New complex EAS installation of the Tien Shan Mountain Cosmic Ray Station

TL;DR

This paper describes the development and testing of a new complex detector system at the Tien Shan Mountain Cosmic Ray Station for studying extensive air showers, including electromagnetic, nuclear, and muonic components, with promising capabilities for future cosmic ray research.

Contribution

The paper introduces a comprehensive new detector installation for cosmic ray air showers, integrating electromagnetic, nuclear, and muonic detectors with advanced calibration and data analysis procedures.

Findings

Detector system successfully tested from 2014-2016.

Measured shower size spectrum aligns with conventional data.

Enhanced dynamic range prospects for future measurements.

Abstract

We present a description of the new complex installation for the study of extensive air showers which was created at the Tien Shan mountain cosmic ray station, as well as the results of the test measurements made there in 2014-2016. At present, the system for registration of electromagnetic shower component consists of $\sim$100 detector points built on the basis of plastic scintillator plates with the sensitive area of 0.25m$^2$ and 1m$^2$, spread equidistantly over $\sim$10$^4$m$^2$ space. The dynamic range of scintillation amplitude measurements is currently about $(3-7)\cdot 10^4$, and there is a prospect of it being extended up to $\sim$10$^6$. The direction of shower arrival is defined by signal delays from a number of the scintillators placed cross-wise at the periphery of the detector system. For the investigation of nuclear active shower components there was created a multi-tier 55m$^2$ ionization-neutron calorimeter with a sum absorber thickness of $\sim$1000g/cm$^2$, typical spatial resolution of the order of 10cm, and dynamic range of ionization measurement channel about $\sim$10$^5$. Also, the use of saturation-free neutron detectors is anticipated for registration of the high- and low-energy hadron components in the region of shower core. A complex of underground detectors is designed for the study of muonic and penetrative nuclear-active components of the shower. The full stack of data acquisition, detector calibration, and shower parameters restoration procedures are now completed, and the newly obtained shower size spectrum and lateral distribution of shower particles occur in agreement with conventional data. Future studies in the field of $10^{14}-10^{17}$eV cosmic ray physics to be held at the new shower installation are discussed.