Abstract

Measurements of the total yield and rotational distribution of hydrogen molecules formed in chemical reactions or emanating from a surface provide detailed information on the dynamics of these interactions. We have developed a technique which uses a two-photon resonant transition (excited with counterpropagating light beams) to the E electronic state followed by a onephoton transition to the autoionizing continuum of the molecular ion to count different isotopic species in specific rotational levels. To calculate the sensitivity and selectivity of the scheme, we have measured the radiative transition rate, the thermally averaged cross section for elastic scattering to a nearby electronic state, and the real and imaginary parts of the inelastic scattering cross section in the E state. Measurements of the total yield and rotational

© 1989 Optical Society of America