Dosimetric applications of α-alanine

Abstract

Irradiation of solid polycrystalline alanine creates a free radical, whose concentration can be measured from its ESR signal. The radical CH3ĊHCOO− of practically unlimited stability at room temperature shows an electronic absorption spectrum in the UV. Modern methods of diffuse reflectance spectrophotometry allow to measure the radical concentration which is proportional to the absorbed dose of radiation. The alanine dosimeter is prepared in a thin layer, adequate both for the congested isodose curves in the case of accelerated electrons irradiation and the method of measurement. Thus the proposed dosimeter is applicable not only for gamma, but also for EB radiation processing in the range of 0.1 to 50 kGy. The application of the dosimeter does not demand to use the ESR spectrometer, even of the type dedicated to alanine dosimetry only, but may be performed by a UV-VIS spectrophotometer equipped with an integrating sphere, permitting measurements of the Kubelka-Munk function.