CLASSICAL CROSS SECTIONS FOR IONIZATION OF HYDROGEN ATOMS BY ELECTRONS.
CLASSICAL CROSS SECTIONS FOR IONIZATION OF HYDROGEN ATOMS BY ELECTRONS.
复制标题
电子电离氢原子的经典截面。
DOI：
10.1088/0370-1328/89/3/307
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发表时间：
1966
期刊：
影响因子：
56.9
通讯作者：
N. A. Valentine
中科院分区：
文献类型：
--
作者：
R. Abrines;I C Percival;N. A. Valentine
用经典的蒙特卡罗方法计算了12个能量E介于阈值和540 eV之间的电子对氢原子基态的电离截面。当E=435 eV时，统计误差约为5%，并且随着截面向阈值方向减小，误差变得相对较大，但E=34 eV的计算范围更广。高能时的截面比实验的要小，低能时的截面比实验的要大，这比经典的脉冲近似有了显著的改进。实验和蒙特卡罗的截面在大约60 eV处是一致的。当经典理论更好时，截面和能量被按比例调整，以便它们适用于最初处于激发能级的原子。截面与束缚电子的初始角动量Li无关，只是略有偏向高Li，特别是在较大的修正碰撞参数下。将ΔE传递到束缚电子的能量分布与Vriens的经典脉冲近似和Born近似进行了比较。经典的脉冲近似对激发的价值不大。
Classical Monte Carlo cross sections are obtained for the ionization from the ground level of the hydrogen atom by electrons with twelve energies E between threshold and 540 ev. Statistical errors are about 5% down to E = 43 5 ev, and become relatively larger as the cross section decreases towards the threshold, with the exception of E = 34 ev, where the calculations are more extensive. Cross sections are less than experiment at high energies, and greater at low energies, where there is a marked improvement on classical impulse approximations. Experiment and Monte Carlo cross sections agree at approximately 60 ev. The cross sections and energies are scaled so that they apply to atoms which are initially in excited levels, when the classical theory is better. The cross section is independent of the initial angular momentum li of the bound electron, except for a slight bias towards high li, especially at large modified impact parameter. The distribution of energy ΔE transferred to the bound electron is compared with Vriens' classical impulse approximation and the Born approximation. The classical impulse approximation is of little value for excitation.