A novel method to use radiochromic dye films to determine dose under proton irradiation

The response of commercial radiochromic dye films exposed to 0.7, 1.5 and 3.0 MeV protons, in the dose interval between 1−103 Gy, has been studied. The response of the plastics (MD-55 and HD-810 from Gafchromic) to the radiation was evaluated by digitalizing and analyzing the films with commercial computer systems. Curves of response as a function of dose show an approximately linear behaviour followed by saturation. The response in the lower dose interval suggests a possible use of these methods in heavy charged particle medical applications. To verify consistency with the traditional spectrophotometer reading procedure, the films were also irradiated and evaluated with 60Co gamma rays.