SIRAD - Personal radiation detectors
SIRAD badge dosimeters provide a visual qualitative measurement of exposure to radiation for mid range dose exposure. This is performed using an active radiochromic dosimeter in a transparent window, combined into a badge assembly. When irradiated, the badges active window turns blue, which can be matched against the given colour chart for a qualitative assessment of the exposure received. Two peaks in the absorption spectra located at 617 nm and 567 nm were found. When analysed with a common computer desktop scanner, the optical density response of the film to radiation exposure is non-linear but reproducible. The net OD of the film was 0.21 when exposed to 50cGyand 0.31 at 200 cGy exposure when irradiated with a 6 MV x-ray energy beam and analysed using a broad spectrum light source. These values reduced when exposed with kilovoltage x-rays with an approximate 30% reducing in sensitivity at 50 kVp. The film provides an adequate measurement and visually qualitative assessment of radiation exposure for levels in the range of 0e50 cGy.