Radiation Measurements 39 (2005) 241 – 244 www.elsevier.com/locate/radmeas Response of PN3 dosimeters to 239 Pu–Be neutrons A. Belafrites a, b , A. Nourreddine a , ∗ , D. Mouhssine a , A. Nachab a , A. Boucenna c a Institut de Recherches Subatomiques, Universite Louis Pasteur, 23 Rue de LWss, BP 28, F-67037 Strasbourg Cedex 2, France b Département de Physique, BP 98, Ouled Aissa, Université de Jijel, 18000, Jijel Algeria c Département de Physique, Université de Sétif, 19000, Sétif Algeria Received 17 March 2004; received in revised form 30 June 2004; accepted 1 July 2004 Abstract CR-39 type PN3 plastic detectors associated with a polyethylene or PN3 radiator or without radiator were exposed to Pu–Be neutrons to evaluate their effectiveness as fast neutron dosimeters. The detectors were chemically etched and track counting was performed using an automated system. It was found that the dosimeter responses were linear up to a neutron dose equivalent of 200 mSv and that the simple PN3 detector without radiator has the same response as the two-element dosimeters and thus appears as a promising fast neutron dosimeter. © 2004 Elsevier Ltd. All rights reserved. Keywords: Fast neutron dosimetry; PN3; Automatic track counting; Response 1. Introduction Nuclear track detectors have found many applications, among them neutron detection ( Vilela et al., 1991; Spurny and Turek, 1978). Thermal neutron dosimetry makes use of a material to produce fission fragments and -particles which are registered and counted. With regard to fast neu- trons (200 keV–10 MeV), detection depends on recoiling nu- clei (protons) from a radiator placed in front of the detector or recoils within the detector itself (Kobzev et al., 2003). CR-39 has been widely investigated for use in a fast neutron dosimeter, because of its sensitivity to protons over a wide range of energy. The objective of the present work is to study the effect of radiators on CR-39, type PN3, registration of fast neutrons ∗ Corresponding author. Tel.: +33-3-88-10-62-14; fax: +33-3-88- 10-62-92. E-mail address: abdelmjid.nourreddine@ires.in2p3.fr (A. Nourreddine). 1350-4487/$ - see front matter © 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.radmeas.2004.07.003 and to determine the range of linearity between dose and track density, when using our automated reading system to count tracks after a chemical etching. 2. Experiment The detectors used in this work consisted of the polycar- bonate CR-39, type PN3, from (NE Technology, Beenham, England), with dimensions 20 × 25 mm 2 and 1.5 mm thick. These detectors were conditioned by the supplier and have a decimal and binary code for automatic identification by the reading system (Fiechtner et al., 1997; Harvey et al., 1997). Three kinds of dosimeter were placed in a pouch (Plastiplast, France; composed from inside to outside of Al (40 m), polyethylene (PE, 20 m), cellulose (40 m). One dosimeter was composed of a PN3 detector and a PE radiator (1 mm thick), another of two PN3 detectors with one serving as radiator, and the other of PN3 alone (with- out radiator). These dosimeters were exposed at normal