Glass Resistive Plate Counters

The detection of charged particles is provided by glass-electrode resistive plate counters (RPCs)[69,70,71,72,73]. Glass RPCs have a long history dating back to the early 1970's [74], but this is the first experiment in which large area glass detectors operated at atmospheric pressure have been used. Resistive plate counters have two parallel plate electrodes with high bulk resistivity ( $\Omega$ cm) separated by a gas-filled gap. In the streamer mode, an ionizing particle traversing the gap initiates a streamer in the gas that results in a local discharge of the plates. This discharge is limited by the high resistivity of the plates and the quenching characteristics of the gas. The discharge induces a signal on external pickup strips, which can be used to record the location and the time of the ionization.