Calculated electron impact ionisation fragmentation patterns
Calculated electron impact ionisation fragmentation patterns
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DOI：
10.1088/1361-6455/ac42db
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发表时间：
2021-12-08
影响因子：
1.6
通讯作者：
Tennyson, Jonathan
中科院分区：
文献类型：
--
作者：
Graves, Vincent;Cooper, Bridgette;Tennyson, Jonathan
总电子碰撞电离截面有许多测量和计算。然而，许多应用，特别是在等离子体物理学中，也需要碎片模式。推导部分横截面的近似方法是基于使用在常用的二元遇到 Bethe 近似中计算的总横截面进行测试的。 CH4、CF4、CCl4 等三个系列分子的部分电离截面； SiH4 和 SiCl4； NH3 和 PH3 使用两种方法进行估算。方法一是半经验方法，使用质谱数据将部分横截面固定在单个电子能量处。第二种是 Huber 等人提出的完全计算方法（2019 J. Chem. Phys. 150 024306）。与实验结果比较表明，质谱法更为准确。然而，由于 Huber 方法不需要实验输入，因此当没有实验数据可用时，该方法可以用作第一近似值。由于质谱有时提供不完整的数据集，因此还探索了基于两种方法的混合方法。
There are many measurements and calculations of total electron impact ionisation cross sections. However, many applications, particularly in plasma physics, also require fragmentation patterns. Approximate methods of deducing partial cross sections are tested based on the use of total cross section computed within the well-used binary encounter Bethe approximation. Partial ionisation cross sections for three series of molecules including CH4, CF4 and CCl4; SiH4 and SiCl4; NH3 and PH3, were estimated using two methods. Method one is semi-empirical and uses mass spectroscopy data to fix the partial cross sections at a single electron energy. The second is a fully computational method proposed by Huber et al (2019 J. Chem. Phys. 150 024306). Comparisons with experimental results suggest that the mass spectroscopy method is more accurate. However, as Huber's method requires no experimental input, this method could be used as a first approximation when no experimental data is available. As mass spectroscopy sometimes provides incomplete datasets, a hybrid method based on the use of both methods is also explored.