Indoor light on thermoluminescence of CVD diamond film used as a high-energy photon dosimeter.
The effect of light on polycrystalline diamond film that was produced by chemical vapor deposition and is used as a thermoluminescent dosimeter should be considered, although some researchers have indicated that such an effect was theoretically unlikely to happen. A 15 min exposure to a normal desk light bulb induces significant thermoluminescence (TL) comparable to a 0.5 Gy exposure to high-energy photons. This light-induced TL will be saturated within 2 h. The saturated TL intensity depends on the frequency of the light and the blue light dominates. The TL peak area at a temperature of 605 K is insensitive to light but is sensitive to high-energy photons. Another peak at about 410 K is caused by light only, because the TL from the ionization radiation at the same location is bleached. The effect of light could be easily distinguished by a numerical or an experimental method. Lamps with a green lampshade or pure red lights are suggested for use as indoor light sources. To reduce the effect of light, pre-heating treatment before readout is also suggested.
Liu
Chi-Chang
CC
Department of Nuclear Science, National Tsing Hua University, 101, Section 2 Kuang Fu Road, Hsinchu 300, Taiwan.
Chu
Tieh-Chi
TC
Lin
Sung-Yen
SY
Lin
Jao-Perng
JP
D018130:Diamond / Q000737:chemistry*; D004307:Dose-Response Relationship, Radiation; D005740:Gases / Q000737:chemistry; D007700:Kinetics; D008027:Light; D016014:Linear Models; D008956:Models, Chemical; D017785:Photons; D013816:Thermodynamics; D013819:Thermoluminescent Dosimetry / Q000295:instrumentation*
D005740:Gases; D018130:Diamond