State-resolved differential cross sections for crossed-beam argon-nitric oxide inelastic scattering by direct ion imaging

摘要: State-to-state differential cross sections for inelasticcollisions of NO with Ar have been measured in a crossedbeam experiment using time-of-flight ion imaging. Rotational rainbow peaks are observed in the angular distributions, and these move to backward scattering angles with increasing final rotational level. The images are analyzed using a Monte Carlo forward convolution program that accounts for the transformation from the center-of-mass differential cross sections to the experimental image. The results are interpreted using a simple two-dimensional hard ellipse model to provide quantitative insight into the anisotropy of the potential energy surface. For NO (J'= 18.5), two rainbow peaks are observed. These double rainbows have been predicted for scattering of atoms from heteronuclear molecules, but they have not previously been directly observed in the angular distributions. The analysis is also used to …