Extension of the α particle energy range in polycarbonate using multiple step chemical and/or electrochemical etching

For ten years polycarbonate has been widely used for the detection of α particles in radon dosimetry. Compared with CR-39 material, the detectable α energy range of about 0.5 to 3 MeV is, however, small after using a chemical pre-etching and electrochemical etching. In order to extend the α energy range the authors investigated: (a) a step-wise combination of chemical and ECE etching, and (b) a two-step ECE technique at low and high frequency. The results of this study show that α particle tracks can be revealed ranging from 0.5 to 5 MeV. For the two-step ECE technique a constant α registration efficiency has been found. (author)