High-Rate Fast-Time GRPC for the high eta CMS muon detectors

With the increase of the LHC luminosity foreseen in the high luminosity version, some detectors currently used in CMS will not sustain high fluences and some need to be replaced. The new ones could provide time information and could reduce the data ambiguity due to the expected high pileup. RPC using low-resistivity materials are proposed to equip the very forward region of the CMS detector. In their single-gap version we will show that they can stand rates of few ${\rm kHz/cm}^2$. We also demonstrate that using multi-gap glass RPC, a time resolution of about 60 ps is achieved.