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Sample records for advanced pulsed power

  1. Advances in high-power harmonic generation: Q-switched lasers with electronically adjustable pulse width

    NASA Astrophysics Data System (ADS)

    Eyres, Loren A.; Morehead, James J.; Gregg, Jeffrey; Richard, Derek J.; Grossman, William

    2006-02-01

    We demonstrate a variable pulse width, internally-frequency-converted, near-diffraction-limited Nd:YAG laser with output power up to 40 Watts at 532 nm and pulse widths electronically adjustable over a 40-300 ns range. The variable pulse width is achieved by clipping the pulse decaying edge with the Q-switch in a laser cavity optimized for post-pulse gain insensitivity. This approach makes possible frequency converted lasers with pulse width and output power substantially independent of repetition rate.

  2. Applications of pulsed power in advanced oxidation and reduction processes for pollution control

    SciTech Connect

    Rosocha, L.A.; Coogan, J.J.; Secker, D.A.; Smith, J.D.

    1993-08-01

    A growing social awareness of the adverse impact of pollutants on our environment and the promulgation of environmental laws and regulations has recently stimulated the development of technologies for pollution abatement and hazardous waste destruction. Pulsed power shows strong promise for contributing to the development of innovative technologies aimed at these applications. At Los Alamos we are engaged in two projects which apply pulsed power technology to the environment: the use of relativistic electron beams and nonequilibrium plasmas for the destruction of hazardous organic compounds in aqueous-based and gaseous-based medial, respectively. Electron beams and nonequilibrium plasmas have also been applied to the treatment of flue gases such as SO{sub x} and NO{sub x} by other researchers. In this paper, we will describe our electron-beam and plasma experiments carried out on hazardous waste destruction. Additionally, we will describe the scaling of electron-beam and nonequilibrium plasma systems to industrial sizes, including discussions of electron accelerator architecture, comparison of continuous-duty versus repetitively pulsed accelerators, plasma-discharge modulators, and needed pulsed power technology development.

  3. Advanced concepts for high-power, short-pulse CO2 laser development

    NASA Astrophysics Data System (ADS)

    Gordon, Daniel F.; Hasson, Victor; von Bergmann, Hubertus; Chen, Yu-hsin; Schmitt-Sody, A.; Penano, Joseph R.

    2016-06-01

    Ultra-short pulse lasers are dominated by solid-state technology, which typically operates in the near-infrared. Efforts to extend this technology to longer wavelengths are meeting with some success, but the trend remains that longer wavelengths correlate with greatly reduced power. The carbon dioxide (CO2) laser is capable of delivering high energy, 10 micron wavelength pulses, but the gain structure makes operating in the ultra-short pulse regime difficult. The Naval Research Laboratory and Air Force Research Laboratory are developing a novel CO2 laser designed to deliver ~1 Joule, ~1 picosecond pulses, from a compact gain volume (~2x2x80 cm). The design is based on injection seeding an unstable resonator, in order to achieve high energy extraction efficiency, and to take advantage of power broadening. The unstable resonator is seeded by a solid state front end, pumped by a custom built titanium sapphire laser matched to the CO2 laser bandwidth. In order to access a broader range of mid infrared wavelengths using CO2 lasers, one must consider nonlinear frequency multiplication, which is non-trivial due to the bandwidth of the 10 micron radiation.

  4. Microwave and Pulsed Power

    SciTech Connect

    Freytag, E.K.

    1993-03-01

    The goals of the Microwave and Pulsed Power thrust area are to identify realizable research and development efforts and to conduct high-quality research in those pulse power and microwave technologies that support existing and emerging programmatic requirements at Lawrence Livermore National Laboratory (LLNL). Our main objective is to work on nationally important problems while enhancing our basic understanding of enabling technologies such as component design and testing, compact systems packaging, exploratory physics experiments, and advanced systems integration and performance. During FY-92, we concentrated our research efforts on the six project areas described in this report. (1) We are investigating the superior electronic and thermal properties of diamond that may make it an ideal material for a high-power, solid-state switch. (2) We are studying the feasibility of using advanced Ground Penetrating Imaging Radar technology for reliable non-destructive evaluation of bridges and other high-value concrete structures. These studies include conceptual designs, modeling, experimental verifications, and image reconstruction of simulated radar data. (3) We are exploring the efficiency of pulsed plasma processing techniques used for the removal of NO{sub x} from various effluent sources. (4) We have finished the investigation of the properties of a magnetically delayed low-pressure gas switch, which was designed here at LLNL. (5) We are applying statistical electromagnetic theory techniques to help assess microwave effects on electronic subsystems, by using a mode stirred chamber as our measurement tool. (6) We are investigating the generation of perfluoroisobutylene (PFIB) in proposed CFC replacement fluids when they are subjected to high electrical stresses and breakdown environments.

  5. Advanced high-speed flywheel energy storage systems for pulsed power application

    NASA Astrophysics Data System (ADS)

    Talebi Rafsanjan, Salman

    Power systems on modern commercial transportation systems are moving to more electric based equipment, thus improving the reliability of the overall system. Electrical equipment on such systems will include some loads that require very high power for short periods of time, on the order of a few seconds, especially during acceleration and deceleration. The current approach to solving this problem is sizing the electrical grid for peak power, rather than the average. A method to efficiently store and discharge the pulsed power is necessary to eliminate the cost and weight of oversized generation equipment to support the pulsed power needs of these applications. Highspeed Flywheel Energy Storage Systems (FESS) are effectively capable of filling the niche of short duration, high cycle life applications where batteries and ultra capacitors are not usable. In order to have an efficient high-speed FESS, performing three important steps towards the design of the overall system are extremely vital. These steps are modeling, analysis and control of the FESS that are thoroughly investigated in this dissertation. This dissertation establishes a comprehensive analysis of a high-speed FESS in steady state and transient operations. To do so, an accurate model for the complete FESS is derived. State space averaging approach is used to develop DC and small-signal AC models of the system. These models effectively simplify analysis of the FESS and give a strong physical intuition to the complete system. In addition, they result in saving time and money by avoiding time consuming simulations performed by expensive packages, such as Simulink, PSIM, etc. In the next step, two important factors affecting operation of the Permanent Magnet Synchronous Machine (PMSM) implemented in the high-speed FESS are investigated in detail and outline a proper control strategy to achieve the required performance by the system. Next, a novel design algorithm developed by S.P. Bhattacharyya is used to

  6. Pulsed power molten salt battery

    NASA Technical Reports Server (NTRS)

    Argade, Shyam D.

    1992-01-01

    It was concluded that carbon cathodes with chlorine work well. Lithium alloy chlorine at 450 C, 1 atm given high power capability, high energy density, DC + pulsing yields 600 pulses, no initial peak, and can go to red heat without burn-up. Electrochemical performance at the cell and cell stack level out under demanding test regime. Engineering and full prototype development for advancing this technology is warranted.

  7. Pulsed power molten salt battery

    NASA Astrophysics Data System (ADS)

    Argade, Shyam D.

    1992-02-01

    It was concluded that carbon cathodes with chlorine work well. Lithium alloy chlorine at 450 C, 1 atm given high power capability, high energy density, DC + pulsing yields 600 pulses, no initial peak, and can go to red heat without burn-up. Electrochemical performance at the cell and cell stack level out under demanding test regime. Engineering and full prototype development for advancing this technology is warranted.

  8. High-power Waveguide Dampers for the Short-Pulse X-Ray Project at the Advanced Photon Source

    SciTech Connect

    Waldschmidt, G J; Liu, J; Middendorf, M E; Nassiri, A; Smith, T L; Wu, G; Henry, J; Mammosser, J D; Rimmer, R A; Wiseman, M

    2012-07-01

    High-power waveguide dampers have been designed and prototyped for the Short-Pulse X-ray (SPX) cavities at the Advanced Photon Source. The cavities will operate at 2.815 GHz and utilize the TM110 dipole mode. As a result, higher-order (HOM) and lower-order mode (LOM) in-vacuum dampers have been designed to satisfy the demanding broadband damping requirements in the APS storage ring. The SPX single-cell cavity consists of two WR284 waveguides for damping the HOMs and one WR284 waveguide for primarily damping the LOM where up to 2kW will be dissipated in the damping material. The damper designs and high-power experimental results will be discussed in this paper.

  9. Induction linacs and pulsed power

    SciTech Connect

    Caporaso, G.J.

    1995-07-11

    Progress in electronic power conversion technology is making possible a new class of induction linacs that can operate at extremely high repetition rates. Advances in insulator technology, pulse forming line design and switching may also lead to a new type of high current accelerator with accelerating gradients at least an order of magnitude greater than those attainable today. The evolution of the induction accelerator pulsed power system will be discussed along with some details of these emerging technologies which are at the frontiers of accelerator technology.

  10. Lithium batteries for pulse power

    NASA Astrophysics Data System (ADS)

    Redey, Laszlo

    New designs of lithium batteries having bipolar construction and thin cell components possess the very low impedance that is necessary to deliver high-intensity current pulses. The research and development and understanding of the fundamental properties of these pulse batteries have reached an advanced level. Ranges of 50 to 300 kW/kg specific power and 80 to 130 Wh/kg specific energy have been demonstrated with experimental high-temperature lithium alloy/transition-metal disulfide rechargeable bipolar batteries in repeated 1- to 100-ms long pulses. Other versions are designed for repetitive power bursts that may last up to 20 or 30 s and yet may attain high specific power (1 to 10 kW/kg). Primary high-temperature Li-alloy/FeS2 pulse batteries (thermal batteries) are already commercially available. Other high-temperature lithium systems may use chlorine or metal-oxide positive electrodes. Also under development are low-temperature pulse batteries: a 50-kW Li/SOCl2 primary batter and an all solid-state, polymer-electrolyte secondary battery. Such pulse batteries could find use in commercial and military applications in the near future.

  11. Lithium batteries for pulse power

    SciTech Connect

    Redey, L.

    1990-01-01

    New designs of lithium batteries having bipolar construction and thin cell components possess the very low impedance that is necessary to deliver high-intensity current pulses. The R D and understanding of the fundamental properties of these pulse batteries have reached an advanced level. Ranges of 50--300 kW/kg specific power and 80--130 Wh/kg specific energy have been demonstrated with experimental high-temperature lithium alloy/transition-metal disulfide rechargeable bipolar batteries in repeated 1- to 100-ms long pulses. Other versions are designed for repetitive power bursts that may last up to 20 or 30 s and yet may attain high specific power (1--10 kW/kg). Primary high-temperature Li-alloy/FeS{sub 2} pulse batteries (thermal batteries) are already commercially available. Other high-temperature lithium systems may use chlorine or metal-oxide positive electrodes. Also under development are low-temperature pulse batteries: a 50-kW Li/SOCl{sub 2} primary batter and an all solid-state, polymer-electrolyte secondary battery. Such pulse batteries could find use in commercial and military applications in the near future. 21 refs., 8 figs.

  12. HIGH POWER PULSED OSCILLATOR

    DOEpatents

    Singer, S.; Neher, L.K.

    1957-09-24

    A high powered, radio frequency pulse oscillator is described for generating trains of oscillations at the instant an input direct voltage is impressed, or immediately upon application of a light pulse. In one embodiment, the pulse oscillator comprises a photo-multiplier tube with the cathode connected to the first dynode by means of a resistor, and adjacent dynodes are connected to each other through adjustable resistors. The ohmage of the resistors progressively increases from a very low value for resistors adjacent the cathode to a high value adjacent the plate, the last dynode. Oscillation occurs with this circuit when a high negative voltage pulse is applied to the cathode and the photo cathode is bombarded. Another embodiment adds capacitors at the resistor connection points of the above circuit to increase the duration of the oscillator train.

  13. Pulse power linac

    DOEpatents

    Villa, Francesco

    1990-01-01

    A linear acceleration for charged particles is constructed of a plurality of transmission line sections that extend between a power injection region and an accelerating region. Each line section is constructed of spaced plate-like conductors and is coupled to an accelerating gap located at the accelerating region. Each gap is formed between a pair of apertured electrodes, with all of the electrode apertures being aligned along a particle accelerating path. The accelerating gaps are arranged in series, and at the injection region the line sections are connected in parallel. At the injection region a power pulse is applied simultaneously to all line sections. The line sections are graduated in length so that the pulse reaches the gaps in a coordinated sequence whereby pulse energy is applied to particles as they reach each of the gaps along the accelerating path.

  14. Switching power pulse system

    DOEpatents

    Aaland, K.

    1983-08-09

    A switching system for delivering pulses of power from a source to a load using a storage capacitor charged through a rectifier, and maintained charged to a reference voltage level by a transistor switch and voltage comparator. A thyristor is triggered to discharge the storage capacitor through a saturable reactor and fractional turn saturable transformer having a secondary to primary turn ratio N of n:l/n = n[sup 2]. The saturable reactor functions as a soaker'' while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor charges, and then switches to a low impedance state to dump the charge of the storage capacitor into the load through the coupling capacitor. The transformer is comprised of a multilayer core having two secondary windings tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe for a linear particle accelerator and capacitance of a pulse forming network. To hold off discharge of the capacitance until it is fully charged, a saturable core is provided around the resistive beampipe to isolate the beampipe from the capacitance until it is fully charged. 5 figs.

  15. Switching power pulse system

    DOEpatents

    Aaland, Kristian

    1983-01-01

    A switching system for delivering pulses of power from a source (10) to a load (20) using a storage capacitor (C3) charged through a rectifier (D1, D2), and maintained charged to a reference voltage level by a transistor switch (Q1) and voltage comparator (12). A thyristor (22) is triggered to discharge the storage capacitor through a saturable reactor (18) and fractional turn saturable transformer (16) having a secondary to primary turn ratio N of n:l/n=n.sup.2. The saturable reactor (18) functions as a "soaker" while the thyristor reaches saturation, and then switches to a low impedance state. The saturable transformer functions as a switching transformer with high impedance while a load coupling capacitor (C4) charges, and then switches to a low impedance state to dump the charge of the storage capacitor (C3) into the load through the coupling capacitor (C4). The transformer is comprised of a multilayer core (26) having two secondary windings (28, 30) tightly wound and connected in parallel to add their output voltage and reduce output inductance, and a number of single turn windings connected in parallel at nodes (32, 34) for the primary winding, each single turn winding linking a different one of the layers of the multilayer core. The load may be comprised of a resistive beampipe (40) for a linear particle accelerator and capacitance of a pulse forming network (42). To hold off discharge of the capacitance until it is fully charged, a saturable core (44) is provided around the resistive beampipe (40) to isolate the beampipe from the capacitance (42) until it is fully charged.

  16. Petawatt pulsed-power accelerator

    DOEpatents

    Stygar, William A.; Cuneo, Michael E.; Headley, Daniel I.; Ives, Harry C.; Ives, legal representative; Berry Cottrell; Leeper, Ramon J.; Mazarakis, Michael G.; Olson, Craig L.; Porter, John L.; Wagoner; Tim C.

    2010-03-16

    A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

  17. Application of Pulsed Electrical Fields for Advanced Cooling and Water Recovery in Coal-Fired Power Plant

    SciTech Connect

    Young Cho; Alexander Fridman

    2009-04-02

    The overall objective of the present work was to develop technologies to reduce freshwater consumption in a cooling tower of coal-based power plant so that one could significantly reduce the need of make-up water. The specific goal was to develop a scale prevention technology based an integrated system of physical water treatment (PWT) and a novel filtration method so that one could reduce the need for the water blowdown, which accounts approximately 30% of water loss in a cooling tower. The present study investigated if a pulsed spark discharge in water could be used to remove deposits from the filter membrane. The test setup included a circulating water loop and a pulsed power system. The present experiments used artificially hardened water with hardness of 1,000 mg/L of CaCO{sub 3} made from a mixture of calcium chloride (CaCl{sub 2}) and sodium carbonate (Na{sub 2}CO{sub 3}) in order to produce calcium carbonate deposits on the filter membrane. Spark discharge in water was found to produce strong shockwaves in water, and the efficiency of the spark discharge in cleaning filter surface was evaluated by measuring the pressure drop across the filter over time. Results showed that the pressure drop could be reduced to the value corresponding to the initial clean state and after that the filter could be maintained at the initial state almost indefinitely, confirming the validity of the present concept of pulsed spark discharge in water to clean dirty filter. The present study also investigated the effect of a plasma-assisted self-cleaning filter on the performance of physical water treatment (PWT) solenoid coil for the mitigation of mineral fouling in a concentric counterflow heat exchanger. The self-cleaning filter utilized shockwaves produced by pulse-spark discharges in water to continuously remove scale deposits from the surface of the filter, thus keeping the pressure drop across the filter at a relatively low value. Artificial hard water was used in the

  18. Pulsed high-power beams

    SciTech Connect

    Reginato, L.L.; Birx, D.L.

    1988-06-01

    The marriage of induction linac technology with nonlinear magnetic modulators has produced some unique capabilities. It is now possible to produce short-pulse electron beams with average currents measured in amperes, at gradients approaching 1-MeV/m, and with power efficiencies exceeding 50%. A 70-Mev, 3-kA induction accelerator (ETA II) constructed at the Lawrence Livermore National Laboratory incorporates the pulse technology concepts that have evolved over the past several years. The ETA II is a linear induction accelerator and provides a test facility for demonstration of the high-average-power components and high-brightness sources used in such accelerators. The pulse drive for the accelerator is based on state-of-the-art magnetic pulse compressors with very high peak-power capability, repetition rates exceeding 1 kHz, and excellent reliability. 6 figs.

  19. Pulsed Power Driven Fusion Energy

    SciTech Connect

    SLUTZ,STEPHEN A.

    1999-11-22

    Pulsed power is a robust and inexpensive technology for obtaining high powers. Considerable progress has been made on developing light ion beams as a means of transporting this power to inertial fusion capsules. However, further progress is hampered by the lack of an adequate ion source. Alternatively, z-pinches can efficiently convert pulsed power into thermal radiation, which can be used to drive an inertial fusion capsule. However, a z-pinch driven fusion explosion will destroy a portion of the transmission line that delivers the electrical power to the z-pinch. They investigate several options for providing standoff for z-pinch driven fusion. Recyclable Transmission Lines (RTLs) appear to be the most promising approach.

  20. Beams 92: Proceedings. Volume 1: Invited papers, pulsed power

    SciTech Connect

    Mosher, D.; Cooperstein, G.

    1993-12-31

    This report contains papers on the following topics: Ion beam papers; electron beam, bremsstrahlung, and diagnostics papers; radiating Z- pinch papers; microwave papers; electron laser papers; advanced accelerator papers; beam and pulsed power applications papers; pulsed power papers; and these papers have been indexed separately elsewhere.

  1. Raytheon advanced pulse-tube cryocoolers

    NASA Astrophysics Data System (ADS)

    Conrad, Ted; Yates, Ryan; Kuo, Daniel; Schaefer, Brian; Arnoult, Matt

    2016-05-01

    Since the 1970s, Raytheon has developed, built, tested and integrated high performance cryocoolers. Our versatile designs for single and multi-stage cryocoolers provide reliable operation for temperatures from 10 to 200 Kelvin with power levels ranging from 50 W to nearly 600 W. These cryocoolers incorporate clearance seals, flexure suspensions, hermetic housings and dynamic balancing to provide long service life and reliable operation in all relevant environments. Recently, Raytheon has developed an advanced regenerator technology capable of operating efficiently at high frequencies and outperforming traditional screen regenerators. The Raytheon Advanced Miniature (RAM-100) cryocooler, a flight packaged, high frequency, single stage pulse tube cooler with an integrated surge volume and inertance tube, has been designed for use with this regenerator. Design details and experimentally measured performance of two iterations of the RAM cryocooler are presented in this paper.

  2. Solid state pulsed power generator

    SciTech Connect

    Tao, Fengfeng; Saddoughi, Seyed Gholamali; Herbon, John Thomas

    2014-02-11

    A power generator includes one or more full bridge inverter modules coupled to a semiconductor opening switch (SOS) through an inductive resonant branch. Each module includes a plurality of switches that are switched in a fashion causing the one or more full bridge inverter modules to drive the semiconductor opening switch SOS through the resonant circuit to generate pulses to a load connected in parallel with the SOS.

  3. High Power Picosecond Laser Pulse Recirculation

    SciTech Connect

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P

    2010-04-12

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering based light sources. We demonstrate up to 36x average power enhancement of frequency doubled sub-millijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  4. High-power picosecond laser pulse recirculation.

    PubMed

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-01

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high-power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering-based light sources. We demonstrate up to 40x average power enhancement of frequency-doubled submillijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses.

  5. High-power picosecond laser pulse recirculation.

    PubMed

    Shverdin, M Y; Jovanovic, I; Semenov, V A; Betts, S M; Brown, C; Gibson, D J; Shuttlesworth, R M; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-01

    We demonstrate a nonlinear crystal-based short pulse recirculation cavity for trapping the second harmonic of an incident high-power laser pulse. This scheme aims to increase the efficiency and flux of Compton-scattering-based light sources. We demonstrate up to 40x average power enhancement of frequency-doubled submillijoule picosecond pulses, and 17x average power enhancement of 177 mJ, 10 ps, 10 Hz pulses. PMID:20596201

  6. High-power pulsed lasers

    SciTech Connect

    Holzrichter, J.F.

    1980-04-02

    The ideas that led to the successful construction and operation of large multibeam fusion lasers at the Lawrence Livermore Laboratory are reviewed. These lasers are based on the use of Nd:glass laser materials. However, most of the concepts are applicable to any laser being designed for fusion experimentation. This report is a summary of lectures given by the author at the 20th Scottish University Summer School in Physics, on Laser Plasma Interaction. This report includes basic concepts of the laser plasma system, a discussion of lasers that are useful for short-pulse, high-power operation, laser design constraints, optical diagnostics, and system organization.

  7. Westinghouse programs in pulsed homopolar power supplies

    NASA Technical Reports Server (NTRS)

    Litz, D. C.; Mullan, E.

    1984-01-01

    This document details Westinghouse's ongoing study of homopolar machines since 1929 with the major effort occurring in the early 1970's to the present. The effort has enabled Westinghouse to develop expertise in the technology required for the design, fabrication and testing of such machines. This includes electrical design, electromagnetic analysis, current collection, mechanical design, advanced cooling, stress analysis, transient rotor performance, bearing analysis and seal technology. Westinghouse is using this capability to explore the use of homopolar machines as pulsed power supplies for future systems in both military and commercial applications.

  8. Nova pulse power design and operational experience

    NASA Astrophysics Data System (ADS)

    Whitham, K.; Larson, D.; Merritt, B.; Christie, D.

    1987-01-01

    Nova is a 100 TW Nd++ solid state laser designed for experiments with laser fusion at Lawrence Livermore National Laboratory (LLNL). The pulsed power for Nova includes a 58 MJ capacitor bank driving 5336 flashlamps with millisecond pulses and subnanosecond high voltages for electro optics. This paper summarizes the pulsed power designs and the operational experience to date.

  9. Advanced Solar Power Systems

    NASA Technical Reports Server (NTRS)

    Atkinson, J. H.; Hobgood, J. M.

    1984-01-01

    The Advanced Solar Power System (ASPS) concentrator uses a technically sophisticated design and extensive tooling to produce very efficient (80 to 90%) and versatile energy supply equipment which is inexpensive to manufacture and requires little maintenance. The advanced optical design has two 10th order, generalized aspheric surfaces in a Cassegrainian configuration which gives outstanding performance and is relatively insensitive to temperature changes and wind loading. Manufacturing tolerances also have been achieved. The key to the ASPS is the direct absorption of concentrated sunlight in the working fluid by radiative transfers in a black body cavity. The basic ASPS design concepts, efficiency, optical system, and tracking and focusing controls are described.

  10. Pulsed power accelerator for material physics experiments

    NASA Astrophysics Data System (ADS)

    Reisman, D. B.; Stoltzfus, B. S.; Stygar, W. A.; Austin, K. N.; Waisman, E. M.; Hickman, R. J.; Davis, J.-P.; Haill, T. A.; Knudson, M. D.; Seagle, C. T.; Brown, J. L.; Goerz, D. A.; Spielman, R. B.; Goldlust, J. A.; Cravey, W. R.

    2015-09-01

    We have developed the design of Thor: a pulsed power accelerator that delivers a precisely shaped current pulse with a peak value as high as 7 MA to a strip-line load. The peak magnetic pressure achieved within a 1-cm-wide load is as high as 100 GPa. Thor is powered by as many as 288 decoupled and transit-time isolated bricks. Each brick consists of a single switch and two capacitors connected electrically in series. The bricks can be individually triggered to achieve a high degree of current pulse tailoring. Because the accelerator is impedance matched throughout, capacitor energy is delivered to the strip-line load with an efficiency as high as 50%. We used an iterative finite element method (FEM), circuit, and magnetohydrodynamic simulations to develop an optimized accelerator design. When powered by 96 bricks, Thor delivers as much as 4.1 MA to a load, and achieves peak magnetic pressures as high as 65 GPa. When powered by 288 bricks, Thor delivers as much as 6.9 MA to a load, and achieves magnetic pressures as high as 170 GPa. We have developed an algebraic calculational procedure that uses the single brick basis function to determine the brick-triggering sequence necessary to generate a highly tailored current pulse time history for shockless loading of samples. Thor will drive a wide variety of magnetically driven shockless ramp compression, shockless flyer plate, shock-ramp, equation of state, material strength, phase transition, and other advanced material physics experiments.

  11. Ranchero Explosive Pulsed Power Experiments

    SciTech Connect

    Goforth, J.H.; Atchison, W.L.; Deninger, W.J.; Fowler, C.M.; Herrera, D.H.; King, J.C.; Lopez, E.A.; Oona, H.; Reinovsky, R.E.; Stokes, J.L.; Sena, F.C.; Tabaka, L.J.; Tasker, D.G.; Torres, D.T.; Lindemuth, I.R.; Faehl, R.J.; Keinigs, R.K.; Taylor, A.J.; Rodriguez, G.; Oro, D.M.; Garcia, O.F.; parker, J.V.; Broste, W.B.

    1999-06-27

    The authors are developing the Ranchero high explosive pulsed power (HEPP) system to power cylindrically imploding solid-density liners for hydrodynamics experiments. The near-term goal is to conduct experiments in the regime pertinent to the Atlas Capacitor bank. That is, they will attempt to implode liners of {approximately}50 g mass at velocities approaching 15 km/sec. The basic building block of the HEPP system is a coaxial generator with a 304.8 mm diameter stator, and an initial armature diameter of 152 mm. The armature is expanded by a high explosive (HE) charge detonated simultaneously along its axis. They have reported a variety of experiments conducted with generator modules 43 cm long and have presented an initial design for hydrodynamic liner experiments. In this paper they give a synopsis of their first system test, and a status report on the development of a generator module that is 1.4 m long.

  12. Prefire identification for pulse power systems

    DOEpatents

    Longmire, Jerry L.; Thuot, Michael E.; Warren, David S.

    1985-01-01

    Prefires in a high-power, high-frequency, multi-stage pulse generator are detected by a system having an EMI shielded pulse timing transmitter associated with and tailored to each stage of the pulse generator. Each pulse timing transmitter upon detection of a pulse triggers a laser diode to send an optical signal through a high frequency fiber optic cable to a pulse timing receiver which converts the optical signal to an electrical pulse. The electrical pulses from all pulse timing receivers are fed through an OR circuit to start a time interval measuring device and each electrical pulse is used to stop an individual channel in the measuring device thereby recording the firing sequence of the multi-stage pulse generator.

  13. Prefire identification for pulse-power systems

    DOEpatents

    Longmire, J.L.; Thuot, M.E.; Warren, D.S.

    1982-08-23

    Prefires in a high-power, high-frequency, multi-stage pulse generator are detected by a system having an EMI shielded pulse timing transmitter associated with and tailored to each stage of the pulse generator. Each pulse timing transmitter upon detection of a pulse triggers a laser diode to send an optical signal through a high frequency fiber optic cable to a pulse timing receiver which converts the optical signal to an electrical pulse. The electrical pulses from all pulse timing receivers are fed through an OR circuit to start a time interval measuring device and each electrical pulse is used to stop an individual channel in the measuring device thereby recording the firing sequence of the multi-stage pulse generator.

  14. Beamlet pulsed-power system

    SciTech Connect

    Larson, D.

    1996-06-01

    The 13-MJ Beamlet pulsed-power system provides power to the 512 flash lamps in the cavity and booster amplifiers. Since the flash lamps pump all of the apertures in the 2 x 2 amplifier array, the capacitor bank provides roughly four times the energy required to pump the single active beam line. During the 40 s prior to the shot, the capacitors are charged by constant-current power supplies. Ignitron switches transfer the capacitor energy to the flash lamps via coaxial cables. A preionization system triggers the flash lamps and delivers roughly 1 % of the capacitor energy 200 {mu}s prior to the main discharge. This is the first time flash-lamp preionization has been used in a large facility. Preionization improves the amplifier efficiency by roughly 5% and increases the lifetime of the flash lamps. LabVIEW control panels provide an operator interface with the modular controls and diagnostics. To improve the reliability of the system, high-energy-density, self-healing, metallized dielectric capacitors are used. High-frequency, voltage-regulated switching power supplies are integrated into each module on Beamlet, allowing greater independence among the modules and improved charge voltage accuracy, flexibility, and repeatability.

  15. Nova pulse power system description and status

    SciTech Connect

    Holloway, R.W.; Whitham, K.; Merritt, B.T.; Gritton, D.G.; Oicles, J.A.

    1981-06-01

    The Nova laser system is designed to produce critical data in the nation's inertial confinement fusion effort. It is the world's largest peak power laser and presents various unique pulse power problems. In this paper, pulse power systems for this laser are described, the evolutionary points from prior systems are pointed out, and the current status of the hardware is given.

  16. Advanced Power Electronics Components

    NASA Technical Reports Server (NTRS)

    Schwarze, Gene E.

    2004-01-01

    This paper will give a description and status of the Advanced Power Electronics Materials and Components Technology program being conducted by the NASA Glenn Research Center for future aerospace power applications. The focus of this research program is on the following: 1) New and/or significantly improved dielectric materials for the development of power capacitors with increased volumetric efficiency, energy density, and operating temperature. Materials being investigated include nanocrystalline and composite ceramic dielectrics and diamond-like carbon films; 2) New and/or significantly improved high frequency, high temperature, low loss soft magnetic materials for the development of transformers/inductors with increased power/energy density, electrical efficiency, and operating temperature. Materials being investigated include nanocrystalline and nanocomposite soft magnetic materials; 3) Packaged high temperature, high power density, high voltage, and low loss SiC diodes and switches. Development of high quality 4H- and 6H- SiC atomically smooth substrates to significantly improve device performance is a major emphasis of the SiC materials program; 4) Demonstration of high temperature (> 200 C) circuits using the components developed above.

  17. Technology of Pulse Power Capacitors

    NASA Astrophysics Data System (ADS)

    Qin, Shanshan

    Polymer film of pulse discharge capacitors operated at high repetition rate dissipates substantial power. The thermal conductivity of biaxially oriented polypropylene (BOPP) is measured as a function of metallization resistivity. The thermal conductivity in the plane of the film is about twice that of bulk polypropylene. Thermal design is optimized based on the measurement for large capacitors with multiple windings in a container. High discharge speed results in high current density at the wire arc sprayed end connections which tend to deteriorate gradually, resulting in capacitor failure during operation. To assure the end connection quality before assembly, a test procedure and apparatus for end connection integrity was developed based on monitoring the partial discharge pattern from end connection during discharge. The mechanism of clearing is analyzed which shows arc extinguishes due to the increased arc length and reduced energy so that capacitor can function normally after breakdown. In the case of a clearing discharge, the power dissipation appears to increase with time, although this is not a feature of previous models. Submicrosecond discharge requires minimizing inductance which can be achieved by optimizing the winding structure so that submicrosecond discharge becomes practical. An analysis of the inductance of multisection, very high voltage capacitors is carried out, which identifies low inductance structures for this type of capacitor.

  18. AN UPDATE ON NIF PULSED POWER

    SciTech Connect

    Arnold, P A; James, G F; Petersen, D E; Pendleton, D L; McHale, G B; Barbosa, F; Runtal, A S; Stratton, P L

    2009-06-22

    The National Ignition Facility (NIF) is a 192-beam laser fusion driver operating at Lawrence Livermore National Laboratory. NIF relies on three large-scale pulsed power systems to achieve its goals: the Power Conditioning Unit (PCU), which provides flashlamp excitation for the laser's injection system; the Power Conditioning System (PCS), which provides the multi-megajoule pulsed excitation required to drive flashlamps in the laser's optical amplifiers; and the Plasma Electrode Pockels Cell (PEPC), which enables NIF to take advantage of a fourpass main amplifier. Years of production, installation, and commissioning of the three NIF pulsed power systems are now complete. Seven-day-per-week operation of the laser has commenced, with the three pulsed power systems providing routine support of laser operations. We present the details of the status and operational experience associated with the three systems along with a projection of the future for NIF pulsed power.

  19. Pulsed Power: Sandia's Plans for the New Millenium

    SciTech Connect

    QUINTENZ,JEFFREY P.

    2000-07-20

    Pulsed power science and engineering activities at Sandia National Laboratories grew out of a programmatic need for intense radiation sources to advance capabilities in radiographic imaging and to create environments for testing and certifying the hardness of components and systems to radiation in hostile environments. By the early 1970s, scientists in laboratories around the world began utilizing pulsed power drivers with very short (10s of nanoseconds) pulse lengths for Inertial Confinement Fusion (ICF) experiments. In the United States, Defense Programs within the Department of Energy has sponsored this research. Recent progress in pulsed power, specifically fast-pulsed-power-driven z pinches, in creating temperatures relevant to ICF has been remarkable. Worldwide developments in pulsed power technologies and increased applications in both defense and industry are contrasted with ever increasing stress on research and development tiding. The current environment has prompted us at Sandia to evaluate our role in the continued development of pulsed power science and to consider options for the future. This presentation will highlight our recent progress and provide an overview of our plans as we begin the new millennium.

  20. Pulsed Power Discharges in Water

    NASA Astrophysics Data System (ADS)

    Kratel, Axel Wolf Hendrik

    An Electrohydraulic Discharge Process (EHD) for the treatment of hazardous chemical wastes in water has been developed. Liquid waste in a 4 L EHD reactor is directly exposed to high-energy pulsed electrical discharges between two submerged electrodes. The high-temperature (> 14,000 K) plasma channel created by an EHD discharge emits ultraviolet radiation, and produces an intense shock wave as it expands against the surrounding water. A simulation of the EHD process is presented along with experimental results. The simulation assumes a uniform plasma channel with a plasma that obeys the ideal gas law and the Spitzer conductivity law. The results agree with previously published data. The simulation is used to predict the total energy efficiency, energy partitioning, maximum plasma channel temperature and pressure for the Caltech Pulsed Power Facility (CPPF). The simulation shows that capacitance, initial voltage and gap length can be used to control the efficiency of the discharge. The oxidative degradation of 4-chlorophenol (4 -CP), 3,4-dichloroaniline (3,4-DCA), and 2,4,6 trinitrotoluene (TNT) in an EHD reactor was explored. The initial rates of degradation for the three substrates are described by a first-order rate equation, where k_{ it 0/} is the zero-order rate constant that accounts for direct photolysis; and k_ {it 1/} is the first-order term that accounts for oxidation in the plasma channel region. For 4-CP in the 4.0 L reactor, the values of these two rate constants are k_{it 0/} = 0.73 +/- 0.08 mu M, and k_{ it 1/} =(9.4 +/- 1.4) times 10^{-4}. For a 200 mu M 4-CP solution this corresponds to an overall intrinsic zero-order rate constant of 0.022 M s^{it -1/} , and a G-value of 4.45 times 10^{-3}. Ozone increases the rate and extent of degradation of the substrates in the EHD reactor. Combined EHD/ozone treatment of a 160 mu M TNT solution resulted in the complete degradation of TNT, and a 34% reduction of the total organic carbon (TOC). The intrinsic

  1. Review of High Power Pulse Transformer Design

    NASA Astrophysics Data System (ADS)

    Zhang, Zhao; Tan, Xiaohua

    Vacuum devices generally work under high power pulse voltage of order 103 V to 106 V, and this pulse voltage could be generated by high power pulse transformer. Relatively, pulse transformer has the advantages of compact structure and excellent repetitiveness. It is expected of short rise-time, wide pulse-width and high energy transferring efficiency in most applications. Aiming at this purpose, it is feasible to select magnetic core with high permeability and high saturation magnetic flux density, use closed core and take some special measures to diminish leakage inductance in the making-process. This paper is a brief summary of high power pulse transformer design. In this paper, the principle, types and characteristics specification of high power pulse transformer are presented, and the design methods of electrical, magnetic and structure parameters are summarized. The methods of shortening rise time, diminishing droop and expanding output pulse-width (electrical parameter design), testing magnetic core materials (magnetic parameter design) and minimizing leakage inductance (structure parameter design) are emphasized.

  2. Pulse power applications of flux compression generators

    SciTech Connect

    Fowler, C.M.; Caird, R.S.; Erickson, D.J.; Freeman, B.L.

    1981-01-01

    Characteristics are presented for two different types of explosive driven flux compression generators and a megavolt pulse transformer. Status reports are given for rail gun and plasma focus programs for which the generators serve as power sources.

  3. High power ultrashort pulse lasers

    SciTech Connect

    Perry, M.D.

    1994-10-07

    Small scale terawatt and soon even petawatt (1000 terawatt) class laser systems are made possible by application of the chirped-pulse amplification technique to solid-state lasers combined with the availability of broad bandwidth materials. These lasers make possible a new class of high gradient accelerators based on the large electric fields associated with intense laser-plasma interactions or from the intense laser field directly. Here, we concentrate on the laser technology to produce these intense pulses. Application of the smallest of these systems to the production of high brightness electron sources is also introduced.

  4. Pulsed power supply for an electrostatic precipitator

    SciTech Connect

    Santamaria, G.T.

    1986-07-15

    An electrostatic precipitator power supply circuit is described for generating voltage pulses on the precipitator while allowing a residual collection voltage to be retained on the precipitator during intervals between pulses, where the voltage of the pulses is substantially in excess of the residual voltage, the power supply circuit comprising: means for generating the high voltage pulses at the secondary inductance of a step-up transformer by discharging a capacitor through the primary inductance of the step-up transformer; the electrostatic precipitator connected to the secondary inductance of the step-up transformer to receive the high voltage pulses; and means for returning a portion of the high voltage pulses to the capacitor, and for maintaining the residual voltage on the precipitator during interpulse periods including means with a variable impedance adapted for providing a maximum impedance during interpulse periods and a minimum impedance during high voltage pulses and means for causing the variable impedance means to exhibit a minimum impedance during the return of a portion of the high voltage pulses.

  5. Low power arcjet thruster pulse ignition

    NASA Technical Reports Server (NTRS)

    Sarmiento, Charles J.; Gruber, Robert P.

    1987-01-01

    An investigation of the pulse ignition characteristics of a 1 kW class arcjet using an inductive energy storage pulse generator with a pulse width modulated power converter identified several thruster and pulse generator parameters that influence breakdown voltage including pulse generator rate of voltage rise. This work was conducted with an arcjet tested on hydrogen-nitrogen gas mixtures to simulate fully decomposed hydrazine. Over all ranges of thruster and pulser parameters investigated, the mean breakdown voltages varied from 1.4 to 2.7 kV. Ignition tests at elevated thruster temperatures under certain conditions revealed occasional breakdowns to thruster voltages higher than the power converter output voltage. These post breakdown discharges sometimes failed to transition to the lower voltage arc discharge mode and the thruster would not ignite. Under the same conditions, a transition to the arc mode would occur for a subsequent pulse and the thruster would ignite. An automated 11 600 cycle starting and transition to steady state test demonstrated ignition on the first pulse and required application of a second pulse only two times to initiate breakdown.

  6. Compact inductive energy storage pulse power system.

    PubMed

    K, Senthil; Mitra, S; Roy, Amitava; Sharma, Archana; Chakravarthy, D P

    2012-05-01

    An inductive energy storage pulse power system is being developed in BARC, India. Simple, compact, and robust opening switches, capable of generating hundreds of kV, are key elements in the development of inductive energy storage pulsed power sources. It employs an inductive energy storage and opening switch power conditioning techniques with high energy density capacitors as the primary energy store. The energy stored in the capacitor bank is transferred to an air cored storage inductor in 5.5 μs through wire fuses. By optimizing the exploding wire parameters, a compact, robust, high voltage pulse power system, capable of generating reproducibly 240 kV, is developed. This paper presents the full details of the system along with the experimental data. PMID:22667637

  7. Compact inductive energy storage pulse power system.

    PubMed

    K, Senthil; Mitra, S; Roy, Amitava; Sharma, Archana; Chakravarthy, D P

    2012-05-01

    An inductive energy storage pulse power system is being developed in BARC, India. Simple, compact, and robust opening switches, capable of generating hundreds of kV, are key elements in the development of inductive energy storage pulsed power sources. It employs an inductive energy storage and opening switch power conditioning techniques with high energy density capacitors as the primary energy store. The energy stored in the capacitor bank is transferred to an air cored storage inductor in 5.5 μs through wire fuses. By optimizing the exploding wire parameters, a compact, robust, high voltage pulse power system, capable of generating reproducibly 240 kV, is developed. This paper presents the full details of the system along with the experimental data.

  8. Electromagnetic pulse and the electric power network

    SciTech Connect

    Klein, K.W.; Barnes, P.R.; Zaininger, H.W.

    1984-01-01

    This paper defines the nuclear electromagnetic pulse (EMP) - electric power system interaction problem. A description of high altitude EMP (HEMP) characteristics, source region EMP (SREMP) characteristics, and magnetohydrodynamics EMP (MHD-EMP) characteristics are presented. The results of initial calculations of EMP induced surges on electric power transmission and distribution lines are presented and compared with lightning induced surges. Potential EMP impacts on electric power systems are discussed, and an overview of the Department of Energy (DOE) EMP research program is presented.

  9. Loads for pulsed power cylindrical implosion experiments

    SciTech Connect

    Anderson, W.E.; Armijo, E.V.; Barthell, B.L.; Bartos, J.J.; Bush, H.; Foreman, L.R.; Garcia, F.P.; Gobby, P.L.; Gomez, V.M.; Gurule, V.A.

    1994-07-01

    Pulse power can be used to generate high energy density conditions in convergent hollow cylindrical geometry through the use of appropriate electrode configuration and cylindrical loads. Cylindrically symmetric experiments are conducted with the Pegasus-H inductive store, capacitor energized pulse power facility at Los Alamos using both precision machined cylindrical liner loads and low mass vapor deposited cylindrical foil loads. The liner experiments investigate solid density hydrodynamic topics. Foil loads vaporize from Joule heating to generate an imploding cylindrical plasma which can be used to simulate some fluxes associated with fusion energy processes. Similar experiments are conducted with {open_quotes}Procyon{close_quotes} inductive store pulse power assemblies energized by explosively driven magnetic flux compression.

  10. Pulsed power systems for the DARHT accelerators

    SciTech Connect

    Downing, J.N.; Parsons, W.M.; Earley, L.M.; Melton, J.G.; Moir, D.C.; Carlson, R.L.; Barnes, G.A.; Builta, L.A.; Eversole, S.A.; Keel, G.I.; Rader, D.C.; Romero, J.A.; Shurter, R.P.

    1991-01-01

    The Dual-Axis Radiographic Hydro Test (DARHT) Facility is being designed to produce high-resolution flash radiographs of hydrodynamics experiments. Two 16- to 20-MeV linear induction accelerators (LIA), with an included angle of 90{degree}, are used to produce intense bremsstrahlung x-ray pulses of short duration (60-ns flat-top). Each accelerator has a 4-MeV electron source that injects an electron beam into a series of 250-kV induction cells. The three major pulsed-power systems are the injectors, the induction-cell pulsed-power (ICPP) units, and the ICPP trigger systems, and are discussed in this paper. 11 refs., 5 figs, 3 tabs.

  11. The repetitive high energy pulsed power module

    SciTech Connect

    Harjes, H.C.; Reed, K.W.; Buttram, M.T.; Turman, B.N.; Neau, E.L.; Martinez, L.; Adcock, J.; Weinbrecht, E.A.; Mann, G.A.; Morgan, F.A.; Laderach, G.E.; Pena, G.; Butler, M.; Schneider, L.X.; Wavrik, R.W.; Penn, K.J.; Weber, G.J.

    1990-01-01

    High average power magnetic pulse compression systems are being considered for use in several applications. One of the key issues in the design of a pulsed power driver for these applications is component reliability, efficiency, and lifetime. In the Repetitive High Energy Pulsed Power (RHEPP) module, pulse compression is done exclusively with magnetic switches (saturable reactors) because such switches have the potential of performing efficiently and reliably for >10{sup 10} shots. The objective of the RHEPP project is to explore the feasibility of using magnetic pulse compression technology in continuous high average power applications. The RHEPP system consists of a compressor which drives a linear induction voltage adder with a diode load. Prime power for the module is supplied by a 600 kW, 120 Hz, alternator (furnished by Westinghouse Electric Corporation). At present, construction and initial testing in a bipolar mode of the first two stages of the compressor has been completed. This system has operated for a total of 332 minutes (4.8 {times} 10{sup 6} pulses) at full power (600 kW) with an efficiency of 94+/{minus}3%. The first stage magnetic switch (MS1) has a pulse compression factor of 8.4 (4.2 ms to 500 {mu}s time to peak). It has two, parallel connected, 67 turn copper coils and a 760 kg core of 2 mil silicon steel with a magnetic cross sectional area of 0. 065 m{sup 2}. The second stage magnetic switch (MS2) has a pulse compression factor of 3 (500 {mu}s to 170 {mu}s). It has two, parallel connected, 36 turn copper coils and a 361 kg core of field annealed 2605CO Metglas with a magnetic area of 0.019 m{sup 2}. A discussion of RHEPP compressor design effort and its baseline design is given. In addition, initial results from the operation of the first two stages are presented. 11 refs., 8 figs., 4 tabs.

  12. Survivable pulse power space radiator

    DOEpatents

    Mims, J.; Buden, D.; Williams, K.

    1988-03-11

    A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometerorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length. 5 figs.

  13. Survivable pulse power space radiator

    DOEpatents

    Mims, James; Buden, David; Williams, Kenneth

    1989-01-01

    A thermal radiator system is described for use on an outer space vehicle, which must survive a long period of nonuse and then radiate large amounts of heat for a limited period of time. The radiator includes groups of radiator panels that are pivotally connected in tandem, so that they can be moved to deployed configuration wherein the panels lie largely coplanar, and to a stowed configuration wherein the panels lie in a stack to resist micrometeorite damage. The panels are mounted on a boom which separates a hot power source from a payload. While the panels are stowed, warm fluid passes through their arteries to keep them warm enough to maintain the coolant in a liquid state and avoid embrittlement of material. The panels can be stored in a largely cylindrical shell, with panels progressively further from the boom being of progressively shorter length.

  14. Experimental research on pulse forming based on high-temperature SMES applied in pulsed power

    NASA Astrophysics Data System (ADS)

    Zhou, Yusheng; Kuang, Jianghua; Tang, Yuejin; Song, Meng; Wei, Bin; Cheng, Shijie; Pan, Yuan

    2009-03-01

    To research the key problems of storage energy and pulse forming in pulsed power, a pulse magnet made of Bi2223/Ag high-temperature superconducting (HTS) tapes applied in pulsed power experiment was developed. After determining electromagnetic characteristics of the magnet, a pulse forming network was designed. HTS magnet was immersed in liquid nitrogen bath, experiments were carried out about discharging pulse current to resistance load based on HTS magnet energy storage (SMES). The results show that pulse current waves were obtained through adjusted circuit construction and magnet parameters by acting delay of switches in the pulse forming network. The technical schemes about pulse forming based on SMES were presented.

  15. Warm dense mater: another application for pulsed power hydrodynamics

    SciTech Connect

    Reinovsky, Robert Emil

    2009-01-01

    Pulsed Power Hydrodynamics (PPH) is an application of low-impedance pulsed power, and high magnetic field technology to the study of advanced hydrodynamic problems, instabilities, turbulence, and material properties. PPH can potentially be applied to the study of the properties of warm dense matter (WDM) as well. Exploration of the properties of warm dense matter such as equation of state, viscosity, conductivity is an emerging area of study focused on the behavior of matter at density near solid density (from 10% of solid density to slightly above solid density) and modest temperatures ({approx}1-10 eV). Conditions characteristic of WDM are difficult to obtain, and even more difficult to diagnose. One approach to producing WDM uses laser or particle beam heating of very small quantities of matter on timescales short compared to the subsequent hydrodynamic expansion timescales (isochoric heating) and a vigorous community of researchers are applying these techniques. Pulsed power hydrodynamic techniques, such as large convergence liner compression of a large volume, modest density, low temperature plasma to densities approaching solid density or through multiple shock compression and heating of normal density material between a massive, high density, energetic liner and a high density central 'anvil' are possible ways to reach relevant conditions. Another avenue to WDM conditions is through the explosion and subsequent expansion of a conductor (wire) against a high pressure (density) gas background (isobaric expansion) techniques. However, both techniques demand substantial energy, proper power conditioning and delivery, and an understanding of the hydrodynamic and instability processes that limit each technique. In this paper we will examine the challenges to pulsed power technology and to pulsed power systems presented by the opportunity to explore this interesting region of parameter space.

  16. Pulsed power performance of PBFA Z

    SciTech Connect

    Spielman, R.B.; Stygar, W.A.; Seamen, J.F.

    1997-08-01

    PBFA Z is a new 60-TW/5-MJ electrical driver located at Sandia National Laboratories. The authors use PBFA Z to drive z pinches. The pulsed power design of PBFA Z is based on conventional single-pulse Marx generator, water-line pulse-forming technology used on the earlier Saturn and PBFA II accelerators. PBFA Z stores 11.4 MJ in its 36 Marx generators, couples 5 MJ in a 60-TW/105-ns pulse to the output water transmission lines, and delivers 3.0 MJ and 50 TW of electrical energy to the z-pinch load. Depending on the initial load inductance and the implosion time, the authors attain peak currents of 16-20 MA with a rise time of 105 ns. Current is fed to the z-pinch load through self magnetically-insulated transmission lines (MITLs). Peak electric fields in the MITLs exceed 2 MV/cm. The current from the four independent conical-disk MITLs is combined together in a double post-hole vacuum convolute with an efficiency greater than 95%. The authors achieved x-ray powers of 200 TW and x-ray energies of 1.9 MJ from tungsten wire-array z-pinch loads.

  17. Pulsed Power Peer Review Committee Report

    SciTech Connect

    BLOOMQUIST,DOUGLAS D.

    2000-12-01

    In 1993, the Government Performance and Results Act (GPRA, PL 103-62) was enacted. GPRA, which applies to all federal programs, has three components: strategic plans, annual performance plans, and metrics to show how well annual plans are being followed. As part of meeting the GRPA requirement in FY2000, a 14-member external peer review panel (the Garwin Committee) was convened on May 17-19, 2000 to review Sandia National Laboratories' Pulsed Power Programs as a component of the Performance Appraisal Process negotiated with the Department of Energy (DOE). The scope of the review included activities in inertial confinement fission (ICF), weapon physics, development of radiation sources for weapons effects simulation, x-ray radiography, basic research in high energy density physics (HEDP), and pulsed power technology research and development. In his charge to the committee, Jeffrey Quintenz, Director of Pulsed Power Sciences (1600) asked that the review be based on four criteria (1) quality of science, technology, and engineering, (2) programmatic performance, management, and planning, (3) relevance to national needs and agency missions, and (4) performance in the operation and construction of major research facilities. In addition, specific programmatic questions were posed by the director and by the DOE-Defense Programs (DP). The accompanying report, produced as a SAND document, is the report of the committee's findings.

  18. Pulsed power peer review committee report.

    SciTech Connect

    Not Available

    2004-08-01

    As part of meeting the GRPA (Government Performance and Results Act) requirements and to provide input to Sandia's annual Performance Evaluation Assessment Report (PEAR) to the National Nuclear Security Administration in FY2004, a 14-member external review committee chaired by Dr. Alvin Trivelpiece was convened by Sandia National Laboratories (SNL) on May 4-6, 2004 to review Sandia National Laboratories' Pulsed Power Programs. The scope of the review included activities in high energy density physics (HEDP), inertial confinement fusion (ICF), radiation/weapon physics, the petawatt laser initiative (PW) and fast ignition, equation-of state studies, radiation effects science and lethality, x-ray radiography, ZR development, basic research and pulsed power technology research and development, as well as electromagnetics and work for others. In his charge to the Committee, Dr. Jeffrey P. Quintenz, Director of Pulsed Power Sciences (Org. 1600) asked that the evaluation and feedback be based on three criteria: (1) quality of technical activities in science, technology, and engineering, (2) programmatic performance, management, and planning, and (3) relevance to national needs and agency missions. In addition, the director posed specific programmatic questions. The accompanying report, produced as a SAND document, is the report of the Committee's finding.

  19. Characterization of power IGBTs under pulsed power conditions

    SciTech Connect

    Dale, Gregory E; Vangordon, James; Kovaleski, Scott

    2009-01-01

    The power insulated gate bipolar transistor (IGBT) is used in many types of applications. Although the use of the power IGBT has been well characterized for many continuous operation power electronics applications, little published information is available regarding the performance of a given IGBT under pulsed power conditions. Additionally, component libraries in circuit simulation software packages have a finite number of IGBTs. This paper presents a process for characterizing the performance of a given power IGBT under pulsed power conditions. Specifically, signals up to 3.5 kV and 1 kA with 1-10 {micro}s pulse widths have been applied to a Powerex QIS4506001 IGBT. This process utilizes least squares curve fitting techniques with collected data to determine values for a set of modeling parameters. These parameters were used in the Oziemkiewicz implementation of the Hefner model for the IGBT that is utilized in some circuit simulation software packages. After the nominal parameter values are determined, they can be inserted into the Oziemkiewicz implementation to simulate a given IGBT.

  20. Pulse Detonation Rocket Magnetohydrodynamic Power Experiment

    NASA Technical Reports Server (NTRS)

    Litchford, R. J.; Jones, J. E.; Dobson, C. C.; Cole, J. W.; Thompson, B. R.; Plemmons, D. H.; Turner, M. W.

    2003-01-01

    The production of onboard electrical power by pulse detonation engines is problematic in that they generate no shaft power; however, pulse detonation driven magnetohydrodynamic (MHD) power generation represents one intriguing possibility for attaining self-sustained engine operation and generating large quantities of burst power for onboard electrical systems. To examine this possibility further, a simple heat-sink apparatus was developed for experimentally investigating pulse detonation driven MHD generator concepts. The hydrogen oxygen fired driver was a 90 cm long stainless steel tube having a 4.5 cm square internal cross section and a short Schelkin spiral near the head end to promote rapid formation of a detonation wave. The tube was intermittently filled to atmospheric pressure and seeded with a CsOH/methanol prior to ignition by electrical spark. The driver exhausted through an aluminum nozzle having an area contraction ratio of A*/A(sub zeta) = 1/10 and an area expansion ratio of A(sub zeta)/A* = 3.2 (as limited by available magnet bore size). The nozzle exhausted through a 24-electrode segmented Faraday channel (30.5 cm active length), which was inserted into a 0.6 T permanent magnet assembly. Initial experiments verified proper drive operation with and without the nozzle attachment, and head end pressure and time resolved thrust measurements were acquired. The exhaust jet from the nozzle was interrogated using a polychromatic microwave interferometer yielding an electron number density on the order of 10(exp 12)/cm at the generator entrance. In this case, MHD power generation experiments suffered from severe near-electrode voltage drops and low MHD interaction; i.e., low flow velocity, due to an inherent physical constraint on expansion with the available magnet. Increased scaling, improved seeding techniques, higher magnetic fields, and higher expansion ratios are expected to greatly improve performance.

  1. Nuclear electromagnetic pulse and the electric power system

    SciTech Connect

    Legro, J.R.; Reed, T.J.

    1985-01-01

    A single, high-altitude nuclear detonation over the continental United States can expose large geographic areas to transient, electromagnetic pulse (EMP). The initial electromagnetic fields produced by this event have been defined as high-altitude electromagnetic pulse (HEMP). Later-time, low frequency fields have been defined as magnetohydrodynamic-electromagnetic pulse (MHD-EMP). Nuclear detonations at, or near the surface of the earth can also produce transient EMP. These electromagnetic phenomena have been defined as source region electromagnetic pulse (SREMP). The Division of Electric Energy Systems (EES) of the United States Department of Energy (DOE) has formulated and implemented a Program Plan to assess the possible effects of the above nuclear EMP on civilian electric power systems. This unclassified research effort is under the technical leadership of the Oak Ridge National Laboratory. This paper presents a brief perspective of EMP phenomenology and important interaction issues for power systems based on research performed by Westinghouse Advanced Systems Technology as a principal subcontractor in the research effort.

  2. High power UV and VUV pulsed excilamps

    NASA Astrophysics Data System (ADS)

    Tarasenko, V.; Erofeev, M.; Lomaev, M.; Rybka, D.

    2008-07-01

    Emission characteristics of a nanosecond discharge in inert gases and its halogenides without preionization of the gap from an auxiliary source have been investigated. A volume discharge, initiated by an avalanche electron beam (VDIAEB) was realized at pressures up to 12 atm. In xenon at pressure of 1.2 atm, the energy of spontaneous radiation in the full solid angle was sim 45 mJ/cm^3, and the FWHM of a radiation pulse was sim 110 ns. The spontaneous radiation power rise in xenon was observed at pressures up to 12 atm. Pulsed radiant exitance of inert gases halogenides excited by VDIAEB was sim 4.5 kW/cm^2 at efficiency up to 5.5 %.

  3. Pulsed power accelerators for particle beam fusion

    SciTech Connect

    Martin, T.H.; Barr, G.W.; VanDevender, J.P.; White, R.A.; Johnson, D.L.

    1980-01-01

    Sandia National Laboratories is completing the construction phase of the Particle Beam Fusion Accelerator-I (PBFA-I). Testing of the 36 module, 30 TW, 1 MJ output accelerator is in the initial stages. The 4 MJ, PBFA Marx generator has provided 3.6 MA into water-copper sulfate load resistors with a spread from first to last Marx firing between 15 to 25 ns and an output power of 5.7 TW. This accelerator is a modular, lower voltage, pulsed power device that is capable of scaling to power levels exceeding 100 TW. The elements of the PBFA technology and their integration into an accelerator system for particle beam fusion will be discussed.

  4. Pulsed Power for Solid-State Lasers

    SciTech Connect

    Gagnon, W; Albrecht, G; Trenholme, J; Newton, M

    2007-04-19

    Beginning in the early 1970s, a number of research and development efforts were undertaken at U.S. National Laboratories with a goal of developing high power lasers whose characteristics were suitable for investigating the feasibility of laser-driven fusion. A number of different laser systems were developed and tested at ever larger scale in pursuit of the optimum driver for laser fusion experiments. Each of these systems had associated with it a unique pulsed power option. A considerable amount of original and innovative engineering was carried out in support of these options. Ultimately, the Solid-state Laser approach was selected as the optimum driver for the application. Following this, the Laser Program at the Lawrence Livermore National Laboratory and the University of Rochester undertook aggressive efforts directed at developing the technology. In particular, at Lawrence Livermore National Laboratory, a series of laser systems beginning with the Cyclops laser and culminating in the present with the National Ignition Facility were developed and tested. As a result, a large amount of design information for solid-state laser pulsed power systems has been documented. Some of it is in the form of published papers, but most of it is buried in internal memoranda, engineering reports and LLNL annual reports. One of the goals of this book is to gather this information into a single useable format, such that it is easily accessed and understood by other engineers and physicists for use with future designs. It can also serve as a primer, which when seriously studied, makes the subsequent reading of original work and follow-up references considerably easier. While this book deals only with the solid-state laser pulsed power systems, in the bibliography we have included a representative cross section of papers and references from much of the very fine work carried out at other institutions in support of different laser approaches. Finally, in recent years, there has

  5. Innovation on high-power long-pulse gyrotrons

    NASA Astrophysics Data System (ADS)

    Litvak, Alexander; Sakamoto, Keishi; Thumm, Manfred

    2011-12-01

    Progress in the worldwide development of high-power gyrotrons for magnetic confinement fusion plasma applications is described. After technology breakthroughs in research on gyrotron components in the 1990s, significant progress has been achieved in the last decade, in particular, in the field of long-pulse and continuous wave (CW) gyrotrons for a wide range of frequencies. At present, the development of 1 MW-class CW gyrotrons has been very successful; these are applicable for self-ignition experiments on fusion plasmas and their confinement in the tokamak ITER, for long-pulse confinement experiments in the stellarator Wendelstein 7-X (W7-X) and for EC H&CD in the future tokamak JT-60SA. For this progress in the field of high-power long-pulse gyrotrons, innovations such as the realization of high-efficiency stable oscillation in very high order cavity modes, the use of single-stage depressed collectors for energy recovery, highly efficient internal quasi-optical mode converters and synthetic diamond windows have essentially contributed. The total tube efficiencies are around 50% and the purity of the fundamental Gaussian output mode is 97% and higher. In addition, activities for advanced gyrotrons, e.g. a 2 MW gyrotron using a coaxial cavity, multi-frequency 1 MW gyrotrons and power modulation technology, have made progress.

  6. Chamber dynamic research with pulsed power

    SciTech Connect

    PETERSON,ROBERT R.; OLSON,CRAIG L.; RENK,TIMOTHY J.; ROCHAU,GARY E.; SWEENEY,MARY ANN

    2000-05-15

    In Inertial Fusion Energy (IFE), Target Chamber Dynamics (TCD) is an integral part of the target chamber design and performance. TCD includes target output deposition of target x-rays, ions and neutrons in target chamber gases and structures, vaporization and melting of target chamber materials, radiation-hydrodynamics in target chamber vapors and gases, and chamber conditions at the time of target and beam injections. Pulsed power provides a unique environment for IFE-TCD validation experiments in two important ways: they do not require the very clean conditions which lasers need and they currently provide large x-ray and ion energies.

  7. Performance of Low-Power Pulsed Arcjets

    NASA Technical Reports Server (NTRS)

    Burton, Rodney L.

    1995-01-01

    The Electric Propulsion Laboratory at UIUC has in place all the capability and diagnostics required for performance testing of low power pulsed and DC arcjets. The UIUC thrust stand is operating with excellent accuracy and sensitivity at very low thrust levels. An important aspect of the experimental setup is the use of a PID controller to maintain a constant thruster position, which reduces hysterisis effects. Electrical noise from the arcjet induces some noise into the thrust signal, but this does not affect the measurement.

  8. Micro-ablation with high power pulsed copper vapor lasers.

    PubMed

    Knowles, M

    2000-07-17

    Visible and UV lasers with nanosecond pulse durations, diffraction-limited beam quality and high pulse repetition rates have demonstrated micro-ablation in a wide variety of materials with sub-micron precision and sub-micron-sized heat-affected zones. The copper vapour laser (CVL) is one of the important industrial lasers for micro-ablation applications. Manufacturing applications for the CVL include orifice drilling in fuel injection components and inkjet printers, micro-milling of micromoulds, via hole drilling in printed circuit boards and silicon machining. Recent advances in higher power (100W visible, 5W UV), diffraction-limited, compact CVLs are opening new possibilities for manufacturing with this class of nanosecond laser.

  9. Narrow high power microwave pulses from a free electron laser

    SciTech Connect

    Marshall, T.C.; Zhang, T.B.

    1995-11-01

    The authors have explored high power microwave ({lambda} = 1.5mm) pulse amplification along a tapered undulator FEL using the 1D Compton FEL equations with slippage. For an appropriate taper, sideband instabilities are suppressed and a short ({approximately}50psec) Gaussian pulse will propagate in a nearly self-similar way as it grows in power, slipping through a much longer electron pulse (beam energy, 750kV; current, 100A; radius = 2mm; length = 200 radiation periods). This is in contrast to the example of pulse propagation in a constant parameter undulator, where the Gaussian pulse breaks up into irregularities identified with sidebanding. Variation of initial pulse width shows convergence to a 50psec wide output pulse. Because of the slippage of the radiation pulse through the electron pulse, the peak microwave pulse intensity, {approximately}3GW/cm2, is about three times the kinetic energy density of the electron beam.

  10. Integrated Pulse Detonation Propulsion and Magnetohydrodynamic Power

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.

    2001-01-01

    The prospects for realizing an integrated pulse detonation propulsion and magnetohydrodynamic (MHD) power system are examined. First, energy requirements for direct detonation initiation of various fuel-oxygen and fuel-air mixtures are deduced from available experimental data and theoretical models. Second, the pumping power requirements for effective chamber scavenging are examined through the introduction of a scavenging ratio parameter and a scavenging efficiency parameter. A series of laboratory experiments were carried out to investigate the basic engineering performance characteristics of a pulse detonation-driven MHD electric power generator. In these experiments, stoichiometric oxy-acetylene mixtures seeded with a cesium hydroxide/methanol spray were detonated at atmospheric pressure in a 1-m-long tube having an i.d. of 2.54 cm. Experiments with a plasma diagnostic channel attached to the end of the tube confirmed the attainment of detonation conditions (p2/p1 approximately 34 and D approximately 2,400 m/sec) and enabled the direct measurement of current density and electrical conductivity (approximately = 6 S/m) behind the detonation wave front, In a second set of experiments, a 30-cm-long continuous electrode Faraday channel, having a height of 2.54 cm and a width of 2 cm, was attached to the end of the tube using an area transition duct. The Faraday channel was inserted in applied magnetic fields of 0.6 and 0.95 T, and the electrodes were connected to an active loading circuit to characterize power extraction dependence on load impedance while also simulating higher effective magnetic induction. The experiments indicated peak power extraction at a load impedance between 5 and 10 Omega. The measured power density was in reasonable agreement with a simple electrodynamic model incorporating a correction for near-electrode potential losses. The time-resolved thrust characteristics of the system were also measured, and it was found that the NM interaction

  11. Integrated Pulse Detonation Propulsion and Magnetohydrodynamic Power

    NASA Technical Reports Server (NTRS)

    Litchford, R. J.; Lyles, Garry M. (Technical Monitor)

    2001-01-01

    The prospects for realizing an integrated pulse detonation propulsion and magnetohydrodynamic (MHD) power system are examined. First, energy requirements for direct detonation initiation of various fuel-oxygen and fuel-air mixtures are deduced from available experimental data and theoretical models. Second, the pumping power requirements for effective chamber scavenging are examined through the introduction of a scavenging ratio parameter and a scavenging efficiency parameter. A series of laboratory experiments were carried out to investigate the basic engineering performance characteristics of a pulse detonation-driven MHD electric power generator. In these experiments, stoichiometric oxy-acetylene mixtures seeded with a cesium hydroxide/methanol spray were detonated at atmospheric pressure in a 1-m-long tube having an i.d. of 2.54 cm. Experiments with a plasma diagnostic channel attached to the end of the tube confirmed the attainment of detonation conditions (p(sub 2)/p(sub 1) approx. 34 and D approx. 2,400 m/sec) and enabled the direct measurement of current density and electrical conductivity (=6 S/m) behind the detonation wave front. In a second set of experiments, a 30-cm-long continuous electrode Faraday channel, having a height of 2.54 cm and a width of 2 cm, was attached to the end of the tube using an area transition duct. The Faraday channel was inserted in applied magnetic fields of 0.6 and 0.95 T. and the electrodes were connected to an active loading circuit to characterize power extraction dependence on load impedance while also simulating higher effective magnetic induction. The experiments indicated peak power extraction at a load impedance between 5 and 10 Ohm. The measured power density was in reasonable agreement with a simple electrodynamic model incorporating a correction for near-electrode potential losses. The time-resolved thrust characteristics of the system were also measured, and it was found that the MHD interaction exerted a

  12. Pulse transmission transceiver architecture for low power communications

    DOEpatents

    Dress, Jr., William B.; Smith, Stephen F.

    2003-08-05

    Systems and methods for pulse-transmission low-power communication modes are disclosed. A method of pulse transmission communications includes: generating a modulated pulse signal waveform; transforming said modulated pulse signal waveform into at least one higher-order derivative waveform; and transmitting said at least one higher-order derivative waveform as an emitted pulse. The systems and methods significantly reduce lower-frequency emissions from pulse transmission spread-spectrum communication modes, which reduces potentially harmful interference to existing radio frequency services and users and also simultaneously permit transmission of multiple data bits by utilizing specific pulse shapes.

  13. PULSED POWER APPLICATIONS IN HIGH INTENSITY PROTON RINGS.

    SciTech Connect

    ZHANG, S.Y.; SANDBERG, J.; ET AL.

    2005-05-16

    Pulsed power technology has been applied in particle accelerators and storage rings for over four decades. It is most commonly used in injection, extraction, beam manipulation, source, and focusing systems. These systems belong to the class of repetitive pulsed power. In this presentation, we review and discuss the history, present status, and future challenge of pulsed power applications in high intensity proton accelerators and storage rings.

  14. Photoconductive Semiconductor Switches for pulsed power applications

    SciTech Connect

    Loubriel, G.M.; Zutavern, F.J.; Denison, G.J.; Helgeson, W.D.; McLaughlin, D.L.; O`Malley, M.W.; Buttram, M.T.

    1993-08-01

    Photoconductive Semiconductor Switches (PCSS) are being used in, or tested for, many different pulsed power applications as diverse as ultrawideband (UWB) transmitters and high current pulsers. Some aspects of the switches that are relevant to most of the applications are: switch lifetime (longevity), switch opening time (related to the lifetime of carriers in the semiconductor), switching jitter, and the required laser energy. This paper will emphasize the results that we have obtained with Si switches for UWB applications. These include: measurement of switch longevity (a total of 80 Coulombs or 40 C/cm for a 2 cm wide switch and 18.4 Coulombs or 73 Coulombs/cm for a 0.25 cm wide switch), switching at high repetition rates (up to 540 Hz), measurement of carrier lifetime decay rates (a fast one of a few {mu}s, and a slow one of about 330 {mu}s), and measurements on the effect of neutron irradiation on carrier lifetimes. The total charge switched seems to be the highest ever reported for a PCSS. We have used these Si switches in a variety of circuits to produce: a monocycle with a period of about 10 ns corresponding to a center frequency of about 84 MHz, and ringing (many pulse) waveforms with periods of about 1 ns and 7.5 ns corresponding to center frequencies of 770 MHz and 133 MHz. We will also discuss recent studies on the switching properties of GaP.

  15. Improved pen harvester for powering a pulse rate sensor

    NASA Astrophysics Data System (ADS)

    Marin, Anthony; Heitzmann, Patrick; Twiefel, Jens; Priya, Shashank

    2012-04-01

    With the continued advancement in electronics the power requirement for micro-sensors has been decreasing opening the possibility for incorporating on-board energy harvesting devices to create self-powered sensors. The requirement for the energy harvesters are small size, light weight and the possibility of a low-budget mass production. In this study, we focus on developing an energy harvester for powering a pulse rate sensor. We propose to integrate an inductive energy harvester within a commonly available pen to harvest vibration energy from normal human motions like jogging and jumping. An existing prototype was reviewed which consists of a magnet wedged between two mechanical springs housed within a cylindrical shell. A single copper coil surrounds the cylindrical shell which harvests energy through Faraday's effect during magnet oscillation. This study reports a design change to the previous prototype providing a significant reduction in the device foot print without causing major losses in power generation. By breaking the single coil in the previous prototype into three separate coils an increase in power density was achieved. Several pulse rate sensors were evaluated to determine a target power requirement of 0.3 mW. To evaluate the prototype as a potential solution, the harvester was excited at various frequencies and accelerations typically produced through jogging and jumping motion. The improved prototype generated 0.043 mW at 0.56 grms and 3 Hz; and 0.13 mW at 1.14 grms at 5 Hz. The design change allowed reduction in total volume from 8.59 cm3 to 1.31 cm3 without significant losses in power generation.

  16. Advances in Solar Power Forecasting

    NASA Astrophysics Data System (ADS)

    Haupt, S. E.; Kosovic, B.; Drobot, S.

    2014-12-01

    The National Center for Atmospheric Research and partners are building a blended SunCast Solar Power Forecasting system. This system includes several short-range nowcasting models and improves upon longer range numerical weather prediction (NWP) models as part of the "Public-Private-Academic Partnership to Advance Solar Power Forecasting." The nowcasting models being built include statistical learning models that include cloud regime prediction, multiple sky imager-based advection models, satellite image-based advection models, and rapid update NWP models with cloud assimilation. The team has also integrated new modules into the Weather Research and Forecasting Model (WRF) to better predict clouds, aerosols, and irradiance. The modules include a new shallow convection scheme; upgraded physics parameterizations of clouds; new radiative transfer modules that specify GHI, DNI, and DIF prediction; better satellite assimilation methods; and new aerosol estimation methods. These new physical models are incorporated into WRF-Solar, which is then integrated with publically available NWP models via the Dynamic Integrated Forecast (DICast) system as well as the Nowcast Blender to provide seamless forecasts at partner utility and balancing authority commercial solar farms. The improvements will be described and results to date discussed.

  17. Pulse Detonation Rocket MHD Power Experiment

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Cook, Stephen (Technical Monitor)

    2002-01-01

    A pulse detonation research engine (MSFC (Marshall Space Flight Center) Model PDRE (Pulse Detonation Rocket Engine) G-2) has been developed for the purpose of examining integrated propulsion and magnetohydrodynamic power generation applications. The engine is based on a rectangular cross-section tube coupled to a converging-diverging nozzle, which is in turn attached to a segmented Faraday channel. As part of the shakedown testing activity, the pressure wave was interrogated along the length of the engine while running on hydrogen/oxygen propellants. Rapid transition to detonation wave propagation was insured through the use of a short Schelkin spiral near the head of the engine. The measured detonation wave velocities were in excess of 2500 m/s in agreement with the theoretical C-J velocity. The engine was first tested in a straight tube configuration without a nozzle, and the time resolved thrust was measured simultaneously with the head-end pressure. Similar measurements were made with the converging-diverging nozzle attached. The time correlation of the thrust and head-end pressure data was found to be excellent. The major purpose of the converging-diverging nozzle was to configure the engine for driving an MHD generator for the direct production of electrical power. Additional tests were therefore necessary in which seed (cesium-hydroxide dissolved in methanol) was directly injected into the engine as a spray. The exhaust plume was then interrogated with a microwave interferometer in an attempt to characterize the plasma conditions, and emission spectroscopy measurements were also acquired. Data reduction efforts indicate that the plasma exhaust is very highly ionized, although there is some uncertainty at this time as to the relative abundance of negative OH ions. The emission spectroscopy data provided some indication of the species in the exhaust as well as a measurement of temperature. A 24-electrode-pair segmented Faraday channel and 0.6 Tesla permanent

  18. Advancing Concentrating Solar Power Research (Fact Sheet)

    SciTech Connect

    Not Available

    2014-02-01

    Researchers at the National Renewable Energy Laboratory (NREL) provide scientific, engineering, and analytical expertise to help advance innovation in concentrating solar power (CSP). This fact sheet summarizes how NREL is advancing CSP research.

  19. High-power ns-pulse fiber laser sources for remote sensors

    NASA Astrophysics Data System (ADS)

    Di Teodoro, Fabio; Belden, Paul; Ionov, Pavel; Werner, Nicolette

    2014-12-01

    The development of fiber-based laser sources for space-borne remote sensors must meet many concurrent requirements including high pulse energy/peak power, excellent beam quality, narrow spectral linewidth, simple thermal management, small volume and mass, low power consumption, rugged packaging, and long-term reliability. To address these requirements, many aspects of pulse fiber laser technology must be advanced beyond the state of the art of traditional optical sources used in telecommunications and materials processing. In this article, we discuss component and solutions that enable pulsed fiber laser sources to support remote sensing from space. We also describe several examples of such sources and characterize their performance.

  20. Hydrodynamics and Material Properties Experiments Using Pulsed Power Techniques*

    NASA Astrophysics Data System (ADS)

    Reinovsky, Robert; Trainor, R. James

    1999-06-01

    Within the last few years a new approach for exploring dynamic material properties and advanced hydrodynamics at extreme conditions has joined the traditional techniques of high velocity guns,and explosives. The principle tool is the high precision, magnetically imploded, near-solid density liner. The most attractive pulse power system for driving such experiments is an ultra-highcurrent, low impedance, microsecond time-scale source that is economical both the build and operate. Liner specifications vary but in general share requirements for a high degree of symmetry and uniformity after implosion. When imploded in free flight to velocities 10-30 km/sec and kinetic energies of from one to 25 MJ/cm of height, liners are attractive impactors for producing strong (>10 Mbar) shocks in the target. Simple geometries can, in principle, produce multi-shock environments to reach off-hugoniot states. When filled with a compressible material, liners can deliver almost adiabatic compression to the target. When the liner surrounds a (small)nearly incompressible target material, for example a condensed noble gas, a liner can deliver enormous pressure to the target almost isentropically. When the compressible material is a magnetic field, flux compression can results in compressed fields above 1000 tesla in macroscopic volumes for materials studies.In this paper we will review basic scaling argumentsthat set the scale of environments available. We will mention the pulse power technology under development at Los Alamos and provide a summary of results from experiments testing solid metal liners under magnetic drive and a few examples of experiments performed withinterim systems. Other papers in this conference will provide specific proposals for pulse power driven shock-wave experiments.

  1. Technological advances in powered wheelchairs.

    PubMed

    Edlich, Richard F; Nelson, Kenneth P; Foley, Marni L; Buschbacher, Ralph M; Long, William B; Ma, Eva K

    2004-01-01

    During the last 40 years, there have been revolutionary advances in power wheelchairs. These unique wheelchair systems, designed for the physically immobile patient, have become extremely diversified, allowing the user to achieve different positions, including tilt, recline, and, more recently, passive standing. Because of this wide diversity of powered wheelchair products, there is a growing realization of the need for certification of wheeled mobility suppliers. Legislation in Tennessee (Consumer Protection Act for Wheeled Mobility) passed in 2003 will ensure that wheeled mobility suppliers must have Assistive Technology Supplier certification and maintain their continuing education credits when fitting individuals in wheelchairs for long-term use. Fifteen other legislative efforts are currently underway in general assemblies throughout the US. Manufacturers, dealers, hospitals, and legislators are working toward the ultimate goal of passing federal legislation delineating the certification process of wheeled mobility suppliers. The most recent advance in the design of powered wheelchairs is the development of passive standing positions. The beneficial effects of passive standing have been documented by comprehensive scientific studies. These benefits include reduction of seating pressure, decreased bone demineralization, increased bladder pressure, enhanced orthostatic circulatory regulation, reduction in muscular tone, decrease in upper extremity muscle stress, and enhanced functional status in general. In February 2003, Permobil, Inc., introduced the powered Permobil Chairman 2K Stander wheelchair, which can tilt, recline, and stand. Other companies are now manufacturing powered wheelchairs that can achieve a passive standing position. These wheelchairs include the Chief SR Powerchair, VERTRAN, and LifeStand Compact. Another new addition to the wheelchair industry is the iBOT, which can elevate the user to reach cupboards and climb stairs but has no passive

  2. Advanced Accessory Power Supply Topologies

    SciTech Connect

    Marlino, L.D.

    2010-06-15

    This Cooperative Research and Development Agreement (CRADA) began December 8, 2000 and ended September 30, 2009. The total funding provided by the Participant (General Motors Advanced Technology Vehicles [GM]) during the course of the CRADA totaled $1.2M enabling the Contractor (UT-Battelle, LLC [Oak Ridge National Laboratory, a.k.a. ORNL]) to contribute significantly to the joint project. The initial task was to work with GM on the feasibility of developing their conceptual approach of modifying major components of the existing traction inverter/drive to develop low cost, robust, accessory power. Two alternate methods for implementation were suggested by ORNL and both were proven successful through simulations and then extensive testing of prototypes designed and fabricated during the project. This validated the GM overall concept. Moreover, three joint U.S. patents were issued and subsequently licensed by GM. After successfully fulfilling the initial objective, the direction and duration of the CRADA was modified and GM provided funding for two additional tasks. The first new task was to provide the basic development for implementing a cascaded inverter technology into hybrid vehicles (including plug-in hybrid, fuel cell, and electric). The second new task was to continue the basic development for implementing inverter and converter topologies and new technology assessments for hybrid vehicle applications. Additionally, this task was to address the use of high temperature components in drive systems. Under this CRADA, ORNL conducted further research based on GM’s idea of using the motor magnetic core and windings to produce bidirectional accessory power supply that is nongalvanically coupled to the terminals of the high voltage dc-link battery of hybrid vehicles. In order not to interfere with the motor’s torque, ORNL suggested to use the zero-sequence, highfrequency harmonics carried by the main fundamental motor current for producing the accessory power

  3. Interagency Advanced Power Group meeting minutes

    SciTech Connect

    Not Available

    1991-12-31

    This document contains the minutes and viewgraphs from a meeting of military personnel on the subject of power generation and distribution systems for military applications. Topics include heating and cooling systems for standard shelters, SDIO power programs, solar dynamic space power systems, hybrid solar dynamic/ photovoltaic systems, pulsed power technology, high-{Tc} superconductors, and actuators and other electronic equipment for aerospace vehicles. Attendees represented the US Air Force, Army, Navy, and NASA. (GHH)

  4. Interagency Advanced Power Group meeting minutes

    SciTech Connect

    Not Available

    1991-01-01

    This document contains the minutes and viewgraphs from a meeting of military personnel on the subject of power generation and distribution systems for military applications. Topics include heating and cooling systems for standard shelters, SDIO power programs, solar dynamic space power systems, hybrid solar dynamic/ photovoltaic systems, pulsed power technology, high-{Tc} superconductors, and actuators and other electronic equipment for aerospace vehicles. Attendees represented the US Air Force, Army, Navy, and NASA. (GHH)

  5. Advanced Concepts: Aneutronic Fusion Power and Propulsion

    NASA Technical Reports Server (NTRS)

    Chapman, John J.

    2012-01-01

    Aneutronic Fusion for In-Space thrust, power. Clean energy & potential nuclear gains. Fusion plant concepts, potential to use advanced fuels. Methods to harness ionic momentum for high Isp thrust plus direct power conversion into electricity will be presented.

  6. The Ranchero explosive pulsed power system

    SciTech Connect

    Goforth, J.H.; Atchison, W.L.; Bartram, D.E.

    1997-09-01

    The authors are currently developing a high explosive pulsed power system concept that they call Ranchero. Ranchero systems consist of series-parallel combinations of simultaneously initiated coaxial magnetic flux compression generators, and are intended to operate in the range from 50 MA to a few hundred MA currents. One example of a Ranchero system is shown here. The coaxial modules lend themselves to extracting the current output either from one end or along the generator midplane. They have previously published design considerations related to the different module configurations, and in this paper they concentrate on the system that they will use for their first imploding liner tests. A single module with end output. The module is 1.4-m long and expands the armature by a factor of two to reach the 30-cm OD stator. The first heavy liner implosion experiments will be conducted in the range of 40--50 MA currents. Electrical tests, to date, have employed high explosive (HE) charges 43-cm long. They have performed tests and related 1D MHD calculations at the 45-MA current level with small loads. From these results, they determine that they can deliver currents of approximately 50 MA to loads of 8 nH.

  7. High power linear pulsed beam annealer

    DOEpatents

    Strathman, Michael D.; Sadana, Devendra K.; True, Richard B.

    1983-01-01

    A high power pulsed electron beam is produced in a system comprised of an electron gun having a heated cathode, control grid, focus ring, and a curved drift tube. The drift tube is maintained at a high positive voltage with respect to the cathode to accelerate electrons passing through the focus ring and to thereby eliminate space charge. A coil surrounding the curved drift tube provides a magnetic field which maintains the electron beam focused about the axis of the tube and imparts motion on electrons in a spiral path for shallow penetration of the electrons into a target. The curvature of the tube is selected so there is no line of sight between the cathode and a target holder positioned within a second drift tube spaced coaxially from the curved tube. The second tube and the target holder are maintained at a reference voltage that decelerates the electrons. A second coil surrounding the second drift tube maintains the electron beam focused about the axis of the second drift tube and compresses the electron beam to the area of the target. The target holder can be adjusted to position the target where the cross section of the beam matches the area of the target.

  8. IBEX - a pulsed power accelerator that generates no prepulse

    SciTech Connect

    Ramirez, J.J.; Corley, J.P.; Mazarakis, M.G.

    1983-01-01

    Intense relativistic electron beams are produced in vacuum diodes driven by pulsed power accelerators. For pulse widths approx. 100 nsec, pulse forming lines (PPL) are used to generate the accelerating voltage pulse. This pulse is produced by sequential switching of stored energy through two or more stages. Capacitance and/or inductive coupling usually results in the generation of a low level prepulse voltage some time during the switching sequence. This prepulse is known to have a substantial effect on the performance of the vacuum diode during the main accelerating pulse. Most accelerators use various schemes for reducing this prepulse to acceptable levels. The Isolated Blumlein PPL concept was developed at Sandia to allow for the generation of the main accelerating pulse without generating a prepulse voltage. This concept was implemented into the IBEX accelerator that generates a 4 MV, 100 kA, 20 nsec output pulse. Design and performance data are presented.

  9. Advanced Radioisotope Power Systems Segmented Thermoelectric Research

    NASA Technical Reports Server (NTRS)

    Caillat, Thierry

    2004-01-01

    Flight times are long; - Need power systems with >15 years life. Mass is at an absolute premium; - Need power systems with high specific power and scalability. 3 orders of magnitude reduction in solar irradiance from Earth to Pluto. Nuclear power sources preferable. The Overall objective is to develop low mass, high efficiency, low-cost Advanced Radioisotope Power System with double the Specific Power and Efficiency over state-of-the-art Radioisotope Thermoelectric Generators (RTGs).

  10. Pulsed Magnetic Welding for Advanced Core and Cladding Steel

    SciTech Connect

    Cao, Guoping; Yang, Yong

    2013-12-19

    To investigate a solid-state joining method, pulsed magnetic welding (PMW), for welding the advanced core and cladding steels to be used in Generation IV systems, with a specific application for fuel pin end-plug welding. As another alternative solid state welding technique, pulsed magnetic welding (PMW) has not been extensively explored on the advanced steels. The resultant weld can be free from microstructure defects (pores, non-metallic inclusions, segregation of alloying elements). More specifically, the following objectives are to be achieved: 1. To design a suitable welding apparatus fixture, and optimize welding parameters for repeatable and acceptable joining of the fuel pin end-plug. The welding will be evaluated using tensile tests for lap joint weldments and helium leak tests for the fuel pin end-plug; 2 Investigate the microstructural and mechanical properties changes in PMW weldments of proposed advanced core and cladding alloys; 3. Simulate the irradiation effects on the PWM weldments using ion irradiation.

  11. NDCX-II PULSED POWER SYSTEM AND INDUCTION CELLS

    SciTech Connect

    Waldron, W.L.; Reginato, L.L.; Leitner, M.

    2009-06-01

    The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL) is currently finalizing the design of NDCX-II, the second phase of the Neutralized Drift Compression Experiment, which will use an ion beam to explore Warm Dense Matter (WDM) and Inertial Fusion Energy (IFE) target hydrodynamics. The ion induction accelerator will include induction cells and Blumleins from the decommissioned Advanced Test Accelerator (ATA) at Lawrence Livermore National Laboratory (LLNL). A test stand has been built at Lawrence Berkeley National Laboratory (LBNL) to test refurbished ATA induction cells and pulsed power hardware for voltage holding and ability to produce various compression and acceleration waveforms. The performance requirements, design modifications, and test results will be presented.

  12. Plasma Switch for High-Power Active Pulse Compressor

    SciTech Connect

    Hirshfield, Jay L.

    2013-11-04

    Results are presented from experiments carried out at the Naval Research Laboratory X-band magnicon facility on a two-channel X-band active RF pulse compressor that employed plasma switches. Experimental evidence is shown to validate the basic goals of the project, which include: simultaneous firing of plasma switches in both channels of the RF circuit, operation of quasi-optical 3-dB hybrid directional coupler coherent superposition of RF compressed pulses from both channels, and operation of the X-band magnicon directly in the RF pulse compressor. For incident 1.2 ?s pulses in the range 0.63 ? 1.35 MW, compressed pulses of peak powers 5.7 ? 11.3 MW were obtained, corresponding to peak power gain ratios of 8.3 ? 9.3. Insufficient bakeout and conditioning of the high-power RF circuit prevented experiments from being conducted at higher RF input power levels.

  13. Multirail electromagnetic launcher powered from a pulsed magnetohydrodynamic generator

    NASA Astrophysics Data System (ADS)

    Afonin, A. G.; Butov, V. G.; Panchenko, V. P.; Sinyaev, S. V.; Solonenko, V. A.; Shvetsov, G. A.; Yakushev, A. A.

    2015-09-01

    The operation of an electromagnetic multirail launcher of solids powered from a pulsed magnetohydrodynamic (MHD) generator is studied. The plasma flow in the channel of the pulsed MHD generator and the possibility of launching solids in a rapid-fire mode of launcher operation are considered. It is shown that this mode of launcher operation can be implemented by matching the plasma flow dynamics in the channel of the pulsed MHD generator and the launching conditions. It is also shown that powerful pulsed MHD generators can be used as a source of electrical energy for rapid-fire electromagnetic rail launchers operating in a burst mode.

  14. The Advanced Photon Source pulsed deflecting cavity RF system.

    SciTech Connect

    Cours, A.; DiMonte, N. P.; Smith, T. L.; Waldschmidt, G.

    2008-01-01

    The Advanced Photon Source Deflecting Cavity System for producing short X-ray pulses uses two multi-cell, S-band cavities to apply a deflecting voltage to the stored electron beam ahead of an undulator that supports a beamline utilizing picosecond X-rays. Two additional multi-cell cavities are then used to cancel out the perturbation and restore the electron beam to its nominal orbit. The pulsed rf system driving the deflecting cavities is described. Design tradeoffs are discussed with emphasis on topology considerations and digital control loops making use of sampling technology in a manner consistent with the present state of the art.

  15. Advanced secondary power system for transport aircraft

    NASA Technical Reports Server (NTRS)

    Hoffman, A. C.; Hansen, I. G.; Beach, R. F.; Plencner, R. M.; Dengler, R. P.; Jefferies, K. S.; Frye, R. J.

    1985-01-01

    A concept for an advanced aircraft power system was identified that uses 20-kHz, 440-V, sin-wave power distribution. This system was integrated with an electrically powered flight control system and with other aircraft systems requiring secondary power. The resulting all-electric secondary power configuration reduced the empty weight of a modern 200-passenger, twin-engine transport by 10 percent and the mission fuel by 9 percent.

  16. ADVANCED POWER SYSTEMS ANALYSIS TOOLS

    SciTech Connect

    Robert R. Jensen; Steven A. Benson; Jason D. Laumb

    2001-08-31

    The use of Energy and Environmental Research Center (EERC) modeling tools and improved analytical methods has provided key information in optimizing advanced power system design and operating conditions for efficiency, producing minimal air pollutant emissions and utilizing a wide range of fossil fuel properties. This project was divided into four tasks: the demonstration of the ash transformation model, upgrading spreadsheet tools, enhancements to analytical capabilities using the scanning electron microscopy (SEM), and improvements to the slag viscosity model. The ash transformation model, Atran, was used to predict the size and composition of ash particles, which has a major impact on the fate of the combustion system. To optimize Atran key factors such as mineral fragmentation and coalescence, the heterogeneous and homogeneous interaction of the organically associated elements must be considered as they are applied to the operating conditions. The resulting model's ash composition compares favorably to measured results. Enhancements to existing EERC spreadsheet application included upgrading interactive spreadsheets to calculate the thermodynamic properties for fuels, reactants, products, and steam with Newton Raphson algorithms to perform calculations on mass, energy, and elemental balances, isentropic expansion of steam, and gasifier equilibrium conditions. Derivative calculations can be performed to estimate fuel heating values, adiabatic flame temperatures, emission factors, comparative fuel costs, and per-unit carbon taxes from fuel analyses. Using state-of-the-art computer-controlled scanning electron microscopes and associated microanalysis systems, a method to determine viscosity using the incorporation of grey-scale binning acquired by the SEM image was developed. The image analysis capabilities of a backscattered electron image can be subdivided into various grey-scale ranges that can be analyzed separately. Since the grey scale's intensity is

  17. Approaches to solar cell design for pulsed laser power receivers

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1993-01-01

    Using a laser to beam power from Earth to a photovoltaic receiver in space could be a technology with applications to many space missions. Extremely high average-power lasers would be required in a wavelength range of 700-1000 nm. However, high-power lasers inherently operate in a pulsed format. Existing solar cells are not well designed to respond to pulsed incident power. To better understand cell response to pulsed illumination at high intensity, the PC-1D finite-element computer model was used to analyze the response of solar cells to continuous and pulsed laser illumination. Over 50 percent efficiency was calculated for both InP and GaAs cells under steady-state illumination near the optimum wavelength. The time-dependent response of a high-efficiency GaAs concentrator cell to a laser pulse was modeled, and the effect of laser intensity, wavelength, and bias point was studied. Three main effects decrease the efficiency of a solar cell under pulsed laser illumination: series resistance, L-C 'ringing' with the output circuit, and current limiting due to the output inductance. The problems can be solved either by changing the pulse shape or designing a solar cell to accept the pulsed input. Cell design possibilities discussed are a high-efficiency, light-trapping silicon cell, and a monolithic, low-inductance GaAs cell.

  18. Recent Advances in RF Pulse Compressor Systems at SLAC

    NASA Astrophysics Data System (ADS)

    Tantawi, Sami G.; Nantista, Christopher D.

    2003-12-01

    We will review the design of the dual-mode X-band rf system proposed for the Next Linear Collider (NLC). Recent experimental data are presented. The system is to produce 400 ns pulses with power levels up to 600 MW. A proof-of-principle experiment is being constructed at SLAC. Four 50 MW klystrons will power a fully dual-moded resonance delay line pulse compression system. Both the transfer line and the delay lines are dual-moded. The modes carried by the transfer line are controlled by the rf phases of the different klystrons. The modes in the delay lines are controlled by a set of mode converters at the input and the end of each delay line. By manipulating the modes in the transfer line, one can achieve either no pulse compression or a pulse compression ratio of 4. The total output power will be 200 MW for 1.6 microseconds or 600 MW for 400 nanoseconds.

  19. Influence of pulse duration on the plasma characteristics in high-power pulsed magnetron discharges

    SciTech Connect

    Konstantinidis, S.; Dauchot, J.P.; Ganciu, M.; Ricard, A.; Hecq, M.

    2006-01-01

    High-power pulsed magnetron discharges have drawn an increasing interest as an approach to produce highly ionized metallic vapor. In this paper we propose to study how the plasma composition and the deposition rate are influenced by the pulse duration. The plasma is studied by time-resolved optical emission and absorption spectroscopies and the deposition rate is controlled thanks to a quartz microbalance. The pulse length is varied between 2.5 and 20 {mu}s at 2 and 10 mTorr in pure argon. The sputtered material is titanium. For a constant discharge power, the deposition rate increases as the pulse length decreases. With 5 {mu}s pulse, for an average power of 300 W, the deposition rate is {approx}70% of the deposition rate obtained in direct current magnetron sputtering at the same power. The increase of deposition rate can be related to the sputtering regime. For long pulses, self-sputtering seems to occur as demonstrated by time-resolved optical emission diagnostic of the discharge. In contrary, the metallic vapor ionization rate, as determined by absorption measurements, diminishes as the pulses are shortened. Nevertheless, the ionization rate is in the range of 50% for 5 {mu}s pulses while it lies below 10% in the case of a classical continuous magnetron discharge.

  20. Power Enhancement Cavity for Burst-Mode Laser Pulses

    SciTech Connect

    Liu, Yun

    2015-01-01

    We demonstrate a novel optical cavity scheme and locking method that can realize the power enhancement of picosecond UV laser pulses operating at a burst mode with arbitrary burst (macropulse) lengths and repetition rates.

  1. An all solid state pulse power source for high PRF induction accelerators

    SciTech Connect

    Kirbie, H., LLNL

    1998-06-01

    Researchers at the Lawrence Livermore National Laboratory (LLNL) are developing a flexible, all solid-state pulsed power source that will enable an induction accelerator to produce mulitkiloampere electron beams at a maximum pulse repetition frequency (prf) of 2 MHz. The prototype source consists of three, 15-kV, 4.8-kA solid-state modulators stacked in an induction adder configuration. Each modulator contains over 1300 field-effect transistors (FETs) that quickly connect and disconnect four banks of energy storage capacitors to a magnetic induction core. The FETs are commanded on and off by an optical signal that determines the duration of the accelerating pulse. Further electronic circuitry is provided that resets the magnetic cores in each modulator immediately after the accelerating pulse. The system produces bursts of five or more pulses with an adjustable pulse width that ranges from 200 ns to 2 {micro}s The pulse duty factor within a burst can be as high as 25% while still allowing time for the induction core to reset. The solid-state modulator described above is called ARM-II and is named for the Advanced Radiographic Machine (ARM)-a powerful radiographic accelerator that will be the principal diagnostic device for the future Advanced Hydrotest Facility (AHF).

  2. Advances in bonding technology for high power diode laser bars

    NASA Astrophysics Data System (ADS)

    Wang, Jingwei; Li, Xiaoning; Hou, Dong; Feng, Feifei; Liu, Yalong; Liu, Xingsheng

    2015-02-01

    Due to their high electrical-optical conversion efficiency, compact size and long lifetime, high power diode lasers have found increased applications in many fields. As the improvement of device technology, high power diode laser bars with output power of tens or hundreds watts have been commercially available. With the increase of high current and output power, the reliability and lifetime of high power diode laser bars becomes a challenge, especially under harsh working conditions and hard-pulse operations. The bonding technology is still one of the bottlenecks of the advancement of high power diode laser bars. Currently, materials used in bonding high power diode laser bars are commonly indium and goldtin solders. Experimental and field application results indicates that the lifetime and reliability of high power diode laser bars bonded by gold-tin solder is much better than that bonded by indium solder which is prone to thermal fatigue, electro-migration and oxidization. In this paper, we review the bonding technologies for high power diode laser bars and present the advances in bonding technology for single bars, horizontal bar arrays and vertical bar stacks. We will also present the challenges and issues in bonding technology for high power diode laser bars and discuss some approaches and strategies in addressing the challenges and issues.

  3. Pulsed pyroelectric crystal-powered gamma source

    SciTech Connect

    Chen, A. X.; Antolak, A. J.; Leung, K.-N.; Raber, T. N.; Morse, D. H.

    2013-04-19

    A compact pulsed gamma generator is being developed to replace radiological sources used in commercial, industrial and medical applications. Mono-energetic gammas are produced in the 0.4 - 1.0 MeV energy range using nuclear reactions such as {sup 9}Be(d,n{gamma}){sup 10}B. The gamma generator employs an RF-driven inductively coupled plasma ion source to produce deuterium ion current densities up to 2 mA/mm{sup 2} and ampere-level current pulses can be attained by utilizing an array extraction grid. The extracted deuterium ions are accelerated to approximately 300 keV via a compact stacked pyroelectric crystal system and then bombard the beryllium target to generate gammas. The resulting microsecond pulse of gammas is equivalent to a radiological source with curie-level activity.

  4. Extended Propagation of Powerful Laser Pulses in Focusing Kerr Media

    NASA Astrophysics Data System (ADS)

    Malkin, V. M.; Fisch, N. J.

    2016-09-01

    Powerful incoherent laser pulses can propagate in focusing Kerr media much longer distances than can coherent pulses, due to the fast phase mixing that prevents transverse filamentation. This distance is limited by 4-wave scattering, which accumulates waves at small transverse wave numbers, where phase mixing is too slow to retain the incoherence and thus prevent the filamentation. However, we identify how this theoretical limit can be overcome by countering this accumulation through transverse heating of the pulse by random fluctuations of the refractive index. Thus, the laser pulse propagation distances are significantly extended, making feasible, in particular, the generation of unprecedentedly intense and powerful short laser pulses in a plasma by means of backward Raman amplification in new random laser regimes.

  5. Characterization of advanced thermionic energy converters for modular power units

    NASA Astrophysics Data System (ADS)

    Thayer, Kevin L.; Ramalingam, Mysore L.; Lamp, Thomas R.

    1995-01-01

    The results of the initial characterization of two advanced, heat pipe cooled planar thermionic energy converters are presented. The advanced converters utilize chemical vapor deposited (CVD) rhenium on molybdenum for both the emitter and collector electrodes. Waste heat is rejected from the collector electrode by a niobium heat pipe that contains sodium as the working fluid. Output power densities in the range from 0.7 to 10.43 watts/cm2 were recorded using sweep blasing for emitter temperatures in the range from 1573 to 1950 K. Tests were conducted to investigate the design of a power conversion circuit for a series string of converters. Static loading of the converters was performed to verify the operation of the converters in an actual application. The dynamic switching characteristics of one converter were measured to evaluate the possibility of interfacing a pulse-width modulated (PWM) power regulator directly to a thermionic source.

  6. Advanced power supplies: Scoping study and technology assessment. Final report

    SciTech Connect

    1998-04-01

    This report presents a scoping study as well as a technology assessment for advanced power supplies used in industrial, commercial and residential applications. The study is focused on applications where electro-technologies provide opportunity for increased use of electricity, or where new processes based on power electronics and electricity use can supplant established methods, creating additional value for utility end-use customers. Target customers can be in the residential, commercial and industrial sectors. In most of the targeted applications, the power delivered to the load is conditioned by a power supply to a form which can be usefully utilized. Frequently, the power supply represents a key cost factor, and often is a primary limiter of the performance achievable in the end-use application process. Identifying where such limits and opportunities exist can open the door to technology advances which benefit the targeted end-user. This report presents power supply requirements in various applications including induction cooking, induction heating, metal finishing, ozonation systems, pulse power incinerators and sterilizers, welding, plasma spraying, corrosion protection, precision welding, magnet supplies, induction hardening, anodizing, and other similar areas. The report highlights the potential for improvements in the power supply itself, and for any resulting improvements in the process, in the reliability, power quality and cost of the system. A market study is then used to prioritize R and D efforts in areas of maximum potential economic impact.

  7. A Tesla-pulse forming line-plasma opening switch pulsed power generator.

    PubMed

    Novac, B M; Kumar, R; Smith, I R

    2010-10-01

    A pulsed power generator based on a high-voltage Tesla transformer which charges a 3.85 Ω/55 ns water-filled pulse forming line to 300 kV has been developed at Loughborough University as a training tool for pulsed power students. The generator uses all forms of insulation specific to pulsed power technology, liquid (oil and water), gas (SF(6)), and magnetic insulation in vacuum, and a number of fast voltage and current sensors are implemented for diagnostic purposes. A miniature (centimeter-size) plasma opening switch has recently been coupled to the output of the pulse forming line, with the overall system comprising the first phase of a program aimed at the development of a novel repetitive, table-top generator capable of producing 15 GW pulses for high power microwave loads. Technical details of all the generator components and the main experimental results obtained during the program and demonstrations of their performance are presented in the paper, together with a description of the various diagnostic tools involved. In particular, it is shown that the miniature plasma opening switch is capable of reducing the rise time of the input current while significantly increasing the load power. Future plans are outlined in the conclusions.

  8. Advanced RF power sources for linacs

    SciTech Connect

    Wilson, P.B.

    1996-10-01

    In order to maintain a reasonable over-all length at high center-of-mass energy, the main linac of an electron-positron linear collider must operate at a high accelerating gradient. For copper (non-superconducting) accelerator structures, this implies a high peak power per unit length and a high peak power per RF source, assuming a limited number of discrete sources are used. To provide this power, a number of devices are currently under active development or conceptual consideration: conventional klystrons with multi-cavity output structures, gyroklystrons, magnicons, sheet-beam klystrons, multiple-beam klystrons and amplifiers based on the FEL principle. To enhance the peak power produced by an rf source, the SLED rf pulse compression scheme is currently in use on existing linacs, and new compression methods that produce a flatter output pulse are being considered for future linear colliders. This paper covers the present status and future outlook for the more important rf power sources and pulse compression systems. It should be noted that high gradient electron linacs have applications in addition to high-energy linear colliders; they can, for example, serve as compact injectors for FEL`s and storage rings.

  9. Realistic Specific Power Expectations for Advanced Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.

    2006-01-01

    Radioisotope Power Systems (RPS) are being considered for a wide range of future NASA space science and exploration missions. Generally, RPS offer the advantages of high reliability, long life, and predictable power production regardless of operating environment. Previous RPS, in the form of Radioisotope Thermoelectric Generators (RTG), have been used successfully on many NASA missions including Apollo, Viking, Voyager, and Galileo. NASA is currently evaluating design options for the next generation of RPS. Of particular interest is the use of advanced, higher efficiency power conversion to replace the previous thermoelectric devices. Higher efficiency reduces the quantity of radioisotope fuel and potentially improves the RPS specific power (watts per kilogram). Power conversion options include Segmented Thermoelectric (STE), Stirling, Brayton, and Thermophotovoltaic (TPV). This paper offers an analysis of the advanced 100 watt-class RPS options and provides credible projections for specific power. Based on the analysis presented, RPS specific power values greater than 10 W/kg appear unlikely.

  10. Advanced power systems for EOS

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila G.; Weinberg, Irving; Flood, Dennis J.

    1991-01-01

    The Earth Observing System, which is part of the International Mission to Planet Earth, is NASA's main contribution to the Global Change Research Program. Five large platforms are to be launched into polar orbit: two by NASA, two by the European Space Agency, and one by the Japanese. In such an orbit the radiation resistance of indium phosphide solar cells combined with the potential of utilizing 5 micron cell structures yields an increase of 10 percent in the payload capability. If further combined with the Advanced Photovoltaic Solar Array, the total additional payload capability approaches 12 percent.

  11. Advanced power systems for EOS

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila G.; Weinberg, Irving; Flood, Dennis J.

    1991-01-01

    The Earth Observing System (EOS), which is part of the International Mission to Planet Earth, is NASA's main contribution to the Global Change Research Program. Five large platforms are to be launched into polar orbit: two by NASA, two by the European Space Agency, and one by the Japanese. In such an orbit the radiation resistance of indium phosphide solar cells combined with the potential of utilizing 5-micron cell structures yields an increase of 10 percent in the payload capability. If further combined with the Advanced Photovoltaic Solar Array, the total additional payload capability approaches 12 percent.

  12. HIGH POWER LONG PULSE PERFORMANCE OF THE DIII-D GYROTRON INSTALLATION

    SciTech Connect

    J. LOHR; Y.A. GORELOV; R.W. CALLIS; H.J. GRUNLOH; J.J. PEAVY; R.I. PINSKER; D. PONCE; R. PRATER; R.A. ELLIS,III

    2002-05-01

    At DIII-D, five 110 GHz gyrotrons are operating routinely for 2.0 s pulses at generated power levels {ge}750 kW per gyrotron. A sixth gyrotron is being installed, which should bring the generated power level to >4 MW and the injected power to about 3.0 MW. The output power now can be modulated by the plasma control system to fix T{sub e} at a desired value. The system is being used as a tool for control of current diffusion, for current profile control and other experiments leading to advanced tokamak operation.

  13. Pulsed power systems for environmental and industrial applications

    NASA Astrophysics Data System (ADS)

    Neau, E. L.

    1994-10-01

    The development of high peak power simulators, laser drivers, free electron lasers, and Inertial Confinement Fusion drivers is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup and industrial manufacturing processes. We discuss a new class of short-pulse, high average power accelerator that achieves megavolt electron and ion beams with 10's of kiloamperes of current and average power levels in excess of 100 kW. Large treatment areas are possible with these systems because kilojoules of energy are available in each output pulse. These systems can use large area x-ray converters for applications requiring grater depth of penetration such as food pasteurization and waste treatment. The combined development of this class of accelerators and applications, and Sandia National Laboratories, is called Quantum Manufacturing.

  14. Pulsed power systems for environmental and industrial applications

    SciTech Connect

    Neau, E.L.

    1993-12-31

    The development of high peak power simulators, laser drivers, free electron lasers, and Inertial Confinement Fusion drivers is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup and industrial manufacturing processes. We discuss a new class of short-pulse, high average power accelerator that achieves megavolt electron and ion beams with 10`s of kiloamperes of current and average power levels in excess of 100 KW. Large treatment areas are possible with these systems because kilojoules of energy are available in each output pulse. These systems can use large area x-ray converters for applications requiring greater depth of penetration such as food pasteurization and waste treatment. The combined development of this class of accelerators and applications, at Sandia National Laboratories, is called Quantum Manufacturing.

  15. Power-conditioning system for the Advanced Test Accelerator

    SciTech Connect

    Newton, M.A.; Smith, M.E.; Birx, D.L.; Branum, D.R.; Cook, E.G.; Copp, R.L.; Lee, F.D.; Reginato, L.L.; Rogers, D.; Speckert, G.C.

    1982-06-01

    The Advanced Test Accelerator (ATA) is a pulsed, linear induction, electron accelerator currently under construction and nearing completion at Lawrence Livermore National Laboratory's Site 300 near Livermore, California. The ATA is a 50 MeV, 10 kA machine capable of generating electron beam pulses at a 1 kHz rate in a 10 pulse burst, 5 pps average, with a pulse width of 70 ns FWHM. Ten 18 kV power supplies are used to charge 25 capacitor banks with a total energy storage of 8 megajoules. Energy is transferred from the capacitor banks in 500 microsecond pulses through 25 Command Resonant Charge units (CRC) to 233 Thyratron Switch Chassis. Each Thyratron Switch Chassis contains a 2.5 microfarad capacitor and is charged to 25 kV (780 joules) with voltage regulation of +- .05%. These capacitors are switched into 10:1 step-up resonant transformers to charge 233 Blumleins to 250 kV in 20 microseconds. A magnetic modulator is used instead of a Blumlein to drive the grid of the injector.

  16. PCF based high power narrow line width pulsed fiber laser

    NASA Astrophysics Data System (ADS)

    Chen, H.; Yan, P.; Xiao, Q.; Wang, Y.; Gong, M.

    2012-09-01

    Based on semiconductor diode seeded multi-stage cascaded fiber amplifiers, we have obtained 88-W average power of a 1063-nm laser with high repetition rate of up to 1.5 MHz and a constant 2-ns pulse duration. No stimulated Brillouin scattering pulse or optical damage occurred although the maximum pulse peak power has exceeded 112 kW. The output laser exhibits excellent beam quality (M2x = 1.24 and M2y = 1.18), associated with a spectral line width as narrow as 0.065 nm (FWHM). Additionally, we demonstrate high polarization extinction ratio of 18.4 dB and good pulse stabilities superior to 1.6 % (RMS).

  17. Advanced piggyback water power generator

    SciTech Connect

    Wiggs, B.R.

    1988-02-16

    A power generating system is described including: a central boat containing gearing and electric and/or power generation equipment, with a forward angled-back deflection screen and a rear non-angled deflection screen, with a smaller outrigger pontoon on each respective side of the central boat, with closed cell, waterproof, plastic foam filling in the central boat and pontoons, and with the bow of the respective outrigger pontoons angled so as to completely turn water away from, and to the outside of, the space and/or incoming water area between each such respective pontooon and the central boat. There are legs with cone shaped bottoms and with wheels attached, with the wheels extending slightly below the cone shaped bottoms; paddle wheels on each side of the central boat, between the central boat, and respective outrigger pontoons, with 90 degree spaced, flat, paddle blades, and with a solid, disk division vertically dividing each respective side paddle wheel in half and extending at right angles to, and from, the central axle, to the outside extreme end of the paddle blades, with each such half of the equally divided paddle wheel being constructed so that the 90 degree spaced paddle blades in one half are offset by 45 degrees from the 90 degree space paddle blades in the other half, and with the extreme ends of each such set of divided paddle wheels being enclosed via a similar solid.

  18. Adaptive pulse width control and sampling for low power pulse oximetry.

    PubMed

    Gubbi, Sagar Venkatesh; Amrutur, Bharadwaj

    2015-04-01

    Remote sensing of physiological parameters could be a cost effective approach to improving health care, and low-power sensors are essential for remote sensing because these sensors are often energy constrained. This paper presents a power optimized photoplethysmographic sensor interface to sense arterial oxygen saturation, a technique to dynamically trade off SNR for power during sensor operation, and a simple algorithm to choose when to acquire samples in photoplethysmography. A prototype of the proposed pulse oximeter built using commercial-off-the-shelf (COTS) components is tested on 10 adults. The dynamic adaptation techniques described reduce power consumption considerably compared to our reference implementation, and our approach is competitive to state-of-the-art implementations. The techniques presented in this paper may be applied to low-power sensor interface designs where acquiring samples is expensive in terms of power as epitomized by pulse oximetry. PMID:25014964

  19. Power Management for Space Advanced Life Support

    NASA Technical Reports Server (NTRS)

    Jones, Harry

    2001-01-01

    Space power systems include the power source, storage, and management subsystems. In current crewed spacecraft, solar cells are the power source, batteries provide storage, and the crew performs any required load scheduling. For future crewed planetary surface systems using Advanced Life Support, we assume that plants will be grown to produce much of the crew's food and that nuclear power will be employed. Battery storage is much more costly than nuclear power capacity and so is not likely to be used. We investigate the scheduling of power demands by the crew or automatic control, to reduce the peak power load and the required generating capacity. The peak to average power ratio is a good measure of power use efficiency. We can easily schedule power demands to reduce the peak power from its maximum, but simple scheduling approaches may not find the lowest possible peak to average power ratio. An initial power scheduling example was simple enough for a human to solve, but a more complex example with many intermittent load demands required automatic scheduling. Excess power is a free resource and can be used even for minor benefits.

  20. Low power pulsed MPD thruster system analysis and applications

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.; Domonkos, Matthew; Gilland, James H.

    1993-01-01

    Pulsed MPD thruster systems were analyzed for application to solar-electric orbit transfer vehicles at power levels ranging from 10 to 40 kW. Potential system level benefits of pulsed propulsion technology include ease of power scaling without thruster performance changes, improved transportability from low power flight experiments to operational systems, and reduced ground qualification costs. Required pulsed propulsion system components include a pulsed applied-field MPD thruster, a pulse-forming network, a charge control unit, a cathode heater supply, and high speed valves. Mass estimates were obtained for each propulsion subsystem and spacecraft component. Results indicate that for payloads of 1000 and 2000 kg, pulsed MPD thrusters can reduce launch mass by between 1000 and 2500 kg relative to hydrogen arcjets, reducing launch vehicle class and launch cost. While the achievable mass savings depends on the trip time allowed for the mission, cases are shown in which the launch vehicle required for a mission is decreased from an Atlas IIAS to an Atlas I or Delta 7920.

  1. Low power pulsed MPD thruster system analysis and applications

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.; Domonkos, Matthew; Gilland, James H.

    1993-01-01

    Pulsed magnetoplasmadynamic (MPD) thruster systems were analyzed for application to solar-electric orbit transfer vehicles at power levels ranging from 10 to 40 kW. Potential system level benefits of pulsed propulsion technology include ease of power scaling without thruster performance changes, improved transportability from low power flight experiments to operational systems, and reduced ground qualification costs. Required pulsed propulsion system components include a pulsed applied-field MPD thruster, a pulse-forming network, a charge control unit, a cathode heater supply, and high speed valves. Mass estimates were obtained for each propulsion subsystem and spacecraft component using off-the-shelf technology whenever possible. Results indicate that for payloads of 1000 and 2000 kg pulsed MPD thrusters can reduce launch mass by between 1000 and 2500 kg over those achievable with hydrogen arcjets, which can be used to reduce launch vehicle class and the associated launch cost. While the achievable mass savings depends on the trip time allowed for the mission, cases are shown in which the launch vehicle required for a mission is decreased from an Atlas IIAS to an Atlas I or Delta 7920.

  2. Investigation of Input Signal Curve Effect on Formed Pulse of Hydraulic-Powered Pulse Machine

    NASA Astrophysics Data System (ADS)

    Novoseltseva, M. V.; Masson, I. A.; Pashkov, E. N.

    2016-04-01

    Well drilling machines should have as high efficiency factor as it is possible. This work proposes factors that are affected by change of input signal pulse curve. A series of runs are conducted on mathematical model of hydraulic-powered pulse machine. From this experiment, interrelations between input pulse curve and construction parameters are found. Results of conducted experiment are obtained with the help of the mathematical model, which is created in Simulink Matlab. Keywords - mathematical modelling; impact machine; output signal amplitude; input signal curve.

  3. Evaluation of Light-Triggered Thyristors for Pulsed Power Applications

    SciTech Connect

    Tully, L K; Fulkerson, E S; Goerz, D A; Speer, R D

    2008-05-20

    Lawrence Livermore National Laboratory has many needs for high reliability, high peak current, high di/dt switches. Solid-state switch technology offers the demonstrated advantage of reliability under a variety of conditions. Light-triggered switches operate with a reduced susceptibility to electromagnetic interference commonly found within pulsed power environments. Despite the advantages, commercially available solid-state switches are not typically designed for the often extreme pulsed power requirements. Testing was performed to bound the limits of devices for pulsed power applications beyond the manufacturers specified ratings. To test the applicability of recent commercial light-triggered solid-state designs, an adjustable high current switch test stand was assembled. Results from testing and subsequent selected implementations are presented.

  4. The VELOCE pulsed power generator for isentropic compression experiments

    SciTech Connect

    Ao, Tommy; Asay, James Russell; Chantrenne, Sophie J.; Hickman, Randall John; Willis, Michael David; Shay, Andrew W.; Grine-Jones, Suzi A.; Hall, Clint Allen; Baer, Melvin R.

    2007-12-01

    Veloce is a medium-voltage, high-current, compact pulsed power generator developed for isentropic and shock compression experiments. Because of its increased availability and ease of operation, Veloce is well suited for studying isentropic compression experiments (ICE) in much greater detail than previously allowed with larger pulsed power machines such as the Z accelerator. Since the compact pulsed power technology used for dynamic material experiments has not been previously used, it is necessary to examine several key issues to ensure that accurate results are obtained. In the present experiments, issues such as panel and sample preparation, uniformity of loading, and edge effects were extensively examined. In addition, magnetohydrodynamic (MHD) simulations using the ALEGRA code were performed to interpret the experimental results and to design improved sample/panel configurations. Examples of recent ICE studies on aluminum are presented.

  5. Exploring new frontiers in the pulsed power laboratory: Recent progress

    NASA Astrophysics Data System (ADS)

    Adamenko, S.; Esaulov, A.; Ulmen, B.; Novikov, V.; Ponomarev, S.; Adamenko, A.; Artyuh, V.; Gurin, A.; Prokopenko, V.; Kolomiyets, V.; Belous, V.; Kim, K.-J.; Miley, G.; Bassuney, A.; Novikov, D.

    One of the most fundamental processes in the Universe, nucleosynthesis of elements drives energy production in stars as well as the creation of all atoms heavier than hydrogen. To harness this process and open new ways for energy production, we must recreate some of the extreme conditions in which it occurs. We present results of experiments using a pulsed power facility to induce collective nuclear interactions producing stable nuclei of virtually every element in the periodic table. A high-power electron beam pulse striking a small metallic target is used to create the extreme dynamic environment. Material analysis studies detect an anomalously high presence of new chemical elements in the remnants of the exploded target supporting theoretical conjectures of the experiment. These results provide strong motivation to continue our research looking for additional proofs that heavy element nucleosynthesis is possible in pulsed power laboratory.

  6. Saving Energy Through Advanced Power Strips (Poster)

    SciTech Connect

    Christensen, D.

    2013-10-01

    Advanced Power Strips (APS) look just like ordinary power strips, except that they have built-in features that are designed to reduce the amount of energy used by many consumer electronics. There are several different types of APSs on the market, but they all operate on the same basic principle of shutting off the supply power to devices that are not in use. By replacing your standard power strip with an APS, you can signifcantly cut the amount of electricity used by your home office and entertainment center devices, and save money on your electric bill. This illustration summarizes the different options.

  7. 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.

  8. A Conceptual Venus Rover Mission Using Advanced Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    Evans, Michael; Shirley, James H.; Abelson, Robert Dean

    2006-01-01

    This concept study demonstrates that a long lived Venus rover mission could be enabled by a novel application of advanced RPS technology. General Purpose Heat Source (GPHS) modules would be employed to drive an advanced thermoacoustic Stirling engine, pulse tube cooler and linear alternator that provides electric power and cooling for the rover. The Thermoacoustic Stirling Heat Engine (TASHE) is a system for converting high-temperature heat into acoustic power which then drives linear alternators and a pulse tube cooler to provide both electric power and coolin6g for the rover. A small design team examined this mission concept focusing on the feasibility of using the TASHE system in this hostile environment. A rover design is described that would provide a mobile platform for science measurements on the Venus surface for 60 days, with the potential of operating well beyond that. A suite of science instruments is described that collects data on atmospheric and surface composition, surface stratigraphy, and subsurface structure. An Earth-Venus-Venus trajectory would be used to deliver the rover to a low entry angle allowing an inflated ballute to provide a low deceleration and low heat descent to the surface. All rover systems would be housed in a pressure vessel in vacuum with the internal temperature maintained by the TASHE at under 50 °C.

  9. Optimizing Advanced Power System Designs Under Uncertainty

    SciTech Connect

    Rubin, E.S.; Diwekar; Frey, H.C.

    1996-12-31

    This paper describes recent developments in ongoing research to develop and demonstrate advanced computer-based methods for dealing with uncertainties that are critical to the design of advanced coal-based power systems. Recent developments include new deterministic and stochastic methods for simulation, optimization, and synthesis of advanced process designs. Results are presented illustrating the use of these new modeling tools for the design and analysis of several advanced systems of current interest to the U.S. Department of Energy, including the technologies of integrated gasification combined cycle (IGCC), advanced pressurized fluid combustion (PFBC), and the externally fired combined cycle (EFCC) process. The new methods developed in this research can be applied generally to any chemical or energy conversion process to reduce the technological risks associated with uncertainties in process performance and cost.

  10. Pulse power 350 V nickel-metal hydride battery power-D-005-00181

    NASA Astrophysics Data System (ADS)

    Eskra, Michael D.; Ralston, Paula; Salkind, Alvin; Plivelich, Robert F.

    Energy-storage devices are needed for applications requiring very high-power over short periods of time. Such devices have various military (rail guns, electromagnetic launchers, and DEW) and commercial applications, such as hybrid electric vehicles, vehicle starting (SLI), and utility peak shaving. The storage and delivery of high levels of burst power can be achieved with a capacitor, flywheel, or rechargeable battery. In order to reduce the weight and volume of many systems they must contain advanced state-of-the-art electrochemical or electromechanical power sources. There is an opportunity and a need to develop energy-storage devices that have improved high-power characteristics compared to existing ultra capacitors, flywheels or rechargeable batteries. Electro Energy, Inc. has been engaged in the development of bipolar nickel-metal hydride batteries, which may fulfil the requirements of some of these applications. This paper describes a module rated at 300 V (255 cells) (6 Ah). The volume of the module is 23 L and the mass is 56 kg. The module is designed to deliver 50 kW pulses of 10 s duration at 50% state-of-charge. Details of the mechanical design of the module, safety considerations, along with the results of initial electrical characterization testing by the customer will be discussed. Some discussion of the possibilities for design optimization is also included.

  11. Advanced power sources for space missions

    NASA Technical Reports Server (NTRS)

    Gavin, Joseph G., Jr.; Burkes, Tommy R.; English, Robert E.; Grant, Nicholas J.; Kulcinski, Gerald L.; Mullin, Jerome P.; Peddicord, K. Lee; Purvis, Carolyn K.; Sarjeant, W. James; Vandevender, J. Pace

    1989-01-01

    Approaches to satisfying the power requirements of space-based Strategic Defense Initiative (SDI) missions are studied. The power requirements for non-SDI military space missions and for civil space missions of the National Aeronautics and Space Administration (NASA) are also considered. The more demanding SDI power requirements appear to encompass many, if not all, of the power requirements for those missions. Study results indicate that practical fulfillment of SDI requirements will necessitate substantial advances in the state of the art of power technology. SDI goals include the capability to operate space-based beam weapons, sometimes referred to as directed-energy weapons. Such weapons pose unprecedented power requirements, both during preparation for battle and during battle conditions. The power regimes for these two sets of applications are referred to as alert mode and burst mode, respectively. Alert-mode power requirements are presently stated to range from about 100 kW to a few megawatts for cumulative durations of about a year or more. Burst-mode power requirements are roughly estimated to range from tens to hundreds of megawatts for durations of a few hundred to a few thousand seconds. There are two likely energy sources, chemical and nuclear, for powering SDI directed-energy weapons during the alert and burst modes. The choice between chemical and nuclear space power systems depends in large part on the total duration during which power must be provided. Complete study findings, conclusions, and eight recommendations are reported.

  12. Magnetic Flux Compression Concept for Nuclear Pulse Propulsion and Power

    NASA Technical Reports Server (NTRS)

    Litchford, Ronald J.

    2000-01-01

    The desire for fast, efficient interplanetary transport requires propulsion systems having short acceleration times and very high specific impulse attributes. Unfortunately, most highly efficient propulsion systems which are within the capabilities of present day technologies are either very heavy or yield very low impulse such that the acceleration time to final velocity is too long to be of lasting interest, One exception, the nuclear thermal thruster, could achieve the desired acceleration but it would require inordinately large mass ratios to reach the range of desired final velocities. An alternative approach, among several competing concepts that are beyond our modern technical capabilities, is a pulsed thermonuclear device utilizing microfusion detonations. In this paper, we examine the feasibility of an innovative magnetic flux compression concept for utilizing microfusion detonations, assuming that such low yield nuclear bursts can be realized in practice. In this concept, a magnetic field is compressed between an expanding detonation driven diamagnetic plasma and a stationary structure formed from a high temperature superconductor (HTSC). In general, we are interested in accomplishing two important functions: (1) collimation of a hot diamagnetic plasma for direct thrust production; and (2) pulse power generation for dense plasma ignition. For the purposes of this research, it is assumed that rnicrofusion detonation technology may become available within a few decades, and that this approach could capitalize on recent advances in inertial confinement fusion ICF) technologies including magnetized target concepts and antimatter initiated nuclear detonations. The charged particle expansion velocity in these detonations can be on the order of 10 (exp 6)- 10 (exp 7) meters per second, and, if effectively collimated by a magnetic nozzle, can yield the Isp and the acceleration levels needed for practical interplanetary spaceflight. The ability to ignite pure

  13. Power dependent pulse delay with asymmetric dual-core hybrid photonic crystal fiber coupler

    NASA Astrophysics Data System (ADS)

    Jing, Qi; Zhang, Xia; Wei, Wei; Huang, Yongqing; Ren, Xiaomin

    2014-02-01

    We propose a novel asymmetric dual-core hybrid photonic crystal fiber (PCF) coupler composed of a silicon tube as the left core and a silica core as the right core. The control of picosecond pulse delay is achievable by means of power adjusting. The transmission modes, dispersion characteristics and coupling coefficients of the proposed coupler are investigated numerically. The results demonstrate that it is possible to obtain 2.0 ps time delay for soliton pulse with 2.0 ps temporal width within 1 cm length. Further numerical results show that the coupler can generate 10.0 ps undistorted time advance within 5 cm length.

  14. Pulsed power drivers for ICF and high energy density physics

    NASA Astrophysics Data System (ADS)

    Ramirez, Juan J.; Matzen, M. Keith; McDaniel, Dillon H.

    Nanosecond Pulsed Power Science and Technology has its origins in the 1960s and over the past decade has matured into a flexible and robust discipline capable of addressing key physics issues of importance to Inertial Confinement Fusion (ICF) and high Energy Density Physics. The major leverage provided by pulsed power is its ability to generate and deliver high energy and high power at low cost and high efficiency. A low-cost, high-efficiency driver is important because of the very large capital investment required for multi-megajoule ignition-class systems. High efficiency is of additional importance for a commercially viable inertial fusion energy option. Nanosecond pulsed power has been aggressively and successfully developed at Sandia over the past twenty years. This effort has led to the development of unique multi-purpose facilities supported by highly capable diagnostic, calculational and analytic capabilities. The Sandia Particle-beam Fusion Program has evolved as part of an integrated national ICF Program. It applies the low-cost, high-efficiency leverage provided by nanosecond pulsed power systems to the longer-term goals of the national program, i.e., the Laboratory Microfusion Facility and Inertial Fusion Energy. A separate effort has led to the application of nanosecond pulsed power to the generation of intense, high-energy laboratory x-ray sources for application to x-ray laser and radiation effects science research. Saturn is the most powerful of these sources to date. It generates (approximately) 500 kilojoules of x-rays from a magnetically driven implosion (Z-pinch). This paper describes results of x-ray physics experiments performed on Saturn, plans for a new Z-pinch drive capability for PBFA-2, and a design concept for the proposed (approximately) 15 MJ Jupiter facility. The opportunities for ICF-relevant research using these facilities will also be discussed.

  15. Pulsed power -- Research and technology at Sandia National Laboratories

    SciTech Connect

    1981-12-31

    Over the past 15 years, steady and sometimes exciting progress has been made in the hybrid technology called Pulsed Power. Based on both electrical engineering and physics, pulsed power involves the generation, modification, and use of electrical pulses up to the multitrillion-watt and multimillion-volt ranges. The final product of these powerful pulses can take diverse forms--hypervelocity projectiles or imploding liners, energetic and intense particle beams, X-ray and gamma-ray pulses, laser light beams that cover the spectrum from ultraviolet to infrared, or powerful microwave bursts. At first, the needs of specific applications largely shaped research and technology in this field. New the authors are beginning to see the reverse--new applications arising from technical capabilities that until recently were though impossible. Compressing and heating microscopic quantities of matter until they reach ultra-high energy density represents one boundary of their scientific exploration. The other boundary might be a defensive weapon that can project vast amounts of highly directed energy over long distances. Other applications of the technology may range from the use of electron beams to sterilize sewage, to laboratory simulation of radiation effects on electronics, to electromagnetic launchings of projectiles into earth or into solar orbits. Eventually the authors hope to use pulsed power to produce an inexhaustible supply of energy by means of inertial confinement fusion (ICF)--a technique for heating and containing deuterium-tritium fuel through compression. Topics covered here are: (1) inertial confinement fusion; (2) simulation technology; (3) development of new technology; and (4) application to directed energy technologies.

  16. Pulse shortening in high-peak-power Reltron tubes

    NASA Astrophysics Data System (ADS)

    Miller, R. Bruce

    1996-10-01

    Most high-peak-power (>= 100 MW) microwave tubes are seemingly limited to an output RF energy per pulse of about 100 J. While Titan's L-band Reltron tubes have achieved 250 J/pulse, we have also observed pulse-shortening phenomena in both the modulating cavity and output cavity regions. We have examined the effects of construction materials, fabrication techniques, vacuum pressure, and conditioning. We will present data from these experiments and discuss a plausible pulse-shortening hypothesis involving electric- field-induced gas evolution and subsequent ionization. We believe that our energy-per-pulse limitations are the result of our current tube construction approach which uses explosive emission cathodes, plastic insulators, and grids to define cavity boundaries. While some simple extensions of this approach offers some hope for increasing the energy per pulse to perhaps 500 joules in L-band, we believe that achieving >= 1 kJ/pulse will require the use of conventional microwave tube construction techniques, including thermionic cathodes, ceramic insulators, and brazed joining with high-temperature bakeout. We will present the design of an L-band Reltron tube having these features.

  17. Active high-power RF switch and pulse compression system

    DOEpatents

    Tantawi, Sami G.; Ruth, Ronald D.; Zolotorev, Max

    1998-01-01

    A high-power RF switching device employs a semiconductor wafer positioned in the third port of a three-port RF device. A controllable source of directed energy, such as a suitable laser or electron beam, is aimed at the semiconductor material. When the source is turned on, the energy incident on the wafer induces an electron-hole plasma layer on the wafer, changing the wafer's dielectric constant, turning the third port into a termination for incident RF signals, and. causing all incident RF signals to be reflected from the surface of the wafer. The propagation constant of RF signals through port 3, therefore, can be changed by controlling the beam. By making the RF coupling to the third port as small as necessary, one can reduce the peak electric field on the unexcited silicon surface for any level of input power from port 1, thereby reducing risk of damaging the wafer by RF with high peak power. The switch is useful to the construction of an improved pulse compression system to boost the peak power of microwave tubes driving linear accelerators. In this application, the high-power RF switch is placed at the coupling iris between the charging waveguide and the resonant storage line of a pulse compression system. This optically controlled high power RF pulse compression system can handle hundreds of Megawatts of power at X-band.

  18. A low power pulsed arcjet thruster for spacecraft propulsion

    NASA Astrophysics Data System (ADS)

    Willmes, Gary Francis

    1997-11-01

    An electrothermal thruster that operates in a pulsed mode at low power (<200 W) is investigated. The thruster, called a pulsed arcjet, uses a capacitor and a pulse- forming electrical circuit to transfer stored electrical energy to a helium propellant gas in 3-10 μsec arc discharges at repetition rates of 550 to 2600 pulses-per- second with pulse energies from 24 to 130 mJ. The arc discharges occur in a cylindrical capillary upstream of a converging-diverging nozzle, and all the energy addition occurs in the subsonic region. Peak currents in the arc are 110 to 270 amps. Pulsed arcjet performance at thermal steady state is measured for two 20 degree half angle conical nozzles with area ratios of 20 and 230. Thrust levels from 10 to 30 mN are measured on an inverted pendulum-type thrust stand, and input power levels from 24 to 119 watts are determined from measurements of pulse rate and breakdown voltage. A maximum specific impulse of 305 seconds is achieved with 38% efficiency. A time-dependent, quasi-1D numerical model is developed to evaluate energy losses in the pulsed arcjet. The numerical model uses a time-marching procedure and the MacCormack predictor-corrector algorithm. Viscous and heat transfer effects are incorporated though a friction factor and an average heat transfer coefficient. A numerical study of nozzle parameters, capillary geometry, wall temperature, and pulse energy shows that the performance is insensitive to capillary and nozzle geometry and that thermal characteristics are the dominant factor affecting performance. The specific impulse and efficiency of the pulsed arcjet are found to be sensitive to wall temperature due to heat transfer losses in the subsonic region. A pulse-forming electrical circuit is developed to reduce energy losses in the storage capacitor, and greater than 85% of the initial stored energy is transferred to the arc in a unipolar pulse. A high current diode installed across the capacitor terminals is used to eliminate

  19. Accelerating Thick Aluminum Liners Using Pulsed Power

    SciTech Connect

    Kyrala, G.A.; Hammerburg, J.E.; Bowers, D.; Stokes, J.; Morgan, D.V.; Anderson, W.E.; Cochrane, J.C.

    1999-06-28

    The authors have investigated the acceleration of very thick cylindrical aluminum liners using the Pegasus II capacitory bank. These accelerated solid liners will be used to impact other objects at velocities below 1.5 km/sec, allowing one to generate and sustain shocks of a few 100 kilobar for a few microseconds. A cylindrical shell of 1100 series aluminum with an initial inner radius of 23.61 mm, an initial thickness of 3.0 mm, and a height of 20 mm, was accelerated using a current pulse of 7.15 MA peak current and a 7.4 microsecond quarter cycle time. The aluminum shell was imploded within confining copper glide planes with decreasing separation with an inward slope of 8 degrees. At impact with a cylindrical target of diameter 3-cm, the liner was moving at 1.4 km/sec and its thickness increased to 4.5 mm. Radial X-ray radiograms of the liner showed both the liner and the glide plane interface. The curvature of the inner surface of the liner was measured before impact with the 15-mm radius target. The radiograms also showed that the copper glide planes distorted as the liner radius decreased and that some axial stress is induced in the liner. The axial stresses did not affect the inner curvature significantly. Post-shot calculations of the liner behavior indicated that the thickness of the glide plane played a significant role in the distortion of the interface between the liner and the glide plane.

  20. Environmental and industrial applications of pulsed power systems

    SciTech Connect

    Neau, E.L.

    1993-10-01

    The technology base formed by the development of high peak power simulators, laser drivers, free electron lasers (FEL`s), and Inertial Confinement Fusion (ICF) drivers from the early 60`s through the late 80`s is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup applications and in supporting new types of industrial manufacturing processes. Some of these processes will require very high average beam power levels of hundreds of kilowatts to perhaps megawatts. In this paper we briefly discuss new technology capabilities and then concentrate on specific application areas that may benefit from the high specific energies and high average powers attainable with short-pulse machines.

  1. Possible high power limitations from RF pulsed heating

    NASA Astrophysics Data System (ADS)

    Pritzkau, David P.; Bowden, Gordon B.; Menegat, Al; Siemann, Robert H.

    1999-05-01

    One of the possible limitations to achieving high power in RF structures is damage to metal surfaces due to RF pulsed heating. Such damage may lead to degradation of RF performance. An experiment to study RF pulsed heating on copper has been developed at SLAC. The experiment consists of operating two pillbox cavities in the TE011 mode using a 50 MW X-Band klystron. The estimated temperature rise of the surface of copper is 350 °C for a power input of 20 MW to each cavity with a pulse length of 1.5 μs. Preliminary results from an experiment performed earlier are presented. A revised design for continued experiments is also presented along with relevant theory and calculations.

  2. Autonomous portable pulsed-periodical generator of high-power radiofrequency-pulses based on gas discharge with hollow cathode.

    PubMed

    Bulychev, Sergey V; Dubinov, Alexander E; L'vov, Igor L; Popolev, Vyacheslav L; Sadovoy, Sergey A; Sadchikov, Eugeny A; Selemir, Victor D; Valiulina, Valeria K; Vyalykh, Dmitry V; Zhdanov, Victor S

    2016-05-01

    Portable autonomous generator of high-power RF-pulses based on the gas discharge with hollow cathode has been designed, fabricated, and tested. Input and output characteristics are the following: discharge current amplitude is 800 A, duration of generated RF-pulses is 350 ns, carrier frequency is ∼90 MHz, power in RF-pulse is 0.5 MW, pulse repetition rate is 0.5 kHz, and device efficiency is ∼25%.

  3. Autonomous portable pulsed-periodical generator of high-power radiofrequency-pulses based on gas discharge with hollow cathode

    NASA Astrophysics Data System (ADS)

    Bulychev, Sergey V.; Dubinov, Alexander E.; L'vov, Igor L.; Popolev, Vyacheslav L.; Sadovoy, Sergey A.; Sadchikov, Eugeny A.; Selemir, Victor D.; Valiulina, Valeria K.; Vyalykh, Dmitry V.; Zhdanov, Victor S.

    2016-05-01

    Portable autonomous generator of high-power RF-pulses based on the gas discharge with hollow cathode has been designed, fabricated, and tested. Input and output characteristics are the following: discharge current amplitude is 800 A, duration of generated RF-pulses is 350 ns, carrier frequency is ˜90 MHz, power in RF-pulse is 0.5 MW, pulse repetition rate is 0.5 kHz, and device efficiency is ˜25%.

  4. Space Shuttle Upgrades Advanced Hydraulic Power System

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Three Auxiliary Power Units (APU) on the Space Shuttle Orbiter each provide 145 hp shaft power to a hydraulic pump which outputs 3000 psi hydraulic fluid to 41 hydraulic actuators. A hydrazine fuel powered APU utilized throughout the Shuttle program has undergone many improvements, but concerns remain with flight safety, operational cost, critical failure modes, and hydrazine related hazards. The advanced hydraulic power system (AHPS), also known as the electric APU, is being evaluated as an upgrade to replace the hydrazine APU. The AHPS replaces the high-speed turbine and hydrazine fuel supply system with a battery power supply and electric motor/pump that converts 300 volt electrical power to 3000 psi hydraulic power. AHPS upgrade benefits include elimination of toxic hydrazine propellant to improve flight safety, reduction in hazardous ground processing operations, and improved reliability. Development of this upgrade provides many interesting challenges and includes development of four hardware elements that comprise the AHPS system: Battery - The battery provides a high voltage supply of power using lithium ion cells. This is a large battery that must provide 28 kilowatt hours of energy over 99 minutes of operation at 300 volts with a peak power of 130 kilowatts for three seconds. High Voltage Power Distribution and Control (PD&C) - The PD&C distributes electric power from the battery to the EHDU. This 300 volt system includes wiring and components necessary to distribute power and provide fault current protection. Electro-Hydraulic Drive Unit (EHDU) - The EHDU converts electric input power to hydraulic output power. The EHDU must provide over 90 kilowatts of stable, output hydraulic power at 3000 psi with high efficiency and rapid response time. Cooling System - The cooling system provides thermal control of the Orbiter hydraulic fluid and EHDU electronic components. Symposium presentation will provide an overview of the AHPS upgrade, descriptions of the four

  5. High peak power optical pulses generated with a monolithic master-oscillator power amplifier.

    PubMed

    Wenzel, Hans; Schwertfeger, Sven; Klehr, Andreas; Jedrzejczyk, Daniel; Hoffmann, Thomas; Erbert, Götz

    2012-06-01

    We present results on a monolithic semiconductor-based master-oscillator power amplifier (MOPA) combining a distributed-feedback (DFB) laser and a tapered amplifier on a single chip. The MOPA reaches an output power of almost 12 W at an emission wavelength around 1064 nm in continuous-wave operation. Pulses with a length of around 100 ps can be obtained either by injecting nanosecond current pulses into the tapered amplifier alone or into both the DFB laser and the tapered amplifier. In the latter case, pulses with a width of 84 ps, a peak power of 42 W, and a spectral width of 160 pm are generated. PMID:22660042

  6. Plasma regimes in high power pulsed magnetron sputtering

    NASA Astrophysics Data System (ADS)

    de Los Arcos, Teresa

    2013-09-01

    High Power Pulsed Magnetron Sputtering (HPPMS) is a relatively recent variation of magnetron sputtering where high power is applied to the magnetron in short pulses. The result is the formation of dense transient plasmas with a high fraction of ionized species, ideally leading to better control of film growth through substrate bias. However, the broad range of experimental conditions accessible in pulsed discharges results in bewildering variations in current and voltage pulse shapes, pulse power densities, etc, which represent different discharge behaviors, making it difficult to identify relevant deposition conditions. The complexity of the plasma dynamics is evident. Within each pulse, plasma characteristics such as plasma composition, density, gas rarefaction, spatial distribution, degree of self-sputtering, etc. vary with time. A recent development has been the discovery that the plasma emission can self-organize into well-defined regions of high and low plasma emissivity above the racetrack (spokes), which rotate in the direction given by the E ×B drift and that significantly influence the transport mechanisms in HPPMS. One seemingly universal characteristic of HPPMS plasmas is the existence of well defined plasma regimes for different power ranges. These regimes are clearly differentiated in terms of plasma conductivity, plasma composition and spatial plasma self-organization. We will discuss the global characteristics of these regimes in terms of current-voltage characteristics, energy-resolved QMS and OES analysis, and fast imaging. In particular we will discuss how the reorganization of the plasma emission into spokes is associated only to specific regimes of high plasma conductivity. We will also briefly discuss the role of the target in shaping the characteristics of the HPPMS plasma, since sputtering is a surface-driven process. This work was supported by the Deutsche Forschungsgemeinschaft (DFG) within the framework of the SFB-TR87.

  7. Plasma relaxation mechanics of pulsed high power microwave surface flashover

    NASA Astrophysics Data System (ADS)

    Beeson, S.; Dickens, J.; Neuber, A.

    2013-09-01

    Microwave transmission and reflection characteristics of pulsed radio frequency field generated plasmas are elucidated for air, N2, and He environments under pressure conditions ranging from 10 to 600 torr. The pulsed, low temperature plasma is generated along the atmospheric side of the dielectric boundary between the source (under vacuum) and the radiating environment with a thickness on the order of 5 mm and a cross sectional area just smaller than that of the waveguide. Utilizing custom multi-standard waveguide couplers and a continuous low power probing source, the scattering parameters were measured before, during, and after the high power microwave pulse with emphasis on the latter. From these scattering parameters, temporal electron density estimations (specifically the longitudinal integral of the density) were calculated using a 1D plane wave-excited model for analysis of the relaxation processes associated. These relaxation characteristics ultimately determine the maximum repetition rate for many pulsed electric field applications and thus are applicable to a much larger scope in the plasma community than just those related to high power microwaves. This manuscript discusses the diagnostic setup for acquiring the power measurements along with a detailed description of the kinematic and chemical behavior of the plasma as it decays down to its undisturbed state under various gas type and pressure conditions.

  8. Plasma relaxation mechanics of pulsed high power microwave surface flashover

    SciTech Connect

    Beeson, S.; Dickens, J.; Neuber, A.

    2013-09-15

    Microwave transmission and reflection characteristics of pulsed radio frequency field generated plasmas are elucidated for air, N{sub 2}, and He environments under pressure conditions ranging from 10 to 600 torr. The pulsed, low temperature plasma is generated along the atmospheric side of the dielectric boundary between the source (under vacuum) and the radiating environment with a thickness on the order of 5 mm and a cross sectional area just smaller than that of the waveguide. Utilizing custom multi-standard waveguide couplers and a continuous low power probing source, the scattering parameters were measured before, during, and after the high power microwave pulse with emphasis on the latter. From these scattering parameters, temporal electron density estimations (specifically the longitudinal integral of the density) were calculated using a 1D plane wave-excited model for analysis of the relaxation processes associated. These relaxation characteristics ultimately determine the maximum repetition rate for many pulsed electric field applications and thus are applicable to a much larger scope in the plasma community than just those related to high power microwaves. This manuscript discusses the diagnostic setup for acquiring the power measurements along with a detailed description of the kinematic and chemical behavior of the plasma as it decays down to its undisturbed state under various gas type and pressure conditions.

  9. Frequency-Domain Methods for Characterization of Pulsed Power Diagnostics

    SciTech Connect

    White, A D; Anderson, R A; Ferriera, T J; Goerz, D A

    2009-07-27

    This paper discusses methods of frequency-domain characterization of pulsed power sensors using vector network analyzer and spectrum analyzer techniques that offer significant simplification over time-domain methods, while mitigating or minimizing the effect of the difficulties present in time domain characterization. These methods are applicable to characterization of a wide variety of sensors.

  10. Evaluation of pulse power devices in electric vehicle propulsion systems

    SciTech Connect

    Burke, A.F. ); Dowgiallo, E.J. )

    1990-01-01

    The application of pulse power devices in electric vehicle propulsion systems to load level the main energy storage battery has been studied. Both high energy density capacitors (ultracapacitors) and high power density, bipolar batteries are considered. Computer simulations of vehicle operation with hybrid (two power source) powertrains indicated the energy storage capacities of the pulse power devices required to load level the main battery are 300 to 500 Wh for the capacitors and 5 to 10 Ah for the bipolar batteries can be reduced from 79 W/kg to about 40 W/kg depending on the vehicle gradeability (speed, percent grade, and length of grade) desired. Evaluation of the status of the technology for the pulse power devices indicated that for both devices, improvements in technology are needed before the devices can be used in EV applications. In the case of the ultracapacitor, the energy density of present devices are 1 to 2 Wh/kg. A minimum energy density of about 5 Wh/kg is needed for electric vehicle applications. Progress in increasing the energy density of ultracapacitors has been rapid in recent years and the prospects for meeting the 5 Wh/kg requirement for EVs appear to be good. For bipolar batteries, a minimum power density of 500 W/kg is needed and the internal resistance must be reduced by about a factor of ten from that found in present designs.

  11. A repetitive long-pulse power generator based on pulse forming network and linear transformer driver.

    PubMed

    Li, Mingjia; Kang, Qiang; Tan, Jie; Zhang, Faqiang; Luo, Min; Xiang, Fei

    2016-06-01

    A compact module for long-pulse power generator, based on Blumlein pulse forming network (PFN), was designed. Two Blumlein PFNs with L-type configuration and 20 Ω characteristic impedance were connected symmetrically to the primary coil of the linear transformer driver (LTD) and driven by an identical high voltage spark switch to ensure two Blumlein PFNs synchronizing operation. The output pulse of the module connected with 10 Ω water load is about 135 kV in amplitude and 200 ns in duration with a rise time of ∼50 ns and a flat top of ∼100 ns. On this basis, a repetitive long-pulse power generator based on PFN-LTD has been developed, which was composed of four modules. The following technical parameters of the generator were achieved on planar diode: output voltage amplitude of ∼560 kV, output current amplitude of ∼10 kA at a repetition rate of 25 Hz. The generator operates stable and outputs more than 10(4) pulses. Meanwhile, the continuous operating time of the generator is up to 60 s. PMID:27370479

  12. A repetitive long-pulse power generator based on pulse forming network and linear transformer driver

    NASA Astrophysics Data System (ADS)

    Li, Mingjia; Kang, Qiang; Tan, Jie; Zhang, Faqiang; Luo, Min; Xiang, Fei

    2016-06-01

    A compact module for long-pulse power generator, based on Blumlein pulse forming network (PFN), was designed. Two Blumlein PFNs with L-type configuration and 20 Ω characteristic impedance were connected symmetrically to the primary coil of the linear transformer driver (LTD) and driven by an identical high voltage spark switch to ensure two Blumlein PFNs synchronizing operation. The output pulse of the module connected with 10 Ω water load is about 135 kV in amplitude and 200 ns in duration with a rise time of ˜50 ns and a flat top of ˜100 ns. On this basis, a repetitive long-pulse power generator based on PFN-LTD has been developed, which was composed of four modules. The following technical parameters of the generator were achieved on planar diode: output voltage amplitude of ˜560 kV, output current amplitude of ˜10 kA at a repetition rate of 25 Hz. The generator operates stable and outputs more than 104 pulses. Meanwhile, the continuous operating time of the generator is up to 60 s.

  13. A repetitive long-pulse power generator based on pulse forming network and linear transformer driver.

    PubMed

    Li, Mingjia; Kang, Qiang; Tan, Jie; Zhang, Faqiang; Luo, Min; Xiang, Fei

    2016-06-01

    A compact module for long-pulse power generator, based on Blumlein pulse forming network (PFN), was designed. Two Blumlein PFNs with L-type configuration and 20 Ω characteristic impedance were connected symmetrically to the primary coil of the linear transformer driver (LTD) and driven by an identical high voltage spark switch to ensure two Blumlein PFNs synchronizing operation. The output pulse of the module connected with 10 Ω water load is about 135 kV in amplitude and 200 ns in duration with a rise time of ∼50 ns and a flat top of ∼100 ns. On this basis, a repetitive long-pulse power generator based on PFN-LTD has been developed, which was composed of four modules. The following technical parameters of the generator were achieved on planar diode: output voltage amplitude of ∼560 kV, output current amplitude of ∼10 kA at a repetition rate of 25 Hz. The generator operates stable and outputs more than 10(4) pulses. Meanwhile, the continuous operating time of the generator is up to 60 s.

  14. Power limitations and pulse distortions in an Yb : KGW chirped-pulse amplification laser system

    SciTech Connect

    Kim, G H; Yang, J; Kulik, A V; Sall, E G; Chizhov, S A; Kang, U; Yashin, V E

    2013-08-31

    We have studied self-action effects (self-focusing and self-phase modulation) and stimulated Raman scattering in an Yb : KGW chirped-pulse amplification laser system. The results demonstrate that self-focusing in combination with thermal lensing may significantly limit the chirped pulse energy in this system (down to 200 μJ) even at a relatively long pulse duration (50 ps). Nonlinear lenses in the laser crystals in combination with thermal lenses bring the regenerative amplifier cavity in the laser system to the instability zone and limit the average output power at pulse repetition rates under 50 kHz. Self-phase modulation, a manifestation of self-action, may significantly distort a recompressed femtosecond pulse at energies near the self-focusing threshold. Stimulated Raman scattering in such a laser has a weaker effect on output parameters than do self-focusing and thermal lensing, and Raman spectra are only observed in the case of pulse energy instability. (nonlinear optical phenomena)

  15. Advanced Power Plant Development and Analyses Methodologies

    SciTech Connect

    G.S. Samuelsen; A.D. Rao

    2006-02-06

    Under the sponsorship of the U.S. Department of Energy/National Energy Technology Laboratory, a multi-disciplinary team led by the Advanced Power and Energy Program of the University of California at Irvine is defining the system engineering issues associated with the integration of key components and subsystems into advanced power plant systems with goals of achieving high efficiency and minimized environmental impact while using fossil fuels. These power plant concepts include ''Zero Emission'' power plants and the ''FutureGen'' H{sub 2} co-production facilities. The study is broken down into three phases. Phase 1 of this study consisted of utilizing advanced technologies that are expected to be available in the ''Vision 21'' time frame such as mega scale fuel cell based hybrids. Phase 2 includes current state-of-the-art technologies and those expected to be deployed in the nearer term such as advanced gas turbines and high temperature membranes for separating gas species and advanced gasifier concepts. Phase 3 includes identification of gas turbine based cycles and engine configurations suitable to coal-based gasification applications and the conceptualization of the balance of plant technology, heat integration, and the bottoming cycle for analysis in a future study. Also included in Phase 3 is the task of acquiring/providing turbo-machinery in order to gather turbo-charger performance data that may be used to verify simulation models as well as establishing system design constraints. The results of these various investigations will serve as a guide for the U. S. Department of Energy in identifying the research areas and technologies that warrant further support.

  16. Advanced Power Plant Development and Analysis Methodologies

    SciTech Connect

    A.D. Rao; G.S. Samuelsen; F.L. Robson; B. Washom; S.G. Berenyi

    2006-06-30

    Under the sponsorship of the U.S. Department of Energy/National Energy Technology Laboratory, a multi-disciplinary team led by the Advanced Power and Energy Program of the University of California at Irvine is defining the system engineering issues associated with the integration of key components and subsystems into advanced power plant systems with goals of achieving high efficiency and minimized environmental impact while using fossil fuels. These power plant concepts include 'Zero Emission' power plants and the 'FutureGen' H2 co-production facilities. The study is broken down into three phases. Phase 1 of this study consisted of utilizing advanced technologies that are expected to be available in the 'Vision 21' time frame such as mega scale fuel cell based hybrids. Phase 2 includes current state-of-the-art technologies and those expected to be deployed in the nearer term such as advanced gas turbines and high temperature membranes for separating gas species and advanced gasifier concepts. Phase 3 includes identification of gas turbine based cycles and engine configurations suitable to coal-based gasification applications and the conceptualization of the balance of plant technology, heat integration, and the bottoming cycle for analysis in a future study. Also included in Phase 3 is the task of acquiring/providing turbo-machinery in order to gather turbo-charger performance data that may be used to verify simulation models as well as establishing system design constraints. The results of these various investigations will serve as a guide for the U. S. Department of Energy in identifying the research areas and technologies that warrant further support.

  17. Workshop on Solid State Switches for Pulsed Power

    NASA Astrophysics Data System (ADS)

    Portnoy, W. M.; Kristiansen, M.

    1983-05-01

    A Workshop on Solid State Pulsed Power Switching was conducted by Texas Tech U at Tamarron, Colorado, in January, 1983 for the US Army Research Office. The Workshop addressed the state-of-the-art in solid state switching, particularly semiconductor switches, and new solid state related switching concepts for pulsed power applications. An important objective of the Workshop was to establish research priorities. Group discussions were augmented by invited presentations. The principal topics included opening switches, high power closing switches, extremely fast risetime closing switches and state transition switches; devices of particular interest were thyristors, avalanche switches and the optically triggered intrinsic switch. The invited papers, along with summaries of the Working Group discussions and recommendations, are presented in this report. A general summary, including suggested research topics, is included.

  18. The NASA Advanced Space Power Systems Project

    NASA Technical Reports Server (NTRS)

    Mercer, Carolyn R.; Hoberecht, Mark A.; Bennett, William R.; Lvovich, Vadim F.; Bugga, Ratnakumar

    2015-01-01

    The goal of the NASA Advanced Space Power Systems Project is to develop advanced, game changing technologies that will provide future NASA space exploration missions with safe, reliable, light weight and compact power generation and energy storage systems. The development effort is focused on maturing the technologies from a technology readiness level of approximately 23 to approximately 56 as defined in the NASA Procedural Requirement 7123.1B. Currently, the project is working on two critical technology areas: High specific energy batteries, and regenerative fuel cell systems with passive fluid management. Examples of target applications for these technologies are: extending the duration of extravehicular activities (EVA) with high specific energy and energy density batteries; providing reliable, long-life power for rovers with passive fuel cell and regenerative fuel cell systems that enable reduced system complexity. Recent results from the high energy battery and regenerative fuel cell technology development efforts will be presented. The technical approach, the key performance parameters and the technical results achieved to date in each of these new elements will be included. The Advanced Space Power Systems Project is part of the Game Changing Development Program under NASAs Space Technology Mission Directorate.

  19. Thermal management in high average power pulsed compression systems

    SciTech Connect

    Wavrik, R.W.; Reed, K.W.; Harjes, H.C.; Weber, G.J.; Butler, M.; Penn, K.J.; Neau, E.L.

    1992-08-01

    High average power repetitively pulsed compression systems offer a potential source of electron beams which may be applied to sterilization of wastes, treatment of food products, and other environmental and consumer applications. At Sandia National Laboratory, the Repetitive High Energy Pulsed Power (RHEPP) program is developing a 7 stage magnetic pulse compressor driving a linear induction voltage adder with an electron beam diode load. The RHEPP machine is being design to deliver 350 kW of average power to the diode in 60 ns FWHM, 2.5 MV, 3 kJ pulses at a repetition rate of 120 Hz. In addition to the electrical design considerations, the repetition rate requires thermal management of the electrical losses. Steady state temperatures must be kept below the material degradation temperatures to maximize reliability and component life. The optimum design is a trade off between thermal management, maximizing overall electrical performance of the system, reliability, and cost effectiveness. Cooling requirements and configurations were developed for each of the subsystems of RHEPP. Finite element models that combine fluid flow and heat transfer were used to screen design concepts. The analysis includes one, two, and three dimensional heat transfer using surface heat transfer coefficients and boundary layer models. Experiments were conducted to verify the models as well as to evaluate cooling channel fabrication materials and techniques in Metglas wound cores. 10 refs.

  20. Thermal management in high average power pulsed compression systems

    SciTech Connect

    Wavrik, R.W.; Reed, K.W.; Harjes, H.C.; Weber, G.J.; Butler, M.; Penn, K.J.; Neau, E.L.

    1992-01-01

    High average power repetitively pulsed compression systems offer a potential source of electron beams which may be applied to sterilization of wastes, treatment of food products, and other environmental and consumer applications. At Sandia National Laboratory, the Repetitive High Energy Pulsed Power (RHEPP) program is developing a 7 stage magnetic pulse compressor driving a linear induction voltage adder with an electron beam diode load. The RHEPP machine is being design to deliver 350 kW of average power to the diode in 60 ns FWHM, 2.5 MV, 3 kJ pulses at a repetition rate of 120 Hz. In addition to the electrical design considerations, the repetition rate requires thermal management of the electrical losses. Steady state temperatures must be kept below the material degradation temperatures to maximize reliability and component life. The optimum design is a trade off between thermal management, maximizing overall electrical performance of the system, reliability, and cost effectiveness. Cooling requirements and configurations were developed for each of the subsystems of RHEPP. Finite element models that combine fluid flow and heat transfer were used to screen design concepts. The analysis includes one, two, and three dimensional heat transfer using surface heat transfer coefficients and boundary layer models. Experiments were conducted to verify the models as well as to evaluate cooling channel fabrication materials and techniques in Metglas wound cores. 10 refs.

  1. Topics in high voltage pulsed power plasma devices and applications

    NASA Astrophysics Data System (ADS)

    Chen, Hao

    Pulsed power technology is one of the tools that is used by scientists and engineers nowadays to produce gas plasmas. The transient ultra high power is able to provide a huge pulse of energy which is sometimes greater than the ionization energy of the gas, and therefore separates the ions and electrons to form the plasma. Sometimes, the pulsed power components themselves are plasma devices. For example, the gas type switches can "turn on" the circuit by creating the plasma channel between the switch electrodes. Mini Back Lighted Thyratron, or as we call it, mini-BLT, is one of these gas type plasma switches. The development of the reduced size and weight "mini-BLT" is presented in this dissertation. Based on the operation characteristics testing of the mini-BLT, suggestions of optimizing the design of the switch are proposed. All the factors such as the geometry of the hollow electrodes and switch housing, the gas condition, the optical triggering source, etc. are necessary to consider when we design and operate the mini-BLT. By reducing the diameter of the cylindrical gas path between the electrodes in the BLT, a novel high density plasma source is developed, producing the plasma in the "squeezed" capillary. The pulsed power generator, of course, is inevitably used to provide the ionization energy for hydrogen gas sealed in the capillary. Plasma diagnostics are necessarily analyzed and presented in detail to properly complete and understand the capillary plasma. This high density plasma source (1019 cm-3) has the potential applications in the plasma wakefield accelerator. The resonant oscillation behavior of the particles in plasmas allows for dynamically generated accelerating electric fields that have orders of magnitude larger than those available in the conventional RF accelerators. Finally, the solid state switches are introduced as a comparison to the gas type switch. Pulsed power circuit topologies such as the Marx Bank, magnetic pulse compression and diode

  2. Advanced Power Batteries for Renewable Energy Applications 3.09

    SciTech Connect

    Shane, Rodney

    2011-12-01

    This report describes the research that was completed under project title Advanced Power Batteries for Renewable Energy Applications 3.09, Award Number DE-EE0001112. The report details all tasks described in the Statement of Project Objectives (SOPO). The SOPO includes purchasing of test equipment, designing tooling, building cells and batteries, testing all variables and final evaluation of results. The SOPO is included. There were various types of tests performed during the project, such as; gas collection, float current monitoring, initial capacity, high rate partial state of charge (HRPSoC), hybrid pulse power characterization (HPPC), high rate capacity, corrosion, software modeling and solar life cycle tests. The grant covered a period of two years starting October 1, 2009 and ending September 30, 2011.

  3. Advanced materials for space nuclear power systems

    SciTech Connect

    Titran, R.H.; Grobstein, T.L. . Lewis Research Center); Ellis, D.L. )

    1991-01-01

    Research on monolithic refractory metal alloys and on metal matrix composites is being conducted at the NASA Lewis Research Center, Cleveland, Ohio, in support of advanced space power systems. The overall philosophy of the research is to develop and characterize new high-temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites (Gr/Cu) for heat rejection fins, and tungsten fiber reinforced niobium matrix composites (W/NB) for fuel containment and structural supports) considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications.

  4. High power infrared QCLs: advances and applications

    NASA Astrophysics Data System (ADS)

    Patel, C. Kumar N.

    2012-01-01

    QCLs are becoming the most important sources of laser radiation in the midwave infrared (MWIR) and longwave infrared (LWIR) regions because of their size, weight, power and reliability advantages over other laser sources in the same spectral regions. The availability of multiwatt RT operation QCLs from 3.5 μm to >16 μm with wall plug efficiency of 10% or higher is hastening the replacement of traditional sources such as OPOs and OPSELs in many applications. QCLs can replace CO2 lasers in many low power applications. Of the two leading groups in improvements in QCL performance, Pranalytica is the commercial organization that has been supplying the highest performance QCLs to various customers for over four year. Using a new QCL design concept, the non-resonant extraction [1], we have achieved CW/RT power of >4.7 W and WPE of >17% in the 4.4 μm - 5.0 μm region. In the LWIR region, we have recently demonstrated QCLs with CW/RT power exceeding 1 W with WPE of nearly 10 % in the 7.0 μm-10.0 μm region. In general, the high power CW/RT operation requires use of TECs to maintain QCLs at appropriate operating temperatures. However, TECs consume additional electrical power, which is not desirable for handheld, battery-operated applications, where system power conversion efficiency is more important than just the QCL chip level power conversion efficiency. In high duty cycle pulsed (quasi-CW) mode, the QCLs can be operated without TECs and have produced nearly the same average power as that available in CW mode with TECs. Multiwatt average powers are obtained even in ambient T>70°C, with true efficiency of electrical power-to-optical power conversion being above 10%. Because of the availability of QCLs with multiwatt power outputs and wavelength range covering a spectral region from ~3.5 μm to >16 μm, the QCLs have found instantaneous acceptance for insertion into multitude of defense and homeland security applications, including laser sources for infrared

  5. Transmission line pulse system for avalanche characterization of high power semiconductor devices

    NASA Astrophysics Data System (ADS)

    Riccio, Michele; Ascione, Giovanni; De Falco, Giuseppe; Maresca, Luca; De Laurentis, Martina; Irace, Andrea; Breglio, Giovanni

    2013-05-01

    Because of the increasing in power density of electronic devices for medium and high power application, reliabilty of these devices is of great interest. Understanding the avalanche behaviour of a power device has become very important in these last years because it gives an indication of the maximum energy ratings which can be seen as an index of the device ruggedness. A good description of this behaviour is given by the static IV blocking characteristc. In order to avoid self heating, very relevant in high power devices, very short pulses of current have to be used, whose value can change from few milliamps up to tens of amps. The most used method to generate short pulses is the TLP (Transmission Line Pulse) test, which is based on charging the equivalent capacitance of a transmission line to high value of voltage and subsequently discharging it onto a load. This circuit let to obtain very short square pulses but it is mostly used for evaluate the ESD capability of semiconductor and, in this environment, it generates pulses of low amplitude which are not high enough to characterize the avalanche behaviour of high power devices . Advanced TLP circuit able to generate high current are usually very expensive and often suffer of distorption of the output pulse. In this article is proposed a simple, low cost circuit, based on a boosted-TLP configuration, which is capable to produce very square pulses of about one hundreds of nanosecond with amplitude up to some tens of amps. A prototype is implemented which can produce pulses up to 20A of amplitude with 200 ns of duration which can characterize power devices up to 1600V of breakdown voltage. Usage of microcontroller based logic make the circuit very flexible. Results of SPICE simulation are provided, together with experimental results. To prove the effectiveness of the circuit, the I-V blocking characteristics of two commercial devices, namely a 600V PowerMOS and a 1200V Trench-IGBT, are measured at different

  6. CHRONICLE: International forum on advanced high-power lasers and applications (AHPLA '99)

    NASA Astrophysics Data System (ADS)

    Afanas'ev, Yurii V.; Zavestovskaya, I. N.; Zvorykin, V. D.; Ionin, Andrei A.; Senatsky, Yu V.; Starodub, Aleksandr N.

    2000-05-01

    A review of reports made on the International Forum on Advanced High-Power Lasers and Applications, which was held at the beginning of November 1999 in Osaka (Japan), is presented. Five conferences were held during the forum on High-Power Laser Ablation, High-Power Lasers in Energy Engineering, High-Power Lasers in Civil Engineering and Architecture, High-Power Lasers in Manufacturing, and Advanced High-Power Lasers. The following trends in the field of high-power lasers and their applications were presented: laser fusion, laser applications in space, laser-triggered lightning, laser ablation of materials by short and ultrashort pulses, application of high-power lasers in manufacturing, application of high-power lasers in mining, laser decommissioning and decontamination of nuclear reactors, high-power solid-state and gas lasers, x-ray and free-electron lasers. One can find complete information on the forum in SPIE, vols. 3885-3889.

  7. Advanced Coal-Based Power Generations

    NASA Technical Reports Server (NTRS)

    Robson, F. L.

    1982-01-01

    Advanced power-generation systems using coal-derived fuels are evaluated in two-volume report. Report considers fuel cells, combined gas- and steam-turbine cycles, and magnetohydrodynamic (MHD) energy conversion. Presents technological status of each type of system and analyzes performance of each operating on medium-Btu fuel gas, either delivered via pipeline to powerplant or generated by coal-gasification process at plantsite.

  8. Advanced space power PEM fuel cell systems

    NASA Technical Reports Server (NTRS)

    Vanderborgh, N. E.; Hedstrom, J.; Huff, J. R.

    1989-01-01

    A model showing mass and heat transfer in proton exchange membrane (PEM) single cells is presented. For space applications, stack operation requiring combined water and thermal management is needed. Advanced hardware designs able to combine these two techniques are available. Test results are shown for membrane materials which can operate with sufficiently fast diffusive water transport to sustain current densities of 300 ma per square centimeter. Higher power density levels are predicted to require active water removal.

  9. Ruthenium Oxide Electrochemical Super Capacitor Optimization for Pulse Power Applications

    NASA Technical Reports Server (NTRS)

    Merryman, Stephen A.; Chen, Zheng

    2000-01-01

    Electrical actuator systems are being pursued as alternatives to hydraulic systems to reduce maintenance time, weight and costs while increasing reliability. Additionally, safety and environmental hazards associated with the hydraulic fluids can be eliminated. For most actuation systems, the actuation process is typically pulsed with high peak power requirements but with relatively modest average power levels. The power-time requirements for electrical actuators are characteristic of pulsed power technologies where the source can be sized for the average power levels while providing the capability to achieve the peak requirements. Among the options for the power source are battery systems, capacitor systems or battery-capacitor hybrid systems. Battery technologies are energy dense but deficient in power density; capacitor technologies are power dense but limited by energy density. The battery-capacitor hybrid system uses the battery to supply the average power and the capacitor to meet the peak demands. It has been demonstrated in previous work that the hybrid electrical power source can potentially provide a weight savings of approximately 59% over a battery-only source. Electrochemical capacitors have many properties that make them well-suited for electrical actuator applications. They have the highest demonstrated energy density for capacitive storage (up to 100 J/g), have power densities much greater than most battery technologies (greater than 30kW/kg), are capable of greater than one million charge-discharge cycles, can be charged at extremely high rates, and have non-explosive failure modes. Thus, electrochemical capacitors exhibit a combination of desirable battery and capacitor characteristics.

  10. INPIStron switched pulsed power for dense plasma pinches

    NASA Technical Reports Server (NTRS)

    Han, Kwang S.; Lee, Ja H.

    1993-01-01

    The inverse plasma switch INPIStron was employed for 10kJ/40kV capacitor bank discharge system to produce focused dense plasmas in hypocycloidal-pinch (HCP) devices. A single unit and an array of multiple HCP's were coupled as the load of the pulsed power circuit. The geometry and switching plasma dynamics were found advantageous and convenient for commutating the large current pulse from the low impedance transmission line to the low impedance plasma load. The pulse power system with a single unit HCP, the system A, was used for production of high temperature plasma focus and its diagnostics. The radially running down plasma dynamics, revealed in image converter photographs, could be simulated by a simple snow-plow model with a correction for plasma resistivity. The system B with an array of 8-HCP units which forms a long coaxial discharge chamber was used for pumping a Ti-sapphire laser. The intense UV emission from the plasma was frequency shifted with dye-solution jacket to match the absorption band of the Ti crystal laser near 500 nm. An untuned laser pulse energy of 0.6 J/pulse was obtained for 6.4 kJ/40 kV discharge, or near 103 times of the explosion limit of conventional flash lamps. For both systems the advantages of the INPIStron were well demonstrated: a single unit is sufficient for a large current (greater than 50 kA) without increasing the system impedance, highly reliable and long life operation and implied scalability for the high power ranges above I(sub peak) = 1 MA and V(sub hold) = 100 kV.

  11. A 16 MJ compact pulsed power system for electromagnetic launch

    NASA Astrophysics Data System (ADS)

    Dai, Ling; Zhang, Qin; Zhong, Heqing; Lin, Fuchang; Li, Hua; Wang, Yan; Su, Cheng; Huang, Qinghua; Chen, Xu

    2015-07-01

    This paper has established a compact pulsed power system (PPS) of 16 MJ for electromagnetic rail gun. The PPS consists of pulsed forming network (PFN), chargers, monitoring system, and current junction. The PFN is composed of 156 pulse forming units (PFUs). Every PFU can be triggered simultaneously or sequentially in order to obtain different total current waveforms. The whole device except general control table is divided into two frameworks with size of 7.5 m × 2.2 m × 2.3 m. It is important to estimate the discharge current of PFU accurately for the design of the whole electromagnetic launch system. In this paper, the on-state characteristics of pulse thyristor have been researched to improve the estimation accuracy. The on-state characteristics of pulse thyristor are expressed as a logarithmic function based on experimental data. The circuit current waveform of the single PFU agrees with the simulating one. On the other hand, the coaxial discharge cable is a quick wear part in PFU because the discharge current will be up to dozens of kA even hundreds of kA. In this article, the electromagnetic field existing in the coaxial cable is calculated by finite element method. On basis of the calculation results, the structure of cable is optimized in order to improve the limit current value of the cable. At the end of the paper, the experiment current wave of the PPS with the load of rail gun is provided.

  12. Pulsed power supply for three APS septum magnets

    SciTech Connect

    McGhee, D.G.

    1991-03-24

    Three septum magnets will be operated at a repetition-rate of 2 Hz. Two of the septum magnets are identical and operate at the same values; these are the synchrotron extraction and the storage ring injection magnets. They are transformer septum magnets, with a primary inductance of 23 {mu}H and resistance of 6.3 m{Omega}, and must be pulsed at a 2 Hz rate to extract beam from the synchrotron and inject beam into the storage ring at 7.7 GeV. The third septum magnet is used to inject electrons into the synchrotron at 650 MeV or positrons at 450 MeV. It is also a transformer septum magnet, with a primary inductance of 21 {mu}H and resistance of 6.7 m{Omega}, and must be pulsed at a 2 Hz rate. A design study was performed of the power supply proposed in the APS Title I design. This supply produces a pulse that is approximately a half-sine-wave with a base width of approximately 1/3 ms; its peakcurrent is adjustable from 470 A to 4.7 kA and is repeatable within {plus_minus}0.05%. The septum steel is reset by a half-sine pulse of reverse polarity a few milliseconds after the forward current pulse. No beam is present during reset. The use of the transformer design minimizes the cost of the capacitors used for energy storage.

  13. Pulsed Power for a Dynamic Transmission Electron Microscope

    SciTech Connect

    dehope, w j; browning, n; campbell, g; cook, e; king, w; lagrange, t; reed, b; stuart, b; Shuttlesworth, R; Pyke, B

    2009-06-25

    Lawrence Livermore National Laboratory (LLNL) has converted a commercial 200kV transmission electron microscope (TEM) into an ultrafast, nanoscale diagnostic tool for material science studies. The resulting Dynamic Transmission Electron Microscope (DTEM) has provided a unique tool for the study of material phase transitions, reaction front analyses, and other studies in the fields of chemistry, materials science, and biology. The TEM's thermionic electron emission source was replaced with a fast photocathode and a laser beam path was provided for ultraviolet surface illumination. The resulting photoelectron beam gives downstream images of 2 and 20 ns exposure times at 100 and 10 nm spatial resolution. A separate laser, used as a pump pulse, is used to heat, ignite, or shock samples while the photocathode electron pulses, carefully time-synchronized with the pump, function as probe in fast transient studies. The device functions in both imaging and diffraction modes. A laser upgrade is underway to make arbitrary cathode pulse trains of variable pulse width of 10-1000 ns. Along with a fast e-beam deflection scheme, a 'movie mode' capability will be added to this unique diagnostic tool. This talk will review conventional electron microscopy and its limitations, discuss the development and capabilities of DTEM, in particularly addressing the prime and pulsed power considerations in the design and fabrication of the DTEM, and conclude with the presentation of a deflector and solid-state pulser design for Movie-Mode DTEM.

  14. A 16 MJ compact pulsed power system for electromagnetic launch.

    PubMed

    Dai, Ling; Zhang, Qin; Zhong, Heqing; Lin, Fuchang; Li, Hua; Wang, Yan; Su, Cheng; Huang, Qinghua; Chen, Xu

    2015-07-01

    This paper has established a compact pulsed power system (PPS) of 16 MJ for electromagnetic rail gun. The PPS consists of pulsed forming network (PFN), chargers, monitoring system, and current junction. The PFN is composed of 156 pulse forming units (PFUs). Every PFU can be triggered simultaneously or sequentially in order to obtain different total current waveforms. The whole device except general control table is divided into two frameworks with size of 7.5 m × 2.2 m × 2.3 m. It is important to estimate the discharge current of PFU accurately for the design of the whole electromagnetic launch system. In this paper, the on-state characteristics of pulse thyristor have been researched to improve the estimation accuracy. The on-state characteristics of pulse thyristor are expressed as a logarithmic function based on experimental data. The circuit current waveform of the single PFU agrees with the simulating one. On the other hand, the coaxial discharge cable is a quick wear part in PFU because the discharge current will be up to dozens of kA even hundreds of kA. In this article, the electromagnetic field existing in the coaxial cable is calculated by finite element method. On basis of the calculation results, the structure of cable is optimized in order to improve the limit current value of the cable. At the end of the paper, the experiment current wave of the PPS with the load of rail gun is provided. PMID:26233401

  15. Application of lasers and pulsed power to coating removal

    NASA Astrophysics Data System (ADS)

    Young, Chris M.; Moeny, William M.; Curry, Randy D.; McDonald, Ken; Bosma, John T.

    1995-03-01

    Lasers and other pulsed power systems are uniquely suited for removal of coatings from a wide variety of substrates. Coatings which can be removed by these systems include paint, adhesives, epoxies, dips, rust, scale, and bird droppings. Suitable substrates include wood, metal, cloth, stone, ceramic, plastics, and even skin. These systems have the advantage over chemical stripping or mechanical abrasion in that the substrate is left virtually unharmed and in many cases the residue is reduced to a form that is more easily disposed of without toxic byproducts or expensive refurbishment. Furthermore, laser and other pulsed power based systems can be operated using only local containment without the need for special operator protective gear or complete enclosure of the substrate structure. Additional advantages are gained in these systems because they typically combine multiple removal mechanisms for greater effectiveness. For example, pulsed lasers create rapid heating of the coating. This rapid heating can result in chemical breakdown of the coating, thermomechanical stress induced dislocation, shock wave agitation, and physical ablation. This paper presents some of the latest research findings on coating removal using these systems. A comparative survey of the system technology, effectiveness, cost, and application is presented. Also presented is a survey of the commercial potential for the systems. Systems which are presented include lasers (CW, pulsed, Infrared, UV, etc.), flashlamps, electro-cathodic debonders, electron beams, and glow discharges.

  16. Basic research on pulsed power for narrowband high-power microwave sources

    NASA Astrophysics Data System (ADS)

    Schamiloglu, Edl; Schoenbach, Karl H.; Vidmar, Robert

    2002-06-01

    Relativistic, intense beam-driven High Power Microwave (HPM) sources emerged as consequence of the development of pulsed power. In this context, pulsed power refers to components of a system following the prime power source, and before the load, which is typically an electron beam diode. Progress in fielding HPM sources on mobile platforms requires developing more compact pulsed power drivers. The Air Force Office of Scientific Research is sponsoring, using resources allocated by DDR&E, a Multidisciplinary University Research Initiative (MURI) program to study basic phenomena and processes that can lead to the design of more compact pulsed power systems. The University of New Mexico is leading a consortium, uniting researchers at Old Dominion University and the University of Nevada-Reno, to study basic phenomena relating to breakdown in solid and liquid dielectrics, high dielectric constant ceramics for use in compact, folded Blumlein transmission lines, gas switches, thermal management in compact pulsed power systems, among other topics. This paper describes the research activities on this program that are being performed in the initial year.

  17. Environmental and industrial applications of pulsed power systems

    SciTech Connect

    Neau, E.L. )

    1994-02-01

    The technology base formed by the development of high peak power simulators, laser drivers, free electron lasers, and Inertial Confinement Fusion drivers from the early 60's through the late 80's is being extended to high average power short-pulse machines with the capabilities of performing new roles in environmental cleanup applications and in supporting new types of industrial manufacturing processes. Processes requiring high volume throughput and moderate dose levels, such as flue gas cleanup and food pasteurization plants, will require very high average beam power levels of hundreds of kilowatts to perhaps several megawatts. In this paper the authors briefly discuss a new class of short-pulse high average power accelerators, now operating in laboratory environments, using semiconductor and magnetic switches to achieve megavolt electron and ion beams with 10's of kiloamperes of current and average power levels in excess of 100 kW. The technology is modular, robust in concept, and appears to be suitable for extension to the megawatt power level. After a brief introduction to the technology, the paper then concentrates on specific application areas that are being explored.

  18. Advanced Power Electronics and Electric Motors Annual Report -- 2013

    SciTech Connect

    Narumanchi, S.; Bennion, K.; DeVoto, D.; Moreno, G.; Rugh, J.; Waye, S.

    2015-01-01

    This report describes the research into advanced liquid cooling, integrated power module cooling, high temperature air cooled power electronics, two-phase cooling for power electronics, and electric motor thermal management by NREL's Power Electronics group in FY13.

  19. Terahertz metrology on power, frequency, spectroscopy, and pulse parameters

    NASA Astrophysics Data System (ADS)

    Wu, Bin; Ying, Cheng Ping; Wang, Heng Fei; Zhang, Peng; Liu, Hong Yuan; Jiang, Bin

    2015-11-01

    Terahertz metrology is becoming more and more important along with the fast development of terahertz technology. This paper reviews the research works of the groups from the physikalisch-technische bundesanstalt (PTB), National institute of standards and technology (NIST), National physical laboratory (NPL), National institute of metrology (NIM) and some other research institutes. The contents mainly focus on the metrology of parameters of power, frequency, spectrum and pulse. At the end of the paper, the prospect of terahertz metrology is predicted.

  20. Advances in industrial high-power lasers

    NASA Astrophysics Data System (ADS)

    Schlueter, Holger

    2005-03-01

    Four major types of laser sources are used for material processing. Excluding Excimer lasers, this paper focuses on advances in High Power CO2 lasers, Solid State Lasers and Diode Lasers. Because of their unrivaled cost to brightness relationship the fast axial flow CO2 laser remains unrivaled for flat-sheet laser cutting. Adding approximately a kW of output power ever four years, this laser type has been propelling the entire sheet metal fabrication industry for the last two decades. Very robust, diffusion cooled annular discharge CO2 lasers with 2kW output power have enabled robot mounted lasers for 3D applications. Solid State Lasers are chosen mainly because of the option of fiber delivery. Industrial applications still rely on lamp-pumped Nd:YAG lasers with guaranteed output powers of 4.5 kW at the workpiece. The introduction of the diode pumped Thin Disc Laser 4.5 kW laser enables new applications such as the Programmable Focus Optics. Pumping the Thin Disc Laser requires highly reliable High Power Diode Lasers. The necessary reliability can only be achieved in a modern, automated semiconductor manufacturing facility. For Diode Lasers, electro-optical efficiencies above 65% are as important as the passivation of the facets to avoid Burn-In power degradation.

  1. Investigation of a high power electromagnetic pulse source

    NASA Astrophysics Data System (ADS)

    Wang, Yuwei; Chen, Dongqun; Zhang, Jiande; Cao, Shengguang; Li, Da; Liu, Chebo

    2012-09-01

    A high power electromagnetic pulse source with a resonant antenna driven by a compact power supply was investigated in this paper. To match the impedance of the resonant antenna and initial power source, a compact power conditioning circuit based on electro exploding opening switch (EEOS) and pulsed transformer was adopted. In the preliminary experiments, an impulse capacitor was used to drive the system. With the opening of the EEOS at the current of 15 kA flowing trough the primary of the transformer, the resonant antenna was rapidly charged to about -370 kV within a time of about 100 ns. When the switch in the resonant antenna closed at the charging voltage of about -202 kV, the peak intensity of the detected electric field at a distance of about 10 m from the center of the source was 7.2 kV/m. The corresponding peak power of the radiated electromagnetic field reached 76 MW, while the total radiated electromagnetic energy was about 0.65 J. The total energy efficiency of the resonant antenna was about 22% which can be improved by increasing the closing rapidity of the switch in the antenna.

  2. Investigation of a high power electromagnetic pulse source.

    PubMed

    Wang, Yuwei; Chen, Dongqun; Zhang, Jiande; Cao, Shengguang; Li, Da; Liu, Chebo

    2012-09-01

    A high power electromagnetic pulse source with a resonant antenna driven by a compact power supply was investigated in this paper. To match the impedance of the resonant antenna and initial power source, a compact power conditioning circuit based on electro exploding opening switch (EEOS) and pulsed transformer was adopted. In the preliminary experiments, an impulse capacitor was used to drive the system. With the opening of the EEOS at the current of 15 kA flowing trough the primary of the transformer, the resonant antenna was rapidly charged to about -370 kV within a time of about 100 ns. When the switch in the resonant antenna closed at the charging voltage of about -202 kV, the peak intensity of the detected electric field at a distance of about 10 m from the center of the source was 7.2 kV∕m. The corresponding peak power of the radiated electromagnetic field reached 76 MW, while the total radiated electromagnetic energy was about 0.65 J. The total energy efficiency of the resonant antenna was about 22% which can be improved by increasing the closing rapidity of the switch in the antenna. PMID:23020399

  3. Development of a linear piston-type pulse power electric generator for powering electric guns

    NASA Astrophysics Data System (ADS)

    Summerfield, Martin

    1993-01-01

    The development of a linear piston-type electric pulse-power generator capable of powering electric guns and EM (rail and coil) guns and ET guns, presently under development, is discussed. The pulse-power generator consists of a cylindrical armature pushed by gases from the combustion of fuel or propellant through an externally produced magnetic field. An arrangement of electrodes and connecting straps serves to extract current from the moving armature and to send it to an external load (the electric gun).

  4. Determination of modeling parameters for power IGBTs under pulsed power conditions

    SciTech Connect

    Dale, Gregory E; Van Gordon, Jim A; Kovaleski, Scott D

    2010-01-01

    While the power insulated gate bipolar transistor (IGRT) is used in many applications, it is not well characterized under pulsed power conditions. This makes the IGBT difficult to model for solid state pulsed power applications. The Oziemkiewicz implementation of the Hefner model is utilized to simulate IGBTs in some circuit simulation software packages. However, the seventeen parameters necessary for the Oziemkiewicz implementation must be known for the conditions under which the device will be operating. Using both experimental and simulated data with a least squares curve fitting technique, the parameters necessary to model a given IGBT can be determined. This paper presents two sets of these seventeen parameters that correspond to two different models of power IGBTs. Specifically, these parameters correspond to voltages up to 3.5 kV, currents up to 750 A, and pulse widths up to 10 {micro}s. Additionally, comparisons of the experimental and simulated data will be presented.

  5. ADVANCED POWER SYSTEMS ASH BEHAVIOR IN POWER SYSTEMS

    SciTech Connect

    ZYGARLICKE, CHRISTOPHER J; MCCOLLOR, DONALD P; KAY, JOHN P; SWANSON, MICHAEL L

    1998-09-01

    The overall goal of this initiative is to develop fundamental knowledge of ash behavior in power systems for the purpose of increasing power production efficiency, reducing operation and maintenance costs, and reducing greenhouse gas emissions into the atmosphere. The specific objectives of this initiative focus primarily on ash behavior related to advanced power systems and include the following: Determine the current status of the fundamental ash interactions and deposition formation mechanisms as already reported through previous or ongoing projects at the EERC or in the literature. Determine sintering mechanisms for temperatures and particle compositions that are less well known and remain for the most part undetermined. Identify the relationship between the temperature of critical viscosity (Tcv ) as measured in a viscometer and the crystallization occurring in the melt. Perform a literature search on the use of heated-stage microscopy (HSM) for examining in situ ash-sintering phenomena and then validate the use of HSM in the determination of viscosity in spherical ash particles. Ascertain the formation and stability of specific mineral or amorphous phases in deposits typical of advanced power systems. Evaluate corrosion for alloys being used in supercritical combustion systems.

  6. Pulse swallowing frequency divider with low power and compact structure

    NASA Astrophysics Data System (ADS)

    Haijun, Gao; Lingling, Sun; Chaobo, Cai; Haiting, Zhan

    2012-11-01

    A pulse swallowing frequency divider with low power and compact structure is presented. One of the DFFs in the divided by 2/3 prescaler is controlled by the modulus control signal, and automatically powered off when it has no contribution to the operation of the prescaler. The DFFs in the program counter and the swallow counter are shared to compose a compact structure, which reduces the power consumption further. The proposed multi-modulus frequency divider was implemented in a standard 65 nm CMOS process with an area of 28 × 22 μm2. The power consumption of the divider is 0.6 mW under 1.2 V supply voltage when operating at 988 MHz.

  7. Sterilizing tissue-materials using pulsed power plasma.

    PubMed

    Heidarkhan Tehrani, Ashkan; Davari, Pooya; Singh, Sanjleena; Oloyede, Adekunle

    2014-04-01

    This paper investigates the potential of pulsed power to sterilize hard and soft tissues and its impact on their physico-mechanical properties. It hypothesizes that pulsed plasma can sterilize both vascular and avascular tissues and the transitive layers in between without deleterious effects on their functional characteristics. Cartilage/bone laminate was chosen as a model to demonstrate the concept, treated at low temperature, at atmospheric pressure, in short durations and in buffered environment using a purposed-built pulsed power unit. Input voltage and time of exposure were assigned as controlling parameters in a full factorial design of experiment to determine physical and mechanical alteration pre- and post-treatment. The results demonstrated that, discharges of 11 kV sterilized samples in 45 s, reducing intrinsic elastic modules from 1.4 ± 0.9 to 0.9 ± 0.6 MPa. There was a decrease of 14.1 % in stiffness and 27.8 % in elastic-strain energy for the top quartile. Mechanical impairment was directly proportional to input voltage (P value < 0.05). Bacterial inactivation was proportional to treatment time for input voltages above 32 V (P < 0.001; R Sq = 0.98). Thermal analysis revealed that helix-coil transition decelerated with exposure time and collagen fibrils were destabilized as denaturation enthalpy reduced by 200 μV. We concluded by presenting a safe operating threshold for pulsed power plasma as a feasible protocol for effective sterilization of connective tissues with varying level of loss in mechanical robustness which we argue to be acceptable in certain medical and tissue engineering application.

  8. Design concepts for a pulse power test facility to simulate EMP surges in overhead power lines. Part I. Fast pulse

    SciTech Connect

    Ramrus, A.

    1986-02-01

    Objective of the study was to create conceptual designs of high voltage pulsers capable of simulating two types of electromagnetic pulses (EMPs) caused by a high-altitude nuclear burst; the slow rise time magnetohydrodynamic (MHD-EMP) and the fast rise time high-altitude EMP (HEMP). The pulser design was directed towards facilities capable of performing EMP vulnerability testing of components used in the national electric power system.

  9. Pulse doubling in zigzag-connected autotransformer-based 12-pulse ac-dc converter for power quality improvement

    NASA Astrophysics Data System (ADS)

    Abdollahi, Rohollah

    2012-12-01

    This paper presents a pulse doubling technique in a 12-pulse ac-dc converter which supplies direct torque controlled motor drives (DTCIMDs) in order to have better power quality conditions at the point of common coupling. The proposed technique increases the number of rectification pulses without significant changes in the installations and yields in harmonic reduction in both ac and dc sides. The 12-pulse rectified output voltage is accomplished via two paralleled six-pulse acdc converters each of them consisting of three-phase diode bridge rectifiers. An autotransformer is designed to supply the rectifiers. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. Independent operation of paralleled diode-bridge rectifiers, i.e. dc-ripple re-injection methodology, requires a Zero Sequence Blocking Transformer (ZSBT). Finally, a tapped interphase reactor is connected at the output of ZSBT to double the pulse numbers of output voltage up to 24 pulses. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse, 12-pulse, and proposed converters from view point of power quality indices. Results show that input current total harmonic distortion (THD) is less than 5% for the proposed topology at various loads.

  10. High-power industrial pulsed CO2 laser

    NASA Astrophysics Data System (ADS)

    Levin, G. I.

    1983-12-01

    The use of a pulsed TEA CO2 laser (with maximum average power 1.0 kW; maximum pulse energy 3.5 J; repetition frequency 400-600 Hz; half-width pulse duration 15 microsec; circular-coupling-aperture beam diameter 6, 8, or 12 mm; and beam divergence 10 mrad) in industrial welding applications is investigated experimentally in carbon and stainless steels, Zr, Ti, and Ni of various thicknesses. The power required to melt the metals is found to be about 120-200 W/sq cm, or 5-6 times less than that for CW lasers. It is shown that deep narrow-seam welds with mechanical properties identical to those of the bulk metal can be obtained with little or no intercrystalline corrosion or thermal distortion of the surrounding area. Disadvantages such as the 65-dB noise level, low welding speed, formation of an overlap at the top and a crater at the bottom of the weld, and root porosity are considered the primary limitations on the applicability of the device tested.

  11. Pulsed Power Aspects of the NIF Plasma Electrode Pockels Cell

    SciTech Connect

    Arnold, P A; Ollis, C W; Hinz, A F; Barbosa, F; Fulkerson, E S

    2005-06-09

    The Plasma Electrode Pockels Cell (PEPC) embodies technology essential to the National Ignition Facility (NIF). Together with a thin-film polarizer, PEPC functions as an optical switch for the main amplifier cavity, allowing optical pulses to be trapped, and then released, and enabling NIF to take advantage of the attendant gain and cost-savings. Details of the genesis, development, and prototyping of the PEPC are well documented. After moving from its laboratory setting to the NIF facility, PEPC--via its performance during the two-year NIF Early Light (NEL) campaign and its ongoing operation during facility build-out--has proven to be a fully functional system. When complete, NIF will accommodate 192 beams, capable of delivering 1.8 MJ to a fusion target. Forty-eight Plasma Electrode Pockels--driven by nearly 300 high-power, high-voltage pulse generators--will support this complement of beams. As deployed, PEPC is a complex association of state-of-the-art optics; low-voltage and high-voltage electronics; and mechanical, gas, and vacuum subsystems--all under computer control. In this paper, we briefly describe each of these elements, but focus on the pulse power aspects of the PEPC system.

  12. An Advanced Time Averaging Modelling Technique for Power Electronic Circuits

    NASA Astrophysics Data System (ADS)

    Jankuloski, Goce

    For stable and efficient performance of power converters, a good mathematical model is needed. This thesis presents a new modelling technique for DC/DC and DC/AC Pulse Width Modulated (PWM) converters. The new model is more accurate than the existing modelling techniques such as State Space Averaging (SSA) and Discrete Time Modelling. Unlike the SSA model, the new modelling technique, the Advanced Time Averaging Model (ATAM) includes the averaging dynamics of the converter's output. In addition to offering enhanced model accuracy, application of linearization techniques to the ATAM enables the use of conventional linear control design tools. A controller design application demonstrates that a controller designed based on the ATAM outperforms one designed using the ubiquitous SSA model. Unlike the SSA model, ATAM for DC/AC augments the system's dynamics with the dynamics needed for subcycle fundamental contribution (SFC) calculation. This allows for controller design that is based on an exact model.

  13. [Research advances of anti-tumor immune response induced by pulse electric field ablation].

    PubMed

    Cui, Guang-ying; Diao, Hong-yan

    2015-11-01

    As a novel tumor therapy, pulse electric field has shown a clinical perspective. This paper reviews the characteristics of tumor ablation by microsecond pulse and nanosecond pulse electric field, and the research advances of anti-tumor immune response induced by pulse electric field ablation. Recent researches indicate that the pulse electric field not only leads to a complete ablation of local tumor, but also stimulates a protective immune response, thereby inhibiting tumor recurrence and metastasis. These unique advantages will show an extensive clinical application in the future. However, the mechanism of anti-tumor immune response and the development of related tumor vaccine need further studies.

  14. Laser-Material Interaction of Powerful Ultrashort Laser Pulses

    SciTech Connect

    Komashko, A

    2003-01-06

    Laser-material interaction of powerful (up to a terawatt) ultrashort (several picoseconds or shorter) laser pulses and laser-induced effects were investigated theoretically in this dissertation. Since the ultrashort laser pulse (USLP) duration time is much smaller than the characteristic time of the hydrodynamic expansion and thermal diffusion, the interaction occurs at a solid-like material density with most of the light energy absorbed in a thin surface layer. Powerful USLP creates hot, high-pressure plasma, which is quickly ejected without significant energy diffusion into the bulk of the material, Thus collateral damage is reduced. These and other features make USLPs attractive for a variety of applications. The purpose of this dissertation was development of the physical models and numerical tools for improvement of our understanding of the process and as an aid in optimization of the USLP applications. The study is concentrated on two types of materials - simple metals (materials like aluminum or copper) and wide-bandgap dielectrics (fused silica, water). First, key physical phenomena of the ultrashort light interaction with metals and the models needed to describe it are presented. Then, employing one-dimensional plasma hydrodynamics code enhanced with models for laser energy deposition and material properties at low and moderate temperatures, light absorption was self-consistently simulated as a function of laser wavelength, pulse energy and length, angle of incidence and polarization. Next, material response on time scales much longer than the pulse duration was studied using the hydrocode and analytical models. These studies include examination of evolution of the pressure pulses, effects of the shock waves, material ablation and removal and three-dimensional dynamics of the ablation plume. Investigation of the interaction with wide-bandgap dielectrics was stimulated by the experimental studies of the USLP surface ablation of water (water is a model of

  15. Pen harvester for powering a pulse rate sensor

    NASA Astrophysics Data System (ADS)

    Bedekar, Vishwas; Oliver, Josiah; Priya, Shashank

    2009-05-01

    Rapid developments in the area of micro-sensors for various applications such as structural health monitoring, bio-chemical sensors and pressure sensors have increased the demand for portable, low cost, high efficiency energy harvesting devices. In this paper, we describe the scheme for powering a pulse rate sensor with a vibration energy harvester integrated inside a pen commonly carried by humans in the pocket close to the heart. Electromagnetic energy harvesting was selected in order to achieve high power at lower frequencies. The prototype pen harvester was found to generate 3 mW at 5 Hz and 1 mW at 3.5 Hz operating under displacement amplitude of 16 mm (corresponding to an acceleration of approximately 1.14 grms at 5 Hz and 0.56 grms at 3.5 Hz, respectively). A comprehensive mathematical modelling and simulations were performed in order to optimize the performance of the vibration energy harvester. The integrated pen harvester prototype was found to generate continuous power of 0.46-0.66 mW under normal human actions such as jogging and jumping which is enough for a small scale pulse rate sensor.

  16. 94 GHz pulsed coherent radar for high power amplifier evaluation

    NASA Astrophysics Data System (ADS)

    Robertson, Duncan A.; Hunter, Robert I.; Gallacher, Thomas F.

    2016-05-01

    We present the design and characterization of a 94 GHz pulsed coherent radar to be used for the evaluation and demonstration of novel wideband, high power vacuum tube amplifier technology. The radar is designed to be fully coherent and exploits a low phase noise architecture to maximize Doppler performance. We selected to use horn-fed Fresnel zone plate lens antennas (FZPs) with 4-level phase quantization as a low cost method of realizing large aperture (0.5 m) antennas. The measured performance of these FZPs agrees closely with the design predictions and exceeds that obtainable with a Cassegrain of an equivalent size.

  17. Pulsed power and electron beams in the 21st century.

    SciTech Connect

    Ekdahl, C. A.

    2002-01-01

    Pulsed power and accelerator technology for high energy density physics, radiography, and simulation has matured to the point that new facilities promise users reliability of quality data return unheard of just a short time ago. By this metric alone these machines and accelerators have graduated from being experiments in their own right, to the solid foundation of a new era of experimental science. The projected performance of a few of these new capabilities will be highlighted, along with some modest speculation concerning their future.

  18. Design concepts for a pulse power test facility to simulate EMP surges. Part II. Slow pulses

    SciTech Connect

    Dethlefsen, R.

    1985-10-01

    The work described in this report was sponsored by the Division of Electric Energy Systems (EES) of the US Department of Energy (DOE) through a subcontract with the Power Systems Technology Program at the Oak Ridge National Laboratory (ORNL). The work deals with the effect of high altitude nuclear bursts on electric power systems. In addition to fast voltage transients, slow, quasi-dc currents are also induced into extended power systems with grounded neutral connections. Similar phenomena at lower magnitude are generated by solar induced electromagnetic pulses (EMP). These have caused power outages, related to solar storms, at northern latitudes. The applicable utility experience is reviewed in order to formulate an optimum approach to future testing. From a wide variety of options two pulser designs were selected as most practical, a transformer-rectifier power supply, and a lead acid battery pulser. both can be mounted on a trailer as required for field testing on utility systems. The battery system results in the least cost. Testing on power systems requires that the dc pulser pass high values of alternating current, resulting from neutral imbalance or from potential fault currents. Batteries have a high ability to pass alternating currents. Most other pulser options must be protected by an ac bypass in the form of an expensive capacitor bank. 8D truck batteries can meet the original specification of 1 kA test current. Improved batteries for higher discharge currents are available.

  19. The Mercury Laser Advances Laser Technology for Power Generation

    SciTech Connect

    Ebbers, C A; Caird, J; Moses, E

    2009-01-21

    The National Ignition Facility (NIF) at Lawrence Livermore Laboratory is on target to demonstrate 'breakeven' - creating as much fusion-energy output as laser-energy input. NIF will compress a tiny sphere of hydrogen isotopes with 1.8 MJ of laser light in a 20-ns pulse, packing the isotopes so tightly that they fuse together, producing helium nuclei and releasing energy in the form of energetic particles. The achievement of breakeven will culminate an enormous effort by thousands of scientists and engineers, not only at Livermore but around the world, during the past several decades. But what about the day after NIF achieves breakeven? NIF is a world-class engineering research facility, but if laser fusion is ever to generate power for civilian consumption, the laser will have to deliver pulses nearly 100,000 times faster than NIF - a rate of perhaps 10 shots per second as opposed to NIF's several shots a day. The Mercury laser (named after the Roman messenger god) is intended to lead the way to a 10-shots-per-second, electrically-efficient, driver laser for commercial laser fusion. While the Mercury laser will generate only a small fraction of the peak power of NIF (1/30,000), Mercury operates at higher average power. The design of Mercury takes full advantage of the technology advances manifest in its behemoth cousin (Table 1). One significant difference is that, unlike the flashlamp-pumped NIF, Mercury is pumped by highly efficient laser diodes. Mercury is a prototype laser capable of scaling in aperture and energy to a NIF-like beamline, with greater electrical efficiency, while still running at a repetition rate 100,000 times greater.

  20. Reliability of high-power pulsed IMPATT diodes

    NASA Astrophysics Data System (ADS)

    Ayyagari, M. S.; Heaton, J. L.; Jansen, N.

    1981-11-01

    Because of their present and future use in military systems, particularly missile seekers, high power pulsed IMPATT reliability is of considerable interest. This report is concerned with a reliability study of gallium arsenide double-drift pulsed IMPATTs of the Read doping profile type, that is both n and p active regions and contains avalanche confining doping structures. Both short-term (freak failure region) and long-term reliability testing have been carried out, comparing performance and failure mechanisms of the gallium arsenide devices with a smaller number of silicon flat profile double-drift devices, and Schottky-barrier, single-drift, low-high-low doping profile gallium arsenide devices. In the second phase of testing, devices were stressed under oscillating conditions, with a set of increasing bias current values, until failure occurred. The test was repeated at 16 different pulse widths and duty cycle combinations allowing determination of the most stringent operating conditions, and evaluation of failure mechanisms characteristic of such overstress. The third phase of testing was directed at examination of long-term reliability and wear-out failure mechanisms. Both a high temperature storage step-stress test and a long-term operation constant stress test were carried out.

  1. Explosive pulsed power system for new radiation sources.

    SciTech Connect

    Oona, H.; Goforth, J. H.; Idzorek, G. C.; Herrera, D. H.; King, J. C.; Lopez, E. A.; Tasker, D. G.; Torres, D. T.

    2004-01-01

    High explosive pulsed power (HEPP) systems are capable of accessing very high energy densities and can reach conditions that are not possible with capacitor bank systems. The Procyon system was developed and used for experiments over a period of six years, and is exemplary of the capabilities of HEPP systems for state-of-the-art research. In this paper we will summarize some of the more interesting aspects of the work done in the past but will suggest ideas toward applications for future research. One of the main, unique features of HEPP systems is that they integrate easily to a particular physics experiment and the power flow can be optimized for a specific test. Magnetic flux compression generators have been an ideal power source for both high current plasma physics and hydrodynamic experimental loads. These experiments have contributed greatly to the understanding of high temperature and density plasmas and more recently to the understanding of instability growth in thick ({approx}1 mm) imploding metal cylinders. Common to all these experiments is the application of a large current pulse to a cylindrically symmetric load. The resulting Lorenz force compresses the load to produce hydrodynamic motion and/or high temperature, high density plasma. In the plasma physics experiments, plasma thermalizes on axis and a black body distribution of x-rays is produced. To get better access to the radiation pulse, the load electrode geometry was modified. For example, by shaping the plasma implosion glide planes, a mass depletion region was formed along one electrode at pinch time which generated a very large voltage drop across a 1-2 mm segment of the pinch, and also produced a high energy ion beam on axis. These results were predicted by magneto-hydro-dynamic (MHD) codes and verified with framing camera and x-ray, pinhole, camera pictures. We have not previously published these features but will take another look and propose possible scenarios for studying and generating

  2. Advanced power electronics and electric machinery program

    SciTech Connect

    None, None

    2007-12-01

    The U.S. Department of Energy (DOE) and the U.S. Council for Automotive Research (composed of automakers Ford, General Motors, and Chrysler) announced in January 2002 a new cooperative research effort. Known as "FreedomCAR" (derived from "Freedom" and "Cooperative Automotive Research"), it represents DOE's commitment to developing public/private partnerships to fund high-risk, high-payoff research into advanced automotive technologies. Efficient fuel cell technology, which uses hydrogen to power automobiles without air pollution, is a very promising pathway to achieving the ultimate vision. The new partnership replaces and builds upon the Partnership for a New Generation of Vehicles initiative that ran from 1993 through 2001.

  3. Compact Fusion Advanced Rankine (CFARII) power cycle

    SciTech Connect

    Logan, B.G.

    1991-08-23

    The Compact Fusion Advanced Rankine (CFARII) power cycle is a direct plasma energy conversion scheme for inertial fusion (ICF) and magnetically-insulated, inertially confined fusion (MICF) reactors utilizing: (1) conversion of plasma thermal ionization and thermal energy into kinetic energy of a supersonic plasma jet, (2) conversion of the plasma jet kinetic energy into DC electricity by slowing down in an ``impulse`` type of magnetohydrodynamic (MHD) generator, and (3) condensation and heat rejection of the exhaust plasma on droplets of recirculating condensate (``raindrop`` condensor). A preliminary evaluation of a particular reference case CFARII Balance-of-Plant (BoP) is found sufficiently attractive (52% gross cycle efficiency, 40 million 1991 $ BoP for 1 GWe gross electric) to warrant further work on several design issues.

  4. Compact Fusion Advanced Rankine (CFARII) power cycle

    SciTech Connect

    Logan, B.G.

    1991-08-23

    The Compact Fusion Advanced Rankine (CFARII) power cycle is a direct plasma energy conversion scheme for inertial fusion (ICF) and magnetically-insulated, inertially confined fusion (MICF) reactors utilizing: (1) conversion of plasma thermal ionization and thermal energy into kinetic energy of a supersonic plasma jet, (2) conversion of the plasma jet kinetic energy into DC electricity by slowing down in an impulse'' type of magnetohydrodynamic (MHD) generator, and (3) condensation and heat rejection of the exhaust plasma on droplets of recirculating condensate ( raindrop'' condensor). A preliminary evaluation of a particular reference case CFARII Balance-of-Plant (BoP) is found sufficiently attractive (52% gross cycle efficiency, 40 million 1991 $ BoP for 1 GWe gross electric) to warrant further work on several design issues.

  5. NUMERICAL SIMULATIONS OF CONVERGING SHOCKS IN PULSED POWER DRIVEN EXPERIMENTS

    SciTech Connect

    R. KANZLEITER; W. ATCHISON; ET AL

    2000-12-01

    The final shot of the current Near Term Liner Experiment (NTLX) series occurred on September 29, 2000. Utilization of a pulsed power source with a standardized liner/target ''cartridge'' produced a uniform implosion to drive hydrodynamic experiments. Diagnostics showed that high quality data of shock propagation can be obtained from pulsed power liner drivers as in the current NTLX series. Very good agreement in calculating shock locations was obtained between the codes used to model the NTLX series, RAGE and RAVEN. RAVEN also accurately predicts liner/target impact as measured by B-Dot probes. Large differences are observed between the calculated and measured positions of converging shock waves even in simple geometrical configurations. Liner/target impact is accurately calculated and similar results are produced for shock velocities in Lucite. RAGE and RAVEN use different hydrodynamic algorithms, yet agree, this focuses current efforts on EOS issues within the outer tin target to resolve discrepancies. Further diagnostics covering shock breakout from the outer tin target and shock propagation shortly thereafter would be highly beneficial.

  6. Pulsed power conditioning system for the Magajoule laser

    NASA Astrophysics Data System (ADS)

    Mexmain, Jean-Marc; Rubin de Cervens, D.; Marret, Jean-Pierre; Roos, V.; Cassany, B.; Eyl, P.; Pere, P.; Havre, Sierra S.; Fauvel, J.; Mathieu, P.; Benin, P.; Callu, G.; Vincent, C.; Michalczyk, Pierre

    2003-07-01

    The CEA is responsible for the Megajoule Laser (LMJ) facility. This facility is a large Flashlamp pump laser (1.8 MJ optical output). CEA entered into a contract with THALES to carry out the pulsed power conditioning system for the Megajoule Laser. The pulsed power conditioning system has a modular design which makes the facility more flexible and safer. This complete primary storage is a 450 MJ energy capacitor bank composed of 270 modules of 1.6 MJ energy. Each module is a stand-alone capacitor bank equipped with twelve 100 kJ capacitors and its embedded control/monitor and diagnostic system which is connected by an optical Ethernet link to the Command Control Supervisor of the facility. In the first step of the LMJ program, called "Line Integration Laser" (LIL), one laser chain will be built. The capacitor bank used to drive the LIL is comprised of 10 modules. This paper describes the design of the modules and the results of testing. The overall electrical performance meets the requirements.

  7. Soft x-ray diagnostics for pulsed power machines

    SciTech Connect

    Idzorek, G.C.; Coulter, W.L.; Walsh, P.J.; Montoya, R.R.

    1995-08-01

    A variety of soft x-ray diagnostics are being fielded on the Los Alamos National Laboratory Pegasus and Procyon pulsed power systems and also being fielded on joint US/Russian magnetized target fusion experiments known as MAGO (Magnitoye Obzhatiye). The authors have designed a low-cost modular photoemissive detector designated the XRD-96 that uses commercial 1100 series aluminum for the photocathode. In addition to photocathode detectors a number of designs using solid state silicon photodiodes have been designed and fielded. They also present a soft x-ray time-integrated pinhole camera system that uses standard type TMAX-400 photographic film that obviates the need for expensive and no longer produced zero-overcoat soft x-ray emulsion film. In a typical experiment the desired spectral energy cuts, signal intensity levels, and desired field of view will determine diagnostic geometry and x-ray filters selected. The authors have developed several computer codes to assist in the diagnostic design process and data deconvolution. Examples of the diagnostic design process and data analysis for a typical pulsed power experiment are presented.

  8. Pulsed Plasma Thruster (PPT) Technology: Earth Observing-1 PPT Operational and Advanced Components Being Developed

    NASA Technical Reports Server (NTRS)

    Pencil, Eric J.; Benson, Scott W.; Arrington, Lynn A.; Frus, John; Hoskins, W. Andrew; Burton, Rodney

    2003-01-01

    In 2002 the pulsed plasma thruster (PPT) mounted on the Earth Observing-1 spacecraft was operated successfully in orbit. The two-axis thruster system is fully incorporated in the attitude determination and control system and is being used to automatically counteract disturbances in the pitch axis of the spacecraft. The first tests conducted in space demonstrated the full range of PPT operation, followed by calibration of control torques from the PPT in the attitude control system. Then the spacecraft was placed in PPT control mode. To date, it has operated for about 30 hr. The PPT successfully controlled pitch momentum during wheel de-spin, solar array acceleration and deceleration during array rewind, and environmental torques in nominal operating conditions. Images collected with the Advanced Landsat Imager during PPT operation have demonstrated that there was no degradation in comparison to full momentum wheel control. In addition, other experiments have been performed to interrogate the effects of PPT operation on communication packages and light reflection from spacecraft surfaces. Future experiments will investigate the possibility of orbit-raising maneuvers, spacecraft roll, and concurrent operation with the Hyperion imager. Future applications envisioned for pulsed plasma thrusters include longer life, higher precision, multiaxis thruster configurations for three-axis attitude control systems or high-precision, formationflying systems. Advanced components, such as a "dry" mica-foil capacitor, a wear-resistant spark plug, and a multichannel power processing unit have been developed under contract with Unison Industries, General Dynamics, and C.U. Aerospace. Over the last year, evaluation tests have been conducted to determine power processing unit efficiency, atmospheric functionality, vacuum functionality, thruster performance evaluation, thermal performance, and component life.

  9. Space Power Architectures for NASA Missions: The Applicability and Benefits of Advanced Power and Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Hoffman, David J.

    2001-01-01

    The relative importance of electrical power systems as compared with other spacecraft bus systems is examined. The quantified benefits of advanced space power architectures for NASA Earth Science, Space Science, and Human Exploration and Development of Space (HEDS) missions is then presented. Advanced space power technologies highlighted include high specific power solar arrays, regenerative fuel cells, Stirling radioisotope power sources, flywheel energy storage and attitude control, lithium ion polymer energy storage and advanced power management and distribution.

  10. Towards Integrated Pulse Detonation Propulsion and MHD Power

    NASA Technical Reports Server (NTRS)

    Litchford, Ron J.; Thompson, Bryan R.; Lineberry, John T.

    1999-01-01

    The interest in pulse detonation engines (PDE) arises primarily from the advantages that accrue from the significant combustion pressure rise that is developed in the detonation process. Conventional rocket engines, for example, must obtain all of their compression from the turbopumps, while the PDE provides additional compression in the combustor. Thus PDE's are expected to achieve higher I(sub sp) than conventional rocket engines and to require smaller turbopumps. The increase in I(sub sp) and the decrease in turbopump capacity must be traded off against each other. Additional advantages include the ability to vary thrust level by adjusting the firing rate rather than throttling the flow through injector elements. The common conclusion derived from these aggregated performance attributes is that PDEs should result in engines which are smaller, lower in cost, and lighter in weight than conventional engines. Unfortunately, the analysis of PDEs is highly complex due to their unsteady operation and non-ideal processes. Although the feasibility of the basic PDE concept has been proven in several experimental and theoretical efforts, the implied performance improvements have yet to be convincingly demonstrated. Also, there are certain developmental issues affecting the practical application of pulse detonation propulsion systems which are yet to be fully resolved. Practical detonation combustion engines, for example, require a repetitive cycle of charge induction, mixing, initiation/propagation of the detonation wave, and expulsion/scavenging of the combustion product gases. Clearly, the performance and power density of such a device depends upon the maximum rate at which this cycle can be successfully implemented. In addition, the electrical energy required for direct detonation initiation can be significant, and a means for direct electrical power production is needed to achieve self-sustained engine operation. This work addresses the technological issues associated

  11. Generation of sub-50 fs pulses from a high-power Yb-doped fiber amplifier.

    PubMed

    Deng, Yujun; Chien, Ching-Yuan; Fidric, Bernard G; Kafka, James D

    2009-11-15

    We demonstrate the generation of 48 fs pulses with 18 W average power and 226 nJ of pulse energy from a Yb-doped fiber amplifier. The system uses a simple stretcher-free single-stage amplifier configuration operating in the parabolic pulse regime. The gain fiber length and pump wavelength are chosen in order to reduce the gain per unit length and generate both shorter pulses and higher pulse energy.

  12. Robust Short-Pulse, High-Peak-Power Laser Transmitter for Optical Communications

    NASA Technical Reports Server (NTRS)

    Wright, Malcolm W.

    2009-01-01

    We report on a pulsed fiber based master oscillator power amplifier laser at 1550 nm to support moderate data rates with high peak powers in a compact package suitable for interplanetary optical communications. To accommodate pulse position modulation, the polarization maintaining laser transmitter generates pulses from 0.1 to 1 ns with variable duty cycle over a pulse repetition frequency range of 10 to 100 MHz.

  13. Safety training and safe operating procedures written for PBFA (Particle Beam Fusion Accelerator) II and applicable to other pulsed power facilities

    SciTech Connect

    Donovan, G.L.; Goldstein, S.A.

    1986-12-01

    To ensure that work in advancing pulsed power technology is performed with an acceptably low risk, pulsed power research facilities at Sandia National Laboratories must satisfy general safety guidelines established by the Department of Energy, policies and formats of the Environment, Safety, and Health (ES and H) Department, and detailed procedures formulated by the Pulsed Power Sciences Directorate. The approach to safety training and to writing safe operating procedures, and the procedures presented here are specific to the Particle Beam Fusion Accelerator II (PBFA II) Facility but are applicable as guidelines to other research and development facilities which have similar hazards.

  14. Advanced Electric Propulsion for Space Solar Power Satellites

    NASA Technical Reports Server (NTRS)

    Oleson, Steve

    1999-01-01

    The sun tower concept of collecting solar energy in space and beaming it down for commercial use will require very affordable in-space as well as earth-to-orbit transportation. Advanced electric propulsion using a 200 kW power and propulsion system added to the sun tower nodes can provide a factor of two reduction in the required number of launch vehicles when compared to in-space cryogenic chemical systems. In addition, the total time required to launch and deliver the complete sun tower system is of the same order of magnitude using high power electric propulsion or cryogenic chemical propulsion: around one year. Advanced electric propulsion can also be used to minimize the stationkeeping propulsion system mass for this unique space platform. 50 to 100 kW class Hall, ion, magnetoplasmadynamic, and pulsed inductive thrusters are compared. High power Hall thruster technology provides the best mix of launches saved and shortest ground to Geosynchronous Earth Orbital Environment (GEO) delivery time of all the systems, including chemical. More detailed studies comparing launch vehicle costs, transfer operations costs, and propulsion system costs and complexities must be made to down-select a technology. The concept of adding electric propulsion to the sun tower nodes was compared to a concept using re-useable electric propulsion tugs for Low Earth Orbital Environment (LEO) to GEO transfer. While the tug concept would reduce the total number of required propulsion systems, more launchers and notably longer LEO to GEO and complete sun tower ground to GEO times would be required. The tugs would also need more complex, longer life propulsion systems and the ability to dock with sun tower nodes.

  15. High-power pulsed thulium fiber oscillator modulated by stimulated Brillouin scattering

    SciTech Connect

    Tang, Yulong Xu, Jianqiu

    2014-01-06

    A pulsed ∼2-μm thulium-doped fiber laser passively modulated by distributed stimulated Brillouin scattering achieves 10.2 W average power and >100 kHz repetition rate with a very simple all-fiber configuration. The maximum pulse energy and peak power surpass 100 μJ and 6 kW, respectively. Another distinct property is that the pulse width is clamped around 17 ns at all power levels. All the average-power, pulse energy, and peak power show the highest values from passively modulated fiber lasers in all wavelength regions.

  16. Single-event upset in advanced PowerPC microprocessors

    NASA Technical Reports Server (NTRS)

    Irom, F.; Swift, G. M.; Farmanesh, F.; Millward, D. G.

    2002-01-01

    Proton and heavy-ion single-event upset susceptibility has been measured for the MotorolaPowerPC7400. The results show that this advanced device has low upset susceptibility, despite the scaling and design advances.

  17. Effects of pulse frequency of input power on the physical and chemical properties of pulsed streamer discharge plasmas in water

    NASA Astrophysics Data System (ADS)

    Ruma; Lukes, P.; Aoki, N.; Spetlikova, E.; Hosseini, S. H. R.; Sakugawa, T.; Akiyama, H.

    2013-03-01

    A repetitive pulsed-power modulator, which employs a magnetic pulse compression circuit with a high-speed thyristor switch, was used to study the effects of the pulse repetition rate of input power on the physical and chemical properties of pulsed discharges in water. Positive high-voltage pulses of 20 kV with repetition rates of up to 1 kHz were used to generate a discharge in water using the point-to-plane electrode geometry. By varying the pulse repetition rate, two distinct modes of the discharge plasma were formed in water. The first mode was characterized by the formation of a corona-like discharge propagating through water in the form of streamer channels. The second mode was formed typically above 500 Hz, when the formation of streamer channels in water was suppressed and all plasmas occurred inside a spheroidal aggregate of very fine gas bubbles surrounding the tip of the high-voltage electrode. The production of hydrogen peroxide, degradation of organic dye Acid Orange 7 (AO7) and inactivation of bacteria Escherichia coli by the discharge in water were studied under different discharge plasma modes in dependence on the pulse repetition rate of input power. The efficiency of both chemical and biocidal processes induced by the plasma in water decreased significantly with pulse repetition rates above 500 Hz.

  18. Stacked Blumlein devices generating high-power, nanosecond-wide electrical pulses

    NASA Astrophysics Data System (ADS)

    Borovina, Dan Lucretiu

    1997-11-01

    Many important advances in modern technology will require input powers which are too high to deliver continuously. Fortunately, constant operation is not necessary for some applications. In those cases, electrical input power can be delivered in pulses with specifically tailored characteristics. The most demanding applications create the need for particular combinations of operating parameters that are important in high-energy lasers, advanced accelerators and the generation of high-power microwaves; and those lie at the focus of this work. Conventional devices had been able to provide some of the parameters in the same arrangement, but none could deliver all of them at once. In 1993, when this work was initiated, the concept of a high-voltage solid state switch capable of being triggered on demand held promise for a solution, despite traditional obstacles. Initially, all common solid-state materials, including GaAs and Si, had been designed for low-power applications, and attempts to extend their performance to higher powers created some problems. For high-voltage operation, these switches required some sort of isolation from the command circuit. Optical triggering solved these problems in a device known as a photoconductive switch. However, for some modern applications, which require pulses with very fast risetimes, conventional photoconductive switch technology was limited by the time required to produce enough charge carriers for commutation. Carrier generation could be accomplished in one of two ways. The first involved the use of an intense laser pulse with a fast risetime to produce all carriers through photon absorption. In this case, the necessary laser had to be large and expensive, and required its own high-power pulser, similar to the one being built, making this approach impractical. The second method involved the initiation of a fast, non- linear, avalanche process within the semiconductor, using a more conventional light pulse. This technique

  19. Advanced Power Electronics for LED Drivers: Advanced Technologies for integrated Power Electronics

    SciTech Connect

    2010-09-01

    ADEPT Project: MIT is teaming with Georgia Institute of Technology, Dartmouth College, and the University of Pennsylvania (UPenn) to create more efficient power circuits for energy-efficient light-emitting diodes (LEDs) through advances in 3 related areas. First, the team is using semiconductors made of high-performing gallium nitride grown on a low-cost silicon base (GaN-on-Si). These GaN-on-Si semiconductors conduct electricity more efficiently than traditional silicon semiconductors. Second, the team is developing new magnetic materials and structures to reduce the size and increase the efficiency of an important LED power component, the inductor. This advancement is important because magnetics are the largest and most expensive part of a circuit. Finally, the team is creating an entirely new circuit design to optimize the performance of the new semiconductors and magnetic devices it is using.

  20. Pulse combustion furnace phase 2: Advancement of developmental technology

    NASA Astrophysics Data System (ADS)

    Belles, F. E.; Griffiths, J. C.

    1982-04-01

    The development of pulse combustion technology, with specific application to furnaces with ultrahigh efficiency is discussed. The performance of a series of pulse combustion burner designs with various input spans within an overall framework of 15,000 to 300,000 Btu per hour was observed. These data are intended to assist designers in selecting appropriate burner component designs to meet their particular needs and also, to provide the means to relate various burner design factors to burner performance, particularly in regards to noise of operation.

  1. Ferroelectric opening switches for large-scale pulsed power drivers.

    SciTech Connect

    Brennecka, Geoffrey L.; Rudys, Joseph Matthew; Reed, Kim Warren; Pena, Gary Edward; Tuttle, Bruce Andrew; Glover, Steven Frank

    2009-11-01

    Fast electrical energy storage or Voltage-Driven Technology (VDT) has dominated fast, high-voltage pulsed power systems for the past six decades. Fast magnetic energy storage or Current-Driven Technology (CDT) is characterized by 10,000 X higher energy density than VDT and has a great number of other substantial advantages, but it has all but been neglected for all of these decades. The uniform explanation for neglect of CDT technology is invariably that the industry has never been able to make an effective opening switch, which is essential for the use of CDT. Most approaches to opening switches have involved plasma of one sort or another. On a large scale, gaseous plasmas have been used as a conductor to bridge the switch electrodes that provides an opening function when the current wave front propagates through to the output end of the plasma and fully magnetizes the plasma - this is called a Plasma Opening Switch (POS). Opening can be triggered in a POS using a magnetic field to push the plasma out of the A-K gap - this is called a Magnetically Controlled Plasma Opening Switch (MCPOS). On a small scale, depletion of electron plasmas in semiconductor devices is used to affect opening switch behavior, but these devices are relatively low voltage and low current compared to the hundreds of kilo-volts and tens of kilo-amperes of interest to pulsed power. This work is an investigation into an entirely new approach to opening switch technology that utilizes new materials in new ways. The new materials are Ferroelectrics and using them as an opening switch is a stark contrast to their traditional applications in optics and transducer applications. Emphasis is on use of high performance ferroelectrics with the objective of developing an opening switch that would be suitable for large scale pulsed power applications. Over the course of exploring this new ground, we have discovered new behaviors and properties of these materials that were here to fore unknown. Some of

  2. A new 40 MA ranchero explosive pulsed power system

    SciTech Connect

    Goforth, James; Herrera, Dennis; Oona, Hank; Torres, David; Atchison, W L; Colgate, S A; Griego, J R; Guzik, J; Holtkamp, D B; Idzorek, G; Kaul, A; Kirkpatrick, R C; Menikoff, R; Reardon, P T; Reinovsky, R E; Rousculp, C L; Sgro, A G; Tabaka, L J; Tierney, T E; Watt, R G

    2009-01-01

    We are developing a new high explosive pulsed power (HEPP) system based on the 1.4 m long Ranchero generator which was developed in 1999 for driving solid density z-pinch loads. The new application requires approximately 40 MA to implode similar liners, but the liners cannot tolerate the 65 {micro}s, 3 MA current pulse associated with delivering the initial magnetic flux to the 200 nH generator. To circumvent this problem, we have designed a system with an internal start switch and four explosively formed fuse (EFF) opening switches. The integral start switch is installed between the output glide plane and the armature. It functions in the same manner as a standard input crowbar switch when armature motion begins, but initially isolates the load. The circuit is completed during the flux loading phase using post hole convolutes. Each convolute attaches the inner (coaxial) output transmission line to the outside of the outer coax through a penetration of the outer coaxial line. The attachment is made with the conductor of an EFF at each location. The EFFs conduct 0.75 MA each, and are actuated just after the internal start switch connects to the load. EFFs operating at these parameters have been tested in the past. The post hole convolutes must withstand as much as 80 kV at peak dl/dt during the Ranchero load current pulse. We describe the design of this new HEPP system in detail, and give the experimental results available at conference time. In addition, we discuss the work we are doing to test the upper current limits of a single standard size Ranchero module. Calculations have suggested that the generator could function at up to {approx}120 MA, the rule of thumb we follow (1 MA/cm) suggests 90 MA, and simple flux compression calculations, along with the {approx}4 MA seed current available from our capacitor bank, suggests 118 MA is the currently available upper limit.

  3. A Cerenkov source of high-power picosecond pulsed microwaves

    SciTech Connect

    Zhang, T.B.; Marshall, T.C.; Hirshfield, J.L. |

    1998-06-01

    One or more electron bunches passing along the axis of a dielectric-lined cylindrical waveguide are shown to emit picosecond pulses of high-power broad-band microwave radiation. The bunches can be generated by an S-band RF gun, and thus spaced from one another by 10.5 cm in a macropulse sequence, or a single more intense bunch can be generated using a laser-illuminated photocathode in the RF gun. Theory is developed for the excitation of TM{sub 0m} modes of this waveguide which propagate at the bunch velocity from Cerenkov radiation emitted by a single intense bunch. A train of picosecond coherent wakefield pulses is shown to follow the bunch, when the waveguide modes have nearly constant spacing in frequency. An example is shown for an alumina-lined waveguide with 10-nC 3--15-ps bunches having an initial energy of 6 MeV. Computations are presented of the mode spectrum of the radiation and its time structure. It is also shown that measurements of the mode spectrum, or of the energy loss of the bunch, can be used to infer the axial density profile of the bunch. Certain features of the theory are compared with the results of a preliminary experiment.

  4. High power linear pulsed beam annealer. [Patent application

    DOEpatents

    Strathman, M.D.; Sadana, D.K.; True, R.B.

    1980-11-26

    A high power pulsed electron beam system for annealing semiconductors is comprised of an electron gun having a heated cathode, control grid and focus ring for confining the pulsed beam of electrons to a predetermined area, and a curved drift tube. The drift tube and an annular Faraday shield between the focus ring and the drift tube are maintained at a high positive voltage with respect to the cathode to accelerate electrons passing through the focus ring, thereby eliminating space charge limitations on the emission of electrons from said gun. A coil surrounding the curved drift tube provides a magnetic field which maintains the electron beam focused about the axis of the tube. The magnetic field produced by the coil around the curved tube imparts motion to electrons in a spiral path for shallow penetration of the electrons into a target. It also produces a scalloped profile of the electron beam. A second drift tube spaced a predetermined distance from the curved tube is positioned with its axis aligned with the axis of the first drift tube. The second drift tube and the target holder are maintained at a reference voltage between the cathode voltage and the curved tube voltage to decelerate the electrons. A second coil surrounding the second drift tube, maintains the electron beam focused about the axis of the second drift tube. The magnetic field of the second coil comprises the electron beam to the area of the semiconductor on the target holder.

  5. Optimization of Industrial Ozone Generation with Pulsed Power

    NASA Astrophysics Data System (ADS)

    Lopez, Jose; Guerrero, Daniel; Freilich, Alfred; Ramoino, Luca; Seton Hall University Team; Degremont Technologies-Ozonia Team

    2013-09-01

    Ozone (O3) is widely used for applications ranging from various industrial chemical synthesis processes to large-scale water treatment. The consequent surge in world-wide demand has brought about the requirement for ozone generation at the rate of several hundreds grams per kilowatt hour (g/kWh). For many years, ozone has been generated by means of dielectric barrier discharges (DBD), where a high-energy electric field between two electrodes separated by a dielectric and gap containing pure oxygen or air produce various microplasmas. The resultant microplasmas provide sufficient energy to dissociate the oxygen molecules while allowing the proper energetics channels for the formation of ozone. This presentation will review the current power schemes used for large-scale ozone generation and explore the use of high-voltage nanosecond pulses with reduced electric fields. The created microplasmas in a high reduced electric field are expected to be more efficient for ozone generation. This is confirmed with the current results of this work which observed that the efficiency of ozone generation increases by over eight time when the rise time and pulse duration are shortened. Department of Physics, South Orange, NJ, USA.

  6. Pulsed power produced counter-propagating supersonic plasma jets

    NASA Astrophysics Data System (ADS)

    Krauland, Christine; Valenzuela, J.; Collins, G.; Mariscal, D.; Narkis, J.; Krasheninnikov, I.; Haque, S.; Hammel, B.; Wallace, M.; Covington, A.; Beg, F.

    2015-11-01

    High-Mach-number, ionized, flowing gases are ubiquitous in the universe, and in many astrophysical environments they take the shape of highly collimated and unidirectional jets. Pulsed power current drivers provide the opportunity to create plasma jets while achieving conditions required to explore radiative cooling, magnetic field advection, shock formation and microinstabilities, all of which are important in the astrophysical environment. We present results from an experimental campaign carried out with the ZEBRA driver (long pulse mode: 0.5 MA in 200 ns current rise) at the Nevada Terawatt Facility where we have performed a comprehensive study of the physics of conical wire array outflows. We have implemented a double conical array configuration in which two counter-propagating jets are produced. Characterization of the jets was done with Faraday rotation, interferometry and an optical streak camera. We will present available data comparing two wire materials (Al and Cu) and the shock formation in different parameter regimes. The work is funded by the Department of Energy Grant No. DE-SC0001063 and DE-NA0001995.

  7. Update on PHELIX Pulsed-Power Hydrodynamics Experiments and Modeling

    NASA Astrophysics Data System (ADS)

    Rousculp, Christopher; Reass, William; Oro, David; Griego, Jeffery; Turchi, Peter; Reinovsky, Robert; Devolder, Barbara

    2013-10-01

    The PHELIX pulsed-power driver is a 300 kJ, portable, transformer-coupled, capacitor bank capable of delivering 3-5 MA, 10 μs pulse into a low inductance load. Here we describe further testing and hydrodynamics experiments. First, a 4 nH static inductive load has been constructed. This allows for repetitive high-voltage, high-current testing of the system. Results are used in the calibration of simple circuit models and numerical simulations across a range of bank charges (+/-20 < V0 < +/-40 kV). Furthermore, a dynamic liner-on-target load experiment has been conducted to explore the shock-launched transport of particulates (diam. ~ 1 μm) from a surface. The trajectories of the particulates are diagnosed with radiography. Results are compared to 2D hydro-code simulations. Finally, initial studies are underway to assess the feasibility of using the PHELIX driver as an electromagnetic launcher for planer shock-physics experiments. Work supported by United States-DOE under contract DE-AC52-06NA25396.

  8. Mach-Zehnder Recording Systems for Pulsed Power Diagnostics

    SciTech Connect

    Miller, E K; McKenna, I; Macrum, G; Baker, D; Tran, V; Rodriguez, E; Kaufman, M I; Tibbits, A; Silbernagel, C T; Waltman, T B; Herrmann, H W; Kim, Y H; Mack, J M; Young, C S; Caldwell, S E; Evans, S C; Sedillo, T J; Stoeffl, W; Grafil, E; Liebman, J; Beeman, B; Watts, P; Carpenter, A; Horsfied, C J; Rubery, M S; Chandler, G A; Torres, J A; Smelser, R M

    2012-10-01

    Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as Z-R at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History (GRH) diagnostic at OMEGA and NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

  9. CENTER FOR PULSED POWER DRIVEN HIGH ENERGY DENSITY PLASMA STUDIES

    SciTech Connect

    Professor Bruce R. Kusse; Professor David A. Hammer

    2007-04-18

    This annual report summarizes the activities of the Cornell Center for Pulsed-Power-Driven High-Energy-Density Plasma Studies, for the 12-month period October 1, 2005-September 30, 2006. This period corresponds to the first year of the two-year extension (awarded in October, 2005) to the original 3-year NNSA/DOE Cooperative Agreement with Cornell, DE-FC03-02NA00057. As such, the period covered in this report also corresponds to the fourth year of the (now) 5-year term of the Cooperative Agreement. The participants, in addition to Cornell University, include Imperial College, London (IC), the University of Nevada, Reno (UNR), the University of Rochester (UR), the Weizmann Institute of Science (WSI), and the P.N. Lebedev Physical Institute (LPI), Moscow. A listing of all faculty, technical staff and students, both graduate and undergraduate, who participated in Center research activities during the year in question is given in Appendix A.

  10. Optical diagnostics for high power pulsed underwater electrical discharge characterization

    NASA Astrophysics Data System (ADS)

    Deroy, J.; Claverie, A.; Avrillaud, G.; Boustie, M.; Mazanchenko, E.; Assous, D.; Chuvatin, A.

    2014-05-01

    In order to evaluate the behavior of a high power pulsed underwater electrical discharge, and especially characterize the pressure generated by such a discharge, we implemented several optical diagnostics. We first observed directly the expansion of the plasma produced by the dielectric breakdown of the water between the electrodes and the resulting gaseous pulsating bubble. This observation led to an estimate of the pressure inside the bubble with respect to time. We then visualized the propagation of the pressure wave generated by the discharge with shadowgraph and Schlieren setup. The obtained velocity was then used to evaluate the theoretical maximum pressure at the pressure front. Finally, we measured the velocity induced by the pressure wave on a thin aluminum disk with a heterodyne velocimeter and used numerical simulation to obtain a temporal form of pressure. These methods and results can be used to develop and assess performances of processes using underwater electrical discharges to generate pressure waves such as electrohydraulic forming.

  11. Optical Diagnostics For High Power Pulsed Underwater Electrical Discharge Characterization

    NASA Astrophysics Data System (ADS)

    Deroy, Julien; Avrillaud, Gilles; Boustie, Michel; Claverie, Alain; Mazanchenko, Ekaterina; Assous, David; Chuvatin, Alexander

    2013-06-01

    In order to evaluate the behavior of a high power pulsed underwater electrical discharge, and especially characterize the pressure generated by such a discharge, we implemented several optical diagnostics. We first observed directly the expansion of the plasma produced by the dielectric breakdown of the water between the electrodes and the resulting gaseous pulsating bubble. This observation led to an estimate of the pressure inside the bubble with respect to time. We then visualized the propagation of the pressure wave generated by the discharge with shadowgraphy and Schlieren set-up. The obtained velocity was then used to evaluate the theoretical maximum pressure at the pressure front. Finally, we measured the velocity induced by the pressure wave on a thin aluminum disk with a heterodyne velocimeter and used numerical simulation to obtain a temporal form of pressure. These methods and results can be used to develop and assess performances of processes using underwater electrical discharges to generate pressure waves such as electrohydraulic forming.

  12. System and method for advanced power management

    DOEpatents

    Atcitty, Stanley; Symons, Philip C.; Butler, Paul C.; Corey, Garth P.

    2009-07-28

    A power management system is provided that includes a power supply means comprising a plurality of power supply strings, a testing means operably connected to said plurality of power supply strings for evaluating performance characteristics of said plurality of power supply strings, and a control means for monitoring power requirements and comprising a switching means for controlling switching of said plurality of power supply strings to said testing means.

  13. Generation of high-power nanosecond pulses from laser diode-pumped Nd:YAG lasers

    NASA Technical Reports Server (NTRS)

    Chan, Kinpui

    1988-01-01

    Simulation results are used to compare the pulse energy levels and pulse energy widths that can be achieved with LD-pumped Nd:YAG lasers for both the pulse-transmission mode (PTM) and pulse-reflection mode (PRM) Q-switching methods for pulse energy levels up to hundreds of microjoules and pulse widths as short as 1 ns. It is shown that high-power pulses with pulse widths as short as 1 ns can be generated with PTM Q-switched in LD-pumped Nd:YAG lasers. With the PRM Q-switching method, pulse widths as short as 2 ns and pulse energy at the level of a few hundred microjoules can also be achieved but require pumping with 8-10-mJ AlGaAs laser diode arrays.

  14. Spacecraft Impacts with Advanced Power and Electric Propulsion

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.; Oleson, Steven R.

    2000-01-01

    A study was performed to assess the benefits of advanced power and electric propulsion systems for various space missions. Advanced power technologies that were considered included multiband gap and thin-film solar arrays, lithium batteries, and flywheels. Electric propulsion options included Hall effect thrusters and Ion thrusters. Several mission case studies were selected as representative of future applications for advanced power and propulsion systems. These included a low altitude Earth science satellite, a LEO communications constellation, a GEO military surveillance satellite, and a Mercury planetary mission. The study process entailed identification of overall mission performance using state-of-the-art power and propulsion technology, enhancements made possible with either power or electric propulsion advances individually, and the collective benefits realized when advanced power and electric propulsion are combined. Impacts to the overall spacecraft included increased payload, longer operational life, expanded operations and launch vehicle class step-downs.

  15. Electromagnetic pulse research on electric power systems: Program summary and recommendations. Power Systems Technology Program

    SciTech Connect

    Barnes, P.R.; McConnell, B.W.; Van Dyke, J.W.; Tesche, F.M.; Vance, E.F.

    1993-01-01

    A single nuclear detonation several hundred kilometers above the central United States will subject much of the nation to a high-altitude electromagnetic pulse (BENT). This pulse consists of an intense steep-front, short-duration transient electromagnetic field, followed by a geomagnetic disturbance with tens of seconds duration. This latter environment is referred to as the magnetohydrodynamic electromagnetic pulse (NMENT). Both the early-time transient and the geomagnetic disturbance could impact the operation of the nation`s power systems. Since 1983, the US Department of Energy has been actively pursuing a research program to assess the potential impacts of one or more BENT events on the nation`s electric energy supply. This report summarizes the results of that program and provides recommendations for enhancing power system reliability under HENT conditions. A nominal HENP environment suitable for assessing geographically large systems was developed during the program and is briefly described in this report. This environment was used to provide a realistic indication of BEMP impacts on electric power systems. It was found that a single high-altitude burst, which could significantly disturb the geomagnetic field, may cause the interconnected power network to break up into utility islands with massive power failures in some areas. However, permanent damage would be isolated, and restoration should be possible within a few hours. Multiple bursts would likely increase the blackout areas, component failures, and restoration time. However, a long-term blackout of many months is unlikely because major power system components, such as transformers, are not likely to be damaged by the nominal HEND environment. Moreover, power system reliability, under both HENT and normal operating conditions, can be enhanced by simple, and often low cost, modifications to current utility practices.

  16. Advanced application flight experiment breadboard pulse compression radar altimeter program

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Design, development and performance of the pulse compression radar altimeter is described. The high resolution breadboard system is designed to operate from an aircraft at 10 Kft above the ocean and to accurately measure altitude, sea wave height and sea reflectivity. The minicomputer controlled Ku band system provides six basic variables and an extensive digital recording capability for experimentation purposes. Signal bandwidths of 360 MHz are obtained using a reflective array compression line. Stretch processing is used to achieve 1000:1 pulse compression. The system range command LSB is 0.62 ns or 9.25 cm. A second order altitude tracker, aided by accelerometer inputs is implemented in the system software. During flight tests the system demonstrated an altitude resolution capability of 2.1 cm and sea wave height estimation accuracy of 10%. The altitude measurement performance exceeds that of the Skylab and GEOS-C predecessors by approximately an order of magnitude.

  17. Advanced modeling techniques in application to plasma pulse treatment

    NASA Astrophysics Data System (ADS)

    Pashchenko, A. F.; Pashchenko, F. F.

    2016-06-01

    Different approaches considered for simulation of plasma pulse treatment process. The assumption of a significant non-linearity of processes in the treatment of oil wells has been confirmed. Method of functional transformations and fuzzy logic methods suggested for construction of a mathematical model. It is shown, that models, based on fuzzy logic are able to provide a satisfactory accuracy of simulation and prediction of non-linear processes observed.

  18. Ultrashort Electron Beam Pulses and Diagnosis by Advanced Linear Accelerators

    NASA Astrophysics Data System (ADS)

    Uesaka, M.; Iijima, H.; Muroya, Y.; Watanabe, T.; Hosokai, T.

    2003-08-01

    240fs 18 MeV low emittance(6 pai mm.mrad) electron beam was generated and its pulse shape was diagnosed by the S-band laser photocathode RF gun and linac. The maximum charge per bunch was 7 nC. This electron pulse was synchronized with 100fs 0.3TW Ti:Sapphire laser with the timing jitter of 330fs(rms). Recently, the Cu cathode(QE10∧-4) was replaced by Mg cathode(QE10∧-3). This system is utilized for radiation chemistry analysis for supercritical water. We have adopted the four diagnostic methods(femtosecond streak camera, coherent transition radiation interferometer, far-infrared polychromator, fluctuation method) and checked their time-resolution precisely. Further, we are doing the experiment on laser plasma cathode by 12TW 50fs laser and He gas jet. Laser plasma wakefield acceleration and electron injection via wavebreaking are planned. We have developed a new theory of self-injection scheme to generate ˜10fs electron pulse. We have already succeeded in observing 40 MeV low emittance electron beam of 14 nC.

  19. Pulse power enhancement of the anaerobic digester process

    SciTech Connect

    Greene, H.W.

    1996-12-31

    A pilot study of the effects of Pulse Power Processing on an anaerobic digester system was completed at the Decatur Utilities Dry Creek Wastewater Treatment Plant, in Decatur Alabama, in September, 1995. This patented method generates several significant effects when all biosolids material is treated as it enters the anaerobic system. Intense, high peak-power plasma arcs are created, one at each end of the parabolic processing chamber, to produce an amplified synergy of alterations to the digester sludge flowing between them. The millisecond electric discharges generate localized temperatures as high as 30,000 K{degrees}, followed by a rapid cooling of the flowing liquid, which produces acoustic shock waves with pressures approaching 5,000 atmospheres. This destructive force: ruptures many of the cell walls of the bacteria and other single-cell organisms, releasing their vacuole fluids; breaks carbon bonds to form smaller organic compounds; and pulverizes large particle conglomerates, increasing the overall surface area of the solids. These beneficial results serve to boost the nutrient source for the anaerobes in the digester. In conjunction with LTV radiation, the formation of excited chemical radicals (including OH{sup -}), and the changes in ionic charge through alteration of the zeta potential, the bioreactor system is turbocharged to enhance the conversion of volatile biosolids to methane gas, which is the natural respiratory by-product of anaerobic digestion.

  20. Short pulse, high power microwave radiation source with a laser-induced sheet plasma mirror

    SciTech Connect

    Higashiguchi, Takeshi; Yugami, Noboru

    2009-05-01

    We have demonstrated the short pulse, high power microwave radiation source using an ultraviolet laser-induced sheet plasma mirror in a gas-filled x-band rectangular waveguide from the conventional microwave sources and components. A laser-induced sheet plasma with an overdense plasma acts as a plasma mirror. The long pulse propagating in the gas-filled waveguide was sliced by the sheet plasma mirror at two different points along the waveguide. We observed about twice the power of the pulse by adding the two sliced microwave pulses produced by this scheme. A maximum peak power of 200 kW with a pulse duration of 10 ns (full width at half maximum) from the long microwave pulse source with a pulse duration of 0.8 mus was observed.

  1. Development of compact rapid charging power supply for capacitive energy storage in pulsed power drivers

    NASA Astrophysics Data System (ADS)

    Sharma, Surender Kumar; Shyam, Anurag

    2015-02-01

    High energy capacitor bank is used for primary electrical energy storage in pulsed power drivers. The capacitors used in these pulsed power drivers have low inductance, low internal resistance, and less dc life, so it has to be charged rapidly and immediately discharged into the load. A series resonant converter based 45 kV compact power supply is designed and developed for rapid charging of the capacitor bank with constant charging current up to 150 mA. It is short circuit proof, and zero current switching technique is used to commute the semiconductor switch. A high frequency resonant inverter switching at 10 kHz makes the overall size small and reduces the switching losses. The output current of the power supply is limited by constant on-time and variable frequency switching control technique. The power supply is tested by charging the 45 kV/1.67 μF and 15 kV/356 μF capacitor banks. It has charged the capacitor bank up to rated voltage with maximum charging current of 150 mA and the average charging rate of 3.4 kJ/s. The output current of the power supply is limited by reducing the switching frequency at 5 kHz, 3.3 kHz, and 1.7 kHz and tested with 45 kV/1.67 μF capacitor bank. The protection circuit is included in the power supply for over current, under voltage, and over temperature. The design details and the experimental testing results of the power supply for resonant current, output current, and voltage traces of the power supply with capacitive, resistive, and short circuited load are presented and discussed.

  2. Development of compact rapid charging power supply for capacitive energy storage in pulsed power drivers.

    PubMed

    Sharma, Surender Kumar; Shyam, Anurag

    2015-02-01

    High energy capacitor bank is used for primary electrical energy storage in pulsed power drivers. The capacitors used in these pulsed power drivers have low inductance, low internal resistance, and less dc life, so it has to be charged rapidly and immediately discharged into the load. A series resonant converter based 45 kV compact power supply is designed and developed for rapid charging of the capacitor bank with constant charging current up to 150 mA. It is short circuit proof, and zero current switching technique is used to commute the semiconductor switch. A high frequency resonant inverter switching at 10 kHz makes the overall size small and reduces the switching losses. The output current of the power supply is limited by constant on-time and variable frequency switching control technique. The power supply is tested by charging the 45 kV/1.67 μF and 15 kV/356 μF capacitor banks. It has charged the capacitor bank up to rated voltage with maximum charging current of 150 mA and the average charging rate of 3.4 kJ/s. The output current of the power supply is limited by reducing the switching frequency at 5 kHz, 3.3 kHz, and 1.7 kHz and tested with 45 kV/1.67 μF capacitor bank. The protection circuit is included in the power supply for over current, under voltage, and over temperature. The design details and the experimental testing results of the power supply for resonant current, output current, and voltage traces of the power supply with capacitive, resistive, and short circuited load are presented and discussed. PMID:25725838

  3. Design and fabrication of hollow-core photonic crystal fibers for high-power ultrashort pulse transportation and pulse compression.

    PubMed

    Wang, Y Y; Peng, Xiang; Alharbi, M; Dutin, C Fourcade; Bradley, T D; Gérôme, F; Mielke, Michael; Booth, Timothy; Benabid, F

    2012-08-01

    We report on the recent design and fabrication of kagome-type hollow-core photonic crystal fibers for the purpose of high-power ultrashort pulse transportation. The fabricated seven-cell three-ring hypocycloid-shaped large core fiber exhibits an up-to-date lowest attenuation (among all kagome fibers) of 40 dB/km over a broadband transmission centered at 1500 nm. We show that the large core size, low attenuation, broadband transmission, single-mode guidance, and low dispersion make it an ideal host for high-power laser beam transportation. By filling the fiber with helium gas, a 74 μJ, 850 fs, and 40 kHz repetition rate ultrashort pulse at 1550 nm has been faithfully delivered at the fiber output with little propagation pulse distortion. Compression of a 105 μJ laser pulse from 850 fs down to 300 fs has been achieved by operating the fiber in ambient air.

  4. Thulium-doped fiber chirped-pulse amplification system with 2 GW of peak power.

    PubMed

    Gaida, C; Gebhardt, M; Stutzki, F; Jauregui, C; Limpert, J; Tünnermann, A

    2016-09-01

    Thulium-doped fibers with ultra large mode-field areas offer new opportunities for the power scaling of mid-IR ultrashort-pulse laser sources. Here, we present a laser system delivering a pulse-peak power of 2 GW and a nearly transform-limited pulse duration of 200 fs in combination with 28.7 W of average power. This performance level has been achieved by optimizing the pulse shape, reducing the overlap with atmospheric absorption lines, and incorporating a climate chamber to reduce the humidity of the atmospheric environment. PMID:27607990

  5. Compact nanosecond pulsed power technology with applications to biomedical engineering, biology, and medicine

    NASA Astrophysics Data System (ADS)

    Gu, Xianyue

    Pulsed power refers to a technology that is suited to drive applications requiring very large power pulses in short bursts. Its recent emerging applications in biology demand compact systems with high voltage electric pulses in nanosecond time range. The required performance of a pulsed power system is enabled by the combined efforts in its design at three levels: efficient and robust devices at the component level, novel circuits and architecture at the system level, and effective interface techniques to deliver fast pulses at the application level. At the component level we are concerned with the power capability of switches and the energy storage density of capacitors. We compare semiconductor materials - Si, GaAs, GaN and SiC - for high voltage, high current, fast FET-type switches, and study the effects of their intrinsic defects on electrical characteristics. We present the fabrication of BST film capacitors on silicon substrates by pulsed laser deposition, and investigate their potential application to high voltage, high energy density capacitors. At the system level, a nanosecond pulse generator is developed for electroperturbation of biological cells. We model and design a Blumlein PFN (Pulse Forming Network) to deliver nanosecond pulses to a cuvette load. The resonant circuit employs four parallel 100 A MOSFET switches and charges the PFN to 8 kV within 350 ns. At the application level, in order to controllably deliver nanosecond electric pulses into tumors, we have designed, fabricated, and tested impulse catheter devices. Frequency responds, breakdown voltages and effective volumes of catheters are evaluated. With comparison of simulation and experimental results, we further develop dielectric dispersion models for RPMI. This thesis presents a set of strongly interdisciplinary studies based on pulsed power technology and towards biomedical applications. Addressed issues include from fundamental materials studies to application engineering designs that

  6. The Advanced Composition Explorer power subsystem

    SciTech Connect

    Panneton, P.E.; Tarr, J.E.; Goliaszewski, L.T.

    1998-07-01

    The Johns Hopkins University Applied Physics Laboratory, under contract with NASA Goddard Space Flight Center, has designed and launched the Advanced Composition Explorer (ACE) spacecraft. ACE is a scientific observatory housing ten instruments, and is located in a halo orbit about the L1 Sun-Earth libration point. ACE is providing real-time solar wind monitoring and data on elemental and isotopic matter of solar and galactic origin. The ACE Electrical Power Subsystem (EPS) is a fault tolerant, solar powered, shunt regulated, direct energy transfer architecture based on the Midcourse Space Experiment (MSX) EPS. The differences are that MSX used oriented solar arrays with a nickel hydrogen-battery defined bus, while ACE uses fixed solar panels with a regulated bus decoupled from its nickel cadmium (NiCd) battery. Also, magnetometer booms are mounted on two of the four ACE solar panels. The required accuracy of the magnetometers impose severe requirements on the magnetic fields induced by the solar array. Other noteworthy features include a solar cell degradation experiment, in-flight battery reconditioning, a battery requalified to a high vibrational environment, and an adjustable bus voltage setpoint. The four solar panels consist of aluminum honeycomb substrates covered with 15.1% efficient silicon cells. The cells are strung using silver interconnects and are back-wired to reduce magnetic emissions below 0.1nT. Pyrotechnic actuated, spring loaded hinges deploy the panels after spacecraft separation from the Delta II launch vehicle. Solar cell experiments on two of the panels track cell performance degradation at L1, and also distinguish any hydrazine impingement degradation which may be caused by the thrusters. Each solar panel uses a digital shunt box, containing blocking diodes and MOSFETs, for short-circuit control of its 5 solar strings. A power box contains redundant analog MOSFET shunts, the 90% efficient boost regulator, and redundant battery chargers

  7. Advance Power Technology Demonstration on Starshine 3

    NASA Technical Reports Server (NTRS)

    Jenkins, Phillip; Scheiman, David; Wilt, David; Raffaelle, Ryne; Button, Robert; Smith, Mark; Kerslake, Thomas; Miller, Thomas

    2002-01-01

    The Starshine 3 satellite will carry several power technology demonstrations. Since Starshine 3 is primarily a passive experiment and does not need electrical power to successfully complete its mission, the requirement for a highly reliable power system is greatly reduced. This creates an excellent opportunity to test new power technologies. Several government and commercial interests have teamed up to provide Starshine 3 with a small power system using state-of-the-art components. Starshine 3 will also fly novel integrated microelectronic power supplies (IMPS) for evaluation.

  8. HIGH ENERGY PULSED POWER SYSTEM FOR AGS SUPER NEUTRINO FOCUSING HORN.

    SciTech Connect

    ZHANG, S.Y.; SANDBERG, J.; WENG, W.-T.

    2005-05-16

    This paper present a preliminary design of a 300 kA, 2.5 Hz pulsed power system. This system will drive the focusing horn of proposed Brookhaven AGS Neutrino Super Beam Facility for Very Long Baseline Neutrino Oscillation Experiment. The peak output power of the horn pulsed power system will reach Giga-watts, and the upgraded AGS will be capable of delivering 1 MW in beam power.

  9. Residual gas analysis for long-pulse, advanced tokamak operation.

    PubMed

    Klepper, C C; Hillis, D L; Bucalossi, J; Douai, D; Oddon, P; Vartanian, S; Colas, L; Manenc, L; Pégourié, B

    2010-10-01

    A shielded residual gas analyzer (RGA) system on Tore Supra can function during plasma operation and is set up to monitor the composition of the neutral gas in one of the pumping ducts of the toroidal pumped limited. This "diagnostic RGA" has been used in long-pulse (up to 6 min) discharges for continuous monitoring of up to 15 masses simultaneously. Comparison of the RGA-measured evolution of the H(2)/D(2) isotopic ratio in the exhaust gas to that measured by an energetic neutral particle analyzer in the plasma core provides a way to monitor the evolution of particle balance. RGA monitoring of corrective H(2) injection to maintain proper minority heating is providing a database for improved ion cyclotron resonance heating, potentially with RGA-base feedback control. In very long pulses (>4 min) absence of significant changes in the RGA-monitored, hydrocarbon particle pressures is an indication of proper operation of the actively cooled, carbon-based plasma facing components. Also H(2) could increase due to thermodesorption of overheated plasma facing components.

  10. Residual gas analysis for long-pulse, advanced tokamak operation

    SciTech Connect

    Klepper, C. C.; Hillis, D. L.; Bucalossi, J.; Douai, D.; Oddon, P.; Vartanian, S.; Colas, L.; Manenc, L.; Pegourie, B.

    2010-10-15

    A shielded residual gas analyzer (RGA) system on Tore Supra can function during plasma operation and is set up to monitor the composition of the neutral gas in one of the pumping ducts of the toroidal pumped limited. This ''diagnostic RGA'' has been used in long-pulse (up to 6 min) discharges for continuous monitoring of up to 15 masses simultaneously. Comparison of the RGA-measured evolution of the H{sub 2}/D{sub 2} isotopic ratio in the exhaust gas to that measured by an energetic neutral particle analyzer in the plasma core provides a way to monitor the evolution of particle balance. RGA monitoring of corrective H{sub 2} injection to maintain proper minority heating is providing a database for improved ion cyclotron resonance heating, potentially with RGA-base feedback control. In very long pulses (>4 min) absence of significant changes in the RGA-monitored, hydrocarbon particle pressures is an indication of proper operation of the actively cooled, carbon-based plasma facing components. Also H{sub 2} could increase due to thermodesorption of overheated plasma facing components.

  11. Residual Gas Analysis for Long-Pulse, Advanced Tokamak Operation

    SciTech Connect

    Klepper, C Christopher; Hillis, Donald Lee; Bucalossi, J.; Douai, D.; OddonCEA, IRFM, P.; VartanianCEA-Cadarach, S.; Colas, L.; Manenc, L.; Pegourie, B.

    2010-01-01

    A shielded residual gas analyzer RGA system on Tore Supra can function during plasma operation and is set up to monitor the composition of the neutral gas in one of the pumping ducts of the toroidal pumped limited. This diagnostic RGA has been used in long-pulse up to 6 min discharges for continuous monitoring of up to 15 masses simultaneously. Comparison of the RGA-measured evolution of the H2 /D2 isotopic ratio in the exhaust gas to that measured by an energetic neutral particle analyzer in the plasma core provides a way to monitor the evolution of particle balance. RGA monitoring of corrective H2 injection to maintain proper minority heating is providing a database for improved ion cyclotron resonance heating, potentially with RGA-base feedback control. In very long pulses 4 min absence of significant changes in the RGA-monitored, hydrocarbon particle pressures is an indication of proper operation of the actively cooled, carbon-based plasma facing components. Also H2 could increase due to thermodesorption of overheated plasma facing components. 2010 American Institute of Physics.

  12. Residual gas analysis for long-pulse, advanced tokamak operationa)

    NASA Astrophysics Data System (ADS)

    Klepper, C. C.; Hillis, D. L.; Bucalossi, J.; Douai, D.; Oddon, P.; Vartanian, S.; Colas, L.; Manenc, L.; Pégourié, B.

    2010-10-01

    A shielded residual gas analyzer (RGA) system on Tore Supra can function during plasma operation and is set up to monitor the composition of the neutral gas in one of the pumping ducts of the toroidal pumped limited. This "diagnostic RGA" has been used in long-pulse (up to 6 min) discharges for continuous monitoring of up to 15 masses simultaneously. Comparison of the RGA-measured evolution of the H2/D2 isotopic ratio in the exhaust gas to that measured by an energetic neutral particle analyzer in the plasma core provides a way to monitor the evolution of particle balance. RGA monitoring of corrective H2 injection to maintain proper minority heating is providing a database for improved ion cyclotron resonance heating, potentially with RGA-base feedback control. In very long pulses (>4 min) absence of significant changes in the RGA-monitored, hydrocarbon particle pressures is an indication of proper operation of the actively cooled, carbon-based plasma facing components. Also H2 could increase due to thermodesorption of overheated plasma facing components.

  13. Basic science with pulsed power & some off-the-wall ideas

    SciTech Connect

    Solem, J.C.

    1995-04-01

    This paper discusses aspects of pulsed power for use in basic research, with a principal emphasis on ATLAS, a planned 36-MJ pulsed-power machine with a circular architechture designed primarily for z-pinch implosion of cylindrical foils. The objective of the paper is to give an overview and touch on subjects which might test the limits of this technology.

  14. Z: A Fast Pulsed Power Generator for Ultra-High Magnetic Field Generation

    SciTech Connect

    Asay, J.R.; Bailey, J.E.; Bernard, M.A.; Hall, C.A.; McDaniel, D.H.; Spielman, R.B.; Struve, K.W.; Stygar, W.A.

    1998-11-04

    Advances in fast, pulsed-power technologies have resulted in the development of very high current drivers that have current rise times - 100 ns. The largest such pulsed power drive r today is the new Z accelerator located at Sandia National Laboratories in Albuquerque, New Mexico. Z is capable of delivering more than 20 MA with a time-to-peak of 105 ns to low inductance (- 1 nH)loads. Such large drivers are capable of directly generating magnetic fields approaching 3 kT in small, 1 -cm3, volumes. In addition to direct field generation, Z can be used to compress an applied, axial seed field with a plasma. Flux compression scheme~: are not new and are, in fact, the basis of all explosive flux-compression generators but we propose the use of plasma armatures rather than solid, conducting armatures. We will present experimental results from the Z accelerator in which magnetic fields - 2 kT are generated and measured with several diagnostics. Issues such as energy loss in solid conductors and dynamic response of current-carrying conductors to very large magnetic fields will be reviewed in context with Z experiments. We will describe planned flux-compression experiments that are expected to create the highest-magnitude uniform-field volumes yet attained in the laboratory.

  15. Antimicrobial nanospheres thin coatings prepared by advanced pulsed laser technique

    PubMed Central

    Holban, Alina Maria; Grumezescu, Valentina; Vasile, Bogdan Ştefan; Truşcă, Roxana; Cristescu, Rodica; Socol, Gabriel; Iordache, Florin

    2014-01-01

    Summary We report on the fabrication of thin coatings based on polylactic acid-chitosan-magnetite-eugenol (PLA-CS-Fe3O4@EUG) nanospheres by matrix assisted pulsed laser evaporation (MAPLE). Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) investigation proved that the homogenous Fe3O4@EUG nanoparticles have an average diameter of about 7 nm, while the PLA-CS-Fe3O4@EUG nanospheres diameter sizes range between 20 and 80 nm. These MAPLE-deposited coatings acted as bioactive nanosystems and exhibited a great antimicrobial effect by impairing the adherence and biofilm formation of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) bacteria strains. Moreover, the obtained nano-coatings showed a good biocompatibility and facilitated the normal development of human endothelial cells. These nanosystems may be used as efficient alternatives in treating and preventing bacterial infections. PMID:24991524

  16. Recent Advances in Pulsed Laser Deposition of Epitaxial Layers

    NASA Astrophysics Data System (ADS)

    Venkatesan, T.

    1997-03-01

    While pulsed laser deposition became popular with the emergance of high temperature superconductors the technique has been rapidly deployed in the development of a number of other oxide materials such as ferroelectric titanates, colossal magneto-resistive manganites, electro-optic tantalates and niobates(Pulsed Laser Deposition of Thin Films, eds. D.B. Chrisey and G.K. Hubler, John Wiley and Sons, New York, 1994.). Most recently this technique has also been used succesfully for the fabrication of a variety of semiconductor materials such as sulfides and nitrides with the Group II and Group III cationic species respectively. Details on the fabrication of a hetero-epitaxial family of AlN (Eg = 6.2 eV), GaN (Eg = 3.6 eV) and TiN (metallic with ρ = 14 μΩ-cm) on sapphire substrates will be discussed. Interesting results in the integration of oxides both as buffer layers for improved epitaxy on sapphire as well as conducting layers for both Ohmic and Schottky contacts on the nitrides will be discussed. Some recent details on the elimination of particles in the fabricated films by the use of off-axis deposition and by the use of a shadow mask and scalling issues will be elaborated on. Work in collaboration with R. Ramesh, R. P. Sharma, M. Rajeswari, Z. W. Dong, Z. Trajanovic, V. Talyanski, R. D. Vispute, L. Salamanca-Riba, (UMD); K. Jones, M. Wood, R. Lareau (ARL-SEDD, Fort Monmouth); M. Spenser (Howard U); S. M. Green, S. Harshavardhan and A. Pique (Neocera, Inc.).

  17. The Wakefield Effects of Pulsed Crab Cavities at the Advanced Photon Source for Short-X-ray Pulse Generation

    SciTech Connect

    Chae, Y.-C.; Waldschmidt, G.; Dolgashev, V.; /SLAC

    2007-11-07

    In recent years we have explored the application to the Advanced Photon Source (APS) of Zholents' crab-cavity based scheme for production of short x-ray pulses. As a near-term project, the APS has elected to pursue a pulsed system using room-temperature cavities. The cavity design has been optimized to heavily damp parasitic modes while maintaining large shunt impedance for the deflecting dipole mode. We evaluated a system consisting of three crab cavities as an impedance source and determined their effect on the single- and multi-bunch instabilities. In the single-bunch instability we used the APS impedance model as the reference system in order to predict the overall performance of the ring when the crab cavities are installed in the future. For multi-bunch instabilities we used a realistic fill pattern, including hybrid-fill, and tracked multiple bunches where each bunch was treated as soft in distribution.

  18. A fast pulsed power source applied to treatment of conducting liquids and air

    SciTech Connect

    Heesch, E.J.M. van; Pemen, A.J.M.; Huijbrechts, P.A.H.J.; Laan, P.C.T. van der; Ptasinski, K.J.; Zanstra, G.J.; Jong, P. de

    2000-02-01

    Two pilot pulsed power sources were developed for fundamental investigations and industrial demonstrations of treatment of conducting liquids. The developed heavy-duty power sources have an output voltage of 100 kV (rise time 10 ns, pulse duration 150 ns, pulse repetition rate maximum 1,000 pps). A pulse energy of 0.5--3 J/pulse and an average pulse power of 1.5 kW have been achieved with an efficiency of about 80%. In addition, adequate electromagnetic compatibility is achieved between the high-voltage pulse sources and the surrounding equipment. Various applications, such as the use of pulsed electric fields (PEF's) or pulsed corona discharges for inactivation of microorganisms in liquids or air, have been tested in the laboratory. For PEF treatment, homogeneous electric fields in the liquid of up to 70 kV/cm at a pulse repetition rate of 10--400 pps could be achieved. The inactivation is found to be 85 kJ/L per log reduction for Pseudomonas fluorescens and 500 kJ/L per log reduction for spores of Bacillus cereus. Corona directly applied to the liquid is found to be more efficient than PEF. With direct corona they achieve 25 kJ/L per log reduction for both Gram positive and Gram negative bacteria. For air disinfection using their corona pulse source, the measured efficiencies are excellent: 2 J/L per log reduction.

  19. Electromagnetic pulse (EMP) interaction with electric power systems. Power Systems Technology Program. Final report

    SciTech Connect

    Zaininger, H.W.

    1984-08-01

    A high altitude nuclear burst, detonated at a height of 50 km or more, causes two types of electromagnetic pulses (EMP) - high altitude EMP (HEMP) and magnetohydrodynamic EMP (MHD-EMP). This high altitude EMP scenario is of principal concern when assessing the effects of EMP on electric power systems, because the total United States can be simultaneously illuminated by HEMP and MHD-EMP can cover a large area of up to several hundred kilometers in diameter. The purpose of this project was first to define typical electrical power system characteristics for EMP analysis, and second, to determine reasonable worst case EMP induced surges on overhead electric power system transmission and distribution lines for reasonable assumptions, using unclassified HEMP and MHD-EMP electric field waveforms.

  20. Exploring the limits of broadband excitation and inversion: II. Rf-power optimized pulses

    NASA Astrophysics Data System (ADS)

    Kobzar, Kyryl; Skinner, Thomas E.; Khaneja, Navin; Glaser, Steffen J.; Luy, Burkhard

    2008-09-01

    In [K. Kobzar, T.E. Skinner, N. Khaneja, S.J. Glaser, B. Luy, Exploring the limits of broadband excitation and inversion, J. Magn. Reson. 170 (2004) 236-243], optimal control theory was employed in a systematic study to establish physical limits for the minimum rf-amplitudes required in broadband excitation and inversion pulses. In a number of cases, however, experimental schemes are not limited by rf-amplitudes, but by the overall rf-power applied to a sample. We therefore conducted a second systematic study of excitation and inversion pulses of varying pulse durations with respect to bandwidth and rf-tolerances, but this time using a modified algorithm involving restricted rf-power. The resulting pulses display a variety of pulse shapes with highly modulated rf-amplitudes and generally show better performance than corresponding pulses with identical pulse length and rf-power, but limited rf-amplitude. A detailed description of pulse shapes and their performance is given for the so-called power-BEBOP and power-BIBOP pulses.

  1. Advanced power conditioning for maglev systems. Final report

    SciTech Connect

    Nerem, A.; Bowles, E.E.; Chapelle, S.; Callanan, R.J.

    1992-08-01

    The final report contains parametric scaling data and computer models of power conditioning equipment applicable to the design of an advanced maglev system. The power conditioning topologies were selected based on data from a literature search, on characteristics of present power semiconductor technology devices, and on actual performance characterization of designs using a circuit analysis program. The analyses show that GTOs are the best switches for traction drives, input power conditioning equipment, and the braking chopper. At lower power levels, as required for auxiliary power and superconducting coil power conditioning, the IGBT appeared to be the best switch.

  2. Combustion and Magnetohydrodynamic Processes in Advanced Pulse Detonation Rocket Engines

    NASA Astrophysics Data System (ADS)

    Cole, Lord Kahil

    A number of promising alternative rocket propulsion concepts have been developed over the past two decades that take advantage of unsteady combustion waves in order to produce thrust. These concepts include the Pulse Detonation Rocket Engine (PDRE), in which repetitive ignition, propagation, and reflection of detonations and shocks can create a high pressure chamber from which gases may be exhausted in a controlled manner. The Pulse Detonation Rocket Induced Magnetohydrodynamic Ejector (PDRIME) is a modification of the basic PDRE concept, developed by Cambier (1998), which has the potential for performance improvements based on magnetohydrodynamic (MHD) thrust augmentation. The PDRIME has the advantage of both low combustion chamber seeding pressure, per the PDRE concept, and efficient energy distribution in the system, per the rocket-induced MHD ejector (RIME) concept of Cole, et al. (1995). In the initial part of this thesis, we explore flow and performance characteristics of different configurations of the PDRIME, assuming quasi-one-dimensional transient flow and global representations of the effects of MHD phenomena on the gas dynamics. By utilizing high-order accurate solvers, we thus are able to investigate the fundamental physical processes associated with the PDRIME and PDRE concepts and identify potentially promising operating regimes. In the second part of this investigation, the detailed coupling of detonations and electric and magnetic fields are explored. First, a one-dimensional spark-ignited detonation with complex reaction kinetics is fully evaluated and the mechanisms for the different instabilities are analyzed. It is found that complex kinetics in addition to sufficient spatial resolution are required to be able to quantify high frequency as well as low frequency detonation instability modes. Armed with this quantitative understanding, we then examine the interaction of a propagating detonation and the applied MHD, both in one-dimensional and two

  3. Plasma-Enhanced Pulsed Laser Deposition of Wide Bandgap Nitrides for Space Power Applications

    NASA Technical Reports Server (NTRS)

    Triplett, G. E., Jr.; Durbin, S. M.

    2004-01-01

    The need for a reliable, inexpensive technology for small-scale space power applications where photovoltaic or chemical battery approaches are not feasible has prompted renewed interest in radioisotope-based energy conversion devices. Although a number of devices have been developed using a variety of semiconductors, the single most limiting factor remains the overall lifetime of the radioisotope battery. Recent advances in growth techniques for ultra-wide bandgap III-nitride semiconductors provide the means to explore a new group of materials with the promise of significant radiation resistance. Additional benefits resulting from the use of ultra-wide bandgap materials include a reduction in leakage current and higher operating voltage without a loss of energy transfer efficiency. This paper describes the development of a novel plasma-enhanced pulsed laser deposition system for the growth of cubic boron nitride semiconducting thin films, which will be used to construct pn junction devices for alphavoltaic applications.

  4. NASA's Advanced Radioisotope Power Conversion Technology Development Status

    NASA Technical Reports Server (NTRS)

    Anderson, David J.; Sankovic, John; Wilt, David; Abelson, Robert D.; Fleurial, Jean-Pierre

    2007-01-01

    NASA's Advanced Radioisotope Power Systems (ARPS) project is developing the next generation of radioisotope power conversion technologies that will enable future missions that have requirements that cannot be met by either photovoltaic systems or by current radioisotope power systems (RPSs). Requirements of advanced RPSs include high efficiency and high specific power (watts/kilogram) in order to meet future mission requirements with less radioisotope fuel and lower mass so that these systems can meet requirements for a variety of future space applications, including continual operation surface missions, outer-planetary missions, and solar probe. These advances would enable a factor of 2 to 4 decrease in the amount of fuel required to generate electrical power. Advanced RPS development goals also include long-life, reliability, and scalability. This paper provides an update on the contractual efforts under the Radioisotope Power Conversion Technology (RPCT) NASA Research Announcement (NRA) for research and development of Stirling, thermoelectric, and thermophotovoltaic power conversion technologies. The paper summarizes the current RPCT NRA efforts with a brief description of the effort, a status and/or summary of the contractor's key accomplishments, a discussion of upcoming plans, and a discussion of relevant system-level benefits and implications. The paper also provides a general discussion of the benefits from the development of these advanced power conversion technologies and the eventual payoffs to future missions (discussing system benefits due to overall improvements in efficiency, specific power, etc.).

  5. Design and development of a prototype 25 kV, 10 A long pulse Marx modulator for high power klystron

    NASA Astrophysics Data System (ADS)

    Acharya, Mahesh; Shrivastava, Purushottam

    2016-02-01

    Research, design, and development of high average power modulators for the proposed Indian Spallation Neutron Source are in progress at Raja Ramanna Centre for Advanced Technology. With this objective, a prototype of 25 kV, 10 A, 1 ms Marx modulator at repetition rate of 1 Hz has been designed and developed which serves as a proof of principle and technology assessment stage for further development of high repetition rate high voltage high average power modulators. Insulated Gate Bipolar Transistor (IGBT) based modules of 2.8 kV switching capability have been used as main modules. The modulator had 8.2% droop in output voltage pulse without any droop compensation circuit. A droop compensation involving 15 corrector modules has been used to reduce the droop up to 1%. We have used IGBT based 250 V switches to realize the corrector module. A microcontroller based control unit was designed and developed for triggering the main and corrector modules. With this control unit, programmable output pulse has been achieved. Electrical isolation between high voltage circuits and control circuit has been achieved by the use of fiber optic based control signal transmission. Output pulses of 1 ms pulse width, 800 ns rise time, and 5 μs fall time have been achieved. The modulator has advantages of modular design, adjustable pulse width, adjustable rise time, and fall time.

  6. Pulsed photothermal profiling of hypervascular lesions: some recent advances

    NASA Astrophysics Data System (ADS)

    Majaron, Boris; Verkruysse, Wim; Tanenbaum, B. S.; Milner, Thomas E.; Nelson, J. Stuart

    2000-05-01

    Pulsed photothermal radiometry (PPTR) can be used for non- invasive depth profiling of port wine stain (PWS) birthmarks, aimed towards optimizing laser therapy on an individual patient basis. Reconstruction of laser-induced temperature profile from the experimentally obtained radiometric signal involves the skin absorption coefficient in the infrared detection band. In the commonly used 3 - 5 micrometer detection band (InSb), the absorption coefficient varies by two orders of magnitude, while assumed to be constant in the reconstruction algorithms used thus far. We discuss the problem of choosing the effective absorption coefficient value to be used under such conditions. Next, we show how to account explicitly for the strong spectral variation of the infrared absorption coefficient in the image reconstruction algorithm. Performance of such improved algorithm is compared to that of the unaugmented version in a numerical simulation of photothermal profiling. Finally, we analyze implementation of a bandpass filter which limits the detection band to 4.5 - 5 micrometer. This reduces the absorption coefficient variation to a level that permits the use of unaugmented algorithm. An experimental test of the latter approach for in vivo characterization of the depth of PWS lesion and epidermal thickness will be presented, including a novel technique that uses two laser excitation wavelengths in order to separate the epidermal and vascular components of the radiometric signal.

  7. High peak power sub-nanosecond mode-locked pulse characteristics of Nd:GGG laser

    NASA Astrophysics Data System (ADS)

    Zhao, Jia; Zhao, Shengzhi; Li, Tao; Li, Yufei; Yang, Kejian; Li, Guiqiu; Li, Dechun; Qiao, Wenchao; Feng, Chuansheng; Wang, Yonggang

    2015-10-01

    Based on the dual-loss modulation, i.e. electro-optic (EO) modulator and GaAs saturable absorber, a sub-nanosecond mode-locked pulsed Nd:GGG laser with kHz repetition rates is presented for the first time. The repetition rate (0.5-10 kHz) of this pulsed laser is controlled by the modulation rate of EO modulator, so high stability can be obtained. The sub-nanosecond pulse width depends on the mode-locked pulse underneath the Q-switched envelope in the Q-switched mode-locked (QML) laser and high peak power can be generated. The condition on the generation of sub-nanosecond pulse and the needed threshold power for different modulation rates of EO are given. The average output power, the pulse width and the peak power versus pump power for different repetition rates are demonstrated. The shortest pulse width is 426 ps and the highest peak power reaches 239.4 kW. The experimental results show that the dual-loss modulation technology with EO and GaAs saturable absorber in QML laser is an efficient method to generate sub-nanosecond mode-locked pulsed laser with kHz repetition rates.

  8. Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

    NASA Technical Reports Server (NTRS)

    Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

    2011-01-01

    The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

  9. Advanced materials for space nuclear power systems

    NASA Technical Reports Server (NTRS)

    Titran, Robert H.; Grobstein, Toni L.; Ellis, David L.

    1991-01-01

    The overall philosophy of the research was to develop and characterize new high temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites for heat rejection fins, and tungsten fiber reinforced niobium matrix composites for fuel containment and structural supports) considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications.

  10. Advanced materials for space nuclear power systems

    NASA Technical Reports Server (NTRS)

    Titran, Robert H.; Grobstein, Toni L.; Ellis, David L.

    1991-01-01

    The overall philosophy of the research was to develop and characterize new high temperature power conversion and radiator materials and to provide spacecraft designers with material selection options and design information. Research on three candidate materials (carbide strengthened niobium alloy PWC-11 for fuel cladding, graphite fiber reinforced copper matrix composites for heat rejection fins, and tungsten fiber reinforced niobium matrix composites for fuel containment and structural supports considered for space power system applications is discussed. Each of these types of materials offers unique advantages for space power applications.

  11. Advanced photovoltaic power system technology for lunar base applications

    NASA Technical Reports Server (NTRS)

    Brinker, David J.; Flood, Dennis J.

    1992-01-01

    The development of an advanced photovoltaic power system that would have application for a manned lunar base is currently planned under the Surface Power element of Pathfinder. Significant mass savings over state-of-the-art photovoltaic/battery systems are possible with the use of advanced lightweight solar arrays coupled with regenerative fuel cell storage. The solar blanket, using either ultrathin GaAs or amorphous silicon solar cells, would be integrated with a reduced-g structure. Regenerative fuel cells with high-pressure gas storage in filament-wound tanks are planned for energy storage. An advanced PV/RFC power system is a leading candidate for a manned lunar base as it offers a tremendous weight advantage over state-of-the-art photovoltaic/battery systems and is comparable in mass to other advanced power generation technologies.

  12. Results of Laboratory Testing of Advanced Power Strips: Preprint

    SciTech Connect

    Earle, L.; Sparn, B.

    2012-08-01

    This paper describes the results of a laboratory investigation to evaluate the technical performance of advanced power strip (APS) devices when subjected to a range of home entertainment center and home office usage scenarios.

  13. Influence of a falling edge on high power microwave pulse combination

    NASA Astrophysics Data System (ADS)

    Li, Jiawei; Huang, Wenhua; Zhu, Qi; Xiao, Renzhen; Shao, Hao

    2016-07-01

    This paper presents an explanation of the influence of a microwave falling edge on high-power microwave pulse combination. Through particle-in-cell simulations, we discover that the falling edge is the driving factor that limits the output power of the combined pulses. We demonstrate that the space charge field, which accumulates to become comparable to the E-field at the falling edge of the former pulse, will trap the electrons in the gas layer and decrease its energy to attain a high ionization rate. Hence, avalanche discharge, caused by trapped electrons, makes the plasma density to approach the critical density and cuts off the latter microwave pulse. An X-band combination experiment is conducted with different pulse intervals. This experiment confirms that the high density plasma induced by the falling edge can cut off the latter pulse, and that the time required for plasma recombination in the transmission channel is several microseconds. To ensure a high output power for combined pulses, the latter pulse should be moved ahead of the falling edge of the former one, and consequently, a beat wave with high peak power becomes the output by adding two pulses with normal amplitudes.

  14. Pulse compression of a high-power thin disk laser using rod-type fiber amplifiers.

    PubMed

    Saraceno, C J; Heckl, O H; Baer, C R E; Südmeyer, T; Keller, U

    2011-01-17

    We report on two pulse compressors for a high-power thin disk laser oscillator using rod-type fiber amplifiers. Both systems are seeded by a standard SESAM modelocked thin disk laser that delivers 16 W of average power at a repetition rate of 10.6 MHz with a pulse energy of 1.5 μJ and a pulse duration of 1 ps. We discuss two results with different fiber parameters with different trade-offs in pulse duration, average power, damage and complexity. The first amplifier setup consists of a Yb-doped fiber amplifier with a 2200 μm2 core area and a length of 55 cm, resulting in a compressed average power of 55 W with 98-fs pulses at a repetition rate of 10.6 MHz. The second system uses a shorter 36-cm fiber with a larger core area of 4500 μm2. In a stretcher-free configuration we obtained 34 W of compressed average power and 65-fs pulses. In both cases peak powers of > 30 MW were demonstrated at several μJ pulse energies. The power scaling limitations due to damage and self-focusing are discussed.

  15. Advancement Of Tritium Powered Betavoltaic Battery Systems

    SciTech Connect

    Staack, G.; Gaillard, J.; Hitchcock, D.; Peters, B.; Colon-Mercado, H.; Teprovich, J.; Coughlin, J.; Neikirk, K.; Fisher, C.

    2015-10-14

    Due to their decades-long service life and reliable power output under extreme conditions, betavoltaic batteries offer distinct advantages over traditional chemical batteries, especially in applications where frequent battery replacement is hazardous, or cost prohibitive. Although many beta emitting isotopes exist, tritium is considered ideal in betavoltaic applications for several reasons: 1) it is a “pure” beta emitter, 2) the beta is not energetic enough to damage the semiconductor, 3) it has a moderately long half-life, and 4) it is readily available. Unfortunately, the widespread application of tritium powered betavoltaics is limited, in part, by their low power output. This research targets improving the power output of betavoltaics by increasing the flux of beta particles to the energy conversion device (the p-n junction) through the use of low Z nanostructured tritium trapping materials.

  16. High-Power Multimode X-Band RF Pulse Compression System for Future Linear Colliders

    SciTech Connect

    Tantawi, S.G.; Nantista, C.D.; Dolgashev, V.A.; Pearson, C.; Nelson, J.; Jobe, K.; Chan, J.; Fant, K.; Frisch, J.; Atkinson, D.; /LLNL, Livermore

    2005-08-10

    We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  17. High-power multimode X-band rf pulse compression system for future linear colliders

    NASA Astrophysics Data System (ADS)

    Tantawi, Sami G.; Nantista, Christopher D.; Dolgashev, Valery A.; Pearson, Chris; Nelson, Janice; Jobe, Keith; Chan, Jose; Fant, Karen; Frisch, Josef; Atkinson, Dennis

    2005-04-01

    We present a multimode X-band rf pulse compression system suitable for a TeV-scale electron-positron linear collider such as the Next Linear Collider (NLC). The NLC main linac operating frequency is 11.424 GHz. A single NLC rf unit is required to produce 400 ns pulses with 475 MW of peak power. Each rf unit should power approximately 5 m of accelerator structures. The rf unit design consists of two 75 MW klystrons and a dual-moded resonant-delay-line pulse compression system that produces a flat output pulse. The pulse compression system components are all overmoded, and most components are designed to operate with two modes. This approach allows high-power-handling capability while maintaining a compact, inexpensive system. We detail the design of this system and present experimental cold test results. We describe the design and performance of various components. The high-power testing of the system is verified using four 50 MW solenoid-focused klystrons run off a common 400 kV solid-state modulator. The system has produced 400 ns rf pulses of greater than 500 MW. We present the layout of our system, which includes a dual-moded transmission waveguide system and a dual-moded resonant line (SLED-II) pulse compression system. We also present data on the processing and operation of this system, which has set high-power records in coherent and phase controlled pulsed rf.

  18. High-Power Laser Pulse Recirculation for Inverse Compton Scattering-Produced Gamma-Rays

    SciTech Connect

    Jovanovic, I; Shverdin, M; Gibson, D; Brown, C

    2007-04-17

    Inverse Compton scattering of high-power laser pulses on relativistic electron bunches represents an attractive method for high-brightness, quasi-monoenergetic {gamma}-ray production. The efficiency of {gamma}-ray generation via inverse Compton scattering is severely constrained by the small Thomson scattering cross section. Furthermore, repetition rates of high-energy short-pulse lasers are poorly matched with those available from electron accelerators, resulting in low repetition rates for generated {gamma}-rays. Laser recirculation has been proposed as a method to address those limitations, but has been limited to only small pulse energies and peak powers. Here we propose and experimentally demonstrate an alternative method for laser pulse recirculation that is uniquely capable of recirculating short pulses with energies exceeding 1 J. Inverse Compton scattering of recirculated Joule-level laser pulses has a potential to produce unprecedented peak and average {gamma}-ray brightness in the next generation of sources.

  19. High-power widely tunable sub-20 fs Gaussian laser pulses for ultrafast nonlinear spectroscopy.

    PubMed

    Metzger, Bernd; Steinmann, Andy; Giessen, Harald

    2011-11-21

    We demonstrate the generation of widely tunable sub-20 fs Gaussian-shaped laser pulses using a grating-based 4-f pulse shaper and a liquid crystal spatial light modulator. Our pump source is an Yb:KGW solitary mode-locked oscillator at 44 MHz repetition rate which is coupled into a large mode area microstructured fiber to generate a broad spectrum from below 900 nm to above 1150 nm. These pulses are precompressed by a prism sequence and subsequently sent into the pulse shaper. We use the multiphoton intrapulse interference phase scan (MIIPS) for phase shaping and iterative amplitude optimization to achieve Gaussian-like tunable sub-20 fs pulses with output powers of up to 142 mW as well as nontunable pulses with 310 mW output power as short as 11.5 fs. PMID:22109462

  20. Combined flux compression and plasma opening switch on the Saturn pulsed power generator.

    PubMed

    Felber, Franklin S; Waisman, Eduardo M; Mazarakis, Michael G

    2010-05-01

    A wire-array flux-compression cartridge installed on Sandia's Saturn pulsed power generator doubled the current into a 3-nH load to 6 MA and halved its rise time to 100 ns. The current into the load, however, was unexpectedly delayed by almost 1 micros. Estimates of a plasma flow switch acting as a long-conduction-time opening switch are consistent with key features of the power compression. The results suggest that microsecond-conduction-time plasma flow switches can be combined with flux compression both to amplify currents and to sharpen pulse rise times in pulsed power drivers.

  1. Combined Flux Compression and Plasma Opening Switch on the Saturn Pulsed Power Generator

    SciTech Connect

    Felber, Franklin S.; Waisman, Eduardo M.; Mazarakis, Michael G.

    2010-05-07

    A wire-array flux-compression cartridge installed on Sandia's Saturn pulsed power generator doubled the current into a 3-nH load to 6 MA and halved its rise time to 100 ns. The current into the load, however, was unexpectedly delayed by almost 1 {mu}s. Estimates of a plasma flow switch acting as a long-conduction-time opening switch are consistent with key features of the power compression. The results suggest that microsecond-conduction-time plasma flow switches can be combined with flux compression both to amplify currents and to sharpen pulse rise times in pulsed power drivers.

  2. Peak power tunable mid-infrared oscillator pumped by a high power picosecond pulsed fiber amplifier with bunch output

    NASA Astrophysics Data System (ADS)

    Wei, Kaihua; Guo, Yan; Lai, Xiaomin; Fan, Shanhui

    2016-07-01

    A high power mid-infrared optical parametric oscillator (OPO) with picosecond pulse bunch output is experimentally demonstrated. The pump source was a high power master oscillation power amplifier (MOPA) picosecond pulsed fiber amplifier. The seed of the MOPA was a gain-switched distributed Bragg reflector (DBR) laser diode (LD) with picosecond pulse operation at a high repetition rate. The seed laser was amplified to 50 W by two-stage pre-amplifiers and a large mode area (LMA) Yb fiber based power-amplifier. A fiber-pigtailed acousto-optic modulator with the first order diffraction transmission was inserted into the second pre-amplifier to form a picosecond pulse bunch train and to change the peak power simultaneously. The power-amplified pulse bunches were focused to pump a wavelength-tunable OPO for emitting high power mid-infrared laser. By adjusting the OPO cavity length, the maximum average idler powers obtained at 3.1, 3.3 and 3.5 μm were 7, 6.6 and 6.4 W respectively.

  3. Advanced Power Regulator Developed for Spacecraft

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The majority of new satellites generate electrical power using photovoltaic solar arrays and store energy in batteries for use during eclipse periods. Careful regulation of battery charging during insolation can greatly increase the expected lifetime of the satellite. The battery charge regulator is usually custom designed for each satellite and its specific mission. Economic competition in the small satellite market requires battery charge regulators that are lightweight, efficient, inexpensive, and modular enough to be used in a wide variety of satellites. A new battery charge regulator topology has been developed at the NASA Lewis Research Center to address these needs. The new regulator topology uses industry-standard dc-dc converters and a unique interconnection to provide size, weight, efficiency, fault tolerance, and modularity benefits over existing systems. A transformer-isolated buck converter is connected such that the high input line is connected in series with the output. This "bypass connection" biases the converter's output onto the solar array voltage. Because of this biasing, the converter only processes the fraction of power necessary to charge the battery above the solar array voltage. Likewise, the same converter hookup can be used to regulate the battery output to the spacecraft power bus with similar fractional power processing. The advantages of this scheme are: 1) Because only a fraction of the power is processed through the dc-dc converter, the single- stage conversion efficiency is 94 to 98 percent; 2) Costly, high-efficiency dc-dc converters are not necessary for high end-to-end system efficiency; 3) The system is highly fault tolerant because the bypass connection will still deliver power if the dc-dc converter fails; and 4) The converters can easily be connected in parallel, allowing higher power systems to be built from a common building block. This new technology will be spaceflight tested in the Photovoltaic Regulator Kit Experiment

  4. Systems Engineering Building Advances Power Grid Research

    SciTech Connect

    Virden, Jud; Huang, Henry; Skare, Paul; Dagle, Jeff; Imhoff, Carl; Stoustrup, Jakob; Melton, Ron; Stiles, Dennis; Pratt, Rob

    2015-08-19

    Researchers and industry are now better equipped to tackle the nation’s most pressing energy challenges through PNNL’s new Systems Engineering Building – including challenges in grid modernization, buildings efficiency and renewable energy integration. This lab links real-time grid data, software platforms, specialized laboratories and advanced computing resources for the design and demonstration of new tools to modernize the grid and increase buildings energy efficiency.

  5. Average power constraints in AlGaAs semiconductor lasers under pulse-position-modulation conditions

    NASA Technical Reports Server (NTRS)

    Katz, J.

    1986-01-01

    In some optical communications systems there are advantages to using low duty-cycle pulsed modulation formats such as pulse-position-modulation. However, because of intrinsic limitations of AlGaAs semiconductor lasers, the average power that they can deliver in a pulsed mode of operation is lower than in a CW mode. The magnitude of this problem and its implications are analyzed in this letter, and one possible solution is mentioned.

  6. SBS-managed high-peak-power nanosecond-pulse fiber-based master oscillator power amplifier.

    PubMed

    Di Teodoro, F; Morais, J; McComb, T S; Hemmat, M K; Cheung, E C; Weber, M; Moyer, R

    2013-07-01

    We report on a compactly packaged Yb-doped fiber-based laser architecture featuring an actively pulse controlled, single-longitudinal-mode seeder and multistage amplifier chain terminated by a "folded" rod-type photonic crystal fiber. In this laser source, stimulated Brillouin scattering (SBS) is the power-limiting factor, but is managed by phase modulating the seeder with a pseudo-random noise signal. Pulse energy/peak power of ~2 mJ/1.5 MW at 10 kHz repetition rate are thus obtained within ~1.55 ns pulses of peak spectral brightness >20 kW cm(-2) sr(-1) Hz(-1). PMID:23811864

  7. SBS-managed high-peak-power nanosecond-pulse fiber-based master oscillator power amplifier.

    PubMed

    Di Teodoro, F; Morais, J; McComb, T S; Hemmat, M K; Cheung, E C; Weber, M; Moyer, R

    2013-07-01

    We report on a compactly packaged Yb-doped fiber-based laser architecture featuring an actively pulse controlled, single-longitudinal-mode seeder and multistage amplifier chain terminated by a "folded" rod-type photonic crystal fiber. In this laser source, stimulated Brillouin scattering (SBS) is the power-limiting factor, but is managed by phase modulating the seeder with a pseudo-random noise signal. Pulse energy/peak power of ~2 mJ/1.5 MW at 10 kHz repetition rate are thus obtained within ~1.55 ns pulses of peak spectral brightness >20 kW cm(-2) sr(-1) Hz(-1).

  8. Genetic algorithm based optimization of pulse profile for MOPA based high power fiber lasers

    NASA Astrophysics Data System (ADS)

    Zhang, Jiawei; Tang, Ming; Shi, Jun; Fu, Songnian; Li, Lihua; Liu, Ying; Cheng, Xueping; Liu, Jian; Shum, Ping

    2015-03-01

    Although the Master Oscillator Power-Amplifier (MOPA) based fiber laser has received much attention for laser marking process due to its large tunabilty of pulse duration (from 10ns to 1ms), repetition rate (100Hz to 500kHz), high peak power and extraordinary heat dissipating capability, the output pulse deformation due to the saturation effect of fiber amplifier is detrimental for many applications. We proposed and demonstrated that, by utilizing Genetic algorithm (GA) based optimization technique, the input pulse profile from the master oscillator (current-driven laser diode) could be conveniently optimized to achieve targeted output pulse shape according to real parameters' constraints. In this work, an Yb-doped high power fiber amplifier is considered and a 200ns square shaped pulse profile is the optimization target. Since the input pulse with longer leading edge and shorter trailing edge can compensate the saturation effect, linear, quadratic and cubic polynomial functions are used to describe the input pulse with limited number of unknowns(<5). Coefficients of the polynomial functions are the optimization objects. With reasonable cost and hardware limitations, the cubic input pulse with 4 coefficients is found to be the best as the output amplified pulse can achieve excellent flatness within the square shape. Considering the bandwidth constraint of practical electronics, we examined high-frequency component cut-off effect of input pulses and found that the optimized cubic input pulses with 300MHz bandwidth is still quite acceptable to satisfy the requirement for the amplified output pulse and it is feasible to establish such a pulse generator in real applications.

  9. A simple sub-nanosecond ultraviolet light pulse generator with high repetition rate and peak power.

    PubMed

    Binh, P H; Trong, V D; Renucci, P; Marie, X

    2013-08-01

    We present a simple ultraviolet sub-nanosecond pulse generator using commercial ultraviolet light-emitting diodes with peak emission wavelengths of 290 nm, 318 nm, 338 nm, and 405 nm. The generator is based on step recovery diode, short-circuited transmission line, and current-shaping circuit. The narrowest pulses achieved have 630 ps full width at half maximum at repetition rate of 80 MHz. Optical pulse power in the range of several hundreds of microwatts depends on the applied bias voltage. The bias voltage dependences of the output optical pulse width and peak power are analysed and discussed. Compared to commercial UV sub-nanosecond generators, the proposed generator can produce much higher pulse repetition rate and peak power.

  10. A new digital pulse power supply in heavy ion research facility in Lanzhou

    NASA Astrophysics Data System (ADS)

    Wang, Rongkun; Chen, Youxin; Huang, Yuzhen; Gao, Daqing; Zhou, Zhongzu; Yan, Huaihai; Zhao, Jiang; Shi, Chunfeng; Wu, Fengjun; Yan, Hongbin; Xia, Jiawen; Yuan, Youjin

    2013-11-01

    To meet the increasing requirements of the Heavy Ion Research Facility in Lanzhou-Cooler Storage Ring (HIRFL-CSR), a new digital pulse power supply, which employs multi-level converter, was designed. This power supply was applied with a multi H-bridge converters series-parallel connection topology. A new control model named digital power supply regulator system (DPSRS) was proposed, and a pulse power supply prototype based on DPSRS has been built and tested. The experimental results indicate that tracking error and ripple current meet the requirements of this design. The achievement of prototype provides a perfect model for HIRFL-CSR power supply system.

  11. Energy capability improvement of power DMOS transistors operating in pulsed conditions

    NASA Astrophysics Data System (ADS)

    Costachescu, Dragos; Pfost, Martin

    2015-01-01

    Modern power DMOS transistors greatly benefit from the continuous advances of the technology, which yield devices with very low area-specific RDS,on figures of merit and therefore allow for significantly reduced active areas. However, in many applications, where the devices must dissipate high amounts of energy and thus are subjected to significant self-heating, the active area is not dictated by RDS,on requirements, but by the energy constraints. In this paper, a simple method of improving the energy capability and reliability of power DMOS transistors operating in pulsed conditions is proposed and experimentally verified. The method consists in redistributing the power density from the hotter to the cooler device regions, hence achieving a more homogeneous temperature distribution and a reduced peak temperature. To demonstrate the principle, a simple gate offset circuit is used to redistribute the current density to the cooler DMOS parts. No technology changes are needed for the implementation, only minor changes to the driver circuit are necessary, with a minimal impact on the additional required active area. Improvements in the energy capability from 9.2% up to 39% have been measured. Furthermore, measurements have shown that the method remains effective also if the operating conditions change significantly. The simplicity and the effectiveness of the implementation makes the proposed method suitable to be used in a wide range of applications.

  12. Long term survival of mice with hepatocellular carcinoma after pulse power ablation with nanosecond pulsed electric fields.

    PubMed

    Chen, X; Zhuang, J; Kolb, J F; Schoenbach, K H; Beebe, S J

    2012-02-01

    Novel therapies are needed for treating hepatocellular carcinoma (HCC) without recurrence in a single procedure. In this work we evaluated anti-neoplastic effects of a pulse power ablation (PPA) with nanosecond pulsed electric fields (nsPEFs), a non-thermal, non-drug, local, regional method and investigated its molecular mechanisms for hepatocellular carcinoma tumor ablation in vivo. An ectopic tumor model was established using C57BL/6 mice with Hepa1-6 hepatocellular carcinoma cells. Pulses with durations of 30 or 100 ns and fast rise times were delivered by a needle or ring electrode with different electric field strengths (33, 50 and 68 kV/cm), and 900 pulses in three treatment sessions (300 pulses each session) or a single 900 pulse treatment. Treated and control tumor volumes were monitored by ultrasound and apoptosis and angiogenesis markers were evaluated by immunohistochemistry. Seventy five percent of primary hepatocellular carcinoma tumors were eradicated with 900 hundred pulses at 100 ns pulses at 68 kV/cm in a single treatment or in three treatment sessions without recurrence within 9 months. Using quantitative analysis, tumors in treated animals showed nsPEF-mediated nuclear condensation (3 h post-pulse), cell shrinkage (1 h), increases in active executioner caspases (caspase-3 > -7 > -6) and terminal deoxynucleotidyl transferase dUTP nick-end-labeling (1 h) with decreases in vascular endothelial growth factor expression (7d) and micro-vessel density (14d). NsPEF ablation eliminated hepatocellular carcinoma tumors by targeting two therapeutic sites, apoptosis induction and inhibition of angiogenesis, both important cancer hallmarks. These data indicate that PPA with nsPEFs is not limited to treating skin cancers and provide a rationale for continuing to investigate pulse power ablation for hepatocellular carcinoma using other models in pre-clinical applications and ultimately in clinical trials. Based on present treatments for specific HCC stages, it

  13. Thor: Modeling of a Megabar Class Pulsed Power Accelerator

    NASA Astrophysics Data System (ADS)

    Haill, T. A.; Reisman, D. B.; Stoltzfus, B. S.; Austin, K. N.; Stygar, W. A.; Brown, J. L.; Davis, J.-P.; Waisman, E. M.

    2015-06-01

    Thor is a compact, economical machine to drive megabar-class shockless compression material physics experiments and multi-mega-ampere HEDP experiments for the physics community. It is capable of driving peak currents up to 7 MA with rise times of 200-500 ns, resulting in material pressures between 1 to 5 Mbar depending upon the load design, and incorporates a pulse tailoring capability required to maintain shockless loading of many materials. Thor is modular in nature with 200 capacitive bricks triggered in groups by independent, de-coupled switches. The current pulse at the load is a simple linear combination of the 200 time-shifted basis pulses. This enables a variety of experiments including shockless compression experiments using smooth ramped pulses, shock-ramp compression experiments using tailored pulses, and strength measurement experiments using flat top pulses. This paper overviews the Thor design and describes an equivalent circuit model of the machine that drives MHD simulations of the load region. 3D ALEGRA MHD simulations explore topics such as the uniformity of the magnetic field along the stripline load and the design modifications to improve uniformity. Optimized current drives and simulations of the aforementioned applications are also presented. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Company, for the U.S. DOE's NNSA under Contract DE-AC04-94AL85000.

  14. Advanced Power Regulator Developed for Spacecraft

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The majority of new satellites generate electrical power using photovoltaic solar arrays and store energy in batteries for use during eclipse periods. Careful regulation of battery charging during insolation can greatly increase the expected lifetime of the satellite. The battery charge regulator is usually custom designed for each satellite and its specific mission. Economic competition in the small satellite market requires battery charge regulators that are lightweight, efficient, inexpensive, and modular enough to be used in a wide variety of satellites. A new battery charge regulator topology has been developed at the NASA Lewis Research Center to address these needs. The new regulator topology uses industry-standard dc-dc converters and a unique interconnection to provide size, weight, efficiency, fault tolerance, and modularity benefits over existing systems. A transformer-isolated buck converter is connected such that the high input line is connected in series with the output. This "bypass connection" biases the converter's output onto the solar array voltage. Because of this biasing, the converter only processes the fraction of power necessary to charge the battery above the solar array voltage. Likewise, the same converter hookup can be used to regulate the battery output to the spacecraft power bus with similar fractional power processing.

  15. Advanced Radioisotope Power Conversion Technology Research and Development

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.

    2004-01-01

    NASA's Radioisotope Power Conversion Technology program is developing next generation power conversion technologies that will enable future missions that have requirements that cannot be met by either the ubiquitous photovoltaic systems or by current Radioisotope Power System (RPS) technology. Performance goals of advanced radioisotope power systems include improvement over the state-of-practice General Purpose Heat Source/Radioisotope Thermoelectric Generator by providing significantly higher efficiency to reduce the number of radioisotope fuel modules, and increase specific power (watts/kilogram). Other Advanced RPS goals include safety, long-life, reliability, scalability, multi-mission capability, resistance to radiation, and minimal interference with the scientific payload. NASA has awarded ten contracts in the technology areas of Brayton, Stirling, Thermoelectric, and Thermophotovoltaic power conversion including five development contracts that deal with more mature technologies and five research contracts. The Advanced RPS Systems Assessment Team includes members from NASA GRC, JPL, DOE and Orbital Sciences whose function is to review the technologies being developed under the ten Radioisotope Power Conversion Technology contracts and assess their relevance to NASA's future missions. Presented is an overview of the ten radioisotope power conversion technology contracts and NASA's Advanced RPS Systems Assessment Team.

  16. Advanced electrical power system technology for the all electric aircraft

    NASA Technical Reports Server (NTRS)

    Finke, R. C.; Sundberg, G. R.

    1983-01-01

    The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg.

  17. Advanced electrical power system technology for the all electric aircraft

    NASA Technical Reports Server (NTRS)

    Finke, R. C.; Sundberg, G. R.

    1983-01-01

    The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg. Previously announced in STAR as N83-24764

  18. Modeling of High Efficiency Solar Cells Under Laser Pulse for Power Beaming Applications

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1994-01-01

    Solar cells may be used as receivers for laser power beaming. To understand the behavior of solar cells when illuminated by a pulsed laser, the time response of gallium arsenide and silicon solar cells to pulsed monochromatic input has been modeled using a finite element solar cell model.

  19. Pulse power generated electric fields as a means to control zebra mussels

    SciTech Connect

    Smythe, A.G.; Lange, C.L.; Doyle, J.F.

    1995-06-01

    In 1994, a study was conducted to determine if pulsed electric fields could reduce zebra mussel settlement rates. The study was a continuation of a study that began in 1991. Several types of fields were generated over the four-year study. The 1994 study concluded that fast rise DC, pulse power signals could stun post-veligers and significantly reduce settlement.

  20. Improving Switching Performance of Power MOSFETs Used in High Rep-Rate, Short Pulse, High-Power Pulsers

    SciTech Connect

    Cook, E G

    2006-09-19

    As their switching and power handling characteristics improve, solid-state devices are finding new applications in pulsed power. This is particularly true of applications that require fast trains of short duration pulses. High voltage (600-1200V) MOSFETs are especially well suited for use in these systems, as they can switch at significant peak power levels and are easily gated on and off very quickly. MOSFET operation at the shortest pulse durations is not constrained by the intrinsic capabilities of the MOSFET, but rather by the capabilities of the gate drive circuit and the system physical layout. This project sought to improve MOSFET operation in a pulsed power context by addressing these issues. The primary goal of this project is to improve the switching performance of power MOSFETs for use in high rep-rate, short pulse, high-power applications by improving the design of the gate drive circuits and the circuit layouts used in these systems. This requires evaluation of new commercial gate drive circuits and upgrading the designs of LLNL-developed circuits. In addition, these circuits must be tested with the fastest available high-voltage power MOSFETs.

  1. Pulse power requirements for large aperture optical switches based on plasma electrode Pockels cells

    SciTech Connect

    Rhodes, M.A.; Taylor, J.

    1992-06-01

    We discuss very large-aperture optical switches (greater than 30 {times} 30 cm) as an enabling technology for inertial confinement fusion drivers based on multipass laser amplifiers. Large-scale laser fusion drivers such as the Nova laser have been based on single-pass amplifier designs in part because of the unavailability of a suitable large-aperture switch. We are developing an optical switch based on a Pockels cell employing plasma-electrodes. A plasma-electrode Pockels cell (PEPC) is a longitudinal-mode Pockels cell in which a plasma discharge is formed on each side of an electro-optic crystal (typically KDP or deuterated KDP, often designated KD*P). The plasmas formed on either side of the crystal act as transparent electrodes for a switching-pulse and are intended to allow uniform charging of the entire crystal. The switching-pulse is a nominally rectangular high-voltage pulse equal to the half-wave voltage V{sub x} ( 8 kV for KD*P or 17 kV for KDP) and is applied across the crystal via the plasma-electrodes. When the crystal is charged to V{sub x}, the polarization of an incoming, linearly polarized, laser beam is rotated by 90{degree}. When used in conjunction with an appropriate, passive polarizer, an optical switch is thus realized. A switch with a clear aperture of 37 {times} 37 cm is now in construction for the Beamlet laser which will serve as a test bed for this switch as well as other technologies required for an advanced NOVA laser design. In this paper, we discuss the unique power electronics requirements of PEPC optical switches.

  2. Pulse power requirements for large aperture optical switches based on plasma electrode Pockels cells

    SciTech Connect

    Rhodes, M.A.; Taylor, J.

    1992-06-01

    We discuss very large-aperture optical switches (greater than 30 [times] 30 cm) as an enabling technology for inertial confinement fusion drivers based on multipass laser amplifiers. Large-scale laser fusion drivers such as the Nova laser have been based on single-pass amplifier designs in part because of the unavailability of a suitable large-aperture switch. We are developing an optical switch based on a Pockels cell employing plasma-electrodes. A plasma-electrode Pockels cell (PEPC) is a longitudinal-mode Pockels cell in which a plasma discharge is formed on each side of an electro-optic crystal (typically KDP or deuterated KDP, often designated KD*P). The plasmas formed on either side of the crystal act as transparent electrodes for a switching-pulse and are intended to allow uniform charging of the entire crystal. The switching-pulse is a nominally rectangular high-voltage pulse equal to the half-wave voltage V[sub x] ( 8 kV for KD*P or 17 kV for KDP) and is applied across the crystal via the plasma-electrodes. When the crystal is charged to V[sub x], the polarization of an incoming, linearly polarized, laser beam is rotated by 90[degree]. When used in conjunction with an appropriate, passive polarizer, an optical switch is thus realized. A switch with a clear aperture of 37 [times] 37 cm is now in construction for the Beamlet laser which will serve as a test bed for this switch as well as other technologies required for an advanced NOVA laser design. In this paper, we discuss the unique power electronics requirements of PEPC optical switches.

  3. Advanced photovoltaic power system technology for lunar base applications

    NASA Technical Reports Server (NTRS)

    Brinker, David J.; Flood, Dennis J.

    1988-01-01

    Advanced photovoltaic/electrochemical (batteries or regenerative fuel cells for storage) power system options for a lunar base are discussed and compared. Estimated system masses are compared with those projected for the SP-100 nuclear system. The results of the comparison are quantified in terms of the mass saved in a scenario which assembles the initial base elements in Low Earth Orbit (LEO) and launches from there to the lunar surface. A brief summary is given of advances in photovoltaic/electrochemical power system technologies currently under development in the NASA/OAST program. A description of the planned focussed technology program for surface power in the new Pathfinder initiative is also provided.

  4. Model-free adaptive control of advanced power plants

    SciTech Connect

    Cheng, George Shu-Xing; Mulkey, Steven L.; Wang, Qiang

    2015-08-18

    A novel 3-Input-3-Output (3.times.3) Model-Free Adaptive (MFA) controller with a set of artificial neural networks as part of the controller is introduced. A 3.times.3 MFA control system using the inventive 3.times.3 MFA controller is described to control key process variables including Power, Steam Throttle Pressure, and Steam Temperature of boiler-turbine-generator (BTG) units in conventional and advanced power plants. Those advanced power plants may comprise Once-Through Supercritical (OTSC) Boilers, Circulating Fluidized-Bed (CFB) Boilers, and Once-Through Supercritical Circulating Fluidized-Bed (OTSC CFB) Boilers.

  5. High Temperature Dynamic Hohlraums on the Pulsed Power Driver Z.

    NASA Astrophysics Data System (ADS)

    Nash, Thomas J.

    1998-11-01

    In the concept of the dynamic hohlraum an imploding z-pinch is optically thick to its own radiation. Radiation may be trapped inside the pinch to give a radiation temperature inside the pinch greater than that outside the pinch. The radiation is typically produced by colliding an outer z-pinch liner onto an inner liner. The collision generates a strongly radiating shock, and the radiation is trapped by the outer liner. As the implosion continues after the collision the radiation temperature may continue to increase due to ongoing PdV work done by the implosion. In principal the radiation temperature may increase to the point at which the outer liner burns through, becomes optically thin, and no longer traps the radiation. One application of the dynamic hohlraum is to drive an ICF pellet with the trapped radiation field. Members of the dynamic hohlraum team at Sandia National Labs have used the pulsed power driver Z (20 MA, 100 ns) to create a dynamic hohlraum with temperature linearly ramping from 100 to 180 eV over 5 ns. On this shot zp214 we imploded a nested tungsten wire array of 4 and 2 cm diameters with masses of 2 and 1 mg onto a 2.5 mg plastic annulus at 5 mm diameter. The current return can on this shot was slotted. We anticipate that the radiation temperature may be increased to over 200 eV by stabilizing the pinch with a solid current return can. A current return can with 9 slots imprints 9 filaments onto the imploding pinch. This degrades the optical trapping and the quality of the liner collision. A 1.6 mm diameter capsule situated inside this dynamic hohlraum of zp214 would see 50 kJ of radiation impinging on its surface before the pinch itself collapses to a 1.6 mm diameter. Dynamic hohlraum shots including pellets are scheduled to take place on Z in September of 1998. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the US-DOE under contract DE-AC04-94AL85000.

  6. Advanced Solar Cells for Satellite Power Systems

    NASA Technical Reports Server (NTRS)

    Flood, Dennis J.; Weinberg, Irving

    1994-01-01

    The multiple natures of today's space missions with regard to operational lifetime, orbital environment, cost and size of spacecraft, to name just a few, present such a broad range of performance requirements to be met by the solar array that no single design can suffice to meet them all. The result is a demand for development of specialized solar cell types that help to optimize overall satellite performance within a specified cost range for any given space mission. Historically, space solar array performance has been optimized for a given mission by tailoring the features of silicon solar cells to account for the orbital environment and average operating conditions expected during the mission. It has become necessary to turn to entirely new photovoltaic materials and device designs to meet the requirements of future missions, both in the near and far term. This paper will outline some of the mission drivers and resulting performance requirements that must be met by advanced solar cells, and provide an overview of some of the advanced cell technologies under development to meet them. The discussion will include high efficiency, radiation hard single junction cells; monolithic and mechanically stacked multiple bandgap cells; and thin film cells.

  7. Advanced high temperature thermoelectrics for space power

    NASA Technical Reports Server (NTRS)

    Lockwood, A.; Ewell, R.; Wood, C.

    1981-01-01

    Preliminary results from a spacecraft system study show that an optimum hot junction temperature is in the range of 1500 K for advanced nuclear reactor technology combined with thermoelectric conversion. Advanced silicon germanium thermoelectric conversion is feasible if hot junction temperatures can be raised roughly 100 C or if gallium phosphide can be used to improve the figure of merit, but the performance is marginal. Two new classes of refractory materials, rare earth sulfides and boron-carbon alloys, are being investigated to improve the specific weight of the generator system. Preliminary data on the sulfides have shown very high figures of merit over short temperature ranges. Both n- and p-type doping have been obtained. Pure boron-carbide may extrapolate to high figure of merit at temperatures well above 1500 K but not lower temperature; n-type conduction has been reported by others, but not yet observed in the JPL program. Inadvertant impurity doping may explain the divergence of results reported.

  8. High efficiency fuel cell/advanced turbine power cycles

    SciTech Connect

    Morehead, H.

    1995-10-19

    An outline of the Westinghouse high-efficiency fuel cell/advanced turbine power cycle is presented. The following topics are discussed: The Westinghouse SOFC pilot manufacturing facility, cell scale-up plan, pressure effects on SOFC power and efficiency, sureCell versus conventional gas turbine plants, sureCell product line for distributed power applications, 20 MW pressurized-SOFC/gas turbine power plant, 10 MW SOFC/CT power plant, sureCell plant concept design requirements, and Westinghouse SOFC market entry.

  9. Autonomous power expert system advanced development

    NASA Technical Reports Server (NTRS)

    Quinn, Todd M.; Walters, Jerry L.

    1991-01-01

    The autonomous power expert (APEX) system is being developed at Lewis Research Center to function as a fault diagnosis advisor for a space power distribution test bed. APEX is a rule-based system capable of detecting faults and isolating the probable causes. APEX also has a justification facility to provide natural language explanations about conclusions reached during fault isolation. To help maintain the health of the power distribution system, additional capabilities were added to APEX. These capabilities allow detection and isolation of incipient faults and enable the expert system to recommend actions/procedure to correct the suspected fault conditions. New capabilities for incipient fault detection consist of storage and analysis of historical data and new user interface displays. After the cause of a fault is determined, appropriate recommended actions are selected by rule-based inferencing which provides corrective/extended test procedures. Color graphics displays and improved mouse-selectable menus were also added to provide a friendlier user interface. A discussion of APEX in general and a more detailed description of the incipient detection, recommended actions, and user interface developments during the last year are presented.

  10. Advanced radioisotope power source options for Pluto Express

    SciTech Connect

    Underwood, M.L.

    1995-12-31

    In the drive to reduce mass and cost, Pluto Express is investigating using an advanced power conversion technology in a small Radioisotope Power Source (RPS) to deliver the required mission power of 74 W(electric) at end of mission. Until this year the baseline power source under consideration has been a Radioisotope Thermoelectric Generator (RTG). This RTG would be a scaled down GPHS RTG with an inventory of 6 General Purpose Heat Sources (GPHS) and a mass of 17.8 kg. High efficiency, advanced technology conversion options are being examined to lower the power source mass and to reduce the amount of radioisotope needed. Three technologies are being considered as the advanced converter technology: the Alkali Metal Thermal-to-Electric Converter (AMTEC), Thermophotovoltaic (TPV) converters, and Stirling Engines. Conceptual designs for each of these options have been prepared. Each converter would require only 2 GPHSs to provide the mission power and would have a mass of 6.1, 7.2, and 12.4 kg for AMTEC, TPV, and Stirling Engines respectively. This paper reviews the status of each technology and the projected performance of an advanced RPS based on each technology. Based on the projected performance and spacecraft integration issues, Pluto Express would prefer to use the AMTEC based RPS. However, in addition to technical performance, selection of a power technology will be based on many other factors.

  11. Development of negative ion extractor in the high-power and long-pulse negative ion source for fusion application

    SciTech Connect

    Kashiwagi, M. Umeda, N.; Tobari, H.; Kojima, A.; Yoshida, M.; Taniguchi, M.; Dairaku, M.; Maejima, T.; Yamanaka, H.; Watanabe, K.; Inoue, T.; Hanada, M.

    2014-02-15

    High power and long-pulse negative ion extractor, which is composed of the plasma grid (PG) and the extraction grid (EXG), is newly developed toward the neutral beam injector for heating and current drive of future fusion machines such as ITER, JT-60 Super Advanced and DEMO reactor. The PG is designed to enhance surface production of negative ions efficiently by applying the chamfered aperture. The efficiency of the negative ion production for the discharge power increased by a factor of 1.3 against that of the conventional PG. The EXG is also designed with the thermal analysis to upgrade the cooling capability for the long pulse operation of >1000 s required in ITER. Though the magnetic field for electron suppression is reduced to 0.75 of that in the conventional EXG due to this upgrade, it was experimentally confirmed that the extracted electron current can be suppressed to the allowable level for the long pulse operation. These results show that newly developed extractor has the high potential for the long pulse extraction of the negative ions.

  12. Improving Reliability of High Power Quasi-CW Laser Diode Arrays Operating in Long Pulse Mode

    NASA Technical Reports Server (NTRS)

    Amzajerdian, Farzin; Meadows, Byron L.; Barnes, Bruce W.; Lockard, George E.; Singh, Upendra N.; Kavaya, Michael J.; Baker, Nathaniel R.

    2006-01-01

    Operating high power laser diode arrays in long pulse regime of about 1 msec, which is required for pumping 2-micron thulium and holmium-based lasers, greatly limits their useful lifetime. This paper describes performance of laser diode arrays operating in long pulse mode and presents experimental data of the active region temperature and pulse-to-pulse thermal cycling that are the primary cause of their premature failure and rapid degradation. This paper will then offer a viable approach for determining the optimum design and operational parameters leading to the maximum attainable lifetime.

  13. Self-similar propagation of high-power parabolic pulses in optical fiber amplifiers.

    PubMed

    Kruglov, V I; Peacock, A C; Dudley, J M; Harvey, J D

    2000-12-15

    Self-similarity techniques are used to study pulse propagation in a normal-dispersion optical fiber amplifier with an arbitrary longitudinal gain profile. Analysis of the nonlinear Schrödinger equation that describes such an amplifier leads to an exact solution in the high-power limit that corresponds to a linearly chirped parabolic pulse. The self-similar scaling of the propagating pulse in the amplifier is found to be determined by the functional form of the gain profile, and the solution is confirmed by numerical simulations. The implications for achieving chirp-free pulses after compression of the amplifier output are discussed.

  14. Advanced concepts for electromagnetic launcher power supplies incorporating magnetic flux compression

    NASA Astrophysics Data System (ADS)

    Driga, M. D.; Fair, H. D.

    1991-01-01

    Advanced concepts of high-energy power supplies for coil launchers are designed to produce high inductive compression ratios and large current and magnetic field multiplication ratios in the range of megaamperes of current and gigawatts of active power. As a consequence of the flexibility of multiwinding rotating generators, such designs provide an extensive range of output pulse shaping in single or multiple pulses, enabling optimum operation of the coil launcher. The interaction of different stationary and rotating electrical windings in strong magnetic fields with feedback generated amplification and nonuniform compensation of the armature reaction is the key to providing a large and flexible spectrum of tailored output pulses, eliminating the need for switching and other large external electromagnetic pulse-forming components. Dynamic interactions between the internal impedance of these generators and the induced electromotive forces in various windings, as well as the role of the external passive circuit components introduced in the launcher circuit (such as capacitors and inductors), are discussed and numerically evaluated. Finally, an adaptive finite-element method numerical code is given which takes into account the relative motion and is designed to evaluate machines incorporating flux compression.

  15. Optical ablation by high-power short-pulse lasers

    SciTech Connect

    Stuart, B.C.; Feit, M.D.; Herman, S.; Rubenchik, A.M.; Shore, B.W.; Perry, M.D.

    1996-02-01

    Laser-induced damage threshold measurements were performed on homogeneous and multilayer dielectrics and gold-coated optics at 1053 and 526 nm for pulse durations {tau} ranging from 140 fs to 1 ns. Gold coatings were found, both experimentally and theoretically, to be limited to 0.6 J/cm{sup 2} in the subpicosecond range for 1053-nm pulses. In dielectrics, we find qualitative differences in the morphology of damage and a departure from the diffusion-dominated {tau}{sup 1/2} scaling that indicate that damage results from plasma formation and ablation for {tau}{le}10 ps and from conventional heating and melting for {tau}{approx_gt}50 ps. A theoretical model based on electron production by multiphoton ionization, joule heating, and collisional (avalanche) ionization is in quantitative agreement with both the pulse-width and the wavelength scaling of experimental results. {copyright} {ital 1996 Optical Society of America.}

  16. Pulse power applications of silicon diodes in EML capacitive pulsers

    NASA Astrophysics Data System (ADS)

    Dethlefsen, Rolf; McNab, Ian; Dobbie, Clyde; Bernhardt, Tom; Puterbaugh, Robert; Levine, Frank; Coradeschi, Tom; Rinaldi, Vito

    1993-01-01

    Crowbar diodes are used for increasing the energy transfer from capacitive pulse forming networks. They also prevent voltage reversal on the energy storage capacitors. 52 mm diameter diodes with a 5 kV reverse blocking voltage, rated 40 kA were successfully used for the 32 MJ SSG rail gun. An uprated diode with increased current capability and a 15 kV reverse blocking voltage has been developed. Transient thermal analysis has predicted the current ratings for different pulse length. Analysis verification is obtained from destructive testing.

  17. Improvement of deoxidization efficiency of nitric monoxide by shortening pulse width of semiconductor opening switch pulse power generator

    NASA Astrophysics Data System (ADS)

    Kakuta, Takatoshi; Yagi, Ippei; Takaki, Koichi

    2015-01-01

    The deoxidization efficiency of nitric monoxide (NO) was improved by shortening the pulse width of the voltage applied to a corona reactor. The deoxidization efficiency of NO was evaluated as the NO removal efficiency in nitrogen (N2) gas containing 200 ppm NO. The corona reactor had a coaxial geometry and consisted of center high-voltage wire and outer grounded cylinder electrodes. A nanosecond high-voltage pulse was generated using an inductive energy storage pulse power circuit with a semiconductor opening switch and was applied to the center wire electrode in the corona reactor. Fast recovery diodes were utilized as a semiconductor opening switch. The pulse width of the applied voltage was reduced from 21 to 14 ns with the arrester connected in parallel to the reactor. The energy efficiency for NO removal was improved from 8.2 to 35.7 g kW-1 h-1 with the arrester connected. The pulse width was also reduced to 8 ns by optimizing the circuit parameters. It was confirmed from observation with an intensified charge-coupled device (ICCD) camera that the streamer corona discharge transited to a glowlike discharge after the streamer propagated from the center wire electrode to the outer cylinder electrode. The duration of the glowlike phase was reduced with the arrester connected. The energy consumed in the glowlike phase was also reduced from 15.7 to 4.6 mJ with the arrester connected.

  18. High-voltage portable pulsed power supply fed by low voltage source

    NASA Astrophysics Data System (ADS)

    Rezanejad, Mohammad; Sheikholeslami, Abdolreza; Adabi, Jafar; Valinejad, Mohammadreza

    2016-05-01

    This article proposes a new structure of voltage multiplier for portable pulsed power applications. In this configuration, which is based on capacitor-diode voltage multiplier, the capacitors are charged by low AC input voltage and discharge through the load in series during pulse generation mode. The proposed topology is achieved by integrating of solid-state switches with conventional voltage multiplier, which can increase the low input voltage step by step and generate high-voltage high-frequency pulsed power across the load. After some discussion, simulations and experimental results are provided to verify the effectiveness of the proposed topology.

  19. Software Framework for Advanced Power Plant Simulations

    SciTech Connect

    John Widmann; Sorin Munteanu; Aseem Jain; Pankaj Gupta; Mark Moales; Erik Ferguson; Lewis Collins; David Sloan; Woodrow Fiveland; Yi-dong Lang; Larry Biegler; Michael Locke; Simon Lingard; Jay Yun

    2010-08-01

    This report summarizes the work accomplished during the Phase II development effort of the Advanced Process Engineering Co-Simulator (APECS). The objective of the project is to develop the tools to efficiently combine high-fidelity computational fluid dynamics (CFD) models with process modeling software. During the course of the project, a robust integration controller was developed that can be used in any CAPE-OPEN compliant process modeling environment. The controller mediates the exchange of information between the process modeling software and the CFD software. Several approaches to reducing the time disparity between CFD simulations and process modeling have been investigated and implemented. These include enabling the CFD models to be run on a remote cluster and enabling multiple CFD models to be run simultaneously. Furthermore, computationally fast reduced-order models (ROMs) have been developed that can be 'trained' using the results from CFD simulations and then used directly within flowsheets. Unit operation models (both CFD and ROMs) can be uploaded to a model database and shared between multiple users.

  20. Upgrade of the SLAC SLED II Pulse Compression System Based on Recent High Power Tests

    SciTech Connect

    Vlieks, A.E.; Fowkes, W.R.; Loewen, R.J.; Tantawi, S.G.; /SLAC

    2011-09-06

    In the Next Linear Collider (NLC) it is expected that the high power rf components be able to handle peak power levels in excess of 400 MW. We present recent results of high power tests designed to investigate the RF breakdown limits of the X-band pulse compression system used at SLAC. (SLED-II). Results of these tests show that both the TE{sub 01}-TE{sub 10} mode converter and the 4-port hybrid have a maximum useful power limit of 220-250 MW. Based on these tests, modifications of these components have been undertaken to improve their peak field handling capability. Results of these modifications will be presented. As part of an international effort to develop a new 0.5-1.5 TeV electron-positron linear collider for the 21st century, SLAC has been working towards a design, referred to as 'The Next Linear Collider' (NLC), which will operate at 11.424 GHz and utilize 50-75 MW klystrons as rf power sources. One of the major challenges in this design, or any other design, is how to generate and efficiently transport extremely high rf power from a source to an accelerator structure. SLAC has been investigating various methods of 'pulse compressing' a relatively wide rf pulse ({ge} 1 {mu}s) from a klystron into a narrower, but more intense, pulse. Currently a SLED-II pulse compression scheme is being used at SLAC in the NLC Test Accelerator (NLCTA) and in the Accelerator Structures Test Area (ASTA) to provide high rf power for accelerator and component testing. In ASTA, a 1.05 {mu}s pulse from a 50 MW klystron was successfully pulse compressed to 205 MW with a pulse width of 150 ns. Since operation in NLC will require generating and transporting rf power in excess of 400 MW it was decided to test the breakdown limits of the SLED-II rf components in ASTA with rf power up to the maximum available of 400 MW. This required the combining of power from two 50 MW klystrons and feeding the summed power into the SLED-II pulse compressor. Results from this experiment demonstrated

  1. Intelligent attenuator for laser pulse energy and power stabilization

    NASA Astrophysics Data System (ADS)

    White, M. S.; Wyatt, R. W.; Brett, A. G.

    1983-06-01

    Encouraging preliminary results are presented from a feed-forward stabilized active optical filter. Its function is to greatly reduce the shot-to-shot and day-to-day pulse energy fluctuations commonly suffered by single shot Q switched lasers and their associated electro-optic gates and switchouts.

  2. High-Power Plasma Switch for 11.4 GHz Microwave Pulse Compressor

    SciTech Connect

    Jay L. Hirshfield

    2010-03-04

    Results obtained in several experiments on active RF pulse compression at X-band using a magnicon as the high-power RF source are presented. In these experiments, microwave energy was stored in high-Q TE01 and TE02 modes of two parallel-fed resonators, and then discharged using switches activated with rapidly fired plasma discharge tubes. Designs and high-power tests of several versions of the compressor are described. In these experiments, coherent pulse superposition was demonstrated at a 5–9 MW level of incident power. The compressed pulses observed had powers of 50–70 MW and durations of 40–70 ns. Peak power gains were measured to be in the range of 7:1–11:1 with efficiency in the range of 50–63%.

  3. Electron-Beam Switches For A High Peak Power Sled-II Pulse Compressor

    SciTech Connect

    Hirshfield, Jay, L.

    2015-12-02

    Omega-P demonstrated triggered electron-beam switches on the L=2 m dual-delay-line X-band pulse compressor at Naval Research Laboratory (NRL). In those experiments, with input pulses of up to 9 MW from the Omega-P/NRL X-band magnicon, output pulses having peak powers of 140-165 MW and durations of 16-20 ns were produced, with record peak power gains M of 18-20. Switch designs are described based on the successful results that should be suitable for use with the existing SLAC SLED-II delay line system, to demonstrate C=9, M=7, and n>>78%, yielding 173ns compressed pulses with peak powers up to 350MW with input of a single 50-MW.

  4. The COMET: A 6-MV, 400-kJ, magnetically-switched pulse-power module

    NASA Astrophysics Data System (ADS)

    Neau, E. L.

    The Inertial Confinement Fusion program at Sandia National Laboratories (SNL) is based on the use of large, economical, multi-module, multimegavolt accelerators to drive ion beam generating diodes or imploding plasma loads. This type of accelerator uses several stages of pulse time compression to raise the peak power to the multi-terrawatt level. Pulsed power accelerators have traditionally relied on the ionization of a gaseous, liquid, or solid material, through one or several channels, to connect one pulse compression stage to a succeeding stage. The large change in inductance of a region enclosing a saturable ferri or ferromagnetic material can, with proper design, be substituted for the more conventional switching techniques in certain applications. The use of amorphous METGLAS 2606SC saturable cores, based on earlier system studies, as a possible low-loss repetitive substitute for the self-closing water switches used in the final stages of one class of the pulse power accelerators was investigated.

  5. Report on audit of funding for advanced radioisotope power systems

    SciTech Connect

    1997-10-17

    The U.S. Department of Energy`s (Department) Advanced Radioisotope Power Systems Program maintains the sole national capability and facilities to produce radioisotope power systems for the National Aeronautics and Space Administration (NASA), the Department of Defense, and other Federal agencies. Projects are conducted with these agencies in accordance with written agreements and are dependent on cost sharing by the user agencies. For the past seven years the program emphasis has been on providing power systems for NASA`s Cassini mission to Saturn, which was launched earlier this month. We initiated this audit to determine whether the Department received proper reimbursement from NASA for the radioisotope power systems produced.

  6. Pulsed power supply for streamer corona electrofilter with 100 KV pseudospark switch

    SciTech Connect

    Bochkov, V.D.; Gnedin, I.N.; Djagiley, V.M.

    1996-12-31

    The pulsed-plasma-based reactor is currently created for the biggest in Moscow region thermal Kashira Power Plant. The reactor is intended to increase a precipitation of fly ash, SO{sub 2} and NO{sub x} from flue gas. The principal parameters of the electrostatic precipitator and pulse power supply for streamer corona discharge are as follows: gas flow rate - 300000 Nm{sup 3}/h gas velocity - 2 m/s, average power - 300 kW, pulse repetition rate - up to 2 kHz. The power supply has a module design with the single module power of about 25-50 kW, pulse voltage up to 120 kV, pulse energy of 30 J, pulse length of 500 ns. The pseudospark switch with hold-off voltage up to 100 kV is used in the module. It is supposed that the switch should offer a possibility to transfer a total charge of about 10{sup 7} C.

  7. Pulse wireless photonic power transfer at high irradiance

    NASA Astrophysics Data System (ADS)

    Dhadwal, Harbans S.; Rastegar, Jahangir; Kwok, Philip

    2014-06-01

    Photonic power conversion combined with a high power laser diode, is a high efficiency solution for rapid, wireless transfer of power to dormant sensors, which have sporadic need for electrical power. In particular, these devices replace, thermal/inductive power sources inside a munition shell, leading to a safe non-radiating environment. Experimental results with a 25 F double-layer, super-capacitor, indicate that the surface irradiance and laser power both determine the minimum energy transfer time. At a power level of 4 W, the energy transfer rate reduces from a 1 J/s to 0.35 J/s as the irradiance level changes from 1125 suns to 63 suns.

  8. Optimization of hybrid power system composed of SMES and flywheel MG for large pulsed load

    NASA Astrophysics Data System (ADS)

    Niiyama, K.; Yagai, T.; Tsuda, M.; Hamajima, T.

    2008-09-01

    A superconducting magnetic storage system (SMES) has some advantages such as rapid large power response and high storage efficiency which are superior to other energy storage systems. A flywheel motor generator (FWMG) has large scaled capacity and high reliability, and hence is broadly utilized for a large pulsed load, while it has comparatively low storage efficiency due to high mechanical loss compared with SMES. A fusion power plant such as International Thermo-Nuclear Experimental Reactor (ITER) requires a large and long pulsed load which causes a frequency deviation in a utility power system. In order to keep the frequency within an allowable deviation, we propose a hybrid power system for the pulsed load, which equips the SMES and the FWMG with the utility power system. We evaluate installation cost and frequency control performance of three power systems combined with energy storage devices; (i) SMES with the utility power, (ii) FWMG with the utility power, (iii) both SMES and FWMG with the utility power. The first power system has excellent frequency power control performance but its installation cost is high. The second system has inferior frequency control performance but its installation cost is the lowest. The third system has good frequency control performance and its installation cost is attained lower than the first power system by adjusting the ratio between SMES and FWMG.

  9. Pulsed power systems for environmental and industrial applications

    SciTech Connect

    Neau, E.L. )

    1994-10-05

    Large treatment areas are possible with these systems because kilojoules of energy are available in each output pulse. These systems can use large area x-ray converters for applications requiring grater depth of penetration such as food pasteurization and waste treatment. The combined development of this class of accelerators and applications, and Sandia National Laboratories, is called Quantum Manufacturing. [copyright][ital American] [ital Institute] [ital of] [ital Physics] 1994

  10. Experiment and theoretical study of the propagation of high power microwave pulse in air breakdown environment

    NASA Technical Reports Server (NTRS)

    Kuo, S. P.; Ren, A.; Zhang, Y. S.

    1991-01-01

    In the study of the propagation of high power microwave pulse, one of the main concerns is how to minimize the energy loss of the pulse before reaching the destination. In the very high power region, one has to prevent the cutoff reflection caused by the excessive ionization in the background air. A frequency auto-conversion process which can lead to reflectionless propagation of powerful EM pulses in self-generated plasmas is studied. The theory shows that under the proper conditions the carrier frequency, omega, of the pulse will indeed shift upward with the growth of plasma frequency, omega(sub pe). Thus, the plasma during breakdown will always remain transparent to the pulse (i.e., omega greater than omega(sub pe)). A chamber experiment to demonstrate the frequency auto-conversion during the pulse propagation through the self-generated plasma is then conducted in a chamber. The detected frequency shift is compared with the theoretical result calculated y using the measured electron density distribution along the propagation path of the pulse. Good agreement between the theory and the experiment results is obtained.

  11. A Conceptual Titan Orbiter Mission Using Advanced Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Abelson, Robert D.; Shirley, James H.; Spilker, Thomas R.

    2006-01-01

    This study details a conceptual follow-on Titan orbiter mission that would provide full global topographic coverage. surface imaging, and meteorological characterization of the atmosphere over a nominal 5-year science mission duration. The baseline power requirement is approx.1 kWe at EOM and is driven by a high power radar instrument that would provide 3-dimensional measurements of atmospheric clouds, precipitation, and surface topography. While this power level is moderately higher than that of the Cassini spacecraft. higher efficiency advanced RPSs could potentially reduce the plutonium usage to less than 1/3rd of that used on the Cassini spacecraft. The Titan Orbiter mission is assumed to launch in 2015. It would utilize advanced RPSs to provide all on-board power.

  12. Agricultural and Food Processing Applications of Pulsed Power and Plasma Technologies

    NASA Astrophysics Data System (ADS)

    Takaki, Koichi

    Agricultural and food processing applications of pulsed power and plasma technologies are described in this paper. Repetitively operated compact pulsed power generators with a moderate peak power are developed for the agricultural and the food processing applications. These applications are mainly based on biological effects and can be categorized as germination control of plants such as Basidiomycota and arabidopsis inactivation of bacteria in soil and liquid medium of hydroponics; extraction of juice from fruits and vegetables; decontamination of air and liquid, etc. Types of pulsed power that have biological effects are caused with gas discharges, water discharges, and electromagnetic fields. The discharges yield free radicals, UV radiation, intense electric field, and shock waves. Biologically based applications of pulsed power and plasma are performed by selecting the type that gives the target objects the adequate result from among these agents or byproducts. For instance, intense electric fields form pores on the cell membrane, which is called electroporation, or influence the nuclei. This paper mainly describes the application of the pulsed power for the germination control of Basidiomycota i.e. mushroom, inactivation of fungi in the soil and the liquid medium in hydroponics, and extraction of polyphenol from skins of grape.

  13. Pulsed power supply for Nova Upgrade. Final report, August 1, 1991 to March 31, 1992

    SciTech Connect

    Bacon, J.L.; Kajs, J.P.; Walls, A.; Weldon, W.F.; Zowarka, R.C.

    1992-12-31

    This report describes work carried out at the Center for Electromechanics at The University of Texas at Austin (CEM-UT). A baseline design of the Nova Upgrade has been completed by Lawrence Livermore National Laboratory. The Nova Upgrade is an 18 beamline Nd: glass laser design utilizing fully relayed 4x4 30 cm aperture segmented optical components. The laser thus consists of 288 independent beamlets nominally producing 1.5 to 2.0 MJ of 0.35 {mu}m light in a 3 to 5 ns pulse. The laser design is extremely flexible and will allow a wide range of pulses to irradiate ICF targets. This facility will demonstrate ignition/gain and the scientific feasibility of ICF for energy and defense applications. The pulsed power requirements for the Nova Upgrade are given. CEM-UT was contracted to study and develop a design for a homopolar generator/inductor (HPG/inductor) opening switch system which would satisfy the pulsed power supply requirements of the Nova Upgrade. The Nd:glass laser amplifiers used in the Nova Upgrade will be powered by light from xenon flashlamps. The pulsed power supply for the Nova Upgrade powers the xenon flashlamps. This design and study was for a power supply to drive flashlamps.

  14. Apparatus for advancing a wellbore using high power laser energy

    DOEpatents

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

    2014-09-02

    Delivering high power laser energy to form a borehole deep into the earth using laser energy. Down hole laser tools, laser systems and laser delivery techniques for advancement, workover and completion activities. A laser bottom hole assembly (LBHA) for the delivery of high power laser energy to the surfaces of a borehole, which assembly may have laser optics, a fluid path for debris removal and a mechanical means to remove earth.

  15. Development of a Power Electronics Controller for the Advanced Stirling Radioisotope Generator

    NASA Technical Reports Server (NTRS)

    Leland, Douglas K.; Priest, Joel F.; Keiter, Douglas E.; Schreiber, Jeffrey G.

    2008-01-01

    Under a U.S. Department of Energy program for radioisotope power systems, Lockheed Martin is developing an Engineering Unit of the Advanced Stirling Radioisotope Generator (ASRG). This is an advanced version of the previously reported SRG110 generator. The ASRG uses Advanced Stirling Convertors (ASCs) developed by Sunpower Incorporated under a NASA Research Announcement contract. The ASRG makes use of a Stirling controller based on power electronics that eliminates the tuning capacitors. The power electronics controller synchronizes dual-opposed convertors and maintains a fixed frequency operating point. The controller is single-fault tolerant and uses high-frequency pulse width modulation to create the sinusoidal currents that are nearly in phase with the piston velocity, eliminating the need for large series tuning capacitors. Sunpower supports this effort through an extension of their controller development intended for other applications. Glenn Research Center (GRC) supports this effort through system dynamic modeling, analysis and test support. The ASRG design arrived at a new baseline based on a system-level trade study and extensive feedback from mission planners on the necessity of single-fault tolerance. This paper presents the baseline design with an emphasis on the power electronics controller detailed design concept that will meet space mission requirements including single fault tolerance.

  16. Modification of film structure by plasma potential control using triode high power pulsed magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Nakano, Takeo; Umahashi, Takuya; Baba, Shigeru

    2014-02-01

    We have designed a new triode configuration in a magnetron sputtering apparatus to control the plasma potential of the discharge. An additional chimney electrode was introduced above the conventional sputter gun to apply a positive voltage. The discharge power was provided by a pulse power source to achieve high power pulsed magnetron sputtering operation. We confirmed that the plasma potential increased with increasing positive electrode voltage. Copper films with substantially flatter surfaces could be obtained on a water-cooled and electrically grounded substrate at an Ar gas pressure of 5 Pa.

  17. A new lead-acid battery for high pulse power applications

    NASA Technical Reports Server (NTRS)

    Rowlette, J. J.; Attia, A. I.

    1987-01-01

    The development of new electronically conductive materials which can withstand the environment of the positive plates has made possible the construction of a high pulse power sealed bipolar lead-acid battery. The new battery is described and its advantages over other electrochemical systems are outlined. Performance projections show that the peak specific power of the battery can be as high as 90 kW/kg, and that a specific power of 5 kW/kg can be sustained over several thousand pulses.

  18. BIOMASS GASIFICATION AND POWER GENERATION USING ADVANCED GAS TURBINE SYSTEMS

    SciTech Connect

    David Liscinsky

    2002-10-20

    A multidisciplined team led by the United Technologies Research Center (UTRC) and consisting of Pratt & Whitney Power Systems (PWPS), the University of North Dakota Energy & Environmental Research Center (EERC), KraftWork Systems, Inc. (kWS), and the Connecticut Resource Recovery Authority (CRRA) has evaluated a variety of gasified biomass fuels, integrated into advanced gas turbine-based power systems. The team has concluded that a biomass integrated gasification combined-cycle (BIGCC) plant with an overall integrated system efficiency of 45% (HHV) at emission levels of less than half of New Source Performance Standards (NSPS) is technically and economically feasible. The higher process efficiency in itself reduces consumption of premium fuels currently used for power generation including those from foreign sources. In addition, the advanced gasification process can be used to generate fuels and chemicals, such as low-cost hydrogen and syngas for chemical synthesis, as well as baseload power. The conceptual design of the plant consists of an air-blown circulating fluidized-bed Advanced Transport Gasifier and a PWPS FT8 TwinPac{trademark} aeroderivative gas turbine operated in combined cycle to produce {approx}80 MWe. This system uses advanced technology commercial products in combination with components in advanced development or demonstration stages, thereby maximizing the opportunity for early implementation. The biofueled power system was found to have a levelized cost of electricity competitive with other new power system alternatives including larger scale natural gas combined cycles. The key elements are: (1) An Advanced Transport Gasifier (ATG) circulating fluid-bed gasifier having wide fuel flexibility and high gasification efficiency; (2) An FT8 TwinPac{trademark}-based combined cycle of approximately 80 MWe; (3) Sustainable biomass primary fuel source at low cost and potentially widespread availability-refuse-derived fuel (RDF); (4) An overall integrated

  19. Combinatorial pulse position modulation for power-efficient free-space laser communications

    NASA Technical Reports Server (NTRS)

    Budinger, James M.; Vanderaar, M.; Wagner, P.; Bibyk, Steven

    1993-01-01

    A new modulation technique called combinatorial pulse position modulation (CPPM) is presented as a power-efficient alternative to quaternary pulse position modulation (QPPM) for direct-detection, free-space laser communications. The special case of 16C4PPM is compared to QPPM in terms of data throughput and bit error rate (BER) performance for similar laser power and pulse duty cycle requirements. The increased throughput from CPPM enables the use of forward error corrective (FEC) encoding for a net decrease in the amount of laser power required for a given data throughput compared to uncoded QPPM. A specific, practical case of coded CPPM is shown to reduce the amount of power required to transmit and receive a given data sequence by at least 4.7 dB. Hardware techniques for maximum likelihood detection and symbol timing recovery are presented.

  20. Investigation of rocket-powered, open-cycle, magnetohydrodynamic generators for high, pulsed power needs in space. Master's thesis

    SciTech Connect

    Power, J.W.

    1986-11-01

    This investigation examined the possibility of using a rocket-powered magnetohydrodynamic generator for pulse power in space of 300 megawatts (MW). The result is a preliminary design of an MHD generator using an open cycle disk channel and a single superconducting solenoid coil. The disk channel acts as a thrust deflector, and internal vanes counteract induced vorticity. The use of a solid-fuel-wafer grain design rocket motor is proposed for increased electrical conductivity and pulse operation of the generator. Using conservative parameters, a generator design capable of being carried on one or two space-shuttle launches is developed with estimated mass of 24,450 kg and estimated power output of 1346 MW. The nominal operation time before refurbishment is 115 seconds; the restriction operation time is deterioration of the channel throat. This design exceeds present nuclear and solar-cell power systems in power output per unit mass.

  1. Superconducting Multi-Cell Deflecting Cavity for Short-Pulse X-Ray Generation at the Advanced Photon Source

    SciTech Connect

    G.J. Waldschmidt, L.H. Morrison, R. Nassiri, R.A. Rimmer, K. Tian, H. Wang

    2009-05-01

    A superconducting multi-cell cavity for the production of short x-ray pulses at the Advanced Photon Source (APS) has been explored as an alternative to a single-cell cavity design in order to improve the packing factor and potentially reduce the number of high-power RF systems and low-level RF controls required. The cavity will operate at 2815 MHz in the APS storage ring and will require heavy damping of parasitic modes to maintain stable beam operation. Novel on-cell dampers, attached directly to the cavity body, have been utilized by taking advantage of the magnetic field null on the equatorial plane in order to enhance damping. Design issues and simulation results will be discussed.

  2. FY2009 Annual Progress Report for Advanced Power Electronics

    SciTech Connect

    Rogers, Susan A.

    2010-01-01

    The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on understanding and improving the way the various new components of tomorrow's automobiles will function as a unified system to improve fuel efficiency.

  3. BORON NITRIDE CAPACITORS FOR ADVANCED POWER ELECTRONIC DEVICES

    SciTech Connect

    N. Badi; D. Starikov; C. Boney; A. Bensaoula; D. Johnstone

    2010-11-01

    This project fabricates long-life boron nitride/boron oxynitride thin film -based capacitors for advanced SiC power electronics with a broad operating temperature range using a physical vapor deposition (PVD) technique. The use of vapor deposition provides for precise control and quality material formation.

  4. Results of Laboratory Testing of Advanced Power Strips

    SciTech Connect

    Earle, L.; Sparn, B.

    2012-08-01

    Presented at the ACEEE Summer Study on Energy Efficiency in Buildings on August 12-17, 2012, this presentation reports on laboratory tests of 20 currently available advanced power strip products, which reduce wasteful electricity use of miscellaneous electric loads in buildings.

  5. A Pulsed Power Supply with Sag Compensation using Controlled Gradational Voltage

    NASA Astrophysics Data System (ADS)

    Suzuki, Akihiro; Yamada, Masaki; Tashiro, Shojirou; Iwata, Akihiko

    A pulsed power supply with sag compensation using controlled gradational voltage to increase the flatness of output waveforms has been developed.The sag compensation circuit consists of compensation units connected in series. Each compensation unit consists of capacitances, diodes, and semiconductor switches. The capacitances of each unit are charged with different voltages by 2n (V0, 2V0, 4V0, ···). The compensation voltages, which has 2n-1 steps, is generated by switching the semiconductor switches of each unit in a binary sequence. Using this method, compensation voltage waveforms up to 6.2kV with 31 steps can be obtained with 5 compensation units. The sag compensation circuit has been adapted to a direct switch type pulsed power supply, which generates 7kV pulsed voltage with a pulse width of 700μs, thus realizing sag compensation.

  6. Suppression of beam induced pulse shortening modes in high power RF generator TW output structures

    SciTech Connect

    Haimson, J.; Mecklenburg, B.

    1992-12-31

    Several different style 11.4 GHz relativistic klystrons, operating with beam pulse widths of 50 ns and using large aperture, tapered phase-velocity TW structures,` have recently demonstrated output RF power levels in the range of 100 to 300 MW without breakdown or pulse shortening. To extend this performance into the long pulse regime (1 {mu}s) or to demonstrate a threefold increase in output power by using higher currents, the existing TW circuit designs must be modified (a) to reduce the cavity maximum surface E-fields by a factor of 2 to 3, and (b) to elevate the current threshold values of the beam induced higher order modes (HOM) to ensure avoidance of RF pulse shortening and associated instabilities. A technique for substantially elevating this threshold current is described, and microwave data and photographs are presented showing the degree of HOM damping achieved in a recently constructed 11.4 GHz TW structure.

  7. Advanced Integrated Power and Attitude Control System (IPACS) study

    NASA Technical Reports Server (NTRS)

    Oglevie, R. E.; Eisenhaure, D. B.

    1985-01-01

    Integrated Power and Attitude Control System (IPACS) studies performed over a decade ago established the feasibility of simultaneously satisfying the demands of energy storage and attitude control through the use of rotating flywheels. It was demonstrated that, for a wide spectrum of applications, such a system possessed many advantages over contemporary energy storage and attitude control approaches. More recent technology advances in composite material rotors, magnetic suspension systems, and power control electronics have triggered new optimism regarding the applicability and merits of this concept. This study is undertaken to define an advanced IPACS and to evaluate its merits for a space station application. System and component designs are developed to establish the performance of this concept and system trade studies conducted to examine the viability of this approach relative to conventional candidate systems. It is clearly demonstrated that an advanced IPACS concept is not only feasible, but also offers substantial savings in mass and life-cycle cost for the space station mission.

  8. Compact Fusion Advanced Rankine (CFARII) power cycle---Operating regimes

    SciTech Connect

    Logan, B.G.

    1991-09-30

    Performance (cost/kWe and efficiency) of generic Compact Fusion Advanced Rankine (CFARII) power conversion is investigated for various working fluids, operating temperatures and pressures, and thermal power levels. A general conclusion is that good CFARII performance is found for a remarkably broad range of materials, temperatures, pressures and power levels, which gives considerable flexibility to future design studies which may apply CFARII energy conversion to specific fusion energy sources such as ICF, MICF, and Mini-PACER. 5 refs, 7 figs., 2 tabs.

  9. Lightweight, Efficient Power Converters for Advanced Turboelectric Aircraft Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Hennessy, Michael J.

    2014-01-01

    NASA is investigating advanced turboelectric aircraft propulsion systems that use superconducting motors to drive multiple distributed turbofans. Conventional electric motors are too large and heavy to be practical for this application; therefore, superconducting motors are required. In order to improve aircraft maneuverability, variable-speed power converters are required to throttle power to the turbofans. The low operating temperature and the need for lightweight components that place a minimum of additional heat load on the refrigeration system open the possibility of incorporating extremely efficient cryogenic power conversion technology. This Phase II project is developing critical components required to meet these goals.

  10. Modeling of high efficiency solar cells under laser pulse for power beaming applications

    NASA Technical Reports Server (NTRS)

    Jain, Raj K.; Landis, Geoffrey A.

    1994-01-01

    Solar cells have been used to convert sunlight to electrical energy for many years and also offer great potential for non-solar energy conversion applications. Their greatly improved performance under monochromatic light compared to sunlight, makes them suitable as photovoltaic (PV) receivers in laser power beaming applications. Laser beamed power to a PV array receiver could provide power to satellites, an orbital transfer vehicle, or a lunar base. Gallium arsenide (GaAs) and indium phosphide (InP) solar cells have calculated efficiencies of more than 50 percent under continuous illumination at the optimum wavelength. Currently high power free-electron lasers are being developed which operate in pulsed conditions. Understanding cell behavior under a laser pulse is important in the selection of the solar cell material and the laser. An experiment by NAsA lewis and JPL at the AVLIS laser facility in Livermore, CA presented experimental data on cell performance under pulsed laser illumination. Reference 5 contains an overview of technical issues concerning the use of solar cells for laser power conversion, written before the experiments were performed. As the experimental results showed, the actual effects of pulsed operation are more complicated. Reference 6 discusses simulations of the output of GaAs concentrator solar cells under pulsed laser illumination. The present paper continues this work, and compares the output of Si and GaAs solar cells.

  11. Signal pulses superimposed on power supply lines improve electrical control

    SciTech Connect

    1996-06-01

    To manipulate or monitor the operation of cranes and hoists, control engineers typically create control schemes that add numerous conductors, festoon systems, bulky dedicated conductor rails, radio and infrared controls. With modern power line communication equipment, power and intelligence can be combined to: add an unlimited number of control circuits without adding a single wire; have data communication without special cables; and eliminate bulky festoon systems and heavy cable track. Available from US Safety Trolley Corp., a SmartRail system superimposes data and control information on the power line to create a fully functional Local Area Network (LAN). The system network is based on the CEBus protocol EIA/IS-60 and uses a spread spectrum power line carrier technology. The heart of this system is the controller which manages all communication and control tasks. A power line coupling circuit couples the data signal from the controller to the a-c power conductors. These power conductors are often TRI-BAR/FOUR-BAR continuous conductor bar systems or existing conductor bar systems. The combination results in a secure data communications and control system for moving equipment.

  12. A circuit used for peak power detecting of the laser pulse

    NASA Astrophysics Data System (ADS)

    Gou, Yongsheng; Liu, Baiyu; Bai, Yonglin; Wang, Bo; Zhu, Bingli; Bai, Xiaohong; Qin, JunJun; Xu, Peng

    2015-02-01

    Based on the principle of capacitor pre-charging, an analog pulse stretch circuit is designed for detecting peak power of narrow laser impulse. Experimental test were carried out. And it could achieve regulation accuracy of 5ps, jitter<600ps. Due to the need of different delay ranges during the practical applications, the analog pulse stretch circuit is optimized. It doesn't only meet the different adjustment ranges, but also maintains high regulation accuracy.

  13. Breaking symmetry in propagation of radially and azimuthally polarized high power laser pulses in underdense plasma

    NASA Astrophysics Data System (ADS)

    Pathak, Naveen; Zhidkov, Alexei; Nakanii, Nobuhiko; Masuda, Shinichi; Hosokai, Tomonao; Kodama, Ryosuke

    2016-03-01

    Propagation of relativistically intense azimuthally or radially polarized laser pulses (RPP) is demonstrated, via 3D particle-in-cell simulations, to be unstable in uniform underdense plasma. Strong breaking of the pulse symmetry occurs for RPP with power exceeding the critical one for self-focusing in transversely uniform plasma with an increment, Γ, close to the well-known Rayleigh-Taylor-like instability depending on the acceleration, α, and the modulated density gradient length, L, as Γ≈(α/L) 1 /2 . In deeper plasma channels, the instability vanishes. Electron self-injection in the pulse wake and resulting acceleration is explored.

  14. Gasification CFD Modeling for Advanced Power Plant Simulations

    SciTech Connect

    Zitney, S.E.; Guenther, C.P.

    2005-09-01

    In this paper we have described recent progress on developing CFD models for two commercial-scale gasifiers, including a two-stage, coal slurry-fed, oxygen-blown, pressurized, entrained-flow gasifier and a scaled-up design of the PSDF transport gasifier. Also highlighted was NETL’s Advanced Process Engineering Co-Simulator for coupling high-fidelity equipment models with process simulation for the design, analysis, and optimization of advanced power plants. Using APECS, we have coupled the entrained-flow gasifier CFD model into a coal-fired, gasification-based FutureGen power and hydrogen production plant. The results for the FutureGen co-simulation illustrate how the APECS technology can help engineers better understand and optimize gasifier fluid dynamics and related phenomena that impact overall power plant performance.

  15. Enabling pulsed power technologies for the generation of intense, nanosecond electric fields

    NASA Astrophysics Data System (ADS)

    Sanders, Jason M.

    This dissertation focuses on the design and implementation of pulsed power systems with an emphasis on systems that generate high peak powers on nanosecond and subnanosecond timescales. These systems are an enabling technology for many areas of scientific research focused on the effects of intense, nanosecond pulsed electric fields or pulsed discharges on physical processes. Researchers at USC use these systems in a variety of diverse application areas, including research into ignition and combustion using nanosecond discharges, research into the effects of pulsed electric fields on biological systems, and research into the efficacy of cold plasma discharges for disinfection. Each of these applications has its own set of pulsed power parameters, and in most cases these parameters necessitate that the systems be custom developed. The bulk of what follows will address the design methodologies, materials, and implementation techniques required for systems capable of generating high current (20 -- 500 Amperes), high voltage (1 kV -- 100 kV), nanosecond pulses. These principles culminate in the presentation of a new, compact, solid state architecture, which has been implemented into a system called the Rapid Pulser. This architecture uses diode opening switches at the output to switch inductively stored energy into a resistive load. To switch properly, these diodes must be pumped in the forward and reverse directions by a current, and this new architecture introduces a pumping circuit that significantly improves pulse shape as well as reduces amplitude jitter, time jitter, complexity, cost, and size. At 1.6 kg, this is the lightest pulsed power system developed at USC's Pulsed Power Lab, which is significant because minimizing size and weight is necessary for applications focused on the ignition and combustion of fuels. A summary of research focused on magnetic and dielectric materials for nonlinear energy compression will also be presented. Nonlinearities inherent to

  16. Advances in Pneumatic-Controlled High-Lift Systems Through Pulsed Blowing

    NASA Technical Reports Server (NTRS)

    Jones, Gregory S.; Englar, Robet J.

    2003-01-01

    Circulation Control technologies have been around for 65 years, and have been successfully demonstrated in laboratories and flight vehicles alike. Yet there are few production aircraft flying today that implement these advances. Circulation Control techniques may have been overlooked due to perceived unfavorable trade offs of mass flow, pitching moment, cruise drag, noise, etc. Improvements in certain aspects of Circulation Control technology are the focus of this paper. This report will describe airfoil and blown high lift concepts that also address cruise drag reduction and reductions in mass flow through the use of pulsed pneumatic blowing on a Coanda surface. Pulsed concepts demonstrate significant reductions in mass flow requirements for Circulation Control, as well as cruise drag concepts that equal or exceed conventional airfoil systems.

  17. Pulse

    MedlinePlus

    ... resting for at least 10 minutes. Take the exercise heart rate while you are exercising. ... pulse rate can help determine if the patient's heart is pumping. ... rate gives information about your fitness level and health.

  18. Enhanced multi-colour gating for the generation of high-power isolated attosecond pulses

    PubMed Central

    Haessler, S.; Balčiūnas, T.; Fan, G.; Chipperfield, L. E.; Baltuška, A.

    2015-01-01

    Isolated attosecond pulses (IAP) generated by high-order harmonic generation are valuable tools that enable dynamics to be studied on the attosecond time scale. The applicability of these IAP would be widened drastically by increasing their energy. Here we analyze the potential of using multi-colour driving pulses for temporally gating the attosecond pulse generation process. We devise how this approach can enable the generation of IAP with the available high-energy kHz-repetition-rate Ytterbium-based laser amplifiers (delivering 180-fs, 1030-nm pulses). We show theoretically that this requires a three-colour field composed of the fundamental and its second harmonic as well as a lower-frequency auxiliary component. We present pulse characterization measurements of such auxiliary pulses generated directly by white-light seeded OPA with the required significantly shorter pulse duration than that of the fundamental. This, combined with our recent experimental results on three-colour waveform synthesis, proves that the theoretically considered multi-colour drivers for IAP generation can be realized with existing high-power laser technology. The high-energy driver pulses, combined with the strongly enhanced single-atom-level conversion efficiency we observe in our calculations, thus make multi-colour drivers prime candidates for the development of unprecedented high-energy IAP sources in the near future. PMID:25997917

  19. Multi-nanosecond high power pulse generation at 7.8GHz with a dielectric-loaded power extractor.

    SciTech Connect

    Conde, M..; Gai, W.; Konecny, R.; Liu, W.; Power, J. G.; Gao, F.; Jing, C.; Wong, T.; Yusof, Z.; High Energy Physics; Illinois Inst. of Tech.; Euclid Techlabs LLC; IEEE

    2009-06-01

    Power extraction from charged particle beams is a prospective way to develop future high power radio frequency (RF) sources. We have designed and tested a 7.8 GHz power extractor based on a dielectric-loaded waveguide. Building upon earlier work on single electron bunch tests, 10 ns and 22 ns megawatt-level RF pulses have been generated with trains consisting of 16 electron bunches each, by using a laser splitting-recombination scheme. In addition, 44 MW of peak power has been generated with a train consisting 4 electron bunches. Behaviors of higher-order-modes are also explored.

  20. Dynamic Behaviors of Materials under Ramp Wave Loading on Compact Pulsed Power Generators

    NASA Astrophysics Data System (ADS)

    Zhao, Jianheng; Luo, Binqiang; Wang, Guiji; Chong, Tao; Tan, Fuli; Liu, Cangli; Sun, Chengwei

    The technique using intense current to produce magnetic pressure provides a unique way to compress matter near isentrope to high density without obvious temperature increment, which is characterized as ramp wave loading, and firstly developed by Sandia in 1998. Firstly recent advances on compact pulsed power generators developed in our laboratory, such as CQ-4, CQ-3-MMAF and CQ-7 devices, are simply introduced here, which devoted to ramp wave loading from 50GPa to 200 GPa, and to ultrahigh-velocity flyer launching up to 30 km/s. And then, we show our progress in data processing methods and experiments of isentropic compression conducted on these devices mentioned above. The suitability of Gruneisen EOS and Vinet EOS are validated by isentropic experiments of tantalum, and the parameters of SCG constitutive equation of aluminum and copper are modified to give better prediction under isentropic compression. Phase transition of bismuth and tin are investigated under different initial temperatures, parameters of Helmholtz free energy and characteristic relaxation time in kinetic phase transition equation are calibrated. Supported by NNSF of China under Contract No.11327803 and 11176002

  1. Electrothermal instability growth in magnetically driven pulsed power liners

    SciTech Connect

    Peterson, Kyle J.; Sinars, Daniel B.; Yu, Edmund P.; Herrmann, Mark C.; Cuneo, Michael E.; Slutz, Stephen A.; Smith, Ian C.; Atherton, Briggs W.; Knudson, Marcus D.; Nakhleh, Charles

    2012-09-15

    This paper explores the role of electro-thermal instabilities on the dynamics of magnetically accelerated implosion systems. Electro-thermal instabilities result from non-uniform heating due to temperature dependence in the conductivity of a material. Comparatively little is known about these types of instabilities compared to the well known Magneto-Rayleigh-Taylor (MRT) instability. We present simulations that show electrothermal instabilities form immediately after the surface material of a conductor melts and can act as a significant seed to subsequent MRT instability growth. We also present the results of several experiments performed on Sandia National Laboratories Z accelerator to investigate signatures of electrothermal instability growth on well characterized initially solid aluminum and copper rods driven with a 20 MA, 100 ns risetime current pulse. These experiments show excellent agreement with electrothermal instability simulations and exhibit larger instability growth than can be explained by MRT theory alone.

  2. Using an active temporal compensating system to achieve the super-Gaussian pulses in high-power lasers

    NASA Astrophysics Data System (ADS)

    Wang, Yulei; Liu, Rui; Yuan, Hang; Li, Sensen; Liu, Zhaohong; Zhu, Xuehua; He, Weiming; Lv, Zhiwei

    2015-08-01

    In high-power solid-state laser, initiative pulse shaping can help improve the output laser's performance. The evaluation for output laser pulse is also incomplete. In this paper, we propose a method of initiative pulse shaping by using arbitrary waveform generator (AWG), and establish a relatively complete evaluation system for the output pulses shape simultaneously. It achieves the super-Gaussian pulse output with high SNR (signal-to-noise ratio). As a consequence, a square laser pulse with pulse adjustable width ~5ns, rising time 197ps is obtained. The power imbalance of the output square pulse is 3.72%. The similarity between the eight-order super-Gaussian pulse and the one we get from experiment reached 99%.

  3. All-fiber high-average power nanosecond-pulsed master-oscillator power amplifier at 2  μm with mJ-level pulse energy.

    PubMed

    Wang, Xiong; Jin, Xiaoxi; Zhou, Pu; Wang, Xiaolin; Xiao, Hu; Liu, Zejin

    2016-03-10

    We present a high-power nanosecond-pulsed Tm-doped fiber amplifier at 1.971 μm based on a master-oscillator power amplifier (MOPA) configuration. When the repetition rate is 500 kHz and the pulse width is 63.3 ns, the average power reaches 238 W, the peak power reaches 7.06 kW, and the pulse energy is 0.477 mJ. When the pulse train's repetition rate is 300 kHz with a pulse width of 63.7 ns, the average power reaches 197 W, the peak power reaches 9.73 kW, and the pulse energy is 0.66 mJ. When the pulse train's repetition rate is 200 kHz with a pulse width of 58.2 ns, the average power reaches 150 W, the peak power reaches 12.1 kW, and the pulse energy is 0.749 mJ. The spectral linewidths of the pulse trains are 0.15, 0.14, and 0.10 nm for 500 kHz repetition rate, 300 kHz repetition rate, and 200 kHz repetition rate, respectively. To the best of our knowledge, this is the first demonstration of high-power nanosecond-pulsed MOPA at 2 μm with the maximum average power reaching 238 W, the maximum peak power reaching 12.1 kW, and the maximum pulse energy reaching 0.749 mJ.

  4. A low-power high-speed ultra-wideband pulse radio transmission system.

    PubMed

    Wei Tang; Culurciello, E

    2009-10-01

    We present a low-power high-speed ultra-wideband (UWB) transmitter with a wireless transmission test platform. The system is specifically designed for low-power high-speed wireless implantable biosensors. The integrated transmitter consists of a compact pulse generator and a modulator. The circuit is fabricated in the 0.5-mum silicon-on-sapphire process and occupies 420 mum times 420 mum silicon area. The transmitter is capable of generating pulses with 1-ns width and the pulse rate can be controlled between 90 MHz and 270 MHz. We built a demonstration/testing system for the transmitter. The transmitter achieves a 14-Mb/s data rate. With 50% duty cycle data, the power consumption of the chip is between 10 mW and 21 mW when the transmission distance is from 3.2 to 4 m. The core circuit size is 70 mum times 130 mum. PMID:23853267

  5. Non-chain pulsed DF laser with an average power of the order of 100 W

    NASA Astrophysics Data System (ADS)

    Pan, Qikun; Xie, Jijiang; Wang, Chunrui; Shao, Chunlei; Shao, Mingzhen; Chen, Fei; Guo, Jin

    2016-07-01

    The design and performance of a closed-cycle repetitively pulsed DF laser are described. The Fitch circuit and thyratron switch are introduced to realize self-sustained volume discharge in SF6-D2 mixtures. The influences of gas parameters and charging voltage on output characteristics of non-chain pulsed DF laser are experimentally investigated. In order to improve the laser power stability over a long period of working time, zeolites with different apertures are used to scrub out the de-excitation particles produced in electric discharge. An average output power of the order of 100 W was obtained at an operating repetition rate of 50 Hz, with amplitude difference in laser pulses <8 %. And under the action of micropore alkaline zeolites, the average power fell by 20 % after the laser continuing working 100 s at repetition frequency of 50 Hz.

  6. High-power pulsed diode laser for automotive scanning radar sensor

    NASA Astrophysics Data System (ADS)

    Kimura, Yuji; Matsushita, Noriyuki; Kato, Hisaya; Abe, Katsunori; Atsumi, Kinya

    2000-02-01

    High performance pulsed AlGaAs/GaAs wide stripe diode laser has been developed for the automotive distance-measuring scanning radar sensor. The laser diode is required high output power of 15 W and a long time reliability in spite of being used in a harsh environment such as wide temperature range, mechanical vibrations at the front bumper and so on. The device is designed by employing a multiple quantum well structure as an active layer for high output power with low drive current and high temperature operations. Moreover we reduce catastrophic optical damage power level and control the beam divergence angle by introducing optimized optical waveguide layers. In the chips bonding part, we developed a new thin film Au-Sn-Ni solder system. The bonding temperature can be lowered by using this system, whereby the thermal damage to the laser diode can be reduced. Furthermore, highly stable bonding is carried out by improving wetting ability in this system. We have achieved more than 22 W light output power at 20A pulse current under room temperature and more than 16 W light output power under 90 degrees Celsius. High reliability over 10,000 hours is performed for automotive use under pulsed operation at 90 degrees Celsius, 50 ns pulse width, 8 kHz frequency and 15 W light output power.

  7. Advanced, High Power, Next Scale, Wave Energy Conversion Device

    SciTech Connect

    Mekhiche, Mike; Dufera, Hiz; Montagna, Deb

    2012-10-29

    The project conducted under DOE contract DE‐EE0002649 is defined as the Advanced, High Power, Next Scale, Wave Energy Converter. The overall project is split into a seven‐stage, gated development program. The work conducted under the DOE contract is OPT Stage Gate III work and a portion of Stage Gate IV work of the seven stage product development process. The project effort includes Full Concept Design & Prototype Assembly Testing building on our existing PowerBuoy technology to deliver a device with much increased power delivery. Scaling‐up from 150kW to 500kW power generating capacity required changes in the PowerBuoy design that addressed cost reduction and mass manufacturing by implementing a Design for Manufacturing (DFM) approach. The design changes also focused on reducing PowerBuoy Installation, Operation and Maintenance (IO&M) costs which are essential to reducing the overall cost of energy. In this design, changes to the core PowerBuoy technology were implemented to increase capability and reduce both CAPEX and OPEX costs. OPT conceptually envisaged moving from a floating structure to a seabed structure. The design change from a floating structure to seabed structure would provide the implementation of stroke‐ unlimited Power Take‐Off (PTO) which has a potential to provide significant power delivery improvement and transform the wave energy industry if proven feasible.

  8. Advancements in high-power diode laser stacks for defense applications

    NASA Astrophysics Data System (ADS)

    Pandey, Rajiv; Merchen, David; Stapleton, Dean; Patterson, Steve; Kissel, Heiko; Fassbender, Wilhlem; Biesenbach, Jens

    2012-06-01

    This paper reports on the latest advancements in vertical high-power diode laser stacks using micro-channel coolers, which deliver the most compact footprint, power scalability and highest power/bar of any diode laser package. We present electro-optical (E-O) data on water-cooled stacks with wavelengths ranging from 7xx nm to 9xx nm and power levels of up to 5.8kW, delivered @ 200W/bar, CW mode, and a power-conversion efficiency of >60%, with both-axis collimation on a bar-to-bar pitch of 1.78mm. Also, presented is E-O data on a compact, conductively cooled, hardsoldered, stack package based on conventional CuW and AlN materials, with bar-to-bar pitch of 1.8mm, delivering average power/bar >15W operating up to 25% duty cycle, 10ms pulses @ 45C. The water-cooled stacks can be used as pump-sources for diode-pumped alkali lasers (DPALs) or for more traditional diode-pumped solid-state lasers (DPSSL). which are power/brightness scaled for directed energy weapons applications and the conductively-cooled stacks as illuminators.

  9. Advanced conversion technologies for small-scale remote power systems

    SciTech Connect

    Lamp, T.R.

    1996-12-31

    Forest fires that endangered remote US Air Force sites equipped with radioisotope thermoelectric generators (RTGs) prompted the assessment of power generating systems that could be substituted for RTGs in small scale (10--120 watt) applications. Other non-RTG sites were also studied during the assessment. The power system assessment was conducted by the US Air Forces` Wright Laboratory and included the evaluation of engine-driven generators, solar, wind generators, propane thermoelectric generators (TEGs), batteries, fuel cells, and power systems based on advanced conversion technologies; such as, thermionics, free piston Stirling Engines (FPSE), alkali metal thermoelectric conversion (AMTEC), and thermophotovoltaics (TPV). The assessment team concluded that continued use of the RTGs is clearly the safest, most reliable, and most economical approach to supplying electrical power for remote, difficult to access locations. If political considerations force the replacement of the RTGs, the likely replacement is a hybrid system consisting of solar-PV with a propane-TEG for off-solar times. The transport of combustible fuels in Arctic environments is extremely expensive. It is this high logistics cost that signaled the need to consider the option of more efficient and cost effective power sources for the remote, Arctic applications. This paper summarizes the assessment of some of the more attractive power systems that are based on the advanced conversion technologies of AMTEC, TPV and FPSE.

  10. Pulse advancement and delay in an integrated-optical two-port ring-resonator circuit: direct experimental observations.

    PubMed

    Uranus, H P; Zhuang, L; Roeloffzen, C G H; Hoekstra, H J W M

    2007-09-01

    We report experimental observations of the negative-group-velocity (v(g)) phenomenon in an integrated-optical two-port ring-resonator circuit. We demonstrate that when the v(g) is negative, the (main) peak of output pulse appears earlier than the peak of a reference pulse, while for a positive v(g), the situation is the other way around. We observed that a pulse splitting phenomenon occurs in the neighborhood of the critical-coupling point. This pulse splitting limits the maximum achievable delay and advancement of a single device as well as facilitating a smooth transition from highly advanced to highly delayed pulse, and vice versa, across the critical-coupling point. PMID:17767325

  11. Pulse advancement and delay in an integrated-optical two-port ring-resonator circuit: direct experimental observations.

    PubMed

    Uranus, H P; Zhuang, L; Roeloffzen, C G H; Hoekstra, H J W M

    2007-09-01

    We report experimental observations of the negative-group-velocity (v(g)) phenomenon in an integrated-optical two-port ring-resonator circuit. We demonstrate that when the v(g) is negative, the (main) peak of output pulse appears earlier than the peak of a reference pulse, while for a positive v(g), the situation is the other way around. We observed that a pulse splitting phenomenon occurs in the neighborhood of the critical-coupling point. This pulse splitting limits the maximum achievable delay and advancement of a single device as well as facilitating a smooth transition from highly advanced to highly delayed pulse, and vice versa, across the critical-coupling point.

  12. Fiber-Optic Distribution Of Pulsed Power To Multiple Sensors

    NASA Technical Reports Server (NTRS)

    Kirkham, Harold

    1996-01-01

    Optoelectronic systems designed according to time-sharing scheme distribute optical power to multiple integrated-circuit-based sensors in fiber-optic networks. Networks combine flexibility of electronic sensing circuits with advantage of electrical isolation afforded by use of optical fibers instead of electrical conductors to transmit both signals and power. Fiber optics resist corrosion and immune to electromagnetic interference. Sensor networks of this type useful in variety of applications; for example, in monitoring strains in aircraft, buildings, and bridges, and in monitoring and controlling shapes of flexible structures.

  13. Combining microwave beams with high peak power and long pulse duration

    SciTech Connect

    Li Guolin; Shu Ting; Yuan Chengwei; Zhang Jun; Jin Zhenxing; Yang Jianhua

    2010-03-15

    The beam combining results with a metal dichroic plate illuminated by the S/X band gigawatt level high power microwaves are presented. According to the previous experiments, the microwave breakdown problem becomes obvious when the peak power and the pulse duration increase, thus, several methods for enhancing the power handling capacity have been considered, and the metal dichroic plates are redesigned to handle the S/X band high power microwaves. Then the design, fabrication, and testing procedure are discussed in detail. The further experimental results reveal that, operated on the self-built accelerator Spark-04, the radiated powers from the S and X band sources have reached 1.8 GW with pulse durations of about 80 ns, and both beams have been successfully operated on the selected dichroic plate without microwave breakdown.

  14. Cost estimate guidelines for advanced nuclear power technologies

    SciTech Connect

    Delene, J.G.; Hudson, C.R. II

    1993-05-01

    Several advanced power plant concepts are currently under development. These include the Modular High Temperature Gas Cooled Reactors, the Advanced Liquid Metal Reactor and the Advanced Light Water Reactors. One measure of the attractiveness of a new concept is its cost. Invariably, the cost of a new type of power plant will be compared with other alternative forms of electrical generation. This report provides a common starting point, whereby the cost estimates for the various power plants to be considered are developed with common assumptions and ground rules. Comparisons can then be made on a consistent basis. This is the second update of these cost estimate guidelines. Changes have been made to make the guidelines more current (January 1, 1992) and in response to suggestions made as a result of the use of the previous report. The principal changes are that the reference site has been changed from a generic Northeast (Middletown) site to a more central site (EPRI`s East/West Central site) and that reference bulk commodity prices and labor productivity rates have been added. This report is designed to provide a framework for the preparation and reporting of costs. The cost estimates will consist of the overnight construction cost, the total plant capital cost, the operation and maintenance costs, the fuel costs, decommissioning costs and the power production or busbar generation cost.

  15. High-power pulsed-current-mode operation of an overdriven tapered amplifier.

    PubMed

    Takase, Ken; Stockton, John K; Kasevich, Mark A

    2007-09-01

    We experimentally investigate the performance of a commercial tapered amplifier diode operating in a pulsed-current mode with a peak current that is significantly higher than the specified maximum continuous current. For a tapered amplifier rated at 500 mW of continuous power, we demonstrate 2.6 W of peak optical output power with 15 mW of injection light for 200 micros, 7 A current pulses. Different failure mechanisms for the tapered amplifier, including thermal and optical damage, are identified under these conditions. PMID:17767324

  16. Improving Power-Supply Regulation for Pulsed Loads

    NASA Technical Reports Server (NTRS)

    Gulick, C. R.; Chan, R. B.

    1982-01-01

    Power supply voltage-regulator circuit speeds up response to sudden load changes. As load increases, additional feedback path is enabled. Path bypasses and provides faster loop response than normal feedback path. Steady-state instability due to faster loop response avoided by progressively disabling bypass loop and allowing normal feedback path to take over.

  17. Prospects for advanced coal-fuelled fuel cell power plants

    NASA Astrophysics Data System (ADS)

    Jansen, D.; Vanderlaag, P. C.; Oudhuis, A. B. J.; Ribberink, J. S.

    1994-04-01

    As part of ECN's in-house R&D programs on clean energy conversion systems with high efficiencies and low emissions, system assessment studies have been carried out on coal gasification power plants integrated with high-temperature fuel cells (IGFC). The studies also included the potential to reduce CO2 emissions, and to find possible ways for CO2 extraction and sequestration. The development of this new type of clean coal technology for large-scale power generation is still far off. A significant market share is not envisaged before the year 2015. To assess the future market potential of coal-fueled fuel cell power plants, the promise of this fuel cell technology was assessed against the performance and the development of current state-of-the-art large-scale power generation systems, namely the pulverized coal-fired power plants and the integrated coal gasification combined cycle (IGCC) power plants. With the anticipated progress in gas turbine and gas clean-up technology, coal-fueled fuel cell power plants will have to face severe competition from advanced IGCC power plants, despite their higher efficiency.

  18. Development and characterization of a high yield transportable pulsed neutron source with efficient and compact pulsed power system

    NASA Astrophysics Data System (ADS)

    Verma, Rishi; Mishra, Ekansh; Dhang, Prosenjit; Sagar, Karuna; Meena, Manraj; Shyam, Anurag

    2016-09-01

    The results of characterization experiments carried out on a newly developed dense plasma focus device based intense pulsed neutron source with efficient and compact pulsed power system are reported. Its high current sealed pseudospark switch based low inductance capacitor bank with maximum stored energy of ˜10 kJ is segregated into four modules of ˜2.5 kJ each and it cumulatively delivers peak current in the range of 400 kA-600 kA (corresponding to charging voltage range of 14 kV-18 kV) in a quarter time period of ˜2 μs. The neutron yield performance of this device has been optimized by discretely varying deuterium filling gas pressure in the range of 6 mbar-11 mbar at ˜17 kV/550 kA discharge. At ˜7 kJ/8.5 mbar operation, the average neutron yield has been measured to be in the order of ˜4 × 109 neutrons/pulse which is the highest ever reported neutron yield from a plasma focus device with the same stored energy. The average forward to radial anisotropy in neutron yield is found to be ˜2. The entire system is contained on a moveable trolley having dimensions 1.5 m × 1 m × 0.7 m and its operation and control (up to the distance of 25 m) are facilitated through optically isolated handheld remote console. The overall compactness of this system provides minimum proximity to small as well as large samples for irradiation. The major intended application objective of this high neutron yield dense plasma focus device development is to explore the feasibility of active neutron interrogation experiments by utilization of intense pulsed neutron sources.

  19. Status of the Short-Pulse X-ray Project at the Advanced Photon Source

    SciTech Connect

    Nassiri, A; Berenc, T G; Borland, M; Brajuskovic, B; Bromberek, D J; Carwardine, J; Decker, G; Emery, L; Fuerst, J D; Grelick, A E; Horan, D; Kaluzny, J; Lenkszus, F; Lill, R M; Liu, J; Ma, H; Sajaev, V; Smith, T L; Stillwell, B K; Waldschmidt, G J; Wu, G; Yang, B X; Yang, Y; Zholents, A; Byrd, J M; Doolittle, L R; Huang, G; Cheng, G; Ciovati, G; Dhakal, P; Eremeev, G V; Feingold, J J; Geng, R L; Henry, J; Kneisel, P; Macha, K; Mammosser, J D; Matalevich, J; Palczewski, A D; Rimmer, R A; Wang, H; Wilson, K M; Wiseman, M; Li, Z; Xiao, L

    2012-07-01

    The Advanced Photon Source Upgrade (APS-U) Project at Argonne will include generation of short-pulse x-rays based on Zholents deflecting cavity scheme. We have chosen superconducting (SC) cavities in order to have a continuous train of crabbed bunches and flexibility of operating modes. In collaboration with Jefferson Laboratory, we are prototyping and testing a number of single-cell deflecting cavities and associated auxiliary systems with promising initial results. In collaboration with Lawrence Berkeley National Laboratory, we are working to develop state-of-the-art timing, synchronization, and differential rf phase stability systems that are required for SPX. Collaboration with Advanced Computations Department at Stanford Linear Accelerator Center is looking into simulations of complex, multi-cavity geometries with lower- and higher-order modes waveguide dampers using ACE3P. This contribution provides the current R&D status of the SPX project.

  20. Power neodymium-glass amplifier of a repetitively pulsed laser

    SciTech Connect

    Vinogradov, Aleksandr V; Gaganov, V E; Garanin, Sergey G; Zhidkov, N V; Krotov, V A; Martynenko, S P; Pozdnyakov, E V; Solomatin, I I

    2011-11-30

    A neodymium-glass diode-pumped amplifier with a zigzag laser beam propagation through the active medium was elaborated; the amplifier is intended for operation in a repetitively pulsed laser. An amplifier unit with an aperture of 20 Multiplication-Sign 25 mm and a {approx}40-cm long active medium was put to a test. The energy of pump radiation amounts to 140 J at a wavelength of 806 nm for a pump duration of 550 {mu}s. The energy parameters of the amplifier were experimentally determined: the small-signal gain per pass {approx}3.2, the linear gain {approx}0.031 cm{sup -1} with a nonuniformity of its distribution over the aperture within 15%, the stored energy of 0.16 - 0.21 J cm{sup -3}. The wavefront distortions in the zigzag laser-beam propagation through the active element of the amplifier did not exceed 0.4{lambda} ({lambda} = 0.63 {mu}m is the probing radiation wavelength).

  1. Power neodymium-glass amplifier of a repetitively pulsed laser

    NASA Astrophysics Data System (ADS)

    Vinogradov, Aleksandr V.; Gaganov, V. E.; Garanin, Sergey G.; Zhidkov, N. V.; Krotov, V. A.; Martynenko, S. P.; Pozdnyakov, E. V.; Solomatin, I. I.

    2011-11-01

    A neodymium-glass diode-pumped amplifier with a zigzag laser beam propagation through the active medium was elaborated; the amplifier is intended for operation in a repetitively pulsed laser. An amplifier unit with an aperture of 20 × 25 mm and a ~40-cm long active medium was put to a test. The energy of pump radiation amounts to 140 J at a wavelength of 806 nm for a pump duration of 550 μs. The energy parameters of the amplifier were experimentally determined: the small-signal gain per pass ~3.2, the linear gain ~0.031 cm-1 with a nonuniformity of its distribution over the aperture within 15%, the stored energy of 0.16 — 0.21 J cm-3. The wavefront distortions in the zigzag laser-beam propagation through the active element of the amplifier did not exceed 0.4λ (λ = 0.63 μm is the probing radiation wavelength).

  2. Design considerations for 100 MJ class flux compression pulse power systems

    SciTech Connect

    Reinovsky, R.E.; Lindemuth, I.R.

    1993-10-01

    With the cost of high performance, capacitor-discharge, pulse power systems continuing around $1--2 per joule and with energy requirements for experiments such as fast compression of magnetized plasmas ranging to 100 MJ and beyond, the need for economical, super-energy pulse power systems is being recognized. Explosively powered flux compressors, capable of delivering 100 MJ to a plasma physics experiment, can be designed, fabricated, and fielded at costs of less than $0.01J per shot. While less economical than laboratory pulsed power systems, if system life exceeds a few hundred full-energy shots, explosive pulse power techniques allow initial experiments to be performed quickly and economically at energies that are prohibitively costly, and hence unavailable, using conventional techniques. A variety of configurations for flux compressors suitable for 100-MJ operation can be considered. Among these, the disk configuration, pioneered by researchers at the All Russian Institute of Experimental Physics has demonstrated both high current and high energy capabilities.

  3. Microsecond gain-switched master oscillator power amplifier (1958 nm) with high pulse energy

    SciTech Connect

    Ke Yin; Weiqiang Yang; Bin Zhang; Ying Li; Jing Hou

    2014-02-28

    An all-fibre master oscillator power amplifier (MOPA) emitting high-energy pulses at 1958 nm is presented. The seed laser is a microsecond gain-switched thulium-doped fibre laser (TDFL) pumped with a commercial 1550-nm pulsed fibre laser. The TDFL operates at a repetition rate f in the range of 10 to 100 kHz. The two-stage thulium-doped fibre amplifier is built to scale the energy of the pulses generated by the seed laser. The maximum output pulse energy higher than 0.5 mJ at 10 kHz is achieved which is comparable with the theoretical maximum extractable pulse energy. The slope efficiency of the second stage amplifier with respect to the pump power is 30.4% at f = 10 kHz. The wavelength of the output pulse laser is centred near 1958 nm at a spectral width of 0.25 nm after amplification. Neither nonlinear effects nor significant amplified spontaneous emission (ASE) is observed in the amplification experiments. (lasers)

  4. Pulsed electron paramagnetic resonance spectroscopy powered by a free-electron laser.

    PubMed

    Takahashi, S; Brunel, L-C; Edwards, D T; van Tol, J; Ramian, G; Han, S; Sherwin, M S

    2012-09-20

    Electron paramagnetic resonance (EPR) spectroscopy interrogates unpaired electron spins in solids and liquids to reveal local structure and dynamics; for example, EPR has elucidated parts of the structure of protein complexes that other techniques in structural biology have not been able to reveal. EPR can also probe the interplay of light and electricity in organic solar cells and light-emitting diodes, and the origin of decoherence in condensed matter, which is of fundamental importance to the development of quantum information processors. Like nuclear magnetic resonance, EPR spectroscopy becomes more powerful at high magnetic fields and frequencies, and with excitation by coherent pulses rather than continuous waves. However, the difficulty of generating sequences of powerful pulses at frequencies above 100 gigahertz has, until now, confined high-power pulsed EPR to magnetic fields of 3.5 teslas and below. Here we demonstrate that one-kilowatt pulses from a free-electron laser can power a pulsed EPR spectrometer at 240 gigahertz (8.5 teslas), providing transformative enhancements over the alternative, a state-of-the-art ∼30-milliwatt solid-state source. Our spectrometer can rotate spin-1/2 electrons through π/2 in only 6 nanoseconds (compared to 300 nanoseconds with the solid-state source). Fourier-transform EPR on nitrogen impurities in diamond demonstrates excitation and detection of EPR lines separated by about 200 megahertz. We measured decoherence times as short as 63 nanoseconds, in a frozen solution of nitroxide free-radicals at temperatures as high as 190 kelvin. Both free-electron lasers and the quasi-optical technology developed for the spectrometer are scalable to frequencies well in excess of one terahertz, opening the way to high-power pulsed EPR spectroscopy up to the highest static magnetic fields currently available. PMID:22996555

  5. Pulsed electron paramagnetic resonance spectroscopy powered by a free-electron laser.

    PubMed

    Takahashi, S; Brunel, L-C; Edwards, D T; van Tol, J; Ramian, G; Han, S; Sherwin, M S

    2012-09-20

    Electron paramagnetic resonance (EPR) spectroscopy interrogates unpaired electron spins in solids and liquids to reveal local structure and dynamics; for example, EPR has elucidated parts of the structure of protein complexes that other techniques in structural biology have not been able to reveal. EPR can also probe the interplay of light and electricity in organic solar cells and light-emitting diodes, and the origin of decoherence in condensed matter, which is of fundamental importance to the development of quantum information processors. Like nuclear magnetic resonance, EPR spectroscopy becomes more powerful at high magnetic fields and frequencies, and with excitation by coherent pulses rather than continuous waves. However, the difficulty of generating sequences of powerful pulses at frequencies above 100 gigahertz has, until now, confined high-power pulsed EPR to magnetic fields of 3.5 teslas and below. Here we demonstrate that one-kilowatt pulses from a free-electron laser can power a pulsed EPR spectrometer at 240 gigahertz (8.5 teslas), providing transformative enhancements over the alternative, a state-of-the-art ∼30-milliwatt solid-state source. Our spectrometer can rotate spin-1/2 electrons through π/2 in only 6 nanoseconds (compared to 300 nanoseconds with the solid-state source). Fourier-transform EPR on nitrogen impurities in diamond demonstrates excitation and detection of EPR lines separated by about 200 megahertz. We measured decoherence times as short as 63 nanoseconds, in a frozen solution of nitroxide free-radicals at temperatures as high as 190 kelvin. Both free-electron lasers and the quasi-optical technology developed for the spectrometer are scalable to frequencies well in excess of one terahertz, opening the way to high-power pulsed EPR spectroscopy up to the highest static magnetic fields currently available.

  6. Advanced Wireless Power Transfer Vehicle and Infrastructure Analysis (Presentation)

    SciTech Connect

    Gonder, J.; Brooker, A.; Burton, E.; Wang, J.; Konan, A.

    2014-06-01

    This presentation discusses current research at NREL on advanced wireless power transfer vehicle and infrastructure analysis. The potential benefits of E-roadway include more electrified driving miles from battery electric vehicles, plug-in hybrid electric vehicles, or even properly equipped hybrid electric vehicles (i.e., more electrified miles could be obtained from a given battery size, or electrified driving miles could be maintained while using smaller and less expensive batteries, thereby increasing cost competitiveness and potential market penetration). The system optimization aspect is key given the potential impact of this technology on the vehicles, the power grid and the road infrastructure.

  7. Solar Power Satellite Development: Advances in Modularity and Mechanical Systems

    NASA Technical Reports Server (NTRS)

    Belvin, W. Keith; Dorsey, John T.; Watson, Judith J.

    2010-01-01

    Space solar power satellites require innovative concepts in order to achieve economically and technically feasible designs. The mass and volume constraints of current and planned launch vehicles necessitate highly efficient structural systems be developed. In addition, modularity and in-space deployment will be enabling design attributes. This paper reviews the current challenges of launching and building very large space systems. A building block approach is proposed in order to achieve near-term solar power satellite risk reduction while promoting the necessary long-term technology advances. Promising mechanical systems technologies anticipated in the coming decades including modularity, material systems, structural concepts, and in-space operations are described

  8. Short-pulse high-power microwave breakdown at high pressures

    NASA Astrophysics Data System (ADS)

    Zhao, Peng-Cheng; Liao, Cheng; Feng, Ju

    2015-02-01

    The fluid model is proposed to investigate the gas breakdown driven by a short-pulse (such as a Gaussian pulse) high-power microwave at high pressures. However, the fluid model requires specification of the electron energy distribution function (EEDF); the common assumption of a Maxwellian EEDF can result in the inaccurate breakdown prediction when the electrons are not in equilibrium. We confirm that the influence of the incident pulse shape on the EEDF is tiny at high pressures by using the particle-in-cell Monte Carlo collision (PIC-MCC) model. As a result, the EEDF for a rectangular microwave pulse directly derived from the Boltzmann equation solver Bolsig+ is introduced into the fluid model for predicting the breakdown threshold of the non-rectangular pulse over a wide range of pressures, and the obtained results are very well matched with those of the PIC-MCC simulations. The time evolution of a non-rectangular pulse breakdown in gas, obtained by the fluid model with the EEDF from Bolsig+, is presented and analyzed at different pressures. In addition, the effect of the incident pulse shape on the gas breakdown is discussed. Project supported by the National Basic Research Program of China (Grant No. 2013CB328904), the NSAF of China (Grant No. U1330109), and 2012 Doctoral Innovation Funds of Southwest Jiaotong University.

  9. Study of Water Purification with Pulsed Power Supply using MOSFET Switches

    NASA Astrophysics Data System (ADS)

    Shimizu, Kazuo; Blajan, Marius; Muramatsu, Shuichi

    A Marx generator using MOSFET switches was built and studied in this paper for water purification. In order to replace the spark gap type of pulse power sources, with miss fire problems and short mechanical lifetime. In case of Marx Generator which generates negative pulses, a maximum output voltage of 3.6 kV, rise time of 40 ns and pulse width of 600 ns, was obtained. Discharge energy of one pulse was about 801 μJ for negative polarity at -2.4 kV. In case of positive pulses, a maximum output voltage of 3.6 kV, rise time of 75 ns and pulse width of 750 ns, was obtained. Discharge energy of one pulse was about 1120 μJ at 2.4 kV. The discharge was generated in bubbling water using a Marx Generator with MOSFET switches. The discoloration of indigo carmine solution was carried out to investigate the feasibility of low voltage discharge in bubbling water. As a result, indigo carmine solution was decolorized, although the discharge voltage was about -2.4 kV. The treatment performance was improved when oxygen was fed in the solution. The discoloration rate was 100 % after treatment time of 15 min with oxygen used as carrier gas. Emission of OH was confirmed and considered to play a role for water purification.

  10. Prospects for advanced rocket-powered launch vehicles

    NASA Astrophysics Data System (ADS)

    Eldred, C. H.; Talay, T. A.

    1986-10-01

    The potential for advanced rocket-powered launch vehicles to meet the challenging cost, operational, and performance demands of space transportation in the early 21st century is examined. Space transportation requirements from recent studies underscoring the need for growth in capacity in support of an increasing diversity of space activities and the need for significant reductions in operational and life-cycle costs are reviewed. Fully reusable rocket powered concepts based on moderate levels of evolutionary advanced technology are described. These vehicles provide a broad range of attractive concept alternatives with the potential to meet demanding operational and cost goals and the flexibility to satisfy a variety of vehicle architecture, mission, vehicle concept, and technology options.

  11. Prospects for advanced rocket-powered launch vehicles

    NASA Astrophysics Data System (ADS)

    Eldred, Charles H.; Talay, Theodore A.

    The potential for advanced rocket-powered launch vehicles to meet the challenging cost, operational, and performance demands of space transportation in the early 21st century is examined. Space transportation requirements from recent studies underscoring the need for growth in capacity in support of an increasing diversity of space activities and the need for significant reductions in operational and life-cycle costs are reviewed. Fully reusable rocket powered concepts based on moderate levels of evolutionary advanced technology are described. These vehicles provide a broad range of attractive concept alternatives with the potential to meet demanding operational and cost goals and the flexibility to satisfy a variety of vehicle architecture, mission, vehicle concept, and technology options.

  12. Space station experiment definition: Advanced power system test bed

    NASA Technical Reports Server (NTRS)

    Pollard, H. E.; Neff, R. E.

    1986-01-01

    A conceptual design for an advanced photovoltaic power system test bed was provided and the requirements for advanced photovoltaic power system experiments better defined. Results of this study will be used in the design efforts conducted in phase B and phase C/D of the space station program so that the test bed capabilities will be responsive to user needs. Critical PV and energy storage technologies were identified and inputs were received from the idustry (government and commercial, U.S. and international) which identified experimental requirements. These inputs were used to develop a number of different conceptual designs. Pros and cons of each were discussed and a strawman candidate identified. A preliminary evolutionary plan, which included necessary precursor activities, was established and cost estimates presented which would allow for a successful implementation to the space station in the 1994 time frame.

  13. Transient magnetized plasma as an optical element for high power laser pulses

    NASA Astrophysics Data System (ADS)

    Nakanii, Nobuhiko; Hosokai, Tomonao; Iwasa, Kenta; Masuda, Shinichi; Zhidkov, Alexei; Pathak, Naveen; Nakahara, Hiroki; Mizuta, Yoshio; Takeguchi, Naoki; Kodama, Ryosuke

    2015-02-01

    Underdense plasma produced in gas jets by low intensity laser prepulses in the presence of a static magnetic field, B ˜0.3 T , is shown experimentally to become an optical element allowing steering of tightly focused high power femtosecond laser pulses within several degrees along with essential enhancement of pulse's focusability. Strong laser prepulses form a density ramp perpendicularly to magnetic field direction and, owing to the light refraction, main laser pulses propagate along the magnetic field even if it is tilted from the laser axis. Electrons generated in the laser pulse wake are well collimated and follow in the direction of the magnetic field; their characteristics are measured to be not sensitive to the tilt of magnetic field up to angles ±5 ° .

  14. A high voltage pulsed power supply for capillary discharge waveguide applications

    SciTech Connect

    Abuazoum, S.; Wiggins, S. M.; Issac, R. C.; Welsh, G. H.; Vieux, G.; Jaroszynski, D. A.; Ganciu, M.

    2011-06-15

    We present an all solid-state, high voltage pulsed power supply for inducing stable plasma formation (density {approx}10{sup 18} cm{sup -3}) in gas-filled capillary discharge waveguides. The pulser (pulse duration of 1 {mu}s) is based on transistor switching and wound transmission line transformer technology. For a capillary of length 40 mm and diameter 265 {mu}m and gas backing pressure of 100 mbar, a fast voltage pulse risetime of 95 ns initiates breakdown at 13 kV along the capillary. A peak current of {approx}280 A indicates near complete ionization, and the r.m.s. temporal jitter in the current pulse is only 4 ns. Temporally stable plasma formation is crucial for deploying capillary waveguides as plasma channels in laser-plasma interaction experiments, such as the laser wakefield accelerator.

  15. Hardware-Software Complex for a Study of High-Power Microwave Pulse Parameters

    NASA Astrophysics Data System (ADS)

    Gal'chenko, V. G.; Gladkova, T. A.

    2016-06-01

    An instrumental complex is developed for a study of high-power microwave pulse parameters. The complex includes a bench for calibrating detectors and a measuring instrument for evaluating the microwave pulse parameters. The calibration of the measurement channels of microwave pulses propagating through different elements of the experimental setup is an important problem of experimental research. The available software for calibration of the measuring channels has a significant disadvantage related with the necessity of input of a number of additional parameters directly into the program. The software realized in the Qt 4.5 C++ medium is presented, which significantly simplifies the process of calibration data input in the dialog mode of setting the parameters of the medium of microwave pulse propagation.

  16. FERROELECTRIC SWITCH FOR A HIGH-POWER Ka-BAND ACTIVE PULSE COMPRESSOR

    SciTech Connect

    Hirshfield, Jay L.

    2013-12-18

    Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW μs-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

  17. High-throughput machining using high average power ultrashort pulse lasers and ultrafast polygon scanner

    NASA Astrophysics Data System (ADS)

    Schille, Joerg; Schneider, Lutz; Streek, André; Kloetzer, Sascha; Loeschner, Udo

    2016-03-01

    In this paper, high-throughput ultrashort pulse laser machining is investigated on various industrial grade metals (Aluminium, Copper, Stainless steel) and Al2O3 ceramic at unprecedented processing speeds. This is achieved by using a high pulse repetition frequency picosecond laser with maximum average output power of 270 W in conjunction with a unique, in-house developed two-axis polygon scanner. Initially, different concepts of polygon scanners are engineered and tested to find out the optimal architecture for ultrafast and precision laser beam scanning. Remarkable 1,000 m/s scan speed is achieved on the substrate, and thanks to the resulting low pulse overlap, thermal accumulation and plasma absorption effects are avoided at up to 20 MHz pulse repetition frequencies. In order to identify optimum processing conditions for efficient high-average power laser machining, the depths of cavities produced under varied parameter settings are analyzed and, from the results obtained, the characteristic removal values are specified. The maximum removal rate is achieved as high as 27.8 mm3/min for Aluminium, 21.4 mm3/min for Copper, 15.3 mm3/min for Stainless steel and 129.1 mm3/min for Al2O3 when full available laser power is irradiated at optimum pulse repetition frequency.

  18. Steam turbine development for advanced combined cycle power plants

    SciTech Connect

    Oeynhausen, H.; Bergmann, D.; Balling, L.; Termuehlen, H.

    1996-12-31

    For advanced combined cycle power plants, the proper selection of steam turbine models is required to achieve optimal performance. The advancements in gas turbine technology must be followed by advances in the combined cycle steam turbine design. On the other hand, building low-cost gas turbines and steam turbines is desired which, however, can only be justified if no compromise is made in regard to their performance. The standard design concept of two-casing single-flow turbines seems to be the right choice for most of the present and future applications worldwide. Only for very specific applications it might be justified to select another design concept as a more suitable option.

  19. Observation of power gain in an inductive pulsed power system with an optically activated semiconductor closing and opening switch

    NASA Astrophysics Data System (ADS)

    Kung, Chun C.; Funk, Eric E.; Chauchard, Eve A.; Rhee, M. J.; Lee, Chi H.; Yan, Li

    1991-03-01

    Peak power gain greater than 15 was obtained with a current charged transmission line and an optically activated semiconductor opening switch. The optical pulse used for activating the switch is generated by a Nd:glass laser emitting at 1. 054 pm. It has a slow rise-time (''--''2OO uS) and a fast fall-time (s1O uS). In the experiment a 2 kV output voltage pulse was achieved with a 5 mm cube GaAs p-i-n diode sitch at 500 V charging voltage.

  20. Generation of sub-100 ps pulses with a peak power of 65 W by gain switching, pulse shortening, and pulse amplification using a semiconductor-based master oscillator-power amplifier system.

    PubMed

    Schwertfeger, Sven; Klehr, Andreas; Hoffmann, Thomas; Liero, Armin; Wenzel, Hans; Erbert, Götz

    2013-05-10

    We present a method of the generation of sub-100 ps pulses with an all-semiconductor master oscillator-power amplifier (MOPA) system, consisting of a three section distributed Bragg reflector (DBR) laser as MO and a two section tapered PA. The pulses generated by the gain-switched DBR laser are first shortened by the ridge-waveguide input section of the PA acting as a saturable absorber and then amplified by the tapered gain region section. We generate laser pulses with a minimum duration of 35 ps and a peak power of more than 65 W. The spectral width is less than 0.25 nm around a center wavelength of 1063 nm. PMID:23669852

  1. 14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When...

  2. 14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When...

  3. 14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When...

  4. 14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When...

  5. 14 CFR 101.25 - Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Power Rockets and Class 3-Advanced High Power Rockets. 101.25 Section 101.25 Aeronautics and Space... OPERATING RULES MOORED BALLOONS, KITES, AMATEUR ROCKETS AND UNMANNED FREE BALLOONS Amateur Rockets § 101.25 Operating limitations for Class 2-High Power Rockets and Class 3-Advanced High Power Rockets. When...

  6. 1  MW peak-power subpicosecond optical pulse source based on a gain-switched laser diode.

    PubMed

    Fang, Yi-Cheng; Chaki, Tomohiro; Hung, Jui-Hung; Yamada, Hirohito; Yokoyama, Hiroyuki

    2016-09-01

    We have generated optical pulses of 1.2 MW peak power and 0.6 ps duration using a 1060 nm band gain-switched laser diode pulse oscillator. Optical pulses are amplified by three-stage ytterbium-doped fiber amplifiers, and remarkable reductions of amplified spontaneous emission noise and temporal duration have been accomplished based on self-phase modulation in the middle-stage amplifier. After the main amplifier, optical pulses were temporally compressed by a grating pair, and this enabled generation of subpicosecond optical pulses with over 1 MW peak power. PMID:27607964

  7. Advances in Resistive Pulse Sensors: Devices bridging the void between molecular and microscopic detection

    PubMed Central

    Kozak, Darby; Anderson, Will; Vogel, Robert; Trau, Matt

    2011-01-01

    Since the first reported use of a biological ion channel to detect differences in single stranded genomic base pairs in 1996, a renaissance in nanoscale resistive pulse sensors has ensued. This resurgence of a technique originally outlined and commercialized over fifty years ago has largely been driven by advances in nanoscaled fabrication, and ultimately, the prospect of a rapid and inexpensive means for genomic sequencing as well as other macromolecular characterization. In this pursuit, the potential application of these devices to characterize additional properties such as the size, shape, charge, and concentration of nanoscaled materials (10 – 900 nm) has been largely overlooked. Advances in nanotechnology and biotechnology are driving the need for simple yet sensitive individual object readout devices such as resistive pulse sensors. This review will examine the recent progress in pore-based sensing in the nanoscale range. A detailed analysis of three new types of pore sensors – in-series, parallel, and size-tunable pores – has been included. These pores offer improved measurement sensitivity over a wider particle size range. The fundamental physical chemistry of these techniques, which is still evolving, will be reviewed. PMID:22034585

  8. Advanced Modular Power Approach to Affordable, Supportable Space Systems

    NASA Technical Reports Server (NTRS)

    Oeftering, Richard C.; Kimnach, Greg L.; Fincannon, James; Mckissock,, Barbara I.; Loyselle, Patricia L.; Wong, Edmond

    2013-01-01

    Recent studies of missions to the Moon, Mars and Near Earth Asteroids (NEA) indicate that these missions often involve several distinct separately launched vehicles that must ultimately be integrated together in-flight and operate as one unit. Therefore, it is important to see these vehicles as elements of a larger segmented spacecraft rather than separate spacecraft flying in formation. The evolution of large multi-vehicle exploration architecture creates the need (and opportunity) to establish a global power architecture that is common across all vehicles. The Advanced Exploration Systems (AES) Modular Power System (AMPS) project managed by NASA Glenn Research Center (GRC) is aimed at establishing the modular power system architecture that will enable power systems to be built from a common set of modular building blocks. The project is developing, demonstrating and evaluating key modular power technologies that are expected to minimize non-recurring development costs, reduce recurring integration costs, as well as, mission operational and support costs. Further, modular power is expected to enhance mission flexibility, vehicle reliability, scalability and overall mission supportability. The AMPS project not only supports multi-vehicle architectures but should enable multi-mission capability as well. The AMPS technology development involves near term demonstrations involving developmental prototype vehicles and field demonstrations. These operational demonstrations not only serve as a means of evaluating modular technology but also provide feedback to developers that assure that they progress toward truly flexible and operationally supportable modular power architecture.

  9. An Advanced Turbo-Brayton Converter for Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    Zagarola, Mark V.; Izenson, Michael G.; Breedlove, Jeffrey J.; O'Connor, George M.; Ketchum, Andrew C.; Jetley, Richard L.; Simons, James K.

    2005-02-01

    Past work has shown that Brayton power converters are an attractive option for high power, long-duration space missions. More recently, Creare has shown that Brayton technology could be scaled with high efficiency and specific power to lower power levels suitable for radioisotope power conversion systems. Creare is currently leading the development of an advanced turbo-Brayton converter under NASA's Prometheus Program. The converter design is based on space-proven cryocooler technologies that have been shown to be safe; to provide long, maintenance-free lifetimes; and to have high reliability, negligible vibration emittance, and low EMI/EMC. The predicted performance of a converter at the beginning of life is greater than 20% (including electronic inefficiencies and overhead) with a converter specific power of greater than 8 We/kg for a test unit and greater than 15 We/kg for a flight unit. The degradation in performance over a 14-year mission lifetime is predicted to be negligible, and the primary life limiting factor is not expected to be an issue for greater than twice the mission duration. Work during the last year focused on the material and fabrication issues associated with a high temperature turbine and a lightweight recuperator, and the performance issues associated with the high-temperature insulation and power conversion electronics. The development of the converter is on schedule. Thermal vacuum testing to demonstrate a technology readiness level of 5 is currently planned for 2006.

  10. Power scaling of supercontinuum seeded megahertz-repetition rate optical parametric chirped pulse amplifiers.

    PubMed

    Riedel, R; Stephanides, A; Prandolini, M J; Gronloh, B; Jungbluth, B; Mans, T; Tavella, F

    2014-03-15

    Optical parametric chirped-pulse amplifiers with high average power are possible with novel high-power Yb:YAG amplifiers with kW-level output powers. We demonstrate a compact wavelength-tunable sub-30-fs amplifier with 11.4 W average power with 20.7% pump-to-signal conversion efficiency. For parametric amplification, a beta-barium borate crystal is pumped by a 140 W, 1 ps Yb:YAG InnoSlab amplifier at 3.25 MHz repetition rate. The broadband seed is generated via supercontinuum generation in a YAG crystal.

  11. Power scaling of supercontinuum seeded megahertz-repetition rate optical parametric chirped pulse amplifiers.

    PubMed

    Riedel, R; Stephanides, A; Prandolini, M J; Gronloh, B; Jungbluth, B; Mans, T; Tavella, F

    2014-03-15

    Optical parametric chirped-pulse amplifiers with high average power are possible with novel high-power Yb:YAG amplifiers with kW-level output powers. We demonstrate a compact wavelength-tunable sub-30-fs amplifier with 11.4 W average power with 20.7% pump-to-signal conversion efficiency. For parametric amplification, a beta-barium borate crystal is pumped by a 140 W, 1 ps Yb:YAG InnoSlab amplifier at 3.25 MHz repetition rate. The broadband seed is generated via supercontinuum generation in a YAG crystal. PMID:24690803

  12. Tungsten Contact and Line Resistance Reduction with Advanced Pulsed Nucleation Layer and Low Resistivity Tungsten Treatment

    NASA Astrophysics Data System (ADS)

    Chandrashekar, Anand; Chen, Feng; Lin, Jasmine; Humayun, Raashina; Wongsenakhum, Panya; Chang, Sean; Danek, Michal; Itou, Takamasa; Nakayama, Tomoo; Kariya, Atsushi; Kawaguchi, Masazumi; Hizume, Shunichi

    2010-09-01

    This paper describes electrical testing results of new tungsten chemical vapor deposition (CVD-W) process concepts that were developed to address the W contact and bitline scaling issues on 55 nm node devices. Contact resistance (Rc) measurements in complementary metal oxide semiconductor (CMOS) devices indicate that the new CVD-W process for sub-32 nm and beyond - consisting of an advanced pulsed nucleation layer (PNL) combined with low resistivity tungsten (LRW) initiation - produces a 20-30% drop in Rc for diffused NiSi contacts. From cross-sectional bright field and dark field transmission electron microscopy (TEM) analysis, such Rc improvement can be attributed to improved plugfill and larger in-feature W grain size with the advanced PNL+LRW process. More experiments that measured contact resistance for different feature sizes point to favorable Rc scaling with the advanced PNL+LRW process. Finally, 40% improvement in line resistance was observed with this process as tested on 55 nm embedded dynamic random access memory (DRAM) devices, confirming that the advanced PNL+LRW process can be an effective metallization solution for sub-32 nm devices.

  13. Inertial-fusion research based on pulsed power

    SciTech Connect

    Yonas, G.

    1982-01-01

    PBFA-II, with design parameters of 3.5 MJ and 100 TW, is being configured to allow us to investigate either imploding foils or ion beams as inertial fusion drivers. The same accelerator can drive a foil with a magnetically insulated electromagnetic flow > 10/sup 12/ W/cm/sup 2/ at 10 MV/cm and also power an ion diode at a source intensity of 10/sup 10/ W/cm/sup 2/ and an accelerating potential approx. 10 MV. Our goal is to obtain 100 TW/cm/sup 2/ and 1 MJ on target for ignition studies.

  14. A low-power, CMOS peak detect and hold circuit for nuclear pulse spectroscopy

    SciTech Connect

    Ericson, M.N.; Simpson, M.L.; Britton, C.L.; Allen, M.D.; Kroeger, R.A.; Inderhees, S.E.

    1994-12-31

    A low-power CMOS peak detecting track and hold circuit optimized for nuclear pulse spectroscopy is presented. The circuit topology eliminates the need for a rectifying diode, reducing the effect of charge injection into the hold capacitor, incorporates a linear gate at the input to prevent pulse pileup, and uses dynamic bias control that minimizes both pedestal and droop. Both positive-going and negative-going pulses are accommodated using a complementary set of track and hold circuits. Full characterization of the design fabricated in 1.2{mu}m CMOS including dynamic range, integral nonlinearity, droop rate, pedestal, and power measurements is presented. Additionally, analysis and design approaches for optimization of operational characteristics are discussed.

  15. Advanced austenitic alloys for fossil power systems. CRADA final report

    SciTech Connect

    Swindeman, R.W.; Cole, N.C.; Canonico, D.A.; Henry, J.F.

    1998-08-01

    In 1993, a Cooperative Research and Development Agreement (CRADA) was undertaken between Oak Ridge National Laboratory and ABB Combustion Engineering t examine advanced alloys for fossil power systems. Specifically, the use of advanced austenitic stainless steels for superheater/reheater construction in supercritical boilers was examined. The strength of cold-worked austenitic stainless steels was reviewed and compared to the strength and ductility of advanced austenitic stainless steels. The advanced stainless steels were found to retain their strength to very long times at temperatures where cold-worked standard grades of austenitic stainless steels became weak. Further, the steels exhibited better long-time stability than the stabilized 300 series stainless steels in either the annealed or cold worked conditions. Type 304H mill-annealed tubing was provided to ORNL for testing of base metal and butt welds. The tubing was found to fall within range of expected strength for 304H stainless steel. The composite 304/308 stainless steel was found to be stronger than typical for the weldment. Boiler tubing was removed from a commercial boiler for replacement by newer steels, but restraints imposed by the boiler owners did not permit the installation of the advanced steels, so a standard 32 stainless steel was used as a replacement. The T91 removed from the boiler was characterized.

  16. High Breakdown Strength, Multilayer Ceramics for Compact Pulsed Power Applications

    SciTech Connect

    Gilmore, B.; Huebner, W.; Krogh, M.L.; Lundstrom, J.M.; Pate, R.C.; Rinehart, L.F.; Schultz, B.C.; Zhang, S.C.

    1999-07-20

    Advanced ceramics are being developed for use in large area, high voltage devices in order to achieve high specific energy densities (>10 6 J/m 3 ) and physical size reduction. Initial materials based on slip cast TiO2 exhibited a high bulk breakdown strength (BDS >300 kV/cm) and high permittivity with low dispersion (e�100). However, strong area and thickness dependencies were noted. To increase the BDS, multilayer dielectric compositions are being developed based on glass/TiO2 composites. The addition of glass increases the density (�99.8% theoretical), forms a continuous grain boundary phase, and also allows the use of high temperature processes to change the physical shape of the dielectric. The permittivity can also be manipulated since the volume fraction and connectivity of the glassy phase can be readily shifted. Results from this study on bulk breakdown of TiO2 multilayer structures with an area of 2cm 2 and 0.1cm thickness have measured 650 kV/cm. Furthermore, a strong dependence of breakdown strength and permittivity has been observed and correlated with microstructure and the glass composition. This paper presents the interactive effects of manipulation of these variables.

  17. Pulse-width-independent low power programmable low temperature poly-Si thin-film transistor shift register

    NASA Astrophysics Data System (ADS)

    Song, Eunji; Song, Seok-Jeong; Nam, Hyoungsik

    2015-05-01

    This paper demonstrates a low power programmable pulse width LTPS TFT shift register which achieves the constant power consumption over various pulse widths with the smaller number of TFTs compared to the previous programmable shift register. The proposed shift register consists of nine n-channel LTPS TFTs and one coupling capacitor. By eliminating the shoot-through current path in a NOT-AND logic, the simulation ensures that the proposed structure reduces the power consumption significantly by 60.5% for two line pulse width and by 88.6% for ten line pulse width from the previous programmable pulse width shift register. The power consumption of 12 shift registers is measured at 0.235 mW, independently of programmed pulse widths.

  18. Pluto/Kuiper Missions with Advanced Electric Propulsion and Power

    NASA Technical Reports Server (NTRS)

    Oleson, S. R.; Patterson, M. J.; Schrieber, J.; Gefert, L. P.

    2001-01-01

    In response to a request by NASA Code SD Deep Space Exploration Technology Program, NASA Glenn Research center performed a study to identify advanced technology options to perform a Pluto/Kuiper mission without depending on a 2004 Jupiter Gravity Assist, but still arriving before 2020. A concept using a direct trajectory with small, sub-kilowatt ion thrusters and Stirling radioisotope power system was shown to allow the same or smaller launch vehicle class (EELV) as the chemical 2004 baseline and allow launch in any year and arrival in the 2014 to 2020 timeframe. With the nearly constant power available from the radioisotope power source such small ion propelled spacecraft could explore many of the outer planetary targets. Such studies are already underway. Additional information is contained in the original extended abstract.

  19. Advanced Rock Drilling Technologies Using High Laser Power

    NASA Astrophysics Data System (ADS)

    Buckstegge, Frederik; Michel, Theresa; Zimmermann, Maik; Roth, Stephan; Schmidt, Michael

    Drilling through hard rock formations causes high mechanical wear and most often environmental disturbance. For the realization of an Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) power plant a new and efficient method for tunneling utilising laser technology to support mechanical ablation of rock formations will be developed. Laser irradiation of inhomogeneous rock surfaces causes irregular thermal expansion leading to the formation of cracks and splintering as well as melting and slag-formation. This study focuses on the interaction of laser irradiation with calcite, porphyrite and siderite rock formations. A high power disc laser system at 1030nm wavelength is used to investigate the specific energy necessary to remove a unit volume depending on interaction times and applied power. Specific energies have been measured and an increase of fragility and brittleness of the rock surface has been observed.

  20. 1400, +/- 900V PEAK PULSE SWITCH MODE POWER SUPPLIES FOR SNS INJECTION KICKERS.

    SciTech Connect

    LAMBIASE,R.ENG,W.SANDBERG,J.DEWAN,S.HOLMES,R.RUST,K.ZENG,J.

    2004-03-10

    This paper describes simulation and experimental results for a 1400A, {+-} 900V peak rated, switch mode power supply for SNS Injection Kicker Magnets. For each magnet (13 m{Omega}, 160{micro}H), the power supply must supply controlled pulses at 60 Hz repetition rate. The pulse current must rise from zero to maximum in less than 1 millisec in a controlled manner, flat top for up to 2 millisec, and should fall in a controlled manner to less than 4A within 500{micro}s. The low current performance during fall time is the biggest challenge in this power supply. The simulation results show that to meet the controlled fall of the current and the current ripple requirements, voltage loop bandwidth of at least 10 kHz and switching frequency of at least 100 kHz are required. To achieve high power high frequency switching with IGBT switches, a series connected topology with three phase shifted (O{sup o}, 60{sup o} & 120{sup o}) converters each with 40 kHz switching frequency (IGBT at 20kHz), has been achieved. In this paper, the circuit topology, relevant system specifications and experimental results that meet the requirements of the power supply are described in detail. A unique six pulse SCR rectifier circuit with capacitor storage has been implemented to achieve minimum pulse width to meet required performance during current fall time below 50A due to the very narrow pulse width and non-linearity from IGBT turn-on/off times.

  1. Femtosecond pulse mode-locked VECSELs

    NASA Astrophysics Data System (ADS)

    Quarterman, A. H.; Wilcox, K. G.

    2014-03-01

    Femtosecond pulse mode-locked VECSELs have become a significant focus of research in the VECSEL community, with recent progress being made in several directions including power scaling. Power scaling advances in femtosecond VECSELs have included increasing the average power to over 5W [1], producing 3.3W average power with 400 fs pulses [2]. Here I report our recent work reducing the pulse duration of Watt-level VECSELs to 355 fs, and also developing approaches to reach sub-250-fs pulse durations using coherent broadening in photonic crystal fiber in the normal dispersion regime and a grating pulse compressor.

  2. Note: High resolution ultra fast high-power pulse generator for inductive load using digital signal processor

    NASA Astrophysics Data System (ADS)

    Flaxer, Eli

    2014-08-01

    We present a new design of a compact, ultra fast, high resolution and high-powered, pulse generator for inductive load, using power MOSFET, dedicated gate driver and a digital signal controller. This design is an improved circuit of our old version controller. We demonstrate the performance of this pulse generator as a driver for a new generation of high-pressure supersonic pulsed valves.

  3. Note: High resolution ultra fast high-power pulse generator for inductive load using digital signal processor.

    PubMed

    Flaxer, Eli

    2014-08-01

    We present a new design of a compact, ultra fast, high resolution and high-powered, pulse generator for inductive load, using power MOSFET, dedicated gate driver and a digital signal controller. This design is an improved circuit of our old version controller. We demonstrate the performance of this pulse generator as a driver for a new generation of high-pressure supersonic pulsed valves.

  4. Concept study of high volume food irradiation with a pulsed power accelerator

    SciTech Connect

    Turman, B.N.; Prestwich, K.R.; Neau, E.L.; Johnson, D.L.; Kensek, R.P.

    1993-12-31

    A concept study was initiated to establish technical requirements and processing cost estimates for a high power, high volume x-radiation food processing facility using pulsed power technology. The design study was directed toward a central processing plant that would transport and process the food products in standard pallets of 1.1m {times} 1.2m {times} 1.2m dimensions. The 1.2m depth of penetration, and a dose uniformity requirement of a factor of 2 between the maximum and minimum dose, led to a decision to employ x-radiation, produced from a 5 MeV electron beam. The electron beam is produced from a large-area cathode and accelerated by a multi-module pulsed power accelerator. The beam power for this design is 500 kW. An example application is developed for illustration, based on produce disinfestation at maximum exposure level of l00 krad and minimum exposure of 50 krad. In order to achieve this ratio of maximum to minimum dose, the pallet is rotated through 3609 while being exposed. The estimated process rate is approximately 30 metric tons/hour. The accelerator design was developed by scaling from the present high average power beam experiments in the Repetitive High Energy Pulsed Power (RHEPP) program, which will deliver an output of 350 kW in a 2.5 MeV beam. The high voltage is achieved by using 250 kV pulses that are added together with inductively-isolated adder cavities. This technology will be described, and results from the RHEPP experiments will be compared with the design requirements for the high power food processor application. Processing issues, technology limits, dose calculations, and cost estimates will be discussed.

  5. Advanced Thermophotovoltaic Devices for Space Nuclear Power Systems

    SciTech Connect

    Wernsman, Bernard; Mahorter, Robert G.; Siergiej, Richard; Link, Samuel D.; Wehrer, Rebecca J.; Belanger, Sean J.; Fourspring, Patrick; Murray, Susan; Newman, Fred; Taylor, Dan; Rahmlow, Tom

    2005-02-06

    Advanced thermophotovoltaic (TPV) modules capable of producing > 0.3 W/cm2 at an efficiency > 22% while operating at a converter radiator and module temperature of 1228 K and 325 K, respectively, have been made. These advanced TPV modules are projected to produce > 0.9 W/cm2 at an efficiency > 24% while operating at a converter radiator and module temperature of 1373 K and 325 K, respectively. Radioisotope and nuclear (fission) powered space systems utilizing these advanced TPV modules have been evaluated. For a 100 We radioisotope TPV system, systems utilizing as low as 2 general purpose heat source (GPHS) units are feasible, where the specific power for the 2 and 3 GPHS unit systems operating in a 200 K environment is as large as {approx} 16 We/kg and {approx} 14 We/kg, respectively. For a 100 kWe nuclear powered (as was entertained for the thermoelectric SP-100 program) TPV system, the minimum system radiator area and mass is {approx} 640 m2 and {approx} 1150 kg, respectively, for a converter radiator, system radiator and environment temperature of 1373 K, 435 K and 200 K, respectively. Also, for a converter radiator temperature of 1373 K, the converter volume and mass remains less than 0.36 m3 and 640 kg, respectively. Thus, the minimum system radiator + converter (reactor and shield not included) specific mass is {approx} 16 kg/kWe for a converter radiator, system radiator and environment temperature of 1373 K, 425 K and 200 K, respectively. Under this operating condition, the reactor thermal rating is {approx} 1110 kWt. Due to the large radiator area, the added complexity and mission risk needs to be weighed against reducing the reactor thermal rating to determine the feasibility of using TPV for space nuclear (fission) power systems.

  6. Advanced Thermophotovoltaic Devices for Space Nuclear Power Systems

    NASA Astrophysics Data System (ADS)

    Wernsman, Bernard; Mahorter, Robert G.; Siergiej, Richard; Link, Samuel D.; Wehrer, Rebecca J.; Belanger, Sean J.; Fourspring, Patrick; Murray, Susan; Newman, Fred; Taylor, Dan; Rahmlow, Tom

    2005-02-01

    Advanced thermophotovoltaic (TPV) modules capable of producing > 0.3 W/cm2 at an efficiency > 22% while operating at a converter radiator and module temperature of 1228 K and 325 K, respectively, have been made. These advanced TPV modules are projected to produce > 0.9 W/cm2 at an efficiency > 24% while operating at a converter radiator and module temperature of 1373 K and 325 K, respectively. Radioisotope and nuclear (fission) powered space systems utilizing these advanced TPV modules have been evaluated. For a 100 We radioisotope TPV system, systems utilizing as low as 2 general purpose heat source (GPHS) units are feasible, where the specific power for the 2 and 3 GPHS unit systems operating in a 200 K environment is as large as ˜ 16 We/kg and ˜ 14 We/kg, respectively. For a 100 kWe nuclear powered (as was entertained for the thermoelectric SP-100 program) TPV system, the minimum system radiator area and mass is ˜ 640 m2 and ˜ 1150 kg, respectively, for a converter radiator, system radiator and environment temperature of 1373 K, 435 K and 200 K, respectively. Also, for a converter radiator temperature of 1373 K, the converter volume and mass remains less than 0.36 m3 and 640 kg, respectively. Thus, the minimum system radiator + converter (reactor and shield not included) specific mass is ˜ 16 kg/kWe for a converter radiator, system radiator and environment temperature of 1373 K, 425 K and 200 K, respectively. Under this operating condition, the reactor thermal rating is ˜ 1110 kWt. Due to the large radiator area, the added complexity and mission risk needs to be weighed against reducing the reactor thermal rating to determine the feasibility of using TPV for space nuclear (fission) power systems.

  7. Asymptotically one-dimensional dynamics of high-peak-power ultrashort laser pulses

    NASA Astrophysics Data System (ADS)

    Voronin, A. A.; Zheltikov, A. M.

    2016-11-01

    Laser fields with peak powers P well above the critical power of self-focusing P cr are intrinsically unstable with respect to modulation instabilities, breaking up into multiple filaments as a part of a quintessentially three-dimensional nonlinear beam dynamics. Here, however, we show that—even for P \\gg P cr—the spatiotemporal field evolution can stay effectively one-dimensional. In this regime, observed as an asymptotic case of large diffraction lengths, the laser field can undergo a rich diversity of pulse transformation scenarios, including, most notably, pulse self-compression to subcycle field waveforms with very high peak powers, while remaining decoupled, within a limited propagation length, from beam dynamics.

  8. Multiple platform application of 3D CAD PIC simulations in pulsed power

    SciTech Connect

    Peratt, A.L.; Mostrom, M.A.

    1995-12-31

    With the availability of 80--125 MHz microprocessors, the methodology developed for the simulation of problems in pulsed power and plasma physics on modern day supercomputers is now amenable to application on a wide range of platforms including laptops and workstations. While execution speeds with these processors do not match those of large scale computing machines, resources such as computer-aided-design (CAD) and graphical analysis codes are available to automate simulation setup and process data. This paper reports on the adaptation of IVORY, a three-dimensional, fully-electromagnetic, particle-in-cell simulation code, to this platform independent CAD environment. The primary purpose of this talk is to demonstrate how rapidly a pulsed power/plasma problem can be scoped out by an experimenter on a dedicated workstation. Demonstrations include a magnetically insulated transmission line, power flow in a graded insulator stack, a relativistic klystron oscillator, and the dynamics of a coaxial thruster for space applications.

  9. Design of pulsed guiding magnetic field for high power microwave generators

    SciTech Connect

    Ju, J.-C. Zhang, H.; Zhang, J.; Shu, T.; Zhong, H.-H.

    2014-09-15

    In this paper, we present a comprehensive study on designing solenoid together with the corresponding power supply system to excite pulsed magnetic field required for high power microwave generators. Particularly, a solenoid is designed and the excited magnetic field is applied to a Ku-band overmoded Cerenkov generator. It is found in experiment that the electron beam is properly guided by the magnetic field and a 1.1 GW high power microwave is achieved at a central frequency of 13.76 GHz. Pulsed solenoid system has the advantages of compactness and low energy consumption, which are of great interest for repetitive operation. The reported studies and results can be generalized to other applications which require magnetic fields.

  10. Design of pulsed guiding magnetic field for high power microwave generators.

    PubMed

    Ju, J-C; Zhang, H; Zhang, J; Shu, T; Zhong, H-H

    2014-09-01

    In this paper, we present a comprehensive study on designing solenoid together with the corresponding power supply system to excite pulsed magnetic field required for high power microwave generators. Particularly, a solenoid is designed and the excited magnetic field is applied to a Ku-band overmoded Cerenkov generator. It is found in experiment that the electron beam is properly guided by the magnetic field and a 1.1 GW high power microwave is achieved at a central frequency of 13.76 GHz. Pulsed solenoid system has the advantages of compactness and low energy consumption, which are of great interest for repetitive operation. The reported studies and results can be generalized to other applications which require magnetic fields. PMID:25273750

  11. Narrow linewidth picosecond pulsed laser with mega-watt peak power at UV wavelength

    SciTech Connect

    Liu, Yun; Huang, Chunning; Deibele, Craig Edmond

    2013-01-01

    We demonstrate a master oscillator power amplifier (MOPA) burst mode laser system to generate 66 ps/402.5 MHz pulses with mega-watt peak power at 355 nm. The seed laser is based on a direct electro-optic modulation of a fiber laser output. A very high extinction ratio (45 dB) has been achieved by using an adaptive bias control. The multi-stage Nd:YAG amplifier system allows a uniformly temporal shaping of macropulses with tunable pulse duration. The light output form the amplifier is converted to 355 nm and over 1 MW UV peak power is obtained when the laser is operating in a 5- s/10-Hz macropulse mode. The laser output has a transform limited spectrum bandwidth with a very narrow linewidth of individual laser mode. The immediate application of the laser system is the laser assisted hydrogen ion beam stripping for the Spallation Neutron Source (SNS).

  12. Computational modeling of pulsed-power-driven magnetized target fusion experiments

    SciTech Connect

    Sheehey, P.; Kirkpatrick, R.; Lindemuth, I.

    1995-08-01

    Direct magnetic drive using electrical pulsed power has been considered impractically slow for traditional inertial confinement implosion of fusion targets. However, if the target contains a preheated, magnetized plasma, magnetothermal insulation may allow the near-adiabatic compression of such a target to fusion conditions on a much slower time scale. 100-MJ-class explosive flux compression generators with implosion kinetic energies far beyond those available with conventional fusion drivers, are an inexpensive means to investigate such magnetized target fusion (MTF) systems. One means of obtaining the preheated and magnetized plasma required for an MTF system is the recently reported {open_quotes}MAGO{close_quotes} concept. MAGO is a unique, explosive-pulsed-power driven discharge in two cylindrical chambers joined by an annular nozzle. Joint Russian-American MAGO experiments have reported D-T neutron yields in excess of 10{sup 13} from this plasma preparation stage alone, without going on to the proposed separately driven NM implosion of the main plasma chamber. Two-dimensional MED computational modeling of MAGO discharges shows good agreement to experiment. The calculations suggest that after the observed neutron pulse, a diffuse Z-pinch plasma with temperature in excess of 100 eV is created, which may be suitable for subsequent MTF implosion, in a heavy liner magnetically driven by explosive pulsed power. Other MTF concepts, such as fiber-initiated Z-pinch target plasmas, are also being computationally and theoretically evaluated. The status of our modeling efforts will be reported.

  13. Thin Object Radiography with a 2.2 MeV Pulsed Power Machine

    NASA Astrophysics Data System (ADS)

    Haines, Todd; Danielson, Jeremy; Wood, W. Monty

    2015-06-01

    An experimental series was performed at a pulsed-power 2.2 MeV flash radiography machine to determine the lower limits of its mass sensitivity. This machine uses a rod-pinch diode with accelerating potential of 2.2 MeV and 50 ns pulse duration. Tungsten, aluminum, and titanium rod anodes were used to tune the emitted bremsstrahlung spectrum; as well as aluminum and beryllium filter materials. Analysis of thin tantalum foils shows a mass sensitivity as low as 300 μg/cm2. This is a factor of 5 better than previous measurements.

  14. High-average-power operation of a pulsed Raman fiber amplifier at 1686 nm.

    PubMed

    Yao, Weichao; Chen, Bihui; Zhang, Jianing; Zhao, Yongguang; Chen, Hao; Shen, Deyuan

    2015-05-01

    We report on high-average-power operation of a pulsed Raman fiber amplifier at ~1686 nm which cannot be covered by rare-earth-doped fiber lasers. The Raman fiber amplifier was pumped by a home-made 1565.2 nm Q-switched Er,Yb fiber laser and worked at a repetition frequency of 184 kHz. With 0.8 km Raman fiber, 4.4 W of average output power at the 1st order Stokes wavelength of 1686.5 nm was obtained for launched pump power of 16.2 W, corresponding to an optical-to-optical conversion efficiency of 27.2%. Further increasing the pump power, high-order Stokes waves grew gradually, resulting in a total output power of 6.7 W at the 19.2 W launched pump power. PMID:25969195

  15. Simultaneous optimization of power and duration of radio-frequency pulse in PARACEST MRI.

    PubMed

    Rezaeian, Mohammad-Reza; Hossein-Zadeh, Gholam-Ali; Soltanian-Zadeh, Hamid

    2016-07-01

    Chemical exchange saturation transfer (CEST) MRI is increasingly used to probe mobile proteins and microenvironment properties, and shows great promise for tumor and stroke diagnosis. The CEST effect is complex and depends not only on the CEST agent concentration, exchange rates, the characteristic of the magnetization transfer (MT), and the relaxation properties of the tissue, but also varies with the experimental conditions such as radio-frequency (RF) pulse power and duration. The RF pulse is one of the most important factors that promote the CEST effect for biological properties such as pH, temperature and protein content, especially for contrast agents with intermediate to fast exchange rates. The CEST effect is susceptible to the RF duration and power. The present study aims at determining the optimal power and the corresponding optimal duration (that maximize the CEST effect) using an off-resonance scheme through a new definition of the CEST effect. This definition is formulated by solving the Bloch-McConnell equation through the R1ρ method (based on the eigenspace solution) for both of the MT and CEST effects as well as their interactions. The proposed formulations of the optimal RF pulse power and duration are the first formulations in which the MT effect is considered. The extracted optimal RF pulse duration and power are compared with those of the MTR asymmetry model in two- and three-pool systems, using synthetic data that are similar to the muscle tissue. To validate them further, the formulations are compared with the empirical formulation of the CEST effect and other findings of the previous researches. By extending our formulations, the optimal power and the corresponding optimal duration (in the biological systems with many chemical exchange sites) can be determined. PMID:26956610

  16. Interaction of electromagnetic pulse with commercial nuclear-power-plant systems

    SciTech Connect

    Ericson, D.M. Jr.; Strawe, D.F.; Sandberg, S.J.; Jones, V.K.; Rensner, G.D.; Shoup, R.W.; Hanson, R.J.; Williams, C.B.

    1983-02-01

    This study examines the interaction of the electromagnetic pulse from a high altitude nuclear burst with commercial nuclear power plant systems. The potential vulnerability of systems required for safe shutdown of a specific nuclear power plant are explored. EMP signal coupling, induced plant response and component damage thresholds are established using techniques developed over several decades under Defense Nuclear Agency sponsorship. A limited test program was conducted to verify the coupling analysis technique as applied to a nuclear power plant. The results are extended, insofar as possible, to other nuclear plants.

  17. Use of powerful infrared pulsed Nd-YAG laser for treating osteogenic sarcoma

    NASA Astrophysics Data System (ADS)

    Biser, Vladimir A.; Kaplan, Michael A.; Kursova, Larisa V.; Neborak, Yuri T.

    1996-01-01

    Powerful infra-red laser radiation may induce necrosis of a malignant tumor located in a human bone without destructing skin cover. A superficial irradiation of the osteogenic sarcoma with an Nd-YAG laser (pulse power no less than 10 MW, average power 100 - 300 mW, time of exposure 10 - 90 min) has resulted in a severe damage of the tumor (more than 90% of the tumor mass) in 57% of cases. A combined laser/gamma irradiation showed a severe damage in 83% of cases. The results obtained suggest that laser radiation with the above parameters combined with gamma radiation may be used in treatment of osteogenic sarcoma.

  18. First high power pulsed tests of a dressed 325 MHz superconducting single spoke resonator at Fermilab

    SciTech Connect

    Madrak, R.; Branlard, J.; Chase, B.; Darve, C.; Joireman, P.; Khabiboulline, T.; Mukherjee, A.; Nicol, T.; Peoples-Evans, E.; Peterson, D.; Pischalnikov, Y.; /Fermilab

    2011-03-01

    In the recently commissioned superconducting RF cavity test facility at Fermilab (SCTF), a 325 MHz, {beta} = 0.22 superconducting single-spoke resonator (SSR1) has been tested for the first time with its input power coupler. Previously, this cavity had been tested CW with a low power, high Q{sub ext} test coupler; first as a bare cavity in the Fermilab Vertical Test Stand and then fully dressed in the SCTF. For the tests described here, the design input coupler with Q{sub ext} {approx} 10{sup 6} was used. Pulsed power was provided by a Toshiba E3740A 2.5 MW klystron.

  19. Mitigation of magnetohydrodynamic electromagnetic pulse (MHD-EMP) effects from commerical electric power systems. Power Systems Technology Program

    SciTech Connect

    Barnes, P.R.; Tesche, F.M.; Vance, E.F.

    1992-03-01

    A large nuclear detonation at altitudes of several hundred kilometers above the earth distorts the earth`s magnetic field and produces a strong magnetohydrodynamic electromagnetic pulse (MHD-EMP). This can adversely affect electrical power systems. In this report, the effects of this nuclear environment on critical facilities connected to the commercial power system are considered. Methods of mitigating the MHD-EMP impacts are investigated, and recommended protection schemes are presented. Guidelines for testing facilities to determine the effects of MHD-EMP and to validate the mitigation methods also are discussed.

  20. Advanced binary geothermal power plants: Limits of performance

    NASA Astrophysics Data System (ADS)

    Bliem, C. J.; Mines, G. L.

    1991-01-01

    The Heat Cycle Research Program is investigating potential improvements to power cycles utilizing moderate temperature geothermal resources to produce electrical power. Investigations have specifically examined Rankine cycle binary power systems. Binary Rankine cycles are more efficient than the flash steam cycles at moderate resource temperature, achieving a higher net brine effectiveness. At resource conditions similar to those at the Heber binary plant, it has been shown that mixtures of saturated hydrocarbons (alkanes) or halogenated hydrocarbons operating in a supercritical Rankine cycle gave improved performance over Rankine cycles with the pure working fluids executing single or dual boiling cycles or supercritical cycles. Recently, other types of cycles have been proposed for binary geothermal service. The feasible limits on efficiency of a plant given practical limits on equipment performance is explored and the methods used in these advanced concept plants to achieve the maximum possible efficiency are discussed. (Here feasible is intended to mean reasonably achievable and not cost effective.) No direct economic analysis was made because of the sensitivity of economic results to site specific input. The limit of performance of three advanced plants were considered. The performance predictions were taken from the developers of each concept. The advanced plants considered appear to be approaching the feasible limit of performance. Ultimately, the plant designer must weigh the advantages and disadvantages of the the different cycles to find the best plant for a given service. In addition, a standard is presented of comparison of the work which has been done in the Heat Cycle Research Program and in the industrial sector by Exergy, Inc. and Polythermal Technologies.

  1. Pulsed power supply system for the fast quadrupoles in the AGS

    SciTech Connect

    Nawrocky, R.J.; Lambiase, R.F.

    1983-01-01

    In the acceleration of polarized protons in the AGS, a number of depolarizing resonances will be encountered. Depolarization due to the so-called intrinsic resonances will be minimized by crossing each resonance in less than one beam revolution period (approx. 2 ..mu..s). This will be accomplished with a set of twelve fast tune-shifting quadrupoles distributed symmetrically around the ring. During a typical acceleration cycle, the fast quads will be energized with a burst of alternating polarity, fast rise/slow fall triangular current pulses. The amplitude of these pulses will vary from 160 A to about 2700 A peak. This paper describes the development of the pulsed power supply for the fast quads, the construction of a prototype modulator, and some of the initial test results obtained with the prototype.

  2. The use of hybrid-power sources for improved performance with pulsed loads

    SciTech Connect

    Roth, E.P.; Nagasubramanian, G.

    1998-04-01

    Electrical characteristics of hybrid power sources consisting of Li-ion cells and double layer capacitors were studied at 25 C and {minus}20 C. The cells were initially evaluated for pulse performance and then measured in hybrid modes of operation. Cells manufactured by Panasonic delivered pulses up to 3A and cells from A and T delivered 4A at 25 C before cell capacity dropped. Measured cell resistances were 0.15 ohms and 0.12 ohms, respectively. These measurements were repeated at {minus}20 C. Direct coupling of the cells and capacitors (dumb hybrid) extended the pulse limits to 5.6A using the Panasonic cells and 9A for the A and T cells. Operation in a smart hybrid mode using uncoupled cell/capacitor discharge allowed full cell capacity usage at 25 C and showed a factor of 5 improvement in delivered capacity at {minus}20 C.

  3. Recent advances of HTS power application research at IEE

    NASA Astrophysics Data System (ADS)

    Ma, Yanwei; Lin, Liangzhen; Xiao, Liye

    2006-06-01

    Recent advances of high temperature superconductors (HTS) for power applications in the Institute of Electrical Engineering (IEE), Chinese academy of Sciences are presented. A 75 meter, 10.5 kV/1.5 kA three phase HTS transmission cable has been successfully demonstrated in a live distribution grid in northwest China. A 10.5 kV/200A bridge-type fault current limiter (FCL) prototype based on Bi-2223 tapes is being tested in a Hunan power plant since August 2005. A 400V/16V/26 kVA three phase HTS transformer was designed, built and tested, and the on site system installation of a 10.5 kV/400V/630 kVA HTS transformer will be finished at Tebian Electric Ltd. soon. In addition, the progress of design and test of SMES is also given.

  4. Thermodynamic analysis of the advanced zero emission power plant

    NASA Astrophysics Data System (ADS)

    Kotowicz, Janusz; Job, Marcin

    2016-03-01

    The paper presents the structure and parameters of advanced zero emission power plant (AZEP). This concept is based on the replacement of the combustion chamber in a gas turbine by the membrane reactor. The reactor has three basic functions: (i) oxygen separation from the air through the membrane, (ii) combustion of the fuel, and (iii) heat transfer to heat the oxygen-depleted air. In the discussed unit hot depleted air is expanded in a turbine and further feeds a bottoming steam cycle (BSC) through the main heat recovery steam generator (HRSG). Flue gas leaving the membrane reactor feeds the second HRSG. The flue gas consist mainly of CO2 and water vapor, thus, CO2 separation involves only the flue gas drying. Results of the thermodynamic analysis of described power plant are presented.

  5. Recent advances in phosphate laser glasses for high power applications

    SciTech Connect

    Campbell, J.H.

    1996-05-14

    Recent advances in Nd-doped phosphate laser glasses for high-peak-power and high-average-power applications are reviewed. Compositional studies have progressed to the point that glasses can be tailored to have specific properties for specific applications. Non-radiative relaxation effects can be accurately modeled and empirical expressions have been developed to evaluate both intrinsic (structural) and extrinsic (contamination induced) relaxation effects. Losses due to surface scattering and bulk glass absorption have been carefully measured and can be accurately predicted. Improvements in processing have lead to high damage threshold (e.g. Pt inclusion free) and high thermal shock resistant glasses with improved edge claddings. High optical quality pieces up to 79 x 45 x 4cm{sup 3} have been made and methods for continuous melting laser glass are under development.

  6. Numerical studies of powerful terahertz pulse generation from a super-radiant surface wave oscillator

    SciTech Connect

    Zhang Hai; Wang Jianguo; Tong Changjiang; Li Xiaoze; Wang Guangqiang

    2009-12-15

    The results of theoretical and numerical studies of coherent stimulated terahertz radiation from intense, subnanosecond electron beam are presented. The mechanism of terahertz pulse generation is associated with self-bunching of the beam and slippage of the wave over the whole electron flow. This so called Cherenkov super-radiance (SR) is used to propose a compact terahertz generator with high peak power. A large cross-section (overmoded), slow wave structure is designed to support the high power handling capability, and the mode competition is avoided by operating the device in the surface wave status. With 2.5 D particle-in-cell simulation, the 'hot' characteristics of the proposed super-radiant terahertz generator are investigated, and the numerical results show that the SR peak power could be further increased by optimizing the amplitude profile of electron pulse. Under the condition of 0.5 ns pulsewidth, 500 kV voltage, and 1.5 kA current, the 110 ps, 680 MW, and 0.14 THz SR pulse is achieved with a power efficiency of 90.67% in TM{sub 01} mode.

  7. Laser triggering of water switches in terrawatt-class pulse power accelerators.

    SciTech Connect

    Woodworth, Joseph Ray; Johnson, David Lee (Titan Pulse Sciences, San Leandro, CA); Wilkins, Frank (Bechtel Nevada, Las Vegas, NV); Van De Valde, David (EG&G Technical Services, Albuquerque, NM); Sarkisov, Gennady Sergeevich; Zameroski, Nathan D.; Starbird, Robert L.

    2005-12-01

    Focused Beams from high-power lasers have been used to command trigger gas switches in pulse power accelerators for more than two decades. This Laboratory-Directed Research and Development project was aimed at determining whether high power lasers could also command trigger water switches on high-power accelerators. In initial work, we determined that focused light from three harmonics of a small pulsed Nd:YAG laser at 1064 nm, 532 nm, and 355 nm could be used to form breakdown arcs in water, with the lowest breakdown thresholds of 110 J/cm{sup 2} or 14 GW/cm{sup 2} at 532 nm in the green. In laboratory-scale laser triggering experiments with a 170-kV pulse-charged water switch with a 3-mm anode-cathode gap, we demonstrated that {approx}90 mJ of green laser energy could trigger the gap with a 1-{sigma} jitter of less than 2ns, a factor of 10 improvement over the jitter of the switch in its self breaking mode. In the laboratory-scale experiments we developed optical techniques utilizing polarization rotation of a probe laser beam to measure current in switch channels and electric field enhancements near streamer heads. In the final year of the project, we constructed a pulse-power facility to allow us to test laser triggering of water switches from 0.6- MV to 2.0 MV. Triggering experiments on this facility using an axicon lens for focusing the laser and a switch with a 740 kV self-break voltage produced consistent laser triggering with a {+-} 16-ns 1-{sigma} jitter, a significant improvement over the {+-} 24-ns jitter in the self-breaking mode.

  8. Initial high-power testing of the ATF (Advanced Toroidal Facility) ECH (electron cyclotron heating) system

    SciTech Connect

    White, T.L.; Bigelow, T.S.; Kimrey, H.D. Jr.

    1987-01-01

    The Advanced Toroidal Facility (ATF) is a moderate aspect ratio torsatron that will utilize 53.2 GHz 200 kW Electron Cyclotron Heating (ECH) to produce nearly current-free target plasmas suitable for subsequent heating by strong neutral beam injection. The initial configuration of the ECH system from the gyrotron to ATF consists of an optical arc detector, three bellows, a waveguide mode analyzer, two TiO/sub 2/ mode absorbers, two 90/sup 0/ miter bends, two waveguide pumpouts, an insulating break, a gate valve, and miscellaneous straight waveguide sections feeding a launcher radiating in the TE/sub 02/ mode. Later, a focusing Vlasov launcher will be added to beam the ECH power to the saddle point in ATF magnetic geometry for optimum power deposition. The ECH system has several unique features; namely, the entire ECH system is evacuated, the ECH system is broadband, forward power is monitored by a newly developed waveguide mode analyzer, phase correcting miter bends will be employed, and the ECH system will be capable of operating short pulse to cw. Initial high-power tests show that the overall system efficiency is 87%. The waveguide mode analyzer shows that the gyrotron mode output consists of 13% TE/sub 01/, 82.6% TE/sub 02/, 2.5% TE/sub 03/, and 1.9% TE/sub 04/. 4 refs.

  9. The delta S (delta R)-2 question: The pulse-length dependence of signal power for Fresnel scatter

    NASA Technical Reports Server (NTRS)

    Hocking, W. K.

    1983-01-01

    It is proposed that the enhanced echoes from the atmosphere observed with a vertically pointing radar are due to reflections from horizontally stratified layers. The general case in which there are many closely spaced layers at random heights is called Fresnel scatter. The variation of received power with transmitter pulse length is examined for various models of Fresnel backscatter. It is shown that for the model most often used in previous work, the power is proportional to the pulse length, and not to the pulse length squared. However, for more general models a more complex pulse length dependence is found.

  10. Ultrasound-modulated optical imaging using a photorefractive interferometer and a powerful long pulse laser

    NASA Astrophysics Data System (ADS)

    Rousseau, Guy; Blouin, Alain; Monchalin, Jean-Pierre

    2009-02-01

    Ultrasound-modulated optical imaging is an emerging biodiagnostic technique which provides the optical spectroscopic signature and the spatial localization of an optically absorbing object embedded in a strongly scattering medium. The transverse resolution of the technique is determined by the lateral extent of ultrasound beam focal zone while the axial resolution is obtained by using short ultrasound pulses. The practical application of this technique is presently limited by its poor sensitivity. Moreover, any method to enhance the signal-to-noise ratio must satisfy the biomedical safety limits. In this paper, we propose to use a pulsed single-frequency laser source to raise the optical peak power applied to the scattering medium and to collect more ultrasonically tagged photons. Such a laser source allows illuminating the tissues mainly during the transit time of the ultrasonic wave. A single-frequency Nd:YAG laser emitting 500-μs pulses with a peak power superior to 100 W was used. Tagged photons were detected with a GaAs photorefractive interferometer characterized by a large optical etendue. When pumped by high intensity laser pulses, such an interferometer provides the fast response time essential to obtain an apparatus insensitive to the speckle decorrelation encountered in biomedical applications. Consequently, the combination of a large-etendue photorefractive interferometer with a high-power pulsed laser could allow obtaining both the sensitivity and the fast response time necessary for biomedical applications. Measurements performed in 30- and 60-mm thick optical phantoms made of titanium dioxide particles dispersed in sunflower oil are presented. Results obtained in 30- and 60-mm thick chicken breast samples are also reported.

  11. A source of high-power pulses of elliptically polarized ultrawideband radiation

    SciTech Connect

    Andreev, Yu. A. Efremov, A. M.; Koshelev, V. I.; Kovalchuk, B. M.; Petkun, A. A.; Sukhushin, K. N.; Zorkaltseva, M. Yu.

    2014-10-01

    Here, we describe a source of high-power ultrawideband radiation with elliptical polarization. The source consisting of a monopolar pulse generator, a bipolar pulse former, and a helical antenna placed into a radioparent container may be used in tests for electromagnetic compatibility. In the source, the helical antenna with the number of turns N = 4 is excited with a high-voltage bipolar pulse. Preliminary, we examined helical antennas at a low-voltage source aiming to select an optimal N and to estimate a radiation center position and boundary of a far-field zone. Finally, characteristics of the source in the operating mode at a pulse repetition rate of 100 Hz are presented in the paper as well. Energy efficiency of the antenna is 0.75 at the axial ratio equal to 1.3. The effective potential of radiation of the source at the voltage amplitudes of the bipolar pulse generator equal to -175/+200 kV reaches 280 kV.

  12. Chamber wall materials response to pulsed ions at power-plant level fluences

    NASA Astrophysics Data System (ADS)

    Renk, T. J.; Provencio, P. P.; Tanaka, T. J.; Olson, C. L.; Peterson, R. R.; Stolp, J. E.; Schroen, D. G.; Knowles, T. R.

    2005-12-01

    Candidate dry-wall materials for the reactor chambers of future laser-driven Inertial Fusion Energy (IFE) power plants have been exposed to ion pulses from RHEPP-1, located at Sandia National Laboratories. These pulses simulate the MeV-level ion pulses with fluences of up to 20 J/cm 2 that can be expected to impinge on the first wall of such future plants. Various forms of tungsten and tungsten alloy were subjected to up to 1600 pulses, usually while being heated to 600 °C. Other metals were exposed as well. Thresholds for roughening and material removal, and evolution of surface morphology were measured and compared with code predictions for materials response. Powder-metallurgy (PM) tungsten is observed to undergo surface roughening and subsurface crack formation that evolves over hundreds of pulses, and which can occur both below and above the melt threshold. This roughening is worse than for other metals, and worse than for either tungsten alloyed with rhenium (W25Re), or for CVD and single-crystal forms of tungsten. Carbon, particularly the form used in composite material, appears to suffer material loss well below its sublimation point. Some engineered materials were also investigated. It appears that some modification to PM tungsten is required for its successful use in a reactor environment.

  13. Low-Power Water Suppression by Hyperbolic Secant Pulses with Controlled Offsets and Delays (WASHCODE)

    NASA Astrophysics Data System (ADS)

    Starčuk, Z.; Starčuk, Z.; Mlynárik, V.; Roden, M.; Horký, J.; Moser, E.

    2001-09-01

    A class of chemical-shift-selective (CHESS) water suppression (WS) schemes is presented in which the characteristic frequency-domain excitation profiles of "adiabatic" full-passage (AFP) RF pulses are utilized for frequency-selective excitation of the water resonance. In the proposed WS schemes, dubbed WASHCODE, hyperbolic secant (HS) pulses were used as the AFP pulses. Besides the high immunity of WS efficiency toward B1 inhomogeneity, these sequences also exhibit extraordinary insensitivity to the dispersion of the water T1 relaxation times. The actual performance of the proposed WS schemes was achieved in particular by optimizing the frequency offsets of WS HS pulses and the time intervals between them. To reduce the RF power requirements of these WS sequences for in vivo applications, HS pulses with the minimum possible frequency bandwidths were employed, which also substantially reduced the adverse effects on the observed proton MR spectra. The proposed WS schemes were evaluated by simulations based on the Bloch equations. Several WS sequences which looked particularly promising were verified experimentally on the human brain on a 3 T MR scanner using very short echo-time STEAM for volume selection and a standard single-loop surface coil for both signal transmission and reception. Routinely, water-suppression factors ranging from 2000 to 4000 were achieved in vivo without additional adjustment of parameters for individual subjects and without violating legal safety limits.

  14. Electromagnetic pulse research on electric power systems: Program summary and recommendations

    SciTech Connect

    Barnes, P.R.; McConnell, B.W.; Van Dyke, J.W. ); Tesche, F.M. , Dallas, TX ); Vance, E.F. , Fort Worth, TX )

    1993-01-01

    A single nuclear detonation several hundred kilometers above the central United States will subject much of the nation to a high-altitude electromagnetic pulse (BENT). This pulse consists of an intense steep-front, short-duration transient electromagnetic field, followed by a geomagnetic disturbance with tens of seconds duration. This latter environment is referred to as the magnetohydrodynamic electromagnetic pulse (NMENT). Both the early-time transient and the geomagnetic disturbance could impact the operation of the nation's power systems. Since 1983, the US Department of Energy has been actively pursuing a research program to assess the potential impacts of one or more BENT events on the nation's electric energy supply. This report summarizes the results of that program and provides recommendations for enhancing power system reliability under HENT conditions. A nominal HENP environment suitable for assessing geographically large systems was developed during the program and is briefly described in this report. This environment was used to provide a realistic indication of BEMP impacts on electric power systems. It was found that a single high-altitude burst, which could significantly disturb the geomagnetic field, may cause the interconnected power network to break up into utility islands with massive power failures in some areas. However, permanent damage would be isolated, and restoration should be possible within a few hours. Multiple bursts would likely increase the blackout areas, component failures, and restoration time. However, a long-term blackout of many months is unlikely because major power system components, such as transformers, are not likely to be damaged by the nominal HEND environment. Moreover, power system reliability, under both HENT and normal operating conditions, can be enhanced by simple, and often low cost, modifications to current utility practices.

  15. Advanced Receiver/Converter Experiments for Laser Wireless Power Transmission

    NASA Technical Reports Server (NTRS)

    Howell, Joe T.; ONeill, Mark; Fork, Richard

    2004-01-01

    For several years NASA Marshall Space Flight Center, UAH and ENTECH have been working on various aspects of space solar power systems. The current activity was just begun in January 2004 to further develop this new photovoltaic concentrator laser receiver/converter technology. During the next few months, an improved prototype will be designed, fabricated, and thoroughly tested under laser illumination. The final paper will describe the new concept, present its advantages over other laser receiver/converter approaches (including planar photovoltaic arrays), and provide the latest experiment results on prototype hardware (including the effects of laser irradiance level and cell temperature). With NASA's new human exploration plans to first return to the Moon, and then to proceed to Mars, the new photovoltaic concentrator laser receiver/converter technology could prove to be extremely useful in providing power to the landing sites and other phases of the missions. For example, to explore the scientifically interesting and likely resource-rich poles of the Moon (which may contain water) or the poles of Mars (which definitely contain water and carbon dioxide), laser power beaming could represent the simplest means of providing power to these regions, which receive little or no sunlight, making solar arrays useless there. In summary, the authors propose a paper on definition and experimental results of a novel photovoltaic concentrator approach for collecting and converting laser radiation to electrical power. The new advanced photovoltaic concentrator laser receiver/converter offers higher performance, lighter weight, and lower cost than competing concepts, and early experimental results are confirming the expected excellent Performance levels. After the small prototypes are successfully demonstrated, a larger array with even better performance is planned for the next phase experiments and demonstrations. Thereafter, a near-term flight experiment of the new technology

  16. Energy and average power scalable optical parametric chirped-pulse amplification in yttrium calcium oxyborate

    NASA Astrophysics Data System (ADS)

    Liao, Zhi M.; Jovanovic, Igor; Ebbers, Chris A.; Fei, Yiting; Chai, Bruce

    2006-05-01

    Optical parametric chirped-pulse amplification (OPCPA) in nonlinear crystals has the potential to produce extremes of peak and average power but is limited either in energy by crystal growth issues or in average power by crystal thermo-optic characteristics. Recently, large (7.5 cm diameter × 25 cm length) crystals of yttrium calcium oxyborate (YCOB) have been grown and utilized for high-average-power second-harmonic generation. Further, YCOB has the necessary thermo-optic properties required for scaling OPCPA systems to high peak and average power operation for wavelengths near 1 μm. We report what is believed to be the first use of YCOB for OPCPA. Scalability to higher peak and average power is addressed.

  17. Energy and average power scalable optical parametric chirped-pulse amplification in yttrium calcium oxyborate.

    PubMed

    Liao, Zhi M; Jovanovic, Igor; Ebbers, Chris A; Fei, Yiting; Chai, Bruce

    2006-05-01

    Optical parametric chirped-pulse amplification (OPCPA) in nonlinear crystals has the potential to produce extremes of peak and average power but is limited either in energy by crystal growth issues or in average power by crystal thermo-optic characteristics. Recently, large (7.5 cm diameter x 25 cm length) crystals of yttrium calcium oxyborate (YCOB) have been grown and utilized for high-average-power second-harmonic generation. Further, YCOB has the necessary thermo-optic properties required for scaling OPCPA systems to high peak and average power operation for wavelengths near 1 microm. We report what is believed to be the first use of YCOB for OPCPA. Scalability to higher peak and average power is addressed.

  18. A modified circuit topology for inductive pulsed power supply based on HTSPPTs

    NASA Astrophysics Data System (ADS)

    Li, Haitao; Zhang, Cunshan; Wang, Teng; Gao, Mingliang; Li, Zhenmei; Zou, Guofeng

    2016-10-01

    High temperature superconducting pulsed power transformer (HTSPPT) provides an efficient method for inductive energy storage and current multiplication. The primary inductor of HTSPPT used for energy storage is made of high temperature superconducting coils, and the secondary inductor used for current pulse generation is made of normal conductor coils. In the initial circuit, the secondary inductor generates current pulse by switching out the coupled primary superconducting inductor. However, during the switching period, the leakage flux caused by imperfect coupling and the sudden change in primary current induce a voltage across the opening switch which exceeds the affordability of modern solid-state switches. In previous studies, a half-cycle oscillatory discharge circuit is proposed to mitigate these problems by using a capacitor to recapture the energy in the leakage flux and to slow down the turnoff of current in the primary. However, there are still some problems should be settled. For example, the output pulse cannot be adjusted, the residual energy cannot be recovered and the capacitor branch circuit may have an impact on the charging process. In the paper, a modified discharge circuit topology is introduced to solve these problems. A multi-module system comprising of several HTSPPTs charging in series connection and discharging in parallel is also designed and simulated. This system can be used to power an electromagnetic emission device.

  19. Present and Future of Semiconductor Pulsed Power Generator ˜Role of Power Semiconductor Devices in Plasma Research˜ 6.High-Speed, Large-Current Power Semiconductors for Pulse Power Generation

    NASA Astrophysics Data System (ADS)

    Takata, Ikunori

    This paper describes the operation principles and limits of power semiconductors. In addition, operation mechanisms of the new pulse power devices, SOS (Semiconductor Opening Switch) and dynistors, are explained qualitatively. The fastest operating power device is the series connection of comparatively low-voltage devices. For large-current operation, a uniformly operating pin-diode structure device is essential. An SOS is constructed from dozens of medium voltage (about 3kV) special hard-recovery diodes. This can shut off 2kA current at 10kV with in 10ns. The dynistor has n+pnp+ four layers and two electrodes. Serial-connected dynistors have the potential to replace thyratrons. These new devices can endure over 10 kA/cm2 at much higher voltage than their static breakdown values in the repetitive use more than 1011 times.

  20. High-power picosecond pulse delivery through hollow core photonic band gap fibers

    NASA Astrophysics Data System (ADS)

    Michieletto, Mattia; Johansen, Mette M.; Lyngsø, Jens K.; Lægsgaard, Jesper; Bang, Ole; Alkeskjold, Thomas T.

    2016-03-01

    We demonstrated robust and bend insensitive fiber delivery of high power laser with diffraction limited beam quality for two different kinds of hollow core band gap fibers. The light source for this experiment consists of ytterbium-doped double clad fiber aeroGAIN-ROD-PM85 in a high power amplifier setup. It provided 22ps pulses with a maximum average power of 95W, 40MHz repetition rate at 1032nm (~2.4μJ pulse energy), with M2 <1.3. We determined the facet damage threshold for a 7-cells hollow core photonic bandgap fiber and showed up to 59W average power output for a 5 meters fiber. The damage threshold for a 19-cell hollow core photonic bandgap fiber exceeded the maximum power provided by the light source and up to 76W average output power was demonstrated for a 1m fiber. In both cases, no special attention was needed to mitigate bend sensitivity. The fibers were coiled on 8 centimeters radius spools and even lower bending radii were present. In addition, stimulated rotational Raman scattering arising from nitrogen molecules was measured through a 42m long 19 cell hollow core fiber.

  1. Tribological and structural properties of titanium nitride and titanium aluminum nitride coatings deposited with modulated pulsed power magnetron sputtering

    NASA Astrophysics Data System (ADS)

    Ward, Logan

    The demand for economical high-performance materials has brought attention to the development of advanced coatings. Recent advances in high power magnetron sputtering (HPPMS) have shown to improve tribological properties of coatings. These coatings offer increased wear and oxidation resistance, which may facilitate the use of more economical materials in harsh applications. This study demonstrates the use of novel forms of HPPMS, namely modulated pulsed-power magnetron sputtering (MPPMS) and deep oscillation magnetron sputtering (DOMS), for depositing TiN and Ti1-xAlxN tribological coatings on commonly used alloys, such as Ti-6Al-4V and Inconel 718. Both technologies have been shown to offer unique plasma characteristics in the physical vapor deposition (PVD) process. High power pulses lead to a high degree of ionization compared to traditional direct-current magnetron sputtering (DCMS) and pulsed magnetron sputtering (PMS). Such a high degree of ionization was previously only achievable by cathodic arc deposition (CAD); however, CAD can lead to increased macroparticles that are unfavorable in high friction and corrosive environments. MPPMS, DOMS, and other HPPMS techniques offer unique plasma characteristics and have been shown to produce coatings with refined grain structure, improved density, hardness, adhesion, and wear resistance. Using DOMS and MPPMS, TiN and Ti1-xAlxN coatings were deposited using PMS to compare microstructures and tribological performance. For Ti1-xAlxN, two sputtering target compositions, Ti 0.5Al0.5 and Ti0.3Al0.7, were used to evaluate the effects of MPPMS on the coating's composition and tribological properties. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) were used to characterize microstructure and crystallographic texture. Several tribological properties were evaluated including: wear rate, coefficient of friction, adhesion, and nanohardness. Results show that substrate

  2. Advanced coal technologies in Czech heat and power systems

    SciTech Connect

    Noskievic, P.; Ochodek, T.

    1998-04-01

    Coal is the only domestic source of fossil fuel in the Czech Republic. The coal reserves are substantial and their share in total energy use is about 60%. Presently necessary steps in making coal utilisation more friendly towards the environment have been taken and fairly well established, and an interest to develop and build advanced coal units has been observed. One IGCC system has been put into operation, and circa 10 AFBC units are in operation or under construction. Preparatory steps have been taken in building an advanced combustion unit fuelled by pulverised coal and retrofit action is taking place in many heating plants. An actual experience has shown two basic problems: (1) Different characteristic of domestic lignite, especially high content of ash, cause problems applying well-tried foreign technologies and apparently a more focused attention shall have to be paid to the quality of coal combusted. (2) Low prices of lignite (regarding energy, lignite is four times cheaper then coal) do not oblige to increase efficiency of the standing equipment applying advanced technologies. It will be of high interest to observe the effect of the effort of the European Union to establish a kind of carbon tax. It could dramatically change the existing scene in clean coal power generation by the logical pressure to increase the efficiency of energy transformation. In like manner the gradual liberalisation of energy prices might have similar consequences and it is a warranted expectation that, up to now not the best, energy balance will improve in near future.

  3. A power ramped pulsed mode laser piercing technique for improved CO 2 laser profile cutting

    NASA Astrophysics Data System (ADS)

    Tirumala Rao, B.; Ittoop, M. O.; Kukreja, L. M.

    2009-11-01

    Laser piercing is one of the inevitable requirements of laser profile cutting process and it has a direct bearing on the quality of the laser cut profiles. We have developed a novel power ramped pulsed mode (PRPM) laser piercing technique to produce much finer pierced holes and to achieve a better control on the process parameters compared to the existing methodology based on normal pulsed mode (NPM). Experiments were carried out with both PRPM and NPM laser piercing on 1.5-mm-thick mild steel using an in-house developed high-power transverse flow continuous wave (CW)-CO 2 laser. Significant improvements in the spatter, circularity of the pierced hole and reproducibility were achieved through the PRPM technique. We studied, in detail, the dynamics of processes involved in PRPM laser piercing and compared that with those of the NPM piercing.

  4. High power, short pulses ultraviolet laser for the development of a new x-ray laser

    SciTech Connect

    Meixler, L.; Nam, C.H.; Robinson, J.; Tighe, W.; Krushelnick, K.; Suckewer, S.; Goldhar, J.; Seely, J.; Feldman, U.

    1989-04-01

    A high power, short pulse ultraviolet laser system (Powerful Picosecond-Laser) has been developed at the Princeton Plasma Physics Laboratory (PPPL) as part of experiments designed to generate shorter wavelength x-ray lasers. With the addition of pulse compression and a final KrF amplifier the laser output is expected to have reached 1/3-1/2 TW (10/sup 12/ watts) levels. The laser system, particularly the final amplifier, is described along with some initial soft x-ray spectra from laser-target experiments. The front end of the PP-Laser provides an output of 20--30 GW (10/sup 9/ watts) and can be focussed to intensities of /approximately/10/sup 16/ W/cm/sup 2/. Experiments using this output to examine the effects of a prepulse on laser-target interaction are described. 19 refs., 14 figs.

  5. Optimizing the performance of TOAD by changing the wavelength and power of control pulse

    NASA Astrophysics Data System (ADS)

    Wen, Liangsheng; Zuo, Peng; Wu, Jian; Lin, Jintong

    2003-09-01

    The performance of terahertz optical asymmetric demultiplexer (TOAD) has been studied by modelling the semiconductor optical amplifier (SOA) in which the intraband effects had been taken into account. Numerical results are coincident with the experiment results. We interpret why there are three peaks in the switching window, which has never been reported before. In addition, we put forward the definition of the flatness of the switching window of TOAD for the first time By analysing the different phase of clockwise and counter clockwise signal pulse changed by SOA, appropriate peak power of control pulseand wavelength of signal and control pulse have been calculated in order to obtain large output power and flat switching window of TOAD.

  6. Specifics of Pulsed Arc Welding Power Supply Performance Based On A Transistor Switch

    NASA Astrophysics Data System (ADS)

    Krampit, N. Yu; Kust, T. S.; Krampit, M. A.

    2016-08-01

    Specifics of designing a pulsed arc welding power supply device are presented in the paper. Electronic components for managing large current was analyzed. Strengths and shortcomings of power supply circuits based on thyristor, bipolar transistor and MOSFET are outlined. As a base unit for pulsed arc welding was chosen MOSFET transistor, which is easy to manage. Measures to protect a transistor are given. As for the transistor control device is a microcontroller Arduino which has a low cost and adequate performance of the work. Bead transfer principle is to change the voltage on the arc in the formation of beads on the wire end. Microcontroller controls transistor when the arc voltage reaches the threshold voltage. Thus there is a separation and transfer of beads without splashing. Control strategies tested on a real device and presented. The error in the operation of the device is less than 25 us, it can be used controlling drop transfer at high frequencies (up to 1300 Hz).

  7. Improving the power efficiency of SOA-based UWB over fiber systems via pulse shape randomization

    NASA Astrophysics Data System (ADS)

    Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

    2016-09-01

    A simple pulse shape randomization scheme is considered in this paper for improving the performance of ultra wide band (UWB) communication systems using On Off Keying (OOK) or pulse position modulation (PPM) formats. The advantage of the proposed scheme, which can be either employed for impulse radio (IR) or for carrier-based systems, is first theoretically studied based on closed-form derivations of power spectral densities. Then, we investigate an application to an IR-UWB over optical fiber system, by utilizing the 4th and 5th orders of Gaussian derivatives. Our approach proves to be effective for 1 Gbps-PPM and 2 Gbps-OOK transmissions, with an advantage in terms of power efficiency for short distances. We also examine the performance for a system employing an in-line Semiconductor Optical Amplifier (SOA) with the view to achieve a reach extension, while limiting the cost and system complexity.

  8. Operation of the power information center: Performance of secretariat functions and information exchange activities in the advanced power field of the interagency advanced power group

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Highlights of activities conducted during the reporting period to facilitate the exchange of technical information among scientists and engineers both within the federal government and within industry are cited. Interagency Advanced Power Group meetings and special efforts, project briefs, and organization development are considered.

  9. Low density, microcellular, dopable, agar/gelatin foams for pulsed power experiments

    SciTech Connect

    McNamara, W.F.; Aubert, J.H.

    1997-04-01

    Low-density, microcellular foams prepared from the natural polymers agar and gelatin have been developed for pulsed-power physics experiments. Numerous experiments were supported with foams having densities at or below 10 mg/cm{sup 3}. For some of the experiments, the agar/gelatin foam was uniformly doped with metallic elements using soluble salts. Depending on the method of preparation, cell sizes were typically below 10 microns and for one process were below 1.0 micron.

  10. Conversion of high explosive chemical energy into energy of powerful nanosecond high-current pulses

    NASA Astrophysics Data System (ADS)

    Gorbachev, K. V.; Mikhaylov, V. M.; Nesterov, E. V.; Stroganov, V. A.; Chernykh, E. V.

    2015-01-01

    This study is a contribution into the development of physicotechnical foundations for generation of powerful nanosecond high-current pulses on the basis of explosively driven magnetic flux compression generators. This problem is solved by using inductive storage of energy for matching comparatively low-voltage explosively driven magnetic flux compression generators and high-impedance loads; short forming lines and vacuum diodes. Experimental data of charging of forming lines are given.

  11. The HEMP (high altitude electromagnetic pulse) response of an overhead power distribution line

    SciTech Connect

    Tesche, F.M.; Barnes, P.R.

    1988-01-01

    A study of the HEMP response of a realistic power distribution system was undertaken, and its results are described in this paper. This study involved the following elements: (1) the use of the new HEMP environment, (2) the use of a multiconductor coupling model, and (3) the measurement of the pulse response of an actual distribution transformer to permit the use of this data in the analysis.

  12. Advanced Stirling Convertor Development for NASA Radioisotope Power Systems

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Wilson, Scott D.; Collins, Josh

    2015-01-01

    Sunpower Inc.'s Advanced Stirling Convertor (ASC) initiated development under contract to the NASA Glenn Research Center and after a series of successful demonstrations, the ASC began transitioning from a technology development project to a flight development project. The ASC has very high power conversion efficiency making it attractive for future Radioisotope Power Systems (RPS) in order to make best use of the low plutonium-238 fuel inventory in the United States. In recent years, the ASC became part of the NASA and Department of Energy (DOE) Advanced Stirling Radioisotope Generator (ASRG) Integrated Project. Sunpower held two parallel contracts to produce ASCs, one with the DOE and Lockheed Martin to produce the ASC-F flight convertors, and one with NASA Glenn for the production of ASC-E3 engineering units, the initial units of which served as production pathfinders. The integrated ASC technical team successfully overcame various technical challenges that led to the completion and delivery of the first two pairs of flightlike ASC-E3 by 2013. However, in late fall 2013, the DOE initiated termination of the Lockheed Martin ASRG flight development contract driven primarily by budget constraints. NASA continues to recognize the importance of high-efficiency ASC power conversion for RPS and continues investment in the technology including the continuation of ASC-E3 production at Sunpower and the assembly of the ASRG Engineering Unit #2. This paper provides a summary of ASC technical accomplishments, overview of tests at Glenn, plans for continued ASC production at Sunpower, and status of Stirling technology development.

  13. Application of advanced austenitic alloys to fossil power system components

    SciTech Connect

    Swindeman, R.W.

    1996-06-01

    Most power and recovery boilers operating in the US produce steam at temperatures below 565{degrees}C (1050{degrees}F) and pressures below 24 MPa (3500 psi). For these operating conditions, carbon steels and low alloy steels may be used for the construction of most of the boiler components. Austenitic stainless steels often are used for superheater/reheater tubing when these components are expected to experience temperatures above 565{degrees}C (1050{degrees}F) or when the environment is too corrosive for low alloys steels. The austenitic stainless steels typically used are the 304H, 321H, and 347H grades. New ferritic steels such as T91 and T92 are now being introduced to replace austenitic: stainless steels in aging fossil power plants. Generally, these high-strength ferritic steels are more expensive to fabricate than austenitic stainless steels because the ferritic steels have more stringent heat treating requirements. Now, annealing requirements are being considered for the stabilized grades of austenitic stainless steels when they receive more than 5% cold work, and these requirements would increase significantly the cost of fabrication of boiler components where bending strains often exceed 15%. It has been shown, however, that advanced stainless steels developed at ORNL greatly benefit from cold work, and these steels could provide an alternative to either conventional stainless steels or high-strength ferritic steels. The purpose of the activities reported here is to examine the potential of advanced stainless steels for construction of tubular components in power boilers. The work is being carried out with collaboration of a commercial boiler manufacturer.

  14. Design and testing of 45 kV, 50 kHz pulse power supply for dielectric barrier discharges

    NASA Astrophysics Data System (ADS)

    Sharma, Surender Kumar; Shyam, Anurag

    2016-10-01

    The design, construction, and testing of high frequency, high voltage pulse power supply are reported. The purpose of the power supply is to generate dielectric barrier discharges for industrial applications. The power supply is compact and has the advantage of low cost, over current protection, and convenient control for voltage and frequency selection. The power supply can generate high voltage pulses of up to 45 kV at the repetitive frequency range of 1 kHz-50 kHz with 1.2 kW input power. The output current of the power supply is limited to 500 mA. The pulse rise time and fall time are less than 2 μs and the pulse width is 2 μs. The power supply is short circuit proof and can withstand variable plasma load conditions. The power supply mainly consists of a half bridge series resonant converter to charge an intermediate capacitor, which discharges through a step-up transformer at high frequency to generate high voltage pulses. Semiconductor switches and amorphous cores are used for power modulation at higher frequencies. The power supply is tested with quartz tube dielectric barrier discharge load and worked stably. The design details and the performance of the power supply on no load and dielectric barrier discharge load are presented.

  15. An experimental study of high power microwave pulsed discharge in nitrogen

    NASA Astrophysics Data System (ADS)

    Mesko, M.; Bonaventura, Z.; Vasina, P.; Kudrle, V.; Tálský, A.; Trunec, D.; Frgala, Z.; Janca, J.

    2006-08-01

    We investigated a plasma excited by high power pulsed microwaves (MWs) (pulse duration 2.5 µs, repetition rate 400 Hz, peak power 105 W, frequency 9.4 GHz) in nitrogen at reduced pressure (pressure range 10-2000 Pa) with the aim of a better understanding of such types of discharge. The construction of the experimental device suppresses the plasma-wall interactions and therefore the volume processes are predominant. To obtain the temporal evolution of the electron density we used two MW interferometers at frequencies of 15 and 35 GHz with dielectric rod waveguides which gives them the capability of localized measurements. We estimated the effective collision frequency from the absorption of a measurement beam. Time resolved optical emission spectroscopy of the 1st negative system and the 2nd positive system was carried out, too. Due to a high power input the discharge dynamics was fast and the steady state was typically reached in 1 µs. We found that the effective collision frequency has the same temporal behaviour as the 2nd positive system of N2, including a characteristic maximum at the beginning of the pulse.

  16. More Efficient Power Conversion for EVs: Gallium-Nitride Advanced Power Semiconductor and Packaging

    SciTech Connect

    2010-02-01

    Broad Funding Opportunity Announcement Project: Delphi is developing power converters that are smaller and more energy efficient, reliable, and cost-effective than current power converters. Power converters rely on power transistors which act like a very precisely controlled on-off switch, controlling the electrical energy flowing through an electrical circuit. Most power transistors today use silicon (Si) semiconductors. However, Delphi is using semiconductors made with a thin layer of gallium-nitride (GaN) applied on top of the more conventional Si material. The GaN layer increases the energy efficiency of the power transistor and also enables the transistor to operate at much higher temperatures, voltages, and power-density levels compared to its Si counterpart. Delphi is packaging these high-performance GaN semiconductors with advanced electrical connections and a cooling system that extracts waste heat from both sides of the device to further increase the device’s efficiency and allow more electrical current to flow through it. When combined with other electronic components on a circuit board, Delphi’s GaN power transistor package will help improve the overall performance and cost-effectiveness of HEVs and EVs.

  17. Mitigation of magnetohydrodynamic electromagnetic pulse (MHD-EMP) effects from commerical electric power systems

    SciTech Connect

    Barnes, P.R. ); Tesche, F.M. , Dallas, TX ); Vance, E.F. , Fort Worth, TX )

    1992-03-01

    A large nuclear detonation at altitudes of several hundred kilometers above the earth distorts the earth's magnetic field and produces a strong magnetohydrodynamic electromagnetic pulse (MHD-EMP). This can adversely affect electrical power systems. In this report, the effects of this nuclear environment on critical facilities connected to the commercial power system are considered. Methods of mitigating the MHD-EMP impacts are investigated, and recommended protection schemes are presented. Guidelines for testing facilities to determine the effects of MHD-EMP and to validate the mitigation methods also are discussed.

  18. Advanced on-site power plant development technology program

    NASA Astrophysics Data System (ADS)

    1989-09-01

    The purpose of the technical effort was to establish a technology base for 200-kW on-site fuel cell power plants. It was conducted in two phases: (1) Component evaluation; and (2) Full-scale system verification. This contract was supplemented by a Gas Research Institute (GRI) contract which was conducted in the 1981 to 1986 time period. This GRI contract concentrated on 200-kW scale component design, thermal management/water treatment system analysis and redesign and advanced DC/AC inverter development. The component evaluation phase generally included subscale component tests, scale-up to full-size 200-kW hardware and full-size hardware tests of the cell stack (in Tasks 1 and 2), the power conditioner (in Task 3), the heat exchangers and ancillary components (in Task 4), and the fuel processor (in Task 5). The full-size cell stack, fuel processor, heat exchangers, and ancillary components from the component development tasks were integrated into a dc system called the Verification Test Article (VTA). The VTA which was fabricated and tested under Task 7 allowed for system integration issues associated with the cell stack, fuel processor, thermal management, and water treatment subsystems to be explored under conditions similar to an actual fuel cell power plant. Key accomplishments of this contract are described.

  19. Advanced tendencies in development of photovoltaic cells for power engineering

    NASA Astrophysics Data System (ADS)

    Strebkov, D. S.

    2015-01-01

    Development of solar power engineering must be based on original innovative Russian and world technologies. It is necessary to develop promising Russian technologies of manufacturing of photovoltaic cells and semiconductor materials: chlorine-free technology for obtaining solar silicon; matrix solar cell technology with an efficiency of 25-30% upon the conversion of concentrated solar, thermal, and laser radiation; encapsulation technology for high-voltage silicon solar modules with a voltage up to 1000 V and a service life up to 50 years; new methods of concentration of solar radiation with the balancing illumination of photovoltaic cells at 50-100-fold concentration; and solar power systems with round-the-clock production of electrical energy that do not require energy storage devices and reserve sources of energy. The advanced tendency in silicon power engineering is the use of high-temperature reactions in heterogeneous modular silicate solutions for long-term (over one year) production of heat and electricity in the autonomous mode.

  20. Advanced power system protection and incipient fault detection and protection of spaceborne power systems

    NASA Technical Reports Server (NTRS)

    Russell, B. Don

    1989-01-01

    This research concentrated on the application of advanced signal processing, expert system, and digital technologies for the detection and control of low grade, incipient faults on spaceborne power systems. The researchers have considerable experience in the application of advanced digital technologies and the protection of terrestrial power systems. This experience was used in the current contracts to develop new approaches for protecting the electrical distribution system in spaceborne applications. The project was divided into three distinct areas: (1) investigate the applicability of fault detection algorithms developed for terrestrial power systems to the detection of faults in spaceborne systems; (2) investigate the digital hardware and architectures required to monitor and control spaceborne power systems with full capability to implement new detection and diagnostic algorithms; and (3) develop a real-time expert operating system for implementing diagnostic and protection algorithms. Significant progress has been made in each of the above areas. Several terrestrial fault detection algorithms were modified to better adapt to spaceborne power system environments. Several digital architectures were developed and evaluated in light of the fault detection algorithms.

  1. Technology and engineering aspects of high power pulsed single longitudinal mode dye lasers

    NASA Astrophysics Data System (ADS)

    Rawat, V. S.; Mukherjee, Jaya; Gantayet, L. M.

    2015-09-01

    Tunable single mode pulsed dye lasers are capable of generating optical radiations in the visible range having very small bandwidths (transform limited), high average power (a few kW) at a high pulse repetition rate (a few tens of kHz), small beam divergence and relatively higher efficiencies. These dye lasers are generally utilized laser dyes dissolved in solvents such as water, heavy water, ethanol, methanol, etc. to provide a rapidly flowing gain medium. The dye laser is a versatile tool, which can lase either in the continuous wave (CW) or in the pulsed mode with pulse duration as small as a few tens of femtoseconds. In this review, we have examined the several cavity designs, various types of gain mediums and numerous types of dye cell geometries for obtaining the single longitudinal mode pulsed dye laser. Different types of cavity configuration, such as very short cavity, short cavity with frequency selective element and relatively longer cavity with multiple frequency selective elements were reviewed. These single mode lasers have been pumped by all kinds of pumping sources such as flash lamps, Excimer, Nitrogen, Ruby, Nd:YAG, Copper Bromide and Copper Vapor Lasers. The single mode dye lasers are either pumped transversely or longitudinally to the resonator axis. The pulse repletion rate of these pump lasers were ranging from a few Hz to a few tens of kHz. Physics technology and engineering aspects of tuning mechanism, mode hop free scanning and dye cell designs are also presented in this review. Tuning of a single mode dye laser with a resolution of a few MHz per step is a technologically challenging task, which is discussed here.

  2. High-power noise-like pulse generation using a 1.56-µm all-fiber laser system.

    PubMed

    Lin, Shih-Shian; Hwang, Sheng-Kwang; Liu, Jia-Ming

    2015-07-13

    We demonstrated an all-fiber, high-power noise-like pulse laser system at the 1.56-µm wavelength. A low-power noise-like pulse train generated by a ring oscillator was amplified using a two-stage amplifier, where the performance of the second-stage amplifier determined the final output power level. The optical intensity in the second-stage amplifier was managed well to avoid not only the excessive spectral broadening induced by nonlinearities but also any damage to the device. On the other hand, the power conversion efficiency of the amplifier was optimized through proper control of its pump wavelength. The pump wavelength determines the pump absorption and therefore the power conversion efficiency of the gain fiber. Through this approach, the average power of the noise-like pulse train was amplified considerably to an output of 13.1 W, resulting in a power conversion efficiency of 36.1% and a pulse energy of 0.85 µJ. To the best of our knowledge, these amplified pulses have the highest average power and pulse energy for noise-like pulses in the 1.56-µm wavelength region. As a result, the net gain in the cascaded amplifier reached 30 dB. With peak and pedestal widths of 168 fs and 61.3 ps, respectively, for the amplified pulses, the pedestal-to-peak intensity ratio of the autocorrelation trace remains at the value of 0.5 required for truly noise-like pulses. PMID:26191882

  3. The ARIES Advanced And Conservative Tokamak (ACT) Power Plant Study

    SciTech Connect

    Kessel, C. E.; Poli, F. M.; Ghantous, K.; Gorelenkov, N.; Tillack, M. S.; Najmabadi, F.; Wang, X. R.; Navaei, D.; Toudeshki, H. H.; Koehly, C.; El-Guebaly, L.; Blanchard, J. P.; Martin, C. J.; Mynsburge, L.; Humrickhouse, P.; Rensink, M. E.; Rognlien, T. D.; Yoda, M.; Abdel-Khalik, S. I.; Hageman, M. D.; Mills, B. H.; Radar, J. D.; Sadowski, D. L.; Snyder, P. B.; St. John, H.; Turnbull, A. D.; Waganer, L. M.; Malang, S.; Rowcliffe, A. F.

    2014-03-05

    Tokamak power plants are studied with advanced and conservative design philosophies in order to identify the impacts on the resulting designs and to provide guidance to critical research needs. Incorporating updated physics understanding, and using more sophisticated engineering and physics analysis, the tokamak configurations have developed a more credible basis compared to older studies. The advanced configuration assumes a self-cooled lead lithium (SCLL) blanket concept with SiC composite structural material with 58% thermal conversion efficiency. This plasma has a major radius of 6.25 m, a toroidal field of 6.0 T, a q95 of 4.5, a {beta}N{sup total} of 5.75, H{sub 98} of 1.65, n/nGr of 1.0, and peak divertor heat flux of 13.7 MW/m{sup 2}. The conservative configuration assumes a dual coolant lead lithium (DCLL) blanket concept with ferritic steel structural material and helium coolant, achieving a thermal conversion efficiency of 45%. The plasma major radius is 9.75 m, a toroidal field of 8.75 T, a q95 of 8.0, a {beta}N{sup total} of 2.5, H{sub 98} of 1.25, n/n{sub Gr} of 1.3, and peak divertor heat flux of 10 MW/m{sup 2}. The divertor heat flux treatment with a narrow power scrape-off width has driven the plasmas to larger major radius. Edge and divertor plasma simulations are targeting a basis for high radiated power fraction in the divertor, which is necessary for solutions to keep the peak heat flux in the range of 10-15 MW/m{sup 2}. Combinations of the advanced and conservative approaches show intermediate sizes. A new systems code using a database approach has been used and shows that the operating point is really an operating zone with some range of plasma and engineering parameters and very similar costs of electricity. Papers in this issue provide more detailed discussion of the work summarized here.

  4. The ARIES Advanced and Conservative Tokamak Power Plant Study

    SciTech Connect

    Kessel, C. E; Tillak, M. S; Najmabadi, F.; Poli, F. M.; Ghantous, K.; Gorelenkov, N.; Wang, X. R.; Navaei, D.; Toudeshki, H. H.; Koehly, C.; EL-Guebaly, L.; Blanchard, J. P.; Martin, C. J.; Mynsburge, L.; Humrickhouse, P.; Rensink, M. E.; Rognlien, T. D.; Yoda, M.; Abdel-Khalik, S. I.; Hageman, M. D.; Mills, B. H.; Rader, J. D.; Sadowski, D. L.; Snyder, P. B.; St. John, H.; Turnbull, A. D.; Waganer, L. M.; Malang, S.; Rowcliffe, A. F.

    2015-12-22

    Tokamak power plants are studied with advanced and conservative design philosophies to identify the impacts on the resulting designs and to provide guidance to critical research needs. Incorporating updated physics understanding and using more sophisticated engineering and physics analysis, the tokamak configurations have developed a more credible basis compared with older studies. The advanced configuration assumes a self-cooled lead lithium blanket concept with SiC composite structural material with 58% thermal conversion efficiency. This plasma has a major radius of 6.25 m, a toroidal field of 6.0 T, a q₉₅ of 4.5, aᵦtotal N of 5.75, an H98 of 1.65, an n/nGr of 1.0, and a peak divertor heat flux of 13.7 MW/m² . The conservative configuration assumes a dual-coolant lead lithium blanket concept with reduced activation ferritic martensitic steel structural material and helium coolant, achieving a thermal conversion efficiency of 45%. The plasma has a major radius of 9.75 m, a toroidal field of 8.75 T, a q₉₅ of 8.0, aᵦtotalN of 2.5, an H₉₈ of 1.25, an n/nGr of 1.3, and a peak divertor heat flux of 10 MW/m² . The divertor heat flux treatment with a narrow power scrape off width has driven the plasmas to larger major radius. Edge and divertor plasma simulations are targeting a basis for high radiated power fraction in the divertor, which is necessary for solutions to keep the peak heat flux in the range 10 to 15 MW/m² . Combinations of the advanced and conservative approaches show intermediate sizes. A new systems code using a database approach has been used and shows that the operating point is really an operating zone with some range of plasma and engineering parameters and very similar costs of electricity. Other papers in this issue provide more detailed discussion of the work summarized here.

  5. The ARIES Advanced and Conservative Tokamak Power Plant Study

    DOE PAGES

    Kessel, C. E; Tillak, M. S; Najmabadi, F.; Poli, F. M.; Ghantous, K.; Gorelenkov, N.; Wang, X. R.; Navaei, D.; Toudeshki, H. H.; Koehly, C.; et al

    2015-12-22

    Tokamak power plants are studied with advanced and conservative design philosophies to identify the impacts on the resulting designs and to provide guidance to critical research needs. Incorporating updated physics understanding and using more sophisticated engineering and physics analysis, the tokamak configurations have developed a more credible basis compared with older studies. The advanced configuration assumes a self-cooled lead lithium blanket concept with SiC composite structural material with 58% thermal conversion efficiency. This plasma has a major radius of 6.25 m, a toroidal field of 6.0 T, a q₉₅ of 4.5, aᵦtotal N of 5.75, an H98 of 1.65, anmore » n/nGr of 1.0, and a peak divertor heat flux of 13.7 MW/m² . The conservative configuration assumes a dual-coolant lead lithium blanket concept with reduced activation ferritic martensitic steel structural material and helium coolant, achieving a thermal conversion efficiency of 45%. The plasma has a major radius of 9.75 m, a toroidal field of 8.75 T, a q₉₅ of 8.0, aᵦtotalN of 2.5, an H₉₈ of 1.25, an n/nGr of 1.3, and a peak divertor heat flux of 10 MW/m² . The divertor heat flux treatment with a narrow power scrape off width has driven the plasmas to larger major radius. Edge and divertor plasma simulations are targeting a basis for high radiated power fraction in the divertor, which is necessary for solutions to keep the peak heat flux in the range 10 to 15 MW/m² . Combinations of the advanced and conservative approaches show intermediate sizes. A new systems code using a database approach has been used and shows that the operating point is really an operating zone with some range of plasma and engineering parameters and very similar costs of electricity. Other papers in this issue provide more detailed discussion of the work summarized here.« less

  6. Nonthermal Biological Treatments Using Discharge Plasma Produced by Pulsed Power 4. Cleaning of Lakes and Marshes by Pulsed Power Produced Streamer Discharges in Water

    NASA Astrophysics Data System (ADS)

    Akiyama, Hidenori; Katsuki, Sunao; Namihira, Takao; Ishibashi, Kazuo; Kiyosaki, Noriaki

    Pulsed power has been used to produce non-thermal plasmas in atmospheric pressure gases that generate a high electric field at the tips of streamer discharges, where high energy electrons, free radicals, ultraviolet rays, and ozone are produced. These manifestations of streamer discharges have been used in the treatment of exhaust gases, removal of volatile and toxic compounds such as dioxin, and the sterilization of microorganisms. Here, large volume streamer discharges in water are described. These streamer discharges in liquids are able to produce a high electric field, high energy electrons, ozone, chemically active species, ultraviolet rays, and shock waves, which readily sterilize microorganisms and decompose molecules and materials. An application of this phenomenon to the cleaning of lakes and marshes is also described.

  7. Detailed performance modeling of a pulsed high-power single-frequency Ti:sapphire laser.

    PubMed

    Wagner, Gerd; Wulfmeyer, Volker; Behrendt, Andreas

    2011-11-01

    Differential absorption lidar (DIAL) is a unique technique for profiling water vapor from the ground up to the lower stratosphere. For accurate measurements, the DIAL laser transmitter has to meet stringent requirements. These include high average power (up to 10 W) and high single-shot pulse energy, a spectral purity >99.9%, a frequency instability <60 MHz rms, and narrow spectral bandwidth (single-mode, <160 MHz). We describe extensive modeling efforts to optimize the resonator design of a Ti:sapphire ring laser in these respects. The simulations were made for the wavelength range of 820 nm, which is optimum for ground-based observations, and for both stable and unstable resonator configurations. The simulator consists of four modules: (1) a thermal module for determining the thermal lensing of the Brewster-cut Ti:sapphire crystal collinear pumped from both ends with a high-power, frequency-doubled Nd:YAG laser; (2) a module for calculating the in-cavity beam propagations for stable and unstable resonators; (3) a performance module for simulating the pumping efficiency and the laser pulse energy; and (4) a spectral module for simulating injection seeding and the spectral properties of the laser radiation including spectral impurity. Both a stable and an unstable Ti:sapphire laser resonator were designed for delivering an average power of 10 W at a pulse repetition frequency of 250 Hz with a pulse length of approximately 40 ns, satisfying all spectral requirements. Although the unstable resonator design is more complex to align and has a higher lasing threshold, it yields similar efficiency and higher spectral purity at higher overall mode volume, which is promising for long-term routine operations. PMID:22086016

  8. High-power ultrasonic processing: Recent developments and prospective advances

    NASA Astrophysics Data System (ADS)

    Gallego-Juarez, Juan A.

    2010-01-01

    Although the application of ultrasonic energy to produce or to enhance a wide variety of processes have been explored since about the middle of the 20th century, only a reduced number of ultrasonic processes have been established at industrial level. However, during the last ten years the interest in ultrasonic processing has revived particularly in industrial sectors where the ultrasonic technology may represent a clean and efficient tool to improve classical existing processes or an innovation alternative for the development of new processes. Such seems to be the case of relevant sectors such as food industry, environment, pharmaceuticals and chemicals manufacture, machinery, mining, etc where power ultrasound is becoming an emerging technology for process development. The possible major problem in the application of high-intensity ultrasound on industrial processing is the design and development of efficient power ultrasonic systems (generators and reactors) capable of large scale successful operation specifically adapted to each individual process. In the area of ultrasonic processing in fluid media and more specifically in gases, the development of the steppedplate transducers and other power ge with extensive radiating surface has strongly contributed to the implementation at semi-industrial and industrial stage of several commercial applications, in sectors such as food and beverage industry (defoaming, drying, extraction, etc), environment (air cleaning, sludge filtration, etc...), machinery and process for manufacturing (textile washing, paint manufacture, etc). The development of different cavitational reactors for liquid treatment in continuous flow is helping to introduce into industry the wide potential of the area of sonochemistry. Processes such as water and effluent treatment, crystallization, soil remediation, etc have been already implemented at semi-industrial and/or industrial stage. Other single advances in sectors like mining or energy have

  9. High power, single mode, all-fiber source of femtosecond pulses at 1550 nm and its use in supercontinuum generation

    NASA Astrophysics Data System (ADS)

    Nicholson, Jeffrey W.; Yablon, A. D.; Westbrook, P. S.; Feder, K. S.; Yan, M. F.

    2004-06-01

    We present a source of high power femtosecond pulses at 1550 nm with compressed pulses at the end of a single mode fiber (SMF) pigtail. The system generates 34 femtosecond pulses at a repetition rate of 46 MHz, with average powers greater than 400 mW. The pulses are generated in a passively modelocked, erbium-doped fiber laser, and amplified in a short, erbium-doped fiber amplifier. The output of the fiber amplifier consists of highly chirped picosecond pulses. These picosecond pulses are then compressed in standard single mode fiber. While the compressed pulses in the SMF pigtail do show a low pedestal that could be avoided with the use of bulk-optic compression, the desire to compress the pulses in SMF is motivated by the ability to splice the single mode fiber to a nonlinear fiber, for continuum generation applications. We demonstrate that with highly nonlinear dispersion shifted fiber (HNLF) fusion spliced directly to the amplifier output, we generate a supercontinuum spectrum that spans more than an octave, with an average power 400 mW. Such a high power, all-fiber supercontinuum source has many important applications including frequency metrology and bio-medical imaging.

  10. High power, single mode, all-fiber source of femtosecond pulses at 1550 nm and its use in supercontinuum generation.

    PubMed

    Nicholson, Jeffrey; Yablon, A; Westbrook, P; Feder, K; Yan, M

    2004-06-28

    We present a source of high power femtosecond pulses at 1550 nm with compressed pulses at the end of a single mode fiber (SMF) pigtail. The system generates 34 femtosecond pulses at a repetition rate of 46 MHz, with average powers greater than 400 mW. The pulses are generated in a passively modelocked, erbium-doped fiber laser, and amplified in a short, erbium-doped fiber amplifier. The output of the fiber amplifier consists of highly chirped picosecond pulses. These picosecond pulses are then compressed in standard single mode fiber. While the compressed pulses in the SMF pigtail do show a low pedestal that could be avoided with the use of bulk-optic compression, the desire to compress the pulses in SMF is motivated by the ability to splice the single mode fiber to a nonlinear fiber, for continuum generation applications. We demonstrate that with highly nonlinear dispersion shifted fiber (HNLF) fusion spliced directly to the amplifier output, we generate a supercontinuum spectrum that spans more than an octave, with an average power 400 mW. Such a high power, all-fiber supercontinuum source has many important applications including frequency metrology and bio-medical imaging. PMID:19483820

  11. Advanced on-site power plant development technology program

    NASA Technical Reports Server (NTRS)

    1984-01-01

    A 30-cell, full area short stack containing advanced cell features was tested for 2900 hours. A stack acid addition approach was selected and will be evaluated on the stack at 5000 hours test time. A brassboard inverter was designed and fabrication was initiated. Evaluation of this brassboard inverter will take place in 1984. A Teflon coated commercial heat exchanger was selected as the preferred approach for the acid condenser. A reformer catalyst with significantly less pressure drop and equivalent performance relative to the 40-K baseline catalyst was selected for the development reformer. The early 40-kW field power plant history was reviewed and adjustments were made to the On-Site Technology Development Program to address critical component issues.

  12. Advanced Gas Turbine (AGT) power-train system development

    NASA Technical Reports Server (NTRS)

    Helms, H. E.; Johnson, R. A.; Gibson, R. K.

    1982-01-01

    Technical work on the design and component testing of a 74.5 kW (100 hp) advanced automotive gas turbine is described. Selected component ceramic component design, and procurement were tested. Compressor tests of a modified rotor showed high speed performance improvement over previous rotor designs; efficiency improved by 2.5%, corrected flow by 4.6%, and pressure ratio by 11.6% at 100% speed. The aerodynamic design is completed for both the gasifier and power turbines. Ceramic (silicon carbide) gasifier rotors were spin tested to failure. Improving strengths is indicated by burst speeds and the group of five rotors failed at speeds between 104% and 116% of engine rated speed. The emission results from combustor testing showed NOx levels to be nearly one order of magnitude lower than with previous designs. A one piece ceramic exhaust duct/regenerator seal platform is designed with acceptable low stress levels.

  13. Advanced interaction media in nuclear power plant control rooms.

    PubMed

    Stephane, Lucas

    2012-01-01

    The shift from analog to digital Instruments (related mainly to information visualization) and Controls in Nuclear Power Plant Main Control Rooms (NPP MCR) is a central current topic of investigation. In NPP MCR, digitalization was implemented gradually, analog and digital systems still coexisting for the two main systems related to safety--Safety Instruments and Control System (SICS) and Process Instruments and Controls System (PICS). My ongoing research focuses on the introduction of Advanced Interaction Media (AIM) such as stereoscopic 3D visualization and multi-touch surfaces in control rooms. This paper proposes a Safety-Centric approach for gathering the Design Rationale needed in the specification of such novel AIM concepts as well as their evaluation through user tests. Beyond methodological research, the final output of the current research is to build an experimental simulator aiming to enhance improvements in Human-Systems Integration (HSI). This paper provides an overview of the topics under consideration.

  14. Recent advances in flexible low power cholesteric LCDs

    NASA Astrophysics Data System (ADS)

    Khan, Asad; Shiyanovskaya, Irina; Montbach, Erica; Schneider, Tod; Nicholson, Forrest; Miller, Nick; Marhefka, Duane; Ernst, Todd; Doane, J. W.

    2006-05-01

    Bistable reflective cholesteric displays are a liquid crystal display technology developed to fill a market need for very low power displays. Their unique look, high reflectivity, bistability, and simple structure make them an ideal flat panel display choice for handheld or other portable devices where small lightweight batteries with long lifetimes are important. Applications ranging from low resolution large signs to ultra high resolution electronic books can utilize cholesteric displays to not only benefit from the numerous features, but also create enabling features that other flat panel display technologies cannot. Flexible displays are the focus of attention of numerous research groups and corporations worldwide. Cholesteric displays have been demonstrated to be highly amenable to flexible substrates. This paper will review recent advances in flexible cholesteric displays including both phase separation and emulsification approaches to encapsulation. Both approaches provide unique benefits to various aspects of manufacturability, processes, flexibility, and conformability.

  15. Use of North Dakota lignite in advanced power systems

    SciTech Connect

    Willson, W.G.; Hurley, J.P.; Sharp, L.

    1992-12-01

    In order to develop critical data for Department of Energy (DOE) and private industry for advanced high-efficiency power systems using North Dakota lignite in pressurized gasification and combustion systems, tests were performed in bench-scale equipment at the Energy and Environmental Research Center (EERC). The primary objectives were to (1) determine the conversion levels for Center ND lignite under pressurized fluid-bed gasification conditions with sorbent addition as a function of temperature, (2) determine the sulfur capture using limestone or dolomite under gasification conditions giving 90% or higher carbon conversion, (3) evaluate char/coal conversion and sulfur capture in a pressurized fluid-bed combustor, (4) assess the potential for bed agglomeration under the preferred operating conditions for both systems.

  16. Candidate advanced energy storage concepts for multimegawatt burst power systems

    NASA Astrophysics Data System (ADS)

    Boretz, John E.; Sollo, Charles

    Three candidate advanced energy storage systems are reviewed and compared with the Thermionic Operating Reactor (THOR) concept. The three systems considered are the flywheel generator, the lithium-metal sulfide battery and the alkaline fuel cell. From a minimum mass viewpoint, only the regenerative fuel cell (RFC) can result in a lighter system than THOR. Because of its lower operating temperature, as compared to THOR, a considerable reduction in materials problems is to be expected when compared to the extremely high operating temperatures of the THOR system. Frozen heat pipes and their impact on response time as well as the complexity of the required retraction/extension mechanism of the THOR system would tend to place the RFC system in a much lower category of development risk. Finally, if spot shielding of sensitive electronic and power conditioning equipment becomes necessary for the reactor radiation environment of the THOR system, the weight advantage of the RFC system may become even greater.

  17. Advanced thermionic reactors for surface nuclear power applications

    NASA Astrophysics Data System (ADS)

    Parlos, Alexander G.; Kent, Karl; Peddicord, Kenneth L.; Khan, Ehsan U.

    1991-09-01

    A preliminary feasibility study on a new concept for a highly compact space reactor power system is presented, consisting of in-core thermionic fuel elements and in-core heat pipes for passive core cooling. The reference fuel considered in this study is uranium carbide. The calculations reported include a neutronic design analysis using a 2D neutron transport model, as well as a simplified 1D thermal analysis of the reactor core, using a preliminary thermal sizing of the in-core heat pipes. Initial results indicate that the proposed core design is thermally and neutronically feasible, with a maximum steady-state fuel temperature below 2000 K. Alternate advanced fuels, such as various oxides of Am-242, result in exceedingly high fuel centerline temperatures because of the associated low thermal conductivities.

  18. Advanced interaction media in nuclear power plant control rooms.

    PubMed

    Stephane, Lucas

    2012-01-01

    The shift from analog to digital Instruments (related mainly to information visualization) and Controls in Nuclear Power Plant Main Control Rooms (NPP MCR) is a central current topic of investigation. In NPP MCR, digitalization was implemented gradually, analog and digital systems still coexisting for the two main systems related to safety--Safety Instruments and Control System (SICS) and Process Instruments and Controls System (PICS). My ongoing research focuses on the introduction of Advanced Interaction Media (AIM) such as stereoscopic 3D visualization and multi-touch surfaces in control rooms. This paper proposes a Safety-Centric approach for gathering the Design Rationale needed in the specification of such novel AIM concepts as well as their evaluation through user tests. Beyond methodological research, the final output of the current research is to build an experimental simulator aiming to enhance improvements in Human-Systems Integration (HSI). This paper provides an overview of the topics under consideration. PMID:22317419

  19. Effect of powerful pulsed and continuous ion beams on the Al- Cu-Mg alloy structure

    NASA Astrophysics Data System (ADS)

    Gushchina, N. V.; Makhin'ko, F. F.; Ovchinnikov, V. V.; Gusel'nikov, V. I.; Remnev, G. E.

    2016-02-01

    The paper considers the results of an electron microscopy study of the VD1 alloy of the Al-Cu-Mg system after cold working and subsequent irradiation with a powerful pulsed ion beam (70% C+ + 30% H+, E = 180 keV) in the pulsed-periodic mode (t = 80 ns, f = 0.1 Hz, j = 200 A/cm2, F = 1-1014 cm-2) and under the conditions of the generation of only one pulse (t = 180 ns, j = 100 A/cm2, F = 2-1015 cm-2). It is established that this irradiation noticeably affects the microstructure of the cold-worked 3 mm thick sheets of VD1 alloy. The initial cellular dislocation structure transforms into a subgrain one. The intensity of structural transformations in the alloy increases with ion current density of a pulse. A similar transformation of a dislocation structure over the entire thickness of the sample is observed under irradiation with continuous Ar+ ion beams (E = 20-40 keV) with not high fluences (1015-1016 cm-2).

  20. Generating high-power short terahertz electromagnetic pulses with a multifoil radiator.

    PubMed

    Vinokurov, Nikolay A; Jeong, Young Uk

    2013-02-01

    We describe a multifoil cone radiator capable of generating high-field short terahertz pulses using short electron bunches. Round flat conducting foil plates with successively decreasing radii are stacked, forming a truncated cone with the z axis. The gaps between the foil plates are equal and filled with some dielectric (or vacuum). A short relativistic electron bunch propagates along the z axis. At sufficiently high particle energy, the energy losses and multiple scattering do not change the bunch shape significantly. When passing by each gap between the foil plates, the electron bunch emits some energy into the gap. Then, the radiation pulses propagate radially outward. For transverse electromagnetic waves with a longitudinal (along the z axis) electric field and an azimuthal magnetic field, there is no dispersion in these radial lines; therefore, the radiation pulses conserve their shapes (time dependence). At the outer surface of the cone, we have synchronous circular radiators. Their radiation field forms a conical wave. Ultrashort terahertz pulses with gigawatt-level peak power can be generated with this device.