Behaviour of /spl rho/ relaxation in polarization cyclic processes by TSDC

It has been studied the p relaxation reproductibility of TSDC discharges obtained from PET-a and PMMA electrets formed by windowing polarization. It has been observed that this relaxation is sensitive to the sample initial conditions. Cyclic charge-discharge treatments, carried out on these samples keeping all the polarization parameters constant, results in a trapping capability increase which seems to have a purely electrical origin and it also seems to be sensitive to electrical ageing.