It was recalled that artificial quartz crystals with high concentrations of Al and Ge had been investigated with regard to hydroxyl defects, caused by 77K irradiation, before and after irradiation at 300K. The hydroxyl defects acted as a source of H atoms which compensated electron-excess Al centers during irradiation. A comparison was made here between variously prepared Ge-doped crystals and a premium crystal. It was found that, during irradiation, some new bands appeared at the expense of already existing bands. A novel defect center which absorbed at 3400/cm was detected in 2 of the Ge-doped crystals. This band was associated with a different species of point defect to the ones that absorbed at this frequency when present as growth defect bands.

H.Bahadur: IEEE Transactions on Nuclear Science, 1996, 43[3], 2085-95