2019, Kokoulin, R. P., Bogdanov, A. G., Mannocchi, G., Petrukhin, A. A., Shutenko, V. V., Yashin, I. I., Yurina, E. A., Кокоулин, Ростислав Павлович, Богданов, Алексей Георгиевич, Петрухин, Анатолий Афанасьевич, Шутенко, Виктор Викторович, Яшин, Игорь Иванович, Юрина, Екатерина Александровна

Data on cosmic ray muon bundles accumulated at the NEVOD-DECOR complex over the period from May 2012 to December 2018 have been analyzed. Local muon density spectra at various zenith angles have been reconstructed and compared with CORSIKA-based simulations. At large zenith angles and high muon multiplicities corresponding to primary particle energies more than about 3 x 10(17) eV an excess of multi-muon events compared to simulations is clearly seen. Present data are compatible with the expectation for recent LHC-adjusted hadron interaction models only under assumption of extremely heavy (iron group nuclei) primary composition. The assumption of a heavy composition is however in contradiction with other EAS observables, such as maximum depth and its fluctuations.

2019, Khokhlov, S. S., Bogdanov, A. G., Khomyakov, V. A., Kindin, V. V., Kokoulin, R. P., Petrukhin, A. A., Shutenko, V. V., Yashin, I. I., Хохлов, Семен Сергеевич, Богданов, Алексей Георгиевич, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Петрухин, Анатолий Афанасьевич, Шутенко, Виктор Викторович, Яшин, Игорь Иванович

Results of analysis of experimental data on cascade showers with energies of 0.1 - 10 TeV initiated by muons in the Cherenkov water detector NEVOD are presented. The method of selection and reconstruction of cascade parameters in the volume of the detector is discussed. Experimental distributions of cascade axes in zenith angle and energy spectrum of cascades are obtained. The measured distributions are compared with results of calculations.

2019, Sveshnikova, L. G., Bezyazeekov, P. A., Boreyko, V., Borodin, A. N., Astapov, I. I., Kindin, V. V., Kokoulin, R. P., Kompaniets, K. G., Petrukhin, A. A., Yashin, I. I., Астапов, Иван Иванович, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Яшин, Игорь Иванович

© 2019, Allerton Press, Inc.Abstract: Work is currently under way in the Tunka Valley, 50 km from Lake Baikal, to create the TAIGA gamma observatory for studying gamma radiation and cosmic ray fluxes in the 1013–1018 eV range of energies. To detect gamma rays with energies above tens of TeV, a hybrid method of detecting showers is implemented. It is based on data obtained by the TAIGA Imaging Atmospheric Cherenkov Telescope (IACT) and the wide-angle TAIGA-HiSCORE array. The preliminary results from processing the telescope’s data for the low-energy region (>2–3 TeV) are presented. Joint events with energy more than 50 TeV are analyzed and compared to Monte Carlo calculations.

2019, Mannocchi, G., Trinchero, G., Amelchakov, M. B., Barbashina, N. S., Bogdanov, A. G., Gromushkin, D. M., Zadeba, E. A., Kindin, V. V., Kokoulin, R. P., Kompaniets, K. G., Chiavassa, A., Likiy, O. I., Petrukhin, A. A., Stenkin, Y. V., Khokhlov, S. S., Shulzhenko, I. A., Shutenko, V. V., Yurin, K. O., Yashin, I. I., Амельчаков, Михаил Борисович, Барбашина, Наталья Сергеевна, Богданов, Алексей Георгиевич, Громушкин, Дмитрий Михайлович, Задеба, Егор Александрович, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Стенькин, Юрий Васильевич, Хохлов, Семен Сергеевич, Шульженко, Иван Андреевич, Шутенко, Виктор Викторович, Яшин, Игорь Иванович

© 2019, Allerton Press, Inc.Abstract: The NEVOD experimental complex was created at MEPhI. It includes several facilities for studying the electron–photon, muon, and hadron components of the EAS in the energy range of 1 PeV to 1 EeV. This work presents the first results for two months of the joint operation of five facilities (NEVOD-EAS, CWD, CTS, PRISMA-32, and DECOR). The problems of synchronizing the facilities and selecting joint events are considered. The experimental data of these facilities are analyzed for different components of the EAS in overlapping energy ranges.

2019, Amelchakov, M. B., Bogdanov, A. G., Khokhlov, S. S., Kokoulin, R. P., Petrukhin, A. A., Shulzhenko, I. A., Yashin, I. I., Амельчаков, Михаил Борисович, Богданов, Алексей Георгиевич, Хохлов, Семен Сергеевич, Кокоулин, Ростислав Павлович, Петрухин, Анатолий Афанасьевич, Шульженко, Иван Андреевич, Яшин, Игорь Иванович

© 2019, Pleiades Publishing, Ltd.The results of the long-term measurements of extensive air showers with the calibration telescope system of the Cherenkov water detector are presented for an energy range of 1014–1017 eV. We have used two independent methods for reconstruction of the charged particle local density spectrum: by the multiplicity of the hit counters and by their amplitude responses. By means of Geant4 calculations, we have shown how the structure of the building and the water tank affect the results of the spectrum reconstruction. We obtained two different exponents of charged particles’ local density spectra for CTS top and bottom plane. The results are compared with CORSIKA calculations and data from other setups.

2019, Budnev, N. M., Bezyazeekov, P. A., Borodin, A. N., Wischnewski, R., Astapov, I. I., Kindin, V. V., Kokoulin, R. P., Kompaniets, K. G., Petrukhin, A. A., Yashin, I. I., Астапов, Иван Иванович, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Яшин, Игорь Иванович

© 2019, Allerton Press, Inc.Abstract: The relevance and benefits of the new TAIGA gamma observatory complex in the Tunka Valley (50 km from Lake Baikal) are discussed. The main aim of the TAIGA installation is to study high-energy gamma radiation and search for cosmic pevatrons. The first series of gamma stations was commissioned in 2019 and covers an area of 1 km2. Its expected integral gamma radiation sensitivity at an energy of 100 TeV over 300 h of source monitoring is (2–5) × 10−13 TeV cm−2 s−1. It is planned to expand the effective area of TAIGA gamma observation to 10 km2 in the future.

2019, Kokoulin, R. P., Barbashina, N. S., Bogdanov, A. G., Kindin, V. V., Kompaniets, K. G., Petrukhin, A. A., Khomyakov, V. A., Khokhlov, S. S., Shutenko, V. V., Yashin, I. I., Кокоулин, Ростислав Павлович, Барбашина, Наталья Сергеевна, Богданов, Алексей Георгиевич, Киндин, Виктор Владимирович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Хохлов, Семен Сергеевич, Шутенко, Виктор Викторович, Яшин, Игорь Иванович

© 2019, Allerton Press, Inc.Abstract: Results are presented from analyzing experimental data on 0.1–10 TeV cascade showers generated by muons in the NEVOD Cherenkov water detector. The procedure for selecting and reconstructing the parameters of events with cascades in the detector volume is discussed. Results are presented from measurements of the zenith angle distribution of cascades for different energies. The measured distributions are compared to results from calculations.

2019, Prosin, V., Astapov, I., Bezyazeekov, P., Borodin, A., Kindin, V., Kokoulin, R., Kompaniets, K., Petrukhin, A., Yashin, I., Астапов, Иван Иванович, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Яшин, Игорь Иванович

The extensive air shower Cherenkov light array Tunka-133 collected data during 7 winter seasons from 2009 to 2017. From 2175 hours of data taking, we derived the differential energy spectrum of cosmic rays in the energy range 6 center dot 10(15) - 2 center dot 10(18) eV. The TAIGA-HiSCORE array is in the process of continuous expansion and modernization. Here we present the results obtained with 28 stations of the first HiSCORE stage from 35 clear moonless nights in the winter of 2017-2018. The combined spectrum of two arrays covers a range of 2 center dot 10(14) - 2 center dot 10(18) eV.

2019, Postnikov, E. B., Bezyazeekov, P. A., Boreyko, V. F., Borodin, A. N., Astapov, I. I., Kindin, V. V., Kokoulin, R. P., Kompaniets, K. G., Petrukhin, A. A., Postnikov, E. B., Yashin, I. I., Астапов, Иван Иванович, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Яшин, Игорь Иванович

© 2019, Allerton Press, Inc.Abstract—: The TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma-ray Astronomy) experiment aims at observing gamma-rays in the energy range from 1 TeV to several 100 TeV. The operation of the observatory is based on a new hybrid approach that combines imaging air Cherenkov telescopes (IACTs) and wide-angle Cherenkov detectors (TAIGA-HiSCORE) for measuring times of extensive air shower (EAS) light front arrival. Monte Carlo simulations are compared to real data to determine the performance of the detector setup. Dedicated software and algorithms are described, model parameters are given, and an overview of the current status of model-based performance studies is presented.

2019, Prosin, V. V., Bezyazeekov, P. A., Boreyko, V., Borodin, A. N., Astapov, I. I., Kindin, V. V., Kokoulin, R. P., Kompaniets, K. G., Petrukhin, A. A., Yashin, I. I., Астапов, Иван Иванович, Киндин, Виктор Владимирович, Кокоулин, Ростислав Павлович, Компаниец, Константин Георгиевич, Петрухин, Анатолий Афанасьевич, Яшин, Игорь Иванович

© 2019, Allerton Press, Inc.Abstract: The Tunka-133 Cherenkov complex for recording extensive air showers (EAS) collected data over seven winters from 2009 to 2017. The differential energy spectra of all particles was acquired in the 6 × 1015–3 × 1018 eV range of energies over 2175 h. The TAIGA-HiSCORE complex is continually being expanded and upgraded. Data acquired by 30 first-line stations over 35 days during the period 2017–2018 is analyzed in this work. As at the Tunka-133 setup, the primary particle energies above 1015 eV are measured using the density of the Cherenkov light flux at a distance of 200 m from a shower’s axis. Data on lower energies are collected by determining the energy of the light flux near a shower’s axis. This results in a spectrum of 2 × 1014–1017 eV. The combined spectrum for the two systems covers a range of 2 × 1014–2 × 1018 eV.