| Research Abstract |
Some radiation-induced luminescence color images, including afterglow (AG) or radiophospherescence, and thermoluminescence (TL), were conveniently photographed by means of a commercially available negative color film after the irradiation of X-ray on pottery slices, named as Sueki. The resultant photographs, particularly AG color images (AGCIs), showed a variety of emission patterns dependent on kinds of minerals or thermal history of pottery. The AGCIs from archaeological pottery slices are subjected to the color image analysis to obtain more quantitative information. The relationships of two color intensity-ratios, such as green/red and blue/red, were found to reflect clearly the origin of pottery. While, the dependence of luminescent color properties on the heating temperatures suggests to clarify thermal history of kilns and potteries using stepwise heating of their ingredient-clay.
The discussion was made on that provenance identification of ancient ceramics and thermal history of
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kilns could be evaluated using AGCIs from the slices.
Basically, the existence of atomic hydrogens or hydrogen radicals besides intense Al-centers was ascertained in ESR spectrum measurements of a variety of natural quartzes after irradiation at 77K.The remarkable decrease of the Al-center signals, coincident with the complete disappearance of ESR-signal due to hydrogen radicals, occurred recognized after warming once up to room temperature, giving positive correlation between the hydrogen radical signals and reducing proportion of the Al-centers. On the basis of these experiments, it was confirmed that hydrogen radicals derived from radiolysis of OH-related impurities could operate as a "killer" of radiation-induced Al-centers, or main origin of blue thermoluminescence (BTL), suggesting important role of a phase-transition temperature of β-quartz/tridymite to the TL-property changes.
Subsequently, a constraction of an automatic luminescence measuring system incorporated a small X-ray generator, involving both TL and OSL (Optically Stimulated Luminescence), is also described. Less
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