Collision spectroscopy with aligned and oriented atoms. Pt. 1

Electron capture processes in the H+-Na(3s) and H+-Na(3p) collisions are experimentally investigated in the 0.3-3 keV energy range using a crossed beam experiment. The excited Na(3p) target is produced with a well-defined alignment using laser pumping. The time of flight technique enables the identification of all the H(n)+Na+ channels populated in the collision. Total cross section ratios σ3p(n=2)/σ3s(n=2), σ3p(n=3)/σ3s(n=2) and σ3s(n=3)/σ3s(n=2) for the production of H(n=2) and H(n=3) are measured in the H+-Na(3s) and H+-Na(3p) collisions. They reveal a strong dominance of the production of H(n=2) in the H+-Na(3p) collision, especially for energies below 1 keV. (orig.)