Thin gap parallel mesh chamber: a sparkless high-rate detector

In this work we describe a parallel geometry gaseous detector constituted by a thin (0.6 mm) amplifying gap preceded by a drift region. The gap is delimited by a metal plate and by a wire mesh. The detector can count up to a rate of 10^7 Hz/mm2 at gain 1000 and retains at lower counting rates the high gains (close to 10^6) that are typical of parallel geometry detectors. Additionally it was found that in the thin amplifying gap the discharges seem to be self-quenched and that full sparks do not develop. This fact, together with the robustness of the electrode materials, makes this an extremely resilient high-rate detector.