Optimization of the sensitization of CR-39 etched track neutron dosemeters with carbon dioxide

Although etched-track detectors, in particular the polyallyl-diglycol carbonate (PADC), i.e. CR-39, are the most popular among passive neutron personal dosimeters (d’Errico and Bos, 2004), there are still challenges to be addressed, such as counting automatically the small recoil proton tracks. A pre-etching treatment with CO2 under pressure is a technique used to enhance the track size and readability, and had been confirmed in various reports (Csige, 1997; Fujii et al., 1995; Yamauchi et al., 2009). However, only a few investigated the response for fast neutrons (Hulber and Selmeczi, 2005; Shimada et al., 2011), and not completely. Therefore, the present study is attempted to confirm the sensitization effect once again and thoroughly analyse the process, in order to identify the optimal conditions for maximum neutron sensitivity. For that, CR-39 plates were irradiated with 241AmBe neutron source, and tested under different treatment time (1 – 5 days) and carbon dioxide pressure (0.1 – 0.5 MPa), which are the two parameters that characterize the pre-etching treatment. An increase, up to X %, of track density was seen