Author/Authors :
Pyrlik، نويسنده , , J and Atiya، نويسنده , , M and Broemmelsiek، نويسنده , , D and Hamacher، نويسنده , , Th and Ispiryan، نويسنده , , M and Korpar، نويسنده , , S and Kri?an، نويسنده , , P and Lau، نويسنده , , K and Maas، نويسنده , , P and McGill، نويسنده , , J and Reeves، نويسنده , , K and Rose، نويسنده , , P and Rosen، نويسنده , , J and Schwarz، نويسنده , , A.S and Schwitters، نويسنده , , Joze Staric، نويسنده , , M، نويسنده ,
Abstract :
We report on aging measurements of a photon detector candidate, based on proportional wire chambers operating in TMAE, for the HERA-B RICH. The detector consisted of 64 cells, each 100 mm long and 8×8 mm2 in area, constructed with brass cathode and 45 μm gold plated tungsten anode wire and was operated at room temperature with 50% TMAE saturated methane. To age the chamber it was exposed for several weeks to UV light from a deuterium lamp at 3 MHz/cm2 counting rate, the expected maximum rate in the HERA-B RICH. The detection efficiency of the chamber for Cherenkov photons, generated in 5 m of argon by a 3 GeV electron testbeam at DESY, was recorded at regular intervals during the aging process. The pulse-height distribution of the chamber was continuously monitored. We found significant chamber gain loss after an exposure equivalent to about one month of running at HERA-B. Based on our results HERA-B decided to employ a multi-anode PMT system as photon detector in the RICH.
