I (6 s  4 P ) Collisional quenching: Application to the IF 491-nm laser

The room-temperature rate constants for quenching of I* (4P) atoms in binary collisions with Ar, Xe, NF3, UF6, and CF3I have been measured to be ≲2×10−13, (8.3±0.5)×10−11, (2.6±0.5)×10−11, (5.8±0.4)×10−10, and (3.8±0.4)×10−10 cm3 sec−1, respectively. These constants were obtained by examining the exponential time decay of the IF (D′→A′) fluorescence in the afterglow of electron beam produced plasmas containing Ar, CF3I, NF3, and the desired quenching gas. Also, further experimental evidence in support of neutral channel formation of IF* via quenching of I* (4P) states by fluorine containing molecules in e-beam-pumped Ar/CF3I/NF3 mixtures is presented.