Double ionization of atoms by electrons

Abstract

General analytical cross sections are derived from first principles, using the classical binary encounter approximation, for electron-impact double ionization of atoms with atomic number Z20 and s or d outer shells with two electrons. The cross sections are compared with their measured values for the ionization of Ca(Z = 20), Sr(Z = 38), Ba(Z = 56), and Hg(Z = 80) atoms in their ground states.

Single and double ionization of magnesium by electron impact: A classical study

“…By examining a large set of double ionizing trajectories associated with Hamiltonian (3), only two distinct double ionization mechanisms have been identified in agreement with the literature: The two-step one interaction (TS1) and two-step two interaction (TS2) mechanisms [30][31][32][33]. Figure 9 represents the TS1 mechanism.…”

Application of Binary Encounter Approximation and Electron Impact on Ionization of Atoms

“…According to the idea suggested by Gryzinski and Kune [2], the double ionization of an atomic target by projectile may proceed via two alternative processes.…”

“…The process of electron-impact double ionization of atoms (  e + X =3  e + X 2+ ) is very difficult to describe theoretically since the interaction of the incident electron with the atomic electrons has a collective character. Gryzinski and Kune [2] presented a general model of electron-impact double ionization of atoms that have atomic numbers 20  Z . He derived general expression for electron impact double ionization cross sections of atoms using the formalism of the binary encounter approach.…”

Single and double ionization of gallium by electron impact

“…As a consequence of this, semiempirical and semiclassical approaches have emerged for calculation of double ionization cross sections [4,[14][15][16]. Recently Gryzinski and Kunc [17] using classical binary encounter approximation derived general analytical expressions for electron impact double ionization cross sections of atoms with atomic number Z ² 20 and s or d outer shells with two electrons. They compared their calculations only with experimental data for Ca, Sr, Ba and Hg atoms.…”

“…In these calculations Hartree-Fock and hydrogenic velocity distributions were used while considering the ejection of the first and the second target electrons respectively. Gryzinski and Kunc [17] have given a discussion on the works of Roy and co-workers [22,24] in detail and pointed out their strengths and weaknesses. They have appreciated the consideration of the contributions of the p electrons from the next inner shell to double ionization of Sr and Ba atoms, prediction of acceptable magnitudes of the cross section of double ionization and the appearance of the secondary peak in the cross section.…”