First results from the upgrade of the Extreme Energy Events experiment

TL;DR

The paper reports on the initial results of upgrading the Extreme Energy Events experiment, which involves expanding and enhancing a large network of cosmic ray muon detectors using advanced MRPC technology.

Contribution

It introduces the technological solutions, quality controls, and performance testing procedures for the new detectors added to the EEE experiment during its upgrade.

Findings

Successful construction and commissioning of 60 new MRPC chambers.

Enhanced detector performance and network coverage.

Implementation of advanced quality control measures.

Abstract

The Extreme Energy Events (EEE) experiment is the largest system in the world completely implemented with Multigap Resistive Plate Chambers (MRPCs). Presently, it consists of a network of 59 muon telescopes, each made of 3 MRPCs, devoted to the study of secondary cosmic rays. Its stations, sometimes hundreds of kilometers apart, are synchronized at a few nanoseconds level via a clock signal delivered by the Global Positioning System. The data collected during centrally coordinated runs are sent to INFN CNAF, the largest center for scientific computing in Italy, where they are reconstructed and made available for analysis. Thanks to the on-line monitoring and data transmission, EEE operates as a single coordinated system spread over an area of about $3 \times 10^5$ km$^2$. In 2017, the EEE collaboration started an important upgrade program, aiming to extend the network with 20 additional stations, with the option to have more in the future. This implies the construction, testing and commissioning of 60 chambers, for a total detector surface of around 80 m$^2$. In this paper, aspects related to this challenging endeavor are covered, starting from the technological solutions chosen to build these state-of-the-art detectors, to the quality controls and the performance tests carried on.