Cs (6D 3/2 )+ H 2 →CsH+H reaction. IV. Rotationally resolved total cross sections

Abstract

The Cs(6D3/2)+H2→CsH [X 1Σ+(v″=0,1; J″)]+H photochemical reaction has been studied in a crossed-beam experiment with electronic excitation of Cs atoms and laser-induced fluorescence detection of CsH products. The reactive cross section is measured at a collision energy of 0.09 eV: σ(6D3/2)=0.04×10−16 cm2. The rotational distributions of CsH products measured on v″=0 for 0⩽J″⩽23 and on v″=1 for 0⩽J″⩽15 are close to statistical ones with 16% of products in v″=1. A quasi-classical 3D trajectory calculation of this reaction yields both rotational and vibrational distributions of CsH products and their angular scattering probability. The reactive cross section measured with Cs(6D3/2) excitation is an order of magnitude smaller than the cross section σ(7P1/2)=0.6×10−16 cm2, which is re-evaluated in this article.