Influence of atomic processes on charge states and fractions of fast heavy ions passing through gaseous, solid, and plasma targets
V.P. Shevelkob aMoscow Institute of Physics and Technology (National Research University), Institutskii per. 9, Dolgoprudny, Moscow Region, 141701, Russian Federation bLebedev Physical Institute, Russian Academy of Sciences, Leninsky prosp. 53, Moscow, 119991, Russian Federation
An overview of experimental data and theoretical methods is given for charge-changing processes of ion beams passing through gaseous, solid and plasma targets. The main attention is paid to electron capture and electron loss processes with heavy many-electron ions (like Arq+, Krq+, Pbq+, Wq+, Uq+) at relatively large and relativistic ion energies E = 50 keV/u—50 GeV/u including multi-electron processes which increase the total cross sections up to about 50% and more. A large volume of the paper is devoted to consideration of the stopping power—the main quantity characterizing kinetic energy losses of ions due to interaction with particles in matter. Electron capture of heavy ions on atoms at low energies E < 10 eV/u and arising isotopic effect are briefly discussed. Dynamics of the charge-state fractions and equilibrium mean charges of the ion beams, interacting with media particles, is considered on the basis of the balance rate equations, including creation of equilibrium charge-state fractions and mean charges, equilibrium target thickness and so on. A short description of the computer programs ETACHA, GLOBAL, CHARGE and BREIT for calculation of the charge-state fractions as a function of the target thickness is given as well as some applications of using the charge-state fractions, e.g., in detection of super-heavy elements and in solving problems in laboratory and astrophysical plasmas. All physical processes and effects considered in the paper are explained in terms of atomic physics using radiative and collisional characteristics of heavy many-electron ions interacting with electrons, atoms, ions and molecules.