The use of ferrous sulphate for dosimetry by post

Abstract

Ferrous sulphate dosemet'er solution in plastic irradiation vessels was posted to three radiotherapy centres for 6oCo irradiation, and taken to a fourth centre for 4 JIv x-ray irradiation, as an experimental trial for the future dosimetry of high energy electron therapy beams. The ferrous sulphate was returned for measurement, and doses calculated from the results have been compared with estimates based on ionization measurements with Farmer-Baldwin dosemeters calibrated at the National Physical Laboratory. FeSO, and ionization dose estimates have not differed by more than 2 % at any centre, and the precision of a short series of measurements a t a single centre is better than l?(,. The irradiation vessels are non-breakahle, cheap, and have been shown to have no adverse effect on solution response.