w-values and energy linearity in xenon gas detectors near the Xe K-absorption edge: simulation and experimental results

Pulse-height distributions from mono-energetic X-rays in the 10- to 41-keV energy range, which includes the xenon K-absorption edge, were simulated in xenon gas detectors with the Monte Carlo technique. The simulation included the absorption of X-rays and the de-excitation of the residual xenon ions, followed by the development of the primary electron cloud. The peaks of the simulated pulse-height distributions were calculated as frequency plots of the number of primary electrons produced per incident X-ray photon. The discontinuities observed in the Fano factor, w-value, energy linearity and energy resolution were found to depend on the extent to which the K-fluorescence produced by the xenon atoms is allowed to escape. The simulation results are compared with experimental values measured with a gas proportional scintillation counter.