Estudo da resposta de cristais de quartzo natural para dosimetria termoluminescente

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

In the last few years, a number of studies have been carried out with the objective of characterizing and/or developing materials with thermoluminescence properties (TL) for the purpose of ionizing radiation dosimetry. The aim of this study consists in the characterization of the thermoluminescence properties of natural quartz crystals, to be used for radiation dosimetry. The quartz crystals used in this study were taken from five deposits in Brazil: Batatal (MG), Governador Valadares (MG), Palmeira (CE), Pium (TO) and SolonÃpolis (CE). Their impurity concentration and geographical coordinates are known. The samples were cut parallel to the crystallographic axis [0001] with of 5x5x1mm. Glow curve analysis of these quartz showed that only the samples from SolonÃpolis and Batatal presented a TL signal in the region of the 200 to 320ÂC for doses ranging from 1,0 to 20,0mGy. The infrared (IR) and visible ultraviolet (UV-VIS) analyses were carried out for the five deposits to further understand this behavior. The repeatability and reproducibility of the quartz TL response of SolonÃpolis and Batatal samples were studied with the peaks in the region from 160 to 320ÂC. The results showed that variations in the quartz response were lower than 3%. The TL dose response evaluated for the gamma radiation of 60Co, 137Cs and x-ray beams with energy from 16 to 65keV showed a linear TL response within the radiation dose range of 1-20mGy. Sensitivity of SolonÃpolis and Batatal quartz samples were found to be higher than TLD-100. This behavior was discussed in relation to the type of charge compensator coupled with substitutional Al+3 ions. The fading of TL response at ambient temperature was also studied and the results showed that during the period of 75 days the TL response of the peak at 160 a 320ÂC decreased only 3%

ASSUNTO(S)

quartz thermoluminescence termoluminescÃncia dosimetria dosimetry engenharia nuclear quartzo

ACESSO AO ARTIGO

Documentos Relacionados