QUARTET EXCITED HALOGEN ATOMS PRODUCED IN THE ELECTRON PULSE IRRADIATION OF RARE-GASES CONTAINING HALOGENATED COMPOUNDS

Quartet excited halogen atoms F(2p(4) 3s, P-4(J)), Cl*(3p(4) 4S, P-4( J)), Br(4p(4) 5s, P-4(J)), and I*(5p(4) 6s, P-4(J)), where the J's ar e 5/2, 3/2 and 1/2, were found to be produced in the electron pulse ir radiation of Ne or Ar containing one of SF6, CCl4, CClF3, CBrF3, CBr2F 2, and CF3I. The population distribution ratios at the stage of produc tion were 1.0(J = 5/2):0.41(J = 3/2):0.06(J = 1/2) for F in Ne contai ning SF6, 1.0(J = 5/2):0.27(J = 3/2):0.14(J = 1/2) for Cl in Ne conta ining CCl4, 1.0(J = 5/2):0.29(J = 3/2):0.2- 0.3(J = 1/2) for Br in Ne containing CBr2F2, and 1.0(J = 5/2):0.13(J = 3/2):0.54(J = 1/2) for I in Ar containing CF3I. The observed ratios considerably differ from those calculated from the Boltzmann distribution law. F(P-4(5/2)), F* (P-4(3/2)), and Cl(P-4(5/2)) are mainly produced by the reactions of lowest triplet excited diatomic molecules of neon with SF6 and CCl4. C l(P-4(3/2) and CI*((4)P1/2) are produced in a rapid process and deact ivated into lower Cl(P-4(5/2)). Several reaction channels probably co ntribute to the formation of Br(P-4(J)) and I*(P-4(J)). Rate constant s for reactions of triplet excited diatomic molecules of neon or argon with these parent molecules were determined from observed absorption decay curves for Ne-2 or Ar-2* in the presence of parent molecules. ( C) 1995 American Institute of Physics.