Technique for studies of state-selective electron capture in collisions involving slow state-prepared multiply charged ions

The intense beams from an ECR ion source/accelerator have been utilised in a new apparatus for studies of state-selective electron capture by multiply charged ions in well defined initial states by double translational energy spectroscopy (DTES). This avoids the ambiguities in previous TES studies carried out with beams containing metastable ions. The effectiveness of DTES is demonstrated by studies of one-electron capture at 4 keV by pure beams of S-1 ground state and P-3 metastable C2+ ions in collisions with H-2, He and Ar.