William M. Hughes

126.1‐nm molecular argon laser

Electron beam excitation of high‐pressure argon has resulted in the first demonstration of laser action from molecular argon at 126.1±0.3 nm. Strong laser action was achieved at pressures up to 6.89 MPa (1000 psia).

Lifetime and quenching rate constants for Kr2F* and Kr2*

A broadband 2.5‐ns‐long argon excimer photolytic source was used to initiate the reaction sequence resulting in the formation of Kr2F*. The resulting fluorescence signal at 400 nm depended on the radiative and quenching processes of Kr2* as well as Kr2F*. The radiative lifetime of Kr2F* was found to be 181±12 ns. The rate constants for quenching by F2 and Kr are 4.3±0.4×10−10 and 6.9±0.7×10−15 cm3 s−1, respectively. The Kr2* coupled lu, Ou lifetime is 280±30 ns and the rate constant for quenching of Kr2* by F2 is 2.1±0.2×10−10 cm3 s−1.

Experiments on 558‐nm argon oxide laser system

Vacuum ultraviolet (VUV) photolysis of N2O immersed in high‐pressure Ar has been used to produce O(1S0) at high density. A two‐chamber apparatus was used to prevent the effects of electron and ion collision in the experimental volume, thereby providing a much clearer kinetic situation. The gain profile and stimulated emission cross section near 558 nm and the upper‐state lifetime were determined for ArO.

High‐power ultraviolet laser radiation from molecular xenon

Experiments have been conducted on high‐pressure Xe gas undergoing excitation by a high‐current pulsed relativistic electron beam. Spectral, temporal, and calorimetric diagnostics were performed. The results establish that lasing in molecular Xe has been achieved with the highest laser power yet obtained in the vacuum ultraviolet. Premature termination of light output indicates the possibility of significant effects due to thermal collisions.

Lasing XeO in liquid argon

We have lased XeO at 547 nm with xenon and N(2)O concentrations of tens of parts in 10(6) in liquid argon. The solution was pumped with a short-pulse 1-MeV e beam. The resulting gain was at least 23% per centimeter.

Efficient high‐energy‐density molecular xenon laser

Electron beam excitation of pure Xe and Xe–Ar and Xe–Ne gas mixtures have been studied. Significant differences in the temporal character of ultraviolet output were observed. Under the best conditions laser output of 75‐MW peak power and 0.76‐J output energy were achieved. The molecular xenon laser is established as having the highest power in the wavelength region short of red.

Liquid excimers: lasing Xe(2) and Kr(2) in liquid argon.

By pumping a small cryogenic cell with a 40-nsec, 1-MeV e-beam pulse, we have excited lasing in dilute mixtures of xenon or krypton in liquid argon. The lasing occurred at 175 nm for the excimer Xe(2) and at 147 nm for Kr(2).

Liquid excimers: lasing Xe sub 2 and Kr sub 2 in liquid argon

By pumping a small cryogenic cell with a 40-nsec, 1-MeV e-beam pulse, we have excited lasing in dilute mixtures of xenon or krypton in liquid argon. The lasing occurred at 175 nm for the excimer Xe(2) and at 147 nm for Kr(2).

Liquid excimers: lasing Xe_2 and Kr_2 in liquid argon

By pumping a small cryogenic cell with a 40-nsec, 1-MeV e-beam pulse, we have excited lasing in dilute mixtures of xenon or krypton in liquid argon. The lasing occurred at 175 nm for the excimer Xe(2) and at 147 nm for Kr(2).

E-Beam-Induced Fluorescence Of Excimers In Cryogenic Solutions

We have detected the fluorescence emitted from excimer molecules formed in e-beam-pumped mixtures in a liquid argon host. The mixtures were both binary (halogen donors in the liquid argon) and ternary (dilute concentrations of donors and other rare gases in the liquid argon). Many excimers were observed, including the rare-gas dimers Xe2, Kr2, and Ar2. Strong fluorescence was seen from XeF, XeCl, and ArO.