Electronic energy partitioning in the reactions of metastable Mg*(3P) and Ca*(3P,1D) atoms with halogenated methanes CX4 (X = F, Cl, Br)

Collisions of metastable Mg*(3P) and Ca*(3P, 1D) atoms with CF4, CCl4, and CBr4 were studied in a beam-gas arrangement. The total attenuation cross sections determined for the reactive systems vary in a wide range increasing with electron affinity of the target gas. The reactions of metastable Mg*(3P) with CX4 yield no chemiluminescence. All Ca* + CX4 reactions give electronically excited CaX* products and the chemiluminescence yield increases with reaction exo-ergicity.