R. U. Beisembaev

Horizon-T extensive air showers detector system operations and performance

“Horizon-T” is an innovative detector system located at Tien Shan high-altitude Science Station (TSHASS) at approximately 3340 meters above the sea level. It consists of eight detection points separated by the distance up to one kilometer that can measure time characteristics of the Extensive Air Showers (EAS) and record signal shapes with time resolution of ~10 ns. It was constructed to register EAS in the energy range above 10 eV coming from a wide range of zenith angles (0 85). The system includes both the plastic scintillator particle detectors as well as the Vavilov Cerenkov radiation detectors subsystem to observe the Cerenkov light from the EAS in the atmosphere directly. The time resolution and signal shape analysis capabilities of the detection points are used to study EAS development in the atmosphere.

Simulation and design of the HT-KZ Ultra-high energy cosmic rays detector system for cosmic rays with energies above 10^17 eV

In the field of High Energy Physics today there are several open topics left. The Higgs boson has been recently discovered, neutrino oscillations are being studied, and some hints of the dark matter have been detected as well. Another remaining mystery is the origin and the nature of the Ultra-High Energy Cosmic Rays. There is an active project at Nazarbayev University to construct the HorizonT-Kazakhstan detector system in collaboration with the Tien Shan high-altitude Science Station (TSHSS), a part of Lebedev Physical Institute of the Russian Academy of Sciences. The full R&D is underway. A significant part of this process is the simulation, testing and construction of individual particle detectors due to the requirements of robustness and high linear range of such detectors combined with low cost and long-term operations with minimal maintenance. In this paper, the latest results of the simulation activities and experiment testing of different detection components as applicable to the HorizonT-Kazakhstan requirements are presented.

Fast and simple glass-based charged particles detector with large linear detection range

In cosmic rays physics often a simple charged particle detector with fast response, best possible pulse time resolution and large linear range is required. For that purpose, we have developed a design that is based on the detection of Cherenkov radiation produced by charged particles in a thick optical glass used as a detection medium by a photomultiplier tube. In this work, the results of detector parameters simulation and experimental verification are presented.

Horizon-T experiment status

Horizon-T is an innovative detector system constructed to study Extensive Air Showers (EAS) in the energy range above 1016 eV coming from a wide range of zenith angles (0o–85o). The system is located at the Tien Shan High-altitude Science Station of the Lebedev Physical Institute of the Russian Academy of Sciences at ∼ 3340 meters above sea level. It consists of eight charged particle detection points separated by distances up to one kilometer as well as an optical detector subsystem to measure the Vavilov-Cherenkov light from the EAS. The time resolution of charged particles and Vavilov-Cherenkov light photons passage of the detector system is a few ns. This level of resolution allows conducting a research of the atmospheric development of individual EAS. This report focuses on a general description of the detector system and the individual sub-systems providing an overview of the operations and latest results.

Observation of Vavilov-Cherenkov radiation and EAS charged particles at large zenith angles

Extensive air showers (EASes) at zenith angles of 70–80 degrees with Vavilov-Cherenkov radiation having two and three maxima were registered at the Tian Shan Mountain Station of the Lebedev Physical Institute. In each such event, the subsequent maxima came with a time delay of 100 or more nanoseconds. Extensive air showers at a zenith angle of 70° with charged particles and Vavilov-Cherenkov radiation were also registered.

Application of student’s criterion for detecting ground level enhancements of solar cosmic ray intensity

Student’s criterion is used to detect ground level enhancements of solar cosmic ray intensity at middle latitudes. Application of this test to the data recorded by Alma-Ata high-altitude neutron monitor made it possible to detect the arrival of solar-origin relativistic particles on November 6, 1997 and August 24, 1998.

Analysis of the method for studying the zenith-angle EAS distribution

The methodical problems related to analysis of the zenith-angle distribution of extensive air showers with Ne > 107 particles are discussed. The effect of the array geometry on the angle measurement error is considered. Possible distortions of angular distribution due to errors have been calculated. The presence of excess showers detected at large zenith angles is shown.