Angle-energy distributions of Penning ions in crossed molecular beams. IV. He(21 S,2 3S)+H2-->He+H2+ +e

Relative doubly differential cross sections for the Penning ionization of H(2) by spin-state-selected metastable He (1s2s) are reported at center-of-mass collision energies E of 3.1 and 4.2 kcal/mol in a crossed supersonic beam experiment employing a rotatable mass spectrometer detector. The measurements are sufficiently dense in velocity space as to avoid having to functionalize the differential cross sections in order to transform the intensities into the c.m. The H(2) (+) product is scattered sharply forward, c.m. Deltatheta