Plastic irradiation vessels for ferrous sulphate dosimetry

Plastic irradiationvessels for ferrous sulphate dosimetry have several advantages over glass, but carry the risk of introducing chemical contamination which might lead to false results.Reports on the performance of various plastics when used for this purpose have been given by Haybittle, Saunders and Swallow (1956), Hall and Oliver (1961), Davies and Law (1963), Svensson, Pettersson and Hettinger (1967) and Pettersson and Hettinger (1967), amongst others.Unfortunately, different specimens of what is nominally the same plastic material may contain different impurities, and hence may differ in their reliability for ferrous sulphate dosimetry.Ideally, plastic irradiation vessels should only be used when a cont'rol experiment has demonstrated their suitability, but this would be a serious handicap to what is often a very convenient procedure.It must be hoped that a good record of satisfactory performance