Development of ammonium tartrate as an ESR dosimeter material for clinicalpurposes

The crystalline substance ammonium tartrate is investigated with respect to its suitability as a clinical dosimetry material, The properties investiga ted are: the radical stability for absorbed doses relevant for clinical use , the improvement in sensitivity when the crystals are deuterated and the l inear electron tranfer (LET)-dependence. After photon irradiation to an abs orbed dose of 20 Gy, the signal increases rapidly during the first 6 h. Aft er this period, the changes are more moderate and can be corrected for. The signal-to-noise ratio of irradiated ammonium tartrate is twice the corresp onding value of alanine. By deuterating the crystals, the sensitivity can b e further improved by a factor of 1.4, As expected, the signal decreases wi th increasing LET of the radiation, but no changes in the spectrum shape wa s observed. (C) 2000 Elsevier Science Ltd. All rights reserved.