C. Belenger et al., DOUBLE-IONIZATION OF NEUTRAL ATOMS, POSITIVE AND NEGATIVE-IONS BY ELECTRON-IMPACT, Journal of physics. B, Atomic molecular and optical physics, 30(11), 1997, pp. 2667-2679
New experimental data on double-ionization cross sections of neutral a
toms, positive and negative ions by electron impact are reported. Thes
e and other relevant data are compared with recent multiple-ionization
semiempirical formulae extended for the case of two-electron ionizati
on. Theory gives analytical dependence of the double-ionization cross
sections on the main parameters of the collision system in a wide ener
gy range. Far the He atom, He-like ions and H- ion high-energy asympto
tic behaviour of the double-ionization cross sections are considered o
n the basis of a quantum mechanical treatment. Suggested cross section
scaling for fast collisions, employing a target-effective nuclear cha
rge, is in good agreement with experimental data.