Nature and Formation Mechanism of γ-Induced Color Centers with Optical Absorption Band 665 nm in KS-4V and KI Quartz Glasses

Abstract

The aim of the experiment was to elucidate the formation mechanism of color centers with optical absorption band in the region 660–680 nm, which are induced in KS-4V and KI quartz glasses under irradiation by ⁶⁰Co γ-rays at dose rate 2.5 Gy/sec and temperature 77, 273, and 310 K in the dose range 30–10⁵ Gy. The 665 nm band is induced efficiently in KI samples, which contain more metallic impurities (<10 ppm). It is shown that the 665 nm band induced in KS-4V after soaking at 300 K for 40 min diminishes by approximately 30% and almost vanishes after 3 h; it is thermally stable at <300 K and is completely annealed at ≥323 K. The accumulation kinetics of color centers of the 665 nm band in KS-4V at >4·10² Gy is caused by rupture of the M⁺O–Si≡ bond near aluminum ≡Al³⁺. In contrast to KS-4 and KI glasses, KU-1 glass is recommended for small windows in the ITR reactor for the visible part of the spectrum.