RESUMO
The present report deals with the experimental observations of the thermally stimulated migration of charge carriers from trapping centres responsible for the main thermoluminescence (TL) peak at 450 K to a deep trap and, also, the optically stimulated transport of carriers from the deep trap to the main trap, which gives rise to the phototransferred TL at 450 K, in anion-defective alpha-Al2O3 crystals. The obtained results provide an experimental proof to the adequacy of the assumptions made in the model of the mutual interaction of the main and deep traps in the crystals under study.
Assuntos
Óxido de Alumínio/efeitos da radiação , Modelos Químicos , Dosimetria Termoluminescente/instrumentação , Simulação por Computador , Desenho Assistido por Computador , Relação Dose-Resposta à Radiação , Desenho de Equipamento , Análise de Falha de Equipamento , Raios gama , Temperatura Alta , Doses de Radiação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Dosimetria Termoluminescente/métodosRESUMO
The results of a study dealing with detection of neutrons in thermoluminescent (TL) photon radiation detectors, type TLD-500, based on an anion-defective corundum have been reported. The detection method uses the transformation of neutron radiation into gamma radiation arising when neutrons are captured by cadmium nuclei. A comparative analysis of the data obtained with the TL detectors and results of radiometric measurements suggested applicability of this method. A sensor with an optimal embodiment providing a relatively high sensitivity has been developed.
Assuntos
Nêutrons , Monitoramento de Radiação/métodos , Dosimetria Termoluminescente/métodos , Monitoramento de Radiação/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Dosimetria Termoluminescente/instrumentaçãoRESUMO
Some new experimental results illustrating the effect of deep traps on luminescent and dosimetric properties of anion-defective single crystals of alpha-Al2O3 have been described. It was found that deep traps had an electronic origin. They were filled thanks to the photoionisation of F-centres and their filling was accompanied by the conversion of F-->F+ centres. The experiments revealed an interactive interaction of deep trapping centres. A model taking into account the thermal ionisation of excited states of F-centres was proposed. This model describes the trap filling process and mechanisms of the radio-, photo- and thermoluminescence, TSC and TSEE of the crystals under study. The sensitivity of TLD-500 detectors based on anion-defective alpha-Al2O3 equalised when deep trapping centres were filled.