Abstract
PM-355 super grade nuclear track detectors were exposed to high gamma absorbed doses up to 5 × 10
5Gy (50 Mrad), with an incremental dose of 2.5 × 10
4Gy, from a 9.03 PBq (244 kCi) Co-60 source. Results indicate that each of the bulk etch rate (
V
b), the track etch rate (
V
t) and the sensitivity (
V) of the detectors increases with the high gamma absorbed dose, but there is a drop in these parameters at the low gamma absorbed dose. The
V
b's for all gamma absorbed doses decreased while their
V
t's and
V increased with increasing etching time. Signs of surface roughness were observed by increasing the gamma absorbed doses and changes in color observed for doses larger than 2 × 10
5Gy. The temperature of the detectors during irradiation reached 40°C. The fission fragment tracks (from a Cf-252 source) disappeared quickly within the etching time (minutes), for total absorbed doses greater than 3 × 10
5Gy, due to their high bulk etch rate.