Fast neutron irradiation effects on CN-85 solid state nuclear track detector

Abstract

Samples from cellulose nitrate (CN-85) sheets of 0.3 mm thickness were irradiated with fast neutrons with equivalent doses in the range 1–10 Sv. The effect of fast neutron irradiation on the thermal properties of CN-85 has been investigated using thermo-gravimetric analysis (TGA) and differential thermo-gravimetric (DTG). The onset temperature of decomposition T o and thermal activation energy of decomposition E a were calculated. The results indicate that the cellulose nitrate detector decomposes, in one main breakdown stage, at temperatures much lower than that of several other SSNTDs due to the weak nitrogen oxygen bonds. Also, the variation of transition temperatures with the equivalent neutron dose has been determined using differential thermal analysis (DTA). The results indicate that the CN-85 thermograms were characterized by the appearance of one endothermic peak due to melting. These melting temperatures were found to be dependent on the equivalent neutron dose. In addition, the effect of both temperature and neutron dose on the intrinsic viscosity of the liquid CN-85 samples were studied. The results indicate that the cellulose nitrate polymer does not have a high resistance to degradation possessed by several other SSNTDs.