高能氩离子辐照SiO2玻璃的正电子寿命谱学研究
고능아리자복조SiO2파리적정전자수명보학연구
Positron lifetime study of SiO2 glass irradiated with high energy Ar ions
  • 万方数据
    核技术 핵기술
    NUCLEAR TECHNIQUES
    2001年 6期 439-444 ,共6页

    朱智勇%孙友梅%金运范%李长林%侯明东%刘昌龙%张崇宏%孟庆华%王志光%陈克勤%鲁光军

    주지용%손우매%금운범%리장림%후명동%류창룡%장숭굉%맹경화%왕지광%진극근%로광군

    二氧化硅玻璃%氩离子辐照%正电子寿命%微观结构 二氧化硅玻璃%氬離子輻照%正電子壽命%微觀結構
    이양화규파리%아리자복조%정전자수명%미관결구
    用1.15GeV的氩离子在室温下对二氧化硅玻璃样品进行了辐照，并通过正电子寿命测量技术研究了辐照后材料微观结构的变化。结果表明，在未辐照二氧化硅玻璃中有近81%的正电子是以正电子素的形式湮灭的；根据o-Ps的撞击湮灭寿命确定出未辐照样品的自由体积分布在0.02—0.13nm3的区域里，平均自由体积半径约为2.5nm。辐照后材料的自由体积分布函数变窄，峰位下移，显示样品经辐照后有密度增大的现象。随着剂量的增大，第二正电子寿命成分的强度逐渐增加，而相应于o-Ps的寿命成分的强度逐渐减小，这被认为是由于辐照产生的电离电子在自由体积中漫游，使正电子与这些漫游电子发生湮灭的几率增大，从而减小了正电子素的形成几率。
    용1.15GeV적아리자재실온하대이양화규파리양품진행료복조，병통과정전자수명측량기술연구료복조후재료미관결구적변화。결과표명，재미복조이양화규파리중유근81%적정전자시이정전자소적형식인멸적；근거o-Ps적당격인멸수명학정출미복조양품적자유체적분포재0.02—0.13nm3적구역리，평균자유체적반경약위2.5nm。복조후재료적자유체적분포함수변착，봉위하이，현시양품경복조후유밀도증대적현상。수착제량적증대，제이정전자수명성분적강도축점증가，이상응우o-Ps적수명성분적강도축점감소，저피인위시유우복조산생적전리전자재자유체적중만유，사정전자여저사만유전자발생인멸적궤솔증대，종이감소료정전자소적형성궤솔。
    SiO2 glass specimens were irradiated with 1.15GeV Ar ions at room temperature.Positron lifetime spectroscopy was applied to investigate the radiation induced microscopic changes.It was found that for the unirradiated specimen about 81% positrons annihilate from positronium (Ps) states.Free volumes of about 2.5nm in radius and distributed from 0.02—0.13nm3 are found from the o-Ps lifetime.Under irradiation the free volume distribution function narrows down and the peak position shifts to lower value,which indicate the densification of the material.With increasing dose,the intensity of the second lifetime component increases whereas the intensity of the component corresponding to o-Ps decreases.This was attributed to the prefered annihilation of positrons with the radiation-ionized electrons wandering in free volumes.
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