Prediction of charge-changing cross sections of low-charged 88Sr, 138Ba and 142Nd ions in a He-gas target at collision energies 50 eV/u–10 GeV/u.

Electron-loss (EL) and electron-capture (EC) cross sections of neutral and low-charged heavy Sr q + , Ba q + and Nd q + ions with charges q = 0, 1 and 2 in collisions with He atoms are predicted in the energy range E = 50 eV/u–10 GeV/u. Experimental data on EL and EC cross sections of these particles colliding with He atoms are practically absent. At relatively low energies E = 8–30 keV, EL cross sections σ 12 of Sr 1 + , Ba 1 + and Nd 1 + ions are predicted from new experimental equilibrium charge-state fractions F 1 and F 2 and calculated EC cross sections. Predicted value for Ba 1 + ions, σ 12 = 6. 8 ⋅ 1 0 − 18 cm 2 , is in a good agreement with the one available experimental point σ 12 exp = 5. 7 ⋅ 1 0 − 18 cm 2 at E = 20 keV (Fedorenko, 1954). Calculations of EL and EC cross sections are performed by available computer codes shortly described in the paper. Theoretically estimated neutral-atom fractions F 0 are found much smaller than the measured F 1 , F 2 , and F 3 charge-state fractions. [ABSTRACT FROM AUTHOR]