Further investigations on CR-39 fast neutron personal dosemeter

A fast neutron personal dosemeter based on CR-39 nuclear track detectors has been developed in as simple a form as possible to be used in routine monitoring. It has been investigated during the last joint irradiation exposures to neutrons organised by EURADOS-CENDOS committee on the application of track detectors in neutron dosimetry. ergy response and the angle dependence of two types of CR-39 material, produced by Pershore Mouldings Ltd (as standard grade material) and American Acrylics (as dosimetry grade material), have been studied using neutron energies ranging from 144 keV up to 66 MeV and the 252Cf neutron spectrum at different angles of incidence, i.e. 0°, 30°, 60° and 85°. Irradiated detectors have been processed using a conventional chemical etching (CE) and a two-step electrochemical etching at low (200 Hz) and high (2 kHz) frequencies (ECE). Under the ECE etching conditions a 80 μSv minimum dose equivalent value is achieved. The response of these detectors to the ambient dose equivalent in the range 0.4–13 mSv has also been studied for monoenergetic neutron beams of 1.2, 5.3 and 15.1 MeV. The dosimetric characteristics of the proposed dosemeter have been much improved by using the ECE conditions. The variations and values of these characteristics approach the required ones in a better way than that given till now in previous works.