[en] The large area coordinate detector (DECOR) represents a multilayer system of plastic streamer tube chamber modules surrounding the Cherenkov water calorimeter NEVOD. Experimental data collected during the test expositions of first DECOR supermodules (8 vertical planes with 8.4 m² working area) have been analysed, angular and spatial reconstruction accuracies have been estimated. The procedure of the selection of events corresponding to detection of parallel tracks (muon bundles originated in the atmosphere) is discussed

[en] The distributions of various characteristics of multiple interaction muon events in liquid-argon spectrometer BARS have been compared with Monte Carlo simulation for a spectrum of muons arising from π, K-decays in the atmosphere. Estimates of the slope of parent particle generation spectrum have been obtained

[en] Experimental data accumulated over a long-term exposure of the big liquid-argon spectrometer BARS at the Institute for High Energy Physics (IHEP, Protvino) in a horizontal flux of cosmic rays are analyzed with the aim of selecting events that correspond to muon-pair production by muons in the sensitive volume of the detector. The results obtained in this way make it possible to perform, for the first time, a direct experimental test of various theoretical estimates of the total cross section for electromagnetic muon-pair production by high-energy muons

[en] A new type of scintillation detector for shower arrays is considered. The detector represents an octagonal scintillation assembly with total area 1 m² divided into sectors. Thickness of the plastic is 20 mm. The light is collected by wavelength shifter bars to the photomultiplier, which is located in the center of the detector. A solution to ensure the uniformity of light collection for any coordinate is proposed. Front-end electronics of the detector consists of the controller, the measuring part (QDC, TDC), the system of calibration and the HV converter. The data acquisition system is based on CAN-open standard. There is also a system of temperature stabilization that guarantees not more than 0.5 deg. deviation of the temperature of measuring part elements. Measuring electronics allows obtaining the dynamic range from 1 up to 10⁴ particles and 1 ns time digitization. The time resolution of the detector is about 3 ns.

[en] The design of the fine grained 300 t liquid argon calorimeter BARS is described. The BARS electronics include about 30 K channels of low noise amplifiers and ADCs. The DAQ system makes it possible to select channels with signals above the chosen threshold. 48 scintillation horoscopes placed inside the liquid argon are used to form the first level trigger. The total number of scintillation counters in liquid argon is 384. Sums of ionization signals are used to produce the second level trigger. Results of the first use of liquid argon calorimetry for the measurements of tagged neutrino interactions, cosmic-ray muon spectra and composition of extensive atmospheric showers are discussed. (author)