Xenon excited state density measurements in electron beam pumped XeCl laser mixtures

Time-dependent density measurements of the lowest xenon excited states (5p⁵6s) in electron beam (e-beam) pumped XeCl laser mixtures (nonlasing) are performed using pulsed hook interferometry. The e-beam pulse length is ≊0.45 μs (full width at half-maximum) with an average excitation rate of ≊250 kW/cm³. Density differences (ΔN*) of transitions at 823.2 nm (6s[3/2]⁰₂ -6p[3/2]₂), 828.0 nm (6s[3/2]⁰₁ -6p[1/2] ₀), and 840.9 nm (6s[3/2]⁰₂ -6p[3/2] ₁) are obtained for various HCl and Xe concentrations. For a 98.3% Ne/1.5% Xe/0.16% HCl mixture at 3000 Torr, ΔN* (823.2 nm) and ΔN*(828.0 nm) are relatively constant at ≊3×10 ¹⁴ and ≊1.7×10¹⁴ cm^-3, respectively. At lower initial HCl concentrations, the ΔN*(823.2 nm) density starts out similar to the 0.16% HCl case, but tends to increase dramatically during the e-beam pulse. For a 0.04% HCl mixture, a ΔN*(840.9 nm) density of ≊4.5×10¹⁵ cm ^-3 is measured at the end of the e-beam pulse. Preliminary comparisons of the data with a computer model show good agreement for HCl concentrations ≥0.16%, but disagreements at leaner concentrations.