MeV能量的重离子辐照GaN的HRXRD研究

分别进行了2.3 MeV20 Ne8+ 离子和5.0 MeV84 Kr19+ 离子辐照GaN样品的实验, 并对实验样品进行了HRXRD的分析。结果发现, 随着这两种离子辐照剂量的增大, GaN的HRXRD谱（0002）衍射峰的峰位出现了向小角侧有规律的移动, 并在较高剂量时衍射峰发生分裂。同时, 对衍射峰的峰位的移动和峰形的变化等现象反映的辐照损伤机制进行了研究, 并探讨了电子能损与核能损各自在晶格损伤中的作用。Irradiation experiments of gallium nitride (GaN) with 2.3 MeV20 Ne8+ and 5.0 MeV84 Kr19+ respectively were performed. The irradiated samples were analyzed using the high\|resolution X\|ray diffraction (HRXRD) spectrometry. It was found that the diffraction peak of GaN (0001) exhibited regular shift to smaller diffraction angles with the increase of ion fluence for the both ions, and the diffraction peak split into a few sub\|peaks at higher irradiation dose. Underlying mechanisms of the observed peak shift and split were investigated, the contributions of different energy losses to the damage accumulation in the irradiated GaN were discussed.     

堆内构件用不锈钢辐照加速应力腐蚀开裂研究进展

 针对核电站堆内构件用不锈钢的辐照加速应力腐蚀开裂（IASCC）问题,分析了发生IASCC 的可能机制,论述了进行IASCC 模拟研究的方法,提出了缓解IASCC 的具体措施。辐照诱导偏析引起的晶界Cr 贫化、辐照硬化与辐照形变是发生IASCC 的可能机制;带电粒子辐照、敏化处理和多尺度模拟是反应堆堆内构件用不锈钢IASCC 研究的主要模拟方法;化学元素控制、微结构处理、应力水平控制与水化学成分控制是缓解不锈钢IASCC 的重要措施。     

Kr离子注入SiC的拉曼光谱研究

应用拉曼光谱研究了5 MeV Kr离子（注量分别为5×1013,2×1014,1×1015 ions/cm2）室温注入6H SiC单晶及其高温退火处理后结构的变化。 研究表明, 注入样品的拉曼光谱中不仅出现了Si—C振动的散射峰, 还产生了同核Si—Si键和C—C键散射峰。 Si—C散射峰强度随退火温度升高而增强, 当退火温度高达1000 ℃时, 已接近未辐照SiC的散射峰强度。晶体Si—Si键散射峰强度随退火温度变化不大, 而非晶Si—Si键散射峰强度随退火温度的增加逐渐消失。相对拉曼强度（Relative Raman Intensity, 简称RRI）随注量的增加逐渐减小并趋于饱和, 且不同退火温度样品的饱和注量不相同; RRI随退火温度的增加逐渐升高, 这在低注量样品中表现得尤为明显。 低、中、高3种注量样品的RRI随退火温度的增加从重合逐渐分离, 并且退火温度越高, 分离越大。 Raman spectroscopy was used to study the structure changes of 6H SiC single crystal implanted with 5 MeV Kr (Krypton) at room temperature and subsequently annealed at high temperature. The Raman spectrum of the implanted SiC displays not only Si—C bonds vibration peaks, but also homonuclear Si—Si and C—C bond vibration peaks. Si—C bond vibration peaks gradually strengthen with increasing temperature. When annealing at 1000 ℃, the peak intensity of Raman spectrum is close to that of virgin specimen. It is found that crystal Si—Si bond vibration peaks do not change when annealing, but amorphous Si—Si bond vibration peaks disappear with increasing annealing temperature. The Relative Raman Intensity (RRI) values decrease with increasing fluence and tend to saturate, but the saturation fluences is different for various anneal temperature. The RRI values increases with raising annealing temperature, which is more obvious in low implanted specimens. At the same time, the RRI values separate gradually with increasing temperature and this phenomenon is strengthened by annealing temperature.     

反应堆压力容器钢辐照硬化脆化的中子注量率效应

 针对中子注量率对核电站反应堆压力容器(RPV)钢辐照硬化脆化的影响,总结了不同铜含量RPV 钢的辐照硬化脆化的中子注量率效应.结果表明,在低铜(Cu≤0.08%)和高铜(Cu>0.08%)RPV 钢中,中子注量率对辐照硬化脆化有不同的作用结果.在中子注量率≤1×10¹² n·cm^-2·s^-1(E>1 MeV)的条件下,中子注量率对低铜RPV 钢辐照硬化脆化无明显影响,在>1×10¹²n·cm^-2·s^-1(E>1 MeV)的条件下,尚无确定结论;高铜RPV 钢辐照至富铜团簇硬化平台后,注量率对硬化脆化无影响,而达到辐照硬化平台之前,注量率对辐照硬化脆化有不同影响.