THE THERMOLUMINESCENCE OF TOSHIBA FD-1 AND FD-7 RPL GLASS

The thermoluminescent response of Toshiba FD-1 and Toshiba FD-7 radiop hotoluminescent dosimetry glass to Co-60 gamma radiation has been stud ied at doses of up to 66 kGy air kerma and 590 kGy air kerma respectiv ely. The FD-1 glass was in the form of rods 1 mm in diameter by 6 mm l ong whereas the FD-7 glass was in the form of blocks of 4.6 mm square and 1.47 mm thick. The FD-1 rods had a pre-dose signal equivalent to 1 80 Gy and were useable up to the maximum dose studied although the res ponse-dose curve was slightly supralinear at low doses. The FD-7 sampl es had a predose of 6.2 Gy and began to show severe saturation beyond about 1 kGy. The specific TL efficiencies (counts.mg.(-1).Gy(-1)) of t he two glass types have been compared with LiF and BeO and found to be some six orders of magnitude lower.