Lanthanide doped alkaline metal sulphates as candidates for EPR dosimetry

Abstract

The applicability of lanthanide doped alkaline metal sulphates as a new type of dosimeters for EPR dosimetery of ionizing radiation has been investigated in an attempt to obtain a dosimeter with better characteristics than the commonly used alanine dosimeter. Irradiation of samples doped with different lanthanides (Y, Ln, Gd) showed that the best sensitivity is obtained using dosimeters doped with Y2(SO4)3. Different procedures for manufacturing dosimeters were studied and an optimum procedure was established. The time stability of the EPR signal of the irradiated Y2(SO4)3 dosimeter was investigated using a 15N-PDT standard and no fading of the EPR signal was observed over at least two weeks. The dose dependence of alanine and Y2(SO4)3 doped K3Na(SO4)2 dosimeters irradiated in the range 20 Gy - 200 kGy was analysed using a combination of 1-hit and 2-hit mechanisms of free radicals creation.