New Eco-gas mixtures for the Extreme Energy Events MRPCs: results and plans

TL;DR

This paper explores new eco-friendly gas mixtures for muon detection in the EEE observatory, testing their efficiency and performance to replace high-GWP gases while maintaining detector quality.

Contribution

It presents the development and testing of environmentally sustainable gas mixtures for MRPC detectors, including experimental results and plans for real telescope validation.

Findings

Tetrafluoropropene-based mixtures show promising efficiency.

New mixtures maintain good time resolution and low streamer fractions.

Preliminary tests at CERN-01 demonstrate feasibility for cosmic muon detection.

Abstract

The Extreme Energy Events observatory is an extended muon telescope array, covering more than 10 degrees both in latitude and longitude. Its 59 muon telescopes are equipped with tracking detectors based on Multigap Resistive Plate Chamber technology with time resolution of the order of a few hundred picoseconds. The recent restrictions on greenhouse gases demand studies for new gas mixtures in compliance with the relative requirements. Tetrafluoropropene is one of the candidates for tetrafluoroethane substitution, since it is characterized by a Global Warming Power around 300 times lower than the gas mixtures used up to now. Several mixtures have been tested, measuring efficiency curves, charge distributions, streamer fractions and time resolutions. Results are presented for the whole set of mixtures and operating conditions, %. A set of tests on a real EEE telescope, with cosmic muons, are being performed at the CERN-01 EEE telescope. The tests are focusing on identifying a mixture with good performance at the low rates typical of an EEE telescope.