Change in conductivity of CR-39 SSNTD due to particle irradiation

The electrical conductivity in gamma irradiated CR-39 SSNTD increase substantially compared to pristine samples. On Si8+ irradiation in pristine samples the conductivity decreases below the resolution of the present measurement. When the gamma preirradiated samples are subjected to Si8+ irradiation (fluence= 5 x 109 to 5 x 1011 particles/cm2) conductivity reveals an increasing tendency. With the increase of Si8+ fluence, the conduction activation energy in these (γ + Si8+) exposed samples changes towards the activation energy of the only γ irradiated samples. These results are explained on the basis of dipolar orientation of the polymer chains. (author)