中高能电子被甲烷及氯代甲烷散射的总截面

Total cross sections for the scattering of electrons from methane and chloromethanes at intermediate and high energies

利用可加性规则 ,使用Hartree_Fock波函数 ,采用由束缚原子概念修正过的复光学势 (由静电势、交换势、修正极化势及吸收势这四部分组成 ) ,在较大的能量 (30— 5 0 0 0eV)范围内对电子被甲烷及氯代甲烷 (CH4 ,CCl4 ,CHCl3,CH2 Cl2 和CH3Cl)散射的总截面进行了计算 ,且将计算结果与实验结果及其他理论计算结果进行了比较 .结果表明 ,利用被束缚原子概念修正过的复光学势及可加性规则进行计算 ,所得结果的精度要比利用未被束缚原子概念修正的复光学势及可加性规则进行计算得到的结果好很多 .因此 ,在复光学势中采用束缚原子概念可提高电子被分子散射的总截面的计算准确度 .

A complex optical model potential modified by incorporating the concept of bonded atom, which takes into consideration the overlapping effect of electron clouds between two atoms in a molecule, is employed to calculate the total cross sections for electron scattering from methane and chloromethanes(CH4, CCl4, CHCl3, CH2 Cl2 and CH3 Cl) over the incident energy range 30-5000eV by using additivity rule model at Hartree-Fock level. In the study, the complex optical model potential composed of static, exchange, correlation polarization plus absorption contributions uses the bonded-atom concept. The quantitative molecular total cross-section results are compared with the experimental data and other calculation results wherever available, and good agreement is obtained. It is shown that the additivity rule model together with the complex optical potential model modified by incorporating the concept of bonded atom can give better results than that unmodified. So, the introduction of the bonded-atom concept in the complex optical model potential improves the accuracy of the total cross-section calculation results of electrons from molecules.