Excitation transfer, lifetimes, and satellite bands in Cs(7p)–Xe collisions

Abstract

Observation of the time-dependence of excitation transfer between Cs 7p 2P1/2 and 2P3/2 levels caused by collisions with xenon are reported. The 2P levels were selectively excited with an N2 laser-pumped dye laser, and the spectrum of the fluorescence radiation was observed with 5 nsec time resolution. The lifetimes of the levels were found to be (2P1/2) 154±2 nsec and (2P3/2) 135±2 nsec, and the 2P1/2 to 2P3/2 transfer cross section at 325±10 °K is 0.150±0.002 Å2. An analysis of the time-dependent decay versus xenon partial pressure shows that the cross section for quenching or collision induced radiation is less than 4×10−3 Å2. This demonstrates that collision induced transitions cannot be important in the formation of near red satellites on the Cs 6s–7p lines perturbed by Xe. In addition, the radiative decay constant for the satellite is identical to that for the line within experimental uncertainty. The correspondence of satellite and line decay curves provides a method of identifying satellites with their parent line.