Characteristics of some track detectors applied for neutron radiography

The track etching method has been employed for neutron radiography purposes, by making use of a cold neutron beam obtained at the IEA-R1 Nuclear Research Reactor. The films used were the Solid State Nuclear Track Detectors CN-85, CR-39, MAKROFOL-E and LR-115, with a natural Boron converter screen. In order to obtain mean track diameter about 3 μ with a minimum overlapping between them, adequate conditions for etching and exposure times about 30 minutes and 3 hours respectively were evaluated. For such conditions exposures of 109 n/cm2 that corresponds to 107 track/cm2 are achieved. Neutron radioagraphs of several materials were performed and the best results in terms of optical contrast, were obtained for the films CN-85 and CR-39. (author)