Speaker
Description
The Compact Muon Solenoid (CMS) Resistive Plate Chamber (RPC) system has operated successfully during the LHC Run 1, Run 2, and Run 3 data-taking periods. During the High-Luminosity Large Hadron Collider (HL-LHC) phase, the instantaneous luminosity is expected to increase by up to a factor of five with respect to the nominal LHC conditions, leading to higher background rates and harsher operating conditions for the CMS RPC detectors. Such conditions could affect detector performance and potentially induce non-recoverable aging effects. To evaluate the long-term behaviour and robustness of the RPC system under HL-LHC conditions, a dedicated longevity test has been carried out at the CERN Gamma Irradiation Facility. In this program, four spare RPC chambers (two RE2 and two RE4) have been exposed to intense gamma irradiation in order to reproduce the expected HL-LHC environment. The irradiation campaign has reached the expected integrated charge for HL-LHC operation for the RE2 and RE4 chambers, respectively, including the expected safety factor. During the test, the main detector performance parameters have been continuously monitored as a function of the accumulated integrated charge. The results obtained from the irradiation studies will be presented.