EPR response of anhydrite crystal (CaSO4) for dosimetry of gamma photon beams

An anhydrite (CaSO4) natural sample was studied as possible dosimeter for low and high gamma doses using the technique of electron paramagnetic resonance (EPR). EPR spectrum showed signals due to (SO3)(-), (SO4)(-) radicals and O center. The anhydrite sample was irradiated with gamma rays with low-dose ranges typical for medical therapy (1-20 Gy) up to high-dose of about 70 kGy. The EPR centers due to (SO3)(-) and (SO4)(-) exhibited a linear dose response in the dose range from 1 Gy to 500 Gy, whilst the 0 center presented a supra-linear dose response in the range of 50 to 5 kGy.

Automated summary

In this study, anhydrite was investigated as a dosimeter for low and high gamma doses using EPR. The EPR spectrum revealed signals from (SO3)(-), (SO4)(-) radicals and O center. The dose response of (SO3)(-) and (SO4)(-) was found to be linear, while the O center exhibited a supra-linear response in the higher dose range.