Aging and rejuvenation of a TMAE+methane multiwire photon detector

A UV sensitive multiwire photon detector has been tested as a possible candidate for the HERA-B RICH. The main obstacle to using such a TMAE+methane filled gas detector in a high rate experiment, appears to be rapid aging in the form of prohibitive loss of chamber gas gain. A special circuit has been designed for heating the anode wires in-situ with elevated currents, thus evaporating the polymer deposits. Heating almost completely recovers the initial gain, but this rejuvenation is unfortunately of short duration. Nevertheless, the cells exposed to periodic heat treatments have an average gain considerably higher than the non-heated cells.