Chemiluminescence from the gas phase reaction of atomic boron with the alkali metal fluorides

Gas phase reactions of boron with CsF, RbF, KF, and NaF were studied in a merged flow. Atomic boron was produced in a microwave discharge of a B2H6–helium mixture. The densities of ground state boron and alkali atoms produced in the reaction were determined by absorption measurements. Light from excited alkali atoms in the reaction region was recorded and the excited state population densities were calculated. Our evidence indicates that alkali atoms (M) in the first excited P states are produced primarily in the direct reaction B+MF→BF+M. Several additional processes contribute to the production of higher excited states. Population inversion is observed between a number of excited states.