Abstract
Luminescence induced by collisions of low‐energy metastable C+( 4P) ions in a beam with H2 and D2 gas was studied spectroscopically. Nine bands of the CH+(b 3Σa 3Π) transition were observed, of which only three had previously been known. Of the corresponding CD+ transition twelve bands were observed for the first time. Vibrational constants were derived which are in good agreement with independent recent ab initio results. Preliminary results on the vibrational distribution of the CH+ (b) reaction product were also obtained.