Poly (vinyl butyral co-poly vinyl alcohol co-vinyl acetate) (PVB-co-PVA/PVAC) combined with 4-(p-nitrophenyl-azo)-1-naphthol dye has been examined a promised dosimeter suitable for high dose ranges. The prepared films have yellow color. This color undergoes color bleaching upon irradiation with gamma rays. Different concentrations were prepared to obtain the suitable dosimeter in the dose range from 3 to 200kGy depending on the dye concentration. Chloral hydrate was then added in different concentrations, as a result the bleaching reaction expedites and in accordance the dose range diminishes to be 35kGy. The effect of chloral hydrate as well as dye concentration on response curve was studied. The radiation efficiency (G-value) was estimated for all the prepared films. Influence of relative humidity during irradiation was estimated as well as stability before and after irradiation.

Sayeda Elewa Eid, Seif Ebraheem and Nehad Magdy