Aging Studies on SWPC and Triple GEM Detectors

This report considers an aging analysis on the triple gas electron multiplier (GEM) technology, that will be installed through projects GE1/1, GE2/1 and ME0 on the CMS muon system. Prior to installation it is important to consider the aging effects caused by radiation on these detectors. Hence, both a GEM and a single wire chamber (SWPC) detector are irradiated with X-ray (Cadmium-109) and Alpha (Americium-241) sources. Rapid aging is achieved through the outgassing of pollutants, increasing the number of radicals and subsequently production of polymers which cause aging. During the whole of the irradiation period, the SWPC collected a charge of 14 mC/cm and the GEM collected a charge of 60mC/cm2. The measured gain is corrected using environmental parameters and along with the energy resolution of the chambers are used to show the aging effects on the detectors. Finally, the gain degradation of the SWPC is 15%, with the GEM showing no degradation at all. These results prove their resilience and pave the way for multiple rapid aging tests that must be carried through for understanding the complicated process of aging.