Energy partitioning in He2+/K collisions

Final state distributions and state-specific reaction cross sections for 1.5–6 keV He2+/K collisions have been determined from data acquired using both neutralized ion beam spectroscopy and direct observation of luminescence from decay of excited collision products. While several minor reaction channels can be identified, it is found that near-resonant processes yielding He2(a 3Σu+) and He2(A 1Σu+) are predominant. These major channels, both of which have cross sections in excess of 100 Å2, lead to substantial production of energetic metastable molecules and VUV continuum radiation extending from about 750 to 850 Å.