Lithium or sodium doped beryllium oxide, BeO(Li: 0.5 mol%) and Be0 (Na: 0.5 molx), were found to be efficient and reliable thermoluminescent phosphors. Glow curves of both BeO(Li) and BeO(Na) have simple peaks at 18OoC. The thermoluminescent spectrum shows a broad band in the ultra-violet region peaking at 330 mp with shoulders near 300 and 390 mp.Besides featuring the characteristic that this material has a photoelectric absorption equivalent to that of biological tissue, the main characteristics of the phosphors, from the point of view of dosimetry include:(1) Exposure response of BeO(Li) is linear from 1 mR to 500 R, and that of BeO(Na) is linear from 2 mR to 100 R.(2) Fading of BeO(Li) is less than 20 % within the first hour and 8 % within the following 30 days, and that of BeO(Na) is less than 10 % within the first hour and 5 % within the following 30 days. Light fading of pray exposed BeO(Li) and BeO(Na) is less than 10% for a light exposure of 300 lux for 10 min.(3) After repeated use, easy annealing (heating at 450 -5OO0C for 1 -10 min) removes the residual dose.(4) The thermoluminescent efficiency remains unchanged after more than 100 cycles of repeated exposure-readout operations.(5) A small amount of tribo-thermoluminescence is emittable; about 15 mR dose equivalent for dropping 10 times from a height of 1 m to concrete floor.

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