银辐射损伤的扰动角关联研究

Study of radiation damage in Ag by perturbed angular correlation

采用时间微分扰动角关联方法研究了由^(109)Ag(α;2n)反应产生的反冲核^(111)In在银中产生的辐射损伤及其退火现象和治愈效应。反冲核在银中产生单空位,实验观察到频率为76.2MHz的恒定的四极相互作用;经673K退火,恒定的四极相互作用消失,作用在探针核上的只是远处缺陷产生的电场梯度分布;经873K退火,辐射损伤全部消失。银中辐射损伤与治愈时间关系测量表明,经360h治愈,探针核仍直接捕获缺陷,但相对成分减小到1/3.5;电场梯度分布宽度随治愈时间增长而减小,150h后,不随治愈时间而变。治愈主要发生在辐照后2—10d。

The time differential perturbed angular correlation method has been used to study the radiation damage in Ag and its annealing behaviour and healing effect. Monovacancies were created by 111In recoils from the reaction 109Ag(α,2n)111In. A unique quadrupole interaction with a sharp frequency of 76.2MHz was observed following the nuclear reaction. After annealing at 673K the unique quadrupole interaction disappeared and the probe nuclei experinced only an interaction of electric field gradient distribution which was caused by distant defects. The radiation damage was completely annealed at 873 K. The dependence of radiation damage on healing time shows that the probe nuclei still trap defects after 15 day healing but with a reduction of a factor of 3.5. The width of electric field gradient distribution decreases with increasing healing time and becomes independent of healing time after 6 day healing. Healing mainly takes place in 2 to 10 days after irradiation.