Measurement of Electron Beam Dose Using Polyvinyl Alcohol\ Silver Nitrate Film

Abstract

Radiation worker in different hospitals exposure to different levels from radiations at a linear accelerator, so it must be use personnel monitoring devices like, thermoluminescent dosimeters (TLD) and film badge. This study we prepared film by dissolving PVA powder (5wt%) in 500 ml distilled water and placed in magnetic stirrer under controlled water bath temperature at 60-70 C and continuous stirring for 3 h. after that we take pure PVA and concentration of (0.01wt) silver nitrate we added to 50 ml PVA, (0.02) silver nitrate we added to 50 ml PVA, (0.03) silver nitrate we added to 50 ml PVA and stirred for 2 hr in darkroom for three day. After prepare the film we take it and exposure to 6Mev electron beam from the linear accelerator machine with applicator cone 10x10 cm to different doses (0, 2,4,6,8 and 10 Gy). After that we use UV-visible light spectrophotometer to measure the wave length of the films and optical densitometer to measure optical density of the films. So we found when the dose level increase the film absorption increase and when the dose level decrease the film absorption decrease. The white color of the film has been changed to yellow, golden and black following the radiation steps up to 10 Gy. The color change of the film reveals different reduction stages of silver ions by irradiation.