WorldWideScience

Sample records for cherenkov radiation

  1. Cherenkov radiation in moving medium

    OpenAIRE

    2010-01-01

    Cherenkov radiation in uniformly moving homogenous isotropic medium without dispersion is studied. Formula for the spectrum of Cherenkov radiation of fermion was derived for the case when the speed of the medium is less than the speed of light in this medium at rest. The properties of Cherenkov spectrum are investigated.

  2. 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.)

  3. Wavelength-shifted Cherenkov radiators

    Science.gov (United States)

    Krider, E. P.; Jacobson, V. L.; Pifer, A. E.; Polakos, P. A.; Kurz, R. J.

    1976-01-01

    The scintillation and Cherenkov responses of plastic Cherenkov radiators containing different wavelength-shifting fluors in varying concentrations have been studied in beams of low energy protons and pions. For cosmic ray applications, where large Cherenkov to scintillation ratios are desired, the optimum fluor concentrations are 0.000025 by weight or less.

  4. Cherenkov radiation oscillator without reflectors

    Science.gov (United States)

    Li, D.; Wang, Y.; Hangyo, M.; Wei, Y.; Yang, Z.; Miyamoto, S.

    2014-05-01

    This Letter presents a Cherenkov radiation oscillator with an electron beam travelling over a finitely thick plate made of negative-index materials. In such a scheme, the external reflectors required in the traditional Cherenkov oscillators are not necessary, since the electromagnetic energy flows backward in the negative-index materials, leading to inherent feedback. We theoretically analyzed the interaction between the electron beam and the electromagnetic wave, and worked out the growth rate and start current through numerical calculations. With the help of particle-in-cell simulation, the theoretical predictions are well demonstrated.

  5. Cherenkov radiation threshold in random inhomogeneous media

    CERN Document Server

    Grichine, V M

    2009-01-01

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

  6. All-fiber femtosecond Cherenkov radiation source

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Møller, Uffe

    2012-01-01

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

  7. Flipping photons backward: reversed Cherenkov radiation

    Directory of Open Access Journals (Sweden)

    Hongsheng Chen

    2011-01-01

    Full Text Available Charged particles moving faster than light in a medium produce Cherenkov radiation. In traditional, positive index-of-refraction materials this radiation travels forward. Metamaterials, with negative indices of refraction, flip the radiation backward. This readily separates it from the particles, providing higher flexibility in photon manipulation and is useful for particle identification and counting. Here we review recent advances in reversed Cherenkov radiation research, including the first demonstration of backward emission. We also discuss the potential for developing new types of devices, such as ones that pierce invisibility cloaks.

  8. Particle identification by Cherenkov and transition radiation

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, R.S.

    1980-09-01

    The Cherenkov counter has a role as a particle identifier for velocities which are too high for Time-of-Flight to be used, and too low for transition radiation detectors to give a useable signal. In beam lines the compensated differential counter is capable of giving the best resolution, but at high momenta the restriction on the spread of particle directions gives unacceptable limits on the beam acceptance. The transition radiation detectors being developed to identify hadrons at relatively low momentum do not have this restriction and might be used instead. For particles produced in an interaction, the ring imaging type of Cherenkov should give the best coverage for multiparticle events, but a threshold counter is much simpler, cheaper and faster where it can give adequate separation. Again at high values of ..gamma.. the resolution of Cherenkov counters will fail and some form of transition radiation detector will be necessary.

  9. Tachyonic Cherenkov radiation in the absorptive aether

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-14

    Dissipative tachyonic Cherenkov densities are derived and tested by performing a spectral fit to the γ-ray flux of supernova remnant (SNR) RX J1713.7 − 3946, measured over five frequency decades up to 100 TeV. The manifestly covariant formalism of tachyonic Maxwell–Proca radiation fields is developed in the spacetime aether, starting with the complex Lagrangian coupled to dispersive and dissipative permeability tensors. The spectral energy and flux densities of the radiation field are extracted by time averaging, the energy conservation law is derived, and the energy dissipation caused by the complex frequency-dependent permeabilities of the aether is quantified. The tachyonic mass-square in the field equations gives rise to transversally/longitudinally propagating flux components, with differing attenuation lengths determined by the imaginary part of the transversal/longitudinal dispersion relation. The spectral fit is performed with the classical tachyonic Cherenkov flux radiated by the shell-shocked electron plasma of SNR RX J1713.7 − 3946, exhibiting subexponential spectral decay. - Highlights: • Tachyonic Maxwell–Proca radiation fields in a dispersive and dissipative spacetime. • Transversal/longitudinal Poynting flux vector and associated spectral energy density. • Energy dissipation quantified by absorption term in the energy conservation law. • Dissipative Cherenkov densities (classical) and tachyonic attenuation lengths. • Cherenkov energy flux from the shocked electron plasma of SNR RX J1713.7 − 3946.

  10. Characterization of coherent Cherenkov radiation source

    Energy Technology Data Exchange (ETDEWEB)

    Smirnov, A.V.

    2015-01-21

    Engineering formulae for calculation of peak, and spectral brightness of resonant long-range wakefield extractor are given. It is shown that the brightness is dominated by beam density in the slow wave structure and antenna gain of the outcoupling. Far field radiation patterns and brightness of circular and high aspect ratio planar radiators are compared. A possibility to approach diffraction limited brightness is demonstrated. The role of group velocity in designing of the Cherenkov source is analyzed. The approach can be applied for design and characterization of various structure-dominated sources (e.g., wakefield extractors with gratings or dielectrics, or FEL-Cherenkov combined sources) radiating into a free space using an antenna (in microwave to sub-mm wave regions). The high group velocity structures can be also effective as energy dechirpers and for diagnostics of microbunched relativistic electron beams.

  11. Recent progress in silica aerogel Cherenkov radiator

    CERN Document Server

    Tabata, Makoto; Kawai, Hideyuki; Kubo, Masato; Sato, Takeshi

    2012-01-01

    In this paper, we present recent progress in the development of hydrophobic silica aerogel as a Cherenkov radiator. In addition to the conventional method, the recently developed pin-drying method for producing high-refractive-index aerogels with high transparency was studied in detail. Optical qualities and large tile handling for crack-free aerogels were investigated. Sufficient photons were detected from high-performance aerogels in a beam test.

  12. 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.

  13. Detection of atmospheric Cherenkov radiation using solar heliostat mirrors

    CERN Document Server

    Ong, R A

    1996-01-01

    The gamma-ray energy region between 20 and 250 GeV is largely unexplored. Ground-based atmospheric Cherenkov detectors offer a possible way to explore this region, but large Cherenkov photon collection areas are needed to achieve low energy thresholds. This paper discusses the development of a Cherenkov detector using the heliostat mirrors of a solar power plant as the primary collector. As part of this development, we built a prototype detector consisting of four heliostat mirrors and used it to record atmospheric Cherenkov radiation produced in extensive air showers created by cosmic ray particles.

  14. X-ray diffraction radiation in conditions of Cherenkov effect

    NARCIS (Netherlands)

    Tishchenko, A. A.; Potylitsyn, A. P.; Strikhanov, M. N.

    2006-01-01

    X-ray diffraction radiation from ultra-relativistic electrons moving near an absorbing target is considered. The emission yield is found to increase significantly in conditions of Cherenkov effect. (c) 2006 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

    Kimura, Rampei; Tanaka, Takahiro; Yamamoto, Kazuhiro; Yamashita, Yasuho

    2016-09-01

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

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

    CERN Document Server

    Kimura, Rampei; Yamamoto, Kazuhiro; Yamashita, Yasuho

    2016-01-01

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

  17. 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.

  18. Optical and radiographical characterization of silica aerogel for Cherenkov radiator

    CERN Document Server

    Tabata, Makoto; Hatakeyama, Yoshikiyo; Kawai, Hideyuki; Morita, Takeshi; Nishikawa, Keiko

    2012-01-01

    We present optical and X-ray radiographical characterization of silica aerogels with refractive index from 1.05 to 1.07 for a Cherenkov radiator. A novel pin-drying method enables us to produce highly transparent hydrophobic aerogels with high refractive index by shrinking wet-gels. In order to investigate the uniformity in the density (i.e., refractive index) of an individual aerogel monolith, we use the laser Fraunhofer method, an X-ray absorption technique, and Cherenkov imaging by a ring imaging Cherenkov detector in a beam test. We observed an increase in density at the edge of the aerogel tiles, produced by pin-drying.

  19. Characteristics of Cherenkov radiation in naturally occurring ice

    Science.gov (United States)

    Mikkelsen, R. E.; Poulsen, T.; Uggerhøj, U. I.; Klein, S. R.

    2016-03-01

    We revisit the theory of Cherenkov radiation in uniaxial crystals. Historically, a number of flawed attempts have been made at explaining this radiation phenomenon, and a consistent error-free description is nowhere available. We apply our calculation to a large modern day telescope—IceCube. Located in Antarctica, this detector makes use of the naturally occurring ice as a medium to generate Cherenkov radiation. However, due to the high pressure at the depth of the detector site, large volumes of hexagonal ice crystals are formed. We calculate how this affects the Cherenkov radiation yield and angular dependence. We conclude that the effect is small, at most about a percent, and would only be relevant in future high-precision instruments like e.g. Precision IceCube Next Generation Upgrade (PINGU). For radio-Cherenkov experiments which use the presence of a clear Cherenkov cone to determine the arrival direction, any variation in emission angle will directly and linearly translate into a change in apparent neutrino direction. In closing, we also describe a simple experiment to test this formalism and calculate the impact of anisotropy on light yields from lead tungstate crystals as used, for example, in the CMS calorimeter at the CERN LHC.

  20. Characteristics of Cherenkov Radiation in Naturally Occuring Ice

    CERN Document Server

    Mikkelsen, R E; Uggerhøj, U I; Klein, S R

    2016-01-01

    We revisit the theory of Cherenkov radiation in uniaxial crystals. Historically, a number of flawed attempts have been made at explaining this radiation phenomenon and a consistent error-free description is nowhere available. We apply our calculation to a large modern day telescope - IceCube. Being located at the Antarctica, this detector makes use of the naturally occuring ice as a medium to generate Cherenkov radiation. However, due to the high pressure at the depth of the detector site, large volumes of hexagonal ice crystals are formed. We calculate how this affects the Cherenkov radiation yield and angular dependence. We conclude that the effect is small, at most about a percent, and would only be relevant in future high precision instruments like e.g. Precision IceCube Next Generation Upgrade (PINGU). For radio-Cherenkov experiments which use the presence of a clear Cherenkov cone to determine the arrival direction, any variation in emission angle will directly and linearly translate into a change in ap...

  1. Constraints on Lorentz violation from gravitational Cherenkov radiation

    CERN Document Server

    Kostelecky, Alan

    2015-01-01

    Limits on gravitational Cherenkov radiation by cosmic rays are obtained and used to constrain coefficients for Lorentz violation in the gravity sector associated with operators of even mass dimensions, including orientation-dependent effects. We use existing data from cosmic-ray telescopes to obtain conservative two-sided constraints on 80 distinct Lorentz-violating operators of dimensions four, six, and eight, along with conservative one-sided constraints on three others. Existing limits on the nine minimal operators at dimension four are improved by factors of up to a billion, while 74 of our explicit limits represent stringent first constraints on nonminimal operators. Prospects are discussed for future analyses incorporating effects of Lorentz violation in the matter sector, the role of gravitational Cherenkov radiation by high-energy photons, data from gravitational-wave observatories, the tired-light effect, and electromagnetic Cherenkov radiation by gravitons.

  2. Lorentz-invariant formulation of Cherenkov radiation by tachyons

    Science.gov (United States)

    Jones, F. C.

    1972-01-01

    Previous treatments of Cherenkov radiation, electromagnetic and gravitational, by tachyons were in error because the prescription employed to cut off the divergent integral over frequency is not a Lorentz invariant procedure. The resulting equation of motion for the tachyon is therefore not covariant. The proper procedure requires an extended, deformable distribution of charge or mass and yields a particularly simple form for the tachyon's world line, one that could be deduced from simple invariance considerations. It is shown that Cherenkov radiation by tachyons implys their ultimate annihilation with an antitachyon and demonstrates a disturbing property of tachyons, namely the impossibility of specifying arbitrary Cauchy data even in a purely classical theory.

  3. Counting Extra Dimensions Magnetic Cherenkov Radiation from High Energy Neutrinos

    CERN Document Server

    Domokos, Gabor K; Kövesi-Domokos, S; Erdas, Andrea

    2003-01-01

    In theories which require a space of dimension d > 4, there is a natural mechanism of suppressing neutrino masses: while Standard Model fields are confined to a 3-brane, right handed neutrinos live in the bulk. Due to Kaluza-Klein excitations, the effective magnetic moments of neutrinos are enhanced. The effective magnetic moment is a monotonically growing function of the energy of the neutrino: consequently, high energy neutrinos can emit observable amounts of magnetic Cherenkov radiation. By observing the energy dependence of the magnetic Cherenkov radiation, one may be able to determine the number of compactified dimensions.

  4. Detection of atmospheric Cherenkov radiation using solar heliostat mirrors

    Science.gov (United States)

    Ong, R. A.; Bhattacharya, D.; Covault, C. E.; Dixon, D. D.; Gregorich, D. T.; Hanna, D. S.; Oser, S.; Québert, J.; Smith, D. A.; Tümer, O. T.; Zych, A. D.

    1996-10-01

    There is considerable interest world-wide in developing large area atmospheric Cherenkov detectors for ground-based gamma-ray astronomy. This interest stems, in large part, from the fact that the gamma-ray energy region between 20 and 250 GeV is unexplored by any experiment. Atmospheric Cherenkov detectors offer a possible way to explore this region, but large photon collection areas are needed to achieve low energy thresholds. We are developing an experiment using the heliostat mirrors of a solar power plant as the primary collecting element. As part of this development, we built a detector using four heliostat mirrors, a secondary Fresnel lens, and a fast photon detection system. In November 1994, we used this detector to record atmospheric Cherenkov radiation produced by cosmic ray particles showering in the atmosphere. The detected rate of cosmic ray events was consistent with an energy threshold near 1 TeV. The data presented here represent the first detection of atmospheric Cherenkov radiation using solar heliostats viewed from a central tower.

  5. Background radiation measurement with water Cherenkov detectors

    Energy Technology Data Exchange (ETDEWEB)

    Bertou, X., E-mail: bertou@cab.cnea.gov.a [CONICET/CNEA, Centro Atomico Bariloche (Argentina); Observatorio Pierre Auger, Av. San Martin Norte 304, 5613 Malarguee (Argentina)

    2011-05-21

    Water Cherenkov Detectors have the nice property of being mostly calorimeters for cosmic ray induced electrons and photons, while providing a clear signal for muons. At large energy deposited in the detector, they observe small extended air showers. This makes them interesting detectors to study the background of cosmic ray secondaries. Using low threshold scaler counters, one can follow the flux of cosmic rays on top of the atmosphere, and/or study atmospheric effects on the cosmic ray shower development. In this paper, background data from the Pierre Auger Observatory are presented. These data are searched for short time-scale variation (one second scale, as expected from Gamma Ray Bursts), and larger time-scale variations, showing modulation effects due to Solar activity (Forbush decreases). Rapid changes in the background flux are also observed during the crossing of storms over the 3000 km{sup 2} of the ground array.

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

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Zhou, Binbin

    2010-01-01

    the dispersive wave. Finally, an investigation of recent experimental results uncovers a four-wave-mixing phenomenon related to Cherenkov radiation that is an additional generation mechanism of long-wavelength radiation that can occur during soliton compression. We discuss the conditions that lead......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....... 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...

  7. Corrugated capillary as THz Cherenkov Smith-Purcell radiator

    Science.gov (United States)

    Lekomtsev, K. V.; Aryshev, A. S.; Tishchenko, A. A.; Ponomarenko, A. A.; Sukharev, V. M.; Terunuma, N.; Urakawa, J.; Strikhanov, M. N.

    2016-07-01

    In this article we discussed Particle In Cell electromagnetic simulations and mechanical design of dielectric capillaries that produce THz Cherenkov Smith-Purcell radiation (ChSPR), arising when a femtosecond electron multi-bunch beam propagates through corrugated and non-corrugated dielectric capillaries with metallic radiation reflectors. We investigated the influence of the four-bunch beam on the SPR field spectrum and on the ChSPR power spectrum, and the influence of the non-central beam propagation on the ChSPR power spectrum. We also discussed the design and assembly of the capillaries, constructed as sets of cylindrical rings.

  8. 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

  9. Coherent Cherenkov radiation as an intense THz source

    Science.gov (United States)

    Bleko, V.; Karataev, P.; Konkov, A.; Kruchinin, K.; Naumenko, G.; Potylitsyn, A.; Vaughan, T.

    2016-07-01

    Diffraction and Cherenkov radiation of relativistic electrons from a dielectric target has been proposed as mechanism for production of intense terahertz (THz) radiation. The use of an extremely short high-energy electron beam of a 4th generation light source (X-ray free electron laser) appears to be very promising. A moderate power from the electron beam can be extracted and converted into THz radiation with nearly zero absorption losses. The initial experiment on THz observation will be performed at CLARA/VELA FEL test facility in the UK to demonstrate the principle to a wider community and to develop the radiator prototype. In this paper, we present our theoretical predictions (based on the approach of polarization currents), which provides the basis for interpreting the future experimental measurements. We will also present our hardware design and discuss a plan of the future experiment.

  10. Relativistic Cherenkov radiation in a magneto-dielectric media

    Directory of Open Access Journals (Sweden)

    2016-09-01

    Full Text Available In this paper, relativistic Cherenkov radiation was studied in a 3-D magneto-dielectric medium. Electric permittivity and magnetic permeability of the medium as functions of frequency, are assumed to satisfy Kramers- Kronig equations. A new interaction Hamiltonian, which is different from Hamiltonian term in non-relativistic state, was introduced by the quantized vector potential field and particle field operator obtained from the second quantization method. The rate of electron energy dissipation was calculated using Fermi’s golden rule.

  11. Modified energy-momentum conservation laws and vacuum Cherenkov radiation

    CERN Document Server

    Carmona, J M; Romeo, B

    2014-01-01

    We present a general parametrization for the leading order terms in a momentum power expansion of a non-universal Lorentz-violating, but rotational invariant, kinematics and its implications for two-body decay thresholds. The considered framework includes not only modified dispersion relations for particles, but also modified energy-momentum conservation laws, something which goes beyond effective field theory. As a particular and relevant example, bounds on the departures from special relativistic kinematics from the non-observation of vacuum Cherenkov radiation are discussed and compared with those obtained within the effective field theory scenario.

  12. The HERMES dual-radiator ring imaging Cherenkov detector

    Science.gov (United States)

    Akopov, N.; Aschenauer, E. C.; Bailey, K.; Bernreuther, S.; Bianchi, N.; Capitani, G. P.; Carter, P.; Cisbani, E.; De Leo, R.; De Sanctis, E.; De Schepper, D.; Djordjadze, 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, W.-D.; 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.; Zohrabian, H.; Zhang, L. F.

    2002-03-01

    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 4F 10, 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.

  13. 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.

  14. Intense Cherenkov-type terahertz electromagnetic radiation from ultrafast laser-plasma interaction

    Institute of Scientific and Technical Information of China (English)

    Hu Qiang-Lin; Liu Shi-Bing; Li Wei

    2008-01-01

    A Cherenkov-type terahertz electromagnetic radiation is revealed, which results efficiently from the collective effects in the time-domain of ultrafast pulsed electron current produced by ultrafast intense laser-plasma interaction.The emitted pulse waveform and spectrum, and the dependence of laser pulse parameters on the structure of the radiation field are investigated numerically. The condition of THz radiation generation in this regime and Cherenkov geometry of the radiation field are studied analytically.

  15. Vacuum Cherenkov radiation and bremsstrahlung from disformal couplings

    Science.gov (United States)

    van de Bruck, Carsten; Burrage, Clare; Morrice, Jack

    2016-08-01

    The simplest way to modify gravity is to extend the gravitational sector to include an additional scalar degree of freedom. The most general metric that can be built in such a theory includes disformal terms, so that standard model fields move on a metric which is the sum of the space time metric and a tensor constructed from first derivatives of the scalar. In such a theory gravitational waves and photons can propagate at different speeds, and these can in turn be different from the maximum speed limit for matter particles. In this work we show that disformal couplings can cause charged particles to emit Cherenkov radiation and bremsstrahlung apparently in vacuum, depending on the background evolution of the scalar field. We discuss the implications of this for observations of cosmic rays, and the constraints that arise for models of dark energy with disformal couplings.

  16. Vacuum Cherenkov radiation and bremsstrahlung from disformal couplings

    CERN Document Server

    van de Bruck, Carsten; Morrice, Jack

    2016-01-01

    The simplest way to modify gravity is to extend the gravitational sector to include an additional scalar degree of freedom. The most general metric that can be built in such a theory includes disformal terms, so that standard model fields move on a metric which is the sum of the space time metric and a tensor constructed from first derivatives of the scalar. In such a theory gravitational waves and photons can propagate at different speeds, and these can in turn be different from the maximum speed limit for matter particles. In this work we show that disformal couplings can cause charged particles to emit Cherenkov radiation and bremsstrahlung apparently in vacuum, depending on the background evolution of the scalar field. We discuss the implications of this for observations of cosmic rays, and the constraints that arise for models of dark energy with disformal couplings.

  17. Cherenkov Radiation from $e^+e^-$ Pairs and Its Effect on $\

    CERN Document Server

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

    2005-01-01

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

  18. 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.

  19. Status of non-destructive bunch length measurement based on coherent Cherenkov radiation

    CERN Document Server

    Zhang, Jianbing; Yu, Tiemin; Deng, Haixiao; Shkitov, Dmitry; Shevelev, Mikhail; Naumenko, Gennady; Potylitsyn, Alexander

    2013-01-01

    As a novel non-destructive bunch length diagnostic of the electron beam, an experimental observation of the coherent Cherenkov radiation generated from a dielectric caesium iodide crystal with large spectral dispersion was proposed for the 30MeV femtosecond linear accelerator at Shanghai Institute of Applied Physics (SINAP). In this paper, the theoretical design, the experimental setup, the terahertz optics, the first angular distribution observations of the coherent Cherenkov radiation, and the future plans are presented.

  20. Cherenkov radiation with massive, C P T -violating photons

    Science.gov (United States)

    Colladay, Don; McDonald, Patrick; Potting, Robertus

    2016-06-01

    The source of C P T violation in the photon sector of the Standard Model Extension arises from a Chern-Simons-like contribution that involves a coupling to a fixed background vector field kAF μ . These Lorentz- and C P T -violating photons have well-known theoretical issues that arise from missing states at low momenta when kAF μ is timelike. In order to make the theory consistent, a tiny mass for the photon can be introduced, well below current experimental bounds. The implementation of canonical quantization can then be implemented as in the C P T -preserving case by using the Stückelberg mechanism. We explicitly construct a covariant basis of properly normalized polarization vectors at fixed three-momentum satisfying the momentum space field equations, in terms of which the vector field can be expanded. As an application of the theory, we calculate the Cherenkov radiation rate for the case of purely timelike kAF μ and find a radiation rate at high energies that has a contribution that does not depend on the mass used to regulate the photons.

  1. Cherenkov Radiation with Massive, CPT-violating Photons

    CERN Document Server

    Colladay, Don; Potting, Robertus

    2016-01-01

    The source of CPT-violation in the photon sector of the Standard Model Extension arises from a Chern-Simons-like contribution that involves a coupling to a fixed background vector field $k_{AF}^\\mu$. These Lorentz- and CPT-violating photons have well-known theoretical issues that arise from missing states at low momenta when $k_{AF}^\\mu$ is timelike. In order to make the theory consistent, a tiny mass for the photon can be introduced, well below current experimental bounds. The implementation of canonical quantization can then be implemented as in the CPT-preserving case by using the St\\"uckelberg mechanism. We explicitly construct a covariant basis of properly-normalized polarization vectors at fixed three-momentum satisfying the momentum space field equations, in terms of which the vector field can be expanded. As an application of the theory, we calculate the Cherenkov radiation rate for the case of purely timelike $k_{AF}^\\mu$, and find a radiation rate at high energies that has a contribution that does n...

  2. Quantum calculation of the Vavilov-Cherenkov radiation by twisted electrons

    Science.gov (United States)

    Ivanov, I. P.; Serbo, V. G.; Zaytsev, V. A.

    2016-05-01

    We present a detailed quantum electrodynamical description of Vavilov-Cherenkov radiation emitted by a relativistic twisted electron in the transparent medium. Simple expressions for the spectral and spectral-angular distributions as well as for the polarization properties of the emitted radiation are obtained. Unlike the plane-wave case, the twisted electron produces radiation within the annular angular region, with enhancement towards its boundaries. Additionally, the emitted photons can have linear polarization not only in the scattering plane but also in the orthogonal direction. We find that the Vavilov-Cherenkov radiation emitted by an electron in a superposition of two vortex states exhibits a strong azimuthal asymmetry. Thus, the Vavilov-Cherenkov radiation offers itself as a convenient diagnostic tool of such electrons and complements the traditional microscopic imaging.

  3. Quantum calculation of the Vavilov-Cherenkov radiation by twisted electrons

    CERN Document Server

    Ivanov, I P; Zaytsev, V A

    2016-01-01

    We present the detailed quantum electrodynamical description of Vavilov-Cherenkov radiation emitted by a relativistic twisted electron in the transparent medium. Simple expressions for the spectral and spectral-angular distributions as well as for the polarization properties of the emitted radiation are obtained. Unlike the plane-wave case, the twisted electron produces radiation within the annular angular region, with enhancement towards its boundaries. Additionally, the emitted photons can have linear polarization not only in the scattering plane but also in the orthogonal direction. We find that the Vavilov-Cherenkov radiation emitted by an electron in a superposition of two vortex states exhibits a strong azimuthal asymmetry. Thus, the Vavilov-Cherenkov radiation offers itself as a convenient diagnostic tool of such electrons and complements the traditional microscopic imaging.

  4. About Modeling the Excitation Conditions of Cherenkov and Diffraction Radiations in Periodic Metal-dielectric Structures

    Directory of Open Access Journals (Sweden)

    G.S. Vorobjov

    2015-06-01

    Full Text Available General procedure for modeling the excitation conditions of Cherenkov and diffraction radiations in periodic metal-dielectric structures is described. It is based on the representation of the electron beam space-charge wave in the form of a dielectric waveguide surface-wave. On the experimental facility of millimeter-wave the basic modes of excitation conditions of spatial harmonics of the Cherenkov and diffraction radiations are simulated. The method is tested by comparing the numerical analysis and experimental results on the layout of the device of the orotron type - generator of diffraction radiation.

  5. A Cherenkov Radiation Detector with High Density Aerogels

    CERN Document Server

    Cremaldi, Lucien; Sonnek, Peter; Summers, Donald J; Reidy, Jim

    2009-01-01

    We have designed a threshold Cherenkov detector at the Rutherford-Appleton Laboratory to identify muons with momenta between 230 and 350 MeV/c. We investigated the properties of three aerogels for the design. The nominal indexes of refraction were n = 1.03, 1.07, 1.12, respectively. Two of the samples are of high density aerogel not commonly used for Cherenkov light detection. We present results of an examination of some optical properties of the aerogel samples and present basic test beam results.

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

    CERN Document Server

    Baryshevsky, Vladimir

    2016-01-01

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

  7. Diagnostics of Electron Beams Based on Cherenkov Radiation in an Optical Fiber

    Science.gov (United States)

    Vukolov, A. V.; Novokshonov, A. I.; Potylitsyn, A. P.; Uglov, S. R.

    2017-02-01

    The use of an optical fiber in which Cherenkov radiation is generated instead of a metal wire for scanning a beam profile allows a compact and noise-proof device for diagnostics of charged particle beams in a wide energy range to be developed. Results of experimental investigation of the yield of Vavilov-Cherenkov radiation generated in optical fibers with thickness in the range from 0.125 to 1 mm by electrons with energy of 5.7 MeV are presented.

  8. On gravitational wave-Cherenkov radiation from photons when passing through diffused dark matters

    Science.gov (United States)

    Yi, Shu-Xu

    2017-03-01

    Analogous to Cherenkov radiation, when a particle moves faster than the propagation velocity of gravitational wave in matter (v > cg), we expect gravitational wave-Cherenkov radiation (GWCR). In the situation that a photon travels across diffuse dark matters, the GWCR condition is always satisfied, photon will thence lose its energy all along the path. This effect has long been ignored in the practice of astrophysics and cosmology without justification with serious calculation. We study this effect for the first time, and shows that this energy loss time of the photon is far longer than the Hubble time and therefore justify the practice of ignoring this effect in the context of astrophysics.

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

    CERN Document Server

    Ullaland, O

    2011-01-01

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

  10. Cherenkov Video Imaging Allows for the First Visualization of Radiation Therapy in Real Time

    Energy Technology Data Exchange (ETDEWEB)

    Jarvis, Lesley A., E-mail: Lesley.a.jarvis@hitchcock.org [Department of Medicine, Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire (United States); Norris Cotton Cancer Center at the Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire (United States); Zhang, Rongxiao [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire (United States); Gladstone, David J. [Department of Medicine, Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire (United States); Norris Cotton Cancer Center at the Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire (United States); Jiang, Shudong [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire (United States); Hitchcock, Whitney [Geisel School of Medicine at Dartmouth College, Hanover, New Hampshire (United States); Friedman, Oscar D.; Glaser, Adam K.; Jermyn, Michael [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire (United States); Pogue, Brian W. [Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire (United States); Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire (United States)

    2014-07-01

    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.

  11. Stimulated excitation of resonant Cherenkov radiation at a large number of neighbouring waveguide modes

    CERN Document Server

    Grigoryan, L Sh; Khachatryan, H F; Grigoryan, M L

    2012-01-01

    The resonance Cherenkov radiation generated from a train of equally-spaced unidimensional electron bunches travelling along the axis of a hollow channel inside an infinite cylindrical waveguide filled with (weakly dispersing) transparent dielectric has been investigated. It was shown that its excitation might be stimulated at a large number of neighboring modes of the waveguide. A visual explanation of this effect is given and the possibility of its observation in the range of terahertz radiation is discussed.

  12. Vacuum Cherenkov Radiation In Quantum Electrodynamics With High-Energy Lorentz Violation

    CERN Document Server

    Anselmi, Damiano

    2011-01-01

    We study phenomena predicted by a renormalizable, CPT invariant extension of the Standard Model that contains higher-dimensional operators and violates Lorentz symmetry explicitly at energies greater than some scale Lambda_{L}. In particular, we consider the Cherenkov radiation in vacuo. In a rather general class of dispersion relations, there exists an energy threshold above which radiation is emitted. The threshold is enhanced in composite particles by a sort of kinematic screening mechanism. We study the energy loss and compare the predictions of our model with known experimental bounds on Lorentz violating parameters and observations of ultrahigh-energy cosmic rays. We argue that the scale of Lorentz violation Lambda_{L} (with preserved CPT invariance) can be smaller than the Planck scale, actually as small as 10^{14}-10^{15} GeV. Our model also predicts the Cherenkov radiation of neutral particles.

  13. Photonic chip based optical frequency comb using soliton induced Cherenkov radiation

    CERN Document Server

    Brasch, Victor; Geiselmann, Michael; Lihachev, Grigoriy; Pfeiffer, Martin H P; Gorodetsky, Michael L; Kippenberg, Tobias J

    2014-01-01

    By continuous wave pumping of a dispersion engineered, planar silicon nitride microresonator, continuously circulating, sub-30fs short temporal dissipative solitons are generated, that correspond to pulses of 6 optical cycles and constitute a coherent optical frequency comb in the spectral domain. Emission of soliton induced Cherenkov radiation caused by higher order dispersion broadens the spectral bandwidth to 2/3 of an octave, sufficient for self referencing, in excellent agreement with recent theoretical predictions and the broadest coherent microresonator frequency comb generated to date. The ability to preserve coherence over a broad spectral bandwidth using soliton induced Cherenkov radiation marks a critical milestone in the development of planar optical frequency combs, enabling on one hand application in e.g. coherent communications, broadband dual comb spectroscopy and Raman spectral imaging, while on the other hand significantly relaxing dispersion requirements for broadband microresonator frequen...

  14. Cherenkov radiation and dielectric based accelerating structures: Wakefield generation, power extraction and energy transfer efficiency

    Science.gov (United States)

    Kanareykin, Alexei

    2010-06-01

    We present here our recent results of the Euclid Techlabs LLC/Argonne National Laboratory/St.Petersburg Electrotechnical University "LETI" collaboration on wakefield high energy acceleration of electron bunches in dielectric based accelerating structures. This program concentrates primarily on Cherenkov radiation studies providing efficient high energy generation aimed at a future 1 TeV collider. We report here on recent experiments in high power Cherenkov radiation and corresponding dielectric material developments and characterizations. Progress in diamond, quartz and microwave low-loss ceramic structure development in GHz and THz frequency ranges is presented. Beam Breakup effects and transverse bunch stability are discussed as well. We e report on recent progress on tunable dielectric based structure development. A special subject of our paper is transformer ratio enhancement schemes providing energy transfer efficiency for the dielectric based wakefield acceleration.

  15. 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.

  16. Cherenkov radiation in a surface wave accelerator based on silicon carbide

    Science.gov (United States)

    Wang, Tianhong; Khudik, Vladimir; Shvets, Gennady

    2016-10-01

    We report on our theoretical investigations of Cherenkov-type emission of surface phonon polaritons (SPPs) by relativistic electron bunches. The polaritons are confined by a planar waveguide comprised of two SiC slabs separated by an air gap. The SPPs are generated in the spectral range known as the reststrahlen band, where the dielectric permittivity of SiC is negative. Two surface modes of the radiation are analyzed: the longitudinal (accelerating) and the transverse (deflecting) ones. Both form Cherenkov cones that are different in the magnitude of the cone angle and the central frequency. However, both exhibits rapid spatial oscillations and beats behind the moving charge. Moreover, the longitudinal mode forms a reversed Cherenkov radiation cone due the negative group velocity for sufficiently small air gaps, but the transverse mode does not. The wakefield acceleration of electron beam inside the structure is also studied. Transverse instabilities and BBU effects can be suppressed by flat driver beam, meanwhile the longitudinal mode can support accelerating fields >1 GeV.

  17. Coherent Cherenkov radiation and laser oscillation in a photonic crystal

    CERN Document Server

    Denis, T; Lee, J H H; van der Meer, R; Strooisma, A; van der Slot, P J M; Vos, W L; Boller, K J

    2016-01-01

    We demonstrate that photonic crystals can be used to generate powerful and highly coherent laser radiation when injecting a beam of free electrons. Using theoretical investigations we present the startup dynamics and coherence properties of such laser, in which gain is provided by matching the optical phase velocity in the photonic crystal to the velocity of the electron beam.

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

    Science.gov (United States)

    2015-07-01

    REPORT DOCUMENTATION PAGE Form Approved OMB No. 0704-0188 Public reporting burden for this collection of information is estimated to...energy  cuts.    This  study  is   documented  in  our   peer-­‐reviewed  paper  called  “Investigation  of  active...proton  therapy  in   radiation  oncology  applications;  and  a  group  of  Los  Alamos  National  Laboratory  ( LANL

  19. Cherenkov imaging during volumetric modulated arc therapy for real-time radiation beam tracking and treatment response monitoring

    Science.gov (United States)

    Andreozzi, Jacqueline M.; Zhang, Rongxiao; Glaser, Adam K.; Gladstone, David J.; Jarvis, Lesley A.; Pogue, Brian W.

    2016-03-01

    External beam radiotherapy utilizes high energy radiation to target cancer with dynamic, patient-specific treatment plans. The otherwise invisible radiation beam can be observed via the optical Cherenkov photons emitted from interaction between the high energy beam and tissue. Using a specialized camera-system, the Cherenkov emission can thus be used to track the radiation beam on the surface of the patient in real-time, even for complex cases such as volumetric modulated arc therapy (VMAT). Two patients undergoing VMAT of the head and neck were imaged and analyzed, and the viability of the system to provide clinical feedback was established.

  20. Design optimization of the proximity focusing RICH with dual aerogel radiator using a maximum-likelihood analysis of Cherenkov rings

    Science.gov (United States)

    Pestotnik, R.; Križan, P.; Korpar, S.; Iijima, T.

    2008-09-01

    The use of a sequence of aerogel radiators with different refractive indices in a proximity focusing Cherenkov ring imaging detector has been shown to improve the resolution of the Cherenkov angle. In order to obtain further information on the capabilities of such a detector, a maximum-likelihood analysis has been performed on simulated data, with the simulation being appropriate for the upgraded Belle detector. The results show that by using a sequence of two aerogel layers with different refractive indices, the K/π separation efficiency is improved in the kinematic region above 3 GeV/ c. In the low momentum region, the focusing configuration (with n1 and n2 chosen such that the Cherenkov rings from different aerogel layers at 4 GeV/ c overlap) shows a better performance than the defocusing one (where the two Cherenkov rings are well separated).

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

    CERN Document Server

    Martínez-Huerta, H

    2016-01-01

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

  2. 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.

  3. Recording Vavilov-Cherenkov radiation in a linear accelerator using a picosecond streak camera

    Science.gov (United States)

    Vorob'ev, N. S.; Gornostaev, P. B.; Gurov, S. M.; Dorokhov, V. L.; Zubko, A. E.; Lozovoi, V. I.; Meshkov, O. I.; Nikiforov, D. A.; Smirnov, A. V.; Shashkov, E. V.; Schelev, M. Ya

    2016-09-01

    Using a picosecond image converter camera with a linear sweep (PS-1/S1 streak camera developed at GPI RAS, Moscow), we have measured temporal parameters of Vavilov-Cherenkov radiation pulses. The radiation was generated by relativistic electrons passing through a quartz cone mounted on the axis of a vacuum chamber of a linear accelerator, which is a part of the VEPP-5 injection complex at the Budker Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences (BINP SB RAS, Novosibirsk). The data obtained in these experiments provide an insight into the processes of formation of electron bunches and their 'quality' in a linear accelerator prior to injection of electrons into the accumulator-cooler. A conclusion is made regarding the advisability of streak camera application in tuning the linear accelerators for optimisation of electron bunch parameters.

  4. 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...... efficiency is up to 25%. Thus, optical Cherenkov waves formed with cascaded nonlinearities could become an efficient source of energetic near- to mid-IR few-cycle pulses....

  5. Design and Experimental Demonstration of Cherenkov Radiation Source Based on Metallic Photonic Crystal Slow Wave Structure

    Science.gov (United States)

    Fu, Tao; Yang, Zi-Qiang; Ouyang, Zheng-Biao

    2016-11-01

    This paper presents a kind of Cherenkov radiation source based on metallic photonic crystal (MPC) slow-wave structure (SWS) cavity. The Cherenkov source designed by linear theory works at 34.7 GHz when the cathode voltage is 550 kV. The three-dimensional particle-in-cell (PIC) simulation of the SWS shows the operating frequency of 35.56 GHz with a single TM01 mode is basically consistent with the theoretically one under the same parameters. An experiment was implemented to testify the results of theory and PIC simulation. The experimental system includes a cathode emitting unit, the SWS, a magnetic system, an output antenna, and detectors. Experimental results show that the operating frequency through detecting the retarded time of wave propagation in waveguides is around 35.5 GHz with a single TM01 mode and an output power reaching 54 MW. It indicates that the MPC structure can reduce mode competition. The purpose of the paper is to show in theory and in preliminary experiment that a SWS with PBG can produce microwaves in TM01 mode. But it still provides a good experimental and theoretical foundation for designing high-power microwave devices.

  6. Cherenkov radiation dosimetry in water tanks - video rate imaging, tomography and IMRT & VMAT plan verification

    Science.gov (United States)

    Pogue, Brian W.; Glaser, Adam K.; Zhang, Rongxiao; Gladstone, David J.

    2015-01-01

    This paper presents a survey of three types of imaging of radiation beams in water tanks for comparison to dose maps. The first was simple depth and lateral profile verification, showing excellent agreement between Cherenkov and planned dose, as predicted by the treatment planning system for a square 5cm beam. The second approach was 3D tomography of such beams, using a rotating water tank with camera attached, and using filtered backprojection for the recovery of the 3D volume. The final presentation was real time 2D imaging of IMRT or VMAT treatments in a water tank. In all cases the match to the treatment planning system was within what would be considered acceptable for clinical medical physics acceptance.

  7. Very high energy emission of Crab-like pulsars driven by the Cherenkov drift radiation

    CERN Document Server

    Osmanov, Z

    2015-01-01

    In this paper we study the generation of very high energy (VHE) emission in Crab-like pulsars driven by means of the feedback of Cherenkov drift waves on distribution of magnetospheric electrons. We have found that the unstable Cherenkov drift modes lead to the quasi-linear diffusion (QLD), keeping the pitch angles from vanishing, which in turn, maintains the synchrotron mechanism. Considering the Crab-like pulsars it has been shown that the growth rate of the Cherenkov drift instability (ChDI) is quite high, indicating high efficiency of the process. Analyzing the mechanism for the typical parameters we have found that the Cherenkov drift emission from the extreme UV to hard $X$-rays is strongly correlated with the VHE synchrotron emission in the GeV band.

  8. Generation of THz-radiation in the Cherenkov decelerating structure with planar geometry at frequency ∼ 0.675 THz

    Science.gov (United States)

    Ashanin, I. A.; Polozov, S. M.

    2016-07-01

    One of the ways to generate THz-radiation is by the relativistic electron bunches travelling through Cherenkov decelerating dielectric filled capillary channel. Sapphire or other dielectric materials can be used for the internal surface coating of the capillary. Relativistic electron bunches of ∼100 µm in diameter and pulse durations of 1 ps or shorter are capable to produce substantial power of THz-radiation. The aperture of Cherenkov decelerating structure should be comparable with the sub-mm wavelength (0.05-3 mm). Such type of decelerating system allows providing of the wide range of operating parameters at the various geometrical sizes. But it is necessary to consider that such capillaries are difficult in production as there is a requirement to drill a small aperture in a long crystal of high hardness but brittle. In this regard it would be desirable to offer transition option from the axial to the planar geometry. Furthermore the ribbon beam has some advantages as focusing at low energies and possessing smaller expansion in the drift space. The authors present design and results of electrodynamics study of the decelerating planar dielectric filling Cherenkov channel at frequency 0.675 THz in this article. It is also delivered characteristic comparison with axial geometry channel. A horn antenna attached to such channel at 0.675 THz resonant frequency is considered.

  9. A search for the analogue to Cherenkov radiation by high energy neutrinos at superluminal speeds in ICARUS

    CERN Document Server

    Antonello, M.; Baibussinov, B.; Baldo Ceolin, M.; Benetti, P.; Calligarich, E.; Canci, N.; Carbonara, F.; Centro, S.; Cesana, A.; Cieslik, K.; Cline, D.B.; Cocco, A.G.; Dabrowska, A.; Dequal, D.; Dermenev, A.; Dolfini, R.; Farnese, C.; Fava, A.; Ferrari, A.; Fiorillo, G.; Gibin, D.; Gigli Berzolari, A.; Gninenko, S.; Guglielmi, A.; Haranczyk, M.; Holeczek, J.; Ivashkin, A.; Kisiel, J.; Kochanek, I.; Lagoda, J.; Mania, S.; Mannocchi, G.; Menegolli, A.; Meng, G.; Montanari, C.; Otwinowski, S.; Periale, L.; Piazzoli, A.; Picchi, P.; Pietropaolo, F.; Plonski, P.; Rappoldi, A.; Raselli, G.L.; Rossella, M.; Rubbia, C.; Sala, P.R.; Scantamburlo, E.; Scaramelli, A.; Segreto, E.; Sergiampietri, F.; Stefan, D.; Stepaniak, J.; Sulej, R.; Szarska, M.; Terrani, M.; Varanini, F.; Ventura, S.; Vignoli, C.; Wang, H.; Yang, X.; Zalewska, A.; Zaremba, K.; Cohen, A.

    2012-01-01

    The OPERA collaboration [1] has claimed evidence of superluminal propagation between CERN and the LNGS with . We find that the neutrino energy distribution of the ICARUS events in LAr agrees with the expectations from the Monte Carlo predictions from an unaffected energy distribution of beam from CERN. Our results therefore refute a superluminal interpretation of the OPERA result according to the Cohen and Glashow prediction [2] for a weak currents analog to Cherenkov radiation. In particular no events with a superluminal Cherenkov like e+e- pair or gamma emission have been directly observed inside the fiducial volume of the "bubble chamber like" ICARUS TPC-LAr detector, setting much stricter limits to the value of delta comparable with the one due to the observations from the SN1987A.

  10. Cherenkov radiation conversion and collection considerations for a gamma bang time/reaction history diagnostic for the NIF.

    Science.gov (United States)

    Herrmann, Hans W; Mack, Joseph M; Young, Carlton S; Malone, Robert M; Stoeffl, Wolfgang; Horsfield, Colin J

    2008-10-01

    Bang time and reaction history measurements are fundamental components of diagnosing inertial confinement fusion (ICF) implosions and will be essential contributors to diagnosing attempts at ignition on the National Ignition Facility (NIF). Fusion gammas provide a direct measure of fusion interaction rate without being compromised by Doppler spreading. Gamma-based gas Cherenkov detectors that convert fusion gamma rays to optical Cherenkov photons for collection by fast recording systems have been developed and fielded at Omega. These systems have established their usefulness in illuminating ICF physics in several experimental campaigns. Bang time precision better than 25 ps has been demonstrated, well below the 50 ps accuracy requirement defined by the NIF system design requirements. A comprehensive, validated numerical study of candidate systems is providing essential information needed to make a down selection based on optimization of sensitivity, bandwidth, dynamic range, cost, and NIF logistics. This paper presents basic design considerations arising from the two-step conversion process from gamma rays to relativistic electrons to UV/visible Cherenkov radiation.

  11. Monte Carlo simulation of the Cherenkov radiation emitted by TeO{sub 2} crystal when crossed by cosmic muons

    Energy Technology Data Exchange (ETDEWEB)

    Casali, N., E-mail: nicola.casali@gmail.com [Dipartimento di Scienze Fisiche e Chimiche, Università degli studi dell' Aquila, Coppito (AQ) (Italy); Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso, Assergi (AQ) (Italy); Bellini, F. [Sapienza Università di roma, P.le A. Moro 2, Roma (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, Roma (Italy); Dafinei, I. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, Roma (Italy); Marafini, M. [Museo Storico della Fisisca e Centro Studi e Ricerche “Enrico Fermi“, Piazza del Viminale 1, Roma (Italy); Morganti, S.; Orio, F.; Pinci, D.; Vignati, M.; Voena, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Roma, P.le A. Moro 2, Roma (Italy)

    2013-12-21

    TeO{sub 2} crystals are currently used as bolometric detectors in experiments searching for the neutrinoless double beta decay of {sup 130}Te. The extreme rarity of the studied signal forces the experiments to reach an ultra low background level. The main background source is represented by α particles emitted by radioactive contaminants placed in the materials that compose and surround the detector. Recent measurements show that a particle discrimination in TeO{sub 2} bolometers detecting the light emitted by β/γ particles is possible, opening the possibility to make large improvements in the performance of experiments based on this kind of materials. In order to understand the nature of this light emission a measurement at room temperature with TeO{sub 2} crystals was performed. According to these results, the detected light was compatible with the Cherenkov emission, even though the scintillation hypothesis could not be discarded. In this work a Monte Carlo (MC) simulation of the Cherenkov radiation emitted by TeO{sub 2} crystal when crossed by cosmic muons was performed. The data from MC and the room temperature measurement are perfectly compatible and prove that the Cherenkov light is the only component of the light yield of TeO{sub 2} crystals.

  12. Statistical properties of Cherenkov and quasi-Cherenkov superradiance

    CERN Document Server

    Anishchenko, S V

    2016-01-01

    We consider the effects of shot noise and particle energy spread on statistical properties of Cherenkov and quasi-Cherenkov superradiance emitted by a relativistic electron beam. In the absence of energy spread, we have found the root-mean-square deviations of both peak radiated power and instability growth time as a function of the number of particles. It is shown that energy spread can lead to a sharp drop in the radiated power of Cherenkov and quasi-Cherenkov superradiance at high currents.

  13. Video-rate optical dosimetry and dynamic visualization of IMRT and VMAT treatment plans in water using Cherenkov radiation

    Energy Technology Data Exchange (ETDEWEB)

    Glaser, Adam K., E-mail: Adam.K.Glaser@dartmouth.edu, E-mail: Brian.W.Pogue@dartmouth.edu; Andreozzi, Jacqueline M.; Davis, Scott C. [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); Pogue, Brian W., E-mail: Adam.K.Glaser@dartmouth.edu, E-mail: Brian.W.Pogue@dartmouth.edu [Department of Physics and Astronomy and Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755 (United States); Fox, Colleen J.; Gladstone, David J. [Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03766 (United States)

    2014-06-15

    Purpose: A novel technique for optical dosimetry of dynamic intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) plans was investigated for the first time by capturing images of the induced Cherenkov radiation in water. Methods: A high-sensitivity, intensified CCD camera (ICCD) was configured to acquire a two-dimensional (2D) projection image of the Cherenkov radiation induced by IMRT and VMAT plans, based on the Task Group 119 (TG-119) C-Shape geometry. Plans were generated using the Varian Eclipse treatment planning system (TPS) and delivered using 6 MV x-rays from a Varian TrueBeam Linear Accelerator (Linac) incident on a water tank doped with the fluorophore quinine sulfate. The ICCD acquisition was gated to the Linac target trigger pulse to reduce background light artifacts, read out for a single radiation pulse, and binned to a resolution of 512 × 512 pixels. The resulting videos were analyzed temporally for various regions of interest (ROI) covering the planning target volume (PTV) and organ at risk (OAR), and summed to obtain an overall light intensity distribution, which was compared to the expected dose distribution from the TPS using a gamma-index analysis. Results: The chosen camera settings resulted in 23.5 frames per second dosimetry videos. Temporal intensity plots of the PTV and OAR ROIs confirmed the preferential delivery of dose to the PTV versus the OAR, and the gamma analysis yielded 95.9% and 96.2% agreement between the experimentally captured Cherenkov light distribution and expected TPS dose distribution based upon a 3%/3 mm dose difference and distance-to-agreement criterion for the IMRT and VMAT plans, respectively. Conclusions: The results from this initial study demonstrate the first documented use of Cherenkov radiation for video-rate optical dosimetry of dynamic IMRT and VMAT treatment plans. The proposed modality has several potential advantages over alternative methods including the real

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

    Directory of Open Access Journals (Sweden)

    Tiago A. Morgado

    2015-06-01

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

  15. 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....

  16. The Non-Imaging CHErenkov (NICHE) Array: A TA/TALE extension using Cherenkov radiation to measure Cosmic Ray Composition to sub-PeV energies

    Science.gov (United States)

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

    2017-01-01

    Co-sited with the Telescope Array (TA) Low Energy (TALE) extension, the Non-Imaging CHErenkov (NICHE) Array will measure the flux and nuclear composition evolution of cosmic rays (CRs) from below 1 PeV to 1 EeV in its eventual full deployment. NICHE will co-measure CR air showers with TA/TALE and will initially be deployed to observe events simultaneously with the TALE telescopes acting in imaging-Cherenkov mode, providing the first hybrid-Cherenkov (simultaneous imaging and non-imaging Cherenkov) measurements of CRs in the Knee region of the CR energy spectrum. NICHE uses easily deployable detectors to measure the amplitude and time-spread of the air-shower Cherenkov signal to achieve an event-by-event measurement of Xmax and energy, each with excellent resolution. First generation detectors are under construction and will form an initial prototype array (jNICHE) that will be deployed in early 2017 at the TA/TALE site. In this talk, the NICHE design, array performance, jNICHE development, and status will be discussed as well as NICHE's ability to measure the cosmic ray nuclear composition as a function of energy.

  17. Influence of slowing down in the radiator on the Cherenkov radiation angular distributions from relativistic heavy ions at FAIR, SPS and LHC energies

    Energy Technology Data Exchange (ETDEWEB)

    Fiks, E.I., E-mail: elenafiks@gmail.com [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Pivovarov, Yu.L. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Bogdanov, O.V. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); INFN Laboratori Nazionali di Frascati, Frascati (RM) (Italy); Geissel, H.; Scheidenberger, C. [Helmholtzzentrum für Schwerionenforschung GSI, Darmstadt (Germany)

    2013-08-15

    The calculations of Cherenkov radiation (ChR) angular distributions from relativistic heavy ions (RHI) at very high energies (from 30 GeV/u up to 3000 GeV/u) taking into account their slowing-down (ionization energy loss) in a radiator are performed for the first time. The slowing-down of RHI in an optically transparent solid radiator can drastically change the ChR angular distributions at RHI energies of order of 1 GeV/u. The results of calculation show that at higher RHI energies (>30 GeV/u) (FAIR, SPS and LHC), the ChR angular distribution (at the reasonable radiator thickness) is very close to the Tamm–Frank distribution and practically does not depend on the RHI slowing-down in a radiator, if only ionization energy loss is taken into account.

  18. 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

    and its spectral distribution have been obtained in an annular geometry. It is demonstrated that noise reduces the amplitude of the radiated wave and broadens its spectrum. The effect of the radiated wave on the fluxon dynamics leads to a considerably smaller linewidth than observed in the usual flux flow...

  19. Experimental Research of the Diffraction and Vavilov-Cherenkov Radiation Generation in a Teflon Target

    CERN Document Server

    Shevelev, M; Potylitsyn, A; Popov, Yu

    2011-01-01

    Geometry of Vavilov-Cherekov (VChR) radiation when an electron moves close to a dielectric target is in analogy to diffraction radiation (DR) geometry. In this case we may expect DR generation from the upstream face of the target besides that VChR. The joint observation of these booth types of radiation is very interesting from the pseudo-photon viewpoint, which is applicable for relativistic electrons. Unexpected results obtained in our experiment insist on reflection about nature both DR and VChR. The experiment was performed on the relativistic electron beam of the microtron of Tomsk Polytechnic University.

  20. A realistic treatment of geomagnetic Cherenkov radiation from cosmic ray air showers

    NARCIS (Netherlands)

    Werner, Klaus; de Vries, Krijn D.; Scholten, Olaf

    2012-01-01

    We present a macroscopic calculation of coherent electro-magnetic radiation from air showers initiated by ultra-high energy cosmic rays, based on currents obtained from three-dimensional Monte Carlo simulations of air showers in a realistic geo-magnetic field. We discuss the importance of a correct

  1. Poster — Thur Eve — 18: Cherenkov Emission By High-Energy Radiation Therapy Beams: A Characterization Study

    Energy Technology Data Exchange (ETDEWEB)

    Zlateva, Y.; El Naqa, I. [Medical Physics Unit, Department of Oncology, McGill University, Montreal, QC (Canada); Quitoriano, N. [Department of Mining and Materials Engineering McGill University, Montreal, QC (Canada)

    2014-08-15

    We investigate Cherenkov emission (CE) by radiotherapy beams via radiation dose-versus-CE correlation analyses, CE detection optimization by means of a spectral shift towards the near-infrared (NIR) window of biological tissue, and comparison of CE to on-board MV imaging. Dose-CE correlation was investigated via simulation and experiment. A Monte Carlo (MC) CE simulator was designed using Geant4. Experimental phantoms include: water; tissue-simulating phantom composed of water, Intralipid®, and beef blood; plastic phantom with solid water insert. The detector system comprises an optical fiber and diffraction-grating spectrometer incorporating a front/back-illuminated CCD. The NIR shift was carried out with CdSe/ZnS quantum dots (QDs), emitting at (650±10) nm. CE and MV images were acquired with a CMOS camera and electronic portal imaging device. MC and experimental studies indicate a strong linear dose-CE correlation (Pearson coefficient > 0.99). CE by an 18-MeV beam was effectively NIR-shifted in water and a tissue-simulating phantom, exhibiting a significant increase at 650 nm for QD depths up to 10 mm. CE images exhibited relative contrast superior to MV images by a factor of 30. Our work supports the potential for application of CE in radiotherapy online imaging for patient setup and treatment verification, since CE is intrinsic to the beam and non-ionizing and QDs can be used to improve CE detectability, potentially yielding image quality superior to MV imaging for the case of low-density-variability, low-optical-attenuation materials (ex: breast/oropharynx). Ongoing work involves microenvironment functionalization of QDs and application of multi-channel spectrometry for simultaneous acquisition of dosimetric and tumor oxygenation signals.

  2. A GPU-based Calculation Method for Near Field Effects of Cherenkov Radiation Induced by Ultra High Energy Cosmic Neutrinos

    CERN Document Server

    Hu, Chia-Yu; Chen, Pisin

    2010-01-01

    The radio approach for detecting the ultra-high energy cosmic neutrinos has become a mature field. The Cherenkov signals in radio detection are originated from the charge excess of particle showers due to Askaryan effect. The conventional way of calculating the Cherenkov pulses by making Fraunhofer approximation fails when the sizes of the elongated showers become comparable with the detection distances. We present a calculation method of Cherenkov pulses based on the finite-difference time-domain (FDTD) method, and attain a satisfying effeciency via the GPU- acceleration. Our method provides a straightforward way of the near field calculation, which would be important for ultra high energy particle showers, especailly the electromagnetic showers induced by the high energy leptons produced in the neutrino charge current interactions.

  3. TH-C-17A-04: Shining Light On the Implementation of Cherenkov Emission in Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Zlateva, Y; Quitoriano, N [I El Naqa, McGill University, Montreal, QC (Canada)

    2014-06-15

    Purpose: We hypothesize that Cherenkov emission (CE) by radiotherapy beams is correlated with radiation dose, CE detection can be maximized by a spectral shift towards the near-infrared (NIR) window of biological tissue, and in certain tissue types (ex. breast/oropharynx), it could prove superior to mega-voltage (MV) imaging. Therefore, we compare CE imaging to onboard MV imaging. Methods: Dose-CE correlation was investigated via simulation and experiment. A Monte Carlo (MC) CE simulator was designed using Geant4. Experimental phantoms include: water; tissuesimulating phantom composed of water, fat emulsion, and beef blood; plastic phantom with solid water insert. The optical spectrometry system consisted of a multi-mode optical fiber and diffraction-grating spectrometer incorporating a front/back-illuminated charge-coupled device (CCD). CdSe/ZnS quantum dots (QDs), emitting at (650±10) nm, were used to achieve NIR shift of the CE signal. CE and MV images were acquired with a complementary metal-oxide-semiconductor (CMOS) camera and an electronic portal imaging device (EPID), respectively. Results: MC and experimental studies indicate a strong linear correlation between radiation dose and CE (Pearson coefficient > 0.99). CE by an 18 MeV beam was effectively shifted towards the NIR in water and in a tissue-simulating phantom, exhibiting a 50% increase at 650 nm for QD depths of ∼3 mm. CE images exhibited relative contrast superior to EPID images by a factor of 30. Conclusion: Our work supports the potential for application of CE in radiotherapy online imaging for patient setup and treatment verification, since CE is intrinsic to the beam and non-ionizing, and QDs can be used to improve CE detectability, yielding image quality superior to MV imaging for the case of low density variability, low optical attenuation materials, such as breast or oropharyngeal cavities. Ongoing work involves microenvironment functionalization of QDs and application of multichannel

  4. 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.

  5. Development of a 144-channel Hybrid Avalanche Photo-Detector for Belle II ring-imaging Cherenkov counter with an aerogel radiator

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, S., E-mail: shohei.nishida@kek.jp [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Adachi, I. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Hamada, N. [Toho University, Funabashi (Japan); Hara, K. [High Energy Accelerator Research Organization (KEK), Tsukuba (Japan); Iijima, T. [Nagoya University, Nagoya (Japan); Iwata, S.; Kakuno, H. [Tokyo Metropolitan University, Hachioji (Japan); Kawai, H. [Chiba University, Chiba (Japan); Korpar, S.; Krizan, P. [Jozef Stefan Institute, Ljubljana (Slovenia); Ogawa, S. [Toho University, Funabashi (Japan); Pestotnik, R.; Ŝantelj, L.; Seljak, A. [Jozef Stefan Institute, Ljubljana (Slovenia); Sumiyoshi, T. [Tokyo Metropolitan University, Hachioji (Japan); Tabata, M. [Chiba University, Chiba (Japan); Tahirovic, E. [Jozef Stefan Institute, Ljubljana (Slovenia); Yoshida, K. [Tokyo Metropolitan University, Hachioji (Japan); Yusa, Y. [Niigata University, Niigata (Japan)

    2015-07-01

    The Belle II detector, a follow up of the very successful Belle experiment, is under construction at the SuperKEKB electron–positron collider at KEK in Japan. For the PID system in the forward region of the spectrometer, a proximity-focusing ring-imaging Cherenkov counter with an aerogel radiator is being developed. For the position sensitive photon sensor, a 144-channel Hybrid Avalanche Photo-Detector has been developed with Hamamatsu Photonics K.K. In this report, we describe the specification of the Hybrid Avalanche Photo-Detector and the status of the mass production.

  6. Measurements of Coherent Cherenkov Radiation in Rock Salt: Implications for GZK Neutrino Underground Detector

    CERN Document Server

    Milincic, R; Saltzberg, D; Field, R C; Guillian, G; Walz, D; Williams, D

    2005-01-01

    We report on further SLAC measurements of the Askaryan effect: coherent radio emission from charge asymmetry in electromagnetic cascades. We used synthetic rock salt as the dielectric medium, with cascades produced by GeV bremsstrahlung photons at the Final Focus Test Beam. We extend our prior discovery measurements to a wider range of parameter space and explore the effect in a dielectric medium of great potential interest to large scale ultra-high energy neutrino detectors: rock salt. We observed strong coherent pulsed radio emission over a frequency band from 0.2-15 GHz. A grid of embedded dual-polarization antennas was used to confirm the linear polarization and track the change of direction of the electric-field vector around the shower. Coherence was observed over 4 orders of magnitude of shower energy. The frequency dependence of the radiation was tested over two orders of magnitude of UHF and microwave frequencies. Based on these results we have performed a simulation of a realistic GZK neutrino teles...

  7. SU-E-CAMPUS-T-04: Measurement of Proton Pencil Beam Spot Profile Using Cherenkov Radiation in Two Dimensional Optical Fiber Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Kim, M; SHIN, D; Park, J; Lim, Y; Lee, S; Kim, J [National Cancer Center, Goyang, Gyeonggi-do (Korea, Republic of); Son, J [National Cancer Center, Goyang, Gyeonggi-do, Korea University, Seoul, Gyeonggi-do (Korea, Republic of); Hwang, U [National Medical Center in Korea, Seoul (Korea, Republic of)

    2014-06-15

    Purpose: Proton therapy aims to deliver a high dose in a well-defined target volume while sparing the healthy surrounding tissues thanks to their inherent depth dose characteristic (Bragg peak). In proton therapy, several techniques can be used to deliver the dose into the target volume. The one that allows the best conformity with the tumor, is called PBS (Pencil Beam Scanning). The measurement of the proton pencil beam spot profile (spot size) and position is very important for the accurate delivery of dose to the target volume with a good conformity. Methods: We have developed a fine segmented detector array to monitor the PBS. A prototype beam monitor using Cherenkov radiation in clear plastic optical fibers (cPOF) has been developed for continuous display of the pencil beam status during the therapeutic proton Pencil Beam Scanning mode operation. The benefit of using Cherenkov radiation is that the optical output is linear to the dose. Pedestal substraction and the gain adjustment between channels are performed. Spot profiles of various pencil beam energies(100 MeV to 226 MeV) are measured. Two dimensional gaussian fit is used to analyze the beam width and the spot center. The results are compared with that of Lynx(Scintillator-based sensor with CCD camera) and EBT3 Film. Results: The measured gaussian widths using fiber array system changes from 13 to 5 mm for the beam energies from 100 to 226 MeV. The results agree well with Lynx and Film within the systematic error. Conclusion: The results demonstrate good monitoring capability of the system. Not only measuing the spot profile but also monitoring dose map by accumulating each spot measurement is available. The x-y monitoing system with 128 channel readout will be mounted to the snout for the in-situ real time monitoring.

  8. Tachyonic Cherenkov emission from Jupiter's radio electrons

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-12-17

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

  9. The BRAHMS ring imaging Cherenkov detector

    Science.gov (United States)

    Debbe, R.; Jørgensen, C. E.; Olness, J.; Yin, Z.

    2007-01-01

    A Ring Imaging Cherenkov detector built for the BRAHMS experiment at the Brookhaven RHIC is described. This detector has a high index of refraction gas radiator. Cherenkov light is focused on a photo-multiplier based photon detector with a large spherical mirror. The combination of momentum and ring radius measurement provides particle identification from 2.5 to 35 GeV/ c for pions and kaons and well above 40 GeV/ c for protons during runs that had the radiator index of refraction set at n-1=1700×10-6.

  10. Results from the 1997 run of the LHCb ring imaging Cherenkov test-beam

    CERN Document Server

    Halley, A; Teixeira-Dias, P; Wilkinson, G; Wilkinson, Guy

    1998-01-01

    Analysis results of data from the ring imaging Cherenkov test-beam using hybrid photo diodes are presented. Details are given of the geometrical arrangement of the prototype and data-taking conditions, together with results of simulation and studies of the detector performance, photon yield and Cherenkov angle resolution using different radiators. Good agreement with simulation is found for both gas and aerogel photon yield calculations and the observed Cherenkov angle resolution.1

  11. Radium-228 analysis of natural waters by Cherenkov counting of Actinium-228

    Energy Technology Data Exchange (ETDEWEB)

    Aleissa, Khalid A.; Almasoud, Fahad I.; Islam, Mohammed S. [Atomic Energy Research Institute, King Abdul Aziz City for Science and Technology, P.O. Box 6086, Riyadh 11442 (Saudi Arabia); L' Annunziata, Michael F. [IAEA Expert, Montague Group, P.O. Box 5033, Oceanside, CA 92052-5033 (United States)], E-mail: mlannunziata@cox.net

    2008-12-15

    The activities of {sup 228}Ra in natural waters were determined by the Cherenkov counting of the daughter nuclide {sup 228}Ac. The radium was pre-concentrated on MnO{sub 2} and the radium purified via ion exchange and, after a 2-day period of incubation to allow for secular equilibrium between the parent-daughter {sup 228}Ra({sup 228}Ac), the daughter nuclide {sup 228}Ac was isolated by ion exchange according to the method of Nour et al. [2004. Radium-228 determination of natural waters via concentration on manganese dioxide and separation using Diphonix ion exchange resin. Appl. Radiat. Isot. 61, 1173-1178]. The Cherenkov photons produced by {sup 228}Ac were counted directly without the addition of any scintillation reagents. The optimum Cherenkov counting window, sample volume, and vial type were determined experimentally to achieve optimum Cherenkov photon detection efficiency and lowest background count rates. An optimum detection efficiency of 10.9{+-}0.1% was measured for {sup 228}Ac by Cherenkov counting with a very low Cherenkov photon background of 0.317{+-}0.013 cpm. The addition of sodium salicylate into the sample counting vial at a concentration of 0.1 g/mL yielded a more than 3-fold increase in the Cherenkov detection efficiency of {sup 228}Ac to 38%. Tests of the Cherenkov counting technique were conducted with several water standards of known activity and the results obtained compared closely with a conventional liquid scintillation counting technique. The advantages and disadvantages of Cherenkov counting compared to liquid scintillation counting methods are discussed. Advantages include much lower Cherenkov background count rates and consequently lower minimal detectable activities for {sup 228}Ra and no need for expensive environmentally unfriendly liquid scintillation cocktails. The disadvantages of the Cherenkov counting method include the need to measure {sup 228}Ac Cherenkov photon detection efficiency and optimum Cherenkov counting volume

  12. Radium-228 analysis of natural waters by Cherenkov counting of Actinium-228.

    Science.gov (United States)

    Aleissa, Khalid A; Almasoud, Fahad I; Islam, Mohammed S; L'Annunziata, Michael F

    2008-12-01

    The activities of (228)Ra in natural waters were determined by the Cherenkov counting of the daughter nuclide (228)Ac. The radium was pre-concentrated on MnO(2) and the radium purified via ion exchange and, after a 2-day period of incubation to allow for secular equilibrium between the parent-daughter (228)Ra((228)Ac), the daughter nuclide (228)Ac was isolated by ion exchange according to the method of Nour et al. [2004. Radium-228 determination of natural waters via concentration on manganese dioxide and separation using Diphonix ion exchange resin. Appl. Radiat. Isot. 61, 1173-1178]. The Cherenkov photons produced by (228)Ac were counted directly without the addition of any scintillation reagents. The optimum Cherenkov counting window, sample volume, and vial type were determined experimentally to achieve optimum Cherenkov photon detection efficiency and lowest background count rates. An optimum detection efficiency of 10.9+/-0.1% was measured for (228)Ac by Cherenkov counting with a very low Cherenkov photon background of 0.317+/-0.013cpm. The addition of sodium salicylate into the sample counting vial at a concentration of 0.1g/mL yielded a more than 3-fold increase in the Cherenkov detection efficiency of (228)Ac to 38%. Tests of the Cherenkov counting technique were conducted with several water standards of known activity and the results obtained compared closely with a conventional liquid scintillation counting technique. The advantages and disadvantages of Cherenkov counting compared to liquid scintillation counting methods are discussed. Advantages include much lower Cherenkov background count rates and consequently lower minimal detectable activities for (228)Ra and no need for expensive environmentally unfriendly liquid scintillation cocktails. The disadvantages of the Cherenkov counting method include the need to measure (228)Ac Cherenkov photon detection efficiency and optimum Cherenkov counting volume, which are not at all required when liquid

  13. The Cherenkov Telescope Array

    Science.gov (United States)

    Connaughton, Valerie

    2014-03-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort dedicated to the design and operation of the next-generation ground-based very high-energy gamma-ray observatory. CTA will improve by about one order of magnitude the sensitivity with respect to the current major arrays (VERITAS, H.E.S.S., and MAGIC) in the core energy range of 100 GeV to 10 TeV, and will extend the viability of the imaging atmospheric Cherenkov technique (IACT) down to tens of GeV and above 100 TeV. In order to achieve such improved performance at both a northern and southern CTA site, four 23m diameter Large Size Telescopes (LST) optimized for low energy gamma rays will be deployed close to the centre of the array. A larger number of Medium Size Telescopes (MST) will be optimized for the core IACT energy range. The southern site will include 25 12m single-mirror MSTs and a US contribution of up to 24 novel dual-mirror design Schwarzschild-Couder (SC) type MSTs with a primary mirror of 9.5m diameter, and will also include an array of Small Size Telescopes (SST) to observe the highest-energy gamma rays from galactic sources. The SSTs can be smaller and more widely separated because more energetic gamma rays produce a larger Cherenkov light pool with many photons. The SSTs achieve a large collection area by covering a wide (10 sq km) footprint on the ground. The CTA project is finishing its preparatory phase, and the pre-production phase will start this year. I will review the status and the expected performance of CTA as well as the main scientific goals for the observatory.

  14. The Cherenkov Telescope Array

    CERN Document Server

    Bigongiari, Ciro

    2016-01-01

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

  15. Study of Cherenkov light lateral distribution function around the knee region in extensive air showers

    Directory of Open Access Journals (Sweden)

    Al-Rubaiee A.

    2015-01-01

    Full Text Available The Cherenkov light lateral distribution function (LDF was simulated with the CORSIKAcode in the energy range (1013 - 1016 eV. This simulation was performed for conditions and configurations of the Tunka EAS Cherenkov array for the two primary particles (p and Fe. Basing on the simulated results, many approximated functions are structured for two primary particles and different zenith angles. This allowed us to reconstruct the EAS events, which is, to determine the type and energy of the primary particles that produced showers from signal amplitudes of Cherenkov radiation measured by the Tunka Cherenkov array experiment. Comparison of the calculated LDF of Cherenkov radiation with that measured at the Tunka EAS array shows the ability to identify the primary particle that initiated the EAS cascades by determining its primary energy around the knee region of the cosmic ray spectrum.

  16. Study of Cherenkov Light Lateral Distribution Function around the Knee Region in Extensive Air Showers

    CERN Document Server

    Al-Rubaiee, A A; M., Marwah; Al-Douri, Y

    2015-01-01

    The Cherenkov light lateral distribution function (LDF) was simulated with the CORSIKA code, in the energy range (10^13-10^16) eV. This simulation was performed for conditions and configurations of the Tunka EAS Cherenkov array for two primary particles (p and Fe). Basing on the simulated results, many approximated functions are structured for two primary particles and different zenith angles. This allowed us to reconstruct the EAS events, which is, to determine the type and energy of the primary particles that produced showers from signal amplitudes of Cherenkov radiation which measured with Tunka Cherenkov array experiment. Comparison of the calculated LDF of Cherenkov radiation with that measured at the Tunka EAS array shows the ability for identifying of the primary particle that initiated the EAS cascades determining of its primary energy around the knee region of the cosmic ray spectrum.

  17. The Ring Imaging Cherenkov Detectors for LHCb

    CERN Document Server

    Papanestis, Antonis

    2005-01-01

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

  18. 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.)

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

    Science.gov (United States)

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

    2010-09-01

    A multi-element detector based on Cherenkov radiation in plastic and on photomultiplier tubes has been constructed that is particularly useful in collider experiments. The detector covers the pseudorapidity interval 3.23BRAHMS.

  20. 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.

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

    CERN Document Server

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

    2000-01-01

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

  2. Combined complex Doppler and Cherenkov effect in left-handed metamaterials

    CERN Document Server

    Ziemkiewicz, David

    2015-01-01

    We derive the formula of the complex Doppler shift in a two-dimensional, dispersive metamaterial and we show that a moving, monochromatic radiation source generates multiple frequency modes. The role of the group velocity is stressed and the Doppler shifted radiation field exhibits features of the Cherenkov effect. The presented theory is also applicable to the case of a moving, nonoscillating charge and explains many peculiar characteristics of the Cherenkov radiation in lefthanded metamaterials such as the backward direction of power emission, the constant radiation angle and the lack of velocity threshold.

  3. DELPHI's Ring Imaging Cherenkov Chamber

    CERN Multimedia

    1989-01-01

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

  4. 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

  5. Cherenkov particle identification in FOCUS

    CERN Document Server

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

    2002-01-01

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

  6. Cherenkov particle identification in FOCUS

    Energy Technology Data Exchange (ETDEWEB)

    Link, J.M.; Reyes, M.; Yager, P.M.; Anjos, J.C.; Bediaga, I.; Goebel, C.; Magnin, J.; Massafferri, A.; Miranda, J.M. de; Pepe, I.M.; Reis, A.C. dos; Carrillo, S.; Casimiro, E.; Cuautle, E.; Sanchez-Hernandez, A.; Uribe, C.; Vazquez, F.; Cinquini, L.; Cumalat, J.P.; O' Reilly, B.; Ramirez, J.E.; Vaandering, E.W.; Butler, J.N.; Cheung, H.W.K.; Gaines, I.; Garbincius, P.H.; Garren, L.A.; Gottschalk, E.; Kasper, P.H.; Kreymer, A.E.; Kutschke, R.; Bianco, S.; Fabbri, F.L.; Sarwar, S.; Zallo, A.; Cawlfield, C.; Kim, D.Y.; Park, K.S.; Rahimi, A.; Wiss, J. E-mail: jew@uiuc.edu; Gardner, R.; Kryemadhi, A.; Chung, Y.S.; Kang, J.S.; Ko, B.R.; Kwak, J.W.; Lee, K.B.; Park, H.; Alimonti, G.; Boschini, M.; D' Angelo, P.; DiCorato, M.; Dini, P.; Giammarchi, M.; Inzani, P.; Leveraro, F.; Malvezzi, S.; Menasce, D.; Mezzadri, M.; Milazzo, L.; Moroni, L.; Pedrini, D.; Pontoglio, C.; Prelz, F.; Rovere, M.; Sala, S.; Davenport III, T.F.; Agostino, L.; Arena, V.; Boca, G.; Bonomi, G.; Gianini, G.; Liguori, G.; Merlo, M.M.; Pantea, D.; Ratti, S.P.; Riccardi, C.; Segoni, I.; Vitulo, P.; Hernandez, H.; Lopez, A.M.; Mendez, H.; Mendez, L.; Montiel, E.; Olaya, D.; Paris, A.; Quinones, J.; Rivera, C.; Xiong, W.; Zhang, Y.; Wilson, J.R.; Cho, K.; Handler, T.; Mitchell, R.; Engh, D.; Johns, W.E.; Hosack, M.; Nehring, M.S.; Sheldon, P.D.; Stenson, K.; Webster, M.S.; Sheaff, M

    2002-05-21

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

  7. The Ring Imaging CHerenkov Detectors of the LHCb Experiment

    CERN Document Server

    Perego, Davide Luigi

    2012-01-01

    Particle identification is a fundamental requirement of the LHCb experiment to fulfill its physics programme. Positive hadron identification is performed by two Ring Imaging CHerenkov (RICH) detectors. This system covers the full angular acceptance of the experiment and is equipped with three Cherenkov radiators to identify particles in a wide momentum range from1 GeV/ c up to 100 GeV/ c . The Hybrid Photon Detectors (HPDs) located outside the detector acceptance provide the photon detection with 500,000 channels. Specific read–out electronics has been developed to readout and process data from the HPDs including data transmission and power distribution. The operation and performanceoftheRICHsystemare ensuredbythe constant controland monitoringoflowandhighvoltage systems,of thegas qualityandenvironmental parameters,ofthe mirror alignment,and finallyofthe detector safety. The description of the LHCb RICH is given. The experience in operating the detector at the Large Hadron Collider is presented and discusse...

  8. The Ring Imaging Cherenkov detector (RICH) of the AMS experiment

    CERN Document Server

    Barão, F; Alcaraz, J; Arruda, L; Barrau, A; Barreira, G; Belmont, E; Berdugo, J; Brinet, M; Buénerd, M; Casadei, D; Casaus, J; Cortina, E; Delgado, C; Díaz, C; Derome, L; Eraud, L; Garcia-Lopez, R J; Gallin-Martel, L; Giovacchini, F; Gonçalves, P; Lanciotti, E; Laurenti, G; Malinine, A; Maña, C; Marin, J; Martínez, G; Menchaca-Rocha, A; Molla, M; Palomares, C; Panniello, M; Pereira, R; Pimenta, M; Protasov, K; Sánchez, E; Seo, E S; Sevilla, N; Torrento, A; Vargas-Trevino, M; Veziant, O

    2006-01-01

    The Alpha Magnetic Spectrometer (AMS) experiment to be installed on the International Space Station (ISS) will be equipped with a proximity focusing Ring Imaging Cherenkov (RICH) detector for measuring the electric charge and velocity of the charged cosmic particles. A RICH prototype consisting of 96 photomultiplier units, including a piece of the conical reflector, was built and its performance evaluated with ion beam data. Preliminary results of the in-beam tests performed with ion fragments resulting from collisions of a 158 GeV/c/nuc primary beam of Indium ions (CERN SPS) on a Pb target are reported. The collected data included tests to the final front-end electronics and to different aerogel radiators. Cherenkov rings for a large range of charged nuclei and with reflected photons were observed. The data analysis confirms the design goals. Charge separation up to Fe and velocity resolution of the order of 0.1% for singly charged particles are obtained.

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

    CERN Document Server

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

    2010-01-01

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

  10. Results and prospects on registration of reflected Cherenkov light of EAS from cosmic particles above 10^{15} eV

    CERN Document Server

    Antonov, R A; Bonvech, E A; Chernov, D V; Dzhatdoev, T A; Finger, Mich; Finger, Mir; Galkin, V I; Podgrudkov, D A; Roganova, T M

    2015-01-01

    We give an overview of the SPHERE experiment based on detection of reflected Vavilov-Cherenkov radiation (Cherenkov light) from extensive air showers in the energy region E>10^{15} eV. A brief history of the reflected Cherenkov light technique is given; the observations carried out with the SPHERE-2 detector are summarized; the methods of the experimental datasample analysis are described. The first results on the primary cosmic ray all-nuclei energy spectrum and mass composition are presented. Finally, the prospects of the SPHERE experiment and the reflected Cherenkov light technique are given.

  11. 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.

  12. Cherenkov Telescopes Results on Pulsar Wind Nebulae and Pulsars

    Science.gov (United States)

    Wilhelmi, Emma De Oña

    The last few years have seen a revolution in very high γ-ray astronomy (VHE; E>100 GeV) driven largely by a new generation of Cherenkov telescopes. These new facilities, namely H.E.S.S. (High Energy Stereoscopic System), MAGIC (Major Atmospheric Gamma Imaging Cherenkov Telescope) and its upgrade MAGIC 2, VERITAS (Very Energetic Radiation Imaging Telescope Array System) and CANGAROO (Collaboration of Australia and Nippon for a Gamma Ray Observatory in the Outback) were designed to increase the flux sensitivity in the energy regime of hundreds of GeV, expanding the observed energy range from 50 to multi-TeV, and fostered as a result a period of rapid growth in our understanding of the Non-ThermalUniverse. As a result of this fast development the number of pulsar wind nebulae (PWNe) detected has increased from a few in the early 90's to more than two dozen of firm candidates nowadays. Also, the low energy threshold achieved allows to investigate the pulsed spectra of the high energy pulsars powering PWNe. A review of the most relevant VHE results concerning pulsars and their relativistic winds is discussed here in the context of Cherenkov telescopes.

  13. The upgraded MAGIC Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

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

  14. 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...... 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...

  15. Cherenkov and Scintillation Properties of Cubic Zirconium

    Science.gov (United States)

    Christl, M.J.; Adams, J.H.; Parnell, T.A.; Kuznetsov, E.N.

    2008-01-01

    Cubic zirconium (CZ) is a high index of refraction (n =2.17) material that we have investigated for Cherenkov counter applications. Laboratory and proton accelerator tests of an 18cc sample of CZ show that the expected fast Cherenkov response is accompanied by a longer scintillation component that can be separated by pulse shaping. This presents the possibility of novel particle spectrometers which exploits both properties of CZ. Other high index materials being examined for Cherenkov applications will be discussed. Results from laboratory tests and an accelerator exposure will be presented and a potential application in solar energetic particle instruments will be discussed

  16. INTENSITY INTERFEROMETRY WITH CHERENKOV TELESCOPES

    Directory of Open Access Journals (Sweden)

    D. B. Kieda

    2010-01-01

    Full Text Available Se discuten las capacidades de arreglos de interferometría de intensidad estelar (SII que se pueden construir usando la siguiente generación de arreglos de telescopios de Cherenkov de imágenes de aire (IACTs. Estos arreglos de IACT tendrán un gran diámetro de - 100 m (> 8 m de re ectores ópticos, ofreciendo cerca de 5000 líneas de base interferométricas, extendiéndose a partir de 50 m a más que 1000 m. La implementación del SII en arreglos de IACT permitirán imágenes de alta resolución (< 0:1 mas en anchos de banda cortos (bandas B/V, que son óptimas para el estudio de estrellas calientes.

  17. Cherenkov Telescope Array Data Management

    CERN Document Server

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

    2015-01-01

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

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

    DEFF Research Database (Denmark)

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

    2013-01-01

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

  19. 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.

  20. NICHE: The Non-Imaging CHErenkov Array

    CERN Document Server

    Bergman, Douglas

    2012-01-01

    The accurate measurement of the Cosmic Ray (CR) nuclear composition around and above the Knee (~ 10^15.5 eV) has been difficult due to uncertainties inherent to the measurement techniques and/or dependence on hadronic Monte Carlo simulation models required to interpret the data. Measurement of the Cherenkov air shower signal, calibrated with air fluorescence measurements, offers a methodology to provide an accurate measurement of the nuclear composition evolution over a large energy range. NICHE will use an array of widely-spaced, non-imaging Cherenkov counters to measure the amplitude and time-spread of the air shower Cherenkov signal to extract CR nuclear composition measurements and to cross-calibrate the Cherenkov energy and composition measurements with TA/TALE fluorescence and surface detector measurements.

  1. Cherenkov terahertz surface plasmon excitation by an electron beam over an ultrathin metal film

    Science.gov (United States)

    Kumar, Pawan; Kumar, Rajeev; Rajouria, Satish Kumar

    2016-12-01

    The mechanism of Cherenkov excitation of terahertz (THz) surface plasma wave (SPW), by a relativistic electron beam propagating over an ultrathin metal film deposited on glass, is investigated. The SPW field falls off exponentially in vacuum as well as glass, while the surface plasmon resonant frequency is lowered by the reduction of film thickness. The SPW field causes density bunching of the beam leading to current modulation and generation of THz radiation via the Cherenkov interaction. The frequency of the THz decreases with the energy of the beam, whereas the growth rate increases.

  2. 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

  3. Cherenkov light detection as a velocity selector for uranium fission products at intermediate energies

    Science.gov (United States)

    Yamaguchi, T.; Enomoto, A.; Kouno, J.; Yamaki, S.; Matsunaga, S.; Suzaki, F.; Suzuki, T.; Abe, Y.; Nagae, D.; Okada, S.; Ozawa, A.; Saito, Y.; Sawahata, K.; Kitagawa, A.; Sato, S.

    2014-12-01

    The in-flight particle separation capability of intermediate-energy radioactive ion (RI) beams produced at a fragment separator can be improved with the Cherenkov light detection technique. The cone angle of Cherenkov light emission varies as a function of beam velocity. This can be exploited as a velocity selector for secondary beams. Using heavy ion beams available at the HIMAC synchrotron facility, the Cherenkov light angular distribution was measured for several thin radiators with high refractive indices (n = 1.9 ~ 2.1). A velocity resolution of ~10-3 was achieved for a 56Fe beam with an energy of 500 MeV/nucleon. Combined with the conventional rigidity selection technique coupled with energy-loss analysis, the present method will enable the efficient selection of an exotic species from huge amounts of various nuclides, such as uranium fission products at the BigRIPS fragment separator located at the RI Beam Factory.

  4. Prototype Test Results of the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE)

    CERN Document Server

    Williams, D A; Manna, D S; Marion, G M; Ong, R A; Tunner, T O; Dragovan, M; Oser, S; Chantel, M C; Bhattacharya, D P; Covault, C E; Fernholx, R

    1998-01-01

    There are currently no experiments, either satellite or ground-based, that are sensitive to astrophysical gamma-rays at energies between 20 and 250 GeV. We are developing the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) to explore this energy range. STACEE will use heliostat mirrors at a solar research facility to collect Cherenkov light from extensive air showers produced by high energy gamma-rays. Here we report on the results of prototype test work at the solar facility of Sandia National Laboratories (Albuquerque, NM). The work demonstrates that the facility is suitable for use as an astrophysical observatory. In addition, using a full scale prototype of part of STACEE, we detected atmospheric Cherenkov radiation at energies lower than any other ground-based experiment to date.

  5. Distributed beam loss monitor based on the Cherenkov effect in an optical fiber

    Science.gov (United States)

    Maltseva, Yu; Emanov, F. A.; Petrenko, A. V.; Prisekin, V. G.

    2015-05-01

    This review discusses a distributed beam loss monitor which is based on the Cherenkov effect in an optical fiber and which has been installed at the VEPP-5 Injection Complex at the Budker Institute of Nuclear Physics. The principle of the device operation consists in detecting the Cherenkov radiation generated in an optical fiber by relativistic charged particles that are produced in an electromagnetic shower when highly relativistic beam particles (electrons or positrons) hit the accelerator vacuum chamber wall. Our experiments used a photomultiplier tube (PMT) to detect the Cherenkov light. Knowing when the PMT signal arrives tells us where the beam loss occurs. Using a 20-m-long optical fiber allowed a detector spatial resolution of 3 m. The way to improve the resolution is to optimize the monitor working conditions and optical fiber and PMT parameters, potentially leading to a resolution of as fine as 0.5 m according to our estimates.

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

    CERN Document Server

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

    2013-01-01

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

  7. 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

  8. Characterization study of silica aerogel for Cherenkov imaging

    Energy Technology Data Exchange (ETDEWEB)

    Sallaz-Damaz, Y. [LPSC, IN2P3/CNRS, 53 av. des Martyrs, 38026 Grenoble Cedex (France); Derome, L., E-mail: derome@lpsc.in2p3.f [LPSC, IN2P3/CNRS, 53 av. des Martyrs, 38026 Grenoble Cedex (France); Mangin-Brinet, M.; Loth, M.; Protasov, K.; Putze, A.; Vargas-Trevino, M.; Veziant, O.; Buenerd, M. [LPSC, IN2P3/CNRS, 53 av. des Martyrs, 38026 Grenoble Cedex (France); Menchaca-Rocha, A.; Belmont, E.; Vargas-Magana, M.; Leon-Vargas, H.; Ortiz-Velasquez, A. [Instituto de Fisica, UNAM, AP 20-364, Mexico DF (Mexico); Malinine, A. [University of Maryland, College Park, MD 20742 (United States); Barao, F.; Pereira, R. [LIP, Avenida Elias Garcia 14-1, P - 1000 Lisboa (Portugal); Bellunato, T.; Matteuzzi, C.; Perego, D.L. [Universita degli Studi di Milano-Bicocca and INFN, Milano (Italy)

    2010-03-01

    Different methods to measure the characteristics of silica aerogel tiles used as Cherenkov radiator in the CREAM and AMS experiments have been investigated to optimize the detector performances. The measurement accuracy dictated by the physics objectives on the velocity and charge resolutions set stringent requirements on the aerogel refractive index determination, namely DELTAnapprox1.5x10{sup -4} and DELTAnapprox5x10{sup -4} for the AMS and CREAM imagers, respectively. The matching of such accuracies for this material turned out to be a metrological challenge, and finally led to a full R and D program, to develop an appropriate characterization procedure. Preliminary studies performed with a standard refractive index measurement technique (laser beam deviation by a prism) have revealed a significant systematic index nonuniformity for the AMS tiles at a level (10{sup -3}), not acceptable considering the aimed accuracy. These large variations were confirmed in a beam test. A second method, mapping the transverse index gradient by deflection of a laser beam entering normally to the tile has then been developed. It is shown that this procedure is suitable to reach the required accuracy, at the price of using both methods combined. The several hundreds of tiles of the radiator plane of the CREAM and AMS Cherenkov imagers were characterized using a simplified procedure, however, appropriate for each case, compromising between the amount of work and the time available. The experimental procedures and set-ups used are described in the text, and the obtained results are reported.

  9. 等离子体填充金属光子晶体Cherenkov辐射源模拟研究∗%Simulation of cherenkov radiation source in a plasma-filled metallic photonic crystal

    Institute of Scientific and Technical Information of China (English)

    傅涛; 欧阳征标

    2016-01-01

    Plasma filling can significantly improve the efficiency and power of a vacuum device. In this paper, we first analyze the dispersion properties of a plasma-filled metal-photonic-crystal slow-wave structure (SWS), and then investigate the interaction procedure between a relativistic electron beam and the Cherenkov radiation in the plasma-filled metallic-photonic-crystal by the particle in cell method. We pay our attention to the influences of plasma density, cathode voltage, and guiding magnetic field on output frequency and power. The results show that the electric field strength in the SWS increases obviously at a fixed plasma density of 50 mTorr (1 mTorr = 0.133 Pa). The device works at a stable single TM01 mode due to the good mode properties of the metal photonic crystal even if plasma is filled in it. The maximum value of Ez field along the z axis of the device increases from 46.34 MV/m without plasma to 79 MV/m with plasma. The value along the x axis increases from 136 MV/m without plasma to 185 MV/m with plasma. The working frequency (35.5 GHz) of the device, obtained from simulation, is consistent with the theoretical estimation (35.4 GHz). The power increases with the cathode voltage between 500 kV and 600 kV while the frequency increases only a little. When the magnetic field B increases, the output power first increases and then decreases. But the frequency is not affected due to the dispersion property. The output power of the device increases 20% when the air pressure increases from 0 to 100 mTorr. However, there is a pretty distribution of the field Ez along the angular direction only in an appropriate plasma density around 50 mTorr. According to the theory and simulation, the output power and efficiency can be improved in an appropriate range of plasma density. These results provide a basis for developing the plasma-filled vacuum devices.%等离子体填充能够明显提高真空电子器件的效率和功率,研究等离子体填充器件具有

  10. Cherenkov light detection as a velocity selector for uranium fission products at intermediate energies

    Energy Technology Data Exchange (ETDEWEB)

    Yamaguchi, T., E-mail: yamaguti@phy.saitama-u.ac.jp [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Enomoto, A.; Kouno, J.; Yamaki, S.; Matsunaga, S.; Suzaki, F.; Suzuki, T. [Department of Physics, Saitama University, Saitama 338-8570 (Japan); Abe, Y.; Nagae, D.; Okada, S.; Ozawa, A.; Saito, Y.; Sawahata, K. [Institute of Physics, University of Tsukuba, Ibaraki 305-8571 (Japan); Kitagawa, A.; Sato, S. [National Institute of Radiological Sciences, Chiba 263-8555 (Japan)

    2014-12-01

    The in-flight particle separation capability of intermediate-energy radioactive ion (RI) beams produced at a fragment separator can be improved with the Cherenkov light detection technique. The cone angle of Cherenkov light emission varies as a function of beam velocity. This can be exploited as a velocity selector for secondary beams. Using heavy ion beams available at the HIMAC synchrotron facility, the Cherenkov light angular distribution was measured for several thin radiators with high refractive indices (n=1.9∼2.1). A velocity resolution of ∼10{sup −3} was achieved for a {sup 56}Fe beam with an energy of 500 MeV/nucleon. Combined with the conventional rigidity selection technique coupled with energy-loss analysis, the present method will enable the efficient selection of an exotic species from huge amounts of various nuclides, such as uranium fission products at the BigRIPS fragment separator located at the RI Beam Factory. - Highlights: • The cone angle of Cherenkov light can be used as a velocity selector of RI beams. • Proof-of-principle experiments are made using heavy ions at intermediate energies. • Results demonstrate successful separation of RI beams produced by fragmentation. • A velocity resolution of 10{sup −3} is achieved for thin high refractive radiators.

  11. Volcanoes muon imaging using Cherenkov telescopes

    CERN Document Server

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

    2015-01-01

    A detailed understanding of a volcano inner structure is one of the key-points for the volcanic hazards evaluation. To this aim, in the last decade, geophysical radiography techniques using cosmic muon particles have been proposed. By measuring the differential attenuation of the muon flux as a function of the amount of rock crossed along different directions, it is possible to determine the density distribution of the interior of a volcano. Up to now, a number of experiments have been based on the detection of the muon tracks crossing hodoscopes, made up of scintillators or nuclear emulsion planes. Using telescopes based on the atmospheric Cherenkov imaging technique, we propose a new approach to study the interior of volcanoes detecting the Cherenkov light produced by relativistic cosmic-ray muons that survive after crossing the volcano. The Cherenkov light produced along the muon path is imaged as a typical annular pattern containing all the essential information to reconstruct particle direction and energ...

  12. Cherenkov TOF PET with silicon photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-21

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

  13. Sites in Argentina for the Cherenkov Telescope Array Project

    CERN Document Server

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

    2013-01-01

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

  14. The HERA-B ring imaging Cherenkov counter

    Energy Technology Data Exchange (ETDEWEB)

    Arino, I.; Bastos, J.; Broemmelsiek, D.; Carvalho, J.; Chmeissani, M.; Conde, P.; Davila, J.; Dujmic, D.; Eckmann, R.; Garrido, L.; Gascon, D.; Hamacher, T.; Gorisek, A.; Ivaniouchenkov, I.; Ispirian, M.; Karabekian, S.; Kim, M.; Korpar, S.; Krizan, P. E-mail: peter.krizan@ijs.si; Kupper, S.; Lau, K.; Maas, P.; McGill, J.; Miquel, R.; Murthy, N.; Peralta, D.; Pestotnik, R.; Pyrlik, J.; Ramachandran, S.; Reeves, K.; Rosen, J.; Schmidt-Parzefall, W.; Schwarz, A.; Schwitters, R.F.; Siero, X.; Staric, M.; Stanovnik, A.; Skrk, D.; Zivko, T

    2004-01-11

    The HERA-B RICH uses a radiation path length of 2.8 m in C{sub 4}F{sub 10} gas and a large 24 m{sup 2} spherical mirror for imaging Cherenkov rings. The photon detector consists of 2240 Hamamatsu multi-anode photomultipliers with about 27 000 channels. A 2:1 reducing two-lens telescope in front of each photomultiplier tube increases the sensitive area at the expense of increased pixel size, resulting in a contribution to the resolution which roughly matches that of dispersion. The counter was completed in January of 1999, and its performance has been steady and reliable over the years it has been in operation. The design performance of the Ring Imaging Cherenkov counter was fully reached: the average number of detected photons in the RICH for a {beta}=1 particle was found to be 33 with a single-hit resolution of 0.7 and 1 mrad in the fine and coarse granularity regions, respectively.

  15. The HERA-B ring imaging Cherenkov counter

    Science.gov (United States)

    Ariño, I.; Bastos, J.; Broemmelsiek, D.; Carvalho, J.; Chmeissani, M.; Conde, P.; Davila, J.; Dujmić, D.; Eckmann, R.; Garrido, L.; Gascon, D.; Hamacher, T.; Gorišek, A.; Ivaniouchenkov, I.; Ispirian, M.; Karabekian, S.; Kim, M.; Korpar, S.; Križan, P.; Kupper, S.; Lau, K.; Maas, P.; McGill, J.; Miquel, R.; Murthy, N.; Peralta, D.; Pestotnik, R.; Pyrlik, J.; Ramachandran, S.; Reeves, K.; Rosen, J.; Schmidt-Parzefall, W.; Schwarz, A.; Schwitters, R. F.; Siero, X.; Starič, M.; Stanovnik, A.; Škrk, D.; Živko, T.

    2004-01-01

    The HERA-B RICH uses a radiation path length of 2.8 m in C 4F 10 gas and a large 24 m2 spherical mirror for imaging Cherenkov rings. The photon detector consists of 2240 Hamamatsu multi-anode photomultipliers with about 27 000 channels. A 2:1 reducing two-lens telescope in front of each photomultiplier tube increases the sensitive area at the expense of increased pixel size, resulting in a contribution to the resolution which roughly matches that of dispersion. The counter was completed in January of 1999, and its performance has been steady and reliable over the years it has been in operation. The design performance of the Ring Imaging Cherenkov counter was fully reached: the average number of detected photons in the RICH for a β=1 particle was found to be 33 with a single-hit resolution of 0.7 and 1 mrad in the fine and coarse granularity regions, respectively.

  16. 110th anniversary of the birth of P A Cherenkov (Scientific session of the Physical Sciences Division of the Russian Academy of Sciences, 17 December 2014)

    Science.gov (United States)

    2015-05-01

    A scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) was held on 17 December 2014 at the conference hall of the Lebedev Physical Institute, RAS, devoted to the 110th anniversary of the birth of Academician P A Cherenkov. The agenda posted on the website of the Physical Sciences Division RAS http://www.gpad.ac.ru comprised the following reports: (1) Bashmakov Yu A (Lebedev Physical Institute, RAS, Moscow) "Prehistory of discovery"; (2) Kadmensky S G (Voronezh State University, Voronezh) "Cherenkov radiation as a serendipity phenomenon"; (3) Denisov S P (Russian Federation State Scientific Center 'Institute for High Energy Physics' of National Research Center 'Kurchatov Institute', Protvino, Moscow region) "Use of Cherenkov counters in accelerator experiments"; (4) Petrukhin A A (National Research Nuclear University 'MEPhI', Moscow) "Cherenkov NEVOD water detector"; (5) Dremin I M (Lebedev Physical Institute, RAS, Moscow) "Cherenkov radiation from gluons in a nuclear medium"; (6) Domogatsky G V (Institute for Nuclear Research, RAS, Moscow) "Cherenkov detectors for high-energy neutrino astrophysics"; (7) Kravchenko E A (Budker Institute of Nuclear Physics, SB RAS, Novosibirsk) "Cherenkov detectors with aerogel radiators"; (8) Malinovski E I (Institute for Nuclear Research, RAS, Moscow) "Cherenkov total absorption spectrometers for high-energy electrons and photons"; (9) Maltseva Yu I (Budker Institute of Nuclear Physics, SB RAS, Novosibirsk) "Distributed beam loss monitor based on the Cherenkov effect in an optical fiber". Papers based on oral reports 1-4, 6-9 are presented below. Some aspects of report 5 can be found in the review by I M Dremin and A V Leonidov published in 2010 in Physics-Uspekhi (Vol. 53, p. 1123). • Cherenkov radiation: from discovery to RICH, Yu A Bashmakov Physics-Uspekhi, 2015, Volume 58, Number 5, Pages 467-471 • Cherenkov radiation as a serendipitous phenomenon, S G Kadmensky Physics

  17. LHCb ring imaging Cherenkov detector mirrors

    CERN Multimedia

    Maximilien Brice

    2005-01-01

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

  18. Progress on Cherenkov Reconstruction in MICE

    CERN Document Server

    Kaplan, Daniel M; Rajaram, Durga; Winter, Miles; Cremaldi, Lucien; Sanders, David; Summers, Don

    2016-01-01

    Two beamline Cherenkov detectors (Ckov-a,-b) support particle identification in the MICE beamline. Electrons and high-momentum muons and pions can be identified with good efficiency. We report on the Ckov-a,-b performance in detecting pions and muons with MICE Step I data and derive an upper limit on the pion contamination in the standard MICE muon beam.

  19. Design and construction of a Cherenkov imager for charge measurement of nuclear cosmic rays

    CERN Document Server

    Bourrion, O; 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; Lee, M H; Lutz, L; Marton, M; Menchaca-Rocha, A; Pelissier, A; Périé, J N; Putze, A; Roudier, S; Sallaz-Damaz, Y; Seo, E S; Scordilis, J P; Yoon, Y S

    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.

  20. 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.

  1. Evidence for Observation of Virtual Radio Cherenkov Fields

    CERN Document Server

    Bean, Alice; Snow, James

    2010-01-01

    We present evidence for observation of virtual electromagnetic fields in the radio domain from experiment T926 at the Fermilab Meson Test Beam Facility. Relativistic protons with 120 GeV energy traversed a sealed electromagnetic cavity and were observed in the radio regime of 200MHz-GHz. Closely related to ordinary Cherenkov radiation, which we also measured, the virtual fields require no acceleration for their existence. The experiment is also the first observation of fields from hadronic showers, an independent and new confirmation of coherent radio emission from ultra-relativistic particles. Conditions of very low signal to noise were overcome by a novel and unbiased filtering strategy that exploits exhaustive studies of correlations in the noise backgrounds. Linear scaling of the signal region with the number of beam particles provides evidence of coherence. Extrapolation to measurement of the field of a single relativistic proton charge is consistent within errors. Our study also illustrates new data pro...

  2. Cherenkov light imaging in astro-particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Mirzoyan, Razmik, E-mail: Razmik.Mirzoyan@mpp.mpg.de

    2014-12-01

    Cherenkov light emission plays a key role in contemporary science; it is widely used in high energy, nuclear, and numerous astro-particle physics experiments. Most astro-particle physics experiments are based on the detection of light, and a vast majority of them on the measurement of Cherenkov light. Cherenkov light emission is measured in gases (used in air-Cherenkov technique), in water (for example, neutrino experiments BAIKAL, Super-Kamiokande, NESTOR, ANTARES, future KM3NeT; cosmic and γ-ray experiments Milagro, HAWC, AUGER) and in ice (IceCube). In this report our goal is not limited to simply listing the multitude of experiments that are based on using Cherenkov emission, but we will clarify the reasons making this emission so important and so frequently used. For completeness we will first give a short historical overview on the discovery and evolution of Cherenkov emission and then we will dwell on its main features and numerous applications in astro-particle physics experiments. - Highlights: • We explain why Cherenkov emission is so important and why it is so widely used. • A brief historical excursion is made to the very beginning of Cherenkov emission. • Imaging of the Cherenkov light emission is discussed in a great detail. • The principle of Cherenkov light imaging in diverse experiments is the same.

  3. 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...

  4. 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.

  5. 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.

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

    Science.gov (United States)

    Wrbanek, John D.; Wrbanek, Susan Y.

    2013-01-01

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

  7. Feasibility of VHE gamma ray detection by an array of imaging atmospheric Cherenkov telescopes using the fluorescence technique

    CERN Document Server

    Contreras, J L; Arqueros, F; López, M; Barrio, J A; Nievas, M

    2015-01-01

    The last 20 years have seen the development of new techniques in Astroparticle Physics providing access to the highest end of the electromagnetic spectrum. It has been shown that some sources emit photons up to energies close to 100 TeV. Yet the fluxes of these photons are incredibly low and new detection techniques are needed to go higher in energy. A new technique that would use the new generation of Cherenkov Telescopes, i.e., the Cherenkov Telescope Array (CTA), is proposed to push further the energy frontier. It is based on the detection of the fluorescence radiation emitted in extensive air showers, a successful method used in ultra-high-energy cosmic ray experiments, like the Pierre Auger Observatory. It would complement the standard imaging atmospheric Cherenkov technique with only minor modifications of the hardware currently being developed for the CTA and would not imply significant extra costs during its planned operation.

  8. Performance of the STACEE Atmospheric Cherenkov Telescope

    CERN Document Server

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

    2000-01-01

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

  9. HAWC - The High Altitude Water Cherenkov Detector

    Science.gov (United States)

    Tepe, Andreas; HAWC Collaboration

    2012-07-01

    The high altitude water Cherenkov observatory (HAWC) is an instrument for the detection of high energy cosmic gamma-rays. Its predecessor Milagro has successfully proven that the water Cherenkov technology for gamma-ray astronomy is a useful technique. HAWC is currently under construction at Sierra Negra in Mexico at an altitude of 4100 m and will include several improvements compared to Milagro. Two complementary DAQ systems of the HAWC detector allow for the observation of a large fraction of the sky with a very high duty cycle and independent of environmental conditions. HAWC will observe the gamma-ray sky from about 100 GeV up to 100 TeV. Also the cosmic ray flux anisotropy on different angular length scales is object of HAWC science. Because of HAWC's large effective area and field of view, we describe its prospects to observe gamma-ray bursts (GRBs) as an example for transient sources.

  10. Mirror Development for the Cherenkov Telescope Array

    CERN Document Server

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

    2013-01-01

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

  11. Bokeh Mirror Alignment for Cherenkov Telescopes

    CERN Document Server

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

    2016-01-01

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

  12. Performance of the STACEE Atmospheric Cherenkov Telescope

    Science.gov (United States)

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

    2001-04-01

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

  13. 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.

  14. Volcanoes muon imaging using Cherenkov telescopes

    Science.gov (United States)

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

    2016-01-01

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

  15. Bokeh mirror alignment for Cherenkov telescopes

    Science.gov (United States)

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

    2016-09-01

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

  16. QUEST: wide angle Cherenkov light measurements at EAS-TOP

    Science.gov (United States)

    EAS-Top Collaboration; Korosteleva, E. E.; Kuzmichev, L. A.; Prosin, V. V.; Lubsandorzhiev, B. K.

    Wide angle Cherenkov light detectors based upon the QUASAR-370 photo-multipliers have been installed on five Cherenkov telescopes of the EAS-TOP array to study the energy spectrum and composition of primary cosmic rays around the knee . The energy threshold of quasars array was close to that of EAS-TOP electromagnetic detectors array. The first results of joint analysis of Cherenkov and electromagnetic data together with the adequate CORSIKA simulation results are discussed.

  17. Optical properties of water for the Yangbajing water cherenkov detector

    Science.gov (United States)

    Gao, Shang-qi; Sun, Zhi-bin; Jiang, Yuan-da; Wang, Chao; Du, Ke-ming

    2011-08-01

    Cherenkov radiation is used to study the production of particles during collisions, cosmic rays detections and distinguishing between different types of neutrinos and electrons. The optical properties of water are very important to the research of Cherenkov Effect. Lambert-beer law is a method to study the attenuation of light through medium. In this paper, optical properties of water are investigated by use of a water attenuation performance test system. The system is composed of the light-emitting diode (LED) light source and the photon receiver models. The LED light source model provides a pulse light signal which frequency is 1 kHz and width is 100ns. In photon receiver model, a high sensitivity photomultiplier tube (PMT) is used to detect the photons across the water. Because the output voltage amplitude of PMT is weak which is from 80mv to 120mV, a low noise pre-amplifier is used to improve the detector precise. An effective detector maximum time window of PMT is 100ns for a long lifetime, so a peak holder circuit is used to hold the maximum peak amplitude of PMT for the induced photons signal before the digitalization. In order to reduce the noise of peak holder, a multi-pulse integration is used before the sampling of analog to digital converter. At last, the detector of photons from the light source to the PMT across the water is synchronized to the pulse width of the LED. In order to calculate the attenuation coefficient and attenuation length of water precisely, the attenuation properties of air-to-water boundary is considered in the calculation.

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

    Science.gov (United States)

    Kim, Y.; Herrmann, H. W.; McEvoy, A. M.; Young, C. S.; Hamilton, C.; Schwellenbach, D. D.; Malone, R. M.; Kaufman, M. I.; Smith, A. S.

    2016-11-01

    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 SiO2 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.

  19. Study of timing performance of Silicon Photomultiplier and application for a Cherenkov detector

    CERN Document Server

    Ahmed, G S M; Marton, J; Suzuki, K

    2010-01-01

    Silicon photomultipliers are very versatile photo detectors due to their high photon detection efficiency, fast response, single photon counting capability, high amplification, and their insensitivity to magnetic fields. At our institute we are studying the performance of these photo detectors at various operating conditions. On the basis of the experience in the laboratory we built a prototype of a timing Cherenkov detector consisting of a quartz radiator with two $3\\times 3$ mm$^2$ MPPCs S10362-33-100C from Hamamatsu Photonics as photodetectors. The MPPC sensors were operated with Peltier cooling to minimize thermal noise and to avoid gain drifts. The test measurements at the DA$\\Phi$NE Beam-Test Facility (BTF) at the Laboratori Nazionali di Frascati (LNF) with pulsed 490 MeV electrons and the results on timing performance with Cherenkov photons are presented.

  20. Tachyonic quantum densities of relativistic electron plasmas: Cherenkov spectra of γ-ray pulsars

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-06-27

    Tachyonic Cherenkov radiation in second quantization can explain the subexponential spectral tails of GeV γ-ray pulsars (Crab pulsar, PSR J1836+5925, PSR J0007+7303, PSR J2021+4026) recently observed with the Fermi-LAT, VERITAS and MAGIC telescopes. The radiation is emitted by a thermal ultra-relativistic electron plasma. The Cherenkov effect is derived from a Maxwell–Proca field with negative mass-square in a dispersive spacetime. The frequency variation of the tachyon mass results in exp(−β{sup ^}ω{sup 1−ρ}) attenuation of the asymptotic Cherenkov energy flux, where β{sup ^} is a decay constant related to the electron temperature and ρ is the frequency scaling exponent of the tachyon mass. An exponent in the range 0<ρ<1 can reproduce the observed subexponential decay of the energy flux. For the Crab pulsar, we find ρ=0.81±0.02, inferred from the substantially weaker-than-exponential decay of its spectral tail measured by MAGIC over an extended energy range. The scaling exponent ρ determines whether the group velocity of the tachyonic γ-rays is sub- or superluminal. - Highlights: • Quantized tachyonic Cherenkov densities lead to subexponential spectral decay. • γ-Ray spectral fits to Crab pulsar, PSR J1836+5925, PSR J0007+7303, PSR J2021+4026. • The polarization of γ-rays is analyzed in the quasiclassical regime and quantum limit. • Three degrees of polarization due to the negative mass-square of the Maxwell–Proca field. • Weibull decay of spectral tails caused by frequency scaling of the tachyon mass.

  1. Fast Cherenkov model of optical photons generation and transportation

    CERN Document Server

    The ATLAS collaboration

    2017-01-01

    This note describes the technical details of Fast Cherenkov model of optical photons generation and transportation: in particular, the mechanism of Cherenkov photons transportation through the straight bar geometry. As an example of usage, the implemetation of the method inside Quartic detector simulation in GEANT4 will be presented and compared to the nominal results.

  2. Recent results on aerogel development for use in Cherenkov counters

    Energy Technology Data Exchange (ETDEWEB)

    Danilyuk, A.F. E-mail: danilyuk@catalysis.nsk.su; Kirillov, V.L.; Savelieva, M.D.; Bobrovnikov, V.S.; Buzykaev, A.R.; Kravchenko, E.A.; Lavrov, A.V.; Onuchin, A.P

    2002-11-21

    Synthesis of silica aerogel for Cherenkov counters is being studied for more than 10 years at the Boreskov Institute of Catalysis in collaboration with the Budker Institute of Nuclear Physics. Index of refraction, light scattering length and light absorption length are optical characteristics which determine the quality of aerogel Cherenkov counter. These parameters were measured for the aerogel produced. The results are presented.

  3. Recent results on aerogel development for use in Cherenkov counters

    CERN Document Server

    Danilyuk, A F; Savelieva, M D; Bobrovnikov, V S; Buzykaev, A R; Kravchenko, E A; Lavrov, A V; Onuchin, A P

    2002-01-01

    Synthesis of silica aerogel for Cherenkov counters is being studied for more than 10 years at the Boreskov Institute of Catalysis in collaboration with the Budker Institute of Nuclear Physics. Index of refraction, light scattering length and light absorption length are optical characteristics which determine the quality of aerogel Cherenkov counter. These parameters were measured for the aerogel produced. The results are presented.

  4. Camera Development for the Cherenkov Telescope Array

    Science.gov (United States)

    Moncada, Roberto Jose

    2017-01-01

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

  5. All-fiber femtosecond Cherenkov laser at visible wavelengths

    DEFF Research Database (Denmark)

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

    2013-01-01

    for the generated CR pulse is 160 fs. The FWHM of the AC of the input pump pulse at 1035 nm is 832 fs. The CR pulse is more than 5 times shorter than the pump pulse, as a result of the nonlinear pump pulse compression in the CR fiber link. We are currently working on achieving an even broader electrical tunability......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...... electrically tunable femtosecond CR output in the visible (VIS) spectral range of 580-630 nm, with the 3 dB spectral bandwidth not exceeding 36 nm, with average power in the milliwatt range. Relative intensity noise (RIN) of this laser, affecting the sensitivity of bio-imaging and microscopy systems, is found...

  6. Gadolinium study for a water Cherenkov detector

    CERN Document Server

    Kibayashi, Atsuko

    2009-01-01

    Modification of large water Cherenkov detectors by addition of gadolinium has been proposed. The large cross section for neutron capture on Gd will greatly improve the sensitivity to antielectron neutrinos from supernovae and reactors. A five-year project to build and develop a prototype detector based on Super-Kamiokande (SK) has started. We are performing various studies, including a material soak test in Gd solution, light attenuation length measurements, purification system development, and neutron tagging efficiency measurements using SK data and a Geant4-based simulation. We present an overview of the project and the recent R&D results.

  7. The Cherenkov Telescope Array Large Size Telescope

    CERN Document Server

    Ambrosi, G; Baba, H; Bamba, A; Barceló, M; de Almeida, U Barres; Barrio, J A; Bigas, O Blanch; Boix, J; Brunetti, L; Carmona, E; Chabanne, E; Chikawa, M; Colin, P; Conteras, J L; Cortina, J; Dazzi, F; Deangelis, A; Deleglise, G; Delgado, C; Díaz, C; Dubois, F; Fiasson, A; Fink, D; Fouque, N; Freixas, L; Fruck, C; Gadola, A; García, R; Gascon, D; Geffroy, N; Giglietto, N; Giordano, F; Grañena, F; Gunji, S; Hagiwara, R; Hamer, N; Hanabata, Y; Hassan, T; Hatanaka, K; Haubold, T; Hayashida, M; Hermel, R; Herranz, D; Hirotani, K; Inoue, S; Inoue, Y; Ioka, K; Jablonski, C; Kagaya, M; Katagiri, H; Kishimoto, T; Kodani, K; Kohri, K; Konno, Y; Koyama, S; Kubo, H; Kushida, J; Lamanna, G; Flour, T Le; López-Moya, M; López, R; Lorenz, E; Majumdar, P; Manalaysay, A; Mariotti, M; Martínez, G; Martínez, M; Mazin, D; Miranda, J M; Mirzoyan, R; Monteiro, I; Moralejo, A; Murase, K; Nagataki, S; Nakajima, D; Nakamori, T; Nishijima, K; Noda, K; Nozato, A; Ohira, Y; Ohishi, M; Ohoka, H; Okumura, A; Orito, R; Panazol, J L; Paneque, D; Paoletti, R; Paredes, J M; Pauletta, G; Podkladkin, S; Prast, J; Rando, R; Reimann, O; Ribó, M; Rosier-Lees, S; Saito, K; Saito, T; Saito, Y; Sakaki, N; Sakonaka, R; Sanuy, A; Sasaki, H; Sawada, M; Scalzotto, V; Schultz, S; Schweizer, T; Shibata, T; Shu, S; Sieiro, J; Stamatescu, V; Steiner, S; Straumann, U; Sugawara, R; Tajima, H; Takami, H; Tanaka, S; Tanaka, M; Tejedor, L A; Terada, Y; Teshima, M; Totani, T; Ueno, H; Umehara, K; Vollhardt, A; Wagner, R; Wetteskind, H; Yamamoto, T; Yamazaki, R; Yoshida, A; Yoshida, T; Yoshikoshi, T

    2013-01-01

    The two arrays of the Very High Energy gamma-ray observatory Cherenkov Telescope Array (CTA) will include four Large Size Telescopes (LSTs) each with a 23 m diameter dish and 28 m focal distance. These telescopes will enable CTA to achieve a low-energy threshold of 20 GeV, which is critical for important studies in astrophysics, astroparticle physics and cosmology. This work presents the key specifications and performance of the current LST design in the light of the CTA scientific objectives.

  8. The AMS-01 Aerogel Threshold Cherenkov counter

    Energy Technology Data Exchange (ETDEWEB)

    Barancourt, D.; Barao, F.; Barbier, G.; Barreira, G.; Buenerd, M.; Castellini, G.; Choumilov, E.; Favier, J.; Fouque, N.; Gougas, A.; Hermel, V.; Kossakowski, R.; Laborie, G.; Laurenti, G.; Lee, S.-C.; Mayet, F. E-mail: frederic.mayet@isn.in2p3.fr; Meillon, B.; Oyang, Y.-T.; Plyaskin, V.; Pojidaev, V.; Rossin, C.; Santos, D.; Vezzu, F.; Vialle, J.P

    2001-06-11

    The Alpha Magnetic Spectrometer in a precursor version (AMS-01), was flown in June 1998 on a 51.6 deg. orbit and at altitudes ranging between 320 and 390 km, on board of the space shuttle Discovery (flight STS-91). AMS-01 included an Aerogel Threshold Cherenkov counter (ATC) to separate p-bar from e{sup -} and e{sup +} from p, for momenta below 3.5 GeV/c. This paper presents a description of the ATC counter and reports on its performances during the flight STS-91.

  9. The AMS-01 Aerogel Threshold Cherenkov counter

    CERN Document Server

    Barancourt, D; Barbier, G; Barreira, G; Buénerd, M; Castellini, G; Choumilov, E; Favier, Jean; Fouque, N; Gougas, Andreas; Hermel, V; Kossakowski, R; Laborie, G; Laurenti, G; Lee, S C; Mayet, F; Meillon, B; Oyang, J Y T; Plyaskin, V; Pozhidaev, V; Rossin, C; Santos, D; Vezzu, F; Vialle, J P

    2001-01-01

    The Alpha Magnetic Spectrometer in a precursor version (AMS-01), was flown in June 1998 on a 51.6 degrees orbit and at altitudes ranging between 320 and 390 km, on board of the space shuttle Discovery (flight STS-91). AMS-01 included an Aerogel Threshold Cherenkov counter (ATC) to separate antiprotons from electrons and positrons from protons, for momenta below 3.5 GeV/c. This paper presents a description of the ATC counter and reports on its performances during the flight STS-91.

  10. Atmospheric Cherenkov Gamma-ray Telescopes

    CERN Document Server

    Holder, Jamie

    2015-01-01

    The stereoscopic imaging atmospheric Cherenkov technique, developed in the 1980s and 1990s, is now used by a number of existing and planned gamma-ray observatories around the world. It provides the most sensitive view of the very high energy gamma-ray sky (above 30 GeV), coupled with relatively good angular and spectral resolution over a wide field-of-view. This Chapter summarizes the details of the technique, including descriptions of the telescope optical systems and cameras, as well as the most common approaches to data analysis and gamma-ray reconstruction.

  11. An Experiment to Demonstrate Cherenkov / Scintillation Signal Separation

    CERN Document Server

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

    2016-01-01

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

  12. Wide-angle cherenkov telescope prototype preliminary data

    Science.gov (United States)

    Timofeev, Lev; Anatoly, Ivanov

    2016-07-01

    This report presents an observation method of Cherenkov light from extensive air showers (EAS) generated by cosmic rays (CRs) above 10^16eV and preliminary observations. The interest in Cherenkov light differential detectors of EAS is caused by the possibility to measure the depth of cascade maximum, Xmax, and/or the shower age via angular and temporal distributions of the Cherenkov signal. In particular, it was shown using EAS model simulations that the pulse width measured at the periphery of the shower, r > 300 m, at sea level is pronouncedly connected with Xmax. Cherenkov detector is a wide-angle telescope working in coincidence with scintillation detectors, integral and differential Cherenkov detectors Yakutsk complex EAS.

  13. Study of wavelength-shifting chemicals for use in large-scale water Cherenkov detectors

    CERN Document Server

    Sweany, M; Dazeley, S; Dunmore, J; Felde, J; Svoboda, R; Tripathi, M

    2011-01-01

    Cherenkov detectors employ various methods to maximize light collection at the photomultiplier tubes (PMTs). These generally involve the use of highly reflective materials lining the interior of the detector, reflective materials around the PMTs, or wavelength-shifting sheets around the PMTs. Recently, the use of water-soluble wavelength-shifters has been explored to increase the measurable light yield of Cherenkov radiation in water. These wave-shifting chemicals are capable of absorbing light in the ultravoilet and re-emitting the light in a range detectable by PMTs. Using a 250 L water Cherenkov detector, we have characterized the increase in light yield from three compounds in water: 4-Methylumbelliferone, Carbostyril-124, and Amino-G Salt. We report the gain in PMT response at a concentration of 1 ppm as: 1.88 $\\pm$ 0.02 for 4-Methylumbelliferone, stable to within 0.5% over 50 days, 1.37 $\\pm$ 0.03 for Carbostyril-124, and 1.20 $\\pm$ 0.02 for Amino-G Salt. The response of 4-Methylumbelliferone was modele...

  14. Roughness tolerances for Cherenkov telescope mirrors

    CERN Document Server

    Tayabaly, K; Canestrari, R; Bonnoli, G; Lavagna, M; Pareschi, G

    2016-01-01

    The Cherenkov Telescope Array (CTA) is a forthcoming international ground-based observatory for very high-energy gamma rays. Its goal is to reach sensitivity five to ten times better than existing Cherenkov telescopes such as VERITAS, H.E.S.S. or MAGIC and extend the range of observation to energies down to few tens of GeV and beyond 100 TeV. To achieve this goal, an array of about 100 telescopes is required, meaning a total reflective surface of several thousands of square meters. Thence, the optimal technology used for CTA mirrors manufacture should be both low-cost (~1000 euros/m2) and allow high optical performances over the 300-550 nm wavelength range. More exactly, a reflectivity higher than 85% and a PSF (Point Spread Function) diameter smaller than 1 mrad. Surface roughness can significantly contribute to PSF broadening and limit telescope performances. Fortunately, manufacturing techniques for mirrors are now available to keep the optical scattering well below the geometrically-predictable effect of ...

  15. The High-Altitude Water Cherenkov Observatory

    Science.gov (United States)

    Mostafá, Miguel A.

    2014-10-01

    The High-Altitude Water Cherenkov (HAWC) observatory is a large field of view, continuously operated, TeV γ-ray experiment under construction at 4,100 m a.s.l. in Mexico. The HAWC observatory will have an order of magnitude better sensitivity, angular resolution, and background rejection than its predecessor, the Milagro experiment. The improved performance will allow us to detect both the transient and steady emissions, to study the Galactic diffuse emission at TeV energies, and to measure or constrain the TeV spectra of GeV γ-ray sources. In addition, HAWC will be the only ground-based instrument capable of detecting prompt emission from γ-ray bursts above 50 GeV. The HAWC observatory will consist of an array of 300 water Cherenkov detectors (WCDs), each with four photomultiplier tubes. This array is currently under construction on the flanks of the Sierra Negra volcano near the city of Puebla, Mexico. The first 30 WCDs (forming an array approximately the size of Milagro) were deployed in Summer 2012, and 100 WCDs will be taking data by May, 2013. We present in this paper the motivation for constructing the HAWC observatory, the status of the deployment, and the first results from the constantly growing array.

  16. The high-altitude water Cherenkov Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Mostafa, Miguel A., E-mail: miguel@psu.edu [Department of Physics, Colorado State University, Ft Collins, CO (United States)

    2014-07-01

    The High-Altitude Water Cherenkov (HAWC) observatory is a large field of view, continuously operated, TeV γ -ray experiment under construction at 4,100ma.s.l. in Mexico. The HAWC observatory will have an order of magnitude better sensitivity, angular resolution, and background rejection than its predecessor, the Milagro experiment. The improved performance will allow to detect both the transient and steady emissions, to study the Galactic diffuse emission at TeV energies, and to measure or constrain the TeV spectra of GeV γ -ray sources. In addition, HAWC will be the only ground-based instrument capable of detecting prompt emission from γ -ray bursts above 50 GeV. The HAWC observatory will consist of an array of 300 water Cherenkov detectors (WCDs), each with four photomultiplier tubes. This array is currently under construction on the flanks of the Sierra Negra volcano near the city of Puebla, Mexico. The first 30 WCDs (forming an array approximately the size of Milagro) were deployed in Summer 2012, and 100 WCDs will be taking data by May, 2013. We present in this paper the motivation for constructing the HAWC observatory, the status of the deployment, and the first results from the constantly growing array. (author)

  17. The High Altitude Water Cherenkov (HAWC) Observatory

    Science.gov (United States)

    Springer, Wayne

    2014-06-01

    The High Altitude Water Cherenkov (HAWC) observatory is a continuously operated, wide field of view detector based upon a water Cherenkov technology developed by the Milagro experiment. HAWC observes, at an elevation of 4100 m on Sierra Negra Mountain in Mexico, extensive air showers initiated by gamma and cosmic rays. The completed detector will consist of 300 closely spaced water tanks each instrumented with four photomultiplier tubes that provide timing and charge information used to reconstruct energy and arrival direction. HAWC has been optimized to observe transient and steady emission from point as well as diffuse sources of gamma rays in the energy range from several hundred GeV to several hundred TeV. Studies in solar physics as well as the properties of cosmic rays will also be performed. HAWC has been making observations at various stages of deployment since completion of 10% of the array in summer 2012. A discussion of the detector design, science capabilities, current construction/commissioning status, and first results will be presented...

  18. The High Altitude Water Cherenkov Observatory

    Science.gov (United States)

    Mostafa, Miguel; HAWC Collaboration

    2016-03-01

    The High Altitude Water Cherenkov (HAWC) Observatory is a continuously operated, wide field of view experiment comprised of an array of 300 water Cherenkov detectors (WCDs) to study transient and steady emission of TeV gamma and cosmic rays. Each 200000 l WCD is instrumented with 4 PMTs providing charge and timing information. The array covers ~22000 m2 at an altitude of 4100 m a.s.l. inside the Pico de Orizaba national park in Mexico. The high altitude, large active area, and optical isolation of the PMTs allows us to reliably estimate the energy and determine the arrival direction of gamma and cosmic rays with significant sensitivity over energies from several hundred GeV to a hundred TeV. Continuously observing 2 / 3 of the sky every 24 h, HAWC plays a significant role as a survey instrument for multi-wavelength studies. The performance of HAWC makes possible the detection of both transient and steady emissions, the study of diffuse emission and the measurement of the spectra of gamma-ray sources at TeV energies. HAWC is also sensitive to the emission from GRBs above 100 GeV. I will highlight the results from the first year of operation of the full HAWC array, and describe the ongoing site work to expand the array by a factor of 4 to explore the high energy range.

  19. The High Altitude Water Cherenkov Observatory

    CERN Document Server

    ,

    2013-01-01

    The High Altitude Water Cherenkov (HAWC) observatory is a large field of view, continuously operated, TeV gamma-ray experiment under construction at 4,100 m a.s.l. in Mexico. The HAWC observatory will have an order of magnitude better sensitivity, angular resolution, and background rejection than its predecessor, the Milagro experiment. The improved performance will allow us to detect both transient and steady emissions, to study the Galactic diffuse emission at TeV energies, and to measure or constrain the TeV spectra of GeV gamma-ray sources. In addition, HAWC will be the only ground-based instrument capable of detecting prompt emission from gamma-ray bursts above 50 GeV. The HAWC observatory will consist of an array of 300 water Cherenkov detectors (WCDs), each with four photomultiplier tubes. This array is currently under construction on the flanks of the Sierra Negra volcano near the city of Puebla, Mexico. The first thirty WCDs (forming an array approximately the size of Milagro) were deployed in Summer...

  20. Optics and radiators for RICH

    CERN Document Server

    Ekelöf, T J C

    1999-01-01

    An overview is given of the basic optics-design principles for Ring Imaging Cherenkov (RICH) counters in High-Energy Physics -- of the earlier evolution of these principles and of the new ideas and techniques that are currently being developed. The characteristics of the different gasses, liquids and solids that are employed as Cherenkov radiators, which are of fundamental importance to the optics design of a RICH counter, are also reviewed.

  1. 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

  2. Proximity focusing RICH detector based on multilayer silica aerogel radiator

    CERN Document Server

    De Leo, R; Bellunato, T; Calvi, M; Cisbani, E; Cusanno, F; Garibaldi, F; Lagamba, L; Marra, M; Marrone, S; Matteuzzi, C; Musico, P; Nappi, E; Perego, D L; Torrioli, S; Vilardi, I

    2010-01-01

    The performance of a proximity focusing Ring Imaging Cherenkov detector equipped with a radiator of silica aerogel is presented. The aerogel tile used is a monolith with variable index of refraction. Cherenkov photons are detected with high granularity by eight Hamamatsu H9500 flat panel multi anode phototubes.

  3. Cherenkov light-based beam profiling for ultrarelativistic electron beams

    Energy Technology Data Exchange (ETDEWEB)

    Adli, E., E-mail: Erik.Adli@fys.uio.no [Department of Physics, University of Oslo, N-0316 Oslo (Norway); SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Gessner, S.J.; Corde, S.; Hogan, M.J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Bjerke, H.H. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States); Department of Physics, Norwegian University of Science and Technology, N-7491 Trondheim (Norway)

    2015-05-21

    We describe a beam profile monitor design based on Cherenkov light emitted from a charged particle beam in an air gap. The main components of the profile monitor are silicon wafers used to reflect Cherenkov light onto a camera lens system. The design allows for measuring large beam sizes, with large photon yield per beam charge and excellent signal linearity with beam charge. The profile monitor signal is independent of the particle energy for ultrarelativistic particles. Different design and parameter considerations are discussed. A Cherenkov light-based profile monitor has been installed at the FACET User Facility at SLAC. We report on the measured performance of this profile monitor.

  4. The Gamma-ray Cherenkov Telescope for the Cherenkov Telescope Array

    CERN Document Server

    Tibaldo, L; Allan, D; Amans, J -P; Armstrong, T P; Balzer, A; Berge, D; Boisson, C; Bousquet, J -J; Brown, A M; Bryan, M; Buchholtz, G; Chadwick, P M; Costantini, H; Cotter, G; Daniel, M K; De Franco, A; De Frondat, F; Dournaux, J -L; Dumas, D; 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; Kraus, M; Lapington, J S; Laporte, P; Lefaucheur, J; Markoff, S; Melse, T; Mohrmann, L; Molyneux, P; Nolan, S J; Okumura, A; Osborne, J P; Parsons, R D; Rosen, S; Ross, D; Rowell, G; 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; Trichard, C; Vink, J; Watson, J J; White, R; Yamane, N; Zech, A; Zink, A; Zorn, J

    2016-01-01

    The Cherenkov Telescope Array (CTA) is a forthcoming ground-based observatory for very-high-energy gamma rays. CTA will consist of two arrays of imaging atmospheric Cherenkov telescopes in the Northern and Southern hemispheres, and will combine telescopes of different types to achieve unprecedented performance and energy coverage. The Gamma-ray Cherenkov Telescope (GCT) is one of the small-sized telescopes proposed for CTA to explore the energy range from a few TeV to hundreds of TeV with a field of view $\\gtrsim 8^\\circ$ and angular resolution of a few arcminutes. The GCT design features dual-mirror Schwarzschild-Couder optics and a compact camera based on densely-pixelated photodetectors as well as custom electronics. In this contribution we provide an overview of the GCT project with focus on prototype development and testing that is currently ongoing. We present results obtained during the first on-telescope campaign in late 2015 at the Observatoire de Paris-Meudon, during which we recorded the first Cher...

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

    CERN Document Server

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

    2014-01-01

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

  6. Redshift measurement of Fermi Blazars for the Cherenkov Telescope Array

    CERN Document Server

    Goldoni, P; Boisson, C; Cotter, G; Williams, D A

    2015-01-01

    Blazars are active galactic nuclei, and the most numerous High Energy (HE) and Very High Energy (VHE) gamma-ray emitters. Their optical emission is often dominated by non-thermal, and, in the case of BL Lacs, featureless continuum radiation. This renders the determination of their redshift extremely difficult. Indeed, as of today only about 50 % of gamma-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 BL Lacs. Using the first Fermi catalogue of sources above 10 GeV (1FHL), we performed simulations which demonstrate that at least half of the 1FHL BL Lacs detectable by CTA will not have a measured redshift. Indeed the organization of observing campaigns to measure the redshift of these blazars has been ...

  7. Particle Identification Using a Ring Imaging Cherenkov Counter

    Science.gov (United States)

    Goodwill, Justin; Benmokthar, Fatiha

    2016-09-01

    The installation of a Ring Imaging Cherenkov counter (RICH) on the CLAS12 spectrometer in Hall B of Jefferson Lab will aid in particle identification, specifically with regard to the separation between protons, pions, kaons. The RICH functions by detecting a ring of radiation that is given off by particles moving faster than the speed of light in a medium through the use of multi-anode photomultiplier tubes (MAPMTs). Because the size of the ring is dependent on the velocity of the particles, one can separate the incoming charged particles. With 391 MAPMTs being used in the specific design at Jefferson Lab, sophisticated electronic systems are needed to achieve complete data acquisition and ensure the safe operation of RICH. To monitor these electronic systems, the slow control system uses a compilation of graphical user interfaces (GUIs) that communicates and, if necessary, changes certain process variables such as the high voltage going to the MAPMTs and the temperature of the system. My actual project focuses on the development of an efficient and reliable slow control system for this detector as well as a java based analyzer for offline data analysis.

  8. Calibration of the Cherenkov Telescope Array

    CERN Document Server

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

    2015-01-01

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

  9. Observer Access to the Cherenkov Telescope Array

    CERN Document Server

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

    2015-01-01

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

  10. 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

  11. TORCH - Cherenkov and Time-of-Flight PID Detector for the LHCb Upgrade at CERN

    Science.gov (United States)

    Föhl, K.; Brook, N.; Castillo García, L.; Conneely, T.; Cussans, D.; Forty, R.; Frei, C.; Gao, R.; Gys, T.; Harnew, N.; Milnes, J.; Piedigrossi, D.; Rademacker, J.; Ros Garcì a, A.; van Dijk, M.

    2016-05-01

    TORCH is a large-area precision time-of-flight detector, based on Cherenkov light production and propagation in a quartz radiator plate, which is read out at its edges. TORCH is proposed for the LHCb experiment at CERN to provide positive particle identification for kaons, and is currently in the Research-and-Development phase. A brief overview of the micro-channel plate photon sensor development, the custom-made electronics, and an introduction to the current test beam activities is given. Optical readout solutions are presented for the potential use of BaBar DIRC bar boxes as part of the TORCH configuration in LHCb.

  12. Study of solar activity by measuring cosmic rays with a water Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Bahena Bias, Angelica [Facultad de ciencias FIsico-Matematicas, Universidad Michoacana de San Nicolas de Hidalgo, Avenida Francisco J. Mujica S/N Ciudad Universitaria C.P. 58030 Morelia, Michoacan (Mexico); Villasenor, Luis, E-mail: anbahena@ifm.umich.mx, E-mail: villasen@ifm.umich.mx [Instituto de Fisica y Matematicas, Universidad Michoacana de San Nicolas de Hidalgo, Avenida Francisco J. Mujica S/N Ciudad Universitaria C.P. 58030 Morelia, Michoacan (Mexico)

    2011-04-01

    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.

  13. Extension of Cherenkov Light LDF Approximation for Yakutsk EAS Array

    Directory of Open Access Journals (Sweden)

    A. A. Al-Rubaiee

    2014-01-01

    Full Text Available The simulation of the Cherenkov light lateral distribution function (LDF in extensive air showers (EAS was performed using CORSIKA code for configuration of Yakutsk EAS array at high energy range for different primary particles (p, Fe, and O2 and different zenith angles. Depending on Breit-Wigner function a parameterization of Cherenkov light LDF was reconstructed on the basis of this simulation as a function of primary energy. A comparison of the calculated Cherenkov light LDF with that measured on the Yakutsk EAS array gives the possibility of identification of the particle initiating the shower and determination of its energy in the knee region of the cosmic ray spectrum. The extrapolation of approximated Cherenkov light LDF for high energies was obtained for primary proton and iron nuclei.

  14. On the "Non-Restricted special Relativity" theory (NRR), and further comments on "Cherenkov vs X-waves"

    CERN Document Server

    Zamboni-Rached, Michel; Besieris, Ioannis M

    2012-01-01

    Our aim in this paper is to recall some essential points of "Extended special Relativity", now more correctly called "Non-Restricted special Relativity" theory (NRR), and in particular of the extended Maxwell Equations; as well as to set forth some further comments on the basic differences between Cherenkov Radiation and the so-called X-shaped Waves, met within the more recent realm of the Non-diffracting Waves (also known as Localized Waves). The occasion is furnished by some very recent Seshadri's comments[1] on a previous article of ours, titled "Cherenkov radiation versus X-shaped localized waves" (see[2], and arXiv:0807.4301[physics.optics]), and not less on NRR itself. OCIS codes: 320.5550; 350.7420; 070.7345; 350.5500; 070.0070; 100.7410; 050.050; 000.1600; 000.2690; 000.6800; 250.5530; 260.0260. PACS nos.: 41.60.Bq; 03.50.De; 03.30.+p; 41.20;Jb; 04.30.Db; 42.25.-p; 42.25.Fx; 47.35.Rs. Keywords: Non-diffracing Waves; Localized Waves; Cherenkov radiation; X-shaped waves; Wave equations; Bessel beams; Su...

  15. Radiation spectrum of an electron moving in a spiralin medium

    Directory of Open Access Journals (Sweden)

    A.V.Konstantinovich

    2007-01-01

    Full Text Available The action of the Doppler effect on the particularities of radiation power spectral distribution of an electron moving in a spiral in a medium has been investigated near the Cherenkov threshold. The fine structure of the electromagnetic radiation spectrum at the Cherenkov threshold and the synchrotron-Cherenkov radiation spectrum for an electron moving along a spiral with non-relativistic longitudinal component of the velocity (i.e., the component parallel to the magnetic induction vector in a transparent isotropic medium have been obtained and studied.

  16. Cherenkov light imaging in astro-particle physics

    Science.gov (United States)

    Mirzoyan, Razmik

    2014-12-01

    Cherenkov light emission plays a key role in contemporary science; it is widely used in high energy, nuclear, and numerous astro-particle physics experiments. Most astro-particle physics experiments are based on the detection of light, and a vast majority of them on the measurement of Cherenkov light. Cherenkov light emission is measured in gases (used in air-Cherenkov technique), in water (for example, neutrino experiments BAIKAL, Super-Kamiokande, NESTOR, ANTARES, future KM3NeT; cosmic and γ-ray experiments Milagro, HAWC, AUGER) and in ice (IceCube). In this report our goal is not limited to simply listing the multitude of experiments that are based on using Cherenkov emission, but we will clarify the reasons making this emission so important and so frequently used. For completeness we will first give a short historical overview on the discovery and evolution of Cherenkov emission and then we will dwell on its main features and numerous applications in astro-particle physics experiments.

  17. Performance of a hybrid photon detector prototype with electrostatic cross-focussing and integrated silicon Pixel readout for Cherenkov ring detection

    CERN Document Server

    Alemi, M; Bibby, J H; Campbell, M; Duane, A; Easo, S; Gys, Thierry; Halley, A W; Piedigrossi, D; Puertolas, D; Rosso, E; Simmons, B; Snoeys, W; Websdale, David M; Wotton, S A; Wyllie, Ken H

    1999-01-01

    We report on the first test beam performance of a hybrid photon detector prototype, using binary readout electronics, intended for use in the ring imaging Cherenkov detectors of the LHCb experiment at the CERN Large Hadron Collider. The photon detector is based on a cross-focussed image intensifier tube geometry. The anode consists of a silicon pixel array bump-bonded to a binary readout chip with matching pixel electronics. The detector has been installed in a quarter-scale prototype vessel of the LHCb ring imaging Cherenkov system. Focussed ring images produced by 120 GeV/c negative pions traversing an air radiator have been recorded. The observed light yield and Cherenkov angle resolution are discussed.

  18. Performance of a hybrid photon detector prototype with electrostatic cross-focussing and integrated silicon pixel readout for Cherenkov ring detection

    Energy Technology Data Exchange (ETDEWEB)

    Alemi, M.; Barber, G.; Bibby, J.; Campbell, M.; Duane, A.; Easo, S.; Gys, T.; Halley, A.; Piedigrossi, D.; Puertolas, D.; Rosso, E.; Simmons, B.; Snoeys, W.; Websdale, D.; Wotton, S.; Wyllie, K

    1999-08-01

    We report on the first test beam performance of a hybrid photon detector prototype, using binary readout electronics, intended for use in the ring imaging Cherenkov detectors of the LHCb experiment at the CERN Large Hadron Collider. The photon detector is based on a cross-focussed image intensifier tube geometry. The anode consists of a silicon pixel array bump-bonded to a binary readout chip with matching pixel electronics. The detector has been installed in a quarter-scale prototype vessel of the LHCb ring imaging Cherenkov system. Focussed ring images produced by 120 GeV/c negative pions traversing an air radiator have been recorded. The observed light yield and Cherenkov angle resolution are discussed.

  19. Sensivity studies for the Cherenkov Telescope Array

    Science.gov (United States)

    Collado, Tarek Hassan

    2015-06-01

    Since the creation of the first telescope in the 17th century, every major discovery in astrophysics has been the direct consequence of the development of novel observation techniques, opening new windows in the electromagnetic spectrum. After Karl Jansky discovered serendipitously the first radio source in 1933, Grote Reber built the first parabolic radio telescope in his backyard, planting the seed of a whole new field in astronomy. Similarly, new technologies in the 1950s allowed the establishment of other fields, such as the infrared, ultraviolet or the X-rays. The highest energy end of the electromagnetic spectrum, the γ-ray range, represents the last unexplored window for astronomers and should reveal the most extreme phenomena that take place in the Universe. Given the technical complexity of γ-ray detection and the extremely relative low fluxes, γ-ray astronomy has undergone a slower development compared to other wavelengths. Nowadays, the great success of consecutive space missions together with the development and refinement of new detection techniques from the ground, has allowed outstanding scientific results and has brought gamma-ray astronomy to a worthy level in par with other astronomy fields. This work is devoted to the study and improvement of the future Cherenkov Telescope Array (CTA), the next generation of ground based γ-ray detectors, designed to observe photons with the highest energies ever observed from cosmic sources.

  20. Proposal for the geometrical distribution of the air cherenkov detectors for CHARM

    Science.gov (United States)

    Morales Reyes, A. R.; Martínez Bravo, O. M.

    2011-04-01

    In this work we propose the geometrical distribution of the air Cherenkov detectors array (ACD), who will be part of the Cosmic High Altitude Radiation Monitor Observatory (CHARM) located at Pico de Orizaba Volcano at 4300 m.a.s.l.. The proposal is based on a library of events built with photons, protons and iron nuclei as primary particles by montecarlo simulations with energies from 1014 eV to 1017 eV. The goal of this detectors will be to determinate the nature of primary cosmic radiation, through measuring the height at which the secondary particles generated reach his maximum number or Xmax, this quantity is related with the effective cross section and finally with the atomic number A of the primary particles. In addition to this we proposed an energy estimator based on the study of the lateral distribution function of the generated events.

  1. Proposal for the geometrical distribution of the air Cherenkov detectors for CHARM

    Energy Technology Data Exchange (ETDEWEB)

    Reyes Morales A R; Bravo Martinez O M, E-mail: hkanzaki@hotmail.com, E-mail: omartin@fcfm.buap.mx [Facultad de Ciencias Fisico Matematicas, Benemerita Universidad Autonoma de Puebla (Mexico)

    2011-04-01

    In this work we propose the geometrical distribution of the air Cherenkov detectors array (ACD), who will be part of the Cosmic High Altitude Radiation Monitor Observatory (CHARM) located at Pico de Orizaba Volcano at 4300 m.a.s.l.. The proposal is based on a library of events built with photons, protons and iron nuclei as primary particles by Monte Carlo simulations with energies from 10{sup 14} eV to 10{sup 17} eV. The goal of this detectors will be to determinate the nature of primary cosmic radiation, through measuring the height at which the secondary particles generated reach his maximum number or X{sub max}, this quantity is related with the effective cross section and finally with the atomic number A of the primary particles. In addition to this we proposed an energy estimator based on the study of the lateral distribution function of the generated events.

  2. 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.

  3. The High-Altitude Water Cherenkov Observatory: First Light

    Science.gov (United States)

    Weisgarber, Thomas

    2013-04-01

    The High-Altitude Water Cherenkov (HAWC) Observatory is under construction at Sierra Negra in the state of Puebla in Mexico. Operation began in September 2012, with the first 30 out of the final 300 water Cherenkov detectors deployed and in data acquisition. The HAWC Observatory is designed to record particle air showers from gamma rays and cosmic rays with TeV energies. Though the detector is only 10% complete, HAWC is already the world's largest water Cherenkov detector in the TeV band. In this presentation, I will summarize the performance of the detector to date and discuss preliminary observations of cosmic-ray and gamma-ray sources. I will also describe deployment plans for the remainder of the detector and outline prospects for TeV observations in the coming year.

  4. Separation of Scintillation and Cherenkov Lights in Linear Alkyl Benzene

    CERN Document Server

    Li, Mohan; Yeh, Minfang; Wang, Zhe; Chen, Shaomin

    2015-01-01

    To separate scintillation and Cherenkov lights in water-based liquid scintillator detectors is a desired feature for future neutrino and proton decay researches. Linear alkyl benzene (LAB) is one important ingredient of a water-based liquid scintillator being developed. In this paper we observed a good separation of scintillation and Cherenkov lights in an LAB sample. The rising and decay times of the scintillation light of the LAB were measured to be $(7.7\\pm3.0)\\ \\rm{ns}$ and $(36.6\\pm2.4)\\ \\rm{ns}$, respectively, while the full width [-3$\\sigma$, 3$\\sigma$] of the Cherenkov light was 12 ns dominated by the time resolution of our photomultiplier tubes. The light yield of the scintillation was measured to be $(1.01\\pm0.12)\\times10^3\\ \\rm{photons}/\\rm{MeV}$.

  5. Lunar Imaging and Ionospheric Calibration for the Lunar Cherenkov Technique

    CERN Document Server

    McFadden, Rebecca; Mevius, Maaijke

    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 ionosphere is an important experimental concern as it reduces the pulse amplitude and subsequent chances of detection. We are continuing to investigate a new method to calibrate the dispersive effect of the ionosphere on lunar Cherenkov pulses via Faraday rotation measurements of the Moon's polarised emission combined with geomagnetic field models. We also extend this work to include radio imaging of the Lunar surface, which provides information on the physical and chemical properties of the lunar surface that may affect experimental strategies for the lunar Cherenkov technique.

  6. The GCT camera for the Cherenkov Telescope Array

    CERN Document Server

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

    2016-01-01

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

  7. Research and Development for a Gadolinium Doped Water Cherenkov Detector

    CERN Document Server

    Renshaw, Andrew

    2012-01-01

    The proposed introduction of a soluble gadolinium (Gd) compound into water Cherenkov detectors can result in a high efficiency for the detection of free neutrons capturing on the Gd. The delayed 8 MeV gamma cascades produced by these captures, in coincidence with a prompt positron signal, serve to uniquely identify electron antineutrinos interacting via inverse beta decay. Such coincidence detection can reduce backgrounds, allowing a large Gd-enhanced water Cherenkov detector to make the first observation of supernova relic neutrinos and high precision measurements of Japan's reactor antineutrino flux, while still allowing for all current physics studies to be continued. Now, a dedicated Gd test facility is operating in the Kamioka Mine. This new facility houses everything needed to successfully operate a Gd doped water Cherenkov detector. Successful running of this facility will demonstrate that adding Gd salt to SK is both safe for the detector and is capable of delivering the expected physics benefits.

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

    CERN Document Server

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

    2001-01-01

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

  9. Cherenkov and Scintillation Light Separation in Organic Liquid Scintillators

    CERN Document Server

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

    2016-01-01

    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 2g/L of PPO as a fluor (LAB/PPO). This is the first such demonstration for 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 0.75 +/- 0.25 ns.

  10. Light Sensor Candidates for the Cherenkov Telescope Array

    CERN Document Server

    Knoetig, M L; Kurz, M; Hose, J; Lorenz, E; Schweizer, T; Teshima, M; Buzhan, P; Popova, E; Bolmont, J; Tavernet, J -P; Vincent, P; Shayduk, M

    2011-01-01

    We report on the characterization of candidate light sensors for use in the next-generation Imaging Atmospheric Cherenkov Telescope project called Cherenkov Telescope Array, a major astro-particle physics project of about 100 telescopes that is currently in the prototyping phase. Our goal is to develop with the manufacturers the best possible light sensors (highest photon detection efficiency, lowest crosstalk and afterpulsing). The cameras of those telescopes will be based on classical super-bi-alkali Photomultiplier tubes but also Silicon Photomultipliers are candidate light sensors. A full characterisation of selected sensors was done. We are working in close contact with several manufacturers, giving them feedback and suggesting improvements.

  11. Gain of double-slab Cherenkov free-electron laser

    Energy Technology Data Exchange (ETDEWEB)

    Li, D. [Institute for laser Technology, suita, Osaka 565-0871 (Japan)], E-mail: dazhi_li@hotmail.com; Huo, G. [Petroleum development center, Shengli Oilfield, SINOPEC, Dongying 257001 (China); Imasak, K. [Institute for laser Technology, suita, Osaka 565-0871 (Japan); Asakawa, M. [Department of pure and applied physics, Faculty of Engineering Science, Kansai University, Osaka 564-8680 (Japan)

    2009-07-21

    A formula is derived for the small-signal gain of a double-slab Cherenkov free-electron laser. The simplified model is composed of a rectangular wave-guide partially filled with two lined parallel dielectric slabs and a sheet electron beam. The theory describes the electron beam as a plasma dielectric moving between the two dielectric slabs. With the help of hydrodynamic approximation, we derived the dispersion equation and the formula of small-signal gain. Through numerical computing, we studied an ongoing experiment of double-slab Cherenkov free-electron laser, and worked out the synchronous frequency and single-pass gain.

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

    CERN Document Server

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

    2013-01-01

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

  13. Long term biological developments in water Cherenkov detector media

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-12-11

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

  14. 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 iono

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

    CERN Document Server

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

    2015-01-01

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

  16. Suppressing the Numerical Cherenkov Instability in FDTD PIC Codes

    CERN Document Server

    Godfrey, Brendan B

    2014-01-01

    A procedure for largely suppressing the numerical Cherenkov instability in finite difference time-domain (FDTD) particle-in-cell (PIC) simulations of cold, relativistic beams is derived, and residual growth rates computed and compared with WARP code simulation results. Sample laser-plasma acceleration simulation output is provided to further validate the new procedure.

  17. An Ultra-High Gradient Cherenkov Wakefield Acceleration Experiment at SLAC FFTB

    Energy Technology Data Exchange (ETDEWEB)

    Rosenzweig, J.B.; Hoover, S.; Hogan, M.J.; Muggli, P.; Thompson, M.; Travish, G.; Yoder, R.; /UCLA /SLAC /Southern California U.

    2005-08-02

    The creation of ultra-high current, ultra-short pulse beams Q=3 nC, {sigma}{sub z} = 20{micro}m at the SLAC FFTB has opened the way for very high gradient plasma wakefield acceleration experiments. We study here the use of these beams in a proposed Cherenkov wakefield experiment, where one may excite electromagnetic wakes in a simple dielectric tube with inner diameter of few 100 microns that exceed the GV/m level. We discuss the scaling of the fields with design geometric design parameters, and choice of dielectric. We also examine measurable aspects of the experiment, such as the total coherent Cerenkov radiation energy one may collect, and the expected aspects of dielectric breakdown at high fields.

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

    Energy Technology Data Exchange (ETDEWEB)

    Budick, B., E-mail: bb2@nyu.ed [New York University, New York, NY 10003 (United States); Beavis, D., E-mail: beavis@bnl.go [Brookhaven National Laboratory, Upton, NY 11973 (United States); Chasman, C., E-mail: chasman@bnl.go [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2010-09-21

    A multi-element detector based on Cherenkov radiation in plastic and on photomultiplier tubes has been constructed that is particularly useful in collider experiments. The detector covers the pseudorapidity interval 3.23<{eta}<5.25 with large acceptance for the products of proton-proton and heavy ion collisions. The detector's primary purposes are determining the vertex of the interaction, providing a minimum bias trigger, finding the start time for time of flight (and other timing applications), and monitoring the luminosity. Monte Carlo simulations describe the pulse height response of the detector well, as does an analytic expression that has been developed. The detector performed well in the RHIC experiment BRAHMS.

  19. An Analog Trigger System for Atmospheric Cherenkov Telescopes

    CERN Document Server

    Barcelo, M; Bigas, O Blanch; Boix, J; Delgado, C; Herranz, D; Lopez-Coto, R; Martinez, G

    2013-01-01

    Arrays of Cherenkov telescopes typically use multi-level trigger schemes to keep the rate of random triggers from the night sky background low. At a first stage, individual telescopes produce a trigger signal from the pixel information in the telescope camera. The final event trigger is then formed by combining trigger signals from several telescopes. In this poster, we present a possible scheme for the Cherenkov Telescope Array telescope trigger, which is based on the analog pulse information of the pixels in a telescope camera. Advanced versions of all components of the system have been produced and working prototypes have been tested, showing a performance that meets the original specifications. Finally, issues related to integrating the trigger system in a telescope camera and in the whole array will be dealt with.

  20. Spectrum of energy depositions in the Auger Water Cherenkov Detector

    Science.gov (United States)

    Salazar, Humberto

    1999-08-01

    The measured spectrum of energy depositions in a Water Cherenkov Detector (WCD) prototype for the Pierre Auger Observatory is presented. A WCD (area 10 m2 )is located in the Puebla University campus at a depth of 800 g/cm2 (2200 m above sea level). Differential and integral spectra in a wide energy deposition range (0.5 - 150 of vertical equivalent muons) are presented. The problem of the WCD "self calibration" procedure (by rate of the muon events) is discussed. The characteristic change of the slopes of the differential spectrum at the transition from single muon signals to EAS signals is also discussed. The measured energy deposition spectrum at extreme signals is used to estimate the linearity of the response of the WCD PMTs. Key words: Auger array, water Cherenkov detector, extensive air showers

  1. Normalized and Asynchronous Mirror Alignment for Cherenkov Telescopes

    CERN Document Server

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

    2016-01-01

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

  2. Schwarzschild-Couder Telescope for the Cherenkov Telescope Array

    CERN Document Server

    Meagher, Kevin J

    2014-01-01

    The Cherenkov Telescope Array (CTA) is the next major ground-based observatory for gamma-ray astronomy. With CTA gamma-ray sources will be studied in the very-high energy gamma-ray range of a few tens of GeV to 100 TeV with up to ten times better sensitivity than available with current generation instruments. We discuss the proposed US contribution to CTA that comprises imaging atmospheric Cherenkov telescope with Schwarzschild-Couder (SC) optics. Key features of the SC telescope are a wide field of view of eight degrees, a finely pixelated camera with silicon photomultipliers as photon detectors, and a compact and power efficient 1 GS/s readout. The progress in both the optical system and camera development are discussed in this paper.

  3. Detection of Cherenkov light emission in liquid argon

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-01-11

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kraehenbuehl, T., E-mail: thomas.kraehenbuehl@phys.ethz.ch [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Anderhub, H. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Backes, M. [Technische Universitaet Dortmund, D-44221 Dortmund (Germany); Biland, A.; Boller, A.; Braun, I. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Bretz, T. [Ecole Polytechnique Federale de Lausanne, CH-1015 Lausanne (Switzerland); Commichau, V.; Djambazov, L. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Dorner, D.; Farnier, C. [ISDC Data Center for Astrophysics, CH-1290 Versoix (Switzerland); Gendotti, A.; Grimm, O.; Gunten, H. von; Hildebrand, D.; Horisberger, U.; Huber, B.; Kim, K.-S. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Koehne, J.-H.; Krumm, B. [Technische Universitaet Dortmund, D-44221 Dortmund (Germany); and others

    2012-12-11

    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.

  5. Measuring Cherenkov Backgrounds from Proportional Counters in SNO

    Science.gov (United States)

    Seibert, Stanley

    2006-04-01

    In the current phase of operation of the Sudbury Neutrino Observatory, He-3 proportional counters have been deployed in the center of the detector to measure neutron production from neutral-current interactions between neutrinos and deuterons in the heavy water. Radioactive decays of Bi-214 and Tl-208 in the counters produce gammas of sufficient energy to photodisintegrate deuterons, which become a background to the neutral current measurement. We have measured the background rate in-situ using Cherenkov light detected with SNO's 9456 inward-looking photomultiplier tubes. A maximum likelihood method is used to separate backgrounds in the heavy water from backgrounds in the proportional counters based upon the spatial distribution of low energy Cherenkov event vertices. Uncertainties on the backgrounds have been estimated using calibration data taken with both a distributed Na-24 source, and a contained Th source deployed at various points in the detector.

  6. Silicon Photomultiplier Camera for Schwarzschild-Couder Cherenkov Telescopes

    CERN Document Server

    Vandenbroucke, J

    2014-01-01

    The Cherenkov Telescope Array (CTA) is an atmospheric Cherenkov observatory that will image the cosmos in very-high-energy gamma rays. CTA will study the highest-energy particle accelerators in the Universe and potentially confirm the particle nature of dark matter. We have designed an innovative Schwarzschild-Couder telescope which uses two mirrors to achieve excellent optical performance across a wide field of view. The small plate scale of the dual-mirror optics enables a compact camera which uses modern technology including silicon photomultipliers and the TARGET application-specific integrated circuit to read out a finely pixelated focal plane of 11,328 channels with modest weight, volume, cost, and power consumption. The camera design is hierarchical and modular at each level, enabling robust construction, operation, and maintenance. A prototype telescope is under construction and will be commissioned at the VERITAS site in Arizona. An array of such telescopes will provide excellent angular resolution a...

  7. Cherenkov loss factor of short relativistic bunches:general approach

    CERN Document Server

    Baturin, S S

    2013-01-01

    The interaction of short relativistic charged particle bunches with waveguides and other accelerator system components is a critical issue for the development of X-ray FELs (free electron lasers) and linear collider projects. Wakefield Cherenkov losses of short bunches have been studied previously for resistive wall, disk-loaded, corrugated and dielectric loaded waveguides. It was noted in various publications [1] that if the slowdown layer is thin, the Cherenkov loss factor of a short bunch does not depend on the guiding system material and is a constant for any given transverse cross section dimensions of the waveguides. In this paper, we consider a new approach to the analysis of loss factors for relativistic short bunches and formulate a general integral relation that allows calculation of the loss factor for a short relativistic bunch passing an arbitrary waveguide system. The loss factors calculated by this new method for various types of waveguides with arbitrary thickness slowdown layers, including in...

  8. Cherenkov Detector for Beam Quality Measurement

    CERN Document Server

    Orfanelli, Stella

    2015-01-01

    A new detector to measure the machine induced background at larger radiihas been developed and installed in the CMS experiment at LHC. Itconsists of 40 modules, each comprising a quartz bar read out by aphotomultiplier. Since Cerenkov radiation is emitted in a forward conearound the charged particle trajectory, these detectors can distinguishthe directions of the machine induced background.The back-end consists of a microTCA readout with excellent time resolution.The performance of the detector modules measured in several test-beamcampaigns will be reported. The installation in CMS will be described, andfirst results about operating the detector during data taking will begiven.

  9. PyFACT: Python and FITS analysis for Cherenkov telescopes

    Science.gov (United States)

    Raue, Martin; Deil, Christoph

    2012-12-01

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

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

    CERN Document Server

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

    2014-01-01

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

  11. Normalized and asynchronous mirror alignment for Cherenkov telescopes

    Science.gov (United States)

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

    2016-09-01

    Imaging Atmospheric Cherenkov Telescopes (IACTs) need imaging optics with large apertures and high image intensities to map the faint Cherenkov light emitted from cosmic ray air showers onto their image sensors. Segmented reflectors fulfill these needs, and as they are composed from mass production mirror facets they are inexpensive and lightweight. However, as the overall image is a superposition of the individual facet images, alignment is a challenge. Here we present a computer vision based star tracking alignment method, which also works for limited or changing star light visibility. Our method normalizes the mirror facet reflection intensities to become independent of the reference star's intensity or the cloud coverage. Using two CCD cameras, our method records the mirror facet orientations asynchronously of the telescope drive system, and thus makes the method easy to integrate into existing telescopes. It can be combined with remote facet actuation, but does not require one to work. Furthermore, it can reconstruct all individual mirror facet point spread functions without moving any mirror. We present alignment results on the 4 m First Geiger-mode Avalanche Cherenkov Telescope (FACT).

  12. 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 ...

  13. Cherenkov counting efficiencies for {beta}{sup -}-emitters in dry state in glass vials

    Energy Technology Data Exchange (ETDEWEB)

    Morita-Murase, Yuko; Murakami, Isao; Homma, Yoshio [Laboratory for Radiopharmaceutical Chemistry, Kyoritsu College of Pharmacy, Tokyo (Japan)

    2000-10-01

    Cherenkov counting efficiencies for standardized {beta}{sup -} -emitters in the dry state at the centre of air-filled glass vials were measured with a liquid scintillation spectrometer. Cherenkov counting efficiencies, which are plotted as a function of the average energy of {beta}{sup -}-particles and the internal conversion electrons, give a straight line on log-log scale. (author)

  14. 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.

  15. The Ring Imaging Cherenkov detector of the AMS experiment: test beam results with a prototype

    CERN Document Server

    Arruda, Luísa; Goncalves, Patrícia; Pereira, Rui

    2008-01-01

    The Alpha Magnetic Spectrometer (AMS) to be installed on the International Space Station (ISS) will be equipped with a proximity Ring Imaging Cherenkov (RICH) detector for measuring the velocity and electric charge of the charged cosmic particles. This detector will contribute to the high level of redundancy required for AMS as well as to the rejection of albedo particles. Charge separation up to iron and a velocity resolution of the order of 0.1% for singly charged particles are expected. A RICH protoptype consisting of a detection matrix with 96 photomultiplier units, a segment of a conical mirror and samples of the radiator materials was built and its performance was evaluated. Results from the last test beam performed with ion fragments resulting from the collision of a 158 GeV/c/nucleon primary beam of indium ions (CERN SPS) on a lead target are reported. The large amount of collected data allowed to test and characterize different aerogel samples and the sodium fluoride radiator. In addition, the reflec...

  16. Development of the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE)

    CERN Document Server

    Ong, R A

    1998-01-01

    STACEE is a proposed atmospheric Cherenkov telescope for ground-based gamma-ray astrophysics between 25 and 500 GeV. The telescope will make use of the large solar mirrors (heliostats) available at a solar research facility to achieve an energy threshold lower than any existing ground-based instrument. This paper describes the development of STACEE, including an overview of the complete instrument design and a discussion of results from recent prototype tests at the large solar heliostat field of Sandia National Laboratories.

  17. 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.

  18. 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.

  19. First scientific contributions from the High Altitude Water Cherenkov Observatory

    Science.gov (United States)

    León Vargas, H.; HAWC Collaboration

    2015-09-01

    The High Altitude Water Cherenkov Observatory (HAWC), located at the slopes of the volcanoes Sierra Negra and Pico de Orizaba in Mexico, was inaugurated on March 20, 2015. However, data taking started in August 2013 with a partially deployed observatory and since then the instrument has collected data as it got closer to its final configuration. HAWC is a ground based TeV gamma-ray observatory with a large field of view that will be used to study the Northern sky with high sensitivity. In this contribution we present some of the results obtained with the partially built instrument and the expected capabilities to detect different phenomena with the complete observatory.

  20. Control Software for the VERITAS Cherenkov Telescope System

    CERN Document Server

    Krawczynski, H; Sembroski, G; Gibbs, K

    2003-01-01

    The VERITAS collaboration is developing a system of initially 4 and eventually 7 Cherenkov Telescopes of the 12 m diameter class for high sensitivity gamma-ray astronomy in the >50 GeV energy range. In this contribution we describe the software that controls and monitors the various VERITAS sub-systems. The software uses an object-oriented approach to cope with the complexities that arise from using sub-groups of the 7 VERITAS telescopes to observe several sources at the same time. Inter-process communication is based on the CORBA Object Request Broker protocol and watch-dog processes monitor the sub-system performance.

  1. Operational performance of the Hall A mirror aerogel Cherenkov counter

    CERN Document Server

    Brash, E J; Lolos, G J; Huber, G M; Meer, R V D; Papandreou, Z

    2002-01-01

    We report the results of an operational test of the efficiency and position sensitivity of a silica-aerogel Cherenkov detector installed in the HRS-E spectrometer in Hall A at Jefferson Lab. The calibration was performed with data from elastic electron scattering from polarized sup 3 He. The response of the photo-multiplier tubes was linearized with a quadratic correction, allowing a unique number of photo-electrons (PEs) to be extracted. The result obtained (approx 7.3 PEs) is consistent with the performance of the prototype detector tested earlier under ideal conditions.

  2. Tests of innovative photon detectors and integrated electronics for the large-area CLAS12 ring-imaging Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Contalbrigo, Marco [INFN, Ferrara, Italy

    2015-07-01

    A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab. Its aim is to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and a densely packed and highly segmented photon detector. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). Extensive tests have been performed on Hamamatsu H8500 and novel flat multi-anode photomultipliers under development and on various types of silicon photomultipliers. A large scale prototype based on 28 H8500 MA-PMTs has been realized and tested with few GeV/c hadron beams at the T9 test-beam facility of CERN. In addition a small prototype was used to study the response of customized SiPM matrices within a temperature interval ranging from 25 down to –25 °C. The preliminary results of the individual photon detector tests and of the prototype performance at the test-beams are here reported.

  3. Tests of innovative photon detectors and integrated electronics for the large-area CLAS12 ring-imaging Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Contalbrigo, M., E-mail: contalbrigo@fe.infn.it

    2015-07-01

    A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab. Its aim is to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and a densely packed and highly segmented photon detector. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). Extensive tests have been performed on Hamamatsu H8500 and novel flat multi-anode photomultipliers under development and on various types of silicon photomultipliers. A large scale prototype based on 28 H8500 MA-PMTs has been realized and tested with few GeV/c hadron beams at the T9 test-beam facility of CERN. In addition a small prototype was used to study the response of customized SiPM matrices within a temperature interval ranging from 25 down to −25 °C. The preliminary results of the individual photon detector tests and of the prototype performance at the test-beams are here reported.

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

    CERN Document Server

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

    2013-01-01

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

  5. FACT -- The G-APD revolution in Cherenkov astronomy

    CERN Document Server

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

    2014-01-01

    Since two years, the FACT telescope is operating on the Canary Island of La Palma. Apart from its purpose to serve as a monitoring facility for the brightest TeV blazars, it was built as a major step to establish solid state photon counters as detectors in Cherenkov astronomy. The camera of the First G-APD Cherenkov Telesope comprises 1440 Geiger-mode avalanche photo diodes (G-APD), equipped with solid light guides to increase the effective light collection area of each sensor. Since no sense-line is available, a special challenge is to keep the applied voltage stable although the current drawn by the G-APD depends on the flux of night-sky background photons significantly varying with ambient light conditions. Methods have been developed to keep the temperature and voltage dependent response of the G-APDs stable during operation. As a cross-check, dark count spectra with high statistics have been taken under different environmental conditions. In this presentation, the project, the developed methods and the e...

  6. 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...

  7. Upgraded cameras for the HESS imaging atmospheric Cherenkov telescopes

    Science.gov (United States)

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

    2016-08-01

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

  8. The readout system of the MAGIC-II Cherenkov Telescope

    CERN Document Server

    Tescaro, D; Barcelo, M; Bitossi, M; Cortina, J; Fras, M; Hadasch, D; Illa, J M; Martínez, M; Mazin, D; Paoletti, R; Pegna, R

    2009-01-01

    In this contribution we describe the hardware, firmware and software components of the readout system of the MAGIC-II Cherenkov telescope on the Canary island La Palma. The PMT analog signals are transmitted by means of optical fibers from the MAGIC-II camera to the 80 m away counting house where they are routed to the new high bandwidth and fully programmable receiver boards (MONSTER), which convert back the signals from optical to electrical ones. Then the signals are split, one half provide the input signals for the level ONE trigger system while the other half is sent to the digitizing units. The fast Cherenkov pulses are sampled by low-power Domino Ring Sampler chips (DRS2) and temporarily stored in an array of 1024 capacitors. Signals are sampled at the ultra-fast speed of 2 GSample/s, which allows a very precise measurement of the signal arrival times in all pixels. They are then digitized with 12-bit resolution by an external ADC readout at 40 MHz speed. The Domino samplers are integrated in the newly...

  9. Scientific verification of High Altitude Water Cherenkov observatory

    Science.gov (United States)

    Marinelli, Antonio; Sparks, Kathryne; Alfaro, Ruben; González, María Magdalena; Patricelli, Barbara; Fraija, Nissim

    2014-04-01

    The High Altitude Water Cherenkov (HAWC) observatory is a TeV gamma-ray and cosmic-ray detector currently under construction at an altitude of 4100 m close to volcano Sierra Negra in the state of Puebla, Mexico. The HAWC [1] observatory is an extensive air-shower array composed of 300 optically isolated water Cherenkov detectors (WCDs). Each WCD contains ~200,000 l of filtered water and four upward-facing photomultiplier tubes. In Fall 2014, when the HAWC observatory will reach an area of 22,000 m2, the sensitivity will be 15 times higher than its predecessor Milagro [2]. Since September 2012, more than 30 WCDs have been instrumented and taking data. This first commissioning phase has been crucial for the verification of the data acquisition and event reconstruction algorithms. Moreover, with the increasing number of instrumented WCDs, it is important to verify the data taken with different configuration geometries. In this work we present a comparison between Monte Carlo simulation and data recorded by the experiment during 24 h of live time between 14 and 15 April of 2013 when 29 WCDs were active.

  10. Scientific verification of High Altitude Water Cherenkov observatory

    Energy Technology Data Exchange (ETDEWEB)

    Marinelli, Antonio, E-mail: antonio.marinelli@fisica.unam.mx [Instituto de Física, Universidad Nacional Autónoma de México, Mexico D.F. (Mexico); Sparks, Kathryne [Department of Physics, Pennsylvania State University, University Park, PA (United States); Alfaro, Ruben [Instituto de Física, Universidad Nacional Autónoma de México, Mexico D.F. (Mexico); González, María Magdalena; Patricelli, Barbara; Fraija, Nissim [Instituto de Astronomia, Universidad Nacional Autónoma de México, Mexico D.F. (Mexico)

    2014-04-01

    The High Altitude Water Cherenkov (HAWC) observatory is a TeV gamma-ray and cosmic-ray detector currently under construction at an altitude of 4100 m close to volcano Sierra Negra in the state of Puebla, Mexico. The HAWC [1] observatory is an extensive air-shower array composed of 300 optically isolated water Cherenkov detectors (WCDs). Each WCD contains ∼200,000 l of filtered water and four upward-facing photomultiplier tubes. In Fall 2014, when the HAWC observatory will reach an area of 22,000 m{sup 2}, the sensitivity will be 15 times higher than its predecessor Milagro [2]. Since September 2012, more than 30 WCDs have been instrumented and taking data. This first commissioning phase has been crucial for the verification of the data acquisition and event reconstruction algorithms. Moreover, with the increasing number of instrumented WCDs, it is important to verify the data taken with different configuration geometries. In this work we present a comparison between Monte Carlo simulation and data recorded by the experiment during 24 h of live time between 14 and 15 April of 2013 when 29 WCDs were active.

  11. The next generation Cherenkov Telescope Array observatory: CTA

    CERN Document Server

    Vercellone, Stefano

    2014-01-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to the VHE gamma-ray astrophysics in the energy range 30 GeV-100 TeV, which will improve by about one order of magnitude the sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS). In order to achieve such improved performance, for both the northern and southern CTA sites, four units of 23m diameter Large Size Telescopes (LSTs) will be deployed close to the centre of the array with telescopes separated by about 100m. A larger number (about 25 units) of 12m Medium Size Telescopes (MSTs, separated by about 150m), will cover a larger area. The southern site will also include up to 24 Schwarzschild-Couder dual-mirror medium-size Telescopes (SCTs) with the primary mirror diameter of 9.5m. Above a few TeV, the Cherenkov light intensity is such that showers can be detected even well outside the light pool by telescopes significantly smaller than the MSTs. To a...

  12. 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.

  13. 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...

  14. Tagging Spallation Backgrounds with Showers in Water-Cherenkov Detectors

    CERN Document Server

    Li, Shirley Weishi

    2015-01-01

    Cosmic-ray muons and especially their secondaries break apart nuclei ("spallation") and produce fast neutrons and beta-decay isotopes, which are backgrounds for low-energy experiments. In Super-Kamiokande, these beta decays are the dominant background in 6--18 MeV, relevant for solar neutrinos and the diffuse supernova neutrino background. In a previous paper, we showed that these spallation isotopes are produced primarily in showers, instead of in isolation. This explains an empirical spatial correlation between a peak in the muon Cherenkov light profile and the spallation decay, which Super-Kamiokande used to develop a new spallation cut. However, the muon light profiles that Super-Kamiokande measured are grossly inconsistent with shower physics. We show how to resolve this discrepancy and how to reconstruct accurate profiles of muons and their showers from their Cherenkov light. We propose a new spallation cut based on these improved profiles and quantify its effects. Our results can significantly benefit ...

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

    CERN Document Server

    ,

    2015-01-01

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

  16. 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...

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

    CERN Document Server

    Dyrda, Michal; Niemiec, Jacek; Stodulski, Marek

    2013-01-01

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

  18. Highlights from the High Altitude Water Cherenkov Observatory

    CERN Document Server

    Pretz, John

    2015-01-01

    The High Altitude Water Cherenkov (HAWC) Gamma-Ray Observatory was completed this year at a 4100-meter site on the flank of the Sierra Negra volcano in Mexico. HAWC is a water Cherenkov ground array with the capability to distinguish 100 GeV - 100 TeV gamma rays from the hadronic cosmic-ray background. HAWC is uniquely suited to study extremely high energy cosmic-ray sources, search for regions of extended gamma-ray emission, and to identify transient gamma-ray phenomena. HAWC will play a key role in triggering multi-wavelength and multi-messenger studies of active galaxies, gamma-ray bursts, supernova remnants and pulsar wind nebulae. Observation of TeV photons also provide unique tests for a number of fundamental physics phenomena including dark matter annihilation and primordial black hole evaporation. Operation began mid-2013 with the partially-completed detector. Multi-TeV emission from the Galactic Plane is clearly seen in the first year of operation, confirming a number of known TeV sources, and a numb...

  19. Ultra-high resolution of radiocesium distribution detection based on Cherenkov light imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, Seiichi, E-mail: s-yama@met.nagoya-u.ac.jp [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Ogata, Yoshimune [Department of Radiological and Medical Laboratory Sciences, Nagoya University Graduate School of Medicine (Japan); Kawachi, Naoki; Suzui, Nobuo; Yin, Yong-Gen; Fujimaki, Shu [Radiotracer Imaging Group, Japan Atomic Energy Agency (Japan)

    2015-03-21

    After the nuclear disaster in Fukushima, radiocesium contamination became a serious scientific concern and research of its effects on plants increased. In such plant studies, high resolution images of radiocesium are required without contacting the subjects. Cherenkov light imaging of beta radionuclides has inherently high resolution and is promising for plant research. Since {sup 137}Cs and {sup 134}Cs emit beta particles, Cherenkov light imaging will be useful for the imaging of radiocesium distribution. Consequently, we developed and tested a Cherenkov light imaging system. We used a high sensitivity cooled charge coupled device (CCD) camera (Hamamatsu Photonics, ORCA2-ER) for imaging Cherenkov light from {sup 137}Cs. A bright lens (Xenon, F-number: 0.95, lens diameter: 25 mm) was mounted on the camera and placed in a black box. With a 100-μm {sup 137}Cs point source, we obtained 220-μm spatial resolution in the Cherenkov light image. With a 1-mm diameter, 320-kBq {sup 137}Cs point source, the source was distinguished within 2-s. We successfully obtained Cherenkov light images of a plant whose root was dipped in a {sup 137}Cs solution, radiocesium-containing samples as well as line and character phantom images with our imaging system. Cherenkov light imaging is promising for the high resolution imaging of radiocesium distribution without contacting the subject.

  20. 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.

  1. A Pointing Solution for the Medium Size Telescopes for the Cherenkov Telescope Array

    CERN Document Server

    Tiziani, D; Oakes, L; Schwanke, U

    2016-01-01

    An important aspect of the calibration of the Cherenkov Telescope Array is the pointing, which enables an exact alignment of each telescope and therefore allows to transform a position in the sky to a point in the plane of the Cherenkov camera and vice versa. The favoured approach for the pointing calibration of the medium size telescopes (MST) is the installation of an optical CCD-camera in the dish of the telescope that captures the position of the Cherenkov camera and of the stars in the night sky simultaneously during data taking. The adaption of this approach is presented in this proceeding.

  2. Superradiance driven by coherent spontaneous emission in a Cherenkov free-electron maser amplifier

    CERN Document Server

    Jaroszynski, D A; McNeil, B W J; Robb, G R M; Aitken, P; Phelps, A D R; Cross, A W; Ronald, K; Shpak, V G; Yalandin, M I; Ginzburg, N S

    2000-01-01

    Superradiance (SR) initiated by coherent spontaneous emission (CSE) has been studied in a 35 GHz high gain free-electron Cherenkov maser. We present experimental results that show the development of ultra-short pulses of radiation in the non-linear superradiant regime which are characterised by a quadratic dependence of the intensity on the current. The self-similar pulses that develop have a duration that scales inversely with the fourth root of the intensity leading to three cycle long pulses at the highest intensity (few MW). The non-linear SR regime is preceded by a stage of linear exponential growth of the microwave pulses with a gain length of 1 cm. The superradiant pulse is shown to evolve from a CSE seed by extrapolating the growth curve. Further confirmation of CSE has been obtained by varying the current pulse shape. By varying the slope of the leading edge, and thus the Fourier components of the longitudinal spectral density, we are able to vary the strength of the CSE source. We compare the experi...

  3. Gas Cherenkov Detectors For Gamma Ray Measurements At The National Ignition Facility (NIF)

    Science.gov (United States)

    Herrmann, Hans W.; Kim, Y. H.; Zylstra, A. B.; Lopez, F. E.; Griego, J.; Fatherley, V. E.; Oertel, J. A.; Batha, S. H.; Carpenter, A.; Khater, H.; Hernandez, J. E.; Rubery, M. S.; Horsfield, C. J.; Gales, S.; Leatherland, A.; Hilsabeck, T.; Kilkenny, J. D.; Malone, R. M.; Hares, J. D.; Milnes, J.; Shmayda, W. T.

    2016-10-01

    New requirements to improve reaction history and ablator areal density measurements at the NIF necessitate diagnostic capability improvements in sensitivity, temporal and spectral response relative to the existing Gamma Reaction History diagnostic (GRH-6m) located 6 meters from target chamber center (TCC). Relative to GRH-6m, a new DIM-based ``Super'' Gas Cherenkov Detector (GCD) will ultimately provide 200x more sensitivity to DT fusion gamma rays, reduce the effective temporal resolution from 100 to 10 ps and lower the energy threshold from 2.9 to 1.8 MeV. Initially, the existing GCD-3 will be placed into a reentrant well, putting it within 4 meters of TCC. This diagnostic platform will allow assessment of the x-ray radiation background environment within the well which will be fed into the shielding design for the follow-on ``Super'' GCD. It will also enable use of a pulse-dilation PMT (PD-PMT) which has the potential to improve the effective measurement bandwidth by 10x relative to current PMT technology. Initial measurements of both GCD-3 on NIF and a PD-PMT prototype on ORION will be discussed.

  4. ``Super'' Gas Cherenkov Detector for Gamma Ray Measurements at the National Ignition Facility

    Science.gov (United States)

    Herrmann, Hans W.; Kim, Y. H.; McEvoy, A. M.; Zylstra, A. B.; Lopez, F. E.; Griego, J. R.; Fatherley, V. E.; Oertel, J. A.; Batha, S. H.; Stoeffl, W.; Church, J. A.; Carpenter, A.; Rubery, M. S.; Horsfield, C. J.; Gales, S.; Leatherland, A.; Hilsabeck, T.; Kilkenny, J. D.; Malone, R. M.; Shmayda, W. T.

    2015-11-01

    New requirements to improve reaction history and ablator areal density measurements at the NIF necessitate improvements in sensitivity, temporal and spectral response relative to the existing Gamma Reaction History diagnostic (GRH-6m) located 6 meters from target chamber center (TCC). A new DIM-based ``Super'' Gas Cherenkov Detector (GCD) will ultimately provide ~ 200x more sensitivity to DT fusion gamma rays, reduce the effective temporal resolution from ~ 100 to ~ 10 ps and lower the energy threshold from 2.9 to 1.8 MeV, relative to GRH-6m. The first phase is to insert the existing coaxial GCD-3 detector into a reentrant well on the NIF chamber which will put it within 4 meters of TCC. This diagnostic platform will allow assessment of the x-ray radiation background environment within the well which will be fed into the shielding design for the follow-on ``Super'' GCD. It will also enable use of a pulse-dilation PMT which has the potential to improve the effective measurement bandwidth by ~ 10x relative to current PMT technology. GCD-3 has been thoroughly tested at the OMEGA Laser Facility and characterized at the High Intensity Gamma Ray Source (HIgS).

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

    CERN Document Server

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

    2015-01-01

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

  6. First year results of the High Altitude Water Cherenkov observatory

    CERN Document Server

    Carramiñana, Alberto

    2016-01-01

    The High Altitude Water Cherenkov (HAWC) gamma-ray observatory is a wide field of view (1.8 Sr) and high duty cycle (>95% up-time) detector of unique capabilities for the study of TeV gamma-ray sources. Installed at an altitude of 4100m in the Northern slope of Volc\\'an Sierra Negra, Puebla, by a collaboration of about thirty institutions of Mexico and the United States, HAWC has been in full operations since March 2015, surveying 2/3 of the sky every sidereal day, monitoring active galaxies and mapping sources in the Galactic Plane to a detection level of 1 Crab per day. This contribution summarizes the main results of the first year of observations of the HAWC gamma-ray observatory.

  7. An Innovative Workspace for The Cherenkov Telescope Array

    CERN Document Server

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

    2016-01-01

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

  8. The major atmospheric gamma-ray imaging Cherenkov telescope

    Science.gov (United States)

    Garczarczyk, Markus; MAGIC Collaboration

    2011-05-01

    MAGIC is a system of two 17 m diameter Imaging Atmospheric Cherenkov Telescopes (IACTs) for ground-based γ-ray astronomy. During many years, starting with the design phase of the first telescope in 2003, the upgrade of the second telescope in 2008 up to now, novel technologies have been developed, commissioned and continuously improved. Most components and subsystems represent nowadays state of the art techniques and are under consideration to be used in future detectors. The large reflector area, together with small diameter, high quantum efficiency (QE) photomultipliers (PMTs) in combination with an improved trigger and readout system permits an analysis threshold of 25 GeV, the lowest among current IACTs. MAGIC overlaps in energy with the upper end of current satellite experiments and gives the unique opportunity, for the first time, to cross-calibrate ground based versus satellite born detectors. Some selected techniques used in MAGIC, which are in context with this conference, are presented.

  9. Data model issues in the Cherenkov Telescope Array project

    CERN Document Server

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

    2015-01-01

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

  10. Signal Temporal Profile of a Water Cherenkov Detector

    Science.gov (United States)

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

    2003-07-01

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

  11. Building Medium Size Telescope Structures for the Cherenkov Telescope Array

    CERN Document Server

    Schulz, A; Oakes, L; Schlenstedt, S; Schwanke, U

    2016-01-01

    The Cherenkov Telescope Array (CTA) is the future instrument in ground-based gamma-ray astronomy in the energy range from 20 GeV to 300 TeV. Its sensitivity will surpass that of current generation experiments by a factor $\\sim$10, facilitated by telescopes of three sizes. The performance in the core energy regime will be dominated by Medium Size Telescopes (MST) with a reflector of 12 m diameter. A full-size mechanical prototype of the telescope structure has been constructed in Berlin. The performance of the prototype is being evaluated and optimisations, among others, facilitating the assembly procedure and mass production possibilities are being implemented. We present the current status of the developments from prototyping towards pre-production telescopes, which will be deployed at the final site.

  12. First year results of the High Altitude Water Cherenkov observatory

    Science.gov (United States)

    Carramiñana, Alberto

    2016-10-01

    The High Altitude Water Cherenkov (HAWC) γ-ray observatory is a wide field of view (1.8 Sr) and high duty cycle (> 95% up-time) detector of unique capabilities for the study of TeV gamma-ray sources. Installed at an altitude of 4100m in the Northern slope of Volcan Sierra Negra, Puebla, by a collaboration of about thirty institutions of Mexico and the United States, HAWC has been in full operations since March 2015, surveying 2/3 of the sky every sidereal day, monitoring active galaxies and mapping sources in the Galactic Plane to a detection level of 1 Crab per day. This contribution summarizes the main results of the first year of observations of the HAWC γ-ray observatory.

  13. Charged Kaon Mass Measurement using the Cherenkov Effect

    CERN Document Server

    Graf, N; Abrams, R J; Akgun, U; Aydin, G; Baker, W; Barnes, P D; Bergfeld, T; Beverly, L; Bujak, A; Carey, D; Dukes, C; Duru, F; Feldman, G J; Godley, A; Gülmez, E; Günaydın, Y O; Gustafson, H R; Gutay, L; Hartouni, E; Hanlet, P; Hansen, S; Heffner, M; Johnstone, C; Kaplan, D; Kamaev, O; Kilmer, J; Klay, J; Kostin, M; Lange, D; Ling, J; Longo, M J; Lu, L C; Materniak, C; Messier, M D; Meyer, H; Miller, D E; Mishra, S R; Nelson, K; Nigmanov, T; Norman, A; Onel, Y; Paley, J M; Park, H K; Penzo, A; Peterson, R J; Raja, R; Rajaram, D; Ratnikov, D; Rosenfeld, C; Rubin, H; Seun, S; Solomey, N; Soltz, R; Swallow, E; Schmitt, R; Subbarao, P; Torun, Y; Tope, T E; Wilson, K; Wright, D; Wu, K

    2009-01-01

    The two most recent and precise measurements of the charged kaon mass use X-rays from kaonic atoms and report uncertainties of 14 ppm and 22 ppm yet differ from each other by 122 ppm. We describe the possibility of an independent mass measurement using the measurement of Cherenkov light from a narrow-band beam of kaons, pions, and protons. This technique was demonstrated using data taken opportunistically by the Main Injector Particle Production experiment at Fermi National Accelerator Laboratory which recorded beams of protons, kaons, and pions ranging in momentum from +37 GeV/c to +63 GeV/c. The measured value is 491.3 +/- 1.7 MeV/c^2, which is within 1.4 sigma of the world average. An improvement of two orders of magnitude in precision would make this technique useful for resolving the ambiguity in the X-ray data and may be achievable in a dedicated experiment.

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

    Rulten, Cameron B

    2014-01-01

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

  16. A New Light Boson from Cherenkov Telescopes Observations?

    CERN Document Server

    Roncadelli, Marco; Mansutti, Oriana

    2010-01-01

    Early indications by H.E.S.S. and the subsequent detection of blazar 3C279 by MAGIC show that the Universe is more transparent to very-high-energy gamma rays than previously thought. We demonstrate that this circumstance can be reconciled with standard blazar emission models provided that photon oscillations into a very light Axion-Like Particle occur in extragalactic magnetic fields. A quantitative estimate of this effect indeed explains the observed spectrum of 3C279. Our prediction can be tested by the satellite-borne Fermi/LAT detector as well as by the ground-based Imaging Atmospheric Cherenkov Telescopes H.E.S.S., MAGIC, CANGAROO III, VERITAS and by the Extensive Air Shower arrays ARGO-YBJ and MILAGRO.

  17. 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.

  18. Application of Geiger-mode photo sensors in Cherenkov detectors

    CERN Document Server

    Ahmed, Gamal; Cargnelli, Michael; Hohler, Roland; Marton, Johann; Orth, Herbert; Suzuki, Ken

    2010-01-01

    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. In our institute 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.

  19. FACT: Towards Robotic Operation of an Imaging Air Cherenkov Telescope

    CERN Document Server

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

    2013-01-01

    The First G-APD Cherenkov Telescope (FACT) became operational at La Palma in October 2011. Since summer 2012, due to very smooth and stable operation, it is the first telescope of its kind that is routinely operated from remote, without the need for a data-taking crew on site. In addition, many standard tasks of operation are executed automatically without the need for manual interaction. Based on the experience gained so far, some alterations to improve the safety of the system are under development to allow robotic operation in the future. We present the setup and precautions used to implement remote operations and the experience gained so far, as well as the work towards robotic operation.

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

    CERN Document Server

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

    2015-01-01

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

  1. Identification of 90Sr/40K Based on Cherenkov Detector for Recovery from the Fukushima Nuclear Accident

    Science.gov (United States)

    Ito, Hiroshi; Han, Soorim; Kobayashi, Atsushi; Kaneko, Naomi; Kawai, Hideyuki; Tabata, Makoto

    Although five years have passed since the Fukushima nuclear accident of 2011, the local fisheries have yet to recover from its effects. One reason for this situation is the difficulty of measuring the radioactivity owing to 90Sr in seafood. After the accident, the radioactivity due to Cs isotopes in samples was measured with precision, which facilitated the enforcement of the maximum concentration of Cs radioisotopes in food at 100 Bq/kg, as defined by the Ministry of Health, Labour and Welfare in Japan. However, 90Sr is more dangerous than Cs isotopes because it has an effective half-life of 18 years and accumulates in the bone. The radioactivity owing to 90Sr in a sample is difficult to measure because the beta rays from 137Cs or 40K also contribute to the signal. When measured based on the endpoint pulse height as determined by a conventional survey meter, the beta ray signal from 90Y (daughter of 90Sr) cannot be differentiated from the beta rays from other sources. To overcome this difficulty, in this study, we develop a Cherenkov detector based on a silica aerogel with a refractive index of 1.034 that can identify beta rays from 90Y within a background of beta rays from 137Cs and 40K. This instrument involves a detector that is sensitive to beta rays from 90Sr but less sensitive to radiation from other sources. This detector comprises a trigger counter that uses scintillating fibers, an aerogel Cherenkov counter with wavelength-shifting fibers, and a veto counter to suppress cosmic rays. We characterize the detector using a 90Sr source, 137Cs source, and pure potassium chloride reagent of 16.6 Bq/g, where the radioactivity of natural 40K is estimated to be 31.7 Bq/g. The following results are obtained: the absolute detection efficiency for 90Sr, 137Cs, and 40K is [2.24 ± 0.01 (stat) ± 0.44 (sys)] × 10-3 Bq-1 s-1, [1.27 ± 0.08 (stat) ± 0.25 (sys)] × 10-6 Bq-1 s-1, and [5.05 ± 2.40 (stat) ± 0.15 (sys)] × 10-5 Bq-1 s-1, respectively. To aid in the

  2. 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.

  3. Ionospheric propagation effects for UHE neutrino detection with the lunar Cherenkov technique

    CERN Document Server

    McFadden, Rebecca; Bray, Justin

    2013-01-01

    Lunar Cherenkov experiments aim to detect nanosecond pulses of Cherenkov emission produced during UHE cosmic ray or neutrino interactions in the lunar regolith. Pulses from these interactions are dispersed, and therefore reduced in amplitude, during propagation through the Earth's ionosphere. Pulse dispersion must therefore be corrected to maximise the received signal to noise ratio and subsequent chances of detection. The pulse dispersion characteristic may also provide a powerful signature to determine the lunar origin of a pulse and discriminate against pulses of terrestrial radio frequency interference (RFI). This characteristic is parameterised by the instantaneous Total Electron Content (TEC) of the ionosphere and therefore an accurate knowledge of the ionospheric TEC provides an experimental advantage for the detection and identification of lunar Cherenkov pulses. We present a new method to calibrate the dispersive effect of the ionosphere on lunar Cherenkov pulses using lunar Faraday rotation measurem...

  4. Extension of Cherenkov Light LDF Parametrization for Tunka and Yakutsk EAS Arrays

    Indian Academy of Sciences (India)

    A. A. Al-Rubaiee

    2014-12-01

    The Cherenkov light Lateral Distribution Function (LDF) from particles initiated Extensive Air Showers (EAS) with ultrahigh energies ( > 1016 eV) was simulated using CORSIKA program for configuration of Tunka and Yakutsk EAS arrays for different primary particles (p, Fe and O2) and different zenith angles. By depending on the Breit–Wigner function, a parametrization of the Cherenkov light LDF was reconstructed on the basis of this simulation as a function of the primary energy. The comparison of the approximated Cherenkov light LDF with that measured on Tunka and Yakutsk EAS arrays gives the possibility of identification of energy spectrum and mass composition of particles initiating EAS about the knee region of the cosmic ray spectrum. The extrapolation of approximated Cherenkov light LDF for energies 20, 30 and 50 PeV was obtained for different primary particles and different zenith angles.

  5. Properties and Performance of Two Wide Field of View Cherenkov/Fluorescence Telescope Array Prototypes

    CERN Document Server

    Zhang, S S; Cao, Z; Chen, S Z; Chen, M J; Chen, Y; Chen, L H; Ding, K Q; He, H H; Liu, J L; Li, X X; Liu, J; Ma, L L; Ma, X H; Sheng, X D; Zhou, B; Zhang, Y; Zhao, J; Zha, M; Xiao, G

    2011-01-01

    A wide field of view Cherenkov/fluorescence telescope array is one of the main components of the Large High Altitude Air Shower Observatory project. To serve as Cherenkov and fluorescence detectors, a flexible and mobile design is adopted for easy reconfiguring of the telescope array. Two prototype telescopes have been constructed and successfully run at the site of the ARGO-YBJ experiment in Tibet. The features and performance of the telescopes are presented.

  6. 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.

  7. Monitoring system for testing the radiation hardness of a KINTEX-7 FPGA

    Science.gov (United States)

    Cojocariu, L. N.; Placinta, V. M.; Dumitru, L.

    2016-03-01

    A much more efficient Ring Imaging Cherenkov sub-detector system will be rebuilt in the second long shutdown of Large Hadron Collider for the LHCb experiment. Radiation-hard electronic components together with Commercial Off-The-Shelf ones will be used in the new Cherenkov photon detection system architecture. An irradiation program was foreseen to determine the radiation tolerance for the new electronic devices, including a Field Programmable Gate Array from KINTEX-7 family of XILINX. An automated test bench for online monitoring of the XC7K70T KINTEX-7 device operation in radiation conditions was designed and implemented by the LHCb Romanian group.

  8. The software architecture to control the Cherenkov Telescope Array

    Science.gov (United States)

    Oya, I.; Füßling, M.; Antonino, P. O.; Conforti, V.; Hagge, L.; Melkumyan, D.; Morgenstern, A.; Tosti, G.; Schwanke, U.; Schwarz, J.; Wegner, P.; Colomé, J.; Lyard, E.

    2016-07-01

    The Cherenkov Telescope Array (CTA) project is an initiative to build two large arrays of Cherenkov gamma- ray telescopes. CTA will be deployed as two installations, one in the northern and the other in the southern hemisphere, containing dozens of telescopes of different sizes. CTA is a big step forward in the field of ground- based gamma-ray astronomy, not only because of the expected scientific return, but also due to the order-of- magnitude larger scale of the instrument to be controlled. The performance requirements associated with such a large and distributed astronomical installation require a thoughtful analysis to determine the best software solutions. The array control and data acquisition (ACTL) work-package within the CTA initiative will deliver the software to control and acquire the data from the CTA instrumentation. In this contribution we present the current status of the formal ACTL system decomposition into software building blocks and the relationships among them. The system is modelled via the Systems Modelling Language (SysML) formalism. To cope with the complexity of the system, this architecture model is sub-divided into different perspectives. The relationships with the stakeholders and external systems are used to create the first perspective, the context of the ACTL software system. Use cases are employed to describe the interaction of those external elements with the ACTL system and are traced to a hierarchy of functionalities (abstract system functions) describing the internal structure of the ACTL system. These functions are then traced to fully specified logical elements (software components), the deployment of which as technical elements, is also described. This modelling approach allows us to decompose the ACTL software in elements to be created and the ow of information within the system, providing us with a clear way to identify sub-system interdependencies. This architectural approach allows us to build the ACTL system model and

  9. The next generation Cherenkov Telescope Array observatory: CTA

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-12-01

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

  10. The next generation Cherenkov Telescope Array observatory: CTA

    Science.gov (United States)

    Vercellone, S.

    2014-12-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to the very high-energy gamma-ray astrophysics in the energy range 30 GeV-100 TeV, which will improve by about one order of magnitude the sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS). In order to achieve such improved performance, for both the northern and southern CTA sites, four units of 23 m diameter Large Size Telescopes (LSTs) will be deployed close to the centre of the array with telescopes separated by about 100 m. A larger number (about 25 units) of 12 m Medium Size Telescopes (MSTs, separated by about 150 m), will cover a larger area. The southern site will also include up to 24 Schwarzschild-Couder dual-mirror medium-size Telescopes (SCTs) with the primary mirror diameter of 9.5 m. Above a few TeV, the Cherenkov light intensity is such that showers can be detected even well outside the light pool by telescopes significantly smaller than the MSTs. To achieve the required sensitivity at high energies, a huge area on the ground needs to be covered by Small Size Telescopes (SSTs) with a field of view of about 10° and an angular resolution of about 0.2°, making the dual-mirror configuration very effective. The SST sub-array will be composed of 50-70 telescopes with a mirror area of about 5-10 m2 and about 300 m spacing, distributed across an area of about 10 km2. In this presentation we will focus on the innovative solution for the optical design of the medium and small size telescopes based on a dual-mirror configuration. This layout will allow us to reduce the dimension and the weight of the camera at the focal plane of the telescope, to adopt Silicon-based photo-multipliers as light detectors thanks to the reduced plate-scale, and to have an optimal imaging resolution on a wide field of view.

  11. 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

  12. Latest news from the High Altitude Water Cherenkov Observatory

    Science.gov (United States)

    González Muñoz, A.; HAWC Collaboration

    2016-07-01

    The High Altitude Water Cherenkov Observatory is an air shower detector designed to study very-high-energy gamma rays (˜ 100 GeV to ˜ 100 TeV). It is located in the Pico de Orizaba National Park, Mexico, at an elevation of 4100 m. HAWC started operations since August 2013 with 111 tanks and in April of 2015 the 300 tanks array was completed. HAWC's unique capabilities, with a field of view of ˜ 2 sr and a high duty cycle of 5%, allow it to survey 2/3 of the sky every day. These features makes HAWC an excellent instrument for searching new TeV sources and for the detection of transient events, like gamma-ray bursts. Moreover, HAWC provides almost continuous monitoring of already known sources with variable gamma-ray fluxes in most of the northern and part of the southern sky. These observations will bring new information about the acceleration processes that take place in astrophysical environments. In this contribution, some of the latest scientific results of the observatory will be presented.

  13. Monte Carlo design studies for the Cherenkov Telescope Array

    CERN Document Server

    Bernlöhr, K; Becherini, Y; Bigas, O Blanch; Carmona, E; Colin, P; Decerprit, G; Di Pierro, F; Dubois, F; Farnier, C; Funk, S; Hermann, G; Hinton, J A; Humensky, T B; Khélifi, B; Kihm, T; Komin, N; Lenain, J -P; Maier, G; Mazin, D; Medina, M C; Moralejo, A; Nolan, S J; Ohm, S; Wilhelmi, E de Oña; Parsons, R D; Arribas, M Paz; Pedaletti, G; Pita, S; Prokoph, H; Rulten, C B; Schwanke, U; Shayduk, M; Stamatescu, V; Vallania, P; Vorobiov, S; Wischnewski, R; Yoshikoshi, T; Zech, A

    2012-01-01

    The Cherenkov Telescopes Array (CTA) is planned as the future instrument for very-high-energy (VHE) gamma-ray astronomy with a wide energy range of four orders of magnitude and an improvement in sensitivity compared to current instruments of about an order of magnitude. Monte Carlo simulations are a crucial tool in the design of CTA. The ultimate goal of these simulations is to find the most cost-effective solution for given physics goals and thus sensitivity goals or to find, for a given cost, the solution best suited for different types of targets with CTA. Apart from uncertain component cost estimates, the main problem in this procedure is the dependence on a huge number of configuration parameters, both in specifications of individual telescope types and in the array layout. This is addressed by simulation of a huge array intended as a superset of many different realistic array layouts, and also by simulation of array subsets for different telescope parameters. Different analysis methods -- in use with cu...

  14. Development of Ring Imaging Cherenkov Detectors for LHCb

    CERN Document Server

    Bellunato, T; Matteuzzi, C

    2003-01-01

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

  15. A Topological Trigger System for Imaging Atmospheric-Cherenkov Telescopes

    CERN Document Server

    Schroedter, M; Byrum, K; Drake, G; Duke, C; Holder, J; Imran, A; Madhavan, A; Krennrich, F; Kreps, A; Smith, A

    2009-01-01

    A fast trigger system is being designed as a potential upgrade to VERITAS, or as the basis for a future array of imaging atmospheric-Cherenkov telescopes such as AGIS. The scientific goal is a reduction of the energy threshold by a factor of 2 over the current threshold of VERITAS of around 130 GeV. The trigger is being designed to suppress both accidentals from the night-sky background and cosmic rays. The trigger uses field-programmable gate arrays (FPGAs) so that it is adaptable to different observing modes and special physics triggers, e.g. pulsars. The trigger consists of three levels: The level 1 (L1.5) trigger operating on each telescope camera samples the discriminated pixels at a rate of 400 MHz and searches for nearest-neighbor coincidences. In L1.5, the received discriminated signals are delay-compensated with an accuracy of 0.078 ns, facilitating a short coincidence time-window between any nearest neighbor of 5 ns. The hit pixels are then sent to a second trigger level (L2) that parameterizes the ...

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

    CERN Document Server

    Bretz, Thomas

    2013-01-01

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

  17. Development of ring imaging Cherenkov detectors for the LHCb experiment

    CERN Document Server

    John, M J J

    2001-01-01

    This thesis reports on work done as part of the development of the Ring Imaging Cherenkov (RICH) detectors of the LHCb experiment. The context of this work is set out in Chapter 1, which includes an overview of the physics of CP violation, followed by a discussion of other experiments that study B physics. LHCb itself is then described, with particular emphasis on its RICH detectors, and the photon detectors to be used therein. The work done by the author to ensure an adequate shielding of the photon detectors in the two RICH detectors from the magnetic fields produced by the LHCb dipole is then presented. A candidate photodetector for the RICH is the Pixel HPD. The author's contribution to the upgrade of the HPD test system to operate at the LHC bunch-crossing rate of 40MHz is the subject of the following section. This system was used to investigate and optimise a method of minimising the threshold distribution of the Pixel HPD's encapsulated readout chip. The final chapter of the thesis concerns the aerogel...

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

    CERN Document Server

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

    2013-01-01

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

  19. A Smart Pixel Camera for future Cherenkov Telescopes

    CERN Document Server

    Hermann, G; Glück, B; Hauser, D; Hermann, German; Carrigan, Svenja; Gl\\"uck, Bernhard; Hauser, Dominik

    2005-01-01

    The Smart Pixel Camera is a new camera for imaging atmospheric Cherenkov telescopes, suited for a next generation of large multi-telescope ground based gamma-ray observatories. The design of the camera foresees all electronics needed to process the images to be located inside the camera body at the focal plane. The camera has a modular design and is scalable in the number of pixels. The camera electronics provides the performance needed for the next generation instruments, like short signal integration time, topological trigger and short trigger gate, and at the same time the design is optimized to minimize the cost per channel. In addition new features are implemented, like the measurement of the arrival time of light pulses in the pixels on the few hundred psec timescale. The buffered readout system of the camera allows to take images at sustained rates of O(10 kHz) with a dead-time of only about 0.8 % per kHz.

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

    CERN Document Server

    Cortina, J

    2015-01-01

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

  1. The Medium Size Telescopes of the Cherenkov Telescope Array

    CERN Document Server

    Pühlhofer, G

    2016-01-01

    The Cherenkov Telescope Array (CTA) is the planned next-generation instrument for ground-based gamma-ray astronomy, covering a photon energy range of ~20 GeV to above 100 TeV. CTA will consist of the order of 100 telescopes of three sizes, installed at two sites in the Northern and Southern Hemisphere. This contribution deals with the 12 meter Medium Size Telescopes (MST) having a single mirror (modified Davies-Cotton, DC) design. In the baseline design of the CTA arrays, 25 MSTs in the South and 15 MSTs in the North provide the necessary sensitivity for CTA in the core energy range of 100 GeV to 10 TeV. DC-MSTs will be equipped with photomultiplier (PMT)-based cameras. Two options are available for these focal plane instruments, that will be provided by the FlashCam and the NectarCAM sub-consortia. In this contribution, a short introduction to the projects and their status is given.

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

    CERN Document Server

    Rocco, Elena; Dalla Torre, Silvia

    2010-01-01

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

  3. CHERENCUBE: Concept definition and implementation challenges of a Cherenkov-based detector block for PET

    Energy Technology Data Exchange (ETDEWEB)

    Somlai-Schweiger, I., E-mail: ian.somlai@tum.de; Ziegler, S. I. [Nuklearmedizinische Klinik und Poliklinik, Klinikum rechts der Isar, Technische Universität München, Ismaninger Strasse 22, München 81675 (Germany)

    2015-04-15

    Purpose: A new concept for a depth-of-interaction (DOI) capable time-of-flight (TOF) PET detector is defined, based only on the detection of Cherenkov photons. The proposed “CHERENCUBE” consists of a cubic Cherenkov radiator with position-sensitive photodetectors covering each crystal face. By means of the spatial distribution of the detected photons and their time of arrival, the point of interaction of the gamma-ray in the crystal can be determined. This study analyzes through theoretical calculations and Monte Carlo simulations the potential advantages of the concept toward reaching a Cherenkov-only detector for TOF-PET with DOI capability. Furthermore, an algorithm for the DOI estimation is presented and the requirements for a practical implementation of the proposed concept are defined. Methods: The Monte Carlo simulations consisted of a cubic crystal with one photodetector coupled to each one of the faces of the cube. The sensitive area of the detector matched exactly the crystal size, which was varied in 1 mm steps between 1 × 1 × 1 mm{sup 3} and 10 × 10 × 10 mm{sup 3}. For each size, five independent simulations of ten thousand 511 keV gamma-rays were triggered at a fixed distance of 10 mm. The crystal chosen was PbWO{sub 4}. Its scintillation properties were simulated, but only Cherenkov photons were analyzed. Photodetectors were simulated having perfect photodetection efficiency and infinite time resolution. For every generated particle, the analysis considered its creation process, parent and daughter particles, energy, origin coordinates, trajectory, and time and position of detection. The DOI determination is based on the distribution of the emission time of all photons per event. These values are calculated as a function of the coordinates of detection and origin for every photon. The common origin is estimated by finding the distribution with the most similar emission time-points. Results: Detection efficiency increases with crystal size from

  4. IceCube: A Cubic Kilometer Radiation Detector

    OpenAIRE

    Klein, S.; IceCube Collaboration

    2008-01-01

    IceCube is a 1 km^3 neutrino detector now being built at the Amundsen-Scott South Pole Station. It consists of 4800 Digital Optical Modules (DOMs) which detect Cherenkov radiation from the charged particles produced in neutrino interactions. IceCube will observe astrophysical neutrinos with energies above about 100 GeV. IceCube will be able to separate \

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

    Chang, Zhe; Wang, Sai; 10.1016/j.physletb.2012.03.002

    2012-01-01

    Recently, Cohen and Glashow [A.G. Cohen, S.L. Glashow, Phys. Rev. Lett. {\\bf 107}, 181803 (2011)] 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 paper, 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.

  7. A Quartz Cherenkov Detector for Compton-Polarimetry at Future e+e- Colliders

    CERN Document Server

    List, Jenny; Vormwald, Benedikt

    2015-01-01

    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 ar...

  8. Results on the Performance of a Broad Band Focussing Cherenkov Counter

    Science.gov (United States)

    Cester, R.; Fitch, V. L.; Montag, A.; Sherman, S.; Webb, R. C.; Witherell, M. S.

    1980-01-01

    The field of ring imaging (broad band differential) Cherenkov detectors has become a very active area of interest in detector development at several high energy physics laboratories. Our group has previously reported on a method of Cherenkov ring imaging for a counter with large momentum and angular acceptance using standard photo multipliers. Recently, we have applied this technique to the design of a set of Cherenkov counters for use in a particle search experiment at Fermi National Accelerator Laboratory (FNAL). This new detector operates over the range 0.998 a delta..beta.. approx. 2 x 10{sup -4}. The acceptance in angle is +- 14 mrad in the horizontal and +- 28 mrad in the vertical. We report here on the performance of this counter.

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

    Science.gov (United States)

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

    2016-09-01

    The Imaging Atmospheric Cherenkov Technique (IACT) has provided very important discoveries in Very High Energy (VHE) γ-ray astronomy for the last two decades, being exploited mainly by experiments such as H.E.S.S., MAGIC and VERITAS. The same technique will be used by the next generation of γ-ray telescopes, Cherenkov Telescope Array - CTA, which is conceived to be an Observatory composed by two arrays strategically placed in both hemispheres, one in the Northern and one in the Southern. Each site will consist of several tens of Cherenkov telescopes of different sizes and will be equipped with about 10000 m2 of reflective surface. Because of its large size, the reflector of a Cherenkov telescope is composed of many individual mirror facets. Cherenkov telescopes operate without any protective system from weather conditions therefore it is important to understand how the reflective surfaces behave under different environmental conditions. This paper describes a study of the behavior of the mirrors in the presence of water vapor condensation. The operational time of a telescope is reduced by the presence of condensation on the mirror surface, therefore, to control and to monitor the formation of condensation is an important issue for IACT observatories. We developed a method based on pictures of the mirrors to identify the areas with water vapor condensation. The method is presented here and we use it to estimate the time and area two mirrors had condensation when exposed to the environmental conditions in the Argentinean site. The study presented here shows important guidelines in the selection procedure of mirror technologies and shows an innovative monitoring tool to be used in future Cherenkov telescopes.

  10. Cherenkov and Fano effects at the origin of asymmetric vector mesons in nuclear media

    CERN Document Server

    Dremin, I M

    2015-01-01

    It is argued that the experimentally observed phenomenon of asymmetric vector mesons produced in nuclear media during high energy nucleus-nucleus collisions can be explained as Cherenkov and Fano effects. The mass distributions of lepton pairs created at meson decays decline from the traditional Breit-Wigner shape in the low-mass wing of the resonance. That is explained by the positive real part of the amplitude in this wing for classic Cherenkov treatment and further detalized in quantum mechanics as the interference of direct and continuum states in Fano effect. The corresponding parameters are found from the comparison with rho-meson data and admit reasonable explanation.

  11. Development of a SiPM Cherenkov camera demonstrator for the CTA observatory telescopes

    OpenAIRE

    Ambrosio, Michelangelo; Ambrosi, Giovanni; Aramo, Carla; Bissaldi, Elisabetta; Boiano, Alfonso; Bonavolontà, Carmela; Fiandrini, Emanuele; Giglietto, Nicola; Giordano, Francesco; Ionica, Maria; de Lisio, Corrado; Masone, Vincenzo; Paoletti, Riccardo; Postolache, Vasile; Rugliancich, Andrea

    2016-01-01

    The Cherenkov Telescope Array (CTA) Consortium is developing the new generation of ground observatories for the detection of ultra-high energy gamma-rays. The Italian Institute of Nuclear Physics (INFN) is participating to the R&D of a possible solution for the Cherenkov photon cameras based on Silicon Photomultiplier (SiPM) detectors sensitive to Near Ultraviolet (NUV) energies. The latest NUV-HD SiPM technology achieved by the collaboration of INFN with Fondazione Bruno Kessler (FBK) is bas...

  12. Reconfigurable ASIC for a Low Level Trigger System in Cherenkov Telescope Cameras

    CERN Document Server

    Gascon, David; Blanch, Oscar; Boix, Joan; Delagnes, Eric; Delgado, Carlos; Freixas, Lluís; Guilloux, Fabrice; López-Coto, Rubén; Griffiths, Scott; Martínez, Gustavo; Martínez, Oscar; Sanuy, Andreu; Tejedor, Luis Ángel

    2016-01-01

    A versatile and reconfigurable ASIC is presented, which implements two different concepts of low level trigger (L0) for Cherenkov telescopes: the Majority trigger (sum of discriminated inputs) and the Sum trigger concept (analogue clipped sum of inputs). Up to 7 input signals can be processed following one or both of the previous trigger concepts. Each differential pair output of the discriminator is also available as a LVDS output. Differential circuitry using local feedback allows the ASIC to achieve high speed (500 MHz) while maintaining good linearity in a 1 Vpp range. Experimental results are presented. A number of prototype camera designs of the Cherenkov Telescope Array (CTA) project will use this ASIC.

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

    Energy Technology Data Exchange (ETDEWEB)

    Anderhub, H. [Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland); Backes, M. [Technische Universitaet Dortmund, 44221 Dortmund (Germany); Biland, A.; Boller, A.; Braun, I. [Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland); Bretz, T. [Ecole Polytechnique Federale de Lausanne, 1015 Lausanne (Switzerland); Commichau, S.; Commichau, V.; Dorner, D.; Gendotti, A. [Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland); Grimm, O., E-mail: oliver.grimm@phys.ethz.c [Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland); Gunten, H. von; Hildebrand, D.; Horisberger, U. [Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland); Koehne, J.-H. [Technische Universitaet Dortmund, 44221 Dortmund (Germany); Kraehenbuehl, T.; Kranich, D.; Lorenz, E.; Lustermann, W. [Eidgenoessische Technische Hochschule Zuerich, 8093 Zuerich (Switzerland); Mannheim, K. [Universitaet Wuerzburg, 97074 Wuerzburg (Germany)

    2011-02-01

    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).

  14. Measuring the Attenuation Length of Water in the CHIPS-M Water Cherenkov Detector

    CERN Document Server

    Amat, F; Bryant, J; Carroll, T J; Germani, S; Joyce, T; Kreisten, B; Marshak, M; Meier, J; Nelson, J; Perch, A; Pfuzner, M; De Rijck, S; Salazar, R; Thomas, J; Trokan-Tenorio, J; Vahle, P; Wade, R; Whitehead, L; Whitney, M

    2016-01-01

    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\\unit{m} vertical column filled with this water, was used to study the transmission of 405nm laser light. Results consistent with attenuation lengths of up to 100m were observed for this wavelength with filtration and UV sterilization alone.

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

    Science.gov (United States)

    Rose, Paul B.; Erickson, Anna S.

    2016-08-01

    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.

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

    CERN Document Server

    Sadeh, Iftach; Schwarz, Joseph; Pietriga, Emmanuel

    2016-01-01

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

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

    Science.gov (United States)

    Amat, F.; Bizouard, P.; Bryant, J.; Carroll, T. J.; Rijck, S. De; Germani, S.; Joyce, T.; Kriesten, B.; Marshak, M.; Meier, J.; Nelson, J. K.; Perch, A. J.; Pfützner, M. M.; Salazar, R.; Thomas, J.; Trokan-Tenorio, J.; Vahle, P.; Wade, R.; Wendt, C.; Whitehead, L. H.; Whitney, M.

    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.

  18. Recent AGN Observations by the Solar Tower Atmospheric Cherenkov Effect Experiment

    Science.gov (United States)

    Kildea, J.; Alabiso, A.; Bramel, D. A.; Carson, J.; Covault, C. E.; Driscoll, D.; Fortin, P.; Gingrich, D. M.; Hanna, D. S.; Jarvis, A.; Lindner, T.; Mukherjee, R.; Mueller, C.; Ong, R. A.; Ragan, K.; Scalzo, R. A.; Williams, D. A.; Zweerink, J.

    2005-02-01

    The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is a ground-based atmospheric Cherenkov telescope for the detection of very high energy gamma rays from Galactic and extra-galactic sources. By utilizing the large collection area provided by the solar mirrors of the National Solar Thermal Test Facility in Albuquerque, New Mexico, STACEE achieves a low energy threshold, around 100 GeV, for the detection of gamma rays. We briefly describe the STACEE detector and detail recent observations of Active Galactic Nuclei.

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

    Science.gov (United States)

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

    2016-07-01

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

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

    CERN Document Server

    Santander, M; Humensky, B; Mukherjee, R

    2015-01-01

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

  1. Coherent radiation of relativistic electrons in wire metamaterial

    Science.gov (United States)

    Soboleva, V.; Naumenko, G.; Bleko, V.

    2016-07-01

    We present in this work the experimental investigation of the interaction of relativistic electron field with wire metamaterial. The measurements of the spectral-angular characteristics of coherent radiation were done in millimeter wavelength region in far-field zone at the relativistic electron beam with energy of 6 MeV. Used target represent the right triangular prism that consist of periodic placed copper wires. We showed that bunched electron beam passing near wire metamaterial prism generates coherent Cherenkov radiation. Spectral angular characteristics of radiation from the wire target were compared with the characteristics of Cherenkov radiation generated in similar experimental conditions in a dielectric target (Teflon prism) that has the same form and sizes.

  2. 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

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

    CERN Document Server

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

    2013-01-01

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

  4. 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.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; 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, M.; Bien, A.; Bifani, S.; Bird, T.; 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. 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, 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.; De Paula, L.; De Silva, W.; 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.; 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, M.; Fontanelli, F.; Forty, R.; 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.; Gaspar, C.; Gauld, R.; Gavardi, L.; Gazzoni, G.; Geraci, A.; Gerick, D.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Giani, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Goebel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; 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, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Humair, T.; Hussain, N.; Hutchcroft, D.; 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.; Kenyon, I. R.; Kenzie, M.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; 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.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; 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, 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, M.; 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.; 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, K.; 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, A.; Owen, 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, 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, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Navarro, A. Puig; Punzi, G.; Qian, 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. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Perez, P. Rodriguez; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; 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, 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.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Sterpka, F.; Stevenson, S.; 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.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Trabelsi, K.; Tran, 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, J. 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, J.; 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, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; 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 root 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

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

    CERN Document Server

    Krizmanic, John F

    2011-01-01

    Future space-based experiments, such as OWL and JEM-EUSO, view large atmospheric and terrestrial neutrino targets. With energy thresholds slightly above 10^19 eV for observing airshowers via air fluorescence, the potential for observing the cosmogenic neutrino flux associated with the GZK effect is limited. However, the forward Cherenkov signal associated with the airshower can be observed at much lower energies. A simulation was developed to determine the Cherenkov signal strength and spatial extent at low-Earth orbit for upward-moving airshowers. A model of tau neutrino interactions in the Earth was employed to determine the event rate of interactions that yielded a tau lepton which would induce an upward-moving airshower observable by a space-based instrument. The effect of neutrino attenuation by the Earth forces the viewing of the Earth's limb to observe the nu_tau-induced Cherenkov airshower signal at above the OWL Cherenkov energy threshold of ~10^16.5 eV for limb-viewed events. Furthermore, the neutri...

  6. Gamma Ray Measurements at OMEGA with the Newest Gas Cherenkov Detector “GCD-3”

    Science.gov (United States)

    McEvoy, A. M.; Herrmann, H. W.; Kim, Y.; Zylstra, A. B.; Young, C. S.; Fatherley, V. E.; Lopez, F. E.; Oertel, J. A.; Sedillo, T. J.; Archuleta, T. N.; Aragonez, R. J.; Malone, R. M.; Horsfield, C. J.; Rubery, M.; Gales, S.; Leatherland, A.; Stoeffl, W.; Gatu Johnson, M.; Shmayda, W. T.; Batha, S. H.

    2016-05-01

    Initial results from the newest Gas Cherenkov Detector (GCD-3) are reported demonstrating improved performance over previous GCD iterations. Increased shielding and lengthening of the Cherenkov photon optical path have resulted in a diminished precursor signal with increased temporal separation between the precursor and the primary DT Cherenkov signal. Design changes resulted in a measured GCD-3 sensitivity comparable to GCD-1 at identical 100 psia CO2 operation. All metal gasket seals and pressure vessel certification to 400 psia operation allow for a GCD-3 lower Cherenkov threshold of 1.8 MeV using the fluorinated gas C2F6 as compared to the 6.3 MeV lower limit of GCD-1 and GCD-2. Calibration data will be used to benchmark GEANT4 and ACCEPT detector models. The GCD-3 acts as a prototype for the Super GCD being fielded at the National Ignition Facility (NIF) as part of the National Diagnostics Plan and will be installed at NIF in early 2016.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1990-04-01

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

  8. The endpoint formalism for the calculation of electromagnetic radiation and its applications in astroparticle physics

    CERN Document Server

    Huege, Tim; Falcke, Heino; Ludwig, Marianne

    2011-01-01

    We present the "endpoint" formalism for the calculation of electromagnetic radiation and illustrate its applications in astroparticle physics. We use the formalism to explain why the coherent radiation from the Askaryan effect is not in general Cherenkov radiation, as the emission directly results from the time-variation of the net charge in the particle shower. Secondly, we illustrate how the formalism has been applied in the air shower radio emission code REAS3 to unify the microscopic and macroscopic views of radio emission from extensive air showers. Indeed, the formalism is completely universal and particularly well-suited for implementation in Monte Carlo codes in the time- and frequency-domains. It easily reproduces well-known "classical mechanisms" such as synchrotron radiation, Vavilov-Cherenkov radiation and transition radiation in the adequate limits, but has the advantage that it continues to work in realistic, complex situations, where the "classical mechanisms" tend to no longer apply and adheri...

  9. Radiation of relativistic electrons in a periodic wire structure

    Energy Technology Data Exchange (ETDEWEB)

    Soboleva, V.V., E-mail: sobolevaveronica@mail.ru; Naumenko, G.A.; Bleko, V.V.

    2015-07-15

    We present in this work the experimental investigation of the interaction of relativistic electron field with periodic wire structures. We used two types of the targets in experiments: flat wire target and sandwich wire target that represent the right triangular prism. The measurements were done in millimeter wavelength region (10–40 mm) on the relativistic electron beam with energy of 6.2 MeV in far-field zone. We showed that bunched electron beam passing near wire metamaterial prism generates coherent Cherenkov radiation. The experiments with flat wire target were carried out in two geometries. In the first geometry the electron beam passed close to the flat wire target surface. In the second case the electron beam passed through the flat wire structure with generation of a coherent backward transition radiation (CBTR). The comparison of the Cherenkov radiation intensity and BTR intensity from the flat wire target and from the flat conductive target (conventional BTR) was made.

  10. The CLEO-III Ring Imaging Cherenkov Detector

    CERN Document Server

    Mountain, R J; Artuso, M; Ayad, R; Azfar, F; Coan, T E; Efimov, A; Fadeev, V; Kopp, S E; Kubota, Y; Lipeles, E; Majumder, G; Schuh, S; Skwarnicki, T; Smith, A; Staeck, J; Stone, S; Viehhauser, G; Volobuev, I P

    1999-01-01

    The CLEO-III Detector upgrade for charged particle identification is discussed. The RICH design uses solid LiF crystal radiators coupled with multi-wire chamber photon detectors, using TEA as the photosensor, and low-noise Viking readout electronics. Results from our beam test at Fermilab are presented.

  11. Aspherical mirrors for the Gamma-ray Cherenkov Telescope, a Schwarschild-Couder prototype proposed for the future Cherenkov Telescope Array

    Science.gov (United States)

    Dournaux, J. L.; Gironnet, J.; Huet, J. M.; Laporte, P.; Chadwick, P.; Dumas, D.; Pech, M.; Rulten, C. B.; Sayède, F.; Schmoll, J.; Sol, H.

    2016-07-01

    The Cherenkov Telescope Array (CTA) project, led by an international collaboration of institutes, aims to create the world's largest next generation Very High-Energy (VHE) gamma-ray telescope array, devoted to observations in a wide band of energy, from a few tens of GeV to more than 100 TeV. The Small-Sized Telescopes (SSTs) are dedicated to the highest energy range. Seventy SSTs are planned in the baseline array design with a required lifetime of about 30 years. The GCT (Gamma-ray Cherenkov Telescope) is one of the prototypes proposed for CTA's SST sub-array. It is based on a Schwarzschild-Couder dual-mirror optical design. This configuration has the benefit of increasing the field-of-view and decreasing the masses of the telescope and of the camera. But, in spite of these many advantages, it was never implemented before in ground-based Cherenkov astronomy because of the aspherical and highly curved shape required for the mirrors. The optical design of the GCT consists of a primary 4 meter diameter mirror, segmented in six aspherical petals, a secondary monolithic 2-meter mirror and a light camera. The reduced number of segments simplifies the alignment of the telescope but complicates the shape of the petals. This, combined with the strong curvature of the secondary mirror, strongly constrains the manufacturing process. The Observatoire de Paris implemented metallic lightweight mirrors for the primary and the secondary mirrors of GCT. This choice was made possible because of the relaxed requirements of optical Cherenkov telescopes compared to optical ones. Measurements on produced mirrors show that these ones can fulfill requirements in shape, PSF and reflectivity, with a clear competition between manufacturing cost and final performance. This paper describes the design of these mirrors in the context of their characteristics and how design optimization was used to produce a lightweight design. The manufacturing process used for the prototype and planned for the

  12. Analogue Sum ASIC for L1 Trigger Decision in Cherenkov Telescope Cameras

    CERN Document Server

    Barrio, Joan Abel; Boix, Joan; Delagnes, Eric; Delgado, Carlos; Coromina, Lluis Freixas; Gascon, David; Guilloux, Fabrice; Coto, Ruben Lopez; Martinez, Gustavo; Sanuy, Andreu; Tejedor, Luis Angel

    2014-01-01

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

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

    CERN Document Server

    Giomi, Matteo; Maier, Gernot

    2016-01-01

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

  14. The Physics and Nuclear Nonproliferation Goals of WATCHMAN: A WAter CHerenkov Monitor for ANtineutrinos

    CERN Document Server

    Askins, M; Bernstein, A; Dazeley, S; Dye, S T; Handler, T; Hatzikoutelis, A; Hellfeld, D; Jaffke, P; Kamyshkov, Y; Land, B J; Learned, J G; Marleau, P; Mauger, C; Gann, G D Orebi; Roecker, C; Rountree, S D; Shokair, T M; Smy, M B; Svoboda, R; Sweany, M; Vagins, M R; van Bibber, K A; Vogelaar, R B; Wetstein, M J; Yeh, M

    2015-01-01

    This article describes the physics and nonproliferation goals of WATCHMAN, the WAter Cherenkov Monitor for ANtineutrinos. The baseline WATCHMAN design is a kiloton scale gadolinium-doped (Gd) light water Cherenkov detector, placed 13 kilometers from a civil nuclear reactor in the United States. In its first deployment phase, WATCHMAN will be used to remotely detect a change in the operational status of the reactor, providing a first- ever demonstration of the potential of large Gd-doped water detectors for remote reactor monitoring for future international nuclear nonproliferation applications. During its first phase, the detector will provide a critical large-scale test of the ability to tag neutrons and thus distinguish low energy electron neutrinos and antineutrinos. This would make WATCHMAN the only detector capable of providing both direction and flavor identification of supernova neutrinos. It would also be the third largest supernova detector, and the largest underground in the western hemisphere. In a...

  15. Sensitivity of a proposed space-based Cherenkov astrophysical-neutrino telescope

    Science.gov (United States)

    Neronov, Andrii; Semikoz, Dmitri V.; Anchordoqui, Luis A.; Adams, James H.; Olinto, Angela V.

    2017-01-01

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

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

    CERN Document Server

    ,

    2015-01-01

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

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

    CERN Document Server

    Adamson, P; Davies, G S; Evans, J J; Guzowski, P; Habig, A; Hartnell, J; Holin, A; Huang, J; Kreymer, A; Kordosky, M; Lang, K; Marshak, M L; Mehdiyev, R; Meier, J; Miller, W; Naples, D; Nelson, J K; Nichol, R J; Patterson, R B; Perch, A; Pfutzner, M; Proga, M; Radovic, A; Sanchez, M C; Schreiner, S; Soldner-Rembold, S; Sousa, A; Thomas, J; Vahle, P; Wendt, C; Whitehead, L H; Wojcicki, S

    2013-01-01

    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.

  18. Observations Of The Egret Blazar W Comae With The Solar Tower Atmospheric Cherenkov Effect Experiment

    CERN Document Server

    Scalzo, R A

    2004-01-01

    The Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE) is a wavefront-sampling atmospheric Cherenkov telescope which uses an array of solar heliostat mirrors as its primary optic. STACEE is designed to detect air showers from astrophysical gamma rays with energies between 50 and 250 GeV. Recent observations of the BL Lac object W Comae (ON+231), made in the spring of 2003 using STACEE, detect no significant gamma ray emission. The implications of this null result for the composition of the relativistic jet in W Comae is discussed, examining both leptonic and hadronic jet models from the literature. The 95% confidence level upper limit on the flux ranges from 1.5–3.5 × 10−10 cm−2 s−1 above 100 GeV for the leptonic models, and from 0.5–1.1 × 10−10 cm−2 s−1 above 150 GeV for the hadronic models.

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

    CERN Document Server

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2014-07-01

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

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

    CERN Document Server

    ,

    2015-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

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

    Science.gov (United States)

    Fatherley, V. E.; Bingham, D. A.; Cartelli, M. D.; DiDomizio, R. A.; Griego, J. R.; Herrmann, H. W.; Lopez, F. E.; Oertel, J. A.; Pollack, M. J.

    2016-11-01

    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.

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

    CERN Document Server

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

    2013-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

  6. Photon Detection Efficiency Measurements of the VERITAS Cherenkov Telescope Photomultipliers after four Years of Operation

    CERN Document Server

    Gazda, Eliza; Otte, Nepomuk; Richards, Gregory

    2016-01-01

    The photon detection efficiency of two sets of R10560-100-20 superbialkali photomultiplier tubes from Hamamatsu were measured between 200 nm and 750 nm to quantify a possible degradation of the photocathode sensitivity after four years of operation in the cameras of the VERITAS Cherenkov telescopes. A sample of 20 photomultiplier tubes, which was removed from the telescopes was compared with a sample of 20 spare photomultiplier tubes, which had been kept in storage. It is found that the average photocathode sensitivity marginally increased below 300 nm and dropped by 10% to 30% above 500 nm. The average photocathode sensitivity folded with the Cherenkov spectrum emitted by particles in air showers, however, reveals a consistent detection yield of 18.9+/-0.2% and 19.1+/-0.2% for the sample removed from the telescope and the spare sample, respectively.

  7. Detection of the Cherenkov light diffused by Sea Water with the ULTRA Experiment

    CERN Document Server

    Agnetta, G; Biondo, B; Brogueira, P; Cappa, A; Catalano, O; Chauvin, J; Staiti, G D'Ali'; Dattoli, M; Espirito-Santo, M C; Fava, L; Galeotti, P; Giarrusso, S; Gugliotta, G; La Rosa, G; Lebrun, D; Maccarone, M C; Mangano, A; Melo, L; Moreggia, S; Pimenta, M; Russo, F; Saavedra, O; Segreto, A; Silva, J C; Stassi, P; Tome', B; Vallania, P; Vigorito, C

    2007-01-01

    The study of Ultra High Energy Cosmic Rays represents one of the most challenging topic in the Cosmic Rays and in the Astroparticle Physics fields. The interaction of primary particles with atmospheric nuclei produces a huge Extensive Air Shower together with isotropic emission of UV fluorescence light and highly directional Cherenkov photons, that are reflected/diffused isotropically by the impact on the Earth's surface or on high optical depth clouds. For space-based observations, detecting the reflected Cherenkov signal in a delayed coincidence with the fluorescence light improves the accuracy of the shower reconstruction in space and in particular the measurement of the shower maximum, giving a strong signature for discriminating hadrons and neutrinos, and helping to estimate the primary chemical composition. Since the Earth's surface is mostly covered by water, the ULTRA (UV Light Transmission and Reflection in the Atmosphere)experiment has been designed to provide the diffusing properties of sea water, ...

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

    CERN Document Server

    Wood, M; Dumm, J; Funk, S

    2015-01-01

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

  9. The aerogel threshold Cherenkov detector for the High Momentum Spectrometer in Hall C at Jefferson Lab

    CERN Document Server

    Asaturyan, R; Fenker, H; Gaskell, D; Huber, G M; Jones, M; Mack, D; Mkrtchyan, H G; Metzger, B; Novikoff, N; Tadevosyan, V; Vulcan, W; Wood, S

    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 pi/K/P, which was achieved by installing an additional threshold Cherenkov counter. Two types of aerogel with n=1.03 and n=1.015 allow one to reach 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.

  10. SiPM and front-end electronics development for Cherenkov light detection

    CERN Document Server

    Ambrosi, G; Bissaldi, E; Ferri, A; Giordano, F; Gola, A; Ionica, M; Paoletti, R; Piemonte, C; Paternoster, G; Simone, D; Vagelli, V; Zappala, G; Zorzi, N

    2015-01-01

    The Italian Institute of Nuclear Physics (INFN) is involved in the development of a demonstrator for a SiPM-based camera for the Cherenkov Telescope Array (CTA) experiment, with a pixel size of 6$\\times$6 mm$^2$. The camera houses about two thousands electronics channels and is both light and compact. In this framework, a R&D program for the development of SiPMs suitable for Cherenkov light detection (so called NUV SiPMs) is ongoing. Different photosensors have been produced at Fondazione Bruno Kessler (FBK), with different micro-cell dimensions and fill factors, in different geometrical arrangements. At the same time, INFN is developing front-end electronics based on the waveform sampling technique optimized for the new NUV SiPM. Measurements on 1$\\times$1 mm$^2$, 3$\\times$3 mm$^2$, and 6$\\times$6 mm$^2$ NUV SiPMs coupled to the front-end electronics are presented

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

    CERN Document Server

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

    2015-01-01

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

  12. 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.

  13. 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.)

  14. Improved Numerical Cherenkov Instability Suppression in the Generalized PSTD PIC Algorithm

    CERN Document Server

    Godfrey, Brendan B

    2015-01-01

    The family of generalized Pseudo-Spectral Time Domain (including the Pseudo-Spectral Analytical Time Domain) Particle-in-Cell algorithms offers substantial versatility for simulating particle beams and plasmas, and well written codes using these algorithms run reasonably fast. When simulating relativistic beams and streaming plasmas in multiple dimensions, they are, however, subject to the numerical Cherenkov instability. Previous studies have shown that instability growth rates can be reduced substantially by modifying slightly the transverse fields as seen by the streaming particles . Here, we offer an approach which completely eliminates the fundamental mode of the numerical Cherenkov instability while minimizing the transverse field corrections. The procedure, numerically computed residual growth rates (from weaker, higher order instability aliases), and comparisons with WARP simulations are presented. In some instances, there are no numerical instabilities whatsoever, at least in the linear regime.

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

    CERN Document Server

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

    2013-01-01

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

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

    CERN Document Server

    Lacki, Brian C

    2014-01-01

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

  17. 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.

  18. Status of the Schwarzchild-Couder Medium-Sized Telescope for the Cherenkov Telescope Array

    CERN Document Server

    Benbow, W

    2016-01-01

    The Cherenkov Telescope Array (CTA) is planned to be the next-generation very-high-energy (VHE; E > 100 GeV) gamma-ray observatory. It is anticipated that CTA will improve upon the sensitivity of the current generation of VHE experiments, such as VERITAS, HESS and MAGIC, by an order of magnitude. CTA is planned to consist of two graded arrays of Cherenkov telescopes with three primary-mirror sizes. A proof-of-concept telescope, based on the dual-mirror Schwarzchild-Couder design, is being constructed on the VERITAS site at the F.L. Whipple Observatory in southern Arizona, USA, and is a candidate design for the medium-sized telescopes. The construction of the telescope will be completed in early 2017, and the status of this project is presented here.

  19. Efficiency calibration of a liquid scintillation counter for {sup 90}Y Cherenkov counting

    Energy Technology Data Exchange (ETDEWEB)

    Vaca, F. [Huelva Univ. (Spain). Dept. de Fisica Aplicada e Ingenieria Electrica; Manjon, G. [Departamento de Fisica Aplicada, E.T.S. de Arquitectura, Universidad de Sevilla, Av. Reina Mercedes, 2, E-41012 Sevilla (Spain); Garcia-Leon, M. [Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Fisica, Universidad de Sevilla, Av. Reina Mercedes, s/n. Apartado 1061, E-41080 Sevilla (Spain)

    1998-04-01

    In this paper a complete and self-consistent method for {sup 90}Sr determination in environmental samples is presented. It is based on the Cherenkov counting of {sup 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.). 6 refs.

  20. R&D project for Gd-doped water Cherenkov detector

    Science.gov (United States)

    Mori, Takaaki; Super-Kamiokande Collaboration

    2013-02-01

    A dedicated test facility for a proposed Gadolinium doped water Cherenkov detector is being constructed in the Kamioka mine near the Super Kamiokande detector. Anti-electron neutrinos (bar ve) from inverse beta decay can be identified with high efficiency by taking advantage of Gd's large cross section on thermal neutron capture and by taking coincidence of a prompt positron and the delayed 8 MeV gamma cascades.

  1. The optical reflector system for the CANGAROO-II imaging atmospheric Cherenkov telescope

    CERN Document Server

    Kawachi, A; Jimbo, J; Kamei, S; Kifune, T; Kubo, H; Kushida, J; Le Bohec, S; Miyawaki, K; Mori, M; Nishijima, K; Patterson, J R; Suzuki, R; Tanimori, T; Yanagita, S; Yoshikoshi, T; Yuki, A

    2001-01-01

    A new imaging atmospheric Cherenkov telescope (CANGAROO-II) with a light-weight reflector has been constructed. Light, robust, and durable mirror facets of containing CFRP (Carbon Fiber Reinforced Plastic) laminates were developed for the telescope. The attitude of each facet can be adjusted by stepping motors. In this paper, we describe the design, manufacturing, alignment procedure, and the performance of the CANGAROO-II optical reflector system.

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

    Science.gov (United States)

    Krizmanic, John F.; Mitchell, John W.

    2011-01-01

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

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

    CERN Document Server

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

    2015-01-01

    This paper describes the concept of an FPGA-based digital camera trigger for imaging atmospheric Cherenkov telescopes, developed for the future Cherenkov Telescope Array (CTA). The proposed camera trigger is designed to select images initiated by the Cherenkov emission of extended air showers from very-high energy (VHE, E>20 GeV) photons and charged particles while suppressing signatures from background light. The trigger comprises three stages. A first stage employs programmable discriminators to digitize the signals arriving from the camera channels (pixels). At the second stage, a grid of low-cost FPGAs is used to process the digitized signals for camera regions with 37 pixels. At the third stage, trigger conditions found independently in any of the overlapping 37-pixel regions are combined into a global camera trigger by few central FPGAs. Trigger prototype boards based on Xilinx FPGAs have been designed, built and tested and were shown to function properly. Using these components a full camera trigger wi...

  4. Inauguration and First Light of the GCT-M Prototype for the Cherenkov Telescope Array

    CERN Document Server

    Watson, J J; Abchiche, A; Allan, D; Amans, J -P; Armstrong, T P; Balzer, A; Berge, D; Boisson, C; Bousquet, J -J; Brown, A M; Bryan, M; Buchholtz, G; Chadwick, P M; Costantini, H; Cotter, G; Daniel, M K; 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; Jegouzo, I; Jogler, T; Kraus, M; Lapington, J S; Laporte, P; Lefaucheur, J; Markoff, S; Melse, T; Mohrmann, L; Molyneux, P; Nolan, S J; Okumura, A; Osborne, J P; Parsons, R D; Rosen, S; Ross, D; Rowell, G; Rulten, C B; Sato, Y; Sayéde, F; Schmoll, J; Schoorlemmer, H; Servillat, M; Sol, H; Stamatescu, V; Stephan, M; Stuik, R; Sykes, J; Tajima, H; Thornhill, J; Tibaldo, L; Trichard, C; Vink, J; White, R; Yamane, N; Zech, A; Zink, A; Zorn, J

    2016-01-01

    The Gamma-ray Cherenkov Telescope (GCT) is a candidate for the Small Size Telescopes (SSTs) of the Cherenkov Telescope Array (CTA). Its purpose is to extend the sensitivity of CTA to gamma-ray energies reaching 300 TeV. Its dual-mirror optical design and curved focal plane enables the use of a compact camera of 0.4 m diameter, while achieving a field of view of above 8 degrees. Through the use of the digitising TARGET ASICs, the Cherenkov flash is sampled once per nanosecond continuously and then digitised when triggering conditions are met within the analogue outputs of the photosensors. Entire waveforms (typically covering 96 ns) for all 2048 pixels are then stored for analysis, allowing for a broad spectrum of investigations to be performed on the data. Two prototypes of the GCT camera are under development, with differing photosensors: Multi-Anode Photomultipliers (MAPMs) and Silicon Photomultipliers (SiPMs). During November 2015, the GCT MAPM (GCT-M) prototype camera was integrated onto the GCT structure...

  5. TARGET: A Digitizing And Trigger ASIC For The Cherenkov Telescope Array

    CERN Document Server

    Funk, S; Katagiri, H; Kraus, M; Okumura, A; Schoorlemmer, H; Shigenaka, A; Tajima, H; Tibaldo, L; Varner, G; Zink, A; Zorn, J

    2016-01-01

    The future ground-based gamma-ray observatory Cherenkov Telescope Array (CTA) will feature multiple types of imaging atmospheric Cherenkov telescopes, each with thousands of pixels. To be affordable, camera concepts for these telescopes have to feature low cost per channel and at the same time meet the requirements for CTA in order to achieve the desired scientific goals. We present the concept of the TeV Array Readout Electronics with GSa/s sampling and Event Trigger (TARGET) Application Specific Circuit (ASIC), envisaged to be used in the cameras of various CTA telescopes, e.g. the Gamma-ray Cherenkov Telescope (GCT), a proposed 2-Mirror Small-Sized Telescope, and the Schwarzschild-Couder Telescope (SCT), a proposed Medium-Sized Telescope. In the latest version of this readout concept the sampling and trigger parts are split into dedicated ASICs, TARGET C and T5TEA, both providing 16 parallel input channels. TARGET C features a tunable sampling rate (usually 1 GSa/s), a 16k sample deep buffer for each chann...

  6. 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.

  7. Calibration of Cherenkov detectors for monoenergetic photon imaging in active interrogation applications

    Science.gov (United States)

    Rose, P. B.; Erickson, A. S.

    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 11B(d,n-γ)12C 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 232Th, show that calibration is possible as long as the energies of photons of interest are distinct.

  8. Field test: first detection of Cherenkov light from air showers with Geiger APDs

    Energy Technology Data Exchange (ETDEWEB)

    Otte, N. [Max-Planck-Inst. fuer Physik, Muenchen (Germany); Biland, A.; Ilia, B.; Felicitas, P.; Ulf, R. [Eidgenoessische Technische Hochschule, Zuerich (Switzerland); Eckart, L. [Max-Planck-Inst. fuer Physik, Muenchen (Germany); Eidgenoessische Technische Hochschule, Zuerich (Switzerland); Dieter, R. [Paul Scherrer Inst., Villigen (Switzerland)

    2007-07-01

    G-APDs are novel semiconductor photon-detectors which offer several advantages compared to conventional photomultiplier tubes in the field of air shower detection. Folded with the Cherenkov spectrum the response of G-APDs is up to a factor of three higher if compared with classical photomultipliers. Moreover they offer high gain ({proportional_to} 10{sup 5}.. 10{sup 6}) at low operation voltages (< 100 V). Under operation they are insensible to excessive and prolonged exposure to light and are mechanical robust. Dark count rates of some G-APDs are below the level of light coming from the night sky. Furthermore G-APDs can be mass-produced which allows to considerably reduce the costs of these sensors. According to the present state of the development of G-APD they promise to be a major progress for {gamma}-ray astronomy. Here we report on first-time tests of the detection of Cherenkov light from air showers with G-APD. We discuss first test results and the advantages and problems of G-APDs in Cherenkov telescopes. (orig.)

  9. Performance of the Gamma-ray Cherenkov Telescope structure: a dual-mirror telescope prototype proposed for the future Cherenkov Telescope Array

    Science.gov (United States)

    Dournaux, J. L.; Amans, J. P.; Dangeon, L.; Fasola, G.; Gironnet, J.; Huet, J. M.; Laporte, P.; Abchiche, A.; Barkaoui, S.; Bousquet, J. J.; Buchholtz, G.; Dumas, D.; Gaudemard, J.; Jégouzo, I.; Poinsignon, P.; Vergne, L.; Sol, H.

    2016-07-01

    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 from 20 GeV to above 100 TeV. Because of this wide energy band, three classes of telescopes, associated with different energy ranges and different mirror sizes, are defined. The Small Size Telescopes (SSTs) are associated with the highest energy range. Seventy of these telescopes are foreseen on the Southern site of the CTA. The large number of telescopes constrains their mechanical structure because easy maintenance and reduced cost per telescope are needed. Moreover, of course, the design shall fulfill the required performance and lifetime in the environment conditions of the site. The Observatoire de Paris started design studies in 2011 of the mechanical structure of the GCT (Gamma-ray Cherenkov Telescope), a four-meter prototype telescope for the SSTs of CTA, from optical and preliminary mechanical designs made by the University of Durham. At the end of 2014 these studies finally resulted in a lightweight ( 8 tons) and stiff design. This structure was based on the dual-mirror Schwarzschild-Couder (SC) optical design, which is an interesting and innovative alternative to the one-mirror Davies-Cotton design commonly used in ground-based Cherenkov astronomy. The benefits of such a design are many since it enables a compact structure, lightweight camera and a good angular resolution across the entire field-of-view. The mechanical structure was assembled on the Meudon site of the Observatoire de Paris in spring 2015. The secondary mirror, panels of the primary mirror and the Telescope Control System were successfully implemented afterwards leading now to a fully operational telescope. This paper focuses on the mechanics of the telescope prototype. It describes the mechanical structure and presents its performance identified from computations or direct measurements. Upgrades of the design

  10. Fabrication of silica aerogel with $n$ = 1.08 for $e^+/\\mu ^+$ separation in a threshold Cherenkov counter of the J-PARC TREK/E36 experiment

    CERN Document Server

    Tabata, Makoto; Kawai, Hideyuki; Igarashi, Youichi; Imazato, Jun; Shimizu, Suguru; Yamazaki, Hirohito

    2015-01-01

    This study presents the development of hydrophobic silica aerogel for use as a radiator in threshold-type Cherenkov counters. These counters are to be used for separating positrons and positive muons produced by kaon decay in the J-PARC TREK/E36 experiment. We chose to employ aerogel with a refractive index of 1.08 to identify charged particles with momenta of approximately 240 MeV/$c$, and the radiator block shape was designed with a trapezoidal cross-section to fit the barrel region surrounding the kaon stopping target in the center of the TREK/E36 detector system. Including spares, we obtained 30 crack-free aerogel blocks segmented into two layers, each layer having a thickness of 2 cm and a length of 18 cm, to fill 12 counter modules. Optical measurements showed that the produced aerogel tiles had the required refractive indices and transparency.

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

    Science.gov (United States)

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

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

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

    Science.gov (United States)

    Ambrosi, G.; Bissaldi, E.; Giglietto, N.; Giordano, F.; Ionica, M.; Paoletti, R.; Rando, R.; Simone, D.; Vagelli, V.

    2017-02-01

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

  13. Status of the array control and data acquisition system for the Cherenkov Telescope Array

    Science.gov (United States)

    Füßling, Matthias; Oya, Igor; Balzer, Arnim; Berge, David; Borkowski, Jerzy; Conforti, Vito; Colomé, Josep; Lindemann, Rico; Lyard, Etienne; Melkumyan, David; Punch, Michael; Schwanke, Ullrich; Schwarz, Joseph; Tanci, Claudio; Tosti, Gino; Wegner, Peter; Wischnewski, Ralf; Weinstein, Amanda

    2016-08-01

    The Cherenkov Telescope Array (CTA) will be the next-generation ground-based observatory using the atmospheric Cherenkov technique. The CTA instrument will allow researchers to explore the gamma-ray sky in the energy range from 20 GeV to 300 TeV. CTA will comprise two arrays of telescopes, one with about 100 telescopes in the Southern hemisphere and another smaller array of telescopes in the North. CTA poses novel challenges in the field of ground-based Cherenkov astronomy, due to the demands of operating an observatory composed of a large and distributed system with the needed robustness and reliability that characterize an observatory. The array control and data acquisition system of CTA (ACTL) provides the means to control, readout and monitor the telescopes and equipment of the CTA arrays. The ACTL system must be flexible and reliable enough to permit the simultaneous and automatic control of multiple sub-arrays of telescopes with a minimum effort of the personnel on-site. In addition, the system must be able to react to external factors such as changing weather conditions and loss of telescopes and, on short timescales, to incoming scientific alerts from time-critical transient phenomena. The ACTL system provides the means to time-stamp, readout, filter and store the scientific data at aggregated rates of a few GB/s. Monitoring information from tens of thousands of hardware elements need to be channeled to high performance database systems and will be used to identify potential problems in the instrumentation. This contribution provides an overview of the ACTL system and a status report of the ACTL project within CTA.

  14. Performance of Silicon Photomultipliers for the Dual-Mirror Medium-Sized Telescopes of the Cherenkov Telescope Array

    CERN Document Server

    Biteau, Jonathan; Dang, Dennis; Doyle, Kevin; Johnson, Caitlin A.; Williams, David A.

    2015-01-01

    Gamma-ray observations in the very-high-energy domain (E > 30 GeV) can exploit the imaging of few-nanosecond Cherenkov flashes from atmospheric particle showers. Photomultipliers have been used as the primary photosensors to detect gamma-ray induced Cherenkov light for the past 25 years, but they are increasingly challenged by the swift progress of silicon photomultipliers (SiPMs). We are working to identify the optimal photosensors for medium-sized Schwarzschild-Couder telescopes (SCT), which are proposed to contribute a significant fraction of the sensitivity of the Cherenkov Telescope Array in its core energy range. We present the capabilities of the latest SiPMs from the Hamamatsu, SensL, and Excelitas companies that we have characterized in our laboratory, and compare them to the SiPMs equipping the prototype SCT camera that is under construction.

  15. Enhancement of the Yakutsk array by atmospheric Cherenkov telescopes to study cosmic rays above $10^{15}$ eV

    CERN Document Server

    Ivanov, A A; Petrov, Z E; Pravdin, M I; Sleptsov, I Ye

    2010-01-01

    The aim of the Yakutsk array enhancement project is to create an instrument to study the highest-energy galactic cosmic rays (CRs) -- their sources, energy spectrum, and mass composition. Additionally, there will be unique capabilities for investigations in the transition region between galactic and extragalactic components of CRs. Using the well-developed imaging atmospheric Cherenkov telescope technique adapted to the energy region $E>10^{15}$ eV, we plan to measure the longitudinal structure parameters of the shower, e.g., angular and temporal distributions of the Cherenkov signal related to $X_{max}$ and the mass composition of CRs. The main advantages of the Yakutsk array, such as its multi-component measurements of extensive air showers, and model-independent CR energy estimation based on Cherenkov light measurements, will be inherited by the instrument to be created.

  16. A quartz Cherenkov detector for Compton-polarimetry at future e{sup +}e{sup -} colliders

    Energy Technology Data Exchange (ETDEWEB)

    List, Jenny [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Vauth, Annika; Vormwald, Benedikt [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hamburg Univ. (Germany). Inst. fuer Experimentalphysik

    2015-02-15

    Precision polarimetry is essential for future e{sup +}e{sup -} 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.

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

    CERN Document Server

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

    2014-01-01

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

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

    CERN Document Server

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

    2008-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  20. 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.

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

    Directory of Open Access Journals (Sweden)

    Anna Barnacka

    2012-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

  3. Measuring TeV cosmic rays at the High Altitude Water Cherenkov Observatory

    OpenAIRE

    BenZvi Segev

    2015-01-01

    The High-Altitude Water Cherenkov Observatory, or HAWC, is an air shower array designed to observe cosmic rays and gamma rays between 100 GeV and 100 TeV. HAWC, located between the peaks Sierra Negra and Pico de Orizaba in central Mexico, will be completed in the spring of 2015. However, the observatory has been collecting data in a partial configuration since mid-2013. With only part of the final array in data acquisition, HAWC has already accumulated a data set of nearly 100 billion air sho...

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

    CERN Document Server

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

    2000-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  6. Performance of the SST-1M telescope for the Cherenkov Telescope Array observatory

    CERN Document Server

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

    2015-01-01

    The single mirror small-size telescope (SST-1M) is one of the telescope projects being proposed for the Cherenkov Telescope Array observatory by a sub-consortium of Polish and Swiss institutions. The SST-1M prototype structure is currently being constructed at the Institute of Nuclear Physics in Cracow, Poland, while the camera will be assembled at the University of Geneva, Switzerland. This prototype enables measurements of parameters having a decisive influence on the telescope performance. We present results of numerical simulations of the SST-1M performance based on such measurements. The telescope effective area, the expected trigger rates and the optical point spread function are calculated.

  7. A new solution for mirror coating in $\\gamma$-ray Cherenkov Astronomy

    CERN Document Server

    Bonardi, Antonio; Hermanutz, Stephan; Santangelo, Andrea

    2014-01-01

    In the $\\gamma$-ray Cherenkov Astronomy framework mirror coating plays a crucial role in defining the light response of the telescope. We carried out a study for new mirror coating solutions with both a numerical simulation software and a vacuum chamber for small sample production. In this article, we present a new mirror coating solution consisting of a 28-layer interferometric SiO$_{2}$-TiO$_{2}$-HfO$_{2}$ design deposited on a glass substrate, whose average reflectance is above $90\\%$ for normally incident light in the wavelength range between 300 and 550 nm.

  8. Particle Identification with Cherenkov detectors in the 2011 CALICE Tungsten Analog Hadronic Calorimeter Test Beam at the CERN SPS

    CERN Document Server

    Dannheim, D; Klempt, W; Lucaci Timoce, A; van der Kraaij, E

    2013-01-01

    In 2011 the CALICE Tungsten Analog Hadronic Calorimeter prototype (W-AHCAL) was exposed to mixed beams of electrons, pions, kaons and protons with momenta from 10 to 300 GeV in the CERN SPS H8 beam line. The selection of pion, kaon and proton samples is based on the information obtained from two Cherenkov threshold counters. This note presents the strategy for the particle identification, as well as the calibration, operation and analysis of the Cherenkov counters. Efficiency and sample-purity estimates are given for the data selected for the W-AHCAL data analysis.

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

    CERN Document Server

    Sharma, Mradul; Koul, M K; Bose, S; Mitra, Abhas

    2014-01-01

    A detailed case study of $\\gamma$-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 $\\gamma$-hadron segregation.

  10. Reconstructing the direction of reactor antineutrinos via electron scattering in Gd-doped water Cherenkov detectors

    Science.gov (United States)

    Hellfeld, D.; Bernstein, A.; Dazeley, S.; Marianno, C.

    2017-01-01

    The potential of elastic antineutrino-electron scattering in a Gd-doped water Cherenkov detector to determine the direction of a nuclear reactor antineutrino flux was investigated using the recently proposed WATCHMAN antineutrino experiment as a baseline model. The expected scattering rate was determined assuming a 13-km standoff from a 3.758-GWt light water nuclear reactor and the detector response was modeled using a Geant4-based simulation package. Background was estimated via independent simulations and by scaling published measurements from similar detectors. Background contributions were estimated for solar neutrinos, misidentified reactor-based inverse beta decay interactions, cosmogenic radionuclides, water-borne radon, and gamma rays from the photomultiplier tubes (PMTs), detector walls, and surrounding rock. We show that with the use of low background PMTs and sufficient fiducialization, water-borne radon and cosmogenic radionuclides pose the largest threats to sensitivity. Directional sensitivity was then analyzed as a function of radon contamination, detector depth, and detector size. The results provide a list of experimental conditions that, if satisfied in practice, would enable antineutrino directional reconstruction at 3σ significance in large Gd-doped water Cherenkov detectors with greater than 10-km standoff from a nuclear reactor.

  11. The design and performance of a prototype water Cherenkov optical time-projection chamber

    CERN Document Server

    Oberla, E

    2015-01-01

    A first experimental test of tracking relativistic charged particles by `drifting' Cherenkov photons in a water-based optical time-projection chamber (OTPC) has been performed at the Fermilab Test Beam Facility. The prototype OTPC detector consists of a 77~cm long, 28~cm diameter, 40~kg cylindrical water mass instrumented with a combination of commercial $5.1\\times5.1$~cm$^2$ micro-channel plate photo-multipliers (MCP-PMT) and $6.7\\times6.7$~cm$^2$ mirrors. Five MCP-PMTs are installed in two columns along the OTPC cylinder in a small-angle stereo configuration. A mirror is mounted opposite each MCP-PMT on the far side of the detector cylinder, effectively doubling the photo-detection efficiency and providing a time-resolved image of the Cherenkov light on the opposing wall. Each MCP-PMT is coupled to an anode readout consisting of thirty 50 Ohm microstrips. A 180-channel data acquisition system digitizes the MCP-PMT signals on one end of the microstrips using the PSEC4 waveform sampling-and-digitizing chip op...

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

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

    Science.gov (United States)

    Giomi, Matteo; Gerard, Lucie; Maier, Gernot

    2016-07-01

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

  15. A method of observing cherenkov light from extensive air shower at Yakutsk EAS array

    Science.gov (United States)

    Timofeev, Lev; Anatoly, Ivanov

    2016-07-01

    Proposed a new method for measuring the cherenkov light from the extensive air shower (EAS) of cosmic rays (CR), which allows to determine not only the primary particle energy and angle of arrival, but also the parameters of the shower in the atmosphere - the maximum depth and "age". For measurements Cherenkov light produced by EAS is proposed to use a ground network of wide-angle telescopes which are separated from each other by a distance 100-300 m depending on the total number of telescopes operating in the coincidence signals, acting autonomously, or includes a detector of the charged components, radio waves, etc. as part of EAS. In a results such array could developed, energy measurement and CR angle of arrival data on the depth of the maximum and the associated mass of the primary particle generating by EAS. This is particularly important in the study of galactic cosmic ray in E> 10^14 eV, where currently there are no direct measurements of the maximum depth of the EAS.

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

    CERN Document Server

    ,

    2015-01-01

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

  17. Reconstructing the direction of reactor antineutrinos via electron scattering in Gd-doped water Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Hellfeld, D. [Texas A & M Univ., College Station, TX (United States); Dazeley, S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Bernstein, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Marianno, C. [Texas A & M Univ., College Station, TX (United States)

    2015-11-25

    The potential of elastic antineutrino-electron scattering (ν¯e + e → ν¯e + e) in a Gd-doped water Cherenkov detector to determine the direction of a nuclear reactor antineutrino flux was investigated using the recently proposed WATCHMAN antineutrino experiment as a baseline model. The expected scattering rate was determined assuming a 13 km standoff from a 3.758 GWt light water nuclear reactor. Background was estimated via independent simulations and by appropriately scaling published measurements from similar detectors. Many potential backgrounds were considered, including solar neutrinos, misidentified reactor-based inverse beta decay interactions, cosmogenic radionuclide and water-borne radon decays, and gamma rays from the photomultiplier tubes, detector walls, and surrounding rock. The detector response was modeled using a GEANT4-based simulation package. The results indicate that with the use of low radioactivity PMTs and sufficient fiducialization, water-borne radon and cosmogenic radionuclides pose the largest threats to sensitivity. The directional sensitivity was then analyzed as a function of radon contamination, detector depth, and detector size. Lastly, the results provide a list of theoretical conditions that, if satisfied in practice, would enable nuclear reactor antineutrino directionality in a Gd-doped water Cherenkov detector approximately 10 km from a large power reactor.

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

    CERN Document Server

    ,

    2015-01-01

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

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

    CERN Document Server

    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 4-11%, 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.

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

    CERN Document Server

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Galkin V I

    2013-06-01

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

  2. GAW - A very large field-of-view Imaging Atmospheric Cherenkov Telescope

    CERN Document Server

    Arruda, Luisa

    2010-01-01

    GAW (Gamma Air Watch) is a pathfinder experiment in the TeV range to test the feasibility of a new generation of Imaging Atmospheric Cherenkov Telescopes (IACT). It combines high flux sensitivity with large field-of-view (FoV=24deg x 24deg) using Fresnel lenses, stereoscopic observational approach and single-photon counting mode. This particular counting mode, in comparison with the usual charge integration one, allows the triggering of events with a smaller number of collected Cherenkov photons keeping a good signal/background separation. GAW is conceived as an array of three identical imaging telescopes with 2.13 m diameter placed at the vertices of an equilateral triangle of 80 m side. The telescope will be built at the Calar Alto Observatory site (Sierra de Los Filabres - Almeria Spain, 2168 m a.s.l.) and is a joint effort of research institutes in Italy, Portugal and Spain. The main characteristics of the experiment will be reported.

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

    CERN Document Server

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

    2013-01-01

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

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

    CERN Document Server

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

    2007-01-01

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

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

    CERN Document Server

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

    2016-01-01

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

  6. Approximation of lateral distribution of atmospheric Cherenkov light at different observation levels. Comparison with previous results

    CERN Document Server

    Mishev, A; Stamenov, J

    2005-01-01

    This work summarizes the results presented at 29th International Cosmic Ray Conference in Pune India. Generally the aim of this work is to obtain the lateral distribution of the atmospheric Cherenkov light in extensive air showers produced by different primary particles in wide energy range and at several observation levels and to fit the obtained lateral distributions. Using one large detector and partially modified CORSIKA code version are obtained the lateral distributions of Cherenkov light flux densities at several observation levels for different particle primaries precisely at 536 g/cm2 Chacaltaya, 700 g/cm2 Moussala and 875 g/cm2 Kartalska field observation levels for hadronic primaries and gamma quanta in the energy range 1011 eV-1016 eV. On the basis of the solution of over-determined inverse problem the approximation of these distributions is obtained. The same model function for all the primaries is used and for the different observation levels. The different model parameters for the different pri...

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

    CERN Document Server

    Fioretti, Valentina; Schussler, Fabian

    2016-01-01

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

  8. 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...

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

    CERN Document Server

    ,

    2015-01-01

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

  10. The Single Mirror Small Sized Telescope For The Cherenkov Telescope Array

    CERN Document Server

    Heller, M; Porcelli, A; Pujadas, I Troyano; Zietara, K; della Volpe, D; Montaruli, T; Cadoux, F; Favre, Y; Aguilar, J A; Christov, A; Prandini, E; Rajda, P; Rameez, M; Bilnik, W; Blocki, J; Bogacz, L; Borkowski, J; Bulik, T; Frankowski, A; Grudzinska, M; Idzkowski, B; Jamrozy, M; Janiak, M; Kasperek, J; Lalik, K; Lyard, E; Mach, E; Mandat, D; Marszalek, A; Miranda, L D Medina; Michalowski, J; Moderski, R; Neronov, A; Niemiec, J; Ostrowski, M; Pasko, P; Pech, M; Schovanek, P; Seweryn, K; Sliusar, V; Skowron, K; Stawarz, L; Stodulska, M; Stodulski, M; Walter, R; Wiecek, M; Zagdanski, A

    2016-01-01

    The Small Size Telescope with Single Mirror (SST-1M) is one of the proposed types of Small Size Telescopes (SST) for the Cherenkov Telescope Array (CTA). About 70 SST telescopes will be part the CTA southern array which will also include Medium Sized Telescopes (MST) in its threshold configuration. Optimized for the detection of gamma rays in the energy range from 5 TeV to 300 TeV, the SST-1M uses a Davies-Cotton optics with a 4 m dish diameter with a field of view of 9 degrees. The Cherenkov light resulting from the interaction of the gamma-rays in the atmosphere is focused onto a 88 cm side-to-side hexagonal photo-detection plane. The latter is composed of 1296 hollow light guides coupled to large area hexagonal silicon photomultipliers (SiPM). The SiPM readout is fully digital readout as for the trigger system. The compact and lightweight design of the SST-1M camera offers very high performance ideal for gamma-ray observation requirement. In this contribution, the concept, design, performance and status of...

  11. 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.

  12. Progress and Recent Results from the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE)

    Science.gov (United States)

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

    1999-05-01

    The Solar Tower Atmopheric Cherenkov Effect Experiment (STACEE) is a new instrument for observing astrophysical sources of gamma-rays in the energy range from 50 to 250 GeV. This energy range corresponds to an ``unopened window," inaccessible to previous ground and space-based experiments. STACEE is located in at the National Solar Thermal Test Facility at Sandia Laboratories in Albuquerque, New Mexico. STACEE uses several large heliostat mirrors at night to collect Cherenkov light from gamma-ray air showers. The first phase of STACEE, using 32 large heliostat mirrors, was completed in the fall of 1998. We describe the performance of STACEE during the 1998-1999 winter observing season. We also describe analysis in progress of several preliminary observations including the Crab nebula and pulsar, supernova remnants, and extra-galactic sources, such as blazars. Construction to expand STACEE is continuing, and we expect the next phase using 64 heliostat mirrors to be completed by the end of 1999.

  13. Observations of Active Galactic Nuclei by the Solar Tower Atmospheric Cherenkov Effect Experiment (STACEE)

    Science.gov (United States)

    Covault, C. E.; Boone, L.M.; Bramel, D.; Carson, J.; Fortin, P.; Gauthier, G.; Gingrich, D.; Hanna, D.; Jarvis, A.; Kildea, J.; Mueller, C.; Mukherjee, R.; Ong, R.A.; Ragan, K.; Scalzo, R.A.; Williams, D.A.; Zweerink, J.

    2003-07-01

    We present new results from observations of Active Galactic Nuclei (AGN) by the STACEE experiment. STACEE is a detector for 50-500 GeV gamma rays which uses the array of heliostat mirrors at the National Solar Thermal Test Facility (NSTTF) located at Sandia Lab oratories, Albuquerque, New Mexico, USA. STACEE uses 64 of these heliostats at night to collect Cherenkov light from air showers due to high energy gamma rays. With a large collecting area, STACEE has good sensitivity below 100 GeV. This allow us to search for gamma rays from extragalactic sources at larger redshift distances (to z of 0.2 or more) than can be studied by more conventional imaging Cherenkov telescopes operating at higher energy thresholds. We summarize recent STACEE observations of W Comae (also known as ON+231), Markarian 421, and H 1426+428. Analysis of observations on these sources in ongoing, and new results will be presented at the conference. We also briefly describe plans for future STACEE observations of AGN in the context of multiwavelength campaigns.

  14. The ASTRI SST-2M prototype for the Cherenkov Telescope Array: opto-mechanical performance

    Science.gov (United States)

    Canestrari, Rodolfo; Giro, Enrico; Sironi, Giorgia; Antolini, Elisa; Fugazza, Dino; Scuderi, Salvatore; Tosti, Gino; Tanci, Claudio; Russo, Federico; Gardiol, Daniele; Fermino, Carlos Eduardo; Stringhetti, Luca; Pareschi, Giovanni; Marchiori, G.; Busatta, A.; Marcuzzi, E.; Folla, I.

    2016-08-01

    ASTRI SST-2M is an end-to-end telescope prototype developed by the Italian National Institute of Astrophysics (INAF) in the framework of the Cherenkov Telescope Array (CTA). The CTA observatory, with a combination of large-, medium-, and small-sized telescopes (LST, MST and SST, respectively), will represent the next generation of imaging atmospheric Cherenkov telescopes. It will explore the very high-energy domain from a few tens of GeV up to few hundreds of TeV. The ASTRI SST-2M telescope structure and mirrors have been installed at the INAF observing station at Serra La Nave, on Mt. Etna (Sicily, Italy) in September 2014. Its performance verification phase began in autumn 2015. Part of the scheduled activities foresees the study and characterization of the optical and opto-mechanical performance of the telescope prototype. In this contribution we report the results achieved in terms of kinematic model analysis, mirrors reflectivity evolution, telescopes positioning, flexures and pointing model and the thermal behavior.

  15. Detection of Shielded Special Nuclear Material With a Cherenkov-Based Transmission Imaging System

    Science.gov (United States)

    Rose, Paul; Erickson, Anna; Mayer, Michael; Jovanovic, Igor

    2015-10-01

    Detection of shielded special nuclear material, SSNM, while in transit, offers a unique challenge. Typical cargo imaging systems are Bremsstrahlung-based and cause an abundance of unnecessary signal in the detectors and doses to the cargo contents and surroundings. Active interrogation with dual monoenergetic photons can unveil the illicit material when coupled with a high-contrast imaging system while imparting significantly less dose to the contents. Cherenkov detectors offer speed, resilience, inherent energy threshold rejection, directionality and scalability beyond the capability of most scintillators. High energy resolution is not a priority when using two well separated gamma rays, 4.4 and 15.1 MeV, generated from low energy nuclear reactions such as 11B(d,n- γ)12C. These gamma rays offer a measure of the effective atomic number, Z, of the cargo by taking advantage of the large difference in photon interaction cross sections, Compton scattering and pair production. This imaging system will be coupled to neutron detectors to provide unique signature of SNM by monitoring delayed neutrons. Our experiments confirm that the Cherenkov imaging system can be used with the monoenergetic source to relate transmission and atomic number of the scanned material.

  16. Cosmic ray composition measurements and cosmic ray background free gamma-ray observations with Cherenkov telescopes

    CERN Document Server

    Neronov, A; Vovk, Ie; Mirzoyan, R

    2016-01-01

    Muon component of extensive air showers (EAS) initiated by cosmic ray particles carries information on the primary particle identity. We show that the muon content of EAS could be measured in a broad energy range from 10-100 TeV up to ultra-high-energy cosmic ray range using wide field-of-view imaging atmospheric Cherenkov telescopes observing strongly inclined or nearly horizontal EAS from the ground of from high altitude. Cherenkov emission from muons in such EAS forms a distinct component (halo or tail) of the EAS image in the telescope camera. We show that detection of the muon signal could be used to measure composition of the cosmic ray spectrum in the energy ranges of the knee, the ankle and of the Galactic-to-extragalactic transition. It could also be used to veto the cosmic ray background in gamma-ray observations. This technique provides a possibility for up to two orders of magnitude improvement of sensitivity for gamma-ray flux in the energy band above 10 PeV, compared to KASCADE-Grande, and an or...

  17. 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.

  18. The source of THz radiation based on dielectric waveguide excited by sequence of electron bunches

    Science.gov (United States)

    Altmark, A. M.; Kanareykin, A. D.

    2016-07-01

    We present a new method for excitation of THz Cherenkov radiation in a dielectric waveguide by relativistic electron bunches. A sequence of bunches generates monochromatic radiation. The frequency of radiation is defined by the distance between the bunches. The studies were carried by using the newly updated BBU-3000 code which permits taking into account a number of additional options: an external quadrupole focusing system, group velocity of the wakefield, and the dielectric material loss factor. In this paper, we present our algorithm for optimizing the number and sequential positions of bunches for generation of narrow band high power THz radiation.

  19. Temporal signatures of the Cherenkov light induced by extensive air showers of cosmic rays detected with the Yakutsk array

    Science.gov (United States)

    Ivanov, A. A.; Timofeev, L. V.

    2016-05-01

    We analyze temporal characteristics of signals from the wide field-of-view (WFOV) Cherenkov telescope (CT) detecting extensive air showers (EAS) of cosmic rays (CRs) in coincidence with surface detectors of the Yakutsk array. Our aim is to reveal causal relationships between measured characteristics and physical properties of EAS.

  20. Temporal signatures of the Cherenkov light induced by extensive air showers of cosmic rays detected with the Yakutsk array

    CERN Document Server

    Ivanov, A A

    2016-01-01

    We analyze temporal characteristics of signals from the wide field-of-view (WFOV) Cherenkov telescope (CT) detecting extensive air showers (EAS) of cosmic rays (CR) in coincidence with surface detectors of the Yakutsk array. Our aim is to reveal causal relationships between measured characteristics and physical properties of EAS.

  1. A Cherenkov-based Beam Loss Scintillator system for beam, background and online luminosity monitoring at the LHCb experiment at CERN

    CERN Document Server

    Alessio, F; Jacobsson, R

    2013-01-01

    The installation of a scintillator-based system in the LHCb cavern was initially proposed in order to observe injection problems around the LHCb interaction region. Thanks to the fact that LHCb had already developed a custom-made electronics board (BPIM) for the LHCb beam pickups and global LHCb timing monitoring, a complete, inexpensive but flexible and robust system was quickly developed and installed few cm from the beam pipe just in front of the LHCb VELO detector in time for the very first beams injected in the LHC. The current and final system – commonly referred to as Beam Loss Scintillator (BLS) system - ultimately played a central role in the fast beam, background and online luminosity monitoring at LHCb. In this paper, the features of the detector – based on quartz radiator and Cherenkov light - are described, including the functionalities that the system acquired during the proton-proton physics programmes in 2009- 2013 thanks to its flexibility, reliability and sensitivity to beam hal...

  2. Progress in Monte Carlo design and optimization of the Cherenkov Telescope Array

    CERN Document Server

    Bernlöhr, K; Becherini, Y; Bigas, O Blanch; Bouvier, A; Carmona, E; Colin, P; Decerprit, G; Di Pierro, F; Dubois, F; Farnier, C; Funk, S; Hermann, G; Hinton, J A; Humensky, T B; Jogler, T; Khélifi, B; Kihm, T; Komin, N; Lenain, J -P; López-Coto, R; Maier, G; Mazin, D; Medina, M C; Moralejo, A; Moderski, R; Nolan, S J; Ohm, S; Wilhelmi, E de Oña; Parsons, R D; Arribas, M Paz; Pedaletti, G; Pita, S; Prokoph, H; Rulten, C B; Schwanke, U; Shayduk, M; Stamatescu, V; Vallania, P; Vorobiov, S; Wischnewski, R; Wood, M; Yoshikoshi, T; Zech, A

    2013-01-01

    The Cherenkov Telescope Array (CTA) will be an instrument covering a wide energy range in very-high-energy (VHE) gamma rays. CTA will include several types of telescopes, in order to optimize the performance over the whole energy range. Both large-scale Monte Carlo (MC) simulations of CTA super-sets (including many different possible CTA layouts as sub-sets) and smaller-scale simulations dedicated to individual aspects were carried out and are on-going. We summarize results of the prior round of large-scale simulations, show where the design has now evolved beyond the conservative assumptions of the prior round and present first results from the on-going new round of MC simulations.

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

    ,

    2015-01-01

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

  5. Performance of the Two Aerogel Cherenkov Detectors of the JLab Hall A Hadron Spectrometer

    CERN Document Server

    Marrone, S; Acha, A; Cisbani, E; Coman, M; Cusanno, F; De Jager, C W; De Leo, R; Gao, H; Garibaldi, F; Higinbotham, D W; Iodice, M; LeRose, J J; Macchia, D; Markowitz, P; Nappia, E; Palmisano, F; Urciuoli, G M; van der Werf, I; Xiang, H; Zhu, L Y

    2008-01-01

    We report on the design and commissioning of two silica aerogel Cherenkov detectors with different refractive indices. In particular, extraordinary performance in terms of the number of detected photoelectrons was achieved through an appropriate choice of PMT type and reflector, along with some design considerations. After four years of operation, the number of detected photoelectrons was found to be noticeably reduced in both detectors as a result of contamination, yellowing, of the aerogel material. Along with the details of the set-up, we illustrate the characteristics of the detectors during different time periods and the probable causes of the contamination. In particular we show that the replacement of the contaminated aerogel and parts of the reflecting material has almost restored the initial performance of the detectors.

  6. Development of a Large-Area Aerogel Cherenkov Counter Onboard BESS

    CERN Document Server

    Asaoka, Y; Yoshimura, K; Ishino, M; Fujikawa, M; Orito, S

    1998-01-01

    This paper describes the development of a threshold type aerogel Cherenkov counter with a large sensitive area of 0.6 m$^2$ to be carried onboard the BESS rigidity spectrometer to detect cosmic-ray antiprotons. The design incorporates a large diffusion box containing 46 finemesh photomultipliers, with special attention being paid to achieving good performance under a magnetic field and providing sufficient endurance while minimizing material usage. The refractive index of the aerogel was chosen to be 1.03. By utilizing the muons and protons accumulated during the cosmic-ray measurements at sea level, a rejection factor of 10$^4$ was obtained against muons with $\\beta \\approx 1$, while keeping 97% efficiency for protons below the threshold.

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

    CERN Document Server

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

    2013-01-01

    We outline the science prospects for gamma-ray bursts (GRBs) with the Cherenkov Telescope Array (CTA), the next-generation ground-based gamma-ray observatory operating at energies above few tens of GeV. With its low energy threshold, large effective area and rapid slewing capabilities, CTA will be able to measure the spectra and variability of GRBs at multi-GeV energies with unprecedented photon statistics, and thereby break new ground in elucidating the physics of GRBs, which is still poorly understood. Such measurements will also provide crucial diagnostics of ultra-high-energy cosmic ray and neutrino production in GRBs, advance observational cosmology by probing the high-redshift extragalactic background light and intergalactic magnetic fields, and contribute to fundamental physics by testing Lorentz invariance violation with high precision. Aiming to quantify these goals, we present some simulated observations of GRB spectra and light curves, together with estimates of their detection rates with CTA. Alth...

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

    Energy Technology Data Exchange (ETDEWEB)

    Aaij, R. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Adeva, B. [Universidad de Santiago de Compostela (Spain); Adinolfi, M. [Bristol Univ. (United Kingdom). H.H. Wills Physics Lab.; and others

    2015-12-15

    A search is performed for heavy long-lived charged particles using 3.0 fb{sup -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 muons. No evidence is found for the production of such long-lived states. The results are expressed as limits on the Drell-Yan production of pairs of long-lived particles, with both particles in the LHCb pseudorapidity acceptance, 1.8 < η < 4.9. The mass-dependent cross-section upper limits are in the range 2-4 fb (at 95 % CL) for masses between 14 and 309 GeV/c{sup 2}. (orig.)

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

    Energy Technology Data Exchange (ETDEWEB)

    Aaij, R. [European Organization for Nuclear Research (CERN), Geneva (Switzerland); Adeva, B. [Universidad de Santiago de Compostela, Santiago de Compostela (Spain); Adinolfi, M. [H.H. Wills Physics Laboratory, University of Bristol, Bristol (United Kingdom); Affolder, A. [Oliver Lodge Laboratory, University of Liverpool, Liverpool (United Kingdom); Ajaltouni, Z. [Clermont Université, Université Blaise Pascal, CNRS/IN2P3, LPC, Clermont-Ferrand (France); and others

    2015-12-15

    A search is performed for heavy long-lived charged particles using 3.0 fb{sup -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 muons. No evidence is found for the production of such long-lived states. The results are expressed as limits on the Drell–Yan production of pairs of long-lived particles, with both particles in the LHCb pseudorapidity acceptance, 1.8<η<4.9. The mass-dependent cross-section upper limits are in the range 2–4 fb (at 95 % CL) for masses between 14 and 309 GeV /c{sup 2}.

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

    CERN Document Server

    Alonso, M Fernandez; Rovero, A C

    2015-01-01

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

  11. The optical reflector system for the CANGAROO-II imaging atmospheric Cherenkov telescope

    Science.gov (United States)

    Kawachi, A.; Hayami, Y.; Jimbo, J.; Kamei, S.; Kifune, T.; Kubo, H.; Kushida, J.; LeBohec, S.; Miyawaki, K.; Mori, M.; Nishijima, K.; Patterson, J. R.; Suzuki, R.; Tanimori, T.; Yanagita, S.; Yoshikoshi, T.; Yuki, A.

    2001-01-01

    A new imaging atmospheric Cherenkov telescope with a light-weight reflector has been constructed. Light, robust, and durable mirror facets of containing carbon fiber reinforced plastic laminates were developed for the telescope. The reflector has a parabolic shape ( f/1.1) with a 30 m 2 surface area, which consists of 60 spherical mirror facets. The image size of each mirror facet is 0°.08 (FWHM) on average. The attitude of each facet can be adjusted by stepping motors. After the first in situ adjustment, a point image of about 0°.14 (FWHM) over 3° field of view was obtained. The effect of gravitational load on the optical system was confirmed to be negligible at the focal plane. The telescope has been in operation with an energy threshold for γ-rays of ≲300 GeV since May 1999.

  12. Towards micro-arcsecond spatial resolution with Air Cherenkov Telescope arrays as optical intensity interferometers

    CERN Document Server

    De Wit, W J; Hinton, J A; White, R J; Daniel, M K; Holder, J

    2008-01-01

    In this poster contribution we highlight the equivalence between an Imaging Air Cherenkov Telescope (IACT) array and an Intensity Interferometer for a range of technical requirements. We touch on the differences between a Michelson and an Intensity Interferometer and give a brief overview of the current IACT arrays, their upgrades and next generation concepts (CTA, AGIS, completion 2015). The latter are foreseen to include 30-90 telescopes that will provide 400-4000 different baselines that range in length between 50m and a kilometre. Intensity interferometry with such arrays of telescopes attains 50 micro-arcseconds resolution for a limiting V magnitude of ~8.5. This technique opens the possibility of a wide range of studies, amongst others, probing the stellar surface activity and the dynamic AU scale circumstellar environment of stars in various crucial evolutionary stages. Here we discuss possibilities for using IACT arrays as optical Intensity Interferometers.

  13. Extended performance gas Cherenkov detector for gamma-ray detection in high-energy density experiments

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, H. W., E-mail: herrmann@lanl.gov; Kim, Y. H.; Young, C. S.; Fatherley, V. E.; Lopez, F. E.; Oertel, J. A.; Batha, S. H. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Malone, R. M. [National Security Technologies, LLC, Los Alamos, New Mexico 87544 (United States); Rubery, M. S.; Horsfield, C. J. [Atomic Weapons Establishment, Aldermaston, Berkshire RG7 4PR (United Kingdom); Stoeffl, W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Zylstra, A. B. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Shmayda, W. T. [Laboratory for Laser Energetics, Rochester, New York 14623 (United States)

    2014-11-15

    A new Gas Cherenkov Detector (GCD) with low-energy threshold and high sensitivity, currently known as Super GCD (or GCD-3 at OMEGA), is being developed for use at the OMEGA Laser Facility and the National Ignition Facility (NIF). Super GCD is designed to be pressurized to ≤400 psi (absolute) and uses all metal seals to allow the use of fluorinated gases inside the target chamber. This will allow the gamma energy threshold to be run as low at 1.8 MeV with 400 psi (absolute) of C{sub 2}F{sub 6}, opening up a new portion of the gamma ray spectrum. Super GCD operating at 20 cm from TCC will be ∼400 × more efficient at detecting DT fusion gammas at 16.7 MeV than the Gamma Reaction History diagnostic at NIF (GRH-6m) when operated at their minimum thresholds.

  14. Extended performance gas Cherenkov detector for gamma-ray detection in high-energy density experimentsa)

    Science.gov (United States)

    Herrmann, H. W.; Kim, Y. H.; Young, C. S.; Fatherley, V. E.; Lopez, F. E.; Oertel, J. A.; Malone, R. M.; Rubery, M. S.; Horsfield, C. J.; Stoeffl, W.; Zylstra, A. B.; Shmayda, W. T.; Batha, S. H.

    2014-11-01

    A new Gas Cherenkov Detector (GCD) with low-energy threshold and high sensitivity, currently known as Super GCD (or GCD-3 at OMEGA), is being developed for use at the OMEGA Laser Facility and the National Ignition Facility (NIF). Super GCD is designed to be pressurized to ≤400 psi (absolute) and uses all metal seals to allow the use of fluorinated gases inside the target chamber. This will allow the gamma energy threshold to be run as low at 1.8 MeV with 400 psi (absolute) of C2F6, opening up a new portion of the gamma ray spectrum. Super GCD operating at 20 cm from TCC will be ˜400 × more efficient at detecting DT fusion gammas at 16.7 MeV than the Gamma Reaction History diagnostic at NIF (GRH-6m) when operated at their minimum thresholds.

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

    CERN Document Server

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

    2013-01-01

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

  16. Measurement of DT fusion and neutron-induced gamma-rays using gas Cherenkov Detector

    Science.gov (United States)

    Kim, Y.; Herrmann, H. W.; Evans, S.; Sedillo, T.; Langenbrunner, J. R.; Young, C. S.; Mack, J. M.; McEvoy, A.; Horsfield, C. J.; Rubery, M.; Ali, Z.; Stoeffl, W.

    2010-08-01

    A secondary gamma experiment was carried out using a Gas Cherenkov Detector (GCD) at the OMEGA laser facility. The primary experimental objective was to simulate neutron-induced secondary gamma production (n-γ) from a NIF implosion capsule, hohlraum, and thermo-mechanical package. The high-band width of the GCD enabled us to detect time delayed and Doppler broadened n-γ signals from five different puck materials (Si, SiO2, Al, Al2O3, Cu) placed near target chamber center. These measurements were used for MCNP & ITS ACCEPT code validation purposes. By a simple change of the GCD CO2 gas pressure the system can effectively eliminate signals induced by n-γ reactions and thereby allow quality measurements of DT fusion γ-rays that are produced at NIF (National Ignition Facility).

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

    CERN Document Server

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

    2013-01-01

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

  18. Layered water Cherenkov detector for the study of ultra high energy cosmic rays

    CERN Document Server

    Letessier-Selvon, Antoine; Blanco, Miguel; Maris, Ioana C; Settimo, Mariangela

    2014-01-01

    We present a new design for the water Cherenkov detectors that are in use in various cosmic ray observatories. This novel design can provide a significant improvement in the independent measurement of the muonic and electromagnetic component of extensive air showers. From such multi-component data an event by event classification of the primary cosmic ray mass becomes possible. According to popular hadronic interaction models, such as EPOS-LHC or QGSJetII-04, the discriminating power between iron and hydrogen primaries reaches Fisher values of $\\sim$ 2 or above for energies in excess of $10^{19}$ eV with a detector array layout similar to that of the Pierre Auger Observatory.

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

    CERN Document Server

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

    2013-01-01

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

  20. Probing supernova shock waves and neutrino flavor transitions in next-generation water-Cherenkov detectors

    CERN Document Server

    Fogli, G L; Mirizzi, A; Montanino, D

    2004-01-01

    Several current projects aim at building a large water-Cherenkov detector, with a fiducial volume about 20 times larger than in the current Super-Kamiokande experiment. These projects include the Underground nucleon decay and Neutrino Observatory (UNO) in the Henderson Mine (Colorado), the Hyper-Kamiokande (HK) detector in the Tochibora Mine (Japan), and the MEgaton class PHYSics (MEMPHYS) detector in the Frejus site (Europe). We study the physics potential of a reference next-generation detector (0.4 Mton of fiducial mass) in providing information on supernova neutrino flavor transitions with unprecedented statistics. After discussing the ingredients of our calculations, we compute neutrino event rates from inverse beta decay ($\\bar\

  1. Operating Water Cherenkov Detectors in high altitude sites for the Large Aperture GRB Observatory

    CERN Document Server

    Allard, D; Asorey, H; Barros, H; Bertou, X; Castillo, M; Chirinos, J M; De Castro, A; Flores, S; González, J; Berisso, M Gomez; Grajales, J; Guada, C; Day, W R Guevara; Ishitsuka, J; López, J A; Martínez, O; Melfo, A; Meza, E; Loza, P Miranda; Barbosa, E Moreno; Murrugarra, C; Núñez, L A; Ormachea, L J Otiniano; Pérez, G; Perez, Y; Ponce, E; Quispe, J; Quintero, C; Rivera, H; Rosales, M; Rovero, A C; Saavedra, O; Salazar, H; Tello, J C; Peralda, R Ticona; Varela, E; Velarde, A; Villaseñor, L; Wahl, D; Zamalloa, M A

    2009-01-01

    Water Cherenkov Detectors (WCD) are efficient detectors for detecting GRBs in the 10 GeV - 1 TeV energy range using the single particle technique, given their sensitivity to low energy secondary photons produced by high energy photons when cascading in the atmosphere. The Large Aperture GRB Observatory (LAGO) operates arrays of WCD in high altitude sites (above 4500 m a.s.l.) in Bolivia, Mexico and Venezuela, with planned extension to Peru. Details on the operation and stability of these WCD in remote sites with high background rates of particles will be detailed, and compared to simulations. Specific issues due to operation at high altitude, atmospheric effects and solar activity, as well as possible hardware enhancements will also be presented.

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

    CERN Document Server

    Dravins, Dainis

    2014-01-01

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

  3. Mass Composition Sensitivity of an Array of Water Cherenkov and Scintillation Detectors

    CERN Document Server

    Gonzalez, Javier G; Roth, Markus

    2011-01-01

    We consider a hybrid array composed of scintillation and water Cherenkov detectors designed to measure the cosmic ray primary mass composition at energies of about 1 EeV. We have developed a simulation and reconstruction chain to study the theoretical performance of such an array. In this work we investigate the sensitivity of mass composition observables in relation to the geometry of the array. The detectors are arranged in a triangular grid with fixed 750 m spacing and the configuration of the scintillator detectors is optimized for mass composition sensitivity. We show that the performance for composition determination can be compared favorably to that of Xmax measurements after the difference in duty cycles is considered.

  4. Strangeonium spectroscopy at 11 GeV/c and Cherenkov Ring Imaging at the SLD

    Energy Technology Data Exchange (ETDEWEB)

    Bienz, T.L.

    1990-07-01

    This thesis is divided into two sections, which describe portions of the data acquisition system and online software for the Cherenkov Ring Imaging Detector (CRID) for the SLD, and analyses of several low cross section strangeonium channels in data from the LASS spectrometer. The CRID section includes a description of the data acquisition system, determination of the preamplifier gain, and development of an online pulse finding algorithm based on deconvolution. Deconvolution uses knowledge of the preamplifier impulse response to aid in pulse finding. The algorithm is fast and shows good single pulse resolution and excellent double pulse resolution in preliminary tests. The strangeonium analyses are based on data from a 4.1 event/nanobarn exposure of the LASS spectrometer in K{sup {minus}}p interactions at 11 GeV/c, and include studies of {Lambda}{eta}{pi}{sup {plus}}{pi}{sup {minus}}, {Lambda}{Kappa}*{Kappa}*, and {Lambda}{phi}{phi}.

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

    CERN Document Server

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

    2016-01-01

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

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

    CERN Document Server

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

    2013-01-01

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

  7. Actuator Development at IAAT for the Cherenkov Telescope Array Medium Size Telescopes

    CERN Document Server

    Diebold, S; Pühlhofer, G; Renner, S; Santangelo, A; Schanz, T; Tenzer, C

    2016-01-01

    The Cherenkov Telescope Array (CTA) will be the future observatory for TeV gamma-ray astronomy. In order to increase the sensitivity and to extend the energy coverage beyond the capabilities of current facilities, its design concept features telescopes of three different size classes. Based on the experience from H.E.S.S. phase II, the Institute for Astronomy and Astrophysics T\\"ubingen (IAAT) develops actuators for the mirror control system of the CTA Medium Size Telescopes (MSTs). The goals of this effort are durability, high precision, and mechanical stability under all environmental conditions. Up to now, several revisions were developed and the corresponding prototypes were extensively tested. In this contribution our latest design revision proposed for the CTA MSTs are presented.

  8. NectarCAM, a camera for the medium sized telescopes of the Cherenkov Telescope Array

    CERN Document Server

    Glicenstein, J-F

    2016-01-01

    NectarCAM is a camera proposed for the medium-sized telescopes of the Cherenkov Telescope Array (CTA) which covers the core energy range of ~100 GeV to ~30 TeV. It has a modular design and is based on the NECTAr chip, at the heart of which is a GHz sampling Switched Capacitor Array and 12-bit Analog to Digital converter. The camera will be equipped with 265 7-photomultiplier modules, covering a field of view of 8 degrees. Each module includes photomultiplier bases, high voltage supply, pre-amplifier, trigger, readout and Ethernet transceiver. The recorded events last between a few nanoseconds and tens of nanoseconds. The expected performance of the camera are discussed. Prototypes of NectarCAM components have been built to validate the design. Preliminary results of a 19-module mini-camera are presented, as well as future plans for building and testing a full size camera.

  9. Techniques And Results For The Calibration Of The MST Prototype For The Cherenkov Telescope Array

    CERN Document Server

    ,

    2016-01-01

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

  10. An Efficient Test Facility For The Cherenkov Telescope Array FlashCam Readout Electronics Production

    CERN Document Server

    Eisenkolb, F; Kalkuhl, C; Pühlhofer, G; Santangelo, A; Schanz, T; Tenzer, C

    2016-01-01

    The Cherenkov Telescope Array (CTA) is the planned next-generation instrument for ground-based gamma-ray astronomy, currently under preparation by a world-wide consortium. The FlashCam group is preparing a photomultiplier-based camera for the Medium Size Telescopes of CTA, with a fully digital Readout System (ROS). For the forthcoming mass production of a substantial number of cameras, efficient test routines for all components are currently under development. We report here on a test facility for the ROS components. A test setup and routines have been developed and an early version of that setup has successfully been used to test a significant fraction of the ROS for the FlashCam camera prototype in January 2016. The test setup with its components and interface, as well as first results, are presented here.

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

    Energy Technology Data Exchange (ETDEWEB)

    Mirzoyan, R. [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Müller, D., E-mail: dmueller@mpp.mpg.de [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Hanabata, Y. [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Hose, J.; Menzel, U. [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Nakajima, D.; Takahashi, M. [Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Teshima, M. [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Institute for Cosmic Ray Research, The University of Tokyo, Kashiwa, Chiba 277-8582 (Japan); Toyama, T. [Max-Planck-Institute for Physics, Föhringer Ring 6, 80805 Munich (Germany); Yamamoto, T. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada-ku, Kobe, Hyogo 658-0072 (Japan)

    2016-07-11

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

  12. Geant4 based simulation of the Water Cherenkov Detectors of the LAGO Project

    CERN Document Server

    Calderón, R; Núñez, L A

    2015-01-01

    To characterize the signals registered by the different types of water Cherenkov detectors (WCD) used by the Latin American Giant Observatory (LAGO) Project, it is necessary to develop detailed simulations of the detector response to the flux of secondary particles at the detector level. These particles are originated during the interaction of cosmic rays with the atmosphere. In this context, the LAGO project aims to study the high energy component of gamma rays bursts (GRBs) and space weather phenomena by looking for the solar modulation of galactic cosmic rays (GCRs). Focus in this, a complete and complex chain of simulations is being developed that account for geomagnetic effects, atmospheric reaction and detector response at each LAGO site. In this work we shown the first steps of a GEANT4 based simulation for the LAGO WCD, with emphasis on the induced effects of the detector internal diffusive coating.

  13. Strange meson spectroscopy in K{omega} and K{phi} at 11 GeV/c and Cherenkov ring imaging at SLD

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Youngjoon

    1993-01-01

    This thesis consists of two independent parts; development of Cherenkov Ring Imaging Detector (CRID) system and analysis of high-statistics data of strange meson reactions from the LASS spectrometer. Part 1: The CRID system is devoted to charged particle identification in the SLAC Large Detector (SLD) to study e{sup +}e{sup {minus}} collisions at {radical}s = m{sub Z{sup 0}}. By measuring the angles of emission of the Cherenkov photons inside liquid and gaseous radiators, {pi}/K/p separation will be achieved up to {approximately}30 GeV/c. The signals from CRID are read in three coordinates, one of which is measured by charge-division technique. To obtain a {approximately}1% spatial resolution in the charge-division, low-noise CRID preamplifier prototypes were developed and tested resulting in <1000 electrons noise for an average photoelectron signal with 2 {times} 10{sup 5} gain. To help ensure the long-term stability of CRID operation at high efficiency, a comprehensive monitoring and control system was developed. Part 2: Results from the partial wave analysis of strange meson final states in the reactions K{sup {minus}}p {yields} K{sup {minus}}{omega}p and K{sup {minus}}p {yields} {bar K}{sup 0}{phi}n are presented. The analyses are based on data from a 4.1 event/nb exposure of the LASS spectrometer in K{sup {minus}}p interactions at 11 GeV/c. The data sample of K{sup {minus}}{omega}p final state contains {approximately}10{sup 5} events. From the partial wave analysis, resonance structures of J{sup P} = 2{sup {minus}}, 3{sup {minus}} and 2{sup +} amplitudes are observed in the K{omega} system. The analysis of 2{sup {minus}} amplitudes provides an evidence for two strange meson states in the mass region around 1.75 GeV/c{sup 2}. The appropriate branching fractions are calculated and compared with the SU(3) predictions. The partial wave analysis of {bar K}{sup 0}{phi} system favors J{sup P} = 1{sup {minus}} and 2{sup +} states in the 1.9--2.0 GeV/c{sup 2} region.

  14. Status of the photomultiplier-based FlashCam camera for the Cherenkov Telescope Array

    Science.gov (United States)

    Pühlhofer, G.; Bauer, C.; Eisenkolb, F.; Florin, D.; Föhr, C.; Gadola, A.; Garrecht, F.; Hermann, G.; Jung, I.; Kalekin, O.; Kalkuhl, C.; Kasperek, J.; Kihm, T.; Koziol, J.; Lahmann, R.; Manalaysay, A.; Marszalek, A.; Rajda, P. J.; Reimer, O.; Romaszkan, W.; Rupinski, M.; Schanz, T.; Schwab, T.; Steiner, S.; Straumann, U.; Tenzer, C.; Vollhardt, A.; Weitzel, Q.; Winiarski, K.; Zietara, K.

    2014-07-01

    The FlashCam project is preparing a camera prototype around a fully digital FADC-based readout system, for the medium sized telescopes (MST) of the Cherenkov Telescope Array (CTA). The FlashCam design is the first fully digital readout system for Cherenkov cameras, based on commercial FADCs and FPGAs as key components for digitization and triggering, and a high performance camera server as back end. It provides the option to easily implement different types of trigger algorithms as well as digitization and readout scenarios using identical hardware, by simply changing the firmware on the FPGAs. The readout of the front end modules into the camera server is Ethernet-based using standard Ethernet switches and a custom, raw Ethernet protocol. In the current implementation of the system, data transfer and back end processing rates of 3.8 GB/s and 2.4 GB/s have been achieved, respectively. Together with the dead-time-free front end event buffering on the FPGAs, this permits the cameras to operate at trigger rates of up to several ten kHz. In the horizontal architecture of FlashCam, the photon detector plane (PDP), consisting of photon detectors, preamplifiers, high voltage-, control-, and monitoring systems, is a self-contained unit, mechanically detached from the front end modules. It interfaces to the digital readout system via analogue signal transmission. The horizontal integration of FlashCam is expected not only to be more cost efficient, it also allows PDPs with different types of photon detectors to be adapted to the FlashCam readout system. By now, a 144-pixel mini-camera" setup, fully equipped with photomultipliers, PDP electronics, and digitization/ trigger electronics, has been realized and extensively tested. Preparations for a full-scale, 1764 pixel camera mechanics and a cooling system are ongoing. The paper describes the status of the project.

  15. SiPM detectors for the ASTRI project in the framework of the Cherenkov Telescope Array

    Science.gov (United States)

    Billotta, Sergio; Marano, Davide; Bonanno, Giovanni; Belluso, Massimiliano; Grillo, Alessandro; Garozzo, Salvatore; Romeo, Giuseppe; Timpanaro, Maria Cristina; Maccarone, Maria Concetta C.; Catalano, Osvaldo; La Rosa, Giovanni; Sottile, Giuseppe; Impiombato, Domenico; Gargano, Carmelo; Giarrusso, Salavtore

    2014-07-01

    The Cherenkov Telescope Array (CTA) is a worldwide new generation project aimed at realizing an array of a hundred ground based gamma-ray telescopes. ASTRI (Astrofisica con Specchi a Tecnologia Replicante Italiana) is the Italian project whose primary target is the development of an end-to-end prototype, named ASTRI SST-2M, of the CTA small size class of telescopes devoted to investigation of the highest energy region, from 1 to 100 TeV. Next target is the implementation of an ASTRI/CTA mini-array based on seven identical telescopes. Silicon Photo-Multipliers (SiPMs) are the semiconductor photosensor devices designated to constitute the camera detection system at the focal plane of the ASTRI telescopes. SiPM photosensors are suitable for the detection of the Cherenkov flashes, since they are very fast and sensitive to the light in the 300-700nm wavelength spectrum. Their drawbacks compared to the traditional photomultiplier tubes are high dark count rates, after-pulsing and optical cross-talk contributions, and intrinsic gains strongly dependent on temperature. Nonetheless, for a single pixel, the dark count rate is well below the Night Sky Background, the effects of cross-talk and afterpulses are typically lower than 20%, and the gain can be kept stable against temperature variations by means of adequate bias voltage compensation strategies. This work presents and discusses some experimental results from a large set of measurements performed on the SiPM sensors to be used for the ASTRI SST-2M prototype camera and on recently developed detectors demonstrating outstanding performance for the future evolution of the project in the ASTRI/CTA mini-array.

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

    Science.gov (United States)

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

    2016-08-01

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

  17. Rich detector with a sodium fluoride radiator: /K identification up to 3 GeV/c

    Energy Technology Data Exchange (ETDEWEB)

    Arnold, R.; Guyonnet, J.L.; Giomataris, Y.; Petroff, P.; Seguinot, J.; Tocqueville, J.; Ypsilantis, T.

    1988-12-15

    The use of a single crystal of sodium fluoride (NaF) as a Cherenkov radiator has been investigated. Its transparency has been measured and found to be good for photon energies below 9.6 eV. Data on its index of refraction are well fitted to a single-pole Sellmeier resonance formula. These data allow a realistic Monte Carlo simulation of a proximity-focused ring imaging Cherenkov (RICH) system. The photon detector is a multiwire proportional chamber (MWPC) with pad readout. The photosensitive gases considered are tetrakis(dimethylamine)ethylene (TMAE) and triethylamine (TEA). The simulation shows that a system having 10 cm radial thickness and 12% of a radiation length of material would identify pions and kaons below 3 GeV/c momentum. The pad dimensions required are about 5 mm x 5 mm.

  18. Contributions of the Cherenkov Telescope Array (CTA) to the 6th International Symposium on High-Energy Gamma-Ray Astronomy (Gamma 2016)

    CERN Document Server

    :,; Abeysekara, U; Abril, Ó; Acero, F; Acharya, B S; Adams, C; Agnetta, G; Aharonian, F; Akhperjanian, A; Albert, A; Alcubierre, M; Alfaro, J; Alfaro, R; Allafort, A J; Aloisio, R; Amans, J -P; Amato, E; Ambrogi, L; Ambrosi, G; Ambrosio, M; Anderson, J; Anduze, M; Angüner, E O; Antolini, E; Antonelli, L A; Antonucci, M; Antonuccio, V; Antoranz, P; Aramo, C; Aravantinos, A; Araya, M; Arcaro, C; Arezki, B; Argan, A; Armstrong, T; Arqueros, F; Arrabito, L; Arrieta, M; Asano, K; Ashley, M; Aubert, P; Singh, C B; Babic, A; Backes, M; Bais, A; Bajtlik, S; Balazs, C; Balbo, M; Balis, D; Balkowski, C; Ballester, O; Ballet, J; Balzer, A; Bamba, A; Bandiera, R; Barber, A; Barbier, C; Barcelo, M; Barkov, M; Barnacka, A; de Almeida, U Barres; Barrio, J A; Basso, S; Bastieri, D; Bauer, C; Becciani, U; Becherini, Y; Tjus, J Becker; Beckmann, V; Bednarek, W; Benbow, W; Ventura, D Benedico; Berdugo, J; Berge, D; Bernardini, E; Bernardini, M G; Bernhard, S; Bernlöhr, K; Bertucci, B; Besel, M -A; Beshley, V; Bhatt, N; Bhattacharjee, P; Bhattacharyya, W; Bhattachryya, S; Biasuzzi, B; Bicknell, G; Bigongiari, C; Biland, A; Bilinsky, A; Bilnik, W; Biondo, B; Bird, R; Bird, T; Bissaldi, E; Bitossi, M; Blanch, O; Blasi, P; Blazek, J; Bockermann, C; Boehm, C; Bogacz, L; Bogdan, M; Bohacova, M; Boisson, C; Boix, J; Bolmont, J; Bonanno, G; Bonardi, A; Bonavolontà, C; Bonifacio, P; Bonnarel, F; Bonnoli, G; Borkowski, J; Bose, R; Bosnjak, Z; Böttcher, M; Bousquet, J -J; Boutonnet, C; Bouyjou, F; Bowman, L; Braiding, C; Brantseg, T; Brau-Nogué, S; Bregeon, J; Briggs, M; Brigida, M; Bringmann, T; Brisken, W; Bristow, D; Britto, R; Brocato, E; Bron, S; Brook, P; Brooks, W; Brown, A M; Brügge, K; Brun, F; Brun, P; Brun, P; Brunetti, G; Brunetti, L; Bruno, P; Buanes, T; Bucciantini, N; Buchholtz, G; Buckley, J; Bugaev, V; Bühler, R; Bulgarelli, A; Bulik, T; Burton, M; Burtovoi, A; Busetto, G; Buson, S; Buss, J; Byrum, K; Cadoux, F; Tovar, J Calvo; Cameron, R; Canelli, F; Canestrari, R; Capalbi, M; Capasso, M; Capobianco, G; Caproni, A; Caraveo, P; Cardenzana, J; Cardillo, M; Carius, S; Carlile, C; Carosi, A; Carosi, R; Carquín, E; Carr, J; Carroll, M; Carter, J; Carton, P -H; Casandjian, J -M; Casanova, S; Casanova, S; Cascone, E; Casiraghi, M; Castellina, A; Mora, J Castroviejo; Catalani, F; Catalano, O; Catalanotti, S; Cauz, D; Cavazzani, S; Cerchiara, P; Chabanne, E; Chadwick, P; Chaleil, T; Champion, C; Chatterjee, A; Chaty, S; Chaves, R; Chen, A; Chen, X; Chen, X; Cheng, K; Chernyakova, M; Chiappetti, L; Chikawa, M; Chinn, D; Chitnis, V R; Cho, N; Christov, A; Chudoba, J; Cieślar, M; Ciocci, M A; Clay, R; Colafrancesco, S; Colin, P; Colley, J -M; Colombo, E; Colome, J; Colonges, S; Conforti, V; Connaughton, V; Connell, S; Conrad, J; Contreras, J L; Coppi, P; Corbel, S; Coridian, J; Cornat, R; Corona, P; Corti, D; Cortina, J; Cossio, L; Costa, A; Costantini, H; Cotter, G; Courty, B; Covino, S; Covone, G; Crimi, G; Criswell, S J; Crocker, R; Croston, J; Cuadra, J; Cumani, P; Cusumano, G; 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Yoshida, A; Yoshida, M; Yoshida, T; Yoshiike, S; Yoshikoshi, T; Yu, P; Zabalza, V; Zaborov, D; Zacharias, M; Zaharijas, G; Zajczyk, A; Zampieri, L; Zandanel, F; Sanchez, R Zanmar; Zaric, D; Zavrtanik, D; Zavrtanik, M; Zdziarski, A; Zech, A; Zechlin, H; Zhao, A; Zhdanov, V; Ziegler, A; Ziemann, J; Ziętara, K; Zink, A; Ziółkowski, J; Zitelli, V; Zoli, A; Zorn, J; Żychowski, P

    2016-01-01

    List of contributions from the Cherenkov Telescope Array (CTA) Consortium presented at the 6th International Symposium on High-Energy Gamma-Ray Astronomy (Gamma 2016), July 11-15, 2016, in Heidelberg, Germany.

  19. MO-AB-BRA-08: Rapid Treatment Field Uniformity Optimization for Total Skin Electron Beam Therapy Using Cherenkov Imaging

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-06-15

    Purpose: To evaluate treatment field heterogeneity resulting from gantry angle choice in total skin electron beam therapy (TSEBT) following a modified Stanford dual-field technique, and determine a relationship between source to surface distance (SSD) and optimized gantry angle spread. Methods: Cherenkov imaging was used to image 62 treatment fields on a sheet of 1.2m x 2.2m x 1.2cm polyethylene following standard TSEBT setup at our institution (6 MeV, 888 MU/min, no spoiler, SSD=441cm), where gantry angles spanned from 239.5° to 300.5° at 1° increments. Average Cherenkov intensity and coefficient of variation in the region of interest were compared for the set of composite Cherenkov images created by summing all unique combinations of angle pairs to simulate dual-field treatment. The angle pair which produced the lowest coefficient of variation was further studied using an ionization chamber. The experiment was repeated at SSD=300cm, and SSD=370.5cm. Cherenkov imaging was also implemented during TSEBT of three patients. Results: The most uniform treatment region from a symmetric angle spread was achieved using gantry angles +/−17.5° about the horizontal axis at SSD=441cm, +/−18.5° at SSD=370.5cm, and +/−19.5° at SSD=300cm. Ionization chamber measurements comparing the original treatment spread (+/−14.5°) and the optimized angle pair (+/−17.5°) at SSD=441cm showed no significant deviation (r=0.999) in percent depth dose curves, and chamber measurements from nine locations within the field showed an improvement in dose uniformity from 24.41% to 9.75%. Ionization chamber measurements correlated strongly (r=0.981) with Cherenkov intensity measured concurrently on the flat Plastic Water phantom. Patient images and TLD results also showed modest uniformity improvements. Conclusion: A decreasing linear relationship between optimal angle spread and SSD was observed. Cherenkov imaging offers a new method of rapidly analyzing and optimizing TSEBT setup

  20. 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.

  1. 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

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2007-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Anderhub, H. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Backes, M., E-mail: michael.backes@physik.tu-dortmund.d [Technische Universitaet Dortmund, D-44221 Dortmund (Germany); Biland, A.; Boller, A.; Braun, I. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Bretz, T. [Ecole Polytechnique Federale de Lausanne, CH-1015 (Switzerland); Commichau, S.; Commichau, V. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Domke, M. [Technische Universitaet Dortmund, D-44221 Dortmund (Germany); Dorner, D. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); ISDC, Data Centre for Astrophysics, CH-1290 Versoix (Switzerland); Gendotti, A.; Grimm, O.; Gunten, H. von; Hildebrand, D.; Horisberger, U. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Koehne, J.-H. [Technische Universitaet Dortmund, D-44221 Dortmund (Germany); Kraehenbuehl, T.; Kranich, D. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland); Krumm, B. [Technische Universitaet Dortmund, D-44221 Dortmund (Germany); Lorenz, E. [ETH Zurich, Institute for Particle Physics, CH-8093 Zurich (Switzerland)

    2011-05-21

    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.

  5. A new analysis method for very high definition Imaging Atmospheric Cherenkov Telescopes as applied to the CAT telescope

    CERN Document Server

    Le Bohec, S; Punch, M; Barrau, A; Bazer-Bachi, R; Cabot, H; Chounet, L M; Debiais, G; Dezalay, J P; Djannati-Ataï, A; Dumora, D; Espigat, P; Fabre, B; Fleury, P; Fontaine, G; George, R; Ghesquière, C; Goret, P; Gouiffes, C; Grenier, I A; Iacoucci, L; Malet, I; Meynadier, C; Munz, F; Palfrey, T A; Paré, E; Pons, Y; Québert, J; Ragan, K; Renault, C; Rivoal, M; Rob, L; Schovanek, P; Smith, D; Tavernet, J P; Vrana, J

    1998-01-01

    A new method of shower-image analysis is presented which appears very powerful as applied to those Cherenkov Imaging Telescopes with very high definition imaging capability. It provides hadron rejection on the basis of a single cut on the image shape, and simultaneously determines the energy of the electromagnetic shower and the position of the shower axis with respect to the detector. The source location is also reconstructed for each individual gamma-ray shower, even with one single telescope, so for a point source the hadron rejection can be further improved. As an example, this new method is applied to data from the CAT (Cherenkov Array at Themis) imaging telescope, which has been operational since Autumn, 1996.

  6. Development of a 13-in. Hybrid Avalanche Photo-Detector (HAPD) for a next generation water Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Nakayama, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)]. E-mail: nakkan@hep.phys.s.u-tokyo.ac.jp; Kusaka, A. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Kakuno, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Abe, T. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Iwasaki, M. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Aihara, H. [Department of Physics, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Shiozawa, M. [Institute for Cosmic Ray Research, University of Tokyo, Higashi-Mozumi, Kamioka-cho, Hida city, Gifu 506-1205 (Japan); Tanaka, M. [Institute for Particle and Nuclear Studies, High Energy Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Kyushima, H. [Electron Tube Division, Hamamatsu Photonics K.K., 314-5 Simokanzo, Iwata City 438-0193, Shizuoka (Japan); Suyama, M. [Electron Tube Division, Hamamatsu Photonics K.K., 314-5 Simokanzo, Iwata City 438-0193, Shizuoka (Japan); Kawai, Y. [Electron Tube Division, Hamamatsu Photonics K.K., 314-5 Simokanzo, Iwata City 438-0193, Shizuoka (Japan)

    2006-11-01

    We have developed a 13-in. Hybrid Avalanche Photo-Detector (HAPD) for photosensors in next generation water Cherenkov type detectors. We study the performance of the HAPD and the results show good time resolution better than {sigma}=1ns, good sensitivity for single photon detection, wide dynamic range, and good uniformity on the photocathode. The HAPD is also expected to be less expensive than large PMTs because of its simpler structure without dynodes.

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

    Science.gov (United States)

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

    2016-05-01

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

  8. 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

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

    CERN Document Server

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

    2013-01-01

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

  10. A simulation study of some observable parameters of Cherenkov photons in EASs of different primaries incident at various angles

    CERN Document Server

    Das, G S; Goswami, U D

    2016-01-01

    We have studied the lateral density, arrival time and angular distributions of Cherenkov photons in Extensive Air Showers (EASs) initiated by $\\gamma$-ray, proton and iron primaries incident with different energies and at different zenith angles. This study is the extension of our earlier work \\cite{Hazarika} to cover almost the whole energy range of ground based $\\gamma$-ray astronomy and to cover a wide range of zenith angles ($\\le 40^\\circ$), as well as the extension to study the angular distribution patterns of Cherenkov photons in EASs. This type of study is important for distinguishing the $\\gamma$-ray initiated showers from the hadronic showers in the ground based $\\gamma$-ray astronomy, where Atmospheric Cherenkov Technique (ACT) is used. Importantly, such study gives an insight on the nature of $\\gamma$-ray and hadronic showers in general. In this work, we used the CORSIKA 6.990 simulation package for the generation of EASs. Similar to the case of Ref.\\cite{Hazarika}, this study also revealed that, t...

  11. The Cherenkov Telescope array on-site integral sensitivity: observing the Crab

    Science.gov (United States)

    Fioretti, Valentina; Bulgarelli, Andrea; Schüssler, Fabian

    2016-07-01

    The Cherenkov Telescope Array (CTA) is the future large observatory in the very high energy (VHE) domain. Operating from 20 GeV to 300 TeV, it will be composed of tens of Imaging Air Cherenkov Telescopes (IACTs) displaced in a large area of a few square kilometers in both the southern and northern hemispheres. Thanks to the wide energy coverage and the tremendous boost in effective area (10 times better than the current IACTs), for the first time a VHE observatory will be able to detect transient phenomena in short exposures. The CTA/DATA On-Site Analysis (OSA) is the system devoted to the development of dedicated pipelines and algorithms to be used at the CTA site for the reconstruction, data quality monitoring, science monitoring and realtime science alerting during observations. The minimum exposure required to issue a science alert is not a general requirement of the observatory but is a function of the astrophysical object under study, because the ability to detect a given source is determined by the integral sensitivity which, in addition to the CTA Monte Carlo simulations, providing the energy-dependent instrument response (e.g. the effective area and the background rate), requires the spectral distribution of the science target. The OSA integral sensitivity is computed here for the most studied source at Gamma-rays, the Crab Nebula, for a set of exposures ranging from 1000 seconds to 50 hours, using the full CTA Southern array. The reason for the Crab Nebula selection as the first example of OSA integral sensitivity is twofold: (i) this source is characterized by a broad spectrum covering the entire CTA energy range; (ii) it represents, at the time of writing, the standard candle in VHE and it is often used as unit for the IACTs sensitivity. The effect of different Crab Nebula emission models on the CTA integral sensitivity is evaluated, to emphasize the need for representative spectra of the CTA science targets in the evaluation of the OSA use cases. Using

  12. The software system for the Control and Data Acquisition for the Cherenkov Telescope Array

    Science.gov (United States)

    Wegner, P.; FüBling, M.; Oya, I.; Hagge, L.; Schwanke, U.; Schwarz, J.; Tosti, G.; Conforti, V.; Lyard, E.; Walter, R.; Oliveira Antonino, P.; Morgenstern, A.

    2016-10-01

    The Cherenkov Telescope Array (CTA), as the next generation ground-based very high-energy gamma-ray observatory, is defining new areas beyond those related to physics. It is also creating new demands on the control and data acquisition system. CTA will consist of two installations, one in each hemisphere, containing tens of telescopes of different sizes. The ACTL (array control and data acquisition) system will consist of the hardware and software that is necessary to control and monitor the CTA array, as well as to time-stamp, read-out, filter and store the scientific data at aggregated rates of a few GB/s. The ACTL system must implement a flexible software architecture to permit the simultaneous automatic operation of multiple sub-arrays of telescopes with a minimum personnel effort on site. In addition ACTL must be able to modify the observation schedule on timescales of a few tens of seconds, to account for changing environmental conditions or to prioritize incoming scientific alerts from time-critical transient phenomena such as gamma-ray bursts. This contribution summarizes the status of the development of the software architecture and the main design choices and plans.

  13. The water Cherenkov detector array for studies of cosmic rays at the University of Puebla

    Science.gov (United States)

    Cotzomi, J.; Moreno, E.; Murrieta, T.; Palma, B.; Pérez, E.; Salazar, H.; Villaseñor, L.

    2005-11-01

    We describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla ( 19∘N, 90∘W, 800 g/cm2) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1 PeV, i.e., around the knee of the cosmic ray spectrum. The array consists of 3 water Cherenkov detectors of 1.86 m2 cross-section and 12 liquid scintillator detectors of 1 m2 distributed in a square grid with a detector spacing of 20 m over an area of 4000 m2. We discuss the calibration and stability of the array for both sets of detectors and report on preliminary measurements and reconstruction of the lateral distributions for the electromagnetic (EM) and muonic components of extensive air showers. We also discuss how the hybrid character of the array can be used to measure mass composition of the primary cosmic rays by estimating the relative contents of muons with respect to the EM component of extensive air showers. This facility is also used to train students interested in the field of cosmic rays.

  14. An attempt to identify the muonic and electromagnetic components of extensive showers in water Cherenkov detectors

    Energy Technology Data Exchange (ETDEWEB)

    Muller, Marcio Aparecido; Chinellato, Jose Augusto [Universidade de Campinas (IFGW/UNICAMP), SP (Brazil). Inst. de Fisica Gleb Wataghin

    2011-07-01

    Full text: One of the purposes of the Pierre Auger Collaboration is to study the mass composition of primary cosmic rays. When a cosmic ray collides in the upper atmosphere, depending on the mass composition, we have different numbers of mesons being produced and therefore different amounts of muons at detector level. For example, showers initiated by proton have less muons than showers initiated by iron nucleus. If we can select the muon signal in Cherenkov tanks, we might be able to infer primary composition. To achieve this goal, we will use the so-called 'Muon Jump Method', which aims to discriminate muons from the electromagnetic component, based on the time structure of their FADC signal. Muons produces on average more signal than electrons or gammas and they induce spiky signals whereas the electromagnetic component produce a continuum of small peaks in the FADC traces. Using this information, we estimate the number of particles for each component, by setting filters the time distribution of the shower front. Therefore, we can infer the primary mass composition. Another important point of this study is to compare the predictions of the hadronic interaction models for each component of the shower front. We present an introduction to the main aspects of the 'Muon Jump Method' as well as some preliminary results we achieved by simulating air showers, reconstructing their main features and filtering the signals of each component. (author)

  15. Two-dimensional, single-photoelectron drift detector for Cherenkov ring imaging

    Energy Technology Data Exchange (ETDEWEB)

    Barrelet, E.; Seguinot, J.; Urban, M.; Ypsilantis, T. (Ecole Polytechnique, 91 - Palaiseau (France)); Ekeloef, T. (European Organization for Nuclear Research, Geneva (Switzerland)); Lund-Jensen, B. (Uppsala Univ. (Sweden)); Tocqueville, J. (College de France, 75 - Paris)

    1982-09-15

    A detector capable of imaging single photoelectrons has been constructed and tested. UV photons (>=5.4 eV) are converted to electrons with high quantum efficiency by photoionization of a small admixture (approx. equal to 1 Torr) of an organic vapour TMAE in a predominantly methane drift and amplifying gas at atmospheric pressure. The produced photoelectrons drift in a uniform applied electric field to a picket fence of proportional wires where each electron is amplified, counted and timed. The two-dimensional source point of each photoelectron is uniquely determined by the hit wire address and the arrival time. The detector has been tested by measuring ionization electrons produced in the drift gas be relativistic charged particles. The limiting precision to which the electron source point can be determined has been measured to be 300 ..mu..m (r.m.s.) in the drift direction and 370 ..mu..m in the wire plane direction. Additional independent error sources due to electron diffusion in the drift gas have been measured to be proportional to the square root of the drift distance with a proportionality constant of 235 ..mu..m/cmsup(1/2) in both directions. Drift velocities of electrons in various predominantly methane gas mixtures have been measured as a function of the applied electric field. The utilization of such a two-dimensional single electron drift detector for Cherenkov ring imaging is presented with a discussion of the advantages and limitations of the drift method for imaging.

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

    CERN Document Server

    Vercellone, Stefano

    2015-01-01

    The Cherenkov Telescope Array (CTA) is a large collaborative effort aimed at the design and operation of an observatory dedicated to very high-energy gamma-ray astrophysics in the energy range from a few tens of GeV to above 100 TeV, which will yield about an order of magnitude improvement in sensitivity with respect to the current major arrays (H.E.S.S., MAGIC, and VERITAS). Within this framework, the Italian National Institute for Astrophysics is leading the ASTRI project, whose main goals are the design and installation on Mt. Etna (Sicily) of an end-to-end dual-mirror prototype of the CTA small size telescope (SST) and the installation at the CTA Southern site of a dual-mirror SST mini-array composed of nine units with a relative distance of about 300 m. The innovative dual-mirror Schwarzschild-Couder optical solution adopted for the ASTRI Project allows us to substantially reduce the telescope plate-scale and, therefore, to adopt silicon photo-multipliers as light detectors. The ASTRI mini-array is a wid...

  17. Criterion of applicable models for planar type Cherenkov laser based on quantum mechanical treatments

    Energy Technology Data Exchange (ETDEWEB)

    Yamada, Minoru [Faculty of Electrical and Computer Engineering, Institute of Science and Engineering Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Fares, Hesham, E-mail: fares_fares4@yahoo.com [Faculty of Electrical and Computer Engineering, Institute of Science and Engineering Kanazawa University, Kakuma-machi, Kanazawa 920-1192 (Japan); Department of Physics, Faculty of Science, Assiut University, Assiut 71516 (Egypt)

    2013-05-01

    A generalized theoretical analysis for amplification mechanism in the planar-type Cherenkov laser is given. An electron is represented to be a material wave having temporal and spatial varying phases with finite spreading length. Interaction between the electrons and the electromagnetic (EM) wave is analyzed by counting the quantum statistical properties. The interaction mechanism is classified into the Velocity and Density Modulation (VDM) model and the Energy Level Transition (ELT) model basing on the relation between the wavelength of the EM wave and the electron spreading length. The VDM model is applicable when the wavelength of the EM wave is longer than the electron spreading length as in the microwave region. The dynamic equation of the electron, which is popularly used in the classical Newtonian mechanics, has been derived from the quantum mechanical Schrödinger equation. The amplification of the EM wave can be explained basing on the bunching effect of the electron density in the electron beam. The amplification gain and whose dispersion relation with respect to the electron velocity is given in this paper. On the other hand, the ELT model is applicable for the case that the wavelength of the EM wave is shorter than the electron spreading length as in the optical region. The dynamics of the electron is explained to be caused by the electron transition between different energy levels. The amplification gain and whose dispersion relation with respect to the electron acceleration voltage was derived on the basis of the quantum mechanical density matrix.

  18. Light sensors selection for the Cherenkov Telescope Array: PMT and SiPM

    Energy Technology Data Exchange (ETDEWEB)

    Shayduk, M., E-mail: mshayduk@googlemail.com [DESY Zeuthen, D-15738 (Germany); Mirzoyan, R.; Kurz, M.; Knoetig, M. [Max-Planck-Institute for Physics, D-80805 Muenchen (Germany); Bolmont, J. [LPNHE Universite Pierre et Marie Curie, Paris (France); Dickinson, H. [Oskar Klein Centre, Stockholm University (Sweden); Lorenz, E. [Max-Planck-Institute for Physics, D-80805 Muenchen (Germany); Tavernet, J.-P. [LPNHE Universite Pierre et Marie Curie, Paris (France); Hose, J.; Teshima, M. [Max-Planck-Institute for Physics, D-80805 Muenchen (Germany); Vincent, P. [LPNHE Universite Pierre et Marie Curie, Paris (France)

    2012-12-11

    The Cherenkov Telescope Array (CTA) is planned as the next generation ground-based instrument (after VERITAS, H.E.S.S. and MAGIC) for astrophysics by means of very high energy {gamma}-rays. The CTA collaboration includes the MAGIC, the H.E.S.S. and the VERITAS collaborations. Also, a large number of astrophysicists from European institutions, from Japan and USA have joined the CTA. The CTA array will comprise about 100 imaging telescopes of three sizes that shall provide one order of magnitude higher sensitivity than the current generation of telescopes. Every telescope will use an imaging camera based on {approx}2000PMTs. We have set up a PMT development program with Hamamatsu (Japan) and Electron Tube Enterprises (England) aiming to produce 1.5 in. PMTs of optimized parameters for the CTA project. The entire scientific community, including the medicine and biology, as well as many industrial applications, where a low light level sensors are necessary, may profit from it. Together with PMTs also SiPMs are interesting sensor candidates for the CTA telescopes. One expects about two times higher photon detection efficiency for SiPM compared to PMT. A set of parameters like the photon detection efficiency, cross-talk, afterpulsing, dark rate together with other important factors were evaluated. Here we report on the progress of these developments, based on detailed measurements.

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

    CERN Document Server

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

    2015-01-01

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

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

    CERN Document Server

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

    2016-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  2. A CMOS Integrating Amplifier for the PHENIX Ring Imaging Cherenkov detector

    Energy Technology Data Exchange (ETDEWEB)

    Wintenberg, A.L.; Jones, J.P. Jr.; Young, G.R. [Oak Ridge National Lab., TN (United States); Moscone, C.G. [Tennessee Univ., Knoxville, TN (United States)

    1997-11-01

    A CMOS integrating amplifier has been developed for use in the PHENIX Ring Imaging Cherenkov (RICH) detector. The amplifier, consisting of a charge-integrating amplifier followed by a variable gain amplifier (VGA), is an element of a photon measurement system comprising a photomultiplier tube, a wideband, gain of 10 amplifier, the integrating amplifier, and an analog memory followed by an ADC and double correlated sampling implemented in software. The integrating amplifier is designed for a nominal full scale input of 160 pC with a gain of 20 mV/pC and a dynamic range of 1000:1. The VGA is used for equalizing gains prior to forming analog sums for trigger purposes. The gain of the VGA is variable over a 3:1 range using a 5 bits digital control, and the risetime is held to approximately 20 ns using switched compensation in the VGA. Details of the design and results from several prototype devices fabricated in 1.2 {micro}m Orbit CMOS are presented. A complete noise analysis of the integrating amplifier and the correlated sampling process is included as well as a comparison of calculated, simulated and measured results.

  3. Investigating D-T Reaction Spectra with the Gas Cherenkov Detector

    Science.gov (United States)

    Huff, Michael A.; Kim, Yong Ho; McEvoy, Aaron; Young, Carlton S.; Mack, Joe M.; Herrmann, Hans W.; Horsfield, Colin J.

    2010-11-01

    In this study, a new analysis of the gamma ray spectra of the D-T fusion reaction using a Gas Cherenkov Detector (GCD) is presented. The D-T reaction is an essential process to understand for the future of fusion science. The reaction produces a He^5* nucleus that usually decays into a He^4 + n. It has been seen that this reaction produces a 16.75 MeV gamma ray .0025% of the time. The Gamma Ray History (GRH) group at Los Alamos proposes that there is an even less often occurrence where a gamma ray of around 12 MeV is produced. As the truth of this statement would affect the future potential yield of fusion reactors using D-T fuel, it is worth investigating. D-T spectra were obtained by detecting the produced gamma ray with the GCD at the University of Rochester OMEGA laser facility. A GCD response curve, calculated by the Monte Carlo modeling software ACCEPT, was used to forward convolve theoretical spectra into what the theoretical curves would have looked like in the GCD data. Results are presented.

  4. Dark matter in satellite galaxies: Will future Iimaging Air Cherenkov Telescopes play a role?

    Energy Technology Data Exchange (ETDEWEB)

    Fornasa, Mattia, E-mail: mfornasa@pd.infn.i [University of Padova and I.N.F.N. sezione di Padova, via Marzolo 8, 35131 Padova (Italy)

    2011-02-21

    Addressing the question about the importance of future Imaging Air Cherenkov Telescopes (IACTs) for indirect detection of Dark Matter (DM), I will review the results of a paper by Bringmann et al. (2008) in which the authors computed the gamma-ray flux from DM annihilation associated to the halos of two reference dwarf Spheroidal galaxies, Draco and Willman 1. The previously neglected contribution of Virtual Internal Bremsstrahlung is also taken into account, which produces, when present, a bump in the higher part of the energy spectrum. The boost factor is the quantity used to describe how far the experiment is from probing interesting DM scenarios and it is computed for the next generation of IACTs, namely MAGIC-II and CTA. Due to the presence of spectral features, the boost factors can vary, becoming dependent to the characteristics of the particular DM candidate, obstacling a clear statement about prospects of detection. However, at least for the case of Willman 1 observed by CTA, boost factors may be below 10, even without considering the effect of substructures or the Sommerfeld enhancement. This, added to the comparison with the prospects of detection by the Fermi satellite, clearly demonstrate that the answer to the question in the title is an affirmative one.

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

    Science.gov (United States)

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

    2016-06-01

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

  6. 4 m Davies-Cotton telescope for the Cherenkov Telescope Array

    CERN Document Server

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

    2013-01-01

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

  7. Detection of D-^3He Fusion γ-Rays using Gas Cherenkov Detectors

    Science.gov (United States)

    Kim, Y.; Herrmann, H. W.; Mack, J. M.; Young, C. S.; Hale, G. M.; Evans, S. C.; Sedillo, T. J.; Cahill, A.; Horsfield, C. J.; Rubery, M. S.; Grafil, E.; Stoeffl, W.; Waugh, C.; Rinderknecht, H. G.; Frenje, J. A.; Petrasso, R. D.; Miller, E. Kirk

    2012-10-01

    The high-energy γ-ray from ^3He(d,γ)^5Li reactions has drawn the attention of the nuclear physics and fusion community as a diagnostic signature to study the ^5Li nuclear structure and the D-^3He fusion reaction. In the past, the D-^3He γ-rays have been measured via accelerator-based beam-target experiments and recently in tokamak-based fusion reactors. In this work, we report the detection of D-^3He fusion γ-rays generated from inertial confinement fusion (ICF) implosions at the OMEGA laser facility. The γ-ray signal observed using Gas Cherenkov Detectors (GCD) is proportional to the independently measured 14.7-MeV fusion proton yield and provides a high-bandwidth alternative to fusion protons for D-^3He burn-history measurements. By comparing γ-rays from D-^3He and D-T implosions, we were able to examine (1) similarities in the γ-ray spectra of D-^3He and D-T and (2) disparities in the γ-to-particle branching ratios of D-^3He and D-T. This experimental work motivates further theoretical investigation of the multichannel ^5Li- and ^5He-system.

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

    CERN Document Server

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

    2013-01-01

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

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

    CERN Document Server

    Linden, Tim

    2013-01-01

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

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

    CERN Document Server

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

    2015-01-01

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

  11. FACT - The First G-APD Cherenkov Telescope: Status and Results

    CERN Document Server

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

    2013-01-01

    The First G-APD Cherenkov telescope (FACT) is the first telescope using silicon photon detectors (G-APD aka. SiPM). It is built on the mount of the HEGRA CT3 telescope, still located at the Observatorio del Roque de los Muchachos, and it is successfully in operation since Oct. 2011. The use of Silicon devices promises a higher photon detection efficiency, more robustness and higher precision than photo-multiplier tubes. The FACT collaboration is investigating with which precision these devices can be operated on the long-term. Currently, the telescope is successfully operated from remote and robotic operation is under development. During the past months of operation, the foreseen monitoring program of the brightest known TeV blazars has been carried out, and first physics results have been obtained including a strong flare of Mrk501. An instantaneous flare alert system is already in a testing phase. This presentation will give an overview of the project and summarize its goals, status and first results.

  12. Measuring TeV cosmic rays at the High Altitude Water Cherenkov Observatory

    Directory of Open Access Journals (Sweden)

    BenZvi Segev

    2015-01-01

    Full Text Available The High-Altitude Water Cherenkov Observatory, or HAWC, is an air shower array designed to observe cosmic rays and gamma rays between 100 GeV and 100 TeV. HAWC, located between the peaks Sierra Negra and Pico de Orizaba in central Mexico, will be completed in the spring of 2015. However, the observatory has been collecting data in a partial configuration since mid-2013. With only part of the final array in data acquisition, HAWC has already accumulated a data set of nearly 100 billion air showers. These events are used to calibrate the detector angular reconstruction using the shadow of the Moon, and to measure the anisotropy in the arrival directions of cosmic rays above 1 TeV. Using data recorded between June 2013 and July 2014, we have observed a significant 10−4 anisotropy consisting of three statistically significant “hotspots” in the cosmic ray flux. We will discuss these first results from HAWC and compare them to previous measurements of anisotropy in the northern and southern sky.

  13. Measuring TeV cosmic rays at the High Altitude Water Cherenkov Observatory

    Science.gov (United States)

    BenZvi, Segev

    2015-12-01

    The High-Altitude Water Cherenkov Observatory, or HAWC, is an air shower array designed to observe cosmic rays and gamma rays between 100 GeV and 100 TeV. HAWC, located between the peaks Sierra Negra and Pico de Orizaba in central Mexico, will be completed in the spring of 2015. However, the observatory has been collecting data in a partial configuration since mid-2013. With only part of the final array in data acquisition, HAWC has already accumulated a data set of nearly 100 billion air showers. These events are used to calibrate the detector angular reconstruction using the shadow of the Moon, and to measure the anisotropy in the arrival directions of cosmic rays above 1 TeV. Using data recorded between June 2013 and July 2014, we have observed a significant 10-4 anisotropy consisting of three statistically significant "hotspots" in the cosmic ray flux. We will discuss these first results from HAWC and compare them to previous measurements of anisotropy in the northern and southern sky.

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

    CERN Document Server

    ,

    2015-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Vagins, Mark R.

    2013-04-10

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

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

    CERN Document Server

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

    2011-01-01

    In the last few years, most of the attention in gamma-ray dark matter (DM) searches has been devoted to neutralino annihilations in nearby dwarf galaxies. However, massive galaxy clusters in the local Universe may constitute very good targets as well. The main aim of this work is to compare both dwarf galaxies and local galaxy clusters in order to elucidate which object class is the best target for gamma-ray DM searches with imaging atmospheric Cherenkov telescopes (IACTs). We have built a mixed dwarfs+clusters sample containing some of the most promising nearby dwarf galaxies and galaxy clusters, and then compute their DM annihilation flux profiles by making use of the latest modeling of their DM density profiles. We also include in our calculations the effect of DM substructure. Willman~1 appears as the best candidate in the sample and, given the morphology of its annihilation signal, it is also one of the objects more readily observable by IACTs. As for galaxy clusters, Virgo represents the one with the hi...

  17. Photon Detectors for the Ring Imaging Cherenkov Counters of the LHCb Experiment

    CERN Document Server

    Plackett, R W R

    2006-01-01

    This thesis reports on the author’s contribution to the development of the Ring Imaging Cherenkov(RICH) detectors in the LHCb experiment due to take data at the CERN Large Hadron Collider in 2007. The first chapter summarises the physics to be explored by the LHCb experiment; measurements of CP violating asymmetries and a study of rare B decay modes. A brief overview of other experiments studying B-physics is presented. The experiment itself is then described, focussing on the RICH system used for particle identification, with particular emphasis on the photondetectors. The thesis then reports on the work done by the author on the design of the RICH1 Magnetic Shield, that allows the photon detectors to operate in the fringe field of the LHCb dipole magnet, while fulfilling the conflicting requirement to provide additional magnetic bending power to aid the LHCb charged particle trigger. The design of all of the many sections of the shield are described in depth and the results of finite element simulations p...

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

    CERN Document Server

    Cavazzani, S; Bulik, T; Ortolani, S

    2012-01-01

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

  19. A decade of dark matter searches with ground-based Cherenkov telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Doro, Michele, E-mail: michele.doro@pd.infn.it [University and INFN Padova, via Marzolo 8, 35131 Padova (Italy); Department of Physics and CERES, Campus Universitat Autonoma Barcelona, 08135 Bellaterra (Spain)

    2014-04-01

    In the general scenario of Weakly Interacting Massive Particles (WIMP), dark matter (DM) can be observed via astrophysical gamma-rays because photons are produced in various DM annihilation or decay processes, either as broad-band or line emission, or because of the secondary processes of charged particles in the final stages of the annihilations or the decays. The energy range of the former processes is accessible by current ground-based Imaging Atmospheric Cherenkov telescopes (IACTs, like H.E.S.S., MAGIC and VERITAS). The strengths of this technique are (a) the expected DM gamma-ray spectra show peculiar features like bumps, spikes and cutoff that make them clearly distinguishable from the smoother astrophysical spectra and (b) the expected DM spectrum is universal and therefore by observing two or more DM targets with the same spectrum, a clear identification (besides detection) of DM would be enabled. The role of IACTs may gain more importance in the future as the results from the LHC may hint to a DM particle with mass at the TeV or above, where the IACTs sensitivity is unsurpassed by other experiments. In this contribution, a review of the search for DM with the current generation of IACT will be presented.

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

    CERN Document Server

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

    2013-01-01

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