利用最新发展起来的适用于低能电子入射的反应显微成像谱仪,对电子轰击He原子近阈值的双电离过程进行了研究,实验测量了反应后4个粒子的全部动量,获得了五重微分截面及出射粒子间的关联信息。着重分析了在入射电子束与出射电子构成的平面内,3个均分系统剩余能量的电子出射角关联关系,并与理论计算进行了比较。研究表明,当两个电子反向出射时,第3个电子垂直于这两个电子动量方向出射的几率最大。在1个电子垂直于平面出射时,通过理论计算结果与平面内出射角分布的比较,发现DS6C理论能够较好地描述实验结果。
An experiment on near threshold double ionization of helium impacted with 106 eV electron has been performed by using the newest developed reaction microscope.In this experiment the momenta of all products after double ionization of helium were measured and the five fold differential cross section was obtained for emitted electrons.The angular correlation between the emitted electrons,which equally shared the excess energy,was analyzed in the plane defined by the projectile and the first detected electron.The experimental result was compared with different theoretical calculations.It was found that DS6C model described the experimental reasonably.