Science.gov

Sample records for laser balancing system

  1. Microprocessor-Controlled Laser Balancing System

    NASA Technical Reports Server (NTRS)

    Demuth, R. S.

    1985-01-01

    Material removed by laser action as part tested for balance. Directed by microprocessor, laser fires appropriate amount of pulses in correct locations to remove necessary amount of material. Operator and microprocessor software interact through video screen and keypad; no programing skills or unprompted system-control decisions required. System provides complete and accurate balancing in single load-and-spinup cycle.

  2. Automatic balancing system with laser unit

    NASA Astrophysics Data System (ADS)

    Giers, A.

    1981-01-01

    A balancing plant for miniature rotor gyroscopes was developed, using a pulsed laser for material removal in order to perform the necessary measurements and balancing processes in one single operation. The plant, consisting of five units, is depicted and illustrated by graphs and photographs. The tests were intended to check the machine, to get experimental data, and to investigate the possibilities of this technology. As compared to conventional procedures, this automatic balancing process with laser compensation is rationalized, is faster, is cheaper, and provides a higher balancing quality. The test results confirm the system reliability as well as the process advantages.

  3. Laser Balancing

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Mechanical Technology, Incorporated developed a fully automatic laser machining process that allows more precise balancing removes metal faster, eliminates excess metal removal and other operator induced inaccuracies, and provides significant reduction in balancing time. Manufacturing costs are reduced as a result.

  4. Laser balancing system for high material removal rates

    NASA Technical Reports Server (NTRS)

    Jones, M. G.; Georgalas, G.; Ortiz, A. L.

    1984-01-01

    A laser technique to remove material in excess of 10 mg/sec from a spinning rotor is described. This material removal rate is 20 times greater than previously reported for a surface speed of 30 m/sec. Material removal enhancement was achieved by steering a focused laser beam with moving optics to increase the time of laser energy interaction with a particular location on the circumferential surface of a spinning rotor. A neodymium:yttrium aluminum garnet (Nd:YAG) pulse laser was used in this work to evaluate material removal for carbon steel, 347 stainless steel, Inconal 718, and titanium 6-4. This technique is applicable to dynamic laser balancing.

  5. Balance System

    NASA Technical Reports Server (NTRS)

    1988-01-01

    TherEx Inc.'s AT-1 Computerized Ataxiameter precisely evaluates posture and balance disturbances that commonly accompany neurological and musculoskeletal disorders. Complete system includes two-strain gauged footplates, signal conditioning circuitry, a computer monitor, printer and a stand-alone tiltable balance platform. AT-1 serves as assessment tool, treatment monitor, and rehabilitation training device. It allows clinician to document quantitatively the outcome of treatment and analyze data over time to develop outcome standards for several classifications of patients. It can evaluate specifically the effects of surgery, drug treatment, physical therapy or prosthetic devices.

  6. Nonlocal systems of balance laws in several space dimensions with applications to laser technology

    NASA Astrophysics Data System (ADS)

    Colombo, Rinaldo M.; Marcellini, Francesca

    2015-12-01

    For a class of systems of nonlinear and nonlocal balance laws in several space dimensions, we prove the local in time existence of solutions and their continuous dependence on the initial datum. The choice of this class is motivated by a new model devoted to the description of a metal plate being cut by a laser beam. Using realistic parameters, solutions to this model obtained through numerical integrations meet qualitative properties of real cuts. Moreover, the class of equations considered comprises a model describing the dynamics of solid particles along a conveyor belt.

  7. Laser balancing demonstration on a high-speed flexible rotor

    NASA Technical Reports Server (NTRS)

    Demuth, R. S.; Rio, R. A.; Fleming, D. P.

    1979-01-01

    This paper describes a flexible rotor system used for two-plane laser balancing and an experimental demonstration of the laser material removal method for balancing. A laboratory test rotor was modified to accept balancing corrections using a laser metal removal method while the rotor is at operating speed. The laser setup hardware required to balance the rotor using two correction planes is described. The test rig optical configuration and a neodymium glass laser were assembled and calibrated for material removal rates. Rotor amplitudes before and after balancing, trial and correction weights, rotor speed during operation of laser, and balancing time were documented. The rotor was balanced through the first bending critical speed using the laser material removal procedure to apply trial weights and correction weights without stopping the rotor.

  8. Active control of a balanced two-stage pendulum vibration isolation system and its application to laser interferometric gravity wave detectors

    SciTech Connect

    Veitch, P.J.; Robertson, N.A.; Cantley, C.A.; Hough, J. )

    1993-05-01

    The investigation of the servo control of the position of the bottom mass in a balanced two-stage pendulum vibration isolation system is reported. Experimental results for a simple prototype system and predictions based on a model presented in this paper are in good agreement. The application of such a system to a high-sensitivity laser interferometric gravity wave detector is discussed.

  9. Balance Evaluation Systems

    NASA Technical Reports Server (NTRS)

    1996-01-01

    NeuroCom's Balance Master is a system to assess and then retrain patients with balance and mobility problems and is used in several medical centers. NeuroCom received assistance in research and funding from NASA, and incorporated technology from testing mechanisms for astronauts after shuttle flights. The EquiTest and Balance Master Systems are computerized posturography machines that measure patient responses to movement of a platform on which the subject is standing or sitting, then provide assessments of the patient's postural alignment and stability.

  10. Laser Systems

    NASA Technical Reports Server (NTRS)

    1985-01-01

    Tunable diode lasers are employed as radiation sources in high resolution infrared spectroscopy to determine spectral characteristics of gaseous compounds. With other laser systems, they are produced by Spectra-Physics, and used to monitor chemical processes, monitor production of quantity halogen lamps, etc. The Laser Analytics Division of Spectra-Physics credits the system's reliability to a program funded by Langley in the 1970s. Company no longer U.S.-owned. 5/22/97

  11. Research on six-degree-of-freedom calibration system for wind tunnel balances with a collimated laser beam

    NASA Astrophysics Data System (ADS)

    Fan, Zhigang; He, Jin; Zuo, Baojun; Li, Runshun; Jia, Yuansheng; Gui, Bing; Qiu, Junwen; Dong, Milin

    2003-02-01

    A newly-developed six-degree-of-freedom calibration system for the wind tunnel balances is introduced. The frame of the system, the functions and the operating principle of different parts are presented in detail. The system is composed of four parts: the automatically loading subsystem, the automatically resetting subsystem, the data-acquisition subsystem and the measurement subsystem. The results of some cell experiments proved that the system can meet the needs of the present calibration task of the balance. Through further improvement, the system can be also used to calibrate other devices with multi degree-of-freedom and measure the minute shifts, such as the guide rail of machine tool and the assembling of large parts and so on.

  12. Active balance system and vibration balanced machine

    NASA Technical Reports Server (NTRS)

    Qiu, Songgang (Inventor); Augenblick, John E. (Inventor); Peterson, Allen A. (Inventor); White, Maurice A. (Inventor)

    2005-01-01

    An active balance system is provided for counterbalancing vibrations of an axially reciprocating machine. The balance system includes a support member, a flexure assembly, a counterbalance mass, and a linear motor or an actuator. The support member is configured for attachment to the machine. The flexure assembly includes at least one flat spring having connections along a central portion and an outer peripheral portion. One of the central portion and the outer peripheral portion is fixedly mounted to the support member. The counterbalance mass is fixedly carried by the flexure assembly along another of the central portion and the outer peripheral portion. The linear motor has one of a stator and a mover fixedly mounted to the support member and another of the stator and the mover fixedly mounted to the counterbalance mass. The linear motor is operative to axially reciprocate the counterbalance mass.

  13. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W.; Paisner, Jeffrey A.; Story, Thomas

    1989-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency and the like, and provides spectral analysis of a laser beam.

  14. Heterodyne laser spectroscopy system

    DOEpatents

    Wyeth, Richard W.; Paisner, Jeffrey A.; Story, Thomas

    1990-01-01

    A heterodyne laser spectroscopy system utilizes laser heterodyne techniques for purposes of laser isotope separation spectroscopy, vapor diagnostics, processing of precise laser frequency offsets from a reference frequency, and provides spectral analysis of a laser beam.

  15. Rotor balancing apparatus and system

    NASA Technical Reports Server (NTRS)

    Lyman, Frank (Inventor); Lyman, Joseph (Inventor)

    1976-01-01

    Rotor balancing apparatus and a system comprising balance probes for measuring unbalance at the ends of a magnetically suspended rotor are disclosed. Each balance probe comprises a photocell which is located in relationship to the magnetically suspended rotor such that unbalance of the rotor changes the amount of light recorded by each photocell. The signal from each photocell is electrically amplified and displayed by a suitable device, such as an oscilloscope.

  16. Laser beam monitoring system

    DOEpatents

    Weil, Bradley S.; Wetherington, Jr., Grady R.

    1985-01-01

    Laser beam monitoring systems include laser-transparent plates set at an angle to the laser beam passing therethrough and light sensor for detecting light reflected from an object on which the laser beam impinges.

  17. Identifying Balance in a Balanced Scorecard System

    ERIC Educational Resources Information Center

    Aravamudhan, Suhanya; Kamalanabhan, T. J.

    2007-01-01

    In recent years, strategic management concepts seem to be gaining greater attention from the academicians and the practitioner's alike. Balanced Scorecard (BSC) concept is one such management concepts that has spread in worldwide business and consulting communities. The BSC translates mission and vision statements into a comprehensive set of…

  18. Heterodyne laser diagnostic system

    DOEpatents

    Globig, Michael A.; Johnson, Michael A.; Wyeth, Richard W.

    1990-01-01

    The heterodyne laser diagnostic system includes, in one embodiment, an average power pulsed laser optical spectrum analyzer for determining the average power of the pulsed laser. In another embodiment, the system includes a pulsed laser instantaneous optical frequency measurement for determining the instantaneous optical frequency of the pulsed laser.

  19. A Balanced Higher Education System

    ERIC Educational Resources Information Center

    Brown, Roger

    2011-01-01

    This article explores what is meant by "a balanced higher education system". It argues that the Clarkian "triangle of coordination" (Clark, 1983) and the more recent model of Martinez and Richardson (2003) should be replaced by one that distinguishes between "self" and "collective" interests in both the academy and the wider society. Such a scheme…

  20. Hypersonic gasdynamic laser system

    SciTech Connect

    Foreman, K.M.; Maciulaitis, A.

    1990-05-22

    This patent describes a visible, or near to mid infra-red, hypersonic gas dynamic laser system. It comprises: a hypersonic vehicle for carrying the hypersonic gas dynamic laser system, and also providing high energy ram air for thermodynamic excitation and supply of the laser gas; a laser cavity defined within the hypersonic vehicle and having a laser cavity inlet for the laser cavity formed by an opening in the hypersonic vehicle, such that ram air directed through the laser cavity opening supports gas dynamic lasing operations at wavelengths less than 10.6{mu} meters in the laser cavity; and an optical train for collecting the laser radiation from the laser cavity and directing it as a substantially collimated laser beam to an output aperture defined by an opening in the hypersonic vehicle to allow the laser beam to be directed against a target.

  1. Laser satellite power systems

    SciTech Connect

    Walbridge, E.W.

    1980-01-01

    A laser satellite power system (SPS) converts solar power captured by earth-orbiting satellites into electrical power on the earth's surface, the satellite-to-ground transmission of power being effected by laser beam. The laser SPS may be an alternative to the microwave SPS. Microwaves easily penetrate clouds while laser radiation does not. Although there is this major disadvantage to a laser SPS, that system has four important advantages over the microwave alternative: (1) land requirements are much less, (2) radiation levels are low outside the laser ground stations, (3) laser beam sidelobes are not expected to interfere with electromagnetic systems, and (4) the laser system lends itself to small-scale demonstration. After describing lasers and how they work, the report discusses the five lasers that are candidates for application in a laser SPS: electric discharge lasers, direct and indirect solar pumped lasers, free electron lasers, and closed-cycle chemical lasers. The Lockheed laser SPS is examined in some detail. To determine whether a laser SPS will be worthy of future deployment, its capabilities need to be better understood and its attractiveness relative to other electric power options better assessed. First priority should be given to potential program stoppers, e.g., beam attenuation by clouds. If investigation shows these potential program stoppers to be resolvable, further research should investigate lasers that are particularly promising for SPS application.

  2. Engineering redox balance through cofactor systems.

    PubMed

    Chen, Xiulai; Li, Shubo; Liu, Liming

    2014-06-01

    Redox balance plays an important role in the production of enzymes, pharmaceuticals, and chemicals. To meet the demands of industrial production, it is desirable that microbes maintain a maximal carbon flux towards target metabolites with no fluctuations in redox. This requires functional cofactor systems that support dynamic homeostasis between different redox states or functional stability in a given redox state. Redox balance can be achieved by improving the self-balance of a cofactor system, regulating the substrate balance of a cofactor system, and engineering the synthetic balance of a cofactor system. This review summarizes how cofactor systems can be manipulated to improve redox balance in microbes.

  3. Laser material processing system

    DOEpatents

    Dantus, Marcos

    2015-04-28

    A laser material processing system and method are provided. A further aspect of the present invention employs a laser for micromachining. In another aspect of the present invention, the system uses a hollow waveguide. In another aspect of the present invention, a laser beam pulse is given broad bandwidth for workpiece modification.

  4. Laser cutting system

    SciTech Connect

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  5. Infrared laser system

    DOEpatents

    Cantrell, Cyrus D.; Carbone, Robert J.; Cooper, Ralph

    1982-01-01

    An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture.

  6. Infrared laser system

    DOEpatents

    Cantrell, Cyrus D.; Carbone, Robert J.; Cooper, Ralph S.

    1977-01-01

    An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture.

  7. Underwater laser system

    NASA Astrophysics Data System (ADS)

    Kushina, Mark E.; Heberle, Geoff; Hope, Michael; Crittenden, Ryan M.; Bethel, Michael

    2002-03-01

    We have developed a solid-state laser operating at 532nm for underwater topographic investigations. The laser system is integrated into a torpedo-like 'towed-body', with the military designation of AQS-20. This laser, along with other sophisticated receiver opto-electronic systems enables detailed underwater bathymetry. CEO designed and manufactured the laser portion of this system. The laser sub-system is comprised of two separate parts: the LTU (Laser Transmitter Unit) and the LEU (Laser Electronics Unit). The LTU and LEU where put through Mil-standard testing for vibration, shock and temperature storage and operation extremes as well as Mil-461C EMI/EMC testing. The Nd:YAG laser operates at a 400 Hz pulse repetition frequency and is controlled remotely, tethered to the system controller in a ship or helicopter. Power monitor circuits allow real time laser health monitoring, which enables input parameter adjustments for consistent laser behavior. The towed body moves forward at a constant rate of speed while this underwater LIDAR system gathers data. All heat generated must be conducted into the outer hull of the towed-body and then, to the surrounding ambient ocean water. The water temperature may vary from 0-35 degrees C.

  8. Laser rocket system analysis

    NASA Technical Reports Server (NTRS)

    Jones, W. S.; Forsyth, J. B.; Skratt, J. P.

    1979-01-01

    The laser rocket systems investigated in this study were for orbital transportation using space-based, ground-based and airborne laser transmitters. The propulsion unit of these systems utilizes a continuous wave (CW) laser beam focused into a thrust chamber which initiates a plasma in the hydrogen propellant, thus heating the propellant and providing thrust through a suitably designed nozzle and expansion skirt. The specific impulse is limited only by the ability to adequately cool the thruster and the amount of laser energy entering the engine. The results of the study showed that, with advanced technology, laser rocket systems with either a space- or ground-based laser transmitter could reduce the national budget allocated to space transportation by 10 to 345 billion dollars over a 10-year life cycle when compared to advanced chemical propulsion systems (LO2-LH2) of equal capability. The variation in savings depends upon the projected mission model.

  9. The Geoscience Laser Altimeter System Laser Transmitter

    NASA Technical Reports Server (NTRS)

    Afzal, R. S.; Dallas, J. L.; Yu, A. W.; Mamakos, W. A.; Lukemire, A.; Schroeder, B.; Malak, A.

    2000-01-01

    The Geoscience Laser Altimeter System (GLAS), scheduled to launch in 2001, is a laser altimeter and lidar for tile Earth Observing System's (EOS) ICESat mission. The laser transmitter requirements, design and qualification test results for this space- based remote sensing instrument are presented.

  10. The human balance system and gender.

    PubMed

    Olchowik, Grażyna; Tomaszewski, Marek; Olejarz, Piotr; Warchoł, Jan; Różańska-Boczula, Monika; Maciejewski, Ryszard

    2015-01-01

    The human body balance system is a complex system of organs and mechanisms, which generate postural reactions to counter the displacement from the equilibrium position of the body centre of gravity, and which control eye movement in order to maintain a stable image of the environment. Computerised Dynamic Posturography (CDP) allows for a quantitative and objective assessment of the sen- sory and motor components of the body balance control system as well as of the integration and adaptive mechanisms in the central nervous system. The aim of this study was to determine the differences, when maintaining body balance, based on the gender of young, healthy people using CDP. The study was carried out on a group of 43 healthy subjects by comparing the effectiveness of the balance system in 22 women and 21 men aged between 20 and 26 years, between 171 and 177 cm in height, and without any clinical symptoms of balance disorders. The men and women were selected such that they did not differ significantly in height and BMI. Using the Equitest posturograph manufactured by NeuroCom International Inc. the following tests were performed: Sensory Organisation Test (SOT), Motor Control Test (MCT) and the Adaptation Test (ADT). The gender of young healthy individuals without any clinical symptoms of balance disorders also does not affect the effectiveness of the sensory system and the use of this signal in maintaining body balance. PMID:25952976

  11. Surface Energy Balance System (SEBS) Handbook

    SciTech Connect

    Cook, DR

    2011-02-14

    A Surface Energy Balance System (SEBS) has been installed collocated with each deployed ECOR system at the Southern Great Plains (SGP), North Slope of Alaska (NSA), Tropical Western Pacific (TWP), ARM Mobile Facility 1 (AMF1), and ARM Mobile Facility 2 (AMF2). The surface energy balance system consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes.

  12. Magnetic suspension and balance systems (MSBSs)

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.; Kilgore, Robert A.

    1987-01-01

    The problems of wind tunnel testing are outlined, with attention given to the problems caused by mechanical support systems, such as support interference, dynamic-testing restrictions, and low productivity. The basic principles of magnetic suspension are highlighted, along with the history of magnetic suspension and balance systems. Roll control, size limitations, high angle of attack, reliability, position sensing, and calibration are discussed among the problems and limitations of the existing magnetic suspension and balance systems. Examples of the existing systems are presented, and design studies for future systems are outlined. Problems specific to large-scale magnetic suspension and balance systems, such as high model loads, requirements for high-power electromagnets, high-capacity power supplies, highly sophisticated control systems and position sensors, and high costs are assessed.

  13. Underwater laser detection system

    NASA Astrophysics Data System (ADS)

    Gomaa, Walid; El-Sherif, Ashraf F.; El-Sharkawy, Yasser H.

    2015-02-01

    The conventional method used to detect an underwater target is by sending and receiving some form of acoustic energy. But the acoustic systems have limitations in the range resolution and accuracy; while, the potential benefits of a laserbased underwater target detection include high directionality, high response, and high range accuracy. Lasers operating in the blue-green region of the light spectrum(420 : 570nm)have a several applications in the area of detection and ranging of submersible targets due to minimum attenuation through water ( less than 0.1 m-1) and maximum laser reflection from estimated target (like mines or submarines) to provide a long range of detection. In this paper laser attenuation in water was measured experimentally by new simple method by using high resolution spectrometer. The laser echoes from different targets (metal, plastic, wood, and rubber) were detected using high resolution CCD camera; the position of detection camera was optimized to provide a high reflection laser from target and low backscattering noise from the water medium, digital image processing techniques were applied to detect and discriminate the echoes from the metal target and subtract the echoes from other objects. Extraction the image of target from the scattering noise is done by background subtraction and edge detection techniques. As a conclusion, we present a high response laser imaging system to detect and discriminate small size, like-mine underwater targets.

  14. Ultra-fast laser system

    DOEpatents

    Dantus, Marcos; Lozovoy, Vadim V

    2014-01-21

    A laser system is provided which selectively excites Raman active vibrations in molecules. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and remote sensing.

  15. Balanced bridge feedback control system

    NASA Technical Reports Server (NTRS)

    Lurie, Boris J. (Inventor)

    1990-01-01

    In a system having a driver, a motor, and a mechanical plant, a multiloop feedback control apparatus for controlling the movement and/or positioning of a mechanical plant, the control apparatus has a first local bridge feedback loop for feeding back a signal representative of a selected ratio of voltage and current at the output driver, and a second bridge feedback loop for feeding back a signal representative of a selected ratio of force and velocity at the output of the motor. The control apparatus may further include an outer loop for feeding back a signal representing the angular velocity and/or position of the mechanical plant.

  16. Coherent laser vision system

    SciTech Connect

    Sebastion, R.L.

    1995-10-01

    The Coherent Laser Vision System (CLVS) is being developed to provide precision real-time 3D world views to support site characterization and robotic operations and during facilities Decontamination and Decommissioning. Autonomous or semiautonomous robotic operations requires an accurate, up-to-date 3D world view. Existing technologies for real-time 3D imaging, such as AM laser radar, have limited accuracy at significant ranges and have variability in range estimates caused by lighting or surface shading. Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no-moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic to coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  17. Excimer laser system Profile-500

    NASA Astrophysics Data System (ADS)

    Atejev, V. V.; Bukreyev, V. S.; Vartapetov, Serge K.; Semenov, A. D.; Sugrobov, V. A.; Turin, V. S.; Fedorov, Sergei N.

    1999-07-01

    The description of ophthalmological excimer laser system 'PROFILE-500' for photorefractive and physiotherapeutic keratectomy is presented. Excimer Laser Systems 'PROFILE- 500' are optical system that use ArF excimer lasers to perform photorefractive keratectomy or LASIK; surgical procedures used to correct myopia, hyperopia and astigmatism.

  18. Laser system preset unit

    DOEpatents

    Goodwin, William L.

    1977-01-01

    An electronic circuit is provided which may be used to preset a digital display unit of a Zeeman-effect layer interferometer system which derives distance measurements by comparing a reference signal to a Doppler signal generated at the output of the interferometer laser head. The circuit presets dimensional offsets in the interferometer digital display by electronically inducing a variation in either the Doppler signal or the reference signal, depending upon the direction of the offset, to achieve the desired display preset.

  19. Laser pointing determination for the geoscience laser altimeter system

    NASA Technical Reports Server (NTRS)

    Miller, Pamela S.; Sirota, J. Marcos

    1998-01-01

    The Geoscience Laser Altimeter System (GLAS) is a space-based lidar being developed to monitor changes in the mass balance of the Earth's polar ice sheets (Thomas et al. 1985). GLAS is part of NASA's Earth Observing System (Schutz 1995), and is being designed to launch into a 600 km circular polar orbit in the year 2001, for continuous operation over 3 to 5 years. The orbit's 94 degree inclination has been selected to allow good coverage and profile patterns over the ice sheets of Greenland and Antarctica. The GLAS mission uses a small dedicated spacecraft provided by Ball Aerospace, which is required to have a very stable nadir and zenith pointing platform which points to within approximately 100 urad (20 arcseconds) of Nadir. Accurate knowledge of the laser beam's pointing angle (in the far field) is critical since pointing the laser beam away from nadir biases the altimetry measurements (Gardner 1992, Bufton et al. 1991). This error is a function of the distance of the laser centroid off nadir multiplied by the orbit altitude and the tangent of the slope angle of the terrain. Most of the ice sheet surface slopes are less than 1? resulting in pointing knowledge bias of only 7.6 cm with 7.3 urad accuracy, and overall single shot height accuracy of approximately 15 cm. However, over a 3 deg surface slope pointing knowledge to approximately 7.3 urad is the largest error source (23 cm) in achieving 26 cm height accuracy. The GLAS design incorporates a stellar reference system (SRS) to relate the laser beam pointing angle to the star field to an accuracy of 7.3 urad. The stellar reference system combines an attitude determination system (ADS) operating from 4 to 10 Hz coupled to a 40 Hz laser reference system (LRS) to perform this task.

  20. Reflective optical imaging system with balanced distortion

    DOEpatents

    Chapman, Henry N.; Hudyma, Russell M.; Shafer, David R.; Sweeney, Donald W.

    1999-01-01

    An optical system compatible with short wavelength (extreme ultraviolet) An optical system compatible with short wavelength (extreme ultraviolet) radiation comprising four reflective elements for projecting a mask image onto a substrate. The four optical elements comprise, in order from object to image, convex, concave, convex and concave mirrors. The optical system is particularly suited for step and scan lithography methods. The invention enables the use of larger slit dimensions associated with ring field scanning optics, improves wafer throughput and allows higher semiconductor device density. The inventive optical system is characterized by reduced dynamic distortion because the static distortion is balanced across the slit width.

  1. Efficacy of virtual reality-based balance training versus the Biodex balance system training on the body balance of adults

    PubMed Central

    Ibrahim, Manal S.; Mattar, Ayman G.; Elhafez, Salam M.

    2016-01-01

    [Purpose] This study investigated efficacy of virtual reality (VR)-based balance training on enhancing balance and postural reactions of adults as a low-cost new modality compared to the established Biodex Balance System (BBS). [Subjects] Thirty normal adults of both genders were divided randomly into two equal-sized experimental groups of 15: BBS balance training and VR balance training. [Methods] The training programmes were conducted in 12 sessions, three 15-min sessions per week. The Nintendo® Wii Fit Plus (NWFP) and its balance board were used to train of the VR group. Each participant answered a questionnaire concerning usability, enjoyment, balance improvement, and fatigue at the end of the training programs. [Results] The study found a significant increase the measure of mean overall balance (OLB) in both groups. No significant difference was found between the groups, but a significant decrease in the mean balance-test time was found for both groups, with no significant difference between the two training methods. The VR programme was rated highly enjoyable by 81.8% of the group. [Conclusion] The Wii Fit Plus system with the balance board as a new VR balance-training technique, can be considered an effective and enjoyable tool for the training of adults’ body balance. PMID:26957722

  2. Efficacy of virtual reality-based balance training versus the Biodex balance system training on the body balance of adults.

    PubMed

    Ibrahim, Manal S; Mattar, Ayman G; Elhafez, Salam M

    2016-01-01

    [Purpose] This study investigated efficacy of virtual reality (VR)-based balance training on enhancing balance and postural reactions of adults as a low-cost new modality compared to the established Biodex Balance System (BBS). [Subjects] Thirty normal adults of both genders were divided randomly into two equal-sized experimental groups of 15: BBS balance training and VR balance training. [Methods] The training programmes were conducted in 12 sessions, three 15-min sessions per week. The Nintendo(®) Wii Fit Plus (NWFP) and its balance board were used to train of the VR group. Each participant answered a questionnaire concerning usability, enjoyment, balance improvement, and fatigue at the end of the training programs. [Results] The study found a significant increase the measure of mean overall balance (OLB) in both groups. No significant difference was found between the groups, but a significant decrease in the mean balance-test time was found for both groups, with no significant difference between the two training methods. The VR programme was rated highly enjoyable by 81.8% of the group. [Conclusion] The Wii Fit Plus system with the balance board as a new VR balance-training technique, can be considered an effective and enjoyable tool for the training of adults' body balance. PMID:26957722

  3. Laser Communication System Design

    NASA Astrophysics Data System (ADS)

    Casey, W. L.; Doughty, G. R.; Houston, , J. G.; Marston, R. K.; O'Pella, L. J.; Vo, L. V.

    1988-11-01

    The Air Force is interested in laser communication systems for a variety of air-to-air applications. Laser data transmission offers significant advantages over RF systems in certain areas including higher data rates with low transmitter power, narrower beam divergence leading to difficulty in interception, narrower field of view coupled with high off-axis energy rejection which makes jamming a very formidable task, and smaller antenna size which creates minimum installation impact on an aircraft. The applications with the greatest near-term potential involve the transfer of data between large aircraft operating in relatively benign dynamic environments normally present at altitudes of about 30,000 feet. Systems performing these strategic data exchange (SDE) functions must operate at ranges of 100 to 200 nautical miles at data rates of 2 to 3 megabits per second and the probability of bit error rates not exceeding 10-6. The paper presents the major communication channel elements of a design for a lasercom system performing SDE roles. The design is established by comparing the advantages of the different approaches. The final design selection is based on the transmitter characteristics required for each system. The characteristics include physical properties, development risk, cost, as well as the flexibility for meeting more stringent system performance specifications without requiring major redesign.

  4. Laser multiplexing system

    DOEpatents

    Johnson, Steve A.; English, Jr., Ronald Edward; White, Ronald K.

    2001-01-01

    A plurality of copper lasers, as radiant power sources, emits a beam of power carrying radiation. A plurality of fiber injection assemblies receives power from the plurality of copper lasers and injects such power into a plurality of fibers for individually transmitting the received power to a plurality of power-receiving devices. The power-transmitting fibers of the system are so arranged that power is delivered therethrough to each of the power-receiving devices such that, even if a few of the radiant power sources and/or fibers fail, the power supply to any of the power receiving devices will not completely drop to zero but will drop by the same proportionate amount.

  5. Surface Energy Balance System (SEBS) Handbook

    SciTech Connect

    Cook, D. R.

    2016-01-01

    A Surface Energy Balance System (SEBS) has been installed collocated with each deployed Eddy Correlation Flux Measurement System (ECOR) at the Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Southern Great Plains (SGP) site, North Slope of Alaska (NSA) site, first ARM Mobile Facility (AMF1), second ARM Mobile Facility (AMF2), and third ARM Mobile Facility (AMF3) at Oliktok Point (OLI). A SEBS was also deployed with the Tropical Western Pacific (TWP) site, before it was decommissioned. Data from these sites, including the retired TWP, are available in the ARM Data Archive. The SEBS consists of upwelling and downwelling solar and infrared radiometers within one net radiometer, a wetness sensor, and soil measurements. The SEBS measurements allow the comparison of ECOR sensible and latent heat fluxes with the energy balance determined from the SEBS and provide information on wetting of the sensors for data quality purposes.

  6. Battery Cell Balancing System and Method

    NASA Technical Reports Server (NTRS)

    Davies, Francis J. (Inventor)

    2014-01-01

    A battery cell balancing system is operable to utilize a relatively small number of transformers interconnected with a battery having a plurality of battery cells to selectively charge the battery cells. Windings of the transformers are simultaneously driven with a plurality of waveforms whereupon selected battery cells or groups of cells are selected and charged. A transformer drive circuit is operable to selectively vary the waveforms to thereby vary a weighted voltage associated with each of the battery cells.

  7. Balancing Hydronic Systems in Multifamily Buildings

    SciTech Connect

    Ruch, Russell; Ludwig, Peter; Maurer, Tessa

    2014-07-01

    In multifamily hydronic systems, temperature imbalance may be caused by undersized piping, improperly adjusted balancing valves, inefficient water temperature and flow levels, and owner/occupant interaction with the boilers, distribution, and controls. The imbalance leads to tenant discomfort, higher energy use intensity, and inefficient building operation. This research, conducted by Building America team Partnership for Advanced Residential Retrofit, explores cost-effective distribution upgrades and balancing measures in multifamily hydronic systems, providing a resource to contractors, auditors, and building owners on best practices to improve tenant comfort and lower operating costs. The team surveyed existing knowledge on cost-effective retrofits for optimizing distribution in typical multifamily hydronic systems, with the aim of identifying common situations and solutions, and then conducted case studies on two Chicago area buildings with known balancing issues in order to quantify the extent of temperature imbalance. At one of these buildings a booster pump was installed on a loop to an underheated wing of the building. This study found that unit temperature in a multifamily hydronic building can vary as much as 61°F, particularly if windows are opened or tenants use intermittent supplemental heating sources like oven ranges. Average temperature spread at the building as a result of this retrofit decreased from 22.1°F to 15.5°F.

  8. Balancing Hydronic Systems in Multifamily Buildings

    SciTech Connect

    Ruch, R.; Ludwig, P.; Maurer, T.

    2014-07-01

    In multifamily hydronic systems, temperature imbalance may be caused by undersized piping, improperly adjusted balancing valves, inefficient water temperature and flow levels, and owner/occupant interaction with the boilers, distribution and controls. The effects of imbalance include tenant discomfort, higher energy use intensity and inefficient building operation. This paper explores cost-effective distribution upgrades and balancing measures in multifamily hydronic systems, providing a resource to contractors, auditors, and building owners on best practices to improve tenant comfort and lower operating costs. The research was conducted by The Partnership for Advanced Residential Retrofit (PARR) in conjunction with Elevate Energy. The team surveyed existing knowledge on cost-effective retrofits for optimizing distribution in typical multifamily hydronic systems, with the aim of identifying common situations and solutions, and then conducted case studies on two Chicago area buildings with known balancing issues in order to quantify the extent of temperature imbalance. At one of these buildings a booster pump was installed on a loop to an underheated wing of the building. This study found that unit temperature in a multifamily hydronic building can vary as much as 61 degrees F, particularly if windows are opened or tenants use intermittent supplemental heating sources like oven ranges. Average temperature spread at the building as a result of this retrofit decreased from 22.1 degrees F to 15.5 degrees F.

  9. Development of a multiplane multispeed balancing system for turbine systems

    NASA Technical Reports Server (NTRS)

    Martin, M. R.

    1984-01-01

    A prototype high speed balancing system was developed for assembled gas turbine engine modules. The system permits fully assembled gas turbine modules to be operated and balanced at selected speeds up to full turbine speed. The balancing system is a complete stand-alone system providing all necesary lubrication and support hardware for full speed operation. A variable speed motor provides the drive power. A drive belt and gearbox provide rotational speeds up to 21,000 rpm inside a vacuum chamber. The heart of the system is a dedicated minicomputer with attendant data acquisition, storage and I/O devices. The computer is programmed to be completely interactive with the operator. The system was installed at CCAD and evaluated by testing 20 T55 power turbines and 20 T53 power turbines. Engine test results verified the performance of the high speed balanced turbines.

  10. Applications of Ion Laser Systems

    NASA Astrophysics Data System (ADS)

    Fletcher, Peter W.

    1987-04-01

    This paper provides an introduction to the more common applications of ion laser systems. Applications discussed include photocoagulation, flow cytometry, laser disk mastering, laser doppler velocimetry, Raman spectroscopy, holography, laser light shows, large screen projection, fingerprint detection, and applications in printing such as color separation and scanning. All these applications are currently in widespread use. At the end of the paper a short review is provided of developing applications such as cardiovascular surgery and semiconductor processing.

  11. Compact laser amplifier system

    DOEpatents

    Carr, R.B.

    1974-02-26

    A compact laser amplifier system is described in which a plurality of face-pumped annular disks, aligned along a common axis, independently radially amplify a stimulating light pulse. Partially reflective or lasing means, coaxially positioned at the center of each annualar disk, radially deflects a stimulating light directed down the common axis uniformly into each disk for amplification, such that the light is amplified by the disks in a parallel manner. Circumferential reflecting means coaxially disposed around each disk directs amplified light emission, either toward a common point or in a common direction. (Official Gazette)

  12. Laser system using ultra-short laser pulses

    DOEpatents

    Dantus, Marcos; Lozovoy, Vadim V.; Comstock, Matthew

    2009-10-27

    A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

  13. SERI laser scanner system

    SciTech Connect

    Matson, R.J.; Cannon, T.W.

    1980-10-01

    A Laser Scanner System (LSS) produces a photoresponse map and can be used for the nondestructive detection of nonuniformities in the photoresponse of a semiconductor device. At SERI the photoresponse maps are used to identify solar cell faults including microcracks, metallization breaks, regions of poor contact between metallization and the underlying emitter surface, and variations in emitter sheet resistance. The SERI LSS is patterned after the LSS unit documented in the NBS Special Publication 400-24 A Laser Scanner for Semiconductor Devices by D.E. Sawyer and D.W. Berning. Assuming reader familiarity with the above publication, the modifications introduced by SERI are specified with the intention that the two reports can be used to reproduce the SERI LSS. The optical and electronic systems are reviewed, briefly discussing the significant items of each. The most notable difference between the two systems is the SERI substitution of commercially available state-of-the-art modular electronics for the discreet component circuitry used in the NBS LSS.

  14. Laser system for isotope separation

    NASA Astrophysics Data System (ADS)

    Shirayama, Shimpey; Mikatsura, Takefumi; Ueda, Hiroaki; Konagai, Chikara

    1990-06-01

    Atomic vapor laser isotope separation (AVLIS) is regarded as the most promising method to obtain srightly enriched economical nuclear fuel for a nuclear power plant. However, achieving a high power laser seems to be the bottle neck in its industrialization. In 1985, after successful development of high power lasers, the U.S. announced that AVLIS would be used for future methods of uranium enrichment. In Japan , Laser Atomic Separation Enrichment Research Associates of Japan (LASER-J), a joint Japanese utility companies research organization, was founded in April, 1987, to push a development program for laser uranium enrichment. Based on research results obtained from Japanese National Labs, and Universities , Laser-J is now constructing an AVLIS experimental facility at Tokai-mura. It is planned to have a 1-ton swu capacity per year in 1991. Previous to the experimental facility construction , Toshiba proceeded with the preliminary testing of an isotope separation system, under contract with Laser-J. Since the copper vapor laser (CVL) and the dye laser (DL) form a good combination , which can obtain high power tunable visible lights ,it is suitable to resonate uranium atoms. The laser system was built and was successfully operated in Toshiba for two years. The system consist of three copper vapor lasers , three dye lasers and appropriate o Atomic vapor laser isotope separation (AVLIS) is regarded as the most promising method to obtain srightly enriched economical nuclear fuel for a nuclear power plant. However, achieving a high power laser seems to be the bottle neck in its industrialization. In 1985, after successful development of high power lasers, the U.S. announced that AVLIS would be used for future methods of uranium enrichment. In Japan , Laser Atomic Separation Enrichment Research Associates of Japan (LASER-J) , a joint Japanese utility companies research organization , was founded in April, 1987, to push a development program for laser uranium enrichment

  15. Laser interlock system

    SciTech Connect

    Woodruff, Steven D; Mcintyre, Dustin L

    2015-01-13

    A method and device for providing a laser interlock having a first optical source, a first beam splitter, a second optical source, a detector, an interlock control system, and a means for producing dangerous optical energy. The first beam splitter is optically connected to the first optical source, the first detector and the second optical source. The detector is connected to the interlock control system. The interlock control system is connected to the means for producing dangerous optical energy and configured to terminate its optical energy production upon the detection of optical energy at the detector from the second optical source below a predetermined detector threshold. The second optical source produces an optical energy in response to optical energy from the first optical source. The optical energy from the second optical source has a different wavelength, polarization, modulation or combination thereof from the optical energy of the first optical source.

  16. Nutrient balance on Nebraska livestock confinement systems.

    PubMed

    Koelsch, R; Lesoing, G

    1999-01-01

    Managing the environmental risk associated with livestock production is a significant challenge. Nitrogen and phosphorus are commonly implicated as the sources of ground and surface water quality problems associated with livestock production. The degree of imbalance between these nutrient inputs and the managed nutrient outputs for a livestock operation defines the magnitude of potential environmental risk and provides insight as to the underlying causes of these challenges. A nitrogen and phosphorus balance was constructed for 33 Nebraska confinement livestock operations. Twenty-five and 17 of these operations experienced significant nitrogen and phosphorus imbalances, respectively (50% more nutrient inputs than outputs). Nutrient inputs on many livestock operations were observed to be two to four times greater than nutrient outputs as managed crop and livestock products. Size of the livestock operation and the degree of integration of livestock with a cropping operation provided only limited explanation of the variation in nutrient balance observed among the individual operations. Management options that contribute to a more favorable nutrient balance were also identified. Management decisions related to feeding program and exporting of manure nutrients to off-farm users were observed to have a substantial impact on the nutrient imbalance. For modern livestock production systems to successfully respond to nutrient-related environmental problems, management strategies must be implemented that address the commonly experienced imbalances of nitrogen and phosphorus. PMID:15526781

  17. Second generation laser manufacturing systems

    NASA Astrophysics Data System (ADS)

    La Rocca, Aldo V.

    1996-03-01

    Laser processing can show its full capacity in laser multiprocessing systems applications in which the laser is not hindered by the constraints imposed when the laser is inserted in conventional systems without reassessing the overall system design. In these cases the laser process performance up to now was kept at very low levels because conventional systems would not need or accept higher ones. Instead now said performance must be brought to the upper limits inasmuch as the lasers will be the pacesetter for the performance of the new systems freed from all the old design bondage. Hence the importance to get the maximum performance from each process singly and from their combinations. Better understanding and control of the fluidynamic effects becomes mandatory because of their paramount role on process energy efficiency and thus process productivity and more important yet quality, repeatability and transferability. At present one of the dedicated laser multiprocessing systems of greatest interest is the laser cut-weld of which several have made appearance on the market. Next to come are the 'augmented' laser multiprocessing obtained by combining the laser with conventional processes in a manner which takes advantages of unexpected synergies permitted by the laser. In this manner, the system is allowed to outperform, in all aspects from productivity to quality, the already much higher performance of dedicated all laser multi- processing system. One of the most important 'augmented' laser multiprocessing is the cut- bend-weld. It should be clear that these flexible multiprocessing machines tend to grow naturally in multistation cells and their aggregation in isles and complete manufacturing centers; i.e., the first viable realizations of computer integrated manufacturing.

  18. Mass balancing and spring element manipulation of micromechanical silicon-gyrometers with ultrashort laser pulses

    NASA Astrophysics Data System (ADS)

    Klug, U.; Rahn, B.; Stute, U.; Ostendorf, A.

    2005-07-01

    Utilisation of ultrashort laser pulses enables high precision in laser micromachining processes. Due to low thermal interaction between laser beam and matter, the vicinity of the laser ablation is free from melt and heat influenced zones. Established laser microstructuring processes on basis of femtosecond laser pulses have been applied for manipulation of micromechanical components of Silicon-gyrometers that are manufactured for the automotive industry. Compensation of mechanical imbalance, and adjustment of resonance frequencies have been successfully performed by mass balancing, and manipulation of the spring elements' geometries by laser ablation with a lateral resolution of 10-20 μm, and a vertical resolution of 500 nm-4 μm. The approach for automated laser processing on wafer-level is demonstrated.

  19. Laser system using regenerative amplifier

    DOEpatents

    Emmett, J.L.

    1980-03-04

    High energy laser system is disclosed using a regenerative amplifier, which relaxes all constraints on laser components other than the intrinsic damage level of matter, so as to enable use of available laser system components. This can be accomplished by use of segmented components, spatial filters, at least one amplifier using solid state or gaseous media, and separated reflector members providing a long round trip time through the regenerative cavity, thereby allowing slower switching and adequate time to clear the spatial filters, etc. The laser system simplifies component requirements and reduces component cost while providing high energy output. 10 figs.

  20. Laser system using regenerative amplifier

    DOEpatents

    Emmett, John L. [Pleasanton, CA

    1980-03-04

    High energy laser system using a regenerative amplifier, which relaxes all constraints on laser components other than the intrinsic damage level of matter, so as to enable use of available laser system components. This can be accomplished by use of segmented components, spatial filters, at least one amplifier using solid state or gaseous media, and separated reflector members providing a long round trip time through the regenerative cavity, thereby allowing slower switching and adequate time to clear the spatial filters, etc. The laser system simplifies component requirements and reduces component cost while providing high energy output.

  1. Magnetic suspension and balance system study

    NASA Technical Reports Server (NTRS)

    Boom, R. W.; Eyssa, Y. M.; Mcintosh, G. E.; Abdelsalam, M. K.

    1984-01-01

    A compact design for a superconducting magnetic suspension and balance system is developed for a 8 ft. x 8 ft. transonic wind tunnel. The main features of the design are: a compact superconducting solenoid in the suspended airplane model; permanent magnet wings; one common liquid helium dewar for all superconducting coils; efficient new race track coils for roll torques; use of established 11 kA cryostable AC conductor; acceptable AC losses during 10 Hz control even with all steel structure; and a 560 liter/hour helium liquefier. Considerable design simplicity, reduced magnet weights, and reduced heat leak results from using one common dewar which eliminates most heavy steel structure between coils and the suspended model. Operational availability is thought to approach 100% for such magnet systems. The weight and cost of the magnet system is approximately one-third that of previous less compact designs.

  2. Development of laser transmission system

    NASA Astrophysics Data System (ADS)

    Song, Jiawu; Zhang, Yulan; Yang, Jiandong; Zhang, Xinming

    1998-08-01

    This paper discusses a light transfer system of therapeutic machine using carbon-dioxide laser. This system is based on imitating human being arm motion principle, consists of optical cardans mainly and can move in three-D space freely. Through it carbon-dioxide laser (which wavelength is 10.6 micrometer) is reflected, focused or diverged and transferred to the different therapeutic part of body to realize the purpose of cutting operation, gasification, cauterization and irradiation. This system includes an indicating system using He-Ne laser, by which carbon-dioxide laser can arrive therapeutic part accurately. This system possesses some advantages e.g. an accurate transfer, large moving range, small power consumption, high power density and easy operation. At present the occupancy in home market of this kind laser transfer system products is over 95%. Some products have been exported to other countries.

  3. Force Balances in Systems of Cylindrical Polyelectrolytes

    PubMed Central

    Brenner, Stephen L.; McQuarrie, Donald A.

    1973-01-01

    A detailed analysis is made of the model system of two parallel cylindrical polyelectrolytes which contain ionizable groups on their surfaces and are immersed in an ionic bathing medium. The interaction between the cylinders is examined by considering the interplay between repulsive electrostatic forces and attractive forces of electrodynamic origin. The repulsive force arises from the screened coulomb interaction between the surface charge distributions on the cylinders and has been treated by developing a solution to the linearized Poisson-Boltzmann equation. The boundary condition at the cylinder surfaces is determined as a self-consistent functional of the potential, with the input consisting of the density of ionizable groups and their dissociation constants. It is suggested that a reasonably accurate representation for the form of the attractive force can be obtained by performing a pairwise summation of the individual interatomic forces. A quantitative estimate is obtained using a Hamaker constant chosen on the basis of rigorous calculations on simpler systems. It is found that a balance exists between these repulsive and attractive forces at separations in good agreement with those observed in arrays of tobacco mosaic virus and in the A band myosin lattice in striated muscle. The behavior of the balance point as a function of the pH and ionic strength of the bathing medium closely parallels that seen experimentally. PMID:4696760

  4. Variable emissivity laser thermal control system

    DOEpatents

    Milner, Joseph R.

    1994-01-01

    A laser thermal control system for a metal vapor laser maintains the wall mperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser.

  5. Laser power conversion system analysis

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Orbit to orbit and orbit to ground laser power conversion systems and power transfer are discussed. A system overview is presented. Pilot program parameters are considered: SLPS assumptions are listed, a laser SPS overview is presented, specifications are listed, and SLPS coats are considered.

  6. Water balance in fuel cells systems.

    SciTech Connect

    Kopasz, J.; Ahmed, S.; Kumar, R.; Krumpelt, M.

    2002-01-10

    Fuel cell systems are attractive for their high efficiency (i.e., electric power generated per weight/volume of fuel,) and lower emissions. These systems are being developed for applications that include transportation (propulsion and auxiliary), remote stationary, and portable. Where these systems use on-board fuel processing of available fuels, the fuel processor requires high-purity water. For utility applications, this water may be available on-site, but for most applications, the process water must be recovered from the fuel cell system exhaust gas. For such applications, it is critically important that the fuel cell system be a net water-producing device. A variety of environmental conditions (e.g., ambient temperature, pressure), fuel cell system design, and operating conditions determine whether the fuel cell system is water-producing or water-consuming. This paper will review and discuss the conditions that determine the net-water balance of a generic fuel cell system and identify some options that will help meet the water needs of the fuel processor.

  7. Voltage balanced multilevel voltage source converter system

    DOEpatents

    Peng, Fang Zheng; Lai, Jih-Sheng

    1997-01-01

    A voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means.

  8. Voltage balanced multilevel voltage source converter system

    DOEpatents

    Peng, F.Z.; Lai, J.S.

    1997-07-01

    Disclosed is a voltage balanced multilevel converter for high power AC applications such as adjustable speed motor drives and back-to-back DC intertie of adjacent power systems. This converter provides a multilevel rectifier, a multilevel inverter, and a DC link between the rectifier and the inverter allowing voltage balancing between each of the voltage levels within the multilevel converter. The rectifier is equipped with at least one phase leg and a source input node for each of the phases. The rectifier is further equipped with a plurality of rectifier DC output nodes. The inverter is equipped with at least one phase leg and a load output node for each of the phases. The inverter is further equipped with a plurality of inverter DC input nodes. The DC link is equipped with a plurality of rectifier charging means and a plurality of inverter discharging means. The plurality of rectifier charging means are connected in series with one of the rectifier charging means disposed between and connected in an operable relationship with each adjacent pair of rectifier DC output nodes. The plurality of inverter discharging means are connected in series with one of the inverter discharging means disposed between and connected in an operable relationship with each adjacent pair of inverter DC input nodes. Each of said rectifier DC output nodes are individually electrically connected to the respective inverter DC input nodes. By this means, each of the rectifier DC output nodes and each of the inverter DC input nodes are voltage balanced by the respective charging and discharging of the rectifier charging means and the inverter discharging means. 15 figs.

  9. Automated system for validating balance performance

    SciTech Connect

    Gibbs, P.W.; Clark, J.P.

    1990-12-31

    Manual tank calibrations often have variabilities of both a random and systematic nature that often affect the quality of the data collected for determining accurate calibration equations. When performing the calibration run, data omissions and transcriptions often occur (forgetting to tare weigh the prover vessel or miswriting a displayed value). A computer can be used to minimize these errors associated with the logging of data. This paper describes a IBM compatible, portable computer based system, developed at the Savannah River Site (SRS), that was used to calibrate three tanks in the second quarter 1990. It received data directly from instrumentation such as Ruska differential pressure sensors and electronic balances, while prompting the technicians to perform the various steps in the calibration procedure. This automated system greatly improved the quality of data for calculating the calibration equation for each of these tanks over previous calibration runs.

  10. Automated system for validating balance performance

    SciTech Connect

    Gibbs, P.W.; Clark, J.P.

    1990-01-01

    Manual tank calibrations often have variabilities of both a random and systematic nature that often affect the quality of the data collected for determining accurate calibration equations. When performing the calibration run, data omissions and transcriptions often occur (forgetting to tare weigh the prover vessel or miswriting a displayed value). A computer can be used to minimize these errors associated with the logging of data. This paper describes a IBM compatible, portable computer based system, developed at the Savannah River Site (SRS), that was used to calibrate three tanks in the second quarter 1990. It received data directly from instrumentation such as Ruska differential pressure sensors and electronic balances, while prompting the technicians to perform the various steps in the calibration procedure. This automated system greatly improved the quality of data for calculating the calibration equation for each of these tanks over previous calibration runs.

  11. BALANCE

    DOEpatents

    Carmichael, H.

    1953-01-01

    A torsional-type analytical balance designed to arrive at its equilibrium point more quickly than previous balances is described. In order to prevent external heat sources creating air currents inside the balance casing that would reiard the attainment of equilibrium conditions, a relatively thick casing shaped as an inverted U is placed over the load support arms and the balance beam. This casing is of a metal of good thernnal conductivity characteristics, such as copper or aluminum, in order that heat applied to one portion of the balance is quickly conducted to all other sensitive areas, thus effectively preventing the fornnation of air currents caused by unequal heating of the balance.

  12. Reflex ring laser amplifier system

    DOEpatents

    Summers, Mark A.

    1985-01-01

    A laser pulse is injected into an unstable ring resonator-amplifier structure. Inside this resonator the laser pulse is amplified, spatially filtered and magnified. The laser pulse is recirculated in the resonator, being amplified, filtered and magnified on each pass. The magnification is chosen so that the beam passes through the amplifier in concentric non-overlapping regions similar to a single pass MOPA. After a number of passes around the ring resonator the laser pulse is spatially large enough to exit the ring resonator system by passing around an output mirror.

  13. Multiple pass laser amplifier system

    DOEpatents

    Brueckner, Keith A.; Jorna, Siebe; Moncur, N. Kent

    1977-01-01

    A laser amplification method for increasing the energy extraction efficiency from laser amplifiers while reducing the energy flux that passes through a flux limited system which includes apparatus for decomposing a linearly polarized light beam into multiple components, passing the components through an amplifier in delayed time sequence and recombining the amplified components into an in phase linearly polarized beam.

  14. Magnetic suspension and balance system advanced study

    NASA Technical Reports Server (NTRS)

    Boom, R. W.; Eyssa, Y. M.; Mcintosh, G. E.; Abdelsalam, M. K.

    1985-01-01

    An improved compact design for a superconducting magnetic suspension and balance system for an 8 ft. x 8 ft. transonic wind tunnel is developed. The original design of an MSBS in NASA Cr-3802 utilized 14 external superconductive coils and a superconductive solenoid in the airplane test model suspended in a wind tunnel. The improvements are in the following areas: test model solenoid options, dynamic force limits on the model, magnet cooling options, structure and cryogenic designs, power supply specifications, and cost and performance evaluations. The improvements are: MSBS cost reduction of 28%, weight; reduction of 43%, magnet system ampere-meter reduction of 38%, helium liquifier capacity reduction by 33%, magnet system stored energy reduction by 55%, AC loss to liquid helium reduced by 76%, system power supply reduced by 68%, test coil pole strength increased by 19%, wing magnetization increased by 40%, and control frequency limit increased by 200% from 10 Hz to 30 Hz. The improvements are due to: magnetic holmium coil forms in the test model, better rare earth permanent magnets in the wings, fiberglass-epoxy structure replacing stainless steel, better coil configuration, and new saddle roll coil design.

  15. iBalance-ABF: a smartphone-based audio-biofeedback balance system.

    PubMed

    Franco, C; Fleury, A; Gumery, P Y; Diot, B; Demongeot, J; Vuillerme, N

    2013-01-01

    This paper proposes an implementation of a Kalman filter, using inertial sensors of a smartphone, to estimate 3-D angulation of the trunk. The developed system monitors the trunk angular evolution during bipedal stance and helps the user to improve balance through a configurable and integrated auditory-biofeedback (ABF) loop. A proof-of-concept study was performed to assess the effectiveness of this so-called iBalance-ABF--smartphone-based audio-biofeedback system--in improving balance during bipedal standing. Results showed that young healthy individuals were able to efficiently use ABF on sagittal trunk tilt to improve their balance in the medial-lateral direction. These findings suggest that the iBalance-ABF system as a telerehabilitation system could represent a suitable solution for ambient assisted living technologies. PMID:23047859

  16. Laser Transmitter Design for the Geoscience Laser Altimeter System

    NASA Technical Reports Server (NTRS)

    Afzal, R. S.; Yu, A. W.; Mamakos, W.; Lukemire, A.; Dallas, J. L.; Schroeder, B.; Green, J. W.

    1998-01-01

    NASA is embarking on a new era of laser remote sensing instruments from space. This paper focuses specifically on the laser technology involved in one of the present NASA missions. The Geoscience Laser Altimeter System (GLAS) scheduled to launch in 2001 is a laser altimeter and lidar for the Earth Observing System's (EOS) ICESat mission. The laser transmitter for this space-based remote sensing instrument is discussed in the context of the mission requirements.

  17. Balanced systems and structures - Reduction, assignment, and perturbations

    NASA Technical Reports Server (NTRS)

    Gawronski, Wodek

    1992-01-01

    New results on properties of balanced linear systems and structures are presented. Balanced representation is defined for systems with poles at an imaginary axis or at the origin. Grammians do not exist in this case, but antigrammians are introduced which make balanced reduction possible. System grammians of specified properties are obtained by assigning the sensor and actuator configuration. The latter is determined using input-output assignment procedures introduced for general systems and specified to structures. A system is said to be uniformly balanced if all its Hankel singular values are equal.

  18. Swept Frequency Laser Metrology System

    NASA Technical Reports Server (NTRS)

    Zhao, Feng (Inventor)

    2010-01-01

    A swept frequency laser ranging system having sub-micron accuracy that employs multiple common-path heterodyne interferometers, one coupled to a calibrated delay-line for use as an absolute reference for the ranging system. An exemplary embodiment uses two laser heterodyne interferometers to create two laser beams at two different frequencies to measure distance and motions of target(s). Heterodyne fringes generated from reflections off a reference fiducial X(sub R) and measurement (or target) fiducial X(sub M) are reflected back and are then detected by photodiodes. The measured phase changes Delta phi(sub R) and Delta phi (sub m) resulting from the laser frequency swept gives target position. The reference delay-line is the only absolute reference needed in the metrology system and this provides an ultra-stable reference and simple/economical system.

  19. The liver: conductor of systemic iron balance

    PubMed Central

    Meynard, Delphine; Babitt, Jodie L.

    2014-01-01

    Iron is a micronutrient essential for almost all organisms: bacteria, plants, and animals. It is a metal that exists in multiple redox states, including the divalent ferrous (Fe2+) and the trivalent ferric (Fe3+) species. The multiple oxidation states of iron make it excellent for electron transfer, allowing iron to be selected during evolution as a cofactor for many proteins involved in central cellular processes including oxygen transport, mitochondrial respiration, and DNA synthesis. However, the redox cycling of ferrous and ferric iron in the presence of H2O2, which is physiologically present in the cells, also leads to the production of free radicals (Fenton reaction) that can attack and damage lipids, proteins, DNA, and other cellular components. To meet the physiological needs of the body, but to prevent cellular damage by iron, the amount of iron in the body must be tightly regulated. Here we review how the liver is the central conductor of systemic iron balance and show that this central role is related to the secretion of a peptide hormone hepcidin by hepatocytes. We then review how the liver receives and integrates the many signals that report the body’s iron needs to orchestrate hepcidin production and maintain systemic iron homeostasis. PMID:24200681

  20. Sleep and energy balance: Interactive homeostatic systems.

    PubMed

    Vanitallie, Theodore B

    2006-10-01

    For early humans, acquisition of food by hunting and/or gathering was a hunger-driven process requiring vigilance and (often) strenuous physical effort during daylight hours. To sustain such activities, hunter-gatherers also needed periodic rest and sleep-pursuits most effectively undertaken at night. In recent years, research has given us new insights into the physiologic underpinnings of these behaviors. Specifically, evidence has been uncovered indicating that the homeostatic regulation of food intake on the one hand and that of sleep on the other hand, are intertwined. Thus, carefully performed studies of eating behavior in rats indicate that duration of sleep after ingestion of a meal is closely correlated to the meal's energy content. In 1999, it was discovered that mice and dogs functionally deficient in the appetite-stimulating hormone, hypocretin-1, become narcoleptic, suggesting the existence of a "hard-wired" connection between regulation of hunger and satiety and regulation of sleep. Administered into the nucleus accumbens shell, hypocretin-1 induces feeding and locomotor activity in Sprague-Dawley rats. Hypocretin neurons in the hypothalamus are responsive to metabolic cues capable of signaling nutritional status. The suprachiasmatic nucleus, the body's principal circadian clock, exchanges information with the hypocretin system about the light/dark cycle and the body's metabolic condition. Circadian Clock mutant mice exhibit an attenuated diurnal feeding rhythm and become hyperphagic and obese. Both disruption of the circadian cycle and sleep deprivation can affect energy balance and, over time, may bring about substantial changes in body composition. Although there is growing evidence that interleukin-6 and several other proinflammatory cytokines are "sleep factors" that also affect energy balance, any possible role they might have in coordinating sleep/wakefulness with food-motivated behavior awaits clarification. Yet, the evidence is increasingly

  1. Nova laser alignment control system

    SciTech Connect

    Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L.; Shelton, R.T.

    1984-03-29

    Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently with the computer system. Automatic alignment is accomplished by using image analysis techniques to determine beam references points from video images acquired along the laser chain. A major goal of the design is to contribute substantially to rapid experimental turnaround and consistent alignment results. This paper describes the computer-based control structure and the software methods developed for aligning this large laser system.

  2. Laser beam alignment system

    DOEpatents

    Kasner, William H.; Racki, Daniel J.; Swenson, Clark E.

    1984-01-01

    A plurality of pivotal reflectors direct a high-power laser beam onto a workpiece, and a rotatable reflector is movable to a position wherein it intercepts the beam and deflects a major portion thereof away from its normal path, the remainder of the beam passing to the pivotal reflectors through an aperture in the rotating reflector. A plurality of targets are movable to positions intercepting the path of light traveling to the pivotal reflectors, and a preliminary adjustment of the latter is made by use of a low-power laser beam reflected from the rotating reflector, after which the same targets are used to make a final adjustment of the pivotal reflectors with the portion of the high-power laser beam passed through the rotating reflector.

  3. Lubricating system for an engine balancing device

    SciTech Connect

    Candea, C.

    1987-07-07

    An internal combustion engine is described having an engine block with cylinder bores, pistons, connecting rods and a crankshaft with the pistons and associated connecting rods movable in the parallel cylinder bores of the engine block when the crankshaft rotates. It generates a periodic unbalance force with each half-rotation of the crankshaft. An improved balancing device generates an opposing force to effectively cancel the unbalance forces of the pistons and connecting rods, comprising: the balancing device including a housing enclosure located beneath the crankshaft and block. The housing has a hollow interior and a pair of apertures at either end. A pair of elongated balance shafts extend in parallelism through the hollow interior with adjacent end portions projecting through the apertures supporting the balance shafts for rotation in the housing; the housing is supported by the block and beneath the crankshaft and with the balance shafts in parallelism with the crankshaft axis. Means are attached to the housing forming an enclosure having an interior enclosing adjacent end portions of the balance shafts which project from an end of the housing; means lubricate the shaft mounting apertures and discharge oil from the interiors of the housing and the enclosure means; a vacuum breaks air bleed means in an upper portion of the enclosure for facilitating the discharge of oil from the enclosure interior.

  4. Guidance system for laser targets

    DOEpatents

    Porter, Gary D.; Bogdanoff, Anatoly

    1978-01-01

    A system for guiding charged laser targets to a predetermined focal spot of a laser along generally arbitrary, and especially horizontal, directions which comprises a series of electrostatic sensors which provide inputs to a computer for real time calculation of position, velocity, and direction of the target along an initial injection trajectory, and a set of electrostatic deflection means, energized according to a calculated output of said computer, to change the target trajectory to intercept the focal spot of the laser which is triggered so as to illuminate the target of the focal spot.

  5. Laser photography system: hardware configuration

    NASA Astrophysics Data System (ADS)

    Piszczek, Marek; Rutyna, Krzysztof; Kowalski, Marcin; Zyczkowski, Marek

    2012-06-01

    Solution presented in this article is a system using image acquisition time gating method. The time-spatial framing method developed by authors was used to build Laser Photography System (LPS). An active vision system for open space monitoring and terrorist threats detection is being built as an effect of recent work lead in the Institute of Optoelectronics, MUT. The device is destined to prevent and recognize possible terrorist threats in important land and marine areas. The aim of this article is to discuss the properties and hardware configuration of the Laser Photography System.

  6. Shilnikov instabilities in laser systems

    SciTech Connect

    Swetits, J.J.; Buoncristiani, A.M.

    1988-11-15

    Experiments on a CO/sub 2/ laser with feedback (F. T. Arecchi, R. Meucci, and W. Gadomski, Phys. Rev. Lett. 58, 2205 (1987)) displayed an extraordinary set of instabilities, identified as Shilnikov chaos. We have investigated the stability structure of a theoretical model developed to describe this laser system and carried out an extensive numerical search for the Shilnikov instability. No computational evidence to support the claim of a Shilnikov instability for model parameters corresponding to the experimental region can be found.

  7. Laser Pyro System Standardization and Man Rating

    NASA Technical Reports Server (NTRS)

    Brown, Christopher W.

    2004-01-01

    This viewgraph presentation reviews an X-38 laser pyro system standardization system designed for a new manned rated program. The plans to approve this laser initiation system and preliminary ideas for this system are also provided.

  8. Underwater laser imaging system (UWLIS)

    SciTech Connect

    DeLong, M.

    1994-11-15

    Practical limitations with underwater imaging systems area reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and resolution necessary for target discovery and identification. The advent of high power lasers operating in the blue-green portion of the visible spectrum (oceanic transmission window) has led to improved experimental illumination systems for underwater imaging. Range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence properties of laser radiation, respectively, to overcome the deleterious effects of common volume back scatter.

  9. A simple laser system for atom interferometry

    NASA Astrophysics Data System (ADS)

    Merlet, S.; Volodimer, L.; Lours, M.; Pereira Dos Santos, F.

    2014-07-01

    We present here a simple laser system for a laser-cooled atom interferometer, where all functions (laser cooling, interferometry and detection) are realized using only two extended cavity laser diodes, amplified by a common tapered amplifier. One laser is locked by frequency modulation transfer spectroscopy, the other being phase locked with an offset frequency determined by an field-programmable gate array-controlled direct digital synthesizer, which allows for efficient and versatile tuning of the laser frequency. Raman lasers are obtained with a double pass acoustooptic modulator. We demonstrate a gravimeter using this laser system, with performances close to the state of the art.

  10. XI UV Laser Trigger System

    SciTech Connect

    Brickeen, B.K.; Morelli, G.L.; Paiva, R.A.; Powell, C.A.; Sundvold, P.D.

    1999-01-26

    The X1 accelerator project at Sandia National Laboratory/New Mexico utilizes SF6 insulated, multi-stage, UV laser triggered gas switches. A 265 nm UV laser system was designed and built to generate eight simultaneous output pulses of 10 mJ each with a 13 nsec pulse width. A 1061 nm solid-state Nd:Cr:GSGG laser was frequency quadrupled using a two-stage doubling process. The 1061 nm fundamental laser energy was frequency doubled with a KTP crystal to 530 nm, achieving 65% conversion efficiency. The 530 nm output was frequency doubled with KD*P crystal to 265 nm, achieving conversion efficiency of 31%. The 265 nm beam pulse was split into eight parallel channels with a system of partially reflecting mirrors. Low timing jitter and stable energy output were achieved. The entire optical system was packaged into a rugged, o-ring sealed, aluminum structure 10''x19''x2.75''. The size of the electronics was 12''x8''x8''. Subsequent accelerator system requirements dictated a redesign of the triggering system for an output beam with less angular divergence. An unstable, crossed porro prism resonator was designed and incorporated into the system. The beam divergence of the redesigned system was successfully decreased to 0.97 mrad in the UV. The resulting frequency doubling efficiencies were 55% to 530 nm and 25% to 265 nm. The optical output remained at 10 mJ in each channel with an 11 nsec pulse width.

  11. Heterodyne laser instantaneous frequency measurement system

    DOEpatents

    Wyeth, Richard W.; Johnson, Michael A.; Globig, Michael A.

    1989-01-01

    A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of th frequency during the pulse.

  12. Heterodyne laser instantaneous frequency measurement system

    DOEpatents

    Wyeth, Richard W.; Johnson, Michael A.; Globig, Michael A.

    1990-01-01

    A heterodyne laser instantaneous frequency measurement system is disclosed. The system utilizes heterodyning of a pulsed laser beam with a continuous wave laser beam to form a beat signal. The beat signal is processed by a controller or computer which determines both the average frequency of the laser pulse and any changes or chirp of the frequency during the pulse.

  13. Strain-gage balance calibration of a magnetic suspension and balance system

    NASA Astrophysics Data System (ADS)

    Roberts, Paul W.; Tcheng, Ping

    A load calibration of the NASA 13-in magnetic suspension and balance system (MSBS) is described. The calibration procedure was originally intended to establish the empirical relationship between the coil currents and the external loads (forces and moments) applied to a magnetically suspended calibrator. However, it was discovered that the performance of a strain-gage balance is not affected when subjected to the magnetic environment of the MSBS. The use of strain-gage balances greatly reduces the effort required to perform a current-vs.-load calibration as external loads can be directly inferred from the balance outputs while a calibrator is suspended in MSBS. It is conceivable that in the future such a calibration could become unnecessary, since an even more important application for the use of a strain-gage balance in MSBS environment is the acquisition of precision aerodynamic force and moment data by telemetering the balance outputs from a suspended model/core/balance during wind tunnel tests.

  14. Strain-gage balance calibration of a magnetic suspension and balance system

    NASA Technical Reports Server (NTRS)

    Roberts, Paul W.; Tcheng, Ping

    1987-01-01

    A load calibration of the NASA 13-in magnetic suspension and balance system (MSBS) is described. The calibration procedure was originally intended to establish the empirical relationship between the coil currents and the external loads (forces and moments) applied to a magnetically suspended calibrator. However, it was discovered that the performance of a strain-gage balance is not affected when subjected to the magnetic environment of the MSBS. The use of strain-gage balances greatly reduces the effort required to perform a current-vs.-load calibration as external loads can be directly inferred from the balance outputs while a calibrator is suspended in MSBS. It is conceivable that in the future such a calibration could become unnecessary, since an even more important application for the use of a strain-gage balance in MSBS environment is the acquisition of precision aerodynamic force and moment data by telemetering the balance outputs from a suspended model/core/balance during wind tunnel tests.

  15. ARGOS laser system mechanical design

    NASA Astrophysics Data System (ADS)

    Deysenroth, M.; Honsberg, M.; Gemperlein, H.; Ziegleder, J.; Raab, W.; Rabien, S.; Barl, L.; Gässler, W.; Borelli, J. L.

    2014-07-01

    ARGOS, a multi-star adaptive optics system is designed for the wide-field imager and multi-object spectrograph LUCI on the LBT (Large Binocular Telescope). Based on Rayleigh scattering the laser constellation images 3 artificial stars (at 532 nm) per each of the 2 eyes of the LBT, focused at a height of 12 km (Ground Layer Adaptive Optics). The stars are nominally positioned on a circle 2' in radius, but each star can be moved by up to 0.5' in any direction. For all of these needs are following main subsystems necessary: 1. A laser system with its 3 Lasers (Nd:YAG ~18W each) for delivering strong collimated light as for LGS indispensable. 2. The Launch system to project 3 beams per main mirror as a 40 cm telescope to the sky. 3. The Wave Front Sensor with a dichroic mirror. 4. The dichroic mirror unit to grab and interpret the data. 5. A Calibration Unit to adjust the system independently also during day time. 6. Racks + platforms for the WFS units. 7. Platforms and ladders for a secure access. This paper should mainly demonstrate how the ARGOS Laser System is configured and designed to support all other systems.

  16. Broken detailed balance at mesoscopic scales in active biological systems.

    PubMed

    Battle, Christopher; Broedersz, Chase P; Fakhri, Nikta; Geyer, Veikko F; Howard, Jonathon; Schmidt, Christoph F; MacKintosh, Fred C

    2016-04-29

    Systems in thermodynamic equilibrium are not only characterized by time-independent macroscopic properties, but also satisfy the principle of detailed balance in the transitions between microscopic configurations. Living systems function out of equilibrium and are characterized by directed fluxes through chemical states, which violate detailed balance at the molecular scale. Here we introduce a method to probe for broken detailed balance and demonstrate how such nonequilibrium dynamics are manifest at the mesosopic scale. The periodic beating of an isolated flagellum from Chlamydomonas reinhardtii exhibits probability flux in the phase space of shapes. With a model, we show how the breaking of detailed balance can also be quantified in stationary, nonequilibrium stochastic systems in the absence of periodic motion. We further demonstrate such broken detailed balance in the nonperiodic fluctuations of primary cilia of epithelial cells. Our analysis provides a general tool to identify nonequilibrium dynamics in cells and tissues. PMID:27126047

  17. Laser addressed holographic memory system

    NASA Technical Reports Server (NTRS)

    Gange, R. A.; Wagle, E. M.; Steinmetz, C. C.

    1973-01-01

    Holographic recall and storage system uses red-lipid microcrystalline wax as storage medium. When laser beam strikes wax, its energy heats point of incidence enough to pass wax through transition temperature. Holograph image can then be written or erased in softened wax.

  18. A Fiber Optic PD Sensor Using a Balanced Sagnac Interferometer and an EDFA-Based DOP Tunable Fiber Ring Laser

    PubMed Central

    Wang, Lutang; Fang, Nian; Wu, Chunxu; Qin, Haijuan; Huang, Zhaoming

    2014-01-01

    A novel fiber-optic acoustic sensor using an erbium-doped fiber amplifier (EDFA)-based fiber ring laser and a balanced Sagnac interferometer for acoustic sensing of the partial discharge (PD) in power transformers is proposed and demonstrated. As a technical background, an experimental investigation on how the variations of the fiber birefringence affect the sensor performances was carried out, and the results are discussed. The operation principles are described, and the relevant formulas are derived. The analytical results show that an EDFA-based fiber ring laser operating in chaotic mode can provide a degree of polarization (DOP) tunable light beam for effectively suppressing polarization fading noises. The balanced Sagnac interferometer can eliminate command intensity noises and enhance the signal-to-noise ratio (SNR). Furthermore, it inherently operates at the quadrature point of the response curve without any active stabilizations. Several experiments are conducted for evaluating the performances of the sensor system, as well as for investigating the ability of the detection of high-frequency acoustic emission signals. The experimental results demonstrate that the DOP of the laser beam can be continuously tuned from 0.2% to 100%, and the power fluctuation in the whole DOP tuning range is less than 0.05 dBm. A high-frequency response up to 300 kHz is reached, and the high sensing sensitivity for detections of weak corona discharges, as well as partial discharges also is verified. PMID:24824371

  19. Emulated laser-acupuncture system.

    PubMed

    Chang, Shu-Chen; Kuo, Che-Chang; Ni, Chien-Hang; Tsai, Chin-Chuan; Yen, San-Fong; Chiu, Ya-Hui; Qu, Ang-Dao; Wang, Chih-Yu

    2014-10-10

    A novel laser-acupuncture system was developed that can be used to implement the manipulation methods of traditional acupuncture, such as lifting and thrusting. A 780 nm laser diode with a maximum power of 90 mW was used as the light source. The focus point of the laser beam was adjustable by changing the position of the lens, facilitating the implementation of the lifting and thrusting methods of traditional Chinese medicine and achieving various stimulation depths at the acupuncture point. The images for the light spots from the outlet of the emulated laser acupuncture were captured at various distances and their sizes were calculated. The result showed that the diameter of the focused light spot (i.e., at the focus point) was 0.11 mm, which is close to the diameter of commonly used needles (with diameters of approximately 0.22 mm). The area of the light spot 1 cm from the focus point was approximately 50 times larger, indicating that the unit power might be 1/50 of the power of the focus point. To study the effect of emulated laser acupuncture on human meridians, after stimulating the Shenmen point (HT7) of five subjects and obtaining their Ryodoraku values of the heart meridian and the small-intestine meridian, a paired t test showed that the laser stimulation incorporating lifting and thrusting was significantly higher than the laser stimulation without lifting and thrusting (p<0.05). The result is consistent with traditional acupuncture in that acupuncture incorporating lift and thrust is more effective than that without lift and thrust. PMID:25322416

  20. Reflex ring laser amplifier system

    SciTech Connect

    Summers, M.A.

    1983-08-31

    The invention is a method and apparatus for providing a reflex ring laser system for amplifying an input laser pulse. The invention is particularly useful in laser fusion experiments where efficient production of high-energy and high power laser pulses is required. The invention comprises a large aperture laser amplifier in an unstable ring resonator which includes a combination spatial filter and beam expander having a magnification greater than unity. An input pulse is injected into the resonator, e.g., through an aperture in an input mirror. The injected pulse passes through the amplifier and spatial filter/expander components on each pass around the ring. The unstable resonator is designed to permit only a predetermined number of passes before the amplified pulse exits the resonator. On the first pass through the amplifier, the beam fills only a small central region of the gain medium. On each successive pass, the beam has been expanded to fill the next concentric non-overlapping region of the gain medium.

  1. Ultra-broadband hybrid infrared laser system

    NASA Astrophysics Data System (ADS)

    Budilova, O. V.; Ionin, A. A.; Kinyaevskiy, I. O.; Klimachev, Yu. M.; Kotkov, A. A.; Kozlov, A. Yu.

    2016-03-01

    A hybrid IR laser system consisting of molecular gas lasers with frequency conversion of laser radiation in a solid-state converter (nonlinear crystal) was developed. One of these gas lasers is a carbon monoxide laser operating in multi-line or single-line mode. Another one is a carbon dioxide laser operating in multi-line mode. The two lasers operate under Q-switching with a joint rotating mirror. Due to sum- and difference-frequency generation in nonlinear crystals, the laser system emits within wavelength range from 2.5 to 16.6 μm. The laser system emitting radiation over such an extremely wide wavelength range (2.7 octaves) is of interest for remote sensing and other applications connected with laser beam propagation in the atmosphere.

  2. Variable emissivity laser thermal control system

    DOEpatents

    Milner, J.R.

    1994-10-25

    A laser thermal control system for a metal vapor laser maintains the wall temperature of the laser at a desired level by changing the effective emissivity of the water cooling jacket. This capability increases the overall efficiency of the laser. 8 figs.

  3. Validation of a robotic balance system for investigations in the control of human standing balance.

    PubMed

    Luu, Billy L; Huryn, Thomas P; Van der Loos, H F Machiel; Croft, Elizabeth A; Blouin, Jean-Sébastien

    2011-08-01

    Previous studies have shown that human body sway during standing approximates the mechanics of an inverted pendulum pivoted at the ankle joints. In this study, a robotic balance system incorporating a Stewart platform base was developed to provide a new technique to investigate the neural mechanisms involved in standing balance. The robotic system, programmed with the mechanics of an inverted pendulum, controlled the motion of the body in response to a change in applied ankle torque. The ability of the robotic system to replicate the load properties of standing was validated by comparing the load stiffness generated when subjects balanced their own body to the robot's mechanical load programmed with a low (concentrated-mass model) or high (distributed-mass model) inertia. The results show that static load stiffness was not significantly (p > 0.05) different for standing and the robotic system. Dynamic load stiffness for the robotic system increased with the frequency of sway, as predicted by the mechanics of an inverted pendulum, with the higher inertia being accurately matched to the load properties of the human body. This robotic balance system accurately replicated the physical model of standing and represents a useful tool to simulate the dynamics of a standing person.

  4. Geoscience laser altimeter system - stellar reference system

    SciTech Connect

    Millar, Pamela S.; Sirota, J. Marcos

    1998-01-15

    GLAS is an EOS space-based laser altimeter being developed to profile the height of the Earth's ice sheets with {approx}15 cm single shot accuracy from space under NASA's Mission to Planet Earth (MTPE). The primary science goal of GLAS is to determine if the ice sheets are increasing or diminishing for climate change modeling. This is achieved by measuring the ice sheet heights over Greenland and Antarctica to 1.5 cm/yr over 100 kmx100 km areas by crossover analysis (Zwally 1994). This measurement performance requires the instrument to determine the pointing of the laser beam to {approx}5 urad (1 arcsecond), 1-sigma, with respect to the inertial reference frame. The GLAS design incorporates a stellar reference system (SRS) to relate the laser beam pointing angle to the star field with this accuracy. This is the first time a spaceborne laser altimeter is measuring pointing to such high accuracy. The design for the stellar reference system combines an attitude determination system (ADS) with a laser reference system (LRS) to meet this requirement. The SRS approach and expected performance are described in this paper.

  5. Parametric infrared tunable laser system

    NASA Technical Reports Server (NTRS)

    Garbuny, M.; Henningsen, T.; Sutter, J. R.

    1980-01-01

    A parametric tunable infrared laser system was built to serve as transmitter for the remote detection and density measurement of pollutant, poisonous, or trace gases in the atmosphere. The system operates with a YAG:Nd laser oscillator amplifier chain which pumps a parametric tunable frequency converter. The completed system produced pulse energies of up to 30 mJ. The output is tunable from 1.5 to 3.6 micrometers at linewidths of 0.2-0.5 /cm (FWHM), although the limits of the tuning range and the narrower line crystals presently in the parametric converter by samples of the higher quality already demonstrated is expected to improve the system performance further.

  6. Ablative Laser Propulsion Using Multi-Layered Material Systems

    NASA Technical Reports Server (NTRS)

    Nehls, Mary; Edwards, David; Gray, Perry; Schneider, T.

    2002-01-01

    Experimental investigations are ongoing to study the force imparted to materials when subjected to laser ablation. When a laser pulse of sufficient energy density impacts a material, a small amount of the material is ablated. A torsion balance is used to measure the momentum produced by the ablation process. The balance consists of a thin metal wire with a rotating pendulum suspended in the middle. The wire is fixed at both ends. Recently, multi-layered material systems were investigated. These multi-layered materials were composed of a transparent front surface and opaque sub surface. The laser pulse penetrates the transparent outer surface with minimum photon loss and vaporizes the underlying opaque layer.

  7. Underwater laser imaging system (UWLIS)

    SciTech Connect

    DeLong, M.L.; Kulp, T.J.

    1995-03-10

    Practical limitations of underwater imaging systems are reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and the resolution necessary for target discovery and identification. The advent of high power lasers operating in the oceanic transmission window of the visible spectrum (blue-green portion) has led to improved experimental illumination systems for underwater imaging The properties of laser bearm in range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence effect of common volume back scatter to reduce or eliminate noise, increase signal to noise levels. Synchronously scanned systems rely on the highly collimated nature of the laser beam for spatial rejection of common volume back scatter. A synchronous, raster-scanning underwater laser imaging system (UWLIS) has been developed at Lawrence liver-more National Laboratory. The present UWLIS system differs from earlier synchronous scanners in its ability to scan in two dimensions at conventional video frame rate (30 Hz). The imaging performance of the present UWLIS was measured at distances of up to 6.3 AL (at a physical distance of 15.2 meters) during an in-water tank test and 4.5 to 5.0 AL (at a physical distance of 30 meters) during open water oceanic testing. The test results indicate that the UWLIS system is already capable of extending the underwater imaging range beyond that of conventional floodlight illuminated SIT cameras. The real or near real time frame rates of the UWLIS make possible operations in a mode in which the platform speed is randomly varied. This is typical of the operational environment in which the platform is often maneuvered above and around rugged seafloor terrain`s and obstacles.

  8. Spectrally balanced chromatic landing approach lighting system

    NASA Technical Reports Server (NTRS)

    Chase, W. D. (Inventor)

    1981-01-01

    Red warning lights delineate the runway approach with additional blue lights juxtaposed with the red lights such that the red lights are chromatically balanced. The red/blue point light sources result in the phenomenon that the red lights appear in front of the blue lights with about one and one-half times the diameter of the blue. To a pilot observing these lights along a glide path, those red lights directly below appear to be nearer than the blue lights. For those lights farther away seen in perspective at oblique angles, the red lights appear to be in a position closer to the pilot and hence appear to be above the corresponding blue lights. This produces a very pronounced three dimensional effect referred to as chromostereopsis which provides valuable visual cues to enable the pilot to perceive his actual position above the ground and the actual distance to the runway.

  9. Laser power conversion system analysis, volume 2

    NASA Technical Reports Server (NTRS)

    Jones, W. S.; Morgan, L. L.; Forsyth, J. B.; Skratt, J. P.

    1979-01-01

    The orbit-to-ground laser power conversion system analysis investigated the feasibility and cost effectiveness of converting solar energy into laser energy in space, and transmitting the laser energy to earth for conversion to electrical energy. The analysis included space laser systems with electrical outputs on the ground ranging from 100 to 10,000 MW. The space laser power system was shown to be feasible and a viable alternate to the microwave solar power satellite. The narrow laser beam provides many options and alternatives not attainable with a microwave beam.

  10. Automated Laser Seeker Performance Evaluation System (ALSPES)

    NASA Astrophysics Data System (ADS)

    Martin, Randal G.; Robinson, Elisa L.

    1988-01-01

    The Automated Laser Seeker Performance Evaluation System (ALSPES), which supports the Hellfire missile and Copperhead projectile laser seekers, is discussed. The ALSPES capabilities in manual and automatic operation are described, and the ALSPES test hardware is examined, including the computer system, the laser/attenuator, optics systems, seeker test fixture, and the measurement and test equipment. The calibration of laser energy and test signals in ALSPES is considered.

  11. Fiber laser coupled optical spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-03-04

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  12. High speed laser tomography system.

    PubMed

    Samsonov, D; Elsaesser, A; Edwards, A; Thomas, H M; Morfill, G E

    2008-03-01

    A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120,000 slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s.

  13. High speed laser tomography system.

    PubMed

    Samsonov, D; Elsaesser, A; Edwards, A; Thomas, H M; Morfill, G E

    2008-03-01

    A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120,000 slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s. PMID:18377040

  14. Delay effects in the human sensory system during balancing.

    PubMed

    Stepan, Gabor

    2009-03-28

    Mechanical models of human self-balancing often use the Newtonian equations of inverted pendula. While these mathematical models are precise enough on the mechanical side, the ways humans balance themselves are still quite unexplored on the control side. Time delays in the sensory and motoric neural pathways give essential limitations to the stabilization of the human body as a multiple inverted pendulum. The sensory systems supporting each other provide the necessary signals for these control tasks; but the more complicated the system is, the larger delay is introduced. Human ageing as well as our actual physical and mental state affects the time delays in the neural system, and the mechanical structure of the human body also changes in a large range during our lives. The human balancing organ, the labyrinth, and the vision system essentially adapted to these relatively large time delays and parameter regions occurring during balancing. The analytical study of the simplified large-scale time-delayed models of balancing provides a Newtonian insight into the functioning of these organs that may also serve as a basis to support theories and hypotheses on balancing and vision.

  15. High power laser perforating tools and systems

    SciTech Connect

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-04-22

    ystems devices and methods for the transmission of 1 kW or more of laser energy deep into the earth and for the suppression of associated nonlinear phenomena. Systems, devices and methods for the laser perforation of a borehole in the earth. These systems can deliver high power laser energy down a deep borehole, while maintaining the high power to perforate such boreholes.

  16. Digital control of wind tunnel magnetic suspension and balance systems

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.; Goodyer, Michael J.; Eskins, Jonathan; Parker, David; Halford, Robert J.

    1987-01-01

    Digital controllers are being developed for wind tunnel magnetic suspension and balance systems, which in turn permit wind tunnel testing of aircraft models free from support interference. Hardware and software features of two existing digital control systems are reviewed. Some aspects of model position sensing and system calibration are also discussed.

  17. Research developing closed loop roll control for magnetic balance systems

    NASA Technical Reports Server (NTRS)

    Covert, E. E.; Haldeman, C. W.

    1981-01-01

    Computer inputs were interfaced to the magnetic balance outputs to provide computer position control and data acquisition. The use of parameter identification of a means of determining dynamic characteristics was investigated. The thyraton and motor generator power supplies for the pitch and yaw degrees of freedom were repaired. Topics covered include: choice of a method for handling dynamic system data; applications to the magnetic balance; the computer interface; and wind tunnel tests, results, and error analysis.

  18. Development of portable laser machining system for laser writing applications

    NASA Astrophysics Data System (ADS)

    Hsiao, Wen-Tse; Tseng, Shih-Feng; Chung, Chien-Kai; Chen, Pin-Hung; Chen, Ming-Fei

    2013-03-01

    This study presents a portable laser machining system that consists of a fiber-optic diode laser source with a wavelength of 808 nm, optic/opto-mechanical components, a laser scanning module, and a laser energy control module. The laser beam quality was measured at different operation frequencies during system evaluation. The experimental results of beam profile evaluation indicate that the enlarged collimated beam was the TEM00 mode with a roundness of approximately of 96%. The output laser power level increased as the pulse frequency increased during laser power evaluation. To control the rotating angle of the galvanometric scanning system, the deflective angle was adjusted using a 0.192 voltage to obtain a deflective value of 1mm and the maximum scan field of 100 × 100mm2. The laser source operated at different frequencies, with pulse widths ranging from 530 to 48 μs. Finally, the proposed machine can also be used for black thick paper laser writing applications.

  19. Airborne laser sensors and integrated systems

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark A.; Gardi, Alessandro; Ramasamy, Subramanian

    2015-11-01

    The underlying principles and technologies enabling the design and operation of airborne laser sensors are introduced and a detailed review of state-of-the-art avionic systems for civil and military applications is presented. Airborne lasers including Light Detection and Ranging (LIDAR), Laser Range Finders (LRF), and Laser Weapon Systems (LWS) are extensively used today and new promising technologies are being explored. Most laser systems are active devices that operate in a manner very similar to microwave radars but at much higher frequencies (e.g., LIDAR and LRF). Other devices (e.g., laser target designators and beam-riders) are used to precisely direct Laser Guided Weapons (LGW) against ground targets. The integration of both functions is often encountered in modern military avionics navigation-attack systems. The beneficial effects of airborne lasers including the use of smaller components and remarkable angular resolution have resulted in a host of manned and unmanned aircraft applications. On the other hand, laser sensors performance are much more sensitive to the vagaries of the atmosphere and are thus generally restricted to shorter ranges than microwave systems. Hence it is of paramount importance to analyse the performance of laser sensors and systems in various weather and environmental conditions. Additionally, it is important to define airborne laser safety criteria, since several systems currently in service operate in the near infrared with considerable risk for the naked human eye. Therefore, appropriate methods for predicting and evaluating the performance of infrared laser sensors/systems are presented, taking into account laser safety issues. For aircraft experimental activities with laser systems, it is essential to define test requirements taking into account the specific conditions for operational employment of the systems in the intended scenarios and to verify the performance in realistic environments at the test ranges. To support the

  20. Laser Safety Audit and Inventory System Database

    SciTech Connect

    AUGUSTONI, ARNOLD L.

    2003-05-01

    A laser safety auditing and inventory system has been in use at Sandia National Laboratories--Albuquerque for the past five years and has recently been considered for adoption by Sandia National Laboratories--Livermore. The system utilizes the ''Microsoft Access'' database application, part of the Office 2000 software package. Audit and inventory data is available on-line for ready access by laser users. Data is updated weekly to provide users with current information relating to laser facility audits and laser inventories.

  1. Fourier domain optical coherence tomography system with balance detection.

    PubMed

    Bradu, Adrian; Podoleanu, Adrian Gh

    2012-07-30

    A Fourier domain optical coherence tomography system with two spectrometers in balance detection is assembled using each an InGaAs linear camera. Conditions and adjustments of spectrometer parameters are presented to ensure anti-phase channeled spectrum modulation across the two cameras for a majority of wavelengths within the optical source spectrum. By blocking the signal to one of the spectrometers, the setup was used to compare the conditions of operation of a single camera with that of a balanced configuration. Using multiple layer samples, balanced detection technique is compared with techniques applied to conventional single camera setups, based on sequential deduction of averaged spectra collected with different on/off settings for the sample or reference beams. In terms of reducing the autocorrelation terms and fixed pattern noise, it is concluded that balance detection performs better than single camera techniques, is more tolerant to movement, exhibits longer term stability and can operate dynamically in real time. The cameras used exhibit larger saturation power than the power threshold where excess photon noise exceeds shot noise. Therefore, conditions to adjust the two cameras to reduce the noise when used in a balanced configuration are presented. It is shown that balance detection can reduce the noise in real time operation, in comparison with single camera configurations. However, simple deduction of an average spectrum in single camera configurations delivers less noise than the balance detection. PMID:23038305

  2. Laser docking system flight experiment

    NASA Technical Reports Server (NTRS)

    Erwin, Harry O.

    1986-01-01

    Experiments necessary in the development of the Laser Docking System (LDS) are described. The LDS would be mounted in the Orbiter payload bay, along with a grid connected by fiber optic link to a computer in the cabin. The tests would be performed to aid in the design of an operational sensor which could track a passive target accurately enough to permit soft docking. Additional data would be gained regarding the LDS performance in space, the effects of Orbiter RCS plume impingement on the target, and refinements needed for the flight hardware. A working model which includes an IR laser steered by galvanometer-driven motors for bouncing beams off retroreflectors mounted on targets is described, together with a 300 ft long indoor test facility. Tests on Orbiter flights would first be in a wholly automatic mode and then in a man-in-the-loop mode.

  3. A Comparison of Two Prototype Laser-Optical Firing Systems

    SciTech Connect

    Gregg L. Morelli; Michelle R. Bright

    2008-08-11

    The design and characterization of small, ruggedized laser-optical subsystems is required for the continued development of robust laser-optical firing systems. Typically, these subsystems must be capable of generating the needed laser optical energy, delivering that energy via fiber-optical cables while taking up occupying a volume as small as possible. A novel beam splitting and fiber injection scheme has been proposed which utilizes two diffractive optical components. These components were utilized to reduce the volume of a previously designed system. A laser-optical prototype system was assembled and tested which utilized this beam splitting and fiber injection scheme along other modifications to the laser module and the power supply. This prototype was based on earlier designs that utilized environmentally proven opto-mechanical sub-assemblies. The system was tested to characterize the laser performance, the splitter-coupler transmission efficiency, channel-to-channel energy balance and fiber interchangeability. The results obtained for this design will be compared to the performance of a prototype system based on a more traditional beam splitting and fiber injection scheme. The traditional design utilized partially reflecting mirrors for beam splitting and plano-convex lenses for fiber injection. These results will be discussed as will their ultimate impact on future designs and packaging strategies.

  4. Short-pulse Laser Capability on the Mercury Laser System

    SciTech Connect

    Ebbers, C; Armstrong, P; Bayramian, A; Barty, C J; Bibeau, C; Britten, J; Caird, J; Campbell, R; Chai, B; Crane, J; Cross, R; Erlandson, A; Fei, Y; Freitas, B; Jovanovic, I; Liao, Z; Molander, B; Schaffers, K; Stuart, B; Sutton, S; Ladran, T; Telford, S; Thelin, P; Utterback, E

    2006-06-22

    Applications using high energy ''petawatt-class'' laser drivers operating at repetition rates beyond 0.01 Hz are only now being envisioned. The Mercury laser system is designed to operate at 100 J/pulse at 10 Hz. We investigate the potential of configuring the Mercury laser to produce a rep-rated, ''petawatt-class'' source. The Mercury laser is a prototype of a high energy, high repetition rate source (100 J, 10 Hz). The design of the Mercury laser is based on the ability to scale in energy through scaling in aperture. Mercury is one of several 100 J, high repetition rate (10 Hz) lasers sources currently under development (HALNA, LUCIA, POLARIS). We examine the possibility of using Mercury as a pump source for a high irradiance ''petawatt-class'' source: either as a pump laser for an average power Ti:Sapphire laser, or as a pump laser for OPCPA based on YCa{sub 4}O(BO{sub 3}){sub 3} (YCOB), ideally producing a source approaching 30 J /30 fs /10 Hz--a high repetition rate petawatt. A comparison of the two systems with nominal configurations and efficiencies is shown in Table 1.

  5. Numerical simulation of imaging laser radar system

    NASA Astrophysics Data System (ADS)

    Han, Shaokun; Lu, Bo; Jiang, Ming; Liu, Xunliang

    2008-03-01

    Rational and effective design of imaging laser radar systems is the key of imaging laser radar system research. Design must fully consider the interrelationship between various parameters. According to the parameters, choose suitable laser, detector and other components. To use of mathematical modeling and computer simulation is an effective imaging laser radar system design methods. This paper based on the distance equation, using the detection statistical methods, from the laser radar range coverage, detection probability, false-alarm rate, SNR to build the laser radar system mathematical models. In the process of setting up the mathematical models to fully consider the laser, atmosphere, detector and other factors on the performance that is to make the models be able to respond accurately the real situation. Based on this using C# and Matlab designed a simulation software.

  6. Precision laser automatic tracking system.

    PubMed

    Lucy, R F; Peters, C J; McGann, E J; Lang, K T

    1966-04-01

    A precision laser tracker has been constructed and tested that is capable of tracking a low-acceleration target to an accuracy of about 25 microrad root mean square. In tracking high-acceleration targets, the error is directly proportional to the angular acceleration. For an angular acceleration of 0.6 rad/sec(2), the measured tracking error was about 0.1 mrad. The basic components in this tracker, similar in configuration to a heliostat, are a laser and an image dissector, which are mounted on a stationary frame, and a servocontrolled tracking mirror. The daytime sensitivity of this system is approximately 3 x 10(-10) W/m(2); the ultimate nighttime sensitivity is approximately 3 x 10(-14) W/m(2). Experimental tests were performed to evaluate both dynamic characteristics of this system and the system sensitivity. Dynamic performance of the system was obtained, using a small rocket covered with retroreflective material launched at an acceleration of about 13 g at a point 204 m from the tracker. The daytime sensitivity of the system was checked, using an efficient retroreflector mounted on a light aircraft. This aircraft was tracked out to a maximum range of 15 km, which checked the daytime sensitivity of the system measured by other means. The system also has been used to track passively stars and the Echo I satellite. Also, the system tracked passively a +7.5 magnitude star, and the signal-to-noise ratio in this experiment indicates that it should be possible to track a + 12.5 magnitude star.

  7. Carbon balances during land conversion in early bioenergy systems

    NASA Astrophysics Data System (ADS)

    Zenone, T.; Chen, J.; Gelfand, I.; Robertson, G. P.; Hamilton, S. K.

    2012-12-01

    In this study, we established a field experiment and deployed seven eddy-covariance towers to quantify the roles of land use change and the subsequent carbon (C) balances of three different bioenergy systems (corn, switchgrass, and mixed prairie species) that were developed from two historical land use types: monocultural grasslands dominated by smooth brome (Bromus inermis Leyss) and lands in the Conservation Reserve Program (CRP). Three CRP fields and three cropland fields were converted to soybean in 2009 (conversion year) before establishing the cellulosic biofuel cropping systems in 2010 (establishment year). A CRP perennial grassland site was kept undisturbed as a reference. Conversion of CRP to soybean induced net C emissions during the conversion year (134 -262 g C m-2 yr-1), while in the same year the net C balance at the CRP grassland reference was -35 g C m-2 yr-1 (i.e., net C sequestration). The establishment of switchgrass and mixed prairie induced a cumulative C balance of -113 g C m-2 (switchgrass from CRP), 250 g C m-2 (switchgrass from cropland), 706 g C m-2 (mixed prairie from CRP), and 59 g C m-2 (mixed prairie from cropland) over the three-year study period. The cumulative three-year C balance of corn converted from CRP and from cropland was -151 g C m-2 and -183 g C m-2, respectively. Eddy flux measurements during cellulosic biofuel crop establishment reveal annual changes in C balance that cannot be detected using conventional mass balance approaches. When end-use of harvested biomass was considered, the C balances for all studied systems, except the reference site, exhibited large C emissions ranging from 150 to 990 g C m-2 over the three-year conversion phase.

  8. High power laser apparatus and system

    NASA Technical Reports Server (NTRS)

    Evans, J. C., Jr.; Brandhorst, H. W., Jr. (Inventor)

    1975-01-01

    A high-power, continuous-wave laser was designed for use in power transmission and energy-collecting systems, and for producing incoherent light for pumping a laser material. The laser has a high repetitive pulsing rate per unit time, resulting in a high-power density beam. The laser is composed of xenon flash tubes powered by fast-charging capacitors flashed in succession by a high-speed motor connected to an automobile-type distributor.

  9. Fission fragment excited laser system

    DOEpatents

    McArthur, David A.; Tollefsrud, Philip B.

    1976-01-01

    A laser system and method for exciting lasing action in a molecular gas lasing medium which includes cooling the lasing medium to a temperature below about 150 K and injecting fission fragments through the lasing medium so as to preferentially excite low lying vibrational levels of the medium and to cause population inversions therein. The cooled gas lasing medium should have a mass areal density of about 5 .times. 10.sup.-.sup.3 grams/square centimeter, relaxation times of greater than 50 microseconds, and a broad range of excitable vibrational levels which are excitable by molecular collisions.

  10. Magnetic suspension and balance system advanced study, 1989 design

    NASA Technical Reports Server (NTRS)

    Boom, Roger W.; Eyssa, Y. M.; Abdelsalam, Moustafa K.; Mcintosh, Glen E.

    1991-01-01

    The objectives are to experimentally confirm several advanced design concepts on the Magnetic Suspension and Balance Systems (MSBS). The advanced design concepts were identified as potential improvements by Madison Magnetics, Inc. (MMI) during 1984 and 1985 studies of an MSBS utilizing 14 external superconductive coils and a superconductive solenoid in an airplane test model suspended in a wind tunnel. This study confirmed several advanced design concepts on magnetic suspension and balance systems. The 1989 MSBS redesign is based on the results of these experiments. Savings of up to 30 percent in supporting magnet ampere meters and 50 percent in energy stored over the 1985 design were achieved.

  11. Laser Doppler And Range Systems For Spacecraft

    NASA Technical Reports Server (NTRS)

    Kinman, P. W.; Gagliardi, R. M.

    1990-01-01

    Report discusses two types of proposed laser systems containing active transponders measuring distance (range) and line-of-sight velocity (via Doppler effect) between deep space vehicle and earth-orbiting satellite. Laser system offers diffraction advantage over microwave system. Delivers comparable power to distant receiver while using smaller transmitting and receiving antennas and less-powerful transmitter. Less subject to phase scintillations caused by passage through such inhomogeneous media as solar corona. One type of system called "incoherent" because range and Doppler measurements do not require coherence with laser carrier signals. Other type of system called "coherent" because successful operation requires coherent tracking of laser signals.

  12. Laser spark distribution and ignition system

    DOEpatents

    Woodruff, Steven; McIntyre, Dustin L.

    2008-09-02

    A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

  13. Climate balance of biogas upgrading systems

    SciTech Connect

    Pertl, A.; Mostbauer, P.; Obersteiner, G.

    2010-01-15

    One of the numerous applications of renewable energy is represented by the use of upgraded biogas where needed by feeding into the gas grid. The aim of the present study was to identify an upgrading scenario featuring minimum overall GHG emissions. The study was based on a life-cycle approach taking into account also GHG emissions resulting from plant cultivation to the process of energy conversion. For anaerobic digestion two substrates have been taken into account: (1) agricultural resources and (2) municipal organic waste. The study provides results for four different upgrading technologies including the BABIU (Bottom Ash for Biogas Upgrading) method. As the transport of bottom ash is a critical factor implicated in the BABIU-method, different transport distances and means of conveyance (lorry, train) have been considered. Furthermore, aspects including biogas compression and energy conversion in a combined heat and power plant were assessed. GHG emissions from a conventional energy supply system (natural gas) have been estimated as reference scenario. The main findings obtained underlined how the overall reduction of GHG emissions may be rather limited, for example for an agricultural context in which PSA-scenarios emit only 10% less greenhouse gases than the reference scenario. The BABIU-method constitutes an efficient upgrading method capable of attaining a high reduction of GHG emission by sequestration of CO{sub 2}.

  14. Climate balance of biogas upgrading systems.

    PubMed

    Pertl, A; Mostbauer, P; Obersteiner, G

    2010-01-01

    One of the numerous applications of renewable energy is represented by the use of upgraded biogas where needed by feeding into the gas grid. The aim of the present study was to identify an upgrading scenario featuring minimum overall GHG emissions. The study was based on a life-cycle approach taking into account also GHG emissions resulting from plant cultivation to the process of energy conversion. For anaerobic digestion two substrates have been taken into account: (1) agricultural resources and (2) municipal organic waste. The study provides results for four different upgrading technologies including the BABIU (Bottom Ash for Biogas Upgrading) method. As the transport of bottom ash is a critical factor implicated in the BABIU-method, different transport distances and means of conveyance (lorry, train) have been considered. Furthermore, aspects including biogas compression and energy conversion in a combined heat and power plant were assessed. GHG emissions from a conventional energy supply system (natural gas) have been estimated as reference scenario. The main findings obtained underlined how the overall reduction of GHG emissions may be rather limited, for example for an agricultural context in which PSA-scenarios emit only 10% less greenhouse gases than the reference scenario. The BABIU-method constitutes an efficient upgrading method capable of attaining a high reduction of GHG emission by sequestration of CO(2).

  15. Coherent laser vision system (CLVS)

    SciTech Connect

    1997-02-13

    The purpose of the CLVS research project is to develop a prototype fiber-optic based Coherent Laser Vision System suitable for DOE`s EM Robotics program. The system provides three-dimensional (3D) vision for monitoring situations in which it is necessary to update geometric data on the order of once per second. The CLVS project plan required implementation in two phases of the contract, a Base Contract and a continuance option. This is the Base Program Interim Phase Topical Report presenting the results of Phase 1 of the CLVS research project. Test results and demonstration results provide a proof-of-concept for a system providing three-dimensional (3D) vision with the performance capability required to update geometric data on the order of once per second.

  16. Ground Energy Balance For Shallow Geothermal Systems

    NASA Astrophysics Data System (ADS)

    Bayer, P.; Rivera, J.

    2015-12-01

    Vertical borehole heat exchangers (BHE) represent the most common applications by far in the field of shallow geothermal energy. They are typically operated for decades for energy extraction from the top 400 m of the subsurface. During this lifetime, thermal anomalies are generated in the ground and surface-near aquifers. These anomalies often grow over the years and compromise the overall performance of the geothermal system. As a basis for prediction and control of the developing energy imbalance in the ground, the focus is often set on the ground temperatures. This is reflected, for instance, in regulative temperature thresholds. As an alternative to temperature, we examine the temporal and spatial variability of heat fluxes and power sources during geothermal heat pump operation. The underlying idea is that knowledge of the primary heat sources is fundamental for the control of ground temperature evolution. For analysis of heat fluxes, an analytical framework for BHE simulation based on Kelvin's line source is re-formulated. This is applied to a synthetic study and for modelling a long-term application in the field. Our results show that during early operation phase, energy is extracted mainly from the underground. Local depletion at the borehole enhances the vertical fluxes with the relative contribution from the bottom reaching a limit of 24 % of the total power demand. The relative contribution from the ground surface becomes dominant for Fourier numbers larger than 0.13. For the full life cycle, vertical heat flux from the ground surface dominates the basal heat flux towards the BHE and it provides about two thirds of the demanded power. Finally, we reveal that the time for ground energy recovery after BHE shutdown may be longer than what is expected from simulated temperature trends.

  17. GOPEX laser transmission and monitoring systems

    NASA Technical Reports Server (NTRS)

    Okamoto, G.; Masters, K.

    1993-01-01

    The laser transmission and monitoring system for the Galileo Optical Experiment (GOPEX) at the Table Mountain Facility (TMF) in Wrightwood, California is described. The transmission system configuration and the data measurement techniques are described. The calibration procedure and the data analysis algorithm are also discussed. The mean and standard deviation of the laser energy transmitted each day of GOPEX show that the laser transmission system performed well and within the limit established in conjunction with the Galileo Project for experiment concurrence.

  18. Stabilization system of a photoinjector drive laser.

    PubMed

    Le Flanchec, V; Blésès, J P; Striby, S; Laget, J P

    1997-11-20

    In the Etude d'un LaSer Accordable linear accelerator, electron bunches consist of trains of picosecond pulses extracted from a photocathode by a drive laser system. The fluctuations of the mean intensity of pulse trains at the output of the laser system are around 3% rms. A feed-forward stabilization system that reduces these fluctuations to better than 0.7% rms for periods of 5 min is presented. PMID:18264399

  19. Stabilization system of a photoinjector drive laser

    NASA Astrophysics Data System (ADS)

    Le Flanchec, Vincent; Blésès, Jean-Paul; Striby, Serge; Laget, Jean-Paul

    1997-11-01

    In the Etude d un LaSer Accordable linear accelerator, electron bunches consist of trains of picosecond pulses extracted from a photocathode by a drive laser system. The fluctuations of the mean intensity of pulse trains at the output of the laser system are around 3% rms. A feed-forward stabilization system that reduces these fluctuations to better than 0.7% rms for periods of 5 min is presented.

  20. Multiplex electric discharge gas laser system

    NASA Technical Reports Server (NTRS)

    Laudenslager, James B. (Inventor); Pacala, Thomas J. (Inventor)

    1987-01-01

    A multiple pulse electric discharge gas laser system is described in which a plurality of pulsed electric discharge gas lasers are supported in a common housing. Each laser is supplied with excitation pulses from a separate power supply. A controller, which may be a microprocessor, is connected to each power supply for controlling the application of excitation pulses to each laser so that the lasers can be fired simultaneously or in any desired sequence. The output light beams from the individual lasers may be combined or utilized independently, depending on the desired application. The individual lasers may include multiple pairs of discharge electrodes with a separate power supply connected across each electrode pair so that multiple light output beams can be generated from a single laser tube and combined or utilized separately.

  1. The Geoscience Laser Altimetry/Ranging System

    NASA Technical Reports Server (NTRS)

    Cohen, Steven C.; Degnan, John J., III; Bufton, Jack L.; Garvin, James B.; Abshire, James B.

    1987-01-01

    The Geoscience Laser Altimetry/Ranging System (GLARS), a combined laser ranging and altimetry system capable of subcentimeter position determinations of retroflector targets and subdecimeter profiling of topography, is described. The system uses advanced but currently available state-of-the-art components. Laboratory, field, and numerical experiments have indicated the suitability of GLARS as an instrument for Eos and other space platforms.

  2. Laser beam modeling in optical storage systems

    NASA Technical Reports Server (NTRS)

    Treptau, J. P.; Milster, T. D.; Flagello, D. G.

    1991-01-01

    A computer model has been developed that simulates light propagating through an optical data storage system. A model of a laser beam that originates at a laser diode, propagates through an optical system, interacts with a optical disk, reflects back from the optical disk into the system, and propagates to data and servo detectors is discussed.

  3. National Ignition Facility system design requirements Laser System SDR002

    SciTech Connect

    Larson, D.W.; Bowers, J.M.; Bliss, E.S.; Karpenko, V.P.; English, E.

    1996-08-20

    This System Design Requirement document establishes the performance, design, development, and test requirements for the NIP Laser System. The Laser System generates and delivers high-power optical pulses to the target chamber, and is composed of all optical puke creating and transport elements from Puke Generation through Final Optics as well as the special equipment that supports, energizes and controls them. The Laser System consists of the following WBS elements: 1.3 Laser System 1.4 Beam Transport System 1.6 Optical Components 1.7 Laser Control 1.8.7 Final Optics.

  4. Increasing cropping system diversity balances productivity, profitability and environmental health

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and can have large negative im...

  5. Dynamically variable spot size laser system

    NASA Technical Reports Server (NTRS)

    Gradl, Paul R. (Inventor); Hurst, John F. (Inventor); Middleton, James R. (Inventor)

    2012-01-01

    A Dynamically Variable Spot Size (DVSS) laser system for bonding metal components includes an elongated housing containing a light entry aperture coupled to a laser beam transmission cable and a light exit aperture. A plurality of lenses contained within the housing focus a laser beam from the light entry aperture through the light exit aperture. The lenses may be dynamically adjusted to vary the spot size of the laser. A plurality of interoperable safety devices, including a manually depressible interlock switch, an internal proximity sensor, a remotely operated potentiometer, a remotely activated toggle and a power supply interlock, prevent activation of the laser and DVSS laser system if each safety device does not provide a closed circuit. The remotely operated potentiometer also provides continuous variability in laser energy output.

  6. Master-Oscillator/Power-Amplifier Laser System

    NASA Technical Reports Server (NTRS)

    Yu, Anthony W.; Krainak, Michael A.; Unger, Glenn L.

    1994-01-01

    Master-oscillator/power-amplifier (MOPA) laser system operates in continuous-wave mode or in amplitude-modulation (e.g., pulse) mode by modulation of oscillator current. Power amplifier is laser-diode-pumped neodymium:yttrium lithium fluoride (Nd:YLF) laser; oscillator is laser diode. Offers relatively high efficiency and power. Because drive current to oscillator modulated, external electro-optical modulator not needed. Potential uses include free-space optical communications, coded laser ranging, and generation of high-power, mode-locked pulses.

  7. Copper vapor laser acoustic thermometry system

    DOEpatents

    Galkowski, Joseph J.

    1987-01-01

    A copper vapor laser (CVL) acoustic thermometry system is disclosed. The invention couples an acoustic pulse a predetermined distance into a laser tube by means of a transducer and an alumina rod such that an echo pulse is returned along the alumina rod to the point of entry. The time differential between the point of entry of the acoustic pulse into the laser tube and the exit of the echo pulse is related to the temperature at the predetermined distance within the laser tube. This information is processed and can provide an accurate indication of the average temperature within the laser tube.

  8. Evaluation of surface energy and radiation balance systems for FIFE

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.; Qian, Ping

    1988-01-01

    The energy balance and radiation balance components were determined at six sites during the First International Satellite Land Surface Climatology Project Field Experiment (FIFE) conducted south of Manhattan, Kansas during the summer of 1987. The objectives were: to determine the effect of slope and aspect, throughout a growing season, on the magnitude of the surface energy balance fluxes as determined by the Energy Balance Method (EBM); to investigate the calculation of the soil heat flux density at the surface as calculated from the heat capacity and the thermal conductivity equations; and to evaluate the performance of the Surface Energy and Radiation Balance System (SERBS). A total of 17 variables were monitored at each site. They included net, solar (up and down), total hemispherical (up and down), and diffuse radiation, soil temperature and heat flux density, air and wet bulb temperature gradients, wind speed and direction, and precipitation. A preliminary analysis of the data, for the season, indicate that variables including net radiation, air temperature, vapor pressure, and wind speed were quite similar at the sites even though the sites were as much as 16 km apart and represented four cardinal slopes and the top of a ridge.

  9. Dual strain gage balance system for measuring light loads

    NASA Technical Reports Server (NTRS)

    Roberts, Paul W. (Inventor)

    1991-01-01

    A dual strain gage balance system for measuring normal and axial forces and pitching moment of a metric airfoil model imparted by aerodynamic loads applied to the airfoil model during wind tunnel testing includes a pair of non-metric panels being rigidly connected to and extending towards each other from opposite sides of the wind tunnel, and a pair of strain gage balances, each connected to one of the non-metric panels and to one of the opposite ends of the metric airfoil model for mounting the metric airfoil model between the pair of non-metric panels. Each strain gage balance has a first measuring section for mounting a first strain gage bridge for measuring normal force and pitching moment and a second measuring section for mounting a second strain gage bridge for measuring axial force.

  10. Data Partitioning and Load Balancing in Parallel Disk Systems

    NASA Technical Reports Server (NTRS)

    Scheuermann, Peter; Weikum, Gerhard; Zabback, Peter

    1997-01-01

    Parallel disk systems provide opportunities for exploiting I/O parallelism in two possible waves, namely via inter-request and intra-request parallelism. In this paper we discuss the main issues in performance tuning of such systems, namely striping and load balancing, and show their relationship to response time and throughput. We outline the main components of an intelligent, self-reliant file system that aims to optimize striping by taking into account the requirements of the applications and performs load balancing by judicious file allocation and dynamic redistributions of the data when access patterns change. Our system uses simple but effective heuristics that incur only little overhead. We present performance experiments based on synthetic workloads and real-life traces.

  11. Characterizing the geomorphic setting of precariously balanced rocks using terrestrial laser scanning technology

    NASA Astrophysics Data System (ADS)

    Haddad, D. E.; Arrowsmith, R.

    2009-12-01

    Terrestrial laser scanning (TLS) technology is rapidly becoming an effective three-dimensional imaging tool. Precariously balanced rocks are a subset of spheroidally weathered boulders. They are balanced on bedrock pedestals and are formed in upland drainage basins and pediments of exhumed plutons. Precarious rocks are used as negative evidence of earthquake-driven extreme ground motions. Field surveys of PBRs are coupled with cosmogenic radionuclide (CRN) surface exposure dating techniques to determine their exhumation rates. These rates are used in statistical simulations to estimate the magnitudes and recurrences of earthquake-generated extreme ground shaking as a means to physically validate seismic hazard analyses. However, the geomorphic setting of PBRs in the landscape is poorly constrained when interpreting their exhumation rates from CRN surface exposure dates. Are PBRs located on steep or gentle hillslopes? Are they located near drainages or hillslope crests? What geomorphic processes control the spatial distribution of PBRs in a landscape, and where do these processes dominate? Because the fundamental hillslope transport laws are largely controlled by local hillslope gradient and contributing area, the location of a PBR is controlled by the geomorphic agents and their rates acting on it. Our latest efforts involve using a combination of TLS and airborne laser swath mapping (ALSM) to characterize the geomorphic situation of PBRs. We used a Riegl LPM 800i (LPM 321) terrestrial laser scanner to scan a ~1.5 m tall by ~1 m wide precariously balanced rock in the Granite Dells, central Arizona. The PBR was scanned from six positions, and the scans were aligned to a point cloud totaling 3.4M points. We also scanned a ~50 m by ~150 m area covering PBR hillslopes from five scan positions. The resulting 5.5M points were used to create a digital terrain model of precarious rocks and their hillslopes. Our TLS- and ALSM-generated surface models and DEMs provide a

  12. Balanced-Viscosity solutions for multi-rate systems

    NASA Astrophysics Data System (ADS)

    Mielke, Alexander; Rossi, Riccarda; Savaré, Giuseppe

    2016-06-01

    Several mechanical systems are modeled by the static momentum balance for the displacement u coupled with a rate-independent flow rule for some internal variable z. We consider a class of abstract systems of ODEs which have the same structure, albeit in a finite-dimensional setting, and regularize both the static equation and the rate-independent flow rule by adding viscous dissipation terms with coefficients εα and ε, where 0 < ε « 1 and α > 0 is a fixed parameter. Therefore for α ≠ 1 u and z have different relaxation rates. We address the vanishing-viscosity analysis as ε ↓ 0 of the viscous system. We prove that, up to a subsequence, (reparameterized) viscous solutions converge to a parameterized curve yielding a Balanced Viscosity solution to the original rate-independent system, and providing an accurate description of the system behavior at jumps. We also give a reformulation of the notion of Balanced Viscosity solution in terms of a system of subdifferential inclusions, showing that the viscosity in u and the one in z are involved in the jump dynamics in different ways, according to whether α > 1, α =1, and α є (0,1).

  13. Laser Systems for Orbital Debris Removal

    SciTech Connect

    Rubenchik, A. M.; Barty, C. P. J.; Beach, R. J.; Erlandson, A. C.; Caird, J. A.

    2010-10-08

    The use of a ground based laser for space debris cleaning was investigated by the ORION project in 1996. Since that study the greatest technological advance in the development of high energy pulsed laser systems has taken place within the NIF project at LLNL. The proposed next laser system to follow the NIF at LLNL will be a high rep rate version of the NIF based on diode-pumping rather than flashlamp excitation; the so called 'LIFE' laser system. Because a single 'LIFE' beamline could be built up in a few year time frame, and has performance characteristics relevant to the space debris clearing problem, such a beamline could enable a near term demonstration of space debris cleaning. Moreover, the specifics of debris cleaning make it possible to simplify the LIFE laser beyond what is required for a fusion drive laser, and so substantially reduce its cost. Starting with the requirements for laser intensity on the target, and then considering beam delivery, we will flow back the laser requirements needed for space debris cleaning. Using these derived requirements we will then optimize the pulse duration, the operational regime, and the output pulse energy of the laser with a focus of simplifying its overall design. Anticipated simplifications include operation in the heat capacity regime, eliminating cooling requirements on the laser gain slabs, and relaxing B-integral and birefrigence requirements.

  14. Laser Systems for Orbital Debris Removal

    SciTech Connect

    Rubenchik, A M; Barty, C P; Beach, R J; Erlandson, A C; Caird, J A

    2010-02-05

    The use of a ground based laser for space debris cleaning was investigated by the ORION project in 1996. Since that study the greatest technological advance in the development of high energy pulsed laser systems has taken place within the NIF project at LLNL. The proposed next laser system to follow the NIF at LLNL will be a high rep rate version of the NIF based on diode-pumping rather than flashlamp excitation; the so called 'LIFE' laser system. Because a single 'LIFE' beamline could be built up in a few year time frame, and has performance characteristics relevant to the space debris clearing problem, such a beamline could enable a near term demonstration of space debris cleaning. Moreover, the specifics of debris cleaning make it possible to simplify the LIFE laser beyond what is required for a fusion drive laser, and so substantially reduce its cost. Starting with the requirements for laser intensity on the target, and then considering beam delivery, we will flow back the laser requirements needed for space debris cleaning. Using these derived requirements we will then optimize the pulse duration, the operational regime, and the output pulse energy of the laser with a focus of simplifying its overall design. Anticipated simplifications include operation in the heat capacity regime, eliminating cooling requirements on the laser gain slabs, and relaxing B-integral and birefrigence requirements.

  15. Laser Systems for Orbital Debris Removal

    NASA Astrophysics Data System (ADS)

    Rubenchik, A. M.; Barty, C. P. J.; Beach, R. J.; Erlandson, A. C.; Caird, J. A.

    2010-10-01

    The use of a ground based laser for space debris cleaning was investigated by the ORION project in 1996. Since that study the greatest technological advance in the development of high energy pulsed laser systems has taken place within the NIF project at LLNL. The proposed next laser system to follow the NIF at LLNL will be a high rep rate version of the NIF based on diode-pumping rather than flashlamp excitation; the so called "LIFE" laser system. Because a single "LIFE" beamline could be built up in a few year time frame, and has performance characteristics relevant to the space debris clearing problem, such a beamline could enable a near term demonstration of space debris cleaning. Moreover, the specifics of debris cleaning make it possible to simplify the LIFE laser beyond what is required for a fusion drive laser, and so substantially reduce its cost. Starting with the requirements for laser intensity on the target, and then considering beam delivery, we will flow back the laser requirements needed for space debris cleaning. Using these derived requirements we will then optimize the pulse duration, the operational regime, and the output pulse energy of the laser with a focus of simplifying its overall design. Anticipated simplifications include operation in the heat capacity regime, eliminating cooling requirements on the laser gain slabs, and relaxing B-integral and birefrigence requirements.

  16. Video Guidance Sensor System with Laser Rangefinder

    NASA Technical Reports Server (NTRS)

    Howard, Richard T. (Inventor); Johnston, Albert S. (Inventor); Book, Michael L. (Inventor); Bryan, Thomas C. (Inventor)

    2003-01-01

    A video guidance sensor system for use in automated docking of a chase vehicle with a target vehicle wherein the chase. vehicle includes a laser rangefinder that uses pulse or phase time of flight measurement to measure distance. The laser rangefinder includes a diode laser pulse or phase driver that produces an output signal to a timing element and simultaneously operates a laser diode. The laser diode produces an intense light beam of a predetermined wavelength which is directed to retroreflectors that are positioned on a passive target. The laser rangefinder includes an avalanche photodetector that produces a corresponding output signal when detecting light reflected from the retroreflectors. The timing element measures a time interval between the output of the laser diode and the detection of light and supplies a corresponding output signal to a computer in order to determine the range of the target vehicle relative to the chase vehicle.

  17. [Design of an integrative laser laryngoscope system].

    PubMed

    Zhang, Yangde; Qiao, Jingliang

    2012-10-01

    Laser technology is widely used in many medical fields such as general surgery, cardio-thoracic surgery, neurosurgery and urology. Laser has the characteristics of identical direction and high energy density, so that a laser knife leaves smooth incisions, less hemorrhage and less infection. The design presented in this paper applied the advanced laser technology in laryngoscopic operations, which increases efficiency and safety of the operation. The design included a laryngoscope, a laser-knife system host machine and a laser-knife, which were integrated in the front of the laryngoscope working terminal. Operators could choose the laser with appropriate wavelength to cut, irradiate, stop bleeding and coagulate the foreign objects or lesions of the larynx. A Chinese national patent (patent number ZL201020537693. 5) has been granted to the design.

  18. Capillary Action may Cool Systems and Precisely balance Chemical Reactions

    NASA Astrophysics Data System (ADS)

    Kriske, Richard

    2011-10-01

    It is well known that it takes no work for Water to rise in a Capillary tube against the force of Gravity. There is a precise balance in this system that resembles Robert Millikan's ``Oil Drop'' experiment, where mass was balanced against the electrostatic force. If at the top of the capillary tube there is evaporation, one can see that the system is cooled as another water molecule has room to move up the column. Furthermore, if the evaporation process can be controlled one photon at a time, a precise balance is created between a photon, and the height/mass of the column. If other molecules are place in the column, they can be moved up and down the column, in a chromatograph way, in a fairly precise manner, by controlling evaporation and molecular weight. If in addition to all of this, the interface of the solution against the walls of the column have Fermi levels, it can be seen as a very precise Electrochemical Device. In the situation of nanotubes, as opposed to trees and plants, these properties can be used to create measure environmental properties and to Balance Chemical Reactions. Forests, and Plants may cool themselves and their environment using this process, and using this process coupled with more energetic photons through photosynthesis.

  19. Personal medical information system using laser card

    NASA Astrophysics Data System (ADS)

    Cho, Seong H.; Kim, Keun Ho; Choi, Hyung-Sik; Park, Hyun Wook

    1996-04-01

    The well-known hospital information system (HIS) and the picture archiving and communication system (PACS) are typical applications of multimedia to medical area. This paper proposes a personal medical information save-and-carry system using a laser card. This laser card is very useful, especially in emergency situations, because the medical information in the laser card can be read at anytime and anywhere if there exists a laser card reader/writer. The contents of the laser card include the clinical histories of a patient such as clinical chart, exam result, diagnostic reports, images, and so on. The purpose of this system is not a primary diagnosis, but emergency reference of clinical history of the patient. This personal medical information system consists of a personal computer integrated with laser card reader/writer, color frame grabber, color CCD camera and a high resolution image scanner optionally. Window-based graphical user interface was designed for easy use. The laser card has relatively sufficient capacity to store the personal medical information, and has fast access speed to restore and load the data with a portable size as compact as a credit card. Database items of laser card provide the doctors with medical data such as laser card information, patient information, clinical information, and diagnostic result information.

  20. Laser Surveillance System for Spent Fuel

    SciTech Connect

    Fiarman, S.; Zucker, M. S.; Bieber, Jr., A. M.

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools (SFSP's) will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a full size laser system operating in air and have used an array of 6 zircaloy BWR tubes to simulate an assembly. The reflective signal from the zircaloy rods is a strong function of position of the assembly, but in all cases is easily discernable from the reference scan of the background with no assembly. A design for a SFSP laser surveillance system incorporating laser ranging is discussed. 10 figures.

  1. Fuzzy Pool Balance: An algorithm to achieve a two dimensional balance in distribute storage systems

    NASA Astrophysics Data System (ADS)

    Wu, Wenjing; Chen, Gang

    2014-06-01

    The limitation of scheduling modules and the gradual addition of disk pools in distributed storage systems often result in imbalances among their disk pools in terms of both disk usage and file count. This can cause various problems to the storage system such as single point of failure, low system throughput and imbalanced resource utilization and system loads. An algorithm named Fuzzy Pool Balance (FPB) is proposed here to solve this problem. The input of FPB is the current file distribution among disk pools and the output is a file migration plan indicating what files are to be migrated to which pools. FPB uses an array to classify the files by their sizes. The file classification array is dynamically calculated with a defined threshold named Tmax that defines the allowed pool disk usage deviations. File classification is the basis of file migration. FPB also defines the Immigration Pool (IP) and Emigration Pool (EP) according to the pool disk usage and File Quantity Ratio (FQR) that indicates the percentage of each category of files in each disk pool, so files with higher FQR in an EP will be migrated to IP(s) with a lower FQR of this file category. To verify this algorithm, we implemented FPB on an ATLAS Tier2 dCache production system. The results show that FPB can achieve a very good balance in both free space and file counts, and adjusting the threshold value Tmax and the correction factor to the average FQR can achieve a tradeoff between free space and file count.

  2. The Theory of Random Laser Systems

    SciTech Connect

    Xunya Jiang

    2002-06-27

    Studies of random laser systems are a new direction with promising potential applications and theoretical interest. The research is based on the theories of localization and laser physics. So far, the research shows that there are random lasing modes inside the systems which is quite different from the common laser systems. From the properties of the random lasing modes, they can understand the phenomena observed in the experiments, such as multi-peak and anisotropic spectrum, lasing mode number saturation, mode competition and dynamic processes, etc. To summarize, this dissertation has contributed the following in the study of random laser systems: (1) by comparing the Lamb theory with the Letokhov theory, the general formulas of the threshold length or gain of random laser systems were obtained; (2) they pointed out the vital weakness of previous time-independent methods in random laser research; (3) a new model which includes the FDTD method and the semi-classical laser theory. The solutions of this model provided an explanation of the experimental results of multi-peak and anisotropic emission spectra, predicted the saturation of lasing modes number and the length of localized lasing modes; (4) theoretical (Lamb theory) and numerical (FDTD and transfer-matrix calculation) studies of the origin of localized lasing modes in the random laser systems; and (5) proposal of using random lasing modes as a new path to study wave localization in random systems and prediction of the lasing threshold discontinuity at mobility edge.

  3. Towards a Load Balancing Middleware for Automotive Infotainment Systems

    NASA Astrophysics Data System (ADS)

    Khaluf, Yara; Rettberg, Achim

    In this paper a middleware for distributed automotive systems is developed. The goal of this middleware is to support the load bal- ancing and service optimization in automotive infotainment and entertainment systems. These systems provide navigation, telecommunication, Internet, audio/video and many other services where a kind of dynamic load balancing mechanisms in addition to service quality optimization mechanisms will be applied by the developed middleware in order to improve the system performance and also at the same time improve the quality of services if possible.

  4. Force Measurements in Magnetic Suspension and Balance System

    NASA Technical Reports Server (NTRS)

    Kuzin, Alexander; Shapovalov, George; Prohorov, Nikolay

    1996-01-01

    The description of an infrared telemetry system for measurement of drag forces in Magnetic Suspension and Balance Systems (MSBS) is presented. This system includes a drag force sensor, electronic pack and transmitter placed in the model which is of special construction, and receiver with a microprocessor-based measuring device, placed outside of the test section. Piezosensitive resonators as sensitive elements and non-magnetic steel as the material for the force sensor are used. The main features of the proposed system for load measurements are discussed and the main characteristics are presented.

  5. Ultra-broadband quantum cascade laser, tunable over 760 cm(-1), with balanced gain.

    PubMed

    Bandyopadhyay, N; Chen, M; Sengupta, S; Slivken, S; Razeghi, M

    2015-08-10

    A heterogeneous quantum cascade laser, consisting of multiple stacks of discrete wavelength quantum cascade stages, emitting in 5.9-10.9 µm, wavelength range is reported. The broadband characteristics are demonstrated with a distributed-feedback laser array, emitting at fixed frequencies at room temperature, covering an emission range of ~760 cm(-1), which is ~59% relative to the center frequency. By appropriate choice of a strained AlInAs/GaInAs material system, quantum cascade stage design and spatial arrangement of stages, the distributed-feedback array has been engineered to exhibit a flat threshold current density across the demonstrated range.

  6. Test performance of the PARSEC laser system

    NASA Astrophysics Data System (ADS)

    Rabien, Sebastian; Davies, Richard I.; Ott, Thomas; Li, Jianlang; Abuter, Roberto; Kellner, Stefan; Neumann, Udo

    2004-10-01

    The PARSEC laser system is designed for the VLT Laser Guide Star Facility to deliver a high power cw laser beam at 589nm, in order to create an artificial guide star in the mesospheric Sodium layer. The laser consists of a resonant, dye based power amplifier which is injection seeded with 589nm, single frequency radiation from a master oscillator. We report on the performance of the system both during the European Acceptance tests, and that which has been achieved in the laboratory. The maximum power we have obtained amounts to 20W cw laser light in a single mode and a single frequency at 589nm. With a beam quality of M2 of 1.05-1.15 and a long term stability without manual intervention, the laser suits all the demands for operation at the VLT.

  7. Application of laser Doppler velocimeter to chemical vapor laser system

    NASA Technical Reports Server (NTRS)

    Gartrell, Luther R.; Hunter, William W., Jr.; Lee, Ja H.; Fletcher, Mark T.; Tabibi, Bagher M.

    1993-01-01

    A laser Doppler velocimeter (LDV) system was used to measure iodide vapor flow fields inside two different-sized tubes. Typical velocity profiles across the laser tubes were obtained with an estimated +/-1 percent bias and +/-0.3 to 0.5 percent random uncertainty in the mean values and +/-2.5 percent random uncertainty in the turbulence-intensity values. Centerline velocities and turbulence intensities for various longitudinal locations ranged from 13 to 17.5 m/sec and 6 to 20 percent, respectively. In view of these findings, the effects of turbulence should be considered for flow field modeling. The LDV system provided calibration data for pressure and mass flow systems used routinely to monitor the research laser gas flow velocity.

  8. Large-scale violation of detailed balance in biological systems

    NASA Astrophysics Data System (ADS)

    Broedersz, Chase; Battle, Christopher; Fakhri, Nikta; Mackintosh, Fred; Schmidt, Christopher

    2015-03-01

    Living systems are out of equilibrium. A fundamental manifestation of non-equilibrium dynamics in biological systems is the violation of detailed balance: at the microscopic level, enzymatic processes such as kinetic proofreading or molecular motor activity clearly violate detailed balance. We study how such non-equilibrium dynamics emerge at macroscopic scales in cellular assemblies. We measure the steady-state dynamics of two systems, beating flagella of Chlamydomonas reinhardtii and mechanosensitive primary cilia protruding from epithelial kidney cells. The flagellum exhibits clear non-equilibrium driving, whereas fluctuations in the primary cilium are difficult to differentiate from Brownian motion. We parameterize the shapes of the flagellum and primary cilium using a low-dimensional representation of their configuration phase space, and use the measured dynamics to infer the steady-state probability distributions and probability currents. For both the flagellum and the primary cilium we find significant, coherent circulating probability currents, demonstrating that these systems violate detailed balance at the mesoscopic scale.

  9. Theory of intrinsic linewidth based on fluctuation-dissipation balance for thermal photons in THz quantum-cascade lasers.

    PubMed

    Yamanishi, Masamichi

    2012-12-17

    Intrinsic linewidth formula modified by taking account of fluctuation-dissipation balance for thermal photons in a THz quantum-cascade laser (QCL) is exhibited. The linewidth formula based on the model that counts explicitly the influence of noisy stimulated emissions due to thermal photons existing inside the laser cavity interprets experimental results on intrinsic linewidth, ~91.1 Hz reported recently with a 2.5 THz bound-to-continuum QCL. The line-broadening induced by thermal photons is estimated to be ~22.4 Hz, i.e., 34% broadening. The modified linewidth formula is utilized as a bench mark in engineering of THz thermal photons inside laser cavities.

  10. High angle of attack position sensing for the Southampton University magnetic suspension and balance system

    NASA Technical Reports Server (NTRS)

    Parker, David H.

    1987-01-01

    An all digital five channel position detection system is to be installed in the Southampton University Magnetic Suspension and Balance System (SUMSBS). The system is intended to monitor a much larger range of model pitch attitudes than has been possible hitherto, up to a maximum of a 90 degree angle of attack. It is based on the use of self-scanning photodiode arrays and illuminating laser light beams, together with purpose built processing electronics. The principles behind the design of the system are discussed, together with the results of testing one channel of the system which was used to control the axial position of a magnetically suspended model in SUMSBS. The removal of optically coupled heave position information from the axial position sensing channel is described.

  11. Active vibration and balance system for closed cycle thermodynamic machines

    NASA Technical Reports Server (NTRS)

    Qiu, Songgang (Inventor); Augenblick, John E. (Inventor); Peterson, Allen A. (Inventor); White, Maurice A. (Inventor)

    2004-01-01

    An active balance system is provided for counterbalancing vibrations of an axially reciprocating machine. The balance system includes a support member, a flexure assembly, a counterbalance mass, and a linear motor or an actuator. The support member is configured for attachment to the machine. The flexure assembly includes at least one flat spring having connections along a central portion and an outer peripheral portion. One of the central portion and the outer peripheral portion is fixedly mounted to the support member. The counterbalance mass is fixedly carried by the flexure assembly along another of the central portion and the outer peripheral portion. The linear motor has one of a stator and a mover fixedly mounted to the support member and another of the stator and the mover fixedly mounted to the counterbalance mass. The linear motor is operative to axially reciprocate the counterbalance mass. A method is also provided.

  12. Offshore Wind Balance-of-System Cost Modeling

    SciTech Connect

    Maness, Michael; Stehly, Tyler; Maples, Ben; Mone, Christopher

    2015-09-29

    Offshore wind balance-of-system (BOS) costs contribute up to 70% of installed capital costs. Thus, it is imperative to understand the impact of these costs on project economics as well as potential cost trends for new offshore wind technology developments. As a result, the National Renewable Energy Laboratory (NREL) developed and recently updated a BOS techno-economic model using project cost estimates created from wind energy industry sources.

  13. The 13-inch magnetic suspension and balance system wind tunnel

    NASA Technical Reports Server (NTRS)

    Johnson, William G., Jr.; Dress, David A.

    1989-01-01

    NASA Langley has a small, subsonic wind tunnel in use with the 13-inch Magnetic Suspension and Balance System (MSBS). The tunnel is capable of speeds up to Mach 0.5. This report presents tunnel design and construction details. It includes flow uniformity, angularity, and velocity fluctuation data. It also compares experimental Mach number distribution data with computed results for the General Electric Streamtube Curvature Program.

  14. Balance of plant options for the heatpipe bimodal system

    NASA Astrophysics Data System (ADS)

    Berte, Marc; Capell, Brent

    1998-01-01

    The Heat pipe Power System (HPS) is a near-term, low-cost space fission power system with the potential for various balance of plant options. The following options have been studied: a low power thermoelectric design (14kWe output), a small Brayton Cycle system (60-75kWe), and a large Brayton Cycle system (250kWe). These systems were analyzed on a preliminary basis, including mass, volume and structure calculations. This analysis has shown that the HPS system can provide power outputs between 10-250kWe with specific powers of ~14 W/kg for a 14kWe model to ~100W/kg for a 250kWe model. The system designs considered in this study utilize a common component base to permit easy expansion and development.

  15. Balance of plant options for the heatpipe bimodal system

    SciTech Connect

    Berte, M.; Capell, B.

    1998-01-01

    The Heat pipe Power System (HPS) is a near-term, low-cost space fission power system with the potential for various balance of plant options. The following options have been studied: a low power thermoelectric design (14kWe output), a small Brayton Cycle system (60{endash}75kWe), and a large Brayton Cycle system (250kWe). These systems were analyzed on a preliminary basis, including mass, volume and structure calculations. This analysis has shown that the HPS system can provide power outputs between 10{endash}250kWe with specific powers of {approximately}14 W/kg for a 14kWe model to {approximately}100W/kg for a 250kWe model. The system designs considered in this study utilize a common component base to permit easy expansion and development. {copyright} {ital 1998 American Institute of Physics.}

  16. Balance of plant options for the heatpipe bimodal system

    SciTech Connect

    Berte, Marc; Capell, Brent

    1998-01-15

    The Heat pipe Power System (HPS) is a near-term, low-cost space fission power system with the potential for various balance of plant options. The following options have been studied: a low power thermoelectric design (14kWe output), a small Brayton Cycle system (60-75kWe), and a large Brayton Cycle system (250kWe). These systems were analyzed on a preliminary basis, including mass, volume and structure calculations. This analysis has shown that the HPS system can provide power outputs between 10-250kWe with specific powers of {approx}14 W/kg for a 14kWe model to {approx}100W/kg for a 250kWe model. The system designs considered in this study utilize a common component base to permit easy expansion and development.

  17. Active polarimeter optical system laser hazard analysis.

    SciTech Connect

    Augustoni, Arnold L.

    2005-07-01

    A laser hazard analysis was performed for the SNL Active Polarimeter Optical System based on the ANSI Standard Z136.1-2000, American National Standard for Safe Use of Lasers and the ANSI Standard Z136.6-2000, American National Standard for Safe Use of Lasers Outdoors. The Active Polarimeter Optical System (APOS) uses a pulsed, near-infrared, chromium doped lithium strontium aluminum fluoride (Cr:LiSAF) crystal laser in conjunction with a holographic diffuser and lens to illuminate a scene of interest. The APOS is intended for outdoor operations. The system is mounted on a height adjustable platform (6 feet to 40 feet) and sits atop a tripod that points the beam downward. The beam can be pointed from nadir to as much as 60 degrees off of nadir producing an illuminating spot geometry that can vary from circular (at nadir) to elliptical in shape (off of nadir). The JP Innovations crystal Cr:LiSAF laser parameters are presented in section II. The illuminating laser spot size is variable and can be adjusted by adjusting the separation distance between the lens and the holographic diffuser. The system is adjusted while platform is at the lowest level. The laser spot is adjusted for a particular spot size at a particular distance (elevation) from the laser by adjusting the separation distance (d{sub diffuser}) to predetermined values. The downward pointing angle is also adjusted before the platform is raised to the selected operation elevation.

  18. High energy chemical laser system

    DOEpatents

    Gregg, D.W.; Pearson, R.K.

    1975-12-23

    A high energy chemical laser system is described wherein explosive gaseous mixtures of a reducing agent providing hydrogen isotopes and interhalogen compounds are uniformly ignited by means of an electrical discharge, flash- photolysis or an electron beam. The resulting chemical explosion pumps a lasing chemical species, hydrogen fluoride or deuterium fluoride which is formed in the chemical reaction. The generated lasing pulse has light frequencies in the 3- micron range. Suitable interhalogen compounds include bromine trifluoride (BrF$sub 3$), bromine pentafluoride (BrF$sub 5$), chlorine monofluoride (ClF), chlorine trifluoride (ClF$sub 3$), chlorine pentafluoride (ClF$sub 5$), iodine pentafluoride (IF$sub 5$), and iodine heptafluoride (IF$sub 7$); and suitable reducing agents include hydrogen (H$sub 2$), hydrocarbons such as methane (CH$sub 4$), deuterium (D$sub 2$), and diborane (B$sub 2$H$sub 6$), as well as combinations of the gaseous compound and/or molecular mixtures of the reducing agent.

  19. Balanced-Rotating-Spray Tank-And-Pipe-Cleaning System

    NASA Technical Reports Server (NTRS)

    Thaxton, Eric A.; Caimi, Raoul E. B.

    1995-01-01

    Spray head translates and rotates to clean entire inner surface of tank or pipe. Cleansing effected by three laterally balanced gas/liquid jets from spray head that rotates about longitudinal axis. Uses much less liquid. Cleaning process in system relies on mechanical action of jets instead of contaminant dissolution. Eliminates very difficult machining needed to make multiple converging/diverging nozzles within one spray head. Makes nozzle much smaller. Basic two-phase-flow, supersonic-nozzle design applied to other spray systems for interior or exterior cleaning.

  20. Space Applications Industrial Laser System (SAILS)

    NASA Technical Reports Server (NTRS)

    Mccay, T. D.; Bible, J. B.; Mueller, R. E.

    1993-01-01

    A program is underway to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. This workstation, called Space Applications Industrial Laser System (SAILS), will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use in constructing the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1996, will be constructed as three modules using standard Get-Away-Special (GAS) canisters. The first module holds the laser head and cooling system, while the second contains a high peak power electrical supply. The third module houses the materials processing workstation and the command and data acquisition subsystems. The laser head and workstation cansisters are linked by a fiber-optic cable to transmit the laser light. The team assembled to carry out this project includes Lumonics Industrial Products (laser), Tennessee Technological University (structural analysis and fabrication), Auburn University Center for Space Power (electrical engineering), University of Waterloo (low-g laser process consulting), and CSTAR/UTSI (data acquisition, control, software, integration, experiment design). This report describes the SAILS program and highlights recent activities undertaken at CSTAR.

  1. Microoptoelectromechanical system (MOEMS) based laser

    DOEpatents

    Hutchinson, Donald P.

    2003-11-04

    A method for forming a folded laser and associated laser device includes providing a waveguide substrate, micromachining the waveguide substrate to form a folded waveguide structure including a plurality of intersecting folded waveguide paths, forming a single fold mirror having a plurality of facets which bound all ends of said waveguide paths except those reserved for resonator mirrors, and disposing a pair of resonator mirrors on opposite sides of the waveguide to form a lasing cavity. A lasing material is provided in the lasing cavity. The laser can be sealed by disposing a top on the waveguide substrate. The laser can include a re-entrant cavity, where the waveguide substrate is disposed therein, the re-entrant cavity including the single fold mirror.

  2. Magnetically switched power supply system for lasers

    NASA Technical Reports Server (NTRS)

    Pacala, Thomas J. (Inventor)

    1987-01-01

    A laser power supply system is described in which separate pulses are utilized to avalanche ionize the gas within the laser and then produce a sustained discharge to cause the gas to emit light energy. A pulsed voltage source is used to charge a storage device such as a distributed capacitance. A transmission line or other suitable electrical conductor connects the storage device to the laser. A saturable inductor switch is coupled in the transmission line for containing the energy within the storage device until the voltage level across the storage device reaches a predetermined level, which level is less than that required to avalanche ionize the gas. An avalanche ionization pulse generating circuit is coupled to the laser for generating a high voltage pulse of sufficient amplitude to avalanche ionize the laser gas. Once the laser gas is avalanche ionized, the energy within the storage device is discharged through the saturable inductor switch into the laser to provide the sustained discharge. The avalanche ionization generating circuit may include a separate voltage source which is connected across the laser or may be in the form of a voltage multiplier circuit connected between the storage device and the laser.

  3. Target isolation system, high power laser and laser peening method and system using same

    DOEpatents

    Dane, C. Brent; Hackel, Lloyd A.; Harris, Fritz

    2007-11-06

    A system for applying a laser beam to work pieces, includes a laser system producing a high power output beam. Target delivery optics are arranged to deliver the output beam to a target work piece. A relay telescope having a telescope focal point is placed in the beam path between the laser system and the target delivery optics. The relay telescope relays an image between an image location near the output of the laser system and an image location near the target delivery optics. A baffle is placed at the telescope focal point between the target delivery optics and the laser system to block reflections from the target in the target delivery optics from returning to the laser system and causing damage.

  4. Review Of Laser Lightcraft Propulsion System

    SciTech Connect

    Davis, Eric W.; Mead, Franklin B. Jr

    2008-04-28

    Laser-powered 'Lightcraft' systems that deliver nano-satellites to LEO have been studied for the Air Force Research Laboratory (AFRL). The study was built on the extensive Lightcraft laser propulsion technology already developed by theoretical and experimental work by the AFRL's Propulsion Directorate at Edwards AFB, CA. Here we review the history and engineering-physics of the laser Lightcraft system and its propulsive performance. We will also review the effectiveness and cost of a Lightcraft vehicle powered by a high-energy laser beam. One result of this study is the significant influence of laser wavelength on the power lost during laser beam propagation through Earth's atmosphere and in space. It was discovered that energy and power losses in the laser beam are extremely sensitive to wavelength for Earth-To-Orbit missions, and this significantly affects the amount of mass that can be placed into orbit for a given maximum amount of radiated power from a ground-based laser.

  5. New generation of medical laser systems

    NASA Astrophysics Data System (ADS)

    Konov, Vitali I.; Prokhorov, Alexander M.; Silenok, Alexander S.

    1990-09-01

    Advantages and fields of application for modern medical laser systems with fiber optic cables optical diagnostics of the irradiated zone and beam parameters optimized for concrete type of operation are considered.

  6. Multiple-laser-energy detection system

    NASA Technical Reports Server (NTRS)

    Jarrett, O., Jr.; Northam, G. B.

    1977-01-01

    Technique monitors energy output of each of four sequentially-pulsed dye lasers for the Airborne LIDAR Oceanographic Probing Experiment system. Fiber optics attached to output mirrors transmit optical signal proportional to output energy.

  7. Pulse shaping on the Nova laser system

    SciTech Connect

    Lawson, J.K.; Speck, D.R.; Bibeau, C.; Weiland, T.L.

    1989-02-06

    Inertial confinement fusion requires temporally shaped pulses to achieve high gain efficiency. Recently, we demonstrated the ability to produce complex temporal pulse shapes at high power at 0.35 microns on the Nova laser system. 2 refs., 2 figs.

  8. 26 CFR 801.1 - Balanced performance measurement system; in general.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (CONTINUED) INTERNAL REVENUE PRACTICE BALANCED SYSTEM FOR MEASURING ORGANIZATIONAL AND EMPLOYEE PERFORMANCE...) of a balanced performance measurement system. (2) Modern management practice and various statutory and regulatory provisions require the IRS to set performance goals for organizational units and...

  9. 26 CFR 801.1 - Balanced performance measurement system; in general.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (CONTINUED) INTERNAL REVENUE PRACTICE BALANCED SYSTEM FOR MEASURING ORGANIZATIONAL AND EMPLOYEE PERFORMANCE...) of a balanced performance measurement system. (2) Modern management practice and various statutory and regulatory provisions require the IRS to set performance goals for organizational units and...

  10. Research of laser ignition detection system

    NASA Astrophysics Data System (ADS)

    Yang, Feng; Zhao, Dong; Xu, Qie; Ai, Xin

    2010-10-01

    Laser ignition is an important means of detonation but the accuracy and security is requested strictly. Based on the above, two points were considered in the design: achieve ignition-Fiber-optical health monitoring in the condition of low-intensity light (ensure the safety of gunpowder); observant the explosive imaging. In the paper, the laser ignition equipment was designed with optical detection and inner optical imaging system for the real-time monitoring to the optical fiber and the process of ignition. This design greatly improved the reliability and the safety of laser ignition system and provided the guarantee for usage and industrialization.

  11. Laser power conversion system analysis, volume 1

    NASA Technical Reports Server (NTRS)

    Jones, W. S.; Morgan, L. L.; Forsyth, J. B.; Skratt, J. P.

    1979-01-01

    The orbit-to-orbit laser energy conversion system analysis established a mission model of satellites with various orbital parameters and average electrical power requirements ranging from 1 to 300 kW. The system analysis evaluated various conversion techniques, power system deployment parameters, power system electrical supplies and other critical supplies and other critical subsystems relative to various combinations of the mission model. The analysis show that the laser power system would not be competitive with current satellite power systems from weight, cost and development risk standpoints.

  12. Highlights of recent balance of system research and evaluation

    SciTech Connect

    Thomas, M.G.; Stevens, J.W.

    1994-10-01

    The cost of most photovoltaic (PV) systems is more a function of the balance of system (BOS) components than the collectors. The exception to this rule is the grid-tied system whose cost is related more directly to the collectors, and secondarily to the inverter/controls. In fact, recent procurements throughout the country document that collector costs for roof-mounted, utility-tied systems (Russell, PV Systems Workshop, 7/94) represent 60% to 70% of the system cost. This contrasts with the current market for packaged stand-alone all PV or PV-hybrid systems where collectors represent only 25% to 35% of the total. Not only are the BOS components the cost drivers in the current cost-effective PV system market place, they are also the least reliable components. This paper discusses the impact that BOS issues have on component performance, system performance, and system cost and reliability. We will also look at recent recommended changes in system design based upon performance evaluations of fielded PV systems.

  13. Magnetic Suspension and Balance Systems: A Selected, Annotated Bibliography

    NASA Technical Reports Server (NTRS)

    Tuttle Marie H.; Kilgore, Robert A.; Boyden, Richmond P.

    1983-01-01

    This publication, containing 206 entries, supersedes an earlier bibliography, NASA TM-80225 (April 1980). Citations for 18 documents have been added in this updated version. Most of the additions report results of recent studies aimed at increasing the research capabilities of magnetic suspension and balance systems, e.g., increasing force and torque capability, increasing angle of attack capability, and increasing overall system reliability. Some of the additions address the problem of scaling from the relatively small size of existing systems to much larger sizes. The purpose of this bibliography is to provide an up-to-date list of publications that might be helpful to persons interested in magnetic suspension and balance systems for use in wind tunnels. The arrangement is generally chronological by date of publication. However, papers presented at conferences or meetings are placed under dates of presentation. The numbers assigned to many of the citations have been changed from those used in the previous bibliography. This has been done in order to allow outdated citations to be removed and some recently discovered older works to be included in their proper chronological order.

  14. Modelling human balance using switched systems with linear feedback control.

    PubMed

    Kowalczyk, Piotr; Glendinning, Paul; Brown, Martin; Medrano-Cerda, Gustavo; Dallali, Houman; Shapiro, Jonathan

    2012-02-01

    We are interested in understanding the mechanisms behind and the character of the sway motion of healthy human subjects during quiet standing. We assume that a human body can be modelled as a single-link inverted pendulum, and the balance is achieved using linear feedback control. Using these assumptions, we derive a switched model which we then investigate. Stable periodic motions (limit cycles) about an upright position are found. The existence of these limit cycles is studied as a function of system parameters. The exploration of the parameter space leads to the detection of multi-stability and homoclinic bifurcations. PMID:21697168

  15. Creating a balanced scorecard for a hospital system.

    PubMed

    Pink, G H; McKillop, I; Schraa, E G; Preyra, C; Montgomery, C; Baker, G R

    2001-01-01

    In 1999, hospitals in Ontario, Canada, collaborated with a university-based research team to develop a report on the relative performance of individual hospitals in Canada's most populated province. The researchers used the balanced-scorecard framework advocated by Kaplan and Norton. Indicators of performance were developed in four areas: clinical utilization and outcomes, patient satisfaction, system integration and change, and financial performance and condition. The process of selecting, calculating, and validating meaningful indicators of financial performance and condition is outlined. Lessons learned along the way are provided. These lessons may prove valuable to other finance researchers and practitioners who are engaged in performance measurement endeavors. PMID:14680029

  16. Modelling human balance using switched systems with linear feedback control.

    PubMed

    Kowalczyk, Piotr; Glendinning, Paul; Brown, Martin; Medrano-Cerda, Gustavo; Dallali, Houman; Shapiro, Jonathan

    2012-02-01

    We are interested in understanding the mechanisms behind and the character of the sway motion of healthy human subjects during quiet standing. We assume that a human body can be modelled as a single-link inverted pendulum, and the balance is achieved using linear feedback control. Using these assumptions, we derive a switched model which we then investigate. Stable periodic motions (limit cycles) about an upright position are found. The existence of these limit cycles is studied as a function of system parameters. The exploration of the parameter space leads to the detection of multi-stability and homoclinic bifurcations.

  17. Laser and solar-photovoltaic space power systems comparison. II.

    NASA Technical Reports Server (NTRS)

    De Young, R. J.; Stripling, J.; Enderson, T. M.; Humes, D. H.; Davis, W. T.

    1984-01-01

    A comparison of total system cost is made between solar photovoltaic and laser/receiver systems. The laser systems assume either a solar-pumped CO2 blackbody transfer laser with MHD receiver or a solar pumped liquid neodymium laser with a photovoltaic receiver. Total system costs are less for the laser systems below 300 km where drag is significant. System costs are highly dependent on altitude.

  18. Repetitive output laser system and method using target reflectivity

    DOEpatents

    Johnson, Roy R.

    1978-01-01

    An improved laser system and method for implosion of a thermonuclear fuel pellet in which that portion of a laser pulse reflected by the target pellet is utilized in the laser system to initiate a succeeding target implosion, and in which the energy stored in the laser system to amplify the initial laser pulse, but not completely absorbed thereby, is used to amplify succeeding laser pulses initiated by target reflection.

  19. Automated retinal robotic laser system instrumentation

    NASA Astrophysics Data System (ADS)

    Barrett, Steven F.; Wright, Cameron H. G.; Jerath, Maya R.; Lewis, R. Stephen, II; Dillard, Bryan C.; Rylander, Henry G., III; Welch, Ashley J.

    1995-05-01

    Researchers at the University of Texas at Austin's Biomedical Engineering Laser Laboratory investigating the medical applications of lasers have worked toward the development of a retinal robotic laser system. The ultimate goal of this ongoing project is to precisely place and control the depth of laser lesions for the treatment of various retinal diseases such as diabetic retinopathy and retinal tears. Researchers at the USAF Academy's Department of Electrical Engineering have also become involved with this research due to similar interests. Separate low speed prototype subsystems have been developed to control lesion depth using lesion reflectance feedback parameters and lesion placement using retinal vessels as tracking landmarks. Both subsystems have been successfully demonstrated in vivo on pigmented rabbits using an argon continuous wave laser. Work is ongoing to build a prototype system to simultaneously control lesion depth and placement. The instrumentation aspects of the prototype subsystems were presented at SPIE Conference 1877 in January 1993. Since then our efforts have concentrated on combining the lesion depth control subsystem and the lesion placement subsystem into a single prototype capable of simultaneously controlling both parameters. We have designed this combined system CALOSOS for Computer Aided Laser Optics System for Ophthalmic Surgery. An initial CALOSOS prototype design is provided. We have also investigated methods to improve system response time. The use of high speed non-standard frame rate CCD cameras and high speed local bus frame grabbers hosted on personal computers are being investigated. A review of system testing in vivo to date is provided in SPIE Conference proceedings 2374-49 (Novel Applications of Lasers and Pulsed Power, Dual-Use Applications of Lasers: Medical session).

  20. Balance impairment and systemic inflammation in chronic obstructive pulmonary disease

    PubMed Central

    Tudorache, Emanuela; Oancea, Cristian; Avram, Claudiu; Fira-Mladinescu, Ovidiu; Petrescu, Lucian; Timar, Bogdan

    2015-01-01

    Background/purpose Chronic obstructive pulmonary disease (COPD), especially in severe forms, is commonly associated with systemic inflammation and balance impairment. The aim of our study was to evaluate the impact on equilibrium of stable and exacerbation (acute exacerbation of COPD [AECOPD]) phases of COPD and to investigate if there is a connection between lower extremity muscle weakness and systemic inflammation. Methods We enrolled 41 patients with COPD (22 stable and 19 in AECOPD) and 20 healthy subjects (control group), having no significant differences regarding the anthropometric data. We analyzed the differences in balance tests scores: Falls Efficacy Scale-International (FES-I) questionnaire, Berg Balance Scale (BBS), Timed Up and Go (TUG) test, Single Leg Stance (SLS), 6-minute walking distance (6MWD), isometric knee extension (IKE) between these groups, and also the correlation between these scores and inflammatory biomarkers. Results The presence and severity of COPD was associated with significantly decreased score in IKE (P<0.001), 6MWD (P<0.001), SLS (P<0.001), and BBS (P<0.001), at the same time noting a significant increase in median TUG score across the studied groups (P<0.001). The AECOPD group vs stable group presented a significant increase in high-sensitive C-reactive protein (hs-CRP) levels (10.60 vs 4.01; P=0.003) and decrease in PaO2 (70.1 vs 59.1; P<0.001). We observed that both IKE scores were significantly and positive correlated with all the respiratory volumes. In both COPD groups, we observed that fibrinogen reversely and significantly correlated with the 6MWD, and FES-I questionnaire is correlated positively with TUG test. Hs-CRP correlated reversely with the walking test and SLS test, while correlating positively with TUG test and FES-I questionnaire. Conclusion According to this study, COPD in advanced and acute stages is associated with an increased history of falls, systemic inflammation, balance impairment, and lower extremity

  1. Analysis of reactor trips originating in balance of plant systems

    SciTech Connect

    Stetson, F.T.; Gallagher, D.W.; Le, P.T.; Ebert, M.W. )

    1990-09-01

    This report documents the results of an analysis of balance-of-plant (BOP) related reactor trips at commercial US nuclear power plants of a 5-year period, from January 1, 1984, through December 31, 1988. The study was performed for the Plant Systems Branch, Office of Nuclear Reactor Regulation, US Nuclear Regulatory Commission. The objectives of the study were: to improve the level of understanding of BOP-related challenges to safety systems by identifying and categorizing such events; to prepare a computerized data base of BOP-related reactor trip events and use the data base to identify trends and patterns in the population of these events; to investigate the risk implications of BOP events that challenge safety systems; and to provide recommendations on how to address BOP-related concerns in regulatory context. 18 refs., 2 figs., 27 tabs.

  2. Magnetic suspension and balance system advanced study, phase 2

    NASA Technical Reports Server (NTRS)

    Boom, R. W.; Abdelsalam, M. K.; Eyssa, Y. M.; Mcintosh, G. E.

    1990-01-01

    The design improvements for the system encompass 14 or 18 external superconductive coils mounted on a 8 x 8 foot wind tunnel, a superconductive model core magnet on a holmium mandrel to fit an F-16 model, model wings of permanent magnet material Nd2Fe14B, and fiber glass epoxy structure. The Magnetic Suspension and Balance System (MSBS) advanced design is confirmed by the successful construction and test of a full size superconductive model core solenoid with holmium mandrel. The solenoid is 75 cm long and 12.6 cm in diameter and produces 6.1 tesla for a hold time of 47 minutes. An integrated coil system design of a new compact configuration without specific coils for roll or pitch shows promise of simplicity; magnet reductions of 30 percent compared to the most recent 1985 design are possible.

  3. Atmospheric Science Measurements by the EOS Geoscience Laser Altimeter System

    NASA Technical Reports Server (NTRS)

    Spinhirne, James

    1999-01-01

    Scheduled for Launch in July 2001, the Geoscience Laser Altimeter System (GLAS) is to be the first satellite instrument to provide full global lidar profiling of clouds and aerosol in the earth's atmosphere. GLAS is an EOS program instrument that is on its own satellite, now called the Ice, Cloud and land Elevation Satellite. The instrument is both a surface laser ranging system and an atmospheric profiling lidar. A most important surface measurement for the instrument is to study the change in the mass balance of the polar ice sheets by measuring the change in regional altitudes to an accuracy of 1.5 cm per year. The strategy to combine the surface measurement with a Cloud and aerosol lidar profiling mission is based on the compatibility of the altimetry instrument requirements with those for the required lidar measurements. The primary atmospheric science goal of the GLAS cloud and aerosol measurement is to determine the radiative forcing and vertically resolved atmospheric heating rate due to cloud and aerosol by directly observing the vertical structure and magnitude of cloud and aerosol parameters that are important for the radiative balance of the earth-atmosphere system, but which are ambiguous or impossible to obtain from existing or planned passive remote sensors. A further goal is to directly measure the height of atmospheric transition layers (inversions) which are important for dynamics and mixing, the planetary boundary layer and lifting condensation level.

  4. Laser Inertial Fusion Energy Control Systems

    SciTech Connect

    Marshall, C; Carey, R; Demaret, R; Edwards, O; Lagin, L; Van Arsdall, P

    2011-03-18

    A Laser Inertial Fusion Energy (LIFE) facility point design is being developed at LLNL to support an Inertial Confinement Fusion (ICF) based energy concept. This will build upon the technical foundation of the National Ignition Facility (NIF), the world's largest and most energetic laser system. NIF is designed to compress fusion targets to conditions required for thermonuclear burn. The LIFE control systems will have an architecture partitioned by sub-systems and distributed among over 1000's of front-end processors, embedded controllers and supervisory servers. LIFE's automated control subsystems will require interoperation between different languages and target architectures. Much of the control system will be embedded into the subsystem with well defined interface and performance requirements to the supervisory control layer. An automation framework will be used to orchestrate and automate start-up and shut-down as well as steady state operation. The LIFE control system will be a high parallel segmented architecture. For example, the laser system consists of 384 identical laser beamlines in a 'box'. The control system will mirror this architectural replication for each beamline with straightforward high-level interface for control and status monitoring. Key technical challenges will be discussed such as the injected target tracking and laser pointing feedback. This talk discusses the the plan for controls and information systems to support LIFE.

  5. Fast Offset Laser Phase-Locking System

    NASA Technical Reports Server (NTRS)

    Shaddock, Daniel; Ware, Brent

    2008-01-01

    Figure 1 shows a simplified block diagram of an improved optoelectronic system for locking the phase of one laser to that of another laser with an adjustable offset frequency specified by the user. In comparison with prior systems, this system exhibits higher performance (including higher stability) and is much easier to use. The system is based on a field-programmable gate array (FPGA) and operates almost entirely digitally; hence, it is easily adaptable to many different systems. The system achieves phase stability of less than a microcycle. It was developed to satisfy the phase-stability requirement for a planned spaceborne gravitational-wave-detecting heterodyne laser interferometer (LISA). The system has potential terrestrial utility in communications, lidar, and other applications. The present system includes a fast phasemeter that is a companion to the microcycle-accurate one described in High-Accuracy, High-Dynamic-Range Phase-Measurement System (NPO-41927), NASA Tech Briefs, Vol. 31, No. 6 (June 2007), page 22. In the present system (as in the previously reported one), beams from the two lasers (here denoted the master and slave lasers) interfere on a photodiode. The heterodyne photodiode output is digitized and fed to the fast phasemeter, which produces suitably conditioned, low-latency analog control signals which lock the phase of the slave laser to that of the master laser. These control signals are used to drive a thermal and a piezoelectric transducer that adjust the frequency and phase of the slave-laser output. The output of the photodiode is a heterodyne signal at the difference between the frequencies of the two lasers. (The difference is currently required to be less than 20 MHz due to the Nyquist limit of the current sampling rate. We foresee few problems in doubling this limit using current equipment.) Within the phasemeter, the photodiode-output signal is digitized to 15 bits at a sampling frequency of 40 MHz by use of the same analog

  6. Laser beam control and diagnostic systems for the copper-pumped dye laser system at Lawrence Livermore National Laboratory

    SciTech Connect

    Bliss, E.S.; Peterson, R.L.; Salmon, J.T.; Thomas, R.A.

    1992-11-01

    The laser system described in the previous paper is used for experiments in which success requires tight tolerances on beam position, direction, and wavefront. Indeed, the optimum performance of the laser itself depends on careful delivery of copper laser light to the dye amplifiers, precise propagation of dye laser beams through restricted amplifier apertures, and accurate monitoring of laser power at key locations. This paper describes the alignment systems, wavefront correction systems, and laser diagnostics systems which ensure that the control requirements of both the laser and associated experiments are met. Because laser isotope separation processes utilize more than one wavelength, these systems monitor and control multiple wavelengths simultaneously.

  7. Experimental nonlinear laser systems: Bigger data for better science?

    SciTech Connect

    Kane, D. M.; Toomey, J. P.; McMahon, C.; Noblet, Y.; Argyris, A.; Syvridis, D.

    2014-10-06

    Bigger data is supporting knowledge discovery in nonlinear laser systems as will be demonstrated with examples from three semiconductor laser based systems – one with optical feedback, a photonic integrated circuit (PIC) chaotic laser and a frequency shifted feedback laser system.

  8. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction laser system. 884.6200... Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a device that images, targets, and controls the power and pulse duration of a laser beam used to ablate a...

  9. Advanced laser systems for photoacoustic imaging

    NASA Astrophysics Data System (ADS)

    Klosner, Marc; Sampathkumar, Ashwin; Chan, Gary; Wu, Chunbai; Gross, Daniel; Heller, Donald F.

    2015-03-01

    We describe the ongoing development of laser systems for advanced photoacoustic imaging (PAI). We discuss the characteristics of these laser systems and their particular benefits for soft tissue imaging and next-generation breast cancer diagnostics. We provide an overview of laser performance and compare this with other laser systems that have been used for early-stage development of PAI. These advanced systems feature higher pulse energy output at clinically relevant repetition rates, as well as a novel wavelength-cycling output pulse format. Wavelength cycling provides pulse sequences for which the output repeatedly alternates between two wavelengths that provide differential imaging. This capability improves co-registration of captured differential images. We present imaging results of phantoms obtained with a commercial ultrasound detector system and a wavelength-cycling laser source providing ~500 mJ/pulse at 755 and 797 nm, operating at 25 Hz. The results include photoacoustic images and corresponding pulse-echo data from a tissue mimicking phantom containing inclusions, simulating tumors in the breast. We discuss the application of these systems to the contrast-enhanced detection of various tissue types and tumors.

  10. Satellite Power Systems (SPS) laser studies. Volume 1: Laser environmental impact study

    NASA Technical Reports Server (NTRS)

    Beverly, R. E., III

    1980-01-01

    The environmental impact of space to Earth power transmission using space borne laser subsystems is emphasized. A laser system is defined, estimates of relevant efficiencies for laser power generation and atmospheric transmission are developed, and a comparison is made to a microwave system. Ancillary issues, such as laser beam spreading, safety and security, mass and volume estimates and technology growth are considered.

  11. Cutting laser systems for ureteral strictures

    NASA Astrophysics Data System (ADS)

    Durek, C.; Knipper, Ansgar; Brinkmann, Ralf; Miller, Ado; Gromoll, Bernd; Jocham, Dieter

    1994-02-01

    Acquired ureteral strictures are still treated either with a stent, balloon dilatation, by open surgery or by endoscopic therapy with a `cold knife' or high current density as intubated ureterotomy. The success rates described in the literature range between 50% and 90%. Using the experimental CTH:YAG laser (wavelength 2120 nm) and CT:YAG laser (wavelength 1950 nm), the reduction of invasiveness and of morbidity was evaluated. First, the CTH:YAG laser was investigated on 540 fresh porcine ureters varying the parameters. With a computerized morphometry system, defect depth, defect width, coagulation depth and coagulation width were measured. Then 21 female pigs underwent 7.5 F - 12 F ureteroscopy with CTH:YAG laser, CT:YAG laser, high current density and `cold knife' ureterotomy. An IVP and sacrification with explanation of the whole urinary tract was done on day 6 and around day 60. In practice, laser application via the endoscope was easy to handle and exact cutting was always seen. The CT:YAG laser seems to have the best success results with low ureteral stricture recurrence rates. However, its clinical use remains to be proven.

  12. Multiple target laser ablation system

    DOEpatents

    Mashburn, Douglas N.

    1996-01-01

    A laser ablation apparatus and method are provided in which multiple targets consisting of material to be ablated are mounted on a movable support. The material transfer rate is determined for each target material, and these rates are stored in a controller. A position detector determines which target material is in a position to be ablated, and then the controller controls the beam trigger timing and energy level to achieve a desired proportion of each constituent material in the resulting film.

  13. Multiple target laser ablation system

    DOEpatents

    Mashburn, D.N.

    1996-01-09

    A laser ablation apparatus and method are provided in which multiple targets consisting of material to be ablated are mounted on a movable support. The material transfer rate is determined for each target material, and these rates are stored in a controller. A position detector determines which target material is in a position to be ablated, and then the controller controls the beam trigger timing and energy level to achieve a desired proportion of each constituent material in the resulting film. 3 figs.

  14. X-ray laser system, x-ray laser and method

    DOEpatents

    London, Richard A.; Rosen, Mordecai D.; Strauss, Moshe

    1992-01-01

    Disclosed is an x-ray laser system comprising a laser containing generating means for emitting short wave length radiation, and means external to said laser for energizing said generating means, wherein when the laser is in an operative mode emitting radiation, the radiation has a transverse coherence length to width ratio of from about 0.05 to 1. Also disclosed is a method of adjusting the parameters of the laser to achieve the desired coherence length to laser width ratio.

  15. Sustaining high performance: dynamic balancing in an otherwise unbalanced system.

    PubMed

    Wolf, Jason A

    2011-01-01

    As Ovid said, "There is nothing in the whole world which is permanent." It is this very premise that frames the discoveries in this chapter and the compelling paradox it has raised. What began as a question of how performance is sustained, unveiled a collection of core organizational paradoxes. The findings ultimately suggest that sustained high performance is not a permanent state an organization achieves, but rather it is through perpetual movement and dynamic balance that sustainability occurs. The idea of sustainability as movement is predicated on the ability of organizational members to move beyond the experience of paradox as an impediment to progress. Through holding three critical "movements"--agile/consistency, collective/individualism, and informative/inquiry--not as paradoxical, but as active polarities, the organizations in the study were able to transcend paradox, and take active steps to continuous achievement in outperforming their peers. The study, focused on a collection of hospitals across the Unites States, reveals powerful stories of care and service, of the profound grace of human capacity, and of clear actions taken to create significant results. All of this was achieved in an environment of great volatility, in essence an unbalanced system. It was the discovery of movement and ultimately of dynamic balancing that allowed the organizations to in this study to move beyond stasis to the continuous "state" of sustaining high performance.

  16. Over-stimulation of the vestibular system and body balance.

    PubMed

    Charles, Corinne; Cian, Corinne; Nougier, Vincent; Bigard, Xavier A; Job, Agnés; Raphel, Christian

    The purpose of this study was to examine whether an over-stimulation of the vestibular system, induced by thousands of time saccadic head stimulations, affects the vestibular sensitivity, and consequently if such a phenomenon could contribute to the deterioration of postural stability observed after a long distance running exercise. Eighteen athletic subjects performed a 20.5 km over ground race with an average speed of 15 km x h(-1), corresponding roughly to 7,500 strides shocks with associated saccadic accelerations transmitted to the head. A preliminary validation of the exercise protocol was realized to confirm the effect of the sustained exercise on body balance by recording standard postural parameters. A visually perceived eye level (VPEL) task was used to indirectly assess otolithic sensitivity motionless or undergoing low centrifugation conditions, before and after exercise. Results obtained from body balance analysis confirmed a decreased postural stability illustrated by increased postural oscillations after the 20.5 km run. Under low centrifugation conditions, results showed a lowering of the VPEL with the increase of the gravito-inertial acceleration in accordance with the literature. However, no significant change in the VPEL after a sustained running exercise was observed. In conclusion, the vestibular sensitivity at the otolithic level does not seem to be altered by an intensive running exercise and then failed to play a key role in the post-exercise deterioration of postural stability. PMID:12867671

  17. Increasing Cropping System Diversity Balances Productivity, Profitability and Environmental Health

    PubMed Central

    Davis, Adam S.; Hill, Jason D.; Chase, Craig A.; Johanns, Ann M.; Liebman, Matt

    2012-01-01

    Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and large negative impacts on the environment. We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain crop productivity. To test this, we conducted a field study from 2003–2011 in Iowa that included three contrasting systems varying in length of crop sequence and inputs. We compared a conventionally managed 2-yr rotation (maize-soybean) that received fertilizers and herbicides at rates comparable to those used on nearby farms with two more diverse cropping systems: a 3-yr rotation (maize-soybean-small grain + red clover) and a 4-yr rotation (maize-soybean-small grain + alfalfa-alfalfa) managed with lower synthetic N fertilizer and herbicide inputs and periodic applications of cattle manure. Grain yields, mass of harvested products, and profit in the more diverse systems were similar to, or greater than, those in the conventional system, despite reductions of agrichemical inputs. Weeds were suppressed effectively in all systems, but freshwater toxicity of the more diverse systems was two orders of magnitude lower than in the conventional system. Results of our study indicate that more diverse cropping systems can use small amounts of synthetic agrichemical inputs as powerful tools with which to tune, rather than drive, agroecosystem performance, while meeting or exceeding the performance of less diverse systems. PMID:23071739

  18. Increasing cropping system diversity balances productivity, profitability and environmental health.

    PubMed

    Davis, Adam S; Hill, Jason D; Chase, Craig A; Johanns, Ann M; Liebman, Matt

    2012-01-01

    Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and large negative impacts on the environment. We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain crop productivity. To test this, we conducted a field study from 2003-2011 in Iowa that included three contrasting systems varying in length of crop sequence and inputs. We compared a conventionally managed 2-yr rotation (maize-soybean) that received fertilizers and herbicides at rates comparable to those used on nearby farms with two more diverse cropping systems: a 3-yr rotation (maize-soybean-small grain + red clover) and a 4-yr rotation (maize-soybean-small grain + alfalfa-alfalfa) managed with lower synthetic N fertilizer and herbicide inputs and periodic applications of cattle manure. Grain yields, mass of harvested products, and profit in the more diverse systems were similar to, or greater than, those in the conventional system, despite reductions of agrichemical inputs. Weeds were suppressed effectively in all systems, but freshwater toxicity of the more diverse systems was two orders of magnitude lower than in the conventional system. Results of our study indicate that more diverse cropping systems can use small amounts of synthetic agrichemical inputs as powerful tools with which to tune, rather than drive, agroecosystem performance, while meeting or exceeding the performance of less diverse systems.

  19. Water-Energy balance in pressure irrigation systems

    NASA Astrophysics Data System (ADS)

    Sánchez, Raúl; Rodríguez-Sinobas, Leonor; Juana, Luis; Laguna, Francisco V.; Castañón, Guillermo; Gil, María; Benitez, Javier

    2013-04-01

    Modernization of irrigation schemes, generally understood as transformation of surface irrigation systems into pressure -sprinkler and trickle- irrigation systems, aims at, among others, improving irrigation efficiency and reduction of operation and maintenance efforts made by the irrigators. Automation techniques become easier after modernization, and operation management plays an important role in energy efficiency issues. Modern systems use to include elevated water reservoirs with enough capacity to irrigate during peak water demand period about 16 to 48 h. However, pressure irrigation systems, in contrast, carry a serious energy cost. Energy requirements depend on decisions taken on management strategies during the operation phase, which are conditioned by previous decisions taken on the design project of the different elements which compose the irrigation system. Most of the countries where irrigation activity is significant bear in mind that modernization irrigation must play a key role in the agricultural infrastructure policies. The objective of this study is to characterize and estimate the mean and variation of the energy consumed by common types of irrigation systems according to their management possibilities. Also is an objective to estimate the fraction of the water reservoirs available along the irrigation campaign for storing the energy from renewable sources during their availability periods. Simulation taking into account all elements comprising the irrigation system has been used to estimate the energy requirements of typical irrigation systems of several crop production systems. The simulation of various types of irrigation systems and management strategies, in the framework imposed by particular cropping systems, would help to develop criteria for improving the energy balance in relation to the irrigation water supply productivity and new opportunities in the renewable energy field.

  20. Laser/rf personnel identification system

    NASA Astrophysics Data System (ADS)

    Zari, Michael C.; Ward, Reeder N.; Hess, David A.; Anderson, Christopher S.

    1995-05-01

    This paper documents the design of a Laser/RF Personnel Identification System developed for the US Army Communications and Electronics Command (CECOM) for soldier identification. The system has dual use applications, including law enforcement officer protection, and includes a laser interrogation unit with a programmable activation code. The interrogation unit is very directive for low probability of intercept (LPI), which is of interest during covert operations. A responder unit, worn by the law enforcement personnel or soldier, transmits an LPI radio frequency (RF) response only after receiving the proper interrogation code. The basic subsystems for the identification system are a laser interrogation unit, an RF responder unit, and a programming/synchronization unit. In this paper, the operating principles for the subsystems are reviewed and design issues are discussed. In addition to the design performed for CECOM, a breadboard system was developed to validate the concept. Hardware implementation is reviewed and field testing of the breadboard is presented.

  1. Laser surveillance system for spent fuel

    SciTech Connect

    Fiarman, S; Zucker, M S; Bieber, Jr, A M

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a laser system and have used it with a simulated BWR assembly. The reflected signal from the zircaloy rods depends on the position of the assembly, but in all cases is easily discernable from the reference scan of background with no assembly.

  2. A pulsed-laser calibration system for the laser backscatter diagnostics at the Omega laser

    SciTech Connect

    Neumayer, P; Sorce, C; Froula, D H; Rekow, V; Loughman, K; Knight, R; Glenzer, S H; Bahr, R; Seka, W

    2009-10-09

    A calibration system has been developed that allows a direct determination of the sensitivity of the laser backscatter diagnostics at the Omega laser. A motorized mirror at the target location redirects individual pulses of a mJ-class laser onto the diagnostic to allow the in-situ measurement of the local point response of the backscatter diagnostics. Featuring dual wavelength capability at the 2nd and 3rd harmonic of the Nd:YAG laser, both spectral channels of the backscatter diagnostics can be directly calibrated. In addition, channel cross-talk and polarization sensitivity can be determined. The calibration system has been employed repeatedly over the last two years and has enabled precise backscatter measurements of both stimulated Brillouin scattering and stimulated Raman scattering in gas-filled hohlraum targets that emulate conditions relevant to those in inertial confinement fusion targets.

  3. Fiber laser front end for high energy petawatt laser systems

    SciTech Connect

    Dawson, J W; Messerly, M J; Phan, H; Mitchell, S; Drobshoff, A; Beach, R J; Siders, C; Lucianetti, A; Crane, J K; Barty, C J

    2006-06-15

    We are developing a fiber laser front end suitable for high energy petawatt laser systems on large glass lasers such as NIF. The front end includes generation of the pulses in a fiber mode-locked oscillator, amplification and pulse cleaning, stretching of the pulses to >3ns, dispersion trimming, timing, fiber transport of the pulses to the main laser bay and amplification of the pulses to an injection energy of 150 {micro}J. We will discuss current status of our work including data from packaged components. Design detail such as how the system addresses pulse contrast, dispersion trimming and pulse width adjustment and impact of B-integral on the pulse amplification will be discussed. A schematic of the fiber laser system we are constructing is shown in figure 1 below. A 40MHz packaged mode-locked fiber oscillator produces {approx}1nJ pulses which are phase locked to a 10MHz reference clock. These pulses are down selected to 100kHz and then amplified while still compressed. The amplified compressed pulses are sent through a non-linear polarization rotation based pulse cleaner to remove background amplified spontaneous emission (ASE). The pulses are then stretched by a chirped fiber Bragg grating (CFBG) and then sent through a splitter. The splitter splits the signal into two beams. (From this point we follow only one beam as the other follows an identical path.) The pulses are sent through a pulse tweaker that trims dispersion imbalances between the final large optics compressor and the CFBG. The pulse tweaker also permits the dispersion of the system to be adjusted for the purpose of controlling the final pulse width. Fine scale timing between the two beam lines can also be adjusted in the tweaker. A large mode area photonic crystal single polarization fiber is used to transport the pulses from the master oscillator room to the main laser bay. The pulses are then amplified a two stage fiber amplifier to 150mJ. These pulses are then launched into the main amplifier

  4. Low-cost laser diagnostic system

    NASA Astrophysics Data System (ADS)

    Ramos, T. J.; Lim, D. R.; Lingenfelter, A. C.

    1985-10-01

    The principal feature of a new laser diagnostic system is real-time display of beam energy profile. This ensures on-line verification of beam mode and stability with capability for computer storage of this information for later analysis. This system provides low-cost control and repeatability, essential in precision metalworking operations.

  5. A Modular Laser Graphics Projection System

    NASA Astrophysics Data System (ADS)

    Newswanger, Craig D.

    1984-05-01

    WED Enterprises has designed and built a modular projection system for the presentation of animated laser shows. This system was designed specifically for use in Disney theme shows. Its modular design allows it to be adapted to many show situations with simple hardware and software adjustments. The primary goals were superior animation, long life, low maintenance and stand alone operation.

  6. Use of a Laser Videodisc System: Attitudes.

    ERIC Educational Resources Information Center

    Kelly, Sarah A.

    1988-01-01

    Describes a study that assessed the attitudes of novice searchers before and after using a laser videodisk system. The discussion covers the relationships between the users' initial attitudes, prior computer experience, and success in using the videodisk system. (11 references) (Author/CLB)

  7. Laser tracking system with automatic reacquisition capability.

    PubMed

    Johnson, R E; Weiss, P F

    1968-06-01

    A laser based tracking system is described that has the capability of automatically performing an acquisition search to locate the target. This work is intended for precision launch phase tracking of the Saturn V launch vehicle. System tracking accuracies limited only by the atmosphere have been demonstrated, as has acquisition over a 1 degrees x 1 degrees field of view.

  8. Airborne space laser communication system and experiments

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Ming; Zhang, Li-zhong; Meng, Li-Xin

    2015-11-01

    Airborne space laser communication is characterized by its high speed, anti-electromagnetic interference, security, easy to assign. It has broad application in the areas of integrated space-ground communication networking, military communication, anti-electromagnetic communication. This paper introduce the component and APT system of the airborne laser communication system design by Changchun university of science and technology base on characteristic of airborne laser communication and Y12 plan, especially introduce the high communication speed and long distance communication experiment of the system that among two Y12 plans. In the experiment got the aim that the max communication distance 144Km, error 10-6 2.5Gbps - 10-7 1.5Gbps capture probability 97%, average capture time 20s. The experiment proving the adaptability of the APT and the high speed long distance communication.

  9. Injection mode-locking Ti-sapphire laser system

    DOEpatents

    Hovater, James Curtis; Poelker, Bernard Matthew

    2002-01-01

    According to the present invention there is provided an injection modelocking Ti-sapphire laser system that produces a unidirectional laser oscillation through the application of a ring cavity laser that incorporates no intracavity devices to achieve unidirectional oscillation. An argon-ion or doubled Nd:YVO.sub.4 laser preferably serves as the pump laser and a gain-switched diode laser serves as the seed laser. A method for operating such a laser system to produce a unidirectional oscillating is also described.

  10. Accidental human laser retinal injuries from military laser systems

    NASA Astrophysics Data System (ADS)

    Stuck, Bruce E.; Zwick, Harry; Molchany, Jerome W.; Lund, David J.; Gagliano, Donald A.

    1996-04-01

    The time course of the ophthalmoscopic and functional consequences of eight human laser accident cases from military laser systems is described. All patients reported subjective vision loss with ophthalmoscopic evidence of retinal alteration ranging from vitreous hemorrhage to retinal burn. Five of the cases involved single or multiple exposures to Q-switched neodymium radiation at close range whereas the other three incidents occur over large ranges. Most exposures were within 5 degrees of the foveola, yet none directly in the foveola. High contrast visual activity improved with time except in the cases with progressive retinal fibrosis between lesion sites or retinal hole formation encroaching the fovea. In one patient the visual acuity recovered from 20/60 at one week to 20/25 in four months with minimal central visual field loss. Most cases showed suppression of high and low spatial frequency contrast sensitivity. Visual field measurements were enlarged relative to ophthalmoscopic lesion size observations. Deep retinal scar formation and retinal traction were evident in two of the three cases with vitreous hemorrhage. In one patient, nerve fiber layer damage to the papillo-macular bundle was clearly evident. Visual performance measured with a pursuit tracking task revealed significant performance loss relative to normal tracking observers even in cases where acuity returned to near normal levels. These functional and performance deficits may reflect secondary effects of parafoveal laser injury.

  11. Laser system for distance, velocity, and angle measurements

    NASA Astrophysics Data System (ADS)

    Pienkowski, Janusz; Rzepka, Janusz

    1995-03-01

    The two frequency laser interferometer, using frequency stabilized HeNe laser 0.63 micrometers , is presented in this paper. The system consists of a laser head, meteo station, and measurement display. The laser system fundamentally measures linear displacement (distance) but can also measure velocity and angle. The resolution and the accuracy of measurements are comparable with parameters of lasers systems produced by Hewlett-Packard 5526A and Spindler & Hoyer ZLI 150.

  12. Skin friction measurements by a new nonintrusive double-laser-beam oil viscosity balance technique

    NASA Technical Reports Server (NTRS)

    Monson, D. J.; Higuchi, H.

    1980-01-01

    A portable dual-laser-beam interferometer that nonintrusively measures skin friction by monitoring the thickness change of an oil film subject to shear stress is described. The method is an advance over past versions in that the troublesome and error-introducing need to measure the distance to the oil leading edge and the starting time for the oil flow has been eliminated. The validity of the method was verified by measuring oil viscosity in the laboratory, and then using those results to measure skin friction beneath the turbulent boundary layer in a low-speed wind tunnel. The dual-laser-beam skin friction measurements are compared with Preston tube measurements, with mean velocity profile data in a 'law-of-the-wall' coordinate system, and with computations based on turbulent boundary-layer theory. Excellent agreement is found in all cases. This validation and the aforementioned improvements appear to make the present form of the instrument usable to measure skin friction reliably and nonintrusively in a wide range of flow situations in which previous methods are not practical.

  13. Injection locked oscillator system for pulsed metal vapor lasers

    DOEpatents

    Warner, Bruce E.; Ault, Earl R.

    1988-01-01

    An injection locked oscillator system for pulsed metal vapor lasers is disclosed. The invention includes the combination of a seeding oscillator with an injection locked oscillator (ILO) for improving the quality, particularly the intensity, of an output laser beam pulse. The present invention includes means for matching the first seeder laser pulses from the seeding oscillator to second laser pulses of a metal vapor laser to improve the quality, and particularly the intensity, of the output laser beam pulse.

  14. Examination of Balance Measures Produced by the Biodex Stability System

    PubMed Central

    Arnold, Brent L.; Schmitz, Randy J.

    1998-01-01

    Objective: Our purpose was to establish normal patterns and relationships of stability using the Biodex Stability System. Design and Setting: The design of this study used both nonexperimental and quasi-experimental methods. All testing was performed in a university sports medicine laboratory. Subjects: Nineteen healthy subjects (8 males, 11 females, age = 24.4 ± 4.2 years; wt = 70.5 ± 20 kg; ht = 171.2 ± 11.7 cm) with no history of lower extremity injury participated in this study. Measurements: For data analysis, the medial/lateral stability index (MLSI), anterior/posterior stability index (APSI), overall stability index (OSI), and time-in-balance scores were recorded. Results: Multiple regression revealed that APSI and MLSI significantly contributed to the OSI, with the APSI accounting for 95% of the OSI variance. Additionally, the percentage of time spent between 0° and 5° from level was significantly greater than the time spent between 6° and 10°, 11° and 15°, and 16° and 20°. Furthermore, the percentage of time spent between 6° and 10° was significantly greater than the time spent between 16° and 20°. Conclusions: These data suggest that uninjured individuals spent the majority of the time balanced within 0° to 5° from level and progressively less time at greater angles. Additionally, the data suggest that the OSI is very closely related to the APSI and receives a relatively small contribution from the MLSI. Because of this small contribution, if the clinician is interested in both anterior-posterior and medial-lateral motions, it may be best to use the MLSI and APSI separately rather than the OSI. PMID:16558529

  15. Problems in the development of autonomous mobile laser systems based on a cw chemical DF laser

    SciTech Connect

    Aleksandrov, B P; Bashkin, A S; Beznozdrev, V N; Parfen'ev, M V; Pirogov, N A; Semenov, S N

    2003-01-31

    The problems involved in designing autonomous mobile laser systems based on high-power cw chemical DF lasers, whose mass and size parameters would make it possible to install them on various vehicles, are discussed. The need for mobility of such lasers necessitates special attention to be paid to the quest for ways and means of reducing the mass and size of the main laser systems. The optimisation of the parameters of such lasers is studied for various methods of scaling their systems. A complex approach to analysis of the optical scheme of the laser system is developed. (special issue devoted to the 80th anniversary of academician n g basov's birth)

  16. Design of laser diode stable output system

    NASA Astrophysics Data System (ADS)

    Liu, Bo; Cao, Rui-ming

    2008-03-01

    High-stability output's system of laser diode is introduced in this paper. The system which is based on the MCU of MSP430 has been designed light power feedback loop and coller of TEC. It includes stable current, protecting circuit, light power feedback loop, temperature controlling, power display and so on. It is also able to control and show the power at the real time. The power could be set by botton too. The software of slow start up, slow close and the protecting relay are adopted by MCU. DRV592 is introduced as PWM driver to control the current of TEC. The duty cycle is generate by MCU. In order to control temperature, it is changed to influence the current of TEC. The power that is sampled by photodiode which is integrated in the laser diode is controlled by the micro-processing. The laser is monitored by voltage control circuit and current control circuit at the real time.

  17. Photovoltaic balance-of-system designs and costs at PVUSA

    SciTech Connect

    Reyes, A.B.; Jennings, C.

    1995-05-01

    This report is one in a series of 1994-1995 PVUSA reports that document PVUSA lessons learned at demonstration sites in California and Texas. During the last 7 years (1988 to 1994), 16 PV systems ranging from 20 kW to 500 kW have been installed. Six 20-kW emerging module technology (EMT) arrays and three turnkey (i.e., vendor designed and integrated) utility-scale systems were procured and installed at PVUSA`s main test site in Davis, California. PVUSA host utilities have installed a total of seven EMT arrays and utility-scale systems in their service areas. Additional systems at Davis and host utility sites are planned. One of PVUSA`s key objectives is to evaluate the performance, reliability, and cost of PV balance-of-system (BOS). In the procurement stage PVUSA encouraged innovative design to improve upon present practice by reducing maintenance, improving reliability, or lowering manufacturing or construction costs. The project team worked closely with suppliers during the design stage not only to ensure designs met functional and safety specifications, but to provide suggestions for improvement. This report, intended for the photovoltaic (PV) industry and for utility project managers and engineers considering PV plant construction and ownership, documents PVUSA utility-scale system design and cost lessons learned. Complementary PVUSA topical reports document: construction and safety experience; five-year assessment of EMTs; validation of the Kerman 500-kW grid-support PV plant benefits; PVUSA instrumentation and data analysis techniques; procurement, acceptance, and rating practices for PV power plants; experience with power conditioning units and power quality.

  18. Vacuum mechatronic laser alignment system on the Nova laser

    SciTech Connect

    Holliday, M.; Wong, K.; Shelton, R.

    1991-11-01

    The experiments conducted on NOVA are done to investigate inertially confined laser fusion reactions. To this end, the ten beams of the laser are aligned to within 30mm. The target chamber employs a vacuum mechatronic based reticle/target positioning system to accomplish this. It is a five degree-of-freedom chamber resident system, known as the Alignment Aids Positioner or AAP. The AAP aids in beam and diagnostic alignment by accurately positioning a reticle at target chamber center to with 7mm. The AAP system increases target positioning and alignment flexibility and accuracy through the use of a computer controlled multi degree-of-freedom stage assembly. This device uses microstepping DC stepper motors with encoders to achieve closed loop control in a 10{sup {minus}6} torr vacuum. The AAP has two positioning regimes to move the alignment reticle and do beam alignment. One is course positioning in the Y-Z plane that moves a high resolution stage assembly to target chamber center. The other regime is high resolution movement in the X,Y,Z and q directions. 5 refs., 9 figs.

  19. The global light system laser station prototype

    NASA Astrophysics Data System (ADS)

    Hunt, Patrick R.

    We describe the design and fabrication of a prototype Global Light System (GLS) laser station for the JEM-EUSO project. The GLS will consist of a network of ground-based Ultraviolet (UV) light-emitting diodes (LEDs) and steered lasers to monitor and calibrate the cosmic ray detector planned for install on the International Space Station (ISS). The GLS units will generate optical signatures in the atmosphere that are comparable to tracks from cosmic ray extensive air showers (EASs). Unlike an EAS, the number, time, energy, location and direction (for lasers) of GLS events can be specified as JEM-EUSO passes 400 km overhead. Laser tracks from the GLS prototype will be recorded by prototype detectors in ground-to-ground tests. Distant tracks with low angular speed are of particular interest because these are the types of EAS tracks that will be measured by JEM-EUSO. To do these ground-to-ground tests, the prototype detectors will need to measure the laser through the atmosphere at low elevation viewing angles. The beam energy can be adjusted from 1 to 90 mJ to compensate for this additional atmospheric attenuation. The frequency-tripled Nd:YAG laser produces 355 nm (7 ns pulse) light. This wavelength is near the center of the UV EAS fluorescence spectrum. The system is housed in a utility trailer that can be transported by a small truck for domestic campaigns or shipped in an industry standard 20 foot container for global deployment. In operation mode, the laser platform inside the trailer is isolated mechanically to maintain beam pointing accuracy. A retractable two stage steering head can point in any direction above the horizon. A slip ring eliminates cable wrap problems. The GLS prototype will be used to test the EUSO-TA detector and will also be used in preflight tests of the EUSO-balloon payload planned for a super pressure balloon mission.

  20. Laser-SPS systems analysis and environmental impact assessment

    NASA Technical Reports Server (NTRS)

    Beverly, R. E., III

    1980-01-01

    The systems feasibility and environmental impact of replacing the microwave transmitters on the Satellite Power System with laser transmitters are examined. The lasers suggested are two molecular-gas electric-discharge lasers (EDL's), namely the CO and CO2 lasers. Calculations are made on system efficiency, atmospheric transmission efficiency, and laser beam spreading. It is found that the present satellite concept using lasers is far too inefficient and massive to be economically viable. However, the safety issues associated with laser power transmission appear tractable, and no effects could be identified which present a real danger of serious injury to the environment, although certain phenomena deserve closer scrutiny.

  1. COHERENT LASER VISION SYSTEM (CLVS) OPTION PHASE

    SciTech Connect

    Robert Clark

    1999-11-18

    The purpose of this research project was to develop a prototype fiber-optic based Coherent Laser Vision System (CLVS) suitable for DOE's EM Robotic program. The system provides three-dimensional (3D) vision for monitoring situations in which it is necessary to update the dimensional spatial data on the order of once per second. The system has total immunity to ambient lighting conditions.

  2. Kinetic modelling of krypton fluoride laser systems

    SciTech Connect

    Jancaitis, K.S.

    1983-11-01

    A kinetic model has been developed for the KrF* rare gas halide laser system, specifically for electron-beam pumped mixtures of krypton, fluorine, and either helium or argon. The excitation produced in the laser gas by the e-beam was calculated numerically using an algorithm checked by comparing the predicted ionization yields in the pure rare gases with their experimental values. The excitation of the laser media by multi-kilovolt x-rays was also modeled and shown to be similar to that produced by high energy electrons. A system of equations describing the transfer of the initial gas excitation into the laser upper level was assembled using reaction rate constants from both experiment and theory. A one-dimensional treatment of the interaction of the laser radiation with the gas was formulated which considered spontaneous and stimulated emission and absorption. The predictions of this model were in good agreement with the fluorescence signals and gain and absorption measured experimentally.

  3. Underwater modulated pulse laser imaging system

    NASA Astrophysics Data System (ADS)

    O'Connor, Shawn; Mullen, Linda J.; Cochenour, Brandon

    2014-05-01

    The detection and identification of underwater threats in coastal areas are of interest to the Navy. When identifying a potential target, both two-dimensional (amplitude versus position) and three-dimensional (amplitude and range versus position) information are important. Laser imaging in turbid coastal waters makes this task challenging due to absorption and scattering in both the forward and backward directions. Conventional imaging approaches to suppress scatter rely on a pulsed laser and a range-gated receiver or an intensity-modulated continuous wave laser and a coherent RF receiver. The modulated pulsed laser imaging system is a hybrid of these two approaches and uses RF intensity modulation on a short optical pulse. The result is an imaging system capable of simultaneously acquiring high-contrast images along with high-precision unambiguous ranges. A working modulated pulsed laser line scanner was constructed and tested with a custom-built transmitter, a large-bandwidth optical receiver, and a high-speed digitizing oscilloscope. The effectiveness of the modulation to suppress both backscatter and forward scatter, as applied to both magnitude and range images, is discussed.

  4. The design of laser scanning galvanometer system

    NASA Astrophysics Data System (ADS)

    Sun, Xiaoling; Zhou, Bin; Xie, Weihao; Zhang, Yuangeng

    2015-02-01

    In this paper, we designed the laser scanning galvanometer system according to our requirements. Based on scanning range of our laser scanning galvanometer system, the design parameters of this system were optimized. During this work, we focused on the design of the f-θ field lens. An optical system of patent lens in the optical manual book, which had three glasses structure, was used in our designs. Combining the aberration theory, the aberration corrections and image quality evaluations were finished using Code V optical design software. An optimum f-θ field lens was designed, which had focal length of 434 mm, pupil diameter of 30 mm, scanning range of 160 mm × 160 mm, and half field angle of 18°×18°. At the last, we studied the influences of temperature changes on our system.

  5. Industrial laser-based coatings removal systems

    NASA Astrophysics Data System (ADS)

    Freiwald, David A.; Peebles, Henry C.; Case, Roger P.

    1998-09-01

    Industrial-cleaning-rate laser systems have been built and tested for removing various types of coatings, such as rad- contaminated coatings, non-rad but hazmat-contaminated coatings (e.g., Pb-based paint), and non-hazardous coatings from various types of substrates such as concrete, metals, and composite materials.

  6. Monolithically integrated absolute frequency comb laser system

    DOEpatents

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  7. Dye system for dye laser applications

    SciTech Connect

    Hammond, P.R.

    1991-05-21

    This patent describes a dye of the DCM family, (2-methyl-6-(2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl)-4H-pyran-4-ylidene)-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

  8. Dye system for dye laser applications

    DOEpatents

    Hammond, Peter R.

    1991-01-01

    A dye of the DCM family, [2-methyl-6-[2-(1,2,3,4-tetrahydro-1-methyl-6-quinolinyl)ethenyl]-4H-pyran -4-ylidene]-propanedinitrile, dissolved in 2-phenoxyethanol, is non-mutagenic, stable and efficient, particularly in a pumped continuous wave laser system.

  9. Systems analysis on laser beamed power

    NASA Technical Reports Server (NTRS)

    Zeiders, Glenn W., Jr.

    1993-01-01

    The NASA SELENE power beaming program is intended to supply cost-effective power to space assets via Earth-based lasers and active optics systems. Key elements of the program are analyzed, the overall effort is reviewed, and recommendations are presented.

  10. T-3 electron-beam-excited laser system

    SciTech Connect

    Klein, R A

    1981-02-01

    A laser system specifically designed to study the kinetics of electron-beam driven systems is described. Details of the system are given along with measurements of the electron-beam uniformity and deposition in the laser medium. Some HF laser results obtained with this system are also given.

  11. Method and system for powering and cooling semiconductor lasers

    SciTech Connect

    Telford, Steven J; Ladran, Anthony S

    2014-02-25

    A semiconductor laser system includes a diode laser tile. The diode laser tile includes a mounting fixture having a first side and a second side opposing the first side and an array of semiconductor laser pumps coupled to the first side of the mounting fixture. The semiconductor laser system also includes an electrical pulse generator thermally coupled to the diode bar and a cooling member thermally coupled to the diode bar and the electrical pulse generator.

  12. The Echo Cliffs Precariously Balanced Rock; Discovery and Terrestrial Laser Scanning

    NASA Astrophysics Data System (ADS)

    Hudnut, K. W.; Amidon, W. H.; Bawden, G. W.; Brune, J. N.; Bond, S.; Graves, R. W.; Haddad, D. E.; Limaye, A.; Lynch, D. K.; Phillips, D. A.; Pounders, E.; Rood, D. H.

    2009-12-01

    We investigate a previously undocumented Precariously Balanced Rock (PBR) located above Echo Cliffs in the western Santa Monica Mountains, using Terrestrial Laser Scanning (TLS). We present the merged and aligned point cloud of TLS data (over 42 million points) and photos to document the Echo Cliffs PBR site. We also present our interpretations of the site, of its geomorphic development, and its possible significance for seismic hazards in the Los Angeles region. The rock lies above the ramp in the fault propagation fold structure that has been interpreted by Davis and Namson as an active structure that may pose a major seismic hazard to the Los Angeles area. The Echo Cliffs PBR stands at just over 14 meters in height, so assuming it acts as an inverse pendulum, it has a 3 to 4 second period of oscillation. This period corresponds to the oscillatory period of a 30 to 40 story building. The rock withstood ground motions during the 1994 Northridge earthquake that we estimate to have been 0.2 g (PGA) and 12 cm/sec (PGV) at this site. It is expected that the Echo Cliffs PBR may provide important constraints on scenario ground motions and thereby improve future simulations. We believe that this is the first application of TLS methods on PBR's, and we find that the high resolution provided by TLS allows us to characterize the detailed shape of the PBR itself, as well as key details of the interface between the rock and pedestal at the cm-level. In addition, the cliff band near the PBR and the geomorphic context of the surrounding hill slope area was also scanned at a coarser resolution, providing data that help to understand the processes by which the PBR formed. An advantage of TLS is that it provides an image of the outline of the rock-pedestal contact surface and adjacent non-contacting surfaces. The TLS also helps quantify the effects of shielding on cosmogenic nuclide production, enhancing the accuracy of our surface exposure age dating.

  13. Quantification of the Balance Error Scoring System with Mobile Technology

    PubMed Central

    Alberts, Jay L.; Thota, Anil; Hirsch, Joshua; Ozinga, Sarah; Dey, Tanujit; Schindler, David D.; Koop, Mandy Miller; Burke, Daniel; Linder, Susan M.

    2015-01-01

    Purpose The aim of this project was to develop a biomechanically based quantification of the Balance Error Scoring System (BESS) using data derived from the accelerometer and gyroscope of a mobile tablet device. Methods Thirty-two healthy youth and adults completed the BESS while an iPad was positioned at the sacrum. Data from the iPad data was compared to position data gathered from a 3D motion capture system. Peak-to-peak (P2P), normalized path length (NPL), and root mean squared (RMS) were calculated for each system and compared. Additionally, a 95% ellipsoid volume, iBESS volume, was calculated using center of mass (COM) movements in the anterior-posterior (AP), mediolateral (ML), and trunk rotation planes of movement to provide a comprehensive, 3-dimensional metric of postural stability. Results Across all kinematic outcomes, data from the iPad were significantly correlated with the same outcomes derived from the motion capture system (Rho range: 0.37- 0.94, p<0.05). The iBESS volume metric was able to detect a difference in postural stability across stance and surface, showing a significant increase in volume in increasingly difficult conditions, while traditional error scoring was not as sensitive to these factors. Conclusions The kinematic data provided by the iPad is of sufficient quality relative to motion capture data to accurately quantify postural stability in healthy young adults. The iBESS volume provides a more sensitive measure of postural stability than error scoring alone, particularly in conditions 1 and 4, which often suffer from floor effects, and condition 5, which can experience ceiling effects. The iBESS metric is ideally suited for clinical and in the field applications in which characterizing postural stability is of interest. PMID:26378948

  14. Software for portable laser light show system

    NASA Astrophysics Data System (ADS)

    Buruchin, Dmitrey J.; Leonov, Alexander F.

    1995-04-01

    Portable laser light show system LS-3500-10M is connected to the parallel port of IBM PC/AT compatible computer. Computer performs output of digital control data describing images. Specially designed control device is used to convert digital data coming from parallel port to the analog signal driving scanner. Capabilities of even cost nothing 286 computer are quite enough for laser graphics control. Technology of scanning used in laser graphics system LS-3500-10M essentially differs from widely spread systems based on galvanometers with mobile core or with mobile magnet. Such devices are based on the same principle of work as electrically driven servo-mechanism. As scanner we use elastic system with hydraulic dampen oscillations and opened loop. For most of applications of laser graphics such system provides satisfactory precision and speed of scanning. LS-3500-10M software gives user ability to create on PC and play his own laser graphics demonstrations. It is possible to render recognizable text and pictures using different styles, 3D and abstract animation. All types of demonstrations can be mixed in slide-show. Time synchronization is supported. Software has the following features: (1) Different types of text output. Built-in text editor for typing and editing of textural information. Different fonts can be used to display text. User can create his own fonts using specially developed font editor. (2) Editor of 3D animation with library of predefined shapes. (3) Abstract animation provided by software routines. (4) Support of different graphics files formats (PCX or DXF). Original algorithm of raster image tracing was implemented. (5) Built-in slide-show editor.

  15. Demonstration of high sensitivity laser ranging system

    NASA Technical Reports Server (NTRS)

    Millar, Pamela S.; Christian, Kent D.; Field, Christopher T.

    1994-01-01

    We report on a high sensitivity semiconductor laser ranging system developed for the Gravity and Magnetic Earth Surveyor (GAMES) for measuring variations in the planet's gravity field. The GAMES laser ranging instrument (LRI) consists of a pair of co-orbiting satellites, one which contains the laser transmitter and receiver and one with a passive retro-reflector mounted in an drag-stabilized housing. The LRI will range up to 200 km in space to the retro-reflector satellite. As the spacecraft pair pass over the spatial variations in the gravity field, they experience along-track accelerations which change their relative velocity. These time displaced velocity changes are sensed by the LRI with a resolution of 20-50 microns/sec. In addition, the pair may at any given time be drifting together or apart at a rate of up to 1 m/sec, introducing a Doppler shift into the ranging signals. An AlGaAs laser transmitter intensity modulated at 2 GHz and 10 MHz is used as fine and medium ranging channels. Range is measured by comparing phase difference between the transmit and received signals at each frequency. A separate laser modulated with a digital code, not reported in this paper, will be used for coarse ranging to unambiguously determine the distance up to 200 km.

  16. The study of laser beam riding guided system based on 980nm diode laser

    NASA Astrophysics Data System (ADS)

    Qu, Zhou; Xu, Haifeng; Sui, Xin; Yang, Kun

    2015-10-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  17. Balanced Flow Metering and Conditioning: Technology for Fluid Systems

    NASA Technical Reports Server (NTRS)

    Kelley, Anthony R.

    2006-01-01

    Revolutionary new technology that creates balanced conditions across the face of a multi-hole orifice plate has been developed, patented and exclusively licensed for commercialization. This balanced flow technology simultaneously measures mass flow rate, volumetric flow rate, and fluid density with little or no straight pipe run requirements. Initially, the balanced plate was a drop in replacement for a traditional orifice plate, but testing revealed substantially better performance as compared to the orifice plate such as, 10 times better accuracy, 2 times faster (shorter distance) pressure recovery, 15 times less acoustic noise energy generation, and 2.5 times less permanent pressure loss. During 2004 testing at MSFC, testing revealed several configurations of the balanced flow meter that match the accuracy of Venturi meters while having only slightly more permanent pressure loss. However, the balanced meter only requires a 0.25 inch plate and has no upstream or downstream straight pipe requirements. As a fluid conditioning device, the fluid usually reaches fully developed flow within 1 pipe diameter of the balanced conditioning plate. This paper will describe the basic balanced flow metering technology, provide performance details generated by testing to date and provide implementation details along with calculations required for differing degrees of flow metering accuracy.

  18. Spaceborne CO2 laser communications systems

    NASA Technical Reports Server (NTRS)

    Mcelroy, J. H.; Mcavoy, N.; Johnson, E. H.; Goodwin, F. E.; Peyton, B. J.

    1975-01-01

    Projections of the growth of earth-sensing systems for the latter half of the 1980's show a data transmission requirement of 300 Mbps and above. Mission constraints and objectives lead to the conclusion that the most efficient technique to return the data from the sensing satellite to a ground station is through a geosynchronous data relay satellite. Of the two links that are involved (sensing satellite to relay satellite and relay satellite to ground), a laser system is most attractive for the space-to-space link. The development of CO2 laser systems for space-to-space applications is discussed with the completion of a 300 Mpbs data relay receiver and its modification into a transceiver. The technology and state-of-the-art of such systems are described in detail.

  19. Potential benefits of magnetic suspension and balance systems

    NASA Technical Reports Server (NTRS)

    Lawing, Pierce L.; Dress, David A.; Kilgore, Robert A.

    1987-01-01

    The potential of Magnetic Suspension and Balance Systems (MSBS) to improve conventional wind tunnel testing techniques is discussed. Topics include: elimination of model geometry distortion and support interference to improve the measurement accuracy of aerodynamic coefficients; removal of testing restrictions due to supports; improved dynamic stability data; and stores separation testing. Substantial increases in wind tunnel productivity are anticipated due to the coalescence of these improvements. Specific improvements in testing methods for missiles, helicopters, fighter aircraft, twin fuselage transports and bombers, state separation, water tunnels, and automobiles are also forecast. In a more speculative vein, new wind tunnel test techniques are envisioned as a result of applying MSBS, including free-flight computer trajectories in the test section, pilot-in-the-loop and designer-in-the-loop testing, shipboard missile launch simulation, and optimization of hybrid hypersonic configurations. Also addressed are potential applications of MSBS to such diverse technologies as medical research and practice, industrial robotics, space weaponry, and ore processing in space.

  20. Optical design and development of a fiber coupled high-power diode laser system for laser transmission welding of plastics

    NASA Astrophysics Data System (ADS)

    Rodríguez-Vidal, Eva; Quintana, Iban; Etxarri, Jon; Azkorbebeitia, Urko; Otaduy, Deitze; González, Francisco; Moreno, Fernando

    2012-12-01

    Laser transmission welding (LTW) of thermoplastics is a direct bonding technique already used in different industrial applications sectors such as automobiles, microfluidics, electronics, and biomedicine. LTW evolves localized heating at the interface of two pieces of plastic to be joined. One of the plastic pieces needs to be optically transparent to the laser radiation whereas the other part has to be absorbent, being that the radiation produced by high power diode lasers is a good alternative for this process. As consequence, a tailored laser system has been designed and developed to obtain high quality weld seams with weld widths between 0.7 and 1.4 mm. The developed laser system consists of two diode laser bars (50 W per bar) coupled into an optical fiber using a nonimaging solution: equalization of the beam parameter product (BPP) in the slow and fast axes by a pair of step-mirrors. The power scaling was carried out by means of a multiplexing polarization technique. The analysis of energy balance and beam quality was performed considering ray tracing simulation (ZEMAX) and experimental validation. The welding experiments were conducted on acrylonitrile/butadiene/styrene (ABS), a thermoplastic frequently used in automotive, electronics and aircraft applications, doped with two different concentrations of carbon nanotubes (0.01% and 0.05% CNTs). Quality of the weld seams on ABS was analyzed in terms of the process parameters (welding speed, laser power and clamping pressure) by visual and optical microscope inspections. Mechanical properties of weld seams were analyzed by mechanical shear tests. High quality weld seams were produced in ABS, revealing the potential of the laser developed in this work for a wide range of plastic welding applications.

  1. Remote measurement of wind speed by laser Doppler systems.

    PubMed

    Hughes, A J; Pike, E R

    1973-03-01

    Several types of laser Doppler velocimeter are considered for remote measurement of wind velocity. Particular attention is given to the range dependence of the mean power SNR when scattering is from natural aerosols. Numerical estimates for two systems are presented, indicating that CO(2) laser systems have considerably greater sensitivity than visible laser systems at ranges greater than a few meters.

  2. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a...

  3. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a...

  4. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a...

  5. 21 CFR 884.6200 - Assisted reproduction laser system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a...

  6. Space Applications of Industrial Laser Systems (SAILS)

    NASA Technical Reports Server (NTRS)

    Mueller, Robert E.; McCay, T. Dwayne; McCay, Mary Helen; Bible, Brice

    1992-01-01

    A program is under way to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. The system will be capable of cutting and welding steel, aluminum and Inconel alloys of the type planned for use on the Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1995, will be constructed as two modules to fit into standard Get Away Special (GAS) canisters. The first can holds the laser and its power supply, to be constructed by our industrial partner, Lumonics Industrial Processing Division. The second canister has the materials processing workstation and the command and data acquisition subsystems. These components will be provided by groups at UTSI and the University of Waterloo. The cans are linked by a fiber-optic cable which transmits the beam from the laser head to the workstation.

  7. Space Applications of Industrial Laser Systems (SAILS)

    NASA Technical Reports Server (NTRS)

    Mueller, Robert E.; McCay, T. Dwayne; McCay, Mary Helen; Bible, Brice

    1995-01-01

    A program is under way to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. The system will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use on Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1995, will be constructed as two modules to fit into the standard Get Away Special (GAS) canisters. The first can holds the laser and its power supply, to be constructed by our industrial partner, Lumonics Industrial Processing Division. The second canister has the materials processing workstation and the command and data acquisition subsystems. These components will be provided by groups at the University of Tennessee Space Institute (UTSI) and the University of Waterloo. The cans are linked by a fiber-optic cable which transmits the beam from the laser head to the workstation.

  8. Commercialization plan laser-based decoating systems

    SciTech Connect

    Freiwald, J.; Freiwald, D.A.

    1998-01-01

    F2 Associates Inc. (F2) is a small, high-technology firm focused on developing and commercializing environmentally friendly laser ablation systems for industrial-rate removal of surface coatings from metals, concrete, and delicate substrates such as composites. F2 has a contract with the US Department of Energy Federal Energy Technology Center (FETC) to develop and test a laser-based technology for removing contaminated paint and other contaminants from concrete and metal surfaces. Task 4.1 in Phase 2 of the Statement of Work for this DOE contract requires that F2 ``document its plans for commercializing and marketing the stationary laser ablation system. This document shall include a discussion of prospects for commercial customers and partners and may require periodic update to reflect changing strategy. This document shall be submitted to the DOE for review.`` This report is being prepared and submitted in fulfillment of that requirement. This report describes the laser-based technology for cleaning and coatings removal, the types of laser-based systems that have been developed by F2 based on this technology, and the various markets that are emerging for this technology. F2`s commercialization and marketing plans are described, including how F2`s organization is structured to meet the needs of technology commercialization, F2`s strategy and marketing approach, and the necessary steps to receive certification for removing paint from aircraft and DOE certification for D and D applications. The future use of the equipment built for the DOE contract is also discussed.

  9. Performance results on the laser portion of the Keck laser guide star system

    SciTech Connect

    Cooke, J B; Danforth, P M; Erbert, G V; Feldman, M; Friedman, H W; Gavel, D T; Jenkins, S L; Jones, H E; Kanz, V K; Kuklo, T; Newman, M J; Pierce, E L; Presta, R W; Salmon, J T; Thompson, G R; Wong, N J

    1998-09-29

    The Laser Guide Star (LGS) system for the Keck II, 10 m telescope consists of two separate but interconnected systems, the laser and the adaptive optics bench. The laser portion of the LGSl is a set of five frequency doubled YAG lasers pumping a master oscillator-power amplifier dye chain to produce up to 30 W of 589 p at 26 kHz of tuned light. Presently the laser system has been set up at the Keck facility in Waimea, HI and is undergoing test and evaluation. When it will be set up on the Keck II telescope, the pump lasers, dye master oscillator and associated control equipment will be located on the dome floor and the dye laser amplifiers, beam control system and diagnostics will be mounted directly on the telescope as shown in Fig. 1, Extensive use of fiber optics for both transmission of the oscillator pulse and the pump laser light has been used.

  10. Optical scanning system for laser velocimeter

    NASA Technical Reports Server (NTRS)

    Rhodes, D. B.

    1977-01-01

    An optical system was developed to provide fast incremental scanning of a backscattered laser velocimeter focus point over a 36-cm distance. The system is used to measure flow velocities at 16 positions along its optical axis and to scan these 16 positions up to 30 times a second. Dwell time at each location is approximately 2 milliseconds. Sample volumes typically are 0.2 mm in diameter by 1.4 cm in length. The optical scanning system consists of a wheel containing plane parallel quartz windows of various thicknesses. The laser velocimeter beams are imaged to a primary focus within the dead airspace of an optical cell. The beams emerging from the cell pass through the windows of the scanning wheel. The refraction of the beams passing through the windows causes an apparent shift of the focus within the optical cell and hence in the test zone. Light scattered from the secondary focus within the test zone is concurrently collected and reimaged through the same optical path which originally projected the primary focus. The reimaged backscattered light containing the velocity information is then collected and focused onto a photomultiplier detector system to complete the scanned laser velocimeter optical system.

  11. Three-component laser anemometer measurement systems

    NASA Technical Reports Server (NTRS)

    Goldman, Louis J.

    1991-01-01

    A brief overview of the different laser anemometer (LA) optical designs available is presented. Then, the LA techniques that can be used to design a three-component measurement system for annular geometries are described. Some of the facility design considerations unique to these LA systems are also addressed. Following this, the facilities and the LA systems that were used to successfully measure the three components of velocity in the blading of annular-flow machines are reviewed. Finally, possible LA system enhancements and future research directions are presented.

  12. Laser safety and hazard analysis for the temperature stabilized BSLT ARES laser system.

    SciTech Connect

    Augustoni, Arnold L.

    2003-08-01

    A laser safety and hazard analysis was performed for the temperature stabilized Big Sky Laser Technology (BSLT) laser central to the ARES system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for Safe Use of Lasers and the 2000 version of the ANSI Standard Z136.6, for Safe Use of Lasers Outdoors. As a result of temperature stabilization of the BSLT laser the operating parameters of the laser had changed requiring a hazard analysis based on the new operating conditions. The ARES laser system is a Van/Truck based mobile platform, which is used to perform laser interaction experiments and tests at various national test sites.

  13. Application of Laser Ablation Processing in Electric Power System Industries

    NASA Astrophysics Data System (ADS)

    Konagai, Chikara; Sano, Yuji; Nittoh, Koichi; Kuwako, Akira

    The present status of laser ablation processing applied in electric power system industries is reviewed. High average power LD-pumped Nd:YAG lasers with Q-switch have been developed and currently introduced into various applications. Optical fiber based laser beam delivery systems for Q-switched pulse laser are also being developed these years. Based on such laser and beam delivery technology, laser ablation processes are gradually introduced in maintenance of nuclear power plant, thermal power plant and electrical power distribution system. Cost effectiveness, robustness and reliability of the process is highly required for wide utilization in these fields.

  14. TIR-1 carbon dioxide laser system for fusion

    NASA Astrophysics Data System (ADS)

    Adamovich, V. A.; Anisimov, V. N.; Afonin, E. A.; Baranov, V. Iu.; Borzenko, V. L.; Kozochkin, S. M.; Maliuta, D. D.; Satov, Iu. A.; Sebrant, A. Iu.; Smakovski, Iu. B.

    1980-03-01

    The paper examines the TIR-1 carbon dioxide laser system for fusion. The current efforts are concentrated on (1) the microsecond laser pulse plasma heating in solenoids and theta pinches, and (2) nanosecond CO2 laser utilization for inertial confinement fusion. The TIR-1 system was designed to develop nanosecond CO2 laser technology and to study laser-target interaction at 10 microns. This system consists of an oscillator-preamplifier that produces about 1-nsec laser pulse with an energy contrast ratio of 1 million, a large triple-pass amplifier, and a target chamber with diagnostic equipment.

  15. Laser Safety and Hazard Analysis for the Trailer (B70) Based AURA Laser System

    SciTech Connect

    AUGUSTONI, ARNOLD L.

    2003-01-01

    A laser safety and hazard analysis was performed for the AURA laser system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for ''Safe Use of Lasers'' and the 2000 version of the ANSI Standard Z136.6, for ''Safe Use of Lasers Outdoors''. The trailer based AURA laser system is a mobile platform, which is used to perform laser interaction experiments and tests at various national test sites. The trailer (B70) based AURA laser system is generally operated on the United State Air Force Starfire Optical Range (SOR) at Kirtland Air Force Base (KAFB), New Mexico. The laser is used to perform laser interaction testing inside the laser trailer as well as outside the trailer at target sites located at various distances from the exit telescope. In order to protect personnel, who work inside the Nominal Hazard Zone (NHZ), from hazardous laser emission exposures it was necessary to determine the Maximum Permissible Exposure (MPE) for each laser wavelength (wavelength bands) and calculate the appropriate minimum Optical Density (OD{sub min}) of the laser safety eyewear used by authorized personnel and the Nominal Ocular Hazard Distance (NOHD) to protect unauthorized personnel who may have violated the boundaries of the control area and enter into the laser's NHZ.

  16. Linkage Of Laser And Handling Systems In Multi Station Operation

    NASA Astrophysics Data System (ADS)

    Petschke, U.; Kramer, R.; Wolff, Udo W.; Beyer, Eckhard

    1989-03-01

    Special requirements are needed for highly flexible, multi station laser processing. Linkage of several lasers with various handling stations causes different kinds of tasks to be solved in the fields of optics, electro mechanics, laser technology and opto electro-nics. A new design for flexible high power CO2 laser beam handling has been developed, including self-checking security systems, laser beam diagnostics, easily adjustable high power beam bending mirrors, high precision motorized mechanics and computer controlled user guidance.

  17. Development of on-line laser power monitoring system

    NASA Astrophysics Data System (ADS)

    Ding, Chien-Fang; Lee, Meng-Shiou; Li, Kuan-Ming

    2016-03-01

    Since the laser was invented, laser has been applied in many fields such as material processing, communication, measurement, biomedical engineering, defense industries and etc. Laser power is an important parameter in laser material processing, i.e. laser cutting, and laser drilling. However, the laser power is easily affected by the environment temperature, we tend to monitor the laser power status, ensuring there is an effective material processing. Besides, the response time of current laser power meters is too long, they cannot measure laser power accurately in a short time. To be more precisely, we can know the status of laser power and help us to achieve an effective material processing at the same time. To monitor the laser power, this study utilize a CMOS (Complementary metal-oxide-semiconductor) camera to develop an on-line laser power monitoring system. The CMOS camera captures images of incident laser beam after it is split and attenuated by beam splitter and neutral density filter. By comparing the average brightness of the beam spots and measurement results from laser power meter, laser power can be estimated. Under continuous measuring mode, the average measuring error is about 3%, and the response time is at least 3.6 second shorter than thermopile power meters; under trigger measuring mode which enables the CMOS camera to synchronize with intermittent laser output, the average measuring error is less than 3%, and the shortest response time is 20 millisecond.

  18. High power laser workover and completion tools and systems

    SciTech Connect

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2014-10-28

    Workover and completion systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser workover and completion of a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform laser workover and completion operations in such boreholes deep within the earth.

  19. Laser beam riding guided system principle and design research

    NASA Astrophysics Data System (ADS)

    Qu, Zhou; Jin, Yi; Xu, Zhou; Xing, Hao

    2016-01-01

    With the development of science and technology, precision-strike weapons has been considered to be important for winning victory in military field. Laser guidance is a major method to execute precision-strike in modern warfare. At present, the problems of primary stage of Laser guidance has been solved with endeavors of countries. Several technical aspects of laser-beam riding guided system have been mature, such as atmosphere penetration of laser beam, clutter inhibition on ground, laser irradiator, encoding and decoding of laser beam. Further, laser beam quality, equal output power and atmospheric transmission properties are qualified for warfare situation. Riding guidance instrument is a crucial element of Laser-beam riding guided system, and is also a vital element of airborne, vehicle-mounted and individual weapon. The optical system mainly consist of sighting module and laser-beam guided module. Photoelectric detector is the most important sensing device of seeker, and also the key to acquire the coordinate information of target space. Currently, in consideration of the 1.06 u m of wavelength applied in all the semi-active laser guided weapons systems, lithium drifting silicon photodiode which is sensitive to 1.06 u m of wavelength is used in photoelectric detector. Compared to Solid and gas laser, diode laser has many merits such as small volume, simple construction, light weight, long life, low lost and easy modulation. This article introduced the composition and operating principle of Laser-beam riding guided system based on 980 nm diode laser, and made a analysis of key technology; for instance, laser irradiator, modulating disk of component, laser zooming system. Through the use of laser diode, Laser-beam riding guided system is likely to have smaller shape and very light.

  20. Optical diagnostics integrated with laser spark delivery system

    DOEpatents

    Yalin, Azer; Willson, Bryan; Defoort, Morgan; Joshi, Sachin; Reynolds, Adam

    2008-09-02

    A spark delivery system for generating a spark using a laser beam is provided, and includes a laser light source and a laser delivery assembly. The laser delivery assembly includes a hollow fiber and a launch assembly comprising launch focusing optics to input the laser beam in the hollow fiber. The laser delivery assembly further includes exit focusing optics that demagnify an exit beam of laser light from the hollow fiber, thereby increasing the intensity of the laser beam and creating a spark. Other embodiments use a fiber laser to generate a spark. Embodiments of the present invention may be used to create a spark in an engine. Yet other embodiments include collecting light from the spark or a flame resulting from the spark and conveying the light for diagnostics. Methods of using the spark delivery systems and diagnostic systems are provided.

  1. Laser multipass system with interior cell configuration

    SciTech Connect

    Borysow, Jacek; Kostinski, Alexander; Fink, Manfred

    2011-10-20

    We ask whether it is possible to restore a multipass system alignment after a gas cell is inserted in the central region. Indeed, it is possible, and we report on a remarkably simple rearrangement of a laser multipass system, composed of two spherical mirrors and a gas cell with flat windows in the middle. For example, for a window of thickness d and refractive index of n, adjusting the mirror separation by approx. 2d(1-1n) is sufficient to preserve the laser beam alignment and tracing. This expression is in agreement with ray-tracing computations and our laboratory experiment. Insofar as our solution corrects for spherical aberrations, it may also find applications in microscopy.

  2. Research on demodulation technology of atmospheric laser communication system base on CPolSK

    NASA Astrophysics Data System (ADS)

    xin, zhou; Liu, Yan; Liu, Zhi; Liu, Dan; Fang, Han-han; Zheng, Min

    2013-08-01

    In order to reduce the impacts of atmospheric turbulence and background light etc. factors to atmospheric laser communication system performance, the atmospheric laser communication system using circular polarization modulation technology is adopted and researched. This system uses polarization shift keying modulation (PloSK), which is a new standard digital modulation technique in optical communication field. In this modulation, two rotation states of the circle polarization light (left handed and right handed) representation logic signal ' 0 ' and ' 1 ', are used to information loaded and data transmission. In the receiver, the modulation optical signal is detected with dual differential probe method. Under the OptiSystem system simulation environment, several direct detection system model based on OOK intensity modulation, single rode circular polarization modulation and circular polarization modulation with balanced detection is constructed, and compares and analysis of the various communication system performance. The results show that: at the same parameter conditions, bit error rate of CPolSK system with balanced detection lower about two orders of magnitude than the OOK system and single rode CPolSK system, the eye diagram and the waveform chart are also significantly better than OOK system's. It can be seen, based on circular polarization shift keying (CPolSK) laser communication system with dual differential detection is superior on anti-interference of atmospheric interference, and reducing error rate, and will be easy to implement.

  3. Laser Docking System Radar flight experiment

    NASA Technical Reports Server (NTRS)

    Erwin, Harry O.

    1986-01-01

    Flight experiments to verify the Laser Docking System Radar are discussed. The docking requirements are summarized, and the breadboarded hardware is described, emphasizing the two major scanning concepts being utilized: a mechanical scanning technique employing galvanometer beamsteerers and an electronic scanning technique using an image dissector. The software simulations used to apply hardware solutions to the docking requirements are briefly discussed, the tracking test bed is described, and the objectives of the flight experiment are reviewed.

  4. Optically pumped isotopic ammonia laser system

    DOEpatents

    Buchwald, Melvin I.; Jones, Claude R.; Nelson, Leonard Y.

    1982-01-01

    An optically pumped isotopic ammonia laser system which is capable of producing a plurality of frequencies in the middle infrared spectral region. Two optical pumping mechanisms are disclosed, i.e., pumping on R(J) and lasing on P(J) in response to enhancement of rotational cascade lasing including stimulated Raman effects, and, pumping on R(J) and lasing on P(J+2). The disclosed apparatus for optical pumping include a hole coupled cavity and a grating coupled cavity.

  5. Laser Research and Development Studies for Laser Guide Star Systems

    SciTech Connect

    Pennington, D.; Beach, R.; Ebbers, C.; Erbert, G.; Nguyen, H.; Page, R.; Payne, S.; Perry, M.

    2000-02-23

    In this paper we consider two CW solid state laser approaches to a 589 nm LGS system. Both are based on the technique of sum-frequency generation, but differ in the cavity architecture. Both technologies are very promising and are worth of further consideration. This preliminary proposal is intended to encompass both designs. A down select shall be performed early in the project execution to focus on the most promising option. The two design options consist of: (1) A dual-frequency resonator with intra-cavity doubling in LB0 offers the promise of a simple architecture and may scale more easily to high power. This design has been shown to be highly reliable, efficient and high power when used in frequency-doubled Nd:YAG lasers for programs at LLNL and in commercial products. The challenge in this design is the demonstration of a high power13 18 nm oscillator with adequate suppression of the 1064 nm line. (2) A MOPA based design uses commercial low power oscillators to produce both wavelengths, then amplifies the wavelengths before doubling. This design requires the demonstration of a 1318 nm amplifier, though the design is scaled from a kW CW amplifier already delivered to a customer at a different wavelength. The design must also demonstrate high power scaling of sum-frequency generation in the relatively new nonlinear material, PPLN. The first step in the process would be to further evaluate the two conceptual options for technical feasibility, cost and constructability. Then a down selection to one design would be conducted. Finally, R&D on that design would then proceed. Minimal testing should be required for this selection. The majority of the funding received would be allocated to development of the design selected.

  6. Hybrid high power femtosecond laser system

    NASA Astrophysics Data System (ADS)

    Trunov, V. I.; Petrov, V. V.; Pestryakov, E. V.; Kirpichnikov, A. V.

    2006-01-01

    Design of a high-power femtosecond laser system based on hybrid chirped pulse amplification (CPA) technique developed by us is presented. The goal of the hybrid principle is the use of the parametric and laser amplification methods in chirped pulse amplifiers. It makes it possible to amplify the low-cycle pulses with a duration of <= fs to terawatt power with a high contrast and high conversion efficiency of the pump radiation. In a created system the Ti:Sapphire laser with 10 fs pulses at 810 nm and output energy about 1-3 nJ will be used like seed source. The oscillator pulses were stretched to duration of about 500 ps by an all-reflective grating stretcher. Then the stretched pulses are injected into a nondegenerate noncollinear optical parametric amplifier (NOPA) on the two BBO crystals. After amplification in NOPA the residual pump was used in a bow-tie four pass amplifier with hybrid active medium (based on Al II0 3:Ti 3+ and BeAl IIO 4:Ti 3+ crystals). The final stage of the amplification system consists of two channels, namely NIR (820 nm) and short-VIS (410 nm). Numerical simulation has shown that the terawatt level of output power can be achieved also in a short-VIS channel at the pumping of the double-crystal BBO NOPA by the radiation of the fourth harmonic of the Nd:YAG laser at 266 nm. Experimentally parametric amplification in BBO crystals of 30-50 fs pulses were investigated and optimized using SPIDER technique and single-shot autocomelator for the realization of shortest duration 40 fs.

  7. LISP: a laser imaging simulation package for developing and testing laser vision systems

    NASA Astrophysics Data System (ADS)

    Wu, Kung C.

    1993-01-01

    The difficulties commonly encountered in developing laser imaging technologies are: (1) high cost of the laser system, and (2) time and cost involved in modeling and maneuvering a physical environment for the desired scenes. In contrast to the real imaging systems, computer generated laser images provide researchers with fast, accurate, cost-effective data for testing and developing algorithms. The laser imaging simulation package (LISP) described in this paper provides an interactive solid modeler that allows users to construct the artificial environment by various solid modelling techniques. Two fast ray tracing algorithms were developed and discussed in this paper for generating the near realistic laser data of any desired scene. These computer generated laser data facilitates the researchers in developing laser imaging algorithms. Thus, LISP not only provides an ideal testbed for developing and testing algorithms, but also an opportunity to explore the limitation of laser imaging applications.

  8. Balancing Accuracy and Computational Efficiency for Ternary Gas Hydrate Systems

    NASA Astrophysics Data System (ADS)

    White, M. D.

    2011-12-01

    phase transitions. This paper describes and demonstrates a numerical solution scheme for ternary hydrate systems that seeks a balance between accuracy and computational efficiency. This scheme uses a generalize cubic equation of state, functional forms for the hydrate equilibria and cage occupancies, variable switching scheme for phase transitions, and kinetic exchange of hydrate formers (i.e., CH4, CO2, and N2) between the mobile phases (i.e., aqueous, liquid CO2, and gas) and hydrate phase. Accuracy of the scheme will be evaluated by comparing property values and phase equilibria against experimental data. Computational efficiency of the scheme will be evaluated by comparing the base scheme against variants. The application of interest will the production of a natural gas hydrate deposit from a geologic formation, using the guest molecule exchange process; where, a mixture of CO2 and N2 are injected into the formation. During the guest-molecule exchange, CO2 and N2 will predominately replace CH4 in the large and small cages of the sI structure, respectively.

  9. Evaluation of a micrometeorological mass balance method employing an open-path laser for measuring methane emissions

    NASA Astrophysics Data System (ADS)

    Desjardins, R. L.; Denmead, O. T.; Harper, L.; McBain, M.; Massé, D.; Kaharabata, S.

    In trials of a mass balance method for measuring methane (CH 4) emissions, sonic anemometers and an open-path laser were used to measure the transport of CH 4 released from a ground-level source across a downwind face 50 m long and 6 m high. Release rates matched emissions expected from dairy herds of 2 to 40 cows. The long laser path permitted inferences from measurements in only two planes, one upwind and one downwind, while the fast-response instruments allowed calculation of instantaneous horizontal fluxes rather than fluxes calculated from mean wind speeds and mean concentrations. The detection limit of the lasers was 0.02 ppmv, with the separation between the transmitters and reflectors being about 50 m. The main conclusions from the 23 trials were: (1) Emissions calculated from mean wind speeds and concentrations overestimated the true emissions calculated from instantaneous measurements by 5%. (2) Because of small changes in methane concentration, the minimum sample size in animal trials would be 10 dairy cows, producing about 40 mg CH 4 s -1. (3) For release rates greater than 40 mg CH 4 s -1 and with sufficient replication, the technique could detect a change in production rate of 9% ( P<=0.05). (4) Attention to perceived weaknesses in the present technique should help towards detecting changes of 5%.

  10. Laser Doppler systems in atmospheric turbulence

    NASA Technical Reports Server (NTRS)

    Murty, S. S. R.

    1976-01-01

    The loss of heterodyne signal power for the Marshall Space Flight Center laser Doppler system due to the random changes in the atmospheric index of refraction is investigated. The current status in the physics of low energy laser propagation through turbulent atmosphere is presented. The analysis and approximate evaluation of the loss of the heterodyne signal power due to the atmospheric absorption, scattering, and turbulence are estimated for the conditions of the January 1973 flight tests. Theoretical and experimental signal to noise values are compared. Maximum and minimum values of the atmospheric attenuation over a two way path of 20 km range are calculated as a function of altitude using models of atmosphere, aerosol concentration, and turbulence.

  11. High-average-power exciplex laser system

    NASA Astrophysics Data System (ADS)

    Sentis, M.

    The LUX high-average-power high-PRF exciplex laser (EL) system being developed at the Institut de Mecanique des Fluides de Marseille is characterized, and some preliminary results are presented. The fundamental principles and design criteria of ELs are reviewed, and the LUX components are described and illustrated, including a closed-circuit subsonic wind tunnel and a 100-kW-average power 1-kHz-PRF power pulser providing avalanche-discharge preionization by either an electron beam or an X-ray beam. Laser energy of 50 mJ has been obtained at wavelength 308 nm in the electron-beam mode (14.5 kV) using a 5300/190/10 mixture of Ne/Xe/HCl at pressure 1 bar.

  12. Advanced laser stratospheric monitoring systems analyses

    NASA Technical Reports Server (NTRS)

    Larsen, J. C.

    1984-01-01

    This report describes the software support supplied by Systems and Applied Sciences Corporation for the study of Advanced Laser Stratospheric Monitoring Systems Analyses under contract No. NAS1-15806. This report discusses improvements to the Langley spectroscopic data base, development of LHS instrument control software and data analyses and validation software. The effect of diurnal variations on the retrieved concentrations of NO, NO2 and C L O from a space and balloon borne measurement platform are discussed along with the selection of optimum IF channels for sensing stratospheric species from space.

  13. Systems Modeling For The Laser Fusion-Fission Energy (LIFE) Power Plant

    SciTech Connect

    Meier, W R; Abbott, R; Beach, R; Blink, J; Caird, J; Erlandson, A; Farmer, J; Halsey, W; Ladran, T; Latkowski, J; MacIntyre, A; Miles, R; Storm, E

    2008-10-02

    A systems model has been developed for the Laser Inertial Fusion-Fission Energy (LIFE) power plant. It combines cost-performance scaling models for the major subsystems of the plant including the laser, inertial fusion target factory, engine (i.e., the chamber including the fission and tritium breeding blankets), energy conversion systems and balance of plant. The LIFE plant model is being used to evaluate design trade-offs and to identify high-leverage R&D. At this point, we are focused more on doing self consistent design trades and optimization as opposed to trying to predict a cost of electricity with a high degree of certainty. Key results show the advantage of large scale (>1000 MWe) plants and the importance of minimizing the cost of diodes and balance of plant cost.

  14. Laser ablation system, and method of decontaminating surfaces

    DOEpatents

    Ferguson, Russell L.; Edelson, Martin C.; Pang, Ho-ming

    1998-07-14

    A laser ablation system comprising a laser head providing a laser output; a flexible fiber optic cable optically coupled to the laser output and transmitting laser light; an output optics assembly including a nozzle through which laser light passes; an exhaust tube in communication with the nozzle; and a blower generating a vacuum on the exhaust tube. A method of decontaminating a surface comprising the following steps: providing an acousto-optic, Q-switched Nd:YAG laser light ablation system having a fiber optically coupled output optics assembly; and operating the laser light ablation system to produce an irradiance greater than 1.times.10.sup.7 W/cm.sup.2, and a pulse width between 80 and 170 ns.

  15. [Design of a mechanical system for the balanceable system of ambulance].

    PubMed

    Zheng, Yi; Luo, Yibin; Zhang, Guangpeng; Zhang, Zhide; Chen, Chaomin

    2010-08-01

    This is the design of a mechanical systems for use in the balanceable system of ambulance, which can keep the medical service bed at the ambulance level, whatever the terrain is. A level detector will detect the level state of the bed and turn it to a signal. The central processing unit will use this signal to analyse and control the movement of the motor. By this design (which uses the rolling rail as a drive transmission and makes three supports of the bed go up and down), the bed will keep level. With the use of this design, the balanceable system of ambulance can counteract 35 degrees. The error is controlled within +/- 1 degree. And the response time is within 0.3 s. The method of registration can be effective for keeping the bed at the ambulance level, and for reducing the chance of making the patient get hurt on the way to hospital.

  16. Comparison of digital controllers used in magnetic suspension and balance systems

    NASA Technical Reports Server (NTRS)

    Kilgore, William A.

    1990-01-01

    Dynamic systems that were once controlled by analog circuits are now controlled by digital computers. Presented is a comparison of the digital controllers presently used with magnetic suspension and balance systems. The overall responses of the systems are compared using a computer simulation of the magnetic suspension and balance system and the digital controllers. The comparisons include responses to both simulated force and position inputs. A preferred digital controller is determined from the simulated responses.

  17. Airborne Laser Altimetry Mapping of the Greenland Ice Sheet: Application to Mass Balance Assessment

    NASA Technical Reports Server (NTRS)

    Abdalati, W.; Krabill, W.; Frederick, E.; Manizade, S.; Martin, C.; Sonntag, J.; Swift, R.; Thomas, R.; Wright, W.; Yungel, J.

    2000-01-01

    In 1998 and '99, the Arctic Ice Mapping (AIM) program completed resurveys of lines occupied 5 years earlier revealing elevation changes of the Greenland ice sheet and identifying areas of significant thinning, thickening and balance. In planning these surveys, consideration had to be given to the spatial constraints associated with aircraft operation, the spatial nature of ice sheet behavior, and limited resources, as well as temporal issues, such as seasonal and interannual variability in the context of measurement accuracy. This paper examines the extent to which the sampling and survey strategy is valid for drawing conclusions on the current state of balance of the Greenland ice sheet. The surveys covered the entire ice sheet with an average distance of 21.4 km between each location on the ice sheet and the nearest flight line. For most of the ice sheet, the elevation changes show relatively little spatial variability, and their magnitudes are significantly smaller than the observed elevation change signal. As a result, we conclude that the density of the sampling and the accuracy of the measurements are sufficient to draw meaningful conclusions on the state of balance of the entire ice sheet over the five-year survey period. Outlet glaciers, however, show far more spatial and temporal variability, and each of the major ones is likely to require individual surveys in order to determine its balance.

  18. Modelling and simulation of large solid state laser systems

    SciTech Connect

    Simmons, W.W.; Warren, W.E.

    1986-01-01

    The role of numerical methods to simulate the several physical processes (e.g., diffraction, self-focusing, gain saturation) that are involved in coherent beam propagation through large laser systems is discussed. A comprehensive simulation code for modeling the pertinent physical phenomena observed in laser operations (growth of small-scale modulation, spatial filter, imaging, gain saturation and beam-induced damage) is described in some detail. Comparisons between code results and solid state laser output performance data are presented. Design and performance estimation of the large Nova laser system at LLNL are given. Finally, a global design rule for large, solid state laser systems is discussed.

  19. Influences of weather phenomena on automotive laser radar systems

    NASA Astrophysics Data System (ADS)

    Rasshofer, R. H.; Spies, M.; Spies, H.

    2011-07-01

    Laser radar (lidar) sensors provide outstanding angular resolution along with highly accurate range measurements and thus they were proposed as a part of a high performance perception system for advanced driver assistant functions. Based on optical signal transmission and reception, laser radar systems are influenced by weather phenomena. This work provides an overview on the different physical principles responsible for laser radar signal disturbance and theoretical investigations for estimation of their influence. Finally, the transmission models are applied for signal generation in a newly developed laser radar target simulator providing - to our knowledge - worldwide first HIL test capability for automotive laser radar systems.

  20. Perturbation analysis of internal balancing for lightly damped mechanical systems with gyroscopic and circulatory forces

    NASA Technical Reports Server (NTRS)

    Blelloch, P. A.; Mingori, D. L.; Wei, J. D.

    1987-01-01

    Approximate expressions are developed for internally balanced singular values corresponding to the modes of mechanical systems with gyroscopic forces, light damping, and small circulatory forces. A brief overview is first given of the balanced realization model reduction method, including a discussion of recent work. The models considered are defined, and a perturbation analysis is used to show that the modal representation becomes asymptotically balanced as damping reduces to zero. The approximate balanced singular values are calculated, and a simple example of a flexible, dual-spin spacecraft is given as an illustration of the results.

  1. Method and system for modulation of gain suppression in high average power laser systems

    DOEpatents

    Bayramian, Andrew James

    2012-07-31

    A high average power laser system with modulated gain suppression includes an input aperture associated with a first laser beam extraction path and an output aperture associated with the first laser beam extraction path. The system also includes a pinhole creation laser having an optical output directed along a pinhole creation path and an absorbing material positioned along both the first laser beam extraction path and the pinhole creation path. The system further includes a mechanism operable to translate the absorbing material in a direction crossing the first laser beam extraction laser path and a controller operable to modulate the second laser beam.

  2. Lasers in Industry: Metalworking Processes and Systems

    NASA Astrophysics Data System (ADS)

    Sona, Alberto

    1988-01-01

    After a brief review of the lasers available for metal-working processes an analysis of the interaction of laser radiation with matter is provided in the power density ranges of practical use namely: (a) High energy density processes (106-107 W/cm2) exploiting focused beams to induce solid to liquid or to vapour state changes to allow the material removal for cutting or the formation of molten an resolidified material channels for welding and joining. (b) Medium energy density processes (104-105 W/cm2) exploiting unfocused beams with a suitable spatial distribution to provide surface treatments without change of state or with surface melting for hardening and cladding. Class (a) processes require a more complex analysis taking into account both the direct energy transfer from the beam to the workpiece by direct absorption and the coupling of the energy via the plasma generated by the interaction. Class (b) processes can be treated with simpler models under the assumption of constant values for the absorption and for the thermal parameters of the target. Temperature dependent parameters can also be considered with added complexity. Finally a short outline will be provided of the systems which can implement in practice the laser metalworking process.

  3. Numerical aperture limits on efficient ball lens coupling of laser diodes to single-mode fibers with defocus to balance spherical aberration

    NASA Technical Reports Server (NTRS)

    Wilson, R. Gale

    1994-01-01

    The potential capabilities and limitations of single ball lenses for coupling laser diode radiation to single-mode optical fibers have been analyzed; parameters important to optical communications were specifically considered. These parameters included coupling efficiency, effective numerical apertures, lens radius, lens refractive index, wavelength, magnification in imaging the laser diode on the fiber, and defocus to counterbalance spherical aberration of the lens. Limiting numerical apertures in object and image space were determined under the constraint that the lens perform to the Rayleigh criterion of 0.25-wavelength (Strehl ratio = 0.80). The spherical aberration-defocus balance to provide an optical path difference of 0.25 wavelength units was shown to define a constant coupling efficiency (i.e., 0.56). The relative numerical aperture capabilities of the ball lens were determined for a set of wavelengths and associated fiber-core diameters of particular interest for single-mode fiber-optic communication. The results support general continuing efforts in the optical fiber communications industry to improve coupling links within such systems with emphasis on manufacturing simplicity, system packaging flexibility, relaxation of assembly alignment tolerances, cost reduction of opto-electronic components and long term reliability and stability.

  4. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: LASER POWER MEASUREMENTS

    EPA Science Inventory

    Laser power abstract
    The reliability of the confocal laser-scanning microscope (CLSM) to obtain intensity measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. The laser power test appears to be one ...

  5. Optimal two-mirror system for laser radiation focusing

    SciTech Connect

    Gitin, Andrey V

    2009-10-31

    An optical system for laser radiation focusing, which consists of parabolic and elliptic mirrors, is considered. It is shown by the method of elementary reflections that the maximum concentration of laser radiation on the target can be achieved at a certain position of these mirrors. (laser applications and other topics in quantum electronics)

  6. A software system for laser design and analysis

    NASA Technical Reports Server (NTRS)

    Cross, P. L.; Barnes, N. P.; Filer, E. D.

    1990-01-01

    A laser-material database and laser-modeling software system for designing lasers for laser-based Light Detection And Ranging (LIDAR) systems are presented. The software system consists of three basic sections: the database, laser models, and interface software. The database contains the physical parameters of laser, optical, and nonlinear materials required by laser models. The models include efficiency calculations, electrooptical component models, resonator, amplifier, and oscillator models, and miscellaneous models. The interface software provides a user-friendly interface between the user and his personal data files, the database, and models. The structure of the software system is essentially in place, while future plans call for upgrading the computer hardware and software in order to support a multiuser multitask environment.

  7. Development of a US Gravitational Wave Laser System for LISA

    NASA Technical Reports Server (NTRS)

    Camp, Jordan B.; Numata, Kenji

    2015-01-01

    A highly stable and robust laser system is a key component of the space-based LISA mission architecture.In this talk I will describe our plans to demonstrate a TRL 5 LISA laser system at Goddard Space Flight Center by 2016.The laser system includes a low-noise oscillator followed by a power amplifier. The oscillator is a low-mass, compact 10mW External Cavity Laser, consisting of a semiconductor laser coupled to an optical cavity, built by the laser vendorRedfern Integrated Optics. The amplifier is a diode-pumped Yb fiber with 2W output, built at Goddard. I will show noiseand reliability data for the full laser system, and describe our plans to reach TRL 5 by 2016.

  8. Solid-state coherent laser radar wind shear measuring systems

    NASA Technical Reports Server (NTRS)

    Huffaker, R. Milton

    1992-01-01

    Coherent Technologies, Inc. (CTI) was established in 1984 to engage in the development of coherent laser radar systems and subsystems with applications in atmospheric remote sensing, and in target tracking, ranging and imaging. CTI focuses its capabilities in three major areas: (1) theoretical performance and design of coherent laser radar system; (2) development of coherent laser radar systems for government agencies such as DoD and NASA; and (3) development of coherent laser radar systems for commercial markets. The topics addressed are: (1) 1.06 micron solid-state coherent laser radar system; (2) wind measurement using 1.06 micron system; and flashlamp-pumped 2.09 micron solid-state coherent laser radar system.

  9. Laser system for a subpicosecond electron linac.

    SciTech Connect

    Crowell, R. A.

    1998-09-25

    At the Argonne Chemistry Division efforts are underway to develop a sub-picosecond electron beam pulse radiolysis facility for chemical studies. The target output of the accelerator is to generate electron pulses that can be adjusted from 3nC in .6ps to 100nC in 45ps. In conjunction with development of the accelerator a state-of-the-art ultrafast laser system is under construction that will drive the linac's photocathode and provide probe pulses that are tunable from the UV to IR spectral regions.

  10. Subpicosecond high-brightness uv laser system

    SciTech Connect

    Gibson, R.B.

    1986-01-01

    A laser system that produces intense subpicosecond pulses of 248 nm light is under development. Ultrashort pulses are generated in the visible in a synchronously-pumped mode-locked dye oscillator, heterodyned into the uv by two KDP crystals, and amplified in a chain of KrF* amplifiers. Front end output of 5 ..mu..J is amplified to 20 mJ and focused to peak intensities of order 10/sup 17/ W cm/sup -2/. Additional amplification is expected to permit experiments at intensities >10/sup 20/ W cm/sup -2/.

  11. Atmospheric refraction errors in laser ranging systems

    NASA Technical Reports Server (NTRS)

    Gardner, C. S.; Rowlett, J. R.

    1976-01-01

    The effects of horizontal refractivity gradients on the accuracy of laser ranging systems were investigated by ray tracing through three dimensional refractivity profiles. The profiles were generated by performing a multiple regression on measurements from seven or eight radiosondes, using a refractivity model which provided for both linear and quadratic variations in the horizontal direction. The range correction due to horizontal gradients was found to be an approximately sinusoidal function of azimuth having a minimum near 0 deg azimuth and a maximum near 180 deg azimuth. The peak to peak variation was approximately 5 centimeters at 10 deg elevation and decreased to less than 1 millimeter at 80 deg elevation.

  12. Photodiodes for ten micrometer laser communication systems

    NASA Technical Reports Server (NTRS)

    Cohen, S. C.

    1972-01-01

    The performance is discussed of 10-micron mercury-cadmiumtelluride and lead-tin-telluride photodiodes in laser heterodyne communication systems. The dependence of detector quantum efficiency, resistance, frequency response, and signal-to-noise ratio on temperature, bias, and local oscillator power are examined. Included in the discussion is an analysis of the feasibility of high temperature operation, and ability of the detector to dissipate power to a heat sink is explored. Some aspects of direct detection response are considered and figures showing flux levels from a blackbody presented.

  13. Laser Schlieren System Detects Sounds Of Leaks

    NASA Technical Reports Server (NTRS)

    Shakkottai, Parthasarathy P.; Alwar, A. Vijayaragavan

    1990-01-01

    Hostile environments monitored safely and noninvasively. Modified laser schlieren system acts as microphone to detect sounds of leaks remotely. Sensitive to acoustical frequencies above audible range and especially suited for monitoring leaks of high-pressure steam from boilers or chemical vapors from processing equipment. Does not require placement of delicate equipment in harsh environment monitored, and no contact needed with boiler or other unit being monitored. Detects sound waves via variation of index of refraction of air at acoustical frequencies. Used to monitor sound frequencies beyond range of human hearing.

  14. Performance of the upgraded Orroral laser ranging system

    NASA Technical Reports Server (NTRS)

    Luck, John M.

    1993-01-01

    The topics discussed include the following: upgrade arrangements, system prior to 1991, elements of the upgrade, laser performance, timing system performance, pass productivity, system precision, system accuracy, telescope pointing and future upgrades and extensions.

  15. Performance and lifetime of high-power diode lasers and diode laser systems

    NASA Astrophysics Data System (ADS)

    Dorsch, Friedhelm; Daiminger, Franz X.

    1999-04-01

    High-power diode lasers have reached output power and reliability to meet requirements for industrial applications. Stacking of laser elements to modules increases the output power, beam shaping techniques allow to focus the radiation of a module to a single spot. An integrated diode laser systems with totally 50 laser bars is shown, that includes cooling, power supply and control unit. The laser radiation is transmitted by an optical fiber and an objective focuses the radiation onto the workpiece with a round spot of less than 1 mm diameter and cw power of more than 1 kW.

  16. 1047 nm laser diode master oscillator Nd:YLF power amplifier laser system

    NASA Technical Reports Server (NTRS)

    Yu, A. W.; Krainak, M. A.; Unger, G. L.

    1993-01-01

    A master oscillator power amplifier (MOPA) laser transmitter system at 1047 nm wavelength using a semiconductor laser diode and a diode pumped solid state (Nd:YLF) laser (DPSSL) amplifier is described. A small signal gain of 23 dB, a near diffraction limited beam, 1 Gbit/s modulation rates and greater than 0.6 W average power are achieved. This MOPA laser has the advantage of amplifying the modulation signal from the laser diode master oscillator (MO) with no signal degradation.

  17. Comparative analysis of net energy balance for satellite power systems (SPS) and other energy systems

    SciTech Connect

    Cirillo, R.R.; Cho, B.S.; Monarch, M.R.; Levine, E.P.

    1980-04-01

    The net energy balance of seven electric energy systems is assessed: two coal-based, one nuclear, two terrestrial solar, and two solar power satellites, with principal emphasis on the latter two systems. Solar energy systems require much less operating energy per unit of electrical output. However, on the basis of the analysis used here, coal and nuclear systems are two to five times more efficient at extracting useful energy from the primary resource base than are the solar energy systems. The payback period for all systems is less than 1.5 years, except for the terrestrial photovoltaic (19.8 yr) and the solar power satellite system (6.4 yr), both of which rely on energy-intensive silicon cells.

  18. Effect of powder characteristics on the balance of radiation energy in coaxial laser sintering

    SciTech Connect

    Niz'ev, V G; Mirzade, F Kh; Khomenko, M D

    2014-09-30

    We have analysed the effect of scattering and absorption by powder microparticles on the transfer of laser energy during laser sintering with powder injection into the sintering zone through a coaxial nozzle. The energy flow into the sintering zone is summed up of a part of the radiation energy transmitted through the dispersion medium to the substrate and the energy carried by the particles heated by the radiation during their transportation from the nozzle to the substrate. We have found that the relative fraction of the energy supply to the substrate by these two channels can be different depending on the process parameters, and therefore the neglect of one of them is generally not justified. It is shown that, when using a two-component powder blend, powder components entering into the interaction zone may have different temperatures, and even be in a different aggregation state (depending on the powder material, particle size and flow parameters). This provides additional opportunities for controlling the process, for example at sintering gradient materials. (laser technology)

  19. Active annular-beam laser autocollimator system.

    PubMed

    Yoder, P R; Schlesinger, E R; Chickvary, J L

    1975-08-01

    An autocollimator using an axicon and a beam expander telescope to generate a 12.5-cm. o.d. annular beam of helium-neon laser light with high (25:1) diameter-to-width ratio has been developed. It is used with a two-axis, electromagnetically actuated mirror assembly to acquire automatically and maintain dynamically autocollimation from a nearby but separately mounted annular mirror. The servo system controls beam alignment even though angular vibratory motions of the annular mirror make it appear to tilt relative to the autocollimator as much as 7 mrad at frequencies below 300 Hz. This paper describes the optical system and the alignment sensing and control system.

  20. Performance calculation and simulation system of high energy laser weapon

    NASA Astrophysics Data System (ADS)

    Wang, Pei; Liu, Min; Su, Yu; Zhang, Ke

    2014-12-01

    High energy laser weapons are ready for some of today's most challenging military applications. Based on the analysis of the main tactical/technical index and combating process of high energy laser weapon, a performance calculation and simulation system of high energy laser weapon was established. Firstly, the index decomposition and workflow of high energy laser weapon was proposed. The entire system was composed of six parts, including classical target, platform of laser weapon, detect sensor, tracking and pointing control, laser atmosphere propagation and damage assessment module. Then, the index calculation modules were designed. Finally, anti-missile interception simulation was performed. The system can provide reference and basis for the analysis and evaluation of high energy laser weapon efficiency.

  1. High power laser downhole cutting tools and systems

    SciTech Connect

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2015-01-20

    Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

  2. Absorption of a single 500 fs laser pulse at the surface of fused silica: Energy balance and ablation efficiency

    NASA Astrophysics Data System (ADS)

    Varkentina, N.; Sanner, N.; Lebugle, M.; Sentis, M.; Utéza, O.

    2013-11-01

    Ablation of fused silica by a single femtosecond laser pulse of 500 fs pulse duration is investigated from the perspective of efficiency of incident photons to remove matter. We measure the reflected and transmitted fractions of the incident pulse energy as a function of fluence, allowing us to recover the evolution of absorption at the material surface. At the ablation threshold fluence, 25% of incident energy is absorbed. At high fluences, this ratio saturates around 70% due to the appearance of a self-triggered plasma mirror (or shielding) effect. By using the energy balance retrieved experimentally and measurements of the ablated volume, we show that the amount of absorbed energy is far above the bonding energy of fused silica at rest and also above the energy barrier to ablate the material under non-equilibrium thermodynamic conditions. Our results emphasize the crucial role of transient plasma properties during the laser pulse and suggest that the major part of the absorbed energy has been used to heat the plasma formed at the surface of the material. A fluence range yielding an efficient and high quality ablation is also defined, which makes the results relevant for femtosecond micromachining processes.

  3. Performance Analysis and Portability of the PLUM Load Balancing System

    NASA Technical Reports Server (NTRS)

    Oliker, Leonid; Biswas, Rupak; Gabow, Harold N.

    1998-01-01

    The ability to dynamically adapt an unstructured mesh is a powerful tool for solving computational problems with evolving physical features; however, an efficient parallel implementation is rather difficult. To address this problem, we have developed PLUM, an automatic portable framework for performing adaptive numerical computations in a message-passing environment. PLUM requires that all data be globally redistributed after each mesh adaption to achieve load balance. We present an algorithm for minimizing this remapping overhead by guaranteeing an optimal processor reassignment. We also show that the data redistribution cost can be significantly reduced by applying our heuristic processor reassignment algorithm to the default mapping of the parallel partitioner. Portability is examined by comparing performance on a SP2, an Origin2000, and a T3E. Results show that PLUM can be successfully ported to different platforms without any code modifications.

  4. Theory of tracking accuracy of laser systems

    NASA Astrophysics Data System (ADS)

    Kazovsky, L.

    1983-06-01

    The peformance of the quadrant detector-based laser tracking system is theoretically evaluated. Measurement span, estimation bias, and estimation variance are analyzed, with the emphasis on the quantitative evaluation of the estimation bias and variance. It is found that the measurement span does not exceed the radius of the light spot. If system specifications restrict estimation bias, then the measurement span must be limited even further, to a fraction of the light spot. The systematic error component of estimation bias is rather large but may be cancelled. Signal-dependent bias decreases when the SNR increases, and increases rapidly when the light spot approaches the end of the measurement span. Estimation variance decreases when the SNR increases, and remains approximately constant as the light spot moves over the measurement span.

  5. Multi-access laser communications transceiver system

    NASA Technical Reports Server (NTRS)

    Ross, Monte (Inventor); Lokerson, Donald C. (Inventor); Fitzmaurice, Michael W. (Inventor); Meyer, Daniel D. (Inventor)

    1993-01-01

    A satellite system for optical communications such as a multi-access laser transceiver system. Up to six low Earth orbiting satellites send satellite data to a geosynchronous satellite. The data is relayed to a ground station at the Earth's surface. The earth pointing geosynchronous satellite terminal has no gimbal but has a separate tracking mechanism for tracking each low Earth orbiting satellite. The tracking mechanism has a ring assembly rotatable about an axis coaxial with the axis of the field of view of the geosynchronous satellite and a pivotable arm mounted for pivotal movement on the ring assembly. An optical pickup mechanism at the end of each arm is positioned for optical communication with one of the orbiting satellites by rotation of the ring.

  6. Yb:FAP and related materials, laser gain medium comprising same, and laser systems using same

    DOEpatents

    Krupke, William F.; Payne, Stephen A.; Chase, Lloyd L.; Smith, Larry K.

    1994-01-01

    An ytterbium doped laser material remarkably superior to all others, including Yb:YAG, comprises Ytterbium doped apatite (Yb:Ca.sub.5 (PO.sub.4).sub.3 F) or Yb:FAP, or ytterbium doped crystals that are structurally related to FAP. The new laser material is used in laser systems pumped by diode pump sources having an output near 0.905 microns or 0.98 microns, such as InGaAs and AlInGaAs, or other narrowband pump sources near 0.905 microns or 0.98 microns. The laser systems are operated in either the conventional or ground state depletion mode.

  7. Cost of photovoltaic energy systems as determined by balance-of-system costs

    NASA Technical Reports Server (NTRS)

    Rosenblum, L.

    1978-01-01

    The effect of the balance-of-system (BOS), i.e., the total system less the modules, on photo-voltaic energy system costs is discussed for multikilowatt, flat-plate systems. Present BOS costs are in the range of 10 to 16 dollars per peak watt (1978 dollars). BOS costs represent approximately 50% of total system cost. The possibility of future BOS cost reduction is examined. It is concluded that, given the nature of BOS costs and the lack of comprehensive national effort focussed on cost reduction, it is unlikely that BOS costs will decline greatly in the next several years. This prognosis is contrasted with the expectations of the Department of Energy National Photovoltaic Program goals and pending legislation in the Congress which require a BOS cost reduction of an order of magnitude or more by the mid-1980s.

  8. New 223-nm excimer laser surgical system for photorefractive keratectomy

    NASA Astrophysics Data System (ADS)

    Bagaev, Sergei N.; Razhev, Alexander M.; Zhupikov, Andrey A.

    1999-02-01

    The using of KrCl (223 nm) excimer laser in ophthalmic devices for Photorefractive Keratectomy (PRK) and phototherapeutic Keratectomy (PTK) is offered. The structure and functions of a new surgical UV ophthalmic laser systems Medilex using ArF (193 nm) or KrCl (223 nm) excimer laser for corneal surgery are presented. The systems Medilex with the new optical delivery system is used for photoablative reprofiling of the cornea to correct refraction errors (myopia, hyperopia and astigmatism) and to treat a corneal pathologies. The use of the 223 nanometer laser is proposed to have advantages over the 193 nanometer laser. The results of application of the ophthalmic excimer laser systems Medilex for treatment of myopia are presented.

  9. Mass Balance Changes and Ice Dynamics of Greenland and Antarctic Ice Sheets from Laser Altimetry

    NASA Astrophysics Data System (ADS)

    Babonis, G. S.; Csatho, B.; Schenk, T.

    2016-06-01

    During the past few decades the Greenland and Antarctic ice sheets have lost ice at accelerating rates, caused by increasing surface temperature. The melting of the two big ice sheets has a big impact on global sea level rise. If the ice sheets would melt down entirely, the sea level would rise more than 60 m. Even a much smaller rise would cause dramatic damage along coastal regions. In this paper we report about a major upgrade of surface elevation changes derived from laser altimetry data, acquired by NASA's Ice, Cloud and land Elevation Satellite mission (ICESat) and airborne laser campaigns, such as Airborne Topographic Mapper (ATM) and Land, Vegetation and Ice Sensor (LVIS). For detecting changes in ice sheet elevations we have developed the Surface Elevation Reconstruction And Change detection (SERAC) method. It computes elevation changes of small surface patches by keeping the surface shape constant and considering the absolute values as surface elevations. We report about important upgrades of earlier results, for example the inclusion of local ice caps and the temporal extension from 1993 to 2014 for the Greenland Ice Sheet and for a comprehensive reconstruction of ice thickness and mass changes for the Antarctic Ice Sheets.

  10. Feedback stabilization system for pulsed single longitudinal mode tunable lasers

    DOEpatents

    Esherick, Peter; Raymond, Thomas D.

    1991-10-01

    A feedback stabilization system for pulse single longitudinal mode tunable lasers having an excited laser medium contained within an adjustable length cavity and producing a laser beam through the use of an internal dispersive element, including detection of angular deviation in the output laser beam resulting from detuning between the cavity mode frequency and the passband of the internal dispersive element, and generating an error signal based thereon. The error signal can be integrated and amplified and then applied as a correcting signal to a piezoelectric transducer mounted on a mirror of the laser cavity for controlling the cavity length.

  11. Compact laser illumination system for endoscopic interventions.

    PubMed

    Blase, Bastian

    2015-08-01

    External cold light sources as well as LEDs are commonly used for abdominal illumination in minimally invasive surgery. Still, both feature certain disadvantages. A new illumination system for endoscopes based on laser diodes is placed in the handle. No external light cables are needed. High conversion and coupling efficiencies and small package size allow for several diodes to be integrated, enabling color mixing and the adjustment of color temperatures. An optical module to collimate and combine the light is described. The heat to be dissipated is stored in a passive latent heat storage based on phase change materials surrounding the optical module. Thereby, operation time is considerably extended, as the handle's temperature is stabilized. To reduce the negative effect of coherent light on optical rough surfaces leading to patterns of spots, several devices for speckle reduction are developed and tested. By combining these components, an assembly of a powerful RGB laser light module for the integration in standard sized endoscopes is formed. PMID:26737628

  12. Wind Tunnel Seeding Systems for Laser Velocimeters

    NASA Technical Reports Server (NTRS)

    Hunter, W. W., Jr. (Compiler); Nichols, C. E., Jr. (Compiler)

    1985-01-01

    The principal motivating factor for convening the Workshop on the Development and Application of Wind Tunnel Seeding Systems for Laser Velocimeters is the necessity to achieve efficient operation and, most importantly, to insure accurate measurements with velocimeter techniques. The ultimate accuracy of particle scattering based laser velocimeter measurements of wind tunnel flow fields depends on the ability of the scattering particle to faithfully track the local flow field in which it is embedded. A complex relationship exists between the particle motion and the local flow field. This relationship is dependent on particle size, size distribution, shape, and density. To quantify the accuracy of the velocimeter measurements of the flow field, the researcher has to know the scattering particle characteristics. In order to obtain optimum velocimeter measurements, the researcher is striving to achieve control of the particle characteristics and to verify those characteristics at the measurement point. Additionally, the researcher is attempting to achieve maximum measurement efficiency through control of particle concentration and location in the flow field.

  13. Laser Doppler velocimetry for continuous flow solar-pumped iodine laser system

    NASA Technical Reports Server (NTRS)

    Tabibi, Bagher M.; Lee, Ja H.

    1991-01-01

    A laser Doppler velocimetry (LDV) system was employed to measure the flow velocity profile of iodide vapor inside laser tubes of 36 mm ID and 20 mm ID. The LDV, which was operated in the forward scatter mode used a low power (15 mW) He-Ne laser beam. Velocity ranges from 1 m/s was measured to within one percent accuracy. The flow velocity profile across the laser tube was measured and the intensity of turbulence was determined. The flow of iodide inside the laser tube demonstrated a mixture of both turbulence and laminar flow. The flowmeter used for the laser system previously was calibrated with the LDV and found to be in good agreement.

  14. Constructing a Low-budget Laser Axotomy System to Study Axon Regeneration in C. elegans

    PubMed Central

    Williams, Wes; Nix, Paola; Bastiani, Michael

    2011-01-01

    Laser axotomy followed by time-lapse microscopy is a sensitive assay for axon regeneration phenotypes in C. elegans1. The main difficulty of this assay is the perceived cost ($25-100K) and technical expertise required for implementing a laser ablation system2,3. However, solid-state pulse lasers of modest costs (<$10K) can provide robust performance for laser ablation in transparent preparations where target axons are "close" to the tissue surface. Construction and alignment of a system can be accomplished in a day. The optical path provided by light from the focused condenser to the ablation laser provides a convenient alignment guide. An intermediate module with all optics removed can be dedicated to the ablation laser and assures that no optical elements need be moved during a laser ablation session. A dichroic in the intermediate module allows simultaneous imaging and laser ablation. Centering the laser beam to the outgoing beam from the focused microscope condenser lens guides the initial alignment of the system. A variety of lenses are used to condition and expand the laser beam to fill the back aperture of the chosen objective lens. Final alignment and testing is performed with a front surface mirrored glass slide target. Laser power is adjusted to give a minimum size ablation spot (<1um). The ablation spot is centered with fine adjustments of the last kinematically mounted mirror to cross hairs fixed in the imaging window. Laser power for axotomy will be approximately 10X higher than needed for the minimum ablation spot on the target slide (this may vary with the target you use). Worms can be immobilized for laser axotomy and time-lapse imaging by mounting on agarose pads (or in microfluidic chambers4). Agarose pads are easily made with 10% agarose in balanced saline melted in a microwave. A drop of molten agarose is placed on a glass slide and flattened with another glass slide into a pad approximately 200 um thick (a single layer of time tape on adjacent

  15. Industrial Applications of High Power CO2 Lasers - System Descriptions

    NASA Astrophysics Data System (ADS)

    Gukelberger, Armin

    1986-10-01

    The laser as a cutting tool for sheet metal cutting has beenl well accepted in industry for many years. Several hundreds of units are used for contour cutting of small and medium-sized series on plane metal sheets up to 6 mm thick. Within the last three years, cutting systems have been expanded in three ways: thicker material up to 12 mm can now be cut by using higher powered lasers (1500 W); with the introduction of flying optic systems which cover sheet dimensions up to 4 m x 3 m, the cutting of larger sized metal sheets is possible. In addition, the use of five or six axis systems allows cutting of three-dimensional plastic and metal material. Besides laser cutting, the acceptance of systems for laser welding applications is increa sing. Several systems have been running in production for a couple of years and laser wel ding will probably become the fastest growing market in laser material processing within the next five years. The laser technology is regarded as a beneficial tool for welding, whenever low heat input and, consequently, low heat distortion is requested. To day's main welding application areas are: components of car engines and transmissions, window spacer and stainless steel tube welding, and also car body welding with laser robots or five axis gantry type systems. The output power of CO2-lasers for welding applications is between 1 and 5 kw in most cases.

  16. Transport aircraft loading and balancing system: Using a CLIPS expert system for military aircraft load planning

    NASA Technical Reports Server (NTRS)

    Richardson, J.; Labbe, M.; Belala, Y.; Leduc, Vincent

    1994-01-01

    The requirement for improving aircraft utilization and responsiveness in airlift operations has been recognized for quite some time by the Canadian Forces. To date, the utilization of scarce airlift resources has been planned mainly through the employment of manpower-intensive manual methods in combination with the expertise of highly qualified personnel. In this paper, we address the problem of facilitating the load planning process for military aircraft cargo planes through the development of a computer-based system. We introduce TALBAS (Transport Aircraft Loading and BAlancing System), a knowledge-based system designed to assist personnel involved in preparing valid load plans for the C130 Hercules aircraft. The main features of this system which are accessible through a convivial graphical user interface, consists of the automatic generation of valid cargo arrangements given a list of items to be transported, the user-definition of load plans and the automatic validation of such load plans.

  17. Spectrally-balanced chromatic approach-lighting system

    NASA Technical Reports Server (NTRS)

    Chase, W. D.

    1977-01-01

    Approach lighting system employing combinations of red and blue lights reduces problem of color-based optical illusions. System exploits inherent chromatic aberration of eye to create three-dimensional effect, giving pilot visual clues of position.

  18. Development of Fiber-Based Laser Systems for LISA

    NASA Technical Reports Server (NTRS)

    Numata, Kenji; Camp, Jordan

    2010-01-01

    We present efforts on fiber-based laser systems for the LISA mission at the NASA Goddard Space Flight Center. A fiber-based system has the advantage of higher robustness against external disturbances and easier implementation of redundancies. For a master oscillator, we are developing a ring fiber laser and evaluating two commercial products, a DBR linear fiber laser and a planar-waveguide external cavity diode laser. They all have comparable performance to a traditional NPRO at LISA band. We are also performing reliability tests of a 2-W Yb fiber amplifier and radiation tests of fiber laser/amplifier components. We describe our progress to date and discuss the path to a working LISA laser system design.

  19. Uncertainty Analysis of the Single-Vector Force Balance Calibration System

    NASA Technical Reports Server (NTRS)

    Parker, Peter A.; Liu, Tianshu

    2002-01-01

    This paper presents an uncertainty analysis of the Single-Vector Force Balance Calibration System (SVS). This study is focused on the uncertainty involved in setting the independent variables during the calibration experiment. By knowing the uncertainty in the calibration system, the fundamental limits of the calibration accuracy of a particular balance can be determined. A brief description of the SVS mechanical system is provided. A mathematical model is developed to describe the mechanical system elements. A sensitivity analysis of these parameters is carried out through numerical simulations to assess the sensitivity of the total uncertainty to the elemental error sources. These sensitivity coefficients provide valuable information regarding the relative significance of the elemental sources of error. An example calculation of the total uncertainty for a specific balance is provided. Results from this uncertainty analysis are specific to the Single-Vector System, but the approach is broad in nature and therefore applicable to other measurement and calibration systems.

  20. New laser system for highly sensitive clinical pulse oximetry

    NASA Astrophysics Data System (ADS)

    Hamza, Mostafa; Hamza, Mohammad

    1996-04-01

    This paper describes the theory and design of a new pulse oximeter in which laser diodes and other compact laser sources are used for the measurement of oxygen saturation in patients who are at risk of developing hypoxemia. The technique depends upon illuminating special sites of the skin of the patient with radiation from modulated laser sources at selected wavelengths. The specific laser wavelengths are chosen based on the absorption characteristics of oxyhemoglobin, reduced hemoglobin and other interfering sources for obtaining more accurate measurements. The laser radiation transmitted through the tissue is detected and signal processing based on differential absorption laser spectroscopy is done in such a way to overcome the primary performance limitations of the conventionally used pulse oximetry. The new laser pulse oximeter can detect weak signals and is not affected by other light sources such as surgical lamps, phototherapy units, etc. The detailed description and operating characteristics of this system are presented.

  1. Speckle averaging system for laser raster-scan image projection

    DOEpatents

    Tiszauer, Detlev H.; Hackel, Lloyd A.

    1998-03-17

    The viewers' perception of laser speckle in a laser-scanned image projection system is modified or eliminated by the addition of an optical deflection system that effectively presents a new speckle realization at each point on the viewing screen to each viewer for every scan across the field. The speckle averaging is accomplished without introduction of spurious imaging artifacts.

  2. Speckle averaging system for laser raster-scan image projection

    DOEpatents

    Tiszauer, D.H.; Hackel, L.A.

    1998-03-17

    The viewers` perception of laser speckle in a laser-scanned image projection system is modified or eliminated by the addition of an optical deflection system that effectively presents a new speckle realization at each point on the viewing screen to each viewer for every scan across the field. The speckle averaging is accomplished without introduction of spurious imaging artifacts. 5 figs.

  3. Mercury: The Los Alamos ICF KrF laser system

    SciTech Connect

    Czuchlewski, S.J.; York, G.W.; Bigio, I.J.; Brucker, J.; Hanson, D.; Honig, E.M.; Kurnit, N.; Leland, W.; McCown, A.W.; McLeod, J.; Rose, E.; Thomas, S.; Thompson, D.

    1993-01-19

    The Mercury KrF laser facility at Los Alamos is being built with the benefit of lessons learned from the Aurora system. An increased understanding of KrF laser engineering, and the designed implementation of system flexibility, will permit Mercury to serve as a tested for a variety of advanced KrF technology concepts.

  4. Mining balance disorders' data for the development of diagnostic decision support systems.

    PubMed

    Exarchos, T P; Rigas, G; Bibas, A; Kikidis, D; Nikitas, C; Wuyts, F L; Ihtijarevic, B; Maes, L; Cenciarini, M; Maurer, C; Macdonald, N; Bamiou, D-E; Luxon, L; Prasinos, M; Spanoudakis, G; Koutsouris, D D; Fotiadis, D I

    2016-10-01

    In this work we present the methodology for the development of the EMBalance diagnostic Decision Support System (DSS) for balance disorders. Medical data from patients with balance disorders have been analysed using data mining techniques for the development of the diagnostic DSS. The proposed methodology uses various data, ranging from demographic characteristics to clinical examination, auditory and vestibular tests, in order to provide an accurate diagnosis. The system aims to provide decision support for general practitioners (GPs) and experts in the diagnosis of balance disorders as well as to provide recommendations for the appropriate information and data to be requested at each step of the diagnostic process. Detailed results are provided for the diagnosis of 12 balance disorders, both for GPs and experts. Overall, the reported accuracy ranges from 59.3 to 89.8% for GPs and from 74.3 to 92.1% for experts.

  5. Mining balance disorders' data for the development of diagnostic decision support systems.

    PubMed

    Exarchos, T P; Rigas, G; Bibas, A; Kikidis, D; Nikitas, C; Wuyts, F L; Ihtijarevic, B; Maes, L; Cenciarini, M; Maurer, C; Macdonald, N; Bamiou, D-E; Luxon, L; Prasinos, M; Spanoudakis, G; Koutsouris, D D; Fotiadis, D I

    2016-10-01

    In this work we present the methodology for the development of the EMBalance diagnostic Decision Support System (DSS) for balance disorders. Medical data from patients with balance disorders have been analysed using data mining techniques for the development of the diagnostic DSS. The proposed methodology uses various data, ranging from demographic characteristics to clinical examination, auditory and vestibular tests, in order to provide an accurate diagnosis. The system aims to provide decision support for general practitioners (GPs) and experts in the diagnosis of balance disorders as well as to provide recommendations for the appropriate information and data to be requested at each step of the diagnostic process. Detailed results are provided for the diagnosis of 12 balance disorders, both for GPs and experts. Overall, the reported accuracy ranges from 59.3 to 89.8% for GPs and from 74.3 to 92.1% for experts. PMID:27619194

  6. Laser radar system for obstacle avoidance

    NASA Astrophysics Data System (ADS)

    Bers, Karlheinz; Schulz, Karl R.; Armbruster, Walter

    2005-09-01

    The threat of hostile surveillance and weapon systems require military aircraft to fly under extreme conditions such as low altitude, high speed, poor visibility and incomplete terrain information. The probability of collision with natural and man-made obstacles during such contour missions is high if detection capability is restricted to conventional vision aids. Forward-looking scanning laser radars which are build by the EADS company and presently being flight tested and evaluated at German proving grounds, provide a possible solution, having a large field of view, high angular and range resolution, a high pulse repetition rate, and sufficient pulse energy to register returns from objects at distances of military relevance with a high hit-and-detect probability. The development of advanced 3d-scene analysis algorithms had increased the recognition probability and reduced the false alarm rate by using more readily recognizable objects such as terrain, poles, pylons, trees, etc. to generate a parametric description of the terrain surface as well as the class, position, orientation, size and shape of all objects in the scene. The sensor system and the implemented algorithms can be used for other applications such as terrain following, autonomous obstacle avoidance, and automatic target recognition. This paper describes different 3D-imaging ladar sensors with unique system architecture but different components matched for different military application. Emphasis is laid on an obstacle warning system with a high probability of detection of thin wires, the real time processing of the measured range image data, obstacle classification und visualization.

  7. OBERON: OBliquity and Energy balance Run on N-body systems

    NASA Astrophysics Data System (ADS)

    Forgan, Duncan H.

    2016-08-01

    OBERON (OBliquity and Energy balance Run on N-body systems) models the climate of Earthlike planets under the effects of an arbitrary number and arrangement of other bodies, such as stars, planets and moons. The code, written in C++, simultaneously computes N body motions using a 4th order Hermite integrator, simulates climates using a 1D latitudinal energy balance model, and evolves the orbital spin of bodies using the equations of Laskar (1986a,b).

  8. Unbalance Identification and Field Balancing of Dual Rotors System with Slightly Different Rotating Speeds

    NASA Astrophysics Data System (ADS)

    Zeng, S.; Wang, X.-X.

    1999-02-01

    The identification of unbalance is the crux of field balancing of dual rotors system with slightly different rotating speeds. On the basis of correlation theory, this paper explains a method called “Single Point Discrete Fourier Transformation (DFT)” to identify the unbalance. By theoretical analysis, the correlation integral time and its maximum possible error are determined. The field balancing experiment on WLZY-350 horizontal spiral centrifuge verifies its precision, reliability and applicability in practice.

  9. Excimer laser system for atmospheric remote sensing of ozone

    NASA Technical Reports Server (NTRS)

    Tan, K. O.; Ogura, G. T.; Mckee, T. J.; Mcgee, T.

    1987-01-01

    A high-power narrow-linewidth XeCl excimer laser system developed for use by NASA in the remote sensing of atmospheric ozone is described. The laser system is designed for incorporation in a DIAL lidar utilizing stimulated Raman generation for the reference wavelength and sophisticated data averaging techniques. The laser output has a linewidth of 0.002 nm and a beam divergence of 0.15 mrad (FWHM). The laser was operated over a six-hour period with a constant average power of 18 W and a wavelength stable to within + or - 0.0006 nm.

  10. Laser absorption spectroscopy system for vaporization process characterization and control

    NASA Astrophysics Data System (ADS)

    Galkowski, Joseph J.; Hagans, Karla G.

    1994-03-01

    In support of the Lawrence Livermore National Laboratory's (LLNL's) Uranium Atomic Vapor Laser Isotope Separation (U-AVLIS) Program, a laser atomic absorption spectroscopy (LAS) system has been developed. This multilaser system is capable of simultaneously measuring the line densities of 238U ground and metastable states, 235U ground and metastable states, iron, and ions at up to nine locations within the separator vessel. Supporting enrichment experiments that last over one hundred hours, this laser spectroscopy system is employed to diagnose and optimize separator system performance, control the electron beam vaporizer and metal feed systems, and provide physics data for the validation of computer models. As a tool for spectroscopic research, vapor plume characterization, vapor deposition monitoring, and vaporizer development, LLNL's LAS laboratory with its six argon-ion-pumped ring dye lasers and recently added Ti:Sapphire and external-cavity diode- lasers has capabilities far beyond the requirements of its primary mission.

  11. Tunable near ultraviolet laser system from a frequency doubled alexandrite laser

    SciTech Connect

    Barnes, N.P.; Gettemy, D.J.; Johnson, T.M.

    1983-09-01

    A laser system which is capable of producing radiation tunable over the region from approximately 0.36-0.40 ..mu.. is described. The laser produces in excess of 5.0 mJ per pulse in a about 0.1 ..mu..s pulse length.

  12. Lasers.

    ERIC Educational Resources Information Center

    Schewe, Phillip F.

    1981-01-01

    Examines the nature of laser light. Topics include: (1) production and characteristics of laser light; (2) nine types of lasers; (3) five laser techniques including holography; (4) laser spectroscopy; and (5) laser fusion and other applications. (SK)

  13. Management Information System Based on the Balanced Scorecard

    ERIC Educational Resources Information Center

    Kettunen, Juha; Kantola, Ismo

    2005-01-01

    Purpose: This study seeks to describe the planning and implementation in Finland of a campus-wide management information system using a rigorous planning methodology. Design/methodology/approach: The structure of the management information system is planned on the basis of the management process, where strategic management and the balanced…

  14. Balancing Management and Leadership in Complex Health Systems

    PubMed Central

    Kwamie, Aku

    2015-01-01

    Health systems, particularly those in low- and middle-income countries (LMICs), need stronger management and leadership capacities. Management and leadership are not synonymous, yet should be considered together as there can be too much of one and not enough of the other. In complex adaptive health systems, the multiple interactions and relationships between people and elements of the system mean that management and leadership, so often treated as domains of the individual, are additionally systemic phenomena, emerging from these relational interactions. This brief commentary notes some significant implications for how we can support capacity strengthening interventions for complex management and leadership. These would necessarily move away from competency-based models focused on training for individuals, and would rather encompass longer-term initiatives explicitly focused on systemic goals of accountability, innovation, and learning. PMID:26673472

  15. FY 2005 Quantum Cascade Laser Alignment System Final Report

    SciTech Connect

    Myers, Tanya L.; Cannon, Bret D.; Wojcik, Michael D.; Broocks, Bryan T.; Stewart, Timothy L.; Hatchell, Brian K.

    2006-01-11

    The Alignment Lasers Task of Pacific Northwest National Laboratory's (PNNL's) Remote Spectroscopy Project (Project PL211I) is a co-funded project between DOE NA-22 and a Classified Client. This project, which began in the second half of FY03, involved building and delivering a Quantum Cascade (QC) Laser Alignment System to be used for testing the pupil alignment of an infrared sensor by measuring the response from four pairs of diametrically opposed QC lasers. PNNL delivered the system in FY04 and provided technical assistance in FY05 culminating into a successful demonstration of the system. This project evolved from the Laser Development Task of PL211I, which is involved in developing novel laser technology to support development of advanced chemical sensors for detecting the proliferation of nuclear weapons. The laser systems are based on quantum cascade (QC) lasers, a new semiconductor source in the infrared. QC lasers can be tailored to emit light throughout the infrared region (3.5 ? 17 ?m) and have high output power and stability. Thus, these lasers provide an infrared source with superb power and spectral stability enabling them to be used for applications such as alignment and calibration in addition to chemical sensing.

  16. High Average Power, High Energy Short Pulse Fiber Laser System

    SciTech Connect

    Messerly, M J

    2007-11-13

    Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.

  17. High-speed modelocked semiconductor lasers and applications in coherent photonic systems

    NASA Astrophysics Data System (ADS)

    Lee, Wangkuen

    1.55-mum high-speed modelocked semiconductor lasers are theoretically and experimentally studied for various coherent photonic system applications. The modelocked semiconductor lasers (MSLs) are designed with high-speed (>5 GHz) external cavity configurations utilizing monolithic two-section curved semiconductor optical amplifiers. By exploiting the saturable absorber section of the monolithic device, passive or hybrid mode-locking techniques are used to generate short optical pulses with broadband optical frequency combs. Laser frequency stability is improved by applying the Pound-Drever-Hall (PDH) frequency stabilization technique to the MSLs. The improved laser performance after the frequency stabilization (a frequency drifting of less than 350 MHz), is extensively studied with respect to the laser linewidth (˜ 3 MHz), the relative intensity noise (RIN) (< -150 dB/Hz), as well as the modal RIN (˜ 3 dB reduction). MSL to MSL, and tunable laser to MSL synchronization is demonstrated by using a dual-mode injection technique and a modulation sideband injection technique, respectively. Dynamic locking behavior and locking bandwidth are experimentally and theoretically studied. Stable laser synchronization between two MSLs is demonstrated with an injection seed power on the order of a few microwatt. Several coherent heterodyne detections based on the synchronized MSL systems are demonstrated for applications in microwave photonic links and ultra-dense wavelength division multiplexing (UD-WDM) system. In addition, efficient coherent homodyne balanced receivers based on synchronized MSLs are developed and demonstrated for a spectrally phase-encoded optical CDMA (SPE-OCDMA) system.

  18. Imaging System With Confocally Self-Detecting Laser.

    DOEpatents

    Webb, Robert H.; Rogomentich, Fran J.

    1996-10-08

    The invention relates to a confocal laser imaging system and method. The system includes a laser source, a beam splitter, focusing elements, and a photosensitive detector. The laser source projects a laser beam along a first optical path at an object to be imaged, and modulates the intensity of the projected laser beam in response to light reflected from the object. A beam splitter directs a portion of the projected laser beam onto a photodetector. The photodetector monitors the intensity of laser output. The laser source can be an electrically scannable array, with a lens or objective assembly for focusing light generated by the array onto the object of interest. As the array is energized, its laser beams scan over the object, and light reflected at each point is returned by the lens to the element of the array from which it originated. A single photosensitive detector element can generate an intensity-representative signal for all lasers of the array. The intensity-representative signal from the photosensitive detector can be processed to provide an image of the object of interest.

  19. A Medical Excimer Laser System For Corneal Surgery And Laser Angioplasty

    NASA Astrophysics Data System (ADS)

    Caro, R. G.; Muller, D. F.

    1987-03-01

    The authors report the design criteria and performance of the ExciMeda UV200 medical excimer laser system. A beam delivery system for controlled photoablative machining of variable power optical lenses in organic material is described. Some of the potential applications of this delivery system in corneal surgery are presented. The uses of the UV200 laser system in other areas of medical research are discussed and, in particular, its application i the field of laser angioplasty is outlined. There has been considerable interest recently in the use of excimer lasers in a variety of fields in medicine. The ultraviolet, high peak power beam emitted by an excimer laser has been shown to be capable of producing very clean and precise cuts in organic material. In particular, cuts can be made in biological material with minimal disturbance of the material adjacent to the cut. For example, tissue can be cut in such a way as to produce negligible charring or vacuolization in adjacent areas of the tissue. This is in marked contrast to the results when organic material is cut by a continuous wave laser such as an Argon ion laser, or c.w. CO2 laser. The potential applications in clinical settings which are suggested by this feature of the interaction of tissue with excimer laser radiation have been largely unrealized outside the laboratory as yet. A primary reason for this is that, until recently, excimer lasers have been available only in a form that was suitable for the scientific laboratory. These lasers required large amounts of space, were not mobile once installed, and required con nection to external sources of water cooling, vacuum exhaust, a high current electrical supply, and a variety of gas bottles including the gases F2 and C12. These systems were not designed with clinical applications in mind, and thus provided unnecessary performance features at the cost of added complexity. They also posed potential electrical and gaseous safety hazards not suitable for a

  20. Mass balances for a biological life support system simulation model

    NASA Technical Reports Server (NTRS)

    Volk, Tyler; Rummel, John D.

    1987-01-01

    Design decisions to aid the development of future space based biological life support systems (BLSS) can be made with simulation models. The biochemistry stoichiometry was developed for: (1) protein, carbohydrate, fat, fiber, and lignin production in the edible and inedible parts of plants; (2) food consumption and production of organic solids in urine, feces, and wash water by the humans; and (3) operation of the waste processor. Flux values for all components are derived for a steady state system with wheat as the sole food source. The large scale dynamics of a materially closed (BLSS) computer model is described in a companion paper. An extension of this methodology can explore multifood systems and more complex biochemical dynamics while maintaining whole system closure as a focus.

  1. System, Apparatus and Method Employing a Dual Head Laser

    NASA Technical Reports Server (NTRS)

    Coyle, Donald B. (Inventor); Stysley, Paul R. (Inventor); Poulios, Demetrios (Inventor)

    2015-01-01

    A system, apparatus and method employing a laser with a split-head, V-assembly gain material configuration. Additionally, the present invention is directed to techniques to better dissipate or remove unwanted energies in laser operations. The present invention is also directed to techniques for better collimated laser beams, with single spatial mode quality (TEM00), with improved efficiency, in extreme environments, such as in outer space.

  2. Integrated design of electrical distribution systems: Phase balancing and phase prediction case studies

    NASA Astrophysics Data System (ADS)

    Dilek, Murat

    Distribution system analysis and design has experienced a gradual development over the past three decades. The once loosely assembled and largely ad hoc procedures have been progressing toward being well-organized. The increasing power of computers now allows for managing the large volumes of data and other obstacles inherent to distribution system studies. A variety of sophisticated optimization methods, which were impossible to conduct in the past, have been developed and successfully applied to distribution systems. Among the many procedures that deal with making decisions about the state and better operation of a distribution system, two decision support procedures will be addressed in this study: phase balancing and phase prediction. The former recommends re-phasing of single- and double-phase laterals in a radial distribution system in order to improve circuit loss while also maintaining/improving imbalances at various balance point locations. Phase balancing calculations are based on circuit loss information and current magnitudes that are calculated from a power flow solution. The phase balancing algorithm is designed to handle time-varying loads when evaluating phase moves that will result in improved circuit losses over all load points. Applied to radial distribution systems, the phase prediction algorithm attempts to predict the phases of single- and/or double phase laterals that have no phasing information previously recorded by the electric utility. In such an attempt, it uses available customer data and kW/kVar measurements taken at various locations in the system. It is shown that phase balancing is a special case of phase prediction. Building on the phase balancing and phase prediction design studies, this work introduces the concept of integrated design, an approach for coordinating the effects of various design calculations. Integrated design considers using results of multiple design applications rather than employing a single application for a

  3. Nova laser system at ultra high fluence levels

    SciTech Connect

    Hunt, J.T.

    1985-01-01

    The Nova experimental facility consists of a ten arm laser system and five experimental stations and was completed in December 1984. Two of these stations are used for inertial confinement fusion (ICF) experiments and the other three are dedicated to doing large aperture (30 to 74 cm) laser experiments. The laser system is deployed in a master oscillator-power amplifier architecture and uses Nd: phosphate glass for the active medium. The fundamental wavelength of the system is 1.05 microns. Frequency converters constructed from potassium dihydrogen phosphate (KDP) crystals are located at the end of each of the ten arms and are used to produce high power frequency doubled (0.53 microns) and tripled (0.35 microns) beams for either ICF or laser experiments. Thus, the Nova laser system can produce high power beams with wavelengths ranging from the infrared to the ultraviolet.

  4. High performance distributed feedback fiber laser sensor array system

    NASA Astrophysics Data System (ADS)

    He, Jun; Li, Fang; Xu, Tuanwei; Wang, Yan; Liu, Yuliang

    2009-11-01

    Distributed feedback (DFB) fiber lasers have their unique properties useful for sensing applications. This paper presents a high performance distributed feedback (DFB) fiber laser sensor array system. Four key techniques have been adopted to set up the system, including DFB fiber laser design and fabrication, interferometric wavelength shift demodulation, digital phase generated carrier (PGC) technique and dense wavelength division multiplexing (DWDM). Experimental results confirm that a high dynamic strain resolution of 305 fɛ/√Hz (@ 1 kHz) has been achieved by the proposed sensor array system. And the multiplexing of eight channel DFB fiber laser sensor array has been demonstrated. The proposed DFB fiber laser sensor array system is suitable for ultra-weak signal detection, and has potential applications in the field of petroleum seismic explorations, earthquake prediction, and security.

  5. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    PubMed Central

    Torbeck, Richard; Bankowski, Richard; Henize, Sarah; Saedi, Nazanin

    2016-01-01

    Background and objectives The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure® laser system (755/532 nm). Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure® laser system for tattoo removal. Study design and methods A PubMed search was conducted using the term “picosecond” combined with “laser”, “dermatology”, and “laser tattoo removal”. Results A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow). Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change. Conclusion Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure® laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments. PMID:27194919

  6. Evaluation of surface energy and radiation balance systems on the Konza Prairie

    NASA Technical Reports Server (NTRS)

    Fritschen, Leo J.

    1987-01-01

    Four Surface Energy and Radiation Balance Systems (SERBS) were installed and operated for two weeks in Kansas during July of 1986. Surface energy and radiation balances were investigated on six sites on the Konza Prairie about 3 km south of Manhattan, Kansas. Measurements were made to allow the computation of these radiation components: total solar and diffuse radiation, reflected solar radiation, net radiation, and longwave radiation upward and downward. Measurements were made to allow the computation of the sensible and latent heat fluxes by the Bowen ratio method using differential psychrometers on automatic exchange mechanisms. The report includes a description of the experimental sites, data acquisition systems and sensors, data acquisitions system operating instructions, and software used for data acquisition and analysis. In addition, data listings and plots of the energy balance components for all days and systems are given.

  7. Laser metrology in food-related systems

    NASA Astrophysics Data System (ADS)

    Mendoza-Sanchez, Patricia; Lopez, Daniel; Kongraksawech, Teepakorn; Vazquez, Pedro; Torres, J. Antonio; Ramirez, Jose A.; Huerta-Ruelas, Jorge

    2005-02-01

    An optical system was developed using a low-cost semiconductor laser and commercial optical and electronic components, to monitor food processes by measuring changes in optical rotation (OR) of chiral compounds. The OR signal as a function of processing time and sample temperature were collected and recorded using a computer data acquisition system. System has been tested during two different processes: sugar-protein interaction and, beer fermentation process. To study sugar-protein interaction, the following sugars were used: sorbitol, trehalose and sucrose, and in the place of Protein, Serum Albumin Bovine (BSA, A-7906 Sigma-Aldrich). In some food processes, different sugars are added to protect damage of proteins during their processing, storage and/or distribution. Different sugar/protein solutions were prepared and heated above critical temperature of protein denaturation. OR measurements were performed during heating process and effect of different sugars in protein denaturation was measured. Higher sensitivity of these measurements was found compared with Differential Scanning Calorimetry, which needs higher protein concentration to study these interactions. The brewing fermentation process was monitored in-situ using this OR system and validated by correlation with specific density measurements and gas chromatography. This instrument can be implemented to monitor fermentation on-line, thereby determining end of process and optimizing process conditions in an industrial setting. The high sensitivity of developed OR system has no mobile parts and is more flexible than commercial polarimeters providing the capability of implementation in harsh environments, signifying the potential of this method as an in-line technique for quality control in food processing and for experimentation with optically active solutions.

  8. Stimulated Brillouin scattering mirror system, high power laser and laser peening method and system using same

    DOEpatents

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2007-04-24

    A laser system, such as a master oscillator/power amplifier system, comprises a gain medium and a stimulated Brillouin scattering SBS mirror system. The SBS mirror system includes an in situ filtered SBS medium that comprises a compound having a small negative non-linear index of refraction, such as a perfluoro compound. An SBS relay telescope having a telescope focal point includes a baffle at the telescope focal point which blocks off angle beams. A beam splitter is placed between the SBS mirror system and the SBS relay telescope, directing a fraction of the beam to an alternate beam path for an alignment fiducial. The SBS mirror system has a collimated SBS cell and a focused SBS cell. An adjustable attenuator is placed between the collimated SBS cell and the focused SBS cell, by which pulse width of the reflected beam can be adjusted.

  9. The 3D laser radar vision processor system

    NASA Technical Reports Server (NTRS)

    Sebok, T. M.

    1990-01-01

    Loral Defense Systems (LDS) developed a 3D Laser Radar Vision Processor system capable of detecting, classifying, and identifying small mobile targets as well as larger fixed targets using three dimensional laser radar imagery for use with a robotic type system. This processor system is designed to interface with the NASA Johnson Space Center in-house Extra Vehicular Activity (EVA) Retriever robot program and provide to it needed information so it can fetch and grasp targets in a space-type scenario.

  10. High average power solid state laser power conditioning system

    SciTech Connect

    Steinkraus, R.F.

    1987-03-03

    The power conditioning system for the High Average Power Laser program at Lawrence Livermore National Laboratory (LLNL) is described. The system has been operational for two years. It is high voltage, high power, fault protected, and solid state. The power conditioning system drives flashlamps that pump solid state lasers. Flashlamps are driven by silicon control rectifier (SCR) switched, resonant charged, (LC) discharge pulse forming networks (PFNs). The system uses fiber optics for control and diagnostics. Energy and thermal diagnostics are monitored by computers.

  11. Quantitative performance targets by using balanced scorecard system: application to waste management and public administration.

    PubMed

    Mendes, Paula; Nunes, Luis Miguel; Teixeira, Margarida Ribau

    2014-09-01

    This article demonstrates how decision-makers can be guided in the process of defining performance target values in the balanced scorecard system. We apply a method based on sensitivity analysis with Monte Carlo simulation to the municipal solid waste management system in Loulé Municipality (Portugal). The method includes two steps: sensitivity analysis of performance indicators to identify those performance indicators with the highest impact on the balanced scorecard model outcomes; and sensitivity analysis of the target values for the previously identified performance indicators. Sensitivity analysis shows that four strategic objectives (IPP1: Comply with the national waste strategy; IPP4: Reduce nonrenewable resources and greenhouse gases; IPP5: Optimize the life-cycle of waste; and FP1: Meet and optimize the budget) alone contribute 99.7% of the variability in overall balanced scorecard value. Thus, these strategic objectives had a much stronger impact on the estimated balanced scorecard outcome than did others, with the IPP1 and the IPP4 accounting for over 55% and 22% of the variance in overall balanced scorecard value, respectively. The remaining performance indicators contribute only marginally. In addition, a change in the value of a single indicator's target value made the overall balanced scorecard value change by as much as 18%. This may lead to involuntarily biased decisions by organizations regarding performance target-setting, if not prevented with the help of methods such as that proposed and applied in this study.

  12. Quantitative performance targets by using balanced scorecard system: application to waste management and public administration.

    PubMed

    Mendes, Paula; Nunes, Luis Miguel; Teixeira, Margarida Ribau

    2014-09-01

    This article demonstrates how decision-makers can be guided in the process of defining performance target values in the balanced scorecard system. We apply a method based on sensitivity analysis with Monte Carlo simulation to the municipal solid waste management system in Loulé Municipality (Portugal). The method includes two steps: sensitivity analysis of performance indicators to identify those performance indicators with the highest impact on the balanced scorecard model outcomes; and sensitivity analysis of the target values for the previously identified performance indicators. Sensitivity analysis shows that four strategic objectives (IPP1: Comply with the national waste strategy; IPP4: Reduce nonrenewable resources and greenhouse gases; IPP5: Optimize the life-cycle of waste; and FP1: Meet and optimize the budget) alone contribute 99.7% of the variability in overall balanced scorecard value. Thus, these strategic objectives had a much stronger impact on the estimated balanced scorecard outcome than did others, with the IPP1 and the IPP4 accounting for over 55% and 22% of the variance in overall balanced scorecard value, respectively. The remaining performance indicators contribute only marginally. In addition, a change in the value of a single indicator's target value made the overall balanced scorecard value change by as much as 18%. This may lead to involuntarily biased decisions by organizations regarding performance target-setting, if not prevented with the help of methods such as that proposed and applied in this study. PMID:25023987

  13. Magnetic suspension and balance system (MSBS) advanced study.I - System design

    NASA Technical Reports Server (NTRS)

    Boom, Roger W.; Abdelsalam, Mostafa K.; Eyssa, Yehia M.; Mcintosh, Glen E.

    1987-01-01

    A magnetic suspension and balance system is designed to support models of aircraft or other objects in wind tunnels by means of magnetic forces. Major design improvements have been achieved, resulting in reductions of the system size, weight, and cost. These improvements are due to: (1) the use of holmium in the model core to increase its magnetic moment, (2) the use of a powerful new permanent magnet material in the model wings, (3) a new arrangement for the roll coils, and (4) the use of a nonmetallic structure to eliminate eddy current losses. The conceptual design of the holmium core superconductive solenoid and of the new permanent magnet wing assembly is described in detail. The discussion includes comparisons of the pole strengths for different model core magnets, the design of a superconducting solenoid and cryostat, and the analysis of model wing magnetic requirements.

  14. Mass balances for a biological life support system simulation model

    NASA Technical Reports Server (NTRS)

    Volk, Tyler; Rumel, John D.

    1987-01-01

    Design decisions to aid the development of future space-based biological life support systems (BLSS) can be made with simulation models. Here the biochemical stoichiometry is developed for: (1) protein, carbohydrate, fat, fiber, and lignin production in the edible and inedible parts of plants; (2) food consumption and production of organic solids in urine, feces, and wash water by the humans; and (3) operation of the waste processor. Flux values for all components are derived for a steady-state system with wheat as the sole food source.

  15. Operation of the APS photoinjector drive laser system.

    SciTech Connect

    Li, Y.; Accelerator Systems Division

    2008-08-04

    The APS photoinjector drive laser system has been in operation since 1999 and is achieving a performance level exceeding the requirement of stable operation of the LEUTL FEL system. One remarkable number is the UV energy stability of better than 2% rms, sometimes less than 1% rms. This report summarizes the operation experience of the laser system and the improvements made along the way. We also outline the route of upgrade of the system and some frontier laser research and development opportunities in ultrabright electron beam generation.

  16. Test techniques for determining laser ranging system performance

    NASA Technical Reports Server (NTRS)

    Zagwodzki, T. W.

    1981-01-01

    Procedures and results of an on going test program intended to evaluate laser ranging system performance levels in the field as well as in the laboratory are summarized. Tests show that laser ranging system design requires consideration of time biases and RMS jitters of individual system components. All simple Q switched lasers tested were found to be inadequate for 10 centimeter ranging systems. Timing discriminators operating over a typical 100:1 dynamic signal range may introduce as much as 7 to 9 centimeters of range bias. Time interval units commercially available today are capable of half centimeter performance and are adequate for all field systems currently deployed. Photomultipliers tested show typical tube time biases of one centimeter with single photoelectron transit time jitter of approximately 10 centimeters. Test results demonstrate that NASA's Mobile Laser Ranging System (MOBLAS) receiver configuration is limiting system performance below the 100 photoelectron level.

  17. Modelling the geometry of a moving laser melt pool and deposition track via energy and mass balances

    NASA Astrophysics Data System (ADS)

    Pinkerton, Andrew J.; Li, Lin

    2004-07-01

    The additive manufacturing technique of laser direct metal deposition allows multiple tracks of full density metallic material to be built to form complex parts for rapid tooling and manufacture. Practical results and theoretical models have shown that the geometries of the tracks are governed by multiple factors. Original work with single layer cladding identified three basic clad profiles but, so far, models of multiple layer, powder-feed deposition have been based on only two of them. At higher powder mass flow rates, experimental results have shown that a layer's width can become greater than the melt pool width at the substrate surface, but previous analytical models have not been able to accommodate this. In this paper, a model based on this third profile is established and experimentally verified. The model concentrates on mathematical analysis of the melt pool and establishes mass and energy balances based on one-dimensional heat conduction to the substrate. Deposition track limits are considered as arcs of circles rather than of ellipses, as used in most established models, reflecting the dominance of surface tension forces in the melt pool, and expressions for elongation of the melt pool with increasing traverse speed are incorporated. Trends in layer width and height with major process parameters are captured and predicted layer dimensions correspond well to the experimental values.

  18. Precision CW laser automatic tracking system investigated

    NASA Technical Reports Server (NTRS)

    Lang, K. T.; Lucy, R. F.; Mcgann, E. J.; Peters, C. J.

    1966-01-01

    Precision laser tracker capable of tracking a low acceleration target to an accuracy of about 20 microradians rms is being constructed and tested. This laser tracking has the advantage of discriminating against other optical sources and the capability of simultaneously measuring range.

  19. Laser cross-flow gas system

    DOEpatents

    Duncan, David B.

    1992-01-01

    A method and laser apparatus are disclosed which provide for a cross-flow of gas near one end of a laser discharge tube. The cross-flow of gas causes a concentration gradient which affects diffusion of contaminants in the discharge tube towards the cross-flow of the gas, which contaminants are then withdrawn from the discharge tube.

  20. Effectiveness of a Wii balance board-based system (eBaViR) for balance rehabilitation: a pilot randomized clinical trial in patients with acquired brain injury

    PubMed Central

    2011-01-01

    Background Acquired brain injury (ABI) is the main cause of death and disability among young adults. In most cases, survivors can experience balance instability, resulting in functional impairments that are associated with diminished health-related quality of life. Traditional rehabilitation therapy may be tedious. This can reduce motivation and adherence to the treatment and thus provide a limited benefit to patients with balance disorders. We present eBaViR (easy Balance Virtual Rehabilitation), a system based on the Nintendo® Wii Balance Board® (WBB), which has been designed by clinical therapists to improve standing balance in patients with ABI through motivational and adaptative exercises. We hypothesize that eBaViR, is feasible, safe and potentially effective in enhancing standing balance. Methods In this contribution, we present a randomized and controlled single blinded study to assess the influence of a WBB-based virtual rehabilitation system on balance rehabilitation with ABI hemiparetic patients. This study describes the eBaViR system and evaluates its effectiveness considering 20 one-hour-sessions of virtual reality rehabilitation (n = 9) versus standard rehabilitation (n = 8). Effectiveness was evaluated by means of traditional static and dynamic balance scales. Results The final sample consisted of 11 men and 6 women. Mean ± SD age was 47.3 ± 17.8 and mean ± SD chronicity was 570.9 ± 313.2 days. Patients using eBaViR had a significant improvement in static balance (p = 0.011 in Berg Balance Scale and p = 0.011 in Anterior Reaches Test) compared to patients who underwent traditional therapy. Regarding dynamic balance, the results showed significant improvement over time in all these measures, but no significant group effect or group-by-time interaction was detected for any of them, which suggests that both groups improved in the same way. There were no serious adverse events during treatment in either group. Conclusions The results suggest that e

  1. Updated laser safety & hazard analysis for the ARES laser system based on the 2007 ANSI Z136.1 standard.

    SciTech Connect

    Augustoni, Arnold L.

    2007-08-01

    A laser safety and hazard analysis was performed for the temperature stabilized Big Sky Laser Technology (BSLT) laser central to the ARES system based on the 2007 version of the American National Standards Institutes (ANSI) Standard Z136.1, for Safe Use of Lasers and the 2005 version of the ANSI Standard Z136.6, for Safe Use of Lasers Outdoors. The ARES laser system is a Van/Truck based mobile platform, which is used to perform laser interaction experiments and tests at various national test sites.

  2. Construction of a femtosecond laser microsurgery system

    PubMed Central

    Steinmeyer, Joseph D; Gilleland, Cody L; Pardo-Martin, Carlos; Angel, Matthew; Rohde, Christopher B; Scott, Mark A; Yanik, Mehmet Fatih

    2014-01-01

    Femtosecond laser microsurgery is a powerful method for studying cellular function, neural circuits, neuronal injury and neuronal regeneration because of its capability to selectively ablate sub-micron targets in vitro and in vivo with minimal damage to the surrounding tissue. Here, we present a step-by-step protocol for constructing a femtosecond laser microsurgery setup for use with a widely available compound fluorescence microscope. The protocol begins with the assembly and alignment of beam-conditioning optics at the output of a femtosecond laser. Then a dichroic mount is assembled and installed to direct the laser beam into the objective lens of a standard inverted microscope. Finally, the laser is focused on the image plane of the microscope to allow simultaneous surgery and fluorescence imaging. We illustrate the use of this setup by presenting axotomy in Caenorhabditis elegans as an example. This protocol can be completed in 2 d. PMID:20203659

  3. Systems Error versus Physicians' Error: Finding the Balance in Medical Education.

    ERIC Educational Resources Information Center

    Casarett, David; Helms, Charles

    1999-01-01

    When physicians ascribe errors to systemic causes, they may be less likely to modify future behaviors and more likely to repeat past errors. Academic medical centers should balance protecting patients from errors that a systems approach can identify against providing optimal education for house officers by teaching them to focus also on personal…

  4. Not as Easy as It Sounds: Designing a Balanced Assessment System

    ERIC Educational Resources Information Center

    Chattergoon, Rajendra; Marion, Scott

    2016-01-01

    Many states and school districts are rethinking how they do educational assessment. A few are going further: attempting to build "balanced," "comprehensive," or "next-generation" assessment systems. At the same time, practitioners and researchers have long mulled the purposes and parts such systems should have. But…

  5. Compensation system for FM-to-AM effects in high-power laser system

    NASA Astrophysics Data System (ADS)

    Chen, Zuiyu; Jiang, Youen; Wang, Jiangfeng; Fan, Wei; Li, Xuechun

    2015-10-01

    In the high-power laser facility, frequency modulation to amplitude modulation (FM-to-AM) effects has seriously affected the power balance between beams and restricted the laser flux levels of safe operation in the system. For FM-to- AM effects produced by gain-narrowing effects, according to the amplifier gain-narrowing function model, after simulating and analyzing the properties of FM-to-AM effects, a corresponding compensation function is designed. Using sinusoidal compensation function, with the use of a birefringent crystal and liquid crystal modulator, adjusting the crystal angle in the range of 45 °, the center wavelength could be reduced in the magnitude of the range from 0 to 30dBm. By changing the voltage of the liquid crystal, the center wavelength could be adjusted within 1051.5-1054.5nm freely. For the regenerative amplifier with the gain of 70dB and input center wavelength of 1053nm and bandwidth of 0.7nm, the output FM-to-AM magnitude could be controlled within ~11% by this compensation system.

  6. Optical laser systems at the Linac Coherent Light Source

    DOE PAGESBeta

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; Edstrom, Steve; Gilevich, Sasha; Glownia, James M.; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C.; Miahnahri, Alan; et al

    2015-04-22

    Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS.

  7. Laser photovoltaic power system synergy for SEI applications

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Hickman, J. M.

    1991-01-01

    Solar arrays can provide reliable space power, but do not operate when there is no solar energy. Photovoltaic arrays can also convert laser energy with high efficiency. One proposal to reduce the required mass of energy storage required is to illuminate the photovoltaic arrays by a ground laser system. It is proposed to locate large lasers on cloud-free sites at one or more ground locations, and use large lenses or mirrors with adaptive optical correction to reduce the beam spread due to diffraction or atmospheric turbulence. During the eclipse periods or lunar night, the lasers illuminate the solar arrays to a level sufficient to provide operating power.

  8. Optical laser systems at the Linac Coherent Light Source

    PubMed Central

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; Edstrom, Steve; Gilevich, Sasha; Glownia, James M.; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C.; Miahnahri, Alan; Milathianaki, Despina; Polzin, Wayne; Ratner, Daniel; Tavella, Franz; Vetter, Sharon; Welch, Marc; White, William E.; Fry, Alan R.

    2015-01-01

    Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS. PMID:25931064

  9. Method for Ground-to-Space Laser Calibration System

    NASA Technical Reports Server (NTRS)

    Lukashin, Constantine (Inventor); Wielicki, Bruce A. (Inventor)

    2014-01-01

    The present invention comprises an approach for calibrating the sensitivity to polarization, optics degradation, spectral and stray light response functions of instruments on orbit. The concept is based on using an accurate ground-based laser system, Ground-to-Space Laser Calibration (GSLC), transmitting laser light to instrument on orbit during nighttime substantially clear-sky conditions. To minimize atmospheric contribution to the calibration uncertainty the calibration cycles should be performed in short time intervals, and all required measurements are designed to be relative. The calibration cycles involve ground operations with laser beam polarization and wavelength changes.

  10. Method for Ground-to-Satellite Laser Calibration System

    NASA Technical Reports Server (NTRS)

    Lukashin, Constantine (Inventor); Wielicki, Bruce A. (Inventor)

    2015-01-01

    The present invention comprises an approach for calibrating the sensitivity to polarization, optics degradation, spectral and stray light response functions of instruments on orbit. The concept is based on using an accurate ground-based laser system, Ground-to-Space Laser Calibration (GSLC), transmitting laser light to instrument on orbit during nighttime substantially clear-sky conditions. To minimize atmospheric contribution to the calibration uncertainty the calibration cycles should be performed in short time intervals, and all required measurements are designed to be relative. The calibration cycles involve ground operations with laser beam polarization and wavelength changes.

  11. Optical laser systems at the Linac Coherent Light Source.

    PubMed

    Minitti, Michael P; Robinson, Joseph S; Coffee, Ryan N; Edstrom, Steve; Gilevich, Sasha; Glownia, James M; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C; Miahnahri, Alan; Milathianaki, Despina; Polzin, Wayne; Ratner, Daniel; Tavella, Franz; Vetter, Sharon; Welch, Marc; White, William E; Fry, Alan R

    2015-05-01

    Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump-probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump-probe experiments to be performed at LCLS.

  12. Solid-state-based laser system as a replacement for Ar+ lasers.

    PubMed

    Beck, Tobias; Rein, Benjamin; Sörensen, Fabian; Walther, Thomas

    2016-09-15

    We report on a solid-state-based laser system at 1028 nm. The light is generated by a diode laser seeded ytterbium fiber amplifier. In two build-up cavities, its frequency is doubled and quadrupled to 514 nm and 257 nm, respectively. At 514 nm, the system delivers up to 4.7 W of optical power. In the fourth harmonic, up to 173 mW are available limited by the nonlinear crystal. The frequency of the laser is mode-hop-free tunable by 16 GHz in 10 ms in the UV. Therefore, the system is suitable as a low maintenance, efficient, and tunable narrowband replacement for frequency doubled Ar+ laser systems.

  13. Solid-state-based laser system as a replacement for Ar+ lasers.

    PubMed

    Beck, Tobias; Rein, Benjamin; Sörensen, Fabian; Walther, Thomas

    2016-09-15

    We report on a solid-state-based laser system at 1028 nm. The light is generated by a diode laser seeded ytterbium fiber amplifier. In two build-up cavities, its frequency is doubled and quadrupled to 514 nm and 257 nm, respectively. At 514 nm, the system delivers up to 4.7 W of optical power. In the fourth harmonic, up to 173 mW are available limited by the nonlinear crystal. The frequency of the laser is mode-hop-free tunable by 16 GHz in 10 ms in the UV. Therefore, the system is suitable as a low maintenance, efficient, and tunable narrowband replacement for frequency doubled Ar+ laser systems. PMID:27628353

  14. Laser cutting of irregular shape object based on stereo vision laser galvanometric scanning system

    NASA Astrophysics Data System (ADS)

    Qi, Li; Zhang, Yixin; Wang, Shun; Tang, Zhiqiang; Yang, Huan; Zhang, Xuping

    2015-05-01

    Irregular shape objects with different 3-dimensional (3D) appearances are difficult to be shaped into customized uniform pattern by current laser machining approaches. A laser galvanometric scanning system (LGS) could be a potential candidate since it can easily achieve path-adjustable laser shaping. However, without knowing the actual 3D topography of the object, the processing result may still suffer from 3D shape distortion. It is desirable to have a versatile auxiliary tool that is capable of generating 3D-adjusted laser processing path by measuring the 3D geometry of those irregular shape objects. This paper proposed the stereo vision laser galvanometric scanning system (SLGS), which takes the advantages of both the stereo vision solution and conventional LGS system. The 3D geometry of the object obtained by the stereo cameras is used to guide the scanning galvanometers for 3D-shape-adjusted laser processing. In order to achieve precise visual-servoed laser fabrication, these two independent components are integrated through a system calibration method using plastic thin film target. The flexibility of SLGS has been experimentally demonstrated by cutting duck feathers for badminton shuttle manufacture.

  15. Optical System Design and Integration of the Mercury Laser Altimeter

    NASA Technical Reports Server (NTRS)

    Ramos-Izquierdo, Luis; Scott, V. Stanley, III; Schmidt, Stephen; Britt, Jamie; Mamakos, William; Trunzo, Raymond; Cavanaugh, John; Miller, Roger

    2005-01-01

    The Mercury Laser Altimeter (MLA). developed for the 2004 MESSENGER mission to Mercury, is designed to measure the planet's topography via laser ranging. A description of the MLA optical system and its measured optical performance during instrument-level and spacecraft-level integration and testing are presented.

  16. Tools for Predicting Optical Damage on Inertial Confinement Fusion-Class Laser Systems

    SciTech Connect

    Nostrand, M C; Carr, C W; Liao, Z M; Honig, J; Spaeth, M L; Manes, K R; Johnson, M A; Adams, J J; Cross, D A; Negres, R A; Widmayer, C C; Williams, W H; Matthews, M J; Jancaitis, K S; Kegelmeyer, L M

    2010-12-20

    Operating a fusion-class laser to its full potential requires a balance of operating constraints. On the one hand, the total laser energy delivered must be high enough to give an acceptable probability for ignition success. On the other hand, the laser-induced optical damage levels must be low enough to be acceptably handled with the available infrastructure and budget for optics recycle. Our research goal was to develop the models, database structures, and algorithmic tools (which we collectively refer to as ''Loop Tools'') needed to successfully maintain this balance. Predictive models are needed to plan for and manage the impact of shot campaigns from proposal, to shot, and beyond, covering a time span of years. The cost of a proposed shot campaign must be determined from these models, and governance boards must decide, based on predictions, whether to incorporate a given campaign into the facility shot plan based upon available resources. Predictive models are often built on damage ''rules'' derived from small beam damage tests on small optics. These off-line studies vary the energy, pulse-shape and wavelength in order to understand how these variables influence the initiation of damage sites and how initiated damage sites can grow upon further exposure to UV light. It is essential to test these damage ''rules'' on full-scale optics exposed to the complex conditions of an integrated ICF-class laser system. Furthermore, monitoring damage of optics on an ICF-class laser system can help refine damage rules and aid in the development of new rules. Finally, we need to develop the algorithms and data base management tools for implementing these rules in the Loop Tools. The following highlights progress in the development of the loop tools and their implementation.

  17. Steam System Balancing and Tuning for Multifamily Residential Buildings in Chicagoland

    SciTech Connect

    Choi, Jayne; Ludwig, Peter; Brand, Larry

    2012-08-01

    Older heating systems often suffer from mis-investment--multiple contractors upgrading parts of systems in inadequate or inappropriate ways that reduce system functionality and efficiency--or from a lack of proper maintenance. This technical report addresses these barriers to information, contractor resources, and cost-savings. Building off of previous research, CNT Energy conducted a study to identify best practices for the methodology, typical costs, and energy savings associated with steam system balancing.

  18. The laser calibration system of the HARP TOF

    NASA Astrophysics Data System (ADS)

    Andreoni, A.; Bondani, M.; Bonesini, M.; Ferri, F.; Gibin, D.; Govoni, P.; Guglielmi, A.; Menegolli, A.; Paganoni, M.; Paleari, F.; Parravicini, A.; Sottocornola-Spinelli, A.; Tonazzo, A.

    2003-09-01

    The calibration and monitoring system constructed for the HARP experiment scintillator-based time of flight system is described. It is based on a Nd-Yag laser with passive Q-switch and active/passive mode-locking, with a custom made laser light injection system based on a bundle of IR monomode optical fibers. A novel ultrafast InGaAs MSM photodiode, with 30 ps risetime, has been used for the laser pulse timing . The first results from the 2001-2002 data taking are presented, showing that drifts in timing down to about 70 ps can be traced.

  19. Technology Solutions Case Study: Balancing Hydronic Systems in Multifamily Buildings, Chicago, Illinois

    SciTech Connect

    2014-09-01

    In multifamily building hydronic systems, temperature imbalance may be caused by undersized piping, improperly adjusted balancing valves, inefficient water temperature and flow levels, and owner/occupant interaction with the boilers, distribution and controls. The effects of imbalance include tenant discomfort, higher energy use intensity and inefficient building operation. In this case study , Partnership for Advanced Residential Retrofit and Elevate Energy. explores cost-effective distribution upgrades and balancing measures in multifamily hydronic systems, providing a resource to contractors, auditors, and building owners on best practices to improve tenant comfort and lower operating costs.

  20. Heat balance design and system modifications for an FSO vessel conversion

    SciTech Connect

    Chen, B.C.M.

    1997-07-01

    Heat balance design and modifications to related systems are studied for an FSO vessel of 400 KDWT. The vessel as envisioned is a converted ultra-large crude carrier (ULCC) built in the 1970`s. The vessel and affiliated installations form a crude oil exporting facility. A vessel operation scenario with assumed data is introduced. Based on the scenario, the preliminary heat balance design for the vessel`s steam power plant is presented. The design dictates several modifications to pertinent systems of the original ULCC.

  1. Space-qualified laser system for the BepiColombo Laser Altimeter.

    PubMed

    Kallenbach, Reinald; Murphy, Eamonn; Gramkow, Bodo; Rech, Markus; Weidlich, Kai; Leikert, Thomas; Henkelmann, Reiner; Trefzger, Boris; Metz, Bodo; Michaelis, Harald; Lingenauber, Kay; DelTogno, Simone; Behnke, Thomas; Thomas, Nicolas; Piazza, Daniele; Seiferlin, Karsten

    2013-12-20

    The space-qualified design of a miniaturized laser for pulsed operation at a wavelength of 1064 nm and at repetition rates up to 10 Hz is presented. This laser consists of a pair of diode-laser pumped, actively q-switched Nd:YAG rod oscillators hermetically sealed and encapsulated in an environment of dry synthetic air. The system delivers at least 300 million laser pulses with 50 mJ energy and 5 ns pulse width (FWHM). It will be launched in 2017 aboard European Space Agency's Mercury Planetary Orbiter as part of the BepiColombo Laser Altimeter, which, after a 6-years cruise, will start recording topographic data from orbital altitudes between 400 and 1500 km above Mercury's surface. PMID:24513938

  2. Selective Laser Sintering of Filled Polymer Systems: Bulk Properties and Laser Beam Material Interaction

    NASA Astrophysics Data System (ADS)

    Wudy, Katrin; Lanzl, Lydia; Drummer, Dietmar

    Additive manufacturing techniques, such as selective laser melting of plastics, generate components directly from a CAD data set without using a specific mold. The range of materials commercially available for selective laser sintering merely includes some semi crystalline polymers mainly polyamides, which leads to an absence of realizable component properties. The presented investigations are concerned with the manufacturing and analysis of components made from filled polymer systems by means of selective laser sintering. The test specimens were generated at varied filler concentration, filler types and manufacturing parameter like laser power or scan speed. In addition to the characterization of the mixed powders, resulting melt depth were analyzed in order to investigate the beam material interaction. The basic understanding of the influence of different fillers, filler concentration and manufacturing parameters on resulting component properties will lead to new realizable component properties and thus fields of application of selective laser sintering.

  3. Detection performance of laser range-gated imaging system

    NASA Astrophysics Data System (ADS)

    Xu, Jun; Li, Xiaofeng; Luo, Jijun; Zhang, Shengxiu; Xu, Yibin

    2010-10-01

    Laser radar is rapidly developing towards very capable sensors for number of applications such as military sensing and guidance, auto collision avoidance, robotic vision and atmospheric sensing. In this paper, the detection performance of non-scanned Laser Rang-gated (LRG) imaging system is studied. In order to compute the detection range of laser active imaging system, the range equation is derived by using laser illuminating model and considering factors which affect system imaging quality. According to the principle of laser radar and the characters of objects and the detectors in special applied setting, it mainly deduced the non-scanned laser radar range equation of the range-gated system, meanwhile, the SNR model of non-scanned LRG imaging system is set up. Then, relationship of the detection probability, the false alarm probability and the signal-to-noise ratio in the non-scanned LRG imaging system are analyzed, the influence factors of system's performance are pointed out, and the solution is proposed. The detection performance simulation software of non-scanned LRG imaging system is designed with MATLAB and the performance of the imaging system is simulated.

  4. Craniomandibular System and Postural Balance after 3-Day Dry Immersion

    PubMed Central

    Treffel, Loïc; Dmitrieva, Liubov; Gauquelin-Koch, Guillemette; Custaud, Marc-Antoine; Blanc, Stéphane; Gharib, Claude; Millet, Catherine

    2016-01-01

    The objective of the study was to determine the influence of simulated microgravity by exposure to dry immersion on the craniomandibular system. Twelve healthy male volunteers participated in a 3-day dry immersion study. Before and immediately after exposure we measured maximal bite force using piezoresistive sensors. The mechanical properties of the jaw and cervical muscles were evaluated before, during, and after dry immersion using MyotonPRO. Because recent studies reported the effects of jaw motor activity on the postural stability of humans, stabilometric measurements of center of pressure were performed before and after dry immersion in two mandibular positions: rest position without jaw clenching, and intercuspidal position during voluntary teeth clenching. Results revealed no significant changes of maximal bite force after dry immersion. All postural parameters were significantly altered by dry immersion. There were however no significant differences in stabilometric data according to mandibular position. Moreover the masseter tonicity increased immediately after the end of dry immersion period. Dry immersion could be used as a valid model for studying the effects of microgravity on human subjects. However, 3 days appear insufficient in duration to evaluate the effects of weightlessness on maximal bite force. Our research suggests a link between postural disturbance after dry immersion and masseter tonicity. PMID:26913867

  5. Craniomandibular System and Postural Balance after 3-Day Dry Immersion.

    PubMed

    Treffel, Loïc; Dmitrieva, Liubov; Gauquelin-Koch, Guillemette; Custaud, Marc-Antoine; Blanc, Stéphane; Gharib, Claude; Millet, Catherine

    2016-01-01

    The objective of the study was to determine the influence of simulated microgravity by exposure to dry immersion on the craniomandibular system. Twelve healthy male volunteers participated in a 3-day dry immersion study. Before and immediately after exposure we measured maximal bite force using piezoresistive sensors. The mechanical properties of the jaw and cervical muscles were evaluated before, during, and after dry immersion using MyotonPRO. Because recent studies reported the effects of jaw motor activity on the postural stability of humans, stabilometric measurements of center of pressure were performed before and after dry immersion in two mandibular positions: rest position without jaw clenching, and intercuspidal position during voluntary teeth clenching. Results revealed no significant changes of maximal bite force after dry immersion. All postural parameters were significantly altered by dry immersion. There were however no significant differences in stabilometric data according to mandibular position. Moreover the masseter tonicity increased immediately after the end of dry immersion period. Dry immersion could be used as a valid model for studying the effects of microgravity on human subjects. However, 3 days appear insufficient in duration to evaluate the effects of weightlessness on maximal bite force. Our research suggests a link between postural disturbance after dry immersion and masseter tonicity. PMID:26913867

  6. Evaluation and testing of semiconductor laser reliability in optic system

    NASA Astrophysics Data System (ADS)

    Tang, Wenyan; Fan, Xianguang; Sun, Heyi

    2007-01-01

    In order to improve the performance of an optic system, a new evaluation and testing methodology for the light source which uses semiconductor laser is presented. A new system, combining high accuracy source and measure capabilities for pulsed testing, is developed to achieve the aim of automatic measurement of Light-Current-Power (LIV) for semiconductor laser. The test can provide customer with L-I, V-I curves and other correlative parameters, such as the threshold current and slope efficiency, and so on. Meanwhile, the change of environment temperature versus lasing wavelength under pulse injection is discussed, and the relationship between the lasing wavelength and the width and cycle of injection pulse is obtained. The temperature character of packaged laser unit is measured conveniently. Making use of the above examined curves and parameters, the reliability of semiconductor laser and quality of device can be compared directly and evaluated accurately. The technique is successfully applied for the evaluation of semiconductor laser reliability.

  7. Self-balancing system of the disk on an elastic shaft

    NASA Astrophysics Data System (ADS)

    Majewski, Tadeusz; Szwedowicz, Dariusz; Melo, Marco A. Meraz

    2015-12-01

    This paper presents an analysis of the automatic balancing of a rigid disk mounted on an elastic shaft. The balancing system consists of two drums at a variable distance from the disk and free balls (or rollers) inside the disk. The balls are able to change positions with respect to the rotor and compensate for rotor unbalance. This paper presents the equations of motion for the disk as well as for the balls during balancing. It is shown that the balls can compensate a part or all of the rotor unbalance depending on the positioning of the drums. There are vibratory forces that push the balls to new positions; these are responsible for the behavior of the balls and the final results. The vibratory forces are defined as a function of the system's parameters and they determine the position of equilibrium of the balls. The stability and efficiency of the method is analyzed in this paper.

  8. Impact of Balance Of System (BOS) costs on photovoltaic power systems

    NASA Technical Reports Server (NTRS)

    Hein, G. F.; Cusick, J. P.; Poley, W. A.

    1978-01-01

    The Department of Energy has developed a program to effect a large reduction in the price of photovoltaic modules, with significant progress already achieved toward the 1986 goal of 50 cents/watt (1975 dollars). Remaining elements of a P/V power system (structure, battery storage, regulation, control, and wiring) are also significant cost items. The costs of these remaining elements are commonly referred to as Balance-of-System (BOS) costs. The BOS costs are less well defined and documented than module costs. The Lewis Research Center (LeRC) in 1976/77 and with two village power experiments that will be installed in 1978. The costs were divided into five categories and analyzed. A regression analysis was performed to determine correlations of BOS Costs per peak watt, with power size for these photovoltaic systems. The statistical relationship may be used for flat-plate, DC systems ranging from 100 to 4,000 peak watts. A survey of suppliers was conducted for comparison with the predicted BOS cost relationship.

  9. Control for laser hemangioma treatment system

    SciTech Connect

    Muckerheide, M.C.

    1982-02-23

    A laser is disclosed for directing a nominally 5 micron wavelength beam at a hemangioma or other variegated lesion. A fiber optic bundle for intercepting radiation reflected from the lesion at an intensity corresponding with the color intensity of the region at which the beam is directed. The output beam from the fiber optic bundle modulates a photodetector stage whose amplified output drives a galvanometer. The galvanometer shaft is coupled to the shaft of a potentiometer which is adjustable to regulate the laser power supply and, hence, the laser output energy level so laser beam energy is reduced when high absorption regions in the lesion are being scanned by the beam and increased as low absorption regions are being scanned.

  10. Laser cutting system for nuclear fuel disassembly

    SciTech Connect

    Weil, B.S.

    1985-01-01

    A significant advancement in fuel reprocessing technology has been made by utilizing a multikilowatt, carbon dioxide laser to perform cutting operations necessary to remove unprocessible hardware from reactor fuel assemblies. 10 figs.

  11. Status of Subaru laser guide star AO system

    NASA Astrophysics Data System (ADS)

    Takami, Hideki; Colley, Stephen; Dinkins, Matt; Eldred, Michael; Guyon, Olivier; Golota, Taras; Hattori, Masayuki; Hayano, Yutaka; Ito, Meguru; Iye, Masanori; Oya, Shin; Saito, Yoshihiko; Watanabe, Makoto

    2006-06-01

    The laser guide star adaptive optics (AO188) system for Subaru Telescope is presented. The system will be installed at the IR Nasmyth platform of Subaru 8 m telescope, whereas the current AO system with 36 elements is operating at the Cassegrain focus. The new AO system has a 188 element wavefront curvature sensor with photon counting APD modules and 188 element bimorph mirror. The laser guide star system has a 4.5 W solid state sum-frequency laser on the Nasmyth platform. The laser launching telescope with 50 cm aperture will be installed at behind the secondary mirror. The laser beam will be transferred to the laser launching telescope using photonic crystal single mode fiber cable. The instrument with the AO system is IRCS, infrared camera and spectrograph which has been used for Cassegrain AO system and new instrument, HiCIAO, high dynamic range infrared camera for exsolar planet detection. The first light of the AO system is planned in 2006.

  12. An equivalent unbalance identification method for the balancing of nonlinear squeeze-film damped rotordynamic systems

    NASA Astrophysics Data System (ADS)

    Torres Cedillo, Sergio G.; Bonello, Philip

    2016-01-01

    The high pressure (HP) rotor in an aero-engine assembly cannot be accessed under operational conditions because of the restricted space for instrumentation and high temperatures. This motivates the development of a non-invasive inverse problem approach for unbalance identification and balancing, requiring prior knowledge of the structure. Most such methods in the literature necessitate linear bearing models, making them unsuitable for aero-engine applications which use nonlinear squeeze-film damper (SFD) bearings. A previously proposed inverse method for nonlinear rotating systems was highly limited in its application (e.g. assumed circular centered SFD orbits). The methodology proposed in this paper overcomes such limitations. It uses the Receptance Harmonic Balance Method (RHBM) to generate the backward operator using measurements of the vibration at the engine casing, provided there is at least one linear connection between rotor and casing, apart from the nonlinear connections. A least-squares solution yields the equivalent unbalance distribution in prescribed planes of the rotor, which is consequently used to balance it. The method is validated on distinct rotordynamic systems using simulated casing vibration readings. The method is shown to provide effective balancing under hitherto unconsidered practical conditions. The repeatability of the method, as well as its robustness to noise, model uncertainty and balancing errors, are satisfactorily demonstrated and the limitations of the process discussed.

  13. Measure Guideline. Steam System Balancing and Tuning for Multifamily Residential Buildings

    SciTech Connect

    Choi, Jayne; Ludwig, Peter; Brand, Larry

    2013-04-01

    This guideline provides building owners, professionals involved in multifamily audits, and contractors insights for improving the balance and tuning of steam systems. It provides readers an overview of one-pipe steam heating systems, guidelines for evaluating steam systems, typical costs and savings, and guidelines for ensuring quality installations. It also directs readers to additional resources for details not included here. Measures for balancing a distribution system that are covered include replacing main line vents and upgrading radiator vents. Also included is a discussion on upgrading boiler controls and the importance of tuning the settings on new or existing boiler controls. The guideline focuses on one-pipe steam systems, though many of the assessment methods can be generalized to two-pipe steam systems.

  14. Reliability of System Identification Techniques to Assess Standing Balance in Healthy Elderly

    PubMed Central

    Maier, Andrea B.; Aarts, Ronald G. K. M.; van Gerven, Joop M. A.; Arendzen, J. Hans; Schouten, Alfred C.; Meskers, Carel G. M.; van der Kooij, Herman

    2016-01-01

    Objectives System identification techniques have the potential to assess the contribution of the underlying systems involved in standing balance by applying well-known disturbances. We investigated the reliability of standing balance parameters obtained with multivariate closed loop system identification techniques. Methods In twelve healthy elderly balance tests were performed twice a day during three days. Body sway was measured during two minutes of standing with eyes closed and the Balance test Room (BalRoom) was used to apply four disturbances simultaneously: two sensory disturbances, to the proprioceptive and the visual system, and two mechanical disturbances applied at the leg and trunk segment. Using system identification techniques, sensitivity functions of the sensory disturbances and the neuromuscular controller were estimated. Based on the generalizability theory (G theory), systematic errors and sources of variability were assessed using linear mixed models and reliability was assessed by computing indexes of dependability (ID), standard error of measurement (SEM) and minimal detectable change (MDC). Results A systematic error was found between the first and second trial in the sensitivity functions. No systematic error was found in the neuromuscular controller and body sway. The reliability of 15 of 25 parameters and body sway were moderate to excellent when the results of two trials on three days were averaged. To reach an excellent reliability on one day in 7 out of 25 parameters, it was predicted that at least seven trials must be averaged. Conclusion This study shows that system identification techniques are a promising method to assess the underlying systems involved in standing balance in elderly. However, most of the parameters do not appear to be reliable unless a large number of trials are collected across multiple days. To reach an excellent reliability in one third of the parameters, a training session for participants is needed and at

  15. A 408 nm Laser System to Drive Stimulated Raman Transitions

    NASA Astrophysics Data System (ADS)

    Archibald, James, II; Erickson, Christopher; Durfee, Dallin

    2011-05-01

    We will discuss a diode laser system that produces two laser beams, differing in frequency by 1 GHz, that can be used to drive Raman transitions in 87Sr+. This system will be used to generate the π and π / 2 pulses in an ion interferometer. The laser consists of a grating stabilized master laser. This is then passed through an AOM and retroreflected back through the AOM in order to provide two frequency-shifted beams. These beams are then used to injection lock two slave lasers, in a scheme similar to the one described in. The AOM can be modulated with a stability better than 1 Hz. Thus we guarantee that the light output from the slaves is at a constant detuning, while drift from the master laser corresponds to common mode drift (to which the Raman transition is less sensitive). We will also discuss a technique used to improve laser stability similar to the scheme described in but using the measured impedance of the diode rather than the amplitude noise on the light to generate an error signal. We will discuss a diode laser system that produces two laser beams, differing in frequency by 1 GHz, that can be used to drive Raman transitions in 87Sr+. This system will be used to generate the π and π / 2 pulses in an ion interferometer. The laser consists of a grating stabilized master laser. This is then passed through an AOM and retroreflected back through the AOM in order to provide two frequency-shifted beams. These beams are then used to injection lock two slave lasers, in a scheme similar to the one described in. The AOM can be modulated with a stability better than 1 Hz. Thus we guarantee that the light output from the slaves is at a constant detuning, while drift from the master laser corresponds to common mode drift (to which the Raman transition is less sensitive). We will also discuss a technique used to improve laser stability similar to the scheme described in but using the measured impedance of the diode rather than the amplitude noise on the light to

  16. Design of laser system for Subaru LGS AO

    NASA Astrophysics Data System (ADS)

    Hayano, Yutaka; Saito, Yoshihiko; Saito, Norihito; Akagawa, Kazuyuki; Kamata, Yukiko; Kanzawa, Tomio; Kurakami, Tomio; Takato, Naruhisa; Colley, Stephen; Eldred, Michael; Kane, Thomas; Guyon, Olivier; Oya, Shin; Watanabe, Makoto; Hattori, Masayuki; Golota, Taras; Dinkins, Matthew; Kobayashi, Naoto; Minowa, Yosuke; Goto, Miwa; Arimoto, Nobuo; Wada, Satoshi; Takami, Hideki; Iye, Masanori

    2004-10-01

    We present the development status of the laser system for Subaru Laser Guide Star Adaptive Optics System. We are manufacturing the quasi-continuous-wave sum frequency laser as a prototype. The optical efficiency of sum frequency generation normalized by the mode-locked fundamental YAG (1064 nm) laser output power is achieved to be 14 % using the non-linear crystal, periodically poled potassium titanyl phosphate (PPKTP). Output power at sodium D2 line was about 260 mW. The optical relay fiber and the laser launching telescope are also described in this paper. For the optical relay fiber, we are testing an index guided photonic crystal fiber (PCF), whose core material is filled by fused silica, and whose clad has close-packed air holes in two dimension. The coupling efficiency was evaluated as about 80 % using 1mW He-Ne laser. We introduce the design of laser launching telescope (LLT), which is a copy of VLT laser launching telescope, and the interface to the Subaru Telescope.

  17. Laser crosslink configurations for RF satellite communications systems

    NASA Astrophysics Data System (ADS)

    Sebacher, K. S.; Lambert, S. G.; Pautler, J. A.; Carter, J. P.

    Predictions of future satellite communications traffic indicate that an increased capacity for satellite communications systems is required. Crosslinks between satellites provide improvements in communications throughput for these systems. Crosslinks also increase system flexibility and remove the dependence of world-wide information flow on relay ground stations located outside the continental United States. Laser crosslinks provide the additional advantage of eliminating susceptibility to space-based or ground-based jammers. Laser terminals are also smaller and require smaller antennas than an RF terminal. This paper describes the advantages of adding laser crosslinks to RF satellite communications systems. Characteristics of the required RF/optical interfaces on-board the satellites are addessed. Terminal configurations that provide reliable, accurate laser communications at high data rates are described.

  18. An airborne laser polarimeter system (ALPS) for terrestrial physics research

    NASA Technical Reports Server (NTRS)

    Kalshoven, James E., Jr.; Dabney, Philip W.

    1988-01-01

    The design of a multispectral polarized laser system for characterizing the depolarization properties of the earth's surface is described. Using a laser as the light source, this airborne system measures the Stokes parameters of the surface to simultaneously arrive at the polarization degree, azimuthal angle, and ellipticity for each wavelength. The technology will be studied for the feasibility of expansion of the sensor to do surface polarization imaging. The data will be used in support of solar polarization studies and to develop laser radiometry as a tool in environmental remote sensing.

  19. Profiling atmospheric water vapor using a fiber laser lidar system.

    PubMed

    De Young, Russell J; Barnes, Norman P

    2010-02-01

    A compact, lightweight, and efficient fiber laser lidar system has been developed to measure water vapor profiles in the lower atmosphere of Earth or Mars. The line narrowed laser consist of a Tm:germanate fiber pumped by two 792 nm diode arrays. The fiber laser transmits approximately 0.5 mJ Q- switched pulses at 5 Hz and can be tuned to water vapor lines near 1.94 microm with linewidth of approximately 20 pm. A lightweight lidar receiver telescope was constructed of carbon epoxy fiber with a 30 cm Fresnel lens and an advanced HgCdTe APD detector. This system has made preliminary atmospheric measurements.

  20. Aircraft Detection System Ensures Free-Space Laser Safety

    NASA Technical Reports Server (NTRS)

    Smithgall, Brian; Wilson, Keith E.

    2004-01-01

    As scientists continue to explore our solar system, there are increasing demands to return greater volumes of data from smaller deep-space probes. Accordingly, NASA is studying advanced strategies based on free-space laser transmissions, which offer secure, high-bandwidth communications using smaller subsystems of much lower power and mass than existing ones. These approaches, however, can pose a danger to pilots in the beam path because the lasers may illuminate aircraft and blind them. Researchers thus are investigating systems that will monitor the surrounding airspace for aircraft that could be affected. This paper presents current methods for safe free space laser propagation.

  1. Technology development of UAV recovery system based on laser detection

    NASA Astrophysics Data System (ADS)

    Zhou, Zhi-wei; Lv, Hua

    2011-06-01

    The recovery technology of unmanned aerial vehicle (UAV) is one of the difficulties of UAV development. This paper presents an automatic UAV recovery guide system, which is based on laser detection technology. The guide system overcomes the problem that the small-sized UAV is not suitable for accurate-point recovery. Comparing to traditional recovery system, this system has some advantage, such as high precision, round-the-clock, flexible and easy testing. Especially, it improved the application level of UAV recovery system with corresponding orientation guide model and accurate orientation tracking technology. High requirements are needed for UAV near field distance measurement with this method. This paper provides a method for UAV close quarters navigation based on laser detection technology. It is a new application for computer vision and photoelectric technology, with fast safe secret and nil interference. UAV recovery system can lead the UAV to tackle net safely. According to current UAV technology development, using laser tracking as terminal guide sensor measure equipment is feasible. The distribution of UAV collision network callback system put the laser recovery guide system behind the tackle net. When the UAV enter the callback phase, laser call back system made the UAV slide down follow the direct orbit by way of searching tracking and orientation. The UAV recovery system setups biaxial automatic turntable, measure the horizontal angle and pitch angle change, provide the deviation of current flight path and destine flight path, also provides the distance information between UAV recovery system by the way of laser measurement. This thesis analyzes the feasibility of this technology, provides the workflow of the UAV when entering the call back process. This paper also presents the correction method of laser error. The simulation result shows this distance measure system can lead the UAV call back safely.

  2. Yb:FAP and related materials, laser gain medium comprising same, and laser systems using same

    DOEpatents

    Krupke, W.F.; Payne, S.A.; Chase, L.L.; Smith, L.K.

    1994-01-18

    An ytterbium doped laser material remarkably superior to all others, including Yb:YAG, comprises ytterbium doped apatite (Yb:Ca[sub 5](PO[sub 4])[sub 3]F) or Yb:FAP, or ytterbium doped crystals that are structurally related to FAP. The new laser material is used in laser systems pumped by diode pump sources having an output near 0.905 microns or 0.98 microns, such as InGaAs and AlInGaAs, or other narrowband pump sources near 0.905 microns or 0.98 microns. The laser systems are operated in either the conventional or ground state depletion mode. 9 figures.

  3. Comparison of laser gyro IMU configurations for reentry systems

    NASA Astrophysics Data System (ADS)

    Majure, Robert G.; Robinson, Thomas A.

    An evaluation is made of future system accuracy requirements, physical criteria, and environmental constraints for ring laser gyro systems that are to be used in reentry vehicles. Attention is given to the configurational issues of inertial measurement unit (IMU) orientation in the vehicle, size and weight reduction, ring laser gyro selection, and tradeoffs of potential integration options for the IMU and the processor. A minimization of external interfaces is accomplished by IMU/data processor integration.

  4. Compact-range coordinate system established using a laser tracker.

    SciTech Connect

    Gallegos, Floyd H.; Bryce, Edwin Anthony

    2006-12-01

    Establishing a Cartesian coordinate reference system for an existing Compact Antenna Range using the parabolic reflector is presented. A SMX (Spatial Metrix Corporation) M/N 4000 laser-based coordinate measuring system established absolute coordinates for the facility. Electric field characteristics with positional movement correction are evaluated. Feed Horn relocation for alignment with the reflector axis is also described. Reference points are established for follow-on non-laser alignments utilizing a theodolite.

  5. Application of Magnetic Suspension and Balance Systems to Ultra-High Reynolds Number Facilities

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.

    1996-01-01

    The current status of wind tunnel magnetic suspension and balance system development is briefly reviewed. Technical work currently underway at NASA Langley Research Center is detailed, where it relates to the ultra-high Reynolds number application. The application itself is addressed, concluded to be quite feasible, and broad design recommendations given.

  6. The mass balance approach: application to interpreting the chemical evolution of hydrologic systems.

    USGS Publications Warehouse

    Plummer, L.N.; Back, W.

    1980-01-01

    Mass balance calculations are applied to observed chemical and isotopic data of three natural water systems involving carbonate reactions in order to define mineral stoichiometry of reactants and products, relative rates of reactions, and mass transfer. One study evaluates reactions in a lagoon on the east coast of the Yucatan Peninsula, Mexico.- from Authors

  7. Science Assessments for All: Integrating Science Simulations into Balanced State Science Assessment Systems

    ERIC Educational Resources Information Center

    Quellmalz, Edys S.; Timms, Michael J.; Silberglitt, Matt D.; Buckley, Barbara C.

    2012-01-01

    This article reports on the collaboration of six states to study how simulation-based science assessments can become transformative components of multi-level, balanced state science assessment systems. The project studied the psychometric quality, feasibility, and utility of simulation-based science assessments designed to serve formative purposes…

  8. Design of laser system for absolute gravimeter based on 87Rb atom interferometer

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Wang, Shaokai; Zhuang, Wei; Fang, Fang; Li, Tianchu

    2015-08-01

    We present a laser system design for an absolute gravimeter based on 87Rb atom interferometer. By skillful design, lasers with 9 different frequencies are based on two diode lasers including tapered amplifier. Two electrical feedback systems are used for laser frequency stabilization and the Raman lasers generation respectively. All other lasers are based on two Raman lasers and realized with frequency shift by acoustic optical modulators. This laser system not only has the compact and simple construction, but meets all requirements for laser power and frequency controlling for the atom interferometer. It has the characteristic of reliability and integrity.

  9. Team-based work and work system balance in the context of agile manufacturing.

    PubMed

    Yauch, Charlene A

    2007-01-01

    Manufacturing agility is the ability to prosper in an environment characterized by constant and unpredictable change. The purpose of this paper is to analyze team attributes necessary to facilitate agile manufacturing, and using Balance Theory as a framework, it evaluates the potential positive and negative impacts related to these team attributes that could alter the balance of work system elements and resulting "stress load" experienced by persons working on agile teams. Teams operating within the context of agile manufacturing are characterized as multifunctional, dynamic, cooperative, and virtual. A review of the literature relevant to each of these attributes is provided, as well as suggestions for future research.

  10. Design concepts and cost studies for magnetic suspension and balance systems. [wind tunnel apparatus

    NASA Technical Reports Server (NTRS)

    Bloom, H. L.

    1982-01-01

    The application of superconducting magnets for suspension and balance of wind tunnel models was studied. Conceptual designs are presented for magnetic suspension and balance system (MSBS) configurations compatible with three high Reynolds number cases representing specified combinations of test conditions and model sizes. Concepts in general met initially specified performance requirements such as duty cycle, force and moment levels, model angular displacement and positioning accuracy with nominal design requirements for support subsystems. Other performance requirements, such as forced model sinusoidal oscillations, and control force magnitude and frequency, were modified so as to alleviate the magnitude of magnet, power, and cryogenic design requirements.

  11. NEW ACTIVE MEDIA AND ELEMENTS OF LASER SYSTEMS: Laser with resonators coupled by a dynamic hologram

    NASA Astrophysics Data System (ADS)

    Gerasimov, V. B.; Golyanov, A. V.; Luk'yanchuk, B. S.; Ogluzdin, Valerii E.; Rubtsova, I. L.; Sugrobov, V. A.; Khizhnyak, A. I.

    1987-11-01

    The nature of operation of a laser with a phase-conjugate mirror utilizing multibeam interaction was found to have a considerable influence on the coupling of its resonator to the resonator of a laser used to pump the mirror. A system of this kind with resonators coupled by a dynamic hologram exhibited "soft" lasing in the presence of a self-pumped phase-conjugate mirror.

  12. Laser System for Precise, Unambiguous Range Measurements

    NASA Technical Reports Server (NTRS)

    Dubovitsky, Serge; Lay, Oliver

    2005-01-01

    The Modulation Sideband Technology for Absolute Range (MSTAR) architecture is the basis of design of a proposed laser-based heterodyne interferometer that could measure a range (distance) as great as 100 km with a precision and resolution of the order of 1 nm. Simple optical interferometers can measure changes in range with nanometer resolution, but cannot measure range itself because interference is subject to the well-known integer-multiple-of-2 -radians phase ambiguity, which amounts to a range ambiguity of the order of 1 m at typical laser wavelengths. Existing rangefinders have a resolution of the order of 10 m and are therefore unable to resolve the ambiguity. The proposed MSTAR architecture bridges the gap, enabling nanometer resolution with an ambiguity range that can be extended to arbitrarily large distances. The MSTAR architecture combines the principle of the heterodyne interferometer with the principle of extending the ambiguity range of an interferometer by using light of two wavelengths. The use of two wavelengths for this purpose is well established in optical metrology, radar, and sonar. However, unlike in traditional two-color laser interferometry, light of two wavelengths would not be generated by two lasers. Instead, multiple wavelengths would be generated as sidebands of phase modulation of the light from a single frequency- stabilized laser. The phase modulation would be effected by applying sinusoidal signals of suitable frequencies (typically tens of gigahertz) to high-speed electro-optical phase modulators. Intensity modulation can also be used

  13. Preparation For Laser Wakefield Experiments Driven by the Texas Petawatt Laser System

    SciTech Connect

    Reed, S. A.; Kalmykov, S.; Gaul, E.; Martinez, M.; Henderson, W.; Dong, P.; Gao, X.; Sanders, J. C.; Wang, X.; Shvets, G.; Ditmire, T.; Downer, M.

    2009-01-22

    Laboratories around the world are planning petawatt laser driven experiments. The Texas petawatt laser offers the ability to demonstrate laser wake field acceleration (LWFA) in a unique regime with pulse duration ({approx}160 fs) shorter than other petawatt scale systems currently in operation or under development. By focusing the 1.25 PW, 200 J, 160 fs pulses to peak intensity {approx}10{sup 19} W/cm{sup 2}, multi-GeV electron bunches can be produced from a low density He gas jet. The rarefied plasma density (5x10{sup 16}-10{sup 17} cm{sup -3}) required for near-resonant LWFA minimizes plasma lensing and offers long dephasing length for electron acceleration over distances ({approx}10 cm) exceeding the Rayleigh range. Because of the high power, the laser can be focused to a spot (r{sub 0}{approx}100 microns) greater than the plasma wavelength (r{sub 0}>{lambda}{sub p}), thus minimizing radial propagation effects. Together these properties enable the laser pulse to self-guide without the use of a preformed channel lending simplicity and stability to the overall acceleration process. Particle-in-cell (PIC) simulations show the laser experiences self-focusing which, because of ultrashort pulse duration, does not lead to a collapse of the wakefield and can generate over 3 GeV electron energy. The presented material will include details of initial measurements of the Texas petawatt laser system, simulations of laser wakefield acceleration for the given laser parameters and the experimental setup currently under construction.

  14. Radionuclide mass balance for the TMI-2 accident: data-base system and preliminary mass balance. Volume 1

    SciTech Connect

    Goldman, M I; Davis, R J; Strahl, J F; Arcieri, W C; Tonkay, D W

    1983-04-01

    After the accident at Three Mile Island, Unit 2 (TMI-2), on March 28, 1979, GEND stated its intention to support an effort to determine, as accurately as possible, the current mass balances of significant radiological toxic species. GEND gave two primary reasons for support this effort: (1) such exercises guarantee completeness of the studies, and (2) mass balance determinations ensure that all important sinks and attentuation mechanisms have been identified. The primary objective of the studies conducted by NUS Corporation was to support the goals of the GEND planners and to continue the mass balance effort by generating a preliminary accounting of key radioactive species following the TMI-2 accident. As a result of these studies, secondary objectives, namely a computerized data base and recommendations, have been achieved to support future work in this area.

  15. Off-line-locked laser diode species monitor system

    NASA Technical Reports Server (NTRS)

    Lee, Jamine (Inventor); Goldstein, Neil (Inventor); Richtsmeier, Steven (Inventor); Bien, Fritz (Inventor); Gersh, Michael (Inventor)

    1995-01-01

    An off-line-locked laser diode species monitor system includes: reference means for including at least one known species having a first absorption wavelength; a laser source for irradiating the reference means and at least one sample species having a second absorption wavelength differing from the first absorption wavelength by a predetermined amount; means for locking the wavelength of the laser source to the first wavelength of the at least one known species in the reference means; a controller for defeating the means for locking and for displacing the laser source wavelength from said first absorption wavelength by said predetermined amount to the second absorption wavelength; and a sample detector device for determining laser radiation absorption at the second wavelength transmitted through the sample to detect the presence of the at least one sample species.

  16. Integration of microalgae systems at municipal wastewater treatment plants: implications for energy and emission balances.

    PubMed

    Menger-Krug, Eve; Niederste-Hollenberg, Jutta; Hillenbrand, Thomas; Hiessl, Harald

    2012-11-01

    Integrating microalgae systems (MAS) at municipal wastewater treatment plants (WWTPs) to produce of bioenergy offers many potential synergies. Improved energy balances provide a strong incentive for WWTPs to integrate MAS, but it is crucial that WWTPs maintain their barrier function to protect water resources. We perform a prospective analysis of energy and emission balances of a WWTP with integrated MAS, based on a substance flow analysis of the elements carbon (C), nitrogen (N), and phosphorus (P). These elements are the main ingredients of wastewater, and the key nutrients for algae growth. We propose a process design which relies solely on resources from wastewater with no external input of water, fertilizer or CO(2). The whole process chain, from cultivation to production of bioelectricity, takes place at the WWTP. Our results show that MAS can considerably improve energy balances of WWTPs without any external resource input. With optimistic assumptions, they can turn WWTPs into net energy producers. While intensive C recycling in MAS considerably improves the energy balance, we show that it also impacts on effluent quality. We discuss the importance of nonharvested biomass for effluent quality and highlight harvesting efficiency as key factor for energy and emission balances of MAS at WWTP.

  17. Integration of microalgae systems at municipal wastewater treatment plants: implications for energy and emission balances.

    PubMed

    Menger-Krug, Eve; Niederste-Hollenberg, Jutta; Hillenbrand, Thomas; Hiessl, Harald

    2012-11-01

    Integrating microalgae systems (MAS) at municipal wastewater treatment plants (WWTPs) to produce of bioenergy offers many potential synergies. Improved energy balances provide a strong incentive for WWTPs to integrate MAS, but it is crucial that WWTPs maintain their barrier function to protect water resources. We perform a prospective analysis of energy and emission balances of a WWTP with integrated MAS, based on a substance flow analysis of the elements carbon (C), nitrogen (N), and phosphorus (P). These elements are the main ingredients of wastewater, and the key nutrients for algae growth. We propose a process design which relies solely on resources from wastewater with no external input of water, fertilizer or CO(2). The whole process chain, from cultivation to production of bioelectricity, takes place at the WWTP. Our results show that MAS can considerably improve energy balances of WWTPs without any external resource input. With optimistic assumptions, they can turn WWTPs into net energy producers. While intensive C recycling in MAS considerably improves the energy balance, we show that it also impacts on effluent quality. We discuss the importance of nonharvested biomass for effluent quality and highlight harvesting efficiency as key factor for energy and emission balances of MAS at WWTP. PMID:23050661

  18. Load Balancing Using Time Series Analysis for Soft Real Time Systems with Statistically Periodic Loads

    NASA Technical Reports Server (NTRS)

    Hailperin, Max

    1993-01-01

    This thesis provides design and analysis of techniques for global load balancing on ensemble architectures running soft-real-time object-oriented applications with statistically periodic loads. It focuses on estimating the instantaneous average load over all the processing elements. The major contribution is the use of explicit stochastic process models for both the loading and the averaging itself. These models are exploited via statistical time-series analysis and Bayesian inference to provide improved average load estimates, and thus to facilitate global load balancing. This thesis explains the distributed algorithms used and provides some optimality results. It also describes the algorithms' implementation and gives performance results from simulation. These results show that our techniques allow more accurate estimation of the global system load ing, resulting in fewer object migration than local methods. Our method is shown to provide superior performance, relative not only to static load-balancing schemes but also to many adaptive methods.

  19. Blue laser system for photo-dynamic therapy

    NASA Astrophysics Data System (ADS)

    Dabu, R.; Carstocea, B.; Blanaru, C.; Pacala, O.; Stratan, A.; Ursu, D.; Stegaru, F.

    2007-03-01

    A blue laser system for eye diseases (age related macular degeneration, sub-retinal neo-vascularisation in myopia and presumed ocular histoplasmosis syndrome - POHS) photo-dynamic therapy, based on riboflavin as photosensitive substance, has been developed. A CW diode laser at 445 nm wavelength was coupled through an opto-mechanical system to the viewing path of a bio-microscope. The laser beam power in the irradiated area is adjustable between 1 mW and 40 mW, in a spot of 3-5 mm diameter. The irradiation time can be programmed in the range of 1-19 minutes. Currently, the laser system is under clinic tests.

  20. Spatial intensity profiling of an industrial laser welding system

    SciTech Connect

    Milewski, J.O.

    1991-12-31

    A investigation was conducted to devise a method to sense the laser beam intensity profile of an industrial laser welding system. The research focuses on monitoring methods and assessing locations within the system where data can be taken which reveal the relationship between the laser beam intensity profile and the input system parameters of the laser beam welding process. Emphasis has been placed on the configuration of a distributed computing environment to acquire, analyze and display the results of the sensed beam profile. Conventional image processing techniques are demonstrated. It was found that a distributed computing environment was useful for processing the large volumes of data generated by this process characterization method, and the distributed computing environment provided the computing power required for computationally intensive analysis and display techniques. The mathematical techniques used to discriminate one data set from another and relate the results to processing conditions are discussed.

  1. The airborne laser ranging system, its capabilities and applications

    NASA Technical Reports Server (NTRS)

    Kahn, W. D.; Degnan, J. J.; Englar, T. S., Jr.

    1982-01-01

    The airborne laser ranging system is a multibeam short pulse laser ranging system on board an aircraft. It simultaneously measures the distances between the aircraft and six laser retroreflectors (targets) deployed on the Earth's surface. The system can interrogate over 100 targets distributed over an area of 25,000 sq, kilometers in a matter of hours. Potentially, a total of 1.3 million individual range measurements can be made in a six hour flight. The precision of these range measurements is approximately + or - 1 cm. These measurements are used in procedure which is basically an extension of trilateration techniques to derive the intersite vector between the laser ground targets. By repeating the estimation of the intersite vector, strain and strain rate errors can be estimated. These quantities are essential for crustal dynamic studies which include determination and monitoring of regional strain in the vicinity of active fault zones, land subsidence, and edifice building preceding volcanic eruptions.

  2. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    DOEpatents

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  3. High removal rate laser-based coating removal system

    DOEpatents

    Matthews, Dennis L.; Celliers, Peter M.; Hackel, Lloyd; Da Silva, Luiz B.; Dane, C. Brent; Mrowka, Stanley

    1999-11-16

    A compact laser system that removes surface coatings (such as paint, dirt, etc.) at a removal rate as high as 1000 ft.sup.2 /hr or more without damaging the surface. A high repetition rate laser with multiple amplification passes propagating through at least one optical amplifier is used, along with a delivery system consisting of a telescoping and articulating tube which also contains an evacuation system for simultaneously sweeping up the debris produced in the process. The amplified beam can be converted to an output beam by passively switching the polarization of at least one amplified beam. The system also has a personal safety system which protects against accidental exposures.

  4. Compact ultrahigh-power laser systems

    SciTech Connect

    Galvanauskas, A.

    1995-11-01

    Compact sources of high energy ultrashort pulses are described. Femtosecond and picosecond optical pulses with microjoule energies are obtained using chirped-pulse fiber amplifiers. Mode-locked fiber lasers and fast-tuned laser diodes are used to generate initial pulses for amplification. Efficient frequency conversion of amplified pulses is demonstrated and microjoule second-harmonic pulses are produced. The first all-fiber chirped pulse amplification circuit is demonstrated. It uses in-fiber chirped Bragg gratings, which replaces conventional diffraction-grating compressors and stretchers.

  5. Optical materials for space based laser systems

    NASA Technical Reports Server (NTRS)

    Buoncristiani, A. M.; Armagan, G.; Byvik, C. E.; Albin, S.

    1989-01-01

    The design features and performance characteristics of a sensitized holmium laser applicable to differential lidar and Doppler windshear measurements are presented, giving attention to the optimal choice of sensitizing/activating dopant ions. This development of a 2-micron region eye-safe laser, where holmium is sensitized by either hulium or erbium, has called for interionic energy transfer processes whose rate will not result in gain-switched pulses that are excessively long for atmospheric lidar and Doppler windshear detection. The application of diamond films for optical component hardening is noted.

  6. Deep trap, laser activated image converting system

    NASA Technical Reports Server (NTRS)

    Maserjian, J. (Inventor)

    1975-01-01

    Receiving an optical image on the surface of a photoconducting semiconductor is presented, storing the image in deep traps of the semiconductor, and later scanning the semiconductor with a laser beam to empty the deep traps, thereby producing a video signal. The semiconductor is illuminated with photons of energy greater than the band gap producing electron-hole pairs in the semiconductor which subsequently fill traps in energy from the band edges. When the laser beam of low energy photons excites the trapped electrons and holes out of the traps into the conduction and valence bands, a photoconductivity can be observed.

  7. Characterization of a Nd:YAG doubled pulsed laser system

    NASA Technical Reports Server (NTRS)

    Williams-Byrd, Julie A.; Barnes, James C.; Barnes, Norman P.; Lockard, George; Little, Alan; Banziger, Curtis; Marsh, Waverly; Nichols, Charles

    1992-01-01

    A description of a frequency doubled, double pulsed Nd:YAG laser that is to be used to pump an injection locked Ti:Sapphire power oscillator is presented. These two lasers make up the transmitter portion of the Lidar Atmospheric Sensing Experiment (LAWSE) instrument. LASE is a Lidar/DIAL experiment that is to measure water vapor in the troposphere. By utilizing the twin concept, both pulses can be produced with a single laser system, thereby minimizing cost, size, and weight. Alignment problems associated with having two separate lasers each produce one of the twin pulses are also alleviated. The LASE transmitter consists of a doubled pulsed Nd:YAG laser that will pump a Ti:Sapphire power oscillator that will be injection-locked by a diode laser. The wavelength of the Ti:Sapphire output will be tunable from 813 to 818 nm. A performance summary of the pump laser is given. The data verify that the pump laser can meet the performance requirements to pump the Ti:Sapphire power oscillator.

  8. Femtosecond laser system for micromachining of the materials

    NASA Astrophysics Data System (ADS)

    Barbucha, R.; Kocik, M.; Tański, M.; Garasz, K.; Petrov, T.; Radzewicz, C.

    2015-01-01

    Femtosecond-pulse laser micromachining is based on a laser ablation phenomenon, i.e. total evaporation of material from the target surface during laser irradiation. It is the most precise method of material removal. Moreover it does not require any post processing. Removal of the material occurs only in the laser focus, since the lack of thermal interaction, neither heat affected zone (HAZ) nor debris ocur. Research results have shown that shortening the duration of the laser pulse significantly reduces HAZ, which translates into the high quality of the machined structures. It is the main argument for the use of femtosecond-pulse lasers in the precise micromachining. In this paper, a femtosecond laser system consisting of a solid-state oscillator and the ytterbium-doped pulse fiber amplifier are presented. Average beam power at 343 nm with mode-locking is 4W @25A and pulse length at the oscillator output is 500 fs. Laser micro and nano-machining has found application in different fields. It's primary use is industrial micromachining of metals, ceramics, polymers, glass, biological material for medical use in eye surgery, and photovoltaic cells.

  9. Bench checkout equipment for spaceborne laser altimeter systems

    NASA Technical Reports Server (NTRS)

    Smith, James C.; Elman, Gregory C.; Christian, Kent D.; Cavanaugh, John F.; Ramos-Izquierdo, Luis; Hopf, Dan E.

    1993-01-01

    This paper addresses the requirements for testing and characterizing spaceborne laser altimeter systems. The Bench Checkout Equipment (BCE) system, test requirements, and flow-down traceability from the instrument system's functional requirements will also be presented. Mars Observer Laser Altimeter (MOLA) and the MOLA BCE are presented as representative of a 'typical' laser altimeter and its corresponding test system. The testing requirements of other or future laser altimeter systems may vary slightly due to the specific spacecraft interface and project requirements. MOLA, the first solid-state interplanetary laser altimeter, was designed to be operational in Mars orbit for two Earth years. MOLA transmits a 7.5 ns pulse at a wavelength of 1.064 microns with a 0.25 mr beam divergence and a pulse repetition rate of 10 Hz. The output energy is specified at 45 mj at the beginning of mapping orbit and 30 mj at the end of one Martian year. MOLA will measure the laser pulse transit time from the spacecraft to the Mars surface and return to a resolution of 1.5 meters.

  10. Laser System for Livermore's Mono Energetic Gamma-Ray Source

    SciTech Connect

    Gibson, D; Albert, F; Bayramian, A; Marsh, R; Messerly, M; Ebbers, C; Hartemann, F

    2011-03-14

    A Mono-energetic Gamma-ray (MEGa-ray) source, based on Compton scattering of a high-intensity laser beam off a highly relativistic electron beam, requires highly specialized laser systems. To minimize the bandwidth of the {gamma}-ray beam, the scattering laser must have minimal bandwidth, but also match the electron beam depth of focus in length. This requires a {approx}1 J, 10 ps, fourier-transform-limited laser system. Also required is a high-brightness electron beam, best provided by a photoinjector. This electron source requires a second laser system with stringent requirements on the beam including flat transverse and longitudinal profiles and fast rise times. Furthermore, these systems must be synchronized to each other with ps-scale accuracy. Using a novel hyper-dispersion compressor configuration and advanced fiber amplifiers and diode-pumped Nd:YAG amplifiers, we have designed laser systems that meet these challenges for the X-band photoinjector and Compton-scattering source being built at Lawrence Livermore National Laboratory.

  11. Preliminary investigations of design philosophies and features applicable to large magnetic suspension and balance systems

    NASA Technical Reports Server (NTRS)

    Britcher, C. P.; Fortescue, P. W.; Allcock, G. A.; Goodyer, M. J.

    1979-01-01

    The technology which is required to allow the principles of magnetic suspension and balance systems (MSBS) to be applied to the high Reynolds number transonic testing of aircraft models is examined. A test facility is presented as comprising a pressurized transonic cryogenic wind tunnel, with the MSBS providing full six degree of freedom control. The electro-magnets which are superconducting and fed from quiet, bipolar power supplies are examined. A model control system having some self adaptive characteristics is discussed.

  12. Laser illuminator and optical system for disk patterning

    DOEpatents

    Hackel, Lloyd A.; Dane, C. Brent; Dixit, Shamasundar N.; Everett, Mathew; Honig, John

    2000-01-01

    Magnetic recording media are textured over areas designated for contact in order to minimize friction with data transducing heads. In fabricating a hard disk, an aluminum nickel-phosphorous substrate is polished to a specular finish. A mechanical means is then used to roughen an annular area intended to be the head contact band. An optical and mechanical system allows thousands of spots to be generated with each laser pulse, allowing the textured pattern to be rapidly generated with a low repetition rate laser and an uncomplicated mechanical system. The system uses a low power laser, a beam expander, a specially designed phase plate, a prism to deflect the beam, a lens to transmit the diffraction pattern to the far field, a mechanical means to rotate the pattern and a trigger system to fire the laser when sections of the pattern are precisely aligned. The system generates an annular segment of the desired pattern with which the total pattern is generated by rotating the optical system about its optic axis, sensing the rotational position and firing the laser as the annular segment rotates into the next appropriate position. This marking system can be integrated into a disk sputtering system for manufacturing magnetic disks, allowing for a very streamlined manufacturing process.

  13. Magnetically induced pulser laser excitation system

    SciTech Connect

    Taylor, R.S.; Leopold, K.

    1987-07-07

    An apparatus is described for exciting a laser having first and second electrodes and containing a gas mixture comprising: preionization means for preionizing the gas mixture, primary energy storage means for storing a sufficient electrical energy for the operation of the laser. Energy transfer means connects the primary energy storage means and the first electrode in an impedance matching manner for transferring the sufficient electrical energy the form of a main discharge voltage pulse, trigger pulse generating means forms a part of the primary energy storage means and for generating a trigger pulse in response to the main discharge voltage pulse. Secondary energy storage means stores an electrical energy, electromagnetic energy transfers means connected between the secondary energy storage means and the second electrode for transferring electromagnetically the electrical energy in the form of a high voltage pulse which breaks down the gas mixture. Switching means connects to the electromagnetic energy transfer means for initiating the electromagnetic energy transfer in response to the trigger pulse. The main discharge voltage pulse is longer in duration than the high voltage pulse. The two pulses are coincidental for a period of time to produce gas breakdown in the laser and to permit the energy transfer means for sufficient energy from the primary energy storage means to the laser.

  14. Q-Switched Raman laser system

    DOEpatents

    George, E. Victor

    1985-01-01

    Method and apparatus for use of a Raman or Brillouin switch together with a conventional laser and a saturable absorber that is rapidly bleached at a predetermined frequency .nu.=.nu..sub.0, to ultimately produce a Raman or Brillouin pulse at frequency .nu.=.nu..sub.0 .+-..nu..sub.Stokes.

  15. The laser lightning rod system: thunderstorm domestication.

    PubMed

    Ball, L M

    1974-10-01

    An unusual application of the laser, namely protection of life and property from lightning, is described. The device relies on multiphoton ionization in mode-locked beams, rather than on collisional (avalanche) electron production. Feasibility is demonstrated numerically, and relevant principles explained. A method of mobile deployment is mentioned, by which economic (as opposed to scientific) feasibility might be achieved. PMID:20134678

  16. Q-switched Raman laser system

    DOEpatents

    George, E.V.

    Method and apparatus for use of a Raman or Brillouin switch together with a conventional laser and a saturable absorber that is rapidly bleached at a predeterimined frequency nu = nu/sub O/, to ultimately produce a Raman or Brillouin pulse at frequency nu = nu/sub O/ +- nu /sub Stokes/.

  17. Advanced Orion Optimized Laser System Analysis

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Contractor shall perform a complete analysis of the potential of the solid state laser in the very long pulse mode (100 ns pulse width, 10-30 hz rep-rate) and in the very short pulse mode (100 ps pulse width 10-30 hz rep rate) concentrating on the operation of the device in the 'hot-rod' mode, where no active cooling the laser operation is attempted. Contractor's calculations shall be made of the phase aberrations which develop during the repped-pulse train, and the results shall feed into the adaptive optics analyses. The contractor shall devise solutions to work around ORION track issues. A final report shall be furnished to the MSFC COTR including all calculations and analysis of estimates of bulk phase and intensity aberration distribution in the laser output beam as a function of time during the repped-pulse train for both wave forms (high-energy/long-pulse, as well as low-energy/short-pulse). Recommendations shall be made for mitigating the aberrations by laser re-design and/or changes in operating parameters of optical pump sources and/or designs.

  18. The laser lightning rod system: thunderstorm domestication.

    PubMed

    Ball, L M

    1974-10-01

    An unusual application of the laser, namely protection of life and property from lightning, is described. The device relies on multiphoton ionization in mode-locked beams, rather than on collisional (avalanche) electron production. Feasibility is demonstrated numerically, and relevant principles explained. A method of mobile deployment is mentioned, by which economic (as opposed to scientific) feasibility might be achieved.

  19. Measurement of the target current by inductive probe during laser interaction on terawatt laser system PALS

    SciTech Connect

    Cikhardt, J.; Klír, D.; Řezáč, K.; Krása, J.; De Marco, M.; Pfeifer, M.; Velyhan, A.; Krouský, E.; Cikhardtová, B.; Kubeš, P.; Kravárik, J.; Ullschmied, J.; Skála, J.

    2014-10-15

    Measurements of the return-current flowing through a solid target irradiated with the sub-nanosecond kJ-class Prague Asterix Laser System is reported. A new inductive target probe was developed which allows us measuring the target current derivative in a kA/ns range. The dependences of the target current on the laser pulse energy for cooper, graphite, and polyethylene targets are reported. The experiment shows that the target current is proportional to the deposited laser energy and is strongly affected by the shot-to-shot fluctuations. The corresponding maximum target charge exceeded a value of 10 μC. A return-current dependence of the electromagnetic pulse produced by the laser-target interaction is presented.

  20. Criteria for the evaluation of laser solar energy converter systems

    NASA Technical Reports Server (NTRS)

    Harries, W. L.

    1985-01-01

    Assuming that a parabolic insolation-collection mirror-based solar pumped laser has a collector and heat emitter whose weights are proportional to their areas, and that the weight of the laser is negligible by comparison, the output power/unit weight can be expressed in terms of the efficiencies and working temperatures of the system. This ratio appears to be several times higher for an IBr laser than for one operating on C3F7I, because the solar utilization efficiency is greater for the former despite its lower working temperature.

  1. A picosecond beam-timing system for the OMEGA laser

    DOE PAGESBeta

    Donaldson, W. R.; Katz, J.; Huff, R.; Hill, E. M.; Kelly, J. H.; Kwaitkowski, J.; Brannon, R. B.; Boni, R.

    2016-05-27

    Here, a timing system is demonstrated for the OMEGA Laser System that guarantees all 60 beams will arrive on target simultaneously with a root mean square variability of 4 ps. The system relies on placing a scattering sphere at the target position to couple the UV light from each beam into a single photodetector.

  2. Computer Output Laser Disk (COLD) Systems--COM Replacement Units.

    ERIC Educational Resources Information Center

    Bolnick, Franklin I.

    1993-01-01

    Explains the COLD (Computer Output Laser Disk) system and describes current applications. Use of the COLD system to replace COM (Computer Output Microfilm) is discussed; advantages and disadvantages of the COLD system are considered; optical disks OD-WORM (Optical Disk-Write Once Read Many) versus CD-ROM are compared; and equipment and software…

  3. Wing tip vortex measurements with laser Doppler systems

    NASA Technical Reports Server (NTRS)

    Fuller, C. E., III

    1973-01-01

    The vortex velocity field produced by a rectangular wing in a subsonic wind tunnel was measured using two laser Doppler velocimeter systems. One system made three dimensional mean velocity measurements and the other made one dimensional turbulence measurements. The systems and test procedures are described and comparisons of the measurements are made. The data defined a strong spiral motion in the vortex formation process.

  4. Automatic balancing of AMB systems using plural notch filter and adaptive synchronous compensation

    NASA Astrophysics Data System (ADS)

    Xu, Xiangbo; Chen, Shao; Zhang, Yanan

    2016-07-01

    To achieve automatic balancing in active magnetic bearing (AMB) system, a control method with notch filters and synchronous compensators is widely employed. However, the control precision is significantly affected by the synchronous compensation error, which is caused by parameter errors and variations of the power amplifiers. Furthermore, the computation effort may become intolerable if a 4-degree-of-freedom (dof) AMB system is studied. To solve these problems, an adaptive automatic balancing control method in the AMB system is presented in this study. Firstly, a 4-dof radial AMB system is described and analyzed. To simplify the controller design, the 4-dof dynamic equations are transferred into two plural functions related to translation and rotation, respectively. Next, to achieve automatic balancing of the AMB system, two synchronous equations are formed. Solution of them leads to a control strategy based on notch filters and feedforward controllers with an inverse function of the power amplifier. The feedforward controllers can be simplified as synchronous phases and amplitudes. Then, a plural phase-shift notch filter which can identify the synchronous components in 2-dof motions is formulated, and an adaptive compensation method that can form two closed-loop systems to tune the synchronous amplitude of the feedforward controller and the phase of the plural notch filter is proposed. Finally, the proposed control strategy is verified by both simulations and experiments on a test rig of magnetically suspended control moment gyro. The results indicate that this method can fulfill the automatic balancing of the AMB system with a light computational load.

  5. Stereo vision based hand-held laser scanning system design

    NASA Astrophysics Data System (ADS)

    Xiong, Hanwei; Xu, Jun; Wang, Jinming

    2011-11-01

    Although 3D scanning system is used more and more broadly in many fields, such computer animate, computer aided design, digital museums, and so on, a convenient scanning device is expansive for most people to afford. In another hand, imaging devices are becoming cheaper, a stereo vision system with two video cameras cost little. In this paper, a hand held laser scanning system is design based on stereo vision principle. The two video cameras are fixed tighter, and are all calibrated in advance. The scanned object attached with some coded markers is in front of the stereo system, and can be changed its position and direction freely upon the need of scanning. When scanning, the operator swept a line laser source, and projected it on the object. At the same time, the stereo vision system captured the projected lines, and reconstructed their 3D shapes. The code markers are used to translate the coordinate system between scanned points under different view. Two methods are used to get more accurate results. One is to use NURBS curves to interpolate the sections of the laser lines to obtain accurate central points, and a thin plate spline is used to approximate the central points, and so, an exact laser central line is got, which guards an accurate correspondence between tow cameras. Another way is to incorporate the constraint of laser swept plane on the reconstructed 3D curves by a PCA (Principle Component Analysis) algorithm, and more accurate results are obtained. Some examples are given to verify the system.

  6. Q-Switched Nd: YAG Laser Micro-Machining System

    SciTech Connect

    Messaoud, S.; Allam, A.; Siserir, F.; Bouceta, Y.; Kerdja, T.; Ouadjaout, D.

    2008-09-23

    In this paper, we present the design of a low cost Q-switched Nd: YAG laser micro-machining system for photo masks fabrication. It consists of: Nd:YAG laser source, beam delivery system, X-Y table, PC, The CCD camera and TV monitor. The synchronization between the laser source and the X-Y table is realised by NI PCI-7342, the two axis MID-7602 and LabVIEW based program. The first step of this work consists of engraving continuous and discontinuous lines on a thin film metal with a 100 {mu}m resolution by using the YG 980 Quantel Q-switched Nd:YAG laser.

  7. Acousto-optic laser projection systems for displaying TV information

    NASA Astrophysics Data System (ADS)

    Gulyaev, Yu V.; Kazaryan, M. A.; Mokrushin, Yu M.; Shakin, O. V.

    2015-04-01

    This review addresses various approaches to television projection imaging on large screens using lasers. Results are presented of theoretical and experimental studies of an acousto-optic projection system operating on the principle of projecting an image of an entire amplitude-modulated television line in a single laser pulse. We consider characteristic features of image formation in such a system and the requirements for its individual components. Particular attention is paid to nonlinear distortions of the image signal, which show up most severely at low modulation signal frequencies. We discuss the feasibility of improving the process efficiency and image quality using acousto-optic modulators and pulsed lasers. Real-time projectors with pulsed line imaging can be used for controlling high-intensity laser radiation.

  8. Stabilized master laser system for differential absorption lidar.

    PubMed

    Dinovitser, Alex; Hamilton, Murray W; Vincent, Robert A

    2010-06-10

    Wavelength accuracy and stability are key requirements for differential absorption lidar (DIAL). We present a control and timing design for the dual-stabilized cw master lasers in a pulsed master-oscillator power-amplifier configuration, which forms a robust low-cost water-vapor DIAL transmitter system. This design operates at 823 nm for water-vapor spectroscopy using Fabry-Perot-type laser diodes. However, the techniques described could be applied to other laser technologies at other wavelengths. The system can be extended with additional off-line or side-line wavelengths. The on-line master laser is locked to the center of a water absorption line, while the beat frequency between the on-line and the off-line is locked to 16 GHz using only a bandpass microwave filter and low-frequency electronics. Optical frequency stabilities of the order of 1 MHz are achieved.

  9. Mid-IR laser system for advanced neurosurgery

    NASA Astrophysics Data System (ADS)

    Klosner, M.; Wu, C.; Heller, D. F.

    2014-03-01

    We present work on a laser system operating in the near- and mid-IR spectral regions, having output characteristics designed to be optimal for cutting various tissue types. We provide a brief overview of laser-tissue interactions and the importance of controlling certain properties of the light beam. We describe the principle of operation of the laser system, which is generally based on a wavelength-tunable alexandrite laser oscillator/amplifier, and multiple Raman conversion stages. This configuration provides robust access to the mid-IR spectral region at wavelengths, pulse energies, pulse durations, and repetition rates that are attractive for neurosurgical applications. We summarize results for ultra-precise selective cutting of nerve sheaths and retinas with little collateral damage; this has applications in procedures such as optic-nerve-sheath fenestration and possible spinal repair. We also report results for cutting cornea, and dermal tissues.

  10. NASA three-laser airborne differential absorption lidar system electronics

    NASA Technical Reports Server (NTRS)

    Allen, R. J.; Copeland, G. D.

    1984-01-01

    The system control and signal conditioning electronics of the NASA three laser airborne differential absorption lidar (DIAL) system are described. The multipurpose DIAL system was developed for the remote measurement of gas and aerosol profiles in the troposphere and lower stratosphere. A brief description and photographs of the majority of electronics units developed under this contract are presented. The precision control system; which includes a master control unit, three combined NASA laser control interface/quantel control units, and three noise pulse discriminator/pockels cell pulser units; is described in detail. The need and design considerations for precision timing and control are discussed. Calibration procedures are included.

  11. The Final Focus Test Beam laser referene system

    SciTech Connect

    Bressler, V.E.; Ruland, R.E.

    1993-05-01

    The original design for the SLAC linac included an alignment reference system with 270 diffraction gratings situated along the 3000 meter linac. These gratings have provided SLAC with a global reference line repeatable to within 200 micro meters. For the Final Focus Test Beam, this laser system has been extended and 13 new diffraction gratings have been installed. Improvements targets and the availability of new instruments allows us to evaluate the performance of the laser reference system at the 510 micro meter level. An explanation of the system and the results of our evaluation are presented.

  12. Laser remote-sensing system analysis for search and rescue.

    PubMed

    Field, C T; Millar, P S

    1999-04-20

    We develop a general model of a laser remote-sensing system for search and rescue using targets marked with fluorescent dye. The dye fluoresces at a longer peak wavelength than the incident radiation, enabling a dye-covered target to be distinguished from the unshifted ground echo by the search system. The principal result is a simple expression derived for the average laser power required to search at a particular rate given a required ground energy density. A similar expression is applicable to imaging lidar systems. The example system shown indicates that active probing for lost planes may be practical. PMID:18319831

  13. Cell-balancing currents in parallel strings of a battery system

    NASA Astrophysics Data System (ADS)

    Dubarry, Matthieu; Devie, Arnaud; Liaw, Bor Yann

    2016-07-01

    Lithium-ion batteries are attractive for vehicle electrification or grid modernization applications. In these applications, battery packs are required to have multiple-cell configurations and battery management system to operate properly and safely. Here, a useful equivalent circuit model was developed to simulate the spontaneous transient balancing currents among parallel strings in a battery system. The simulation results were validated with experimental data to illustrate the accuracy and validity of the model predictions. Understanding the transient behavior of such cell and string balancing in a parallel circuit configuration is very important to assess the impacts of current fluctuation and cell variability on a battery system's performance, regarding durability, reliability, safety, abuse tolerance and failure prevention, including possible short circuit or open circuit conditions. Additional features and advantages, including the ability to assessing impacts on the performance of the string assemblies from string swapping or cell/module replacement in the strings, could be realized to aid battery management, maintenance and repair.

  14. A new postural balance control system for rehabilitation training based on virtual cycling.

    PubMed

    Song, Chul Gyu; Kim, Jong Yun; Kim, Nam Gyun

    2004-06-01

    A new rehabilitation training system was developed to improve postural balance control by combining virtual reality technology with an unfixed bicycle. Twenty healthy subjects participated in the present study by riding the virtual cycling system under two different conditions: with or without visual feedback. Data were collected on the following parameters: path deviation, cycling velocity, etc. As a result of conducting the repeated training, results showed improvement not only in the ability to control balance and weight shift but also in the overall cycling ability including the degree of path deviation and the cycling speed. It was concluded that the system was effective as a training device and, in addition, the technology might have a wider applicability to the rehabilitation field.

  15. Diode laser satellite systems for beamed power transmission

    NASA Technical Reports Server (NTRS)

    Williams, M. D.; Kwon, J. H.; Walker, G. H.; Humes, D. H.

    1990-01-01

    A power system composed of an orbiting laser satellite and a surface-based receiver/converter is described. Power is transmitted from the satellite to the receiver/converter by laser beam. The satellite components are: (1) solar collector; (2) blackbody; (3) photovoltaic cells; (4) heat radiators; (5) laser system; and (6) transmission optics. The receiver/converter components are: receiver dish; lenticular lens; photocells; and heat radiator. Although the system can be adapted to missions at many locations in the solar system, only two are examined here: powering a lunar habitat; and powering a lunar rover. Power system components are described and their masses, dimensions, operating powers, and temperatures, are estimated using known or feasible component capabilities. The critical technologies involved are discussed and other potential missions are mentioned.

  16. Beam-path conditioning for high-power laser systems

    SciTech Connect

    Stephens, T.; Johnson, D.; Languirand, M.

    1990-01-01

    Heating of mirrors and windows by high-power radiation from a laser transmitter produces turbulent density gradients in the gas near the optical surfaces. If the gradients are left uncontrolled, the resulting phase errors reduce the intensity on the target and degrade the signal returned to a receiver. Beam path conditioning maximizes the efficiency of the optical system by alleviating thermal turbulence within the beam path. Keywords: High power radiation, Beam path, Optical surface, Laser beams, Reprints. (JHD)

  17. Wavelength stabilized multi-kW diode laser systems

    NASA Astrophysics Data System (ADS)

    Köhler, Bernd; Unger, Andreas; Kindervater, Tobias; Drovs, Simon; Wolf, Paul; Hubrich, Ralf; Beczkowiak, Anna; Auch, Stefan; Müntz, Holger; Biesenbach, Jens

    2015-03-01

    We report on wavelength stabilized high-power diode laser systems with enhanced spectral brightness by means of Volume Holographic Gratings. High-power diode laser modules typically have a relatively broad spectral width of about 3 to 6 nm. In addition the center wavelength shifts by changing the temperature and the driving current, which is obstructive for pumping applications with small absorption bandwidths. Wavelength stabilization of high-power diode laser systems is an important method to increase the efficiency of diode pumped solid-state lasers. It also enables power scaling by dense wavelength multiplexing. To ensure a wide locking range and efficient wavelength stabilization the parameters of the Volume Holographic Grating and the parameters of the diode laser bar have to be adapted carefully. Important parameters are the reflectivity of the Volume Holographic Grating, the reflectivity of the diode laser bar as well as its angular and spectral emission characteristics. In this paper we present detailed data on wavelength stabilized diode laser systems with and without fiber coupling in the spectral range from 634 nm up to 1533 nm. The maximum output power of 2.7 kW was measured for a fiber coupled system (1000 μm, NA 0.22), which was stabilized at a wavelength of 969 nm with a spectral width of only 0.6 nm (90% value). Another example is a narrow line-width diode laser stack, which was stabilized at a wavelength of 1533 nm with a spectral bandwidth below 1 nm and an output power of 835 W.

  18. Ring-laser gyroscope system using dispersive element(s)

    NASA Technical Reports Server (NTRS)

    Smith, David D. (Inventor)

    2010-01-01

    A ring-laser gyroscope system includes a ring-laser gyroscope (RLG) and at least one dispersive element optically coupled to the RLG's ring-shaped optical path. Each dispersive element has a resonant frequency that is approximately equal to the RLG's lasing frequency. A group index of refraction defined collectively by the dispersive element(s) has (i) a real portion that is greater than zero and less than one, and (ii) an imaginary portion that is less than zero.

  19. Laser etching of enamel for direct bonding with an Er,Cr:YSGG hydrokinetic laser system.

    PubMed

    Uşümez, Serdar; Orhan, Metin; Uşümez, Aslihan

    2002-12-01

    Irradiation of enamel with laser energy changes the physical and chemical characteristics of the enamel surface, and these alterations hold promise for the conditioning of enamel for bonding procedures. This laboratory study examined the influence of laser irradiation of enamel at 2 different power settings with an erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) hydrokinetic laser system (Millennium System, Biolase Technology, Inc; San Clemente, Calif) on the shear bond strength of orthodontic appliances and compared these with that of acid-etching. The prepared surfaces of 40 noncarious, intact, extracted premolars were exposed to laser energy: 20 teeth at 2-W setting (5.6 J/cm(2)) and 20 teeth at 1-W setting (2.7 J/cm(2)) of the commercial laser unit. Twenty teeth were etched with 37% orthophosphoric acid. Brackets were bonded with an orthodontic no-mix adhesive, and shear bond strength was determined with a universal testing machine. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Etched and restored surfaces of an acid-etched tooth and a 2-W laser-irradiated tooth were examined with scanning electron microscopy (SEM). Laser treatment under 2 W resulted in bond strengths of 7.11 +/- 4.56 megapascals (MPa), which was not significantly different from that of acid etching (8.23 +/- 2.30 MPa). Laser irradiation at 1 W resulted in bond strengths of 5.64 +/- 3.19 MPa, which was significantly different from that of acid etching (P <.05). However, large SD and coefficient of variation values of both laser groups made reliability of this method as an enamel conditioner questionable. Scanning electron microscopy studies of the restored irradiated surfaces showed good surface characteristics, whereas the lased surface was still more irregular than the restored acid-etched sample. Although laser devices are effectively used in some other areas of dentistry, enamel conditioning with an Er,Cr:YSGG laser cannot be considered a successful

  20. Laser etching of enamel for direct bonding with an Er,Cr:YSGG hydrokinetic laser system.

    PubMed

    Uşümez, Serdar; Orhan, Metin; Uşümez, Aslihan

    2002-12-01

    Irradiation of enamel with laser energy changes the physical and chemical characteristics of the enamel surface, and these alterations hold promise for the conditioning of enamel for bonding procedures. This laboratory study examined the influence of laser irradiation of enamel at 2 different power settings with an erbium, chromium: yttrium, scandium, gallium, garnet (Er,Cr:YSGG) hydrokinetic laser system (Millennium System, Biolase Technology, Inc; San Clemente, Calif) on the shear bond strength of orthodontic appliances and compared these with that of acid-etching. The prepared surfaces of 40 noncarious, intact, extracted premolars were exposed to laser energy: 20 teeth at 2-W setting (5.6 J/cm(2)) and 20 teeth at 1-W setting (2.7 J/cm(2)) of the commercial laser unit. Twenty teeth were etched with 37% orthophosphoric acid. Brackets were bonded with an orthodontic no-mix adhesive, and shear bond strength was determined with a universal testing machine. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Etched and restored surfaces of an acid-etched tooth and a 2-W laser-irradiated tooth were examined with scanning electron microscopy (SEM). Laser treatment under 2 W resulted in bond strengths of 7.11 +/- 4.56 megapascals (MPa), which was not significantly different from that of acid etching (8.23 +/- 2.30 MPa). Laser irradiation at 1 W resulted in bond strengths of 5.64 +/- 3.19 MPa, which was significantly different from that of acid etching (P <.05). However, large SD and coefficient of variation values of both laser groups made reliability of this method as an enamel conditioner questionable. Scanning electron microscopy studies of the restored irradiated surfaces showed good surface characteristics, whereas the lased surface was still more irregular than the restored acid-etched sample. Although laser devices are effectively used in some other areas of dentistry, enamel conditioning with an Er,Cr:YSGG laser cannot be considered a successful

  1. 76 FR 2368 - Balance Power Systems, LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-01-13

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Balance Power Systems, LLC; Supplemental Notice That Initial Market-Based... supplemental notice in the above-referenced proceeding of Balance Power Systems, LLC's application for...

  2. Intra-Rater and Inter-Rater Reliability of the Balance Error Scoring System in Pre-Adolescent School Children

    ERIC Educational Resources Information Center

    Sheehan, Dwayne P.; Lafave, Mark R.; Katz, Larry

    2011-01-01

    This study was designed to test the intra- and inter-rater reliability of the University of North Carolina's Balance Error Scoring System in 9- and 10-year-old children. Additionally, a modified version of the Balance Error Scoring System was tested to determine if it was more sensitive in this population ("raw scores"). Forty-six normally…

  3. Design and performance of a laser guide star system for the Keck II telescope

    SciTech Connect

    Friedman, H. W., LLNL

    1998-05-18

    A laser system to generate sodium-layer guide stars has been designed, built and delivered to the Keck Observatory in Hawaii. The system uses frequency doubled YAG lasers to pump liquid dye lasers and produces 20 W of average power. The design and performance results of this laser system are presented.

  4. Laser Ground System for Communication Experiments with ARTEMIS

    NASA Astrophysics Data System (ADS)

    Kuzkov, Volodymyr; Volovyk, Dmytro; Kuzkov, Sergii; Sodnik, Zoran; Pukha, Sergii; Caramia, Vincenzo

    2012-10-01

    The ARTEMIS satellite with the OPALE laser communication terminal on-board was launched on 12 July, 2001. 1789 laser communications sessions were performed between ARTEMIS and SPOT-4 (PASTEL) from 01 April 2003 to 09 January 2008 with total duration of 378 hours. Regular laser communication experiments between ESA's Optical Ground Station (OGS - altitude 2400 m above see level) and ARTEMIS in various atmosphere conditions were also performed. The Japanese Space Agency (JAXA) launched the KIRARI (OICETS) satellite with laser communication terminal called LUCE. Laser communication links between KIRARI and ARTEMIS were successfully realized and international laser communications experiments from the KIRARI satellite were also successfully performed with optical ground stations located in the USA (JPL), Spain (ESA OGS), Germany (DLR), and Japan (NICT). The German Space Agency (DLR) performed laser communication links between two LEO satellites (TerraSAR-X and NFIRE), demonstrating data transfer rates of 5.6Gbit/s and performed laser communication experiments between the satellites and the ESA optical ground station. To reduce the influence of weather conditions on laser communication between satellites and ground stations, a network of optical stations situated in different atmosphere regions needs to be created. In 2002, the Main Astronomical Observatory (MAO) started the development of its own laser communication system to be placed into the Cassegrain focus of its 0.7m AZT-2 telescope (Fe = 10.5m), located in Kyiv 190 meters above sea level. The work was supported by the National Space Agency of Ukraine and by ESA ARTEMIS has an orbital position of 21.4° E and an orbital inclination of more than 9.75°. As a result we developed a precise tracking system for AZT-2 telescope (weighing more than 2 tons) using micro-step motors. Software was developed for computer control of the telescope to track the satellite's orbit and a tracking accuracy of 0.6 arcsec was achieved

  5. Field-Testing of an Active Laser Tracking System

    NASA Astrophysics Data System (ADS)

    Markov, V.; Khiznyak, A.; Woll, D.; Liu, S.

    Comprehensive space surveillance demands a more accurate technique in tracking multi-dimensional state vector (3D coordinate, velocity, vibration, etc.) of the space objects. RF radiometric techniques typically can not provide the needed accuracy, while passive optical (and laser) tracking systems can provide distance to the object and its angular position, but not a direct reading of velocity, the parameter of primary importance for space object tracking and characterization. Addressing this problem with active optical tracking techniques is challenging because of the great distances involved, the high velocity of the satellites, and the optical aberrations induced by the atmosphere. We have proposed a phase conjugation based laser tracking concept, and accomplished the first version of design and engineering of a prototype for an Active Laser Tracking System (ALTS). In its current state the ALTS is capable to demonstrate the very basics operational principles of the proposed active tracking technique. We then performed a number of experiments to prove operational capabilities of this prototype both at MetroLaser's lab environment and at Edwards AFB Test Range. In its current architecture the ALTS is comprised of two laser cavities, Master and Slave that are coupled through a Phase Conjugate Mirror (PCM) formed in a non-linear medium (NLM) set at Master laser cavity. By pumping NLM and forming PCM, Master laser establishes the cavities coupling mode and injects the photons in the slave cavity. It is essential that the specific features of the PCM not only serve to couple ALTS cavities, but also serves to compensate optical aberrations of the ALTS (gain media and optical elements of the laser resonator). Due to its ability to compensate optical aberrations, phase conjugate resonators are capable of sustaining oscillation with a remote target as an output coupler. The entire system comprises of several modules, including a laser, emitting/receiving telescope, gimbal

  6. Low cost laser weld monitoring system

    SciTech Connect

    Leong, K.H.

    1997-04-01

    Laser beam welding is a joining technology that has gained increased acceptance because of its high speed, precision, and low heat effects compared to conventional arc welding methods. Argonne National Laboratory in collaboration with the automotive industry has developed a robust on-line weld monitor capable of sensing weld surface changes and penetration. The development of the weld monitor took tin account the constraints and operating environment of the factor floor in addition to monitoring needs for quality assurance. The on-line non-intrusive weld monitor developed is rugged and simple to use, does not require power to operate, is weld spatter protected and low cost; features that are desired for the factor floor. The weld monitoring technology is available for licensing. An exclusive license has been awarded to Spawr Industries for an inline weld monitor for CO{sub 2} laser applications. Licensing of the weld monitor for other implementations in CO{sub 2} and Nd:YAG laser applications are available.

  7. Population-based learning of load balancing policies for a distributed computer system

    NASA Technical Reports Server (NTRS)

    Mehra, Pankaj; Wah, Benjamin W.

    1993-01-01

    Effective load-balancing policies use dynamic resource information to schedule tasks in a distributed computer system. We present a novel method for automatically learning such policies. At each site in our system, we use a comparator neural network to predict the relative speedup of an incoming task using only the resource-utilization patterns obtained prior to the task's arrival. Outputs of these comparator networks are broadcast periodically over the distributed system, and the resource schedulers at each site use these values to determine the best site for executing an incoming task. The delays incurred in propagating workload information and tasks from one site to another, as well as the dynamic and unpredictable nature of workloads in multiprogrammed multiprocessors, may cause the workload pattern at the time of execution to differ from patterns prevailing at the times of load-index computation and decision making. Our load-balancing policy accommodates this uncertainty by using certain tunable parameters. We present a population-based machine-learning algorithm that adjusts these parameters in order to achieve high average speedups with respect to local execution. Our results show that our load-balancing policy, when combined with the comparator neural network for workload characterization, is effective in exploiting idle resources in a distributed computer system.

  8. Quantitative data quality metrics for 3D laser radar systems

    NASA Astrophysics Data System (ADS)

    Stevens, Jeffrey R.; Lopez, Norman A.; Burton, Robin R.

    2011-06-01

    Several quantitative data quality metrics for three dimensional (3D) laser radar systems are presented, namely: X-Y contrast transfer function, Z noise, Z resolution, X-Y edge & line spread functions, 3D point spread function and data voids. These metrics are calculated from both raw and/or processed point cloud data, providing different information regarding the performance of 3D imaging laser radar systems and the perceptual quality attributes of 3D datasets. The discussion is presented within the context of 3D imaging laser radar systems employing arrays of Geiger-mode Avalanche Photodiode (GmAPD) detectors, but the metrics may generally be applied to linear mode systems as well. An example for the role of these metrics in comparison of noise removal algorithms is also provided.

  9. Design of a perfect balance system for active upper-extremity exoskeletons.

    PubMed

    Smith, Richard L; Lobo-Prat, Joan; van der Kooij, Herman; Stienen, Arno H A

    2013-06-01

    Passive gravity compensation in exoskeletons significantly reduces the amount of torque and energy needed from the actuators. So far, no design has been able to achieve perfect balance without compromising the exoskeleton characteristics. Here we propose a novel design that integrates an existing statically-balanced mechanism with two springs and four degrees of freedom into a general-purpose exoskeleton design, that can support any percentage of the combined weight of exoskeleton and arm. As it allows for three rotational degrees of freedom at the shoulder and one at the elbow, it does not compromise exoskeleton characteristics and can be powered with any choice of passive or active actuation method. For instance, with this design a perfectly balanced exoskeleton design with inherently safe, passive actuators on each joint axis becomes possible. The potential reduction in required actuator torque, power and weight, simplification of control, improved dynamic performance, and increased safety margin, all while maintaining perfect balance, are the major advantages of the design, but the integrated systems does add a significant amount of complexity. Future integration in an actual exoskeleton should prove if this tradeoff is beneficial. PMID:24187195

  10. Design of a perfect balance system for active upper-extremity exoskeletons.

    PubMed

    Smith, Richard L; Lobo-Prat, Joan; van der Kooij, Herman; Stienen, Arno H A

    2013-06-01

    Passive gravity compensation in exoskeletons significantly reduces the amount of torque and energy needed from the actuators. So far, no design has been able to achieve perfect balance without compromising the exoskeleton characteristics. Here we propose a novel design that integrates an existing statically-balanced mechanism with two springs and four degrees of freedom into a general-purpose exoskeleton design, that can support any percentage of the combined weight of exoskeleton and arm. As it allows for three rotational degrees of freedom at the shoulder and one at the elbow, it does not compromise exoskeleton characteristics and can be powered with any choice of passive or active actuation method. For instance, with this design a perfectly balanced exoskeleton design with inherently safe, passive actuators on each joint axis becomes possible. The potential reduction in required actuator torque, power and weight, simplification of control, improved dynamic performance, and increased safety margin, all while maintaining perfect balance, are the major advantages of the design, but the integrated systems does add a significant amount of complexity. Future integration in an actual exoskeleton should prove if this tradeoff is beneficial.

  11. A Reliability of the Prototype Trunk Training System for Sitting Balance

    PubMed Central

    Jeong, Juri; Park, Dae-Sung; Lee, Hyelim; Eun, Seondeok

    2014-01-01

    [Purpose] Cerebral palsy is a disorder that affects balance in the sitting position. Cerebral palsy patients need trunk muscle strengthening and balance training. In order to improve trunk control sensory-motor control training is carried out on an unstable surface. We have developed a Trunk Training System (TTS) that can provide visual feedback using a tilt sensor for balance training in the sitting position. Before using the TTS for training children with cerebral palsy experiments were conducted with healthy adult subjects and the TTS to gather basic data for its improvement. [Subjects] The subjects were 11 healthy men (n=3) and women (n=8). [Methods] Subjects trained at two levels (5°, 10°), in four different directions (anterior, posterior, left, right), three times each. TTS outcome indices (stability index, performance time) were measured. [Results] The stability index and performance time showed high correlation (−0.6balance. Additional experiments will be needed to investigate the validity of the TTS measurements. PMID:25435691

  12. Novel atmospheric extinction measurement techniques for aerospace laser system applications

    NASA Astrophysics Data System (ADS)

    Sabatini, Roberto; Richardson, Mark

    2013-01-01

    Novel techniques for laser beam atmospheric extinction measurements, suitable for manned and unmanned aerospace vehicle applications, are presented in this paper. Extinction measurements are essential to support the engineering development and the operational employment of a variety of aerospace electro-optical sensor systems, allowing calculation of the range performance attainable with such systems in current and likely future applications. Such applications include ranging, weaponry, Earth remote sensing and possible planetary exploration missions performed by satellites and unmanned flight vehicles. Unlike traditional LIDAR methods, the proposed techniques are based on measurements of the laser energy (intensity and spatial distribution) incident on target surfaces of known geometric and reflective characteristics, by means of infrared detectors and/or infrared cameras calibrated for radiance. Various laser sources can be employed with wavelengths from the visible to the far infrared portions of the spectrum, allowing for data correlation and extended sensitivity. Errors affecting measurements performed using the proposed methods are discussed in the paper and algorithms are proposed that allow a direct determination of the atmospheric transmittance and spatial characteristics of the laser spot. These algorithms take into account a variety of linear and non-linear propagation effects. Finally, results are presented relative to some experimental activities performed to validate the proposed techniques. Particularly, data are presented relative to both ground and flight trials performed with laser systems operating in the near infrared (NIR) at λ = 1064 nm and λ = 1550 nm. This includes ground tests performed with 10 Hz and 20 kHz PRF NIR laser systems in a large variety of atmospheric conditions, and flight trials performed with a 10 Hz airborne NIR laser system installed on a TORNADO aircraft, flying up to altitudes of 22,000 ft.

  13. Measurement system with high accuracy for laser beam quality.

    PubMed

    Ke, Yi; Zeng, Ciling; Xie, Peiyuan; Jiang, Qingshan; Liang, Ke; Yang, Zhenyu; Zhao, Ming

    2015-05-20

    Presently, most of the laser beam quality measurement system collimates the optical path manually with low efficiency and low repeatability. To solve these problems, this paper proposed a new collimated method to improve the reliability and accuracy of the measurement results. The system accuracy controlled the position of the mirror to change laser beam propagation direction, which can realize the beam perpendicularly incident to the photosurface of camera. The experiment results show that the proposed system has good repeatability and the measuring deviation of M2 factor is less than 0.6%.

  14. Infrared Laser System for Extended Area Monitoring of Air Pollution

    NASA Technical Reports Server (NTRS)

    Snowman, L. R.; Gillmeister, R. J.

    1971-01-01

    An atmospheric pollution monitoring system using a spectrally scanning laser has been developed by the General Electric Company. This paper will report on an evaluation of a breadboard model, and will discuss applications of the concept to various ambient air monitoring situations. The system is adaptable to other tunable lasers. Operating in the middle infrared region, the system uses retroreflectors to measure average concentrations over long paths at low, safe power levels. The concept shows promise of meeting operational needs in ambient air monitoring and providing new data for atmospheric research.

  15. Fiber optic coherent laser radar 3d vision system

    SciTech Connect

    Sebastian, R.L.; Clark, R.B.; Simonson, D.L.

    1994-12-31

    Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic of coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  16. Numerical control system of battery welding with pulsed YAG laser

    NASA Astrophysics Data System (ADS)

    Zhang, Guoshun; Yang, Zhaoxia; Zhang, Taishi; Wei, Zhigang; Li, Chaoyang

    1999-09-01

    This article briefly introduces the pulse YAG laser welding system, a new research achievement of my section. This system can weld the electric pole, the holly board and other aluminum parts of lithium battery, and the process of loading, unloading, compressing and welding can be completed automatically. Moreover, the software proprietary of the system is very good, and its interface is friendly too. In order to achieve optimum welding effect, we have designed special laser discharging waveform. Its rise delay time, fall delay time, and width are all designed specially. With this special technology, the welding spot we get is smooth like mirror, and the welding intensity can be controlled conveniently.

  17. Measurement system with high accuracy for laser beam quality.

    PubMed

    Ke, Yi; Zeng, Ciling; Xie, Peiyuan; Jiang, Qingshan; Liang, Ke; Yang, Zhenyu; Zhao, Ming

    2015-05-20

    Presently, most of the laser beam quality measurement system collimates the optical path manually with low efficiency and low repeatability. To solve these problems, this paper proposed a new collimated method to improve the reliability and accuracy of the measurement results. The system accuracy controlled the position of the mirror to change laser beam propagation direction, which can realize the beam perpendicularly incident to the photosurface of camera. The experiment results show that the proposed system has good repeatability and the measuring deviation of M2 factor is less than 0.6%. PMID:26192526

  18. A laser imaging system for helicopter avoidance obstacle

    NASA Astrophysics Data System (ADS)

    Wang, WeiRan; Yuan, HongChun; Jin, Yuan

    2006-09-01

    Rotorcraft flying in low-altitude is endangered by power lines or telephone wires. The development of automated tools that can detect obstacles in the flight path and warn the crew would significantly reduce the workload of pilot and increase the safety. Detection and warning are rudimental demand and desire for Helicopter Avoidance Obstacle System (HAOS). And that, An advanced HAOS may be capable of classifying thin obstacles and enhanced vision with distances of obstacles. A laser 3D imaging system for helicopter avoidance obstacle (HAO) had been developed successfully. The laser 3D imaging helicopter avoidance obstacle system can not only detect thin obstacles but also catch more information of all objects of the area in front of the helicopter as possible. Then the information is transformed into intuitionist 3D image modality. In this paper, special features and characteristic of the laser imaging system for HAO are analyzed and discussed. Several design gist for this system are proposed. Especially, the developed zero backlash imaging technology and real-time dynamic imaging synchronizing with radar space scanning are described. The technique implementation problem and the system structure are given as well. Finally, the results of system ground test are presented. The ground test of the developed laser imaging system has demonstrated that the developed imaging system performance can achieve and satisfy commendably the requirements of the mission to prevent "wire strike".

  19. Tunable solid state laser system for dermatology applications

    NASA Astrophysics Data System (ADS)

    Azar, Zion; Bank, Alexander; Donskoy, Dmitri M.; Nechitailo, Vladimir S.

    1994-12-01

    The Q-switched Nd:YAG laser is the most recent in a series of pulsed laser systems for plastic surgery. The 532 nm wavelength has been shown to be absorbed by a variety of chromophores. These include tattoo pigments, oxygenated hemoglobin and melanin-containing epidermal cells. A simple multi-line solid state laser module pumped by double-frequency Q- switched YAG laser is presented. This solid state multi-line module enables tuning of the wavelength in the yellow spectral range to 560 nm or to 580 nm for dermatology applications. Conversion efficiency in excess of 70% was achieved at 10 Hz pulse repetition frequency and output energy per pulse of approximately 200 mJ.

  20. Stretchers and compressors for ultra-high power laser systems

    SciTech Connect

    Yakovlev, I V

    2014-05-30

    This review is concerned with pulse stretchers and compressors as key components of ultra-high power laser facilities that take advantage of chirped-pulse amplification. The potentialities, characteristics, configurations and methods for the matching and alignment of these devices are examined, with particular attention to the history of the optics of ultra-short, ultra-intense pulses before and after 1985, when the chirped-pulse amplification method was proposed, which drastically changed the view of the feasibility of creating ultra-high power laser sources. The review is intended primarily for young scientists and experts who begin to address the amplification and compression of chirped pulses, experts in laser optics and all who are interested in scientific achievements in the field of ultra-high power laser systems. (review)