Effects of atomic hydrogen and annealing temperatures on some radiation-induced phenomena in differently originated quartz

The existence of atomic hydrogen besides intense Al-centers was ascertained in ESR spectrum measurements of a variety of natural quartzes after irradiation at 77 K. The remarkable decrease of the Al-hole center signals, coincident with the complete disappearance of ESR-signal due to atomic hydrogen, was observed upon heating to room temperature. A positive correlation was established between the atomic hydrogen signals and the reducing proportion of the Al-hole centers. Additionally, the thermal annealing treatments of the quartz samples beyond 800 degreesC before irradiation induced the significant decrease of H-0 as well as the removal of OH absorbance in IR-spectra around 3500 cm(-1). On the basis of these experiments, it was confirmed that the atomic hydrogen derived from the radiolysis of OH-related impurities could operate as a "killer" of radiation-induced Al-centers, presumably main holes of blue thermoluminescence (BTL). These results play an important role in the phase-transition temperature of beta -quartz/tridymite on the TL-property changes. The red thermoluminescence (RTL)-related centers were also searched using ESR spectra with the aid of the annealing experiments. (C) 2001 Elsevier Science Ltd. All rights reserved.