THERMALLY STIMULATED LUMINESCENCE AND ELECTRON-PARAMAGNETIC RESONANCE STUDIES OF ACTINIDE DOPED CALCIUM CHLOROPHOSPHATE

Electron paramagnetic resonance [EPR] and thermally stimulated luminescence [TSL] studies were conducted on self [alpha]-irradiated Pu-239 doped calcium chloro phosphate and gamma-irradiated (Pu/UQ22+)-Pu-239-U-238 doped calcium chloro phosphate to elucidate the role of the electron/hole traps in thermally stimulated reactions and to obtain trap parameters from both TSL and EPR data. TSL glow peaks around 135 K (# peak 1), 190 K (# peak 2), 435 K (# peak 5) and 490 K (# peak 7) were observed and their spectral characteristics have shown that Pu3+ and UO66- act as luminescent centres in calcium chloro phosphate with respective dopants. EPR studies have shown the formation of the radical ions H0, PO42-, O-, O2- and [ClO]2- under different conditions. Whereas the [ClO]2- radical being stable up to 700 K, was not found to have any role in TSL processes, the thermal destruction of other centres was found to be primarily responsible for the TSL peaks observed. The trap depth values were determined both by using the TSL data and also the temperature variation of EPR spectra of these centres.