双阱-集团壳模型中的质心运动伪态

本文指出了用微观双阱-集团壳模型来研究裂变和重离子反应过程中存在着质心运动伪态问题,推出了分解质心运动伪态波函数的一般表达式,并以Be⁸(α-α)为例,说明了伪态的存在,定量地计算了伪态成分以及它对能量矩阵元的修正。通过Be⁸核的分析,我们得到的结论是:虽然伪态成分仅占百分之几,但对于微观裂变位垒修正是很明显的,它甚至要超过库仑能对位垒的修正,因此在精确的定量计算中质心运动伪态是必须要考虑的。尤其是在核粒子数增多以及包含高激发态时,质心运动伪态更需仔细考虑。

SPURIOUS STATES OF MOTION OF THE CENTER OF MASS IN THE DOUBLE WELL-CLUSTER SHELL MODEL

In this paper we use the microscopic "double well-cluster shell model" to discuss the existence of spurious states of motion of the center of mass during nuclear fission and heavy ion reactions. We outline the derivation of the general formulae with which the ,wave functions of the motion of the center of mass can be separated. Taking Be⁸ as an example, the existence of the spurious states is illustrated, and the components of these states and their corrections to the energy matrix elements are quantitatively evaluated.Through the analysis of the results of Be⁸ mentioned above, we conclude: although the propartion of the spurious states is only several per cent, their corrections to the fission barrier are significant, even larger then the corrections due to coulomb energy, and it is necessary to take them into account in accurate quantitative calculations. For a heavier nucleus, or higher excited states, the spurious states of the motion of the center of mass should be considered in more detail.