Ronald W. Waynant

High efficiency microwave discharge XeCl laser

Efficiency of a microwave discharge XeCl laser exceeding 1% is demonstrated, an increase of more than one order of magnitude over previously reported values. Laser pulse durations of 320 ns are also reported.

200‐MHz electrodeless discharge excitation of an XeF laser

Two hundred megahertz electrodeless rf discharge excitation of an XeF laser is reported. Laser output of total duration exceeding 300 ns is observed. Onset of discharge inhomogeneity is found to limit duration of the laser pulse and to influence recovery of the active medium.

Destruction of ground state XeCl molecules by HCl and rare gas collisions

Rate constants for quenching of several XeCl (X) vibrational levels by the rare gases and HCl have been measured. The temporally resolved decay of the population densities of the XeCl (X, v″=0–2) levels was monitored using a frequency‐doubled tunable dye laser. Within experimental error, the measured rate constants did not vary with vibrational number, and the temperature dependence of the rates over the range 300⩽T⩽375 °K was found to be consistent with the previously measured XeCl (X) dissociation energy (∼250 cm−1). The rate constants for the destruction of XeCl (X, v″=0) state molecules by HCl, Xe, Ar and Ne at 300 °K were determined to be (2.20.5) ×10−11, (5.60.8) ×10−12, (0.60.06) ×10−13, and (1.00.15) ×10−13 cm3 sec−1, respectively.

XeF(C) state lifetime and quenching by rare gases and fluorine donors

The lifetime and quenching rate constants for the XeF(C) state have been measured when that state is produced by flash photolysis of XeF2 in the presence of such quenching gases as He, Ne, N2, Xe, Ar, XeF2, NF3, and F2. The lifetime measured in this manner is 957 ns and the quenching rate constants are 1.2×10−13, 3×10−13, 4×10−13, 1×10−12, 9×10−14, 1.7×10−10, 1.6×10−11, and 8×10−11 cm3 sec−1, respectively.

Spontaneous emission lifetime of the C → A band of the XeF molecule

The radiative lifetime of the blue C \rightarrow A transition of XeF has been measured to be 93 ± 5 ns by monitoring the exponentially decaying 460 nm emission following rapid electron impact dissociation of XeF 2 . By varying the XeF 2 partial pressure, the rate constant for quenching of XeF ( C ) by XeF 2 was determined to be (1.8 \pm 0.5) \cdot 10^{-10} cm3. s-1. Finally, knowledge of the XeF B and C state lifetimes yields a revised value of 610 ± 60 cm-1for the B to C state energy defect.

Efficient XeF laser excited by a proton beam

The efficient generation of stimulated emission from XeF at 351 and 353 nm has been achieved by pumping RG/Xe/NF3 gas mixtures (RG=argon, neon, or helium) with an intense (∼10 A cm−2) beam of ∼200‐keV protons. For an active medium (T=300 °K) consisting of Ar, Xe, and NF3 at a total pressure of 1 atm and 30% cavity output coupling, the volumetric output, efficiency, and threshold pump power for the laser were determined to be 5–10 J/liter amagat, 1.7±0.7%, and 1.5 MW cm−3, respectively. Much lower efficiencies were obtained for neon and helium diluent mixtures.