辐照LiF单晶中色心的正电子寿命谱研究  

Study of color centers in irradiated LiF crystal by positron lifetime technique

作　　者：彭郁卿[1] 郑万辉 张怡萍 包于洪 李胜华[1] 

机构地区：[1]中国科学院上海原子核研究所,上海交通大学

出　　处：《核技术》1996年第12期709-711,共3页Nuclear Techniques

摘　　要：用６０Ｃｏ源的γ射线辐照纯的ＬｉＦ单晶，剂量范围为０．９９×１０３－１．３×１０６Ｇｙ；用快－慢符合系统测量正电子寿命谱；给出了第二寿命成分τ２及其强度差△Ｉ２随照射剂量的变化。结果表明，在剂量Ｄ≤１×１０４Ｇｙ范围内，τ２基本不变，平均值为２９１ｐｓ，△Ｉ２∝Ｄ１／２，与Ｆ心浓度ＮＦ∝Ｄ１／２系相似，表明有△Ｉ２∝ＮＦ；当剂量增加，Ｆ聚集心出现后，τ２变大，Ｉ２增加变慢，直至出现饱和。The pure LiF crystals were irradiated by 60Co γ-ray with irradiated dose in the range from 0.99×103 to 1.38× 106Gy.The positron lifetime spectra were then measured using a fast-slow coincidence system.The second lifetime component τ2and its intensity difference △I2 were presented. When the irradiated dose D<1 ×104Gy,τ2 is essentially unchanged,while the △I2 is directly proportional to D1/2.Therefore △I2∝NF can be derived since the concentration of F-center NF is also directly proportional to D1/2.As the dose increases futher,the τ2 is increased but the increase of △I2 is very slow till saturation.

关 键 词：单晶 色心 正电子寿命 氟化锂 

分 类 号：O773[理学—晶体学]