| Autor: |
HAYAMI, Hiroyuki, AKUTSU, Takeji, ISHITANI, Tadayoshi, SUZUKI, Koichi |
| Zdroj: |
Journal of Nuclear Science and Technology; February 1993, Vol. 30 Issue: 2 p95-106, 12p |
| Abstrakt: |
AbstractThere are increasing demands for pure-silica-core image guides used in many radiation fields, in which more quantitative estimation of the radiation resistivity is required. We proposed two different methods suited for studying the resistivity of the image guides; one is based on average visual radiation-induced loss in which spectral luminous efficiency is taken into account and the other on shift of a point on the chromaticity diagram. Then, the resistivity of four kinds of core materials was evaluated under repeated irradiation conditions. The results show that the order of good resistivity among test samples is F, F+OH, OH and Cl+OH contained materials. This contradicts the results previously reported as OH-contained material has the best resistivity. Recovery of the radiation-induced loss was observed in each sample, most noticeably in Cl-contained material, when the samples were left in atmospheric ambient at room temperature for a certain period. The recovered transmittance was, however, lost quickly just after repeated irradiation. Radiation-induced defects in the materials were investigated by ESR spectroscopy. The increase of the defect density is smaller in the F-contained material than in other materials. From these results it is concluded that F-doping has superior effect to suppress radiation-induced degradation in silica glass. |
| Databáze: |
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