Differential cross sections and collision-induced rotational alignment in inelastic scattering of NO(X) by Xe

Abstract

Fully Λ-doublet resolved differential cross sections and collision-induced rotational alignment moments have been measured for the NO(X)-Xe collision system at a collision energy of 519 cm −1 . The experiments combine initial quantum state selection, employing a hexapole inhomogeneous electric field, with quantum state resolved detection, using (1+1 ′ ) resonantly enhanced multiphoton ionization and velocity map ion imaging. The differential cross sections and polarization dependent differential cross sections are shown to agree well with quantum mechanical scattering calculations performed on ab initio potential energy surfaces [J. K los et al. J. Chem. Phys. 137, 014312 (2012)]. By comparison with quasi-classical trajectory calculations, quantum mechanical scattering calculations on a hard-shell potential, and kinematic apse model calculations, the effects of the attractive part of the potential on the measured differential cross sections and collision-induced rotational alignment moments are assessed.

Probing the location of the unpaired electron in spin–orbit changing collisions of NO with Ar

“…68 Consistent with this picture of a more impulsive, lower impact parameter collision are the more backward scattered differential cross sections measured for spin-orbit excited NO after collisions with Ar, Kr, and Xe. 66,[69][70][71][72][73] In the present work, we focus on transitions from the rotational and spin-orbit ground state to the spin-orbit excited manifold,…”

Stereodynamics of rotational energy transfer in NO(A2Σ+) + Kr collisions

“…5,10,13 However, it has been shown to break down in NO(X) + Kr and Xe scattering, attributed to the stronger attractive forces in these more polarizable systems. [14][15][16] In these measurements of NO(A) + Kr scattering, there is good agreement between QS and KA models for backward scattering for all N 0 , indicating that collisions at low-l that probe the repulsive wall are well described by the KA model. In contrast, significant disagreements are seen between QS and KA models for forward scattering, which the PCSs show is arising for all N 0 from the attractive regions of the PES.…”

“…[5][6][7] The resulting systematic work on collisions with He, Ne, Ar and Kr has provided very stringent tests of the latest ab initio PESs, confirming the high degree of accuracy attained by modern coupled cluster methods for these systems. 5,6,[8][9][10][11][12][13][14][15][16] The measurements have also provided great insight into the process of inelastic scattering. This includes the importance of interference effects, both in the forward direction, where high-frequency oscillations are observed that can be viewed as arising from diffraction effects, and as low-frequency oscillations across sideways and backwards scattering that can be explained through interference from multiple paths arising from collisions at the ends and the sides of the NO.…”

“…In these systems significant deviations from the KA model have been observed, and attributed to the attractive interactions. [14][15][16] In contrast to the extensive work on NO(X) + Rg rotational energy transfer discussed above, there has been substantially less work on scattering of electronically excited species, i.e. the complementary NO(A 2 S + ) + Rg systems.…”