Collision energy-resolved study of the emission cross-section and the Penning ionization cross-section in the reaction of BrCN with He*(23S)

The dissociative excitation of BrCN producing CN(B2Σ+) fragment by the collision of He*(23S) was investigated by the collision energy-resolved electron and emission spectroscopy using time-of-flight method with a high-intensity He* beam. The Penning electrons ejected from BrCN and the subsequent CN(B2Σ+–X2Σ+) emission were measured as a function of collision energy in the range of 90–180 meV. The formation of CN(B2Σ+) is concluded to proceed dominantly via the promotion of an electron from Π-character orbital, by comparison between the collision energy dependence of the partial Penning ionization cross-sections and the CN(B2Σ+–X2Σ+) emission cross-section.