Electron paramagnetic resonance radiation dosimetry: possible inorganic alternatives to the EPR/alanine dosimeter
Abstract
The intensity of the EPR spectrum of γ-irradiated L-α-alanine has been accepted by the International Atomic Energy Agency as a secondary standard for high-dose (10–100 000 Gy) dosimetry. The alanine dosimeter is not without its disadvantages, however, and in this article alternative EPR dosimeters are explored. These include SO–3 in irradiated K2CH2(SO3)2 and CO–2 in irradiated sodium formate (NaHCO2), both of which have some advantages over CH3CHCO–2 in L-α-alanine. Using as a readout parameter the peak-to-peak excursion of the strongest line, these systems have a four-fold sensitivity advantage over alanine. The radicals SO–3 and CO–2 are, moreover, found in a wide variety of matrices, and it may be possible find one in which they are even stronger.
The need to discover a dosimeter material sensitive enough to function in the ‘clinical’ dose range (below 10 Gy) is emphasized.