Speaker
Description
Resistive Plate Chambers (RPCs) are gaseous detectors widely used in particle physics, for example, in the muon system of the CMS detector at the CERN Large Hadron Collider (LHC), as they provide fast timing information for efficient muon triggering. In view of the upcoming High-Luminosity (HL) LHC phase, an improved RPC detector (iRPC) has been developed to cope with the significantly higher particle rates and radiation levels expected during future operation.
The upgraded detectors are designed to extend the geometrical acceptance of the CMS muon trigger system toward the high pseudorapidity region, up to |η| ≈ 2.4. From a technological perspective, iRPCs feature a reduced gas gap and thinner electrodes compared to conventional RPCs, together with low-resistivity electrode materials. These design choices allow efficient operation in high-rate environments while maintaining good timing performance and detector stability.
In addition, the reduced charge delivered per avalanche results in smaller signals, requiring the use of dedicated and highly sensitive front-end electronics and is expected to mitigate aging effects under the demanding HL-LHC conditions.
Performance studies of the iRPC prototype have been carried out at the Gamma Irradiation Facility (GIF++) at CERN, demonstrating stable operation and high efficiency under intense background conditions with irradiation rates up to about 2 kHz/cm².
In parallel, dedicated R&D activities are ongoing to identify environmentally friendly gas mixtures for RPC operation, motivated by the need to replace high Global Warming Potential gases currently used in the CMS RPC system.
This contribution presents recent results on the performance and validation of the iRPC prototype under high background conditions, as well as ongoing investigations of eco-friendly gas mixtures for future RPC operation.