Electron capture by protons and helium ions from lithium, sodium, and magnesium

Cross sections for single-electron capture by protons and single- and double-electron capture by helium ions from atomic lithium, sodium, and magnesium targets are presented. The absolute cross sections were measured by using the growth-curve method. Impact energies are in the range 2--100 kV q, where q is the projectile charge state. The present data are compared with previous experimental and theoretical work.