MOLECULAR ELECTRON IONIZATION CROSS SECTIONS AT 70-EV
MOLECULAR ELECTRON IONIZATION CROSS SECTIONS AT 70-EV
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DOI：
10.1021/j100845a050
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发表时间：
1969-01-01
影响因子：
--
通讯作者：
KEVAN, L
中科院分区：
文献类型：
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作者：
BERAN, JA;KEVAN, L
原子和分子的电子电离截面对于辐射化学数据的评估、离子-分子反应的质谱研究和热力学测量以及等离子体和空间物理学都具有重要意义。它们也构成了有关电子碰撞的基本问题之一。在电子电离截面的实验和理论方面都有大量的工作。电子电离截面随着阈值能量的增加而迅速增加，通常在50 ~ 80 eV之间达到平坦的最大值，在更高的能量下下降缓慢。在高电子动能（bbb1kev）下，截面的实验能量依赖性与基于玻恩近似的简单理论有很好的一致性。2然而，在实验中，横截面对分子结构的依赖性在理论上并没有得到满意的预测。在与质谱和辐射化学研究相关的较低电子能量（70 eV）下，理论甚至更多
Electron ionization cross sections for atoms and molecules are of importance for evaluation of radiation chem-ical data, for mass spectrometric studies of ion-molecule reactions and thermodynamic measurements, and for plasma and space physics. They also constitute one of the fundamental problems concerning electron impact collisions. There has been considerable work on both the experimental and theoretical aspects of electron ionization cross sections. Electron ionization cross sec-tions increase rather rapidly with energy from thresh-old, reach a flat maximum usually between 50 and 80 eV, and decrease slowly at higher energies. At high electron kinetic energy (> 1 keV) there is good agree-ment between the experimental energydependence of the cross section and simpletheory based on the Born approximation. 2 However, the experimental depen-dence of cross section on molecular structure is not sat-isfactorily predicted by theory. At lowerelectron en-ergies which are relevant to mass spectrometric and ra-diation chemical studies (70 eV) the theory is even more