Study of vibrational energy transfer at a surface by a time-of-flight method

A single collision, time-of-flight extension of the VEM method for the study of molecule-surface vibrational energy transfer is introduced. This refined technique helps election between possible alternative trial analytic forms of the collisional transition probability function. A gaussian form is preferred over a boltzmann-exponential form for cyclobutene isomerization to 1,3-butadiene energized by collisions at a seasoned silica surface at 800 K. The study illustrates the difference between conventional accommodation coefficient measurements, which examine average energy changes, and the present studies which explore the energy transport at high levels corresponding to chemical reaction thresholds.