RADIATION-DOSIMETRY BASED ON THE RADIOPHOTOLUMINESCENCE OF SYNTHETIC DIAMOND

A dosimetric method based upon the radiophotoluminescence of synthetic diamond crystals of low paramagnetic nitrogen concentration has been developed. By using light of 404 nm, it is shown that the thermally accessible charge-trapping states which are responsible for the thermoluminescence characteristics of the crystal can be de-excited to give a dosimetric technique with a response that is linear to radiation doses up to 10 Gy. When an excitation wavelength of 296 nm is used to empty the thermally inaccessible charge-trapping states, radiation doses up to 20 kGy are linearly measured. It is concluded that synthetic diamond crystals, with such favourable physical properties as near tissue equivalency and chemical inertness, have potential application as photoluminescence dosimeters in medical physics, radiobiology and radioprocessing.