Determination of track counting loss threshold of spark counter due to high track densities on strippable LR115 II nuclear track detectors

Abstract

Nuclear track etched detectors are widely used for radon measurements. At the Department of Physics, University of Osijek, the strippable nuclear track detectors LR115 type II are used for indoor radon measurements and their tracks are counted by a spark counter. The probability of track counting loss by saturation rises with the track density.A hundred of strippable nuclear track etched films LR115 type II were irradiated with a constant flux of α-particles in different times using a home-made “KVOD” device for controlling time of irradiation and a saturation effect at high track densities (above 6000 tr/cm2) was observed. The track counting loss threshold of 6200 tr/cm2 was determined for the used type of spark counter and a correction function for track counting was found. Direct counting of aluminium sublimated spots and tracks by the optical counting system confirmed the validity of track counting correcting formula for this type of spark counter.