heat conduction away from the active region. Since the efficiency of the coherent light generation is a decreasing function of temperature, a maximum exists in the curve of output versus input power. A mathematical model of the injection laser is employed to investigate how this maximum output power varies as a function of several design parameters of the injection laser. The optimum design is presented for the case of continuous operation in a 77°K environment and discuss pulsed operation of low-duty cycle in a 300°K environment. TAB (NASA-CR-74730) CFSTI: HC $2.00/MF $0.50 CSCL 20E Details are given of a proposed light backscattering experiment to probe a hypothetical layer at about or slightly above a height of 100 km. The objectives of the experiment are to investigate the implication of G. Fiocco that some particulate matter is present in the atmosphere at this altitude. Also, observations are to be extended and performed operationally for a period of at least one year in order to determine if there is a local or a seasonal character associated with Fiocco's findings. Theoretical background and system design is considered, with the laser taken as one starting point in the design of the proposed system. Consideration is given to molecular scattering by atmospheric gases since it may provide a remote measurement of atmospheric density, and also because it will tend to obscure the presence of other scatterers such as dust particles. C.T.C. 4. SCYLLA IV POWER-CROWBARRED MEASUREMENTS E. M. Little, W. E. Quinn, F. L. Ribe, and G. A. Sawyer P 17-24 refs 5. SCYLLA IV OPERATION R. F. Gribble, E. M. Little, N. Lowry, L. H. Mc Dowell, and W. E. Quinn p 25-27 6. SCYLLAC PLANS p 28-29 7. SCYLLA IV CURVED SECTOR EXPERIMENTS W. H. Borkenhagen and W. E. Quinn p 30-31 8. POSSIBLE SINGLE-TURN MIRROR INSERTS FOR SCYLLAC EXPERIMENTS D. A. Baker, R. F. Gribble. W. E. Quinn, and F. L. Ribe p 32-35 refs 9. ANALOG SOLUTION OF MULTIPOLE STABILIZ ING CONDUCTORS G. A. Sawyer p 36-38 10. SCYLLACITA, A SMALL THETA-PINCH MACHINE E. Dolnick, R. Dike, E. Kemp, and G. A. Sawyer p 39-41 11. SCYLLA I LASER EXPERIMENTS P. N. Mace and G. H. Mc Call p 42-44 ref 12. TEST OF GIANT-PULSE RUBY LASER FOR SCATTERING EXPERIMENT T. Langham, A. S. Rawcliffe, F. L. Ribe, D. Steinhaus, and K. Thomas P 45-46 13. FABRY-Perot MonacHROMATOR FOR SCATTERING EXPERIMENT F. L. Ribe and K. S. Thomas P 47 14. HYDROMAGNETIC PLASMA GUN PROGRAM I. Henins and J. Marshall p 48-67 refs 15. TRANSVERSE INJECTION J. E. Hammel p 68-70 16. EQUIPMENT DEVELOPMENT AND TESTING I. Henins et al p 71-81 17. NEW MATHEMATICAL PHYSICS GROUP W. B. Riesenfeld p 82-83 18. INVESTIGATION OF dl/B STABLE CLOSED SYSTEMS D. A. Baker p 84-85 19. PLASMA BOUNDARY CALCULATIONS T. A. Oliphant p 86 20. COMPUTATION OF ELECTRIC AND MAGNETIC FIELDS K. R. Crandall and H. R. Lewis p 87-88 21. MAGNETIC MOMENT SERIES H. R. Lewis p 89 22. THERMONUCLEAR REACTOR BLANKETS G. I p 90 ref Bell N66-25513# Lincoln Lab., Mass. Inst of Tech.. Lexington OPTICAL COMMUNICATIONS EMPLOYING SEMICONDUCTOR LASERS Technical Report No. 392 Edward J. Chatterton 9 Jun. 1965 73 p refs (Contract AF 19(628)-500) (ESD-TDR-65-232: AD-630243) CFSTI: HC $3.00/MF $0.75 This report discusses the development of optical communications employing semiconductor lasers-both noncoherent and coherent. The large modulation bandwidth obtainable with these devices permits the development of frequency and pulse-modulation communications systems which overcome scintillation noise produced by the turbulent atmosphere. Emphasis has been placed on the development of communications systems for 98-percent weather capability over short ranges, rather than fairweather capability over long ranges. The development of supporting technology is presented in the areas of semiconductor lasers fiber optics. optical systems, narrowband optical filters, photomultipliers. and frequency- and pulse-modulation electron circuitry and components. Measurements of optical signals over a two-mile path under a full variety of weather conditions have permitted a comparative evaluation of AM, FM and PM systems. The results show clearly the advantage of frequency modulation N66-25558*# National Aeronautics and Space Administration. Marshall Space Flight Center. Huntsville. Ala EXPERIMENTAL MEASUREMENT OF OPTICAL ANGULAR DEVIATION CAUSED BY ATMOSPHERIC TURBULENCE AND REFRACTION Robert L. Kurtz and James L. Hayes Washington, NASA, May 1966 60 p refs (NASA-TN-D-3439) CFSTI HC $3.00/MF $0.50 CSCL 17H Atmospheric turbulence causes the image of a stationary optical source to fluctuate in intensity and position. The amplitude and frequency of this random position fluctuation have been measured. Data were recorded over a period of approximately six months and over two different path lengths. The system and site are described Data are analyzed and tabulated to show the amplitude of fluctuations in various meteorological conditions A sample of these data is statistically analyzed to determine the limitations of an optical tracking system. Author N66-25866# Illinois Univ., Urbana Gaseous Electronics Lab. AN INVESTIGATION OF ELECTRONIC RECOMBINATION IN HELIUM AND ARGON AFTERGLOW PLASMAS BY MEANS OF LASER INTERFEROMETRIC MEASUREMENTS Scientific Report No. 2 M A. Gusinow. J. B. Gerardo, and J. T. Verdeyen 15 Feb. 1966 118 p refs (Grant DA-ARO(D)-31-124-G582) (AROD-4832-7; AD-630074) CFSTI: HC $4.00/MF $0.75 Two helium-neon laser interferometers were used to obtain the electron and neutral atom densities in an afterglow plasma. The interferometric technique utilized allows one to obtain both the spatial and temporal dependence of the electron decay. The two gases studied were helium and argon at 2-8 Torr and 0.3-0.8 Torr respectively. The electron density was in the range 2x1013 <N. <1015cm-3 and the electron temperature in the range 1000<T.<7000°K. The electron temperature was measured by comparing the relative atomic line intensities and by inference from the recombination coefficient. The electronic recombination in helium, argon, and helium-argon mixtures was found to follow closely the predictions of Bates. Kingston, and McWhirter for collisional-radiative recombination (Proc. Phys. Soc. 83:43, (1964)). In the range of electron temperature and density studied the recombination coefficient exhibited an approximate T-9/2 dependence. The electron temperature Inferred from the measured recombination coefficient indicates a pronounced electron temperature gradient across the tube which is believed to be due to electron heating effects in the afterglow. Author (TAB) N66-25900# Air Force Systems Command, Kirtland AFB. N Mex Air Force Weapons Lab. INVESTIGATION OF A LASER TRIGGERED SPARK GAP Technical Report, Jan. 1964-Dec. 1965 Winston K Pendleton (Air Force Inst. of Tech.) and Arthur H. Guenther Mar. 1966 27 prefs (AFWL-TR-65-32; AD-629905) CFSTI: HC $2.00/MF $0.50 The influence of parameters affecting the laser triggering of a high-voltage electrical sphere-sphere gap has been experimentally investigated. Of primary interest was the delay time between arrival of the laser pulse and current flow across the gap. This delay was studied as a function of total laser beam power (0-80 MW); dielectric gas (SF6, N2. air): gas pressure (100-1400 Torr) electrode spacing (0.4-1.5 cm); gap electric field (10-100kV/cm); and focus point location between two 5 cm diam stainless steel spheres. Delay times less than 10 nsec were observed in SF6 at atmospheric pressure with corresponding low jitter. For the cases studied delay times varied inversely with the electric field, gas pressure, and focus point distance from the anode surface. Above a certain laser beam power the delay time was not a significant function of laser power for the range studied. Applications of laser triggering are discussed with a description of current and future research areas. Author (TAB) N66-26252*# Smithsonian Astrophysical Observatory, Cambridge, Mass. PHOTOGRAPHIC MEASUREMENTS OF THE ENERGY DISTRIBUTION IN THE BEAM OF A RUBY LASER C. G. Lehr, L. A. Maestre, and P. H. Anderson 25 Mar. 1966 22 p refs (Grant NSG-87-60) (NASA-CR-75102; SAO Special Rept.-205) CFSTI: HC $1.00/ MF $0.50 CSCL 20E The beam of a Q-switched ruby laser was directed toward a diffusely reflecting target at a distance of about 1/2 mile. The image on the target was photographed with a hand camera and the resulting films were measured with a microdensitometer. Two stop-openings were used for the photographs. The films exposed with the smaller stop-opening showed concentrations of energy with intensities up to 700 times the background energy. These concentrations are probably representative of the actual laser beam but they could be diffraction effects caused by irregularities in the surface of the diffuse target. The films exposed with the larger stop-opening were used to measure this background energy. Its average value was about half the nominal value of the energy determined from calorimetric measurements. This factor of one-half may be the combined effect of several losses that were neglected in the photometric measurements. The angular divergence of the beam was also measured. Author bus. N66-26261*# Ohio State Univ. Research Foundation, Colum- 1 Apr. 1966 11 p Its Rept.-1093-30 (NASA-CR-74971) CFSTI: HC $1.00/MF $0.50 CSCL 09F Investigations on water vapor absorption in the submillimeter region are reported. The absorption positions are considered to agree with published theoretical values. However, a significant time delay was noticed, which had a degrading influence on measurements. Modifications in the analog-digital conversion and recording system are reported to decrease digital noise and increase reliability. The completed construction of an external-mirror CO2 laser and the initiation of a laser made of glass parts bolted together are mentioned. N.E.N. N66-26341# Air Force Cambridge Research Labs., Bedford, Mass. Optical Physics Lab. THERMALLY INDUCED EFFECTS IN SOLID STATE LASER RODS Richard Lee Townsend, Jr. Jan. 1966 45 p refs Its Phys. Sci. Res. Paper No. 188 (AFCRL-66-57; AD-630608) CFSTI: HC $4.60/MF $0.50 An experiment was performed to measure changes in optical length of ruby and neodymium in glass laser rods both during and after excitation by the pump flash. A TwymanGreen interferometer was used to produce fringes, the fringe movement being correlated with changes in optical length. Movement and distortion of fringes was observed using a multiframe image converter camera. The results show that all rods expand linearly with time during the time the pump is on and that all rods develop a distortion which is dependent on the radial energy density distribution within the rod. After the pump goes off the rods begin a relaxation back to the unexcited state. The relaxation is interrupted when hot air propagates from the flash tube to the rod causing the rod to reheat and causing an extremely concave appearance. The rods then relax slowly to an equilibrium state with ruby reaching this state in much shorter times (0.4 sec) then glass due to its higher thermal conductivity. These results stress the importance of uniform pumping if low beam divergence is to be achieved. Immersion of the rod in an index-matching infraredabsorbing fluid would be desirable not only to pump the laser uniformly but also to shield it from the infrared radiation which causes concave distortions after 20 msec. Author (TAB) N66-26436# TEM-Pres Research, Inc.. State College, Pa. LIGHT SCATTERING TECHNIQUES FOR CRYSTAL EVALUATION Final Report, 1 Jul.-31 Dec. 1965 V. Vand, E. A. Margerum, F. Schwab, and R. I. Harker 31 Jan. 1966 111 p refs (Contract AF 19(628)-5213) (AFCRL-66-119; AD-631041) CFSTI: HC $4.00/MF $0.75 The work described in this report has resulted in (1) the development of the theory of light scattering by various crystal imperfections, (2) the production of computer programs for the calculation of light scattering functions. (3) the computer tabulation of specific values for scattering factors or amplitude functions, intensity functions and Mie coefficients as a function of various selected angles of scattering from 0 to 180 degrees and various sizes of spherical voids from 10 to 10.000 A radius. (4) specific tables of the functions of pi and tau occurring in Mie's theory for light scattering calculations. and (5) an engineering design of an optical system utilizing a continuous laser for observing, evaluating, recording and determining the arrangement of defects in crystals. Author (TAB) N66-26501# Air Force Systems Command, Wright-Patterson AFB, Ohio. Foreign Technology Div. A RED BEAM IN THE BLACK SKY V. Chernyshev 1 Feb. 1966 10 p Transl. into ENGLISH from Krasnaya Zvezda (Moscow), 14 Mar. 1965 p 1 (FTD-TT-65-1683/1+4; AD-629473) CFSTI: HC $1.10/MF $0.50 The importance and applications of the ruby laser in transmitting information through space is briefly reviewed. The dimensions of the laser are indicated. Some problems connected with the use of a very narrow beam in locating an object in space are outlined. It is pointed out that Doppler shifts, relative rates of motion of objects, and spacecraft velocity and direction can be measured with great accuracy using lasers. N.E.N. N66-26512# Columbia Univ., New York. Plasma Lab. Bertram Pariser [1965] 110 p refs (Rept.-24; AD-627363) CFSTI: HC $4.00/MF $0.75 Afterglow plasmas are optically pumped with broadband radiation produced by a xenon flash lamp. The neon metastable concentration is decreased to less than 50 percent during the pumping, and a net depopulation results at the conclusion of the flash. A depopulation of the helium metastable is seen only during the pumping flash. By optically pumping neon metastables to the lower laser level, the laser lines (6328 Å and 1.15 microns) are quenched. Amplifications of the 1.15 micron laser line is observed when the population of the upper laser level is increased by selectively pumping neon metastables. Metastable collisions with heated electrons also result in a depopulation of the neon concentration. With further heating, the electrons gain enough energy to increase the metastable population by colliding with neutral neon atoms. Biondi's theory on ionizing collisions is examined while controlling the metastable population with optical pumping. The experimental data support the theory that metastable collisions are an important ionization process in an afterglow. Author (TAB) N66-26570# Illinois Univ., Urbana. Gaseous Electronics Lab. SPECTROSCOPIC AND MICROWAVE INVESTIGATION OF LASERING PLASMAS Scientific Report No. 4 L. A. C. Weaver and L. Goldstein Feb 1966 177 p refs (Contract AF 19(628)-3307) (AFCRL-66-89; AD-629925) CFSTI: HC $5.00/MF $1 00 The relationship between the process of lasering. the electron gas, and the excited state populations of the active medium are studied for the noble gas lasers. Microwave signals are employed to perturb the electron gas, and resultant alteration of laser output is investigated. The effects of lasering upon the microwave propagation constant, noise radiation temperature, discharge current and spectral emission are investigated experimentally in He-Ne gas lasers, and radiative cascade patterns in noble gases are described by an idealized theoretical model. TAB N66-27687# International Business Machines Corp., Yorktown Heights, N. Y. Thomas J. Watson Research Center. INJECTION LASER STUDY Final Technical Report, 1 Jun. 1963-31 May 1965 K. Konnerth, F. F. Morehead, F. Stern, P. R. Wagner, and K. Weiser [1965] 79 p refs (Contract DA-36-039-AMC-02349(E)) (Rept.-8; AD-631499) CFSTI: HC $3.00/MF $0.75 Many GaAs injection laser diodes show a substantial delay between the application of a current pulse and the onset of lasing if they are operated near room temperature and at currents just above threshold. A model for this effect based on trapping of carriers gives good agreement both with the delay results and with experimental data on the time dependence of spontaneous emission for currents below threshold, provided that the density of trapping states is about ten times the threshold carrier concentration. No independent evidence for the existence of these states has been obtained. The dependence of current and light emission on voltage in Cd Te diodes was studied. The current varies as exp (qV/2kT) at low current levels, and as exp (qV/kT) at higher current levels. Emission is observed with photon energies considerably greater than the applied voltage. Thermodynamic considerations restrict the efficiency of such radiation from one-step processes, and account in part for the low quantum efficiency found at room temperature. In GaAs structures with a highresistance p-type layer surrounded by high-conductivity p-type layers, ambipolar negative resistance, efficient light emission. and lasing were observed. The origin of the electrons is thought to be avalanching in the strong electric field found to present in these all p-type structures. TAB Data taken in 1965 confirm previous measurements made with a conventional light source in 1962 and with a laser source in 1964. The data continue to indicate a difference in the propagation characteristics of the two sources. This difference is ascribed to the different beam geometries. but it disappears when an integrating sphere with a 4-inch aperture is used for a receiver and a beam compression device is employed. Thus the laser and conventional sources have similar gross propagation properties although the data still indicate the presence of scattering effects. Thus the range of underwater laser devices may be longer than anticipated. The data also indicate that appreciable portions of the irradiance is far from the axis. Author (TAB) N66-27897# Massachusetts Inst. of Tech.. Cambridge. (Contract Nonr-3963(22): ARPA Order 306: Proj. Defender) (MIT-DSR-4979; AD-631039) CFSTI: HC $1.00/MF $0.50 Contents: Linewidth of Raman scattering, by J. R. Murray, A. P. Sheng, J. D. Ducuing: Stimulated Raman absorption in liquids, by t J. R. Murray, A. P. Sheng, J. D. Ducuing: Two photon absorption processes, by J. R. Murray. A. P. Sheng, A. Javan; Ramam scattering in gases-linewidth phenomena by J. R. Murray, A. P. Sheng, A. Javan. TAB (NASA-CR-75643) CFSTI: HC $3.00/MF $0.75 CSCL 20E A four-month study of laser techniques for detecting and measuring vibrations of a spacecraft model on a shake table has been conducted. An interference mapping technique. similar to holography in some respects, was developed. It appears that the coherent detection systems may be useful in measuring vibrations down to one micron peak amplitude or perhaps less, even on diffusely reflecting surfaces. The microwave systems provide the poorest sensitivity. The interference mapping system gives a visual indication of surface tilt or gradient of normal displacement, and thus can provide a useful map of positions of maximum and minimum displacement. Most of the systems were tested experimentally; results were generally in good agreement with the analysis. This report contains a detailed description of each approach, a comparison of the relative performances of the various systems, and recommendations for further investigation and development of the most promising techniques. Author N66-28300# Library of Congress, Washington, D. C. Aerospace Technology Div. CHICOM STATE-OF-THE-ART IN ELECTRONICS AREA Surveys of Chinese Communist Scientific and Technical Literature 14 Jan. 1966 16 p refs Compilation of Abstracts (ATD-66-6; TT-66-61094; AD-631546) CFSTI: HC $1.00/MF $0.50 This compilation of abstracts is based on CHICOM open sources published 1964-1965. It is the first report in a series. The fifteen abstracts are arranged alphabetically by author. The following information is included: ammonia maser, semiconductor developments, radio transmitter, TV transmitter, calcium tungstate crystal, neodymium-containing laser, pulse laser, continuous-wave laser, subminiature radio direction finder, miniature electron tube, pentode electron tube, tunnel diode. atmospheric propagation, antenna, short wave backscatter sounding, oscillator tube, audiofrequency carrier telegraph transmitter, teletypewriter, and carrierwave telephone. A list of 7 Chinese journals searched in compiling the report is provided. There is no bibliography. Author (TAB) N66-28336# Institut für Plasmaphysik G.m.b. H., Garching (West Germany). A GIANT PULSE LASER WITH A TRIGGERABLE PASSIVE Q-SWITCH PERFORMANCE K. Maischberger May 1966 20 p refs Presented at the 4th Symp. on Eng. Probl. in Thermonuclear Res., Frascati, Italy. 23-27 May 1966 (IPP-4/34) CFSTI: HC $1.00/MF $0.50 A method of ruby laser operation is described which produces fast, intense, and triggerable giant laser pulses by Q-switching with a selective saturable organic dye. The ruby rod 5/8 in. in diameter and 7 in. long is used in an ellipsoid pump configuration. The passive Q-switch element is placed between the 90° rod with a TIR chisel and a separate end mirror. A double-pulse circuit energizes a linear flash tube. A preionizing pulse fires the main capacitor bank. After a suitable delay a second trigger signal switches the energy of a capacitor to the flash tube load. This short high-power pulse, now not current limited, will start laser action corresponding to the second trigger signal on conditions which will be discussed. The jitter relative to the second trigger signal, the energy and power output of the resulting giant pulses is reported. Author N66-28382*# Cornell Aeronautical Lab., Inc., Buffalo, N. Y. LASIG II: PULSED LASER ION GENERATOR STUDY Final Report R. E. Biss and A. S. Gilmour, Jr. 5 Oct. 1965 173 p ref (Contract NAS3-5919) (NASA-CR-54154; CAL-UB-1989-E-4) CFSTI: HC $5.00/MF $1.00 CSCL 20E Thirteen materials were illuminated in vacuum with the focused output of a pulsed ruby laser. Illumination of materiais such as chromium, columbium, tantalum, thorium, tungsten and zirconium resulted in the emission of ion currents of 3 to 4 amperes. Thrusts from this laser-induced emission have been measured at over 4 millipounds. An average ion energy of 40 electron volts, with a specific impulse of 660 seconds has been obtained. Measurements were made on the density and energy distribution of the emitted ions. Author N66-28461# Naval Air Test Center. Patuxent River, Md. Robert B. Davis In NRL The Shock and Vibration Bull. An absolute accelerometer calibrator utilizing a laser as the standard reference has been developed. The calibrator consists of a laser photodiode and appropriate electronic readout equipment, and is easy to operate with a direct digital readout for displacements greater than one-half of a wavelength The present resolution of the prototype calibrator is one-tenth of a wavelength. The results of this development are discussed. Author N66-28514# Naval Research Lab., Washington, D. C. REPORT OF NRL PROGRESS Apr. 1966 49 prefs (PB-169690) CFSTI: $1.25 N66-28515# Naval Research Lab., Washington, D. C. Radiometry Branch. LASER ACTION IN TRIPLY ACTIVATED GLASS H. W. Gandy, R. J. Ginther, and J. F. Weller In its Rept. of NRL Progr. Apr. 1966 p 1-9 refs (See N66-28514 16-23) CFSTI: $1.25 Pulsed optical excitation experiments performed at liquid nitrogen temperature upon confocal etalons fabricated from barium crown glass triply activated with UO22+, Nd3+, and Yb3+ having indicated that either Nd3+ or Yb3+ or both ions can be excited to exhibit laser oscillations. This controllable selection of the lasing species was demonstrated in both the free running and self Q switched modes of optical resonator operation. A physical description of the processes involved in these experiments is given followed by a theoretical description of the excited state population kinetics of doubly activated luminescent systems. Author N66-28553# TRG. Inc., Melville, N. Y. RESEARCH ON PROPERTIES OF LASER DEVICES First (Contract AF 49(638)-1535; ARPA Order 356, Proj. Defender) (TRG-034-TR-1; AD-627353) CFSTI: HC $3.00/MF $0.75 CONTENTS: 1. MANGANESE COLLISION LASER p 3-9 refs 2. RARE EARTH COLLISION LASER p 10-15 refs 3. PHOTODISSOCIATION LASERS p 16-26 refs 4. THERMO-OPTICAL EFFECTS IN SOLID-STATE LASER MEDIA p 27 5. LASER PUMPING LASER p 28-33 6. DYNAMIC OPTICAL PATH DISTORTIONS IN LASER RODS S. D. Sims, A. Stein, and C. Roth 16 p (See N66-28554 16-16) 7. END PUMPING OF AN R, RUBY LASER BY AN R2 RUBY LASER 7 p (See N66-28555 16-16) N66-28554# TRG, Inc., Melville, N. Y. DYNAMIC OPTICAL PATH DISTORTIONS IN LASER RODS S. D. Sims, A. Stein, and C. Roth In its Res. on Properties of Laser Devices [1965] 16 p (See N66-28553 16-16) CFSTI: HC $3.00/MF $0.75 (Contract Nonr-3833(00)) High quality ruby crystals and improved glass laser materials doped with neodymium were investigated in order to study optical path distortions in laser rods. It was found that significant distortions were introduced as a result of thermal gradient evolution during the optical pumping cycle. Since laser action occurs only during the pumping pulse, or shortly thereafter in the case of Q-switching, primary emphasis was placed on the time interval of the pumping pulse. Thus a Q-switched laser was found to be a highly effective interferometer illumination source in cases where high time resolution is desired. A side benefit from the use of this technique was that the resulting observations are almost precisely reproducible from shot to shot. Thereafter, it is noted, optical correction can be employed to improve resonator performance at any desired time. This is particularly useful in Q-switching lasers, where the resonator characteristics need only be good during the development of the output pulse. DT. N66-28555# TRG. Inc., Melville, N. Y. END PUMPING OF AN R, RUBY LASER BY AN R2 RUBY LASER In its Res. on Properties of Laser Devices [1965] 7 p (See N66-28553 16-16) CFSTI: HC $3.00/MF $0.75 An analysis and steady state solution are given for a proposed experiment in which an R2 ruby laser is to be used to pump an R, ruby laser. This technique is to provide a means for reducing optical path distortions, caused by thermal gradient evolution, by decreasing to a minimum the pump light which must be absorbed. In this case, very little heat deposition is expected. Consequently, it is noted, the radiance of the R, laser should be improved to whatever extent its performance had been limited by thermal effects. D.T. N66-28726# Korad Corp., Santa Monica, Calif. R. A. Sehr and W. J. Rundle Jan. 1966 28 p refs Refinements in the experimental technique for growing p-n junctions from liquid solution resulted in highly uniform and dislocation-free n-layers on p-substrates. High pressure diffused laser diodes were fabricated with thresholds between 50 and 70 amperes at 300°K, and typical power outputs of two watts with 50 nsec pulses and a repetition rate of 1000 pps. Some lasers, mounted on special headers containing a pulse transformer, were operated at 8000 pps with 100 nsec pulses producing a beam of 1.5 watt optical peak power within a beam angle of 12°. Author (TAB) N66-28920# Ballistic Research Labs.. Aberdeen Proving Ground, Md. Terminal Ballistics Lab. USE OF A LANGMUIR PROBE FOR ELECTRON TEMPERATURE DETERMINATION IN A LASER-INDUCED PLASMA William F. Braerman Dec. 1965 49 prefs (BRL-MR-1715: AD-631517) CFSTI: HC $2.00/MF $0.50 The possibility of using Langmuir probes for electron temperature determination in a laser-induced plasma has been demonstrated. Laser input energies less than 15 joules have been used and electron temperatures on the order of 0.5 ev have been inferred at various distances from the target. The beam was focused to approximately a 1 mm diameter spot. It is shown that the probe current of the start of the pulse follows the laser spiking. Author (TAB) N66-28923# Library of Congress. Washington, D. C. Aerospace Technology Div. FOREIGN SCIENCE BULLETIN, VOLUME 2, NUMBER 5 May 1966 58 p refs |