Electron Impact Ionisation of Metastable 2s-state Hydrogen Atoms

Abstract

The triple differential cross section for ionisation of hydrogen atoms in the metastable 2s-state by electrons of 250 eV incidence energy has been calculated following the multiple scattering theory of Das and Seal (1993). The results are compared with the first Born results and with the results of some other theories. Additional features are noted in the cross section curves of the present calculation. These offer wider scope for the experimental study of ionisation of hydrogen atoms in their metastable states.

The First Born Triple Differential Cross-Section for Ionization of H(3P) by Electron Impact in the Asymmetric Coplanar Geometry

“…In Figure 4 and Figure 5, the present results are exposed with larger magnitude in both recoil and binary regions than the corresponding compared results of 2S and 2P metastable states [17] [20].…”

“…In Figure 6, both present results of metastable 3P and metastable 2P-states [20] results display higher magnitude peak positions than the metastable 2S-state [17] results. But interestingly, with the increase of scattering angle, the present First Born results represent lower magnitude than the metastable 2P-state results [20].…”

“…But in the binary region the opposite peak values of 2S-metastable state [17] are very sharp than the corresponding 2P-state [20] and 3P-state results.…”

“…The ejected electron energy is 1 5 eV E = . Theory: full curve (Green): Present first born result, dash curve (Red): 2P-state first born result [20] and dash dotted curve (Blue): 2S-state first born result [17]. [20] and the present 3P-states hydrogen atoms by electron impact whereas, metastable 2S -state results [17] show dissimilar peak-pattern in recoil region but completely opposite peak pattern in binary region.…”

Energy Spectrum of Ejected Electrons of H(2P) Ionization by Electrons in Coplanar Asymmetric Geometry

“…The theoretical and experimental study in electron atom ionization collision on differential cross sections has become increasingly interesting over four decades for relativistic [1][2][3][4][5] as well as non-relativistic [6][7][8][9][10][11][12][13][14][15][16][17] energies. Various theoretical models applying differential kinematical conditions have been vastly used for experimental measurements.…”