Efficiency of generation of optical centers in KS-4V and KU-1 quartz glasses at neutron and gamma irradiation

Pure quartz glasses of KS-4V and KU-1 types are candidates for optical plasma diagnostic system in ITER. The purpose of experiment was to study the efficiency of defect production in these glasses under irradiation with ⁶⁰Со γ-quanta (5.7 Gy/s) dose range of 10 ²–10 ⁷ Gy and the fission reactor neutrons in the fluency range of 10 ²⁰–10 ²³ n/m ² and gammas simulating the plasma influence. In KU-1 (1000 ppm OH) the accumulation kinetics of E′-(5.75 eV) and NBO-(1.9 eV) centers at γ - doses ⩾ 5 × 10 5 Gy and neutron fluencies <10 ²¹ n/m ² is faster, than that in KS-4V glasses (<0.1 ppm OH) that is caused by rupture of hydrogen bonds. At fluencies >10 ²¹ n/m ² the NBO accumulation kinetics is slower in KU-1 than in KS-4B, because highly mobile hydrogen atoms access to the generated NBO centers. In KS-4V irradiated to γ-doses10 ²–5 × 10 ³ Gy a new unstable absorption band at 1.8 eV was found, which is caused by the glass synthesis conditions and alkali metal impurities. The transparency at 3.5–6.2 eV at fluencies 10 ²⁰–5 × 10 ²¹ n/m ² is higher in KS-4V than KU-1. However at fluencies >10 ²¹ n/m ² in KS-4V the photoluminescence band at 2.7 eV is more intensive and distorts a diagnosed signal. The transparency in 3.5–1.2 eV at fluencies >10 ²¹ n/m ² is higher in KU-1 than KS-4V.