Monte Carlo simulation study of the characteristics of Xe-Ne gas mixtures as detection media in gas proportional ionization counters

A Monte Carlo simulation has been developed to investigate the performance of Xe-Ne filled proportional ionization counters, with a special interest on the intrinsic energy resolution R-int as a function of the Xe-Ne mixtures composition. The Monte Carlo simulation reproduces the growth of single-electron-initiated avalanches in cylindrical geometry, and the results for R-int are discussed in terms of the influence of the Penning ionization on the statistical parameter f characterizing the fluctuations of single-electron avalanches gain. The results for R-int, and f, as well as for the multiplication factor M, are calculated for each mixture as a function of the reduced anode voltage K = V/ In (c/a), where V is the voltage applied to the anode-wire and c/a is the cathode-to-anode radius ratio.