The precision of the IACT mechanical mounts of the TAIGA observatory

The TAIGA (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) observatory is located in the Tunka valley (~50 km west from the southern shore of Lake Baikal) at an altitude of 675m a.s.l. The TAIGA observatory aims to address gamma-ray astronomy at energies from a few TeV to several PeV and CR physics from 100 TeV to several EeV. Its main feature is the complementary, hybrid approach to distinguish CR events from those of gamma rays. Currently TAIGA consists of ~80 wide-angle air Cherenkov detectors (HiSCORE stations), three ~4m diameter IACTs and several hundred surface and underground muon detectors, grouped in three jointly operating arrays. The exceptional feature of the TAIGA IACT array is it’s topology that allows one to aim for the optimal cost/performance by scanning the optimal inter-telescope distances from 300m up to 600m. The IACTs have alt-azimuth type mounts and 576-pixel imaging cameras in the foci, covering 9.6° aperture in the sky. The segmented reflectors of ~10m² area follow the Davis-Cotton design. The largest diameter of the hexagonal shape reflector is 4.3m and the focal length is 4.75m. The rigid telescope mount provides a maximum displacement of EAS image below 2mm (i.e. ≤ 0.024°) in the photodetector plane. The main parameters of IACTs are of a crucial importance for their efficient operation and is presented

Design features and data acquisition system of the TAIGA-Muon scintillation array

The TAIGA-Muon scintillation array is located in the Tunka Valley. It is a part of the single TAIGA experimental complex. Its construction has started in the summer of 2019. By the autumn of 2019, the first three clusters were installed. We describe the design of the TAIGA-Muon array, the data acquisition (DAQ) sistem, reading and control systems

TAIGA—an advanced hybrid detector complex for astroparticle physics and high energy gamma-ray astronomy in the Tunka valley

The TAIGA observatory addresses ground-based gamma-ray astronomy at energies from a few TeV to several PeV, cosmic ray physics from 100 TeV to several EeV as well as for search for axion-like particles, Lorentz violations and another evidence of New Physics. In 2020 year a one square kilometer TAIGA setup should be put in operation

An approach for identification of ultrahigh energy extensive air showers with scintillation detectors at TAIGA experiment

The TAIGA astroparticle observatory is under development at Tunka valley close to the Baikal Lake. This simulation study is concentrated on the ultrahigh energy extensive air showers (EAS) induced by gamma-quanta or proton in the range from 1 PeV to 10 PeV and zenith angle ranging 0°–45°. For this work, a set of air showers was created by CORSIKA software package. The list of useful secondary particles at the ground level is produced using the COAST library package. The interaction of secondary particles with the soil and detectors was simulated with GEANT4 package. The method based on neural network has been developed for the separation of EAS induced by gamma-quanta or proton. The air showers having energy ranging 1–10 PeV show more than 90% of identification efficiency of protons while keeping identification efficiency of gamma around 50% or more

Development of a novel wide-angle gamma-ray imaging air Cherenkov telescope with SiPM-based camera for the TAIGA hybrid installation

The TAIGA complex-detector is designed to study gamma and cosmic rays in the energy range above 30 TeV. We are developing a novel wide-angle imaging air Cherenkov telescope with a SiPM based camera with a field of view of 15–20ˆ and an aperture of around 1 m2. In this report we present the design of the telescope imaging camera (optical and data acquisition systems), based on 1000–1200 SiPMs. The prototype of such camera, based on 49 SiPMs, is operating at the TAIGA's site in the Tunka valley since September 2019. The design of the prototype and the preliminary results of data analysis is presented

Development of scintillation detectors with light collection via wavelength shifting light guides for TAIGA experiment

The TAIGA gamma observatory is continuing its deployment at the Tunka valley, close to lake Baikal. The new, original detectors, able to work under severe conditions of Siberia, were developed to increase the TAIGA sensitivity for the study of gamma-quanta at energies about 1 PeV and above. The distinguishing feature of the detectors is the use of the wavelength shifting light guides for scintillation light collection on a photodetector. Several designs of the counters have been tested: equipped with PMT or SiPM photo-detectors, acrylic or polystyrene based scintillators with thickness from 1 to 5 cm and detecting area from 0.75 to 1.0 m$^{2}$. The data on the amplitude of the signal from cosmic muons measured in different points within the counter are presented. The first 48 counters were produced and deployed in 2019 at the TAIGA experiment. They form 3 stations each with 8 surface detectors and 8 underground detectors buried at the depth of 1.7 m. After two winters, all counters are working

SiPM-based camera for gamma-ray imaging air Cherenkov telescope

The current status of the equipment development for the new wide-angle gamma-ray imaging air Cherenkov telescope for TAIGA hybrid installation is presented. A front-end electronic and data acquisition system board based on the Zynq family Xilinx FPGA chips specially designed for this project have been produced and are being tested. A detailed description if presented for internal structure of the four main subsystems: four 8-channel 100 MHz ADCs, board’s control system, internal clock and synchronization system and the power supply system. Additionally, the current status of a small scale prototype telescope SIT consisting of 49 SiPM is presented. The telescope includes a digital camera for observing the stars and weather condition. The SIT-HiSCORE synchronization systems and the telemetry information collection had been tested

Status of the TAIGA Experiment: From Cosmic-Ray Physics to Gamma Astronomy in Tunka Valley

The importance and advantages of the hybrid approach developed within the TAIGA project for studying the high-energy section of the spectrum of gamma radiation in the Universe are discussed. The pilot complex of the TAIGA gamma observatory with an area of 1 km${}^{2}$ is briefly described along with the lines of its development, and the first results obtained on this basis are given

Energy Spectrum and Mass Composition of Cosmic Rays from the Data of the Astrophysical Complex TAIGA

The differential energy spectrum of cosmic rays in the energy range of 3 × 10$^{14}$–3 × 10$^{18}$ eV and the corrected dependence of the mean depth of the maximum 〈X$_{max}$〉 of an extensive air shower (EAS) inside the wide energy range of 10$^{15}$–3 × 10$^{17}$ eV have been obtained from the data of the Tunka-133 array for 7 years of operation (2009–2017) and the TAIGA-HiSCORE array for the 2019–2020 season of operation. At the extremely high energy, our results agree with the results of the Pierre Auger Observatory based on direct measurements of the maximum depth by the observation of fluorescent light from EAS. The recalculation from the 〈X$_{max}$〉 to the parameter $\left\langle {\ln A} \right\rangle$, which characterizes the average composition of the primary cosmic rays, is presented

TAIGA—A hybrid array for high-energy gamma astronomy and cosmic-ray physics

The combination of a wide angle timing Cherenkov array and Imaging Atmospheric Cherenkov Telescopes operated in mono mode offers a cost-effective way to construct a few square kilometers array for ultrahigh-energy gamma astronomy. The first stage of the TAIGA Observatory (Tunka Advanced Instrument for cosmic ray physics and Gamma Astronomy) is described here. It will comprise TAIGA-HiSCORE - 120 wide angle Cherenkov stations distributed over an area of 1.0 km 2 and three IACTs (TAIGA-IACT)