Dosimeter Film Based on Ethyl Violet-Bromophenol Blue Dyed Poly(Vinyl Alcohol)

Dyed poly(vinyl alcohol) (PVA) films, prepared by a simple technique of casting aqueous solutions of PVA containing a mixture of Ethyl violet and bromophenol blue (EV-BPB) on a horizontal glass plate, are useful as routine high-dose dosimeter in the 1 - 30 kGy range. The color of films changes from violet to yellow when exposed to gamma radiation. The response of this dosimeter depends up on the concentration of chloral hydrate (CH) in the polymer material. The radiation chemical yield (G-value) of PVA dyed film was calculated and found to increase by increasing concentration of chloral hydrate. Post-irradiation storage on the response of the films are discussed. The overall combined uncertainty (at 2σ) associated with measurement of response (ΔA mm-1) at 600 nm for dose range 1 - 15 kGy is 5.6%.