THE EFFECT OF FORMULATION CHANGES ON THE RESPONSE TO ULTRAVIOLET AND IONIZING-RADIATION OF RADIOCHROMIC DYE FILMS

Radiochromic dye films have been studied to optimise the formulation i n order to increase their sensitivity to ultraviolet and ionising radi ation. The films consist of certain substituted triphenylmethane leuco dyes incorporated in an acid solution with polyacetal resins, which c an be cast into thin, colourless, transparent films. Upon irradiation they become deeply coloured due to dye formation (without development) ; they are analysed for dosimetry by absorption spectrophotometry at t he visible wavelength of maximum absorption, in terms of increase of a bsorbance, relative to delivered absorbed dose. Ultraviolet response f unctions were obtained for different films, in which the concentration s of each of the constituents, the dye precursors, as well as the type s of acids and solvents were varied. A new formulation is suggested fo r radiochromic dye films useful in the gamma ray dose range from 5 kGy to 35 kGy.