Determination of the state production ratios , and from fast () mixed-state He-like ion beams in collisions with H2 targets

Abstract

New results are presented on the ratio concerning the production cross sections of Li-like quartet and doublet P states formed in energetic ion–atom collisions by single electron transfer to the metastable component of the He-like ion beam. Spin statistics predict a value of R m = 2 independent of the collision system in disagreement with most reported measurements of . A new experimental approach is presented for the evaluation of R m having some practical advantages over earlier approaches. It also allows for the determination of the separate contributions of ground- and metastable-state beam components to the measured spectra. Applying our technique to zero-degree Auger projectile spectra from 4.5 MeV (Benis et al 2002 Phys. Rev. A 65 064701) and 25.3 MeV (Zamkov et al 2002 Phys. Rev. A 65 062706) mixed state He-like ion collisions with H2 targets, we report new values of for boron and for fluorine. In addition, the ratios of and populations from either the metastable and/or ground state beam component, also relevant to this analysis, are evaluated and compared to previously reported results for carbon collisions on helium (Strohschein et al 2008 Phys. Rev. A 77 022706) including a critical comparison to theory.