Photo-luminescence of Riso B3 and PVB films for application in radiation dosimetry

Riso B3 film dosimeters (23 mum) prepared from poly(vinyl butyral) (PVB) in corporating pararosaniline cyanide, as the radiation-sensitive element and PVB films (25 mum) prepared from PVB without any additives are investigated for gamma -radiation measurement using spectrofluorimetry based on their e mission properties. The unirradiated Riso B3 film when excited at 554 nm sh ows an emission band at 602 nm while PVB film shows an emission band at 305 nm when excited at 235 nm wavelength. The fluorescence intensity of both e mission bands decreases with the increase of absorbed dose due to the damag e caused by ionizing radiation. The useful dose range of Riso B3 film exten ds up to 120 kGy while that of PVB film extends up to 60 kGy. The response of Riso B3 film increases with the increase of relative humidity during irr adiation while that of PVB has less effect in the humidity range of 20-70%. The percent uncertainty associated with the measurement of the dose respon se was found to be +/- 3% (1 sigma) for both films. Riso B3 and PVB films s how good post-irradiation stability in dark and indirect daylight where the deviation in the response overall a 2-month storage period was found to be +/- 5% for Riso B3 and +/- 2% for PVB. (C) 2001 Elsevier Science Ltd. All rights reserved.