摘要
把气凝硅胶作为可变能量的电子偶素源,用时间选择γ能谱仪研究电子偶素在氧气中的运动,验证快速电子偶素与氧分子非弹性碰撞发生的态的转换效应,测得在两个阈能附近的截面为2.1×10^(-17)cm^2和6.6×10^(-18)cm^2。研究慢速电子偶素与氧分子弹性碰撞交换电子所致态转换,发现过程的截面与电子偶素平均速广的平方根成反比,这一过程可以提供比较干净的仲态电子偶素源进行其它精密物理实验。
Using a silica aerogel sample with introduced oxygen gas as a variable energy positronium Source,the triplet to singlet conversion of positronium in the elastic and inelastic collisions between positronium atoms and oxygen molecules has been inves- tigated with a time selecting energy spectrometer.We have found that the conversion cross section σ_(0-p)is proportional to■for slow positronium in the elastic coll- isons,where v is the mean velocity of positronium,and for the inelastic processes the cross sections are estimated to be σ_(0-p)= 2.1 × 10^(-17)cm^2 and 6.6 × 10^(-18)cm^2 res- pectively at kinetic energies of positronium near two thresholds.
出处
《高能物理与核物理》
CSCD
北大核心
1990年第4期289-295,共7页
High Energy Physics and Nuclear Physics
基金
国家自然科学基金资助课题
