Problems associated with the use of the radiochromic dye film as a radiation dose meter

Abstract

A thorough investigation has been made of the problems involved in using a dye film dose meter for precision dosimetry at high doses, using both low- and high-LET radiation. The study includes: time course of coloration following irradiation at various dose levels; dose response after irradiation in vacuum or at atmospheric pressure; dose response dependency of temperature during irradiation and dose rate effects at high doses. The dose response characteristics have been measured mainly at 510 nm and over a dose range from 1 kGy to 10 4 kGy, which ranges from the lowest detectable dose to saturation of coloration. The dose response has been found to depend strongly on: the time span between irradiation and measurement; the irradiation temperature; and the dose rate at doses above 50 kGy for low-LET radiation. Irradiation in vacuum (〉1 Pa) and in air produced the same dose response. This work supplements previous investigations of the dye film, which were mainly carried out at lower doses.