Comparative aging studies on a Single Wire Proportional Chamber

In order to extend previous studies and test additional variables playing a role in the aging processes, a single wire proportional chamber was specially designed. In this contribution, the author will present the result of two types of tests performed on this single wire proportional chamber. During the first test, the single wire proportional chamber was irradiated with X-rays and alpha particles with the same hit rate until the same collected charge (\SI[per-mode=symbol]{1.4}{\milli\coulomb\per\centi\meter}) was reached. Nevertheless the performance loss during the x-ray irradiation was larger, traces of polymers were found on the wire only in the case of alpha irradiation. The second test was performed irradiating the single wire proportional chamber with alphas and X-rays, but this time with the same anodic current i.e. very different hit rate. The irradiation continued until the wire chamber lost about half of the initial gas gain. In the case of alpha irradiation the integrated charge needed for the goal was lower with respect to the one needed during the x-ray radiation: \SI[per-mode=symbol]{9.5}{} and \SI[per-mode=symbol]{33.0}{\milli\coulomb\per\centi\meter}, respectively. However, the electron microscope analysis revealed, once again, a large polymer deposit on the alpha irradiated wire while no deposit was found on the X-ray irradiated one.