Time resolved VUV spectroscopy using synchrotron radiation: fluorescent lifetimes of atomic Kr and Xe

Synchrotron radiation from the Stanford positron electron accelerator ring (SPEAR) was used to excite the np5 (n+1) s states in Kr(n = 4) and Xe (n = 5). Utilization of the excellent time structure of this facility made possible the first direct measurement of the lifetimes of these states. The results for Kr are (in jl coupling notation): tau(5s[3/2]1)=3.18+-0.12 ns; tau (5s[1/2]1)=3.11+-0.12 ns; for Xe, tau(6s[3/2]1)=3.46+-0.09 ns; tau(6s[1/2]1)=3.44+-0.07 ns. In addition the lifetime of the Xe 5p5[3/2]5d[3/2] J = 1 state was found to be 1.40+- 0.07 ns. Effects due to radiation trapping are discussed. (Auth.)