Huygens–Fresnel picture for electron-molecule elastic scattering
Huygens–Fresnel picture for electron-molecule elastic scattering
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电子-分子弹性散射的惠更斯-菲涅尔图
DOI：
10.1140/epjd/e2017-80421-2
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
A. Msezane
中科院分区：
文献类型：
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作者：
A. Baltenkov;A. Msezane
在非重叠原子势模型的框架下，计算了慢电子与C2和H2分子的弹性散射截面。对于多个电子被靶散射的振幅，分子连续谱的波函数被表示为一个平面波和两个由原子球中心产生的球面波的组合。该波函数遵循惠更斯-菲涅耳原理，根据该原理，由两个中心的系统散射的电子波伴随着两个球面波的产生;它们的相互作用产生远离目标的衍射图案。每一个惠更斯波又是具有不同轨道角动量和投影的部分球面波的叠加。这些分波的振幅由电子被孤立原子势弹性散射的相应相位定义。在数值计算中，考虑了相位偏移和相位偏移。因此，干涉电子波的数目等于8：其中两个是这些型波，其余6个波是具有不同m值的p型波。在封闭形式（而不是在S-矩阵展开的形式）的散射振幅的计算减少到解决一个系统的八个非齐次代数方程。计算了电子被空间固定分子和随机取向分子散射的微分截面和总截面。最后，我们讨论了任意非球势情形下S矩阵方法的特殊性。图形摘要
AbstractThe elastic scattering cross sections for a slow electron by C2and H2molecules have been calculated within the framework of the non-overlapping atomic potential model. For the amplitudes of the multiple electron scattering by a target the wave function of the molecular continuum is represented as a combination of a plane wave and two spherical waves generated by the centers of atomic spheres. This wave function obeys the Huygens–Fresnel principle according to which the electron wave scattering by a system of two centers is accompanied by generation of two spherical waves; their interaction creates a diffraction pattern far from the target. Each of the Huygens waves, in turn, is a superposition of the partial spherical waves with different orbital angular momentaland their projectionsm. The amplitudes of these partial waves are defined by the corresponding phases of electron elastic scattering by an isolated atomic potential. In numerical calculations thes- andp-phase shifts are taken into account. So the number of interfering electron waves is equal to eight: two of which are thes-type waves and the remaining six waves are of thep-type with differentmvalues. The calculation of the scattering amplitudes in closed form (rather than in the form of S-matrix expansion) is reduced to solving a system of eight inhomogeneous algebraic equations. The differential and total cross sections of electron scattering by fixed-in-space molecules and randomly oriented ones have been calculated as well. We conclude by discussing the special features of the S-matrix method for the case of arbitrary non-spherical potentials.Graphical abstract