Updates to TRACK_TEST and TRACK_VISION Computer Programs.

Dragoslav Nikezic,Kwan Ngok Yu,Jelena M Stajic

doi:10.3390/polym13040560

Abstract

The computer programs TRACK_TEST and TRACK_VISION were previously developed to model profiles and optical appearances of tracks developed in solid-state nuclear track detectors. The programs were based on a track development model that involved the bulk etch rate Vb and the track etch rate Vt or the V function (i.e., Vt/Vb). The present work reported our work to update and modify these two programs. In the revised TRACK_TEST, two new V functions were added and enabled. Sample results for the CR-39 detector obtained using the three original and the two new V functions were compared. Discrepancies were within ~10% and <14% for incident alpha-particle energies of 1 MeV and >1 MeV, respectively. Another major revision of TRACK_TEST was to enable calculations for the Makrofol detector. In the revised TRACK_VISION, the two new V functions, as well as the option for the Makrofol detector, were also added. The experimental results on the Makrofol detectors were obtained (irradiated with 3.6-MeV alpha particles under normal incidence and then etched to achieve a removed detector thickness of 30 μm) for comparisons with the modeled results using the revised TRACK_VISION. The track diameters obtained from the experiment and model were 24.7 and 23.2 μm, respectively. Moreover, a bright area in the central parts, together with an outer dark ring, were present in both the simulated and experimental tracks. The track-opening diameters and the general optical appearances of the tracks were in good agreement.

Highlights

Solid-state nuclear track detectors (SSNTDs) have been widely used for radon measurements through counting and/or characterizing the tracks created by the incident alpha particles emitted form radon gas and its progeny and by the subsequent chemical etching
When a heavy, charged particle passes through an SSNTD, a cylinder consisting of free chemical radicals and other chemical species is formed along the trajectory, and this cylinder is referred to as a “latent track”
When the irradiated SSNTD is immersed into an aggressive solution called an etchant, the latent track will undergo more intensive chemical reactions compared to the unirradiated areas, leading to formation of a “track” that can be observed under an optical microscope

Summary

Introduction

Solid-state nuclear track detectors (SSNTDs) have been widely used for radon measurements through counting and/or characterizing the tracks created by the incident alpha particles emitted form radon gas and its progeny and by the subsequent chemical etching (see, e.g., References [1,2,3,4,5,6,7]). It is noted that optical features of the etched tracks, such as their optical appearances (bright and dark areas, etc.) can provide useful information on track parameters, such as track depths, measurements of which using common optical microscopes remain difficult To tackle these challenges, our group developed the computer program TRACK_TEST [9] in 2006 to theoretically model alpha-particle track profiles, which enabled the determination of parameters, including the lengths of the major and minor axes, as well as the depths of the tracks. There have been advancements in the field, such as the publication of new V functions, as well as continuous requests from various research groups for the creation of modifications and new options, e.g., for modeling for the Makrofol detector, the two programs TRACK_TEST and TRACK_VISION have not yet been updated or modified since their first publications. A three-dimensional track is subsequently rendered through the rotation of the points on the two-dimensional track wall around the particle trajectory, from which the track opening contour, as well as the major and minor axes, are determined

Adding Two V Functions

Adding Makrofol Option

Programming and Simulation

Findings

Conclusions