The analog Resistive Plate Chamber detector of the ARGO-YBJ experiment

TL;DR

The paper describes the implementation and performance of an analog readout system for Resistive Plate Chambers in the ARGO-YBJ experiment, enhancing the ability to measure particle densities in extensive air showers for energies up to 10 PeV.

Contribution

It introduces an analog readout system for RPCs in ARGO-YBJ, enabling detailed charge measurements at the shower core for high-energy cosmic ray studies.

Findings

Successful implementation of analog readout on the entire central carpet

Enhanced measurement of particle density at the shower core

Improved data quality for high-energy cosmic ray analysis

Abstract

The ARGO-YBJ experiment has been in stable data taking from November 2007 till February 2013 at the YangBaJing Cosmic Ray Observatory (4300 m a.s.l.). The detector consists of a single layer of Resistive Plate Chambers (RPCs) ( about 6700 m^2}) operated in streamer mode. The signal pick-up is obtained by means of strips facing one side of the gas volume. The digital readout of the signals, while allows a high space-time resolution in the shower front reconstruction, limits the measurable energy to a few hundred TeV. In order to fully investigate the 1-10 PeV region, an analog readout has been implemented by instrumenting each RPC with two large size electrodes facing the other side of the gas volume. Since December 2009 the RPC charge readout has been in operation on the entire central carpet (about 5800 m^2). In this configuration the detector is able to measure the particle density at the core position where it ranges from tens to many thousands of particles per m^2. Thus ARGO-YBJ provides a highly detailed image of the charge component at the core of air showers. In this paper we describe the analog readout of RPCs in ARGO-YBJ and discuss both the performance of the system and the physical impact on the EAS measurements.