Raman pump/probe measurements of statehyphen;tohyphen;state energy transfer rates in thev=1 state of H2

摘要

We have measured statehyphen;resolved rotational energy transfer rates of H2(v=1) in collisions with H2(v=0) at 295 K, using optical pump/probe techniques. A single rotational level was populated using stimulated Raman pumping, and the degree of collisionhyphen;induced population transfer was monitored using either coherent antihyphen;Stokes Raman spectroscopy (CARS) or resonancehyphen;enhanced multiphoton ionization spectroscopy (REMPI). The CARS and REMPI results are in good agreement; averages of the two sets of rates are 180plusmn;27times;106sminus;1thinsp;amagatminus;1forj=0rarr;2 and 50plusmn;8times;106sminus;1thinsp;amagatminus;1forj=1rarr;3. We also observed transfer of vibrational excitation from paraspinv=1 states to orthov=0 states due tovndash;vexchange, measuring a rate of 1.9plusmn;0.8times;106sminus;1thinsp;amagatminus;1for this process.