Collision processes involving heavy many-electron ions interacting with neutral atoms
I.Yu. Tolstikhina a, b
V.P. Shevelko a
a Lebedev Physical Institute, Russian Academy of Sciences, Leninsky prosp. 53, Moscow, 119991, Russian Federation
b Moscow Institute of Physics and Technology (State University), Institutskii per. 9, Dolgoprudnyi, Moscow Region, 141700, Russian Federation
An overview is given of experimental data on and methods for the calculation of effective cross sections for charge-exchange (electron capture) and electron-loss (projectile ionization) processes involving heavy many-electron ions (like Xeq+, Pbq+, Wq+, Uq+) colliding with neutral atoms (H, He, N, Ne, Ar, Kr, Xe) at energies E ranging from low (≈ 10 keV/u) to relativistic (≈ 10 GeV/u). Because these charge-changing processes occur with a high probability (cross-section values reach up to 10−14—10−16 cm2 at the maximum), they strongly influence the kinetics of laboratory and astrophysical plasmas as well as determining ion beam lifetimes in accelerators. The paper also discusses multielectron capture and loss processes which, for heavy projectiles, increase in importance to account for up to and over 50% of the total cross section. Also covered are the influence of the inner-shell electrons of both colliding systems and the role of isotopic effects in the electron capture of very slow (E ≈ 10–100 eV/u) ions on the hydrogen isotopes H, D, and T. A brief description is given of suitable computer programs for calculating electron-capture and electron-loss cross sections for complex atoms and ions over a wide range of collision energies.