Synergistic Effects of Surface Reaction and Radiation Defects on Tritium Release Behavior from Solid Breeding Materisla of Fusion Reactor Blanket

(1)本文用漫反射法和傅里叶变换红外光谱法研究了在高温（1073 K）下，在控制D_2O或D_2分压条件下Li_2O表面羟基的变化。在2748，2717，2660，2620，2540，2520，2490 cm ~ 2处观察到O-D伸缩振动的多个峰，<-1>显示出随温度和大气层变化的不同行为。多峰表明D_2O在表面的吸附是不均匀的。当向吹扫气中加入D_2时，2540 cm-1<-1>和2490 cm-1的峰强度<-1>增加。这表明表面受到氧势的影响。将观察到的峰归属于表面键合结构。(2)建立了反应堆辐照下可控气氛下高温发光和氚释放的In-siru观测系统。在77 K反应堆辐照、800 K离子辐照和77- 300 K γ射线辐照下，原位发光研究发现，在235 nm、305 nm、340 nm、375 nm、430 nm和510 nm处有多个发光带，这些发光带属于自陷激子（σ-和π-极化跃迁），F^0、F^+、F_2和F_2心分别受羟基影响。研究了温度、辐照种类和气氛等因素的影响。并由此阐明了缺陷形成和发光的机理。同时发现缺陷发光与氚释放行为之间存在相关性，表明表面反应与辐照缺陷之间存在协同作用。(3)在此基础上，建立了考虑表面反应和缺陷影响的氚释放模型。

(1) Hydroxyl groups on the surface of Li_2O were studied by using diffuse reflectance method with Fourier transform infrared spectroscopy at high temperature up to 1073K under controlled D_2O or D_2 partial pressure. Multiple peaks due to stretching vibration of O-D were observed at 2748,2717,2660,2620,2540,2520,2490cm^<-1> showing different behavior with temperature and atrnosphere. Multiple peaks mean that surface is not homogeneous for D_2O adsorption. When D_2 was added to sweep gas, peak intensities of 2540cm^<-1> and 2490 cm^<-1> increased. This indicates that the surface is influenced by oxygen potential. Assignment of the observed peaks to the surface bonding structure was conducted.(2) In-siru observation system of luminescence and tritium release at high temperature under controlled atmosphere under reactor irradiation was constructed. In-situ luminescence studies were also conducted under reactor irradiation at 77K,ion irradiation up to 800K and gamma-ray irradiation at 77-300K.Luminescence spectra were found to be consisted of several emission bands at 235nm, 305nm, 340nm, 375nm, 430nm and 510nm, which were assigned to self-trapped exiton (sigma-and pi-polarized transitions.), F^0, F^+, F_2, and F_2 center affected by a hydroxide group, respectively. Effects of temperature, irradiation species and atmosphere were studied. Mechanism of defect formation and luminescence emission was elucidated from them. Correlation was also found between luminescence emission from the defects and tritium release behavior, indicating synerism between surface reaction and radiation defects.(3) From these results, tritium release model was constructed which includes surface reaction and the effect of defect.