No abstract available

[en] Investigation on the production HgCd* in an e-beam preionized quasi-stable discharge have theoretically predicted and experimentally demonstrated that fluorescence efficiencies of approx. 50% can be achieved. Spectra of the emission for a discharge pumped mixture of Cd/Hg/Ne show the HgCd* continuum peaking at 470 nm and absolute fluence measurements indicate [HgCd*] approx. 10¹⁶ cm³. Measurements of the gain/absorption of this mixed metal exciplex show absorption of the HgCd* excited state across the entire band. The absorption peaked at the blue end of the continuum (457 nm) and decreased to approx. 1% in 40 cm at the red end of the continuum

No abstract available

[en] The discharge in an electron-beam-sustainer atmospheric pressure CO₂ laser is investigated. An arbitrary two-dimensional geometry is employed in calculating the electric field. The conductivity is a function of the local electric field, the loss rate, and the ionization rate, the third of which is proportional to the energy deposition by high-energy electrons. The predicted discharge nonuniformities are compared with experimental results. Experimental evidence indicates that the discharge is recombination dominated. (U.S.)

[en] Laser action has been obtained in atmospheric-pressure mixtures of 0.1% F₂/2% Kr/97.9% Ar at 248.5 and 249.5 nm with electron-beam-controlled discharge pumping. The laser and discharge characteristics are explored as a function of discharge electric field and total mixture pressure. These preliminary measurements indicate laser output energies up to 6 mJ with a pulse length of 90 nsec. Limiting efficiencies for this laser system are discussed

[en] Measurements of the output energy and intrinsic efficiency of an electron beam pumped ArXe laser operating on the 1.73 μm line are reported. A 220 kV electron beam was used to pump either an 11 x 11 x 50 cm³ or an 11 x 11 x 25 cm³ active volume. Small-signal gain, nonsaturable loss, and saturation flux were deduced via a Rigrod analysis of the output energies as a function of output coupler reflectivity. Electron beam pump powers ranging from 2.2 to 16.2 kW/cm³ were employed. At a pump power of 2.2 kW/cm³ a small signal of 0.035 cm^-1, a gain to loss ratio of 272, and a saturation flux of 2.1 kW/cm² were determined. Intrinsic efficiencies of 4 percent were obtained at the lower pump powers. From the measurements of the laser output it is clear that the secondary electrons have a significant impact on the laser kinetics and efficiency

No abstract available

[en] A simple accurate method for normalizing the absolute magnitude of measured relative rare-gas excitation cross-section data to published measurements of the first Townsend coefficient is presented. Using a code which solved the Boltzmann equation we have determined that the predicted first Townsend coefficient is a very sensitive function of the electron impact excitation cross section. In Ar and Kr we have found that a 10% change in the cross section results in a 30% change in the first Townsend coefficient

[en] The diffusion of high-energy electrons (> or = 10 keV) in the presence of an electric field is discussed. Solutions are obtained by extending the Bethe age theory to include effects of the applied electric field. Since we restrict ourselves to the P₁ approximation, the results are only valid for diffuse beams, i.e., beams whose distribution function can be adequately described by a current and number density. The solution predicts a range enhancement in the presence of an accelerating electric field. A simple exponential decay is obtained when the electric field is large enough so that the electrons gain as much energy in the electric field as they lose by inelastic collisions. The validity and accuracy of the solutions and predictions are discussed

[en] The collisional deactivation by electrons of the upper laser levels of KrF* and ArF* has been measured. The rare-gas/fluorine binary mixtures were excited by a beam of fast electrons. These electron beam pulses were long enough to allow the use of a steady-state analysis of the fluorescence. Quenching rate constants near 2 x 10^-7 cm³/sec have been obtained