Electron capture from lithium and its ions by high-energy protons

The continuum-distorted wave method is used to calculate cross sections for electron capture by fast protons from the lithium atom and its related positive ions. With the exception of Li 2+ (1 2 S), each target electronic state is described by a Hartree-Fock wavefunction. For the lithium atom, capture can occur from either the K or L shell and the resulting ion can exist either in its ground state 1 1 S or in one of the excited states 2 1 S or 2 3 S; cross sections are tabulated for each of these states for capture into the hydrogen levels (nl). Results for the individual capture states (nl) are also reported for the Li + target. Total capture cross sections are calculated for each target by means of the Oppenheimer n -3 rule. For Li and Li + , total cross sections are also evaluated at E<200 keV. A procedure for determining the effective screening of the target nucleus by the uncaptured electrons is discussed and the sensitivity of the cross sections with respect to such screening is examined.