[Show abstract][Hide abstract] ABSTRACT: Up to several 10s of TeV, Imaging Air Cherenkov Telescopes (IACTs) have proven to be
the instruments of choice for GeV/TeV gamma-ray astronomy due to their good reconstrucion
quality and gamma-hadron separation power. However, sensitive observations at and above
100 TeV require very large effective areas (10 km 2 and more), which the current and planned
telescopes do not achieve.
The alternative to IACTs are shower front sampling arrays (non-imaging technique or
timing-arrays) with a large area and a wide field of view. Such experiments provide good core
position, energy and angular resolution, but only poor gamma-hadron separation. Combining
both experimental approaches, using the strengths of both techniques, could optimize the
sensitivity to the highest energies.
The TAIGA project plans to combine the non-imaging HiSCORE  array with small
( 10m 2 ) imaging telescopes. This paper covers simulation results of this hybrid approach.
Journal of Physics Conference Series 08/2015; 632:012040. DOI:10.1088/1742-6596/632/1/012040
[Show abstract][Hide abstract] ABSTRACT: TAIGA stands for " Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy " and is a project to build a complex, hybrid detector system for ground-based gamma-ray astronomy from a few TeV to several PeV, and for cosmic ray studies from 100 TeV to 1 EeV. TAIGA will search for " PeVatrons " (ultra-high energy gamma-ray sources) and measure the composition and spectrum of cosmic rays in the knee region (100 TeV – 10 PeV) with good energy resolution and high statistics. TAIGA will include Tunka-HiSCORE (an array of wide-angle air Cherenkov stations), an array of Imaging Atmospheric Cherenkov Telescopes, an array of particle detectors, both on the surface and underground, and the TUNKA-133 air Cherenkov array.
Journal of Physics Conference Series 08/2015; 632:012034. DOI:10.1088/1742-6596/632/1/012034
[Show abstract][Hide abstract] ABSTRACT: The gamma-ray energy regime beyond 10 TeV is crucial for the search for the most energetic Galactic accelerators. The energy spectra of most known gamma-ray emitters only reach up to few 10s of TeV, with 80 TeV from the Crab Nebula being the highest energy so far observed significantly. Uncovering their spectral shape up to few 100 TeV could answer the question whether some of these objects are cosmic ray pevatrons, i.e. Galactic PeV accelerators. Sensitive observations in this energy range and beyond require very large effective detector areas of several 10s to 100 square-km. While imaging air Cherenkov telescopes have proven to be the
instruments of choice in the GeV to TeV energy range, very large area telescope arrays are limited by the number of required readout channels per square-km. Alternatively, the shower front sampling technique allows to instrument large effective areas and also naturally provides large viewing angles of the instrument. Solely measuring the shower front light density and timing (hence timing-arrays), the primary particle properties are reconstructed on the basis of the measured lateral density function and the shower front arrival times. This presentation gives an overview of the technique, its goals, and future perspective.
Journal of Physics Conference Series 08/2015; 632:012042. DOI:10.1088/1742-6596/632/1/012042
[Show abstract][Hide abstract] ABSTRACT: A large-scale coordinate-tracking setup for registering the near-horizontal muon flux from ultrahigh energy cosmic rays is under development at the MEPhI. The setup is based on drift chambers from the neutrino detector at the Institute of High Energy Physics’ U-70 accelerator, which have a large sensitive area (1.85 m2) and good angular and spatial resolution with a relatively low number of measuring channels.
Bulletin of the Russian Academy of Sciences Physics 03/2015; 79(3):377-379. DOI:10.3103/S1062873815030454
[Show abstract][Hide abstract] ABSTRACT: The use of muon detectors in order to improve the rejection of background EAS produced by protons and nuclei is proposed as part of the wide-aperture Tunka-HiSCORE γ-ray telescope project. The area of the muon detector and the depth of the bulk soil layer required for effective suppression of the electron-photon component of EAS are substantiated. Results from tests of the IHEP muon detector with light collected by WLS fibers are discussed.
Bulletin of the Russian Academy of Sciences Physics 03/2015; 79(3):392-394. DOI:10.3103/S1062873815030442
[Show abstract][Hide abstract] ABSTRACT: An approach to the estimating the parameters of cascade showers with unknown axes, generated in NEVOD Cherenkov water detector (CWD) by muons with zenith angles in the range from 50° to 90°, is described. A technique for estimating the position of a cascade axis using the CWD response is proposed, along with criteria that would allow us to select events with cascades from ones with intense releases of energy. The technique and the criteria are tested on cascades generated by near-horizon high-energy muons, registered by the DECOR tracking detector. Preliminary results from measuring the energy spectrum of cascade showers are presented.
Bulletin of the Russian Academy of Sciences Physics 03/2015; 79(3):371-373. DOI:10.3103/S1062873815030272
[Show abstract][Hide abstract] ABSTRACT: Results from studying the amplitude response of PMTs and estimating the probability of correctly determining the direction of a particle track using quasispherical modules for different water transparencies and detection thresholds are described. Events are selected by the scintillation counters of the system of calibration telescopes and supermodules of the DECOR coordinate-tracking detector. Experimental data obtained before and after the startup of a new water purification system are used in the analysis.
Bulletin of the Russian Academy of Sciences Physics 03/2015; 79(3):421-423. DOI:10.3103/S1062873815030284
[Show abstract][Hide abstract] ABSTRACT: The NEVOD-EAS setup is designed for independent estimation of the EAS parameters recorded in the NEVOD-DECOR experiment in the region of the energy spectrum knee. The setup’s recording system is based on the clusters of scintillation detectors for the EAS electron-photon component, located on the territory of MEPhI. Characteristics of the shower array recording system that ensure detection, data acquisition and primary processing, and the time synchronization of clusters are discussed, along with results of studying the nonuniformity of NEVOD-EAS scintillation detector responses.
Bulletin of the Russian Academy of Sciences Physics 03/2015; 79(3):389-391. DOI:10.3103/S1062873815030417
[Show abstract][Hide abstract] ABSTRACT: New results from investigating the flux of atmospheric muons scattered from the ground to the upper hemisphere, obtained with the NEVOD-DECOR experimental complex from December 2011 to March 2013, are presented.
Bulletin of the Russian Academy of Sciences Physics 03/2015; 79(3):374-376. DOI:10.3103/S106287381503034X
[Show abstract][Hide abstract] ABSTRACT: The first results from measuring spectra of the local density of charged particles in extensive air showers in the energy range of ∼1014-1015 eV on the SCT setup (part of the NEVOD experimental complex), obtained using two independent methods, are presented. Experimental data are compared to calculations performed using the CORSIKA program.
Bulletin of the Russian Academy of Sciences Physics 03/2015; 79(3):368-370. DOI:10.3103/S1062873815030065
[Show abstract][Hide abstract] ABSTRACT: The first results from studying the energy deposits of inclined muon bundles in a Cherenkov water detector on the Earth’s surface are presented. The general response of the NEVOD Cherenkov calorimeter’s PMT is used as a measure of the energy deposited (proportional to the muon energy losses in the detector’s matter), while the local muon density at the point of observation is estimated using data from the DECOR coordinate-tracking detector. It is found that the energy deposit normalized to the muon density depends largely on the zenith angle. A comparison of the experimental results and those from EAS muon component simulations using the CORSIKA package shows that the average energy of muons detected in the bundles grows rapidly as the zenith angle increases, reaching ∼500 GeV near the horizon.
Bulletin of the Russian Academy of Sciences Physics 03/2015; 79(3):365-367. DOI:10.3103/S1062873815030314
[Show abstract][Hide abstract] ABSTRACT: The method for reconstructing the cascade curve by the Cherenkov radiation in water of the NEVOD detector with a dense spatial array of optical modules is discussed. Cascades are generated by near-horizontal muons which are separated by the DECOR coordinate detector. The cascade curves and the cascade energy spectrum measured in an ∼8000-hour measurement series are presented.
Bulletin of the Lebedev Physics Institute 10/2014; 41(10):292-296. DOI:10.3103/S1068335614100042 · 0.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: TAIGA stands for ``Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy'' and is a project to built a complex, hybrid detector system for ground-based gamma-ray astronomy from a few TeV to several PeV, and for cosmic ray studies from 100 TeV to 1 EeV. TAIGA will search for ``PeVatrons'' (ultra-high energy gamma-ray sources) and measure the composition and spectrum of cosmic rays in the knee region (100 TeV–10 PeV) with good energy resolution and high statistics. TAIGA will include Tunka-HiSCORE — an array of wide-angle air Cherenkov stations, an array of Imaging Atmospheric Cherenkov Telescopes, an array of particle detectors, both on the surface and underground and the TUNKA-133 air Cherenkov array.
Journal of Instrumentation 09/2014; 9(09):C09021-C09021. DOI:10.1088/1748-0221/9/09/C09021 · 1.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The project of the tracking detector designed for a joint operation with Cherenkov water detector NEVOD and based on the drift chambers from the neutrino experiment at the IHEP accelerator U-70 is presented. The project is aimed at solving a problem called `muon puzzle' — growing with energy excess of muon content in EAS in comparison with contemporary models of their development, which was registered in various experiments. Joint operation of the coordinate-tracking detector and Cherenkov water calorimeter will allow to measure energy of muon groups and to answer the question about the reasons of the muon flux excess.
Journal of Instrumentation 08/2014; 9(08):C08018. DOI:10.1088/1748-0221/9/08/C08018 · 1.40 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The results of the analysis of the first experimental data on the energy release of inclined muon groups of cosmic rays in the water Cherenkov detector, obtained at the NEVOD-DECOR complex, are presented. It was found that the average specific energy release in the Cherenkov calorimeter (normalized to the muon densitymeasured by the data of the coordinate detector)weakly depends on the muon density; however, the significant dependence on the zenith angle is observed, which indicates an increase in the average muon energy in groups with an increase in the zenith angle.
Bulletin of the Lebedev Physics Institute 08/2014; 41(8):218-221. DOI:10.3103/S1068335614080028 · 0.25 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In this work we present recent progress in Geant4 electromagnetic physics modelling, with an emphasis on the new refinements for the processes of multiple and single scattering, ionisation, high energy muon interactions, and gamma induced processes. The future LHC upgrade to 13 TeV will bring new requirements regarding the quality of electromagnetic physics simulation: energy, particle multiplicity, and statistics will be increased. The evolution of CPU performance and developments for Geant4 multi-threading connected with Geant4 electromagnetic physics sub-packages will also be discussed.
Journal of Physics Conference Series 06/2014; 513(2):022015. DOI:10.1088/1742-6596/513/2/022015
[Show abstract][Hide abstract] ABSTRACT: A technique for measuring the cascade shower energy in the NEVOD Cherenkov water detector with a spatial lattice of quasi-spherical modules is discussed. The technique allows the number of cascade particles that move near the shower axis to be reconstructed on the basis of analysis of response amplitudes of triggered photomultiplier tubes. The technique of cascade-curve reconstruction was applied to cascade showers generated by near-horizontal high-energy muons extracted by means of the DECOR coordinate-tracking detector arranged around the Cherenkov water detector. The first results of measuring the energy spectrum of cascade showers of 10-1000 GeV are presented.
Physics of Particles and Nuclei Letters 12/2013; 11(1). DOI:10.1134/S1547477114020071
[Show abstract][Hide abstract] ABSTRACT: In many cosmic rays experiments at very and ultra-high energies, an excess of muons (including those of very high energy, >100 TeV) is observed that cannot be explained within existing models of hadron interactions. This excess is usually explained in terms of the heavier mass composition of primary cosmic rays. However, the excess over the predicted values even for extremely heavy compositions, and especially the observed excesses of muons with energies of >100 TeV, requires that we consider other possibilities with respect to the generation of muons, including changes in models of hadron interaction.
Bulletin of the Russian Academy of Sciences Physics 11/2013; 77(11):1322-1325. DOI:10.3103/S1062873813110063
[Show abstract][Hide abstract] ABSTRACT: New technique of EAS investigations based on the measurements of local
muon density spectra (LMDS) is developed. Application of this method to
investigations of inclined EAS allows exploration of CR energy interval
from 1015 to 1019eV by means of a relatively small
detector with area ˜100m2 due to very strong dependence
of EAS muon density on zenith angle. During 2002-2007, long-term
NEVOD-DECOR experiment (about 20,000 h live time) was conducted, and
more than two million muon bundles in zenith angle interval 30-88
degrees were registered. Comparison of experimental data with results of
CORSIKA-based simulations showed that the new method is sensitive to all
main peculiarities of CR energy spectrum: the knee, increase of the
energy spectrum slope with energy, the second knee. But the observed
progressive excess of muon bundles with the increase of primary CR
energy in comparison with simulations (even for pure iron composition)
can indicate the appearance of new processes of muon generation. In this
case, for correct investigations of EAS, the experimental arrays must be
supplemented by detectors which can measure or evaluate the energy of
The European Physical Journal Conferences 06/2013; 53:08001-. DOI:10.1051/epjconf/20135308001