Evaluation of the thermally and optically stimulated response of an Italian Obsidian irradiated in Co-60 beams

Autor(es)

Antonio, Patricia L. ; Oliveira, Raquel A. P. ; Khoury, Helen J. ; Caldas, Linda V. E.

• Tipo de documento: Artigo Científico
• Fonte: Radiation Physics and Chemistry; v. 155, p. 6-pg., 2019-02-01.

Resumo

From Obsidian silicate, in its natural form, pellets were manufactured adding Teflon to the material in powder. These pellets were exposed to the gamma radiation beams of a Co-60 source in a dose interval from 10 Gy to 10 kGy. The Obsidian in powder was investigated in relation to its physical and chemical characteristics, by means of the X-ray diffraction, scanning electronic microscopy and energy-dispersive X-ray spectroscopy techniques. After the irradiation procedure, the signal of the samples was evaluated by means of three techniques: thermoluminescence (TL), optically stimulated luminescence (OSL) and thermally stimulated exoelectron emission (TSEE). The objective of this work was to verify the TL, OSL and TSEE response of the Obsidian + Teflon pellets after exposure to high doses of gamma radiation. Different response characterization tests were performed, as TL and TSEE emission curves, OSL signal decay, reproducibility, dose-response curves, lower detection limits and fading. From these results, it can be observed that the Obsidian + Teflon pellets present good conditions to be used as high dose gamma radiation detectors; the results obtained with the OSL technique were the most adequate in terms of response in function of absorbed dose. The fading of the signals, varying from about 26% (TSEE) to 44% (OSL), in a time interval of 360 h post-irradiation, also showed favorable results for the use of this material as radiation detector, when the measurements are taken after a defined time interval. (AU)

• Processo FAPESP: 08/57863-2 - P&D em metrologia das radiações
• Beneficiário: Linda Viola Ehlin Caldas
• Modalidade de apoio: Auxílio à Pesquisa - Temático
• Processo FAPESP: 14/12732-9 - Determinação de um sistema de referência e de um dosímetro de rotina utilizando técnicas luminescentes por fototransferência, para dosimetria de doses altas em irradiadores gama
• Beneficiário: Patrícia de Lara Antonio
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado