Study of avalanche mode operation of resistive plate chambers with different gas gap structures

The operation of narrow gap, wide gap and multigap resistive plate chambers in an avalanche mode was studied. No advantage in avalanche–streamer separation was found for the wide gap and multigap chambers operating with Ar-based mixture as compared with the narrow gap chamber. For dense tetrafluoroethane-based mixture, proportionality was observed between streamer-free plateau width and total gas thickness, in rough agreement with corresponding shift of the maximum of avalanche charge distributions from zero. The best result was obtained for double-gap chamber with the read-out electrode located between two subgaps.