Fast-electron-impact ionization process by 3p of hydrogen-like ions in Debye plasmas

Abstract

The plasma screening of fast-electron-impact-ionization by excited state (3p) of Hydrogen-like ions was investigated in the first Born approximation with a plasma screening length δ varying from 1000a0 to 10a0. The generalized oscillator strength densities showed dramatic changes: some accessional minima occurred along with a remarkable enhancement in certain continuum-energy domains. The double-differential cross sections exhibit not only the same structures as the Bethe surface for moderate and large momentum transfers, but also a broadened enhancement for small momentum transfers. The single-differential cross sections exhibit a near-zero-energy-enhancement and prodigious multiple-shape resonances, depending on the continuum energy and the plasma screening length. These features are analogous to those of the photo-ionization cross section. These findings, for both types of cross section, can be explained by processes associated with continuum electrons, as long as the potential has a short-range character.

Review of quantum collision dynamics in Debye plasmas

“…al. [30,31] also studied the fast-electron-impact ionization process of hydrogen-like ions in Debye plasmas. They considered the single differential ionization cross sections (SDCS) of hydrogen-like ions in their 2s and 2p initial states and focused on the low energy spectrum of ejected electrons.…”

“…For the three-body systems in Debye plasmas, significant attention has been paid to the screening effects on the resonant states (such as doubly excited states in two electron atomic systems or resonances in electron-atom scattering). These states play very important roles in the threshold electron dynamics, resulting in the dramatic changes of the threshold photoionization [26] and electron-impact excitation [27][28][29] and ionization [30,31]. Ho and his associates have performed systematic and comprehensive investigations of doubly excited states or resonances of the typical three-body systems with the screening potentials, such as the hydrogen negative ion (H -) [32][33][34][35][36], the positronium negative ion (Ps -) [37][38][39][40][41], helium [42][43][44] and helium-like ions [45,46].…”

Resonances in nonrelativistic free-free Gaunt factors with screened Coulomb interaction

“…In closing this section we note that similar resonant structures with the same physics origin have been observed in the cross sections for photoionization of hydrogen-like ions [23,29] and negative hydrogen ion [30], low-energy electron impact excitation of hydrogen atom near the n=2 and n=3 thresholds [31][32][33] and fast-electron impact ionization of hydrogen-like ions [34,35] processes in Debye plasmas.…”

Debye-screening effect on electron-impact excitation of helium-like Al11+ and Fe24+ ions

“…Later, the Debye-screened impact cross sections were calculated for H-like ions by using the Born approximation and close-coupling methods, [7] semiclassical impact-parameter formalism [17] and relativistic distorted-wave (RDW) method, [18] as well as for He-like ions by using the RDW method. [19][20][21] Moreover, the Debyescreening effect on the electron-impact ionization of H-like ions [22] and multielectron Ne 4+ and Au 47+ ions has been studied with the SDH potential. [23] Yoon and Jung [13] have performed a comparison of the Debye-screened behavior between the SDH and NSDH potentials for the EIE process of H-like ions.…”