Test of CMS barrel muon drift chambers in high-radiation environment

Large-area prototypes of the CMS barrel muon chambers have been extensively investigated, especially at the “Gamma Irradiation Facility” at CERN, an experimental area which has been specifically constructed to test particle detectors in a muon beam in presence of a uniform high-rate irradiation. The dependence of chamber resolution and detection efficiency upon the background rate has been studied systematically.