorio para configuraciones de equilibrio aisladas, y , en primer orden de amplitudes, los mismos potenciales para los sistemas binarios próximos. Se ha elaborado un método analítico, en primer orden respecto de las amplitudes, para la determinación del potencial de marea en sistemas binarios próximos en el cual se manifiesta la forma de la componente secundaria del sistema

  15. Physics and astrophysics with gamma-ray telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Vandenbroucke, J. [Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2012-08-15

    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 {approx}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 {approx}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 possible. In addition to elucidating the processes of high-energy astrophysics, gamma-ray telescopes are making essential contributions to fundamental physics topics including quantum gravity, gravitational waves, and dark matter. I summarize the current census of astrophysical gamma-ray sources, highlight some recent discoveries relevant to fundamental physics, and describe the synergetic connections between gamma-ray and neutrino astronomy. This is a brief overview intended in particular for particle physicists and neutrino astronomers, based on a presentation at the Neutrino 2010 conference in Athens, Greece. I focus in particular on results from Fermi (which was launched soon after Neutrino 2008), and conclude with a description of the next generation of instruments, namely HAWC and the Cherenkov Telescope Array.

  16. Development of an underwater high sensitivity Cherenkov detector: Sea Urchin

    International Nuclear Information System (INIS)

    Camerini, U.; McGibney, D.; Roberts, A.

    1982-01-01

    The need for a high gain, high sensitivity Cherenkov light sensor to be used in a deep underwater muon and neutrino detector (DUMAND) array has led to the design of the Sea Urchin detector. In this design a spherical photocathode PMTis optically coupled through a glass hemisphere to a large number of glass spines, each of which is filled with a wavelength-shifting (WLS) solution of a high quantum efficiency phosphor. The Cherenkov radiation is absorbed in the spine, isotropically re-radiated at a longer wavelength, and a fraction of the fluorescent light is internally reflected in the spine, and guided to the photomultiplier concentrically located in the glass hemisphere. Experiments measuring the optical characteristics of the spines and computer programs simulating light transformation and detection cross sections are described. Overall optical gains in the range 5-10 are achieved. The WLS solution is inexpensive, and may have other applications. (orig.)

  17. Study of a Cherenkov TOF-PET module

    Science.gov (United States)

    Korpar, S.; Dolenec, R.; Križan, P.; Pestotnik, R.; Stanovnik, A.

    2013-12-01

    An apparatus, consisting of two PbF2 crystals, each coupled to a multichannel plate photomultiplier (MCP-PMT), has been constructed in order to measure the time-of-flight (TOF) of the two 511 keV annihilation photons produced in positron emission tomography (PET). Excellent timing is achieved by detecting the prompt Cherenkov photons produced by the absorption of the 511 keV gamma photons. The present work describes the measurement and image reconstruction of two 22Na point sources. In addition, the influence of the radiator thickness and the Cherenkov light absorption cut-off of the crystal on the efficiency and the timing resolution have been studied by Monte Carlo simulation.

  18. A quartz Cherenkov detector for polarimetry at the ILC

    International Nuclear Information System (INIS)

    Vauth, Annika

    2014-09-01

    At the proposed International Linear Collider (ILC), the use of polarised electron and positron beams is a key ingredient of the physics program. A measurement of the polarisation with a yet unprecedented precision of δP / P =0.25% is required. To achieve this, Compton polarimeter measurements in front of and behind the collision point are foreseen. In this thesis, a novel concept for a detector for ILC polarimetry is introduced to eliminate one of the dominating systematics limiting the previous best measurement of beam polarisation: a detector using quartz as Cherenkov medium could increase the tolerance against non-linear photodetector responses. The high refractive index of quartz results in a higher Cherenkov light yield compared to conventional Cherenkov gases. This could allow single-peak resolution in the Cherenkov photon spectra produced by the Compton electrons at the polarimeters. The detailed simulation studies presented in this work imply that such single-peak resolution is possible. Considerations for the choice of a suitable detector geometry are discussed. A four-channel prototype has been constructed and successfully operated in a first testbeam campaign at the DESY testbeam, confirming simulation predictions. Although further studies have to be considered to quantify all aspects of the detector response, the findings of the analysis of the data from the first testbeam are promising with regards to reaching the desired light yield. In the final part of this thesis, the application of a detector concept allowing single-peak resolution to the polarisation measurement at the ILC is examined. Two of the main sources of systematic uncertainties on the polarimeter measurements are detector non-linearities and misalignments. The performance of the suggested quartz detector concept in Monte Carlo studies promises a control of these systematics which meets the precision requirements for ILC polarimetry.

  19. The fluid systems for the SLD Cherenkov ring imaging detector

    International Nuclear Information System (INIS)

    Abe, K.; Hasegawa, K.; Hasegawa, Y.; Iwasaki, Y.; Suekane, F.; Yuta, H.; Baird, K.; Jacques, P.; Kalelkar, M.; Plano, R.; Stamer, P.; Word, G.; Bean, A.; Caldwell, D.O.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Yellin, S.; Ben-David, R.; Manly, S.; Snyder, J.; Turk, J.; Cavalli-Sforza, M.; Coyle, P.; Coyne, D.; Gagnon, P.; Liu, X.; Schneider, M.; Williams, D.A.; Coller, J.; Shank, J.T.; Whitaker, J.S.; d'Oliveira, A.; Johnson, R.A.; Martinez, J.; Nussbaum, M.; Santha, A.K.S.; Sokoloff, M.D.; Stockdale, I.; Wilson, R.J.

    1992-10-01

    We describe the design and operation of the fluid delivery, monitor and control systems for the SLD barrel Cherenkov Ring Imaging Detector (CRID). The systems deliver drift gas (C 2 H 6 + TMAE), radiator gas (C 5 F 12 + N 2 ) and radiator liquid (C 6 F 14 ). Measured critical quantities such as electron lifetime in the drift gas and ultra-violet (UV) transparencies of the radiator fluids, together with the operational experience, are also reported

  20. The new Tunka-133 EAS Cherenkov array: Status of 2009

    International Nuclear Information System (INIS)

    Antokhonov, B.V.; Beregnev, S.F.; Budnev, N.M.; Chvalaev, O.B.; Chiavassa, A.; Gress, O.A.; Kalmykov, N.N.; Karpov, N.N.; Korosteleva, E.E.; Kozhin, V.A.; Kuzmichev, L.A.; Lubsandorzhiev, B.K.; Mirgazov, R.R.; Panasyuk, M.I.; Pankov, L.V.; Prosin, V.V.; Ptuskin, V.S.; Semeney, Yu.A.; Shaibonov, B.; Silaev, A.A.

    2011-01-01

    The deployment of the new Extensive air shower Cherenkov installation Tunka-133 with about 1 km 2 geometric acceptance area was completed in October 2009. The array will permit a detailed long-term study of the cosmic ray energy spectrum and mass composition in the energy range 10 15 -10 18 eV with a unique and more elaborate method. The array construction and data acquisition system, preliminary results and plans for future development are presented.

  1. Experimental and numerical investigations of a Cherenkov plasma maser

    International Nuclear Information System (INIS)

    Huet, D.; Pompier, F.; Vezinet, R.; Courtois, L.; Cubaynes, F.; Lalle, B.; Laporte, P.

    2005-01-01

    We are investigating the performances of a new tunable and low frequency (2-6 GHz band) Cherenkov plasma master driven by a 600 kV, 100 ns Tesla generator. We present experimental results in terms of energy and spectrum and their comparison with 2D computer simulations results versus voltage, plasma density and B field levels. The accelerator is presented in the first part of the paper [ru

  2. Recent results from the DELPHI barrel ring imaging Cherenkov counter

    International Nuclear Information System (INIS)

    Anassontzis, E.G.; Ioannou, P.; Kalkanis, G.; Katsanevas, S.; Kontaxis, I.; Kourkoumelis, C.; Nounos, S.; Preve, P.; Resvanis, L.K.; Brunet, J.M.; Dolbeau, J.; Guglielmo, L.; Ledroit, F.; Poutot, D.; Tristram, G.

    1991-01-01

    The DELPHI detector, installed at LEP, is equipped with RICH (Ring Imaging Cherenkov) counters. The Barrel part incorporates a liquid (C 6 F 14 ) and a gaseous (C 5 F 12 ) radiator providing particle identification up to 20GeV/c. The Cherenkov protons of both radiators are detected by TPC-like photon detectors. The drift gas (75% CH 4 + 25% C 2 H 6 ) is doped with TMAE, but which the UV Cherenkov photons are converted into single free photo-electrons. These are drifted towards MWPC's at the end of the drift tubes and the space coordinates of the conversion point are determined. One half of the Barrel RICH is now equipped with drift tubes and has provided results from the liquid radiator since spring 1990. The gas radiator has been tested with C 2 F 6 as a preliminary filling since August 1990. The data obtained demonstrate the good particle identification potential. For the liquid radiator the number of detected photons per ring in hadron jets is N=8, whereas for muon pairs (single tracks) N=10 has been obtained. For the gas radiator 2.1 photons per track were observed, which demonstrates the good functioning of the focussing mirrors, as the C 2 F 6 this is close to the expected value

  3. Characterization of Multianode Photomultiplier Tubes for a Cherenkov Detector

    Science.gov (United States)

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

    2017-09-01

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

  4. A Cherenkov viewing device for used-fuel verification

    International Nuclear Information System (INIS)

    Attas, E.M.; Chen, J.D.; Young, G.J.

    1990-01-01

    A Cherenkov viewing device (CVD) has been developed to help verify declared inventories of used nuclear fuel stored in water bays. The device detects and amplifies the faint ultraviolet Cherenkov glow from the water surrounding the fuel, producing a real-time visible image on a phosphor screen. Quartz optics, a UV-pass filter and a microchannel-plate image-intensifier tube serve to form the image, which can be photographed or viewed directly through an eyepiece. Normal fuel bay lighting does not interfere with the Cherenkov light image. The CVD has been successfully used to detect anomalous PWR, BWR and CANDU (CANada Deuterium Uranium: registered trademark) fuel assemblies in the presence of normal-burnup assemblies stored in used-fuel bays. The latest version of the CVD, known as Mark IV, is being used by inspectors from the International Atomic Energy agency for verification of light-water power-reactor fuel. Its design and operation are described, together with plans for further enhancements of the instrumentation. (orig.)

  5. Cherenkov radiation in a plasma-filled, dielectric coaxial waveguide

    International Nuclear Information System (INIS)

    Wu Jianqiang

    2004-01-01

    Using the self-consistent linear field theory, Cherenkov radiation excitated by the beam-wave interaction of a thin annular relativistic electron beam in a plasma-filled, dielectric coaxial cylindrical waveguide was analyzed. The dispersion equation of the interaction, the synchronized condition and the wave growth rate were derived. The energy exchange between the wave and the electron beam in the presence of background plasma was discussed, and the effects of plasma density on the dispersion characteristics, the wave growth rate and the beam-wave energy exchange were calculated and discussed. It was clear that the Cherenkov radiation results from the coupling between the slow TM mode propagated along the waveguide and the negative-energy space-charge mode propagated along the beam, and the coupling strength is proportional to the beam density. It was theoretically demonstrated that due to the background plasma, the plasma-filled coaxial cylindrical Cherenkov maser could operate at higher frequency, get higher wave growth rate, or have higher beam current at the same operating frequency, leading to higher microwave output power. (authors)

  6. Development of an underwater Cherenkov detector to reveal sources of technogenic radionuclides

    International Nuclear Information System (INIS)

    Chernyaev, A.M.; Gaponov, I.A.; Lapushkina, L.V.

    1999-01-01

    The major difference of the Cherenkov underwater detector from a scintillation detector is that its operation does not require a primary transducer (scintillator). Detected particle energy conversion into a light flash occurs directly in sea water (radiator) due to the Cherenkov effect. Consequently, photoreceiver of the underwater Cherenkov detector registers light from radiator of actually infinite volume. The circumstance is of principle importance, as it permits attaining the utmost sensitivity in case of the minimal overall dimensions and weight of detecting equipment

  7. Massive Cherenkov neutrino facilities?their evolution, their future: Twenty-five years at these International Neutrino Conferences

    International Nuclear Information System (INIS)

    Sulak, Lawrence R.

    2005-01-01

    This review traces the evolution of massive water Cherenkov tracking calorimeters. Pioneering concepts, first presented in this conference a quarter of a century ago, have led to 1) IMB, the first large detector (10kT), which was designed primarily to search for proton decay, and secondarily to be sensitive to supernova neutrinos and atmospheric oscillations, and 2) Dumand, an attempt to initiate the search for TeV astrophysical neutrinos with a prototype for a 1 km 3 telescope. The concepts and initial work on IMB influenced subsequent detectors: Kamiokande, Super-K, SNO, and, in part, Kamland. These detectors have to their credit the elucidation of the physics of atmospheric, solar, reactor and supernova neutrinos. With the advent of the K2K beam, controlled accelerator neutrinos confirm the atmospheric studies. The path breaking developments of Dumand now are incorporated in the high-volume Amanda and Antares detectors, as well as their sequels, IceCube and the proposed Cubic Kilometer detector. The future (ultimate?) facilities have new physics challenges: A high-resolution megaton detector, eventually coupled with an intense accelerator neutrino source, is critical for precision studies of neutrino oscillation parameters and for the potential discovery of CP violation in the lepton sector. The Gigaton TeV neutrino telescopes (IceCube and Cubic Kilometer) seek to open high-energy neutrino astronomy, still an elusive goal. (Amanda, IceCube, and UNO, as well as Minos, Icarus and other large neutrino facilities using non-Cherenkov technologies, are treated in other contributions to this volume.)

  8. Visual sensations during megavoltage radiotherapy to the orbit attributable to Cherenkov radiation

    International Nuclear Information System (INIS)

    Newman, Francis; Asadi-Zeydabadi, Masoud; Durairaj, Vikram D.; Ding Meisong; Stuhr, Kelly; Kavanagh, Brian

    2008-01-01

    During megavoltage photon and electron beam radiotherapy treatment involving the eye, patients commonly report visual sensations; 'nerve stimulation' is the conventional explanation. We propose that the phenomenon can be attributed to Cherenkov radiation inside the eye. The threshold electron energy for Cherenkov radiation in water is 260 keV. The human retina is able to perceive approximately 5-14 visible photons in 0.001 s. A single 500 keV electron traversing 1 mm of water will induce nearly 15 Cherenkov visible range photons. We propose that a portal image involving the eye will produce sufficient Cherenkov radiation to be detected by the retina

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

    Science.gov (United States)

    Glaser, Adam Kenneth

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

  10. Status of the new Sum-Trigger system for the MAGIC telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Garcia, Jezabel; Schweizer, Thomas; Nakajima, Daisuke [Max Planck Institute for Physics, Muenchen (Germany); Dazzi, Francesco [Dipartimento di Fisica dell' Universita di Udine (Italy); INFN, sez. di Trieste (Italy)

    2013-07-01

    MAGIC is a stereoscopic system of two 17 meters Imaging Air Cherenkov Telescopes for gamma-ray astronomy operating in stereo mode. The telescopes are located at about 2.200 metres above sea level in the Observatorio del Roque de los Muchachos (ORM), in the Canary island of La Palma. Lowering the energy threshold of Cherenkov Telescopes is crucial for the observation of Pulsars, High redshift AGNs and GRBs. The Sum-Trigger, based on the analogue sum of a patch of pixels has a lower threshold compared to conventional digital triggers. The Sum-Trigger principle has been proven experimentally in 2007 by decreasing the energy threshold of the first Magic telescope (Back then operating in mono mode) from 55 GeV down to 25 GeV. The first VHE detection for the Crab Pulsar was achieved due to this low threshold. After the upgrade of the MAGIC I and MAGIC II cameras and readout systems, we are planning to install a new Sum-Trigger system in both telescopes in Summer 2013. This trigger system will be operated for the first time in stereo mode. At the conference we report about the status and the performance of the new Sum-Trigger-II system.

  11. Search for magnetic monopoles with the neutrino telescope ANTARES

    International Nuclear Information System (INIS)

    Picot-Clemente, N.

    2010-01-01

    The ANTARES neutrino telescope is located at a 2500 meters depth, and is composed of an array of 900 photomultipliers installed for the detection of Cherenkov light emitted by neutrino-induced muons, after having interacted with matter, and in order to reconstruct their directions. However, besides of being capable of detecting high energy neutrinos, neutrino telescopes could measure the incoming flux of magnetic monopoles in the detector. In this work, were first presented the different methods used in order to calibrate the photomultipliers, which are the heart of a neutrino telescope. The possibility of detecting magnetic monopoles with ANTARES was then discussed, and a first analysis optimised for the search for high velocity magnetic monopoles showed the great sensitivity offered by the telescope. Finally, a track reconstruction algorithm was modified, and a new analysis this time sensitive over a wider range of velocities was performed. After the application of the last analysis on the data taken in 2008 with the ANTARES telescope, new upper limits on the upward going magnetic monopole flux, of masses lower than 10 14 GeV were obtained, and are the best experimental constraints on their flux for the velocity region β ∼ [0.65, 0.995]. (author)

  12. Application of Cherenkov light observation to reactor measurements (3). Evaluation of spent fuel elements of LWRs with Cherenkov light estimation system

    International Nuclear Information System (INIS)

    Yamamoto, Keiichi; Takeuchi, Tomoaki; Tsuchiya, Kunihiko; Hayashi, Takayasu; Kosuge, Fumiaki

    2016-11-01

    Development of the reactor measurement system has been carried out to obtain the real-time in-core nuclear and thermal information, where the quantitative measurement of brightness of Cherenkov light was investigated. The system would be applied as a monitoring system in severe accidents and for the advanced operation management technology in existing LWRs. This report summarized the modification of Cherenkov light estimation system described JAEA-Testing 2015-001 and the result of the burn-up evaluation by Cherenkov light image emitted from spent fuel elements of LWRs with the modified system. (author)

  13. Observations of VHE γ-Ray Sources with the MAGIC Telescope

    Science.gov (United States)

    Bartko, H.

    2008-10-01

    The MAGIC telescope with its 17m diameter mirror is today the largest operating single-dish Imaging Air Cherenkov Telescope (IACT). It is located on the Canary Island La Palma, at an altitude of 2200m above sea level, as part of the Roque de los Muchachos European Northern Observatory. The MAGIC telescope detects celestial very high energy γ-radiation in the energy band between about 50 GeV and 10 TeV. Since Autumn of 2004 MAGIC has been taking data routinely, observing various objects like supernova remnants (SNRs), γ-ray binaries, Pulsars, Active Galactic Nuclei (AGN) and Gamma-ray Bursts (GRB). We briefly describe the observational strategy, the procedure implemented for the data analysis, and discuss the results for individual sources. An outlook to the construction of the second MAGIC telescope is given.

  14. Virtual Telescope Alignment System

    Data.gov (United States)

    National Aeronautics and Space Administration — Next-generation space telescopes require two spacecraft to fly in a coordinated fashion in space forming a virtual telescope. Achieving and maintaining this precise...

  15. ATST telescope mount: telescope of machine tool

    Science.gov (United States)

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

    2012-09-01

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

  16. Cherenkov light as a source of photochemical reactions in irradiated solutions of nitrile of malachite green

    Energy Technology Data Exchange (ETDEWEB)

    Stuglik, Z; Grodkowski, J

    1986-10-01

    Experimental data on photochemical activity of Cherenkov light are presented. Malachite green leucocyanide was used to detect the photochemical effects. The G value of Cherenkov light from the region 200-330 nm (number of quanta formed per 100 eV absorbed energy of ionizing radiation) in ethanol was estimated to be in the range of 0.0027-0.049. 14 references.

  17. Cherenkov light as a source of photochemical reactions in irradiated solutions of nitrile of malachite green

    International Nuclear Information System (INIS)

    Stuglik, Z.; Grodkowski, J.

    1986-01-01

    Experimental data on photochemical activity of Cherenkov light are presented. Malachite green leucocyanide was used to detect the photochemical effects. The G value of Cherenkov light from the region 200-330 nm (number of quanta formed per 100 eV absorbed energy of ionizing radiation) in ethanol was estimated to be in the range of 0.0027-0.049. (author)

  18. The forward ring imaging Cherenkov detector of DELPHI

    International Nuclear Information System (INIS)

    Adam, W.; Albrecht, E.; Ambec, I.; Augustinus, A.; Barnoux, C.; Bostjancic, B.; Botner, O.; Budziak, A.P.; Caloba, L.P.; Carecchio, P.; Cavalli, P.; Ceelie, L.; Cereseto, R.; Cerutti, G.; Dahl-Jensen, E.; Dam, P.; Damgaard, G.; Koning, N. de; De la Vega, A.S.; Dimitriou, N.; Dulinski, W.; Eek, L.O.; Ekeloef, T.; Erikson, J.; Florek, A.; Florek, B.; Fontanelli, F.; Fontenille, A.; Galuszka, K.; Garcia, J.; Gracco, V.; Hallgren, A.; Hao, W.; Henkes, T.; Isenhower, D.; Johansson, H.; Karvelas, E.; Kindblom, P.; Koene, B.; Korporaal, A.; Kostarakis, P.; Lenzen, G.; Lindqvist, L.E.; Lorenz, P.; Loukas, D.; Lund-Jensen, B.; Maltezos, A.; Markou, A.; Mattsson, L.; Medbo, J.; Michalowski, J.; Montano, F.; Nielsen, B.S.; Ostler, J.M.; Pakonski, K.; Perdikis, C.; Polok, G.; Robohm, A.; Sajot, G.; Sannino, M.; Saragas, E.; Schyns, E.; Squarcia, S.; Stavropoulos, G.; Stodulski, M.; Stopa, Z.; Thadome, J.; Theodosiou, G.E.; Traspedini, L.; Turala, M.; Ullaland, O.; Waerm, A.; Werner, J.; Xyroutsikos, S.; Zavrtanik, M.; Zevgolatakos, E.

    1994-01-01

    The Forward Ring Imaging Cherenkov detector of the DELPHI experiment at LEP provides hadron identification at polar angles 15 6 F 14 and a volume of gaseous C 4 F 10 , in combination provide coverage of momenta up to 40 GeV/c. A single array of photosensitive Time Projection Chambers registers the impact points of ultraviolet photons from both radiators. The design of the detector and of its readout system is described. First results obtained with a partly installed detector are reported. (orig.)

  19. Cherenkov Radiation from a Pseudospark-sourced Electron Beam

    International Nuclear Information System (INIS)

    Phelps, A.D.R.; Yin, H.; Cross, A.W.; He, W.; Ronald, K.

    2003-01-01

    Electron beam generation from a multi-gap pseudospark discharge was investigated. A pseudospark-sourced electron beam has two phases, an initial hollow cathode phase (HCP) beam followed by a conductive phase (CP) beam. The beam brightness was measured by a field-free collimator to be 109 and 1011 Am-2rad-2 for the hollow cathode phase (HCP) beam and the conductive phase (CP) beam respectively. The initial HCP beam from an eight-gap pseudospark discharge was applied in a Cherenkov interaction between the electron beam and the TM01 mode of a 60-cm long alumina-lined waveguide. It was found experimentally that significant microwave radiation was generated only when the dielectric was present in the interaction space. If there was no dielectric in the cylindrical waveguide, then a very small background microwave output was detected even when the guide B-field was absent. This demonstrated, in conjunction with the observation that the microwave output signal was independent of the guide magnetic field over the range 0.13 to 0.26 T, that the radiation from the experiment was due to the Cherenkov interaction mechanism. In addition, two components of the microwave pulse were observed corresponding to the two energy components of the electron beam during the pseudospark discharge breakdown. These results demonstrated that the microwave radiation was generated by Cherenkov amplification of the broadband emission from the pseudospark discharge itself. A background signal level of around 100 W was measured in the frequency range 20 - 50 GHz with a percentage of (2.7 ± 0.6)% in the frequency range 25.5 - 28.6 GHz, when the dielectric lining was removed from the maser. The frequency of the microwave output after the Cherenkov maser interaction was measured to be mainly around 25.5 GHz and the dominating mode was identified as being TM01. The duration of the microwave pulse was approximately 80 ns, with a peak power of around 2 ± 0.2 kW. The gain of this amplifier was measured

  20. MEMPHYS: A large scale water Cherenkov detector at Frejus

    International Nuclear Information System (INIS)

    Bellefon, A. de; Dolbeau, J.; Gorodetzky, P.; Katsanevas, S.; Patzak, T.; Salin, P.; Tonazzo, A.; Bouchez, J.; Busto, J.; Campagne, J.E.; Cavata, C.; Mosca, L.; Dumarchez, J.; Mezzetto, M.; Volpe, C.

    2006-07-01

    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 θ 13 and the CP-violating phase δ. (authors)

  1. Getting the traces (FADCs) of a water Cherenkov detector signal

    International Nuclear Information System (INIS)

    Ponce, E.; Salazar, H.; Martinez, O.; Moreno, E.

    2003-01-01

    In this work we present the electronics developed into a complete data acquisition system (DAS) for a water Cherenkov detector (WCD) in order to detect cosmic rays with energies from 1 x 1014 to 1 x 1016 eV. The components are: a high voltage source, a bleeder circuit for each photomultiplier, an electronic unit to amplify, compare, determine coincidence and sum the signals produced by the PMTs, a control circuit to digitalize and store the information corresponding to a valid event and finally an interface to a PC to record data for further analysis. The sampling rate of the system is 40 MHz

  2. Feasibility of a next generation underground water Cherenkov detector: UNO

    International Nuclear Information System (INIS)

    Jung, Chang Kee

    2000-01-01

    The feasibility of a next generation underground water Cherenkov detector is examined and a conceptual design (UNO) is presented. The design has a linear detector configuration with a total volume of 650 kton which is 13 times the total volume of the Super-Kamiokande detector. It corresponds to a 20 times increase in fiducial volume for physics analysis. The physics goals of UNO are to increase the sensitivity of the search for nucleon decay by a factor of ten and to make precision measurements of the solar and atmospheric neutrino properties. In addition, the detection sensitivity for supernova neutrinos will reach as far as the Andromeda galaxy

  3. Cherenkov Ring Imaging Detector front-end electronics

    International Nuclear Information System (INIS)

    Antilogus, P.; Aston, D.; Bienz, T.; Bird, F.; Dasu, S.; Dunwoodie, W.; Hallewell, G.; Kawahara, H.; Kwon, Y.; Leith, D.; Marshall, D.; Muller, D.; Nagamine, T.; Oxoby, G.; Ratcliff, B.; Rensing, P.; Schultz, D.; Shapiro, S.; Simopoulos, C.; Solodov, E.; Suekane, F.; Toge, N.; Va'Vra, J.; Williams, S.; Wilson, R.J.; Whitaker, J.S.; Bean, A.; Caldwell, D.; Duboscq, J.; Huber, J.; Lu, A.; Mathys, L.; McHugh, S.; Morrison, R.; Witherell, M.; Yellin, S.; Coyle, P.; Coyne, D.; Spencer, E.; d'Oliveira, A.; Johnson, R.A.; Martinez, J.; Nussbaum, M.; Santha, A.K.S.; Shoup, A.; Stockdale, I.; Jacques, P.; Plano, R.; Stamer, P.; Abe, K.; Hasegawa, K.; Yuta, H.

    1990-10-01

    The SLD Cherenkov Ring Imaging Detector use a proportional wire detector for which a single channel hybrid has been developed. It consists of a preamplifier, gain selectable amplifier, load driver amplifier, power switching, and precision calibrator. For this hybrid, a bipolar, semicustom integrated circuit has been designed which includes video operational amplifiers for two of the gain stages. This approach allows maximization of the detector volume, allows DC coupling, and enables gain selection. System tests show good noise performance, calibration precision, system linearity, and signal shape uniformity over the full dynamic range. 10 refs., 8 figs

  4. THGEM based photon detector for Cherenkov imaging applications

    CERN Document Server

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

    2010-01-01

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

  5. Performance of the MAGIC telescopes under moonlight

    Science.gov (United States)

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

    2017-09-01

    MAGIC, a system of two imaging atmospheric Cherenkov telescopes, achieves its best performance under dark conditions, i.e. in absence of moonlight or twilight. Since operating the telescopes only during dark time would severely limit the duty cycle, observations are also performed when the Moon is present in the sky. Here we develop a dedicated Moon-adapted analysis to characterize the performance of MAGIC under moonlight. We evaluate energy threshold, angular resolution and sensitivity of MAGIC under different background light levels, based on Crab Nebula observations and tuned Monte Carlo simulations. This study includes observations taken under non-standard hardware configurations, such as reducing the camera photomultiplier tubes gain by a factor ∼1.7 (reduced HV settings) with respect to standard settings (nominal HV) or using UV-pass filters to strongly reduce the amount of moonlight reaching the cameras of the telescopes. The Crab Nebula spectrum is correctly reconstructed in all the studied illumination levels, that reach up to 30 times brighter than under dark conditions. The main effect of moonlight is an increase in the analysis energy threshold and in the systematic uncertainties on the flux normalization. The sensitivity degradation is constrained to be below 10%, within 15-30% and between 60 and 80% for nominal HV, reduced HV and UV-pass filter observations, respectively. No worsening of the angular resolution was found. Thanks to observations during moonlight, the maximal duty cycle of MAGIC can be increased from ∼18%, under dark nights only, to up to ∼40% in total with only moderate performance degradation.

  6. Liverpool Telescope and Liverpool Telescope 2

    Science.gov (United States)

    Copperwheat, C. M.; Steele, I. A.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Jermak, H.; Marchant, J. M.; Mottram, C. J.; Piascik, A.; Smith, R. J.

    2016-12-01

    The Liverpool Telescope is a fully robotic optical/near-infrared telescope with a 2-metre clear aperture, located at the Observatorio del Roque de los Muchachos on the Canary Island of La Palma. The telescope is owned and operated by Liverpool John Moores University, with financial support from the UK's Science and Technology Facilities Council. The telescope began routine science operations in 2004 and is a common-user facility with time available through a variety of committees via an open, peer reviewed process. Seven simultaneously mounted instruments support a broad science programme, with a focus on transient follow-up and other time domain topics well suited to the characteristics of robotic observing. Development has also begun on a successor facility, with the working title `Liverpool Telescope 2', to capitalise on the new era of time domain astronomy which will be brought about by the next generation of survey facilities such as LSST. The fully robotic Liverpool Telescope 2 will have a 4-metre aperture and an improved response time. In this paper we provide an overview of the current status of both facilities.

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

    International Nuclear Information System (INIS)

    Saunders, Sara L; Andreozzi, Jacqueline M; Pogue, Brian W; Glaser, Adam K

    2016-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-15

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

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

    CERN Document Server

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

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

  10. Light collection and its fluctuation in Cherenkov and scintillation spectrometers

    International Nuclear Information System (INIS)

    Kitaev, D.F.; Samedov, V.V.; Stolyarova, E.L.

    1982-01-01

    The GAMMA program for calculating light collection in the Cherenkov and scintillation counters is described. Together with the shower modelling program the GAMNA program can be used for evaluating the output signal and energy resolution of shower spectrometers. Principle formulae and block diagram of the program are given. Results of test calculations performed on the example of scintillation counters of culindrical and rectangular shapes were considered. Modelling of the radiation polarization envisaged in the program permits to take account of the effect of selective discrimination of photoelectron amplifier photocathode. The program analyzes, for the present situation, calculation errors which permits to plan in advance the calculation with the given accuracy. The program permits to use additional subprograms together with it where it is possible to take account of other peculiarities of light collection, for example, the presence of outer reflectors and focusing elements of light collection systems, particle slowing down in the spectrometer radiator expressed in the change of angle of semiaperture of the Cherenkov radiation cone. It is concluded on the basis of analyzing results of test calculations that the choosen technique and algorithms of light collection coefficient calculation in spectrometer radiators are correct

  11. Spectrometer of Cherenkov radiation rings with hodoscopic photomultipliers

    International Nuclear Information System (INIS)

    Abramov, V.V.; Alekseev, A.V.; Baldin, B.Yu.

    1983-01-01

    Characteristics of SKOCH Cherenkov radiation ring spectrometer intended for identification of π- and K-mesons and protons in a wide divergent beam in the pulse range of 5.5-30 GeV/s are investigated. The spectrometer detecting system is based on using the hodoscopic photoelectron multipliers (HPEM). The HPEM specific feature is that they have an extended cathode and permit to determine the coordinate of an incident photon by measuring the time of photoelectron drift to a dinode system. The spectrometer has been tested at the FODS facility in the secondary particle beam with angular divergence equal to 16x6 mrad and aperture of 400x200 mm in the pulse range of 6-20 GeV/s. The range of Cherenkov radiation angle detection is 40-100 mrad which corresponds to the particle velocity range of 0.996-1. The angular and radial aperture is 30 mrad, the diameter is 420 mm. The obtained velocity resolution is 6x10 -5

  12. Workshop on Non-Imaging Cherenkov at High Energy

    CERN Document Server

    2013-01-01

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

  13. The great Melbourne telescope

    CERN Document Server

    Gillespie, Richard

    2011-01-01

    Erected at Melbourne Observatory in 1869, the telescope was the second largest in the world, designed to explore the nature of the nebulae in the southern skies. Richard Gillespie, head of the History and Technology department at the Melbourne museum has written an entertaining account of the telescope's extraordinary history and tells the story through an amazing cast of characters whose lives intersected with the telescope.

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

    CERN Document Server

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

    2003-01-01

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

  15. Cherenkov rings from aerogel detected by four large-area hybrid photodiodes

    International Nuclear Information System (INIS)

    Bellunato, T.; Braem, A.; Buzykaev, A.R.; Calvi, M.; Chesi, E.; Danilyuk, A.F.; Easo, S.; Jolly, S.; Joram, C.; Kravchenko, E.A.; Liko, D.; Matteuzzi, C.; Musy, M.; Negri, P.; Neufeld, N.; Onuchin, A.P.; Seguinot, J.; Wotton, S.

    2003-01-01

    We report on the results obtained using thick samples of silica aerogel as radiators for a Ring Imaging Cherenkov counter. Four large-diameter hybrid photodiodes with 2048 channels have been used as photon detectors. Pions and protons with momenta ranging from 6 to 10 GeV/c were separated and identified. The number of photoelectrons and the radius of the Cherenkov rings together with the Cherenkov angle resolution were measured. A comparison with a simulation program based on GEANT4 is discussed

  16. Study of TeV range cosmic ray detection with Cherenkov imaging techniques

    International Nuclear Information System (INIS)

    Ansari, R.; Gaillard, J.M.; Parrour, G.

    1992-03-01

    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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-08-11

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

  18. Breaking the Gender Binary: Feminism and Transgressive Female Desire in Lucía Etxebarria's Beatriz y los cuerpos celestes and La Eva futura/La letra futura

    Directory of Open Access Journals (Sweden)

    Lauren Applegate

    2013-06-01

    Full Text Available The popular texts of Spanish author Lucía Etxebarria have created a polemical social phenomenon in contemporary Spain for their blatant depiction of a world of violence, drugs, and experimental sex of the late-millennium youth culture of Generación X. These topics, along with Etxebarria's public persona and feminist ideology, have fomented much public criticism and given rise to discussion of the current status of feminism, gender norms, and women's authorship in Spain today. This article analyzes Etxebarria's novel Beatriz y los cuerpos celestes and her collection of feminist essays La Eva futura/La letra futura, demonstrating that Etxebarria's depiction of female desire and sexuality within their cultural context challenges the notion that feminism has no more to achieve and breaks the gender binary by imagining a gender-anonymous world. Beatriz delves into the life of the title character, a young woman whose experience with a dissolute social culture and her attempts to understand herself cause her to question stereotypical standards of womanhood and eroticism and to declare that she fits into no such preconceived notions. Beatriz is a literary inscription of Etxebarria's feminist ideology as posited in La Eva futura, insofar as both these texts blur the line between feminism and postfeminism and engage with consumerist culture and identity. Moreover, they construe a philosophy that pushes the boundaries of normative discourse by misciting hegemonic notions of femininity and sexuality and creating the potential for change through such mis-repetition of hegemonic discourse. Ultimately, Etxebarria's work strives for a transgressive, unbound, and fluid female desire that is in continuous reconstruction and defies heteronormative definition.

  19. The Advanced Gamma-ray Imaging System (AGIS): Telescope Optical System Designs

    Science.gov (United States)

    Vassiliev, Vladimir; Buckley, Jim; Falcone, Abe; Fegan, Steven; Finley, John; Gaurino, Victor; Hanna, David; Kaaret, Philip; Konopelko, Alex; Krawczynski, Henric; Romani, Roger; Weekes, Trevor

    2008-04-01

    AGIS is a conceptual design for a future ground-based gamma-ray observatory based on an array of ˜100 imaging atmospheric Cherenkov telescopes (IACTs) with a sensitivity to gamma-rays in the energy range 40 GeV-100 TeV. The anticipated improvement of AGIS sensitivity, angular resolution, and reliability of operation imposes demanding technological and cost requirements on the design of the IACTs. In this submission we focus on the optical system (OS) of the AGIS telescopes and consider options which include traditional Davies-Cotton and the other prime- focus telescope designs, as well as a novel two-mirror aplanatic OS originally proposed by Schwarzschild. Emerging new mirror production technologies based on replication processes such as cold and hot glass slumping, cured CFRP, and electroforming provide new opportunities for cost effective solutions for the design of the OS. We evaluate the capabilities of these mirror fabrication methods for the AGIS project.

  20. Observation of Galactic Sources of Very High Energy γ-RAYS with the Magic Telescope

    Science.gov (United States)

    Bartko, H.

    The MAGIC telescope with its 17m diameter mirror is today the largest operating single-dish Imaging Air Cherenkov Telescope (IACT). It is located on the Canary Island La Palma, at an altitude of 2200 m above sea level, as part of the Roque de los Muchachos European Northern Observatory. The MAGIC telescope detects celestial very high energy γ-radiation in the energy band between about 50 GeV and 10 TeV. Since the autumn of 2004 MAGIC has been taking data routinely, observing various objects, like supernova remnants (SNRs), γ-ray binaries, Pulsars, Active Galactic Nuclei (AGN) and Gamma-ray Bursts (GRB). We briefly describe the observational strategy, the procedure implemented for the data analysis, and discuss the results of observations of Galactic Sources.

  1. The camera of the fifth H.E.S.S. telescope. Part I: System description

    Energy Technology Data Exchange (ETDEWEB)

    Bolmont, J., E-mail: bolmont@in2p3.fr [LPNHE, Université Pierre et Marie Curie Paris 6, Université Denis Diderot Paris 7, CNRS/IN2P3, 4 Place Jussieu, F-75252 Paris Cedex 5 (France); Corona, P.; Gauron, P.; Ghislain, P.; Goffin, C.; Guevara Riveros, L.; Huppert, J.-F.; Martineau-Huynh, O.; Nayman, P.; Parraud, J.-M.; Tavernet, J.-P.; Toussenel, F.; Vincent, D.; Vincent, P. [LPNHE, Université Pierre et Marie Curie Paris 6, Université Denis Diderot Paris 7, CNRS/IN2P3, 4 Place Jussieu, F-75252 Paris Cedex 5 (France); Bertoli, W.; Espigat, P.; Punch, M. [APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cité, 10, rue Alice Domon et Léonie Duquet, F-75205 Paris Cedex 13 (France); Besin, D.; Delagnes, E.; Glicenstein, J.-F. [CEA Saclay, DSM/IRFU, F-91191 Gif-Sur-Yvette Cedex (France); and others

    2014-10-11

    In July 2012, as the four ground-based gamma-ray telescopes of the H.E.S.S. (High Energy Stereoscopic System) array reached their tenth year of operation in Khomas Highlands, Namibia, a fifth telescope took its first data as part of the system. This new Cherenkov detector, comprising a 614.5 m{sup 2} reflector with a highly pixelized camera in its focal plane, improves the sensitivity of the current array by a factor two and extends its energy domain down to a few tens of GeV. The present part I of the paper gives a detailed description of the fifth H.E.S.S. telescope's camera, presenting the details of both the hardware and the software, emphasizing the main improvements as compared to previous H.E.S.S. camera technology.

  2. Application of Geiger-mode photosensors in Cherenkov detectors

    Energy Technology Data Exchange (ETDEWEB)

    Gamal, Ahmed, E-mail: gamal.ahmed@assoc.oeaw.ac.a [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria); Al-Azhar University, Faculty of Science, Physics Department, Cairo (Egypt); Paul, Buehler; Michael, Cargnelli [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria); Roland, Hohler [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Johann, Marton [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria); Herbert, Orth [GSI Helmholtzzentrum fuer Schwerionenforschung GmbH, Darmstadt (Germany); Ken, Suzuki [Stefan Meyer Institute for Subatomic Physics of the Austrian Academy of Sciences, Vienna (Austria)

    2011-05-21

    Silicon-based photosensors (SiPMs) working in the Geiger-mode represent an elegant solution for the readout of particle detectors working at low-light levels like Cherenkov detectors. Especially the insensitivity to magnetic fields makes this kind of sensors suitable for modern detector systems in subatomic physics which are usually employing magnets for momentum resolution. We are characterizing SiPMs of different manufacturers for selecting sensors and finding optimum operating conditions for given applications. Recently we designed and built a light concentrator prototype with 8x8 cells to increase the active photon detection area of an 8x8 SiPM (Hamamatsu MPPC S10931-100P) array. Monte Carlo studies, measurements of the collection efficiency, and tests with the MPPC were carried out. The status of these developments are presented.

  3. On Tamm's problem in the Vavilov-Cherenkov radiation theory

    International Nuclear Information System (INIS)

    Afanas'ev, G.N.; Kartavenko, V.G.; Stepanovskij, Yu.P.

    1999-01-01

    We analyze the well-known Tamm's problem treating the charge motion on a finite space interval with the velocity exceeding light velocity in medium. By comparing Tamm's approximate formulae with the exact ones we prove that the former do not properly describe Cherenkov radiation terms. We also investigate Tamm's formula cos θ T = 1/βn defining the position of the maximum of the field strengths in the Fourier representation. Numerical analysis of the Fourier components of field strengths shows that they have a well pronounced maximum at θ = θ T only for the charge motion on the sufficiently small interval. As an interval grows, many maxima appear. For the charge motion on an infinite interval there is infinite number of maxima of the same amplitude. The quantum analysis of Tamm's formula leads to the same results

  4. Cherenkov effect as a probe of photonic nanostructures

    International Nuclear Information System (INIS)

    Garcia de Abajo, F.J.; Pattantyus-Abraham, A.G.; Wolf, M.O.; Zabala, N.; Rivacoba, A.; Echenique, P.M.

    2003-01-01

    Electron energy-loss spectroscopy (EELS) is shown to be an excellent source of information both on photonic crystal bands and on radiation modes of complex nanostructures. Good agreement is reported between measurements and parameter-free calculations of EELS in porous alumina films, where Cherenkov radiation is scattered by the pores to yield a strong 8.3-eV (7-eV) feature for 120-keV (200-keV) electrons. The latter is related to the bands of two-dimensional photonic crystals formed by air cylinders in an alumina matrix with similar near-range ordering. Finally, the band structure is proved to be directly mapped by angle-resolved EELS

  5. All-fiber femtosecond Cherenkov laser at visible wavelengths

    DEFF Research Database (Denmark)

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

    2013-01-01

    -matching condition [1]. The resonant ultrafast wave conversion via the fiber-optic CR mechanism is instrumental for applications in biophotonics such as bio-imaging and microscopy [2]. In this work, we demonstrate a highly-stable all-fiber, fully monolithic CR system based on an Yb-fiber femtosecond laser, producing...... to be as low as -103 dBc/Hz. This is 2 orders of magnitudes lower noise as compared to spectrally-sliced supercontinuum, which is the current standard of ultrafast fiber-optic generation at visible wavelength. The layout of the laser system is shown in Fig. 1(a). The system consists of two parts: an all-fiber......Fiber-optic Cherenkov radiation (CR), also known as dispersive wave generation or non-solitonic radiation, is produced in small-core photonic crystal fibers (PCF) when a soliton perturbed by fiber higher-order dispersion co-propagates with a dispersive wave fulfilling a certain phase...

  6. Programmable trigger for electron pairs in ring image Cherenkov counters

    International Nuclear Information System (INIS)

    Glab, J.; Baur, R.; Manner, R.

    1990-01-01

    This paper describes a programmable trigger processor for the recognition of Cherenkov rings in a RICH counter. It identifies open electron pairs and suppresses close conversion and Dalitz pairs within 20 μs. More generally, the system can be used for correlating pixel images with pattern masks in order to locate all relatively well defined patterns of a certain type. The trigger processor consists of a systolic processor array of 160 x 176, i.e., 28,160 identical processing elements (PEs) that filter out open electron pairs, and a pseudo adder array that determines whether there was at least one such pair. The processor array is assembled of 20 x 22 VLSI chips containing 8 x 8 PEs each. The semi-custom chip has been developed in 2 μ CMOS standard cell technology

  7. Silicon photomultiplier as a detector of Cherenkov photons

    International Nuclear Information System (INIS)

    Korpar, S.; Dolenec, R.; Hara, K.; Iijima, T.; Krizan, P.; Mazuka, Y.; Pestotnik, R.; Stanovnik, A.; Yamaoka, M.

    2008-01-01

    A novel photon detector-i.e. the silicon photomultiplier-whose main advantage over conventional photomultiplier tubes is the operation in high magnetic fields, has been tested as a photon detector in a proximity focusing RICH with aerogel radiator. This type of RICH counter is proposed for the upgrade of the Belle detector at the KEK B-factory. Recently produced silicon photomultipliers show less noise and have larger size, which are important issues for a large area photon detector. We measured the single photon pulse height distribution, the timing resolution and the position sensitivity for different silicon photomultipliers (Hamamatsu MPPC HC025, HC050, and HC100). The silicon photomultipliers were then used to detect Cherenkov photons emitted by cosmic ray particles in a proximity focusing aerogel RICH. Various light guides were investigated in order to increase the detection efficiency

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

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Zhou, Binbin

    2010-01-01

    -matching point is located in the absorption region of the crystal, effectively absorbing the generated dispersive wave. By calculating the phase-matching curves for typically used frequency conversion crystals, we point out that the mid-IR absorption in the crystal in many cases automatically will filter away....... The beating between the dispersive wave and the soliton generates trailing temporal oscillations on the compressed soliton. Insertion of a simple short-wave pass filter after the crystal can restore a clean soliton. On the other hand, bandpass filtering around the dispersive wave peak results in near......We show through theory and numerics that when few-cycle femtosecond solitons are generated through cascaded (phase-mismatched) second-harmonic generation, these broadband solitons can emit optical Cherenkov radiation in the form of linear dispersive waves located in the red part of the spectrum...

  9. The HERMES dual-radiator ring imaging Cherenkov detector

    CERN Document Server

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

    2002-01-01

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

  10. Recent results from the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    Van Elewyck, Véronique

    2014-01-01

    The ANTARES neutrino telescope is currently the largest operating water Cherenkov detector and the largest neutrino detector in the Northern Hemisphere. Its main scientific target is the detection of high-energy (TeV and beyond) neutrinos from cosmic accelerators, as predicted by hadronic interaction models, and the measurement of the diffuse neutrino flux. Its location allows for surveying a large part of the Galactic Plane, including the Galactic Centre. In addition to the standalone searches for point-like and diffuse high-energy neutrino signals, ANTARES has developed a range of multi-messenger strategies to exploit the close connection between neutrinos and other cosmic messengers such as gamma-rays, charged cosmic rays and gravitational waves. This contribution provides an overview of the recently conducted analyses, including a search for neutrinos from the Fermi bubbles region, searches for optical counterparts with the TAToO program, and searches for neutrinos in correlation with gamma-ray bursts, blazars, and microquasars. Further topics of investigation, covering e.g. the search for neutrinos from dark matter annihilation, searches for exotic particles and the measurement of neutrino oscillations, are also reviewed

  11. Ionization and pulse lethargy effects in inverse Cherenkov accelerators

    International Nuclear Information System (INIS)

    Sprangle, P.; Hubbard, R.F.; Hafizi, B.

    1997-01-01

    Ionization processes limit the accelerating gradient and place an upper limit on the pulse duration of the electromagnetic driver in the inverse Cherenkov accelerator (ICA). Group velocity slippage, i.e., pulse lethargy, on the other hand, imposes a lower limit on the pulse duration. These limits are obtained for two ICA configurations in which the electromagnetic driver (e.g., laser or millimeter wave source) is propagated in a waveguide that is (i) lined with a dielectric material or (ii) filled with a neutral gas. In either configuration the electromagnetic driving field is guided and has an axial electric field with phase velocity equal to the speed of light in vacuum, c. The intensity of the driver in the ICA, and therefore the acceleration gradient, is limited by tunneling and collisional ionization effects. Partial ionization of the dielectric liner or gas can lead to significant modification of the dispersive properties of the waveguide, altering the phase velocity of the accelerating field and causing particle slippage, thus disrupting the acceleration process. An additional limitation on the pulse duration is imposed since the group velocity of the driving pulse is less than c and the pulse slips behind the accelerated electrons. Hence for sufficiently short pulses the electrons outrun the pulse, terminating the acceleration. Limitations on the driver pulse duration and accelerating gradient, due to ionization and pulse lethargy, are estimated for the two ICA configurations. Maximum accelerating gradients and pulse durations are presented for a 10 μm, 1 mm, and 1 cm wavelength electromagnetic driver. The combination of ionization and pulse lethargy effects impose severe limitations on the maximum energy gain in inverse Cherenkov accelerators. copyright 1997 The American Physical Society

  12. Observing the Sun with Coronado telescopes telescopes

    CERN Document Server

    Pugh, Philip

    2007-01-01

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

  13. Ghost telescope and ghost Fourier telescope with thermal light

    International Nuclear Information System (INIS)

    Gong Wenlin; Han Shensheng

    2011-01-01

    As important observation tools, telescopes are very useful in remote observations. We report a proof-of-principle experimental demonstration of ghost telescope scheme and show that, by measuring the intensity correlation of two light fields and only changing the position of the detector in the reference path, ghost telescope and ghost Fourier telescope can be obtained even if a single-pixel detector is fixed in Fresnel region of the object. Differences between conventional telescope and ghost telescope are also discussed.

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

    CERN Document Server

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

    2001-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    We investigate the noise properties of a femtosecond all-fiber Cherenkov radiation source with emission wavelength around 600 nm, based on an Yb-fiber laser and a highly-nonlinear photonic crystal fiber. A relative intensity noise as low as - 103 dBc/Hz, corresponding to 2.48 % pulse-to-pulse...... fluctuation in energy, was observed at the Cherenkov radiation output power of 4.3 mW, or 150 pJ pulse energy. This pulse-to-pulse fluctuation is at least 10.6 dB lower compared to spectrally-sliced supercontinuum sources traditionally used for ultrafast fiberbased generation at visible wavelengths. Low noise...... makes allfiber Cherenkov sources promising for biophotonics applications such as multi-photon microscopy, where minimum pulse-to-pulse energy fluctuation is required. We present the dependency of the noise figure on both the Cherenkov radiation output power and its spectrum....

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

    DEFF Research Database (Denmark)

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

    2000-01-01

    The nonlinear dynamics of fluxons in Josephson systems with dispersion and thermal fluctuations is analyzed using the "quasiparticle" approach to investigate the influence of noise on the Cherenkov radiation effect. Analytical expressions for the stationary amplitude of the emitted radiation...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-11

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

  18. The positioning system of the ANTARES Neutrino Telescope

    International Nuclear Information System (INIS)

    Adrián-Martínez, S; Ardid, M; Ageron, M; Samarai, I Al; Aubert, J-J; Bertin, V; Aguilar, J A; Albert, A; André, M; Anghinolfi, M; Anton, G; Anvar, S; Jesus, A C Assis; Astraatmadja, T; Baret, B; Basa, S; Biagi, S

    2012-01-01

    The ANTARES neutrino telescope, located 40 km off the coast of Toulon in the Mediterranean Sea at a mooring depth of about 2475 m, consists of twelve detection lines equipped typically with 25 storeys. Every storey carries three optical modules that detect Cherenkov light induced by charged secondary particles (typically muons) coming from neutrino interactions. As these lines are flexible structures fixed to the sea bed and held taut by a buoy, sea currents cause the lines to move and the storeys to rotate. The knowledge of the position of the optical modules with a precision better than 10 cm is essential for a good reconstruction of particle tracks. In this paper the ANTARES positioning system is described. It consists of an acoustic positioning system, for distance triangulation, and a compass-tiltmeter system, for the measurement of the orientation and inclination of the storeys. Necessary corrections are discussed and the results of the detector alignment procedure are described.

  19. The positioning system of the ANTARES Neutrino Telescope

    Science.gov (United States)

    Adrián-Martínez, S.; Ageron, M.; Aguilar, J. A.; Samarai, I. Al; Albert, A.; André, M.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardid, M.; Assis Jesus, A. C.; 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.; Cârloganu, 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.; Enzenhöfer, A.; Ernenwein, J.-P.; Escoffier, S.; Fermani, P.; Ferri, M.; Flaminio, V.; Folger, F.; Fritsch, U.; Fuda, J.-L.; Galatà, S.; Gay, P.; Giacomelli, G.; Giordano, V.; Gómez-González, J. P.; Graf, K.; Guillard, G.; Halladjian, G.; Hallewell, G.; van Haren, H.; Hartman, J.; Heijboer, A. J.; Hello, Y.; Hernández-Rey, J. J.; Herold, B.; Hößl, 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.; Lefèvre, D.; Le Van Suu, A.; Lim, G.; Lo Presti, D.; Loehner, H.; Loucatos, S.; Mangano, S.; Marcelin, M.; Margiotta, A.; Martínez-Mora, J. A.; Meli, A.; Montaruli, T.; Moscoso, L.; Motz, H.; Neff, M.; Nezri, E.; Niess, V.; Palioselitis, D.; Păvălaş, 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.; Rivière, C.; Robert, A.; Roensch, K.; Rostovtsev, A.; Ruiz-Rivas, J.; Rujoiu, M.; Russo, G. V.; Salesa, F.; Samtleben, D. F. E.; Schöck, F.; Schuller, J.-P.; Schüssler, F.; Seitz, T.; Shanidze, R.; Simeone, F.; Spies, A.; Spurio, M.; Steijger, J. J. M.; Stolarczyk, Th; Sánchez-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.; Zúñiga, J.

    2012-08-01

    The ANTARES neutrino telescope, located 40 km off the coast of Toulon in the Mediterranean Sea at a mooring depth of about 2475 m, consists of twelve detection lines equipped typically with 25 storeys. Every storey carries three optical modules that detect Cherenkov light induced by charged secondary particles (typically muons) coming from neutrino interactions. As these lines are flexible structures fixed to the sea bed and held taut by a buoy, sea currents cause the lines to move and the storeys to rotate. The knowledge of the position of the optical modules with a precision better than 10 cm is essential for a good reconstruction of particle tracks. In this paper the ANTARES positioning system is described. It consists of an acoustic positioning system, for distance triangulation, and a compass-tiltmeter system, for the measurement of the orientation and inclination of the storeys. Necessary corrections are discussed and the results of the detector alignment procedure are described.

  20. Optical telescopes for COMPASS RICH1 up-grade

    CERN Document Server

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

    2006-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  2. Measurable difference in Cherenkov light between gamma and hadron induced EAS

    Energy Technology Data Exchange (ETDEWEB)

    Cabot, H.; Meynadier, Ch. [Universite de Perpignan, Groupe de Physique Fondamentale, Perpignan (France); Sobczynska, D. [Experimental Physics Department, University of Lodz, Lodz (Poland); Szabelska, B. [Soltan Institute for Nuclear Studies, Lodz (Poland); Szabelski, J. [Universite de Perpignan, Groupe de Physique Fondamentale, Perpignan (France)]|[Soltan Institute for Nuclear Studies, Lodz (Poland); Wibig, T. [Experimental Physics Department, University of Lodz, Lodz (Poland)

    1997-12-31

    We describe the possibly measurable difference in the Cherenkov light component of EAS induced by en electromagnetic particle (i.e. e{sup +}, e{sup -} or {gamma}) and induced by a hadron (i.e. proton or heavier nuclei) in TeV range. The method can be applied in experiments which use wavefront sampling method of EAS Cherenkov light detection (e.g. THEMISTOCLE, ASGAT). (author) 16 refs, 9 figs

  3. Cherenkov radiation as a means of radio isotope diagnosis of eyeball tumors

    International Nuclear Information System (INIS)

    Moshnikov, O.S.; Kolesnichenko, V.N.

    1986-01-01

    Radiophosphorus indication of eye new-growths can be accomplished through registration of beta-particle or Cherenkov radiation. In both cases the criterion for the conclusion to be drawn from the experimental results is the relative increment of the count rate. The article analyses the specific features of the equipment aimed at recording Cherenkov radiation in the process of radiophosphorus studied in ophthalmology, and discusses the method for these studies. (orig.)

  4. Design and construction of a Cherenkov detector for Compton polarimetry at the ILC

    International Nuclear Information System (INIS)

    Bartels, Christoph

    2010-11-01

    This paper describes the design and construction of a Cherenkov detector conceived with regard to high energy Compton polarimeters for the International Linear Collider, where beam diagnostic systems of unprecedented precision must complement the interaction region detectors to pursue an ambitious physics programme. Besides the design of the Cherenkov detector, detailed simulation studies and first testbeam results are presented. Good agreement of beam data with expectations from Monte Carlo simulations is observed. (orig.)

  5. Design and construction of a Cherenkov detector for Compton polarimetry at the ILC

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, Christoph [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Inst. fuer Experimentalphysik; Ebert, Joachim; Hartin, Anthony; Helebrant, Christian; Kaefer, Daniela; List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2010-11-15

    This paper describes the design and construction of a Cherenkov detector conceived with regard to high energy Compton polarimeters for the International Linear Collider, where beam diagnostic systems of unprecedented precision must complement the interaction region detectors to pursue an ambitious physics programme. Besides the design of the Cherenkov detector, detailed simulation studies and first testbeam results are presented. Good agreement of beam data with expectations from Monte Carlo simulations is observed. (orig.)

  6. The large binocular telescope.

    Science.gov (United States)

    Hill, John M

    2010-06-01

    The Large Binocular Telescope (LBT) Observatory is a collaboration among institutions in Arizona, Germany, Italy, Indiana, Minnesota, Ohio, and Virginia. The telescope on Mount Graham in Southeastern Arizona uses two 8.4 m diameter primary mirrors mounted side by side. A unique feature of the LBT is that the light from the two Gregorian telescope sides can be combined to produce phased-array imaging of an extended field. This cophased imaging along with adaptive optics gives the telescope the diffraction-limited resolution of a 22.65 m aperture and a collecting area equivalent to an 11.8 m circular aperture. This paper describes the design, construction, and commissioning of this unique telescope. We report some sample astronomical results with the prime focus cameras. We comment on some of the technical challenges and solutions. The telescope uses two F/15 adaptive secondaries to correct atmospheric turbulence. The first of these adaptive mirrors has completed final system testing in Firenze, Italy, and is planned to be at the telescope by Spring 2010.

  7. The performance of a prototype array of water Cherenkov detectors for the LHAASO project

    Energy Technology Data Exchange (ETDEWEB)

    An, Q. [University of Science and Technology of China, Hefei 230026 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); Bai, Y.X.; Bi, X.J.; Cao, Z. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chang, J.F. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); Chen, G.; Chen, M.J. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chen, S.M. [Tsinghua University, Beijing 100084 (China); Chen, S.Z. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chen, T.L. [University of Tibet, Lhasa 851600 (China); Chen, X. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Chen, Y.T. [University of Yunnan, Kunming 650091 (China); Cui, S.W. [Normal University of Hebei, Shijiazhuang 050016 (China); Dai, B.Z. [University of Yunnan, Kunming 650091 (China); Du, Q. [Tsinghua University, Beijing 100084 (China); Danzengluobu [University of Tibet, Lhasa 851600 (China); Feng, C.F. [University of Shandong, Jinan 250100 (China); Feng, S.H.; Gao, B. [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); Gao, S.Q. [National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China); and others

    2013-10-01

    A large high-altitude air-shower observatory (LHAASO) is to be built at Shangri-La, Yunnan Province, China. This observatory is intended to conduct sub-TeV gamma astronomy, and as an important component of the LHAASO project, a water Cherenkov detector array (WCDA) is proposed. To investigate engineering issues and fully understand the water Cherenkov technique for detecting air showers, a prototype array at 1% scale of the LHAASO-WCDA has been built at Yang-Ba-Jing, Tibet, China. This paper introduces the prototype array setup and studies its performance by counting rate of each photomultiplier tube (PMT), trigger rates at different PMT multiplicities, and responses to air showers. Finally, the reconstructed shower directions and angular resolutions of the detected showers for the prototype array are given. -- Highlights: • The technique of the water Cherenkov array is studied. • Engineering issues of the water Cherenkov array are investigated. • The PMTs and electronics of the water Cherenkov array are tested. • Some key parameters of the water Cherenkov array are measured.

  8. The performance of a prototype array of water Cherenkov detectors for the LHAASO project

    International Nuclear Information System (INIS)

    An, Q.; Bai, Y.X.; Bi, X.J.; Cao, Z.; Chang, J.F.; Chen, G.; Chen, M.J.; Chen, S.M.; Chen, S.Z.; Chen, T.L.; Chen, X.; Chen, Y.T.; Cui, S.W.; Dai, B.Z.; Du, Q.; Danzengluobu; Feng, C.F.; Feng, S.H.; Gao, B.; Gao, S.Q.

    2013-01-01

    A large high-altitude air-shower observatory (LHAASO) is to be built at Shangri-La, Yunnan Province, China. This observatory is intended to conduct sub-TeV gamma astronomy, and as an important component of the LHAASO project, a water Cherenkov detector array (WCDA) is proposed. To investigate engineering issues and fully understand the water Cherenkov technique for detecting air showers, a prototype array at 1% scale of the LHAASO-WCDA has been built at Yang-Ba-Jing, Tibet, China. This paper introduces the prototype array setup and studies its performance by counting rate of each photomultiplier tube (PMT), trigger rates at different PMT multiplicities, and responses to air showers. Finally, the reconstructed shower directions and angular resolutions of the detected showers for the prototype array are given. -- Highlights: • The technique of the water Cherenkov array is studied. • Engineering issues of the water Cherenkov array are investigated. • The PMTs and electronics of the water Cherenkov array are tested. • Some key parameters of the water Cherenkov array are measured

  9. Investigating the Cherenkov light lateral distribution function for primary proton and iron nuclei in extensive air showers

    International Nuclear Information System (INIS)

    Al-Rubaiee, A.A.; Hashim, U.; Al-Douri, Y.

    2015-01-01

    The lateral distribution function (LDF) of Cherenkov radiation in extensive air showers (EAS) was simulated by CORSIKA program for the conditions of Yakutsk Cherenkov array at high energy range (10 13 -10 16 eV) for two primary particles (p and Fe) for different zenith angles. Using Breit-Wigner function for analyzing Cherenkov light LDF, a parameterization of Cherenkov light LDF was reconstructed by depending on CORSIKA simulation as a function of primary energy. The comparison between the estimated Cherenkov light LDF and the LDF that was measured on the Yakutsk EAS array gives the ability of particle identification that initiated the shower and determination of particle's energy around the knee region. The extrapolation of approximated Cherenkov light LDF for energies 20 and 30 PeV was obtained for primary particles (p and Fe)

  10. Goddard Robotic Telescope (GRT)

    Data.gov (United States)

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

  11. Automatic Photoelectric Telescope Service

    International Nuclear Information System (INIS)

    Genet, R.M.; Boyd, L.J.; Kissell, K.E.; Crawford, D.L.; Hall, D.S.; BDM Corp., McLean, VA; Kitt Peak National Observatory, Tucson, AZ; Dyer Observatory, Nashville, TN)

    1987-01-01

    Automatic observatories have the potential of gathering sizable amounts of high-quality astronomical data at low cost. The Automatic Photoelectric Telescope Service (APT Service) has realized this potential and is routinely making photometric observations of a large number of variable stars. However, without observers to provide on-site monitoring, it was necessary to incorporate special quality checks into the operation of the APT Service at its multiple automatic telescope installation on Mount Hopkins. 18 references

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-06-15

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Bartels, Christoph

    2011-10-15

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

  14. Vacuum Cherenkov radiation for Lorentz-violating fermions

    Science.gov (United States)

    Schreck, M.

    2017-11-01

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

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

    International Nuclear Information System (INIS)

    Bartels, Christoph

    2011-10-01

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

  16. PPO-ethanol system as wavelength shifter for the Cherenkov counting technique using a liquid scintillation counter

    International Nuclear Information System (INIS)

    Takiue, M.; Fujii, H.; Ishikawa, H.

    1984-01-01

    2,5-diphenyloxazole (PPO) has been proposed as a wavelength shifter for Cherenkov counting. Since PPO is not incorporated with water, we have introduced the fluor into water in the form of micelle using a PPO-ethanol system. This technique makes it possible to obtain a high Cherenkov counting efficiency under stable sample conditions, attributed to the proper spectrometric features of the PPO. The 32 P Cherenkov counting efficiency (68.4%) obtained from this technique is 1.62 times as large as that measured with a conventional Cherenkov technique. (orig.)

  17. SiPM as photon counter for Cherenkov detectors

    International Nuclear Information System (INIS)

    Roy, B.J.; Orth, H.; Schwarz, C.; Wilms, A.; Peters, K.

    2009-01-01

    Silicon photomultipliers (SiPMs) are very new type of photon counting devices that show great promise to be used as detection device in combination with scintillators/ Cherenkov radiators. SiPM is essentially an avalanche photo-diode operated in limited Geiger mode. They have been considered as potential readout devices for DIRC counter of the PANDA detector which is one of the large experiment at FAIR- the new international facility to be built at GSI, Darmstadt. In addition, the potential use of SiPM includes medical diagnosis, fluorescence measurement and high energy physics experiments. The SiPM module is a photon counting device capable of low light level detection. It is essentially an opto-semiconductor device with excellent photon counting capability and possesses great advantages over the conventional PMTs because of low voltage operation and insensitivity to magnetic fields. In many of the high energy physics experiments, the photon sensors are required to operate in high magnetic fields precluding the use of conventional PMTs. This problem can be over come with the use of SiPMs. With this motivation in mind, we have developed a SiPM test facility and have tested several commercially available SiPM for their performance study and comparison with other photon counting devices

  18. Prototype study of the Cherenkov imager of the AMS experiment

    International Nuclear Information System (INIS)

    Aguayo, P.; Aguilar-Benitez, M.; Arruda, L.; Barao, F.; Barreira, G.; Barrau, A.; Baret, B.; Belmont, E.; Berdugo, J.; Boudoul, G.; Borges, J.; Buenerd, M.; Casadei, D.; Casaus, J.; Delgado, C.; Diaz, C.; Derome, L.; Eraud, L.; Gallin-Martel, L.; Giovacchini, F.; Goncalves, P.; Lanciotti, E.; Laurenti, G.; Malinine, A.; Mana, C.; Marin, J.; Martinez, G.; Menchaca-Rocha, A.; Palomares, C.; Pereira, R.; Pimenta, M.; Protasov, K.; Sanchez, E.; Seo, E.-S.; Sevilla, I.; Torrento, A.; Vargas-Trevino, M.; Veziant, O.

    2006-01-01

    The AMS experiment includes a Cherenkov imager for mass and charge identification of charged cosmic rays. A second generation prototype has been constructed and its performances evaluated both with cosmic ray particles and with beam ions. In-beam tests have been performed using secondary nuclei from the fragmentation of 20GeV/c per nucleon Pb ions and 158GeV/c per nucleon In from the CERN SPS in 2002 and 2003. Partial results are reported. The performances of the prototype for the velocity and the charge measurements have been studied over the range of ion charge Z-bar 30. A sample of candidate silica aerogel radiators for the flight model of the detector has been tested. The measured velocity resolution of the detector was found to scale with Z -1 as expected, with a value σ(β)/β∼0.7-110 -3 for singly charged particles and an asymptotic limit in Z of 0.4-0.6x10 -4 . The measured charge resolution obtained for the n=1.05 aerogel radiator material selected for the flight model of the detector is σ(Z)=0.18 (statistical) -bar 0.015 (systematic), ensuring a good charge separation up to the iron element, for the prototype in the reported experimental conditions

  19. Optimization of the digital Silicon Photomultiplier for Cherenkov light detection

    International Nuclear Information System (INIS)

    Frach, T

    2012-01-01

    The Silicon Photomultiplier is a promising alternative to fast vacuum photodetectors. We developed a fully digital implementation of the Silicon Photomultiplier. The sensor is based on a single photon avalanche photodiode (SPAD) integrated in a standard CMOS process. Photons are detected directly by sensing the voltage at the SPAD anode using a dedicated cell electronics block next to each diode. This block also contains active quenching and recharge circuits as well as a one bit memory for the selective inhibit of detector cells. A balanced trigger network is used to propagate the trigger signal from all cells to the integrated time-to-digital converter. Photons are detected and counted as digital signals, thus making the sensor less susceptible to temperature variations and electronic noise. The integration with CMOS logic has the added benefit of low power consumption and possible integration of data post-processing in the sensor. In this paper, we discuss the sensor architecture together with its characteristics, and its possible optimizations for applications requiring the detection of Cherenkov light.

  20. TORCH—a Cherenkov based time-of-flight detector

    Energy Technology Data Exchange (ETDEWEB)

    Dijk, M.W.U. van, E-mail: m.vandijk@bristol.ac.uk [H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Brook, N.H. [H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Castillo García, L. [European Organisation for Nuclear Research (CERN), CH-1211 Geneva 23 (Switzerland); Laboratory for High Energy Physics, Ecole Polytechnique Fédérale de Lausanne, CH-1015 Lausanne (Switzerland); Cowie, E.N.; Cussans, D. [H.H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); D' Ambrosio, C. [European Organisation for Nuclear Research (CERN), CH-1211 Geneva 23 (Switzerland); Fopma, J. [Denys Wilkinson Laboratory, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Forty, R.; Frei, C. [European Organisation for Nuclear Research (CERN), CH-1211 Geneva 23 (Switzerland); Gao, R. [Denys Wilkinson Laboratory, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Gys, T. [European Organisation for Nuclear Research (CERN), CH-1211 Geneva 23 (Switzerland); Harnew, N.; Keri, T. [Denys Wilkinson Laboratory, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Piedigrossi, D. [European Organisation for Nuclear Research (CERN), CH-1211 Geneva 23 (Switzerland)

    2014-12-01

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

  1. Robotic and Survey Telescopes

    Science.gov (United States)

    Woźniak, Przemysław

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

  2. The South Pole Telescope

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-11-04

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

  3. In-beam test of a DIRC Cherenkov radiator with SiPM

    International Nuclear Information System (INIS)

    Kroeck, B.; Hayrapetyan, A.; Foehl, K.; Merle, O.; Dueren, M.; Roy, B.J.; Peters, K.

    2009-01-01

    One of the crucial points for any high energy physics experiment is to obtain a good pion/kaon separation i.e. particle identification (PID). For particles in minimum ionising range, the conventional methods of PID using energy loss and time of flight become insufficient. In such a situation, the measurement of velocity of particles using Cherenkov radiation is an effective tool for PID in combination with momentum information from a tracking detector. The PANDA experiment at FAIR/ GSI plans to use a novel technique for PID with detection of internally reflected Cherenkov (DIRC) light. DIRC uses, in contrast to the conventional gas Cherenkov detectors, a solid radiator and total internal reflection to guide Cherenkov photons onto a detection plane where it will be detected by advanced photon counters. A SiPM is a very new generation photon counter that has several advantages over conventional PMTs. Several prototype Cherenkov detectors with different readout systems are being developed for R and D studies. One such prototype detector with Geiger-APD readout has been built at Giessen and was tested in-beam at GSI. The present report provides details of the very first test measurement

  4. Telescopes and Techniques

    CERN Document Server

    Kitchin, C R

    2013-01-01

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

  5. Amateur Telescope Making

    Science.gov (United States)

    Tonkin, Stephen

    Many amateur astronomers make their own instruments, either because of financial considerations or because they are just interested. Amateur Telescope Making offers a variety of designs for telescopes, mounts and drives which are suitable for the home-constructor. The designs range from simple to advanced, but all are within the range of a moderately well-equipped home workshop. The book not only tells the reader what he can construct, but also what it is sensible to construct given what time is available commercially. Thus each chapter begins with reasons for undertaking the project, then looks at theoretical consideration before finishing with practical instructions and advice. An indication is given as to the skills required for the various projects. Appendices list reputable sources of (mail order) materials and components. The telescopes and mounts range from "shoestring" (very cheap) instruments to specialist devices that are unavailable commercially.

  6. The Advanced Gamma-ray Imaging System (AGIS) Telescope Optical System Designs

    Science.gov (United States)

    Bugaev, V.; Buckley, J.; Diegel, S.; Falcone, A.; Fegan, S.; Finley, J.; Guarino, V.; Hanna, D.; Kaaret, P.; Konopelko, A.; Krawczynski, H.; Ramsey, B.; Romani, R.; Vassiliev, V.; Weekes, T.

    2008-12-01

    AGIS is a conceptual design for a future ground-based gamma-ray observatory operating in the energy range 25 GeV-100 TeV, which is based on an array of ~20-100 imaging atmospheric Cherenkov telescopes (IACTs). The desired improvement in sensitivity, angular resolution, and reliability of operation of AGIS imposes demanding technological and cost requirements on the design of the IACTs. We are considering several options for the optical system (OS) of the AGIS telescopes, which include the traditional Davies-Cotton design as well as novel two-mirror design. Emerging mirror production technologies based on replication processes such as cold and hot glass slumping, cured carbon fiber reinforced plastic (CFRP), and electroforming provide new opportunities for cost-effective solutions for the design of the OS.

  7. The Calibration Units of the KM3NeT neutrino telescope

    Science.gov (United States)

    Baret, B.; Keller, P.; Clark, M. Lindsey

    2016-04-01

    KM3NeT is a network of deep-sea neutrino telescopes to be deployed in the Mediterranean Sea that will perform neutrino astronomy and oscillation studies. It consists of three-dimensional arrays of thousands of optical modules that detect the Cherenkov light induced by charged particles resulting from the interaction of a neutrino with the surrounding medium. The performance of the neutrino telescope relies on the precise timing and positioning calibration of the detector elements. Other environmental conditions which may affect light and sound transmission, such as water temperature and salinity, must also be continuously monitored. This contribution describes the technical design of the first Calibration Unit, to be deployed on the French site as part of KM3NeT Phase 1.

  8. The Advanced Gamma-ray Imaging System (AGIS): Schwarzschild-Couder (SC) Telescope Mechanical and Optical System Design

    Science.gov (United States)

    Byrum, Karen L.; Vassiliev, V.; AGIS Collaboration

    2010-03-01

    AGIS is a concept for the next-generation ground-based gamma-ray observatory. It will be an array of 36 imaging atmospheric Cherenkov telescopes (IACTs) sensitive in the energy range from 50 GeV to 200 TeV. The required improvements in sensitivity, angular resolution, and reliability of operation relative to the present generation instruments imposes demanding technological and cost requirements on the design of AGIS telescopes. In this submission, we outline the status of the development of the optical and mechanical systems for a novel Schwarzschild-Couder two-mirror aplanatic telescope. This design can provide a field of view and angular resolution significantly better to those offered by the traditional Davies-Cotton optics utilized in present-day IACTs. Other benefits of the novel design include isochronous focusing and compatibility with cost-effective, high quantum efficiency image sensors such as multi-anode PMTs, silicon PMTs (SiPMs), or image intensifiers.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-11

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

  10. First studies of 500-nm Cherenkov radiation from 255-MeV electrons in a diamond crystal

    Energy Technology Data Exchange (ETDEWEB)

    Takabayashi, Y., E-mail: takabayashi@saga-ls.jp [SAGA Light Source, 8-7 Yayoigaoka, Tosu, Saga 841-0005 (Japan); Fiks, E.I. [National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); Pivovarov, Yu.L. [National Research Tomsk Polytechnic University, 634050 Tomsk (Russian Federation); National Research Tomsk State University, 634050 Tomsk (Russian Federation)

    2015-06-12

    The first experiment on Cherenkov light from 255-MeV electrons passing through a 50-μm-thick diamond crystal in a special geometry allowing extraction of 500-nm Cherenkov light at a right angle with respect to the electron beam direction has been performed at the injector linac of SAGA Light Source accelerator facility. The dependence of 500-nm Cherenkov light intensity (separated by a band-pass filter) on the crystal rotation angle was measured by a CCD detector. The experimentally obtained rocking curve with an intense maximum is theoretically explained as the projector effect of Cherenkov light deflected by the exit surface of the crystal. The width of the rocking curve is explained by the convolution of the standard Tamm–Frank angular distribution of Cherenkov radiation with chromatic aberration, the multiple scattering of electrons in a crystal, and initial electron beam angular divergence. In addition, it is found that the Cherenkov light intensity did not change under the (220) planar channeling condition, which is consistent with a recent theory. - Highlights: • Cherenkov light from 255-MeV electrons in a diamond crystal has been investigated. • The Cherenkov light from channeled electrons has been observed for the first time. • The experimental results are in good agreement with theory.

  11. A quartz Cherenkov detector for Compton-polarimetry at future e+e- colliders

    International Nuclear Information System (INIS)

    List, Jenny; Vauth, Annika; Vormwald, Benedikt; Hamburg Univ.

    2015-02-01

    Precision polarimetry is essential for future e + e - colliders and requires Compton polarimeters designed for negligible statistical uncertainties. In this paper, we discuss the design and construction of a quartz Cherenkov detector for such Compton polarimeters. The detector concept has been developed with regard to the main systematic uncertainties of the polarisation measurements, namely the linearity of the detector response and detector alignment. Simulation studies presented here imply that the light yield reachable by using quartz as Cherenkov medium allows to resolve in the Cherenkov photon spectra individual peaks corresponding to different numbers of Compton electrons. The benefits of the application of a detector with such single-peak resolution to the polarisation measurement are shown for the example of the upstream polarimeters foreseen at the International Linear Collider. Results of a first testbeam campaign with a four-channel prototype confirming simulation predictions for single electrons are presented.

  12. Extensive air showers and diffused Cherenkov light detection: The ULTRA experiment

    International Nuclear Information System (INIS)

    Agnetta, G.; Assis, P.; Biondo, B.

    2007-01-01

    The Uv Light Transmission and Reflection in the Atmosphere (ULTRA) experiment has been designed to provide quantitative measurements of the backscattered Cherenkov signal associated to the Extensive Air Showers (EAS) at the impact point on the Earth surface. The knowledge of such information will test the possibility to detect the diffused Cherenkov light spot from space within the Ultra high-energy cosmic ray observation. The Cherenkov signal is necessary to give an absolute reference for the track, allowing the measurement of the shower maximum and easing the separation between neutrino and hadronic showers. In this paper we discuss the experimental set-up with detailed information on the detection method; the in situ and laboratory calibrations; the simulation of the expected detector response and finally the preliminary results on the detector performance

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

    International Nuclear Information System (INIS)

    Chang Zhe; Li Xin; Wang Sai

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-10-15

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

  15. Evaluation of new 5 inch photomultiplier for use in threshold Cherenkov detectors with aerogel radiator

    International Nuclear Information System (INIS)

    Wojtsekhowski, B.; Zorn, C.; Flyckt, S.O.

    2000-01-01

    A cost effective alternative to UV-sensitive 5 inch PMTs often used with threshold Aerogel Cherenkov detectors has been developed and tested. The photomultiplier -XP4572-is a variation of the Photonis XP4512 glass window tube with improved electron collection efficiency. Fast timing and high gain were only moderately compromised. The effective quantum efficiency has been measured as twice that of a Burle 8854 Quantacon when exposed to a Cherenkov spectrum generated by Ru-106 electrons (les;3.54 MeV) through 1 cm of high index, high transparency Matsushita Electric aerogel (n=1.05). This new phototube is being installed in an aerogel-based Cherenkov detector for Hall A at Jefferson Lab

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

    CERN Document Server

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

    1999-01-01

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

  17. Exploring Galileo's Telescope

    Science.gov (United States)

    Straulino, Samuele; Terzuoli, Alessandra

    2010-01-01

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

  18. Taiwan Automated Telescope Network

    Directory of Open Access Journals (Sweden)

    Dean-Yi Chou

    2010-01-01

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

  19. The Falcon Telescope Network

    Science.gov (United States)

    Chun, F.; Tippets, R.; Dearborn, M.; Gresham, K.; Freckleton, R.; Douglas, M.

    2014-09-01

    The Falcon Telescope Network (FTN) is a global network of small aperture telescopes developed by the Center for Space Situational Awareness Research in the Department of Physics at the United States Air Force Academy (USAFA). Consisting of commercially available equipment, the FTN is a collaborative effort between USAFA and other educational institutions ranging from two- and four-year colleges to major research universities. USAFA provides the equipment (e.g. telescope, mount, camera, filter wheel, dome, weather station, computers and storage devices) while the educational partners provide the building and infrastructure to support an observatory. The user base includes USAFA along with K-12 and higher education faculty and students. Since the FTN has a general use purpose, objects of interest include satellites, astronomical research, and STEM support images. The raw imagery, all in the public domain, will be accessible to FTN partners and will be archived at USAFA in the Cadet Space Operations Center. FTN users will be able to submit observational requests via a web interface. The requests will then be prioritized based on the type of user, the object of interest, and a user-defined priority. A network wide schedule will be developed every 24 hours and each FTN site will autonomously execute its portion of the schedule. After an observational request is completed, the FTN user will receive notification of collection and a link to the data. The Falcon Telescope Network is an ambitious endeavor, but demonstrates the cooperation that can be achieved by multiple educational institutions.

  20. Prospects for Cherenkov telescope array observations of the young supernova Remnant RX J1713.7-3946

    Czech Academy of Sciences Publication Activity Database

    Acero, F.; Aloisio, R.; Amans, J.; Blažek, Jiří; Chudoba, Jiří; Ebr, Jan; Janeček, Petr; Mandát, Dušan; Palatka, Miroslav; Prouza, Michael; Schovánek, Petr; Trávníček, Petr; Vraštil, Michal

    2017-01-01

    Roč. 840, č. 2 (2017), s. 1-14, č. článku 74. ISSN 0004-637X R&D Projects: GA MŠk(CZ) 7AMB14AR005; GA MŠk LE13012; GA ČR(CZ) GA14-17501S; GA MŠk LG14019 Institutional support: RVO:68378271 Keywords : cosmic rays * gamma rays: ISM * ISM: individual objects (RX J1713.7-3946, G347.3-0.5) Subject RIV: BF - Elementary Particles and High Energy Physics OBOR OECD: Particles and field physics Impact factor: 5.533, year: 2016

  1. The central pixel of the MAGIC telescope for optical observations

    Science.gov (United States)

    Lucarelli, F.; Barrio, J. A.; Antoranz, P.; Asensio, M.; Camara, M.; Contreras, J. L.; Fonseca, M. V.; Lopez, M.; Miranda, J. M.; Oya, I.; Reyes, R. De Los; Firpo, R.; Sidro, N.; Goebel, F.; Lorenz, E.; Otte, N.

    2008-05-01

    The MAGIC telescope has been designed for the observation of Cherenkov light generated in Extensive Air Showers initiated by cosmic particles. However, its 17 m diameter mirror and optical design makes the telescope suitable for direct optical observations as well. In this paper, we report about the development of a system based on the use of a dedicated photo-multiplier (PMT) for optical observations. This PMT is installed in the centre of the MAGIC camera (the so-called central pixel). An electro-to-optical system has been developed in order to transmit the PMT output signal by an optical fibre to the counting room, where it is digitized and stored for off-line analysis. The performance of the system using the optical pulsation of the Crab nebula as calibration source is presented. The time required for a 5σ detection of the Crab pulsar in the optical band is less than 20 s. The central pixel will be mainly used to perform simultaneous observations of the Crab pulsar both in the optical and γ-ray regimes. It will also allow for periodic testing of the precision of the MAGIC timing system using the Crab rotational optical pulses as a very precise timing reference.

  2. The KM3NeT deep-sea neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

    Margiotta, Annarita

    2014-12-01

    KM3NeT is a deep-sea research infrastructure being constructed in the Mediterranean Sea. It will host the next generation Cherenkov neutrino telescope and nodes for a deep sea multidisciplinary observatory, providing oceanographers, marine biologists, and geophysicists with real time measurements. The neutrino telescope will complement IceCube in its field of view and exceed it substantially in sensitivity. Its main goal is the detection of high energy neutrinos of astrophysical origin. The detector will have a modular structure with six building blocks, each consisting of about 100 Detection Units (DUs). Each DU will be equipped with 18 multi-PMT digital optical modules. The first phase of construction has started and shore and deep-sea infrastructures hosting the future KM3NeT detector are being prepared in offshore Toulon, France and offshore Capo Passero on Sicily, Italy. The technological solutions for the neutrino detector of KM3NeT and the expected performance of the neutrino telescope are presented and discussed. - Highlights: • A deep-sea research infrastructure is being built in the Mediterranean Sea. • It will host a km{sup 3}-size neutrino telescope and a deep-sea multidisciplinary observatory. • The main goal of the neutrino telescope is the search for Galactic neutrino sources. • A major innovation is adopted in the design of the optical module. • 31 3 in. photomultiplier tubes (PMTs) will be hosted in the same glass sphere.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-02-01

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

  4. Reconstruction algorithms in the Super-Kamiokande large water Cherenkov detector

    International Nuclear Information System (INIS)

    Shiozawa, M.

    1999-01-01

    The Super-Kamiokande experiment, using a large underground water Cherenkov detector, has started its operation since first April, 1996. One of the main physics goals of this experiment is to measure the atmospheric neutrinos. Proton decay search is also an important topic. For these analyses, all measurement of physical quantities of an event such as vertex position, the number of Cherenkov rings, momentum, particle type and the number of decay electrons, is automatically performed by reconstruction algorithms. We attain enough quality of the analyses using these algorithms and several impressive results have been addressed

  5. Monitor and control systems for the SLD Cherenkov Ring Imaging Detector

    International Nuclear Information System (INIS)

    Antilogus, P.; Aston, D.; Bienz, T.; Boston Univ., MA; California Univ., Santa Barbara, CA; California Univ., Santa Cruz, CA; Cincinnati Univ., OH; Rutgers--the State Univ., Piscataway, NJ; Tohoku Univ., Sendai

    1989-10-01

    To help ensure the stable long-term operation of a Cherenkov Ring Detector at high efficiency, a comprehensive monitor and control system is being developed. This system will continuously monitor and maintain the correct operating temperatures, and will provide an on-line monitor and maintain the correct operating temperatures, and will provide an on-line monitor of the pressures, flows, mixing, and purity of the various fluids. In addition the velocities and trajectories of Cherenkov photoelectrons drifting within the imaging chambers will be measured using a pulsed uv lamp and a fiberoptic light injection system. 9 refs., 6 figs

  6. Reconstruction algorithms in the Super-Kamiokande large water Cherenkov detector

    CERN Document Server

    Shiozawa, M

    1999-01-01

    The Super-Kamiokande experiment, using a large underground water Cherenkov detector, has started its operation since first April, 1996. One of the main physics goals of this experiment is to measure the atmospheric neutrinos. Proton decay search is also an important topic. For these analyses, all measurement of physical quantities of an event such as vertex position, the number of Cherenkov rings, momentum, particle type and the number of decay electrons, is automatically performed by reconstruction algorithms. We attain enough quality of the analyses using these algorithms and several impressive results have been addressed.

  7. Stability and linearity control of spectrometric channels of the Cherenkov counters using controllable units

    International Nuclear Information System (INIS)

    Kollar, D.; Kollarova, L.; Khorvat, P.

    1976-01-01

    A system is elaborated to control stability and linearity of the Cherenkov counter spectrometric channels in an experiment on a magnetic monopole search. Linearity of a light characteristic of a photoelectric multiplier is checked with the help of the calibrated light-strikings of light emitting diodes with flare intensity adjusted by controlling generator voltage across the mercury body. A program algorithm is presented for checking stability and linearity of the Cherenkov counter spectrometric channels which helps to consider the fatigue effects of the photoelectric multiplier resulting from the considerable loads

  8. A Cherenkov imager for the charge measurement of the elements of nuclear cosmic radiation

    International Nuclear Information System (INIS)

    Sallaz-Damaz, Y.

    2008-10-01

    A Cherenkov imager, CHERCAM (Cherenkov Camera) has been designed and built for the CREAM (Cosmic Ray Energetics and Mass) balloon-borne experiment. The instrument will perform charge measurements of nuclear cosmic-ray over a range extending from proton to iron in the energy domain from 10 10 to 10 15 eV. This work has focused on the development of CHERCAM by creating a simulation of the detector and on the aerogel plan characterization for the radiator. But it has also expanded on the technical aspects of the construction of the detector and its various tests, as well as the development of calibration software and data analysis. (author)

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

    CERN Document Server

    Carson, Laurence

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

  10. Cherenkov detectors for spatial imaging applications using discrete-energy photons

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Paul B.; Erickson, Anna S., E-mail: erickson@gatech.edu [Georgia Institute of Technology, Nuclear and Radiological Engineering, G.W. Woodruff School of Mechanical Engineering, 770 State St., Atlanta, Georgia 30332 (United States)

    2016-08-14

    Cherenkov detectors can offer a significant advantage in spatial imaging applications when excellent timing response, low noise and cross talk, large area coverage, and the ability to operate in magnetic fields are required. We show that an array of Cherenkov detectors with crude energy resolution coupled with monochromatic photons resulting from a low-energy nuclear reaction can be used to produce a sharp image of material while providing large and inexpensive detector coverage. The analysis of the detector response to relative transmission of photons with various energies allows for reconstruction of material's effective atomic number further aiding in high-Z material identification.

  11. Measuring the emulsion stability in Cherenkov radiation with insignificant modification of a liquid scintillation spectrometer

    International Nuclear Information System (INIS)

    Wiechen, A.; Lorenzen, P.Ch.; Reimerdes, E.H.

    1984-01-01

    A method is described by which the stability of emulsions can be measured by a modified liquid scintillation counter. The 226 Ra external standard source of a commercially available equipment, fixed in the measuring position, is used for the production of Cherenkov radiation in a sample of an emulsion. This Cherenkov radiation is absorbed by the sample due to its turbidity. The turbidity of emulsions follows a typical course with time designated as creaming-up-curve. These curves can be registered automatically in digital form. (author)

  12. Remote Cherenkov imaging-based quality assurance of a magnetic resonance image-guided radiotherapy system.

    Science.gov (United States)

    Andreozzi, Jacqueline M; Mooney, Karen E; Brůža, Petr; Curcuru, Austen; Gladstone, David J; Pogue, Brian W; Green, Olga

    2018-06-01

    Tools to perform regular quality assurance of magnetic resonance image-guided radiotherapy (MRIgRT) systems should ideally be independent of interference from the magnetic fields. Remotely acquired optical Cherenkov imaging-based dosimetry measurements in water were investigated for this purpose, comparing measures of dose accuracy, temporal dynamics, and overall integrated IMRT delivery. A 40 × 30.5 × 37.5 cm 3 water tank doped with 1 g/L of quinine sulfate was imaged using an intensified charge-coupled device (ICCD) to capture the Cherenkov emission while being irradiated by a commercial MRIgRT system (ViewRay™). The ICCD was placed down-bore at the end of the couch, 4 m from treatment isocenter and behind the 5-Gauss line of the 0.35-T MRI. After establishing optimal camera acquisition settings, square beams of increasing size (4.2 × 4.2 cm 2 , 10.5 × 10.5 cm 2 , and 14.7 × 14.7 cm 2 ) were imaged at 0.93 frames per second, from an individual cobalt-60 treatment head, to develop projection measures related to percent depth dose (PDD) curves and cross beam profiles (CPB). These Cherenkov-derived measurements were compared to ionization chamber (IC) and radiographic film dosimetry data, as well as simulation data from the treatment planning system (TPS). An intensity-modulated radiotherapy (IMRT) commissioning plan from AAPM TG-119 (C4:C-Shape) was also imaged at 2.1 frames per second, and the single linear sum image from 509 s of plan delivery was compared to the dose volume prediction generated by the TPS using gamma index analysis. Analysis of standardized test target images (1024 × 1024 pixels) yielded a pixel resolution of 0.37 mm/pixel. The beam width measured from the Cherenkov image-generated projection CBPs was within 1 mm accuracy when compared to film measurements for all beams. The 502 point measurements (i.e., pixels) of the Cherenkov image-based projection percent depth dose curves (pPDDs) were compared to p

  13. The big data telescope

    International Nuclear Information System (INIS)

    Finkel, Elizabeth

    2017-01-01

    On a flat, red mulga plain in the outback of Western Australia, preparations are under way to build the most audacious telescope astronomers have ever dreamed of - the Square Kilometre Array (SKA). Next-generation telescopes usually aim to double the performance of their predecessors. The Australian arm of SKA will deliver a 168-fold leap on the best technology available today, to show us the universe as never before. It will tune into signals emitted just a million years after the Big Bang, when the universe was a sea of hydrogen gas, slowly percolating with the first galaxies. Their starlight illuminated the fledgling universe in what is referred to as the “cosmic dawn”.

  14. Radio telescope control

    CERN Document Server

    Schraml, J

    1972-01-01

    An on-line computer control process developed for the 100-m radio telescope of the Max-Planck-Institut fur Radioastronomie in Bonn is described. The instrument is the largest fully steerable antenna in the world. Its operation started on May 31st 1972. It is controlled by a Ferranti Argus 500 on-line computer. The first part of the paper deals with the process itself, the radio telescope and its operation, and the demands resulting for the control program. The second part briefly describes the computer and its hardware. The final part introduces the architecture of the executive program in general, which has been tailored to meet the demands of the process and the hardware. The communication between the observer and the system, the format of data on magnetic tape and an on-line reduction of position measurements are considered. (0 refs).

  15. [Galileo and his telescope].

    Science.gov (United States)

    Strebel, Christoph

    2006-01-01

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

  16. Workshop: Neutrino telescopes

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    Despite being the most elusive of the known particles, neutrinos provide vital new physics insights. Most neutrino knowledge so far has come from studies using beams from reactors and accelerators, but in recent years important new contributions have resulted from investigation of natural neutrinos from cosmic rays, nearby stars (the sun), or distant sources, such as the 1987 supernova. The supernova observations marked the start of a new era in neutrino astronomy, but neutrino telescopes were anyway assured of an important ongoing role

  17. Workshop: Neutrino telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1990-05-15

    Despite being the most elusive of the known particles, neutrinos provide vital new physics insights. Most neutrino knowledge so far has come from studies using beams from reactors and accelerators, but in recent years important new contributions have resulted from investigation of natural neutrinos from cosmic rays, nearby stars (the sun), or distant sources, such as the 1987 supernova. The supernova observations marked the start of a new era in neutrino astronomy, but neutrino telescopes were anyway assured of an important ongoing role.

  18. Fast Fourier transform telescope

    International Nuclear Information System (INIS)

    Tegmark, Max; Zaldarriaga, Matias

    2009-01-01

    We propose an all-digital telescope for 21 cm tomography, which combines key advantages of both single dishes and interferometers. The electric field is digitized by antennas on a rectangular grid, after which a series of fast Fourier transforms recovers simultaneous multifrequency images of up to half the sky. Thanks to Moore's law, the bandwidth up to which this is feasible has now reached about 1 GHz, and will likely continue doubling every couple of years. The main advantages over a single dish telescope are cost and orders of magnitude larger field-of-view, translating into dramatically better sensitivity for large-area surveys. The key advantages over traditional interferometers are cost (the correlator computational cost for an N-element array scales as Nlog 2 N rather than N 2 ) and a compact synthesized beam. We argue that 21 cm tomography could be an ideal first application of a very large fast Fourier transform telescope, which would provide both massive sensitivity improvements per dollar and mitigate the off-beam point source foreground problem with its clean beam. Another potentially interesting application is cosmic microwave background polarization.

  19. A detailed study of FDIRC prototype with waveform digitizing electronics in cosmic ray telescope using 3D tracks

    Science.gov (United States)

    Nishimura, K.; Dey, B.; Aston, D.; Leith, D. W. G. S.; Ratcliff, B.; Roberts, D.; Ruckman, L.; Shtol, D.; Varner, G. S.; Va'vra, J.

    2013-02-01

    We present a detailed study of a novel Cherenkov imaging detector called the Focusing DIRC (FDIRC) with waveform digitizing electronics. In this study, the FDIRC prototype has been instrumented with seven Hamamatsu H-8500 MaPMTs. Waveforms from 384 pixels are digitized with waveform sampling electronics based on the BLAB2 ASIC, operating at a sampling speed of ∼2.5 GSa/s. The FDIRC prototype was tested in a large cosmic ray telescope (CRT) providing 3D muon tracks with ∼1.5 mrad angular resolution and muon energy of Emuon> 1.6 GeV. In this study we provide a detailed analysis of the tails in the Cherenkov angle distribution as a function of various variables, compare experimental results with simulation, and identify the major contributions to the tails. We demonstrate that to see the full impact of these tails on the Cherenkov angle resolution, it is crucial to use 3D tracks, and have a full understanding of the role of reconstruction ambiguities. These issues could not be fully explored in previous FDIRC studies where the beam was perpendicular to the quartz radiator bars. This work is relevant for the final FDIRC prototype of the PID detector at SuperB, which will be tested this year in the CRT setup.

  20. A Detailed Study of FDIRC Prototype with Waveform Digitizing Electronics in Cosmic Ray Telescope Using 3D Tracks

    International Nuclear Information System (INIS)

    Nishimura, K.; Dey, B.; Aston, D.; Leith, D.W.G.S.; Ratcliff, B.; Roberts, D.; Ruckman, L.; Shtol, D.; Varner, G.S.; Va'vra, J.

    2012-01-01

    We present a detailed study of a novel Cherenkov imaging detector called the Focusing DIRC (FDIRC) with waveform digitizing electronics. In this test study, the FDIRC prototype has been instrumented with seven Hamamatsu H-8500 MaPMTs. Waveforms from ∼450 pixels are digitized with waveform sampling electronics based on the BLAB2 ASIC, operating at a sampling speed of ∼2.5 GSa/s. The FDIRC prototype was tested in a large cosmic ray telescope (CRT) providing 3D muon tracks with ∼1.5 mrad angular resolution and muon energy of E muon > 1.6 GeV. In this study we provide a detailed analysis of the tails in the Cherenkov angle distribution as a function of various variables, compare experimental results with simulation, and identify the major contributions to the tails. We demonstrate that to see the full impact of these tails on the Cherenkov angle resolution, it is crucial to use 3D tracks, and have a full understanding of the role of ambiguities. These issues could not be fully explored in previous FDIRC studies where the beam was perpendicular to the quartz radiator bars. This work is relevant for the final FDIRC prototype of the PID detector at SuperB, which will be tested this year in the CRT setup.

  1. Cherenkov and scintillation light separation on the CheSS experiment

    Science.gov (United States)

    Caravaca, Javier; Land, Benjamin; Descamps, Freija; Orebi Gann, Gabriel D.

    2016-09-01

    Separation of the scintillation and Cherenkov light produced in liquid scintillators enables outstanding capabilities for future particle detectors, the most relevant being: particle directionality information in a low energy threshold detector and improved particle identification. The CheSS experiment uses an array of small, fast photomultipliers (PMTs) and state-of-the-art electronics to demonstrate the reconstruction of a Cherenkov ring in liquid scintillator using two techniques: based on the photon density and using the photon hit time information. A charged particle ionizing a scintillation medium produces a prompt Cherenkov cone and late isotropic scintillation light, typically delayed by several ns. The fast response of our PMTs and DAQ provides a precision well below the ns level, making possible the time separation. Furthermore, the usage of the new developed water-based liquid scintillators (WbLS) enhances the separation since it allows tuning of the Cherenkov/Scintillation ratio. Latest results on the separation for pure liquid scintillators and WbLS will be presented.

  2. Gaseous photomultipliers for the readout of scintillators and detection Cherenkov radiation

    International Nuclear Information System (INIS)

    Peskov, V.; Borovik-Romanov, A.

    1993-11-01

    The latest achievements in the development of gaseous detectors for registering UV and visible photons are described. Possible modifications of their design for some particular applications such as the readout of crystal scintillators. noble liquids, fibers and for large area Cherenkov detectors are discussed

  3. Cherenkov light based measurement of extensive air showers around the knee with the HEGRA experiment

    Energy Technology Data Exchange (ETDEWEB)

    Aharonian, F.; Akhperjanian, A.G.; Barrio, J.A.; Belgarian, A.S.; Bernloehr, K.; Bojahr, H.; Contreras, J.L.; Cortina, J.; Daum, A.; Deckers, T.; Denninghoff, S.; Fernandez, J.; Fonseca, V.; Gonzales, J.C.; Heinzelmann, G.; Hemberger, M.; Hermann, G.; Hess, M.; Heusler, A.; Hofmann, W.; Hohl, H.; Horns, D.; Kankanyan, R.; Kestel, M.; Kirstein, O.; Koehler, C.; Konopelko, A.; Kornmayer, H.; Kranich, D.; Krawczynski, H.; Lampeitl, H.; Lindner, A.; Lorenz, E.; Magnussen, N.; Meyer, H.; Mirzoyan, R.; Moralejo, A.; Padilla, L.; Panter, M.; Petry, D.; Plaga, R.; Plyasheshnikov, A.; Prahl, J.; Prosch, C.; Puehlhofer, G.; Rauterberg, G.; Renault, C.; Rhode, W.; Roehring, A.; Sahakian, V.; Samorski, M.; Schmele, D.; Schroeder, F.; Stamm, W.; Voelk, H.J.; Wiebel-Sooth, B

    1999-03-01

    Data of the wide angle atmospheric Cherenkov light detector array AIROBICC and the scintillator matrix of the HEGRA air shower detector complex are combined to determine the energy spectrum and coarse composition of charged cosmic rays in the energy interval from 300 TeV to 10 PeV.

  4. Features and performance of a large gas Cherenkov detector with threshold regulation

    Energy Technology Data Exchange (ETDEWEB)

    Alberdi, J.; Alvarez-Taviel, J.; Asenjo, L.; Colino, N.; Diez-Hedo. F.; Duran, I.; Gonzalez, J.; Hernandez, J.J.; Ladron de Guevara, P.; Marquina, M.A.

    1988-01-15

    We present here the development, main features and calibration procedures for a new type of gas Cherenkov detector, based upon the ability to control its threshold by regulating the temperature of the gas used as radiator. We also include the performance of this detector in particle identification.

  5. An iterative method for the analysis of Cherenkov rings in the HERA-B RICH

    International Nuclear Information System (INIS)

    Staric, M.; Krizan, P.

    1999-01-01

    A new method is presented for the analysis of data recorded with a Ring Imaging Cherenkov (RICH) counter. The method, an iterative sorting of hits on the photon detector, is particularly useful for events where rings overlap considerably. The algorithm was tested on simulated data for the HERA-B experiment

  6. Construction and performance of two multicell Cherenkov counters used in FRAMM-NA1 spectrometer

    International Nuclear Information System (INIS)

    Amendolia, S.R.; Batignani, G.; Bedeschi, F.; Bertolucci, E.; Bettoni, D.; Bosisio, L.; Bottigli, U.; Bradaschia, C.; Budinich, M.; Dell'Orso, M.; Fidecaro, F.; Foa, L.; Focardi, E.; Giazotto, A.; Giorgi, M.A.; Liello, F.; Marrocchesi, P.S.; Mensa, A.; Menzione, A.; Ristori, L.; Rolandi, L.; Scribano, A.; Stanga, R.; Stefanini, A.; Tonelli, G.

    1983-01-01

    Two small dimension multicell Cherenkov counters have been built for FRAMM-NA1 multiparticle spectrometer to identify pions and kaons in the momentum range between 5 and 22 GeV/c. The performances achieved and the construction details are reported. (orig.)

  7. Cherenkov and anomalous Doppler effects in the relaxation of an electron beam

    International Nuclear Information System (INIS)

    Muschietti, L.; Appert, K.; Vaclavik, J.

    1981-01-01

    The interplay between the Cherenkov and anomalous Doppler interactions in the relaxation of a warm electron beam is investigated by numerical means. The most important feature in the interplay is found to be a nonelastic isotropization. A simple semianalytical model which allows one to estimate various quantities relevant to the relaxation process is also presented

  8. Search for long-lived heavy charged particles using a ring imaging Cherenkov technique at LHCb

    NARCIS (Netherlands)

    Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Cartelle, P. Alvarez; Alves, A. A., Jr.; Amato, S.; Amerio, S.; Amhis, Y.; Everse, LA; Anderlini, L.; Anderson, J.; Andreotti, M.; Andrews, J.E.; Appleby, R. B.; Gutierrez, O. Aquines; Archilli, F.; d'Argent, P.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Bel, L. J.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bertolin, A.; Bettler, M-O.; Van Beuzekom, Martin; Bien, A.; Bifani, S.; Bird, T.D.; Birnkraut, A.; Bizzeti, A.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Perez, D. H. Campora; Capriotti, L.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carniti, P.; Carson, L.; Carvalho Akiba, K.; Casanova Mohr, R.; Casse, G.; Cassina, L.; Garcia, L. Castillo; Cattaneo, M.; Cauet, Ch; Cavallero, G.; Cenci, R.; Charles, M.; Charpentier, Ph; Chefdeville, M.; Chen, S.; Cheung, S-F.; Chiapolini, N.; Chrzaszcz, M.; Vidal, X. Cid; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Crocombe, A.; CruzTorres, M.; Cunliffe, S.; Currie, C.R.; D'Ambrosio, C.; Dalseno, J.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; de Miranda, J. M.; Paula, L.E.; da-Silva, W.S.; De Simone, P.; Dean, C-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Deleage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Dey, B.; Di Canto, A.; Di Ruscio, F.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suarez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; ElRifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H. M.; Evans, T. M.; Falabella, A.; Faerber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, R.; Ferguson, D.; Fernandez Albor, V.; Ferrari, F.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, Mark; Fontanelli, F.; Forty, R.; De Aguiar Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Torreira, A. Gallas; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; Garcia Pardinas, J.; Garofoli, J.; Tico, J. Garra; Garrido, L.; Gascon, D.; Carvalho-Gaspar, M.; Gauld, Rhorry; Gavardi, L.; Gazzoni, G.; Geraci, A.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T. J.; Ghez, Ph; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.Q.; Gotti, C.; Gandara, M. Grabalosa; Diaz, R. Graciani; Cardoso, L. A. Granado; Grauges, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Gruenberg, O.; Gui, B.; Gushchin, E.; Guz, Yu; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Hess, H.M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D. E.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M. H.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.M.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G. D.; Lai, A.; Lambert, D.M.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T. E.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J. P.; Lefevre, R.; Leflat, A.; Lefrancois, J.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, S.C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Manning, P.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Maerki, R.; Marks, J.; Martellotti, G.; Martinelli-Boneschi, F.; Santos, D. Martinez; Martinez-Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Mauri, A.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; Mcnab, A.; McNulty, R.; McSkelly, B.; Meadows, B. T.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M. N.; Mitzel, D. S.; Molina Rodriguez, J.; Monteil, S.; Morandin, M.; Morawski, P.; Morda, A.; Morello, M. J.; Moron, J.; Morris, A. B.; Mountain, R.; Muheim, F.; Mueller, J.; Mueller, Karl; Mueller, V.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Osorio Rodrigues, B.; Otalora Goicochea, J. M.; Otto, E.A.; Owen, R.P.; Oyanguren, A.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L.L.; Parkes, C.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, D.A.; Pellegrino, A.; Penso, G.; Altarelli, M. Pepe; Perazzini, S.; Perret, P.; Pescatore, L.; Petridis, K.; Petrolini, A.; Olloqui, E. Picatoste; Pietrzyk, B.; Pilar, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Poikela, T.; Polci, F.; Poluektov, A.; Polyakov, I.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, M. E.; Price, J.D.; Prisciandaro, J.; Pritchard, C.A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, Y.W.; Quagliani, R.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M.; dos Reis, A. C.; Ricciardi, S.; Richards, Jennifer S; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, L.E.T.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, van Hapere; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, R. H.; Schlupp, M.; Schmelling, M.; Schmelzer, T.; Schmidt, B.; Schneider, O.; Schopper, A.; Schune, M. H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Coutinho, R. Silva; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, E.; Smith, E.; Smith, J; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; de Souza, D.K.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson-Moore, P.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Tekampe, T.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M. N.; Todd, Jim; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, N.T.M.T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Garcia, M. Ubeda; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Gomez, R. Vazquez; Vazquez Regueiro, P.; Vazquez Sierra, C.; Vecchi, S.; Velthuis, M.J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voss, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, John; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Weiden, A.; Whitehead, M.; Wiedner, D.; Wilkinson, G.; Wilkinson, M.; Williams, M.; Williams, M.P.; Williams, M.; Wilson, James F; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.J.; Wyllie, K.; Xie, Y.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.

    2015-01-01

    A search is performed for heavy long-lived charged particles using 3.0 fb(-1) of proton-proton collisions collected at √s = 7 and 8 TeV with the LHCb detector. The search is mainly based on the response of the ring imaging Cherenkov detectors to distinguish the heavy, slow-moving particles from

  9. The atmospheric Cherenkov technique in searches for exploding primordial black holes

    International Nuclear Information System (INIS)

    Danaher, S.; Fegan, D.J.; Porter, N.A.; Weekes, T.C.

    1981-01-01

    The Cherenkov technique has been used with a number of detectors, ranging from 1.5 m 2 mirrors to the Central Receiver Test Facility of 8400 m 2 . Limits have been set to the flux of primordial black holes for various models of the evaporation process. (author)

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

    International Nuclear Information System (INIS)

    Salles, Brício M.; Mesquita, Amir Z.

    2017-01-01

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

  11. A long liquid Cherenkov counter for 300 to 460 MeV/c pion beams

    International Nuclear Information System (INIS)

    Zavrtanik, D.; Sever, F.; Plesko, M.; Music, M.; Kernel, G.

    1984-01-01

    A long liquid Cherenkov counter has been used to measure the proportion of muons in positive and negative pion beams in the momentum range between 300 and 460 MeV/c. A nine-parameter function fits all the spectra well. The data show a smooth dependence on incident momenta and agree with calculations of pion and muon pulse heights. (orig.)

  12. The Vavilov-Cherenkov radiation in a medium with a nonzero absorption coefficient

    International Nuclear Information System (INIS)

    Beshtoev, Kh.M.

    1997-01-01

    Distribution of the field around a charged relativistic particle in a medium is discussed. It is shown that the Vavilov-Cherenkov radiation exists in the case when the velocity of the charged particle is equal to the velocity of light in the medium. A simple approach is proposed to avoid singularity in the medium Electrodynamics

  13. Measurement of aerogel performance for ring image Cherenkov detector of HERMES

    International Nuclear Information System (INIS)

    Kanesaka, Jiro; Zhang Linfeng; Sato, Fumiko; Suetsugu, Kentaro; Sakami, Yasuhiro; Shibata, Toshiaki

    1999-01-01

    The first experiment of ring image Cherenkov detector (RICH) used aerogel in the world was reported in this paper. We built RICH using aerogel as illuminant for HERMES. The refractive index and size of all aerogel tiles were measured in order to select them for construction of RICH. The select conditions of tile were 113.1 -4 , the dispersion of refractive index of aerogel tile, which condition was fitted to the accuracy of Cherenkov light emission angle of RICH. The mean thickness, transmission and reflection of tile, the thickness of corner of tile (thickness of surface), the refractive index dependence on position and temperature were measured. The effect of thickness of tile on the shift of Cherenkov emission angle was 6.1% the maximum value per one tile and 0.18% mean value of center. The effect of position dependence of refractive index on the Cherenkov light emission angle was agreed with the effect of dispersion of thickness of tile. The transmission and reflection of tile were almost same as the theoretical value. (S.Y.)

  14. Cherenkov-type diagnostics of fast electrons beams escaping from MCF facilities

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L.; Malinowski, K.; Mirowski, R.; Rabinski, M.; Sadowski, M.J.; Zebrowski, J. [Institute for Nuclear Studies - IPJ, 05-400 Otwock-Swierk (Poland)

    2011-07-01

    The paper presents the feasibility study, the measuring system and the first experimental results of a new method developed for direct detection of high-energy (super-thermal, ripple-born and runaway) electrons generated in magnetic confinement fusion (MCF) facilities. The technique in question is based on registration of the Cherenkov radiation, emitted by energetic electrons, moving through a transparent medium (radiator) with a velocity higher than the velocity of light in this material. The main aim of our studies was to develop a diagnostic technique applicable for measurements of fast electron beams within MCF devices. The IPJ team proposed Cherenkov-type probes because of their high spatial- and temporal-resolutions. The most important results of applications of the presented Cherenkov-type diagnostics have proved that the one- and four-channel versions of the detecting head are useful for studies of the fast (ripple-born and runaway) electrons in different MCF experiments. Experience collected during the described studies allows to introduce some changes in the radiator configuration and to modify the Cherenkov probe design. This document is composed of a paper followed by a poster

  15. A Cherenkov radiator for FEL-synchronized VUV-pulses at a linac-based FEL

    NARCIS (Netherlands)

    Goloviznin, V. V.; Oepts, D.; van der Wiel, M. J.

    1997-01-01

    A possible way to carry out two-color IR+VUV pump-probe experiments at linac-based FELs is proposed. The idea is to supply an FEL facility with a gas cell filled with helium or hydrogen, so that the electron beam, upon passage through the undulator, could be used to generate ultraviolet Cherenkov

  16. A Cherenkov radiator for FEL-synchronized VUV-pulses at a linac-based FEL

    NARCIS (Netherlands)

    Goloviznin, V.V.; Oepts, W.; Wiel, van der M.J.

    1997-01-01

    A possible way to carry out two-color IR + VUV pump-probe experiments at linac-based FELs is proposed. The idea is to supply an FEL facility with a gas cell filled with helium or hydrogen, so that the electron beam, upon passage through the undulator, could be used to generate ultraviolet Cherenkov

  17. Signal intensity analysis and optimization for in vivo imaging of Cherenkov and excited luminescence

    Science.gov (United States)

    LaRochelle, Ethan P. M.; Shell, Jennifer R.; Gunn, Jason R.; Davis, Scott C.; Pogue, Brian W.

    2018-04-01

    During external beam radiotherapy (EBRT), in vivo Cherenkov optical emissions can be used as a dosimetry tool or to excite luminescence, termed Cherenkov-excited luminescence (CEL) with microsecond-level time-gated cameras. The goal of this work was to develop a complete theoretical foundation for the detectable signal strength, in order to provide guidance on optimization of the limits of detection and how to optimize near real time imaging. The key parameters affecting photon production, propagation and detection were considered and experimental validation with both tissue phantoms and a murine model are shown. Both the theoretical analysis and experimental data indicate that the detection level is near a single photon-per-pixel for the detection geometry and frame rates commonly used, with the strongest factor being the signal decrease with the square of distance from tissue to camera. Experimental data demonstrates how the SNR improves with increasing integration time, but only up to the point where the dominance of camera read noise is overcome by stray photon noise that cannot be suppressed. For the current camera in a fixed geometry, the signal to background ratio limits the detection of light signals, and the observed in vivo Cherenkov emission is on the order of 100×  stronger than CEL signals. As a result, imaging signals from depths  <15 mm is reasonable for Cherenkov light, and depths  <3 mm is reasonable for CEL imaging. The current investigation modeled Cherenkov and CEL imaging of two oxygen sensing phosphorescent compounds, but the modularity of the code allows for easy comparison of different agents or alternative cameras, geometries or tissues.

  18. MO-A-BRD-06: In Vivo Cherenkov Video Imaging to Verify Whole Breast Irradiation Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, R; Glaser, A [Dartmouth College, Hanover, NH - New Hampshire (United States); Jarvis, L [Dartmouth-Hitchcock Medical Center, City Of Lebanon, New Hampshire (United States); Gladstone, D [Dartmouth-Hitchcock Medical Center, Hanover, City of Lebanon (Lebanon); Andreozzi, J; Hitchcock, W; Pogue, B [Dartmouth College, Hanover, NH (United States)

    2014-06-15

    Purpose: To show in vivo video imaging of Cherenkov emission (Cherenkoscopy) can be acquired in the clinical treatment room without affecting the normal process of external beam radiation therapy (EBRT). Applications of Cherenkoscopy, such as patient positioning, movement tracking, treatment monitoring and superficial dose estimation, were examined. Methods: In a phase 1 clinical trial, including 12 patients undergoing post-lumpectomy whole breast irradiation, Cherenkov emission was imaged with a time-gated ICCD camera synchronized to the radiation pulses, during 10 fractions of the treatment. Images from different treatment days were compared by calculating the 2-D correlations corresponding to the averaged image. An edge detection algorithm was utilized to highlight biological features, such as the blood vessels. Superficial dose deposited at the sampling depth were derived from the Eclipse treatment planning system (TPS) and compared with the Cherenkov images. Skin reactions were graded weekly according to the Common Toxicity Criteria and digital photographs were obtained for comparison. Results: Real time (fps = 4.8) imaging of Cherenkov emission was feasible and feasibility tests indicated that it could be improved to video rate (fps = 30) with system improvements. Dynamic field changes due to fast MLC motion were imaged in real time. The average 2-D correlation was about 0.99, suggesting the stability of this imaging technique and repeatability of patient positioning was outstanding. Edge enhanced images of blood vessels were observed, and could serve as unique biological markers for patient positioning and movement tracking (breathing). Small discrepancies exists between the Cherenkov images and the superficial dose predicted from the TPS but the former agreed better with actual skin reactions than did the latter. Conclusion: Real time Cherenkoscopy imaging during EBRT is a novel imaging tool that could be utilized for patient positioning, movement tracking

  19. Observation of Cherenkov rings using a low-pressure parallel-plate chamber and a solid cesium-iodide photocathode

    International Nuclear Information System (INIS)

    Lockyer, N.S.; Millan, J.E.; Lu, C.; McDonald, K.T.; Lopez, A.

    1993-01-01

    We have observed Cherenkov rings from minimum-ionizing particles using a low-pressure, parallel-plate pad-chamber with a cesium-iodide solid photocathode. This detector is blind to minimum-ionizing particles, and sensitive to Cherenkov photons of wavelengths 170-210 nm. An average of 5 photoelectrons per Cherenkov ring were detected using a 2-cm-thick radiator of liquid C 6 F 14 . This paper reports on the chamber construction, photocathode preparation and testbeam results. (orig.)

  20. Stability and behavior of the outer array of small water Cherenkov detectors, outriggers, in the HAWC observatory

    OpenAIRE

    Capistrán, T.; Torres, I.; Moreno, E.; collaboration, for the HAWC

    2017-01-01

    The High-Altitude Water Cherenkov (HAWC) Observatory is used for detecting TeV gamma rays. HAWC is operating at 4,100 meters above level sea on the slope of the Sierra Negra Volcano in the State of Puebla, Mexico, and consists of an array of 300 water Cherenkov detectors (WCDs) covering an area of 22,000 $m^2$. Each WCD is equipped with four photomultiplier tubes (PMTs) to detect Cherenkov emission in the water from secondary particles of extensive air-shower (EAS) that are produced in the in...

  1. The Planck Telescope reflectors

    Science.gov (United States)

    Stute, Thomas

    2004-09-01

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

  2. Cherenkov imaging method for rapid optimization of clinical treatment geometry in total skin electron beam therapy

    Energy Technology Data Exchange (ETDEWEB)

    Andreozzi, Jacqueline M., E-mail: Jacqueline.M.Andreozzi.th@dartmouth.edu, E-mail: Lesley.A.Jarvis@hitchcock.org; Glaser, Adam K. [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755 (United States); Zhang, Rongxiao [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Gladstone, David J.; Williams, Benjamin B.; Jarvis, Lesley A., E-mail: Jacqueline.M.Andreozzi.th@dartmouth.edu, E-mail: Lesley.A.Jarvis@hitchcock.org [Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03766 (United States); Pogue, Brian W. [Thayer School of Engineering and Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States)

    2016-02-15

    Purpose: A method was developed utilizing Cherenkov imaging for rapid and thorough determination of the two gantry angles that produce the most uniform treatment plane during dual-field total skin electron beam therapy (TSET). Methods: Cherenkov imaging was implemented to gather 2D measurements of relative surface dose from 6 MeV electron beams on a white polyethylene sheet. An intensified charge-coupled device camera time-gated to the Linac was used for Cherenkov emission imaging at sixty-two different gantry angles (1° increments, from 239.5° to 300.5°). Following a modified Stanford TSET technique, which uses two fields per patient position for full body coverage, composite images were created as the sum of two beam images on the sheet; each angle pair was evaluated for minimum variation across the patient region of interest. Cherenkov versus dose correlation was verified with ionization chamber measurements. The process was repeated at source to surface distance (SSD) = 441, 370.5, and 300 cm to determine optimal angle spread for varying room geometries. In addition, three patients receiving TSET using a modified Stanford six-dual field technique with 6 MeV electron beams at SSD = 441 cm were imaged during treatment. Results: As in previous studies, Cherenkov intensity was shown to directly correlate with dose for homogenous flat phantoms (R{sup 2} = 0.93), making Cherenkov imaging an appropriate candidate to assess and optimize TSET setup geometry. This method provided dense 2D images allowing 1891 possible treatment geometries to be comprehensively analyzed from one data set of 62 single images. Gantry angles historically used for TSET at their institution were 255.5° and 284.5° at SSD = 441 cm; however, the angles optimized for maximum homogeneity were found to be 252.5° and 287.5° (+6° increase in angle spread). Ionization chamber measurements confirmed improvement in dose homogeneity across the treatment field from a range of 24.4% at the initial

  3. Deep space telescopes

    CERN Multimedia

    CERN. Geneva

    2006-01-01

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

  4. Antares Reference Telescope System

    International Nuclear Information System (INIS)

    Viswanathan, V.K.; Kaprelian, E.; Swann, T.; Parker, J.; Wolfe, P.; Woodfin, G.; Knight, D.

    1983-01-01

    Antares is a 24-beam, 40-TW carbon-dioxide laser-fusion system currently nearing completion at the Los Alamos National Laboratory. The 24 beams will be focused onto a tiny target (typically 300 to 1000 μm in diameter) located approximately at the center of a 7.3-m-diameter by 9.3-m-long vacuum (10 - 6 torr) chamber. The design goal is to position the targets to within 10 μm of a selected nominal position, which may be anywhere within a fixed spherical region 1 cm in diameter. The Antares Reference Telescope System is intended to help achieve this goal for alignment and viewing of the various targets used in the laser system. The Antares Reference Telescope System consists of two similar electro-optical systems positioned in a near orthogonal manner in the target chamber area of the laser. Each of these consists of four subsystems: (1) a fixed 9X optical imaging subsystem which produces an image of the target at the vidicon; (2) a reticle projection subsystem which superimposes an image of the reticle pattern at the vidicon; (3) an adjustable front-lighting subsystem which illuminates the target; and (4) an adjustable back-lighting subsystem which also can be used to illuminate the target. The various optical, mechanical, and vidicon design considerations and trade-offs are discussed. The final system chosen (which is being built) and its current status are described in detail

  5. SNAP Telescope Latest Developments

    Science.gov (United States)

    Lampton, M.; SNAP Collaboration

    2004-12-01

    The coming era of precision cosmology imposes new demands on space telescopes with regard to spectrophotometric accuracy and image stability. To meet these requirements for SNAP we have developed an all reflecting two-meter-class space telescope of the three-mirror anastigmat type. Our design features a large flat annular field (1.5 degrees = 580mm diameter) and a telephoto advantage of 6, delivering a 22m focal length within an optical package length of only 3.5 meters. The use of highly stable materials (Corning ULE glass and carbon-fiber reinforced cyanate ester resin for the metering structure) combined with agressive distributed thermal control and an L2 orbit location will lead to unmatched figure stability. Owing to our choice of rigid structure with nondeployable solar panels, finite-element models show no structural resonances below 10Hz. An exhaustive stray light study has been completed. Beginning in 2005, two industry studies will develop plans for fabrication, integration and test, bringing SNAP to a highly realistic level of definition. SNAP is supported by the Office of Science, US DoE, under contract DE-AC03-76SF00098.

  6. Origins Space Telescope

    Science.gov (United States)

    Cooray, Asantha; Origins Space Telescope Study Team

    2018-01-01

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

  7. Realisation and tests of a compressed gas Cherenkov counter. Study of the pollution of a beam (1961); Realisation et essais d'un compteur cherenkov a gaz comprime etude de la pollution d'un faisceau (1961)

    Energy Technology Data Exchange (ETDEWEB)

    Duboc, J; Banaigs, J; Detoeuf, J F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1961-07-01

    The realisation of a compressed as Cherenkov counter permits the study of the pollution of a beam of {pi} mesons with momentum varying from 220 to 11000 MeV/c. (authors) [French] La realisation d'un compteur Cherenkov a gaz sous pression permet l'etude de la pollution d'un faisceau de mesons {pi} d'impulsions comprise entre 220 et 1100 MeV/c. (auteurs)

  8. Cost Modeling for Space Telescope

    Science.gov (United States)

    Stahl, H. Philip

    2011-01-01

    Parametric cost models are an important tool for planning missions, compare concepts and justify technology investments. This paper presents on-going efforts to develop single variable and multi-variable cost models for space telescope optical telescope assembly (OTA). These models are based on data collected from historical space telescope missions. Standard statistical methods are used to derive CERs for OTA cost versus aperture diameter and mass. The results are compared with previously published models.

  9. Effect of Vavilov–Cherenkov radiation cone transformation upon entry of a relativistic electron into a substance layer

    Energy Technology Data Exchange (ETDEWEB)

    Kishchin, I. A.; Kubankin, A. S., E-mail: kubankin@bsu.edu.ru; Nikulicheva, T. B.; Al-Omari; Sotnikov, A. V.; Starovoitov, A. S. [Belgorod National Research University (Russian Federation)

    2016-12-15

    Transformation of the Vavilov–Cherenkov radiation cone under grazing interaction of a relativistic electron with a layer of substance is theoretically studied. It is shown that this effect can occur when the electron enters the substance layer.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2012-08-15

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

  11. Determining the primary cosmic ray energy from the total flux of Cherenkov light measured at the Yakutsk EAS array

    International Nuclear Information System (INIS)

    Ivanov, A. A.; Knurenko, S. P.; Sleptsov, I. E.

    2007-01-01

    We present a method for determining the energy of the primary particle that generates an extensive air shower (EAS) of comic rays based on measuring the total flux of Cherenkov light from the shower. Applying this method to Cherenkov light measurements at the Yakutsk EAS array has allowed us to construct the cosmic ray energy spectrum in the range 10 15 - 3 x 10 19 eV

  12. A new approach to the theory of Cherenkov radiation based on relativistic generalization of the Landau criterion

    International Nuclear Information System (INIS)

    Chefranov, S.G.

    2004-01-01

    Relativistic generalization of the Landau criterion is obtained which, in contrast to the classical Tamm-Frank and Ginzburg theories, determines the primary energy mechanism of emission of nonbremsstrahlung Cherenkov radiation. It is shown that Cherenkov radiation may correspond to a threshold energetically favorable conversion of the condensate (ultimately long-wavelength) elementary Bose perturbations of a medium into transverse Cherenkov photons emitted by the medium proper during its interaction with a sufficiently fast charged particle. The threshold conditions of emission are determined for a medium with an arbitrary refractive index n, including the case of isotropic plasma with n < 1 for which the classical theory of Cherenkov radiation prohibits such direct and effective nonbremsstrahlung emission of these particular transverse high-frequency electromagnetic waves. It is established that these conditions of emission agree with the data of well-known experiments on the threshold for observation of Cherenkov radiation, whereas the classical theory only corresponds to the conditions of observation of the interference maximum of this radiation. The possibility of direct effective emission of nonbremsstrahlung Cherenkov radiation, not taken into account in the classical theory, is considered for many observed astrophysical phenomena (type III solar radio bursts, particle acceleration by radiation, etc.)

  13. Silicon Telescope Detectors

    CERN Document Server

    Gurov, Yu B; Sandukovsky, V G; Yurkovski, J

    2005-01-01

    The results of research and development of special silicon detectors with a large active area ($> 8 cm^{2}$) for multilayer telescope spectrometers (fulfilled in the Laboratory of Nuclear Problems, JINR) are reviewed. The detector parameters are listed. The production of totally depleted surface barrier detectors (identifiers) operating under bias voltage two to three times higher than depletion voltage is described. The possibility of fabrication of lithium drifted counters with a very thin entrance window on the diffusion side of the detector (about 10--20 $\\mu$m) is shown. The detector fabrication technique has allowed minimizing detector dead regions without degradation of their spectroscopic characteristics and reliability during long time operation in charge particle beams.

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

    Science.gov (United States)

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

    2017-07-01

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

  15. The performance of a prototype array of water Cherenkov detectors for the LHAASO project

    Science.gov (United States)

    An, Q.; Bai, Y. X.; Bi, X. J.; Cao, Z.; Chang, J. F.; Chen, G.; Chen, M. J.; Chen, S. M.; Chen, S. Z.; Chen, T. L.; Chen, X.; Chen, Y. T.; Cui, S. W.; Dai, B. Z.; Du, Q.; Danzengluobu; Feng, C. F.; Feng, S. H.; Gao, B.; Gao, S. Q.; Ge, M. M.; Gu, M. H.; Hao, X. J.; He, H. H.; Hou, C.; Hu, H. B.; Hu, X. B.; Huang, J.; Huang, W. P.; Jia, H. Y.; Jiang, K.; Liu, J.; Liu, J. L.; Liu, J. S.; Liu, S. B.; Liu, Y.; Liu, Y. N.; Li, Q. J.; Li, C.; Li, F.; Li, H. C.; Li, X. R.; Lu, H.; Lv, H. K.; Mao, Y. J.; Ma, L. L.; Ma, X. H.; Shao, J.; Shao, M.; Sheng, X. D.; Sun, G. X.; Sun, Z. B.; Tang, Z. B.; Wu, C. Y.; Wu, H. R.; Wu, Q.; Xiao, G.; Xu, Y.; Yang, Q. Y.; Yang, R.; Yao, Z. G.; You, X. H.; Yuan, A. F.; Zhang, B. K.; Zhang, H. M.; Zhang, S. R.; Zhang, S. S.; Zhang, X. Y.; Zhang, Y.; Zhang, L.; Zhai, L. M.; Zhao, J.; Zhao, L.; Zhao, Z. G.; Zha, M.; Zhou, B.; Zhu, F. R.; Zhu, K. J.; Zhuang, J.; Zuo, X.

    2013-10-01

    A large high-altitude air-shower observatory (LHAASO) is to be built at Shangri-La, Yunnan Province, China. This observatory is intended to conduct sub-TeV gamma astronomy, and as an important component of the LHAASO project, a water Cherenkov detector array (WCDA) is proposed. To investigate engineering issues and fully understand the water Cherenkov technique for detecting air showers, a prototype array at 1% scale of the LHAASO-WCDA has been built at Yang-Ba-Jing, Tibet, China. This paper introduces the prototype array setup and studies its performance by counting rate of each photomultiplier tube (PMT), trigger rates at different PMT multiplicities, and responses to air showers. Finally, the reconstructed shower directions and angular resolutions of the detected showers for the prototype array are given.

  16. Real-time track-less Cherenkov ring fitting trigger system based on Graphics Processing Units

    Science.gov (United States)

    Ammendola, R.; Biagioni, A.; Chiozzi, S.; Cretaro, P.; Cotta Ramusino, A.; Di Lorenzo, S.; Fantechi, R.; Fiorini, M.; Frezza, O.; Gianoli, A.; Lamanna, G.; Lo Cicero, F.; Lonardo, A.; Martinelli, M.; Neri, I.; Paolucci, P. S.; Pastorelli, E.; Piandani, R.; Piccini, M.; Pontisso, L.; Rossetti, D.; Simula, F.; Sozzi, M.; Vicini, P.

    2017-12-01

    The parallel computing power of commercial Graphics Processing Units (GPUs) is exploited to perform real-time ring fitting at the lowest trigger level using information coming from the Ring Imaging Cherenkov (RICH) detector of the NA62 experiment at CERN. To this purpose, direct GPU communication with a custom FPGA-based board has been used to reduce the data transmission latency. The GPU-based trigger system is currently integrated in the experimental setup of the RICH detector of the NA62 experiment, in order to reconstruct ring-shaped hit patterns. The ring-fitting algorithm running on GPU is fed with raw RICH data only, with no information coming from other detectors, and is able to provide more complex trigger primitives with respect to the simple photodetector hit multiplicity, resulting in a higher selection efficiency. The performance of the system for multi-ring Cherenkov online reconstruction obtained during the NA62 physics run is presented.

  17. Detection of ultraviolet Cherenkov light from high energy cosmic ray atmospheric showers: A field test

    International Nuclear Information System (INIS)

    Bartoli, B.; Peruzzo, L.; Sartori, G.; Bedeschi, F.; Bertolucci, E.; Mariotti, M.; Menzione, A.; Ristori, L.; Stefanini, A.; Zetti, F.; Scribano, A.; Budinich, M.; Liello, F.

    1991-01-01

    We present the results of a test with a prototype apparatus aimed to detect the ultraviolet Cherenkov light in the wavelenght range 2000-2300A, emitted by high energy cosmic ray showers. The system consists of a gas proportional chamber, with TMAE vapour as the photosensitive element, placed on the focal plane of a 1.5 m diameter parabolic mirror. The test was done during the summer of 1989 with cosmic ray showers seen in coincidence with the EAS-TOP experiment, an extended atmospheric shower charged particle array now being exploited at Campo Imperatore, 1900 m above sea level, on top of the Gran Sasso underground Laboratory of INFN. The results were positive and show that a full scale ultraviolet Cherenkov experiment with good sensitivity, angular resolution and virtually no background from moonlight or even daylight can be envisaged. (orig.)

  18. Background level of natural radioactivities in a giant water Cherenkov detector and its surrounding environment

    International Nuclear Information System (INIS)

    Yamamoto, Masayoshi; Sakanoue, Masanobu; Komura, Kazuhisa; Ueno, Kaoru

    1989-01-01

    The KAMIOKANDE-II water Cherenkov detector for the measurement of nucleon decay and/or solar neutrino has been operating in the underground laboratory at a depth of 2,700 m.w.e. (meter water equivalent) in Kamioka mine of Gifu Prefecture. Concentrations of 238 U, 232 Th, 226 Ra and 222 Rn as the major background sources have been measured for various kinds of rocks, mine water, mine air and high purity water used as a detector during the period from August 1986 to December 1987. The concentration levels of these radionuclides and their seasonal variation have become clear. Some of these results have provided useful informations for decreasing the background level of water Cherenkov detector. (author)

  19. Large-area atmospheric Cherenkov detectors for high-energy gamma-ray astronomy

    International Nuclear Information System (INIS)

    Ong, R.A.

    1996-01-01

    This paper describes the development of new ground-based gamma-ray detectors to explore the energy region between 20 and 200 GeV. This region in energy is interesting because it is currently unexplored by any experiment. The proposed detectors use the atmospheric Cherenkov technique, in which Cherenkov radiation produced in the gamma-ray air showers is detected using mirrors and light-sensitive devices. The important feature of the proposed experiments is the use of large mirror collection areas, which should allow for a significant improvement (i.e. reduction) in energy threshold over existing experiments. Large mirror areas are available for relatively low cost at central tower solar power plants, and there are two groups developing gamma-ray experiments using solar heliostat arrays. This paper summarizes the progress in the design of experiments using this novel approach

  20. Data analysis for solar neutrinos observed by water Cherenkov detectors{sup *}

    Energy Technology Data Exchange (ETDEWEB)

    Koshio, Yusuke [Okayama University, Okayama (Japan)

    2016-04-15

    A method of analyzing solar neutrino measurements using water-based Cherenkov detectors is presented. The basic detection principle is that the Cherenkov photons produced by charged particles via neutrino interaction are observed by photomultiplier tubes. A large amount of light or heavy water is used as a medium. The first detector to successfully measure solar neutrinos was Kamiokande in the 1980's. The next-generation detectors, i.e., Super-Kamiokande and the Sudbury Neutrino Observatory (SNO), commenced operation from the mid-1990's. These detectors have been playing the critical role of solving the solar neutrino problem and determining the neutrino oscillation parameters over the last decades. The future prospects of solar neutrino analysis using this technique are also described. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-05-11

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

  2. Design and construction of a Cherenkov imager for charge measurement of nuclear cosmic rays

    Energy Technology Data Exchange (ETDEWEB)

    Bourrion, O; Bernard, C; Bondoux, D; Bouly, J L; Bouvier, J; Boyer, B; Brinet, M; Buenerd, M; Damieux, G; Derome, L; Eraud, L; Foglio, R; Fombaron, D; Grondin, D; Marton, M; Pelissier, A [Laboratoire de Physique Subatomique et de Cosmologie, Universite Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut Polytechnique de Grenoble, 53, rue des Martyrs, Grenoble (France); Lee, M H; Lutz, L [University of Maryland, College Park MD 20742 (United States); Menchaca-Rocha, A [Instituto de Fisica, UNAM, A.P. 20-364, 01000 Mexico DF (Mexico); Perie, J N, E-mail: olivier.bourrion@lpsc.in2p3.fr [Universite de Toulouse, INSA, UPS, Mines Albi, ISAE, ICA (Institut Clement Ader), 133, avenue de Rangueil, F-31077 Toulouse (France)

    2011-06-15

    A proximity focusing Cherenkov imager called CHERCAM, has been built for the charge measurement of nuclear cosmic rays with the CREAM instrument. It consists of a silica aerogel radiator plane across from a detector plane equipped with 1,600 1'' diameter photomultipliers. The two planes are separated by a ring expansion gap. The Cherenkov light yield is proportional to the charge squared of the incident particle. The expected relative light collection accuracy is in the few percents range. It leads to an expected single element separation over the range of nuclear charge Z of main interest 1 {<=} Z{approx}<26. CHERCAM is designed to fly with the CREAM balloon experiment. The design of the instrument and the implemented technical solutions allowing its safe operation in high altitude conditions (radiations, low pressure, cold) are presented.

  3. Design and construction of a Cherenkov imager for charge measurement of nuclear cosmic rays

    International Nuclear Information System (INIS)

    Bourrion, O; Bernard, C; Bondoux, D; Bouly, J L; Bouvier, J; Boyer, B; Brinet, M; Buenerd, M; Damieux, G; Derome, L; Eraud, L; Foglio, R; Fombaron, D; Grondin, D; Marton, M; Pelissier, A; Lee, M H; Lutz, L; Menchaca-Rocha, A; Perie, J N

    2011-01-01

    A proximity focusing Cherenkov imager called CHERCAM, has been built for the charge measurement of nuclear cosmic rays with the CREAM instrument. It consists of a silica aerogel radiator plane across from a detector plane equipped with 1,600 1'' diameter photomultipliers. The two planes are separated by a ring expansion gap. The Cherenkov light yield is proportional to the charge squared of the incident particle. The expected relative light collection accuracy is in the few percents range. It leads to an expected single element separation over the range of nuclear charge Z of main interest 1 ≤ Z∼<26. CHERCAM is designed to fly with the CREAM balloon experiment. The design of the instrument and the implemented technical solutions allowing its safe operation in high altitude conditions (radiations, low pressure, cold) are presented.

  4. Interference effects on guided Cherenkov emission in silicon from perpendicular, oblique, and parallel boundaries

    Science.gov (United States)

    Couillard, M.; Yurtsever, A.; Muller, D. A.

    2010-05-01

    Waveguide electromagnetic modes excited by swift electrons traversing Si slabs at normal and oblique incidence are analyzed using monochromated electron energy-loss spectroscopy and interpreted using a local dielectric theory that includes relativistic effects. At normal incidence, sharp spectral features in the visible/near-infrared optical domain are directly assigned to p -polarized modes. When the specimen is tilted, s -polarized modes, which are completely absent at normal incidence, become visible in the loss spectra. In the tilted configuration, the dispersion of p -polarized modes is also modified. For tilt angles higher than ˜50° , Cherenkov radiation, the phenomenon responsible for the excitation of waveguide modes, is expected to partially escape the silicon slab and the influence of this effect on experimental measurements is discussed. Finally, we find evidence for an interference effect at parallel Si/SiO2 interfaces, as well as a delocalized excitation of guided Cherenkov modes.

  5. Interference effects on guided Cherenkov emission in silicon from perpendicular, oblique, and parallel boundaries

    International Nuclear Information System (INIS)

    Couillard, M.; Yurtsever, A.; Muller, D. A.

    2010-01-01

    Waveguide electromagnetic modes excited by swift electrons traversing Si slabs at normal and oblique incidence are analyzed using monochromated electron energy-loss spectroscopy and interpreted using a local dielectric theory that includes relativistic effects. At normal incidence, sharp spectral features in the visible/near-infrared optical domain are directly assigned to p-polarized modes. When the specimen is tilted, s-polarized modes, which are completely absent at normal incidence, become visible in the loss spectra. In the tilted configuration, the dispersion of p-polarized modes is also modified. For tilt angles higher than ∼50 deg. Cherenkov radiation, the phenomenon responsible for the excitation of waveguide modes, is expected to partially escape the silicon slab and the influence of this effect on experimental measurements is discussed. Finally, we find evidence for an interference effect at parallel Si/SiO 2 interfaces, as well as a delocalized excitation of guided Cherenkov modes.

  6. Dispersion relation and growth rate in a Cherenkov free electron laser: Finite axial magnetic field

    International Nuclear Information System (INIS)

    Kheiri, Golshad; Esmaeilzadeh, Mahdi

    2013-01-01

    A theoretical analysis is presented for dispersion relation and growth rate in a Cherenkov free electron laser with finite axial magnetic field. It is shown that the growth rate and the resonance frequency of Cherenkov free electron laser increase with increasing axial magnetic field for low axial magnetic fields, while for high axial magnetic fields, they go to a saturation value. The growth rate and resonance frequency saturation values are exactly the same as those for infinite axial magnetic field approximation. The effects of electron beam self-fields on growth rate are investigated, and it is shown that the growth rate decreases in the presence of self-fields. It is found that there is an optimum value for electron beam density and Lorentz relativistic factor at which the maximum growth rate can take place. Also, the effects of velocity spread of electron beam are studied and it is found that the growth rate decreases due to the electron velocity spread

  7. Cherenkov-type diamond detectors for measurements of fast electrons in the TORE-SUPRA tokamak

    International Nuclear Information System (INIS)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Malinowski, K.; Mirowski, R.; Lotte, Ph.; Gunn, J.; Pascal, J-Y.; Colledani, G.; Basiuk, V.; Goniche, M.; Lipa, M.

    2010-01-01

    The paper presents a schematic design and tests of a system applicable for measurements of fast electron pulses emitted from high-temperature plasma generated inside magnetic confinement fusion machines, and particularly in the TORE-SUPRA facility. The diagnostic system based on the registration of the Cherenkov radiation induced by fast electrons within selected solid radiators is considered, and electron low-energy thresholds for different radiators are given. There are some estimates of high thermal loads, which might be deposited by intense electron beams upon parts of the diagnostic equipment within the TORE-SUPRA device. There are some proposed measures to overcome this difficulty by the selection of appropriate absorption filters and Cherenkov radiators, and particularly by the application of a fast-moving reciprocating probe. The paper describes the measuring system, its tests, as well as some results of the preliminary measurements of fast electrons within TORE-SUPRA facility.

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

    International Nuclear Information System (INIS)

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

    2004-01-01

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

  9. Design of on-line steam generator leak monitoring system based on Cherenkov counting technique

    International Nuclear Information System (INIS)

    Dileep, B.N.; D'Cruz, S.J.; Biju, P.; Jashi, K.B.; Prabhakaran, V.; Venkataramana, K.; Managanvi, S.S.

    2006-01-01

    The methodology developed by Nuclear Power Corporation of India Ltd. for identification of leaky Steam Generator (SG) by monitoring 134 I activity in the blow down water is a very high sensitive method. However, this technique can not be put into use as an on-line system. A new method of on-line detection of SG leak and identify the offending SG based on Cherenkov counting technique is explained in this paper. It identifies the leak by detecting Cherenkov radiation produced by the hard beta emitting radio nuclides escaped into feed water during leak in an operating reactor. A simulated system shows that a leak rate of 2 kg/h can be detected by the proposed system, while coolant 134 I activity is 3.7 MBq/l (100μCi/l). (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-15

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

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

    CERN Document Server

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

    2000-01-01

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

  12. Single-Cycle Terahertz Pulse Generation from OH1 Crystal via Cherenkov Phase Matching

    Science.gov (United States)

    Uchida, Hirohisa; Oota, Kengo; Okimura, Koutarou; Kawase, Kodo; Takeya, Kei

    2018-06-01

    OH1 crystal is an organic nonlinear optical crystal with a large nonlinear optical constant. However, it has dispersion of refractive indices in the terahertz (THz) frequency. This limits the frequencies that satisfy the phase matching conditions for THz wave generation. In this study, we addressed the phase matching conditions for THz wave generation by combining an OH1 crystal with prism-coupled Cherenkov phase matching. We observed the generation of single-cycle THz pulses with a spectrum covering a frequency range of 3 THz. These results prove that combining prism-coupled Cherenkov phase matching with nonlinear optical crystals yields a THz wave generation method that is insusceptible to crystal dispersion.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-30

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

  14. Development of the fast and efficient gamma detector using Cherenkov light for TOF-PET

    Science.gov (United States)

    Canot, C.; Alokhina, M.; Abbon, P.; Bard, J. P.; Tauzin, G.; Yvon, D.; Sharyy, V.

    2017-12-01

    In this paper we present two configurations of innovative gamma detectors using Cherenkov light for time-of-flight—Positron Emission Tomography (PET). The first uses heavy crystals as a Cherenkov radiator to develop a demonstrator for a whole body PET scanner with high detection efficiency. We demonstrated a 30% detection efficiency and a 180 ps (FWHM) time resolution, mainly limited by the time transit spread of the photomultiplier. The second configuration uses an innovative liquid, the TriMethyl Bismuth, to develop a high precision brain-scanning PET device with time-of-flight capability. According to Geant4 simulation, we expect to reach a precision of 150 ps (FWHM) and an efficiency of about 25%.

  15. Cherenkov-type diamond detectors for measurements of fast electrons in the TORE-SUPRA tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Malinowski, K.; Mirowski, R. [Andrzej Soltan Institute for Nuclear Studies (IPJ), Otwock-Swierk 05-400 (Poland); Lotte, Ph.; Gunn, J.; Pascal, J-Y.; Colledani, G.; Basiuk, V.; Goniche, M.; Lipa, M. [CEA, IRFM, St Paul-lez-Durance F-13108 (France)

    2010-01-15

    The paper presents a schematic design and tests of a system applicable for measurements of fast electron pulses emitted from high-temperature plasma generated inside magnetic confinement fusion machines, and particularly in the TORE-SUPRA facility. The diagnostic system based on the registration of the Cherenkov radiation induced by fast electrons within selected solid radiators is considered, and electron low-energy thresholds for different radiators are given. There are some estimates of high thermal loads, which might be deposited by intense electron beams upon parts of the diagnostic equipment within the TORE-SUPRA device. There are some proposed measures to overcome this difficulty by the selection of appropriate absorption filters and Cherenkov radiators, and particularly by the application of a fast-moving reciprocating probe. The paper describes the measuring system, its tests, as well as some results of the preliminary measurements of fast electrons within TORE-SUPRA facility.

  16. Single particle detecting telescope system

    International Nuclear Information System (INIS)

    Yamamoto, I.; Tomiyama, T.; Iga, Y.; Komatsubara, T.; Kanada, M.; Yamashita, Y.; Wada, T.; Furukawa, S.

    1981-01-01

    We constructed the single particle detecting telescope system for detecting a fractionally charged particle. The telescope consists of position detecting counters, wall-less multi-cell chambers, single detecting circuits and microcomputer system as data I/0 processor. Especially, a frequency of double particle is compared the case of the single particle detecting with the case of an ordinary measurement

  17. Building the Hubble Space Telescope

    International Nuclear Information System (INIS)

    O'dell, C.R.

    1989-01-01

    The development of the design for the Hubble Space Telescope (HST) is discussed. The HST optical system is described and illustrated. The financial and policy issues related to the development of the HST are considered. The actual construction of the HST optical telescope is examined. Also, consideration is given to the plans for the HST launch

  18. Infrared up-conversion telescope

    DEFF Research Database (Denmark)

    2014-01-01

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

  19. Efficiency calibration of a liquid scintillation counter for 90Y Cherenkov counting

    International Nuclear Information System (INIS)

    Vaca, F.; Garcia-Leon, M.

    1998-01-01

    In this paper a complete and self-consistent method for 90 Sr determination in environmental samples is presented. It is based on the Cherenkov counting of 90 Y with a conventional liquid scintillation counter. The effects of color quenching on the counting efficiency and background are carefully studied. A working curve is presented which allows to quantify the correction in the counting efficiency depending on the color quenching strength. (orig.)

  20. The possibilities of constructing a very big Cherenkov detector with usage of a light spectrum shifters

    International Nuclear Information System (INIS)

    Akimov, Yu.K.

    1980-01-01

    A version of Cherenkov detector (V approximately 10 4 tonns) for nuclear instability searches and for neutrino investigations is suggested. The detector has a 4π-anticoincidence screen and is characterized by a relatively uniform sensitivity at a moderate number of photomultipliers. For light collecting the wavelength shifters are used which absorb blue light and reemit it in the green light. Wavelength shifters provide almost a one-order increase of light collecting. Detector possibilities are discussed [ru

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-01

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

  2. Sum-frequency nonlinear Cherenkov radiation generated on the boundary of bulk medium crystal.

    Science.gov (United States)

    Wang, Xiaojing; Cao, Jianjun; Zhao, Xiaohui; Zheng, Yuanlin; Ren, Huaijin; Deng, Xuewei; Chen, Xianfeng

    2015-12-14

    We demonstrated experimentally a method to generate the sum-frequency Nonlinear Cherenkov radiation (NCR) on the boundary of bulk medium by using two synchronized laser beam with wavelength of 1300 nm and 800 nm. It is also an evidence that the polarization wave is always confined to the boundary. Critical conditions of surface sum-frequency NCR under normal and anomalous dispersion condition is discussed.

  3. BaYb2F8, a new radiation hard Cherenkov radiator for electromagnetic calorimeters

    International Nuclear Information System (INIS)

    Aseev, A.A.; Devitsin, E.G.; Komar, A.A.; Kozlov, V.A.; Hovsepyan, Yu.I.; Potashov, S.Yu.; Sokolovsky, K.A.; Uvarova, T.V.; Vasilchenko, V.G.

    1992-01-01

    Radiation hardness and optical properties of a new Cherenkov radiator, heavy fluoride BaYb 2 F 8 doped with various elements, have been studied. The above mentioned crystal has the density of 7 g/cm 3 , the radiation length is 1.28 cm and the Moliere radius 2.44 cm. High radiation hardness has been demonstrated for BaYb 2 F 8 doped with Tm, Pr, Tb. (orig.)

  4. NESTOR - Neutrino Extended Submarine Telescope with Oceanographic Research

    CERN Multimedia

    2002-01-01

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

  5. Indirect detection of dark matter with the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    Lambard, G.

    2008-01-01

    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.)

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

    CERN Document Server

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

    2012-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-11-15

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

  8. Modeling the Effects of Mirror Misalignment in a Ring Imaging Cherenkov Detector

    Science.gov (United States)

    Hitchcock, Tawanda; Harton, Austin; Garcia, Edmundo

    2012-03-01

    The Very High Momentum Particle Identification Detector (VHMPID) has been proposed for the ALICE experiment at the Large Hadron Collider (LHC). This detector upgrade is considered necessary to study jet-matter interaction at high energies. The VHMPID identifies charged hadrons in the 5 GeV/c to 25 GeV/c momentum range. The Cherenkov photons emitted in the VHMPID radiator are collected by spherical mirrors and focused onto a photo-detector plane forming a ring image. The radius of this ring is related to the Cherenkov angle, this information coupled with the particle momentum allows the particle identification. A major issue in the RICH detector is that environmental conditions can cause movements in mirror position. In addition, chromatic dispersion causes the refractive index to shift, altering the Cherenkov angle. We are modeling a twelve mirror RICH detector taking into account the effects of mirror misalignment and chromatic dispersion using a commercial optical software package. This will include quantifying the effects of both rotational and translational mirror misalignment for the initial assembly of the module and later on particle identification.

  9. Noise simulation and rejection for the DELPHI Barrel Ring Imaging Cherenkov detector

    International Nuclear Information System (INIS)

    Bloch, D.

    1996-01-01

    The performance of Ring Imaging Cherenkov detectors is severely affected by the background noise due to the necessity of detecting single electrons. Furthermore, in the majority of the existing RICHs, the charged particles to be identified also cross the sensitive area of the apparatus thus creating secondary effects. The different noise sources and the background behaviour have been studied for the DELPHI RICH in order to efficiently clean the Cherenkov rings from the background while preserving the majority of the signal. Particular care has been taken to optimize the parameters of the Cherenkov image ''cleaning'' for the gas and the liquid radiators separately. For Z 0 hadronic decays 70% background rejection has been achieved, whilst 85% of the signal has been retained. This paper also presents a simulation of the noise producing mechanisms where ionization electrons, δ-rays, feedback electrons created during avalanches and electronic noise are modeled according to the measured parameters. Good agreement between data and simulation has been achieved. (orig.)

  10. Calibration of Cherenkov detectors for monoenergetic photon imaging in active interrogation applications

    Energy Technology Data Exchange (ETDEWEB)

    Rose, P.B., E-mail: prose6@gatech.edu; Erickson, A.S., E-mail: anna.erickson@me.gatech.edu

    2015-11-01

    Active interrogation of cargo containers using monoenergetic photons offers a rapid and low-dose approach to search for shielded special nuclear materials. Cherenkov detectors can be used for imaging of the cargo provided that gamma ray energies used in interrogation are well resolved, as the case in {sup 11}B(d,n-γ){sup 12}C reaction resulting in 4.4 MeV and 15.1 MeV photons. While an array of Cherenkov threshold detectors reduces low energy background from scatter while providing the ability of high contrast transmission imaging, thus confirming the presence of high-Z materials, these detectors require a special approach to energy calibration due to the lack of resolution. In this paper, we discuss the utility of Cherenkov detectors for active interrogation with monoenergetic photons as well as the results of computational and experimental studies of their energy calibration. The results of the studies with sources emitting monoenergetic photons as well as complex gamma ray spectrum sources, for example {sup 232}Th, show that calibration is possible as long as the energies of photons of interest are distinct.

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

    CERN Document Server

    Sbrizzi, A

    2007-01-01

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

  12. Cherenkov Video Imaging Allows for the First Visualization of Radiation Therapy in Real Time

    International Nuclear Information System (INIS)

    Jarvis, Lesley A.; Zhang, Rongxiao; Gladstone, David J.; Jiang, Shudong; Hitchcock, Whitney; Friedman, Oscar D.; Glaser, Adam K.; Jermyn, Michael; Pogue, Brian W.

    2014-01-01

    Purpose: To determine whether Cherenkov light imaging can visualize radiation therapy in real time during breast radiation therapy. Methods and Materials: An intensified charge-coupled device (CCD) camera was synchronized to the 3.25-μs radiation pulses of the clinical linear accelerator with the intensifier set × 100. Cherenkov images were acquired continuously (2.8 frames/s) during fractionated whole breast irradiation with each frame an accumulation of 100 radiation pulses (approximately 5 monitor units). Results: The first patient images ever created are used to illustrate that Cherenkov emission can be visualized as a video during conditions typical for breast radiation therapy, even with complex treatment plans, mixed energies, and modulated treatment fields. Images were generated correlating to the superficial dose received by the patient and potentially the location of the resulting skin reactions. Major blood vessels are visible in the image, providing the potential to use these as biological landmarks for improved geometric accuracy. The potential for this system to detect radiation therapy misadministrations, which can result from hardware malfunction or patient positioning setup errors during individual fractions, is shown. Conclusions: Cherenkoscopy is a unique method for visualizing surface dose resulting in real-time quality control. We propose that this system could detect radiation therapy errors in everyday clinical practice at a time when these errors can be corrected to result in improved safety and quality of radiation therapy

  13. Photon counting with a FDIRC Cherenkov prototype readout by SiPM arrays

    Energy Technology Data Exchange (ETDEWEB)

    Marrocchesi, P.S., E-mail: marrocchesi@pi.infn.it [Department of Physical Sciences, Earth and Environment, Via Roma 56, I-53100 Siena (Italy); INFN Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); Bagliesi, M.G. [Department of Physical Sciences, Earth and Environment, Via Roma 56, I-53100 Siena (Italy); Basti, A. [Department of Physics, University of Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); INFN Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); Bigongiari, G.; Bonechi, S.; Brogi, P. [Department of Physical Sciences, Earth and Environment, Via Roma 56, I-53100 Siena (Italy); INFN Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); Checchia, C.; Collazuol, G. [Department of Physics and Astronomy, University of Padova, Padova, Italy, and INFN-Padova, 35131 Padova (Italy); Maestro, P. [Department of Physical Sciences, Earth and Environment, Via Roma 56, I-53100 Siena (Italy); INFN Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); Morsani, F. [INFN Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy); Piemonte, C. [Fondazione Bruno Kessler (FBK), I-38122 Trento (Italy); Stolzi, F.; Suh, J.E; Sulaj, A. [Department of Physical Sciences, Earth and Environment, Via Roma 56, I-53100 Siena (Italy); INFN Sezione di Pisa, Largo Bruno Pontecorvo 3, I-56127 Pisa (Italy)

    2017-02-11

    A prototype of a Focused Internal Reflection Cherenkov, equipped with 16 arrays of NUV-SiPM, was tested at CERN SPS in March 2015 with beams of relativistic ions at 13, 19 and 30 GeV/n obtained from fragmentation of an Ar primary beam. The detector, designed to identify cosmic nuclei, features a Fused Silica radiator bar optically connected to a cylindrical mirror of the same material and an imaging focal plane of dimensions ∼4 cm×3 cm covered with a total of 1024 SiPM photosensors. Thanks to the outstanding performance of the SiPM arrays, the detector could be operated in photon counting mode as a fully digital device. The Cherenkov pattern was recorded together with the total number of detected photoelectrons increasing as Z{sup 2} as a function of the atomic number Z of the beam particle. In this paper, we report on the characterization and test of the SiPM arrays and the performance of the Cherenkov prototype for the charge identification of the beam particles.

  14. Proposal of coherent Cherenkov radiation matched to circular plane wave for intense terahertz light source

    International Nuclear Information System (INIS)

    Sei, Norihiro; Sakai, Takeshi; Hayakawa, Ken; Tanaka, Toshinari; Hayakawa, Yasushi; Nakao, Keisuke; Nogami, Kyoko; Inagaki, Manabu

    2015-01-01

    Highlights: • We proposed a new intense terahertz-wave source based on coherent Cherenkov radiation (CCR). • A hollow conical dielectric is used to generate the CCR beam. • The wave front of the CCR beam can be matched to the basal plane. • The peak-power of the CCR beam is above 1 MW per micropulse with a short interval of 350 ps. - Abstract: We propose a high-peak-power terahertz-wave source based on an electron accelerator. By passing an electron beam through a hollow conical dielectric with apex facing the incident electron beam, the wave front of coherent Cherenkov radiation generated on the inner surface of the hollow conical dielectric matches the basal plane. Using the electron beam generated at the Laboratory for Electron Beam Research and Application at Nihon University, the calculated power of coherent Cherenkov radiation that matched the circular plane (CCR-MCP) was above 1 MW per micropulse with a short interval of 350 ps, for wavelengths ranging from 0.5 to 5 mm. The electron beam is not lost for generating the CCR-MCP beam by using the hollow conical dielectric. It is possible to combine the CCR-MCP beams with other light sources based on an accelerator

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

    International Nuclear Information System (INIS)

    Spinelli, Antonello E.; Boschi, Federico; D'Ambrosio, Daniela; Calderan, Laura; Marengo, Mario; Fenzi, Alberto; Menegazzi, Marta; Sbarbati, Andrea; Del Vecchio, Antonella; Calandrino, Riccardo

    2011-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-08-21

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-01-21

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

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

  19. SU-G-IeP4-06: Feasibility of External Beam Treatment Field Verification Using Cherenkov Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Black, P; Na, Y; Wuu, C [Columbia University, New York, NY (United States)

    2016-06-15

    Purpose: Cherenkov light emission has been shown to correlate with ionizing radiation (IR) dose delivery in solid tissue. In order to properly correlate Cherenkov light images with real time dose delivery in a patient, we must account for geometric and intensity distortions arising from observation angle, as well as the effect of monitor units (MU) and field size on Cherenkov light emission. To test the feasibility of treatment field verification, we first focused on Cherenkov light emission efficiency based on MU and known field size (FS). Methods: Cherenkov light emission was captured using a PI-MAX4 intensified charge coupled device(ICCD) system (Princeton Instruments), positioned at a fixed angle of 40° relative to the beam central axis. A Varian TrueBeam linear accelerator (linac) was operated at 6MV and 600MU/min to deliver an Anterior-Posterior beam to a 5cm thick block phantom positioned at 100cm Source-to-Surface-Distance(SSD). FS of 10×10, 5×5, and 2×2cm{sup 2} were used. Before beam delivery projected light field images were acquired, ensuring that geometric distortions were consistent when measuring Cherenkov field discrepancies. Cherenkov image acquisition was triggered by linac target current. 500 frames were acquired for each FS. Composite images were created through summation of frames and background subtraction. MU per image was calculated based on linac pulse delay of 2.8ms. Cherenkov and projected light FS were evaluated using ImageJ software. Results: Mean Cherenkov FS discrepancies compared to light field were <0.5cm for 5.6, 2.8, and 8.6 MU for 10×10, 5×5, and 2×2cm{sup 2} FS, respectably. Discrepancies were reduced with increasing field size and MU. We predict a minimum of 100 frames is needed for reliable confirmation of delivered FS. Conclusion: Current discrepancies in Cherenkov field sizes are within a usable range to confirm treatment delivery in standard and respiratory gated clinical scenarios at MU levels appropriate to

  20. Seismic Imager Space Telescope

    Science.gov (United States)

    Sidick, Erkin; Coste, Keith; Cunningham, J.; Sievers,Michael W.; Agnes, Gregory S.; Polanco, Otto R.; Green, Joseph J.; Cameron, Bruce A.; Redding, David C.; Avouac, Jean Philippe; hide

    2012-01-01

    A concept has been developed for a geostationary seismic imager (GSI), a space telescope in geostationary orbit above the Pacific coast of the Americas that would provide movies of many large earthquakes occurring in the area from Southern Chile to Southern Alaska. The GSI movies would cover a field of view as long as 300 km, at a spatial resolution of 3 to 15 m and a temporal resolution of 1 to 2 Hz, which is sufficient for accurate measurement of surface displacements and photometric changes induced by seismic waves. Computer processing of the movie images would exploit these dynamic changes to accurately measure the rapidly evolving surface waves and surface ruptures as they happen. These measurements would provide key information to advance the understanding of the mechanisms governing earthquake ruptures, and the propagation and arrest of damaging seismic waves. GSI operational strategy is to react to earthquakes detected by ground seismometers, slewing the satellite to point at the epicenters of earthquakes above a certain magnitude. Some of these earthquakes will be foreshocks of larger earthquakes; these will be observed, as the spacecraft would have been pointed in the right direction. This strategy was tested against the historical record for the Pacific coast of the Americas, from 1973 until the present. Based on the seismicity recorded during this time period, a GSI mission with a lifetime of 10 years could have been in position to observe at least 13 (22 on average) earthquakes of magnitude larger than 6, and at least one (2 on average) earthquake of magnitude larger than 7. A GSI would provide data unprecedented in its extent and temporal and spatial resolution. It would provide this data for some of the world's most seismically active regions, and do so better and at a lower cost than could be done with ground-based instrumentation. A GSI would revolutionize the understanding of earthquake dynamics, perhaps leading ultimately to effective warning

  1. Transmission of light in deep sea water at the site of the ANTARES neutrino telescope

    Science.gov (United States)

    ANTARES Collaboration; Aguilar, J. A.; Albert, A.; Amram, P.; Anghinolfi, M.; Anton, G.; Anvar, S.; Ardellier-Desages, F. E.; Aslanides, E.; Aubert, J.-J.; Azoulay, R.; Bailey, D.; Basa, S.; Battaglieri, M.; Becherini, Y.; Bellotti, R.; Beltramelli, J.; Bertin, V.; Billault, M.; Blaes, R.; Blanc, F.; Bland, R. W.; de Botton, N.; Boulesteix, J.; Bouwhuis, M. C.; Brooks, C. B.; Bradbury, S. M.; Bruijn, R.; Brunner, J.; Bugeon, F.; Burgio, G. F.; Cafagna, F.; Calzas, A.; Caponetto, L.; Carmona, E.; Carr, J.; Cartwright, S. L.; Cecchini, S.; Charvis, P.; Circella, M.; Colnard, C.; Compère, C.; Croquette, J.; Cooper, S.; Coyle, P.; Cuneo, S.; Damy, G.; van Dantzig, R.; Deschamps, A.; de Marzo, C.; Destelle, J.-J.; de Vita, R.; Dinkelspiler, B.; Dispau, G.; Drougou, J.-F.; Druillole, F.; Engelen, J.; Favard, S.; Feinstein, F.; Ferry, S.; Festy, D.; Fopma, J.; Fuda, J.-L.; Gallone, J.-M.; Giacomelli, G.; Girard, N.; Goret, P.; Gournay, J.-F.; Hallewell, G.; Hartmann, B.; Heijboer, A.; Hello, Y.; Hernández-Rey, J. J.; Herrouin, G.; Hößl, J.; Hoffmann, C.; Hubbard, J. R.; Jaquet, M.; de Jong, M.; Jouvenot, F.; Kappes, A.; Karg, T.; Karkar, S.; Karolak, M.; Katz, U.; Keller, P.; Kooijman, P.; Korolkova, E. V.; Kouchner, A.; Kretschmer, W.; Kudryavtsev, V. A.; Lafoux, H.; Lagier, P.; Lamare, P.; Languillat, J.-C.; Laubier, L.; Legou, T.; Le Guen, Y.; Le Provost, H.; Le van Suu, A.; Lo Nigro, L.; Lo Presti, D.; Loucatos, S.; Louis, F.; Lyashuk, V.; Magnier, P.; Marcelin, M.; Margiotta, A.; Maron, C.; Massol, A.; Mazéas, F.; Mazeau, B.; Mazure, A.; McMillan, J. E.; Michel, J.-L.; Millot, C.; Milovanovic, A.; Montanet, F.; Montaruli, T.; Morel, J.-P.; Moscoso, L.; Nezri, E.; Niess, V.; Nooren, G. J.; Ogden, P.; Olivetto, C.; Palanque-Delabrouille, N.; Payre, P.; Petta, C.; Pineau, J.-P.; Poinsignon, J.; Popa, V.; Potheau, R.; Pradier, T.; Racca, C.; Randazzo, N.; Real, D.; van Rens, B. A. P.; Réthoré, F.; Ripani, M.; Roca-Blay, V.; Romeyer, A.; Rollin, J.-F.; Romita, M.; Rose, H. J.; Rostovtsev, A.; Ruppi, M.; Russo, G. V.; Sacquin, Y.; Saouter, S.; Schuller, J.-P.; Schuster, W.; Sokalski, I.; Suvorova, O.; Spooner, N. J. C.; Spurio, M.; Stolarczyk, T.; Stubert, D.; Taiuti, M.; Thompson, L. F.; Tilav, S.; Usik, A.; Valdy, P.; Vallage, B.; Vaudaine, G.; Vernin, P.; Virieux, J.; Vladimirsky, E.; de Vries, G.; de Witt Huberts, P.; de Wolf, E.; Zaborov, D.; Zaccone, H.; Zakharov, V.; Zavatarelli, S.; de Zornoza, J. D.; Zúñiga, J.

    2005-02-01

    The ANTARES neutrino telescope is a large photomultiplier array designed to detect neutrino-induced upward-going muons by their Cherenkov radiation. Understanding the absorption and scattering of light in the deep Mediterranean is fundamental to optimising the design and performance of the detector. This paper presents measurements of blue and UV light transmission at the ANTARES site taken between 1997 and 2000. The derived values for the scattering length and the angular distribution of particulate scattering were found to be highly correlated, and results are therefore presented in terms of an absorption length λabs and an effective scattering length λscteff. The values for blue (UV) light are found to be λabs ≃ 60(26) m, λscteff≃265(122)m, with significant (˜15%) time variability. Finally, the results of ANTARES simulations showing the effect of these water properties on the anticipated performance of the detector are presented.

  2. Camera selection for real-time in vivo radiation treatment verification systems using Cherenkov imaging.

    Science.gov (United States)

    Andreozzi, Jacqueline M; Zhang, Rongxiao; Glaser, Adam K; Jarvis, Lesley A; Pogue, Brian W; Gladstone, David J

    2015-02-01

    To identify achievable camera performance and hardware needs in a clinical Cherenkov imaging system for real-time, in vivo monitoring of the surface beam profile on patients, as novel visual information, documentation, and possible treatment verification for clinicians. Complementary metal-oxide-semiconductor (CMOS), charge-coupled device (CCD), intensified charge-coupled device (ICCD), and electron multiplying-intensified charge coupled device (EM-ICCD) cameras were investigated to determine Cherenkov imaging performance in a clinical radiotherapy setting, with one emphasis on the maximum supportable frame rate. Where possible, the image intensifier was synchronized using a pulse signal from the Linac in order to image with room lighting conditions comparable to patient treatment scenarios. A solid water phantom irradiated with a 6 MV photon beam was imaged by the cameras to evaluate the maximum frame rate for adequate Cherenkov detection. Adequate detection was defined as an average electron count in the background-subtracted Cherenkov image region of interest in excess of 0.5% (327 counts) of the 16-bit maximum electron count value. Additionally, an ICCD and an EM-ICCD were each used clinically to image two patients undergoing whole-breast radiotherapy to compare clinical advantages and limitations of each system. Intensifier-coupled cameras were required for imaging Cherenkov emission on the phantom surface with ambient room lighting; standalone CMOS and CCD cameras were not viable. The EM-ICCD was able to collect images from a single Linac pulse delivering less than 0.05 cGy of dose at 30 frames/s (fps) and pixel resolution of 512 × 512, compared to an ICCD which was limited to 4.7 fps at 1024 × 1024 resolution. An intensifier with higher quantum efficiency at the entrance photocathode in the red wavelengths [30% quantum efficiency (QE) vs previous 19%] promises at least 8.6 fps at a resolution of 1024 × 1024 and lower monetary cost than the EM-ICCD. The

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

    Science.gov (United States)

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

    2017-06-01

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

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

    Science.gov (United States)

    Brunner, S E; Schaart, D R

    2017-06-07

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

  5. The Advanced Gamma-ray Imaging System (AGIS): Telescope Mechanical Designs

    Science.gov (United States)

    Guarino, V.; Buckley, J.; Byrum, K.; Falcone, A.; Fegan, S.; Finley, J.; Hanna, D.; Horan, D.; Kaaret, P.; Konopelko, A.; Krawczynski, H.; Krennrich, F.; Wagner, R.; Woods, M.; Vassiliev, V.

    2008-04-01

    The concept of a future ground-based gamma-ray observatory, AGIS, in the energy range 40 GeV-100 TeV is based on an array of sim 100 imaging atmospheric Cherenkov telescopes (IACTs). The anticipated improvements of AGIS sensitivity, angular resolution and reliability of operation impose demanding technological and cost requirements on the design of IACTs. The relatively inexpensive Davies-Cotton telescope design has been used in ground-based gamma-ray astronomy for almost fifty years and is an excellent option. We are also exploring alternative designs and in this submission we focus on the recent mechanical design of a two-mirror telescope with a Schwarzschild-Couder (SC) optical system. The mechanical structure provides support points for mirrors and camera. The design was driven by the requirement of minimizing the deflections of the mirror support structures. The structure is also designed to be able to slew in elevation and azimuth at 10 degrees/sec.

  6. Nanobeacon: A low cost time calibration instrument for the KM3NeT neutrino telescope

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-11-18

    The KM3NeT collaboration aims at the construction of a multi-km3 high-energy neutrino telescope in the Mediterranean Sea consisting of a matrix of pressure resistant glass spheres holding each one a set (31) of small area photomultipliers. The main goal of the telescope is to observe cosmic neutrinos through the Cherenkov light induced in sea water by charged particles produced in neutrino interactions with the surrounding medium. A relative time calibration between photomultipliers of the order of 1 ns is required to achieve an optimal performance. Due to the high volume to be covered by KM3NeT, a cost reduction of the different systems is a priority. To this end a very low price calibration device, the so called Nanobeacon, has been designed and developed. At present one of such devices has already been integrated successfully at the KM3NeT telescope and eight of them in the Nemo Tower Phase II. In this article the main properties and operation of this device are described.

  7. Lightweighted ZERODUR for telescopes

    Science.gov (United States)

    Westerhoff, T.; Davis, M.; Hartmann, P.; Hull, T.; Jedamzik, R.

    2014-07-01

    The glass ceramic ZERODUR® from SCHOTT has an excellent reputation as mirror blank material for earthbound and space telescope applications. It is known for its extremely low coefficient of thermal expansion (CTE) at room temperature and its excellent CTE homogeneity. Recent improvements in CNC machining at SCHOTT allow achieving extremely light weighted substrates up to 90% incorporating very thin ribs and face sheets. In 2012 new ZERODUR® grades EXPANSION CLASS 0 SPECIAL and EXTREME have been released that offer the tightest CTE grades ever. With ZERODUR® TAILORED it is even possible to offer ZERODUR® optimized for customer application temperature profiles. In 2013 SCHOTT started the development of a new dilatometer setup with the target to drive the industrial standard of high accuracy thermal expansion metrology to its limit. In recent years SCHOTT published several paper on improved bending strength of ZERODUR® and lifetime evaluation based on threshold values derived from 3 parameter Weibull distribution fitted to a multitude of stress data. ZERODUR® has been and is still being successfully used as mirror substrates for a large number of space missions. ZERODUR® was used for the secondary mirror in HST and for the Wolter mirrors in CHANDRA without any reported degradation of the optical image quality during the lifetime of the missions. Some years ago early studies on the compaction effects of electron radiation on ZERODUR® were re analyzed. Using a more relevant physical model based on a simplified bimetallic equation the expected deformation of samples exposed in laboratory and space could be predicted in a much more accurate way. The relevant ingredients for light weighted mirror substrates are discussed in this paper: substrate material with excellent homogeneity in its properties, sufficient bending strengths, space radiation hardness and CNC machining capabilities.

  8. Advanced Athermal Telescopes, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposed innovative athermal telescope design uses advanced lightweight and high-stiffness material of Beryllium-Aluminum (Be-38Al). Peregrine's expertise with...

  9. The JCMT Telescope Management System

    Science.gov (United States)

    Tilanus, Remo P. J.; Jenness, Tim; Economou, Frossie; Cockayne, Steve

    Established telescopes often face a challenge when trying to incorporate new software standards and utilities into their existing real-time control system. At the JCMT we have successfully added important new features such as a Relational Database (the Telescope Management System---TMS), an online data Archive, and WWW based utilities to an, in part, 10-year old system. The new functionality was added with remarkably few alterations to the existing system. We are still actively expanding and exploring these new capabilities.

  10. Alt-Az Spacewatch Telescope

    Science.gov (United States)

    Gehrels, Tom

    1997-01-01

    This grant funded about one third of the cost of the construction of a telescope with an aperture 1.8 meters in diameter to discover asteroids and comets and investigate the statistics of their populations and orbital distributions. This telescope has been built to the PI's specifications and installed in a dome on Kitt Peak mountain in Arizona. Funds for the dome and building were provided entirely by private sources. The dome building and telescope were dedicated in a ceremony at the site on June 7, 1997. The attached abstract describes the parameters of the telescope. The telescope is a new item of capital property. It is permanently located in University of Arizona building number 910 in the Steward Observatory compound on Kitt Peak mountain in the Tohono O'odham Nation, Arizona. fts property tag number is A252107. This grant did not include funds for the coma corrector lens, instrument derotator, CCD detector, detector electronics, or computers to acquire or process the data. It also did not include funds to operate the telescope or conduct research with it. Funds for these items and efforts are pending from NASA and other sources.

  11. The Submillimeter Telescope (SMT) project

    International Nuclear Information System (INIS)

    Martin, R.N.; Baars, J.W.M.

    1990-01-01

    To exploit the potential of submillimeter astronomy, the Submillimeter Telescope (SMT) will be located at an altitude of 3178 meters on Emerald Peak 75 miles northeast of Tucson in Southern Arizona. The instrument is an altazimuth mounted f/13.8 Cassegrain homology telescope with two Nasmyth and bent Cassegrain foci. It will have diffraction limited performance at a wavelength of 300 microns and an operating overall figure accuracy of 15 microns rms. An important feature of the SMT is the construction of the primary and secondary reflectors out of aluminum-core CFRP face sheet sandwich panels, and the reflector backup structure and secondary support out of CFRP structural elements. This modern technology provides both a means for reaching the required precision of the SMT for both night and day operation (basically because of the low coefficient of thermal expansion and high strength-to-weight ratio of CFRP) and a potential route for the realization of lightweight telescopes of even greater accuracy in the future. The SMT will be the highest accuracy radio telescope ever built (at least a factor of 2 more accurate than existing telescopes). In addition, the SMT will be the first 10 m-class submillimeter telescope with a surface designed for efficient measurements at the important 350 microns wavelength atmospheric window. 9 refs

  12. Detection of magnetic monopoles in the future neutrino telescope Antares and characterization of the photomultiplier pulse treatment; Etude de la detection de monopoles magnetiques au sein du futur telescope a neutrinos antares et caracterisation des performances du traitement des impulsions des photomultiplicateurs

    Energy Technology Data Exchange (ETDEWEB)

    Ricol, J.St

    2002-10-01

    Grand unified theories (GUT) involve phase transitions in the early universe, that could create topological defects, like magnetic monopoles. Monopoles main characteristics are shown and in particular energy losses and flux limits. High energy neutrino telescopes offer a new opportunity for magnetic monopole search. The study of the photomultiplier pulse treatment by the Antares detector front-end electronics indicates that this one is well adapted to the telescope needs. The pulses detailed analysis has allowed to obtain a time measurement precision lower than 0.6 ns and electronic noise and saturation have no relevant effect on the telescope performances. Relativistic monopoles generate a large amount of light, that leads to an effective area for the Antares detector of about 0.06 km{sup 2} for velocities {beta}{sub mon} = 0.6 and 0.35 km{sup 2} for velocities {beta}{sub mon} {approx} 1. Monopole track are well reconstructed and the velocity determination is made with an error lower than few percents, which represents a decisive result for the background rejection, caused by high energy muons with a velocity {beta}{sub {mu}} {approx} 1. The very dispersive light emission of monopoles below the Cherenkov limit, 0.6 {approx}< {beta}{sub mon} {<=} 0.74, via the delta-rays produced by ionisation, does not allow an accurate expecting signal and the bad reconstructed muons rejection must be improved. Above the Cherenkov limit, {beta}{sub mon} {>=} 0.8, bad reconstructed events can be rejected from the Cherenkov emission parametrisation. A magnetic monopole signal can then clearly be distinguished from background. (author)

  13. Cherenkov radiation-based three-dimensional position-sensitive PET detector: A Monte Carlo study.

    Science.gov (United States)

    Ota, Ryosuke; Yamada, Ryoko; Moriya, Takahiro; Hasegawa, Tomoyuki

    2018-05-01

    Cherenkov radiation has recently received attention due to its prompt emission phenomenon, which has the potential to improve the timing performance of radiation detectors dedicated to positron emission tomography (PET). In this study, a Cherenkov-based three-dimensional (3D) position-sensitive radiation detector was proposed, which is composed of a monolithic lead fluoride (PbF 2 ) crystal and a photodetector array of which the signals can be readout independently. Monte Carlo simulations were performed to estimate the performance of the proposed detector. The position- and time resolution were evaluated under various practical conditions. The radiator size and various properties of the photodetector, e.g., readout pitch and single photon timing resolution (SPTR), were parameterized. The single photon time response of the photodetector was assumed to be a single Gaussian for the simplification. The photo detection efficiency of the photodetector was ideally 100% for all wavelengths. Compton scattering was included in simulations, but partly analyzed. To estimate the position at which a γ-ray interacted in the Cherenkov radiator, the center-of-gravity (COG) method was employed. In addition, to estimate the depth-of-interaction (DOI) principal component analysis (PCA), which is a multivariate analysis method and has been used to identify the patterns in data, was employed. The time-space distribution of Cherenkov photons was quantified to perform PCA. To evaluate coincidence time resolution (CTR), the time difference of two independent γ-ray events was calculated. The detection time was defined as the first photon time after the SPTR of the photodetector was taken into account. The position resolution on the photodetector plane could be estimated with high accuracy, by using a small number of Cherenkov photons. Moreover, PCA showed an ability to estimate the DOI. The position resolution heavily depends on the pitch of the photodetector array and the radiator

  14. Very-high-energy gamma-ray observations of the Type Ia Supernova SN 2014J with the MAGIC telescopes

    Science.gov (United States)

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

    2017-06-01

    Context. In this work we present data from observations with the MAGIC telescopes of SN 2014J detected on January 21 2014, the closest Type Ia supernova since Imaging Air Cherenkov Telescopes started to operate. Aims: We aim to probe the possibility of very-high-energy (VHE; E ≥ 100 GeV) gamma rays produced in the early stages of Type Ia supernova explosions. Methods: We performed follow-up observations after this supernova (SN) explosion for five days, between January 27 and February 2 2014. We searched for gamma-ray signals in the energy range between 100 GeV and several TeV from the location of SN 2014J using data from a total of 5.5 h of observations. Prospects for observing gamma rays of hadronic origin from SN 2014J in the near future are also being addressed. Results: No significant excess was detected from the direction of SN 2014J. Upper limits at 95% confidence level on the integral flux, assuming a power-law spectrum, dF/dE ∝ E- Γ, with a spectral index of Γ = 2.6, for energies higher than 300 GeV and 700 GeV, are established at 1.3 × 10-12 and 4.1 × 10-13 photons cm-2 s-1, respectively. Conclusions: For the first time, upper limits on the VHE emission of a Type Ia supernova are established. The energy fraction isotropically emitted into TeV gamma rays during the first 10 days after the supernova explosion for energies greater than 300 GeV is limited to 10-6 of the total available energy budget ( 1051 erg). Within the assumed theoretical scenario, the MAGIC upper limits on the VHE emission suggest that SN 2014J will not be detectable in the future by any current or planned generation of Imaging Atmospheric Cherenkov Telescopes.

  15. Optical Cherenkov radiation by cascaded nonlinear interaction: an efficient source of few-cycle energetic near- to mid-IR pulses

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Zhou, Binbin

    2011-01-01

    When ultrafast noncritical cascaded second-harmonic generation of energetic femtosecond pulses occur in a bulk lithium niobate crystal optical Cherenkov waves are formed in the near- to mid-IR. Numerical simulations show that the few-cycle solitons radiate Cherenkov (dispersive) waves in the λ = 2...

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

    Science.gov (United States)

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

    2009-04-13

    Terahertz (THz) wave generation based on nonlinear frequency conversion is promising way for realizing a tunable monochromatic bright THz-wave source. Such a development of efficient and wide tunable THz-wave source depends on discovery of novel brilliant nonlinear crystal. Important factors of a nonlinear crystal for THz-wave generation are, 1. High nonlinearity and 2. Good transparency at THz frequency region. Unfortunately, many nonlinear crystals have strong absorption at THz frequency region. The fact limits efficient and wide tunable THz-wave generation. Here, we show that Cherenkov radiation with waveguide structure is an effective strategy for achieving efficient and extremely wide tunable THz-wave source. We fabricated MgO-doped lithium niobate slab waveguide with 3.8 microm of thickness and demonstrated difference frequency generation of THz-wave generation with Cherenkov phase matching. Extremely frequency-widened THz-wave generation, from 0.1 to 7.2 THz, without no structural dips successfully obtained. The tuning frequency range of waveguided Cherenkov radiation source was extremely widened compare to that of injection seeded-Terahertz Parametric Generator. The tuning range obtained in this work for THz-wave generation using lithium niobate crystal was the widest value in our knowledge. The highest THz-wave energy obtained was about 3.2 pJ, and the energy conversion efficiency was about 10(-5) %. The method can be easily applied for many conventional nonlinear crystals, results in realizing simple, reasonable, compact, high efficient and ultra broad band THz-wave sources.

  17. Simple method of determining induced 32P activity following burning of sulfur tablets by measuring Cherenkov radiation

    International Nuclear Information System (INIS)

    Kubicek, I.

    1986-01-01

    A method is described allowing the detemination of induced beta activity of phosphorus-32 using Cherenkov radiation, following the burning of sulfur tablets in the measuring vesels. A mixture of phosphoric acid and sodium phosphate solutions was used as the medium for the production of Cherenkov radiation. The losses of activity during sulfur tablet burning, the detection efficiency and the minimum detectable activity for which the minimum determinable dose was estimated, were determined. The results obtained by measurement with Cherenkov radiation are compared with other techniques of phosphorus-32 detection. The method was tested at VUPL Bratislava on detectors irradited using a 252 Cf fast neutron source. From Caswell's data, the fluence-to-kerma conversin factor was determined for a neutron spectrum calculated by the Monte Carlo method. Tissue kerma was estimated from the neutron fluence corresponding to the appropriate values of saturated activity per 1 sulfur-32 nucleus. (author)

  18. Alignment and phasing of deployable telescopes

    Science.gov (United States)

    Woolf, N. J.; Ulich, B. L.

    1983-01-01

    The experiences in coaligning and phasing the Multi-Mirror Telescope (MMT), together with studies in setting up radio telescopes, are presented. These experiences are discussed, and on the basis they furnish, schemes are suggested for coaligning and phasing four large future telescopes with complex primary mirror systems. These telescopes are MT2, a 15-m-equivalent MMT, the University of California Ten Meter Telescope, the 10 m sub-mm wave telescope of the University of Arizona and the Max Planck Institute for Radioastronomy, and the Large Deployable Reflector, a future space telescope for far-IR and sub-mm waves.

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

    International Nuclear Information System (INIS)

    Cecchini, S.; D'Antone, I.; Degli Esposti, L.; 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-designed solar cells and large conventional photovoltaic areas is presented. A discussion on the obtained and achievable sensitivities follows

  20. Application of machine learning techniques to lepton energy reconstruction in water Cherenkov detectors

    Science.gov (United States)

    Drakopoulou, E.; Cowan, G. A.; Needham, M. D.; Playfer, S.; Taani, M.

    2018-04-01

    The application of machine learning techniques to the reconstruction of lepton energies in water Cherenkov detectors is discussed and illustrated for TITUS, a proposed intermediate detector for the Hyper-Kamiokande experiment. It is found that applying these techniques leads to an improvement of more than 50% in the energy resolution for all lepton energies compared to an approach based upon lookup tables. Machine learning techniques can be easily applied to different detector configurations and the results are comparable to likelihood-function based techniques that are currently used.

  1. Residual heat estimation by using Cherenkov radiation in Tehran Research Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Arkani, M. [Department of Nuclear Engineering, Azad University, Tehran (Iran, Islamic Republic of); Gharib, M. [Tehran Research Reactor, Nuclear Science and Technology Research Institute (NSTRI), Tehran 14395-836 (Iran, Islamic Republic of)], E-mail: mgharib@aeoi.org.ir

    2008-11-11

    An experiment is set up in Tehran 5 MW research reactor to observe Cherenkov radiation response during post-shutdown periods. An ordinary PC camera is used for this purpose. Theoretical estimation of the total power including decay heat and neutronic power is checked against detector response. A general agreement suggests that the same setup could equally serve as an independent channel for similar purposes in other reactors. This suggested that a similar setup based on present experience could be utilized in other reactors especially with the aim of fuel surveillance and monitoring.

  2. Detection of Cherenkov radiation: the inverse problem to generation of nondiffracting beams

    Czech Academy of Sciences Publication Activity Database

    Miler, Miroslav; Pala, Jan

    2003-01-01

    Roč. 33, 2-3 (2003), s. 307-313 ISSN 0078-5466. [Polish-Czech-Slovak Optica l Conference on Wave and Quantum Aspects of Contemporary Optics PCS /13./. Krzyzowa, 09.09.2002-13.09.2002] R&D Projects: GA ČR GA102/01/0429 Institutional research plan: CEZ:AV0Z2067918 Keywords : Cherenkov radiation * holographic optica l elements * laser beams * diffraction Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 0.221, year: 2003

  3. Study of solar activity by measuring cosmic rays with a water Cherenkov detector

    International Nuclear Information System (INIS)

    Bahena Bias, Angelica; Villasenor, Luis

    2011-01-01

    We report on an indirect study of solar activity by using the Forbush effect which consists on the anti-correlation between the intensity of solar activity and the intensity of secondary cosmic radiation detected at ground level at the Earth. We have used a cylindrical water Cherenkov detector to measure the rate of arrival of secondary cosmic rays in Morelia Mich., Mexico, at 1950 m.a.s.l. We describe the analysis required to unfold the effect of atmospheric pressure and the search for Forbush decreases in our data, the latter correspond to more than one year of continuous data collection.

  4. Residual heat estimation by using Cherenkov radiation in Tehran Research Reactor

    International Nuclear Information System (INIS)

    Arkani, M.; Gharib, M.

    2008-01-01

    An experiment is set up in Tehran 5 MW research reactor to observe Cherenkov radiation response during post-shutdown periods. An ordinary PC camera is used for this purpose. Theoretical estimation of the total power including decay heat and neutronic power is checked against detector response. A general agreement suggests that the same setup could equally serve as an independent channel for similar purposes in other reactors. This suggested that a similar setup based on present experience could be utilized in other reactors especially with the aim of fuel surveillance and monitoring.

  5. Gas Time-of-Flight Cherenkov Detector with Radiofrequency Phototube for FP420

    International Nuclear Information System (INIS)

    Margaryan, A.

    2011-01-01

    In this paper, the gas Cherenkov detector with radiofrequency phototube is considered as a fast-timing detector for FP420 project. The detector serves for precise Time-of-Flight measurements of forward going protons, capable of accurate vertex reconstruction and background rejection at high luminosities. The proposed technique is a high resolution (∼ 5 ps FWHM for a single proton), high rate (∼ MHz) and highly stable (less than 1 ps) timing technique capable to detect up to several tens events in a short (∼ 1 ns) time interval. (author)

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

    CERN Document Server

    Nappi, E

    2003-01-01

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

  7. Comparison of Cherenkov excited fluorescence and phosphorescence molecular sensing from tissue with external beam irradiation.

    Science.gov (United States)

    Lin, Huiyun; Zhang, Rongxiao; Gunn, Jason R; Esipova, Tatiana V; Vinogradov, Sergei; Gladstone, David J; Jarvis, Lesley A; Pogue, Brian W

    2016-05-21

    Ionizing radiation delivered by a medical linear accelerator (LINAC) generates Cherenkov emission within the treated tissue. A fraction of this light, in the 600-900 nm wavelength region, propagates through centimeters of tissue and can be used to excite optical probes in vivo, enabling molecular sensing of tissue analytes. The success of isolating the emission signal from this Cherenkov excitation background is dependent on key factors such as: (i) the Stokes shift of the probe spectra; (ii) the excited state lifetime; (iii) the probe concentration; (iv) the depth below the tissue surface; and (v) the radiation dose used. Previous studies have exclusively focused on imaging phosphorescent dyes, rather than fluorescent dyes. However there are only a few biologically important phosphorescent dyes and yet in comparison there are thousands of biologically relevant fluorescent dyes. So in this study the focus was a study of efficacy of Cherenkov-excited luminescence using fluorescent commercial near-infrared probes, IRDye 680RD, IRDye 700DX, and IRDye 800CW, and comparing them to the well characterized phosphorescent probe Oxyphor PtG4, an oxygen sensitive dye. Each probe was excited by Cherenkov light from a 6 MV external radiation beam, and measured in continuous wave or time-gated modes. The detection was performed by spectrally resolving the luminescence signals, and measuring them with spectrometer-based separation on an ICCD detector. The results demonstrate that IRDye 700DX and PtG4 allowed for the maximal signal to noise ratio. In the case of the phosphorescent probe, PtG4, with emission decays on the microsecond (μs) time scale, time-gated acquisition was possible, and it allowed for higher efficacy in terms of the probe concentration and detection depth. Phantoms containing the probe at 5 mm depth could be detected at concentrations down to the nanoMolar range, and at depths into the tissue simulating phantom near 3 cm. In vivo studies showed that 5

  8. Analytical method for determining colour intensities based on Cherenkov radiation colour quenching

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Gomez, C; Lopez-Gonzalez, J deD; Ferro-Garcia, M A [Univ. of Granada, Granada (Spain). Faculty of Sciences, Dept. of Inorganic Chemistry. Radiochemistry Section; Consejo Superior de Investigaciones Cientificas, Granada (Spain). Dept. of Chemical Research Coordinated Centre)

    1983-01-01

    A study was made for determining color intensities using as luminous non-monochromatic source produced by the Cherenkov emission in the walls of a glass capillary which acts as luminous source itself inside the colored solution to be evaluated. The reproducibility of this method has been compared with the spectrophotometric assay; the relative errors of both analytical methods have been calculated for different concentrations of congo red solution in the range of minimal error, according to Ringbom's criterion. The sensitivity of this analytical method has been studied for the two ..beta..-emitters employed: /sup 90/Sr//sup 90/Y and /sup 204/Tl.

  9. The response of wavelength shifting panels in large water Cherenkov systems

    International Nuclear Information System (INIS)

    Bakich, A.M.; Peak, L.S.

    1986-01-01

    This paper describes a series of tests performed with a panel Bicron wavelength shifting acrylic plastic (BC-480) coupled to an EMI 9623B photomultiplier tube. The aim was to effectively increase the cathode coverage and its sensitivity to incident Cherenkov radiation, so that such a system could be employed in a solar neutrino detector. Measurements of the uniformity and effective efficiency of the system have been made and compared with the results of various simulation runs. The effects of side mirrors, back reflector, water interface and possible shaping of the panel to enhance its response are also assessed. (orig.)

  10. TU-AB-BRA-12: Quality Assurance of An Integrated Magnetic Resonance Image Guided Adaptive Radiotherapy Machine Using Cherenkov Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Andreozzi, J; Bruza, P; Saunders, S; Pogue, B [Dartmouth College, Hanover, NH (United States); Mooney, K; Curcuru, A; Green, O [Washington University School of Medicine, Saint Louis, MO (United States); Gladstone, D [Dartmouth-Hitchcock Med. Ctr., Lebanon, NH (Lebanon)

    2016-06-15

    Purpose: To investigate the viability of using Cherenkov imaging as a fast and robust method for quality assurance tests in the presence of a magnetic field, where other instruments can be limited. Methods: Water tank measurements were acquired from a clinically utilized adaptive magnetic resonance image guided radiation therapy (MR-IGRT) machine with three multileaf-collimator equipped 60Co sources. Cherenkov imaging used an intensified charge coupled device (ICCD) camera placed 3.5m from the treatment isocenter, looking down the bore of the 0.35T MRI into a water tank. Images were post-processed to make quantitative comparison between Cherenkov light intensity with both film and treatment planning system predictions, in terms of percent depth dose curves as well as lateral beam profile measurements. A TG-119 commissioning test plan (C4: C-Shape) was imaged in real-time at 6.33 frames per second to investigate the temporal and spatial resolution of the Cherenkov imaging technique. Results: A .33mm/pixel Cherenkov image resolution was achieved across 1024×1024 pixels in this setup. Analysis of the Cherenkov image of a 10.5×10.5cm treatment beam in the water tank successfully measured the beam width at the depth of maximum dose within 1.2% of the film measurement at the same point. The percent depth dose curve for the same beam was on average within 2% of ionization chamber measurements for corresponding depths between 3–100mm. Cherenkov video of the TG-119 test plan provided qualitative agreement with the treatment planning system dose predictions, and a novel temporal verification of the treatment. Conclusions: Cherenkov imaging was successfully used to make QA measurements of percent depth dose curves and cross beam profiles of MRI-IGRT radiotherapy machines after only several seconds of beam-on time and data capture; both curves were extracted from the same data set. Video-rate imaging of a dynamic treatment plan provided new information regarding temporal

  11. Note: Measurements of fast electrons in the TORE-SUPRA tokamak by means of modified Cherenkov-type diamond detector

    Energy Technology Data Exchange (ETDEWEB)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Jakubowski, M. J.; Malinowski, K.; Mirowski, R. [National Centre for Nuclear Research (NCBJ), 7 Andrzeja Soltana Str., 05-400 Otwock (Poland); Lotte, Ph.; Goniche, M.; Gunn, J.; Colledani, G.; Pascal, J.-Y.; Basiuk, V. [CEA, IRFM, F-13108 Saint Paul-lez-Durance (France)

    2013-01-15

    The Note reports on experimental studies of ripple born fast electrons within the TORE-SUPRA facility, which were performed by means of a modified measuring head equipped with diamond detectors designed especially for recording the electron-induced Cherenkov radiation. There are presented signals produced by fast electrons in the TORE-SUPRA machine, which were recorded during two experimental campaigns performed in 2010. Shapes of these electron-induced signals are considerably different from those observed during the first measurements carried out by the prototype Cherenkov probe in 2008. An explanation of the observed differences is given.

  12. Note: Measurements of fast electrons in the TORE-SUPRA tokamak by means of modified Cherenkov-type diamond detector

    International Nuclear Information System (INIS)

    Jakubowski, L.; Sadowski, M. J.; Zebrowski, J.; Rabinski, M.; Jakubowski, M. J.; Malinowski, K.; Mirowski, R.; Lotte, Ph.; Goniche, M.; Gunn, J.; Colledani, G.; Pascal, J.-Y.; Basiuk, V.

    2013-01-01

    The Note reports on experimental studies of ripple born fast electrons within the TORE-SUPRA facility, which were performed by means of a modified measuring head equipped with diamond detectors designed especially for recording the electron-induced Cherenkov radiation. There are presented signals produced by fast electrons in the TORE-SUPRA machine, which were recorded during two experimental campaigns performed in 2010. Shapes of these electron-induced signals are considerably different from those observed during the first measurements carried out by the prototype Cherenkov probe in 2008. An explanation of the observed differences is given.

  13. Trick or Treat and Telescopes

    Science.gov (United States)

    Buratti, Bonnie J.; Meinke, Bonnie K.; Schmude, Richard W.

    2017-10-01

    Based on an activity that DPS member Richard Schmude Jr. has been doing for years, with over 5000 children reached, DPS initiated in 2016 a pilot program entitled “Trick-or-Treat and Telescopes.” DPS encouraged its members to put out their telescopes during trick-or-treat time on Halloween, in their own lawns or in a neighbor’s lawn with better viewing (or more traffic). The program will be continued in 2017. This year should offer good viewing with a waxing gibbous moon and Saturn visible. The program was also advertised though the Night Sky Network, a consortium of astronomy clubs. The following website gives advice and connections to resources.https://dps.aas.org/education/trick-or-treat-and-telescopes acknowledged.

  14. Scientific management of Space Telescope

    Science.gov (United States)

    Odell, C. R.

    1981-01-01

    A historical summay is given on the science management of the Space Telescope, the inception of which began in 1962, when scientists and engineers first recommended the development of a nearly diffraction limited substantial-size optical telescope. Phase A, the feasibility requirements generation phase, began in 1971 and consisted largely of NASA scientists and a NASA design. Phase B, the preliminary design phase, established a tiered structure of scientists, led by the Large Space Telescope operations and Management Work Group. A Mission Operations Working Group headed six instrument definition teams to develop the essential instrument definitions. Many changes took place during Phase B, before design and development, which began in 1978 and still continues today.

  15. Space Telescope maintenance and refurbishment

    Science.gov (United States)

    Trucks, H. F.

    1983-01-01

    The Space Telescope (ST) represents a new concept regarding spaceborne astronomical observatories. Maintenance crews will be brought to the orbital worksite to make repairs and replace scientific instruments. For major overhauls the telescope can be temporarily returned to earth with the aid of the Shuttle. It will, thus, be possible to conduct astronomical studies with the ST for two decades or more. The five first-generation scientific instruments used with the ST include a wide field/planetary camera, a faint object camera, a faint object spectrograph, a high resolution spectrograph, and a high speed photometer. Attention is given to the optical telescope assembly, the support systems module, aspects of mission and science operations, unscheduled maintenance, contingency orbital maintenance, planned on-orbit maintenance, ground maintenance, ground refurbishment, and ground logistics.

  16. LSST telescope and site status

    Science.gov (United States)

    Gressler, William J.

    2016-07-01

    The Large Synoptic Survey Telescope (LSST) Project1 received its construction authorization from the National Science Foundation in August 2014. The Telescope and Site (T and S) group has made considerable progress towards completion in subsystems required to support the scope of the LSST science mission. The LSST goal is to conduct a wide, fast, deep survey via a 3-mirror wide field of view optical design, a 3.2-Gpixel camera, and an automated data processing system. The summit facility is currently under construction on Cerro Pachón in Chile, with major vendor subsystem deliveries and integration planned over the next several years. This paper summarizes the status of the activities of the T and S group, tasked with design, analysis, and construction of the summit and base facilities and infrastructure necessary to control the survey, capture the light, and calibrate the data. All major telescope work package procurements have been awarded to vendors and are in varying stages of design and fabrication maturity and completion. The unique M1M3 primary/tertiary mirror polishing effort is completed and the mirror now resides in storage waiting future testing. Significant progress has been achieved on all the major telescope subsystems including the summit facility, telescope mount assembly, dome, hexapod and rotator systems, coating plant, base facility, and the calibration telescope. In parallel, in-house efforts including the software needed to control the observatory such as the scheduler and the active optics control, have also seen substantial advancement. The progress and status of these subsystems and future LSST plans during this construction phase are presented.

  17. Nonlineart theory of relativistic beam-plasma instabilities in the regime of the collective Cherenkov effect

    Energy Technology Data Exchange (ETDEWEB)

    Bobylev, Yu. V. [L.N. Tolstoy Tula State Pedagogical University (Russian Federation); Kuzelev, M. V. [Moscow State University (Russian Federation); Rukhadze, A. A. [Russian Academy of Sciences, Prokhorov Institute of General Physics (Russian Federation)

    2008-02-15

    A general mathematical model is proposed that is based on the Vlasov kinetic equation with a self-consistent field and describes the nonlinear dynamics of the electromagnetic instabilities of a relativistic electron beam in a spatially bounded plasma. Two limiting cases are analyzed, namely, high-frequency (HF) and low-frequency (LF) instabilities of a relativistic electron beam, of which the LF instability is a qualitatively new phenomenon in comparison with the known Cherenkov resonance effects. For instabilities in the regime of the collective Cherenkov effect, the equations containing cubic nonlinearities and describing the nonlinear saturation of the instabilities of a relativistic beam in a plasma are derived by using the methods of expansion in small perturbations of the trajectories and momenta of the beam electrons. Analytic expressions for the amplitudes of the interacting beam and plasma waves are obtained. The analytical results are shown to agree well with the exact solutions obtained numerically from the basic general mathematical model of the instabilities in question. The general mathematical model is also used to discuss the effects associated with variation in the constant component of the electron current in a beam-plasma system.

  18. Development of new photon detection device for Cherenkov and fluorescence radiation

    Directory of Open Access Journals (Sweden)

    Tinti A.

    2013-06-01

    Full Text Available Recent progress on the development of a new solid state detector allowed the use of finely pixelled photocathodes obtained from silicon semiconductors. SiPM detectors seem to be an ideal tool for the detection of Cherenkov and fluorescence light in spite of their not yet resolved criticism for operating temperature and intrinsic noise. The main disadvantage of SiPM in this case is the poor sensitivity in the wavelength range 300-400 nm, where the Cherenkov light and fluorescence radiation are generated. We report on the possibility to realize a new kind of pixelled photodetector based on the use of silicon substrate with carbon nanotube compounds, more sensitive to the near UV radiation. Also if at the very beginning, the development of such detector appears very promising and useful for astroparticle physics, both in the ground based arrays and in the space experiments. The detectors are ready to be operated in conditions of measurements without signal amplification.

  19. Uncertainty and Detection Limit in Determination of 89,90Sr by Cherenkov Counting

    International Nuclear Information System (INIS)

    Grahek, Z.; Karanovic, G.; Nodilo, M.

    2013-01-01

    The methodology for the rapid determination of 89,90Sr in normal and emergency situations is given. Methodology is based on simultaneous separation of strontium and yttrium from samples and quantitative 89,90Sr determination by Cherenkov counting within three days. Methodology for quantitative determination by Cherenkov counting based on following changes of sample activity during the time is described and discussed. It has been shown that 89,90Sr can be determined with acceptable accuracy when 89Sr/90Sr ratio is over 10:1. Obtained results show that by using low level liquid scintillation counter it can be possible to determine 89Sr and 90Sr in broad range of concentration activities (1 - 1000 Bq (kgL) -1 ) with uncertainties below 10% within 2-3 days. Results also show that accuracy of determination of 89Sr (and 90Sr) depends on determination of difference between separation and counting time when activity ratio of 89Sr/90Sr is high. Analysis of combined uncertainty shows that it mainly depends on uncertainty of efficiency and recovery determination, uncertainty of activities determination for both isotopes and level of background radiation. Portion of each in combined uncertainty depend on level of activity of each isotope and its activity ratio.(author)

  20. The aerogel Ring Imaging Cherenkov system at the Belle II spectrometer

    Science.gov (United States)

    Pestotnik, R.; Adachi, I.; Dolenec, R.; Hataya, K.; Iori, S.; Iwata, S.; Kakuno, H.; Kataura, R.; Kawai, H.; Kindo, H.; Kobayashi, T.; Korpar, S.; Križan, P.; Kumita, T.; Mrvar, M.; Nishida, S.; Ogawa, K.; Ogawa, S.; Šantelj, L.; Sumiyoshi, T.; Tabata, M.; Yonenaga, M.; Yusa, Y.

    2017-12-01

    In the forward end-cap of the Belle II spectrometer, a proximity focusing Ring Imaging Cherenkov counter with an aerogel radiator will be installed. The detector will occupy a limited space inside solenoid magnet with longitudinal field of 1.5 T. It will consist of a double layer aerogel radiator, an expansion volume and a photon detector. 420 Hamamatsu hybrid avalanche photo sensors with 144 channels each will be used to read out single Cherenkov photons with high efficiency. More than 60,000 analog signals will be digitized and processed in the front end electronics and send to the unified experiment data acquisition system. The detector components have been successfully produced and are now being installed in the spectrometer. Tested before on the bench, they are currently being installed in the mechanical frame. Part of the detector have been commissioned and connected to the acquisition system to register the cosmic ray particles. The first preliminary results are in accordance with previous expectations. We expect an excellent performance of the device which will allow at least a 4σ separation of pions from kaons in the experiment kinematic region from 0.5 GeV/c to 4 GeV/c.

  1. Multi-anode photon-multiplier readout electronics for the LHCb ring imaging Cherenkov detectors

    CERN Document Server

    Smale, N J

    2004-01-01

    A readout system for the Ring Imaging CHerenkov (RICH) detectors of the LHCb experiment has been developed. Two detector technologies for the measurement of Cherenkov photons are considered, the Multi-Anode Photo-Multiplier Tube (MAPMT) and the Hybrid Photon Detector (HPD), both of which meet the RICH requirements. The properties of the MAPMT are evaluated using a controlled single-photon source; a pixel-to-pixel gain variation of ~3 and a typical signal to noise of ~20 is measured. The relative tube efficiency is found to be reduced by ~26 % due to the detailed focusing structure of the MAPMT device. A radiation hard application-specific integrated circuit (ASIC) chip, the Beetle1.2MA0, has been developed to capture and store signals from a pair of MAPMTs. The Beetle1.2MA0 is built on the architecture of the Beetle family that was designed for silicon strip detectors, the difference being a modified front-end amplifier. The 128 input-channels of the Beetle1.2MA0 have a charge-sensitive pre-amplifier followed...

  2. Prism-coupled Cherenkov phase-matched terahertz wave generation using a DAST crystal.

    Science.gov (United States)

    Suizu, Koji; Shibuya, Takayuki; Uchida, Hirohisa; Kawase, Kodo

    2010-02-15

    Terahertz (THz) wave generation based on nonlinear frequency conversion is a promising method for realizing a tunable monochromatic high-power THz-wave source. Unfortunately, many nonlinear crystals have strong absorption in the THz frequency region. This limits efficient and widely tunable THz-wave generation. The Cherenkov phase-matching method is one of the most promising techniques for overcoming these problems. Here, we propose a prism-coupled Cherenkov phase-matching (PCC-PM) method, in which a prism with a suitable refractive index at THz frequencies is coupled to a nonlinear crystal. This has the following advantages. Many crystals can be used as THz-wave emitters; the phase-matching condition inside the crystal does not have to be observed; the absorption of the crystal does not prevent efficient generation of radiation; and pump sources with arbitrary wavelengths can be employed. Here we demonstrate PCC-PM THz-wave generation using the organic crystal 4-dimethylamino-N-metyl-4-stilbazolium tosylate (DAST) and a Si prism coupler. We obtain THz-wave radiation with tunability of approximately 0.1 to 10 THz and with no deep absorption features resulting from the absorption spectrum of the crystal. The obtained spectra did not depend on the pump wavelength in the range 1300 to 1450 nm. This simple technique shows promise for generating THz radiation using a wide variety of nonlinear crystals.

  3. Vavilov-Cherenkov and transition radiations on the dielectric and metallic spheres

    International Nuclear Information System (INIS)

    Afanasiev, G.N.; Kartavenko, V.G.; Stepanovsky, Yu.P.

    2003-01-01

    Closed expressions are obtained for angular and frequency radiation intensities produced by a charge moving inside the dielectric sphere S, with observations made outside S (in fact, this is a typical experimental situation when a charge moves in one medium while measurements are made in the other one). It is shown that the difference in media properties inside and outside S drastically affects angular and frequency distributions. Also, a charge motion is considered which begins and terminates in medium 2 and which passes either through the dielectric sphere filled with medium 1 or through the metallic one. The energy flux in medium 2 involves the Vavilov-Cherenkov, transition radiation and the one arising from the charge instantaneous beginning and termination of motion. The evaluated angular and frequency distributions for various charge velocities and medium properties inside and outside S show that the standard identification of the charge velocity by its radiation on the part of the charge trajectory where βn>1 is not always valid. We analyze also the frequently used interpretation of the transition radiation in terms of instantaneous charge deceleration in one medium and its sudden acceleration in another one, and find them as to be insufficient. On the other hand, attempts to interpret the transition radiation in terms of semi-infinite motions terminating in one medium and beginning in the other one turn out to be correct if one takes into account the terms corresponding to the Vavilov-Cherenkov radiation

  4. A monolithic silicon detector telescope

    International Nuclear Information System (INIS)

    Cardella, G.; Amorini, F.; Cabibbo, M.; Di Pietro, A.; Fallica, G.; Franzo, G.; Figuera, P.; Papa, M.; Pappalardo, G.; Percolla, G.; Priolo, F.; Privitera, V.; Rizzo, F.; Tudisco, S.

    1996-01-01

    An ultrathin silicon detector (1 μm) thick implanted on a standard 400 μm Si-detector has been built to realize a monolithic telescope detector for simultaneous charge and energy determination of charged particles. The performances of the telescope have been tested using standard alpha sources and fragments emitted in nuclear reactions with different projectile-target colliding systems. An excellent charge resolution has been obtained for low energy (less than 5 MeV) light nuclei. A multi-array lay-out of such detectors is under construction to charge identify the particles emitted in reactions induced by low energy radioactive beams. (orig.)

  5. Artificial Intelligence in Autonomous Telescopes

    Science.gov (United States)

    Mahoney, William; Thanjavur, Karun

    2011-03-01

    Artificial Intelligence (AI) is key to the natural evolution of today's automated telescopes to fully autonomous systems. Based on its rapid development over the past five decades, AI offers numerous, well-tested techniques for knowledge based decision making essential for real-time telescope monitoring and control, with minimal - and eventually no - human intervention. We present three applications of AI developed at CFHT for monitoring instantaneous sky conditions, assessing quality of imaging data, and a prototype for scheduling observations in real-time. Closely complementing the current remote operations at CFHT, we foresee further development of these methods and full integration in the near future.

  6. SU-C-201-07: Towards Clinical Cherenkov Emission Dosimetry: Stopping Power-To-Cherenkov Power Ratios and Beam Quality Specification of Clinical Electron Beams

    International Nuclear Information System (INIS)

    Zlateva, Y; Seuntjens, J; El Naqa, I

    2016-01-01

    Purpose: We propose a Cherenkov emission (CE)-based reference dosimetry method, which in contrast to ionization chamber-based dosimetry, employs spectrum-averaged electron restricted mass collision stopping power-to-Cherenkov power ratios (SCRs), and we examine Monte Carlo-calculated SCRs and beam quality specification of clinical electron beams. Methods: The EGSnrc user code SPRRZnrc was modified to compute SCRs instead of stopping-power ratios (single medium: water; cut-off: CE threshold (observing Spencer-Attix conditions); CE power: Frank-Tamm). SCRs are calculated with BEAMnrc for realistic electron beams with nominal energies of 6–22 MeV from three Varian accelerators (TrueBeam Clinac 21EX, Clinac 2100C/D) and for mono-energetic beams of energies equal to the mean electron energy at the water surface. Sources of deviation between clinical and mono-energetic SCRs are analyzed quantitatively. A universal fit for the beam-quality index R_5_0 in terms of the depth of 50% CE C_5_0 is carried out. Results: SCRs at reference depth are overestimated by mono-energetic values by up to 0.2% for a 6-MeV beam and underestimated by up to 2.3% for a 22-MeV beam. The variation is mainly due to the clinical beam spectrum and photon contamination. Beam angular spread has a small effect across all depths and energies. The influence of the electron spectrum becomes increasingly significant at large depths, while at shallow depths and high beam energies photon contamination is predominant (up to 2.0%). The universal data fit reveals a strong linear correlation between R_5_0 and C_5_0 (ρ > 0.99999). Conclusion: CE is inherent to radiotherapy beams and can be detected outside the beam with available optical technologies, which makes it an ideal candidate for out-of-beam high-resolution 3D dosimetry. Successful clinical implementation of CE dosimetry hinges on the development of robust protocols for converting measured CE to radiation dose. Our findings constitute a key step

  7. Neutrino telescopes in the World

    International Nuclear Information System (INIS)

    Ernenwein, J.-P.

    2007-01-01

    Neutrino astronomy has rapidly developed these last years, being the only way to get specific and reliable information about astrophysical objects still poorly understood.Currently two neutrino telescopes are operational in the World: BAIKAL, in the lake of the same name in Siberia, and AMANDA, in the ices of the South Pole. Two telescopes of the same type are under construction in the Mediterranean Sea: ANTARES and NESTOR. All these telescopes belong to a first generation, with an instrumented volume smaller or equal to 0.02 km3. Also in the Mediterranean Sea, the NEMO project is just in its starting phase, within the framework of a cubic kilometer size neutrino telescope study. Lastly, the ICECUBE detector, with a volume reaching about 1 km3, is under construction on the site of AMANDA experiment, while an extension of the BAIKAL detector toward km3 is under study. We will present here the characteristics of these experiments, as well as the results of their observations

  8. Push-To Telescope Mathematics

    Science.gov (United States)

    Teets, Donald

    2012-01-01

    Two coordinate systems are related here, one defined by the earth's equator and north pole, the other by the orientation of a telescope at some location on the surface of the earth. Applying an interesting though somewhat obscure property of orthogonal matrices and using the cross-product simplifies this relationship, revealing that a surprisingly…

  9. GISOT: a giant solar telescope

    Science.gov (United States)

    Hammerschlag, Robert H.; von der Lühe, Oskar F.; Bettonvil, Felix C.; Jägers, Aswin P.; Snik, Frans

    2004-10-01

    A concept is presented for an extremely large high-resolution solar telescope with an aperture of 11 m and diffraction limited for visual wavelengths. The structure of GISOT will be transparent to wind and placed on a transparent stiff tower. For efficient wind flushing, all optics, including the primary mirror, will be located above the elevation axis. The aperture will be of the order of 11 m, not rotatively symmetrical, but of an elongated shape with dimensions 11 x 4 m. It consists of a central on-axis 4 m mirror with on both sides 3 pieces of 2 m mirrors. The optical layout will be kept simple to guarantee quality and minimize stray light. A Coudé room for instruments is planned below the telescope. The telescope will not be housed in a dome-like construction, which interferes with the open principle. Instead the telescope will be protected by a foldable tent construction with a diameter of the order of 30 m, which doesn"t form any obstruction during observations, but can withstand the severe weather circumstances on mountain sites. Because of the nature of the solar scene, extremely high resolution in only one dimension is sufficient to solve many exciting problems in solar physics and in this respect the concept of GISOT is very promising.

  10. The Thirty-Meter Telescope

    Indian Academy of Sciences (India)

    2016-01-27

    Jan 27, 2016 ... The Thirty-Meter Telescope international observatory will enable transformational observations over the full cosmic timeline all the way from the first luminous objects in the Universe to the planets and moons of our own solar system. To realize its full scientific potential, TMT will be equipped with a powerful ...

  11. Monster telescope hunts blue planets

    CERN Multimedia

    Leake, J

    2003-01-01

    BRITAIN is to back a project to build the world's biggest telescope - so powerful that it could see life-bearing planets in other solar systems. It will need the largest mirror ever built at about 100 metres in diameter (1/2 page).

  12. Design of a general purpose data collection module for the NuTel telescope

    International Nuclear Information System (INIS)

    Velikzhanin, Y.S.; Chi, Y.; Hou, W.S.; Hsu, C.C.; Shiu, J.G.; Ueno, K.; Wang, M.Z.; Yeh, P.

    2005-01-01

    We have developed a Data Collection Module (DCM) to digitize, store and select data from the NuTel telescope, which observes Cherenkov photons from near horizontal air showers. Multi-anode photo-multiplier tubes (MAPMT) are used as photon-sensitive devices. DCM processes 32 input signals from the charge-sensitive pre-amplifiers located close to the MAPMT. The module design uses 40-MHz 10-bit pipeline ADCs and medium-size FPGAs. A programmable gain/attenuation control x0.5-2 is applied to each channel before the ADC providing a comfortable operation with a multi-channel system using MAPMT as photon-sensitive device because the gain of MAPMT fluctuates from channel to channel as 1:3. DCM has a flexible on-board trigger inside FPGA firmware. The system design is made in 32-bit 33-MHz cPCI. Thirty-two DCMs housed in two crates process signals from the two telescopes of 512 channels each looking to the same direction for coincidence

  13. Characterization benches for neutrino telescope Optical Modules at the APC laboratory

    Science.gov (United States)

    Avgitas, Theodore; Creusot, Alexandre; Kouchner, Antoine

    2016-04-01

    As has been demonstrated by the first generation of neutrino telescopes Antares and IceCube, precise knowledge of the photon detection efficiency of optical modules is of fundamental importance for the understanding of the instrument and accurate event reconstruction. Dedicated test benches have been developed to measure all related quantities for the Digital Optical Modules of the KM3NeT neutrino telescope being currently deployed in the Mediterranean sea. The first bench is a black box with robotic arms equipped with a calibrated single photon source or laser which enable a precise mapping of the detection efficiency at arbitrary incident angles as well as precise measurements of the time delays induced by the photodetection chain. These measurement can be incorporated and compared to full GEANT MonteCarlo simulations of the optical modules. The second bench is a 2 m×2 m ×2 m water tank equipped with muon hodoscopes on top and bottom. It enables to study and measure the angular dependence of the DOM's detection efficiency of the Cherenkov light produced in water by relativistic muons, thus reproducing in situ detection conditions. We describe these two benches and present their first results and status.

  14. Maintenance and testing of anodized aluminum mirrors on the Whipple 10 m Whipple Telescope

    Science.gov (United States)

    Badran, H. M.; Weekes, T. C.

    2001-08-01

    Threshold energy sensitivity depends not only on the high reflectivity of the mirrors used in atmospheric Cherenkov telescopes but also on the maintenance of this reflectivity over months/years. The successful application of a mirror maintenance technique depends on the type of mirror coating and the contamination that must be removed. The uncovered mirrors in use on the 10-m Whipple gamma-ray telescope are anodized aluminum mirrors. A standard cleaning technique for such mirrors is not available. With the aim of extending the life of the aluminum coating exposed to the Mt ˙Hopkins environment, several cleaning procedures were tested on mirrors that had been exposed for three years. Evaluation of the most effective cleaners is presented. Preliminary results are also presented from a long-term experiment using newly coated mirrors at the proposed VERITAS site and at the current 10 m site. This experiment is designed to reveal the rates at which the reflectance degrades as a function of time, depth of anodization, storage direction, degree of covering, and maintenance procedures.

  15. Overdenture dengan Pegangan Telescopic Crown

    Directory of Open Access Journals (Sweden)

    Pambudi Santoso

    2014-06-01

    Full Text Available Kaitan presisi merupakan alat retensi mekanis yang menghubungkan antara satu atau lebih pegangan gigi tiruan, yang bertujuan untuk menambah retensi dan/atau stabilisasi. Kaitan presisi dapat digunakan secara luas pada gigi tiruan cekat, gigi tiruan sebagian lepasan, overdenture, implant untuk retensi overdenture, dan protesa maksilo fasial. Overdenture dengan kaitan presisi dapat membantu dalam pembagian beban kunyah, meminimalkan trauma pada gigi pegangan dan jaringan lunak, meminimalkan resorbsi tulang, dan meningkatkan estetik dan pengucapan suara. Salah satu jenis dari kaitan presisi adalah telescopic crown, terdiri dari 2 macam mahkota, yaitu mahkota primer yang melekat secara permanen pada gigi penyangga, dan mahkota sekunder yang melekat pada gigi tiruan. Tujuan pemaparan kasus ini adalah untuk memberikan informasi tentang rehabilitasi pasien edentulous sebagian rahang atas dengan telescopic crown..  Pasien wanita berusia 45 tahun datang ke klinik prostodonsia RSGM Prof.Soedomo dengan keluhan ingin dibuatkan gigi tiruan. Pasien kehilangan gigi 11 12 15 16 17 21 22 24 25 26 dan 27 yang diindikasikan untuk pembuatan overdenture gigi tiruan sebagian lepasan (GTS kerangka logam dengan pegangan telescopic crown pada gigi 13 dan 14 dengan sistem parallel-sided crown. Tahap-tahap pembuatan telescopic crown yaitu mencetak model study dengan catatan gigit pendahuluan. Perawatan saluran dilakukan pada akar gigi 13, dilanjutkan pemasangan pasak fiber serta rewalling dinding bukal. Gigi 13 dan 14 dilakukan preparasi mahkota penuh, dilanjutkan dengan pencetakan model kerja untuk coping primer dan kerangka logam dengan metode double impression. Coping primer disementasi pada gigi penyangga, dilanjutkan pasang coba coping sekunder beserta kerangka logam. Selanjutnya dilakukan pencatatan gigit, pencetakan model kerja, penyusunan gigi dan pasang coba penyusunan gigi pada pasien. Prosedur dilanjutkan dengan proses di laboratorium, serta insersi pada

  16. WE-AB-303-04: A Tissue Model of Cherenkov Emission From the Skin Surface During Megavoltage X-Ray Radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Wiles, A. N.; Loyalka, S. K. [University of Missouri, Columbia, MO (United States); Izaguirre, E. W. [University of Missouri, Columbia, MO (United States); Baylor Scott & White Health, Temple, TX (United States)

    2015-06-15

    Purpose: To develop a tissue model of Cherenkov radiation emitted from the skin surface during external beam radiotherapy. Imaging Cherenkov radiation emitted from human skin allows visualization of the beam position and potentially surface dose estimates, and our goal is to characterize the optical properties of these emissions. Methods: We developed a Monte Carlo model of Cherenkov radiation generated in a semi-infinite tissue slab by megavoltage x-ray beams with optical transmission properties determined by a two-layered skin model. We separate the skin into a dermal and an epidermal layer in our model, where distinct molecular absorbers modify the Cherenkov intensity spectrum in each layer while we approximate the scattering properties with Mie and Rayleigh scattering from the highly structured molecular organization found in human skin. Results: We report on the estimated distributions of the Cherenkov wavelength spectrum, emission angles, and surface distribution for the modeled irradiated skin surface. The expected intensity distribution of Cherenkov radiation emitted from skin shows a distinct intensity peak around 475 nm, the blue region of the visible spectrum, between a pair of optical absorption bands in hemoglobin and a broad plateau beginning near 600 nm and extending to at least 700 nm where melanin and hemoglobin absorption are both low. We also find that the Cherenkov intensity decreases with increasing angle from the surface normal, the majority being emitted within 20 degrees of the surface normal. Conclusion: Our estimate of the spectral distribution of Cherenkov radiation emitted from skin indicates an advantage to using imaging devices with long wavelength spectral responsivity. We also expect the most efficient imaging to be near the surface normal where the intensity is greatest; although for contoured surfaces, the relative intensity across the surface may appear to vary due to decreasing Cherenkov intensity with increased angle from the

  17. TH-CD-201-04: A Study of Cherenkov Light Generated and Collected in Plastic Scintillation Detector

    Energy Technology Data Exchange (ETDEWEB)

    Archambault, L [CHUQ Pavillon Hotel-Dieu de Quebec, Quebec, QC (Canada); Papaconstadopoulos, P [McGill Montreal General Hospital, Montreal, QC (Canada); Seuntjens, J [McGill Montreal General Hospital, Montreal, QC (Canada); McGill University, Montreal, Quebec (Canada); Bouchard, H [CHUM-Hospital Notre-Dame, Montreal, QC (Canada)

    2016-06-15

    Purpose: To study Cherenkov light emission in plastic scintillation detectors (PSDs) from a theoretical point of view to identify situations that may arise where the calibration coefficient obtained in one condition is not applicable to another condition. By identifying problematic situations, we hope to provide guidance on how to confidently use PSDs. Methods: Cherenkov light emission in PSD was modelled using basic physical principles. In particular, changes in refractive index as a function of wavelength were accounted for using the Sellmeier empirical equation. Both electron and photon beams were considered. For photons, realistic distributions of secondary charged particles were calculated using Klein-Nishina’s formula. Cherenkov production and collection in PSDs were studied for a range of parameters including beam energy, charged particle momentum distribution, detector orientation and material composition. Finally, experimental validation was made using a commercial plastic scintillation detector. Results: In specific situations, results show that the Cherenkov spectrum coupled in the PSD can deviate from its expected behaviour (i.e. one over the square of the wavelength). In these cases were the model is realistic it is possible to see a peak wavelength instead of a monotonically decreasing function. Consequences of this phenomenon are negligible when the momentum of charged particle is distributed randomly, but in some clinically relevant cases, such as an electron beam at depth close to R50 or for photon beams with minimal scatter component, the value of the calibration coefficient can be altered. Experimental tests with electron beams showed changes in the Cherenkov light ratio, the parameter used in the calibration of PSDs, up to 2–3% depending on the PSD orientation. Conclusion: This work is the first providing a physical explanation for apparent change in PSD calibration coefficient. With this new information at hand, it will be possible to

  18. The Dutch Open Telescope: History, Status, Prospects

    NARCIS (Netherlands)

    Rutten, R.J.

    1999-01-01

    After many years of persistent telescope design and telescope construction, R.H. Hammerschlag has installed his Dutch Open Telescope (DOT) on La Palma. I brie y review its history and design. The future of optical solar physics at Utrecht hinges on a recently-funded three- year DOT science

  19. Tests of a prototype multiplexed fiber-optic ultra-fast FADC data acquisition system for the MAGIC telescope

    International Nuclear Information System (INIS)

    Bartko, H.; Goebel, F.; Mirzoyan, R.; Pimpl, W.; Teshima, M.

    2005-01-01

    Ground-based Atmospheric Air Cherenkov Telescopes (ACTs) are successfully used to observe very high energy (VHE) gamma rays from celestial objects. The light of the night sky (LONS) is a strong background for these telescopes. The gamma ray pulses being very short, an ultra-fast read-out of an ACT can minimize the influence of the LONS. This allows one to lower the so-called tail cuts of the shower image and the analysis energy threshold. It could also help to suppress other unwanted backgrounds. Fast 'flash' analog-to-digital converters (FADCs) with GSamples/s are available commercially; they are, however, very expensive and power consuming. Here we present a novel technique of Fiber-Optic Multiplexing which uses a single 2 GSamples/s FADC to digitize 16 read-out channels consecutively. The analog signals are delayed by using optical fibers. The multiplexed (MUX) FADC read-out reduces the cost by about 85% compared to using one ultra-fast FADC per read-out channel. Two prototype multiplexers, each digitizing data from 16 channels, were built and tested. The ultra-fast read-out system will be described and the test results will be reported. The new system will be implemented for the read-out of the 17 m diameter MAGIC telescope camera

  20. A study to measure νsub(μ)-e scattering with a water Cherenkov detector

    International Nuclear Information System (INIS)

    Candelle, J.M.

    1985-11-01

    A new technique is proposed to study the elastic diffusion νsub(μ)e. This technique consists in collecting the Cherenkov light created by the charged particles in a water tank. This method was tested at CERN, with electron, muon, pion, and gamma beams. The aim of the test was to know if it is possible to measure precisely the diffusion angle of electrons with a good electron-hadron, and electron-gamma discrimination. We obtained a very good angular resolution, close to 6 mrd√E(GeV). The hadronic rejection rate is close to 10 -3 . The electron-gamma discrimination is less clear; for an electron acceptance of 80%, the gamma rejection factor is equal to 5. Furthermore, the data are consistent with the number of 50 photo-electrons emitted in the water by centimeter. This technique could be used to measure sin 2 thetasub(w) with an absolute precision of 0.005 [fr