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The DARPA-NRL Laser Program is concerned with the development of laser technology in three project areas: chemical infrared lasers, electrical infrared lasers and electronic-state lasers. The chemical infrared laser program includes studies of pulsed HCl laser systems and molecular energy transfer processes. Data have been collected which suggests that intramolecular energy transfer occurs in SF6 at a rate 1,000 times the gas kinetic collision rate. The electrical infrared program emphasizes electric-discharge gasdynamic lasers and electron-beam pumping of potential laser systems in the mid-infrared. Several new energy transfer lasers have been discovered and a detailed discussion of the study of direct excitation HCl lasers is given. A number of excitation approaches are being evaluated for application to electronic state gas lasers. A most important step in the development of rare-gas halide lasers is the reporting here of the operation of XeF and KrF lasers in self-sustained discharges. Chemical pumping of atomic states is shown to lead to sufficient population for lasing and related quenching studies are described. Transverse discharge excitation of metal vapor lasers has been reduced to practice and coherent anti-Stokes Raman spectroscopy is being developed for probing the number density and vibrational temperature of gaseous species in a lasing medium.

The DARPA-NRL Laser Program is concerned with the development of laser technology with the emphasis on electronic state lasers and the associated physics. Electrically excited infrared lasers and intramolecular energy transfer are also being studied. Progress is reported in all areas with the major highlights being (1) the observation of quasi-CW lasing in XeF (2) the discovery of the KrCl laser at 223 nm (3) advancement of discharge-pumped rare- gas halide lasers and their understanding, and (4) improvements in the performance of the CO-C2H2 and CO-CS2 energy transfer lasers which are being studied in the electric-discharge gasdynamic laser facility.

The ARPA-NRL Laser Program is concerned with the development of laser technology in three project areas: Chemical Infrared Lasers, Electrical Infrared Lasers and Electronic State Lasers. The Chemical Infrared Laser Program is focussed on DF-CO2 supersonic transfer laser experiments designed to evaluate chemical augmentation of gas dynamic lasers. Augmentation has been observed but is limited by deactivation processes. The temperature dependence of energy transfer processes in CO, CO2, and N2O has been measured. The Electrical Infrared Laser Program has two primary projects, short-pulse CO2 laser technology and electric-discharge gas dynamic lasers (EDGDL). The short pulse laser project has successfully been completed culminating in reliable 70 J single-pulse operation. A compact high-pressure e-beam-controlled CO2 laser has been developed for the generation of picosecond laser pulses. Infrared fluorescence from HCl generated by energy transfer from vibrationally excited D2 has been measured.

The use of flow to enhance the performance of gas lasers is discussed. In particular, an attempt to demonstrate the use of high speed flow in conjunction with the H2:Cl2 chemical laser is described. The failure of the attempted demonstration was due to the inefficiency of the reaction in converting the reaction energy to vibrational energy in the product molecule. The principles of the theory presented may be applied when a reaction of high efficiency is employed. A brief review of the literature of excitation in chemical reactions is given and it is concluded that a reaction with HI:Cl is the most promising. The use of this reaction to produce a high powered (1000 watts) pulsed chemical laser has been experimentally demonstrated. By using high speed flow, conversion to cw operation should be possible.

The ARPA-NRL High Energy Laser Program is concerned with the development of laser technology in three project areas: Chemical Infrared Lasers, Electrical Infrared Lasers and Electronic State Lasers. The Chemical Infrared Laser Program is concerned with the developement of the DF-CO2 supersonic transfer chemical laser, the study of the CO vibrational distribution from exothermic reactions which produce CO and the measurement of energy transfer rates of CO. The objective of the DF-CO2 program is the chemical augmentation of gasdynamic CO2 lasers. V-V and V-R,T energy transfer rates have been measured for CO-additive mixtures and the temperature dependence of some of these rates has been investigated. The Electrical Infrared Laser Program consists of two primary projects, short-pulse CO2 laser technology and electric- discharge gasdynamic lasers (EDGDL). Advances in pulse switch out technology and measurements of gain profiles and spectral content are reported. Components for an EDGDL apparatus for the investigation of the D2(*) - HCl transfer laser have been fabricated and are being assembled., See also AD0779261.

The reaction F + HCl yields HF + Cl has been used to produce C. W. chemical laser action. This has been accomplished by mixing two supersonic streams of the reactant species in a shock tunnel. The time duration of the laser action is two orders of magnitude longer than the natural laser pulse in a non-flowing system, i.e. it is limited only by the flow time of the shock tunnel. (Author)

An infrared chemiluminescence technique has been used to measure the rates of the following energy transfer reactions at 295 plus or minus 5K: (a) HF(v) + CO2 to HF(v - 1) + CO2 for v = 1,2,3,4,5; (b) DF(v) + CO2 to DF(v - 1) + CO2 for v = 1,2,3,; (c) HF(v) + HF to HF(v - 1) + HF for v = 2,3,4,5,; and (d) DF(v) + HG to DF(v - 1) + HF for v = 1,2. The rate constants for reactions (a), (b), (c), and (d) may be used in kinetic model analyses of hydrogen fluoride and related lasers. A very brief discussion is given of new aspects of the chemistry of excited states important to the development of chemical lasers. (Author)