Test-beam aging studies of a TMAE prototype for the HERA-B RICH

The aging properties of a wire chamber, operating in a methane/TMAE gas mixture, were studied in a beam test. We emphasize here the precautions taken to minimize aging due to materials used in the chamber, and the redundancy in the design of the test. We compare our aging results to those recorded in the literature and find good agreement in the overall aging properties as a function of dose. We also report the results of increasing the high voltage of the aged chamber to restore the gain.