Selfcalibrated alanine/EPR dosimeters: A new generation of solid state/EPR dosimeters

Abstract

Alanine/EPR dosimeters are well established as secondary, reference dosimeters for high-energy radiation. However, there are various sources of uncertainty in the evaluation of absorbed dose. This arises primarily from the necessity to calibrate each EPR spectrometer and each batch of dosimeters before their use. In order to overcome this disadvantage, a new generation alanine/EPR dosimeter has been developed, and its possibilities as a radiation detector are reported. Principally, it is a mixture of alanine, some quantity of EPR active substance, and a binding material. The EPR active substance, acting as an internal EPR standard, is chosen to have EPR parameters which are independent of the irradiation dose. The simultaneous recording of the spectra of both the sample and the standard under the same experimental conditions and the estimation of the ratioI _alanine/I _Mn as a function of the absorbed dose strongly reduces the uncertainties. The response of these dosimeters for⁶⁰Co γ-radiation exhibits excellent linearity and reproducibility in the range of absorbed dose, 10²−5·10⁴ Gy.