氢负离子在磁场和电介质表面附近光剥离的研究

摘要

Using the closed orbit theory,we study the photo-detachment of H~- in a magnetic field near a dielectric surface.The photodetachment cross section of this system is also derived and calculated.It is found that the photo-detachment cross section is not only related to the magnetic field strength,but also depends on the dielectric constant.For a given ion-surface distance and dielectric constant,with the increase of the magnetic field strength,the number of the closed orbits increases greatly and the oscillatory structure in the photo-detachment cross section becomes much more complicated.On the other hand,for a given magnetic field strength,the dielectric constant also has a great influence on the photo-detachment process of negative ion.Above the ionization threshold,the photo-detachment cross section becomes oscillatory.With the increase of the dielectric constant,the oscillatory structure in the crosssection becomes much more complicated.Therefore we can control the photo-detachment of negative ion by changing the magnetic field strength and the dielectric constant.This study provides a new understanding of the photo-detachment process of negative ion in the presence of external fields and surfaces.%利用闭合轨道理论,研究了变化的磁场和不同电介质表面对氢负离子光剥离截面的影响,并推导出了该体系下的光剥离截面公式.结果发现,氢负离子的光剥离截面不仅与磁场的强度有关,而且还与电介质常数有关.当氢负离子到电介质表面的距离和电介质常数一定时,体系的光剥离截面中的振荡随磁场的变化而明显变化.随着磁场强度的增大,体系的闭合轨道数目增多,光剥离截面的振荡越来越复杂.当氢负离子到电介质表面的距离和磁场强度一定时,电介质常数的变化对光剥离截面的影响也很重要,随着电介质常数的增大,体系的闭合轨道数目增多,光剥离截面的振荡也变得越来越复杂.因此,可以通过改变磁场强度和电解质常数来调整负离子的光剥离截面.此结果对于研究负离子体系在表面附近和外场中的光剥离问题具有一定的参考价值.