Cs. Chou et Kc. Lin, COLLISIONAL DEACTIVATION OF K IN THE HIGH-LYING S-2 AND D-2 STATES BYHE, NE, AND AR, The Journal of chemical physics, 105(7), 1996, pp. 2719-2725
By measuring time-resolved fluorescence signals, we have obtained radi
ative lifetimes and total cross sections for collisional deactivation
by He, Ne, and Ar of K n S-2 and (n-2)D-2 states (n=7-11). The radiati
ve lifetimes obtained agree with those previously reported. The cross
sections, in the range of 15-180 Angstrom(2), generally increase with
increasing the principal quantum number. Their magnitudes for the n S-
2 and (n-2)D-2 states are similar. The results are closely related to
the geometric size of the excited K states, and weakly dependent on th
eir orbital angular momentum. Our case differs from the K-H-2, collis
ion, in which the electron harpoon mechanism should be involved. Our c
ase also differs from the collision of Na with rare gas; the latter e
asily induces l-mixing (l greater than or equal to 2) of the same n. W
e have also found that the relative efficiency for He and Ar is differ
ent in quenching of the low-lying and the high-lying K states. When n
is small, the total cross section of deactivation by He collision is l
arger than that by Ar collision, but is reversed for the high-lying st
ates. Detailed discussion on these phenomena is presented. (C) 1996 Am
erican Institute of Physics.