Radiation Protection Dosimetry Advance Access originally published online on August 25, 2006
Radiation Protection Dosimetry 2007 123(2):143-147; doi:10.1093/rpd/ncl108
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Usability of VTL from natural quartz grains for retrospective dosimetry
1 Nuclear Fuel Cycle Engineering Laboratories, Japan Atomic Energy Agency, Tokai-mura, Naka-gun, Ibaraki 319-1194, Japan
2 Niigata University, Nino-cho, Niigata-shi, Niigata 950-2181, Japan
* Corresponding author: fujita.hiroki{at}jaea.go.jp
Received March 28, 2006, amended July 25, 2006, accepted July 30, 2006
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Abstract |
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To develop retrospective dosimetry of unexpected radiation accident, basic studies on violet thermoluminescence (VTL) phenomena were conducted using natural quartz grains. All VTL glowcurves of as-received samples did not exhibit peaks <250°C, although for artificially irradiated quartz samples there were VTL peaks in the temperature region <250°C. Therefore, accident doses could be estimated without the interference of naturally accumulated doses by VTL measurements from natural quartz. The mean lives of VTL were evaluated by the various heating rates method and the range of values was found to be between some days and ten thousands of years depending on each peak. Especially, the mean life of VTL peak at 200°C was years order. Furthermore, the lower detection limit was calculated to be tens of mGy from the response curve. This value was lower than that of other methods such as ESR dosimetry. From these results, we conclude that VTL dosimetry can be preferred for accidental evaluation.