Department of Physics, D. J. College, Baraut (Baghpat), UP, India, 250611.
Rapid Commun Mass Spectrom. 2013 Jan 15;27(1):223-37. doi: 10.1002/rcm.6433.
Electron collision with methyl halides CH(3)X (X = F, Cl, Br) plays an important role in various atmospheric and plasma modelling processes. The gaseous methyl halides are harmful to the troposphere and the stratospheric ozone layer. Knowledge of the ionization cross sections and ionization rate coefficients of the free gaseous halides is therefore desirable in the study of these processes.
The partial single and double differential cross-sections with the integral ionization cross-sections of the gaseous halides by electron collision were calculated using a modified Jain-Khare semi-empirical approach. The ionization rate coefficients corresponding to partial ionization cross-sections were calculated by the Maxwell-Boltzmann distribution of energy.
The Jain-Khare formalism has different approaches for the evaluation of single differential, double differential and integral ionization cross-sections. The partial single differential cross-sections as a function of energy loss (sum of ionization threshold and the secondary electron energy) suffered by the incident electron were calculated at incident electron energies of 100 and 200 eV. The double differential cross-sections were computed at the same electron energies and scattering angles of 30° and 60°. The behavior of double differential cross-sections with scattering angles from 0° to 180° at constant secondary electron energies of 10 and 20 eV and fixed primary electron energies 100 and 200 eV was also calculated. The partial and total (sum of all partial cross-sections) integral ionization cross-sections were evaluated from the ionization threshold to 1000 eV.
The applied formalism is useful for the calculation of partial and total integral/or differential cross-sections at low energies. The integral ionization cross-sections showed good agreement with available experimental/or theoretical data. The data obtained for these compounds were not previously available, so the results will be of value to the experimental and theoretical community concerned with plasma and atmospheric processes.
电子与甲基卤化物 CH(3)X（X = F、Cl、Br）的碰撞在各种大气和等离子体建模过程中起着重要作用。气态甲基卤化物对对流层和平流层臭氧层有害。因此，在研究这些过程时，需要了解游离气态卤化物的电离截面和电离率系数。
使用改进的 Jain-Khare 半经验方法计算了电子碰撞气态卤化物的部分单微分和双微分截面以及积分电离截面。通过能量的麦克斯韦-玻尔兹曼分布计算了对应于部分电离截面的电离率系数。
Jain-Khare 形式主义有不同的方法来评估单微分、双微分和积分电离截面。在入射电子能量为 100 和 200 eV 时，计算了作为入射电子能量损失（电离阈值和二次电子能量之和）函数的部分单微分截面。在相同的电子能量和散射角 30°和 60°下计算了双微分截面。还计算了在固定二次电子能量为 10 和 20 eV 且固定初级电子能量为 100 和 200 eV 时，从 0°到 180°的双微分截面随散射角的变化。还从电离阈值到 1000 eV 评估了部分和总（所有部分截面之和）积分电离截面。
所应用的形式主义在低能下计算部分和总积分/微分截面是有用的。积分电离截面与现有的实验/理论数据吻合较好。这些化合物的数据以前没有，因此结果将对与等离子体和大气过程有关的实验和理论界具有价值。
