50—5000eV电子被C_4H_8O,C_5H_(10)O_2,C_6H_5CH_3和C_4H_8O_2散射的总截面  

Total cross sections of electron scattering by large molecules C_4H_8O,C_5H_(10)O_2,C_6H_5CH_3 and C_4H_8O_2 at 50—5000 eV

作　　者：施德恒[1,2] 孙金锋[2] 刘玉芳[2] 朱遵略[2] 马恒[2] 

机构地区：[1]信阳师范学院物理电子工程学院,信阳464000 [2]河南师范大学物理与信息工程学院,新乡453007

出　　处：《物理学报》2008年第12期7612-7618,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:10574039);河南省高校科技创新人才支持计划(批准号:2008HASTIT008)资助的课题~~

摘　　要：使用电子被C,H和O原子散射总截面的实验数据,利用修正后的可加性规则计算了能量为50—5000eV的电子被4个复杂大分子C4H8O,C5H10O2,C6H5CH3和C4H8O2散射的总截面,并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,即使是在几十电子伏的入射能量下,修正后的可加性规则计算出的总截面依然能与实验结果符合很好,而使用未修正的可加性规则进行计算,即使是在几百电子伏的入射能量下得到的总截面仍偏离实验值较远.分析表明,未修正的可加性规则计算得到的总截面在中低能区过大、随电子入射能量的增加而衰减太快的问题是由可加性规则本身引起的,其实质是未考虑低能下分子内原子间的相互屏蔽对散射总截面的计算所带来的影响.Using the modified additivity rule （AR） approach, the total cross sections （TCSs） for electron scattering by large molecules C4H8O,C5H10O2,C6H5CH3 and C4H8O2 are calculated over a wide energy range from 50 to 5000 eV by employing the experimental TCS results of electron scattering from atoms C, H and O. Here the atomic TCSs are derived from the experimental TCS results of simple molecules （H2 , O2 , CO）. The quantitative TCSs are compared with those obtained by measurements and other theories wherever available. It is shown that there is excellent accordance between the theories obtained by the modified AR approach and the measurements even at energies of several tens of eV. And it is also shown that the problem that the log-log TCS curves obtained by the original AR approach are steeper than those obtained by the experiments, is introduced by the AR model itself. The intrinsic reason is that the mutual screening effects are not taken into consideration in the original AR approach at lower energies.

关 键 词：电子散射 可加性规则 总截面 几何屏蔽效应 

分 类 号：O562.5[理学—原子与分子物理]