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Proceedings of the Estonian Academy of Sciences.

Chemistry

 

Volume 55 No. 3 September 2006

 

Thermoluminescent dosimeter Li₂B₄O₇:Mn,Si – a false-dose problem; 123–131

Mikhail Danilkin, Mihkel Kerikmäe, Aleksei Kirillov, Aime Lust, Arno Ratas, Lilli Paama, and Viktor Seeman

(full article in PDF format)

Abstract. The false-dose effects are investigated in the thermoluminescent detectors of ionizing radiation based on Li₂B₄O₇:Mn,Si. To reveal the mechanism of daylight sensitivity, thermoluminescence, EPR, and luminescence excitation studies and technological experiments were undertaken. A 400 nm light was shown to be most effective to store the dose and to excite the luminescence band near 600 nm. A charge-transfer complex of a casual titanium impurity is supposed to be responsible for daylight false-dose storage. Another mechanism of a false-dose storage is supposed to be caused by a thermally induced stress, which yields a high-temperature thermoluminescence of Li₂B₄O₇:Mn,Si detectors. Increasing the temperature of the sintering of tablets eliminates both false-dose effects. Possible models of energy storage are discussed.

Key words: thermoluminescence, dosimetry, false dose, lithium tetraborate, daylight sensitivity, luminescence spectra, EPR spectra.

 

 

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