【摘要】 本文计算了氦原子的有效核电荷和慢电子在氦原子场中的畸变波函数,并用单电子波函数和含有关联作用的双电子波函数,分别计算了氦原于对慢电子弹性散射的 S、P、d、f分波相移、分波截面、微分散射截面、散射总截面和动量转移截面。计算中考虑到了入射电子与靶原子间的极化作用和交换作用。计算结果表明,在慢电子散射问题中,极化与交换作用很重要,必须予以考虑。除此以外,靶原子中电子波函数的准确程度对计算结果的影响也很大,也必须注意。利用比较准确的含有关联作用的双电子波函数计算的结果较之用简单的单电子波函数计算的结果有明显的改进,前者与实验结果符合得很好。更多还原

【Abstract】 First, we have calculated total cross-sections and momentum-transfer cross-sections for the scattering of slow electrons by helium atom by simple wave function .However, there is large discrepancy between the calculated results and experimental data at low energies less than 5ev .Hence a further study of the problem with more accurate wave function is quite necessary.By use of the more accurate wave function for helium atomwe have derived the analytic potential function for the incident electron with the helium atom, including the exchange and polarization effects. With the partial wave method, we have further calculated the distorted wave functions, phase shifts, scattering cross-sections and momentum-transfer cross-sections for the slow electrons moving in the atomic field represented by the derived potential function. The numerical results for the scattering cross-sections and momentum-transfer cross-sections arc in good agreement with experiments.From the results of the present calculations, we know that both the polarization and exchange effects are very important for the incident electron with energy lower than 10 ev.The two effects would greatly be lower the cross-section for the slow electrons .Hence in the calculation of cross-sections for the scattering of slow electrons from atoms, both the polarization and exchange effects must be taken into account.更多还原