The Giant Radio Array for Neutrino Detection (GRAND) is a planned large-scale observatory of ultra-high-energy (UHE) cosmic particles, with energies exceeding 10
8
GeV. Its goal is to solve the ...long-standing mystery of the origin of UHE cosmic rays. To do this, GRAND will detect an unprecedented number of UHE cosmic rays and search for the undiscovered UHE neutrinos and gamma rays associated to them with unmatched sensitivity. GRAND will use large arrays of antennas to detect the radio emission coming from extensive air showers initiated by UHE particles in the atmosphere. Its design is modular: 20 separate, independent sub-arrays, each of 10000 radio antennas deployed over 10000 km
2
. A staged construction plan will validate key detection techniques while achieving important science goals early. Here we present the science goals, detection strategy, preliminary design, performance goals, and construction plans for GRAND.
The Giant Radio Array for Neutrino Detection Martineau-Huynh, Olivier; Kotera, Kumiko; Bustamente, Mauricio ...
EPJ Web of Conferences,
01/2016, Letnik:
116
Journal Article, Conference Proceeding
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High-energy neutrino astronomy will probe the working of the most violent phenomena in the Universe. The Giant Radio Array for Neutrino Detection (GRAND) project consists of an array of ∼ 105 radio ...antennas deployed over ∼ 200 000 km2 in a mountainous site. It aims at detecting high-energy neutrinos via the measurement of air showers induced by the decay in the atmosphere of τ leptons produced by the interaction of cosmic neutrinos under the Earth surface. Our objective with GRAND is to reach a neutrino sensitivity of 5 × 10−11E−2 GeV−1 cm−2 s−1 sr−1 above 3 × 1016 eV. This sensitivity ensures the detection of cosmogenic neutrinos in the most pessimistic source models, and up to 100 events per year are expected for the standard models. GRAND would also probe the neutrino signals produced at the potential sources of UHECRs.
A wide field-of-view (FoV) is one of the most important goals for future ground-based γ-ray astronomy, and it is especially crucial for detailed studies of temporal and spectral characteristics of ...solitary events, such as γ-ray bursts (GRBs), highly variable sources like blazars, or potential very high energy (VHE) electromagnetic counterparts of gravitational waves (GWs). Atmospheric Cherenkov Telescope (ACT) based on refractive optics and operated at a very high altitude observatory may be an appropriate solution. In the present study, we report the characteristics and performance of a large FoV ACT prototype based on a refractive convex water lens. A reconstruction method for estimating the arrival direction of the air shower was developed by combining the water-lens telescope and the Extensive Air Shower (EAS) array. The Cherenkov images of the air showers were obtained by a water-lens prototype with 48 pixels, an FoV of 15°×13°, and a median angular resolution of ∼0.9°.
The High Altitude Detection of Astronomical Radiation (HADAR) experiment is a refracting terrestrial telescope array based on the atmospheric Cherenkov imaging technique. It focuses the Cherenkov ...light emitted by extensive air showers through a large aperture water-lens system for observing very-high-energy gamma-rays and cosmic rays. With the advantages of a large field-of-view (FOV) and low energy threshold, the HADAR experiment operates in a large-scale sky scanning mode to observe galactic sources. This study presents the prospects of using the HADAR experiment for the sky survey of TeV gamma-ray sources from TeVCat and provids a one-year survey of statistical significance. Results from the simulation show that a total of 23 galactic point sources, including five supernova remnant sources and superbubbles, four pulsar wind nebula sources, and I.sub.4 unidentified sources, were detected in the HADAR FOV with a significance greater than 5 standard deviations (a). The statistical significance for the Crab Nebula during one year of operation reached 346.0 sigma and the one-year integral sensitivity of HADAR above 1 TeV was ~1.3%-2.4% of the flux from the Crab Nebula. Keywords HADAR, Galactic sources, significance, gamma rays
The High Altitude Detection of Astronomical Radiation (HADAR) experiment is a refracting terrestrial telescope array based on the atmospheric Cherenkov imaging technique. It focuses the Cherenkov ...light emitted by extensive air showers through a large aperture water-lens system for observing very-high-energy γ-rays and cosmic rays. With the advantages of a large field-of-view (FOV) and low energy threshold, the HADAR experiment operates in a large-scale sky scanning mode to observe galactic sources. This study presents the prospects of using the HADAR experiment for the sky survey of TeV γ-ray sources from TeVCat and provids a one-year survey of statistical significance. Results from the simulation show that a total of 23 galactic point sources, including five supernova remnant sources and superbubbles, four pulsar wind nebula sources, and 14 unidentified sources, were detected in the HADAR FOV with a significance greater than 5 standard deviations ( σ). The statistical significance for the Crab Nebula during one year of operation reached 346.0 σ and the one-year integral sensitivity of HADAR above 1 TeV was ~1.3%-2.4% of the flux from the Crab Nebula.
A scintillation detector array composed of 115 detectors and covering an area of about 20000 m
2
was installed at the end of 2016 at the Yangbajing international cosmic ray observatory and has been ...taking data since then. The array is equipped with electronics from Large High Altitude Air Shower Observatory Square Kilometer Complex Array (LHAASO-KM2A) and, in turn, currently serves as the largest debugging and testing platform for the LHAASO-KM2A. Furthermore, the array was used to study the performance of a wide field-of-view air Cherenkov telescope by providing accurate information on the shower core, direction and energy, etc. This work is mainly dealing with the scintillation detector array. The experimental setup and the offline calibration are described in detail. Then, a thorough comparison between the data and Monte Carlo (MC) simulations is presented and a good agreement is obtained. With the even-odd method, the resolutions of the shower direction and core are measured. Finally, successful observations of the expected Moon’s and Sun’s shadows of cosmic rays (CRs) verify the measured angular resolution.
Composition measurement of cosmic rays (CRs) around the knee of the CR energy spectrum is crucial for studying the processes of particle acceleration and propagation of Galactic CRs. The Square ...Kilometer Array (KM2A) of Large High Altitude Air Shower Observatory (LHAASO) can provide precise measurement of the muonic and electromagnetic (em.) components in CR-induced extensive air showers, and hence a good chance to disentangle the CR composition. Here we propose an approach of decomposing CR compositions with the number ratio between muons and em. particles (\(N_{\mu}\)/\(N_{\rm e}\)) observed by LHAASO-KM2A: we reconstruct the energy spectra of individual CR compositions by fitting \(N_{\mu}\)/\(N_{\rm e}\) distributions in each reconstructed energy bin using the template shapes of \(N_{\mu}\)/\(N_{\rm e}\) distributions of individual CR compositions based on Monte Carlo (MC) simulation. We evaluate the performance of this approach with MC tests where mock data of LHAASO-KM2A are generated by MC simulation. We show that the input composition model can be well recovered in this approach, independent of the CR composition model adopted in the MC simulation for the template distributions. The uncertainties of the reconstructed spectra at < 20 PeV, mainly limited by simulation statistics, are \(\le\) 7% for proton, He, and Fe groups, and \(\le\) 8% and \(\le\) 16% for CNO and MgAlSi groups, respectively.
GRANDProto35 is the first stage of the GRAND project. It will be composed of an array of 35 radio antennas and 24 scintillation detectors, the radio and scintillating subarrays being triggered ...independently. The scintillation detector array allow to cross check,through an offline treatment, if the selected radio candidates are indeed air shower events and thus quantitatively determine the detection efficiency of the radio array. The Hamamatsu R7725 is candidate for the scintillation detector photomultiplier. The characteristics of the PMT will directly affects the time and energy resolution, dynamic detection range of a scintillation detector.In order to cover the large dynamic range, voltage divider circuit featured with dual-readoutwas designed for the PMT. In this paper,details about the system setup, measurement method and results will be described. Some characteristics of PMT were calibrated and researched: the absolution gain, single photoelectron (SPE) energy resolution, transit time spread (TTS), linear dynamic range and temperature dependence of PMT gain.
The High Altitude Detection of Astronomical Radiation (HADAR) experiment is a refracting terrestrial telescope array based on the atmospheric Cherenkov imaging technique. It focuses the Cherenkov ...light emitted by extensive air showers through a large aperture water-lens system for observing very-high-energy-rays and cosmic rays. With the advantages of a large field-of-view (FOV) and low energy threshold, the HADAR experiment operates in a large-scale sky scanning mode to observe galactic sources. This study presents the prospects of using the HADAR experiment for the sky survey of TeV {\gamma}-ray sources from TeVCat and provids a one-year survey of statistical significance. Results from the simulation show that a total of 23 galactic point sources, including five supernova remnant sources and superbubbles, four pulsar wind nebula sources, and 14 unidentified sources, were detected in the HADAR FOV with a significance greater than 5 standard deviations ({\sigma}). The statistical significance for the Crab Nebula during one year of operation reached 346.0 {\sigma} and the one-year integral sensitivity of HADAR above 1TeV was ~1.3%-2.4% of the flux from the Crab Nebula.
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