Heavy charged particle nuclear track counting statistics and count loss estimation in high density track images

Abstract

In this paper statistical error of count loss in track counting of intensely irradiated solid state nuclear track detectors is studied. Track counting statistics for the chemically etched solid state nuclear track detectors as one of the most commonly used passive detectors are studied in this paper for the counting errors occurred in high densities of nuclear tracks which correspond to high accumulative doses of heavy charged particles, e.g. environmental Alphas of Radon and its daughters. Co-occurrences of two or more particles in close spatial positions cause overlapping of nuclear tracks observable after the etching process and this issue influences the accuracy of counting process. In case of higher densities of nuclear tracks, the overlapping tracks in the track detector correspond to the dead time behavior of paralyzable model in active detectors which leads to miscounting of receiving pulses. However, for both models binomial distribution of Poisson statistics can be taken into account to obtain a relation between the true number of incident particles, those that have formed a nuclear track, and themeasured count of detected objects which include both singular tracks and overlapped tracks. This modeling is accredited due to the randomness in the nature of irradiation. It will be shown that in high density nuclear tracks images, where there are significant numbers of overlapping tracks, using the statistical correction of a true form is mandatory. Otherwise the measurement system is not reliable.