Excitation of hydrogen atoms in collisions with helium atoms: the role of electron–electron interaction

Abstract

Cross sections for producing H(nl) excited state atoms in H(1s)+He(1s 2 ) collisions are calculated using the CTMC method, at impact energies ranging from 20 eV to 100 keV. The role of the electron correlation is studied. In the first step, the interactions between each pair of the three electrons are neglected. This leads to disagreement of the calculated total cross section for producing H(2l) atoms with previous experimental and theoretical results. In a second step, the electron-electron interaction is taken into account in a rigorous way, that is, in the form of the pure Coulomb potential. To make sure that the He target is stable before the collision, phenomenological potentials for the electron-helium-nucleus interactions that simulate the Heisenberg principle are included in addition to the Coulomb potential. The excitation cross section calculated in the frame of this model is in remarkable agreement with previous data in the range between 200 eV and 5 keV. At other energies, discrepancies are revealed, but only by a factor of less than 2 at high energies. The present results show the decisive role of the electronelectron interaction during collisions. In addition, they demonstrate the ability of classical mechanics to take into account the effects of the electron correlation.

Transverse Momentum Transfer Distributions Following Single Ionization in 3.6 MeV/amu Au53+ + He Collisions: A 4-Body Classical Treatment

“…Unfortunately, a complete four-body description of a collision is difficult to implement using quantum mechanics, due to electron correlation. Nevertheless, since classical mechanics has been proven to be an alternative to quantum mechanics and give excellent qualitative and quantitative results in 4-body ion-atom collisions, at high or low impact energies [14,15], 4-body classical Monte Carlo (4B-CTMC) method was applied in this study to the collision system 3.6 MeV Au 53+ + He to determine q ⊥ distributions d 2 σ SI /dq ⊥ dE e . The advantage of the present method is to treat at the same time single ionization (SI), which is of interest here, and simultaneous target ionization and excitation (IE), according to previous calculations by Fainstein and Gulyás [10].…”

A review on plasma combustion of fuel in internal combustion engines

“…Calculated energy distributions of the H atom electrons following H + He collisions, at projectile energies of 1 and 100 keV 55. …”

Doubly and Triply Differential Cross Sections for Single Ionization of He by Fast Au53+ Using a Multi-Body Quasiclassical Model

“…The pseudo-potential V β H r βi , p βi , where β denotes each nucleus and i the index for each electron, was first introduced in nuclear physics [14] and then adapted for atomic structures [15] as well as ion-atom [16,17] and ion-molecule collisions [18]. Its expression is:…”