POSTIRRADIATION STABILITY OF RESPONSE OF AN AQUEOUS COUMARIN DOSIMETER

Aqueous solution of coumarin (alpha-benzopyrone) has been evaluated spectrophotometrically as a gamma-ray dosimeter. In the present study measurements have been made at peak wavelength of 347 nm as well as at two other wavelengths (i.e. 360 and 370 nm). The response of the dosimeter with respect to absorbed dose is linear in the range of 0.05 to 0.5 kGy when absorption measurements are made at 347 nm. However, this dose range can be increased up to 0.8 kGy if analyzed at longer wavelengths of 360 and 370 nm. Post-irradiation stability at room temperature in the dark show that the response increases gradually till 6 d. Afterwards the response is almost stabilized up to 42 d at all the wavelengths studied.