C 6+ -impact ionization of helium in the perpendicular plane: Ionization to the ground state, excitation-ionization, and relativistic effects
C 6+ -impact ionization of helium in the perpendicular plane: Ionization to the ground state, excitation-ionization, and relativistic effects
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C 6 -氦在垂直平面内的碰撞电离：电离到基态、激发电离和相对论效应
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发表时间：
2010
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通讯作者：
H. Walters
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作者：
M. McGovern;C. Whelan;H. Walters
在寻找理论和实验之间的差异在垂直平面几何的C{sup 6+}电离的He在100 MeV/amu，我们已经使用第一和第二玻恩近似检查电离到激发态He{sup +}是否可能是显着的，相对论效应是否可能是重要的，是否有实质性的灵敏度的He波函数在计算中使用。我们找不到对这种差异的任何解释。在这三种可能性中，只有相对论效应被证明是重要的，但只是在改变横截面的整体归一化方面，而不是在改变其形状方面，这是与实验一致的先决条件。第二玻恩计算与先前的碰撞参数耦合赝态结果[Phys.Rev.A81，042704（2010）]非常雅阁，并且再次证实，靶核对抛射体的弹性散射不能解释这种差异。计算扩展到2 MeV/amu的较低的冲击能量。在这里，在垂直平面的几何形状，电离激发他{sup +}状态变得显着，我们发现一个有趣的“振荡”结构中的基态和激发态的横截面。与一些相关的实验数据进行比较，更多的是，尽管一致性很差，可能是因为需要包括实验分辨率，但数据中存在细微差别，反映了计算中的结构。«少
In search of the discrepancy between theory and experiment in perpendicular plane geometry for C{sup 6+} ionization of He at 100 MeV/amu, we have used the first and second Born approximations to examine whether ionization to an excited He{sup +} state could be significant, whether relativistic effects could be important, and whether there is substantive sensitivity to the He wave functions used in the calculations. We fail to find any explanation of the discrepancy. Of the three possibilities, only relativistic effects turn out to be significant but then only in changing the overall normalization of the cross section, not in changing its shape, which is a prerequisite to getting agreement with experiment. The second Born calculations are in excellent accord with previous impact parameter coupled pseudostate results [Phys. Rev. A 81, 042704 (2010)] and confirm, yet again, that elastic scattering of the projectile by the target nucleus cannot explain the discrepancy. The calculations are extended to the lower impact energy of 2 MeV/amu. Here, in perpendicular plane geometry, ionization to excited He{sup +} states becomes significant and we find an interesting 'oscillatory' structure in both the ground- and excited-state cross sections. Comparison is made with some relative experimental data and,more » although the agreement is poor, possibly because of the need to include experimental resolutions, there are nuances in the data that mirror the structures in the calculations.« less