Regularities in the reversible change of polymer dielectric properties in the range of high dose rates

Reversible changes of dielectric loss tangent (tg delta) and dielectric constant (epsilon') are studied for a wide range of nonpolar and polar, amorphous and partially crystalline polymers in the dose rates between 102 and 2.105 rad/s. It is shown that all the polymers under study, with respect to the variation mode of their dielectric properties in a radiation field at a dose rate over 103 rad/s, can be subdivided into the following two groups: nonpolar or weakly polar, and polar polymers. The first group is characterized by a sharp increase in tg delta in the process of irradiation, whilst epsilon' shows either no variation or slightly grows. After radiation has been discontinued, tg delta and epsilon' assume their initial values. The second group of the materials has one common feature consisting in a significant tg delta drop within the entire frequency range under study (30-404 Hz). In the course of time, after radiation has been discontinued, tg delta approximates the initial value