Simulation of the measured ionisation-cluster distributions of alpha-particles in nanometric volumes of propane

In the last years, the probability of the formation of ionisation clusters by primary alpha particles at 5.4 MeV in nanometric volumes of propane (20.6 and 24.0 nm in a material of density 1.0 g cm(-3)) was studied experimentally and by Monte Carlo simulation. Calculations were performed taking into account the single electron detection efficiency of the track-nanodosimetric counter, which was estimated on the base of Monte Carlo calculations of electron transport inside the detector. Now a new evaluation of the efficiency has been performed, pointing out a value lower than previously estimated. Besides, the efficiency of the counter in resolving temporally the collected electrons has been calculated, together with its effect on the measured distribution. On the base of these evaluations, a new comparison has been performed between measurements and calculations, pointing out a better agreement than previously reported.