Determination of Internal-State Distributions of Surface Scattered Molecules: Incomplete Rotational Accommodation of NO on Ag(111)

Abstract

Laser-induced fluorescence has been used to measure the rotational-state distribution of nitric oxide scattered from clean, single-crystal silver. Each resulting distribution is described by a rotational temperature within the statistical uncertainty. As the surface temperature is increased from 475 to 615 to 720 K, the calculated rotational temperature varies from 360\ifmmode\pm\else\textpm\fi{}50 to 430\ifmmode\pm\else\textpm\fi{}90 to 405\ifmmode\pm\else\textpm\fi{}60 K, respectively. This shows that not only is rotational accommodation incomplete, but the degree of accommodation may decrease at the highest surface temperature studied.