This report presents the results obtained during the first half of the year 1974 in the study of MHD powered gas lasers. Key results of the work thus far are: Changes to the shock tunnel and test facility include a modified cesium seed injection system, relocation of the secondary diaphragm, installation of a primary double diaphragm and a new CO2 probe laser. Gain measurements previously reported have been repeated, with substantial improvement in the signal attributable to the above changes....
Topics: DTIC Archive, Zauderer, Bert, GENERAL ELECTRIC CO PHILADELPHIA PA SPACE DIV, *CARBON DIOXIDE...
A long-wave infrared camera was used in an imaging pyrometric mode to determine the spatially resolved outer surface temperature of sapphire samples heated with a carbon dioxide (CO2) laser. Tests were conducted by APL at the Laser Hardened Materials Evaluation Laboratory, Wright-Patterson Air Force Base, Ohio. Sapphire disks were assessed first to demonstrate the CO2 laser heating technique and the capabilities of the infrared pyrometry system. Additional testing was conducted on sapphire...
Topics: DTIC Archive, Terry, David H., JOHNS HOPKINS UNIV LAUREL MD APPLIED PHYSICS LAB, *SAPPHIRE,...
Pulsed laser sheet velocimetry yields nonintrusive measurements of two-dimensional velocity vectors across an extended planar region of a flow. Current processing techniques offer high precision (1 pct) velocity estimates, but can require several hours of processing time on specialized array processors. Under some circumstances, a simple, fast, less accurate (approx. 5 pct), data reduction technique which also gives unambiguous velocity vector information is acceptable. A direct space domain...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE LASERS, CURRENT SHEETS, FLOW VELOCITY, LASER...
Platinized tin oxide surfaces used for low-temperature CO oxidation in CO2 lasers have been characterized before and after reduction in CO at 125 and 250 C using ion scattering spectroscopy (ISS) and X ray photoelectron spectroscopy (XPS). XPS indicates that the Pt is present initially as PtO2. Reduction at 125 C converts the PtO2 to Pt(OH)2 while reduction at 250 C converts the PtO2 to metallic Pt. ISS shows that the Pt in the outermost atomic layer of the catalyst is mostly covered by...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE LASERS, CARBON MONOXIDE LASERS, CATALYSTS,...
Pulsed CO2 lasers have many applications in aeronautics, space research, weather monitoring and other areas. Full exploitation of the potential of these lasers is hampered by the dissociation of CO2 that occurs during laser operation. The development of closed-cycle CO2 lasers requires active CO-O2 recombination (CO oxidation) catalysts and design methods for implementation of catalysts inside lasers. The performance criteria and constraints involved in the design of catalyst configurations for...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE, CARBON DIOXIDE LASERS, CATALYSTS, COMPUTER...
Three concepts for an unmanned, solar powered, cargo spacecraft for Mars support missions were investigated. These spacecraft are designed to carry a 50,000 kg payload from a low Earth orbit to a low Mars orbit. Each design uses a distinctly different propulsion system: A Solar Radiation Absorption (SRA) system, a Solar-Pumped Laser (SPL) system and a solar powered magnetoplasmadynamic (MPD) arc system. The SRA directly converts solar energy to thermal energy in the propellant through a novel...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE LASERS, CARGO SPACECRAFT,...
The steps and engineering trades and analyses used in establishing the initial requirements and in developing a concept and configuration for the laser atmospheric wind sounder (LAWS) instrument. A summary of the performance anticipated from the baseline configuration, and a bibliography are presented. LAWS, which is a facility instrument of the Earth observing system (EOS), is the culmination of over 20 years of effort in the field of laser Doppler wind sensing and will be the first instrument...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC SOUNDING, CARBON DIOXIDE LASERS, DOPPLER RADAR,...
Experimental and theoretical studies were performed of atmospheric aerosol backscatter and atmospheric dynamics with Doppler lidar as a primary tool. Activities include field and laboratory measurement and analysis efforts. The primary focus of activities related to understanding aerosol backscatter is the GLObal Backscatter Experiment (GLOBE) program. GLOBE is a multi-element effort designed toward developing a global aerosol model to describe tropospheric clean background backscatter...
Topics: NASA Technical Reports Server (NTRS), AEROSOLS, AIRBORNE EQUIPMENT, ATMOSPHERIC SCATTERING,...
Significant advances were made in the growth technology of silver thiogallate (AgGaS2) and silver selenogallate (AgGaSe2). High efficiency harmonic generation of carbon dioxide laser radiation and tunable infrared parametric oscillation were demonstrated using these materials. Nonliner frequency conversion in the infrared was limited by the optical properties and the size of the available nonlinear materials. The development of these materials has reduced some of the limitations and generated...
Topics: NASA Technical Reports Server (NTRS), CRYSTAL GROWTH, GALLIUM SELENIDES, PHASE MATCHING, SILVER...
The possible uses of pulsed carbon dioxide lasers for analysis of plasmas and flows need appropriate infrared image converters. Emphasis was placed on liquid crystal detectors and their operational modes. Performance characterstics and selection criteria, such as high sensitivity, short reaction time, and high spatial resolution are discussed.
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE LASERS, FLOW VISUALIZATION, INFRARED...
The development and technical realization of the method of laser sounding of the atmosphere based on the effects of mixing of reference and external fields of scattering inside a laser cavity are presented. An approximate theory of the method was developed on the basis of the investigations using the model of a three-mirror laser. The nonlinear effect of a wideband laser on frequency-dependent external influences of the atmosphere was investigated. The field measurements of gaseous composition...
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC SOUNDING, BACKSCATTERING, COHERENT RADIATION,...
A set of eleven measurements of the water vapor continuum absorption in the 840 to 1100 sq cm spectral region is reviewed and compared with spectral models maintained by the Air Force Geophysics Laboratory. The measurements were made in four different ways: spectrometer with a White cell, CO2 laser with a White cell, CO2 laser with a spectrophone, and broadband radiation source over a long atmospheric path. Where possible, the data were selected at a water vapor partial pressure of ten torr...
Topics: NASA Technical Reports Server (NTRS), ABSORPTION SPECTRA, PHOTOACOUSTIC SPECTROSCOPY, WATER VAPOR,...
A new local oscillator housing was built which seems to have improved laser life. Laser cooling was changed from internal water cooling to the more convenient thermal contact cooling. At the present time, a conclusion can not be made if the 20 percent reduction in power output is the result of poorer cooling or poorer grating alignment. The coupling-starting network was improved from 55 to about 90 percent. It can be adjusted by varying trimmers C sub 1 and C sub 2 to match RF power levels...
Topics: NASA Technical Reports Server (NTRS), HOUSINGS, INFRARED RADIOMETERS, LIFE (DURABILITY),...
The development of eye-safe, solid-state Lidar systems is discussed, with an emphasis on Coherent Doppler Lidar for Atmospheric Wind Measurements. The following subject areas are covered: tunable Ho DIAL (Differential Absorption Lidar)/lidar atmospheric measurements; atmospheric turbulence measurements and detector arrays; diurnal measurements of C(sub n)(sup 2) for KSC lidar measurements; and development of single-frequency Ho laser/lidar.
Topics: NASA Technical Reports Server (NTRS), ATMOSPHERIC TURBULENCE, BACKSCATTERING, CARBON DIOXIDE...
This study investigated the impact of elevated temperatures on the electromagnetic performance of the LI-2200 thermal protection system. A 15-kilowatt CO2 laser was used to heat an LI-2200 specimen to 3000 F while electromagnetic measurements were performed over the frequency range of l9 to 21 GHz. The electromagnetic measurement system consisted of two Dual-Lens Spot-Focusing (DLSF) antennas, a sample support structure, and an HP-8510B vector network analyzer. Calibration of the...
Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC MEASUREMENT, HIGH TEMPERATURE, LASER HEATING,...
Past co-operation between the NASA Earth Science and Applications Division and the CSIRO and Australian university researchers has led to a number of mutually beneficial activities. These include the deployment of the C-130 aircraft with TIMS, AIS, and NS001 sensors in Australia in 1985; collaboration between scientists from the USA and Australia in soils research which has extended for the past decade; and in the development of imaging spectroscopy where DSIRO and NASA have worked closely...
Topics: NASA Technical Reports Server (NTRS), AUSTRALIA, IMAGING TECHNIQUES, LASER SPECTROMETERS, RADAR...
Pulse tailored laser welding has been applied to wrought, wrought grain grown, and cast Inconel 718 using a CO2 laser. Prior to welding, the material was characterized metallographically and the solid state transformation regions were identified using Differential Scanning Calorimetry and high temperature x-ray diffraction. Bead on plate welds (restrained and unrestrained) were then produced using a matrix of pulse duty cycles and pulsed average power. Subsequent characterization included heat...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE LASERS, CAST ALLOYS, INCONEL (TRADEMARK),...
A laser-excited system for determination of the oxygen isotope composition of small quantities of silicate and oxide minerals was constructed and tested at JSC. This device is the first reported to use a commercially available helium cryostat to transfer and purify oxygen gas quantitatively within the system. The system uses oxygen gas instead of the conventional CO2 for mass spectrometer analyses. This modification of technique permits determination of all three stable oxygen isotopes, an...
Topics: NASA Technical Reports Server (NTRS), OXYGEN ISOTOPES, LASER APPLICATIONS, ISOTOPIC LABELING,...
We proposed to perform a comprehensive design study of a 16-element heterodyne array receiver for SOFIA. The array was designed to utilize hot-electron bolometers in an efficient, low-cost waveguide mount to achieve low noise performance between approx. 1500 and 2400 GHz. Due to the prevailing physical conditions in the interstellar medium, this frequency range is one of the richest in the FIR portion of the spectrum. An array designed for this wavelength range will make excellent use of the...
Topics: NASA Technical Reports Server (NTRS), DESIGN ANALYSIS, HETERODYNING, ARRAYS, RECEIVERS, HOT...
In order to better understand the budget of carbon dioxide in the Earth's atmosphere it is necessary to develop a global high precision understanding of the carbon dioxide column. In order to uncover the 'missing sink that is responsible for the large discrepancies in the budget as we presently understand it calculation has indicated that measurement accuracy on the order of 1 ppm is necessary. Because typical column average CO2 has now reached 380 ppm this represents a precision on the order...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE LASERS, OPTICAL RADAR, LASER SPECTROSCOPY,...
Research on the feasibility of using a laser subsystem as an additional option for the transmission of the satellite power system (STS) power is presented. Current laser work and predictions for future laser performance provide a level of confidence that the development of a laser power transmission system is technologically feasible in the time frame required to develop the SBS. There are significant economic advantages in lower ground distribution costs and a reduction of more than two orders...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE LASERS, LASER APPLICATIONS, SATELLITE POWER...
A review of recent developments in high power, carbon dixoide laser welding is presented. Deep penetration welding in stainless steel to 0.5-in. thick, high speed welding in thin gage rimmed steel and gas shielded welding in Ti-6Al-4V alloy are described. The effects of laser power, power density, focusing optics, gas-shielding techniques, material properties and weld speed on weld quality and penetration are discussed. It is shown that laser welding performance in thin materials is comparable...
Topics: NASA Technical Reports Server (NTRS), CARBON DIOXIDE LASERS, GAS WELDING, STAINLESS STEELS,...
To produce a noble metal-on-metal oxide catalyst on an inert, high-surface-area support material (that functions as a catalyst at approximately room temperature using chloride-free reagents), for use in a carbon dioxide laser, requires two steps: First, a commercially available, inert, high-surface-area support material (silica spheres) is coated with a thin layer of metal oxide, a monolayer equivalent. Very beneficial results have been obtained using nitric acid as an oxidizing agent because...
Topics: NASA Technical Reports Server (NTRS), CATALYSTS, NOBLE METALS, TIN OXIDES, RARE GASES, TRANSITION...
The presentation will consist of showing arc jet data mysterious to the modelers. It will show pictures from an arc jet test where a material (unidentified) exhibited a failure mode that nobody understands followed by thermocouple data from arc jet tests on another (unidentified) material of interest in which the T/Cs exhibit repeatable, consistent, fascinating yet frustrating response characteristics that have the modelers stumped. This all happens between RT and 200 F. Unless we figure out...
Topics: NASA Technical Reports Server (NTRS), ABLATIVE MATERIALS, THERMAL PROTECTION, FAILURE MODES,...
This final technical report describes the result of two programs concerned with high power laser propagation through the atmosphere that are particularly important to the Navy high energy laser program. The first study deals with an experimental laboratory simulation of moving stagnation zones a problem which can be quite serious for the Navy application. The second study is the propagation and non-linear interaction of a high intensity laser with water droplets or fog, again in a laboratory...
Topics: DTIC Archive, Fowler, M. C., UNITED TECHNOLOGIES RESEARCH CENTER EAST HARTFORD CT, *PROPAGATION,...
New techniques for making time-resolved studies of atoms in highly excited (Rydberg) states were investigated. In particular, attempts were made to observe coherent transient effects produced via CO2 laser irradiation, from a high density atomic Rydberg vapor produced by stepwise dye laser excitation, but no such effects were observable. It was found that this result was due to a very rapid collisional decay process which occurs in a Rydberg gas at the densities required for transient...
Topics: DTIC Archive, Shoemaker,Richard L, ARIZONA UNIV TUCSON OPTICAL SCIENCES CENTER, *TRANSIENTS,...
Topics: DTIC Archive, Gullberg, K, ROYAL AIRCRAFT ESTABLISHMENT FARNBOROUGH (UNITED KINGDOM), *CARBON...
We have developed a method of fabricating permanently curved hollow metallic waveguides of both constant and tapered inside diameter. This method is based on the use of soluble glass mandrels. In tests with laboratory C02 lasers we have shown that even without interior dielectric layers these devices can exhibit low loss; e.g., a 22 cm long, 2mm ID guide with a 65 degree exterior bend transmits more than 90% of properly launched input radiation. We discuss methods of cooling these devices and...
Topics: DTIC Archive, Altkorn, R, MIDWEST BIO-LASER INST CHICAGO IL, *WAVEGUIDES, *LASERS, *SURGERY, TEST...
The use of the LASER as a tool to improve the properties of electrodeposits for wear and erosion resistance is introduced. The microstructures and microhardness of LASER treated electrodeposits of chromium (Cr) and duplex coatings of chromium over cobalt (Co) onto steel are shown. Cobalt as an underlay is shown to produce superior structures compared to chromium directly on steel which suffers from the formation of brittle phases at the chromium-steel interface.
Topics: DTIC Archive, Greco, V P, ARMY ARMAMENT RESEARCH AND DEVELOPMENT CENTER WATERVLIET NY LARGE CALIBER...
Typescript
Topics: Carbon monoxide, Carbon dioxide lasers, Catalysts, Oxidation
224
224
Jul 11, 2010
07/10
by
ZONOV, Y. Y. V
texts
eye 224
favorite 0
comment 0
THE USES OF ARTIFICIAL SATELLITES FOR STUDYING THE PROCESSES IN THE SPREAD OF INDUSTRIAL WASTES IN NATURE AND FOR ACHIEVING INSPECTIONS FOR COMPLIANCE WITH LEGAL REQUIREMENTS ARE DISCUSSED. THE DEVELOPMENT OF SENSORS FOR DETECTING GASEOUS EMISSIONS FROM INDUSTRIAL PROCESSES IS EXAMINED. THE USE OF SATELLITE-BORNE PHOTOGRAPHY FOR DETERMINING THE NATURE OF OCEAN CURRENTS AND THE DIFFUSION PROCESSES OF TURBID WATERS IS EXAMINED. PHOTOGRAPHIC SAMPLES OF VARIOUS GEOGRAPHICAL REGIONS TO SHOW...
Topics: CARBON DIOXIDE LASERS, COLD CATHODES, PERFORMANCE TESTS, COPPER, COPPER ALLOYS, FABRICATION, SILVER...
This report contains copies of journal articles, and papers appearing in conference proceedings describing optics research at Lincoln Laboratory during the period 1 July 1976 through 31 December 1977. Also included are preprints of articles accepted by journals and conference proceedings during this period as well as a list of meeting speeches given during this period. Additional information on the Optics Program may be found in the ARPA/STO Program and ARPA/TTO Program HOWLS Semiannual...
Topics: DTIC Archive, MASSACHUSETTS INST OF TECH LEXINGTON LINCOLN LAB, *DIODE LASERS, OPTICAL RADAR,...
Some laser-induced reactions of BF3, BCl3 or B(CH3)3 with NF3, N2F4 or C2H4 have been studied. These reactions were initiated by the multiphoton absorption of the infrared radiation from a CW CO2 laser. In addition to numerous gaseous products, infrared spectra of solids, that have been identified as belonging to BF4 and BN, were observed. When possible, visible emission, which accompanied some of the reaction, was photographed. Analysis has shown it to be due, in part, to C2 and CN when carbon...
Topics: DTIC Archive, McDonald,J K, ARMY MISSILE COMMAND REDSTONE ARSENAL AL RESEARCH DIRECTORATE,...
245
245
Jun 27, 2010
06/10
by
Powell, E. A.; Zinn, B. T
texts
eye 245
favorite 0
comment 0
Analytical technique for solving nonlinear combustion problems associated with liquid propellant rocket engines
Topics: CADMIUM TELLURIDES, MERCURY TELLURIDES, PHOTODIODES, RADIATION DETECTORS, CARBON DIOXIDE LASERS,...
330
330
Jun 26, 2011
06/11
by
NON
texts
eye 330
favorite 0
comment 0
A fuel cell power system for use in a weightless environment, such as in space, includes a device for removing water from a water-hydrogen mixture condensed from the exhaust from the fuel cell power section of the system. Water is removed from the mixture in a centrifugal separator, and is fed into a holding, pressure operated water discharge valve via a Pitot tube. Entrained nondissolved hydrogen is removed from the Pitot tube by a bleed orifice in the Pitot tube before the water reaches the...
Topics: CATALYSTS, TIN OXIDES, CARBON DIOXIDE LASERS, PATENTS
The object of this study was to test a new method of sterilizing endodontic instruments by using a carbon dioxide laser system. This was done by contaminating endodontic reamers with spores, exposing them to a carbon dioxide laser beam, and checking for their viability by standard microbiologic techniques. It was found that 100% of the spores were killed by the carbon dioxide laser. This holds promise as an effective method of sterilizing endodontic instruments in the future. (Author)
Topics: DTIC Archive, Hooks,Thomas W, ARMY INST OF DENTAL RESEARCH WASHINGTON D C, *CARBON DIOXIDE LASERS,...
This report summarizes research on corneal damage from exposures to multiple pulses of CO(2) laser radiation at 10.6 (micrometer) and Tm: YAG laser radiation at 2.02 (micrometer). Retinal damage from sources with rectangular irradiance distributions was also modeled. Thresholds for CO(2) exposures were determined for sequences of up to 1024 pulses (80 ns duration) at frequencies of 10 and 16 Hz. Thresholds for Tm: YAG exposures were determined sequences of up to 128 pulses (0.300 5 duration) at...
Topics: DTIC Archive, McCally, Russell L, JOHNS HOPKINS UNIV LAUREL MD, *INFRARED RADIATION, *CORNEA, YAG...
Steady state photolysis experiments were conducted to gain information relevant to the construction of a continuous wave electronic to vibrational pumped infrared laser. An Ar+ laser =488 nm) was used to produce the electronically excited state Br(2P1/2) (B*) via photolysis of molecular bromine. Energy was then transferred to the near resonant vibrational state CO2(101) (CO2cross) via the collisional quenching of Br* by CO2. The dependence of the 2.71 micron Br0 and 4.3 micron CO2cross...
Topics: DTIC Archive, Karis, Stephen J, AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF...
KCl crystals pulled from pretreated melts under an Ti gettered inert atmosphere have been shown to have as low an absorption as crystals grown by the RAP Bridgman method. A simple optical method has been developed to analyze KCl:Eu for Eu content. Radiation damage significantly increases the 10.6 micrometers absorption of both KCl and NaCl. The absorption increase is caused by the F-aggregate centers. This result probably rules out the use of radiation strengthened KCl for high power laser...
Topics: DTIC Archive, Martin, Joel J, Butler, Charles T, Sibley, William A, OKLAHOMA STATE UNIV STILLWATER...
The Objective of the research was to elucidate the physical and chemical factors that control ignition of double base propellants. Detailed experimental and analytical investigations were conducted to understand the ignition processes that occur at and near the propellant surface, to determine the connection between the ignitability of a propellant and its other combustion characteristics, to quantify the peculiarities of radiative ignition in comparison with hot gas ignition, and to develop a...
Topics: DTIC Archive, Summerfield, Martin, Caveny, L. H., Ohlemiller, T. J., DeLuca, L., PRINCETON UNIV NJ...
Thermal coupling of CO2 laser energy to metal surfaces of aluminum, titanium, stainless steel and copper has been measured under large-spot, repetitively pulsed conditions using the AVCO Humdinger, Sr., laser. Measurements were made at atmospheric pressure with a Mach 0.4 air flow transverse to the target surface and in a low-pressure environment of approx. 3 torr. The multipulse coupling measured with Humdinger, Sr., is consistently less than previous measurements of single-pulse and...
Topics: DTIC Archive, Manlief, Scott K, Mooney, Daniel L, Marcus, Stephen, MASSACHUSETTS INST OF TECH...
We report here the first experimental attempt to measure the mean energy of photoexcited carriers in n-InSb using the Shubnikov de Haas (SdH) effect as a temperature probe. Preliminary measurements with a mecahnically chopped CO2 laser beam have shown that the laser radiation changes the amplitude of the SdH oscillations. The research being done is directed at obtaining fundamental information concerning the effects of CO and CO2 laser radiation on the quantum transport properties on n-InSb....
Topics: DTIC Archive, Seiler,David G, NORTH TEXAS STATE UNIV DENTON DEPT OF PHYSICS, *OPTICAL PROPERTIES,...
Topics: DTIC Archive, Syczewski,Michael, FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH, *FOREIGN...
The corneas of Dutch belted rabbits were exposed for 0.5 sec to the radiation from a carbon dioxide laser (lambda = 10.6 microns) emitting a Gaussian beam with a 1/e radius of r = sigma = 2.65 mm at the corneal plane. The 1/e radiant exposure required for a 50% probability (ED50) of producing a minimum visible lesion within 30 minutes postexposure was 4.71 J/sq cm. The 1/e radiant exposure is the incident beam energy delivered in 0.5 sec divided by the area of a circle of radius r = 2.65 mm,...
Topics: DTIC Archive, Mikesell,George W , Jr, SCHOOL OF AEROSPACE MEDICINE BROOKS AFB TX, *CURVATURE,...
This article presents the two-dimensional distribution of saturation gain parameters in traverse flow discharge carbon dioxide lasers as well as the laws for their changes along with changes in radiation fields. Use was made of microscopic physical mechanisms to make notes and explanations. We used three types of stability oscillation conditions to respectively calculate the light strength distributions within cavities and output powers. Moreover, this provides a comparison for discussion and...
Topics: DTIC Archive, Chen, Liyin, FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OH, *CARBON DIOXIDE LASERS,...
Two rate equations are important in determining the stability of the discharge. The first is the electron production and loss and the second is the metastable production and loss where ne is the electron density, nm is the metastable density, alpha is the recombination rate, beta is the attachment rate, (sigma v) is the electron impact metastable production rates constant and tau m is the metastable lifetime. The ionization rate constant v in Eq. (1) is assumed to be the result of metastable...
Topics: DTIC Archive, Jacob, Jonah, SCIENCE RESEARCH LAB INC SOMERVILLE MA, *IONIZATION, *CARBON DIOXIDE...
Ignition experiments on nitrate-ester and nitramine propellants have been conducted in a closed bomb. The ignition source was a variable ( 100 W) cw C02 laser. Ambient conditions were room temperature and atmospheric pressure. Air, argon, and nitrogen gases were used. Times to detect and changes in emission rate which are attributed to onset of flamespreading have been compared with ignition delay calculations using a condensed phase radiant ignition model. Reasonable values for thermochemical...
Topics: DTIC Archive, Cohen, Arthur, ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD, *LASERS, *DELAY,...
Substantial reduction in the absorption at 10.6 micrometers is required before chalcogenide glasses can be used with high-energy CO2 lasers. In this program, new methods for compounding high-purity TI-1173 glass (composition Ge28Sb12Se60) and TI-20 glass (composition Ge33As12Se55) were developed. At the present stage of purity, the absorption for TI-1173 at 10.6 micrometers is about 0.01/cm. The absorption is dominated by the silica content of the glass and can be lowered if the impurity is...
Topics: DTIC Archive, Hilton, A R, TEXAS INSTRUMENTS INC DALLAS CENTRAL RESEARCH LABS, *INFRARED OPTICAL...
This program is concerned with three project areas: Chemical Infrared Lasers, Electrical Infrared Lasers and Electronic State Lasers. The Chemical Infrared Laser Program is concerned with the development of pulsed HCl laser systems and the study of molecular energy transfer processes. Several new sources of Cl atoms have been identified that lead to improved HCl laser performance. Low-temperature vibrational relaxation measurements in CO2 mixtures indicate a minimum in the relaxation rates near...
Topics: DTIC Archive, NAVAL RESEARCH LAB WASHINGTON DC, *CHEMICAL LASERS, *GAS DYNAMIC LASERS, *GAS LASERS,...
Rhesus monkeys were trained to report the presence of heat produced by a CO2 laser system. Four, 8, and 16 mm diameter beams were directed at the cornea, lids, and face of the animals at irradiances ranging from 1 to 200 mw/sq cm, and the results compared to those of other investigators who utilized human subjects. Several conclusions can be made based upon this study. (1) The cornea does not appear to be sensitive to heat produced by a CO2 laser system at irradiances twice the recommended...
Topics: DTIC Archive, Randolph, David I., Stuck, Bruce E., LETTERMAN ARMY INST OF RESEARCH PRESIDIO OF SAN...
