Ba+(6p 2P) gas phase collisional quenching and intramultiplet mixing

Collisional quenching and intramultiplet mixing of Ba+ (6p 2P/sub 1/2,3/2/) has been studied by laser-pumping 6p 2P3/sub //2 and measurement of the 6p 2P3/sub //2 to 6p 2P1/sub //2 population ratio under steady-state conditions. Gas phase Ba+ was generated by the methods of two photon ionization of Ba and by multiphoton dissociation and ionization of BaI2. The cross sections for quenching of 6p 2P1/sub //2 by N2, CH4, C2H6, and C2H4 are 17 A2, < or =3, < or =6, and 120 A2, respectively. The cross sections for 6p 2P3/sub //2→6p 6p 2P1/sub //2 mixing by N2, CH4, C2H6, and C2H4 are 24, 70, 100, and 80 A2, respectively. These cross sections are comparable to those of the alkali neutrals