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The effect of post- and pre-high doses of γ–radiation in CR-39 plastic detectors has been studied in the dose range of 3×101−106 Gy. Some properties like bulk-etch rate (V B), track-etch rate (V T), sensitivity (V T/V B) and efficiency have been found out for different gamma doses from a 60Co source in CR-39. It is found that V B and V T remain almost invariant up to gamma doses of 104 Gy. Then they start increasing slowly till 105 Gy. Between 105 Gy and 106 Gy there is a sharp increase of V B and V T values for pre- and post-gamma exposed samples. The present data are compared with the previous literature.

An alpha track was selected through a number of successive CR-39 sheets in a high energy nuclear reaction experiment. The experiment was aimed at identifying particles emitted at an angle of 25° to the beam direction when bombarding a copper disk with relativistic fluorine ions. Most of these particles were identified as protons and alpha particles. The experiment showed that the inlet energy of an alpha particle to be detectable in CR-39 plastic is 53.4 MeV per nucleon. The CR-39 range of such particles is ∼2 cm long. The corresponding range for a proton is ∼1 mm long. The track diameter at positions on the track length can display the damage as a function of the depth in the CR-39 material. In addition, the track length is measured along the particle trajectories in CR-39 sheets for a single track as a function of residual range in the CR-39 material. The restricted energy loss (REL) for alpha tracks in CR-39 is calculated using the Henke–Benton computer program. Comparison between the REL and the damag...

The formation of etched tracks in solid-state nuclear track detectors is usually described by assuming an unequivocal correlation of the etch-rate ratio with the energy loss of charged particles. For alpha particles, this assumption could be verified within the scatter of the experimental data. In this article, the dependence of the depth (x) on the track etch rate (V T) was determined experimentally by track length measurement. It is found that the track etch rate as a function of the depth within the detector follows the Bragg curve. The track etch rate has been found to be described by a generalization of the restricted energy loss, in good approximation along the trajectories of alpha particles.