GAMMA RADIATION DETECTION

摘要

A gamma radiation dosimeter comprises a polyester film substrate 10, of which a central circular region 12 is coated with a gamma-radiation sensitive layer 14 which is covered by an overlayer 16. The radiation- sensitive layer 14 is formed from styrene- acrylonitrile copolymer and contains 1-bromoadamantane and a leuco dye. The overlayer 16 is formed from an acrylic resin binder containing a UV-absorber. The central region 12 is surround by an annular region 18 which is divided into six equally-sized sections 18a.....18f. Each section 18a.....18f is printed in a colour which corresponds to the colour developed in the central region 14 when it has been exposed to successive increasing amounts of gamma radiation. After exposure of the device, the amount of radiation to which the device has been exposed can be determined by comparing the colour generated in the region 14 with the colours of the sections 18a.....18f. The colour of the section most closely corresponding to that of the central region indicates the dose of gamma radiation which the device, and any other object similarly exposed, has received.