低能电子碰撞He^+(e,2e)反应绝对三重微分截面的理论研究

A THEORETICAL STUDY ON ABSOLUTE TRIPLE DIFFERENTIAL CROSS SECTIONS FOR NEAR THRESHOLD He +(e,2e) REACTIONS

利用Ｂｅｒａｋｄａｒ和Ｂｒｉｇｇｓ对ＢＢＫ波函数Ｓｏｍｍｅｒｆｅｌｄ参数的修正结果，即考虑第三个粒子存在对两个粒子间相互作用的影响，考虑了入射道的库仑相互作用及出射粒子的交换对称性，计算了在共面等能分配几何情况下低能电子碰撞Ｈｅ＋（ｅ，２ｅ）反应绝对三重微分截面．结果表明，入射道库仑场对较低的入射能量及小的碰撞参数的三重微分截面影响较大．

Abstract  A correlated three body continuum wave function proposed by Brauner et al . has recently been modified further to allow for the three body effects by introducing Sommerfeld parameters (Berakdar and Briggs),it is used to calculate the triple differential cross sections for electron impact ionization of He + in coplanar equal energy sharing and symmetric geometry. The initial channel wave function involves a Coulomb wave function due to the long range Coulomb attraction between the incident electron and the screened ionic nucleus. Since the present work deals with symmetric collisions, the electron exchang effect between the two continuum electrons has been taken into account properly. It is shown that the initial channel Coulomb field play a major role in determining the triple differential cross sections at near threshold incident energy and small impact parameter values. 