Evaluation of an indigenously manufactured Garfilm-EM—250 μm thick polyester film as a dosimeter for high-dose applications

Dosimetric characteristics of indigenously manufactured ‘Garfilm-EM’—a 250 μm thick polyester film—were evaluated spectrophotometrically for its possible application as a routine film dosimeter in gamma radiation processing. Available commercially in large batches, this film is cheap, has a good clarity, consistent thickness, is scratch resistant and is easy to handle. Radiation-induced changes in the absorption spectra of Garfilm were analysed and based on the results obtained, 340 nm was chosen as the wavelength of absorption measurements. The reproducibility of the response of these films for cobalt-60 gamma rays was found to be within ±2.7% (1σ). In the present study, influence of environmental conditions during irradiation like irradiation temperature, relative humidity, oxygen content and dose rate on dose response of Garfilm were also investigated systematically. From the studies carried out, Garfilm-EM has been found to have a good potential for its use as a dosimeter in the absorbed dose range 20–220 kGy due to its linear dose–response relationship, good pre- and post-irradiation stability and reproducibility.