Characteristics of a double gap resistive plate chamber for the endcap region of CMS/LHC: data vs. simulation in avalanche mode

We present the detailed analysis of the time and charge signals of a prototype double gap resistive plate chamber for the endcap region of the compact muon solenoid detector at CERN LHC. We demonstrate that the operating high-voltage plateau can be extended at least up to 400 V with the present design. The simple avalanche multiplication model can reproduce the experimental charge spectra reasonably well at the beginning of the high-voltage plateau region. The effective Townsend coefficient is estimated in the avalanche mode operation.