Investigations into the thermal defect of tissue-equivalent plastic

The thermal defect, defined as the fraction of absorbed radiation energy which is not converted to heat energy in the calorimetric dosimetry absorber was investigated for A-150 tissue-equivalent plastic. Studies to measure the thermal defect as a function of proton energy and for various energies of alpha particles and the heavy recoil nuclei produced in tissue by neutrons are proposed along with a proposal to compare the thermal defects of A-150 plastic obtained from different laboratories and molded under diverse conditions. A description of these studies, now under way, is given