OPTIMIZATION AND MODELING OF ELECTROCHEMICALLY ETCHED POLYCARBONATE TRACK DETECTORS

Electrochemically etched polycarbonate nuclear track detectors have be en used to detect the beta-delayed alpha-decay of the Na-20 nuclei tha t were produced in the study of the astrophysically important Ne-19(p, gamma)Na-20 reaction. The application required preceding investigation s and developments. The insensitivity to beta-radiation has been confi rmed in off-line irradiations with beta-sources up to doses of 20000 G y. The density of intrinsic background tracks has been reduced to a me an value of 1.3 +/- 0.1 cm(-2). The response function for alpha-detect ion as a function of energy and angle of incidence has been determined using Rutherford backscattered alpha-particles. A model for electroch emical etching that is generally valid for all ions and plastic detect ors has been developed. It successfully reproduced the measured respon se function and track diameters.