Abstract
we recently developed a radiation indicator using a photogravure ink. This indicator allows simple assessment of absorbed doses of γ-rays used for sterilization of medical supplies and absorbed doses of γ-rays and electron beams emploied in various kinds of industrial fields. This indicator was prepared by coating the packing paper with an indicator ink made primarily of diethylaminoazobenzene. When γ- rays were irradiated onto this indicator at a dose rate of 25.7kGy/h, a color of the indicator changed in proportion to the strength of a dose and was well reproducible. Prior to irradiation, the color of the indicator was yellow. This color changed to orange from yellow at an absorbed dose of 10kGy, to red at 25kGy (a dose used for sterilization) and to purplish red at 50kGy. Within dose rate ranges of 1.41-33.4kGy/h, the color was changed in proportional to only absorbed doses as independent of the dose rate. The dose-response curve of the indicator for electron beam irradiation which was generated by a linear electron accelerator is in good agreement with that for γ-ray irradiation.
