Sample records for magnetics high voltage

  1. Magnetic shielding of Hall thrusters at high discharge voltages

    SciTech Connect (OSTI)

    Mikellides, Ioannis G., E-mail: Ioannis.G.Mikellides@jpl.nasa.gov; Hofer, Richard R.; Katz, Ira; Goebel, Dan M. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109 (United States)

    2014-08-07T23:59:59.000Z

    A series of numerical simulations and experiments have been performed to assess the effectiveness of magnetic shielding in a Hall thruster operating in the discharge voltage range of 300–700?V (I{sub sp}???2000–2700?s) at 6?kW, and 800?V (I{sub sp} ? 3000) at 9?kW. At 6?kW, the magnetic field topology with which highly effective magnetic shielding was previously demonstrated at 300?V has been retained for all other discharge voltages; only the magnitude of the field has been changed to achieve optimum thruster performance. It is found that magnetic shielding remains highly effective for all discharge voltages studied. This is because the channel is long enough to allow hot electrons near the channel exit to cool significantly upon reaching the anode. Thus, despite the rise of the maximum electron temperature in the channel with discharge voltage, the electrons along the grazing lines of force remain cold enough to eliminate or reduce significantly parallel gradients of the plasma potential near the walls. Computed maximum erosion rates in the range of 300–700?V are found not to exceed 10{sup ?2}?mm/kh. Such rates are ?3 orders of magnitude less than those observed in the unshielded version of the same thruster at 300?V. At 9?kW and 800?V, saturation of the magnetic circuit did not allow for precisely the same magnetic shielding topology as that employed during the 6-kW operation since this thruster was not designed to operate at this condition. Consequently, the maximum erosion rate at the inner wall is found to be ?1 order of magnitude higher (?10{sup ?1}?mm/kh) than that at 6?kW. At the outer wall, the ion energy is found to be below the sputtering yield threshold so no measurable erosion is expected.

  2. Magnetic lens apparatus for a low-voltage high-resolution electron microscope

    DOE Patents [OSTI]

    Crewe, Albert V. (Palos Park, IL)

    1996-01-01T23:59:59.000Z

    A lens apparatus in which a beam of charged particles of low accelerating voltage is brought to a focus by a magnetic field, the lens being situated behind the target position. The lens comprises an electrically-conducting coil arranged around the axis of the beam and a magnetic pole piece extending along the axis of the beam at least within the space surrounded by the coil. The lens apparatus comprises the sole focusing lens for high-resolution imaging in a low-voltage scanning electron microscope.

  3. A design for a high voltage magnet coil ringer test set

    SciTech Connect (OSTI)

    Koska, W. [Fermi National Accelerator Lab., Batavia, IL (United States); Sims, R.E. [Superconducting Super Collider Lab., Dallas, TX (United States)

    1992-04-01T23:59:59.000Z

    By discharging a bank of charged capacitors through a high power SCR switch into an SSC dipole magnet assembly, it is possible to ``ring`` the coil and develop a voltage stress of greater than 50 volts turn-to-turn, thereby verifying the insulation integrity. We will present an overview of the test set design for a 2 kV isolated SCR firing circuit, including safety features, selectable capacitor banks, and digital waveform storage system. Results from testing typical coils and magnets will be included. Possible upgrades are also discussed.

  4. A design for a high voltage magnet coil ringer test set

    SciTech Connect (OSTI)

    Koska, W. (Fermi National Accelerator Lab., Batavia, IL (United States)); Sims, R.E. (Superconducting Super Collider Lab., Dallas, TX (United States))

    1992-04-01T23:59:59.000Z

    By discharging a bank of charged capacitors through a high power SCR switch into an SSC dipole magnet assembly, it is possible to ring'' the coil and develop a voltage stress of greater than 50 volts turn-to-turn, thereby verifying the insulation integrity. We will present an overview of the test set design for a 2 kV isolated SCR firing circuit, including safety features, selectable capacitor banks, and digital waveform storage system. Results from testing typical coils and magnets will be included. Possible upgrades are also discussed.

  5. Electric power high-voltage transmission lines: Design options, cost, and electric and magnetic field levels

    SciTech Connect (OSTI)

    Stoffel, J.B.; Pentecost, E.D.; Roman, R.D.; Traczyk, P.A.

    1994-11-01T23:59:59.000Z

    This report provides background information about (1) the electric and magnetic fields (EMFs) of high-voltage transmission lines at typical voltages and line configurations and (2) typical transmission line costs to assist on alternatives in environmental documents. EMF strengths at 0 {+-} 200 ft from centerline were calculated for ac overhead lines, and for 345 and 230-kV ac underground line and for a {+-}450-kV dc overhead line. Compacting and height sensitivity factors were computed for the variation in EMFs when line conductors are moved closer or raised. Estimated costs for the lines are presented and discussed so that the impact of using alternative strategies for reducing EMF strengths and the implications of implementing the strategies can be better appreciated.

  6. High voltage pulse conditioning

    DOE Patents [OSTI]

    Springfield, Ray M. (Sante Fe, NM); Wheat, Jr., Robert M. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

  7. High Voltage Safety Act

    Broader source: Energy.gov [DOE]

    The purpose of the High Voltage Safety Act is to prevent injury to persons and property and interruptions of utility service resulting from accidental or inadvertent contact with high-voltage...

  8. ABBGroup-1-High voltage lab

    E-Print Network [OSTI]

    Basse, Nils Plesner

    oscillations are due to travelling waves in the heating volume. #12;©ABBGroup-9- 3-Sep-07 2. High voltage phase interrupts the injected current, it is stressed by the transient recovery voltage (TRV) oscillating©ABBGroup-1- 3-Sep-07 High voltage lab Research on high voltage gas circuit breakers Nils P. Basse

  9. High voltage DC power supply

    DOE Patents [OSTI]

    Droege, Thomas F. (Batavia, IL)

    1989-01-01T23:59:59.000Z

    A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively.

  10. High voltage DC power supply

    DOE Patents [OSTI]

    Droege, T.F.

    1989-12-19T23:59:59.000Z

    A high voltage DC power supply having a first series resistor at the output for limiting current in the event of a short-circuited output, a second series resistor for sensing the magnitude of output current, and a voltage divider circuit for providing a source of feedback voltage for use in voltage regulation is disclosed. The voltage divider circuit is coupled to the second series resistor so as to compensate the feedback voltage for a voltage drop across the first series resistor. The power supply also includes a pulse-width modulated control circuit, having dual clock signals, which is responsive to both the feedback voltage and a command voltage, and also includes voltage and current measuring circuits responsive to the feedback voltage and the voltage developed across the second series resistor respectively. 7 figs.

  11. Characterization of the self magnetic pinch diode at high voltages for flash radiography.

    SciTech Connect (OSTI)

    Cordova, Steve Ray; Portillo, Salvador; Oliver, Bryan Velten; Threadgold, James R. (Atomic Weapons Establishment Aldermaston, Reading Berkshire, U.K.); Crotch, Ian (Atomic Weapons Establishment Aldermaston, Reading Berkshire, U.K.); Ziska, Derek Raymond

    2008-10-01T23:59:59.000Z

    The Sandia Laboratories Advanced Radiographic Technologies Department, in collaboration with the United Kingdom Atomic Weapons Establishment, has been conducting research into the development of the Self-Magnetic-Pinched diode as an x-ray source suitable for flash radiographic experiments. We have demonstrated that this source is capable of meeting and exceeding the initial requirements of 250 rads (measured at one meter) with a 2.75 mm source spot-size. Recent experiments conducted on the RITS-6 accelerator have demonstrated the ability of this diode to meet intermediate requirements with a sub 3 mm source spot size and a dose in excess of 400 rads at one meter.

  12. Temperature controlled high voltage regulator

    DOE Patents [OSTI]

    Chiaro, Jr., Peter J. (Clinton, TN); Schulze, Gerald K. (Knoxville, TN)

    2004-04-20T23:59:59.000Z

    A temperature controlled high voltage regulator for automatically adjusting the high voltage applied to a radiation detector is described. The regulator is a solid state device that is independent of the attached radiation detector, enabling the regulator to be used by various models of radiation detectors, such as gas flow proportional radiation detectors.

  13. High voltage photovoltaic power converter

    DOE Patents [OSTI]

    Haigh, Ronald E. (Arvada, CO); Wojtczuk, Steve (Cambridge, MA); Jacobson, Gerard F. (Livermore, CA); Hagans, Karla G. (Livermore, CA)

    2001-01-01T23:59:59.000Z

    An array of independently connected photovoltaic cells on a semi-insulating substrate contains reflective coatings between the cells to enhance efficiency. A uniform, flat top laser beam profile is illuminated upon the array to produce electrical current having high voltage. An essentially wireless system includes a laser energy source being fed through optic fiber and cast upon the photovoltaic cell array to prevent stray electrical signals prior to use of the current from the array. Direct bandgap, single crystal semiconductor materials, such as GaAs, are commonly used in the array. Useful applications of the system include locations where high voltages are provided to confined spaces such as in explosive detonation, accelerators, photo cathodes and medical appliances.

  14. Low power, scalable multichannel high voltage controller

    DOE Patents [OSTI]

    Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

    2008-03-25T23:59:59.000Z

    A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

  15. Low power, scalable multichannel high voltage controller

    DOE Patents [OSTI]

    Stamps, James Frederick (Livermore, CA); Crocker, Robert Ward (Fremont, CA); Yee, Daniel Dadwa (Dublin, CA); Dils, David Wright (Fort Worth, TX)

    2006-03-14T23:59:59.000Z

    A low voltage control circuit is provided for individually controlling high voltage power provided over bus lines to a multitude of interconnected loads. An example of a load is a drive for capillary channels in a microfluidic system. Control is distributed from a central high voltage circuit, rather than using a number of large expensive central high voltage circuits to enable reducing circuit size and cost. Voltage is distributed to each individual load and controlled using a number of high voltage controller channel switches connected to high voltage bus lines. The channel switches each include complementary pull up and pull down photo isolator relays with photo isolator switching controlled from the central high voltage circuit to provide a desired bus line voltage. Switching of the photo isolator relays is further controlled in each channel switch using feedback from a resistor divider circuit to maintain the bus voltage swing within desired limits. Current sensing is provided using a switched resistive load in each channel switch, with switching of the resistive loads controlled from the central high voltage circuit.

  16. Planar LTCC transformers for high voltage flyback converters.

    SciTech Connect (OSTI)

    Schofield, Daryl (NASCENT Technology Inc. , Watertown, SD); Schare, Joshua M.; Glass, Sarah Jill; Roesler, Alexander William; Ewsuk, Kevin Gregory; Slama, George (NASCENT Technology Inc. , Watertown, SD); Abel, Dave (NASCENT Technology Inc. , Watertown, SD)

    2007-06-01T23:59:59.000Z

    This paper discusses the design and use of low-temperature (850 C to 950 C) co-fired ceramic (LTCC) planar magnetic flyback transformers for applications that require conversion of a low voltage to high voltage (> 100V) with significant volumetric constraints. Measured performance and modeling results for multiple designs showed that the LTCC flyback transformer design and construction imposes serious limitations on the achievable coupling and significantly impacts the transformer performance and output voltage. This paper discusses the impact of various design factors that can provide improved performance by increasing transformer coupling and output voltage. The experiments performed on prototype units demonstrated LTCC transformer designs capable of greater than 2 kV output. Finally, the work investigated the effect of the LTCC microstructure on transformer insulation. Although this paper focuses on generating voltages in the kV range, the experimental characterization and discussion presented in this work applies to designs requiring lower voltage.

  17. High-voltage air-core pulse transformers

    SciTech Connect (OSTI)

    Rohwein, G. J.

    1981-01-01T23:59:59.000Z

    General types of air core pulse transformers designed for high voltage pulse generation and energy transfer applications are discussed with special emphasis on pulse charging systems which operate up to the multi-megavolt range. The design, operation, dielectric materials, and performance are described. It is concluded that high voltage air core pulse transformers are best suited to applications outside the normal ranges of conventional magnetic core transformers. In general these include charge transfer at high power levels and fast pulse generation with comparatively low energy. When properly designed and constructed, they are capable of delivering high energy transfer efficiency and have demonstrated superior high voltage endurance. The principal disadvantage of high voltage air core transformers is that they are not generally available from commercial sources. Consequently, the potential user must become thoroughly familiar with all aspects of design, fabrication and system application before he can produce a high performance transformer system. (LCL)

  18. ABBGroup-1-High voltage lab

    E-Print Network [OSTI]

    Basse, Nils Plesner

    . GENERATION System voltage: 12-24 kV Rated current: 6000-24000 A Max. short-circuit current: 50-500 kA TRANSMISSION System voltage: 72-800 kV Rated current: 2500-4000 A Max. short-circuit current: 25-63 k. It is designed to protect an electrical circuit from damage caused by overload or short-circuit. A circuit

  19. High voltage MOSFET switching circuit

    DOE Patents [OSTI]

    McEwan, T.E.

    1994-07-26T23:59:59.000Z

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET. 2 figs.

  20. High voltage MOSFET switching circuit

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    The problem of source lead inductance in a MOSFET switching circuit is compensated for by adding an inductor to the gate circuit. The gate circuit inductor produces an inductive spike which counters the source lead inductive drop to produce a rectangular drive voltage waveform at the internal gate-source terminals of the MOSFET.

  1. High-Voltage Solid Polymer Batteries for Electric Drive Vehicles...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Voltage Solid Polymer Batteries for Electric Drive Vehicles High-Voltage Solid Polymer Batteries for Electric Drive Vehicles 2012 DOE Hydrogen and Fuel Cells Program and...

  2. Electro-optic high voltage sensor

    DOE Patents [OSTI]

    Davidson, James R.; Seifert, Gary D.

    2003-09-16T23:59:59.000Z

    A small sized electro-optic voltage sensor capable of accurate measurement of high voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation. A polarization beam displacer separates the input beam into two beams with orthogonal linear polarizations and causes one linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels effect elliptically polarizes the beam as it travels through the crystal. A reflector redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization. The system may include a detector for converting the output beams into electrical signals and a signal processor for determining the voltage based on an analysis of the output beams.

  3. Compact high voltage solid state switch

    DOE Patents [OSTI]

    Glidden, Steven C.

    2003-09-23T23:59:59.000Z

    A compact, solid state, high voltage switch capable of high conduction current with a high rate of current risetime (high di/dt) that can be used to replace thyratrons in existing and new applications. The switch has multiple thyristors packaged in a single enclosure. Each thyristor has its own gate drive circuit that circuit obtains its energy from the energy that is being switched in the main circuit. The gate drives are triggered with a low voltage, low current pulse isolated by a small inexpensive transformer. The gate circuits can also be triggered with an optical signal, eliminating the trigger transformer altogether. This approach makes it easier to connect many thyristors in series to obtain the hold off voltages of greater than 80 kV.

  4. Modular high voltage power supply for chemical analysis

    DOE Patents [OSTI]

    Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

    2010-05-04T23:59:59.000Z

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  5. Modular high voltage power supply for chemical analysis

    SciTech Connect (OSTI)

    Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

    2007-01-09T23:59:59.000Z

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC--DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC--DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  6. Modular high voltage power supply for chemical analysis

    SciTech Connect (OSTI)

    Stamps, James F. (Livermore, CA); Yee, Daniel D. (Dublin, CA)

    2008-07-15T23:59:59.000Z

    A high voltage power supply for use in a system such as a microfluidics system, uses a DC-DC converter in parallel with a voltage-controlled resistor. A feedback circuit provides a control signal for the DC-DC converter and voltage-controlled resistor so as to regulate the output voltage of the high voltage power supply, as well as, to sink or source current from the high voltage supply.

  7. Chapter 17. High-Voltage Systems and Dielectric Materials High-Voltage Systems and Dielectric Materials

    E-Print Network [OSTI]

    -Voltage Systems and Dielectric Materials 17-2 RLE Progress Report 152 provides very useful insight into pre-breakdown in high voltage conduction and breakdown phenomena. 1. Mechanisms Behind Positive Streamers and Their Distinct Propagation Modes in Transformer Oil Sponsors This work was supported by ABB Corporate Research

  8. High Voltage Electrolyte for Lithium Batteries

    Broader source: Energy.gov (indexed) [DOE]

    Argonne's Fluorinated Compounds as High Voltage Electrolytes (HVEs) O O O O O O EC EMC O O O CF CF 3 CF 3 O O O CF 3 F 2 HC C F 2 O F 2 C CF 2 H 6 Code Name Chemical...

  9. Electro-optic high voltage sensor

    DOE Patents [OSTI]

    Davidson, James R. (Idaho Falls, ID); Seifert, Gary D. (Idaho Falls, ID)

    2002-01-01T23:59:59.000Z

    A small sized electro-optic voltage sensor capable of accurate measurement of high levels of voltages without contact with a conductor or voltage source is provided. When placed in the presence of an electric field, the sensor receives an input beam of electromagnetic radiation into the sensor. A polarization beam displacer serves as a filter to separate the input beam into two beams with orthogonal linear polarizations. The beam displacer is oriented in such a way as to rotate the linearly polarized beams such that they enter a Pockels crystal having at a preferred angle of 45 degrees. The beam displacer is therefore capable of causing a linearly polarized beam to impinge a crystal at a desired angle independent of temperature. The Pockels electro-optic effect induces a differential phase shift on the major and minor axes of the input beam as it travels through the Pockels crystal, which causes the input beam to be elliptically polarized. A reflecting prism redirects the beam back through the crystal and the beam displacer. On the return path, the polarization beam displacer separates the elliptically polarized beam into two output beams of orthogonal linear polarization representing the major and minor axes. The system may include a detector for converting the output beams into electrical signals, and a signal processor for determining the voltage based on an analysis of the output beams. The output beams are amplitude modulated by the frequency of the electric field and the amplitude of the output beams is proportional to the magnitude of the electric field, which is related to the voltage being measured.

  10. Electronic high voltage generator with a high temperature superconducting coil

    SciTech Connect (OSTI)

    Jin, J.X.; Liu, H.K.; Dou, S.X. [Univ. of Wollongong (Australia)] [and others

    1996-12-31T23:59:59.000Z

    A novel method for generating high voltages from a low voltage DC source, by using a capacitor and inductor in a R, L, C resonant circuit has been developed with the consideration of using a high temperature superconducting (HTS) coil. To generate high voltages the polarity of a low voltage battery source is reversed each half resonant cycle, the control being achieved by an electronic switch. Resistance in the circuit limits the voltages that can be built up. By replacing a copper winding inductor with another inductor which has a HTS winding, the magnitude of achievable voltages is substantially increased. A (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10+x} multifilament HTS wire is considered in this work to make the superconducting inductor. The high voltages generated are not capable of supplying low impedance loads, however, possible applications of the generator include electrical partial discharge testing and insulation resistance testing. It could also be used as a testing method for the HTS itself with respect to the critical current and AC loss measurement.

  11. Structural Optimization of High Voltage Transmission Line Towers considering

    E-Print Network [OSTI]

    Colominas, Ignasi

    Structural Optimization of High Voltage Transmission Line Towers considering Continuum and Discrete/or to common designs largely repeated (e.g. automotive compo- nents), and high voltage transmission towers can than conventional designs of high voltage transmission line towers. The optimization model proposed

  12. Production of high voltage by ion bombardment

    E-Print Network [OSTI]

    Phinney, Lucas Carter

    2003-01-01T23:59:59.000Z

    . . . 35 FIGIJRE Page 19 I-V curve for the ammeter setup . . 35 20 Diagram of the leakage current test setup . . . . . . 37 21 Voltmeter readings at each high voltage interval . . . . . , 38 CHAPTER I INTRODUCTION Direct energy conversion... streaming into the source There is also a moveable shutter that can stop the beam &om entering the beam line. A Varian VHS-6 diffusion pump is connected at the bottom of the glass cross. Its function is to maintain a vacuum in this part of the accelerator...

  13. A Charge Pump that Generates Negative High Voltage with Variable Voltage , Eugene Ivanova,

    E-Print Network [OSTI]

    Ayers, Joseph

    A Charge Pump that Generates Negative High Voltage with Variable Voltage Gain Jun Zhaob, , Eugene, Massachusetts 02115, U.S.A. Abstract A cross-coupled structure based charge pump that generates negative high. The proposed negative charge pump is designed to deliver 40 uA with a wide supply range from 2.5V to 5.5V using

  14. Distributed Voltage and Current Control of Multi-Terminal High-Voltage Direct

    E-Print Network [OSTI]

    Dimarogonas, Dimos

    }@kth.se.) Abstract: High-voltage direct current (HVDC) is a commonly used technology for long-distance power for multi-terminal HVDC (MTDC) systems is proposed. Under certain conditions on the controller gains factor behind long-distance power transmission. High-voltage direct current (HVDC) is a commonly used

  15. Nanoscale Morphological and Chemical Changes of High Voltage...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Nanoscale Morphological and Chemical Changes of High Voltage Lithium-Manganese Rich NMC Composite Cathodes with Cycling Friday, August 29, 2014 Renewable energy is critical for the...

  16. Measurement of high voltage using Rutherford backscattering spectrometry

    E-Print Network [OSTI]

    Abrego, Celestino Pete

    2007-04-25T23:59:59.000Z

    A novel variation of Rutherford Backscattering Spectrometry (RBS) has been utilized to measure a high voltage collected on an aluminum target by Direct Energy Conversion. The maximum high voltage on the target was measured to be 97.5 kV +/- 2 k...

  17. (Insulating materials and large high voltage electric systems)

    SciTech Connect (OSTI)

    Dale, S.J.

    1990-09-18T23:59:59.000Z

    The traveler attended the 33rd Session of CIGRE (The International Conference on Large High Voltage Electric Systems in Paris, France) as a US technical expert advisor the Study Committee 15, Insulating Materials. Over 200 papers were discussed, contributed from over 45 countries at the conference on all aspects of electric power generation and transmission. Of special interest was a panel session on superconducting technology for electric power systems and the participation on a new task force on the electrical insulation at cryogenic temperatures. Significant insight was gained into the development of superconducting power technologies in Europe and Japan. CIGRE has set up a committee to follow the development in research on the biological effects of electric and magnetic fields. The traveler also visited the Centre for Electric Power Engineering at the University of Strathclyde, Glasgow, Scotland and discussed research on degradation of polymeric cable insulation and gas insulated equipment. 5 refs.

  18. E-beam high voltage switching power supply

    DOE Patents [OSTI]

    Shimer, D.W.; Lange, A.C.

    1996-10-15T23:59:59.000Z

    A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 figs.

  19. E-beam high voltage switching power supply

    DOE Patents [OSTI]

    Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

    1996-01-01T23:59:59.000Z

    A high-power power supply produces a controllable, constant high voltage put under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

  20. Electrical system architecture having high voltage bus

    DOE Patents [OSTI]

    Hoff, Brian Douglas (East Peoria, IL); Akasam, Sivaprasad (Peoria, IL)

    2011-03-22T23:59:59.000Z

    An electrical system architecture is disclosed. The architecture has a power source configured to generate a first power, and a first bus configured to receive the first power from the power source. The architecture also has a converter configured to receive the first power from the first bus and convert the first power to a second power, wherein a voltage of the second power is greater than a voltage of the first power, and a second bus configured to receive the second power from the converter. The architecture further has a power storage device configured to receive the second power from the second bus and deliver the second power to the second bus, a propulsion motor configured to receive the second power from the second bus, and an accessory motor configured to receive the second power from the second bus.

  1. High Voltage Electrolyte for Lithium Batteries

    Broader source: Energy.gov (indexed) [DOE]

    5.0E-04 1.0E-03 2 2.2 2.4 2.6 2.8 Voltage (V) dQdV (AhV) 1 st Charge 1.2M LiPF 6 ECEMC 37 1 st Charge 1.0M LiPF 6 TMS1NM3 55 with 2% and 4% VC 1 st Charge 1.0M LiPF 6 TMS...

  2. Optically triggered high voltage switch network and method for switching a high voltage

    DOE Patents [OSTI]

    El-Sharkawi, Mohamed A. (Renton, WA); Andexler, George (Everett, WA); Silberkleit, Lee I. (Mountlake Terrace, WA)

    1993-01-19T23:59:59.000Z

    An optically triggered solid state switch and method for switching a high voltage electrical current. A plurality of solid state switches (350) are connected in series for controlling electrical current flow between a compensation capacitor (112) and ground in a reactive power compensator (50, 50') that monitors the voltage and current flowing through each of three distribution lines (52a, 52b and 52c), which are supplying three-phase power to one or more inductive loads. An optical transmitter (100) controlled by the reactive power compensation system produces light pulses that are conveyed over optical fibers (102) to a switch driver (110') that includes a plurality of series connected optical triger circuits (288). Each of the optical trigger circuits controls a pair of the solid state switches and includes a plurality of series connected resistors (294, 326, 330, and 334) that equalize or balance the potential across the plurality of trigger circuits. The trigger circuits are connected to one of the distribution lines through a trigger capacitor (340). In each switch driver, the light signals activate a phototransistor (300) so that an electrical current flows from one of the energy reservoir capacitors through a pulse transformer (306) in the trigger circuit, producing gate signals that turn on the pair of serially connected solid state switches (350).

  3. Unravelling the Performance Degradation Mechanisms in High-voltage...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Unravelling the Performance Degradation Mechanisms in High-voltage Lithium-ion Battery Composite Oxide Electrodes Apr 11 2014 02:00 PM - 03:00 PM Debasish Mohanty, ORNL, Oak Ridge...

  4. High voltage electrical amplifier having a short rise time

    DOE Patents [OSTI]

    Christie, David J. (Pleasanton, CA); Dallum, Gregory E. (Livermore, CA)

    1991-01-01T23:59:59.000Z

    A circuit, comprising an amplifier and a transformer is disclosed that produces a high power pulse having a fast response time, and that responds to a digital control signal applied through a digital-to-analog converter. The present invention is suitable for driving a component such as an electro-optic modulator with a voltage in the kilovolt range. The circuit is stable at high frequencies and during pulse transients, and its impedance matching circuit matches the load impedance with the output impedance. The preferred embodiment comprises an input stage compatible with high-speed semiconductor components for amplifying the voltage of the input control signal, a buffer for isolating the input stage from the output stage; and a plurality of current amplifiers connected to the buffer. Each current amplifier is connected to a field effect transistor (FET), which switches a high voltage power supply to a transformer which then provides an output terminal for driving a load. The transformer comprises a plurality of transmission lines connected to the FETs and the load. The transformer changes the impedance and voltage of the output. The preferred embodiment also comprises a low voltage power supply for biasing the FETs at or near an operational voltage.

  5. Planar LTCC transformers for high voltage flyback converters: Part II.

    SciTech Connect (OSTI)

    Schofield, Daryl (NASCENTechnology, Inc., Watertown, SD); Schare, Joshua M., Ph.D.; Slama, George (NASCENTechnology, Inc., Watertown, SD); Abel, David (NASCENTechnology, Inc., Watertown, SD)

    2009-02-01T23:59:59.000Z

    This paper is a continuation of the work presented in SAND2007-2591 'Planar LTCC Transformers for High Voltage Flyback Converters'. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechnoloy, Inc, who collaborated in the design and manufacturing of the planar LTCC flyback converters. The output/volume requirements were targeted to DoD application for hard target/mini fuzing at around 1500 V for reasonable primary peak currents. High voltages could be obtained but with considerable higher current. Work had begun on higher voltage systems and is where this report begins. Limits in material properties and processing capabilities show that the state-of-the-art has limited our practical output voltage from such a small part volume. In other words, the technology is currently limited within the allowable funding and interest.

  6. Design & Fabrication of a High-Voltage Photovoltaic Cell

    SciTech Connect (OSTI)

    Felder, Jennifer; /North Carolina State U. /SLAC

    2012-09-05T23:59:59.000Z

    Silicon photovoltaic (PV) cells are alternative energy sources that are important in sustainable power generation. Currently, applications of PV cells are limited by the low output voltage and somewhat low efficiency of such devices. In light of this fact, this project investigates the possibility of fabricating high-voltage PV cells on float-zone silicon wafers having output voltages ranging from 50 V to 2000 V. Three designs with different geometries of diffusion layers were simulated and compared in terms of metal coverage, recombination, built-in potential, and conduction current density. One design was then chosen and optimized to be implemented in the final device design. The results of the simulation serve as a feasibility test for the design concept and provide supportive evidence of the effectiveness of silicon PV cells as high-voltage power supplies.

  7. High voltage switch triggered by a laser-photocathode subsystem

    DOE Patents [OSTI]

    Chen, Ping; Lundquist, Martin L.; Yu, David U. L.

    2013-01-08T23:59:59.000Z

    A spark gap switch for controlling the output of a high voltage pulse from a high voltage source, for example, a capacitor bank or a pulse forming network, to an external load such as a high gradient electron gun, laser, pulsed power accelerator or wide band radar. The combination of a UV laser and a high vacuum quartz cell, in which a photocathode and an anode are installed, is utilized as triggering devices to switch the spark gap from a non-conducting state to a conducting state with low delay and low jitter.

  8. E-beam high voltage switching power supply

    DOE Patents [OSTI]

    Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

    1997-01-01T23:59:59.000Z

    A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360.degree./n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load.

  9. E-beam high voltage switching power supply

    DOE Patents [OSTI]

    Shimer, D.W.; Lange, A.C.

    1997-03-11T23:59:59.000Z

    A high power, solid state power supply is described for producing a controllable, constant high voltage output under varying and arcing loads suitable for powering an electron beam gun or other ion source. The present power supply is most useful for outputs in a range of about 100-400 kW or more. The power supply is comprised of a plurality of discrete switching type dc-dc converter modules, each comprising a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, and an output rectifier for producing a dc voltage at the output of each module. The inputs to the converter modules are fed from a common dc rectifier/filter and are linked together in parallel through decoupling networks to suppress high frequency input interactions. The outputs of the converter modules are linked together in series and connected to the input of the transmission line to the load through a decoupling and line matching network. The dc-dc converter modules are phase activated such that for n modules, each module is activated equally 360{degree}/n out of phase with respect to a successive module. The phased activation of the converter modules, combined with the square current waveforms out of the step up transformers, allows the power supply to operate with greatly reduced output capacitance values which minimizes the stored energy available for discharge into an electron beam gun or the like during arcing. The present power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle using simulated voltage feedback signals and voltage feedback loops. Circuitry is also provided for sensing incipient arc currents reflected at the output of the power supply and for simultaneously decoupling the power supply circuitry from the arcing load. 7 figs.

  10. High voltage stability performance of a gamma ray detection device

    SciTech Connect (OSTI)

    Abdullah, Nor Arymaswati; Lombigit, Lojius; Rahman, Nur Aira Abd [Technical Support Division, Malaysian Nuclear Agency, 43000 Kajang, Selangor (Malaysia)

    2014-02-12T23:59:59.000Z

    An industrial grade digital radiation survey meter device is currently being developed at Malaysian Nuclear Agency. This device used a cylindrical type Geiger Mueller (GM) which acts as a detector. GM detector operates at relatively high direct current voltages depend on the type of GM tube. This thin/thick walled cylindrical type of GM tube operates at 450-650 volts range. Proper value and stability performance of high voltage are important parameters to ensure that this device give a reliable radiation dose measurement. This paper will present an assessment of the stability and performance of the high voltage supply for radiation detector. The assessment is performed using System Identification tools box in MATLAB and mathematical statistics.

  11. Gaseous insulators for high voltage electrical equipment

    DOE Patents [OSTI]

    Christophorou, Loucas G. (Oak Ridge, TN); James, David R. (Knoxville, TN); Pace, Marshall O. (Knoxville, TN); Pai, Robert Y. (Concord, TN)

    1981-01-01T23:59:59.000Z

    Gaseous insulators comprise compounds having high attachment cross sections for electrons having energies in the 0-1.3 electron volt range. Multi-component gaseous insulators comprise compounds and mixtures having overall high electron attachment cross sections in the 0-1.3 electron volt range and moderating gases having high cross sections for inelastic interactions with electrons of energies 1-4 electron volts. Suitable electron attachment components include hexafluorobutyne, perfluorobutene-2, perfluorocyclobutane, perfluorodimethylcyclobutane, perfluorocyclohexene, perfluoromethylcyclohexane, hexafluorobutadiene, perfluoroheptene-1 and hexafluoroazomethane. Suitable moderating gases include N.sub.2, CO, CO.sub.2 and H.sub.2. The gaseous insulating mixture can also contain SF.sub.6, perfluoropropane and perfluorobenzene.

  12. Radio-Frequency Interference (RFI) From Extra-High-Voltage (EHV) Transmission Lines

    E-Print Network [OSTI]

    Ellingson, Steven W.

    -current (HVAC) transmission lines; high-voltage direct-current (HVDC) transmission lines will be addressed

  13. HTS High Gradient Magnetic Separation system

    SciTech Connect (OSTI)

    Daugherty, M.A.; Coulter, J.Y.; Hults, W.L. [and others

    1996-09-01T23:59:59.000Z

    We report on the assembly, characterization and operation of a high temperature superconducting (HTS) magnetic separator. The magnet is made of 624 m of Silver/BSCCO superconducting wire and has overall dimensions of 18 cm OD, 15.5 cm height and 5 cm ID. The HTS current leads are designed to operate with the warm end at 75 K and the cold end cooled by a two stage Gifford-McMahon cryocooler. The upper stage of the cryocooler cools the thermal shield and two heat pipe thermal intercepts. The lower stage of the cryocooler cools the HTS magnet and the bottom end of the HTS current leads. The HTS magnet was initially characterized in liquid cryogens. We report on the current- voltage (I-V) characteristics of the HTS magnet at temperatures ranging from 15 to 40 K. At 40 K the magnet can generate a central field of 2.0 T at a current of 120 A.

  14. Ultra-compact Marx-type high-voltage generator

    DOE Patents [OSTI]

    Goerz, David A. (Brentwood, CA); Wilson, Michael J. (Modesto, CA)

    2000-01-01T23:59:59.000Z

    An ultra-compact Marx-type high-voltage generator includes individual high-performance components that are closely coupled and integrated into an extremely compact assembly. In one embodiment, a repetitively-switched, ultra-compact Marx generator includes low-profile, annular-shaped, high-voltage, ceramic capacitors with contoured edges and coplanar extended electrodes used for primary energy storage; low-profile, low-inductance, high-voltage, pressurized gas switches with compact gas envelopes suitably designed to be integrated with the annular capacitors; feed-forward, high-voltage, ceramic capacitors attached across successive switch-capacitor-switch stages to couple the necessary energy forward to sufficiently overvoltage the spark gap of the next in-line switch; optimally shaped electrodes and insulator surfaces to reduce electric field stresses in the weakest regions where dissimilar materials meet, and to spread the fields more evenly throughout the dielectric materials, allowing them to operate closer to their intrinsic breakdown levels; and uses manufacturing and assembly methods to integrate the capacitors and switches into stages that can be arranged into a low-profile Marx generator.

  15. Current isolating epitaxial buffer layers for high voltage photodiode array

    DOE Patents [OSTI]

    Morse, Jeffrey D. (Martinez, CA); Cooper, Gregory A. (Pleasant Hill, CA)

    2002-01-01T23:59:59.000Z

    An array of photodiodes in series on a common semi-insulating substrate has a non-conductive buffer layer between the photodiodes and the semi-insulating substrate. The buffer layer reduces current injection leakage between the photodiodes of the array and allows optical energy to be converted to high voltage electrical energy.

  16. Field Optimization of Three Dimensional High Voltage C. Trinitis

    E-Print Network [OSTI]

    Stamatakis, Alexandros

    Field Optimization of Three Dimensional High Voltage Equipment C. Trinitis Lehrstuhl f The goal of finding an optimal electric field strength distribution for arbitrary three di­ mensional­ cal optimization algorithm. The package ob­ tained from these three components is then able

  17. High Voltage DC Transmission 1.0 Introduction

    E-Print Network [OSTI]

    McCalley, James D.

    1 High Voltage DC Transmission 1.0 Introduction HVDC has been applied in electric power systems for many years now. Figure 1 illustrates worldwide many of the HVDC applications [1]. Fig. 1 ABB provides a webpage which summarizes HVDC projects by type and capacity or by commissioning year [2]. Wikipedia [3

  18. High Voltage DC Transmission 2 1.0 Introduction

    E-Print Network [OSTI]

    McCalley, James D.

    1 High Voltage DC Transmission 2 1.0 Introduction Interconnecting HVDC within an AC system requires on use of switching devices collectively referred to in the HVDC community as valves. Valves may be non. Fig. 1 There have been three types of devices for implementing HVDC converter circuits: mercury

  19. Voltage control of magnetic anisotropy in Fe films with quantum well states

    E-Print Network [OSTI]

    Bauer, Uwe

    The influence of a gate voltage on magnetic anisotropy is investigated in a thin Fe film epitaxially grown on a Ag(1,1,10) substrate and covered by MgO. Oscillations in step-induced magnetic anisotropy due to quantum well ...

  20. High voltage dc--dc converter with dynamic voltage regulation and decoupling during load-generated arcs

    DOE Patents [OSTI]

    Shimer, D.W.; Lange, A.C.

    1995-05-23T23:59:59.000Z

    A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules. 5 Figs.

  1. High voltage dc-dc converter with dynamic voltage regulation and decoupling during load-generated arcs

    DOE Patents [OSTI]

    Shimer, Daniel W. (Danville, CA); Lange, Arnold C. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A high-power power supply produces a controllable, constant high voltage output under varying and arcing loads. The power supply includes a voltage regulator, an inductor, an inverter for producing a high frequency square wave current of alternating polarity, an improved inverter voltage clamping circuit, a step up transformer, an output rectifier for producing a dc voltage at the output of each module, and a current sensor for sensing output current. The power supply also provides dynamic response to varying loads by controlling the voltage regulator duty cycle and circuitry is provided for sensing incipient arc currents at the output of the power supply to simultaneously decouple the power supply circuitry from the arcing load. The power supply includes a plurality of discrete switching type dc--dc converter modules.

  2. Switch contact device for interrupting high current, high voltage, AC and DC circuits

    DOE Patents [OSTI]

    Via, Lester C.; Witherspoon, F. Douglas; Ryan, John M.

    2005-01-04T23:59:59.000Z

    A high voltage switch contact structure capable of interrupting high voltage, high current AC and DC circuits. The contact structure confines the arc created when contacts open to the thin area between two insulating surfaces in intimate contact. This forces the arc into the shape of a thin sheet which loses heat energy far more rapidly than an arc column having a circular cross-section. These high heat losses require a dramatic increase in the voltage required to maintain the arc, thus extinguishing it when the required voltage exceeds the available voltage. The arc extinguishing process with this invention is not dependent on the occurrence of a current zero crossing and, consequently, is capable of rapidly interrupting both AC and DC circuits. The contact structure achieves its high performance without the use of sulfur hexafluoride.

  3. Fiber optic current monitor for high-voltage applications

    DOE Patents [OSTI]

    Renda, G.F.

    1992-04-21T23:59:59.000Z

    A current monitor which derives its power from the conductor being measured for bidirectionally measuring the magnitude of current (from DC to above 50 khz) flowing through a conductor across which a relatively high level DC voltage is applied, includes a pair of identical transmitter modules connected in opposite polarity to one another in series with the conductor being monitored, for producing from one module a first light signal having an intensity directly proportional to the magnitude of current flowing in one direction through the conductor during one period of time, and from the other module a second light signal having an intensity directly proportional to the magnitude of current flowing in the opposite direction through the conductor during another period of time, and a receiver located in a safe area remote from the high voltage area for receiving the first and second light signals, and converting the same to first and second voltage signals having levels indicative of the magnitude of current being measured at a given time. 6 figs.

  4. Advanced Gate Drive for the SNS High Voltage Converter Modulator

    SciTech Connect (OSTI)

    Nguyen, M.N.; Burkhart, C.; Kemp, M.A.; /SLAC; Anderson, D.E.; /Oak Ridge

    2009-05-07T23:59:59.000Z

    SLAC National Accelerator Laboratory is developing a next generation H-bridge switch plate [1], a critical component of the SNS High Voltage Converter Modulator [2]. As part of that effort, a new IGBT gate driver has been developed. The drivers are an integral part of the switch plate, which are essential to ensuring fault-tolerant, high-performance operation of the modulator. The redesigned driver improves upon the existing gate drive in several ways. The new gate driver has improved fault detection and suppression capabilities; suppression of shoot-through and over-voltage conditions, monitoring of dI/dt and Vce(sat) for fast over-current detection and suppression, and redundant power isolation are some of the added features. In addition, triggering insertion delay is reduced by a factor of four compared to the existing driver. This paper details the design and performance of the new IGBT gate driver. A simplified schematic and description of the construction are included. The operation of the fast over-current detection circuits, active IGBT over-voltage protection circuit, shoot-through prevention circuitry, and control power isolation breakdown detection circuit are discussed.

  5. Vehicle Technologies Office Merit Review 2015: High-Voltage, High-Capacity Polyanion Cathodes

    Broader source: Energy.gov [DOE]

    Presentation given by U of Texas at Austin at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high-voltage, high...

  6. High Power, High Voltage FETs in Linear Applications: A User's Perspective

    SciTech Connect (OSTI)

    N. Greenough, E. Fredd, S. DePasquale

    2009-09-21T23:59:59.000Z

    The specifications of the current crop of highpower, high-voltage field-effect transistors (FETs) can lure a designer into employing them in high-voltage DC equipment. Devices with extremely low on-resistance and very high power ratings are available from several manufacturers. However, our experience shows that high-voltage, linear operation of these devices at near-continuous duty can present difficult reliability challenges at stress levels well-below their published specifications. This paper chronicles the design evolution of a 600 volt, 8 ampere shunt regulator for use with megawatt-class radio transmitters, and presents a final design that has met its reliability criteria.

  7. High power impulse magnetron sputtering: Current-voltage-time characteristics indicate the onset of sustained self-sputtering

    E-Print Network [OSTI]

    Anders, Andre; Andersson, Joakim; Ehiasarian, Arutiun

    2008-01-01T23:59:59.000Z

    target voltage starts to slightly droop for higher voltages,1000 V, the actual voltage droops and shows less stability.see a large voltage droop, especially at high current). We

  8. Distribution System Voltage Performance Analysis for High-Penetration Photovoltaics

    SciTech Connect (OSTI)

    Liu, E.; Bebic, J.

    2008-02-01T23:59:59.000Z

    This report examines the performance of commonly used distribution voltage regulation methods under reverse power flow.

  9. High voltage design structure for high temperature superconducting device

    DOE Patents [OSTI]

    Tekletsadik, Kasegn D. (Rexford, NY)

    2008-05-20T23:59:59.000Z

    In accordance with the present invention, modular corona shields are employed in a HTS device to reduce the electric field surrounding the HTS device. In a exemplary embodiment a fault current limiter module in the insulation region of a cryogenic cooling system has at least one fault current limiter set which employs a first corona shield disposed along the top portion of the fault current limiter set and is electrically coupled to the fault current limiter set. A second corona shield is disposed along the bottom portion of the fault current limiter set and is electrically coupled to the fault current limiter set. An insulation barrier is disposed within the insulation region along at least one side of the fault current limiter set. The first corona shield and the second corona shield act together to reduce the electric field surrounding the fault limiter set when voltage is applied to the fault limiter set.

  10. Experimental validation of a high voltage pulse measurement method.

    SciTech Connect (OSTI)

    Cular, Stefan; Patel, Nishant Bhupendra; Branch, Darren W.

    2013-09-01T23:59:59.000Z

    This report describes X-cut lithium niobate's (LiNbO3) utilization for voltage sensing by monitoring the acoustic wave propagation changes through LiNbO3 resulting from applied voltage. Direct current (DC), alternating current (AC) and pulsed voltage signals were applied to the crystal. Voltage induced shift in acoustic wave propagation time scaled quadratically for DC and AC voltages and linearly for pulsed voltages. The measured values ranged from 10 - 273 ps and 189 ps - 2 ns for DC and non-DC voltages, respectively. Data suggests LiNbO3 has a frequency sensitive response to voltage. If voltage source error is eliminated through physical modeling from the uncertainty budget, the sensor's U95 estimated combined uncertainty could decrease to ~0.025% for DC, AC, and pulsed voltage measurements.

  11. An earth-isolated optically coupled wideband high voltage probe powered by ambient light

    E-Print Network [OSTI]

    Bellan, Paul M.

    An earth-isolated optically coupled wideband high voltage probe powered by ambient light Xiang Zhai) An earth-isolated optically coupled wideband high voltage probe powered by ambient light Xiang Zhaia online 9 October 2012) An earth-isolated optically-coupled wideband high voltage probe has been developed

  12. Induction of nuclear fission by high-voltage application

    E-Print Network [OSTI]

    Hirokazu Maruyama

    2007-11-20T23:59:59.000Z

    In nuclear power generation, fissile materials are mainly used. For example, $U^{235}$ is fissile and therefore quite essential for use of nuclear energy. However, the material $U^{235}$ has very small natural abundance less than 1 %. We should seek possibility of utilizing fissionable materials such as $U^{238}$ because natural abundance of such fissionable materials is generally much larger than fissile ones. In this paper, we show that thermal neutrons with vanishing kinetic energy can induce nuclear fission when high voltage is applied to fissionable materials. To obtain this result, we use the liquid-drop model for nuclei. Finally, we propose how fissionable materials can be utilized.

  13. Worldwide reliability surveys of high voltage circuit breakers

    SciTech Connect (OSTI)

    Heising, C.R.

    1995-05-01T23:59:59.000Z

    This article reports on the results of two CIGRE 13.06 Working Group worldwide surveys of the reliability of high voltage circuit breakers, 63 kV and above. The first inquiry included 78,000 breaker-years of ``in service data`` from 102 utilities in 22 countries during the years 1974--1977 and included all interrupting technologies. The second inquiry included 70,708 breaker-years from 132 utilities in 22 countries for the years 1988--1991 and only included single-pressure SF6 breakers, because this is what most utilities are now buying. Thirty-one US utilities submitted data.

  14. Self-monitoring high voltage transmission line suspension insulator

    DOE Patents [OSTI]

    Stemler, Gary E. (Vancouver, WA); Scott, Donald N. (Vancouver, WA)

    1981-01-01T23:59:59.000Z

    A high voltage transmission line suspension insulator (18 or 22) which monitors its own dielectric integrity. A dielectric rod (10) has one larger diameter end fitting attachable to a transmission line and another larger diameter end fitting attachable to a support tower. The rod is enclosed in a dielectric tube (14) which is hermetically sealed to the rod's end fittings such that a liquidtight space (20) is formed between the rod and the tube. A pressurized dielectric liquid is placed within that space. A discoloring dye placed within this space is used to detect the loss of the pressurized liquid.

  15. An accurate continuous calibration system for high voltage current transformer

    SciTech Connect (OSTI)

    Tong Yue; Li Binhong [College of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei Province (China)

    2011-02-15T23:59:59.000Z

    A continuous calibration system for high voltage current transformers is presented in this paper. The sensor of this system is based on a kind of electronic instrument current transformer, which is a clamp-shape air core coil. This system uses an optical fiber transmission system for its signal transmission and power supply. Finally the digital integrator and fourth-order convolution window algorithm as error calculation methods are realized by the virtual instrument with a personal computer. It is found that this system can calibrate a high voltage current transformer while energized, which means avoiding a long calibrating period in the power system and the loss of power metering expense. At the same time, it has a wide dynamic range and frequency band, and it can achieve a high accuracy measurement in a complex electromagnetic field environment. The experimental results and the on-site operation results presented in the last part of the paper, prove that it can reach the 0.05 accuracy class and is easy to operate on site.

  16. DIII-D ICRF high voltage power supply regulator upgrade

    SciTech Connect (OSTI)

    Cary, W.P.; Burley, B.L.; Grosnickle, W.H.

    1997-11-01T23:59:59.000Z

    For reliable operation and component protection, of the 2 MW 30--120 MHz ICRF Amplifier System on DIII-D, it is desirable for the amplifier to respond to high VSWR conditions as rapidly as possible. This requires a rapid change in power which also means a rapid change in the high voltage power supply current demands. An analysis of the power supply`s regulator dynamics was needed to verify its expected operation during such conditions. Based on this information it was found that a new regulator with a larger dynamic range and some anticipation capability would be required. This paper will discuss the system requirements, the as-delivered regulator performance, and the improved performance after installation of the new regulator system. It will also be shown how this improvement has made the amplifier perform at higher power levels more reliably.

  17. High-voltage atmospheric breakdown across intervening rutile dielectrics.

    SciTech Connect (OSTI)

    Williamson, Kenneth Martin; Simpson, Sean; Coats, Rebecca Sue; Jorgenson, Roy Eberhardt; Hjalmarson, Harold Paul; Pasik, Michael Francis

    2013-09-01T23:59:59.000Z

    This report documents work conducted in FY13 on electrical discharge experiments performed to develop predictive computational models of the fundamental processes of surface breakdown in the vicinity of high-permittivity material interfaces. Further, experiments were conducted to determine if free carrier electrons could be excited into the conduction band thus lowering the effective breakdown voltage when UV photons (4.66 eV) from a high energy pulsed laser were incident on the rutile sample. This report documents the numerical approach, the experimental setup, and summarizes the data and simulations. Lastly, it describes the path forward and challenges that must be overcome in order to improve future experiments for characterizing the breakdown behavior for rutile.

  18. Understanding and Improving High Voltage Vacuum Insulators for Microsecond Pulses

    SciTech Connect (OSTI)

    Javedani, J B; Goerz, D A; Houck, T L; Lauer, E J; Speer, R D; Tully, L K; Vogtlin, G E; White, A D

    2007-03-05T23:59:59.000Z

    High voltage insulation is one of the main areas of pulsed power research and development, and dielectric breakdown is usually the limiting factor in attaining the highest possible performance in pulsed power devices. For many applications the delivery of pulsed power into a vacuum region is the most critical aspect of operation. The surface of an insulator exposed to vacuum can fail electrically at an applied field more than an order or magnitude below the bulk dielectric strength of the insulator. This mode of breakdown, called surface flashover, imposes serious limitations on the power flow into a vacuum region. This is especially troublesome for applications where high voltage conditioning of the insulator and electrodes is not practical and for applications where relatively long pulses, on the order of several microseconds, are required. The goal of this project is to establish a sound fundamental understanding of the mechanisms that lead to surface flashover, and then evaluate the most promising techniques to improve vacuum insulators and enable high voltage operation at stress levels near the intrinsic bulk breakdown limits of the material. The approach we proposed and followed was to develop this understanding through a combination of theoretical and computation methods coupled with experiments to validate and quantify expected behaviors. In this report we summarize our modeling and simulation efforts, theoretical studies, and experimental investigations. The computational work began by exploring the limits of commercially available codes and demonstrating methods to examine field enhancements and defect mechanisms at microscopic levels. Plasma simulations with particle codes used in conjunction with circuit models of the experimental apparatus enabled comparisons with experimental measurements. The large scale plasma (LSP) particle-in-cell (PIC) code was run on multiprocessor platforms and used to simulate expanding plasma conditions in vacuum gap regions. Algorithms were incorporated into LSP to handle secondary electron emission from dielectric materials to enable detailed simulations of flashover phenomenon. Theoretical studies were focused on explaining a possible mechanism for anode initiated surface flashover that involves an electron avalanche process starting near the anode, not a mechanism involving bulk dielectric breakdown. Experiments were performed in Engineering's Pulsed Power Lab using an available 100-kV, 10-{micro}s pulse generator and vacuum chamber. The initial experiments were done with polyethylene insulator material in the shape of a truncated cone cut at +45{sup o} angle between flat electrodes with a gap of 1.0 cm. The insulator was sized so there were no flashovers or breakdowns under nominal operating conditions. Insulator flashover or gap closure was induced by introducing a plasma source, a tuft of velvet, in proximity to the insulator or electrode.

  19. High-speed, sub-pull-in voltage MEMS switching.

    SciTech Connect (OSTI)

    Spahn, Olga Blum; Brewer, Steven; Olsson, Roy H.; Bogart, Gregory R.; Luck, David L.; Watts, Michael R.; Shaw, Michael J.; Nielson, Gregory N.; Resnick, Paul James; Tigges, Christopher P.; Grossetete, Grant David

    2008-01-01T23:59:59.000Z

    We have proposed and demonstrated MEMS switching devices that take advantage of the dynamic behavior of the MEMS devices to provide lower voltage actuation and higher switching speeds. We have explored the theory behind these switching techniques and have demonstrated these techniques in a range of devices including MEMS micromirror devices and in-plane parallel plate MEMS switches. In both devices we have demonstrated switching speeds under one microsecond which has essentially been a firm limit in MEMS switching. We also developed low-loss silicon waveguide technology and the ability to incorporate high-permittivity dielectric materials with MEMS. The successful development of these technologies have generated a number of new projects and have increased both the MEMS switching and optics capabilities of Sandia National Laboratories.

  20. Effect of high-voltage nanosecond pulses on complex plasmas

    SciTech Connect (OSTI)

    Pustylnik, M. Y.; Ivlev, A. V.; Thomas, H. M.; Morfill, G. E. [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, 85741 Garching (Germany); Vasilyak, L. M.; Vetchinin, S. P.; Polyakov, D. N.; Fortov, V. E. [Joint Institute for High Temperatures, Russian Academy of Sciences, Izhorskaya 13/19, 125412 Moscow (Russian Federation)

    2009-11-15T23:59:59.000Z

    Influence of high-voltage (1-11 kV) pulses of nanosecond (20 ns) duration on microparticles levitating in a rf plasma is studied. It is shown that the pulses produce significant influence on the plasma, causing perturbations with the relaxation time of the order of 10{sup -4} s. This time is sufficient for the microparticle to acquire significant kinetic energy. Application of repetitive pulses leads to the vertical oscillations of the microparticles. Clusters, consisting of small number of microparticles, exhibit parametric instabilities of horizontal modes under the effect of repetitive pulses. It was shown that the parametric instability is caused by the vertical oscillations of the microparticles in the nonuniform environment of the sheath.

  1. Summary of multiterminal high-voltage direct current transmission technology

    SciTech Connect (OSTI)

    Biggs, R.B.; Jewell, W.T.

    1984-05-01T23:59:59.000Z

    This report summarizes the present state of multiterminal (MT) high-voltage direct current (HVDC) power transmission. The purpose is to reassess the need for HVDC circuit breakers and to identify needed research for MT HVDC. The fundamentals of this technology are presented, and previous research and development is reviewed. Although no MT HVDC systems have yet been built, many concepts have been proposed. Some require a dc breaker, and others do not. Both options have advantages and disadvantages for various applications, so the selection will depend on the proposed application. Research is needed to define operating characteristics of various MT HVDC systems. In some applications, dc breakers will be useful, so research into HVDC interruption should continue. Also, dc fault detection and control algorithms for MT systems should be studied.

  2. Low-profile high-voltage compact gas switch

    SciTech Connect (OSTI)

    Goerz, D.A.; Wilson, M.J.; Speer, R.D.

    1997-06-30T23:59:59.000Z

    This paper discusses the development and testing of a low-profile, high-voltage, spark-gap switch designed to be closely coupled with other components into an integrated high-energy pulsed-power source. The switch is designed to operate at 100 kV using SF6 gas pressurized to less than 0.7 MPa. The volume of the switch cavity region is less than 1.5 cm3, and the field stress along the gas-dielectric interface is as high as 130 kV/cm. The dielectric switch body has a low profile that is only I -cm tall at its greatest extent and nominally 2-mm thick over most of its area. This design achieves a very low inductance of less than 5 nH, but results in field stresses exceeding 500 kV/cm in the dielectric material. Field modeling was done to determine the appropriate shape for the highly stressed insulator and electrodes, and special manufacturing techniques were employed to mitigate the usual mechanisms that induce breakdown and failure in solid dielectrics. Static breakdown tests verified that the switch operates satisfactorily at 100 kV levels. The unit has been characterized with different shaped electrodes having nominal gap spacings of 2.0, 2.5, and 3.0 mm. The relationship between self-break voltage and operating pressure agrees well with published data on gas properties, accounting for the field enhancements of the electrode shapes being used. Capacitor discharge tests in a low inductance test fixture exhibited peak currents up to 25 kA with characteristic frequencies of the ringdown circuit ranging from 10 to 20 MHz. The ringdown waveforms and scaling of measured parameters agree well with circuit modeling of the switch and test fixture. Repetitive operation has been demonstrated at moderate rep-rates up to 15 Hz, limited by the power supply being used. Preliminary tests to evaluate lifetime of the compact switch assembly have been encouraging. In one case, after more than 7,000 high-current ringdown tests with approximately 30 C of total charge transferred, the switch continued to operate satisfactorily with no apparent tracking or deterioration of the insulator.

  3. High sensitivity bulk electro-optic modulator field sensor for high voltage environments

    E-Print Network [OSTI]

    Shy,Jow-Tsong

    High sensitivity bulk electro-optic modulator field sensor for high voltage environments Mao December 2004) An optical electric field sensor is an effective instrument for surveying the electric attacked by unexpected electrical shocks through the metal cable of the sensor. Sensing by optical sensors

  4. High voltage power supply with modular series resonant inverters

    DOE Patents [OSTI]

    Dreifuerst, G.R.; Merritt, B.T.

    1995-07-18T23:59:59.000Z

    A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360{degree}/n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit. 11 figs.

  5. High voltage power supply with modular series resonant inverters

    DOE Patents [OSTI]

    Dreifuerst, Gary R. (Livermore, CA); Merritt, Bernard T. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360.degree./n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply. Where it is desired to make electrical isolation breaks, tubes comprised of insulating material such as nylon are used to provide insulation and continue the fluid circuit.

  6. Design, conditioning, and performance of a high voltage, high brightness dc photoelectron gun with variable gap

    SciTech Connect (OSTI)

    Maxson, Jared; Bazarov, Ivan; Dunham, Bruce; Dobbins, John; Liu, Xianghong; Smolenski, Karl [Cornell Laboratory for Accelerator-Based Sciences and Education, Cornell University, Ithaca, New York 14853 (United States)

    2014-09-15T23:59:59.000Z

    A new high voltage photoemission gun has been constructed at Cornell University which features a segmented insulator and a movable anode, allowing the cathode-anode gap to be adjusted. In this work, we describe the gun's overall mechanical and high voltage design, the surface preparation of components, as well as the clean construction methods. We present high voltage conditioning data using a 50 mm cathode-anode gap, in which the conditioning voltage exceeds 500 kV, as well as at smaller gaps. Finally, we present simulated emittance results obtained from a genetic optimization scheme using voltage values based on the conditioning data. These results indicate that for charges up to 100 pC, a 30 mm gap at 400 kV has equal or smaller 100% emittance than a 50 mm gap at 450 kV, and also a smaller core emittance, when placed as the source for the Cornell energy recovery linac photoinjector with bunch length constrained to be <3 ps rms. For 100 pC up to 0.5 nC charges, the 50 mm gap has larger core emittance than the 30 mm gap, but conversely smaller 100% emittance.

  7. activated si-gaas high-voltage: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Summary: ??This thesis is concerned with developing a new approach to high voltage transformers condition monitoring, which involve partial discharge (PD) measurement and...

  8. Method and apparatus for connecting high voltage leads to a high temperature super-conducting transformer

    SciTech Connect (OSTI)

    Golner, Thomas M.; Mehta, Shirish P.

    2005-07-26T23:59:59.000Z

    A method and apparatus for connecting high voltage leads to a super-conducting transformer is provided that includes a first super-conducting coil set, a second super-conducting coil set, and a third super-conducting coil set. The first, second and third super-conducting coil sets are connected via an insulated interconnect system that includes insulated conductors and insulated connectors that are utilized to connect the first, second, and third super-conducting coil sets to the high voltage leads.

  9. High frequency AC power converter for low voltage circuits

    E-Print Network [OSTI]

    Salazar, Nathaniel Jay Tobias

    2012-01-01T23:59:59.000Z

    This thesis presents a novel AC power delivery architecture that is suitable for VHF frequency (50-100MHz) polyphase AC/DC power conversion in low voltage integrated circuits. A complete AC power delivery architecture was ...

  10. Radio-frequency powered glow discharge device and method with high voltage interface

    DOE Patents [OSTI]

    Duckworth, Douglas C. (Knoxville, TN); Marcus, R. Kenneth (Clemson, SC); Donohue, David L. (Vienna, AT); Lewis, Trousdale A. (Oak Ridge, TN)

    1994-01-01T23:59:59.000Z

    A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components.

  11. Radio-frequency powered glow discharge device and method with high voltage interface

    DOE Patents [OSTI]

    Duckworth, D.C.; Marcus, R.K.; Donohue, D.L.; Lewis, T.A.

    1994-06-28T23:59:59.000Z

    A high voltage accelerating potential, which is supplied by a high voltage direct current power supply, is applied to the electrically conducting interior wall of an RF powered glow discharge cell. The RF power supply desirably is electrically grounded, and the conductor carrying the RF power to the sample held by the probe is desirably shielded completely excepting only the conductor's terminal point of contact with the sample. The high voltage DC accelerating potential is not supplied to the sample. A high voltage capacitance is electrically connected in series between the sample on the one hand and the RF power supply and an impedance matching network on the other hand. The high voltage capacitance isolates the high DC voltage from the RF electronics, while the RF potential is passed across the high voltage capacitance to the plasma. An inductor protects at least the RF power supply, and desirably the impedance matching network as well, from a short that might occur across the high voltage capacitance. The discharge cell and the probe which holds the sample are configured and disposed to prevent the probe's components, which are maintained at ground potential, from bridging between the relatively low vacuum region in communication with the glow discharge maintained within the cell on the one hand, and the relatively high vacuum region surrounding the probe and cell on the other hand. The probe and cell also are configured and disposed to prevent the probe's components from electrically shorting the cell's components. 11 figures.

  12. Chapter 19. High Voltage Insulation, Diagnostics and Energetic Electron and Photon Beam Interactions

    E-Print Network [OSTI]

    Chapter 19. High Voltage Insulation, Diagnostics and Energetic Electron and Photon Beam Interactions 19-1 High Voltage Insulation, Diagnostics and Energetic Electron and Photon Beam Interactions 1. DC Properties of Modern Filled Epoxy Insulation Academic and Research Staff Dr. Chathan Cooke Sponsor

  13. High voltage transformers. (Latest citations from the Inspec database). NewSearch

    SciTech Connect (OSTI)

    Not Available

    1994-11-01T23:59:59.000Z

    The bibliography contains citations concerning materials and performance of insulators used for high voltage transformers. Topics examine use of mica-fibers, gases, mica filled epoxies, and ceramics. Effects of insulation aging are reviewed, and acceptance testing of high voltage power transformers and apparatus is also examined. (Contains a minimum of 104 citations and includes a subject term index and title list.)

  14. High voltage transformers. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect (OSTI)

    NONE

    1996-08-01T23:59:59.000Z

    The bibliography contains citations of selected patents concerning high voltage transformers. Included are hybrid, video, rectifier, x-ray diagnostic generator, temperature control system, and printed circuit wound high voltage transformers. The fabrication, assembly, and testing of these transformers are also presented. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  15. High voltage transformers. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect (OSTI)

    NONE

    1995-07-01T23:59:59.000Z

    The bibliography contains citations of selected patents concerning high voltage transformers. Included are hybrid, video, rectifier, x-ray diagnostic generator, temperature control system, and printed circuit wound high voltage transformers. The fabrication, assembly, and testing of these transformers are also presented. (Contains 50-250 citations and includes a subject term index and title list.)

  16. High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

    DOE Patents [OSTI]

    Murty, Balarama Vempaty (West Bloomfield, MI)

    2000-01-01T23:59:59.000Z

    A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle's high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle's climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.

  17. Voltage Sequence Control Based High-Current Rectifier System

    E-Print Network [OSTI]

    Paderborn, Universität

    of transformer. A passive filter is added at the primary side to achieve power factor improvement over the range of output voltage. This scheme is optimized to determine optimum turns ratio of the transformer and optimum not enforce unity power factor operation and guidelines provided by harmonic standards such as IEEE-519

  18. Public Opinions of Building Additional High-Voltage Electric Power Lines

    E-Print Network [OSTI]

    Tesfatsion, Leigh

    Public Opinions of Building Additional High-Voltage Electric Power Lines A Report to the National-Voltage Electric Power Lines: A Report to the National Science Foundation and the Electric Power Research Center to build new power lines. Residents living in counties with planned routes for new transmission lines

  19. Impact of High Wind Penetration on the Voltage Profile of Distribution Systems

    E-Print Network [OSTI]

    Pota, Himanshu Roy

    of wind generator the voltage of the system may become lower than acceptable voltage level due and wind generator is presented. Simulation results are given in Section III which shows the impact of high--In this paper, simulation results showing the effect of lower and higher penetration of distributed wind

  20. An ultra-low voltage high gain operational transconductance amplifier for biomedical

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    An ultra-low voltage high gain operational transconductance amplifier for biomedical applications that work at ultra low voltage power supply. Moreover, low power dissipation is essential in these systems dissipation is also proposed in [5]. Differential pairs are commonly used as input stages, in an ultra-low

  1. Coupled Dual Interleaved Flyback Converter for High Input Voltage Application

    E-Print Network [OSTI]

    Lehman, Brad

    components, including transformers and inductors, significantly influences the overall profiles magnetic core to store the energy in the power transformer. A Flyback converter is a popular choice for low. All the center and outer legs are gapped, and the transformers are integrated into one magnetic core

  2. High voltage ignition of high pressure microwave powered UV light sources

    SciTech Connect (OSTI)

    Frank, J.D.; Cekic, M.; Wood, C.H. [Fusion U.V. Curing Systems Corp., Gaithersburg, MD (United States)

    1997-12-31T23:59:59.000Z

    Industrial microwave powered (electrodeless) light sources have been limited to quiescent pressures of {approximately}300 Torr of buffer gas and metal-halide fills. The predominant reason for such restrictions has been the inability to microwave ignite the plasma due to the collisionality of higher pressure fills and/or the electronegativity of halide bulb chemistries. Commercially interesting bulb fills require electric fields for ionization that are often large multiples of the breakdown voltage for air. Many auxiliary ignition methods are evaluated for efficiency and practicality before the choice of a high-voltage system with a retractable external electrode. The scheme utilizes a high voltage pulse power supply and a novel field emission source. Acting together they create localized condition of pressure reduction and high free electron density. This allows the normal microwave fields to drive this small region into avalanche, ignite the bulb, and heat the plasma to its operating point (T{sub e} {approx} 0.5 eV). This process is currently being used in a new generation of lamps, which are using multi-atmospheric excimer laser chemistries and pressure and constituent enhanced metal-halide systems. At the present time, production prototypes produce over 900 W of radiation in a 30 nm band, centered at 308 nm. Similarly, these prototypes when loaded with metal-halide bulb fills produce over 1 kW of radiation in 30 nm wide bands, centered about the wavelength of interest.

  3. High-voltage crowbar protection for the large CDF axial drift chamber

    SciTech Connect (OSTI)

    Binkley, M.; Mukherjee, A.; Stuermer, W.; Wagner, R.L.; /Fermilab

    2004-01-01T23:59:59.000Z

    The Central Outer Tracker (COT) is a big cylindrical drift chamber that provides charged particle tracking for the Collider Detector at Fermilab experiment. To protect the COT, the large stored energy in the high voltage system needs to be removed quickly when a problem is sensed. For the high voltage switch, a special-order silicon-controlled-rectifier was chosen over more readily available integrated gate bipolar transistors because of layout and reliability questions. The considerations concerning the high voltage switch, the prototype performance, and the experience of more than two years of running are described.

  4. An Annotated Bibliography of High-Voltage Direct-Current Transmission and Flexible AC Transmission (FACTS) Devices, 1991-1993.

    SciTech Connect (OSTI)

    Litzenberger, Wayne; Lava, Val

    1994-08-01T23:59:59.000Z

    References are contained for HVDC systems, converter stations and components, overhead transmission lines, cable transmission, system design and operations, simulation of high voltage direct current systems, high-voltage direct current installations, and flexible AC transmission system (FACTS).

  5. 130kV 130A High Voltage Switching Mode Power Supply for Neutral Injections – Control Issues and Algorithms

    E-Print Network [OSTI]

    130kV 130A High Voltage Switching Mode Power Supply for Neutral Injections – Control Issues and Algorithms

  6. Princeton Power Systems (TRL 5 6 Component)- Marine High-Voltage Power Conditioning and Transmission System with Integrated Energy Storage

    Broader source: Energy.gov [DOE]

    Princeton Power Systems (TRL 5 6 Component) - Marine High-Voltage Power Conditioning and Transmission System with Integrated Energy Storage

  7. Light-weight DC to very high voltage DC converter

    DOE Patents [OSTI]

    Druce, Robert L. (Union City, CA); Kirbie, Hugh C. (Dublin, CA); Newton, Mark A. (Livermore, CA)

    1998-01-01T23:59:59.000Z

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current.

  8. Light-weight DC to very high voltage DC converter

    DOE Patents [OSTI]

    Druce, R.L.; Kirbie, H.C.; Newton, M.A.

    1998-06-30T23:59:59.000Z

    A DC-DC converter capable of generating outputs of 100 KV without a transformer comprises a silicon opening switch (SOS) diode connected to allow a charging current from a capacitor to flow into an inductor. When a specified amount of charge has flowed through the SOS diode, it opens up abruptly; and the consequential collapsing field of the inductor causes a voltage and current reversal that is steered into a load capacitor by an output diode. A switch across the series combination of the capacitor, inductor, and SOS diode closes to periodically reset the SOS diode by inducing a forward-biased current. 1 fig.

  9. HIGH-VOLTAGE SPINEL AND POLYANION CATHODES | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGrid Integration0-1HAWAI'I CLEANDepartmentDOEHIGH-VOLTAGE

  10. High voltage repetitive pulsed nanosecond discharges as a selective source of reactive species

    E-Print Network [OSTI]

    Guerra García, Carmen

    2011-01-01T23:59:59.000Z

    High voltage nanosecond duration discharges can be used in a repetitive manner to create a sustained pool of short lived excited species and ions and long-lived radicals in a gas. Although the suitability of the Repetitive ...

  11. Current mode integrators and their applications in low-voltage high frequency CMOS signal processing

    E-Print Network [OSTI]

    1993-01-01T23:59:59.000Z

    Low voltage CMOS fully differential integrators for high frequency continuous-time filters using current-mode techniques are presented.. Current mode techniques are employed to avoid the use of the floating differential pair, in order to achieve...

  12. Vehicle Technologies Office Merit Review 2014: High-Voltage Solid Polymer Batteries for Electric Drive Vehicles

    Broader source: Energy.gov [DOE]

    Presentation given by Seeo, Inc. at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high-voltage solid polymer...

  13. High voltage transformers. (Latest citations from the INSPEC database). Published Search

    SciTech Connect (OSTI)

    NONE

    1996-02-01T23:59:59.000Z

    The bibliography contains citations concerning materials and performance of insulators used for high voltage transformers. Topics examine use of mica-fibers, gases, mica filled epoxies, and ceramics. Effects of insulation aging are reviewed, and acceptance testing of high voltage power transformers and apparatus is also examined. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  14. High voltage transformers. (Latest citations from the INSPEC database). Published Search

    SciTech Connect (OSTI)

    NONE

    1997-05-01T23:59:59.000Z

    The bibliography contains citations concerning materials and performance of insulators used for high voltage transformers. Topics examine use of mica-fibers, gases, mica filled epoxies, and ceramics. Effects of insulation aging are reviewed, and acceptance testing of high voltage power transformers and apparatus is also examined.(Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  15. Cermet insert high voltage holdoff improvement for ceramic/metal vacuum devices

    DOE Patents [OSTI]

    Ierna, W.F.

    1986-03-11T23:59:59.000Z

    An improved metal-to-ceramic seal is provided wherein the ceramic body of the seal contains an integral region of cermet material in electrical contact with the metallic member, e.g., an electrode, of the seal. The seal is useful in high voltage vacuum devices, e.g., vacuum switches, and increases the high-voltage holdoff capabilities of such devices. A method of fabricating such seals is also provided.

  16. Cermet insert high voltage holdoff for ceramic/metal vacuum devices

    DOE Patents [OSTI]

    Ierna, William F. (Seminole, FL)

    1987-01-01T23:59:59.000Z

    An improved metal-to-ceramic seal is provided wherein the ceramic body of the seal contains an integral region of cermet material in electrical contact with the metallic member, e.g., an electrode, of the seal. The seal is useful in high voltage vacuum devices, e.g., vacuum switches, and increases the high-voltage holdoff capabilities of such devices. A method of fabricating such seals is also provided.

  17. TiN coated aluminum electrodes for DC high voltage electron guns

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

    2015-05-01T23:59:59.000Z

    Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloymore »(Ti-6Al-4V). Following gas conditioning, each TiN-coated aluminum electrode reached ?225?kV bias voltage while generating less than 100?pA of field emission (« less

  18. High voltage fault current limiter having immersed phase coils

    DOE Patents [OSTI]

    Darmann, Francis Anthony

    2014-04-22T23:59:59.000Z

    A fault current limiter including: a ferromagnetic circuit formed from a ferromagnetic material and including at least a first limb, and a second limb; a saturation mechanism surrounding a limb for magnetically saturating the ferromagnetic material; a phase coil wound around a second limb; a dielectric fluid surrounding the phase coil; a gaseous atmosphere surrounding the saturation mechanism.

  19. Development of Low-Voltage and Large Current DC Power Supply with High-Frequency Transformer Coupling

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    Development of Low-Voltage and Large Current DC Power Supply with High-Frequency Transformer excellent performance. Keywords DC power supply, low-voltage and large-current, high-frequency transformer Iobe (MACOHO Co., Ltd.) Abstract This paper describes low-voltage and large-current DC power supplies

  20. Atmospheric pressure plasma jet with high-voltage power supply based on piezoelectric transformer

    SciTech Connect (OSTI)

    Babij, Micha?; Kowalski, Zbigniew W., E-mail: zbigniew.w.kowalski@pwr.wroc.pl; Nitsch, Karol; Gotszalk, Teodor [Wroc?aw University of Technology, Wybrze?e Wyspia?skiego 27, 50-370 Wroc?aw (Poland)] [Wroc?aw University of Technology, Wybrze?e Wyspia?skiego 27, 50-370 Wroc?aw (Poland); Silberring, Jerzy [AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Kraków (Poland)] [AGH University of Science and Technology, Al. A. Mickiewicza 30, 30-059 Kraków (Poland)

    2014-05-15T23:59:59.000Z

    The dielectric barrier discharge plasma jet, an example of the nonthermal atmospheric pressure plasma jet (APPJ), generates low-temperature plasmas that are suitable for the atomization of volatile species and can also be served as an ionization source for ambient mass and ion mobility spectrometry. A new design of APPJ for mass spectrometry has been built in our group. In these plasma sources magnetic transformers (MTs) and inductors are typically used in power supplies but they present several drawbacks that are even more evident when dealing with high-voltage normally used in APPJs. To overcome these disadvantages, high frequency generators with the absence of MT are proposed in the literature. However, in the case of miniaturized APPJs these conventional power converters, built of ferromagnetic cores and inductors or by means of LC resonant tank circuits, are not so useful as piezoelectric transformer (PT) based power converters due to bulky components and small efficiency. We made and examined a novel atmospheric pressure plasma jet with PT supplier served as ionization source for ambient mass spectrometry, and especially mobile spectrometry where miniaturization, integration of components, and clean plasma are required. The objective of this paper is to describe the concept, design, and implementation of this miniaturized piezoelectric transformer-based atmospheric pressure plasma jet.

  1. Addition and subtraction of spin pumping voltages in magnetic hybrid structures

    SciTech Connect (OSTI)

    Azevedo, A., E-mail: aac@df.ufpe.br; Alves Santos, O.; Cunha, R. O.; Rezende, S. M. [Departamento de Física, Universidade Federal de Pernambuco, 50670-901 Recife, PE (Brazil); Rodríguez-Suárez, R. [Facultad de Física, Pontificia Universidad Católica de Chile, Casilla 306, Santiago (Chile)

    2014-04-14T23:59:59.000Z

    We report an investigation of the spin pumping voltage generated in bilayers of ferromagnetic/normal metal in which the ferromagnetic layer is yttrium iron garnet or Permalloy and the normal-metal layer is Pt or Ta. We also investigated a special case in which the voltage is detected in single layer of Permalloy under ferromagnetic resonance condition. It is shown that the spin pumping voltage generated in metallic bilayers have contributions from both layers and the resulting voltage depends on the relative signs of charge currents generated by the inverse spin Hall effect. For instance, the spin pumping voltage generated in Ta has the same sign as the one generate in single layer of Permalloy, but contrary to the voltage generated in Pt. When the voltage is measured in shunted metallic bilayers, the resulting voltage can be a sum or a subtraction of the voltages generated in both layers.

  2. HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS

    E-Print Network [OSTI]

    Taylor, C.

    2011-01-01T23:59:59.000Z

    D. C. 'Niobium-Titanium Superconducting Material s ', in S.14, 1982 HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS C.SUMAG-68 HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS* C.

  3. Low Voltage High Precision Spatial Light ModulatorsFinal Report

    SciTech Connect (OSTI)

    Papavasiliou, A P

    2005-02-09T23:59:59.000Z

    The goal of this project was to make LLNL a leader in Spatial Light Modulators (SLMs) by developing the technology that will be needed by the next generation of SLMs. We would use new lower voltage actuators and bond those actuators directly to controlling circuitry to break the fundamental limitations that constrain current SLM technology. This three-year project was underfunded in the first year and not funded in the second year. With the funding that was available, we produced actuators and designs for the controlling circuitry that would have been integrated in the second year. Spatial light modulators (SLMs) are arrays of tiny movable mirrors that modulate the wave-fronts of light. SLMs can correct aberrations in incoming light for adaptive optics or modulate light for beam control, optical communication and particle manipulation. MicroElectroMechanical Systems (MEMS) is a technology that utilizes the microfabrication tools developed by the semiconductor industry to fabricate a wide variety of tiny machines. The first generation of MEMS SLMs have improved the functionality of SLMs while drastically reducing per pixel cost making arrays on the order of 1000 pixels readily available. These MEMS SLMs however are limited by the nature of their designs to be very difficult to scale above 1000 pixels and have very limited positioning accuracy. By co-locating the MEMS mirrors with CMOS electronics, we will increase the scalability and positioning accuracy. To do this we will have to make substantial advances in SLM actuator design, and fabrication.

  4. Gigahertz Non-Volatile Voltage Tuned Magnetic Film Inductors using a Ni/NiFe Core

    E-Print Network [OSTI]

    Lewis, Mark Dylan

    2012-01-01T23:59:59.000Z

    energy harvesting, magnetic recording devices, and electric and magnetic field tunable microwaveenergy harvesting, magnetic recording devices, and electric and magnetic field tunable microwave

  5. Connecting Renewables Directly to the Grid: Resilient Multi-Terminal HVDC Networks with High-Voltage High-Frequency Electronics

    SciTech Connect (OSTI)

    None

    2012-01-23T23:59:59.000Z

    GENI Project: GE is developing electricity transmission hardware that could connect distributed renewable energy sources, like wind farms, directly to the grid—eliminating the need to feed the energy generated through intermediate power conversion stations before they enter the grid. GE is using the advanced semiconductor material silicon carbide (SiC) to conduct electricity through its transmission hardware because SiC can operate at higher voltage levels than semiconductors made out of other materials. This high-voltage capability is important because electricity must be converted to high-voltage levels before it can be sent along the grid’s network of transmission lines. Power companies do this because less electricity is lost along the lines when the voltage is high.

  6. High Temperature, Permanent Magnet Biased Magnetic Bearings

    E-Print Network [OSTI]

    Gandhi, Varun R.

    2010-07-14T23:59:59.000Z

    , then the molding process was carried out to form the potting cement on the each stator. After this the stators are baked in the oven and once ready the magnets and back-irons are put onto the stator. Shown below in Figure 3-11 is an assembly tool designed... rings. The bearing and its support rings were then carried onto the test rig and mounted at one end of the table. Throughout the assembly process a lot of care had to be taken so as to avoid damaging of the permanent magnets, stator and its coils...

  7. The design, construction, and operation of long-distance high-voltage electricity transmission technologies.

    SciTech Connect (OSTI)

    Molburg, J. C.; Kavicky, J. A.; Picel, K. C.

    2008-03-03T23:59:59.000Z

    This report focuses on transmission lines, which operate at voltages of 115 kV and higher. Currently, the highest voltage lines comprising the North American power grid are at 765 kV. The grid is the network of transmission lines that interconnect most large power plants on the North American continent. One transmission line at this high voltage was built near Chicago as part of the interconnection for three large nuclear power plants southwest of the city. Lines at this voltage also serve markets in New York and New England, also very high demand regions. The large power transfers along the West Coast are generally at 230 or 500 kV. Just as there are practical limits to centralization of power production, there are practical limits to increasing line voltage. As voltage increases, the height of the supporting towers, the size of the insulators, the distance between conductors on a tower, and even the width of the right-of-way (ROW) required increase. These design features safely isolate the electric power, which has an increasing tendency to arc to ground as the voltage (or electrical potential) increases. In addition, very high voltages (345 kV and above) are subject to corona losses. These losses are a result of ionization of the atmosphere, and can amount to several megawatts of wasted power. Furthermore, they are a local nuisance to radio transmission and can produce a noticeable hum. Centralized power production has advantages of economies of scale and special resource availability (for instance, hydro resources), but centralized power requires long-distance transfers of power both to reach customers and to provide interconnections for reliability. Long distances are most economically served at high voltages, which require large-scale equipment and impose a substantial footprint on the corridors through which power passes. The most visible components of the transmission system are the conductors that provide paths for the power and the towers that keep these conductors at a safe distance from each other and from the ground and the natural and built environment. Common elements that are generally less visible (or at least more easily overlooked) include the maintained ROW along the path of the towers, access roads needed for maintenance, and staging areas used for initial construction that may be restored after construction is complete. Also visible but less common elements along the corridor may include switching stations or substations, where lines of similar or different voltages meet to transfer power.

  8. High-Voltage Insulators and Components - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School football High School footballHigh-Pressure

  9. Highline Pacific Northwests High-Voltage Transmission System

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School football High SchoolBundles to Living

  10. Static reactive power compensators for high-voltage power systems. Final report

    SciTech Connect (OSTI)

    Not Available

    1981-04-01T23:59:59.000Z

    A study conducted to summarize the role of static reactive power compensators for high voltage power system applications is described. This information should be useful to the utility system planning engineer in applying static var systems (SVS) to high voltage as (HVAC) systems. The static var system is defined as a form of reactive power compensator. The general need for reactive power compensation in HVAC systems is discussed, and the static var system is compared to other devices utilized to provide reactive power compensation. Examples are presented of applying SVS for specific functions, such as the prevention of voltage collapse. The operating principles of commercially available SVS's are discussed in detail. The perormance and active power loss characteristics of SVS types are compared.

  11. Optimizing performance per watt on GPUs in High Performance Computing: temperature, frequency and voltage effects

    E-Print Network [OSTI]

    Price, D C; Barsdell, B R; Babich, R; Greenhill, L J

    2014-01-01T23:59:59.000Z

    The magnitude of the real-time digital signal processing challenge attached to large radio astronomical antenna arrays motivates use of high performance computing (HPC) systems. The need for high power efficiency (performance per watt) at remote observatory sites parallels that in HPC broadly, where efficiency is an emerging critical metric. We investigate how the performance per watt of graphics processing units (GPUs) is affected by temperature, core clock frequency and voltage. Our results highlight how the underlying physical processes that govern transistor operation affect power efficiency. In particular, we show experimentally that GPU power consumption grows non-linearly with both temperature and supply voltage, as predicted by physical transistor models. We show lowering GPU supply voltage and increasing clock frequency while maintaining a low die temperature increases the power efficiency of an NVIDIA K20 GPU by up to 37-48% over default settings when running xGPU, a compute-bound code used in radio...

  12. Design and validation of a high-voltage levitation circuit for electrostatic accelerometers

    SciTech Connect (OSTI)

    Li, G.; Wu, S. C.; Zhou, Z. B.; Bai, Y. Z.; Hu, M.; Luo, J. [MOE Key Laboratory of Fundamental Physical Quantities Measurements, School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)] [MOE Key Laboratory of Fundamental Physical Quantities Measurements, School of Physics, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China)

    2013-12-15T23:59:59.000Z

    A simple high-voltage circuit with a voltage range of 0 to 900 V and an open-loop bandwidth of 11 kHz is realized by using an operational amplifier and a MOSFET combination. The circuit is used for the levitation of a test mass of 71 g, suspended below the top-electrodes with a gap distance of 57 ?m, so that the performance of an electrostatic accelerometer can be tested on the ground. The translation noise of the accelerometer, limited by seismic noise, is about 4 × 10{sup ?8} m/s{sup 2}/Hz{sup 1/2} at 0.1 Hz, while the high-voltage coupling noise is one-order of magnitude lower.

  13. Dual design resistor for high voltage conditioning and transmission lines

    DOE Patents [OSTI]

    Siggins, Timothy Lynn (Newport News, VA); Murray, Charles W. (Hayes, VA); Walker, Richard L. (Norfolk, VA)

    2007-01-23T23:59:59.000Z

    A dual resistor for eliminating the requirement for two different value resistors. The dual resistor includes a conditioning resistor at a high resistance value and a run resistor at a low resistance value. The run resistor can travel inside the conditioning resistor. The run resistor is capable of being advanced by a drive assembly until an electrical path is completed through the run resistor thereby shorting out the conditioning resistor and allowing the lower resistance run resistor to take over as the current carrier.

  14. Method of making high breakdown voltage semiconductor device

    DOE Patents [OSTI]

    Arthur, Stephen D. (Scotia, NY); Temple, Victor A. K. (Jonesville, NY)

    1990-01-01T23:59:59.000Z

    A semiconductor device having at least one P-N junction and a multiple-zone junction termination extension (JTE) region which uniformly merges with the reverse blocking junction is disclosed. The blocking junction is graded into multiple zones of lower concentration dopant adjacent termination to facilitate merging of the JTE to the blocking junction and placing of the JTE at or near the high field point of the blocking junction. Preferably, the JTE region substantially overlaps the graded blocking junction region. A novel device fabrication method is also provided which eliminates the prior art step of separately diffusing the JTE region.

  15. Development of Low-Voltage and Large-Current DC Power Supply with High-Frequency Transformer Coupling

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    Development of Low-Voltage and Large-Current DC Power Supply with High-Frequency Transformer-voltage and large-current DC power supply with a high-frequency transformer coupling. The power supply is simply·,Zü"gg"X·C~R,êC"_N^"X Keywords: DC power supply, low-voltage and large-current, high-frequency transformer, leakage inductance 1

  16. Realizing high-voltage thin film lateral bipolar transistors on SOI with a collector-tub

    E-Print Network [OSTI]

    Kumar, M. Jagadesh

    Realizing high-voltage thin film lateral bipolar transistors on SOI with a collector-tub Sukhendu-dimensional device simulation to examine the effect of a collector tub on the collector breakdown of the SOI based BJTs. This method involves creating a collector tub by etching the buried oxide followed by an n

  17. STRUCTURAL HEALTH MONITORING OF HIGH VOLTAGE ELECTRICAL SWITCH CERAMIC INSULATORS IN SEISMIC AREAS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    STRUCTURAL HEALTH MONITORING OF HIGH VOLTAGE ELECTRICAL SWITCH CERAMIC INSULATORS IN SEISMIC AREAS damage. 7th European Workshop on Structural Health Monitoring July 8-11, 2014. La Cité, Nantes, France European Workshop on Structural Health Monitoring (2014)" #12;(a) (b) Figure 1 : a) Elect

  18. The powerful high-voltage glow discharge electron gun and power unit on its base

    SciTech Connect (OSTI)

    Chernov, V.A. [All-Russian Electrotechnical Institute, Moscow (Russian Federation)

    1994-12-31T23:59:59.000Z

    The technical and operational characteristics and features of powerful electron gun with cold cathodes on the basis of high-voltage glow discharge (HGD) are submitted. The systems, ensuring their work are described. Some results of operation and applications of these non-traditional electron guns are presented.

  19. Correlation of PDN Impedance with Jitter and Voltage Margin for High Speed Channels

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    Correlation of PDN Impedance with Jitter and Voltage Margin for High Speed Channels Vishal Laddha vishal.laddha@gatech.edu, madhavan.swaminathan@ece.gatech.edu Abstract: Timing margin (jitter and plane cutouts is a major source of jitter and noise introduced by the package and the printed circuit

  20. CONTROL SYSTEM FOR THE ORNL MULTICHARGED ION RESEARCH FACILITY HIGH-VOLTAGE PLATFORM

    E-Print Network [OSTI]

    CONTROL SYSTEM FOR THE ORNL MULTICHARGED ION RESEARCH FACILITY HIGH-VOLTAGE PLATFORM M. E for the 250-kV platform and beamlines for accelerating and transporting ions produced by an all- permanent of the electrical potentials of the installation, that is at the source, platform, and ground potentials, are inter

  1. Droop Compensation with soft Switching for High Voltage Converter Modulator (HVCM)

    SciTech Connect (OSTI)

    Bland, Michael [University of Nottingham; Scheinker, Alexander [Los Alamos National Laboratory; Clare, Jon [University of Nottingham; Watson, Alan [University of Nottingham; Ji, Chao [University of Nottingham; Reass, William [Los Alamos National Laboratory

    2012-06-04T23:59:59.000Z

    High Voltage Converter Modulators (HVCM) offer significant performance advantages over conventional modulator technologies for long pulse applications. One of the key advantages of HVCM technology is the ability to compensate for capacitor bank voltage droop. Achieving droop compensation without incurring significant additional switching loss has not been possible in existing designs. This paper presents an analysis of the 'Y-point' variant of the HVCM topology using the Combined Phase and Frequency Modulation (CPFM) technique. This, combined with the addition of a 'lossless' snubber circuit, enables droop compensation while achieving soft switching over the entire pulse duration. The rise time and overshoot of the output voltage pulse is optimized using an iterative extreme seeking algorithm. The optimization reduces the rise time from 100 {micro}s to 50 {micro}s with no overshoot. This will lead to an increase in overall accelerator efficiency.

  2. Partial discharge measurements on a high voltage direct current mass impregnated paper cable

    SciTech Connect (OSTI)

    Jeroense, M.J.P. [NKF KABEL B.V., Delft (Netherlands); Kreuger, F.H. [Delft Univ. of Technology (Netherlands)

    1996-12-31T23:59:59.000Z

    Partial discharge measurement has been a good tool for the quality assurance of cables under alternating voltage. With the growing interest in High Voltage Direct Current cables it seems therefore logical to extend this technique for use at direct voltage. The paper describes this technique as used on a HVDC cable with mass impregnated paper. The different phases of operation (no load, full load, cooling phase, etc.) are characterized by a different discharge behavior. Special attention is given to the dangerous cooling phase. Models have been developed which can explain the discharge patterns that were measured. This paper gives an insight in the electrical behavior of a HVDC cable with mass impregnated paper insulation.

  3. High-Voltage Terminal Test of Test Stand for 1-MV Electrostatic Accelerator

    E-Print Network [OSTI]

    Park, Sae-Hoon

    2015-01-01T23:59:59.000Z

    The Korea Multipurpose Accelerator Complex (KOMAC) has been developing a 300-kV test stand for a 1-MV electrostatic accelerator ion source. The ion source and accelerating tube will be installed in a high-pressure vessel. The ion source in the high-pressure vessel is required to have a high reliability. The test stand has been proposed and developed to confirm the stable operating conditions of the ion source. The ion source will be tested at the test stand to verify the long-time operating conditions. The test stand comprises a 300-kV high-voltage terminal, a battery for the ion-source power, a 60-Hz inverter, 200-MHz RF power, a 5-kV extraction power supply, a 300-kV accelerating tube, and a vacuum system. The results of the 300-kV high-voltage terminal tests are presented in this paper.

  4. A simple high-voltage high current spark gap with subnanosecond jitter triggered by femtosecond laser filamentation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1 A simple high-voltage high current spark gap with subnanosecond jitter triggered by femtosecond and able to switch currents in excess of 10 kA with sub-nanosecond jitter. The spark gap is remotely with a nanosecond jitter time2-7 . The jitter could be reduced to hundred of picoseconds with a SF6 filled cell8

  5. Quantitative Modeling of High Temperature Magnetization Dynamics

    SciTech Connect (OSTI)

    Zhang, Shufeng

    2009-03-01T23:59:59.000Z

    Final Technical Report Project title: Quantitative Modeling of High Temperature Magnetization Dynamics DOE/Office of Science Program Manager Contact: Dr. James Davenport

  6. Development of the Fast Scintillation Detector with Programmable High Voltage Adjustment Suitable for Moessbauer Spectroscopy

    SciTech Connect (OSTI)

    Prochazka, R.; Frydrych, J. [Center for Nanomaterial Research, Faculty of Science Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Pechousek, J. [Center for Nanomaterial Research, Faculty of Science Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Experimental Physics, Faculty of Science, 17. listopadu 1192/12, 771 46 Olomouc (Czech Republic)

    2010-07-13T23:59:59.000Z

    This work is focused on a development of a compact fast scintillation detector suitable for Moessbauer spectroscopy (low energy X-ray/{gamma}-ray detection) where high counting rates are inevitable. Optimization of this part was necessary for a reliable function, better time resolution and to avoid a detector pulses pile-up effect. The pile-up effect decreases the measurement performance, significantly depends on the source activity and also on the pulse duration. Our new detection unit includes a fast scintillation crystal YAP:Ce, an R6095 photomultiplier tube, a high voltage power supply socket C9028-01 assembly, an AD5252 digital potentiometer with an I2C interface and an AD8000 ultra fast operation preamplifier. The main advantages of this solution lie in a short pulse duration (less than 200 ns), stable operation for high activities, programmable gain of the high voltage supply and compact design in the aluminum housing.

  7. Using Dielectric Losses to De-Ice Power Transmission Lines with 100 kHz High-Voltage

    E-Print Network [OSTI]

    Using Dielectric Losses to De-Ice Power Transmission Lines with 100 kHz High-Voltage Excitation J DIELECTRIC LOSSES TO DE-ICE POWER TRANSMISSION LINES . . . 1 Using Dielectric Losses to De-Ice Power Transmission Lines with 100 kHz High-Voltage Excitation Joshua D. McCurdy, Charles R. Sullivan and Victor F

  8. Charge Collection and Capacitance-Voltage analysis in irradiated n-type magnetic Czochralski silicon detectors

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    to permit higher operating voltage, decrease the noise and avoid self-heating effects. The current- forward electrical measurements facilitates the planning of experiments, and for many years C

  9. Impact of high-power stress on dynamic ON-resistance of high-voltage GaN HEMTs Donghyun Jin

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    Impact of high-power stress on dynamic ON-resistance of high-voltage GaN HEMTs Donghyun Jin-resistance (RON) in high- voltage GaN High-Electron-Mobility Transistors (HEMTs). We use a newly proposed dynamic. All rights reserved. 1. Introduction In the last decade, GaN Field-Effect Transistors have emerged

  10. CRYOGENIC LIFETIME TESTS ON A COMMERCIAL EPOXY RESIN HIGH VOLTAGE BUSHING

    SciTech Connect (OSTI)

    Schwenterly, S W [ORNL; Pleva, Ed [Waukesha Electric Systems, Waukesha, WI; Ha, Tam T [ORNL

    2012-01-01T23:59:59.000Z

    High-temperature superconducting (HTS) power devices operating in liquid nitrogen frequently require high-voltage bushings to carry the current leads from the superconducting windings to the room temperature grid connections. Oak Ridge National Laboratory is collaborating with Waukesha Electric Systems, SuperPower, and Southern California Edison to develop and demonstrate an HTS utility power transformer. Previous dielectric high voltage tests in support of this program have been carried out in test cryostats with commercial epoxy resin bushings from Electro Composites Inc. (ECI). Though the bushings performed well in these short-term tests, their long-term operation at high voltage in liquid nitrogen needs to be verified for use on the utility grid. Long-term tests are being carried out on a sample 28-kV-class ECI bushing. The bushing has a monolithic cast, cycloaliphatic resin body and is fire- and shatter-resistant. The test cryostat is located in an interlocked cage and is energized at 25 kVac around the clock. Liquid nitrogen (LN) is automatically refilled every 9.5 hours. Partial discharge, capacitance, and leakage resistance tests are periodically performed to check for deviations from factory values. At present, over 2400 hours have been accumulated with no changes in these parameters. The tests are scheduled to run for four to six months.

  11. Tests of industrial ethylene-propylene rubber high voltage cable for cryogenic use

    E-Print Network [OSTI]

    Balhan, B; Goddard, B; Muratori, G; Otwinowski, S; Rieubland, Jean Michel; Wang, H; CERN. Geneva. SPS and LEP Division

    1999-01-01T23:59:59.000Z

    At the beginning of 1999 UCLA has received a prototype High Voltage Cryogenic Cable supplied fee of charge by Pirelli. The cable is intended for more than ten years of service at 100 kV D.C. and liquid argon temperature. Thecable uses an all welded construction, whichi is axially tight and free of ionizable voids. The cable was submitted to a number of mechanical and electrical tests as described below.

  12. Round-robin artificial contamination test on high voltage dc insulators

    SciTech Connect (OSTI)

    Naito, K.; Schneider, H.M.

    1995-07-01T23:59:59.000Z

    This paper summarizes the results of a worldwide round-robin test of high voltage dc (HVDC) insulators, which was carried out in six laboratories aiming at standardization of the method for artificial contamination tests on HVDC insulators. Flashover characteristics of three kinds of specimens were evaluated by the clean fog and the salt fog procedures. Sufficient information is now available to allow the preparation of provisional international specifications for artificial contamination testing of HVDC insulators.

  13. Soft Magnetic Materials in High-Frequency, High-Power Conversion Applications

    E-Print Network [OSTI]

    McHenry, Michael E.

    Voltage DC (HVDC) technologies aim to improve the effi- ciency of power networks and benefit from high

  14. Marine High Voltage Power Conditioning and Transmission System with Integrated Storage DE-EE0003640 Final Report

    SciTech Connect (OSTI)

    Frank Hoffmann, PhD; Aspinall, Rik

    2012-12-10T23:59:59.000Z

    Design, Development, and test of the three-port power converter for marine hydrokinetic power transmission. Converter provides ports for AC/DC conversion of hydrokinetic power, battery storage, and a low voltage to high voltage DC port for HVDC transmission to shore. The report covers the design, development, implementation, and testing of a prototype built by PPS.

  15. LINUDANS -Research and development of high voltage towers. Reykjavik University is working in Collaboration with Linudans, research based company specialized

    E-Print Network [OSTI]

    Karlsson, Brynjar

    LINUDANS - Research and development of high voltage towers. Reykjavik University is working problems regarding the growing energy transport. All products of Linudans are green and environmentally voltage towers is the main focus of Linudans. The company has developed an innovative concept which serves

  16. High performance magnet power supply optimization

    SciTech Connect (OSTI)

    Jackson, L.T.

    1988-01-01T23:59:59.000Z

    The power supply system for the joint LBL--SLAC proposed accelerator PEP provides the opportunity to take a fresh look at the current techniques employed for controlling large amounts of dc power and the possibility of using a new one. A basic requirement of +- 100 ppM regulation is placed on the guide field of the bending magnets and quadrupoles placed around the 2200 meter circumference of the accelerator. The optimization questions to be answered by this paper are threefold: Can a firing circuit be designed to reduce the combined effects of the harmonics and line voltage combined effects of the harmonics and line voltage unbalance to less than 100 ppM in the magnet field. Given the ambiguity of the previous statement, is the addition of a transistor bank to a nominal SCR controlled system the way to go or should one opt for an SCR chopper system running at 1 KHz where multiple supplies are fed from one large dc bus and the cost--performance evaluation of the three possible systems.

  17. A high voltage pulsed power supply for capillary discharge waveguide applications

    SciTech Connect (OSTI)

    Abuazoum, S.; Wiggins, S. M.; Issac, R. C.; Welsh, G. H.; Vieux, G.; Jaroszynski, D. A. [Department of Physics, Scottish Universities Physics Alliance, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Ganciu, M. [Low Temperature Plasma Department, National Institute of Lasers, Plasma and Radiation Physics, 077125, Magurele, Bucharest (Romania)

    2011-06-15T23:59:59.000Z

    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.

  18. Novel Nonflammable Electrolytes for Secondary Magnesium Batteries and High Voltage Electrolytes for Electrochemcial Supercapacitors

    SciTech Connect (OSTI)

    Dr. Brian Dixon

    2008-12-30T23:59:59.000Z

    Magnesium has been used successfully in primary batteries, but its use in rechargeable cells has been stymied by the lack of suitable non-aqueous electrolyte that can conduct Mg+2 species, combined with poor stripping and plating properties. The development of a suitable cathode material for rechargeable magnesium batteries has also been a roadblock, but a nonflammable electrolyte is key. Likewise, the development of safe high voltage electrochemical supercapaitors has been stymied by the use of flammable solvents in the liquid electrolyte; to wit, acetonitrile. The purpose of the research conducted in this effort was to identify useful compositions of magnesium salts and polyphosphate solvents that would enable magnesium ions to be cycled within a secondary battery design. The polyphosphate solvents would provide the solvent for the magnesium salts while preventing the electrolyte from being flammable. This would enable these novel electrolytes to be considered as an alternative to THF-based electrolytes. In addition, we explored several of these solvents together with lithium slats for use as high voltage electrolytes for carbon-based electrochemical supercapacitors. The research was successful in that: 1) Magnesium imide dissolved in a phosphate ester solvent that contains a halogented phosphate ester appears to be the preferred electrolyte for a rechargeable Mg cell. 2) A combination of B-doped CNTs and vanadium phosphate appear to be the cathode of choice for a rechargeable Mg cell by virtue of higher voltage and better reversibility. 3) Magnesium alloys appear to perform better than pure magnesium when used in combination with the novel polyphosphate electrolytes. Also, this effort has established that Phoenix Innovationâ??s family of phosphonate/phosphate electrolytes together with specific lithium slats can be used in supercapacitor systems at voltages of greater than 10V.

  19. A new class of high force, low-voltage, compliant actuation system

    SciTech Connect (OSTI)

    RODGERS,M. STEVEN; KOTA,SRIDHAR; HETRICK,JOEL; LI,ZHE; JENSEN,BRIAN D.; KRYGOWSKI,THOMAS W.; MILLER,SAMUEL L.; BARNES,STEPHEN MATTHEW; BURG,MICHAEL STANLEY

    2000-04-10T23:59:59.000Z

    Although many actuators employing electrostatic comb drives have been demonstrated in a laboratory environment, widespread acceptance in mass produced microelectromechanical systems (MEMS) may be limited due to issues associated with low drive force, large real estate demands, high operating voltages, and reliability concerns due to stiction. On the other hand, comb drives require very low drive currents, offer predictable response, and are highly compatible with the fabrication technology. The expand the application space and facilitate the widespread deployment of self-actuated MEMS, a new class of advanced actuation systems has been developed that maintains the highly desirable aspects of existing components, while significantly diminishing the issues that could impede large scale acceptance. In this paper, the authors will present low-voltage electrostatic actuators that offer a dramatic increase in force over conventional comb drive designs. In addition, these actuators consume only a small fraction of the chip area previously used, yielding significant gains in power density. To increase the stroke length of these novel electrostatic actuators, the authors have developed highly efficient compliant stroke amplifiers. The coupling of compact, high-force actuators with fully compliant displacement multipliers sets a new paradigm for highly integrated microelectromechanical systems.

  20. HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS

    E-Print Network [OSTI]

    Taylor, C.

    2011-01-01T23:59:59.000Z

    D. C. 'Niobium-Titanium Superconducting Material s ', in S.Nb -Ti and Nb3Sn superconductors. , •• ,""" s. S. Clamp, Tie14, 1982 HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS C.

  1. Evaluation of electropolished stainless steel electrodes for use in DC high voltage photoelectron guns

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    BastaniNejad, Mahzad; Elmustafa, Abdelmageed A.; Forman, Eric; Covert, Steven; Hansknecht, John; Hernandez-Garcia, Carlos; Poelker, Matthew; Das, Lopa; Kelley, Michael; Williams, Phillip

    2015-07-01T23:59:59.000Z

    DC high voltage photoelectron guns are used to produce polarized electron beams for accelerator-based nuclear and high-energy physics research. Low-level field emission (~nA) from the cathode electrode degrades the vacuum within the photogun and reduces the photoelectron yield of the delicate GaAs-based photocathode used to produce the electron beams. High-level field emission (>?A) can cause significant damage the photogun. To minimize field emission, stainless steel electrodes are typically diamond-paste polished, a labor-intensive process often yielding field emission performance with a high degree of variability, sample to sample. As an alternative approach and as comparative study, the performance of electrodes electropolishedmore »by conventional commercially available methods is presented. Our observations indicate the electropolished electrodes exhibited less field emission upon the initial application of high voltage, but showed less improvement with gas conditioning compared to the diamond-paste polished electrodes. In contrast, the diamond-paste polished electrodes responded favorably to gas conditioning, and ultimately reached higher voltages and field strengths without field emission, compared to electrodes that were only electropolished. The best performing electrode was one that was both diamond-paste polished and electropolished, reaching a field strength of 18.7 MV/m while generating less than 100 pA of field emission. The speculate that the combined processes were the most effective at reducing both large and small scale topography. However, surface science evaluation indicates topography cannot be the only relevant parameter when it comes to predicting field emission performance.« less

  2. Charge and fluence lifetime measurements of a dc high voltage GaAs photogun at high average current

    SciTech Connect (OSTI)

    J. Grames, R. Suleiman, P.A. Adderley, J. Clark, J. Hansknecht, D. Machie, M. Poelker, M.L. Stutzman

    2011-04-01T23:59:59.000Z

    GaAs-based dc high voltage photoguns used at accelerators with extensive user programs must exhibit long photocathode operating lifetime. Achieving this goal represents a significant challenge for proposed high average current facilities that must operate at tens of milliamperes or more. This paper describes techniques to maintain good vacuum while delivering beam, and techniques that minimize the ill effects of ion bombardment, the dominant mechanism that reduces photocathode yield of a GaAs-based dc high voltage photogun. Experimental results presented here demonstrate enhanced lifetime at high beam currents by: (a) operating with the drive laser beam positioned away from the electrostatic center of the photocathode, (b) limiting the photocathode active area to eliminate photoemission from regions of the photocathode that do not support efficient beam delivery, (c) using a large drive laser beam to distribute ion damage over a larger area, and (d) by applying a relatively low bias voltage to the anode to repel ions created within the downstream beam line. A combination of these techniques provided the best total charge extracted lifetimes in excess of 1000 C at dc beam currents up to 9.5 mA, using green light illumination of bulk GaAs inside a 100 kV photogun.

  3. Degradation of Photovoltaic Modules Under High Voltage Stress in the Field: Preprint

    SciTech Connect (OSTI)

    del Cueto, J. A.; Rummel, S. R.

    2010-08-01T23:59:59.000Z

    The degradation in performance for eight photovoltaic (PV) modules stressed at high voltage (HV) is presented. Four types of modules--tandem-junction and triple-junction amorphous thin-film silicon, plus crystalline and polycrystalline silicon modules--were tested, with a pair of each biased at opposite polarities. They were deployed outdoors between 2001 and 2009 with their respective HV leakage currents through the module encapsulation continuously monitored with a data acquisition system, along with air temperature and relative humidity. For the first 5 years, all modules were biased continuously at fixed 600 VDC, day and night. In the last 2 years, the modules were step-bias stressed cyclically up and down in voltage between 10 and 600 VDC, in steps of tens to hundreds of volts. This allowed characterization of leakage current versus voltage under a large range of temperature and moisture conditions, facilitating determination of leakage paths. An analysis of the degradation is presented, along with integrated leakage charge. In HV operation: the bulk silicon modules degraded either insignificantly or at rates of 0.1%/yr higher than modules not biased at HV; for the thin-film silicon modules, the added loss rates are insignificant for one type, or 0.2%/yr-0.6%/yr larger for the other type.

  4. DC BUFFERING AND FLOATING CURRENT FOR A HIGH VOLTAGE IMB APPLICATION

    SciTech Connect (OSTI)

    J.L. Morrison

    2014-08-01T23:59:59.000Z

    An interface technique for the latest generation of the Impedance Measurement Box (IMB) has been conceived to enable measurement of impedance spectra for battery modules up to 300V. A 300V capable or higher IMB is an enabling technology for in-situ diagnostics within electric vehicle charging stations or battery back-ups within power distribution sub-stations. It is possible that the existing IMB can be adapted via a 300V interface module to a test battery with voltage significantly greater than 50V. Recently a new concept was conceived for the calibration, algorithm and electronics of the IMB. That algorithm and calibration for that concept have been physically validated. The principal feature of the new electronics is the floating current source excitation of the battery under test. The single ended current excitation of the battery under test, used in the 50V IMB, requires that the negative terminal of the test battery must be the analog ground for the IMB. The new floating current technique allows the test battery to be fully high impedance isolated for a measurement. That isolation will improve IMB noise immunity and enable interrogation of cells internal to a battery module. All these techniques still use the same rapid concept for impedance measurement with the IMB. The purpose of this disclosure is to provide an overview of the analytical validation for three concepts to interface the floating current excitation to a high voltage battery. Recursive simulation models were used in different test scenarios to validate the various new concepts. The analysis will show that it is possible to interface the floating signal current to obtain an impedance measurement on a high voltage test battery. Additionally, the analysis will investigate stress seen by electronics while testing a 300V battery.

  5. Design Techniques for High Speed Low Voltage and Low Power Non-Calibrated Pipeline Analog to Digital Converters

    E-Print Network [OSTI]

    Assaad, Rida Shawky

    2011-02-22T23:59:59.000Z

    DESIGN TECHNIQUES FOR HIGH SPEED LOW VOLTAGE AND LOW POWER NON-CALIBRATED PIPELINE ANALOG TO DIGITAL CONVERTERS A Dissertation by RIDA SHAWKY ASSAAD Submitted to the Office of Graduate Studies of Texas A&M University... in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2009 Major Subject: Electrical Engineering DESIGN TECHNIQUES FOR HIGH SPEED LOW VOLTAGE AND LOW POWER NON-CALIBRATED PIPELINE ANALOG TO DIGITAL...

  6. A Fusing Switch for Fault Suppression in the SNS High Voltage Converter Modulators

    SciTech Connect (OSTI)

    Kemp, Mark A.; Burkhart, Craig; Nguyen, Minh N.; /SLAC; Anderson, David E.; /Oak Ridge

    2009-08-03T23:59:59.000Z

    The High Voltage Converter Modulators (HVCMs) at the Spallation Neutron Source (SNS) have operated in excess of a combined 250,000 hours. Performance and reliability improvements to the HVCM are ongoing to increase modulator availability as accelerator system demands increase. There is a relatively large amount of energy storage in the HVCMs, {approx}180 kJ. This energy has the potential to dump into unsuppressed faults, cause damage, and increase the time to repair. The 'fusing switch' concept involves isolation of this stored energy from the location of the most common faults. This paper introduces this concept and its application to the HVCMs.

  7. The commercial development of water repellent coatings for high voltage transmission lines

    SciTech Connect (OSTI)

    Hunter, Scott Robert [ORNL

    2013-10-01T23:59:59.000Z

    The purpose of the Cooperative Research and Development Agreement (CRADA) between UT-Battelle, LLC and Southwire Company was to jointly develop a low cost, commercially viable, water-repellant anti-icing coating system for high voltage transmission lines. Icing of power lines and other structures caused by freezing rain events occurs annually in the United States, and leads to severe and prolonged power outages. These outages cause untold economic and personal distress for many American families and businesses. Researchers at the Department of Energy s Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee have previously developed a set of superhydrophobic coatings with remarkable anti-icing properties that could potentially be sprayed or painted onto high-tension power lines and pylons. These coatings drastically reduce ice accumulation on these structures during freezing rain events. The project involved obtaining technical input, supplies and test high voltage cables from Southwire, along with the joint development of anti-icing coating techniques, which would result in a commercial license agreement between Southwire and ORNL, and potentially other companies requiring water repellent anti-icing coatings.

  8. The commercial development of water repellent coatings for high voltage transmission lines

    SciTech Connect (OSTI)

    Hunter, S. R. [ORNL] [ORNL; Daniel, A. [Southwire Company] [Southwire Company

    2013-10-31T23:59:59.000Z

    The purpose of the Cooperative Research and Development Agreement (CRADA) between UT-Battelle, LLC and Southwire Company was to jointly develop a low cost, commercially viable, water-repellant anti-icing coating system for high voltage transmission lines. Icing of power lines and other structures caused by freezing rain events occurs annually in the United States, and leads to severe and prolonged power outages. These outages cause untold economic and personal distress for many American families and businesses. Researchers at the Department of Energy?s Oak Ridge National Laboratory (ORNL) in Oak Ridge, Tennessee have previously developed a set of superhydrophobic coatings with remarkable anti-icing properties that could potentially be sprayed or painted onto high-tension power lines and pylons. These coatings drastically reduce ice accumulation on these structures during freezing rain events. The project involved obtaining technical input, supplies and test high voltage cables from Southwire, along with the joint development of anti-icing coating techniques, which would result in a commercial license agreement between Southwire and ORNL, and potentially other companies requiring water repellent anti-icing coatings.

  9. Measurement of low radioactivity background in a high voltage cable by high resolution inductively coupled plasma mass spectrometry

    SciTech Connect (OSTI)

    Vacri, M. L. di; Nisi, S.; Balata, M. [Gran Sasso National Laboratory, Chemistry Service, SS 17bis km 18.910, 67100 Assergi (Aq) (Italy)] [Gran Sasso National Laboratory, Chemistry Service, SS 17bis km 18.910, 67100 Assergi (Aq) (Italy)

    2013-08-08T23:59:59.000Z

    The measurement of naturally occurring low level radioactivity background in a high voltage (HV) cable by high resolution inductively coupled plasma mass spectrometry (HR ICP MS) is presented in this work. The measurements were performed at the Chemistry Service of the Gran Sasso National Laboratory. The contributions to the radioactive background coming from the different components of the heterogeneous material were separated. Based on the mass fraction of the cable, the whole contamination was calculated. The HR ICP MS results were cross-checked by gamma ray spectroscopy analysis that was performed at the low background facility STELLA (Sub Terranean Low Level Assay) of the LNGS underground lab using HPGe detectors.

  10. Stabilization of turbulent lifted jet flames assisted by pulsed high voltage discharge

    SciTech Connect (OSTI)

    Criner, K.; Cessou, A.; Louiche, J.; Vervisch, P. [CORIA UMR 6614 CNRS-Universite et INSA de Rouen, University of Rouen, 76801 Saint Etienne du Rouvray (France)

    2006-01-01T23:59:59.000Z

    To reduce fuel consumption or the pollutant emissions of combustion (furnaces, aircraft engines, turbo-reactors, etc.), attempts are made to obtain lean mixture combustion regimes. These lead to poor stability of the flame. Thus, it is particularly interesting to find new systems providing more flexibility in aiding flame stabilization than the usual processes (bluff-body, stabilizer, quarl, swirl, etc.). The objective is to enlarge the stability domain of flames while offering flexibility at a low energy cost. Evidence is presented that the stabilization of a turbulent partially premixed flame of more than 10 kW can be enhanced by pulsed high-voltage discharges with power consumption less than 0.1% of the power of the flame. The originality of this work is to demonstrate that very effective stabilization of turbulent flames is obtained when high-voltage pulses with very short rise times are used (a decrease by 300% in terms of liftoff height for a given exit jet velocity can be reached) and to provide measurements of minimum liftoff height obtained with discharge over a large range of the stability domain of the lifted jet flame.

  11. Journal of Magnetism and Magnetic Materials 281 (2004) 272275 Effects of high magnetic field annealing on texture and

    E-Print Network [OSTI]

    Garmestani, Hamid

    Journal of Magnetism and Magnetic Materials 281 (2004) 272­275 Effects of high magnetic field annealing on texture and magnetic properties of FePd D.S. Lia, *, H. Garmestania , Shi-shen Yanb , M China c National High Magnetic Field Laboratory, Florida State University, 1800 East Paul Dirac Drive

  12. C-H surface diamond field effect transistors for high temperature (400?°C) and high voltage (500?V) operation

    SciTech Connect (OSTI)

    Kawarada, H., E-mail: kawarada@waseda.jp [Faculty of Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Institute of Nano-Science and Nano-Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Kagami Memorial Laboratory for Material Science and Technology, Waseda University, Shinjuku, Tokyo 169-0051 (Japan); Tsuboi, H.; Naruo, T.; Yamada, T.; Xu, D.; Daicho, A.; Saito, T. [Faculty of Science and Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Hiraiwa, A. [Institute of Nano-Science and Nano-Engineering, Waseda University, Shinjuku, Tokyo 169-8555 (Japan)

    2014-07-07T23:59:59.000Z

    By forming a highly stable Al{sub 2}O{sub 3} gate oxide on a C-H bonded channel of diamond, high-temperature, and high-voltage metal-oxide-semiconductor field-effect transistor (MOSFET) has been realized. From room temperature to 400?°C (673?K), the variation of maximum drain-current is within 30% at a given gate bias. The maximum breakdown voltage (V{sub B}) of the MOSFET without a field plate is 600?V at a gate-drain distance (L{sub GD}) of 7 ?m. We fabricated some MOSFETs for which V{sub B}/L{sub GD}?>?100?V/?m. These values are comparable to those of lateral SiC or GaN FETs. The Al{sub 2}O{sub 3} was deposited on the C-H surface by atomic layer deposition (ALD) at 450?°C using H{sub 2}O as an oxidant. The ALD at relatively high temperature results in stable p-type conduction and FET operation at 400?°C in vacuum. The drain current density and transconductance normalized by the gate width are almost constant from room temperature to 400?°C in vacuum and are about 10 times higher than those of boron-doped diamond FETs.

  13. High voltage power supply systems for electron beam and plasma technologies. Its new element base

    SciTech Connect (OSTI)

    Dermengi, P.G.; Kureghan, A.S.; Pokrovsky, S.V.; Tchvanov, V.A.

    1994-12-31T23:59:59.000Z

    Transforming technique and high voltage technique supplementing each other more and more unite in indivisible constructions of modern apparatuses and systems and applicated in modern technologies providing its high efficiency. Specially worked out, ecologically clean, inertial, inflammable perfluororganic liquid is used in elements and electronic apparatuses simultaneously as insulating and cooling media. This liquid is highly fluid, fills tiny cavities in construction elements and in the places of high concentration of losses, where maximum local overheating of active parts or apparatus constructions takes place, it transforms to boiling state with highly intensive taking off of heat energy from cooled surface point. For instance, being cooled by mentioned perfluororganic liquid, copper wire can conduct current to 50 A/mm{sup 2} density, but in ordinary conditions of transformers, reactors and busses, current density can reach only few Amperes. Possibility of considerable increasing of current density, that is reached by means of intensive cooling, provided by worked out liquid, and taking into account its incredibly high insulating features (liquid has electric strength to 50 KV/mm) allows to provide optimum heat regime of active parts of transformers. reactors, condenser, semiconductor devices, resistors, construction elements and electrotechnical apparatus in general. Particularly high effect of decreasing of weight and dimensions characteristics of elements and electrotechnical apparatus in general can be reached under working out of special constructions of each element and apparatus details, adapted to use of mentioned liquid as insulating and cooling media.

  14. High temperature magnetic properties of SmCo5/-Fe(Co) bulk nanocomposite magnets

    E-Print Network [OSTI]

    Liu, J. Ping

    High temperature magnetic properties of SmCo5/-Fe(Co) bulk nanocomposite magnets Chuanbing Rong://apl.aip.org/about/rights_and_permissions #12;High temperature magnetic properties of SmCo5/a-Fe(Co) bulk nanocomposite magnets Chuanbing Rong,1 containing no heavy rare earths for power applications, SmCo5/Fe bulk nanocomposite magnets with enhanced

  15. Health-hazard evaluation report HETA 81-415-1385, High Voltage Maintenance Corporation, Mentor, Ohio

    SciTech Connect (OSTI)

    Kominsky, J.R.; Lipscomb, J.

    1983-10-01T23:59:59.000Z

    In September 1981 the National Institute for Occupational Safety and Health (NIOSH) was requested to evaluate exposures to polychlorinated biphenyls (PCBs) and to chlorinated benzenes and ethanes for electricians at High Voltage Maintenance (HVM) Corp., Mentor, Ohio. The HVM Corp. services electrical power transformers and capacitors on a contract basis with the work performed both in the field and at the Mentor facilities. On the basis of the data collected, NIOSH concludes that workers were exposed to potentially toxic concentrations of airborne 1,1,1-trichloroethane and PCBs. Significant PCB contamination of work surfaces demonstrate a potential for continued exposure to PCBs via skin contact and ingestion. PCB blood levels also indicate excessive absorption of PCBs. Recommendations for decontamination of the buildings and exposure controls are offered in Section VIII of this report.

  16. Process for measuring degradation of sulfur hexafluoride in high voltage systems

    DOE Patents [OSTI]

    Sauers, I.

    1985-04-23T23:59:59.000Z

    This invention is a method of detecting the presence of toxic and corrosive by-products in high voltage systems produced by electrically induced degradation of SF/sub 6/ insulating gas in the presence of certain impurities. It is an improvement over previous methods because it is extremely sensitive, detecting by-products present in parts per billion concentrations, and because the device employed is of a simple design and takes advantage of the by-products natural affinity for fluoride ions. The method employs an ion-molecule reaction cell in which negative ions of the by-products are produced by fluorine attachment. These ions are admitted to a negative ion mass spectrometer and identified by their spectra. This spectrometry technique is an improvement over conventional techniques because the negative ion peaks are strong and not obscured by a major ion spectra of the SF/sub 6/ component as is the case in positive ion mass spectrometry.

  17. Process for measuring degradation of sulfur hexafluoride in high voltage systems

    DOE Patents [OSTI]

    Sauers, Isidor (Knoxville, TN)

    1986-01-01T23:59:59.000Z

    This invention is a method of detecting the presence of toxic and corrosive by-products in high voltage systems produced by electrically induced degradation of SF.sub.6 insulating gas in the presence of certain impurities. It is an improvement over previous methods because it is extremely sensitive, detecting by-products present in parts per billion concentrations, and because the device employed is of a simple design and takes advantage of the by-products natural affinity for fluoride ions. The method employs an ion-molecule reaction cell in which negative ions of the by-products are produced by fluorine attachment. These ions are admitted to a negative ion mass spectrometer and identified by their spectra. This spectrometry technique is an improvement over conventional techniques because the negative ion peaks are strong and not obscured by a major ion spectra of the SF.sub.6 component as is the case in positive ion mass spectrometry.

  18. Materials Physics Applications: The National High Magnetic Field...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Pulsed Magnetic Field Laboratory of the NHMFL in the form of a 1.4 GVA inertial storage motor-generator for high field pulsed magnets. In addition to the 60 Tesla Long Pulse Magnet...

  19. FINE-GRAINED NANOCRYSTALLINE SILICON P-LAYER FOR HIGH OPEN CIRCUIT VOLTAGE A-SI:H SOLAR CELLS

    E-Print Network [OSTI]

    Deng, Xunming

    FINE-GRAINED NANOCRYSTALLINE SILICON P-LAYER FOR HIGH OPEN CIRCUIT VOLTAGE A-SI:H SOLAR CELLS of Michigan, Ann Arbor, MI 48109, USA ABSTRACT Hydrogenated amorphous silicon (a-Si:H) single- junction solar). It is found that the p-layer that leads to high Voc a-Si:H solar cells is a mixed-phase material that contains

  20. High magnetic field ohmically decoupled non-contact technology

    DOE Patents [OSTI]

    Wilgen, John (Oak Ridge, TN) [Oak Ridge, TN; Kisner, Roger (Knoxville, TN) [Knoxville, TN; Ludtka, Gerard (Oak Ridge, TN) [Oak Ridge, TN; Ludtka, Gail (Oak Ridge, TN) [Oak Ridge, TN; Jaramillo, Roger (Knoxville, TN) [Knoxville, TN

    2009-05-19T23:59:59.000Z

    Methods and apparatus are described for high magnetic field ohmically decoupled non-contact treatment of conductive materials in a high magnetic field. A method includes applying a high magnetic field to at least a portion of a conductive material; and applying an inductive magnetic field to at least a fraction of the conductive material to induce a surface current within the fraction of the conductive material, the surface current generating a substantially bi-directional force that defines a vibration. The high magnetic field and the inductive magnetic field are substantially confocal, the fraction of the conductive material is located within the portion of the conductive material and ohmic heating from the surface current is ohmically decoupled from the vibration. An apparatus includes a high magnetic field coil defining an applied high magnetic field; an inductive magnetic field coil coupled to the high magnetic field coil, the inductive magnetic field coil defining an applied inductive magnetic field; and a processing zone located within both the applied high magnetic field and the applied inductive magnetic field. The high magnetic field and the inductive magnetic field are substantially confocal, and ohmic heating of a conductive material located in the processing zone is ohmically decoupled from a vibration of the conductive material.

  1. High voltage-high power components for large space power distribution systems

    SciTech Connect (OSTI)

    Renz, D.D.

    1984-08-01T23:59:59.000Z

    For over a decade, Lewis Research Center has been developing space power components. These components include a family of bi-polar power switching transistors, fast switching power diodes, heat pipe cooled high-frequency transformers and inductors, high frequency conduction cooled transformers, high powerhigh frequency capacitors, remote power controllers and rotary power transfer devices. Many of these components such as the power switching transistors, power diodes and the high frequency capacitor are commercially available. All the other components have been developed to the prototype level. Series resonant dc/dc converters have been built to the 25 kW level.

  2. Mechanisms of deflagration-to-detonation transition under initiation by high-voltage nanosecond discharges

    SciTech Connect (OSTI)

    Rakitin, Aleksandr E.; Starikovskii, Andrei Yu. [Physics of Nonequilibrium Systems Lab, Moscow Institute of Physics and Technology, 9 Institutski Lane, Dolgoprudny 141700 (Russian Federation)

    2008-10-15T23:59:59.000Z

    An experimental study of detonation initiation in a stoichiometric propane-oxygen mixture by a high-voltage nanosecond gas discharge was performed in a detonation tube with a single-cell discharge chamber. The discharge study performed in this geometry showed that three modes of discharge development were realized under the experimental conditions: a spark mode with high-temperature channel formation, a streamer mode with nonuniform gas excitation, and a transient mode. Under spark and transient initiation, simultaneous ignition inside the discharge channel occurred, forming a shock wave and leading to a conventional deflagration-to-detonation transition (DDT) via an adiabatic explosion. The DDT length and time at 1 bar of initial pressure in the square smooth tube with a 20-mm transverse size amounted to 50 mm and 50{mu}s, respectively. The streamer mode of discharge development at an initial pressure of 1 bar resulted in nonuniform mixture excitation and a successful DDT via a gradient mechanism, which was confirmed by high-speed time resolved ICCD imaging. The gradient mechanism implied a longer DDT time of 150{mu}s, a DDT run-up distance of 50 mm, and an initiation energy of 1 J, which is two orders of magnitude less than the direct initiation energy for a planar detonation under these conditions. (author)

  3. Permanent magnet design for high-speed superconducting bearings

    DOE Patents [OSTI]

    Hull, J.R.; Uherka, K.L.; Abdoud, R.G.

    1996-09-10T23:59:59.000Z

    A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure is disclosed. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing. 9 figs.

  4. Permanent magnet design for high-speed superconducting bearings

    DOE Patents [OSTI]

    Hull, John R. (5519 S. Bruner, Hinsdale, IL 60521); Uherka, Kenneth L. (830 Ironwood, Frankfort, IL 60423); Abdoud, Robert G. (13 Country Oaks La., Barrington Hills, IL 60010)

    1996-01-01T23:59:59.000Z

    A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing.

  5. An Ultra-Compact Marx-Type High-Voltage Generator

    SciTech Connect (OSTI)

    Goerz, D; Ferriera, T; Nelson, D; Speer, R; Wilson, M

    2001-06-15T23:59:59.000Z

    This paper discusses the design of an ultra-compact, Marx-type, high-voltage generator. This system incorporates high-performance components that are closely coupled and integrated into an extremely compact assembly. Low profile, custom ceramic capacitors with coplanar extended electrodes provide primary energy storage. Low-inductance, spark-gap switches incorporate miniature gas cavities imbedded within the central region of the annular shaped capacitors, with very thin dielectric sections separating the energy storage capacitors. Carefully shaped electrodes and insulator surfaces are used throughout to minimize field enhancements, reduce fields at triple-point regions, and enable operation at stress levels closer to the intrinsic breakdown limits of the dielectric materials. Specially shaped resistors and inductors are used for charging and isolation during operation. Forward-coupling ceramic capacitors are connected across successive switch-capacitor-switch stages to assist in switching. Pressurized SF, gas is used for electrical insulation in the spark-gap switches and throughout the unit. The pressure housing is constructed entirely of dielectric materials, with segments that interlock with the low-profile switch bodies to provide an integrated support structure for all of the components. This ultra-compact Marx generator employs a modular design that can be sized as needed for a particular application. Units have been assembled with 4, 10, and 30 stages and operated at levels up to 100 kV per stage.

  6. A three-level buck converter to regulate a high-voltage DC-to-AC inverter

    E-Print Network [OSTI]

    Schrock, Kenneth C

    2008-01-01T23:59:59.000Z

    A three-level buck converter is designed and analyzed, and shown to be suitable as a high-voltage down converter as a pre-regulation stage for a 600 watt DC-to-AC power inverter. Topology selection for the inverter is ...

  7. Magnetic nanowire based high resolution magnetic force microscope probes

    E-Print Network [OSTI]

    Qin, Lu-Chang

    -resolution magnetic force microscope probes using preformed magnetic nanowires. Nickel and cobalt nanowires produced by electrodeposition were directly assembled onto the tip of a commercial atomic force microscope cantilever

  8. Redesign of the H-Bridge Switch Plate of the SNS High Voltage Converter Modulator

    SciTech Connect (OSTI)

    Kemp, M.A.; Burkhart, C.; Nguyen, M.N.; /SLAC; Anderson, D.E.; /Oak Ridge

    2009-05-07T23:59:59.000Z

    The 1-MW High Voltage Converter Modulators [1] have operated in excess of 250,000 hours at the Spallation Neutron Source. Increased demands on the accelerator performance require increased modulator reliability. An effort is underway at SLAC National Accelerator Laboratory to redesign the modulator H-bridge switch plate with the goals of increasing reliability and performance [2]. The major difference between the SLAC design and the existing design is the use of press-pack IGBTs. Compared to other packaging options, these IGBTs have been shown to have increased performance in pulsed-power applications, have increased cooling capability, and do not fragment and disassemble during a fault event. An overview of the SLAC switch plate redesign is presented. Design steps including electrical modeling of the modulator and H-bridge, development of an integrated IGBT clamping mechanism, and fault tests are discussed. Experimental results will be presented comparing electrical performance of the SLAC switch plate to the existing switchplate under normal and fault conditions.

  9. Assessment of research directions for high-voltage direct-current power systems. Final report

    SciTech Connect (OSTI)

    Long, W F

    1982-09-01T23:59:59.000Z

    High voltage direct current (HVDC) power transmission continues to be an emerging technology nearly thirty years after its introduction into modern power systems. To date its use has been restricted to either specialized applications having identifiable economic advantages (e.g., breakeven distance) or, rarely, applications where decoupling is needed. Only recently have the operational advantages (e.g., power modulation) of HVDC been realized on operating systems. A research project whose objective was to identify hardware developments and, where appropriate, system applications which can exemplify cost and operational advantages of integrated ac/dc power systems is discussed. The three principal tasks undertaken were: assessment of equipment developments; quantification of operational advantages; and interaction with system planners. Interest in HVDC power transmission has increased markedly over the past several years, and many new systems are now being investigated. The dissemination of information about HVDC, including specifically the symposium undertaken for Task 3, is a critical factor in fostering an understanding of this important adjunct to ac power transmission.

  10. High performance magnetic bearing systems using high temperature superconductors

    DOE Patents [OSTI]

    Abboud, Robert G. (Barrington Hills, IL)

    1998-01-01T23:59:59.000Z

    A magnetic bearing apparatus and a method for providing at least one stabilizing force in a magnetic bearing structure with a superconducting magnetic assembly and a magnetic assembly, by providing a superconducting magnetic member in the superconducting magnetic assembly with a plurality of domains and arranging said superconducting magnetic member such that at least one domain has a domain C-axis vector alignment angularly disposed relative to a reference axis of the magnetic member in the magnetic assembly.

  11. High performance magnetic bearing systems using high temperature superconductors

    DOE Patents [OSTI]

    Abboud, R.G.

    1998-05-05T23:59:59.000Z

    Disclosed are a magnetic bearing apparatus and a method for providing at least one stabilizing force in a magnetic bearing structure with a superconducting magnetic assembly and a magnetic assembly, by providing a superconducting magnetic member in the superconducting magnetic assembly with a plurality of domains and arranging said superconducting magnetic member such that at least one domain has a domain C-axis vector alignment angularly disposed relative to a reference axis of the magnetic member in the magnetic assembly. 7 figs.

  12. Optical pumping magnetic resonance in high magnetic fields: Characterization of nuclear relaxation during pumping

    E-Print Network [OSTI]

    Augustine, Mathew P.

    Optical pumping magnetic resonance in high magnetic fields: Characterization of nuclear relaxation during pumping Matthew P. Augustine and Kurt W. Zilm Department of Chemistry, Yale University, New Haven exchange with optically pumped Rb vapor is investigated in high magnetic field. Operation in a high field

  13. High voltage power supply. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect (OSTI)

    NONE

    1996-03-01T23:59:59.000Z

    The bibliography contains citations of selected patents concerning high voltage power supply systems and devices. References describe direct and high current power supplies, microprocessor controlled and programmable systems, amplifiers, power supply stabilization, power circuit protection, feedback control, and pulse modulation. Applications cover laser systems, x-ray tubes, electrophoresis, video apparatus, radar and electronic warfare systems, helmet mounted display, and electrosurgery. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  14. High voltage power supply. (Latest citations from the US Patent bibliographic file with exemplary claims). Published Search

    SciTech Connect (OSTI)

    NONE

    1997-06-01T23:59:59.000Z

    The bibliography contains citations of selected patents concerning high voltage power supply systems and devices. References describe direct and high current power supplies, microprocessor controlled and programmable systems, amplifiers, power supply stabilization, power circuit protection, feedback control, and pulse modulation. Applications cover laser systems, x-ray tubes, electrophoresis, video apparatus, radar and electronic warfare systems, helmet mounted display, and electrosurgery. (Contains 50-250 citations and includes a subject term index and title list.) (Copyright NERAC, Inc. 1995)

  15. Graphene-oxide-coated LiNi0.5Mn1.5O4 as high voltage cathode for lithium ion batteries with high energy

    E-Print Network [OSTI]

    Zhou, Chongwu

    Graphene-oxide-coated LiNi0.5Mn1.5O4 as high voltage cathode for lithium ion batteries with high Since Sony rst commercialized lithium ion batteries in the early 1990s, the market for lithium ion of the great success of lithium ion battery technology developed for portable electronic devices, higher

  16. Applications of high-speed dust injection to magnetic fusion

    SciTech Connect (OSTI)

    Wang, Zhehui [Los Alamos National Laboratory; Li, Yangfang [Max Planck Institute for Extraterrestrial Physics, Germany

    2012-08-08T23:59:59.000Z

    It is now an established fact that a significant amount of dust is produced in magnetic fusion devices due to plasma-wall interactions. Dust inventory must be controlled, in particular for the next-generation steady-state fusion machines like ITER, as it can pose significant safety hazards and degrade performance. Safety concerns are due to tritium retention, dust radioactivity, toxicity, and flammability. Performance concerns include high-Z impurities carried by dust to the fusion core that can reduce plasma temperature and may even induce sudden termination of the plasma. We have recognized that dust transport, dust-plasma interactions in magnetic fusion devices can be effectively studied experimentally by injection of dust with known properties into fusion plasmas. Other applications of injected dust include diagnosis of fusion plasmas and edge localized mode (ELM)'s pacing. In diagnostic applications, dust can be regarded as a source of transient neutrals before complete ionization. ELM's pacing is a promising scheme to prevent disruptions and type I ELM's that can cause catastrophic damage to fusion machines. Different implementation schemes are available depending on applications of dust injection. One of the simplest dust injection schemes is through gravitational acceleration of dust in vacuum. Experiments at Los Alamos and Princeton will be described, both of which use piezoelectric shakers to deliver dust to plasma. In Princeton experiments, spherical particles (40 micron) have been dropped in a systematic and reproducible manner using a computer-controlled piezoelectric bending actuator operating at an acoustic (0,2) resonance. The circular actuator was constructed with a 2.5 mm diameter central hole. At resonance ({approx} 2 kHz) an applied sinusoidal voltage has been used to control the flux of particles exiting the hole. A simple screw throttle located {approx}1mm above the hole has been used to set the magnitude of the flux achieved for a given voltage. Particle fluxes ranging from a few tens of particle per second up to thousands of particles per second have been achieved using this simple device. To achieve higher dust injection speed, another key consideration is how to accelerate dust at controlled amount. In addition to gravity, other possible acceleration mechanisms include electrostatic, electromagnetic, gas-dragged, plasma-dragged, and laser-ablation-based acceleration. Features and limitations of the different acceleration methods will be discussed. We will also describe laboratory experiments on dust acceleration.

  17. Characterization of the Li(Si)/CoS(2) couple for a high-voltage, high-power thermal battery

    SciTech Connect (OSTI)

    GUIDOTTI,RONALD A.; REINHARDT,FREDERICK W.

    2000-02-01T23:59:59.000Z

    In order to determined the capabilities of a thermal battery with high-voltage and high-power requirements, a detailed characterization of the candidate LiSi/LiCl-LiBr-LiF/CoS{sub 2} electrochemical couple was conducted. The rate capability of this system was investigated using 0.75 inch-dia. and 1.25 inch-dia. single and multiple cells under isothermal conditions, where the cells were regularly pulsed at increasingly higher currents. Limitations of the electronic loads and power supplies necessitated using batteries to obtain the desired maximum current densities possible for this system. Both 1.25 inch-dia. and 3 inch-dia. stacks were used with the number of cells ranging from 5 to 20. Initial tests involved 1.25 inch-dia. cells, where current densities in excess of 15 A/cm{sup 2} (>200 W/cm{sup 2}) were attained with 20-cell batteries during 1-s pulses. In subsequent follow-up tests with 3 inch-dia., 10-cell batteries, ten 400-A 1-s pulses were delivered over an operating period often minutes. These tests formed the foundation for subsequent full-sized battery tests with 125 cells with this chemistry.

  18. Improving magnet designs with high and low field regions

    E-Print Network [OSTI]

    Bjørk, R; Smith, A; Pryds, N

    2014-01-01T23:59:59.000Z

    A general scheme for increasing the difference in magnetic flux density between a high and a low magnetic field region by removing unnecessary magnet material is presented. This is important in, e.g., magnetic refrigeration where magnet arrays has to deliver high field regions in close proximity to low field regions. Also, a general way to replace magnet material with a high permeability soft magnetic material where appropriate is discussed. As an example these schemes are applied to a two dimensional concentric Halbach cylinder design resulting in a reduction of the amount of magnet material used by 42% while increasing the difference in flux density between a high and a low field region by 45%.

  19. High voltage capability electrical coils insulated with materials containing SF.sub.6 gas

    DOE Patents [OSTI]

    Lanoue, Thomas J. (Muncie, IN); Zeise, Clarence L. (Penn Township, Allegheny County, PA); Wagenaar, Loren (Muncie, IN); Westervelt, Dean C. (Acme, PA)

    1988-01-01T23:59:59.000Z

    A coil is made having a plurality of layers of adjacent metal conductor windings subject to voltage stress, where the windings have insulation therebetween containing a small number of minute disposed throughout its cross-section, where the voids are voids filled with SF.sub.6 gas to substitute for air or other gaseous materials in from about 60% to about 95% of the cross-sectional void volume in the insulation, thus incorporating an amount of SF.sub.6 gas in the cross-section of the insulation effective to substantially increase corona inception voltages.

  20. AlGaN/GaN High-Electron-Mobility Transistor Employing an Additional Gate for High-Voltage Switching Applications

    E-Print Network [OSTI]

    Seo, Kwang Seok

    AlGaN/GaN High-Electron-Mobility Transistor Employing an Additional Gate for High-Voltage Switching 16, 2004; accepted May 10, 2005; published September 8, 2005) We have proposed and fabricated an AlGaN/GaN: GaN, AlGaN, HEMT, switch 1. Introduction GaN has attracted attention for high-power and high

  1. Calculation and measurement of a neutral air flow velocity impacting a high voltage capacitor with asymmetrical electrodes

    SciTech Connect (OSTI)

    Malík, M., E-mail: michal.malik@tul.cz; Primas, J.; Kopecký, V.; Svoboda, M. [Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec, 461 17 (Czech Republic)] [Faculty of Mechatronics, Informatics and Interdisciplinary Studies, Technical University of Liberec, Liberec, 461 17 (Czech Republic)

    2014-01-15T23:59:59.000Z

    This paper deals with the effects surrounding phenomenon of a mechanical force generated on a high voltage asymmetrical capacitor (the so called Biefeld-Brown effect). A method to measure this force is described and a formula to calculate its value is also given. Based on this the authors derive a formula characterising the neutral air flow velocity impacting an asymmetrical capacitor connected to high voltage. This air flow under normal circumstances lessens the generated force. In the following part this velocity is measured using Particle Image Velocimetry measuring technique and the results of the theoretically calculated velocity and the experimentally measured value are compared. The authors found a good agreement between the results of both approaches.

  2. Current-voltage-time characteristics of the reactive Ar/N{sub 2} high power impulse magnetron sputtering discharge

    SciTech Connect (OSTI)

    Magnus, F.; Sveinsson, O. B.; Olafsson, S. [Science Institute, University of Iceland, Dunhaga 3, Reykjavik IS-107 (Iceland); Gudmundsson, J. T. [Science Institute, University of Iceland, Dunhaga 3, Reykjavik IS-107 (Iceland); University of Michigan-Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240 (China)

    2011-10-15T23:59:59.000Z

    The discharge current and voltage waveforms have been measured in a reactive high power impulse magnetron sputtering (HiPIMS) Ar/N{sub 2} discharge with a Ti target for 400 {mu}s long pulses. We observe that the current waveform in the reactive Ar/N{sub 2} HiPIMS discharge is highly dependent on the pulse repetition frequency, unlike the non-reactive Ar discharge. The current is found to increase significantly as the frequency is lowered. This is attributed to an increase in the secondary electron emission yield during the self-sputtering phase, when the nitride forms on the target at low frequencies. In addition, self-sputtering runaway occurs at lower discharge voltages when nitrogen is added to the discharge. This illustrates the crucial role of self-sputtering in the behavior of the reactive HiPIMS discharge.

  3. Performance Analysis of a Hybrid Asymmetric Multilevel Inverter for High Voltage Active Power Filter Applications

    E-Print Network [OSTI]

    Catholic University of Chile (Universidad Católica de Chile)

    . of Electrical Engineering (2) Dept. of Electrical Engineering Universidad de Concepción Universidad Católica de and reactive power in power distribution systems [1], [2], [3]. Although many technical papers related power to compensate converter losses and to keep the dc voltages constant. Simulated results for steady

  4. Alternative p-doped hole transport material for low operating voltage and high efficiency organic light-emitting diodes

    SciTech Connect (OSTI)

    Murawski, Caroline, E-mail: caroline.murawski@iapp.de; Fuchs, Cornelius; Hofmann, Simone; Leo, Karl [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Str. 1, 01062 Dresden (Germany); Gather, Malte C. [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Str. 1, 01062 Dresden (Germany); SUPA, School of Physics and Astronomy, University of St Andrews, North Haugh, St Andrews, KY16 9SS Scotland (United Kingdom)

    2014-09-15T23:59:59.000Z

    We investigate the properties of N,N?-[(Diphenyl-N,N?-bis)9,9,-dimethyl-fluoren-2-yl]-benzidine (BF-DPB) as hole transport material (HTL) in organic light-emitting diodes (OLEDs) and compare BF-DPB to the commonly used HTLs N,N,N?,N?-tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD), 2,2?,7,7?-tetrakis(N,N?-di-p-methylphenylamino)-9,9?-spirobifluorene (Spiro-TTB), and N,N?-di(naphtalene-1-yl)-N,N?-diphenylbenzidine (NPB). The influence of 2,2?-(perfluoronaphthalene-2,6-diylidene)dimalononitrile (F6-TCNNQ p-dopant) concentration in BF-DPB on the operation voltage and efficiency of red and green phosphorescent OLEDs is studied; best results are achieved at 4?wt. % doping. Without any light extraction structure, BF-DPB based red (green) OLEDs achieve a luminous efficacy of 35?.1?lm/W (74?.0?lm/W) at 1000?cd/m{sup 2} and reach a very high brightness of 10?000 cd/m{sup 2} at a very low voltage of 3.2 V (3.1 V). We attribute this exceptionally low driving voltage to the high ionization potential of BF-DPB which enables more efficient hole injection from BF-DPB to the adjacent electron blocking layer. The high efficiency and low driving voltage lead to a significantly lower luminous efficacy roll-off compared to the other compounds and render BF-DPB an excellent HTL material for highly efficient OLEDs.

  5. Effect of High-Voltage Heterojunction Bipolar Transistor Collector Design on f(T) and f(MAX)

    SciTech Connect (OSTI)

    Ashby, C.I.H.; Baca, A.G.; Chang, P.C.; Hietala, V.M.

    1999-03-02T23:59:59.000Z

    High-speed InGaP/GaAs heterojunction bipolar transistors (HBTs) for high-voltage circuit applications have been investigated. In order to obtain ideal IV characteristics, a lightly doped (N{sub DC} = 7.5 x 10{sup 15} cm{sup {minus}3}) thick (W{sub C} = 3.5 {micro}m) layer of GaAs was used as the collector layer. The devices fabricated have shown breakdown voltage exceeding 65 V. Device operated at up to a 60V bias, which is the highest operating voltage reported up to date for single heterojunction HBTs. Peak {line_integral}{sub T} and {line_integral}{sub MAX} values of 18 GHz and 29 GHz, respectively, have been achieved on a device with emitter area of 4x 12.5 {micro}m{sup 2}. Both {line_integral}{sub T} and {line_integral}{sub Max} degrades with higher bias, which is related to the elongation of the collector depletion width.

  6. Frontiers in Planetary and Stellar Magnetism through High-Performance...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hwang, project co-PI Frontiers in Planetary and Stellar Magnetism through High-Performance Computing PI Name: Jonathan Aurnou PI Email: aurnou@ucla.edu Institution: University...

  7. Cryocooler applications for high-temperature superconductor magnetic bearings.

    SciTech Connect (OSTI)

    Niemann, R. C.

    1998-05-22T23:59:59.000Z

    The efficiency and stability of rotational magnetic suspension systems are enhanced by the use of high-temperature superconductor (HTS) magnetic bearings. Fundamental aspects of the HTS magnetic bearings and rotational magnetic suspension are presented. HTS cooling can be by liquid cryogen bath immersion or by direct conduction, and thus there are various applications and integration issues for cryocoolers. Among the numerous cryocooler aspects to be considered are installation; operating temperature; losses; and vacuum pumping.

  8. Bose Glass of Quasiparticles in Doped Quantum Magnet Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Bose Glass of Quasiparticles in Doped Quantum Magnet Gregory S. Boebinger, National High Magnetic. This BEC can localize in the presence of disorder caused by Br- doping to form a Bose Glass. The BEC-Bose Glass (BEC-BG) transition can be carefully controlled by magnetic field, allowing us to sensitively

  9. Optical voltage reference

    DOE Patents [OSTI]

    Rankin, R.; Kotter, D.

    1994-04-26T23:59:59.000Z

    An optical voltage reference for providing an alternative to a battery source is described. The optical reference apparatus provides a temperature stable, high precision, isolated voltage reference through the use of optical isolation techniques to eliminate current and impedance coupling errors. Pulse rate frequency modulation is employed to eliminate errors in the optical transmission link while phase-lock feedback is employed to stabilize the frequency to voltage transfer function. 2 figures.

  10. NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSVOLUME 12 N0. 1 2005

    E-Print Network [OSTI]

    Weston, Ken

    , and Geochemistry 14 MAGNET SCIENCE & TECHNOLOGY Engineering Materials, Instrumentation, and Magnet Technology Magnet Science & Technology 42 7 including Engineering Materials, Instrumentation, and Magnet TechnologyNATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSVOLUME 12 · N0. 1 · 2005 OPERATED BY: FLORIDA STATE

  11. Analysis of system wide distortion in an integrated power system utilizing a high voltage DC bus and silicon carbide power devices

    E-Print Network [OSTI]

    Fallier, William F. (William Frederick)

    2007-01-01T23:59:59.000Z

    This research investigates the distortion on the electrical distribution system for a high voltage DC Integrated Power System (IPS). The analysis was concentrated on the power supplied to a propulsion motor driven by an ...

  12. An accurate online calibration system based on combined clamp-shape coil for high voltage electronic current transformers

    SciTech Connect (OSTI)

    Li, Zhen-hua; Li, Hong-bin; Zhang, Zhi [CEEE of Huazhong University of Science and Technology, Wuhan 430074 (China) [CEEE of Huazhong University of Science and Technology, Wuhan 430074 (China); State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Wuhan 430074 (China)

    2013-07-15T23:59:59.000Z

    Electronic transformers are widely used in power systems because of their wide bandwidth and good transient performance. However, as an emerging technology, the failure rate of electronic transformers is higher than that of traditional transformers. As a result, the calibration period needs to be shortened. Traditional calibration methods require the power of transmission line be cut off, which results in complicated operation and power off loss. This paper proposes an online calibration system which can calibrate electronic current transformers without power off. In this work, the high accuracy standard current transformer and online operation method are the key techniques. Based on the clamp-shape iron-core coil and clamp-shape air-core coil, a combined clamp-shape coil is designed as the standard current transformer. By analyzing the output characteristics of the two coils, the combined clamp-shape coil can achieve verification of the accuracy. So the accuracy of the online calibration system can be guaranteed. Moreover, by employing the earth potential working method and using two insulating rods to connect the combined clamp-shape coil to the high voltage bus, the operation becomes simple and safe. Tests in China National Center for High Voltage Measurement and field experiments show that the proposed system has a high accuracy of up to 0.05 class.

  13. MAGNET ENGINEERING AND TEST RESULTS OF THE HIGH FIELD MAGNET R AND D PROGRAM AT BNL.

    SciTech Connect (OSTI)

    COZZOLINO,J.; ANERELLA,M.; ESCALLIER,J.; GANETIS,G.; GHOSH,A.; GUPTA,R.; HARRISON,M.; JAIN,A.; MARONE,A.; MURATORE,J.; PARKER,B.; SAMPSON,W.; SOIKA,R.; WANDERER,P.

    2002-08-04T23:59:59.000Z

    The Superconducting Magnet Division at Brookhaven National Laboratory (BNL) has been carrying out design, engineering, and technology development of high performance magnets for future accelerators. High Temperature Superconductors (HTS) play a major role in the BNL vision of a few high performance interaction region (IR) magnets that would be placed in a machine about ten years from now. This paper presents the engineering design of a ''react and wind'' Nb{sub 3}Sn magnet that will provide a 12 Tesla background field on HTS coils. In addition, the coil production tooling as well as the most recent 10-turn R&D coil test results will be discussed.

  14. Lithium pellet injection into high pressure magnetically confined plasmas

    E-Print Network [OSTI]

    Böse, Brock (Brock Darrel)

    2010-01-01T23:59:59.000Z

    The ablation of solid pellets injected into high temperature magnetically confined plasmas is characterized by rapid oscillations in the ablation rate, and the formation of field aligned filaments in the ablatant. High ...

  15. Magnetization and magnetostriction in highly magnetostrictive materials

    SciTech Connect (OSTI)

    Thoelke, J.B.

    1993-05-26T23:59:59.000Z

    The majority of this research has been in developing a model to describe the magnetostrictive properties of Terfenol-D, Tb{sub 1{minus}x}Dy{sub x}Fe{sub y} (x = 0.7-0.75 and y = 1.8--2.0), a rare earth-iron alloy which displays much promise for use in device applications. In the first chapter an introduction is given to the phenomena of magnetization and magnetostriction. The magnetic processes responsible for the observed magnetic properties of materials are explained. An overview is presented of the magnetic properties of rare earths, and more specifically the magnetic properties of Terfenol-D. In the second chapter, experimental results are presented on three composition of Tb{sub 1{minus}x}Dy{sub x}Fe{sub y} with x = 0.7, y= 1.9, 1.95, and x= 0.73, y= 1.95. The data were taken for various levels of prestress to show the effects of composition and microstructure on the magnetic and magnetostrictive properties of Terfenol-D. In the third chapter, a theoretical model is developed based on the rotation of magnetic domains. The model is used to explain the magnetic and magnetostrictive properties of Terfenol-D, including the observed negative strictions and large change in strain. The fourth chapter goes on to examine the magnetic properties of Terfenol-D along different crystallographic orientations. In the fifth chapter initial data are presented on the time dependence of magnetization in nickel.

  16. Study of static reactive power compensators for high-voltage power systems. Final report, May 12, 1981

    SciTech Connect (OSTI)

    Byerly, R.T.; Bennon, R.J.; Taylor, E.R. Jr.; Poznaniak, D.T.

    1981-05-12T23:59:59.000Z

    A general study of the application of static VAR compensators (SVC's) to high-voltage transmission systems has been performed. Considerable emphasis has been placed on improvements to synchronous stability, and it is shown that SVC's can provide significant benefits in terms of damping for unstable modes of oscillation and increases in transient stability limits. This report includes descriptions of static VAR compensators, technical and economic comparisons of different compensators, compensator models for system studies, comprehensive study procedures, study results for two small-scale systems, and guidelines for SVC application.

  17. Recommended practice for fire protection for electric generating plants and high voltage direct current converter stations. 2005 ed.

    SciTech Connect (OSTI)

    NONE

    2005-07-01T23:59:59.000Z

    The standard outlines fire safety recommendations for gas, oil, coal, and alternative fuel electric generating plants including high voltage direct current converter stations and combustion turbine units greater than 7500 hp used for electric generation. Provisions apply to both new and existing plants. The document provides fire prevention and fire protection recommendations for the: safety of construction and operating personnel; physical integrity of plant components; and continuity of plant operations. The 2005 edition includes revisions and new art that clarify existing provisions. 5 annexes.

  18. Magnetic lens apparatus for use in high-resolution scanning electron microscopes and lithographic processes

    DOE Patents [OSTI]

    Crewe, Albert V. (Dune Acres, IN)

    2000-01-01T23:59:59.000Z

    Disclosed are lens apparatus in which a beam of charged particlesis brought to a focus by means of a magnetic field, the lens being situated behind the target position. In illustrative embodiments, a lens apparatus is employed in a scanning electron microscopeas the sole lens for high-resolution focusing of an electron beam, and in particular, an electron beam having an accelerating voltage of from about 10 to about 30,000 V. In one embodiment, the lens apparatus comprises an electrically-conducting coil arranged around the axis of the beam and a magnetic pole piece extending along the axis of the beam at least within the space surrounded by the coil. In other embodiments, the lens apparatus comprises a magnetic dipole or virtual magnetic monopole fabricated from a variety of materials, including permanent magnets, superconducting coils, and magnetizable spheres and needles contained within an energy-conducting coil. Multiple-array lens apparatus are also disclosed for simultaneous and/or consecutive imaging of multiple images on single or multiple specimens. The invention further provides apparatus, methods, and devices useful in focusing charged particle beams for lithographic processes.

  19. Table 1. Design specifications of ultra-high speed PM motor. Supply voltage (V) 12

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    by the engine to compress inlet air to the engine cylinder. The supercharger electrically driven by the UHS combustion engine with a belt from a crankshaft, and compress the air flow to the engine cylinder, for example, magnet eddy-current loss that is proportional to square of the operating frequency

  20. Mitigated-force carriage for high magnetic field environments

    DOE Patents [OSTI]

    Ludtka, Gerard M; Ludtka, Gail M; Wilgen, John B; Murphy, Bart L

    2014-05-20T23:59:59.000Z

    A carriage for high magnetic field environments includes a first work-piece holding means for holding a first work-piece, the first work-piece holding means being disposed in an operable relationship with a work-piece processing magnet having a magnetic field strength of at least 1 Tesla. The first work-piece holding means is further disposed in operable connection with a second work-piece holding means for holding a second work-piece so that, as the first work-piece is inserted into the magnetic field, the second work-piece is simultaneously withdrawn from the magnetic field, so that an attractive magnetic force imparted on the first work-piece offsets a resistive magnetic force imparted on the second work-piece.

  1. Microwave magnetic dynamics in highly conducting magnetic nanostructures

    SciTech Connect (OSTI)

    Kostylev, M.; Ivanov, E.; Samarin, S. [School of Physics M013, The University of Western Australia, Crawley, WA 6009 (Australia); Ding, J.; Adeyeye, A. O. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)

    2014-05-07T23:59:59.000Z

    We performed low-noise broadband microstrip ferromagnetic resonance (FMR) measurements of the resonant modes of an array of metallic ferromagnetic nanostripes. In addition to a strong signal of the fundamental mode, we observed up to five weak-amplitude peaks in the field-resolved FMR traces, depending on the frequency. These higher-order absorption peaks have been theoretically identified as due to resonant excitation of odd and even standing spin waves across the direction of confinement in array plane (i.e., across the stripe width). The theory we developed suggests that the odd modes become excited in the spatially uniform microwave field of the FMR setup due to the large conductivity of metals. This promotes excitation of large-amplitude eddy currents in the sample by the incident microwave magnetic field and ultimately results in excitation of these modes. Following this theory, we found that the eddy current contribution is present only for patterned materials and when the microwave magnetic field is incident on one surface of sample surface, as it is in the case of a microstrip FMR.

  2. Improving the performance of stainless-steel DC high voltage photoelectron gun cathode electrodes via gas conditioning with helium or krypton

    SciTech Connect (OSTI)

    Bastaninejad, Mahzad [ODU; Elmustafa, Abdelmageed [ODU; Forman, Eric I. [JLAB; Clark, James [JLAB; Covert, Steven R. [JLAB; Grames, Joseph M. [JLAB; Hansknecht, John C. [JLAB; Hernandez-Garcia, Carlos [JLAB; Poelker, Bernard [JLAB; Suleiman, Riad S. [JLAB

    2014-10-01T23:59:59.000Z

    Gas conditioning was shown to eliminate field emission from cathode electrodes used inside DC high voltage photoelectron guns, thus providing a reliable means to operate photoguns at higher voltages and field strengths. Measurements and simulation results indicate that gas conditioning eliminates field emission from cathode electrodes via two mechanisms: sputtering and implantation, with the benefits of implantation reversed by heating the electrode. We have studied five stainless steel electrodes (304L and 316LN) that were polished to approximately 20 nm surface roughness using diamond grit, and evaluated inside a high voltage apparatus to determine the onset of field emission as a function of voltage and field strength. The field emission characteristics of each electrode varied significantly upon the initial application of voltage but improved to nearly the same level after gas conditioning using either helium or krypton, exhibiting less than 10 pA field emission at ?225 kV bias voltage with a 50 mm cathode/anode gap, corresponding to a field strength of ~13 MV/m. Field emission could be reduced with either gas, but there were conditions related to gas choice, voltage and field strength that were more favorable than others.

  3. HIGH VOLTAGE TERMINAL IN COSY ELECTRON COOLER V.A. Chekavinskiy, E.A. Bekhtenev, I.A. Gusev, M.N. Kondaurov, V.R. Kozak, E.A. Kuper, V.R.

    E-Print Network [OSTI]

    Kozak, Victor R.

    HIGH VOLTAGE TERMINAL IN COSY ELECTRON COOLER V.A. Chekavinskiy, E.A. Bekhtenev, I.A. Gusev, M acceleration system ­ high voltage terminal. All power and control electronics were placed in a single isolated Voltage Terminal (HVT) in electron cooler is intended for generating of electron cooling beam

  4. Mechanical design of a high field common coil magnet

    SciTech Connect (OSTI)

    Caspi, S.; Chow, K.; Dietderich, D.; Gourlay, S.; Gupta, R.; McInturff, A.; Millos, G.; Scanlan, R.

    1999-03-18T23:59:59.000Z

    A common coil design for high field 2-in-1 accelerator magnets has been previously presented as a 'conductor-friendly' option for high field magnets applicable for a Very Large Hadron Collider. This paper presents the mechanical design for a 14 tesla 2-in-1 dipole based on the common coil design approach. The magnet will use a high current density Nb{sub 3}Sn conductor. The design addresses mechanical issues particular to the common coil geometry: horizontal support against coil edges, vertical preload on coil faces, end loading and support, and coil stresses and strains. The magnet is the second in a series of racetrack coil magnets that will provide experimental verification of the common coil design approach.

  5. Quantum Vacuum Friction in Highly Magnetized Neutron Stars

    E-Print Network [OSTI]

    Arnaud Dupays; Carlo Rizzo; Dimitar Bakalov; Giovanni F. Bignami

    2008-04-25T23:59:59.000Z

    In this letter we calculate the energy loss of highly magnetized neutron star due to friction with quantum vacuum, namely Quantum Vacuum Friction (QVF). Taking into account one-loop corrections in the effective Heisenberg-Euler Lagrangian of the light-light interaction, we derive an analytic expression for QVF allowing us to consider magnetic field at the surface of the star as high as $10^{11} $T. In the case of magnetars with high magnetic field above the QED critical field, we show that the energy loss by QVF dominates the energy loss process. This has important consequences, in particular on the inferred value of the magnetic field. This also indicates the need for independent measurements of magnetic field, energy loss rate, and of the braking index to fully characterize magnetars.

  6. High-Frequency Resistivity of Soft Magnetic Granular Films

    E-Print Network [OSTI]

    permeability was measured and used to predict the power loss expected when granular films are used as high-frequency core materials for film inductors. The power loss is predicted to be lower than that of commercial Ni permeability, power loss, soft magnetic film. I. INTRODUCTION SOFT magnetic granular films are considered ideal

  7. Nanosecond pulsed electric fields (nsPEFs) low cost generator design using power MOSFET and Cockcroft-Walton multiplier circuit as high voltage DC source

    SciTech Connect (OSTI)

    Sulaeman, M. Y.; Widita, R. [Department of Physics, Nuclear Physics and Biophysics Research Division, Faculty of Mathematics and Natural Science, Institut Teknologi Bandung, Bandung (Indonesia)

    2014-09-30T23:59:59.000Z

    Purpose: Non-ionizing radiation therapy for cancer using pulsed electric field with high intensity field has become an interesting field new research topic. A new method using nanosecond pulsed electric fields (nsPEFs) offers a novel means to treat cancer. Not like the conventional electroporation, nsPEFs able to create nanopores in all membranes of the cell, including membrane in cell organelles, like mitochondria and nucleus. NsPEFs will promote cell death in several cell types, including cancer cell by apoptosis mechanism. NsPEFs will use pulse with intensity of electric field higher than conventional electroporation, between 20–100 kV/cm and with shorter duration of pulse than conventional electroporation. NsPEFs requires a generator to produce high voltage pulse and to achieve high intensity electric field with proper pulse width. However, manufacturing cost for creating generator that generates a high voltage with short duration for nsPEFs purposes is highly expensive. Hence, the aim of this research is to obtain the low cost generator design that is able to produce a high voltage pulse with nanosecond width and will be used for nsPEFs purposes. Method: Cockcroft-Walton multiplier circuit will boost the input of 220 volt AC into high voltage DC around 1500 volt and it will be combined by a series of power MOSFET as a fast switch to obtain a high voltage with nanosecond pulse width. The motivation using Cockcroft-Walton multiplier is to acquire a low-cost high voltage DC generator; it will use capacitors and diodes arranged like a step. Power MOSFET connected in series is used as voltage divider to share the high voltage in order not to damage them. Results: This design is expected to acquire a low-cost generator that can achieve the high voltage pulse in amount of ?1.5 kV with falltime 3 ns and risetime 15 ns into a 50? load that will be used for nsPEFs purposes. Further detailed on the circuit design will be explained at presentation.

  8. The National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    of Contents Table of contents cHaPTeR 1 The Year in Review 6 cHaPTeR 3 Magnets & Materials 44 cHaPTeR 4 User The year in Review cHaPTeR 1 The Year in Review by Gregory Boebinger, MagLab Director 2012: Another

  9. Coexisting Superconductivity and Magnetism in UCoGe Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Coexisting Superconductivity and Magnetism in UCoGe Gregory S. Boebinger, National High Magnetic focused on the coexistence of superconductivity and ferromagnetism, including UGe2, URhGe, and UCoGe. In these materials, superconductivity develops below the ferromagnetic Curie temperature TC without destroying

  10. High precision magnetic susceptibility of novel magnets and superconductors

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHigh School football High School football Fancy footworke ne rgy data

  11. Magnetic Fields in High-Density Stellar Matter

    E-Print Network [OSTI]

    German Lugones

    2005-04-20T23:59:59.000Z

    I briefly review some aspects of the effect of magnetic fields in the high density regime relevant to neutron stars, focusing mainly on compact star structure and composition, superconductivity, combustion processes, and gamma ray bursts.

  12. Cerium-Based Magnets: Novel High Energy Permanent Magnet Without Critical Elements

    SciTech Connect (OSTI)

    None

    2012-01-01T23:59:59.000Z

    REACT Project: Ames Laboratory will develop a new class of permanent magnets based on the more commonly available element cerium for use in both EVs and renewable power generators. Cerium is 4 times more abundant and significantly less expensive than the rare earth element neodymium, which is frequently used in today’s most powerful magnets. Ames Laboratory will combine other metal elements with cerium to create a new magnet that can remain stable at the high temperatures typically found in electric motors. This new magnetic material will ultimately be demonstrated in a prototype electric motor, representing a cost-effective and efficient alternative to neodymium-based motors.

  13. High magnetic field processing of liquid crystalline polymers

    DOE Patents [OSTI]

    Smith, Mark E. (Los Alamos, NM); Benicewicz, Brian C. (Los Alamos, NM); Douglas, Elliot P. (Los Alamos, NM)

    1998-01-01T23:59:59.000Z

    A process of forming bulk articles of oriented liquid crystalline thermoset material, the material characterized as having an enhanced tensile modulus parallel to orientation of an applied magnetic field of at least 25 percent greater than said material processed in the absence of a magnetic field, by curing a liquid crystalline thermoset precursor within a high strength magnetic field of greater than about 2 Tesla, is provided, together with a resultant bulk article of a liquid crystalline thermoset material, said material processed in a high strength magnetic field whereby said material is characterized as having a tensile modulus parallel to orientation of said field of at least 25 percent greater than said material processed in the absence of a magnetic field.

  14. High magnetic field processing of liquid crystalline polymers

    DOE Patents [OSTI]

    Smith, M.E.; Benicewicz, B.C.; Douglas, E.P.

    1998-11-24T23:59:59.000Z

    A process of forming bulk articles of oriented liquid crystalline thermoset material, the material characterized as having an enhanced tensile modulus parallel to orientation of an applied magnetic field of at least 25 percent greater than said material processed in the absence of a magnetic field, by curing a liquid crystalline thermoset precursor within a high strength magnetic field of greater than about 2 Tesla, is provided, together with a resultant bulk article of a liquid crystalline thermoset material, said material processed in a high strength magnetic field whereby said material is characterized as having a tensile modulus parallel to orientation of said field of at least 25 percent greater than said material processed in the absence of a magnetic field.

  15. Study of HTS Wires at High Magnetic Fields

    SciTech Connect (OSTI)

    Turrioni, D.; Barzi, E.; Lamm, M.J.; Yamada, R.; Zlobin, A.V.; Kikuchi, A.; /Fermilab

    2009-01-01T23:59:59.000Z

    Fermilab is working on the development of high field magnet systems for ionization cooling of muon beams. The use of high temperature superconducting (HTS) materials is being considered for these magnets using Helium refrigeration. Critical current (I{sub c}) measurements of HTS conductors were performed at FNAL and at NIMS up to 28 T under magnetic fields at zero to 90 degree with respect to the sample face. A description of the test setups and results on a BSCCO-2223 tape and second generation (2G) coated conductors are presented.

  16. Very low 1/f barrier noise in sputtered MgO magnetic tunnel junctions with high tunneling magnetoresistance

    SciTech Connect (OSTI)

    Feng, J. F.; Chen, J. Y.; Kurt, H.; Coey, J. M. D. [CRANN and School of Physics, Trinity College, Dublin 2 (Ireland)

    2012-12-15T23:59:59.000Z

    Low frequency 1/f barrier noise has been investigated in sputtered MgO magnetic tunnel junctions (MTJs) with a tunneling magnetoresistance ratio of up to 330% at room temperature. The lowest normalized noise parameter {alpha} of the tunnel barrier reaches 2.5 Multiplication-Sign 10{sup -12}-2.1 Multiplication-Sign 10{sup -11} {mu}m{sup 2}, which is comparable to that found in MTJs with the MgO barrier grown by MBE or electron-beam evaporation. This normalized barrier noise is almost bias independent in the voltage range of up to {+-}1.2 V. The low noise level and high voltage stability may reflect the high quality of the sputtered MgO with a uniform distribution of defects in the MgO layer.

  17. Cryogenic properties of dispersion strengthened copper for high magnetic fields

    SciTech Connect (OSTI)

    Toplosky, V. J.; Han, K.; Walsh, R. P. [National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Swenson, C. A. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2014-01-27T23:59:59.000Z

    Cold deformed copper matrix composite conductors, developed for use in the 100 tesla multi-shot pulsed magnet at the National High Magnetic Field Laboratory (NHMFL), have been characterized. The conductors are alumina strengthened copper which is fabricated by cold drawing that introduces high dislocation densities and high internal stresses. Both alumina particles and high density of dislocations provide us with high tensile strength and fatigue endurance. The conductors also have high electrical conductivities because alumina has limited solubility in Cu and dislocations have little scattering effect on conduction electrons. Such a combination of high strength and high conductivity makes it an excellent candidate over other resistive magnet materials. Thus, characterization is carried out by tensile testing and fully reversible fatigue testing. In tensile tests, the material exceeds the design criteria parameters. In the fatigue tests, both the load and displacement were measured and used to control the amplitude of the tests to simulate the various loading conditions in the pulsed magnet which is operated at 77 K in a non-destructive mode. In order to properly simulate the pulsed magnet operation, strain-controlled tests were more suitable than load controlled tests. For the dispersion strengthened coppers, the strengthening mechanism of the aluminum oxide provided better tensile and fatigue properties over convention copper.

  18. Magnetic Refrigeration Technology for High Efficiency Air Conditioning

    SciTech Connect (OSTI)

    Boeder, A; Zimm, C

    2006-09-30T23:59:59.000Z

    Magnetic refrigeration was investigated as an efficient, environmentally friendly, flexible alternative to conventional residential vapor compression central air conditioning systems. Finite element analysis (FEA) models of advanced geometry active magnetic regenerator (AMR) beds were developed to minimize bed size and thus magnet mass by optimizing geometry for fluid flow and heat transfer and other losses. Conventional and magnetocaloric material (MCM) regenerator fabrication and assembly techniques were developed and advanced geometry passive regenerators were built and tested. A subscale engineering prototype (SEP) magnetic air conditioner was designed, constructed and tested. A model of the AMR cycle, combined with knowledge from passive regenerator experiments and FEA results, was used to design the regenerator beds. A 1.5 Tesla permanent magnet assembly was designed using FEA and the bed structure and plenum design was extensively optimized using FEA. The SEP is a flexible magnetic refrigeration platform, with individually instrumented beds and high flow rate and high frequency capability, although the current advanced regenerator geometry beds do not meet performance expectations, probably due to manufacturing and assembly tolerances. A model of the AMR cycle was used to optimize the design of a 3 ton capacity magnetic air conditioner, and the system design was iterated to minimize external parasitic losses such as heat exchanger pressure drop and fan power. The manufacturing cost for the entire air conditioning system was estimated, and while the estimated SEER efficiency is high, the magnetic air conditioning system is not cost competitive as currently configured. The 3 ton study results indicate that there are other applications where magnetic refrigeration is anticipated to have cost advantages over conventional systems, especially applications where magnetic refrigeration, through the use of its aqueous heat transfer fluid, could eliminate intermediate heat exchangers or oil distribution issues found in traditional vapor compression systems.

  19. A High-Frequency Resonant Inverter Topology With Low-Voltage Stress

    E-Print Network [OSTI]

    Rivas, Juan M.

    This paper presents a new switched-mode resonant inverter, which we term the inverter, that is well suited to operation at very high frequencies and to rapid on/off control. Features of this inverter topology include low ...

  20. Charge-pump voltage converter

    DOE Patents [OSTI]

    Brainard, John P. (Albuquerque, NM); Christenson, Todd R. (Albuquerque, NM)

    2009-11-03T23:59:59.000Z

    A charge-pump voltage converter for converting a low voltage provided by a low-voltage source to a higher voltage. Charge is inductively generated on a transfer rotor electrode during its transit past an inductor stator electrode and subsequently transferred by the rotating rotor to a collector stator electrode for storage or use. Repetition of the charge transfer process leads to a build-up of voltage on a charge-receiving device. Connection of multiple charge-pump voltage converters in series can generate higher voltages, and connection of multiple charge-pump voltage converters in parallel can generate higher currents. Microelectromechanical (MEMS) embodiments of this invention provide a small and compact high-voltage (several hundred V) voltage source starting with a few-V initial voltage source. The microscale size of many embodiments of this invention make it ideally suited for MEMS- and other micro-applications where integration of the voltage or charge source in a small package is highly desirable.

  1. Conceptual Design of the 45 T Hybrid Magnet at the Nijmegen High Field Magnet Laboratory

    E-Print Network [OSTI]

    Wiegers, SAJ; Bird, M D; Rook, J; Perenboom, J A A J; Wiegers, S A J; Bonito-Oliva, A; den Ouden, A

    2010-01-01T23:59:59.000Z

    A 45 T Hybrid Magnet System is being developed at the Nijmegen High Field Magnet Laboratory as part of the Nijmegen Center for Advanced Spectroscopy. The 45 T Hybrid Magnet System will be used in combination with far-infra-red light produced by a Free Electron Laser under construction directly adjacent to the High Field Magnet Laboratory. The superconducting outsert magnet will consist of three CICC coils wound on a single coil form, using Nb3Sn strands. A test program for strand and cable qualification is underway. The CICC will carry 13 kA and the coils will produce 12 T on axis field in a 600 mm warm bore. The nominal operating temperature will be 4.5 K maintained with forced-flow supercritical helium. The insert magnet will produce 33 T at 40 kA in a 32 mm bore consuming 20 MW, and will consist of four coils. The insert magnet will be galvanically and mechanically isolated from the outsert magnet. Complete system availability for users is expected in 2014. In this paper we will report on the conceptual de...

  2. Tuning magnetic disorder in diluted magnetic semiconductors using high fields to 89 Tesla

    SciTech Connect (OSTI)

    Crooker, Scott A [Los Alamos National Laboratory; Samarth, Nitin [PENN STATE U

    2008-01-01T23:59:59.000Z

    We describe recent and ongoing studies at the National High Magnetic Field Laboratory at Los Alamos using the new '100 Tesla Multi-Shot Magnet', which is presently delivering fields up to {approx}89 T during its commissioning. We discuss the first experiments performed in this magnet system, wherein the linewidth of low-temperature photoluminescence spectra was used to directly reveal the degree of magnetic alloy disorder 'seen' by excitons in single Zn{sub 0.80}Cd{sub 0.22}Mn{sub 0.08}Se quantum wells. The magnetic potential landscape in II-VI diluted magnetic semiconductors (DMS) is typically smoothed when the embedded Mn{sup 2+} spins align in an applied field. However, an important (but heretofore untested) prediction of current models of compositional disorder is that magnetic alloy fluctuations in many DMS compounds should increase again in very large magnetic fields approaching 100 T. We observed precisely this increase above {approx}70 T, in agreement with a simple model of magnetic alloy disorder.

  3. Proceedings of the seventh international conference on high voltage electron microscopy

    SciTech Connect (OSTI)

    Fisher, R.M.; Gronsky, R.; Westmacott, K.H. (eds.)

    1983-01-01T23:59:59.000Z

    Eight-four papers are arranged under the following headings: high resolution, techniques and instrumentation, radiation effects, in-situ and phase transformations, minerals and ceramics, and semiconductors and thin films. Twenty-three papers were abstracted separately for the data base; three of the remainder had previously been abstracted. (DLC)

  4. Peak Power Bi-directional Transfer From High Speed Flywheel to Electrical Regulated Bus Voltage System

    E-Print Network [OSTI]

    Szabados, Barna

    life cycle. A reduced life cycle will translate into high maintenance costs since the batteries have devices capable of a minimum power of 400 W/kg, energy of 200 Wh/kg, a life cycle of 2500 at a cost vehicle during both acceleration and regenerative braking. The life cycle of the electric vehicle

  5. Development of fast cooling pulsed magnets at the Wuhan National High Magnetic Field Center

    SciTech Connect (OSTI)

    Peng, Tao; Sun, Quqin; Zhao, Jianlong; Jiang, Fan; Li, Liang; Xu, Qiang [Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan (China)] [Wuhan National High Magnetic Field Center, Huazhong University of Science and Technology, Wuhan (China); Herlach, Fritz [Department of Physics, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)] [Department of Physics, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)

    2013-12-15T23:59:59.000Z

    Pulsed magnets with fast cooling channels have been developed at the Wuhan National High Magnetic Field Center. Between the inner and outer sections of a coil wound with a continuous length of CuNb wire, G10 rods with cross section 4 mm × 5 mm were inserted as spacers around the entire circumference, parallel to the coil axis. The free space between adjacent rods is 6 mm. The liquid nitrogen flows freely in the channels between these rods, and in the direction perpendicular to the rods through grooves provided in the rods. For a typical 60 T pulsed magnetic field with pulse duration of 40 ms, the cooling time between subsequent pulses is reduced from 160 min to 35 min. Subsequently, the same technology was applied to a 50 T magnet with 300 ms pulse duration. The cooling time of this magnet was reduced from 480 min to 65 min.

  6. Epidemiologic study of Holstein dairy cow performance and reproduction near a high-voltage direct - current powerline

    SciTech Connect (OSTI)

    Martin, F.B.; Bender, A.; Steuernagel, G.; Robinson, R.A.; Revsbech, R.; Sorensen, D.K.; Williamson, N.; Williams, A.

    1986-01-01T23:59:59.000Z

    The development and operation of a high-voltage direct-current (HVDC) transmission line in rural Minnesota generated public concern over potential adverse effects to nearby residents and their livestock. Electrical parameters near an HVDC line decline rapidly with distance, but effects on ambient space charge have been detected out to 1 mile. To identify potential adverse effects of HVDC line operation on livestock, case-control and cohort study methods were used to examine various indices of Holstein performance in relation to distance from the line and the onset of line operation. It was believed that these indices would reflect changes in physiologic function or overt health effects that might arise from the HVDC environment. High-quality performance data from existing Dairy Herd Improvement Association (DHIA) records were obtained for 97% of qualifying herds located within 10 miles of the line. The large number of animals and years of observation provided high statistical power to detect even small systematic changes in performance. No significant differences in milk production or reproductive capacity were associated with presumed exposure to the HVDC environment. The absence of measurable effects in a large sentinel animal population may have implications for the assessment of human health risks related to HVDC transmission lines.

  7. High average power magnetic modulator for metal vapor lasers

    DOE Patents [OSTI]

    Ball, Don G. (Livermore, CA); Birx, Daniel L. (Oakley, CA); Cook, Edward G. (Livermore, CA); Miller, John L. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    A three-stage magnetic modulator utilizing magnetic pulse compression designed to provide a 60 kV pulse to a copper vapor laser at a 4.5 kHz repetition rate is disclosed. This modulator operates at 34 kW input power. The circuit includes a step up auto transformer and utilizes a rod and plate stack construction technique to achieve a high packing factor.

  8. SUPER HIGH-SPEED MINIATURIZED PERMANENT MAGNET SYNCHRONOUS MOTOR

    E-Print Network [OSTI]

    Wu, Thomas

    with the design of permanent magnet synchronous motors (PMSM) to operate at super-high speed with high efficiency. The designed and fabricated PMSM was successfully tested to run upto 210,000 rpm The designed PMSM has 2000 W concept of electrical machines. After that, the modeling of PMSM for dynamic simulation is provided

  9. Pulsed Current-Voltage-Temperature Characteristics of AlGaN/GaN High Electron Mobility Transistor under Isothermal Conditions

    E-Print Network [OSTI]

    Seo, Kwang Seok

    , such as current collapse (power slump), the self-heating effect and the power scaling problem. In this paper, we have studied the self-heating effect using pulsed current-voltage (IV) and current- voltage self-heating affects the AlGaN/GaN HEMT's operation. It can be thought that a reason for the power

  10. Coil Winding for the Series-Connected Hybrid Magnet Mark D. Bird, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Coil Winding for the Series-Connected Hybrid Magnet Mark D. Bird, National High Magnetic Field will produce for MagLab users magnetic fields of 36T featuring unprecedented (1ppm) homogeneity. Winding of the superconducting coil, the largest component of the magnet windings, is well underway. The superconducting coil

  11. High-Voltage Solid Polymer Batteries for Electric Drive Vehicles | SciTech

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) EnvironmentalGyroSolé(tm) Harmonicbet WhenHiggsmiddlewareHigh-PressureOffice

  12. From: Laurie Smith To: Congestion Study Comments Subject: High Voltage Transmission Lines

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport inEnergy0.pdf Flash2010-60.pdf2Jessi O"Bannon To:Kay Foreman To:KerynHigh

  13. Apparatus for storing high magnetic fields having reduced mechanical forces and reduced magnetic pollution

    DOE Patents [OSTI]

    Prueitt, M.L.; Mueller, F.M.; Smith, J.L.

    1991-04-09T23:59:59.000Z

    The present invention identifies several configurations of conducting elements capable of storing extremely high magnetic fields for the purpose of energy storage or for other uses, wherein forces experienced by the conducting elements and the magnetic field pollution produced at locations away from the configuration are both significantly reduced over those which are present as a result of the generation of such high fields by currently proposed techniques. It is anticipated that the use of superconducting materials will both permit the attainment of such high fields and further permit such fields to be generated with vastly improved efficiency. 15 figures.

  14. Apparatus for storing high magnetic fields having reduced mechanical forces and reduced magnetic pollution

    DOE Patents [OSTI]

    Prueitt, Melvin L. (Los Alamos, NM); Mueller, Fred M. (Los Alamos, NM); Smith, James L. (Los Alamos, NM)

    1991-01-01T23:59:59.000Z

    The present invention identifies several configurations of conducting elements capable of storing extremely high magnetic fields for the purpose of energy storage or for other uses, wherein forces experienced by the conducting elements and the magnetic field pollution produced at locations away from the configuration are both significantly reduced over those which are present as a result of the generation of such high fields by currently proposed techniques. It is anticipated that the use of superconducting materials will both permit the attainment of such high fields and further permit such fields to be generated with vastly improved efficiency.

  15. Perpendicular local magnetization under voltage control in Ni films on ferroelectric BaTiO3 substrates

    E-Print Network [OSTI]

    Ghidini, Massimo; Maccherozzi, Francesco; Moya, Xavier; Phillips, Lee C.; Yan, Wenjing; Soussi, Jordane; Métallier, Nicolas; Vickers, Mary E.; Steinke, Nina -J.; Mansell, Rhodri; Barnes, Crispin H. W.; Dhesi, Sarnjeet S.; Mathur, Neil D.

    2015-01-12T23:59:59.000Z

    of Parma viale G. P. Usberti 7/A , Parma 43124 , Italy Dr. F. Maccherozzi, Prof. S. S. Dhesi Diamond Light Source Chilton, Didcot , Oxfordshire OX11 0DE , UK Dr. N.-J. Steinke, Dr. R. Mansell, Prof. C. H. W. Barnes Cavendish Laboratory... , minimizing stray-fi eld energy. The IP component of magnetization lies perpendicular to this IP direction, along the same direction in adjacent stripes. In polycrystalline fi lms of negative-magnetostriction Ni, which show stripe domains above a critical...

  16. Towards Integrated Design and Modeling of High Field Accelerator Magnets

    SciTech Connect (OSTI)

    Caspi, S.; Ferracin, P.

    2006-06-01T23:59:59.000Z

    The next generation of superconducting accelerator magnets will most likely use a brittle conductor (such as Nb{sub 3}Sn), generate fields around 18 T, handle forces that are 3-4 times higher than in the present LHC dipoles, and store energy that starts to make accelerator magnets look like fusion magnets. To meet the challenge and reduce the complexity, magnet design will have to be more innovative and better integrated. The recent design of several high field superconducting magnets have now benefited from the integration between CAD (e.g. ProE), magnetic analysis tools (e.g. TOSCA) and structural analysis tools (e.g. ANSYS). Not only it is now possible to address complex issues such as stress in magnet ends, but the analysis can be better detailed an extended into new areas previously too difficult to address. Integrated thermal, electrical and structural analysis can be followed from assembly and cool-down through excitation and quench propagation. In this paper we report on the integrated design approach, discuss analysis results and point out areas of future interest.

  17. Infrared detection with high-{Tc} bolometers and response of Nb tunnel junctions to picosecond voltage pulses

    SciTech Connect (OSTI)

    Verghese, S.

    1993-05-01T23:59:59.000Z

    Oxide superconductors with high critical temperature {Tc} make sensitive thermometers for several types of infrared bolometers. The authors built composite bolometers with YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} thermometers on sapphire substrates which have higher sensitivity than competing thermal detectors which operate at temperatures above 77 K. A 1 x 1 mm bolometer with gold black serving as the radiation absorber has useful sensitivity for wavelengths 20--100 {mu}m. A 3 x 3 mm bolometer with a bismuth film as the absorber operates from 20--100 {mu}m. High-{Tc} bolometers which are fabricated with micromachining techniques on membranes of Si or Si{sub 3}N{sub 4} have potential application to large-format arrays which are used for infrared imaging. A nonisothermal high-{Tc} bolometer can be fabricated on a membrane of yttria-stabilized zirconia (YSZ) which is in thermal contact with the heat sink along the perimeter of the membrane. A thermal analysis indicates that the YSZ membrane bolometer can have improved sensitivity compared to the sapphire bolometer for spectrometer applications. The quasiparticle tunneling current in a superconductor-insulator-superconductor (SIS) junction is highly nonlinear in the applied voltage. The authors have made the first measurement of the linear response of the quasiparticle current in a Nb/AlO{sub x}/Nb junction over a broad bandwidth from 75--200 GHz. Nonlinear measurements made with these pulses may provide information about the quasiparticle lifetime. Preliminary data from such measurements are presented.

  18. Voltage breakdown limits at a high material temperature for rapid pulse heating in a vacuum

    SciTech Connect (OSTI)

    Pincosy, P A; Speer, R

    1999-06-07T23:59:59.000Z

    The proposed Advanced Hydro Facility (AHF) is required to produce multi-pulse radiographs. Electron beam pulse machines with sub-microsecond repetition are not yet available to test the problem of electron beam propagation through the hydro-dynamically expanding plasma from the nearby previously heated target material. A proposed test scenario includes an ohmically heated small volume of target material simulating the electron beam heating, along with an actual electron beam pulse impinging on nearby target material. A pulse power heating circuit was tested to evaluate the limits of pulse heating a small volume of material to tens of kilo-joules per gram. The main pulse heating time (50 to 100 ns) was to simulate the electron beam heating of a converter target material. To avoid skin heating non-uniformity a longer time scale pulse of a few microseconds first heats the target material to a few thousand degrees near the liquid to vapor transition. Under this state the maximum electric field that the current carrying conductor can support is the important parameter for insuring that the 100 ns heating pulse can deposit sufficient power. A small pulse power system was built for tests of this limit. Under cold conditions the vacuum electric field hold-off limit has been quoted as high as many tens of kilovolts per centimeter. The tests for these experiments found that the vacuum electric field hold-off was limited to a few kilovolts per centimeter when the material approached melting temperatures. Therefore the proposed test scenario for AHF was not achievable.*

  19. IEEE International Conference on Power and Energy (PECon 08), December 1-3, 2008, Johor Baharu, Malaysia Variable High Frequency Voltage Source for an

    E-Print Network [OSTI]

    Hammerton, James

    , Malaysia Variable High Frequency Voltage Source for an Ohmic Heating Process A. Toudeshki, N. Mariun SMIEEE: arashtoudeshki@gmail.com Abstract-- Heating is an important step in food processing. A new method of heating uses the natural electrical resistance of the food to generate heat. In this method electrical energy

  20. High and ulta-high gradient quadrupole magnets

    SciTech Connect (OSTI)

    Brunk, W.O.; Walz, D.R.

    1985-05-01T23:59:59.000Z

    Small bore conventional dc quadrupoles with apertures from 1 to 2.578cm were designed and prototypes built and measured. New fabrication techniques including the use of wire electric discharge milling (EDM) to economically generate the pole tip contours and aperture tolerances are described. Magnetic measurement data from a prototype of a 1cm aperture quadrupole with possible use in future e/sup +//e/sup -/ super colliders are presented. At a current of 400A, the lens achieved a gradient of 2.475 T/cm, and had an efficiency of 76.6%.

  1. Homogenous BSCCO-2212 Round Wires for Very High Field Magnets

    SciTech Connect (OSTI)

    Dr. Scott Campbell

    2012-06-30T23:59:59.000Z

    The performance demands on modern particle accelerators generate a relentless push towards higher field magnets. In turn, advanced high field magnet development places increased demands on superconducting materials. Nb3Sn conductors have been used to achieve 16 T in a prototype dipole magnet and are thought to have the capability for {approx}18 T for accelerator magnets (primarily dipoles but also higher order multipole magnets). However there have been suggestions and proposals for such magnets higher than 20 T. The High Energy Physics Community (HEP) has identified important new physics opportunities that are enabled by extremely high field magnets: 20 to 50 T solenoids for muon cooling in a muon collider (impact: understanding of neutrinos and dark matter); and 20+ T dipoles and quadrupoles for high energy hadron colliders (impact: discovery reach far beyond present). This proposal addresses the latest SBIR solicitation that calls for grant applications that seek to develop new or improved superconducting wire technologies for magnets that operate at a minimum of 12 Tesla (T) field, with increases up to 15 to 20 T sought in the near future (three to five years). The long-term development of accelerator magnets with fields greater than 20 T will require superconducting wires having significantly better high-field properties than those possessed by current Nb{sub 3}Sn or other A15 based wires. Given the existing materials science base for Bi-2212 wire processing, we believe that Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (Bi-2212) round wires can be produced in km-long piece lengths with properties suitable to meet both the near term and long term needs of the HEP community. The key advance will be the translation of this materials science base into a robust, high-yield wire technology. While the processing and application of A15 materials have advanced to a much higher level than those of the copper oxide-based, high T{sub c} (HTS) counterparts, the HTS materials have the very significant advantage of an extremely high H{sub c2}. For this reason, Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub y} (Bi-2212, or 2212) in the form of a multifilamentary Ag alloy matrix composite is beginning to attract the interest of the magnet community for future extremely high-field magnets or magnet-insert coils for 4.2K operation. Fig. 1 shows an example of excellent JE (engineering current density) in Bi-2212 round wire at fields up to 45 T, demonstrating the potential for high field applications of this material. For comparison, the Nb{sub 3}Sn wires used in magnets in the 16-18 T range typically perform with J{sub E} in the range 200-500 A/mm{sup 2}; the Bi-2212 wire retains this level of performance to fields at least as high as 45 T, and probably significantly higher. Bi-2212 conductors have in fact been used to generate a 25 T field in a superconducting insert magnet. These two factors- the very high field critical current performance of Bi-2212, and the already demonstrated capability of this material for high field magnets up to 25 T, strongly suggest this material as a leading contender for the next generation high field superconducting (HFS) wire. This potential was recognized by the US Academy of Science's Committee on Opportunities in High Magnetic Field Science. Their report of the same name specifically calls out the high field potential for this material, and suggests that 30 T magnets appear feasible based on the performance of 2212. There are several requirements for HFS conductors. The most obvious is J{sub E} (B, T), the engineering current density at the field and temperature of operation. As shown in Fig. 1, Bi-2212 excels in this regard. Stability requirements for magnets dictate that the effective filament diameter should be less than 30 micrometers, something that Bi-2212 multifilamentary wire can uniquely satisfy among the HFS superconducting wire technologies. Additional requirements include mechanical properties that prevent stress limitation of J{sub E} at the operating conditions, resistive transition index (n-value) suffic

  2. Effect of the change in the load resistance on the high voltage pulse transformer of the intense electron-beam accelerators

    SciTech Connect (OSTI)

    Cheng Xinbing; Liu Jinliang; Qian Baoliang; Zhang Yu; Zhang Hongbo [College of Photoelectrical Science and Engineering, National University of Defense Technology, Hunan 410073 (China)

    2009-11-15T23:59:59.000Z

    A high voltage pulse transformer (HVPT) is usually used as a charging device for the pulse forming line (PFL) of intense electron-beam accelerators (IEBAs). Insulation of the HVPT is one of the important factors that restrict the development of the HVPT. Until now, considerable effort has been focused on minimizing high field regions to avoid insulation breakdown between windings. Characteristics of the HVPT have been widely discussed to achieve these goals, but the effects of the PFL and load resistance on HVPT are usually neglected. In this paper, a HVPT is used as a charging device for the PFL of an IEBA and the effect of the change in the load resistance on the HVPT of the IEBA is presented. When the load resistance does not match the wave impedance of the PFL, a high-frequency bipolar oscillating voltage will occur, and the amplitude of the oscillating voltage will increase with the decrease in the load resistance. The load resistance approximates to zero and the amplitude of the oscillating voltage is much higher. This makes it easier for surface flashover along the insulation materials to form and decrease the lifetime of the HVPT.

  3. Use of High Magnetic Field to Control Microstructural Evolution in Metallic and Magnetic Materials

    SciTech Connect (OSTI)

    Ludtka, G.M.; Mackiewicz- Ludtka, G.; Wilgen, J.B.; Kisner, R.A.

    2010-06-27T23:59:59.000Z

    The Amendment 1, referred to as Phase 2, to the original CRADA NFE-06-00414 added tasks 3 through 7 to the original statement of work that had two main tasks that were successfully accomplished in Phase 1 of this project. In this Phase 2 CRADA extension, extensive research and development activities were conducted using high magnetic field processing effects for the purpose of manipulating microstructure in the SAE 5160 steel to refine grain size isothermally and to develop nanocrystalline spacing pearlite during continuous cooling, and to enhance the formability/forgability of the non-ferrous precipitation hardening magnesium alloy AZ90 by applying a high magnetic field during deformation processing to investigate potential magnetoplasticity in this material. Significant experimental issues (especially non-isothermal conditions evolving upon insertion of an isothermal sample in the high magnetic field) were encountered in the isothermal phase transformation reversal experiments (Task 4) that later were determined to be due to various condensed matter physics phenomenon such as the magnetocaloric (MCE) effect that occurs in the vicinity of a materials Curie temperature. Similarly the experimental deformation rig had components for monitoring deformation/strain (Task 3) that were susceptible to the high magnetic field of the ORNL Thermomagnetic Processing facility 9-T superconducting magnet that caused electronic components to fail or record erroneous (very noisy) signals. Limited experiments on developing nanocrystalline spacing pearlite were not sufficient to elucidate the impact of high magnetic field processing on the final pearlite spacing since significant statistical evaluation of many pearlite colonies would need to be done to be conclusive. Since extensive effort was devoted to resolving issues for Tasks 3 and 7, only results for these focused activities are included in this final CRADA report along with those for Task 7 (described in the Objectives Section of this report).

  4. Experimental and theoretical studies of a high temperature cesium-barium tacitron, with application to low voltage-high current inversion. Final report, April 1, 1993--February 28, 1994

    SciTech Connect (OSTI)

    Murray, C.S.; El-Genk, M.S.

    1994-02-01T23:59:59.000Z

    A low voltage/high current switch refer-red as ``Cs-Ba tacitron`` is studied for use as a dc to ac inverter in high temperature and/or ionizing radiation environments. The operational characteristics of the Cs-Ba tacitron as a switch were investigated experimentally in three modes: (a) breakdown mode, (b) I-V mode, and (c) current modulation mode. Operation parameters measured include switching frequencies up to 20 kHz, hold-off voltages up to 200 V, current densities in excess of 15 A/CM{sup 2}, switch power density of 1 kW/cm{sup 2}, and a switching efficiency in excess of 90 % at collector voltages greater than 30 V. Also, if the discharge current is circuit limited to a value below the maximum thermal emission current density, the voltage drop is constant and below 3 V.

  5. Conjugate High Latitude Measurements along the 40 Magnetic Meridian

    E-Print Network [OSTI]

    Michigan, University of

    ­ 12 Volt system · Six 40 Wae Solar Panels · Sixteen 100 Ah AGM sealed leadConjugate High Latitude Measurements along the 40º Magnetic Meridian: Autonomous Adaptive Low-Power the 2014 season marked as red squares. #12;Autonomous Adaptive Low-Power Instrument

  6. Development of high temperature superconductors for magnetic field applications

    SciTech Connect (OSTI)

    Larbalestier, D.C.

    1991-12-31T23:59:59.000Z

    The key requirement for magnetic field applications of high temperature superconductor (HTS) materials is to have conductors with high transport critical current density available for magnet builders. After 3 or 4 years of being without any such object, conductor makers have had recent success in producing simple conductor prototypes. These have permitted the construction of simple HTS magnets having self fields exceeding 1 tesla at 4K. Thus the scientific feasibility of making powerful HTS magnets has been demonstrated. Attention to the technological aspects of making HTS conductors for magnets with strong flux pinning and reduced superconducting granularity is now sensible and attractive. However, extrinsic defects such as filament sausaging, cracking, misaligned grains and other perturbation to long range current flow must be controlled at a low level if the benefit of intrinsic improvements to the critical current density is to be maintained in the conductor form. Due to the great complexity of the HTS materials, there is sometimes confusion as to whether a given sample has an intrinsically or extrinsically limited critical current density. Systematic microstructure variation experiments and resistive transition analysis are shown to be particularly helpful in this phase of conductor development.

  7. Effects of magnetic flux density and substrate bias voltage on Ni films prepared on a flexible substrate material using unbalanced magnetron sputtering assisted by inductively coupled plasma

    SciTech Connect (OSTI)

    Koda, Tatsunori [Graduate School of Science and Technology, Hiroshima Institute of Technology, 2-1-1, Miyake, Saeki-ku, Hiroshima 7315193 (Japan); Toyota, Hiroshi, E-mail: h.toyota.za@it-hiroshima.ac.jp [Department of Electronics and Computer Engineering, Hiroshima Institute of Technology, 2-1-1, Miyake, Saeki-ku, Hiroshima 7315193 (Japan)

    2014-03-15T23:59:59.000Z

    The authors fabricated Ni films on a flexible substrate material using unbalanced magnetron sputtering assisted by inductively coupled plasma. The effects of magnetic flux density B{sub C} and substrate DC bias voltage V{sub S} on the Ni film structures were investigated. For V{sub S}?=??40?V, the average surface grain size D{sub G} measured by atomic force microscopy for B{sub C}?=?0, 3, and 5?mT was 88.2, 95.4, and 104.4?nm, respectively. In addition, D{sub G} increased with V{sub S}. From x-ray diffraction measurements, the (111) and (200) peaks were clearly visible for the fabricated Ni films. The ratio of the integrated intensities of I(111)/I(200) increased with V{sub S}. For V{sub S}?=??40?V and B{sub C}?=?3?mT, a film resistivity ? of 8.96?×?10{sup ?6} ? cm was observed, which is close to the Ni bulk value of 6.84?×?10{sup ?6} ? cm. From these results, the authors determined that the structure of the fabricated Ni films on the flexible substrate material was affected by the values of B{sub C} and V{sub S}.

  8. DESIGN STUDY OF THE DIPOLE MAGNET FOR THE RHIC EBIS HIGH ENERGY TRANSPORT LINE

    E-Print Network [OSTI]

    DESIGN The bending section in EBIS HEBT line consists of two identical H type magnets with a slit betweenDESIGN STUDY OF THE DIPOLE MAGNET FOR THE RHIC EBIS HIGH ENERGY TRANSPORT LINE Takeshi Kanesue magnet body should be laminated. In this paper, design methods of the dipole magnet to optimize magnetic

  9. Statistical analysis of the dynamics of secondary electrons in the flare of a high-voltage beam-type discharge

    SciTech Connect (OSTI)

    Demkin, V. P.; Mel'nichuk, S. V. [National Research Tomsk State University, 36, Lenin Ave., 634050 Tomsk (Russian Federation)

    2014-09-15T23:59:59.000Z

    In the present work, results of investigations into the dynamics of secondary electrons with helium atoms in the presence of the reverse electric field arising in the flare of a high-voltage pulsed beam-type discharge and leading to degradation of the primary electron beam are presented. The electric field in the discharge of this type at moderate pressures can reach several hundred V/cm and leads to considerable changes in the kinetics of secondary electrons created in the process of propagation of the electron beam generated in the accelerating gap with a grid anode. Moving in the accelerating electric field toward the anode, secondary electrons create the so-called compensating current to the anode. The character of electron motion and the compensating current itself are determined by the ratio of the field strength to the concentration of atoms (E/n). The energy and angular spectra of secondary electrons are calculated by the Monte Carlo method for different ratios E/n of the electric field strength to the helium atom concentration. The motion of secondary electrons with threshold energy is studied for inelastic collisions of helium atoms and differential analysis is carried out of the collisional processes causing energy losses of electrons in helium for different E/n values. The mechanism of creation and accumulation of slow electrons as a result of inelastic collisions of secondary electrons with helium atoms and selective population of metastable states of helium atoms is considered. It is demonstrated that in a wide range of E/n values the motion of secondary electrons in the beam-type discharge flare has the character of drift. At E/n values characteristic for the discharge of the given type, the drift velocity of these electrons is calculated and compared with the available experimental data.

  10. High pressure apparatus for transport properties study in high magnetic field

    SciTech Connect (OSTI)

    Alsmadi, A. M. (Abdel M.); Nakotte, H. (Heinrich); Honda, F.; Sechovsky, V. (Vladimir); Mikulina, O. (Olga); Kamarad, J.; Lacerda, A. H. (Alex H.)

    2002-01-01T23:59:59.000Z

    We have designed a high pressure apparatus for measuring electrical-transport properties at low temperatures, high magnetic field and hydrostatic pressure up to 10 kbar. Details of the high-pressure cell and an exemplary study on UNiAI are described and discussed briefly.

  11. 3-Axis Magnetic Sensor Hybrid The Honeywell HMC2003 is a high sensitivity, three-axis magnetic sensor hybrid

    E-Print Network [OSTI]

    Kleinfeld, David

    3-Axis Magnetic Sensor Hybrid HMC2003 The Honeywell HMC2003 is a high sensitivity, three-axis magnetic sensor hybrid assembly used to measure low magnetic field strengths. Honeywell's most sensitive Reference, Traffic Detection, Proximity Detection and Medical Devices Honeywell continues to maintain

  12. Iron Arsenides--The New Family of High TC Magnetic Superconductors

    E-Print Network [OSTI]

    Weston, Ken

    Iron Arsenides--The New Family of High TC Magnetic Superconductors Jeff Lynn NIST Center Superconductors · (Brief) History of Magnetic Superconductors ­ Magnetic Impurities ­ Long Range Magnetic Order: Coexistence and Competition · Cuprate Superconductors--Highly Correlated Electron Systems ­ Undoped systems

  13. High average power magnetic modulator for copper lasers

    SciTech Connect (OSTI)

    Cook, E.G.; Ball, D.G.; Birx, D.L.; Branum, J.D.; Peluso, S.E.; Langford, M.D.; Speer, R.D.; Sullivan, J.R.; Woods, P.G.

    1991-06-14T23:59:59.000Z

    Magnetic compression circuits show the promise of long life for operation at high average powers and high repetition rates. When the Atomic Vapor Laser Isotope Separation (AVLIS) Program at Lawrence Livermore National Laboratory needed new modulators to drive their higher power copper lasers in the Laser Demonstration Facility (LDF), existing technology using thyratron switched capacitor inversion circuits did not meet the goal for long lifetimes at the required power levels. We have demonstrated that magnetic compression circuits can achieve this goal. Improving thyratron lifetime is achieved by increasing the thyratron conduction time, thereby reducing the effect of cathode depletion. This paper describes a three stage magnetic modulator designed to provide a 60 kV pulse to a copper laser at a 4. 5 kHz repetition rate. This modulator operates at 34 kW input power and has exhibited MTBF of {approx}1000 hours when using thyratrons and even longer MTBFs with a series of stack of SCRs for the main switch. Within this paper, the electrical and mechanical designs for the magnetic compression circuits are discussed as are the important performance parameters of lifetime and jitter. Ancillary circuits such as the charge circuit and reset circuit are shown. 8 refs., 5 figs., 1 tab.

  14. Inner surface flash-over of insulator of low-inductance high-voltage self-breakdown gas switch and its application

    SciTech Connect (OSTI)

    Zhang, Hong-bo, E-mail: walkman67@163.com; Liu, Jin-liang [College of Opto-electronic Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China)] [College of Opto-electronic Science and Engineering, National University of Defense Technology, Changsha, Hunan 410073 (China)

    2014-04-15T23:59:59.000Z

    In this paper, the inner surface flash-over of high-voltage self-breakdown switch, which is used as a main switch of pulse modulator, is analyzed in theory by employing the method of distributed element equivalent circuit. Moreover, the field distortion of the switch is simulated by using software. The results of theoretical analysis and simulation by software show that the inner surface flash-over usually starts at the junction points among the stainless steel, insulator, and insulation gas in the switch. A switch with improved structure is designed and fabricated according to the theoretical analysis and simulation results. Several methods to avoid inner surface flash-over are used to improve the structure of switch. In experiment, the inductance of the switch is no more than 100 nH, the working voltage of the switch is about 600 kV, and the output voltage and current of the accelerator is about 500 kV and 50 kA, respectively. And the zero-to-peak rise time of output voltage at matched load is less than 30 ns due to the small inductance of switch. The original switch was broken-down after dozens of experiments, and the improved switch has been worked more than 200 times stably.

  15. High Magnetic Field Multipoles Generated by Superconductor Magnetization within a Set of Nested Superconducting Correction Coils

    E-Print Network [OSTI]

    Green, M.A.

    2011-01-01T23:59:59.000Z

    magnetization of the superconductor in the long correctorsMultipoles Generated by Superconductor Magnetization WithinMULTIPOLES GENERATED BY SUPERCONDUCTOR MAGNETIZATION WITHIN

  16. ON HIGHLY CLUMPED MAGNETIC WIND MODELS FOR COOL EVOLVED STARS

    SciTech Connect (OSTI)

    Harper, G. M. [School of Physics, Trinity College, Dublin 2 (Ireland)

    2010-09-10T23:59:59.000Z

    Recently, it has been proposed that the winds of non-pulsating and non-dusty K and M giants and supergiants may be driven by some form of magnetic pressure acting on highly clumped wind material. While many researchers believe that magnetic processes are responsible for cool evolved stellar winds, existing MHD and Alfven wave-driven wind models have magnetic fields that are essentially radial and tied to the photosphere. The clumped magnetic wind scenario is quite different in that the magnetic flux is also being carried away from the star with the wind. We test this clumped wind hypothesis by computing continuum radio fluxes from the {zeta} Aur semiempirical model of Baade et al., which is based on wind-scattered line profiles. The radio continuum opacity is proportional to the electron density squared, while the line scattering opacity is proportional to the gas density. This difference in proportionality provides a test for the presence of large clumping factors. We derive the radial distribution of clump factors (CFs) for {zeta} Aur by comparing the nonthermal pressures required to produce the semiempirical velocity distribution with the expected thermal pressures. The CFs are {approx}5 throughout the sub-sonic inner wind region and then decline outward. These implied clumping factors lead to excess radio emission at 2.0 cm, while at 6.2 cm it improves agreement with the smooth unclumped model. Smaller clumping factors of {approx}2 lead to better overall agreement but also increase the discrepancy at 2 cm. These results do not support the magnetic clumped wind hypothesis and instead suggest that inherent uncertainties in the underlying semiempirical model probably dominate uncertainties in predicted radio fluxes. However, new ultraviolet line and radio continuum observations are needed to test the new generations of inhomogeneous magnetohydrodynamic wind models.

  17. Minimizing Simultaneous Switching Noise at Reduced Power with Constant-Voltage Power Transmission Lines for High-Speed Signaling

    E-Print Network [OSTI]

    Swaminathan, Madhavan

    plane structure with a power transmission line (PTL). In this paper, a new power delivery scheme called Constant Voltage Power Transmission Line (CV-PTL) is shown to significantly reduce switching noise while, and measurements. Keywords Power delivery network, simultaneous switching noise, power transmission line 1

  18. 3430 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. 61, NO. 8, OCTOBER 2012 Experimental Validation of High-Voltage-Ratio

    E-Print Network [OSTI]

    Simões, Marcelo Godoy

    -voltage current-source like device that produces electricity and heat directly from input hydrogen and oxygen carbon dioxide emissions under the assumption that the hydrogen can be produced from renewable-energy sources such as photovoltaic and wind energy or as a subprod- uct of currently wasted energy of large

  19. Voltage balanced multilevel voltage source converter system

    DOE Patents [OSTI]

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

    1997-07-01T23:59:59.000Z

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

  20. High-field magnets using high-critical-temperature superconducting thin films

    DOE Patents [OSTI]

    Mitlitsky, Fred (Livermore, CA); Hoard, Ronald W. (Livermore, CA)

    1994-01-01T23:59:59.000Z

    High-field magnets fabricated from high-critical-temperature superconducting ceramic (HTSC) thin films which can generate fields greater than 4 Tesla. The high-field magnets are made of stackable disk-shaped substrates coated with HTSC thin films, and involves maximizing the critical current density, superconducting film thickness, number of superconducting layers per substrate, substrate diameter, and number of substrates while minimizing substrate thickness. The HTSC thin films are deposited on one or both sides of the substrates in a spiral configuration with variable line widths to increase the field.

  1. High-field magnets using high-critical-temperature superconducting thin films

    DOE Patents [OSTI]

    Mitlitsky, F.; Hoard, R.W.

    1994-05-10T23:59:59.000Z

    High-field magnets fabricated from high-critical-temperature superconducting ceramic (HTSC) thin films which can generate fields greater than 4 Tesla are disclosed. The high-field magnets are made of stackable disk-shaped substrates coated with HTSC thin films, and involves maximizing the critical current density, superconducting film thickness, number of superconducting layers per substrate, substrate diameter, and number of substrates while minimizing substrate thickness. The HTSC thin films are deposited on one or both sides of the substrates in a spiral configuration with variable line widths to increase the field. 4 figures.

  2. A transistor-only power-efficient high-frequency voltage-mode stimulator for a multichannel system

    E-Print Network [OSTI]

    Serdijn, Wouter A.

    to that of traditional stimulation. The system has a voltage-mode output and therefore safety aspects such as charge operation. dl CRs CCel el S S S 1 2 3 4 S (a) System with parasitics 0 50 100 150 200 250 300 350 -5 -4 -3 is controlled. The simplest model for the tissue is an RC series circuit. In this model the capacitance Cdl

  3. Voltage regulation in linear induction accelerators

    DOE Patents [OSTI]

    Parsons, William M. (Santa Fe, NM)

    1992-01-01T23:59:59.000Z

    Improvement in voltage regulation in a Linear Induction Accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance.

  4. Voltage regulation in linear induction accelerators

    DOE Patents [OSTI]

    Parsons, W.M.

    1992-12-29T23:59:59.000Z

    Improvement in voltage regulation in a linear induction accelerator wherein a varistor, such as a metal oxide varistor, is placed in parallel with the beam accelerating cavity and the magnetic core is disclosed. The non-linear properties of the varistor result in a more stable voltage across the beam accelerating cavity than with a conventional compensating resistance. 4 figs.

  5. NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSVOLUME 11 N0.1 2004

    E-Print Network [OSTI]

    Weston, Ken

    NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSVOLUME 11 · N0.1 · 2004 OPERATED BY: FLORIDA STATE R E V I E W BIOLOGY BIOCHEMISTRY CHEMISTRY CRYOGENICS ENGINEERING MATERIALS GEOCHEMISTRY INSTRUMENTATION KONDO/HEAVY FERMION SYSTEMS MAGNET TECHNOLOGY MAGNETIC RESONANCE TECHNIQUES MAGNETISMAND MAGNETIC

  6. NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSSPECIAL EDITION VOLUME 13 N0. 1 2006

    E-Print Network [OSTI]

    Weston, Ken

    , and Geochemistry 16 MAGNET SCIENCE & TECHNOLOGY Engineering Materials, Instrumentation, and Magnet Technology 20NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSSPECIAL EDITION VOLUME 13 · N0. 1 · 2006 SUPPORTED HIGHLIGHTS FROM Life Sciences Chemistry Magnet Science & Technology Condensed Matter Page 15 #12;NHMFLREPORTS

  7. Voltage control of magnetism in ferromagnetic structures L. Herrera Dieza, W. Linc, A. Bernand-Mantela, L Rannoa, D. Givorda, L. Vilab, Patrick

    E-Print Network [OSTI]

    Boyer, Edmond

    . The observation of carrier-mediated ferromagnetism in diluted magnetic semiconductor (DMS) systems, namely

  8. Simulations of magnetic hysteresis loops at high temperatures

    SciTech Connect (OSTI)

    Plumer, M. L.; Whitehead, J. P.; Fal, T. J. [Department of Physics and Physical Oceanography, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador A1B 3X7 (Canada); Ek, J. van [Western Digital Corporation, San Jose, California 94588 (United States); Mercer, J. I. [Department of Computer Science, Memorial University of Newfoundland, St. John's, Newfoundland and Labrador A1B 3X7 (Canada)

    2014-09-28T23:59:59.000Z

    The kinetic Monte-Carlo algorithm as well as standard micromagnetics are used to simulate MH loops of high anisotropy magnetic recording media at both short and long time scales over a wide range of temperatures relevant to heat-assisted magnetic recording. Microscopic parameters, common to both methods, were determined by fitting to experimental data on single-layer FePt-based media that uses the Magneto-Optic Kerr effect with a slow sweep rate of 700 Oe/s. Saturation moment, uniaxial anisotropy, and exchange constants are given an intrinsic temperature dependence based on published atomistic simulations of FePt grains with an effective Curie temperature of 680 K. Our results show good agreement between micromagnetics and kinetic Monte Carlo results over a wide range of sweep rates. Loops at the slow experimental sweep rates are found to become more square-shaped, with an increasing slope, as temperature increases from 300 K. These effects also occur at higher sweep rates, typical of recording speeds, but are much less pronounced. These results demonstrate the need for accurate determination of intrinsic thermal properties of future recording media as input to micromagnetic models as well as the sensitivity of the switching behavior of thin magnetic films to applied field sweep rates at higher temperatures.

  9. Oldest Known Magnet's Secrets Revealed Under High Pressures ...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    dichroism technique is readily applied to most magnetic materials without the need for isotope enrichment, and provides a true measure of long-range magnetic order." Other...

  10. High Field Magnet R&D in the USA

    E-Print Network [OSTI]

    Gourlay, S.A.

    2011-01-01T23:59:59.000Z

    beam instmmentation, accelerator physics shIdies, and designShldy in terms of accelerator physics and magnet design.magnet technology and accelerator physics and approach the

  11. > REPLACE THIS LINE WITH YOUR PAPER IDENTIFICATION NUMBER (DOUBLE-CLICK HERE TO EDIT) < 1 Abstract--In high current, high voltage, high temperature

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and high current applications, such as HVDC transmission [1] or pulsed power application [2], a thyristor

  12. NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSVOLUME 11 N0.2 2004

    E-Print Network [OSTI]

    Weston, Ken

    , recognized as the world leader in magnet science, engineering, and experimental infrastructureNATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSVOLUME 11 · N0.2 · 2004 OPERATED BY: FLORIDA STATE: National High Magnetic Field Laboratory 1800 East Paul Dirac Drive Tallahassee, Florida 32310-3706 Tel: 850

  13. Spectral Mapping of Protein Torsion Angles National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Spectral Mapping of Protein Torsion Angles National High Magnetic Field Laboratory NMR Spectroscopy spectra. #12;Spectral Mapping of Protein Torsion Angles National High Magnetic Field Laboratory NMR, in recording signals that are dependent on the orientation of the atoms with respect to the magnetic field, we

  14. Ultra-High Intensity Magnetic Field Generation in Dense Plasma

    SciTech Connect (OSTI)

    Fisch, Nathaniel J

    2014-01-08T23:59:59.000Z

    I. Grant Objective The main objective of this grant proposal was to explore the efficient generation of intense currents. Whereasthefficient generation of electric current in low-­?energy-­? density plasma has occupied the attention of the magnetic fusion community for several decades, scant attention has been paid to carrying over to high-­?energy-­? density plasma the ideas for steady-­?state current drive developed for low-­?energy-­? density plasma, or, for that matter, to inventing new methodologies for generating electric current in high-­?energy-­?density plasma. What we proposed to do was to identify new mechanisms to accomplish current generation, and to assess the operation, physics, and engineering basis of new forms of current drive in regimes appropriate for new fusion concepts.

  15. CIGRE WG 13.06 studies on the reliability of single pressure SF6-gas high-voltage circuit-breakers

    SciTech Connect (OSTI)

    Janssen, A.L.J. [KEMA, Arnhem (Netherlands)] [KEMA, Arnhem (Netherlands); Brunke, J.H.; Heising, C.R.; Lanz, W.

    1996-01-01T23:59:59.000Z

    The final results of the CIGRE second international inquiry on the reliability of high voltage circuit-breakers in service are presented. In the seventies the first international inquiry, that covered all technology circuit-breakers, was conducted. The second international inquiry was limited to single pressure SF6 gas circuit-breakers, thus showing the improvements due to this technology. The main conclusion is that the reliability concerning Major Failures has increased considerably and that the maintainability of modern SF6 circuit-breakers is much better than the older technology circuit-breakers. Also the conclusions from several other studies, based on the results of the inquiries, are presented.

  16. High Field Magnetization measurements of uranium dioxide single crystals (P08358- E003-PF)

    SciTech Connect (OSTI)

    K. Gofryk; N. Harrison; M. Jaime

    2014-12-01T23:59:59.000Z

    Conclusions: Our preliminary high field magnetic measurements of UO2 are consistent with a complex nature of the magnetic ordering in this material, compatible with the previously proposed non-collinear 3-k magnetic structure. Further extensive magnetic studies on well-oriented (<100 > and <111>) UO2 crystals are planned to address the puzzling behavior of UO2 in both antiferromagnetic and paramagnetic states at high fields.

  17. High Performance Superconducting Wire in High Applied Magnetic Fields via Nanoscale Defect Engineering

    SciTech Connect (OSTI)

    Goyal, Amit [ORNL; Wee, Sung Hun [ORNL; Zuev, Yuri L [ORNL; Cantoni, Claudia [ORNL

    2008-01-01T23:59:59.000Z

    High temperature superconducting (HTS) wires capable of carrying large critical currents with low dissipation levels in high applied magnetic fields are needed for a wide range of applications. In particular, for electric power applications involving rotating machinery, such as large-scale motors and generators, a high critical current, Ic, and a high engineering critical current density, JE, in applied magnetic fields in the range of 3 5 Tesla (T) at 65 K are required. In addition, exceeding the minimum performance requirements needed for these applications results in a lower fabrication cost, which is regarded as crucial to realize or enable many large-scale bulk applications of HTS materials. Here we report the fabrication of short segments of a potential superconducting wire comprised of a 4 m thick YBa2Cu3O7? (YBCO) layer on a biaxially textured substrate with a 50% higher Ic and JE than the highest values reported previously. The YBCO film contained columns of self-assembled nanodots of BaZrO3 (BZO) roughly oriented along the c-axis of YBCO. Although the YBCO film was grown at a high deposition rate, three-dimensional self-assembly of the insulating BZO nanodots still occurred. For all magnetic field orientations, minimum Ic and JE at 65 K, 3 T for the wire were 353 A cm?1 and 65.4 kA cm?2, respectively.

  18. Presented by the National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    ! Cooling holes on the Bitter plates let cold water run through the magnet so it doesn't get too hot. l magnets found in houses. The answers will fit into the crossword puzzle below. ACROSS Where you store milk

  19. Effect of high-pressure on molecular magnetism 

    E-Print Network [OSTI]

    Prescimone, Alessandro

    2010-01-01T23:59:59.000Z

    The effect of pressure on a number of magnetically interesting compounds such as single-molecule magnets and dimeric copper and manganese molecules has been investigated to probe the validity of ambient magneto-structural ...

  20. Compressing magnetic fields with high-energy lasersa... J. P. Knauer,1,b

    E-Print Network [OSTI]

    Compressing magnetic fields with high-energy lasersa... J. P. Knauer,1,b O. V. Gotchev,1,2,3 P. Y, Rochester, New York 14623, USA 3 Department of Mechanical Engineering, University of Rochester, 250 East-driven magnetic-field compression producing a magnetic field of tens of megaGauss is reported for the first time

  1. Nanoscale Diffusion Studies of Lipid Membranes National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Magnetic Resonance Imaging & Spectroscopy User Facility, University of Florida Chemical Engineering We haveNanoscale Diffusion Studies of Lipid Membranes National High Magnetic Field Laboratory Advanced for the facility's future use. This will serve to enhance infrastructure for research and education at the Magnet

  2. SUMMERVOLUME 14 No.31 SUMMER 2007 VOLUME 14 NO. 3 NATIONAL HIGH MAGNETIC FIELD LABORATORY

    E-Print Network [OSTI]

    Weston, Ken

    a team of engineers capable of pushing magnetic fields to new highs? you already know the answer to announce that a key person who helped lead the magnet engineering team to world prominence no longer has of the Magnet Science & Technology group, as well as its chief engineer. In addition to keeping many balls

  3. Design of a High Performance Ferrite Magnet-Assisted Synchronous Reluctance Motor for an

    E-Print Network [OSTI]

    Paderborn, Universität

    Design of a High Performance Ferrite Magnet- Assisted Synchronous Reluctance Motor for an Electric) ferrite-based permanent magnet-assisted synchronous reluctance motor has been designed for an electric vehicle application. The design steps are outlined. Ferrite magnets have been chosen over conventional Nd

  4. Helium gas bubble trapped in liquid helium in high magnetic field

    SciTech Connect (OSTI)

    Bai, H., E-mail: bai@magnet.fsu.edu; Hannahs, S. T.; Markiewicz, W. D.; Weijers, H. W. [National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32310 (United States)

    2014-03-31T23:59:59.000Z

    High magnetic field magnets are used widely in the area of the condensed matter physics, material science, chemistry, geochemistry, and biology at the National High Magnetic Field Laboratory. New high field magnets of state-of-the-art are being pursued and developed at the lab, such as the current developing 32?T, 32?mm bore fully superconducting magnet. Liquid Helium (LHe) is used as the coolant for superconducting magnets or samples tested in a high magnetic field. When the magnetic field reaches a relatively high value the boil-off helium gas bubble generated by heat losses in the cryostat can be trapped in the LHe bath in the region where BzdBz/dz is less than negative 2100 T{sup 2}/m, instead of floating up to the top of LHe. Then the magnet or sample in the trapped bubble region may lose efficient cooling. In the development of the 32?T magnet, a prototype Yttrium Barium Copper Oxide coil of 6 double pancakes with an inner diameter of 40?mm and an outer diameter of 140?mm was fabricated and tested in a resistive magnet providing a background field of 15?T. The trapped gas bubble was observed in the tests when the prototype coil was ramped up to 7.5?T at a current of 200?A. This letter reports the test results on the trapped gas bubble and the comparison with the analytical results which shows they are in a good agreement.

  5. Controlling interactions between highly-magnetic atoms with Feshbach resonances

    E-Print Network [OSTI]

    Svetlana Kotochigova

    2014-10-14T23:59:59.000Z

    This paper reviews current experimental and theoretical progress in the study of dipolar quantum gases of ground and meta-stable atoms with a large magnetic moment. We emphasize the anisotropic nature of Feshbach resonances due to coupling to fast-rotating resonant molecular states in ultracold s-wave collisions between magnetic atoms in external magnetic fields. The dramatic differences in the distribution of resonances of magnetic $^7$S$_3$ chromium and magnetic lanthanide atoms with a submerged 4f shell and non-zero electron angular momentum is analyzed. We focus on Dysprosium and Erbium as important experimental advances have been recently made to cool and create quantum-degenerate gases for these atoms. Finally, we describe progress in locating resonances in collisions of meta-stable magnetic atoms in electronic P states with ground-state atoms, where an interplay between collisional anisotropies and spin-orbit coupling exists.

  6. NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSSUMMER EDITION VOLUME 13 N0. 3 2006

    E-Print Network [OSTI]

    Weston, Ken

    UPPort scientists neWs FroM tHe dc FieLd FaciLitY: QUantUM HaLL eFFect in graPHene at HigH Magnetic FieLds ed NEARING COMPLETION 14 NEWS FROM THE DC FIELD FACILITY QuantuM Hall effect In grapHene at HIgH MagnetIc f

  7. Section IV.D.3 for DOE 2013 Annual Report: Novel Phosphazene-based Compounds to Enhance Safety and Stability of Cell Chemistries for High Voltage Applications (INL)

    SciTech Connect (OSTI)

    Kevin L. Gering; Mason K. Harrup; Eric J. Dufek; Sergiy V. Sazhin; Harry W. Rollins; David K. Jamison; Fred F. Stewart; John Burba

    2013-09-01T23:59:59.000Z

    Electrolytes play a central role in performance and aging in most electrochemical systems. As automotive and grid applications place a higher reliance on electrochemical stored energy, it becomes more urgent to have electrolyte components that enable optimal battery performance while promoting battery safety and longevity. Safety remains a foremost concern for widespread utilization of Li-ion technology in electric-drive vehicles, especially as the focus turns to higher voltage systems (5V). This work capitalizes on the long established INL expertise regarding phosphazene chemistry, aimed at battery-viable compounds for electrolytes and electrodes that are highly tolerant to abusive conditions. This report showcases our 2013 work for the DOE applied battery research (ABR) program, wherein testing results are summarized for INL electrolytes and alternative anode materials.

  8. Charging a Battery-Powered Device with a Fiber-Optically Connected Photonic Power System for Achieving High-Voltage Isolation

    SciTech Connect (OSTI)

    Lizon, David C [Los Alamos National Laboratory; Gioria, Jack G [Los Alamos National Laboratory; Dale, Gregory E [Los Alamos National Laboratory; Snyder, Hans R [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    This paper describes the development and testing of a system to provide isolated power to the cathode-subsystem electronics of an x-ray tube. These components are located at the cathode potential of several hundred kilovolts, requiring a supply of power isolated from this high voltage. In this design a fiber-optically connected photonic power system (PPS) is used to recharge a lithium-ion battery pack, which will subsequently supply power to the cathode-subsystem electronics. The suitability of the commercially available JDSU PPS for this application is evaluated. The output of the ppe converter is characterized. The technical aspects of its use for charging a variety of Li-Ion batteries are discussed. Battery charge protection requirements and safety concerns are also addressed.

  9. Measurement of the internal stress and electric field in a resonating piezoelectric transformer for high-voltage applications using the electro-optic and photoelastic effects

    SciTech Connect (OSTI)

    VanGordon, James A.; Kovaleski, Scott D., E-mail: kovaleskis@missouri.edu; Norgard, Peter; Gall, Brady B. [Department of Electrical and Computer Engineering, University of Missouri, Columbia, Missouri 65211 (United States)] [Department of Electrical and Computer Engineering, University of Missouri, Columbia, Missouri 65211 (United States); Dale, Gregory E. [High Power Electrodynamics Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [High Power Electrodynamics Group, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

    2014-02-15T23:59:59.000Z

    The high output voltages from piezoelectric transformers are currently being used to accelerate charged particle beams for x-ray and neutron production. Traditional methods of characterizing piezoelectric transformers (PTs) using electrical probes can decrease the voltage transformation ratio of the device due to the introduction of load impedances on the order of hundreds of kiloohms to hundreds of megaohms. Consequently, an optical diagnostic was developed that used the photoelastic and electro-optic effects present in piezoelectric materials that are transparent to a given optical wavelength to determine the internal stress and electric field. The combined effects of the piezoelectric, photoelastic, and electro-optic effects result in a time-dependent change the refractive indices of the material and produce an artificially induced, time-dependent birefringence in the piezoelectric material. This induced time-dependent birefringence results in a change in the relative phase difference between the ordinary and extraordinary wave components of a helium-neon laser beam. The change in phase difference between the wave components was measured using a set of linear polarizers. The measured change in phase difference was used to calculate the stress and electric field based on the nonlinear optical properties, the piezoelectric constitutive equations, and the boundary conditions of the PT. Maximum stresses of approximately 10 MPa and electric fields of as high as 6 kV/cm were measured with the optical diagnostic. Measured results were compared to results from both a simple one-dimensional (1D) model of the piezoelectric transformer and a three-dimensional (3D) finite element model. Measured stresses and electric fields along the length of an operating length-extensional PT for two different electrical loads were within at least 50 % of 3D finite element simulated results. Additionally, the 3D finite element results were more accurate than the results from the 1D model for a wider range of electrical load impedances under test.

  10. NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSSPRING EDITION VOLUME 13 N0. 2 2006

    E-Print Network [OSTI]

    Weston, Ken

    NATIONAL HIGH MAGNETIC FIELD LABORATORY REPORTSSPRING EDITION VOLUME 13 · N0. 2 · 2006 SUPPORTED BY OF FLORIDA · LOS ALAMOS NATIONAL LABORATORY Pulsed Field Facility: Heat caPacity in tHe 20 t dilution ReFRigeRatoR tRiPle Resonance PRobe #12;NHMFLREPORTS C O N T E N T S Published by: National High Magnetic Field

  11. High-Energy Composite Permanent Magnets: High-Energy Permanent Magnets for Hybrid Vehicles and Alternative Energy

    SciTech Connect (OSTI)

    None

    2010-02-15T23:59:59.000Z

    Broad Funding Opportunity Announcement Project: The University of Delaware is developing permanent magnets that contain less rare earth material and produce twice the energy of the strongest rare earth magnets currently available. The University of Delaware is creating these magnets by mixing existing permanent magnet materials with those that are more abundant, like iron. Both materials are first prepared in the form of nanoparticles via techniques ranging from wet chemistry to ball milling. After that, the nanoparticles must be assembled in a 3-D array and consolidated at low temperatures to form a magnet. With small size particles and good contact between these two materials, the best qualities of each allow for the development of exceptionally strong composite magnets.

  12. The influence of a magnetic field on turbulent heat transfer of a high Prandtl number fluid

    SciTech Connect (OSTI)

    Nakaharai, H. [Department of Advanced Energy Engineering Science, Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga-kouen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Takeuchi, J.; Morley, N.B.; Abdou, M.A. [Mechanical and Aerospace Engineering Department, University of California, Los Angeles, CA 90095-1597 (United States); Yokomine, T. [Faculty of Energy Engineering Science, Kyushu University, Kasuga-kouen 6-1, Kasuga, Fukuoka 816-8580 (Japan); Kunugi, T. [Department of Nuclear Engineering, Kyoto University, Yoshida, Sakyo, Kyoto 606-8501 (Japan); Satake, S. [Department of Applied Electronics, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510 (Japan)

    2007-10-15T23:59:59.000Z

    The influence of a transverse magnetic field on the local and average heat transfer of an electrically conducting, turbulent fluid flow with high Prandtl number was studied experimentally. The mechanism of heat transfer modification due to magnetic field is considered with aid of available numerical simulation data for turbulent flow field. The influence of the transverse magnetic field on the heat transfer was to suppress the temperature fluctuation and to steepen the mean temperature gradient in near-wall region in the direction parallel to the magnetic field. The mean temperature gradient is not influenced compared to the temperature fluctuation in the direction vertical to the magnetic field. (author)

  13. Abstract--This paper discusses an optimum design of an ultra high-speed permanent-magnet synchronous motor

    E-Print Network [OSTI]

    Fujimoto, Hiroshi

    -magnet synchronous motor (PMSM), which is applied to a supercharger of an automotive engine. Although the motor (PMSM), which is specifically applied to the electric supercharger of the automotive engines. Although the PMSM is operated by an inverter with a 12-V DC bus voltage for an adjustable-speed drive, it must

  14. Infrared detection with high-[Tc] bolometers and response of Nb tunnel junctions to picosecond voltage pulses

    SciTech Connect (OSTI)

    Verghese, S.

    1993-05-01T23:59:59.000Z

    Oxide superconductors with high critical temperature [Tc] make sensitive thermometers for several types of infrared bolometers. The authors built composite bolometers with YBa[sub 2]Cu[sub 3]O[sub 7[minus][delta

  15. Automatic voltage imbalance detector

    DOE Patents [OSTI]

    Bobbett, Ronald E. (Los Alamos, NM); McCormick, J. Byron (Los Alamos, NM); Kerwin, William J. (Tucson, AZ)

    1984-01-01T23:59:59.000Z

    A device for indicating and preventing damage to voltage cells such as galvanic cells and fuel cells connected in series by detecting sequential voltages and comparing these voltages to adjacent voltage cells. The device is implemented by using operational amplifiers and switching circuitry is provided by transistors. The device can be utilized in battery powered electric vehicles to prevent galvanic cell damage and also in series connected fuel cells to prevent fuel cell damage.

  16. High-Efficiency Plasma Refuelling by Pellet Injection from the Magnetic High-Field Side into ASDEX Upgrade

    SciTech Connect (OSTI)

    Lang, P.T.; Buechl, K.; Kaufmann, M.; Lang, R.S.; Mertens, V.; Mueller, H.W.; Neuhauser, J. [Max-Planck-Institut fuer Plasmaphysik, EURATOM-IPP Association, Garching (Germany)] [Max-Planck-Institut fuer Plasmaphysik, EURATOM-IPP Association, Garching (Germany); ASDEX Upgrade% NI Teams

    1997-08-01T23:59:59.000Z

    High-efficiency refuelling of ELMy {ital H}-mode tokamak discharges with solid deuterium pellets injected from the magnetic high-field side is demonstrated. Compared to standard low-field side injection, the fuelling efficiency was enhanced by a factor of 4, the pellet penetration more than 2 times. This experimental result can be qualitatively explained by the magnetic force pushing a diamagnetic plasma cloud towards lower magnetic field, causing rapid particle loss for shallow low-field side injection, but enhancing fuelling efficiency and pellet penetration for high-field side injection. {copyright} {ital 1997} {ital The American Physical Society}

  17. Evaluation of permanent magnets for high temperature operations

    E-Print Network [OSTI]

    Van Hees, Elizabeth

    1985-01-01T23:59:59.000Z

    . Page 18 25 39 41 43 54 TABLE LIST OF TABLES Page I Magnetic Parameters of Magnet Samples. II Average Mass of Magnet Samples I II Barium Ferrite Anneal ling Data IV SmCo5 (Unsintered) Annealling Data 16 26 47 VI VII VIII Alnico 8... Annealling Data . Alnico 5 Annea'lling Data . Alnico 8 -- Alnico 5 Comparison. SmCo5 (Sintered) Annealling Data 48 50 52 53 LIST OF FIGURES Figure Page The structure of the Bloch wall separating domains 4a Hysteresis loop of a ferromagnetic...

  18. Toroidal magnetic detector for high resolution measurement of muon momenta

    DOE Patents [OSTI]

    Bonanos, P.

    1992-01-07T23:59:59.000Z

    A muon detector system including central and end air-core superconducting toroids and muon detectors enclosing a central calorimeter/detector. Muon detectors are positioned outside of toroids and all muon trajectory measurements are made in a nonmagnetic environment. Internal support for each magnet structure is provided by sheets, located at frequent and regularly spaced azimuthal planes, which interconnect the structural walls of the toroidal magnets. In a preferred embodiment, the shape of the toroidal magnet volume is adjusted to provide constant resolution over a wide range of rapidity. 4 figs.

  19. Recent Test Results of the High Field Nb3Sn Dipole Magnet HD2

    SciTech Connect (OSTI)

    Ferracin, P.; Bingham, B.; Caspi, S.; Cheng, D. W.; Dietderich, D. R.; Felice, H.; Hafalia, A. R.; Hannaford, C. R.; Joseph, J.; Lietzke, A. F.; Lizarazo, J.; Sabbi, G.; Wang, X.

    2009-10-19T23:59:59.000Z

    The 1 m long Nb{sub 3}Sn dipole magnet HD2, fabricated and tested at Lawrence Berkeley National Laboratory, represents a step towards the development of block-type accelerator quality magnets operating in the range of 13-15 T. The magnet design features two coil modules composed of two layers wound around a titanium-alloy pole. The layer 1 pole includes a round cutout to provide room for a bore tube with a clear aperture of 36 mm. After a first series of tests where HD2 reached a maximum bore field of 13.8 T, corresponding to an estimated peak field on the conductor of 14.5 T, the magnet was disassembled and reloaded without the bore tube and with a clear aperture increased to 43 mm. We describe in this paper the magnet training observed in two consecutive tests after the removal of the bore tube, with a comparison of the quench performance with respect to the previous tests. An analysis of the voltage signals recorded before and after training quenches is then presented and discussed, and the results of coil visual inspections reported.

  20. Effect of AlPO4-Nanoparticle Coating Concentration on High-Cutoff-Voltage Electrochemical Performances in

    E-Print Network [OSTI]

    Cho, Jaephil

    , * a School of Materials Science and Engineering and Research Center for Energy Conversion and Storage, Seoul National University, Seoul, Korea b Department of Applied Chemistry, Kumoh National Institute of Technology material has been used in most com- mercial Li-ion cells due to its high energy density and good electro

  1. Effect of Trapping on the Critical Voltage for Degradation in GaN High Electron Mobility Transistors

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    power and high frequency applications. Si is an attractive substrate for GaN HEMTs because of its lower and thermal mismatch between GaN and Si as compared to the more commonly used substrate, SiC, results in more regardless of the characteristics of the substrate. II. EXPERIMENTAL We studied experimental AlxGa1­xN/GaN

  2. IEEE TRANSACTIONS ON MAGNETICS, VOL. 49, NO. 7, JULY 2013 4009 Coupled Inductors With Crossed Anisotropy

    E-Print Network [OSTI]

    Shepard, Kenneth

    regulators (IVRs) offer the potential of scalable power supplies that improve dynamic voltage and frequency structures have been fabricated and tested for use in high-power-density integrated voltage regulator (IVR by four Cu windings creating four coupled inductors. The magnetic core is made of laminations of ultra

  3. Evaluation of Magnetic Materials for Very High Frequency Power Applications

    E-Print Network [OSTI]

    Han, Yehui

    This paper investigates the loss characteristics of RF magnetic materials for power conversion applications in the 10 to 100 MHz range. A measurement method is proposed that provides a direct measurement of an inductor ...

  4. Proc. International Symposium on Circuits and Systems (ISCAS), vol. 5, pp 653 -656, Geneva (Switzerland), May 2000 Low Power/Low Voltage High Speed CMOS Differential

    E-Print Network [OSTI]

    Fayomi, Christian

    @vlsi.polymtl.ca ABSTRACT A new CMOS differential latched comparator suitable for low voltage, low-power application domains. At the same time, designing analog circuits that can operate from a low-voltage supply on a single ended design configuration. It consists of two operational transconductance amplifiers (NMOS

  5. Dielectric-wall linear accelerator with a high voltage fast rise time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators

    DOE Patents [OSTI]

    Caporaso, G.J.; Sampayan, S.E.; Kirbie, H.C.

    1998-10-13T23:59:59.000Z

    A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 12 figs.

  6. Design, construction and operational results of the IGBT controlled solid state modulator high voltage power supply used in the high power RF systems of the Low Energy Demonstration Accelerator of the accelerator production of tritium (APT) project

    SciTech Connect (OSTI)

    Bradley, J.T. III; Rees, D.; Przeklasa, R.S. [Los Alamos National Lab., NM (United States); Scott, M.C. [Continental Electronics Corp., Dallas, TX (United States)

    1998-12-31T23:59:59.000Z

    The 1700 MeV, 100 mA Accelerator Production of Tritium (APT) Proton Linac will require 244 1 MW, continuous wave RF systems. 1 MW continuous wave klystrons are used as the RF source and each klystron requires 95 kV, 17 A of beam voltage and current. The cost of the DC power supplies is the single largest percentage of the total RF system cost. Power supply reliability is crucial to overall RF system availability and AC to DC conversion efficiency affects the operating cost. The Low Energy Demonstration Accelerator (LEDA) being constructed at Los Alamos National Laboratory (LANL) will serve as the prototype and test bed for APT. The design of the RF systems used in LEDA is driven by the need to field test high efficiency systems with extremely high reliability before APT is built. The authors present a detailed description and test results of one type of advanced high voltage power supply system using Insulated Gate Bipolar Transistors (IGBTs) that has been used with the LEDA High Power RF systems. The authors also present some of the distinctive features offered by this power supply topology, including crowbarless tube protection and modular construction which allows graceful degradation of power supply operation.

  7. New High Field Magnet for Neutron Scattering at Hahn-Meitner Institute

    E-Print Network [OSTI]

    M Steiner; D A Tennant; P Smeibidl

    Abstract. The Berlin Neutron Scattering Center BENSC at the Hahn-Meitner-Institute (HMI) is a user facility for the study of structure and dynamics of condensed matter with neutrons and synchrotron radiation with special emphasis on experiments under extreme conditions. Neutron scattering is uniquely suited to study magnetic properties on a microscopic length scale, because neutrons have comparable wavelengths and, due to their magnetic moment, they interact with the atomic magnetic moments. Magnetic interactions and magnetic phenomena depend on thermodynamic parameters like magnetic field, temperature and pressure. At HMI special efforts are being made to offer outstanding sample environments such as very low temperatures or high magnetic fields or combination of both. For the future a dedicated instrument for neutron scattering at extreme fields is under construction, the Extreme Environment Diffractometer ExED. For this instrument the existing superconducting magnets as well as a future hybrid system can be used. The highest fields, above 30 T will be produced by the planned series-connected hybrid magnet system, designed and constructed in collaboration with the National High Magnetic Field Laboratory, Tallahassee, FL. 1.

  8. High energy product permanent magnet having improved intrinsic coercivity and method of making same

    DOE Patents [OSTI]

    Ramesh, Ramamoorthy (Berkeley, CA); Thomas, Gareth (Berkeley, CA)

    1990-01-01T23:59:59.000Z

    A high energy rare earth-ferromagnetic metal permanent magnet is disclosed which is characterized by improved intrinsic coercivity and is made by forming a particulate mixture of a permanent magnet alloy comprising one or more rare earth elements and one or more ferromagnetic metals and forming a second particulate mixture of a sintering alloy consisting essentially of 92-98 wt. % of one or more rare earth elements selected from the class consisting of Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and mixtures of two or more of such rare earth elements, and 2-8 wt. % of one or more alloying metals selected from the class consisting of Al, Nb, Zr, V, Ta, Mo, and mixtures of two or more of such metals. The permanent magnet alloy particles and sintering aid alloy are mixed together and magnetically oriented by immersing the mixture in an axially aligned magnetic field while cold pressing the mixture. The compressed mixture is then sintered at a temperature above the melting point of the sintering aid and below the melting point of the permanent magnet alloy to thereby coat the particle surfaces of the permanent magnetic alloy particles with the sintering aid while inhibiting migration of the rare earth element in the sintering aid into the permanent magnet alloy particles to thereby raise the intrinsic coercivity of the permanent magnet alloy without substantially lowering the high energy of the permanent magnet alloy.

  9. Laminated grid and web magnetic cores

    DOE Patents [OSTI]

    Sefko, John (Monroeville, PA); Pavlik, Norman M. (Plum Borough, PA)

    1984-01-01T23:59:59.000Z

    A laminated magnetic core characterized by an electromagnetic core having core legs which comprise elongated apertures and edge notches disposed transversely to the longitudinal axis of the legs, such as high reluctance cores with linear magnetization characteristics for high voltage shunt reactors. In one embodiment the apertures include compact bodies of microlaminations for more flexibility and control in adjusting permeability and/or core reluctance.

  10. Development of a high quality kicker magnet system

    SciTech Connect (OSTI)

    Dinkel, J.; Hanna, B.; Jensen, C.; Qunell, D.; Reilly, R.

    1993-05-01T23:59:59.000Z

    Presently, there are 6 proton and 6 antiproton bunches used for collider operation in the Fermilab Tevatron. As the number of particles in these bunches increases, experimenter`s detectors begin to saturate. To alleviate this situation, protons and antiprotons will be redistributed in 36 bunches instead of 6 to reduce the number of interactions per crossing. In order to carry this out, the rise and fall times of the Tevatron antiproton injection kicker which deflects the antiprotons onto the closed orbit must be reduced to accommodate the increased number of bunches circulating in the machine. To meet these criteria, it is necessary to reduce the inductance per unit length as seen by the driving source in order to achieve the necessary propagation time through the magnet, For a given aperture, this can be readily done using a picture frame design powered with two pulses of opposite polarity. Two magnets are required, each with a magnetic length of 2.41 m.

  11. The Influence of Isotopic Mass, Edge Magnetic Shear and Input Power on High Density ELMy H-modes in JET

    E-Print Network [OSTI]

    The Influence of Isotopic Mass, Edge Magnetic Shear and Input Power on High Density ELMy H-modes in JET

  12. NHMFL Breaks the 100 Tesla Barrier Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    NHMFL Breaks the 100 Tesla Barrier Gregory S. Boebinger, National High Magnetic Field Laboratory. 109no. 31 12404-12407 On March 22nd 2012, the NHMFL ­ Pulsed Field Facility broke the 100T tesla barrier, setting a world record of 100.75 tesla for a non-destructive magnet. By using advanced

  13. Instrumentation for Measurement of Strain Dependence of Nb3Sn Conductors National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Instrumentation for Measurement of Strain Dependence of Nb3Sn Conductors National High Magnetic Field Laboratory Magnet Science and Technology, Florida State University An NHMFL User Collaboration Grants Program (UCGP) award is supporting students from the FAMU-FSU College of Engineering as part

  14. A field-reversed magnetic configuration and applications of high-temperature FRC plasma

    SciTech Connect (OSTI)

    Ryzhkov, S. V., E-mail: ryzhkov@power.bmstu.ru [Bauman Moscow State Technical University (Russian Federation)

    2011-12-15T23:59:59.000Z

    As applied to a tokomak, a magnetic trap for confinement of a plasma with an inverted field or a magnetic field reversed configuration (FRC) is one of the most promising alternatives of the systems with high {beta}. A brief review of the latest data on FRC and potential directions of using such configurations in addition to energy generation in thermonuclear reactors (TNRs) is proposed.

  15. A 4000-A HVDC (high-voltage direct-current) circuit breaker with fast fault-clearing capability: Final report

    SciTech Connect (OSTI)

    Not Available

    1988-04-01T23:59:59.000Z

    This project is a follow-up of the first development of a 500 kV HVDC airblast circuit breaker (EPRI project 1507-3). The objective was to increase the current interrupting capability from 2200 A to 4000 A and shorten its fault clearing time. A high current 500 kV HVDC circuit breaker has been built using the passive commutation circuit. The breaker is modular in construction and can be designed for a wide variety of system conditions. More than 400 current interruptions were carried out successfully. Tests have shown that this circuit breaker is capable of interrupting more than 4000 A dc. Practical breakers with current interrupting capability of even 5500 A dc could be built. The circuit breaker operation and the fault-clearing process can be materially speeded up if the trip signal is given as soon as the fault is detected and without waiting for the current levels to come down in response to converter control action. The new dc breakers are shown to be capable of withstanding these transient arc currents of 8000 A without affecting its ability to interrupt the direct current that follows the transient. This transient current withstand capability is greater than is likely to occur during dc faults. The fault clearing time of this HVDC circuit breaker is comparable to the fault clearing time of conventional ac breakers for ac faults. The developed HVDC circuit breaker is now commercially available and can be supplied for use in HVDC systems. Its use in such systems is expected to provide flexibility in system design and contribute to system stability. 38 refs., 52 figs., 9 tabs.

  16. Energy deposition studies for the High-Luminosity Large Hadron Collider inner triplet magnets

    E-Print Network [OSTI]

    Mokhov, N V; Tropin, I S; Cerutti, F; Esposito, L S; Lechner, A

    2015-01-01T23:59:59.000Z

    A detailed model of the High Luminosity LHC inner triplet region with new large-aperture Nb3Sn magnets, field maps, corrector packages, and segmented tungsten inner absorbers was built and implemented into the FLUKA and MARS15 codes. In the optimized configuration, the peak power density averaged over the magnet inner cable width is safely below the quench limit. For the integrated luminosity of 3000 fb-1, the peak dose in the innermost magnet insulator ranges from 20 to 35 MGy. Dynamic heat loads to the triplet magnet cold mass are calculated to evaluate the cryogenic capability. In general, FLUKA and MARS results are in a very good agreement.

  17. Total current collapse in High-Voltage GaN MIS-HEMTs induced by Zener trapping D. Jin, J. Joh*, S. Krishnan*, N. Tipirneni*, S. Pendharkar* and J. A. del Alamo

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    Total current collapse in High-Voltage GaN MIS-HEMTs induced by Zener trapping D. Jin, J. Joh*, S collapse in GaN MIS-HEMTs for >600 V operation. Extreme trapping leading to total current collapse has been trapping ("Zener trapping") inside the AlGaN barrier or the GaN channel layers. The trapping takes place

  18. Hybrid magnet devices for molecule manipulation and small scale high gradient-field applications

    DOE Patents [OSTI]

    Humphries, David E. (El Cerrito, CA); Hong, Seok-Cheol (Seoul, KR); Cozzarelli, legal representative, Linda A. (Berkeley, CA); Pollard, Martin J. (El Cerrito, CA); Cozzarelli, Nicholas R. (Berkeley, CA)

    2009-01-06T23:59:59.000Z

    The present disclosure provides a high performance hybrid magnetic structure made from a combination of permanent magnets and ferromagnetic pole materials which are assembled in a predetermined array. The hybrid magnetic structure provides means for separation and other biotechnology applications involving holding, manipulation, or separation of magnetizable molecular structures and targets. Also disclosed are hybrid magnetic tweezers able to exert approximately 1 nN of force to 4.5 .mu.m magnetic bead. The maximum force was experimentally measured to be .about.900 pN which is in good agreement with theoretical estimations and other measurements. In addition, a new analysis scheme that permits fast real-time position measurement in typical geometry of magnetic tweezers has been developed and described in detail.

  19. Magnet Technology for Power Converters: Nanocomposite Magnet Technology for High Frequency MW-Scale Power Converters

    SciTech Connect (OSTI)

    None

    2012-02-27T23:59:59.000Z

    Solar ADEPT Project: CMU is developing a new nanoscale magnetic material that will reduce the size, weight, and cost of utility-scale PV solar power conversion systems that connect directly to the grid. Power converters are required to turn the energy that solar power systems create into useable energy for the grid. The power conversion systems made with CMU’s nanoscale magnetic material have the potential to be 150 times lighter and significantly smaller than conventional power conversion systems that produce similar amounts of power.

  20. Voltage Control Technical Conference

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Intro Voltage Control Conference - BPA Active Power Control in Wind Parks - Siemens Interconnection Criteria for Frequency Response Requirements - NERC Model Validation...

  1. Ultra-High-Energy Cosmic Rays from a Magnetized Strange Star Central Engine for Gamma-Ray Bursts

    E-Print Network [OSTI]

    O. Esquivel; D. Page

    2008-04-04T23:59:59.000Z

    Ultra-high-energy cosmic rays (UHECRs) have been tried to be related to the most varied and powerful sources known in the universe. Gamma-ray bursts (GRBs) are natural candidates. Here, we argue that cosmic rays can be accelerated by large amplitude electromagnetic waves (LAEMWs) when the MHD approximation of the field in the wind generated by the GRB's magnetized central engine breaks down. The central engine considered here is a strange star born with differential rotation from the accretion induced conversion of a neutron star into a strange star in a low-mass X-ray binary system. The LAEMWs generated this way accelerate light ions to the highest energies $E = q\\eta\\Delta\\Phi_{max}$ with an efficiency $\\eta \\sim 10^{-1}$ that accounts for all plausible energy losses. Alternatively, we also consider the possibility that, once formed, the LAEMWs are unstable to creation of a relativistically strong electromagnetic turbulence due to an overturn instability. Under this assumption, a lower limit to the efficiency of acceleration is estimated to be about $\\eta \\sim 10^{-2.5}$. Due to their age, low mass X-ray binary systems can be located in regions of low interstellar medium density as, e.g., globular clusters or even intergalactic medium in case of high proper motion systems, and cosmic ray energy losses due to proton collisions with photons at the decelerating region are avoided, thus opening the possibility for particles to exploit the full voltage available, well beyond that currently observed.

  2. Tokamaks with high-performance resistive magnets: advanced test reactors and prospects for commercial applications

    SciTech Connect (OSTI)

    Bromberg, L.; Cohn, D.R.; Williams, J.E.C.; Becker, H.; Leclaire, R.; Yang, T.

    1981-10-01T23:59:59.000Z

    Scoping studies have been made of tokamak reactors with high performance resistive magnets which maximize advantages gained from high field operation and reduced shielding requirements, and minimize resistive power requirements. High field operation can provide very high values of fusion power density and n tau/sub e/ while the resistive power losses can be kept relatively small. Relatively high values of Q' = Fusion Power/Magnet Resistive Power can be obtained. The use of high field also facilitates operation in the DD-DT advanced fuel mode. The general engineering and operational features of machines with high performance magnets are discussed. Illustrative parameters are given for advanced test reactors and for possible commercial reactors. Commercial applications that are discussed are the production of fissile fuel, electricity generation with and without fissioning blankets and synthetic fuel production.

  3. Transmit field pattern control for high field magnetic resonance imaging with integrated RF current sources 

    E-Print Network [OSTI]

    Kurpad, Krishna Nagaraj

    2005-11-01T23:59:59.000Z

    The primary design criterion for RF transmit coils for MRI is uniform transverse magnetic (B1) field. Currently, most high frequency transmit coils are designed as periodic, symmetric structures that are resonant at the ...

  4. Method for producing through extrusion an anisotropic magnet with high energy product

    DOE Patents [OSTI]

    Chandhok, Vijay K.

    2004-09-07T23:59:59.000Z

    A method for producing an anisotropic magnet with high energy product through extrusion and, more specifically, by placing a particle charge of a composition from the which magnet is to be produced in a noncircular container, heating the container and particle charge and extruding the container and particle charge through a noncircular extrusion die in such a manner that one of the cross-sectional axes or dimension of the container and particle charge is held substantially constant during the extrusion to compact the particle charge to substantially full density by mechanical deformation produced during the extrusion to achieve a magnet with anisotropic magnetic properties along the axes or dimension thereof and, more specifically, a high energy product along the transverse of the smallest cross-sectional dimension of the extruded magnet.

  5. Investigation of the spatiotemporal characteristics of the electric field in the Ne-H{sub 2} plasma of a beam-type high-voltage pulsed discharge

    SciTech Connect (OSTI)

    Demkin, V. P.; Mel'nichuk, S. V.; Borisov, A. V.; Bardin, S. S. [National Research Tomsk State University, 36, Lenin Ave., 634050 Tomsk (Russian Federation)] [National Research Tomsk State University, 36, Lenin Ave., 634050 Tomsk (Russian Federation)

    2013-12-15T23:59:59.000Z

    In the present work, the spatiotemporal dynamics of the electric field E(x, t) of plasma produced by a beam-type high-voltage pulsed discharge is investigated. The electric field strength E(x, t) in an accelerating gap and in a plasma flare was determined from the measured Stark splitting of the H{sub ?} hydrogen line. The obtained dependence E(x, t) was used to calculate the electron distribution function and the spectral line intensities in the accelerating gap and in the plasma flare by the method of statistical modeling. The calculated population of He atomic states excited by electron impact and their comparison with the measured spectral line intensities I(?, x, t) demonstrate that a reverse electric field retarding the electron motion and leading to electron beam degradation must be present in the plasma flare near the grid. Measurement of the field strength from the Stark splitting of the H{sub ?} line demonstrates that it can reach considerable values.

  6. Influence of co-field and cross field flow of mineral oil with and without additives on conduction current and breakdown voltage in highly nonuniform fields

    SciTech Connect (OSTI)

    Megahed, I.Y.; Abdallah, M.A. [Univ. of Alexandria (Egypt). Electrical Engineering Dept.; Zaky, A.A. [Arab Academy for Science and Technology, Alexandria (Egypt)

    1996-12-31T23:59:59.000Z

    The paper presents the results of the effect of enforced co-field and cross-field oil flow on the conduction current and breakdown voltage of degassed oil, oil saturated with O{sub 2} and with SF6 and oil containing 1-methylnaphthalene (MN) and dimethylaniline (DMA) as additives. Direct voltage and a point-to-plane electrode geometry were used and results were obtained for both polarities of the point electrode. A general conclusion from all experiments is that oil flow, whether co-field or cross-field, raises the breakdown voltage and lowers the conduction current. The results also show that the exception of DMA, all additives both gaseous (O{sub 2} and SF6) or solid (MN) raised the breakdown voltage and reduced conduction current, compared with degassed oil, for both polarities of the point electrode. These effects are attributed to the electron-trapping properties of the additives.

  7. High gradient magnetic separation of iron oxide minerals from soil clays

    E-Print Network [OSTI]

    Schulze, Darrell Gene

    1977-01-01T23:59:59.000Z

    HIGH GRADIENT MAGNETIC SEPARATION OF IRON OXIDE MINERALS FROM SOIL CLAYS A Thesis by DARRELL GENE SCHULZE Submitted to the Graduate College of Texas AIM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... December 1977 Major Subject: Soil Science HIGH GRADIENT MAGNETIC SEPARATION OF IRON OXIDE MINERALS FROM SOIL CLAYS A Thesis DARRELL GENE SCHULZE Approved as to style and content by: (Chairman of C ittee) epartm t) j (Member) (Membe December 1977...

  8. Stable High Beta Plasmas Confined by a Dipole Magnetic Field D. T. Garnier,

    E-Print Network [OSTI]

    Mauel, Michael E.

    Stable High Beta Plasmas Confined by a Dipole Magnetic Field D. T. Garnier, A. Hansen, M. E. Mauel Center, MIT, Cambridge, MA 02139 (Dated: October 21, 2005) Abstract Stable high-beta plasma is created we report the first production of high beta plasma confined by a laboratory dipole using neutral gas

  9. Ultra-high speed permanent magnet axial gap alternator with multiple stators

    DOE Patents [OSTI]

    Hawsey, Robert A. (Oak Ridge, TN); Bailey, J. Milton (Knoxville, TN)

    1991-01-01T23:59:59.000Z

    An ultra-high speed, axial gap alternator that can provide an output to a plurality of loads, the alternator providing magnetic isolation such that operating conditions in one load will not affect operating conditions of another load. This improved alternator uses a rotor member disposed between a pair of stator members, with magnets disposed in each of the rotor member surfaces facing the stator members. The magnets in one surface of the rotor member, which alternate in polarity, are isolated from the magnets in the other surface of the rotor member by a disk of magnetic material disposed between the two sets of magents. In the preferred embodiment, this disk of magnetic material is laminated between two layers of non-magnetic material that support the magnets, and the magnetic material has a peripheral rim that extends to both surfaces of the rotor member to enhance the structural integrity. The stator members are substantially conventional in construction in that equally-spaced and radially-oriented slots are provided, and winding members are laid in these slots. A unit with multiple rotor members and stator members is also described.

  10. Voltage verification unit

    DOE Patents [OSTI]

    Martin, Edward J. (Virginia Beach, VA)

    2008-01-15T23:59:59.000Z

    A voltage verification unit and method for determining the absence of potentially dangerous potentials within a power supply enclosure without Mode 2 work is disclosed. With this device and method, a qualified worker, following a relatively simple protocol that involves a function test (hot, cold, hot) of the voltage verification unit before Lock Out/Tag Out and, and once the Lock Out/Tag Out is completed, testing or "trying" by simply reading a display on the voltage verification unit can be accomplished without exposure of the operator to the interior of the voltage supply enclosure. According to a preferred embodiment, the voltage verification unit includes test leads to allow diagnostics with other meters, without the necessity of accessing potentially dangerous bus bars or the like.

  11. The National High Magnetic Field Laboratory was represented by staff from its Center for Integrating Research and Learning

    E-Print Network [OSTI]

    McQuade, D. Tyler

    to drop a magnet seemingly in slow motion through a copper pipe. The USA Science and Engineering Festival and Engineering Festival National High Magnetic Field Laboratory Funding Grants: G.S. Boebinger (NSF DMR-1157490The National High Magnetic Field Laboratory was represented by staff from its Center

  12. 740 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 12, NO. 1, MARCH 2002 High-Resolution Nuclear Magnetic Resonance

    E-Print Network [OSTI]

    Wider, Gerhard

    740 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 12, NO. 1, MARCH 2002 High research depend on high- field superconducting magnets with outstanding homogeneity and excellent long term, superconducting magnets, TROSY. I. INTRODUCTION IN THE half century since its discovery, nuclear magnetic

  13. Vehicle Technologies Office Merit Review 2014: High Energy Density Li-ion Cells for EV’s Based on Novel, High Voltage Cathode Material Systems

    Broader source: Energy.gov [DOE]

    Presentation given by Farasis Energy, Inc. at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high energy density Li...

  14. Vehicle Technologies Office Merit Review 2015: High Energy Density Li-ion Cells for EV’s Based on Novel, High Voltage Cathode Material Systems

    Broader source: Energy.gov [DOE]

    Presentation given by Farasis at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about high energy density Li-ion cells for...

  15. High frequency transformers and high Q factor inductors formed using epoxy-based magnetic polymer materials

    DOE Patents [OSTI]

    Sanchez, Robert O.; Gunewardena, Shelton; Masi, James V.

    2005-03-29T23:59:59.000Z

    An electrical component in the form of an inductor or transformer is disclosed which includes one or more coils and a magnetic polymer material located near the coils or supporting the coils to provide an electromagnetic interaction therewith. The magnetic polymer material is preferably a cured magnetic epoxy which includes a mercaptan derivative having a ferromagnetic atom chemically bonded therein. The ferromagnetic atom can be either a transition metal or rare-earth atom.

  16. High frequency transformers and high Q factor inductors formed using epoxy-based magnetic polymer materials

    DOE Patents [OSTI]

    Sanchez, Robert O. (Los Lunas, NM); Gunewardena, Shelton (Walnut, CA); Masi, James V. (Cape Elizabeth, ME)

    2007-11-27T23:59:59.000Z

    An electrical component in the form of an inductor or transformer is disclosed which includes one or more coils and a magnetic polymer material located near the coils or supporting the coils to provide an electromagnetic interaction therewith. The magnetic polymer material is preferably a cured magnetic epoxy which includes a mercaptan derivative having a ferromagnetic atom chemically bonded therein. The ferromagnetic atom can be either a transition metal or rare-earth atom.

  17. High damping properties of magnetic particles doped rubber composites at wide frequency

    SciTech Connect (OSTI)

    Tian, Ye, E-mail: schtiany@163.com [Research Center for Engineering Technology of Polymeric Composites of Shanxi Province, North University of China, Taiyuan 030051 (China); College of Material Science and Engineering, North University of China, Taiyuan 030051 (China); Liu, Yaqing, E-mail: lyq@nuc.edu.cn [Research Center for Engineering Technology of Polymeric Composites of Shanxi Province, North University of China, Taiyuan 030051 (China); College of Material Science and Engineering, North University of China, Taiyuan 030051 (China); He, Minhong; Zhao, Guizhe; Sun, Youyi [Research Center for Engineering Technology of Polymeric Composites of Shanxi Province, North University of China, Taiyuan 030051 (China); College of Material Science and Engineering, North University of China, Taiyuan 030051 (China)

    2013-05-15T23:59:59.000Z

    Highlights: ? A new kind of permanent magnetic rubber was prepared. ? The microstructure and magnetic properties were investigated. ? The mechanical and damping properties were discussed. ? The new material is expected to be an isolator material to a changed frequency. - Abstract: A new kind of rubber composite was prepared by doping SrFe{sub 12}O{sub 19} nanoparticles coated with silane coupling agents (Si-69) into nitrile butadiene rubber (NBR) matrix, which was characterized by the scanning electron microscopy and X-ray spectroscopy. The results showed that the SrFe{sub 12}O{sub 19} nanoparticles were well dispersed in rubber matrix. Furthermore, the mechanical and magnetic properties of the rubber composites were investigated, in which the high tensile strength (15.8 MPa) and high saturation magnetization (22.9 emu/g) were observed. What is more, the high loss factor of the rubber composites was also obtained in a wide frequency range (0–100 Hz) at high loading (80 phr). The result is attributed to that the permanent magnetic field in rubber nanocomposites can absorb shock energy. These results indicate that the new kind of permanent magnetic rubber is expected to be a smart isolator material, in which the isolator will be able to adapt to a changed frequency.

  18. High resolution detection and excitation of resonant magnetic perturbations in a wall-stabilized tokamak

    SciTech Connect (OSTI)

    Maurer, David A. [Physics Department, Auburn University, Auburn, Alabama 36849 (United States); Shiraki, Daisuke; Levesque, Jeffrey P.; Bialek, James; Angelini, Sarah; Byrne, Patrick; DeBono, Bryan; Hughes, Paul; Mauel, Michael E.; Navratil, Gerald A.; Peng Qian; Rhodes, Dov; Rath, Nickolaus; Stoafer, Christopher [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

    2012-05-15T23:59:59.000Z

    We report high-resolution detection of the 3D plasma magnetic response of wall-stabilized tokamak discharges in the High Beta Tokamak-Extended Pulse [T. H. Ivers et al., Phys. Plasmas 3, 1926 (1996)] device. A new adjustable conducting wall has been installed on HBT-EP made up of 20 independent, movable, wall segments instrumented with three distinct sets of 40 modular coils that can be independently driven to generate a wide variety of magnetic perturbations. High-resolution detection of the plasma response is made with 216 poloidal and radial magnetic sensors that have been located and calibrated with high-accuracy. Static and dynamic plasma responses to resonant and non-resonant magnetic perturbations are observed through measurement of the step-response following a rapid change in the toroidal phase of the applied perturbations. Biorthogonal decomposition of the full set of magnetic sensors clearly defines the structures of naturally occurring external kinks as being composed of independent m/n = 3/1 and 6/2 modes. Resonant magnetic perturbations were applied to discharges with pre-existing, saturated m/n = 3/1 external kink mode activity. This m/n = 3/1 kink mode was observed to lock to the applied perturbation field. During this kink mode locked period, the plasma resonant response is characterized by a linear, a saturated, and a disruptive plasma regime dependent on the magnitude of the applied field and value of the edge safety factor and plasma rotation.

  19. Influence of high magnetic field on the luminescence of Eu{sup 3+}-doped glass ceramics

    SciTech Connect (OSTI)

    Jiang, Wei; Chen, Weibo; Chen, Ping; Xu, Beibei; Zheng, Shuhong; Guo, Qiangbing; Liu, Xiaofeng, E-mail: xfliu@zju.edu.cn, E-mail: qjr@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); Zhang, Junpei; Han, Junbo [Wuhan National High Magnetic field Center, Huazhong University of Science and Technology, Wuhan, Hubei 430074 (China); Qiu, Jianrong, E-mail: xfliu@zju.edu.cn, E-mail: qjr@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027 (China); State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou, Guangdong 510640 (China)

    2014-09-28T23:59:59.000Z

    Rare earth (RE) doped materials have been widely exploited as the intriguing electronic configuration of RE ions offers diverse functionalities from optics to magnetism. However, the coupling of magnetism with photoluminescence (PL) in such materials has been rarely reported in spite of its fundamental significance. In the present paper, the effect of high pulsed magnetic field on the photoluminescence intensity of Eu{sup 3+}-doped nano-glass-ceramics has been investigated. In our experiment, Eu-doped oxyfluoride glass and glass ceramic were prepared by the conventional melt-quenching process and controlled heat treatment. The results demonstrate that the integrated PL intensity of Eu{sup 3+} decreases with the enhancement of magnetic field, which can be interpreted in terms of cooperation effect of Zeeman splitting and magnetic field induced change in site symmetry. Furthermore, as a result of Zeeman splitting, both blue and red shift in the emission peaks of Eu{sup 3+} can be observed, and this effect becomes more prominent with the increase of magnetic field. Possible mechanisms associated with the observed magneto-optical behaviors are suggested. The results of the present paper may open a new gate for modulation of luminescence by magnetic field and remote optical detection of magnetic field.

  20. MAGNETIC FIELD STRUCTURE IN A HIGH-MASS OUTFLOW/DISK SYSTEM

    SciTech Connect (OSTI)

    Beuther, H. [Max-Planck-Institute for Astronomy, Koenigstuhl 17, 69117 Heidelberg (Germany); Vlemmings, W. H. T. [Argelander Institute for Astronomy, University of Bonn, Auf dem Huegel 71, 53121 Bonn (Germany); Rao, R. [Academia Sinica, Institute of Astronomy and Astrophysics, Taipei, Taiwan (China); Van der Tak, F. F. S., E-mail: beuther@mpia.d, E-mail: wouter@astro.uni-bonn.d, E-mail: rrao@sma.hawaii.ed, E-mail: vdtak@sron.n [SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen (Netherlands)

    2010-11-20T23:59:59.000Z

    To characterize the magnetic field structure of the outflow and core region within a prototypical high-mass star-forming region, we analyzed polarized CO(3-2)-for the first time observed with the Submillimeter Array-as well as 880 {mu}m submillimeter continuum emission from the high-mass outflow/disk system IRAS 18089-1732. Both emission features with polarization degrees at a few percent level indicate that the magnetic field structure is largely aligned with the outflow/jet orientation from small core scales to larger outflow scales. Although quantitative estimates are crude, the analysis indicates that turbulent energy dominates over magnetic energy. The data also suggest a magnetic field strength increase from the lower-density envelope to the higher-density core.

  1. 9 T high magnetic field annealing effects on FeN bulk sample

    SciTech Connect (OSTI)

    Jiang, Yanfeng; Wang, Jian-Ping, E-mail: jpwang@umn.edu [Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minneota 55455 (United States); Dabade, Vivekanand; James, Richard D. [Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Brady, Michael P.; Rios, Orlando [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831–6115 (United States)

    2014-05-07T23:59:59.000Z

    ??-Fe{sub 16}N{sub 2} has been suggested as a promising candidate for future rare-earth-free magnets. In this paper, we report to use high magnetic field (9?T) assisted post-annealing process to enhance the Fe{sub 16}N{sub 2} phase formation in FeN bulk rod samples during the ?? ? ?? phase transformation and thus improve its magnetic properties. It was found by X-ray Diffraction measurement that the volume ratio of Fe{sub 16}N{sub 2} phase was increased up to 22%, which corresponds to an increase in the amount of transformation from ?? ? ?? up to 78%. Also, the saturation magnetization (M{sub s}) of the prepared FeN rod sample was increased to 227?emu/g with its coercivity up to 376?Oe at room temperature. A working mechanism for the high field assisted post-annealing process was presented.

  2. High-pressure Magic Angle Spinning Nuclear Magnetic Resonance...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    advantage of ceramic cylinders for withstanding very high-pressure utilized, but also plastic bushings can be glued tightly in place so that other plastic sealing mechanisms...

  3. STATUS OF HIGH TEMPERATURE SUPERCONDUCTOR MAGNET R AND D AT BNL.

    SciTech Connect (OSTI)

    GUPTA,R.; ANERELLA,M.; COZZOLINO,J.; ESCALLIER,J.; GANETIS,G.; GHOSH,A.; ET AL.

    2004-01-22T23:59:59.000Z

    We report the status and test results of the High Temperature Superconductor (HTS) cable and magnet R&D at Brookhaven National Laboratory (BNL). If successful, this will enhance the performance and reduce the cost of operation of magnets that must absorb a large amount of energy. The need for developing this technology has been seen in a number of high field magnet applications for high energy colliders, and a medium field application in the proposed Rare Isotope Accelerator (RIA). The likelihood of the future use of HTS is improving because of the availability of longer and more uniform length tapes and cables and because of the ongoing construction and test experience at BNL and elsewhere. The design of a super-ferric quadrupole, that must survive the very high radiation environment of RIA, and operate at 20-40 K, is also presented.

  4. A table-top, repetitive pulsed magnet for nonlinear and ultrafast spectroscopy in high magnetic fields up to 30 T

    SciTech Connect (OSTI)

    Noe, G. Timothy; Lee, Joseph; Woods, Gary L. [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States)] [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Nojiri, Hiroyuki [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)] [Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan); Léotin, Jean [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, Toulouse (France)] [Laboratoire National des Champs Magnétiques Intenses, CNRS-UJF-UPS-INSA, Toulouse (France); Kono, Junichiro, E-mail: kono@rice.edu [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States) [Department of Electrical and Computer Engineering, Rice University, Houston, Texas 77005 (United States); Department of Physics and Astronomy, Rice University, Houston, Texas 77005, USA and Department of Materials Science and NanoEngineering, Rice University, Houston, Texas 77005 (United States)

    2013-12-15T23:59:59.000Z

    We have developed a mini-coil pulsed magnet system with direct optical access, ideally suited for nonlinear and ultrafast spectroscopy studies of materials in high magnetic fields up to 30 T. The apparatus consists of a small coil in a liquid nitrogen cryostat coupled with a helium flow cryostat to provide sample temperatures down to below 10 K. Direct optical access to the sample is achieved with the use of easily interchangeable windows separated by a short distance of ?135 mm on either side of the coupled cryostats with numerical apertures of 0.20 and 0.03 for measurements employing the Faraday geometry. As a demonstration, we performed time-resolved and time-integrated photoluminescence measurements as well as transmission measurements on InGaAs quantum wells.

  5. COLLECTION OF AIRBORNE PARTICLES BY A HIGH-GRADIENT PERMANENT MAGNETIC METHOD

    SciTech Connect (OSTI)

    Cheng, Mengdawn [ORNL; Allman, Steve L [ORNL; Ludtka, Gerard Michael [ORNL; Avens, Larry R [ORNL

    2014-01-01T23:59:59.000Z

    We report on the use of magnetic force in collection of airborne particles by a high- gradient permanent magnetic separation (HGPMS) device. Three aerosol particles of different magnetic susceptibility (NaCl, CuO, and Fe2O3) were generated in the electrical mobility size range of 10 to 200 nm and were used to study HGPMS collection. One HGPMS matrix element, made of stainless steel wool, was used in the device configuration. Three flow rates were selected to simulate the environmental wind speeds of interest to the study. Magnetic force was found to exhibit an insignificant effect on the separation of NaCl particles, even in the HGPMS configuration. Diffusion was a major mechanism in the removal of the diamagnetic particles; however, diffusion is insignificant under the influence of a high-gradient magnetic field for paramagnetic or ferromagnetic particles. The HGPMS showed high-performance collection (> 99%) of paramagnetic CuO and ferromagnetic Fe2O3 particles for particle sizes greater than or equal to 60 nm. As the wind speed increases, the influence of the magnetic force weakens, and the capability to remove particles from the gas stream diminishes. The results suggest that the HGPMS principle could be explored for development of an advanced miniaturized passive aerosol collector.

  6. Method for preparing high cure temperature rare earth iron compound magnetic material

    DOE Patents [OSTI]

    Huang, Yuhong (West Hills, CA); Wei, Qiang (West Hills, CA); Zheng, Haixing (Oak Park, CA)

    2002-01-01T23:59:59.000Z

    Insertion of light elements such as H,C, or N in the R.sub.2 Fe.sub.17 (R=rare earth metal) series has been found to modify the magnetic properties of these compounds, which thus become prospective candidates for high performance permanent magnets. The most spectacular changes are increases of the Curie temperature, T.sub.c, of the magnetization, M.sub.s, and of coercivity, H.sub.c, upon interstitial insertion. A preliminary product having a component R--Fe--C,N phase is produced by a chemical route. Rare earth metal and iron amides are synthesized followed by pyrolysis and sintering in an inert or reduced atmosphere, as a result of which, the R--Fe--C,N phases are formed. Fabrication of sintered rare earth iron nitride and carbonitride bulk magnet is impossible via conventional process due to the limitation of nitridation method.

  7. Magnetic Pattern Fabrication and Characterization for Next Generation High Density Magnetic Recording System

    E-Print Network [OSTI]

    Lee, Beomseop

    2011-01-01T23:59:59.000Z

    bit patterned media (BPM), capable of achieving magneticfrom the transitions in the BPM film under study. Throughoutthe EBL-fabricated ultra-high-density BPM media. vi Table of

  8. Insight into the Atomic Structure of High-Voltage Spinel LiNi0.5Mn1.5O4 Cathode Material in the First Cycle

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Huang, Xuejie; Yu, Xiqian; Lin, Mingxiang; Ben, Liubin; Sun, Yang; Wang, Hao; Yang, Zhenzhong; Gu, Lin; Yang, Xiao -Qing; Zhao, Haofei; et al

    2015-01-13T23:59:59.000Z

    Application of high-voltage spinel LiNi0.5Mn1.5O4 cathode material is the closest and the most realistic approach to meeting the midterm goal of lithium-ion batteries for electric vehicles (EVs) and plug-in hybrid electric vehicles (HEVs). However, this application has been hampered by long-standing issues, such as capacity degradation and poor first-cycle Coulombic efficiency of LiNi0.5Mn1.5O4 cathode material. Although it is well-known that the structure of LiNi0.5Mn1.5O4 into which Li ions are reversibly intercalated plays a critical role in the above issues, performance degradation related to structural changes, particularly in the first cycle, are not fully understood. Here, we report detailed investigations ofmore »local atomic-level and average structure of LiNi0.5Mn1.5O4 during first cycle (3.5–4.9 V) at room temperature. We observed two types of local atomic-level migration of transition metals (TM) ions in the cathode of a well-prepared LiNi0.5Mn1.5O4//Li half-cell during first charge via an aberration-corrected scanning transmission electron microscopy (STEM). Surface regions (~2 nm) of the cycled LiNi0.5Mn1.5O4 particles show migration of TM ions into tetrahedral Li sites to form a Mn3O4-like structure. However, subsurface regions of the cycled particles exhibit migration of TM ions into empty octahedral sites to form a rocksalt-like structure. The migration of these TM ions are closely related to dissolution of Ni/Mn ions and building-up of charge transfer impedance, which contribute significantly to the capacity degradation and the poor first-cycle Coulombic efficiency of spinel LiNi0.5Mn1.5O4 cathode material. Accordingly, we provide suggestions of effective stabilization of LiNi0.5Mn1.5O4 structure to obtain better electrochemical performance.« less

  9. Insight into the Atomic Structure of High-Voltage Spinel LiNi0.5Mn1.5O4 Cathode Material in the First Cycle

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Huang, Xuejie [Chinese Academy of Sciences, Beijing (China); Yu, Xiqian [Brookhaven National Laboratory (BNL), Upton, NY (United States); Lin, Mingxiang [Chinese Academy of Sciences, Beijing (China); Ben, Liubin [Chinese Academy of Sciences, Beijing (China); Sun, Yang [Chinese Academy of Sciences, Beijing (China); Wang, Hao [Chinese Academy of Sciences, Beijing (China); Yang, Zhenzhong [Chinese Academy of Sciences, Beijing (China); Gu, Lin [Chinese Academy of Sciences, Beijing (China); Yang, Xiao -Qing [Brookhaven National Laboratory (BNL), Upton, NY (United States); Zhao, Haofei [Chinese Academy of Sciences, Beijing (China); Yu, Richeng [Chinese Academy of Sciences, Beijing (China); Armand, Michel [CIC Energigune, Alava (Spain)

    2015-01-13T23:59:59.000Z

    Application of high-voltage spinel LiNi0.5Mn1.5O4 cathode material is the closest and the most realistic approach to meeting the midterm goal of lithium-ion batteries for electric vehicles (EVs) and plug-in hybrid electric vehicles (HEVs). However, this application has been hampered by long-standing issues, such as capacity degradation and poor first-cycle Coulombic efficiency of LiNi0.5Mn1.5O4 cathode material. Although it is well-known that the structure of LiNi0.5Mn1.5O4 into which Li ions are reversibly intercalated plays a critical role in the above issues, performance degradation related to structural changes, particularly in the first cycle, are not fully understood. Here, we report detailed investigations of local atomic-level and average structure of LiNi0.5Mn1.5O4 during first cycle (3.5–4.9 V) at room temperature. We observed two types of local atomic-level migration of transition metals (TM) ions in the cathode of a well-prepared LiNi0.5Mn1.5O4//Li half-cell during first charge via an aberration-corrected scanning transmission electron microscopy (STEM). Surface regions (~2 nm) of the cycled LiNi0.5Mn1.5O4 particles show migration of TM ions into tetrahedral Li sites to form a Mn3O4-like structure. However, subsurface regions of the cycled particles exhibit migration of TM ions into empty octahedral sites to form a rocksalt-like structure. The migration of these TM ions are closely related to dissolution of Ni/Mn ions and building-up of charge transfer impedance, which contribute significantly to the capacity degradation and the poor first-cycle Coulombic efficiency of spinel LiNi0.5Mn1.5O4 cathode material. Accordingly, we provide suggestions of effective stabilization of LiNi0.5Mn1.5O4 structure to obtain better electrochemical performance.

  10. 1 a publication of the National High Magnetic Field Laboratory1111111 a pa pa pa pa pa pa pppublublubublublublblublblblblbllblbblblbblbbbbbbbbbbbbbblbbbbblubbbbbbbbbbbbblllbbbbbblblbbbbbbbbbbbbbllbbbb icaicaicacicicaicciicicicciiciciciccciciccccciiiiciiii

    E-Print Network [OSTI]

    Weston, Ken

    related research in all areas of science and engineering.The Magnet Lab is supported by the National1 a publication of the National High Magnetic Field Laboratory1111111 a pa pa pa pa pa pa magnet lab packs a big punch. InThisIssue VOLUME 3: ISSUE 2 F E A T U R E S Flux is a twice

  11. Table of Contents Page 2National High Magnetic Field Laboratory and Its Forecasted Impact on the Florida Economy

    E-Print Network [OSTI]

    Weston, Ken

    Impact on the Florida Economy History and Evaluation of the Economic Impact of the Magnet Lab Forecasted Impact on the Florida Economy The National Science Foundation (NSF) awarded the National High generated by Magnet Lab activities across the broader statewide economy. Since 1990, the Magnet Lab has

  12. Reply to "Comment on `Microwave vortex dissipation of superconducting Nd-Ce-Cu-O epitaxial films in high magnetic fields' "

    E-Print Network [OSTI]

    Yeh, Nai-Chang

    in high magnetic fields' " N.-C. Yeh1 and D. M. Strayer2 1Department of Physics, California Institute of Technology, Pasadena, California 91125, USA 2 Jet Propulsion Laboratory, California Institute of Technology of these modes are insensitive to the application of external magnetic fields, be- cause magnetic fields do

  13. Computer Aided Design and Modeling of High Frequency Magnetic Components *

    E-Print Network [OSTI]

    Paderborn, Universität

    - cy multiwinding transformers and inductors in any power electronics applications. Depending circuitry and 0 the skin effect inside the windings of high frequen- cy transformers and resonant inductors University of Paderborn, FB 14 Power Electronics and Electrical Drives Pohlweg 47 33098 Paderborn, Germany

  14. High-Energy Permanent Magnets for Hybrid Vehicles and Alternative Energy Uses

    SciTech Connect (OSTI)

    Hadjipanayis, George C. [University of Delaware] [University of Delaware; McCallum, William R. [Ames Laboratory] [Ames Laboratory; Sellmyer, David J. [University of Nebraska, Lincoln] [University of Nebraska, Lincoln; Harris, Vincent [Northeastern University] [Northeastern University; Carpenter, Everett E. [Virginia Commonwealth University] [Virginia Commonwealth University; Liu, Jinfang [Electron Energy Corporation] [Electron Energy Corporation

    2013-12-17T23:59:59.000Z

    The report summarizes research undertaken by a multidisciplinary team aimed at the development of the next generation high-energy permanent magnets. The principal approach was relied on bottom-up fabrication of anisotropic nanocomposite magnets. Our efforts resulted in further development of the theoretical concept and fabrication principles for the nanocomposites and in synthesis of a range of rare-earth-based hard magnetic nanoparticles. Even though we did not make a breakthrough in the assembly of these hard magnetic particles with separately prepared Fe(Co) nanoparticles and did not obtain a compact nanocomposite magnet, our performed research will help to direct the future efforts, in particular, towards nano-assembly via coating, when the two phases which made the nanocomposite are first organized in core-shell-structured particles. Two other approaches were to synthesize (discover) new materials for the traditional singe-material magnets and the nanocomposite magnets. Integrated theoretical and experimental efforts lead to a significant advance in nanocluster synthesis technique and yielded novel rare-earth-free nanostructured and nanocomposite materials. Examination of fifteen R-Fe-X alloy systems (R = rare earth), which have not been explored earlier due to various synthesis difficulties reveal several new ferromagnetic compounds. The research has made major progress in bottom-up manufacturing of rare-earth-containing nanocomposite magnets with superior energy density and open new directions in development of higher-energy-density magnets that do not contain rare earths. The advance in the scientific knowledge and technology made in the course of the project has been reported in 50 peer-reviewed journal articles and numerous presentations at scientific meetings.

  15. Electro-optical voltage sensor head

    DOE Patents [OSTI]

    Woods, Gregory K. (Idaho Falls, ID)

    1998-01-01T23:59:59.000Z

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  16. auxiliary voltage converter: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Voltage Switching inverter working at 20 kHz and an output stage (high frequency transformers, Schottky rectifi ers and output filter... Jrgensen, H E; Dupaquier, A;...

  17. High Performance Permanent Magnets for Advanced Motors | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(Fact Sheet), GeothermalGridHYDROGEN TOTechnologyHighLouisiana |

  18. The High-Energy Polarization-Limiting Radius of Neutron Star Magnetospheres II -- Magnetized Hydrogen Atmospheres

    E-Print Network [OSTI]

    Jeremy S. Heyl; Don Lloyd; Nir J. Shaviv

    2005-02-17T23:59:59.000Z

    In the presence of strong magnetic fields, the vacuum becomes a birefringent medium. We show that this QED effect couples the direction of the polarization of photons leaving the NS surface, to the direction of the magnetic field along the ray's path. We analyze the consequences that this effect has on aligning the polarization vectors to generate large net polarizations, while considering thermal radiation originating from a thermal hydrogen atmosphere. Counter to previous predictions, we show that the thermal radiation should be highly polarized even in the optical. When detected, this polarization will be the first demonstration of vacuum birefringence. It could be used as a tool to prove the high magnetic field nature of AXPs and it could also be used to constrain physical NS parameters, such as $R/M$, to which the net polarization is sensitive.

  19. A High-Order Finite-Volume Algorithm for Fokker-Planck Collisions in Magnetized Plasmas

    SciTech Connect (OSTI)

    Xiong, Z; Cohen, R H; Rognlien, T D; Xu, X Q

    2007-04-18T23:59:59.000Z

    A high-order finite volume algorithm is developed for the Fokker-Planck Operator (FPO) describing Coulomb collisions in strongly magnetized plasmas. The algorithm is based on a general fourth-order reconstruction scheme for an unstructured grid in the velocity space spanned by parallel velocity and magnetic moment. The method provides density conservation and high-order-accurate evaluation of the FPO independent of the choice of the velocity coordinates. As an example, a linearized FPO in constant-of-motion coordinates, i.e. the total energy and the magnetic moment, is developed using the present algorithm combined with a cut-cell merging procedure. Numerical tests include the Spitzer thermalization problem and the return to isotropy for distributions initialized with velocity space loss cones. Utilization of the method for a nonlinear FPO is straightforward but requires evaluation of the Rosenbluth potentials.

  20. Electron launching voltage monitor

    DOE Patents [OSTI]

    Mendel, C.W.; Savage, M.E.

    1992-03-17T23:59:59.000Z

    An electron launching voltage monitor measures MITL voltage using a relationship between anode electric field and electron current launched from a cathode-mounted perturbation. An electron launching probe extends through and is spaced from the edge of an opening in a first MITL conductor, one end of the launching probe being in the gap between the MITL conductor, the other end being adjacent a first side of the first conductor away from the second conductor. A housing surrounds the launching probe and electrically connects the first side of the first conductor to the other end of the launching probe. A detector detects the current passing through the housing to the launching probe, the detected current being representative of the voltage between the conductors. 5 figs.

  1. New vertical cryostat for the high field superconducting magnet test station at CERN

    SciTech Connect (OSTI)

    Vande Craen, A.; Atieh, S.; Bajko, M.; Benda, V.; Rijk, G. de; Favre, G.; Giloux, C.; Minginette, P.; Parma, V.; Perret, P.; Pirotte, O.; Ramos, D.; Viret, P. [CERN European Organization for Nuclear Research, Meyrin 1211, Geneva 23, CH (Switzerland); Hanzelka, P. [Institute of Scientific Instruments of the ASCR, Kralovopolska 147, 612 64 Brno, CZ (Czech Republic)

    2014-01-29T23:59:59.000Z

    In the framework of the R and D program for new superconducting magnets for the Large Hadron Collider accelerator upgrades, CERN is building a new vertical test station to test high field superconducting magnets of unprecedented large size. This facility will allow testing of magnets by vertical insertion in a pressurized liquid helium bath, cooled to a controlled temperature between 4.2 K and 1.9 K. The dimensions of the cryostat will allow testing magnets of up to 2.5 m in length with a maximum diameter of 1.5 m and a mass of 15 tons. To allow for a faster insertion and removal of the magnets and reducing the risk of helium leaks, all cryogenics supply lines are foreseen to remain permanently connected to the cryostat. A specifically designed 100 W heat exchanger is integrated in the cryostat helium vessel for a controlled cooling of the magnet from 4.2 K down to 1.9 K in a 3 m{sup 3} helium bath. This paper describes the cryostat and its main functions, focusing on features specifically developed for this project. The status of the construction and the plans for assembly and installation at CERN are also presented.

  2. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1987-11-17T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile. 2 figs.

  3. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, Ronald S. (Livermore, CA)

    1987-01-01T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  4. Low voltage arc formation in railguns

    DOE Patents [OSTI]

    Hawke, R.S.

    1985-08-05T23:59:59.000Z

    A low voltage plasma arc is first established across the rails behind the projectile by switching a low voltage high current source across the rails to establish a plasma arc by vaporizing a fuse mounted on the back of the projectile, maintaining the voltage across the rails below the railgun breakdown voltage to prevent arc formation ahead of the projectile. After the plasma arc has been formed behind the projectile a discriminator switches the full energy bank across the rails to accelerate the projectile. A gas gun injector may be utilized to inject a projectile into the breech of a railgun. The invention permits the use of a gas gun or gun powder injector and an evacuated barrel without the risk of spurious arc formation in front of the projectile.

  5. Threshold voltage extraction circuit

    E-Print Network [OSTI]

    Hoon, Siew Kuok

    2000-01-01T23:59:59.000Z

    to that of the saturation method. However, instead of fixing Vos ? Vos, the drain current is measured as a function of Vos while Vns is fixed at a constant low voltage of 100mV to ensure operation in the linear MOSFET region. Neglecting channel length modulation effect... transistors are layout next to the DUT of the NMOS and PMOS Vr extraction circuits respectively for extraction of Vr via graphical means. GRAPHICAL METHOD OF THE THRESHOLD-VOLTAGE MEASUREMENT Using the graphical method, the characteristics of 4n versus Vos...

  6. Symmetry Breaking in Graphene Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Symmetry Breaking in Graphene Gregory S. Boebinger, National High Magnetic Field Laboratory DMR. In this experiment, Landau levels in graphene were used to study the breaking of SU(4) symmetry--a higher dimensional states by their spin polarization. It was found that graphene turns into either a spin ferromagnet

  7. Phase transitions in Dual-Gated Bilayer Graphene Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Phase transitions in Dual-Gated Bilayer Graphene Gregory S. Boebinger, National High Magnetic Field Laboratory DMR-Award 0654118 DC Field Facility Bilayer graphene, consisting of two layers of carbon atoms of the degeneracy of the electronic states in the graphene bilayer. Resistivity plotted as a function of the front

  8. ElectroMagnetic Radiations of FPGAs: High Spatial Resolution Cartography and Attack of a

    E-Print Network [OSTI]

    Boyer, Edmond

    ElectroMagnetic Radiations of FPGAs: High Spatial Resolution Cartography and Attack, a "root of trust" must be defined, insulated and then carefully protected. Until very recently, this role agencies) have tackled the issue of protecting ASICs from side-channel attacks (SCAs). In the meantime

  9. IMPACT OF MAGNETIC ENVIRONMENT ON THE GENERATION OF HIGH-ENERGY NEUTRONS AT THE SUN

    E-Print Network [OSTI]

    Usoskin, Ilya G.

    IMPACT OF MAGNETIC ENVIRONMENT ON THE GENERATION OF HIGH-ENERGY NEUTRONS AT THE SUN L. G. KOCHAROV and J. TORSTI Space Research Laboratory, Department of Physics, SF-20014 Turku University, Finland F. TANG and H. ZIRIN Big Bear Solar Observatory, Caltech, Pasadena CA 91125, U.S.A. G. A. KOVALTSOV and I

  10. Biaxial testing of high strength carbon fiber composite cylinders for pulsed magnet reinforcement

    E-Print Network [OSTI]

    Garmestani, Hamid

    envelope) of composite materials. This methodology was applied to two different carbon/epoxy basedBiaxial testing of high strength carbon fiber composite cylinders for pulsed magnet reinforcement N A methodology is introduced to test carbon-fiber-reinforced, hoop-wound composite cylinders for their biaxial

  11. Proton Transport by the Influenza M2 Protein Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Proton Transport by the Influenza M2 Protein Gregory S. Boebinger, National High Magnetic Field infections) in native like lipid bilayers has allowed us to determine a novel mechanism for proton transport that has not been observed in any other protein. At the heart of this proton channel is a set of 4

  12. HIGH-SPEED AXIAL-FLUX PERMANENT MAGNET MICROMOTORS WITH ELECTROPLATED WINDINGS

    E-Print Network [OSTI]

    the other. The folded-coil stator fabrication process is detailed, followed by the motor driver topology- plated multi-phase stator windings and their use in a high-speed permanent magnet micromotor. As the stator windings of an axial- flux micromotor, both single-plated folded coils, and two-layer double

  13. Fermi Surface of Uranium at Ambient Pressure Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    Fermi Surface of ­Uranium at Ambient Pressure Gregory S. Boebinger, National High Magnetic Field Laboratory DMR-Award 0654118 DC Field Facility User Program The fermi surface of ­Uranium has been measured surface of alpha-uranium at ambient pressure, Phys. Rev. B Rapid Commun., 80, 241101 (2009). B//c-axis B

  14. Design of optimal digital controller for stable super-high-speed permanent-magnet synchronous

    E-Print Network [OSTI]

    Wu, Thomas

    collaborative design scheme of a super-high-speed permanent-magnet synchronous motor (PMSM) and its digital stability and performance. Since the systematic design of the PMSM can ensure its stability over the full the efficiency and performance of the PMSM. The unique feature in the proposed optimal V/f control is its design

  15. High-Temperature Superconducting Cable Testing Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    and need for improvement. A 20-strand cable sample was wound into a 12-turn coil, which is also a first of HTS coil technology needed, for example, for the design of a 60 T DC hybrid magnet at the MagLab PhD student who recently formed a company to develop his ideas for making cables out of REBCO coated

  16. The Curie-Weiss constant of solid 3He on the melting curve at high magnetic fields

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    magnetic fields. A plastic Pomeranchuk cell [9] was precooled down to 3 mK by a dilution refrigerator [10JL-625 The Curie-Weiss constant of solid 3He on the melting curve at high magnetic fields H. Godfrin by NMR at high magnetic fields (7.2 teslas). The result (03B8 ~ - 3 mK) is in agreement with low field

  17. Concept of Quasi-Capacitive Tapping of Bipolar Voltage-Controlled Oscillators

    E-Print Network [OSTI]

    Serdijn, Wouter A.

    Concept of Quasi-Capacitive Tapping of Bipolar Voltage-Controlled Oscillators Aleksandar Tasic the active part of the oscillator and the LC-tank, as proposed in this paper, the voltage swing over the tank of high- performance bipolar voltage-controlled oscillators (VCO's). As the voltage-controlled oscillators

  18. Stress Analysis of a High Temperature Superconductor Coil Wound With Bi-2223/Ag Tapes for High Field HTS/LTS NMR Magnet Application

    E-Print Network [OSTI]

    Kiyoshi, Tsukasa

    The electromagnetic stress distribution inside a HTS insert is one of the key issues for construction of a high field high/low temperature superconductor (HTS/LTS) magnet. The rmiddotJmiddotB formulae is widely used for ...

  19. FURMAN NMR SAFETY INFORMATION Standard safety guidelines have been put in place for work around the high-field magnets, and all users

    E-Print Network [OSTI]

    Earth's magnetic field 6.0 x 10-5 T at the equator Refrigerator Magnet .0100-.0150 T MRI Medical the high-field magnets, and all users must take proper precautions to prevent expensive instrument damage and serious personal injury, including death. NMR Magnetic Field Strength · Remember: The magnetic field

  20. Wide-range voltage modulation

    SciTech Connect (OSTI)

    Rust, K.R.; Wilson, J.M.

    1992-06-01T23:59:59.000Z

    The Superconducting Super Collider`s Medium Energy Booster Abort (MEBA) kicker modulator will supply a current pulse to the abort magnets which deflect the proton beam from the MEB ring into a designated beam stop. The abort kicker will be used extensively during testing of the Low Energy Booster (LEB) and the MEB rings. When the Collider is in full operation, the MEBA kicker modulator will abort the MEB beam in the event of a malfunction during the filling process. The modulator must generate a 14-{mu}s wide pulse with a rise time of less than 1 {mu}s, including the delay and jitter times. It must also be able to deliver a current pulse to the magnet proportional to the beam energy at any time during ramp-up of the accelerator. Tracking the beam energy, which increases from 12 GeV at injection to 200 GeV at extraction, requires the modulator to operate over a wide range of voltages (4 kV to 80 kV). A vacuum spark gap and a thyratron have been chosen for test and evaluation as candidate switches for the abort modulator. Modulator design, switching time delay, jitter and pre-fire data are presented.

  1. Far-infrared properties of superconducting YBa2Cu3O7-d films in high magnetic fields

    E-Print Network [OSTI]

    Tanner, David B.

    Far-infrared properties of superconducting YBa2Cu3O7-d films in high magnetic fields H.L. Liua,*, A of Physics, University of Florida, Gainesville, FL 32611, USA b National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306, USA c Jet Propulsion Laboratory, California Institute

  2. HIGH-POWER PRECISION CURRENT SUPPLY IST2-1000M FOR ELEMENTS OF MAGNETIC SYSTEMS OF ACCELERATORS AND

    E-Print Network [OSTI]

    Kozak, Victor R.

    HIGH-POWER PRECISION CURRENT SUPPLY IST2-1000M FOR ELEMENTS OF MAGNETIC SYSTEMS OF ACCELERATORS. These supplies are intended to power magnetic systems of accelerators, requiring high stability and low ripples current at non-inductive load % 0,02 Rate of current raise without disturbing operation of the system

  3. A Sliding Ring Coil for Neuroimaging at 21.1 T Gregory S. Boebinger, National High Magnetic Field Laboratory

    E-Print Network [OSTI]

    Weston, Ken

    A Sliding Ring Coil for Neuroimaging at 21.1 T Gregory S. Boebinger, National High Magnetic Field interference; and 4. anesthesia & vacuum lines for animal care. #12;A Sliding Ring Coil for Neuroimaging at 21 sliding tuner ring for neuroimaging in high field vertical magnets: Ex and in vivo applications at 21.1 T

  4. Cost Effective Open Geometry HTS MRI System amended to BSCCO 2212 Wire for High Field Magnets

    SciTech Connect (OSTI)

    Kennth Marken

    2006-08-11T23:59:59.000Z

    The original goal of this Phase II Superconductivity Partnership Initiative project was to build and operate a prototype Magnetic Resonance Imaging (MRI) system using high temperature superconductor (HTS) coils wound from continuously processed dip-coated BSCCO 2212 tape conductor. Using dip-coated tape, the plan was for MRI magnet coils to be wound to fit an established commercial open geometry, 0.2 Tesla permanent magnet system. New electronics and imaging software for a prototype higher field superconducting system would have added significantly to the cost. However, the use of the 0.2 T platform would allow the technical feasibility and the cost issues for HTS systems to be fully established. Also it would establish the energy efficiency and savings of HTS open MRI compared with resistive and permanent magnet systems. The commercial goal was an open geometry HTS MRI running at 0.5 T and 20 K. This low field open magnet was using resistive normal metal conductor and its heat loss was rather high around 15 kolwatts. It was expected that an HTS magnet would dissipate around 1 watt, significantly reduce power consumption. The SPI team assembled to achieve this goal was led by Oxford Instruments, Superconducting Technology (OST), who developed the method of producing commercial dip coated tape. Superconductive Components Inc. (SCI), a leading US supplier of HTS powders, supported the conductor optimization through powder optimization, scaling, and cost reduction. Oxford Magnet Technology (OMT), a joint venture between Oxford Instruments and Siemens and the world’s leading supplier of MRI magnet systems, was involved to design and build the HTS MRI magnet and cryogenics. Siemens Magnetic Resonance Division, a leading developer and supplier of complete MRI imaging systems, was expected to integrate the final system and perform imaging trials. The original MRI demonstration project was ended in July 2004 by mutual consent of Oxford Instruments and Siemens. Between the project start and that date a substantial shift in the MRI marketplace occurred, with rapid growth for systems at higher fields (1.5 T and above) and a consequent decline in the low field market (<1.0 T). While the project aim appeared technically attainable at that time, the conclusion was reached that the system and market economics do not warrant additional investment. The program was redirected to develop BSCCO 2212 multifilament wire development for high field superconducting magnets for NMR and other scientific research upon an agreement between DOE and Oxford Instruments, Superconducting Technology. The work t took place between September, 2004 and the project end in early 2006 was focused on 2212 multifilamentary wire. This report summarizes the technical achievements both in 2212 dip coated for an HTS MRI system and in BSCCO 2212 multifilamentary wire for high field magnets.

  5. Controller design and implementation for a 6-degree-of-freedom magnetically levitated positioner with high precision 

    E-Print Network [OSTI]

    Yu, Ho

    2005-11-01T23:59:59.000Z

    This thesis presents the controller design and implementation of a high-precision 6-degree-of-freedom (6-DOF) magnetically levitated (maglev) positioner. This high-precision positioning system consists of a novel ...

  6. The formation of reverse shocks in magnetized high energy density supersonic plasma flows

    SciTech Connect (OSTI)

    Lebedev, S. V., E-mail: s.lebedev@imperial.ac.uk, E-mail: l.suttle10@imperial.ac.uk; Suttle, L.; Swadling, G. F.; Bennett, M.; Bland, S. N.; Burdiak, G. C.; Chittenden, J. P.; Grouchy, P. de; Hall, G. N.; Hare, J. D.; Kalmoni, N.; Niasse, N.; Patankar, S.; Smith, R. A.; Suzuki-Vidal, F. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom)] [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Burgess, D.; Clemens, A. [Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom)] [Astronomy Unit, School of Physics and Astronomy, Queen Mary University of London, London E1 4NS (United Kingdom); Ciardi, A. [LERMA, Observatoire de Paris and École Normale Supérieure Université Pierre et Marie Curie, UMR 8112 CNRS, 75231 Paris (France)] [LERMA, Observatoire de Paris and École Normale Supérieure Université Pierre et Marie Curie, UMR 8112 CNRS, 75231 Paris (France); Sheng, L. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom) [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Yuan, J. [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom) [Blackett Laboratory, Imperial College, London SW7 2BW (United Kingdom); Institute of Fluid Physics, China Academy of Engineering Physics, Mianyang 621900 (China); and others

    2014-05-15T23:59:59.000Z

    A new experimental platform was developed, based on the use of supersonic plasma flow from the ablation stage of an inverse wire array z-pinch, for studies of shocks in magnetized high energy density physics plasmas in a well-defined and diagnosable 1-D interaction geometry. The mechanism of flow generation ensures that the plasma flow (Re{sub M}???50, M{sub S}???5, M{sub A}???8, V{sub flow}???100?km/s) has a frozen-in magnetic field at a level sufficient to affect shocks formed by its interaction with obstacles. It is found that in addition to the expected accumulation of stagnated plasma in a thin layer at the surface of a planar obstacle, the presence of the magnetic field leads to the formation of an additional detached density jump in the upstream plasma, at a distance of ?c/?{sub pi} from the obstacle. Analysis of the data obtained with Thomson scattering, interferometry, and local magnetic probes suggests that the sub-shock develops due to the pile-up of the magnetic flux advected by the plasma flow.

  7. The Cyclotron Fundamental Exposed in the High-Field Magnetic Variable V884 Her

    E-Print Network [OSTI]

    G. D. Schmidt; L. Ferrario; D. T. Wickramasinghe; P. S. Smith

    2000-12-22T23:59:59.000Z

    High-quality phase-resolved optical spectropolarimetry is presented for the magnetic cataclysmic variable V884 Her. The overall circular polarization during active accretion states is low and only slightly variable in the range 5000-8000A. However, the polarization is highly structured with wavelength, showing very broad polarization humps, narrow features that are associated with weak absorption lines in the total spectral flux, and sharp reversals across each major emission line. The polarization reversals arise from Zeeman splitting in the funnel gas in a longitudinal magnetic field B~30kG. The set of narrow, polarized absorption features matches the Zeeman pattern of hydrogen for a nearly uniform magnetic field of B=150MG, indicating that the features are "halo" absorption lines formed in a relatively cool reversing layer above the shock. With this identification, the broad polarization humps centered near 7150A and below 4000A are assigned to cyclotron emission from the fundamental and first harmonic (n=2), respectively. V884 Her is only the second AM Her system known with a field exceeding 100MG, and the first case in which the cyclotron fundamental has been directly observed from a magnetic white dwarf.

  8. Spin-torque diode radio-frequency detector with voltage tuned resonance

    SciTech Connect (OSTI)

    Skowro?ski, Witold, E-mail: skowron@agh.edu.pl; Frankowski, Marek; Stobiecki, Tomasz [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Wrona, Jerzy [AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Singulus Technologies, Kahl am Main 63796 (Germany); Ogrodnik, Piotr [Faculty of Physics, Warsaw University of Technology, ul. Koszykowa 75, 00-662 Warsaw (Poland); AGH University of Science and Technology, Department of Electronics, Al. Mickiewicza 30, 30-059 Kraków (Poland); Barna?, Józef [Faculty of Physics, Adam Mickiewicz University, ul. Umultowska 85, 61-614 Pozna? (Poland); Institute of Molecular Physics, Polish Academy of Sciences, Smoluchowskiego 17, 60-179 Pozna? (Poland)

    2014-08-18T23:59:59.000Z

    We report on a voltage-tunable radio-frequency (RF) detector based on a magnetic tunnel junction (MTJ). The spin-torque diode effect is used to excite and/or detect RF oscillations in the magnetic free layer of the MTJ. In order to reduce the overall in-plane magnetic anisotropy of the free layer, we take advantage of the perpendicular magnetic anisotropy at the interface between ferromagnetic and insulating layers. The applied bias voltage is shown to have a significant influence on the magnetic anisotropy, and thus on the resonance frequency of the device. This influence also depends on the voltage polarity. The obtained results are accounted for in terms of the interplay of spin-transfer-torque and voltage-controlled magnetic anisotropy effects.

  9. Michael Scholl, mss4@wustl.edu (A paper written under the guidance of Prof. Raj Jain) Download High availability is one of the major goals of smart grid systems. This paper examines the availability of wind turbines, a high voltage DC (HVDC)

    E-Print Network [OSTI]

    Jain, Raj

    the availability of wind turbines, a high voltage DC (HVDC) transmission system, and a supervisory control and data of a Wind Turbine 3.2 Availability Data 3.3 Sensitivity Analysis 4. HVDC Transmission System 4.1 Parts of a HVDC Transmission System 4.2 Availability Data 4.3 Sensitivity Analysis 5. Control System 5.1 Parts

  10. Magnetic Field Safety Magnetic Field Safety

    E-Print Network [OSTI]

    McQuade, D. Tyler

    Magnetic Field Safety Training #12;Magnetic Field Safety Strong Magnetic Fields exist around energized magnets. High magnetic fields alone are a recognized hazard only for personnel with certain medical conditions such as pacemakers, magnetic implants, or embedded shrapnel. In addition, high magnetic

  11. INTEGRATED GHz VOLTAGE CONTROLLED OSCILLATORS

    E-Print Network [OSTI]

    Kinget, Peter

    INTEGRATED GHz VOLTAGE CONTROLLED OSCILLATORS Peter Kinget Bell Labs - Lucent Technologies Murray Hill, NJ (USA) Abstract The voltage controlled oscillator (VCO) is a critical sub. We focus on the de- sign of a critical sub-block: the voltage controlled oscillator (VCO). We review

  12. Electro-optic voltage sensor for sensing voltage in an E-field

    DOE Patents [OSTI]

    Woods, Gregory K. (Idaho Falls, ID); Renak, Todd W. (Idaho Falls, ID)

    1999-01-01T23:59:59.000Z

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  13. Electro-optic voltage sensor for sensing voltage in an E-field

    DOE Patents [OSTI]

    Woods, G.K.; Renak, T.W.

    1999-04-06T23:59:59.000Z

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages is disclosed. The system employs a transmitter, a sensor disposed adjacent to but out of direct electrical contact with a conductor on which the voltage is to be measured, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor where the beam undergoes the Pockels electro-optic effect. The electro-optic effect causes phase shifting in the beam, which is in turn converted to a pair of independent beams, from which the voltage of a system based on its E-field is determined when the two beams are normalized by the signal processor. The sensor converts the beam by splitting the beam in accordance with the axes of the beam`s polarization state (an ellipse whose ellipticity varies between -1 and +1 in proportion to voltage) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured. 18 figs.

  14. R AND D FOR ACCELERATOR MAGNETS WITH REACT AND WIND HIGH TEMPERATURE SUPERCONDUCTORS.

    SciTech Connect (OSTI)

    GUPTA,R.; ANERELLA,M.; COZZOLINO,J.; ESCALLIER,J.; GANETIS,G.; GHOSH,A.; HARRISON,M.; JAIN,A.; MARONE,A.; MURATORE,J.; PARKER,B.; SAMPSON,W.; WANDERER,P.

    2001-09-24T23:59:59.000Z

    High Temperature Superconductors (HTS) have the potential to change the design and operation of future particle accelerators beginning with the design of high performance interaction regions. HTS offers two distinct advantages over conventional Low Temperature Superconductors (LTS)--they retain a large fraction of their current carrying capacity (a) at high fields and (b) at elevated temperatures. The Superconducting Magnet Division at Brookhaven National Laboratory (BNL) has embarked on a new R&D program for developing technology needed for building accelerator magnets with HTS. We have adopted a ''React & Wind'' approach to deal with the challenges associated with the demanding requirements of the reaction process. We have developed several ''conductor friendly'' designs to deal with the challenges associated with the brittle nature of HTS. We have instituted a rapid turn around program to understand and to develop this new technology in an experimental fashion. Several R&D coils and magnets with HTS tapes and ''Rutherford'' cables have been built and tested. We have recently performed field quality measurements to investigate issues related to the persistent currents. In this paper, we report the results to date and plans and possibilities for the future.

  15. A prototype high-temperature superconducting coil for the 32 T all-superconducting magnet was constructed with YBCO tape and

    E-Print Network [OSTI]

    Weston, Ken

    A prototype high-temperature superconducting coil for the 32 T all- superconducting magnet T All-Superconducting Magnet Hubertus W. Weijers, W.D. Markiewicz, H. Bai, S.T. Hannahs National High

  16. Shrink Tube Insulation Apparatus for Rebco Superconducting Tapes for Use in High Field Magnets

    E-Print Network [OSTI]

    Whittington, Andrew

    An increasing number of applications require the use of high temperature superconductors (HTS) such as (RE=Rare Earth) Ba2Cu3O7-x (REBCO) coated conductors [1]. HTS conductors show particularly great potential for high field magnets applications [1] due to their high upper critical fields [2], But several groups have shown that REBCO coated conductors are prone to delamination failure [3] [4] [5]. Under relatively low transverse stress the HTS film separates from the substrate and the conductor degrades [6]. This is problematic due to high transverse stresses that occur in fully epoxy impregnated solenoids wound with this conductor. Application of thin walled heat shrink tubing introduces a weak plane around the conductor, preventing delamination degradation [7]. However, manual application of the shrink tubing is impractical, requiring three operators limited to insulating 100 m lengths or less of REBCO conductor. The high risk of damage to the conductor, also associated with this process, shows the need for...

  17. Narrowband high temperature superconducting receiver for low frequency radio waves

    DOE Patents [OSTI]

    Reagor, David W. (Los Alamos, NM)

    2001-01-01T23:59:59.000Z

    An underground communicating device has a low-noise SQUID using high temperature superconductor components connected to detect a modulated external magnetic flux for outputting a voltage signal spectrum that is related to the varying magnetic flux. A narrow bandwidth filter may be used to select a portion of the voltage signal spectrum that is relatively free of power line noise to output a relatively low noise output signal when operating in a portion of the electromagnetic spectra where such power line noise exists. A demodulator outputs a communication signal, which may be an FM signal, indicative of a modulation on the modulated external magnetic flux.

  18. Physical and magnetic properties of highly aluminum doped strontium ferrite nanoparticles prepared by auto-combustion route

    E-Print Network [OSTI]

    Liu, J. Ping

    Physical and magnetic properties of highly aluminum doped strontium ferrite nanoparticles prepared-Hexaferrite Al doped Sr-Ferrite High Coercivity Ferrite a b s t r a c t Highly Al3þ ion doped nanocrystalline Sr microscope show growth of needle shaped ferrites with high aspect ratio at Al3þ ion content exceeding xZ2. Al

  19. Determination of the Non-Ideal Response of a High Temperature Tokamak Plasma to a Static External Magnetic Perturbation via

    E-Print Network [OSTI]

    Fitzpatrick, Richard

    that at the other surfaces is rotating. I. INTRODUCTION Tokamak plasmas are highly sensitive to externally generated of "locked" (i.e., non-rotating) magnetic island chains on so-called "ra- tional" magnetic flux that are distributed throughout the bulk of the plasma. In a tokamak equilibrium with a realistic aspect

  20. Fast magnetic field annihilation in the relativistic collisionless regime driven by two ultra-short high-intensity laser pulses

    E-Print Network [OSTI]

    Gu, Y J; Kumar, D; Liu, Y; Singh, S K; Esirkepov, T Zh; Bulanov, S V; Weber, S; Korn, G

    2015-01-01T23:59:59.000Z

    The magnetic quadrupole structure formation during the interaction of two ultra-short high power laser pulses with a collisionless plasma is demonstrated with 2.5-dimensional particle-in-cell simulations. The subsequent expansion of the quadrupole is accompanied by magnetic field annihilation in the ultrarelativistic regime, when the magnetic field can not be sustained by the plasma current. This results in a dominant contribution of the displacement current exciting a strong large scale electric?field. This field leads to the conversion of magnetic energy into kinetic energy of accelerated electrons inside the thin current sheet.

  1. AC transport in p-Ge/GeSi quantum well in high magnetic fields

    SciTech Connect (OSTI)

    Drichko, I. L.; Malysh, V. A.; Smirnov, I. Yu.; Golub, L. E.; Tarasenko, S. A. [A.F. Ioffe Physical Technical Institute of Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation); Suslov, A. V. [National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Mironov, O. A. [Warwick SEMINANO R and D Center, University of Warwick Science Park, Coventry CV4 7EZ (United Kingdom); Kummer, M.; Känel, H. von [Laboratorium für Festkörperphysik ETH Zürich, CH-8093 Zürich (Switzerland)

    2014-08-20T23:59:59.000Z

    The contactless surface acoustic wave technique is implemented to probe the high-frequency conductivity of a high-mobility p-Ge/GeSi quantum well structure in the regime of integer quantum Hall effect (IQHE) at temperatures 0.3–5.8 K and magnetic fields up to 18 T. It is shown that, in the IQHE regime at the minima of conductivity, holes are localized and ac conductivity is of hopping nature and can be described within the “two-site” model. The analysis of the temperature and magnetic-field-orientation dependence of the ac conductivity at odd filing factors enables us to determine the effective hole g-factor, |g{sub zz}|?4.5. It is shown that the in-plane component of the magnetic field leads to a decrease in the g-factor as well as increase in the cyclotron mass, which is explained by orbital effects in the complex valence band of germanium.

  2. Triple voltage dc-to-dc converter and method

    DOE Patents [OSTI]

    Su, Gui-Jia (Knoxville, TN)

    2008-08-05T23:59:59.000Z

    A circuit and method of providing three dc voltage buses and transforming power between a low voltage dc converter and a high voltage dc converter, by coupling a primary dc power circuit and a secondary dc power circuit through an isolation transformer; providing the gating signals to power semiconductor switches in the primary and secondary circuits to control power flow between the primary and secondary circuits and by controlling a phase shift between the primary voltage and the secondary voltage. The primary dc power circuit and the secondary dc power circuit each further comprising at least two tank capacitances arranged in series as a tank leg, at least two resonant switching devices arranged in series with each other and arranged in parallel with the tank leg, and at least one voltage source arranged in parallel with the tank leg and the resonant switching devices, said resonant switching devices including power semiconductor switches that are operated by gating signals. Additional embodiments having a center-tapped battery on the low voltage side and a plurality of modules on both the low voltage side and the high voltage side are also disclosed for the purpose of reducing ripple current and for reducing the size of the components.

  3. Characterization of a high-temperature superconducting conductor on round core cables in magnetic fields up to 20 T

    SciTech Connect (OSTI)

    van der Laan, Danko [Advanced Conductor Technologies; Noyes, Patrick [National High Magnetic Field Laboratory; Miller, George [National High Magnetic Field Laboratory; Weijers, Hubertus [National High Magnetic Field Laboratory; Willering, Gerard [CERN

    2013-02-13T23:59:59.000Z

    The next generation of high-field magnets that will operate at magnetic fields substantially above 20 T, or at temperatures substantially above 4.2 K, requires high-temperature superconductors (HTS). Conductor on round core (CORC) cables, in which RE-Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} (RE = rare earth) (REBCO) coated conductors are wound in a helical fashion on a fl?exible core, are a practical and versatile HTS cable option for low-inductance, high-field magnets. We performed the first tests of CORC magnet cables in liquid helium in magnetic fields of up to 20 T. A record critical current I{sub c} of 5021 A was measured at 4.2 K and 19 T. In a cable with an outer diameter of 7.5 mm, this value corresponds to an engineering current density J{sub e} of 114 A mm{sup -2} , the highest J{sub e} ever reported for a superconducting cable at such high magnetic fields. Additionally, the first magnet wound from an HTS cable was constructed from a 6 m-long CORC cable. The 12-turn, double-layer magnet had an inner diameter of 9 cm and was tested in a magnetic field of 20 T, at which it had an I{sub c} of 1966 A. The cables were quenched repetitively without degradation during the measurements, demonstrating the feasibility of HTS CORC cables for use in high-field magnet applications.

  4. Polarization-preserving confocal microscope for optical experiments in a dilution refrigerator with high magnetic field

    E-Print Network [OSTI]

    Maksym Sladkov; M. P. Bakker; A. U. Chaubal; D. Reuter; A. D. Wieck; C. H. van der Wal

    2010-10-09T23:59:59.000Z

    We present the design and operation of a fiber-based cryogenic confocal microscope. It is designed as a compact cold-finger that fits inside the bore of a superconducting magnet, and which is a modular unit that can be easily swapped between use in a dilution refrigerator and other cryostats. We aimed at application in quantum optical experiments with electron spins in semiconductors and the design has been optimized for driving with, and detection of optical fields with well-defined polarizations. This was implemented with optical access via a polarization maintaining fiber together with Voigt geometry at the cold finger, which circumvents Faraday rotations in the optical components in high magnetic fields. Our unit is versatile for use in experiments that measure photoluminescence, reflection, or transmission, as we demonstrate with a quantum optical experiment with an ensemble of donor-bound electrons in a thin GaAs film.

  5. Polarization-preserving confocal microscope for optical experiments in a dilution refrigerator with high magnetic field

    E-Print Network [OSTI]

    Sladkov, Maksym; Chaubal, A U; Reuter, D; Wieck, A D; van der Wal, C H

    2010-01-01T23:59:59.000Z

    We present the design and operation of a fiber-based cryogenic confocal microscope. It is designed as a compact cold-finger that fits inside the bore of a superconducting magnet, and which is a modular unit that can be easily swapped between use in a dilution refrigerator and other cryostats. We aimed at application in quantum optical experiments with electron spins in semiconductors and the design has been optimized for driving with, and detection of optical fields with well-defined polarizations. This was implemented with optical access via a polarization maintaining fiber together with Voigt geometry at the cold finger, which circumvents Faraday rotations in the optical components in high magnetic fields. Our unit is versatile for use in experiments that measure photoluminescence, reflection, or transmission, as we demonstrate with a quantum optical experiment with an ensemble of donor-bound electrons in a thin GaAs film.

  6. Regulation loops for the ring magnet power supplies in the SSC accelerator complex

    SciTech Connect (OSTI)

    Tacconi, E.; Christiansen, C.

    1993-05-01T23:59:59.000Z

    The SSC complex consists of five cascaded accelerators: The linear accelerator (linac) and four synchrotrons: The low energy booster (LEB), the medium energy booster (MEB), the high energy booster (HEB), and the collider. Twelve- or 24-pulse phase-controlled SCR power supplies are used to energize the ring magnets. Each power supply has a voltage loop designed to regulate the voltage applied to the magnets. The voltage regulation loops for these synchrotrons and the current regulation for the LEB are analyzed in this work. The digital voltage regulator is fiber-optic isolated from the power converter. It has a closed-loop bandwidth of 150 Hz with band rejections for 60-Hz and 120-Hz perturbations. The LEB has a very precise current regulation system composed of a feedforward compensator, a fast feedback regulator, and a slow synchronous regulator. The current regulation design is corroborated by computer simulations.

  7. High-resolution spectra of solar magnetic features. I. Analysis of penumbral fine structure

    SciTech Connect (OSTI)

    Lites, B.W.; Skumanich, A.; Scharmer, G.B. (High Altitude Observatory, Boulder, CO (USA) Kungliga Svenska Vetenskapsakademien, Stockholm (Sweden))

    1990-05-01T23:59:59.000Z

    The Swedish Vacuum Telescope on La Palma was used to obtain spectra of the magnetic-sensitive Fe I 630.25 nm line under conditions of exceptional angular resolution (0.32 arcsec) and high spectral resolution (FWHM 2.5 pm). Simultaneous 0.02 s CCD exposures of both the spectrum and the slit-jaw image effectively 'freeze' the atmospheric seeing motions and permit unambiguous identification of the spectra of the various penumbral structures. These spectra reveal the magnetic field strength in penumbral filaments through an intensity fit of the Zeeman splitting of this line. The observations show that: (1) the field strength varies from about 2100 G near the umbra-penumbra boundary to about 900 G at the outer edge of the penumbra, (2) the observed fluctuation of penumbral magnetic field is much less dramatic than the fluctuation in intensity, (3) there is a suggestion of a rapid change in field inclination between some light and dark filaments near the edge of the penumbra, and (4) there is no obvious correlation between Doppler shift (in part due to the Evershed flow) and filament intensity. 43 refs.

  8. The impact of Hall physics on magnetized high energy density plasma jets

    SciTech Connect (OSTI)

    Gourdain, P.-A.; Seyler, C. E.; Atoyan, L.; Greenly, J. B.; Hammer, D. A.; Kusse, B. R.; Pikuz, S. A.; Potter, W. M.; Schrafel, P. C.; Shelkovenko, T. A. [Cornell University, Ithaca, New York 14853 (United States)] [Cornell University, Ithaca, New York 14853 (United States)

    2014-05-15T23:59:59.000Z

    Hall physics is often neglected in high energy density plasma jets due to the relatively high electron density of such jets (n{sub e}???10{sup 19}?cm{sup ?3}). However, the vacuum region surrounding the jet has much lower densities and is dominated by Hall electric field. This electric field redirects plasma flows towards or away from the axis, depending on the radial current direction. A resulting change in the jet density has been observed experimentally. Furthermore, if an axial field is applied on the jet, the Hall effect is enhanced and ignoring it leads to serious discrepancies between experimental results and numerical simulations. By combining high currents (?1 MA) and magnetic field helicity (15° angle) in a pulsed power generator such as COBRA, plasma jets can be magnetized with a 10?T axial field. The resulting field enhances the impact of the Hall effect by altering the density profile of current-free plasma jets and the stability of current-carrying plasma jets (e.g., Z-pinches)

  9. Low virial parameters in molecular clouds: Implications for high-mass star formation and magnetic fields

    SciTech Connect (OSTI)

    Kauffmann, Jens; Pillai, Thushara [Astronomy Department, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Goldsmith, Paul F., E-mail: jens.kauffmann@astro.caltech.edu, E-mail: tpillai@astro.caltech.edu [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Boulevard, Pasadena, CA 91109 (United States)

    2013-12-20T23:59:59.000Z

    Whether or not molecular clouds and embedded cloud fragments are stable against collapse is of utmost importance for the study of the star formation process. Only 'supercritical' cloud fragments are able to collapse and form stars. The virial parameter ? = M {sub vir}/M, which compares the virial mass to the actual mass, provides one way to gauge stability against collapse. Supercritical cloud fragments are characterized by ? ? 2, as indicated by a comprehensive stability analysis considering perturbations in pressure and density gradients. Past research has suggested that virial parameters ? ? 2 prevail in clouds. This would suggest that collapse toward star formation is a gradual and relatively slow process and that magnetic fields are not needed to explain the observed cloud structure. Here, we review a range of very recent observational studies that derive virial parameters <<2 and compile a catalog of 1325 virial parameter estimates. Low values of ? are in particular observed for regions of high-mass star formation (HMSF). These observations may argue for a more rapid and violent evolution during collapse. This would enable 'competitive accretion' in HMSF, constrain some models of 'monolithic collapse', and might explain the absence of high-mass starless cores. Alternatively, the data could point at the presence of significant magnetic fields ?1 mG at high gas densities. We examine to what extent the derived observational properties might be biased by observational or theoretical uncertainties. For a wide range of reasonable parameters, our conclusions appear to be robust with respect to such biases.

  10. High performance electrical, magnetic, electromagnetic and electrooptical devices enabled by three dimensionally ordered nanodots and nanorods

    DOE Patents [OSTI]

    Goyal, Amit (Knoxville, TN), Kang; Sukill (Knoxville, TN)

    2012-02-21T23:59:59.000Z

    Novel articles and methods to fabricate same with self-assembled nanodots and/or nanorods of a single or multicomponent material within another single or multicomponent material for use in electrical, electronic, magnetic, electromagnetic and electrooptical devices is disclosed. Self-assembled nanodots and/or nanorods are ordered arrays wherein ordering occurs due to strain minimization during growth of the materials. A simple method to accomplish this when depositing in-situ films is also disclosed. Device applications of resulting materials are in areas of superconductivity, photovoltaics, ferroelectrics, magnetoresistance, high density storage, solid state lighting, non-volatile memory, photoluminescence, thermoelectrics and in quantum dot lasers.

  11. QUENCH PROTECTION AND DESIGN OF LARGE HIGH CURRENT DENSITY SUPERCONDUCTING MAGNETS

    E-Print Network [OSTI]

    Green, M.A.

    2010-01-01T23:59:59.000Z

    failure in the TPC superconducting magnet," Proceedings ofstrain on epoxy-impregnated superconducting composties," inQuench protection for superconduct­ ing magnets with a

  12. Vehicle Technologies Office Merit Review 2015: Enabling High-Energy/Voltage Lithium-Ion Cells for Transportation Applications: Part 2 Materials

    Broader source: Energy.gov [DOE]

    Presentation given by Argonne National Laboratory at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about enabling high...

  13. Vehicle Technologies Office Merit Review 2015: Enabling High-Energy/Voltage Lithium-Ion Cells for Transportation Applications: Part 3 Electrochemistry

    Broader source: Energy.gov [DOE]

    Presentation given by Argonne National Laboratory at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about enabling high...

  14. Vehicle Technologies Office Merit Review 2015: Enabling High-Energy/Voltage Lithium-Ion Cells for Transportation Applications: Part 1 Baseline Protocols and Analysis

    Broader source: Energy.gov [DOE]

    Presentation given by Argonne National Laboratory at 2015 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about enabling high...

  15. Energy Efficiency in Low Voltage Hall Thrusters Jerry L. Ross

    E-Print Network [OSTI]

    King, Lyon B.

    Energy Efficiency in Low Voltage Hall Thrusters Jerry L. Ross Lyon B. King Energy efficiency/s of xenon. Acceleration and current efficiencies were compared to thrust efficiency over a range of magnet coil current values of 0 A - 2.5 A. Acceleration efficiencies were obtained with a 4-grid Retarding

  16. A High Field Magnet Design for A Future Hadron Collider==== R. Gupta, K. Chow, D. Dietderich, S. Gourlay, G. Millos, A. McInturff, R. Scanlan

    E-Print Network [OSTI]

    Gupta, Ramesh

    A High Field Magnet Design for A Future Hadron Collider==== R. Gupta, K. Chow, D. Dietderich, S the completion of LHC. This paper presents a high field magnet design option based on Nb3Sn technology. A preliminary magnetic and mechanical design of a 14-16 T, 2-in-1 dipole based on the "common coil design

  17. Thermal effect on magnetic parameters of high-coercivity cobalt ferrite

    SciTech Connect (OSTI)

    Chagas, E. F., E-mail: efchagas@fisica.ufmt.br; Ponce, A. S.; Prado, R. J.; Silva, G. M. [Instituto de Física, Universidade Federal de Mato Grosso, 78060-900 Cuiabá-MT (Brazil); Bettini, J. [Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, 13083-970 Campinas (Brazil); Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Físicas, Rua Xavier Sigaud 150 Urca. Rio de Janeiro (Brazil)

    2014-07-21T23:59:59.000Z

    We prepared very high-coercivity cobalt ferrite nanoparticles synthesized by a combustion method and using short-time high-energy mechanical milling to increase strain and the structural defects density. The coercivity (H{sub C}) of the milled sample reached 3.75 kOe—a value almost five times higher than that obtained for the non-milled material (0.76 kOe). To investigate the effect of the temperature on the magnetic behavior of the milled sample, we performed a thermal treatment on the milled sample at 300, 400, and 600?°C for 30 and 180?min. We analyzed the changes in the magnetic behavior of the nanoparticles due to the thermal treatment using the hysteresis curves, Williamson-Hall analysis, and transmission electron microscopy. The thermal treatment at 600?°C causes decreases in the microstructural strain and density of structural defects resulting in a significant decrease in H{sub C}. Furthermore, this thermal treatment increases the size of the nanoparticles and, as a consequence, there is a substantial increase in the saturation magnetization (M{sub S}). The H{sub C} of the samples treated at 600?°C for 30 and 180?min were 2.24 and 1.93 kOe, respectively, and the M{sub S} of these same samples increased from 57?emu/g to 66 and 70?emu/g, respectively. The H{sub C} and the M{sub S} are less affected by the thermal treatment at 300 and 400?°C.

  18. Couples Magnetic and Structural Transitions in High-Purity Dy and Gd5SbxGe4-x

    SciTech Connect (OSTI)

    Alexander S. Chernyshov

    2006-08-09T23:59:59.000Z

    Magnetic materials exhibiting magnetic phase transitions simultaneously with structural rearrangements of their crystal lattices hold a promise for numerous applications including magnetic refrigeration, magnetomechanical devices and sensors. We undertook a detailed study of a single crystal of dysprosium metal, which is a classical example of a system where magnetic and crystallographic sublattices can be either coupled or decoupled from one another. Magnetocaloric effect, magnetization, ac magnetic susceptibility, and heat capacity of high purity single crystals of dysprosium have been investigated over broad temperature and magnetic field intervals with the magnetic field vector parallel to either the a- or c-axes of the crystal. Notable differences in the behavior of the physical properties when compared to Dy samples studied in the past have been observed between 110 K and 125 K, and between 178 K and {approx}210 K. A plausible mechanism based on the formation of antiferromagnetic clusters in the impure Dy has been suggested in order to explain the reduction of the magnetocaloric effect in the vicinity of the Neel point. Experimental and theoretical investigations of the influence of commensurability effects on the magnetic phase diagram and the value of the magnetocaloric effect have been conducted. The presence of newly found anomalies in the physical properties has been considered as evidence of previously unreported states of Dy. The refined magnetic phase diagram of dysprosium with the magnetic field vector parallel to the a-axis of a crystal has been constructed and discussed. The magnetic and crystallographic properties of Gd{sub 5}Sb{sub x}Ge{sub 4-x} pseudo-binary system were studied by x-ray diffraction (at room temperature), heat capacity, ac-magnetic susceptibility, and magnetization in the temperature interval 5-320 K in magnetic fields up to 100 kOe. The magnetic properties of three composition (x = 0.5, 1,2) were examined in detail. The Gd{sub 5}Sb{sub 2}Ge{sub 2} compound that adopts Tm{sub 5}Sb{sub 2}Si{sub 2}-type of structure (space group is Cmca), shows a second order FM-PM transition at 200 K, whereas Gd{sub 5}Sb{sub x}Ge{sub 4-x} compounds for x = 0.5 and x = 1 (Sm{sub 5}Ge{sub 4}-type of structure, space group is Pnma) exhibit first order phase transformations at 45 K and 37 K, respectively.

  19. Design, performance, and cost characteristics of high temperature superconducting magnetic energy storage

    SciTech Connect (OSTI)

    Schoenung, S.M.; Meier, W.R. (W.J. Schafer Associates, Inc., Pleasanton, CA (United States)); Fagaly, R.L.; Heiberger, M.; Stephens, R.B.; Leuer, J.A.; Guzman, R.A. (General Atomics, San Diego, CA (United States))

    1993-03-01T23:59:59.000Z

    A conceptual design for superconducting magnetic energy storage (SMES) using oxide superconductors with higher critical temperature than metallic superconductors has been analyzed for design features, refrigeration requirements, and estimated costs of major components. The study covered the energy storage range from 2 to 200 MWh at power levels from 4 to 400 MW. A SMES that uses high temperature superconductors (HTS) and operates at high magnetic field (e.g., 10 tesla), can be more compact than a comparable, conventional low-temperature device at lower field. The refrigeration power required for a higher temperature unit (20 to 77 Kelvin) will be less by 60 to 90 percent. The improvement in energy efficiency is significant for small units, but less important for large ones. The material cost for HTS units is dominated by the cost of superconductor, so that the total cost of an HTS system will be comparable to a low temperature system only if the superconductor price in $/Ampere-meter is made comparable by increasing current density or decreasing wire cost.

  20. Optical pumping and spectroscopy of Cs vapor at high magnetic field

    SciTech Connect (OSTI)

    Olsen, B. A.; Patton, B.; Jau, Y.-Y.; Happer, W. [Joseph Henry Laboratory, Department of Physics, Princeton University, Princeton, New Jersey 08544 (United States)

    2011-12-15T23:59:59.000Z

    We have measured changes in the ground-state populations of Cs vapor induced by optical pumping at high magnetic field. The 2.7-T field of our experiments is strong enough to decouple the nuclear and electronic spins, allowing us to independently measure each population. The spatial dependence of the Cs populations in small amounts of buffer gas obeys a simple coupled diffusion model and the relative populations reveal the details of relaxation within the vapor cell. Optical pumping can produce high nuclear polarization in the Cs vapor due to perturbations of the hyperfine interaction during collisions with buffer-gas particles and depending on the pumping transition, radiation trapping can strongly influence the electronic and nuclear polarizations in the vapor.

  1. Mode conversion and absorption of fast waves at high ion cyclotron harmonics in inhomogeneous magnetic fields

    SciTech Connect (OSTI)

    Cho, Suwon, E-mail: swcho@kgu.ac.kr [Department of Physics, Kyonggi University, Suwon, Kyonggi-Do 443-760 (Korea, Republic of)] [Department of Physics, Kyonggi University, Suwon, Kyonggi-Do 443-760 (Korea, Republic of); Kwak, Jong-Gu [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of)] [National Fusion Research Institute, Daejeon 305-806 (Korea, Republic of)

    2014-04-15T23:59:59.000Z

    The propagation and absorption of high harmonic fast waves is of interest for non-inductive current drives in fusion experiments. The fast wave can be coupled with the ion Bernstein wave that propagates in the high magnetic field side of an ion cyclotron harmonic resonance layer. This coupling and the absorption are analyzed using the hot plasma dispersion relation and a wave equation that was converted from an approximate dispersion relation for the case where ?{sub i}=k{sub ?}{sup 2}?{sub i}{sup 2}/2?1 (where k{sub ?} is the perpendicular wave number and ?{sub i} is the ion Larmor radius). It is found that both reflection and conversion may occur near the harmonic resonance layer but that they decrease rapidly, giving rise to a sharp increase in the absorption as the parallel wave number increases.

  2. Harmonic control of multiple-stator induction machines for voltage regulation

    E-Print Network [OSTI]

    Holloway, Jack Wade, 1980-

    2004-01-01T23:59:59.000Z

    Small, one to a few horsepower, three-phase induction machines with three sets of electrically-isolated, magnetically-coupled stator winding circuits are described. A voltage inverter is developed and used to drive one set ...

  3. Using fiberglass volumes for VPI of superconductive magnetic systems’ insulation

    SciTech Connect (OSTI)

    Andreev, I. S.; Bezrukov, A. A.; Pischugin, A. B. [Sredne-Nevskiy Shipyard (SNSZ), 10 Zavodskaya str., c. Pontonniy, Saint-Petersburg (Russian Federation); Bursikov, A. S.; Klimchenko, Y. A.; Marushin, E. L.; Mednikov, A. A.; Rodin, I. Y.; Stepanov, D. B. [The D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (NIIEFA), 3 Doroga na Metallostroy, Metallostroy, Saint-Petersburg (Russian Federation)

    2014-01-29T23:59:59.000Z

    The paper describes the method of manufacturing fiberglass molds for vacuum pressure impregnation (VPI) of high-voltage insulation of superconductive magnetic systems (SMS) with epoxidian hot-setting compounds. The basic advantages of using such vacuum volumes are improved quality of insulation impregnation in complex-shaped areas, and considerable cost-saving of preparing VPI of large-sized components due to dispensing with the stage of fabricating a metal impregnating volume. Such fiberglass vacuum molds were used for VPI of high-voltage insulation samples of an ITER reactor’s PF1 poloidal coil. Electric insulation of these samples has successfully undergone a wide range of high-voltage and mechanical tests at room and cryogenic temperatures. Some results of the tests are also given in this paper.

  4. A compact bellows-driven diamond anvil cell for high-pressure, low-temperature magnetic measurements

    SciTech Connect (OSTI)

    Feng, Yejun [The Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States) [The Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States); Silevitch, D. M.; Rosenbaum, T. F. [The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States)] [The James Franck Institute and Department of Physics, The University of Chicago, Chicago, Illinois 60637 (United States)

    2014-03-15T23:59:59.000Z

    We present the design of an efficient bellows-controlled diamond anvil cell that is optimized for use inside the bores of high-field superconducting magnets in helium-3 cryostats, dilution refrigerators, and commercial physical property measurement systems. Design of this non-magnetic pressure cell focuses on in situ pressure tuning and measurement by means of a helium-filled bellows actuator and fiber-coupled ruby fluorescence spectroscopy, respectively. We demonstrate the utility of this pressure cell with ac susceptibility measurements of superconducting, ferromagnetic, and antiferromagnetic phase transitions to pressures exceeding 8 GPa. This cell provides an opportunity to probe charge and magnetic order continuously and with high resolution in the three-dimensional Magnetic Field–Pressure–Temperature parameter space.

  5. Design and commissioning of a high magnetic field muon spin relaxation spectrometer at the ISIS pulsed neutron and muon source

    SciTech Connect (OSTI)

    Lord, J. S.; McKenzie, I.; Baker, P. J.; Cottrell, S. P.; Giblin, S. R.; Hillier, A. D.; Holsman, B. H.; King, P. J. C.; Nightingale, J. B.; Pratt, F. L.; Rhodes, N. J. [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom); Blundell, S. J.; Lancaster, T. [Clarendon Laboratory, Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU (United Kingdom); Good, J.; Mitchell, R.; Owczarkowski, M.; Poli, S. [Cryogenic Limited, 30 Acton Park Industrial Estate, The Vale, Acton, London W3 7QE (United Kingdom); Scheuermann, R. [Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Salman, Z. [ISIS Facility, STFC Rutherford Appleton Laboratory, Chilton, Oxon OX11 0QX (United Kingdom); Clarendon Laboratory, Department of Physics, Oxford University, Parks Road, Oxford OX1 3PU (United Kingdom)

    2011-07-15T23:59:59.000Z

    The high magnetic field (HiFi) muon instrument at the ISIS pulsed neutron and muon source is a state-of-the-art spectrometer designed to provide applied magnetic fields up to 5 T for muon studies of condensed matter and molecular systems. The spectrometer is optimised for time-differential muon spin relaxation studies at a pulsed muon source. We describe the challenges involved in its design and construction, detailing, in particular, the magnet and detector performance. Commissioning experiments have been conducted and the results are presented to demonstrate the scientific capabilities of the new instrument.

  6. High-Pressure Thermodynamic Properties of f-electron Metals, Transition Metal Oxides, and Half-Metallic Magnets

    SciTech Connect (OSTI)

    Richard T. Scalettar; Warren E. Pickett

    2005-08-02T23:59:59.000Z

    This project involves research into the thermodynamic properties of f-electron metals, transition metal oxides, and half-metallic magnets at high pressure. These materials are ones in which the changing importance of electron-electron interactions as the distance between atoms is varied can tune the system through phase transitions from localized to delocalized electrons, from screened to unscreened magnetic moments, and from normal metal to one in which only a single spin specie can conduct. Three main thrusts are being pursued: (i) Mott transitions in transition metal oxides, (ii) magnetism in half-metallic compounds, and (iii) large volume-collapse transitions in f-band metals.

  7. Magnetic lensing of extremely high energy cosmic rays in a galactic wind

    E-Print Network [OSTI]

    Diego Harari; Silvia Mollerach; Esteban Roulet

    2000-05-24T23:59:59.000Z

    We show that in the model of Galactic magnetic wind recently proposed to explain the extremely high energy (EHE) cosmic rays so far observed as originating from a single source (M87 in the Virgo cluster), the magnetic field strongly magnifies the fluxes and produces multiple images of the source. The apparent position on Earth of the principal image moves, for decreasing energies, towards the galactic south. It is typically amplified by an order of magnitude at $E/Z\\sim 2\\times 10^{20}$ eV, but becomes strongly demagnified below $10^{20}$ eV. At energies below $E/Z\\sim 1.3\\times 10^{20}$ eV, all events in the northern galactic hemisphere are due to secondary images, which have huge amplifications ($>10^2$). This model would imply strong asymmetries between the north and south galactic hemispheres, such as a (latitude dependent) upper cut-off value below $2\\times 10^{20}$ eV for CR protons arriving to the south and lower fluxes in the south than in the north above $10^{20}$ eV. The large resulting magnifications reduce the power requirements on the source, but the model needs a significant tunning between the direction to the source and the symmetry axis of the wind. If more modest magnetic field strengths were assumed, a scenario in which the observed EHE events are heavier nuclei whose flux is strongly lensed becomes also plausible and would predict that a transition from a light composition to a heavier one could take place at the highest energies.

  8. October 6, 2006 V. Ghazikhanian 1 TOF Low Voltage System Review

    E-Print Network [OSTI]

    Llope, William J.

    TOF Low Voltage Power System. The TOF low voltage system is based on the Wiener PL512 low noise, high45 plugs #12;October 6, 2006 V. Ghazikhanian Tray Low Voltage Power System. Totalof120 the plot of the dark current data on slide]. The DC power will be transmitted via DC transmission lines

  9. Fast Optimization of Nano-CMOS Voltage-Controlled Oscillator using Polynomial Regression and Genetic Algorithm

    E-Print Network [OSTI]

    Mohanty, Saraju P.

    Fast Optimization of Nano-CMOS Voltage-Controlled Oscillator using Polynomial Regression in a current-starved 50nm voltage-controlled oscillator (VCO). Accurate polynomial-regression based models have-CMOS), Voltage-Controlled Oscillator (VCO). 1. Introduction Digital design exploration and optimization is highly

  10. The vertical voltage termination technique characterizations of single die multiple 600V power

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    The vertical voltage termination technique ­ characterizations of single die multiple 600V power.grenoble-inp.fr Abstract-- Deep trench terminations are commonly known as a technique to achieve ideal breakdown voltages for high voltage devices. This paper presents the use of deep trench terminations as an original concept

  11. Local Dynamic Reactive Power for Correction of System Voltage Problems

    SciTech Connect (OSTI)

    Kueck, John D [ORNL; Rizy, D Tom [ORNL; Li, Fangxing [ORNL; Xu, Yan [ORNL; Li, Huijuan [University of Tennessee, Knoxville (UTK); Adhikari, Sarina [ORNL; Irminger, Philip [ORNL

    2008-12-01T23:59:59.000Z

    Distribution systems are experiencing outages due to a phenomenon known as local voltage collapse. Local voltage collapse is occurring in part because modern air conditioner compressor motors are much more susceptible to stalling during a voltage dip than older motors. These motors can stall in less than 3 cycles (.05s) when a fault, such as on the sub-transmission system, causes voltage to sag to 70 to 60%. The reasons for this susceptibility are discussed in the report. During the local voltage collapse, voltages are depressed for a period of perhaps one or two minutes. There is a concern that these local events are interacting together over larger areas and may present a challenge to system reliability. An effective method of preventing local voltage collapse is the use of voltage regulation from Distributed Energy Resources (DER) that can supply or absorb reactive power. DER, when properly controlled, can provide a rapid correction to voltage dips and prevent motor stall. This report discusses the phenomenon and causes of local voltage collapse as well as the control methodology we have developed to counter voltage sag. The problem is growing because of the use of low inertia, high efficiency air conditioner (A/C) compressor motors and because the use of electric A/C is growing in use and becoming a larger percentage of system load. A method for local dynamic voltage regulation is discussed which uses reactive power injection or absorption from local DER. This method is independent, rapid, and will not interfere with conventional utility system voltage control. The results of simulations of this method are provided. The method has also been tested at the ORNL s Distributed Energy Communications and Control (DECC) Laboratory using our research inverter and synchronous condenser. These systems at the DECC Lab are interconnected to an actual distribution system, the ORNL distribution system, which is fed from TVA s 161kV sub-transmission backbone. The test results are also provided and discussed. The simulations and testing show that local voltage control from DER can prevent local voltage collapse. The results also show that the control can be provided so quickly, within 0.5 seconds, that is does not interfere with conventional utility methods.

  12. Feasibility study of Nb3Al Rutherford cable for high field accelerator magnet application

    SciTech Connect (OSTI)

    Yamada, R.; /Fermilab; Kikuchi, A.; /Tsukuba Magnet Lab.; Ambrosio, G.; Andreev, N.; Barzi, E.; Cooper, C.; Feher, S.; Kashikhin, V.V.; Lamm, M.; Novitski, I.; /Fermilab; Takeuchi, T.; /Tsukuba Magnet Lab.; Tartaglia, M.; Turrioni, D.; /Fermilab; Verweij, A.P.; /CERN; Wake, M.; Willering, G; /Tsukuba Magnet Lab.; Zlobin, A.V.; /Fermilab

    2006-08-01T23:59:59.000Z

    Feasibility study of Cu stabilized Nb{sub 3}Al strand and Rutherford cable for the application to high field accelerator magnets are being done at Fermilab in collaboration with NIMS. The Nb{sub 3}Al strand, which was developed and manufactured at NIMS in Japan, has a non-copper Jc of about 844 A/mm{sup 2} at 15 Tesla at 4.2 K, a copper content of 50%, and filament size of about 50 microns. Rutherford cables with 27 Nb{sub 3}Al strands of 1.03 mm diameter were fabricated and tested. Quench tests on a short cable were done to study its stability with only its self field, utilizing a high current transformer. A pair of 2 meter long Nb{sub 3}Al cables was tested extensively at CERN at 4.3 and 1.9 K up to 11 Tesla including its self field with a high transport current of 20.2 kA. In the low field test we observed instability near splices and in the central region. This is related to the flux-jump like behavior, because of excessive amount of Nb in the Nb{sub 3}Al strand. There is possibility that the Nb in Nb{sub 3}Al can cause instability below 2 Tesla field regions. We need further investigation on this problem. Above 8 Tesla, we observed quenches near the critical surface at fast ramp rate from 1000 to 3000 A/sec, with quench velocity over 100 m/sec. A small racetrack magnet was made using a 14 m of Rutherford cable and successfully tested up to 21.8 kA, corresponding to 8.7 T.

  13. High-precision description and new properties of a spin-1 particle in a magnetic field

    E-Print Network [OSTI]

    Alexander J. Silenko

    2014-06-09T23:59:59.000Z

    The exact Foldy-Wouthuysen Hamiltonian is derived for a pointlike spin-1 particle with a normal magnetic moment in a nonuniform magnetic field. For a uniform magnetic field, it is exactly separated into terms linear and quadratic in spin. New unexpected properties of a particle with an anomalous magnetic moment are found. Spin projections of a particle moving in a uniform magnetic field are not integer and the tensor polarization is asymmetric in the plane orthogonal to the field. Previously described spin-tensor effects caused by the tensor magnetic polarizability exist not only for nuclei but also for pointlike particles.

  14. Solar coronal magnetic field topology inferred from high resolution optical and x-ray movies

    SciTech Connect (OSTI)

    Tarbell, T.; Frank, Z.; Hurlburt, N.; Morrison, M.; Shine, R.; Title, A.; Acton, L.

    1993-01-01T23:59:59.000Z

    The authors are using high resolution digital movies of solar active regions in optical and X-ray wavelengths to study solar flares and other transients. The optical movies were collected at the Swedish Solar Observatory on La Palma using the Lockheed tunable filtergraph system, in May-July, 1992. They include longitudinal and transverse magnetograms, H-alpha Doppler and intensity images at many wavelengths, Ca K, Na D, and white light images. Simultaneous X-ray images from Yohkoh are available much of the time. Several ways to establish the connectivity of some coronal magnetic field lines are being explored. Some of the clues available are: magnetic footpoint polarities and transverse field direction; H-alpha fibrils and loops seen in several wavelengths; proper motion and Dopper shifts of blobs moving along field lines; footprint brightening in micro-flares; spreading of flare ribbons during gradual phases of flares; X-ray morphology and correlations with H-alpha; and draining of flare loops. Examples of each of these will be shown on video.

  15. Dynamic simulation of voltage collapses

    SciTech Connect (OSTI)

    Deuse, J.; Stubbe, M. (Tractebel, Brussels (Belgium))

    1993-08-01T23:59:59.000Z

    Most of the time the voltage collapse phenomena are studied by means of computer programs designed for the calculation of steady state conditions. But in the real world, the simultaneous occurrences of losses of synchronism, of AVR dynamics or of transformer tap changes call for a full dynamic simulation of voltage phenomena. The present paper shows some examples of dynamic simulations of voltage phenomena using a new general purpose stability program (EUROSTAG), covering in a continuous way the classical fields of transient, mid-term and long-term stability, and also the quasi steady state conditions of a power system.

  16. Investigation of a high impedance magnetically insulated transmission line oscillator with hollow load

    SciTech Connect (OSTI)

    Zhou Heng; Shu Ting; Li Zhiqiang [College of Opto-electric Science and Engineering, National University of Defense Technology, Hunan 410073 (China)

    2012-09-15T23:59:59.000Z

    A novel high-impedance magnetically insulated transmission line oscillator (MILO) with greatly restrained power deposition on the anode has been investigated. Methods to increase the MILO impedance and decrease the anode current are discussed. A MILO with impedance of 30 {Omega} and power conversion efficiency of 25% is presented by particle-in-cell simulations. Compared with the previous MILO in our lab, the anode current of the proposed MILO is reduced about 50%, the power conversion efficiency doubles, and the power deposition on anode is reduced nearly one half. Furthermore, considerations for reducing the power deposition on load have also been carried out in MILO design, and the load current is reduced to 4.6 kA, only 17% of the total anode current. Finally, a hollow load was introduced to reduce the power deposition density on the load, without decreasing the power conversion efficiency.

  17. Thermal and high magnetic field treatment of materials and associated apparatus

    DOE Patents [OSTI]

    Kisner, Roger A.; Wilgen, John B.; Ludtka, Gerard M.; Jaramillo, Roger A.; Mackiewicz-Ludtka, Gail

    2010-06-29T23:59:59.000Z

    An apparatus and method for altering characteristics, such as can include structural, magnetic, electrical, optical or acoustical characteristics, of an electrically-conductive workpiece utilizes a magnetic field within which the workpiece is positionable and schemes for thermally treating the workpiece by heating or cooling techniques in conjunction with the generated magnetic field so that the characteristics of the workpiece are effected by both the generated magnetic field and the thermal treatment of the workpiece.

  18. Thermal and high magnetic field treatment of materials and associated apparatus

    DOE Patents [OSTI]

    Kisner, Roger A.; Wilgen, John B.; Ludtka, Gerard M.; Jaramillo, Roger A.; Mackiewicz-Ludtka, Gail

    2007-01-09T23:59:59.000Z

    An apparatus and method for altering characteristics, such as can include structural, magnetic, electrical, optical or acoustical characteristics, of an electrically-conductive workpiece utilizes a magnetic field within which the workpiece is positionable and schemes for thermally treating the workpiece by heating or cooling techniques in conjunction with the generated magnetic field so that the characteristics of the workpiece are effected by both the generated magnetic field and the thermal treatment of the workpiece.

  19. Unraveling the voltage fade mechanism in layer Li-Mn-rich electrode: formation of the tetrahedral cations for spinel conversion

    SciTech Connect (OSTI)

    Mohanty, Debasish [ORNL; Li, Jianlin [ORNL; Abraham, Daniel P [Argonne National Laboratory (ANL); Huq, Ashfia [ORNL; Payzant, E Andrew [ORNL; Wood III, David L [ORNL; Daniel, Claus [ORNL

    2014-01-01T23:59:59.000Z

    Discovery of high-voltage layered lithium-and manganese-rich (LMR) composite oxide electrode has dramatically enhanced the energy density of current Li-ion energy storage systems. However, practical usage of these materials is currently not viable because of their inability to maintain a consistent voltage profile (voltage fading) during subsequent charge-discharge cycles. This report rationalizes the cause of this voltage fade by providing the evidence of layer to spinel-like (LSL) structural evolution pathways in the host Li1.2Mn0.55Ni0.15Co0.1O2 LMR composite oxide. By employing neutron powder diffraction, and temperature dependent magnetic susceptibility, we show that LSL structural rearrangement in LMR oxide occurs through a tetrahedral cation intermediate via: i) diffusion of lithium atoms from octahedral to tetrahedral sites of the lithium layer [(LiLioct LiLitet] which is followed by the dispersal of the lithium ions from the adjacent octahedral site of the metal layer to the tetrahedral sites of lithium layer [LiTM oct LiLitet]; and ii) migration of Mn from the octahedral sites of the transition metal layer to the permanent octahedral site of lithium layer via tetrahedral site of lithium layer [MnTMoct MnLitet MnLioct)]. The findings opens the door to the potential routes to mitigate this atomic restructuring in the high-voltage LMR composite oxide cathodes by manipulating the composition/structure for practical use in high-energy-density lithium-ion batteries.

  20. Saving Megawatts with Voltage Optimization

    E-Print Network [OSTI]

    Wilson, T.; Bell, D.

    2010-01-01T23:59:59.000Z

    that had been installed at several electric utility distribution substations in the U.S. and Canada. These systems, being operated in Conservation Voltage Regulation mode, have provided significant energy conservation where they have been installed...

  1. Voltage tunable microwave ferrite resonator

    E-Print Network [OSTI]

    Oates, Daniel E.

    A novel method of implementing a tunable resonator using an applied voltage is presented. Stress is used to tune a microstrip resonator fabricated on a polycrystalline ferrite substrate. The stress was applied either ...

  2. A Common Coil Magnet for Testing High Field Superconductors* , J.P. Cozzolino, M.A. Harrison, W.B. Sampson, P.J. Wanderer

    E-Print Network [OSTI]

    Gupta, Ramesh

    . The performance of the magnet is summarized along with test results from insert coils wound from N3 Sn ribbon racetrack shaped coils readily wound from high aspect ratio conductor. In this geometry the magnet has two coil magnet. The turns on the right form one half of the upper and lower dipoles, but are part

  3. Rotor Design for High Pressure Magic Angle Spinning Nuclear Magnetic Resonance

    SciTech Connect (OSTI)

    Turcu, Romulus V.F.; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Z.

    2013-01-01T23:59:59.000Z

    High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low 1H and 13C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe2+)3Si2O5(OH)4), in contact with liquid water in water-saturated supercritical CO2 (scCO2) at 150 bar and 50 deg C. This mineral is relevant to the deep geologic disposal of CO2, but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields.

  4. Development of novel high-performance six-axis magnetically levitated instruments for nanoscale applications

    E-Print Network [OSTI]

    Verma, Shobhit

    2005-11-01T23:59:59.000Z

    and the sample. While working in noncontact mode the AFM tip does not touch the sample but gets the topographic image of sample from attractive force [13]. The AFM have resolution up to 10 pm. The basic working principle of AFM is very much like a record...-earth permanent-magnet-biased magnetic-bearing suspension [48]. The permanent magnet provides bias flux and the electromagnet can increase or reduce flux of the permanent magnet. The flux path of the electromagnet does not pass through the permanent magnet so...

  5. A Matter of Quantum Voltages

    SciTech Connect (OSTI)

    Sellner, Bernhard; Kathmann, Shawn M.

    2014-11-14T23:59:59.000Z

    Voltages inside matter are relevant to crystallization, materials science, biology, catalysis, and aqueous chemistry. Electron holography is able to measure the variation of voltages in matter and modern supercomputers allow the calculation of quantum voltages with practically unlimited spatial and temporal resolution of bulk systems. Of particular interest is the Mean Inner Potential (Vo) - the spatial average of these voltages. Voltages are very sensitive to the distribution of electrons and provide metrics to understand interactions in condensed phases. In the present study, we find excellent agreement with measurements of Vo for vitrified water and salt crystals and demonstrate the impact of covalent and ionic bonding as well as intermolecular/atomic interactions. Furthermore, we predict Vo as well as the fluctuations of these voltages in aqueous NaCl electrolytes and characterize the changes in their behavior as the resolution increases below the size of atoms. This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. This research used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

  6. Multilevel cascade voltage source inverter with seperate DC sources

    DOE Patents [OSTI]

    Peng, Fang Zheng (Knoxville, TN); Lai, Jih-Sheng (Blacksburg, VA)

    2002-01-01T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  7. Multilevel cascade voltage source inverter with seperate DC sources

    DOE Patents [OSTI]

    Peng, Fang Zheng (Oak Ridge, TN); Lai, Jih-Sheng (Knoxville, TN)

    1997-01-01T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  8. Multilevel cascade voltage source inverter with seperate DC sources

    DOE Patents [OSTI]

    Peng, Fang Zheng; Lai, Jih-Sheng

    2001-04-03T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations.

  9. Multilevel cascade voltage source inverter with separate DC sources

    DOE Patents [OSTI]

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

    1997-06-24T23:59:59.000Z

    A multilevel cascade voltage source inverter having separate DC sources is described herein. This inverter is applicable to high voltage, high power applications such as flexible AC transmission systems (FACTS) including static VAR generation (SVG), power line conditioning, series compensation, phase shifting and voltage balancing and fuel cell and photovoltaic utility interface systems. The M-level inverter consists of at least one phase wherein each phase has a plurality of full bridge inverters equipped with an independent DC source. This inverter develops a near sinusoidal approximation voltage waveform with only one switching per cycle as the number of levels, M, is increased. The inverter may have either single-phase or multi-phase embodiments connected in either wye or delta configurations. 15 figs.

  10. Characterization of High Current RRP(R) Wires as a Function of Magnetic Field, Temperature and Strain

    SciTech Connect (OSTI)

    Godeke, A.; Mentink, M.G.T.; Dietderich, D. R.; den Ouden, A.

    2009-08-16T23:59:59.000Z

    A new instrument for the characterization of superconducting materials as a function of Magnetic Field, Temperature and Strain, was designed, constructed and tested at Lawrence Berkeley National Laboratory (LBNL). A U-shaped bending spring was selected, since that design has proven to enable accurate characterizations of a multitude of superconducting materials for more than a decade. The new device is validated though measurements on very high current Rod Restack Processed (RRP) Internal-Tin (IT) wires, for which we will present initial results, including parameterizations of the superconducting phase boundaries and comparisons with other wire types. Accurate parametrization of modern high magnetic field conductors is important for the analysis of the performance of magnet systems.

  11. High magnetic shear gain in a liquid sodium stable couette flow experiment A prelude to an alpha - omega dynamo

    SciTech Connect (OSTI)

    Colgate, Stirling [Los Alamos National Laboratory; Li, Jui [Los Alamos National Laboratory; Finn, John [Los Alamos National Laboratory; Pariev, Vladimir [Los Alamos National Laboratory; Beckley, Howard [NM INSTIT. OF MINING AND TECH; Si, Jiahe [NM INSTIT. OF MINING AND TECH.; Martinic, Joe [NM INSTIT. OF MINING AND TECH.; Westpfahl, David [NM INSTIT. OF TECH.; Slutz, James [NM INSTIT. OF MINING AND TECH.; Westrom, Zeb [NM INSTIT. OF TECH.; Klein, Brianna [NM INSTIT. OF MINING AND TECH.

    2010-11-08T23:59:59.000Z

    The {Omega}-phase of the liquid sodium {alpha}-{Omega} dynamo experiment at NMIMT in cooperation with LANL has successfully demonstrated the production of a high toroidal field, B{sub {phi}} {approx_equal} 8 x B{sub r} from the radial component of an applied poloidal magnetic field, B{sub r}. This enhanced toroidal field is produced by rotational shear in stable Couette Row within liquid sodium at Rm {approx_equal} 120. The small turbulence in stable Taylor-Couette Row is caused by Ekman Row where ({delta}v/v){sup 2} {approx} 10{sup -3}. This high {Omega}-gain in low turbulence flow contrasts with a smaller {Omega}-gain in higher turbulence, Helmholtz-unstable shear flows. This result supports the ansatz that large scale astrophysical magnetic fields are created within semi-coherent large scale motions in which turbulence plays a diffusive role that enables magnetic flux linkage.

  12. Magnetic latching solenoid

    DOE Patents [OSTI]

    Marts, Donna J. (Idaho Falls, ID); Richardson, John G. (Idaho Falls, ID); Albano, Richard K. (Idaho Falls, ID); Morrison, Jr., John L. (Idaho Falls, ID)

    1995-01-01T23:59:59.000Z

    This invention discloses a D.C. magnetic latching solenoid that retains a moving armature in a first or second position by means of a pair of magnets, thereby having a zero-power requirement after actuation. The first or second position is selected by reversing the polarity of the D.C. voltage which is enough to overcome the holding power of either magnet and transfer the armature to an opposite position. The coil is then de-energized.

  13. Depth-resolved ultra-violet spectroscopic photo current-voltage measurements for the analysis of AlGaN/GaN high electron mobility transistor epilayer deposited on Si

    SciTech Connect (OSTI)

    Ozden, Burcu; Yang, Chungman; Tong, Fei; Khanal, Min P.; Mirkhani, Vahid; Sk, Mobbassar Hassan; Ahyi, Ayayi Claude; Park, Minseo, E-mail: park@physics.auburn.edu [Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)

    2014-10-27T23:59:59.000Z

    We have demonstrated that the depth-dependent defect distribution of the deep level traps in the AlGaN/GaN high electron mobility transistor (HEMT) epi-structures can be analyzed by using the depth-resolved ultra-violet (UV) spectroscopic photo current-voltage (IV) (DR-UV-SPIV). It is of great importance to analyze deep level defects in the AlGaN/GaN HEMT structure, since it is recognized that deep level defects are the main source for causing current collapse phenomena leading to reduced device reliability. The AlGaN/GaN HEMT epi-layers were grown on a 6 in. Si wafer by metal-organic chemical vapor deposition. The DR-UV-SPIV measurement was performed using a monochromatized UV light illumination from a Xe lamp. The key strength of the DR-UV-SPIV is its ability to provide information on the depth-dependent electrically active defect distribution along the epi-layer growth direction. The DR-UV-SPIV data showed variations in the depth-dependent defect distribution across the wafer. As a result, rapid feedback on the depth-dependent electrical homogeneity of the electrically active defect distribution in the AlGaN/GaN HEMT epi-structure grown on a Si wafer with minimal sample preparation can be elucidated from the DR-UV-SPIV in combination with our previously demonstrated spectroscopic photo-IV measurement with the sub-bandgap excitation.

  14. Electro-optic voltage sensor with beam splitting

    DOE Patents [OSTI]

    Woods, Gregory K. (Cornelius, OR); Renak, Todd W. (Idaho Falls, ID); Davidson, James R. (Idaho Falls, ID); Crawford, Thomas M. (Idaho Falls, ID)

    2002-01-01T23:59:59.000Z

    The invention is a miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware typically found in the prior art. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  15. Electro-optic voltage sensor with Multiple Beam Splitting

    DOE Patents [OSTI]

    Woods, Gregory K. (Cornelius, OR); Renak, Todd W. (Idaho Falls, ID); Crawford, Thomas M. (Idaho Falls, ID); Davidson, James R. (Idaho Falls, ID)

    2000-01-01T23:59:59.000Z

    A miniature electro-optic voltage sensor system capable of accurate operation at high voltages without use of the dedicated voltage dividing hardware. The invention achieves voltage measurement without significant error contributions from neighboring conductors or environmental perturbations. The invention employs a transmitter, a sensor, a detector, and a signal processor. The transmitter produces a beam of electromagnetic radiation which is routed into the sensor. Within the sensor the beam undergoes the Pockels electro-optic effect. The electro-optic effect produces a modulation of the beam's polarization, which is in turn converted to a pair of independent conversely-amplitude-modulated signals, from which the voltage of the E-field is determined by the signal processor. The use of converse AM signals enables the signal processor to better distinguish signal from noise. The sensor converts the beam by splitting the beam in accordance with the axes of the beam's polarization state (an ellipse) into at least two AM signals. These AM signals are fed into a signal processor and processed to determine the voltage between a ground conductor and the conductor on which voltage is being measured.

  16. Over Voltage in a Multi-sectioned Solenoid during a Quenching

    SciTech Connect (OSTI)

    Guo, Xinglong; Wang, Li; Pan, Heng; Wu, Hong; Liu, Xiaokun; Chen, Anbin; Green, M.A.; Xu, F.Y.

    2009-06-21T23:59:59.000Z

    Accurate analysis of over voltage in the superconducting solenoid during a quench is one of the bases for quench protection system design. Classical quench simulation methods can only give rough estimation of the over voltage within a magnet coil. In this paper, for multi-sectioned superconducting solenoid, based on the classical assumption of ellipsoidal normal zone, three-dimension al temperature results are mapped to the one-dimension of the wire, the temperature distribution along the wire and the resistances of each turn are obtained. The coil is treated as circuit comprised of turn resistances, turn self and mutual inductances. The turn resistive voltage, turn inductive voltage, and turn resultant voltage along the wire are calculated. As a result, maximum internal voltages, the layer-to-layer voltages and the turn-to-turn voltages are better estimated. Utilizing this method, the over voltage of a small solenoid and a large solenoid during quenching have been studied. The result shows that this method can well improve the over voltage estimate, especially when the coil is larger.

  17. Ultra-high-resolution Observations of MHD Waves in Photospheric Magnetic Structures

    E-Print Network [OSTI]

    Jess, David B

    2015-01-01T23:59:59.000Z

    Here we review the recent progress made in the detection, examination, characterisation and interpretation of oscillations manifesting in small-scale magnetic elements in the solar photosphere. This region of the Sun's atmosphere is especially dynamic, and importantly, permeated with an abundance of magnetic field concentrations. Such magnetic features can span diameters of hundreds to many tens of thousands of km, and are thus commonly referred to as the `building blocks' of the magnetic solar atmosphere. However, it is the smallest magnetic elements that have risen to the forefront of solar physics research in recent years. Structures, which include magnetic bright points, are often at the diffraction limit of even the largest of solar telescopes. Importantly, it is the improvements in facilities, instrumentation, imaging techniques and processing algorithms during recent years that have allowed researchers to examine the motions, dynamics and evolution of such features on the smallest spatial and temporal ...

  18. Voltage, energy and power in electric circuits

    E-Print Network [OSTI]

    Berzins, M.

    Voltage, energy and power in electric circuits Science teaching unit #12;Disclaimer The Department-2008DVD-EN Voltage, energy and power in electric circuits #12;#12;© Crown copyright 2008 1The National Strategies | Secondary Voltage, energy and power in electric circuits 00094-2008DVD-EN Contents Voltage

  19. Demonstration of high performance negative central magnetic shear discharges on the DIII-D tokamak

    SciTech Connect (OSTI)

    Rice, B.W. [Lawrence Livermore National Lab., CA (United States); Burrell, K.H.; Lao, L.L. [General Atomics, San Diego, CA (United States)] [and others

    1996-01-01T23:59:59.000Z

    Reliable operation of discharges with negative central magnetic shear has led to significant increases in plasma performance and reactivity in both low confinement, L-mode, and high confinement, H-mode, regimes in the DIII-D tokamak. Using neutral beam injection early in the initial current ramp, a large range of negative shear discharges have been produced with durations lasting up to 3.2 s. The total non- inductive current (beam plus bootstrap) ranges from 50% to 80% in these discharges. In the region of shear reversal, significant peaking of the toroidal rotation [f{sub {phi}} {approx} 30-60 kHz] and ion temperature [T{sub i}(0) {approx} 15-22 keV] profiles are observed. In high power discharges with an L-mode edge, peaked density profiles are also observed. Confinement enhancement factors up to H {equivalent_to} {tau}{sub E}/{tau}{sub ITER-89P} {approx} 2.5 with an L-mode edge, and H {approx} 3.3 in an Edge Localized Mode (ELM)-free H-mode, are obtained. Transport analysis shows both ion thermal diffusivity and particle diffusivity to be near or below standard neoclassical values in the core. Large pressure peaking in L- mode leads to high disruptivity with {Beta}{sub N} {equivalent_to} {Beta}{sub T}/(I/aB) {<=} 2.3, while broader pressure profiles in H- mode gives low disruptivity with {Beta}{sub N} {<=} 4.2.

  20. Used MRI magnets get a second chance at life in high-energy physics...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    spectrometer that uses the radioactive beams from FRIB at minimal cost," said Argonne nuclear physicist Birger Back. Both magnets have already been delivered to Argonne, and...

  1. Electro-optic voltage sensor head

    DOE Patents [OSTI]

    Crawford, Thomas M. (Idaho Falls, ID); Davidson, James R. (Idaho Falls, ID); Woods, Gregory K. (Cornelius, OR)

    1999-01-01T23:59:59.000Z

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers.

  2. Electro-optic voltage sensor head

    DOE Patents [OSTI]

    Crawford, T.M.; Davidson, J.R.; Woods, G.K.

    1999-08-17T23:59:59.000Z

    The invention is an electro-optic voltage sensor head designed for integration with existing types of high voltage transmission and distribution apparatus. The sensor head contains a transducer, which comprises a transducing material in which the Pockels electro-optic effect is observed. In the practice of the invention at least one beam of electromagnetic radiation is routed into the transducing material of the transducer in the sensor head. The beam undergoes an electro-optic effect in the sensor head when the transducing material is subjected to an E-field. The electro-optic effect is observed as a differential phase a shift, also called differential phase modulation, of the beam components in orthogonal planes of the electromagnetic radiation. In the preferred embodiment the beam is routed through the transducer along an initial axis and then reflected by a retro-reflector back substantially parallel to the initial axis, making a double pass through the transducer for increased measurement sensitivity. The preferred embodiment of the sensor head also includes a polarization state rotator and at least one beam splitter for orienting the beam along major and minor axes and for splitting the beam components into two signals which are independent converse amplitude-modulated signals carrying E-field magnitude and hence voltage information from the sensor head by way of optic fibers. 6 figs.

  3. Superconducting FCL using a combined inducted magnetic field trigger and shunt coil

    DOE Patents [OSTI]

    Tekletsadik, Kasegn D. (Rexford, NY)

    2007-10-16T23:59:59.000Z

    A single trigger/shunt coil is utilized for combined induced magnetic field triggering and shunt impedance. The single coil connected in parallel with the high temperature superconducting element, is designed to generate a circulating current in the parallel circuit during normal operation to aid triggering the high temperature superconducting element to quench in the event of a fault. The circulating current is generated by an induced voltage in the coil, when the system current flows through the high temperature superconducting element.

  4. Optically initiated silicon carbide high voltage switch

    DOE Patents [OSTI]

    Caporaso, George J. (Livermore, CA); Sampayan, Stephen E. (Manteca, CA); Sullivan, James S. (Livermore, CA); Sanders; David M. (Livermore, CA)

    2011-02-22T23:59:59.000Z

    An improved photoconductive switch having a SiC or other wide band gap substrate material, such as GaAs and field-grading liners composed of preferably SiN formed on the substrate adjacent the electrode perimeters or adjacent the substrate perimeters for grading the electric fields.

  5. Lookout device for high voltage circuit breaker

    SciTech Connect (OSTI)

    Kozlowski, L.J.; Shirey, L.A.

    1991-12-31T23:59:59.000Z

    An improved lockout assembly is provided for a circuit breaker to lock the switch handle into a selected switch position. The lockout assembly includes two main elements, each having a respective foot for engaging a portion of the upper housing wall of the circuit breaker. The first foot is inserted into a groove in the upper housing wall, and the second foot is inserted into an adjacent aperture (e.g., a slot) in the upper housing wall. The first foot is slid under and into engagement with a first portion, and the second foot is slid under and into engagement with a second portion of the upper housing wall. At the same time the respective two feet are placed in engagement with the respective portions of the upper housing wall, two holes, one on each of the respective two main elements of the assembly, are placed in registration; and a locking device, such as a special scissors equipped with a padlock, is installed through the registered holes to secure the lockout assembly on the circuit breaker. When the lockout assembly of the invention is secured on the circuit breaker, the switch handle of the circuit breaker is locked into the selected switch position and prevented from being switched to another switch position.

  6. Lockout device for high voltage circuit breaker

    DOE Patents [OSTI]

    Kozlowski, L.J.; Shirey, L.A.

    1993-01-26T23:59:59.000Z

    An improved lockout assembly is provided for a circuit breaker to lock the switch handle into a selected switch position. The lockout assembly includes two main elements, each having a respective foot for engaging a portion of the upper housing wall of the circuit breaker. The first foot is inserted into a groove in the upper housing wall, and the second foot is inserted into an adjacent aperture (e.g., a slot) in the upper housing wall. The first foot is slid under and into engagement with a first portion, and the second foot is slid under and into engagement with a second portion of the upper housing wall. At the same time the respective two feet are placed in engagement with the respective portions of the upper housing wall, two holes, one on each of the respective two main elements of the assembly, are placed in registration; and a locking device, such as a special scissors equipped with a padlock, is installed through the registered holes to secure the lockout assembly on the circuit breaker. When the lockout assembly of the invention is secured on the circuit breaker, the switch handle of the circuit breaker is locked into the selected switch position and prevented from being switched to another switch position.

  7. Lockout device for high voltage circuit breaker

    SciTech Connect (OSTI)

    Kozlowski, Lawrence J. (New Kensington, PA); Shirey, Lawrence A. (North Huntingdon, PA)

    1993-01-01T23:59:59.000Z

    An improved lockout assembly is provided for a circuit breaker to lock the switch handle into a selected switch position. The lockout assembly includes two main elements, each having a respective foot for engaging a portion of the upper housing wall of the circuit breaker. The first foot is inserted into a groove in the upper housing wall, and the second foot is inserted into an adjacent aperture (e.g., a slot) in the upper housing wall. The first foot is slid under and into engagement with a first portion, and the second foot is slid under and into engagement with a second portion of the upper housing wall. At the same time the repsective two feet are placed in engagement with the respective portions of the upper housing wall, two holes, one on each of the respective two main elements of the assembly, are placed in registration; and a locking device, such as a special scissors equipped with a padlock, is installed through the registered holes to secure the lockout assembly on the circuit breaker. When the lockout assembly of the invention is secured on the circuit breaker, the switch handle of the circuit breaker is locked into the selected switch position and prevented from being switched to another switch position.

  8. Polymerizable Additive for Passivating High Voltage Cathodes

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    In this research project, we are studying the use of organic monomers as electrolyte additives that will oxidize and polymerize to form stable passivation films on the surface of...

  9. High voltage photo switch package module

    DOE Patents [OSTI]

    Sullivan, James S; Sanders, David M; Hawkins, Steven A; Sampayan, Stephen E

    2014-02-18T23:59:59.000Z

    A photo-conductive switch package module having a photo-conductive substrate or wafer with opposing electrode-interface surfaces, and at least one light-input surface. First metallic layers are formed on the electrode-interface surfaces, and one or more optical waveguides having input and output ends are bonded to the substrate so that the output end of each waveguide is bonded to a corresponding one of the light-input surfaces of the photo-conductive substrate. This forms a waveguide-substrate interface for coupling light into the photo-conductive wafer. A dielectric material such as epoxy is then used to encapsulate the photo-conductive substrate and optical waveguide so that only the metallic layers and the input end of the optical waveguide are exposed. Second metallic layers are then formed on the first metallic layers so that the waveguide-substrate interface is positioned under the second metallic layers.

  10. Effect of dopants on the magnetic properties of MnZn ferrites for high frequency power supplies

    SciTech Connect (OSTI)

    Znidarsic, A.; Limpel, M.; Drofenik, M. [Univ. of Ljubljana (Slovenia)] [Univ. of Ljubljana (Slovenia)

    1995-03-01T23:59:59.000Z

    The effect of additions on the magnetic properties of MnZn ferrites for high frequency power supplies was studied. The investigation revealed that various combinations of dopants added to the ferrite modify the grain boundary resistivity and the magnetic permeability spectra at constant microstructure. Particularly, the combined effect of Sn{sup 4+}, Ti{sup 4+} and Ta{sup 5+} was found to increase the grain boundary resistivity in the ferrites studied and remarkably decrease the power loss at higher frequencies.

  11. Magnetic dipole discharges. II. Cathode and anode spot discharges and probe diagnostics

    SciTech Connect (OSTI)

    Stenzel, R. L.; Urrutia, J. M. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)] [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States); Ionita, C.; Schrittwieser, R. [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)] [Institute for Ion Physics and Applied Physics, University of Innsbruck, A-6020 Innsbruck (Austria)

    2013-08-15T23:59:59.000Z

    The high current regime of a magnetron-type discharge has been investigated. The discharge uses a permanent magnet as a cold cathode which emits secondary electrons while the chamber wall or a grounded electrode serves as the anode. As the discharge voltage is increased, the magnet develops cathode spots, which are short duration arcs that provide copious electrons to increase the discharge current dramatically. Short (1 ?s), high current (200 A) and high voltage (750 V) discharge pulses are produced in a relaxation instability between the plasma and a charging capacitor. Spots are also observed on a negatively biased plane Langmuir probe. The probe current pulses are as large as those on the magnet, implying that the high discharge current does not depend on the cathode surface area but on the properties of the spots. The fast current pulses produce large inductive voltages, which can reverse the electrical polarity of the magnet and temporarily operate it as an anode. The discharge current may also oscillate at the frequency determined by the charging capacitor and the discharge circuit inductance. Each half cycle of high-current current pulses exhibits a fast (?10 ns) current rise when a spot is formed. It induces high frequency (10–100 MHz) transients and ringing oscillations in probes and current circuits. Most probes behave like unmatched antennas for the electromagnetic pulses of spot discharges. Examples are shown to distinguish the source of oscillations and some rf characteristics of Langmuir probes.

  12. Ancillary service details: Voltage control

    SciTech Connect (OSTI)

    Kirby, B.; Hirst, E.

    1997-12-01T23:59:59.000Z

    Voltage control is accomplished by managing reactive power on an alternating-current power system. Reactive power can be produced and absorbed by both generation and transmission equipment. Reactive-power devices differ substantially in the magnitude and speed of response and in their capital costs. System operators, transmission owners, generators, customers, power marketers, and government regulators need to pay close attention to voltage control as they restructure the U.S. electricity industry. Voltage control can affect reliability and commerce in three ways: (1) Voltages must be maintained within an acceptable range for both customer and power-system equipment to function properly. (2) The movement of reactive power consumes transmission resources, which limits the ability to move real power and worsens congestion. (3) The movement of reactive power results in real-power losses. When generators are required to supply excessive amounts of reactive power, their real-power production must be curtailed. These opportunity costs are not currently compensated for in most regions. Current tariffs are based on embedded costs. These embedded-cost tariffs average about $0.51/MWh, equivalent to $1.5 billion annually for the United States as a whole. Although this cost is low when compared with the cost of energy, it still aggregates to a significant amount of money. This report takes a basic look at why the power system requires reactive power (an appendix explains the fundamentals of real and reactive power). The report then examines the various types of generation and transmission resources used to supply reactive power and to control voltage. Finally it discusses how these resources are deployed and paid for in several reliability regions around the country. As the U.S. electricity industry is restructured, the generation, transmission, and system-control equipment and functions that maintain voltages within the appropriate ranges are being deintegrated.

  13. An Adaptive Voltage Control Algorithm with Multiple Distributed Energy

    SciTech Connect (OSTI)

    Li, Huijuan [University of Tennessee, Knoxville (UTK); Li, Fangxing [ORNL; Adhikari, Sarina [ORNL; Xu, Yan [ORNL; Rizy, D Tom [ORNL; Kueck, John D [ORNL

    2009-01-01T23:59:59.000Z

    Distributed energy resources (DE) with power electronics (PE) interfaces with the right control are capable of providing reactive power related ancillary services. Voltage regulation in particular has drawn much attention. In this paper the challenges to control multiple DEs to regulate the local voltage in distribution systems is addressed and a decentralized adaptive voltage control method is proposed. The simulation results in different system conditions show that this adaptive voltage control method is capable of satisfying the fast response speed requirement without causing oscillation or instability of the system. Since this method has high tolerance to the shortage of the system parameters and can be widely adaptive to the variable operation situations of the power systems, it is very suited for the utility application.

  14. IEEE 342 Node Low Voltage Networked Test System

    SciTech Connect (OSTI)

    Schneider, Kevin P.; Phanivong, Phillippe K.; Lacroix, Jean-Sebastian

    2014-07-31T23:59:59.000Z

    The IEEE Distribution Test Feeders provide a benchmark for new algorithms to the distribution analyses community. The low voltage network test feeder represents a moderate size urban system that is unbalanced and highly networked. This is the first distribution test feeder developed by the IEEE that contains unbalanced networked components. The 342 node Low Voltage Networked Test System includes many elements that may be found in a networked system: multiple 13.2kV primary feeders, network protectors, a 120/208V grid network, and multiple 277/480V spot networks. This paper presents a brief review of the history of low voltage networks and how they evolved into the modern systems. This paper will then present a description of the 342 Node IEEE Low Voltage Network Test System and power flow results.

  15. Inverse-Compton drag on a Highly Magnetized GRB jet in Stellar Envelope

    E-Print Network [OSTI]

    Ceccobello, Chiara

    2015-01-01T23:59:59.000Z

    The collimation and evolution of relativistic outflows in $\\gamma$-ray bursts (GRBs) are determined by their interaction with the stellar envelope through which they travel before reaching the much larger distance where the energy is dissipated and $\\gamma$-rays are produced. We consider the case of a Poynting flux dominated relativistic outflow and show that it suffers strong inverse-Compton (IC) scattering drag near the stellar surface and the jet is slowed down to sub-relativistic speed if its initial magnetization parameter ($\\sigma_0$) is larger than about 10$^5$. If the temperature of the cocoon surrounding the jet were to be larger than about 10 keV, then an optically thick layer of electrons and positrons forms at the interface of the cocoon and the jet, and one might expect this pair screen to protect the interior of the jet from IC drag. However, the pair screen turns out to be ephemeral, and instead of shielding the jet it speeds up the IC drag on it. Although a high $\\sigma_0$ jet might not surviv...

  16. Very high energy emission as a probe of relativistic magnetic reconnection in pulsar winds

    E-Print Network [OSTI]

    Mochol, Iwona

    2015-01-01T23:59:59.000Z

    The population of gamma-ray pulsars, including Crab observed in the TeV range, and Vela detected above 50 GeV, challenges existing models of pulsed high-energy emission. Such models should be universally applicable, yet they should account for spectral differences among the pulsars. We show that the gamma-ray emission of Crab and Vela can be explained by synchrotron radiation from the current sheet of a striped wind, expanding with a modest Lorentz factor $\\Gamma\\lesssim100$ in the Crab case, and $\\Gamma\\lesssim50$ in the Vela case. In the Crab spectrum a new synchrotron self-Compton component is expected to be detected by the upcoming experiment CTA. We suggest that the gamma-ray spectrum directly probes the physics of relativistic magnetic reconnection in the striped wind. In the most energetic pulsars, like Crab, with $\\dot{E}_{38}^{3/2}/P_{-2}\\gtrsim0.002$ (where $\\dot{E}$ is the spin down power, $P$ is the pulsar period, and $X=X_i\\times10^i$ in CGS units), reconnection proceeds in the radiative cooling ...

  17. High-Temperature Elasticity, Cation Disorder and Magnetic Transition in Magnesioferrite

    SciTech Connect (OSTI)

    Antao,S.; Jackson, I.; Li, B.; Kung, J.; Chen, J.; Hassan, I.; Liebermann, R.; Parise, J.

    2007-01-01T23:59:59.000Z

    The elastic moduli of magnesioferrite spinel, MgFe2O4, and their temperature dependence have been determined for the first time by ultrasonic measurements on a polycrystalline specimen. The measurements were carried out at 300 MPa and to 700 C in a gas-medium high-pressure apparatus. On heating, both the elastic bulk (K S) and shear (G) moduli decrease linearly to 350 C. By combining with extant thermal-expansion data, the values for the room-temperature K S and G, and their temperature derivatives are as follows: K 0 = 176.3(7) GPa, G 0 = 80.1(2) GPa, ({partial_derivative}K S/{partial_derivative}T) P = -0.032(3) GPa K-1 and ({partial_derivative}G/{partial_derivative}T) P = -0.012(1) GPa K-1. Between 350 and 400 C, there are abrupt increases of 1.4% in both of the elastic moduli; these closely coincide with the magnetic Curie transition that was observed by thermal analyses at about 360 C.

  18. Multi-bit magnetic memory using Fe8 high spin molecules

    E-Print Network [OSTI]

    Keren, Amit

    16 10 17 10 18 10 19 10 20 QTM Magnetic cores Disk file Magnetic bubble Thin film Optical disk IBM molecule behaves independently. #12;8 [Fe8O2(OH)12(C6H15N3)6]Br7(H2O)Br8H2O Fe8 Molecule Iron Carbon

  19. High PRF high current switch

    DOE Patents [OSTI]

    Moran, Stuart L. (Fredericksburg, VA); Hutcherson, R. Kenneth (College Park, MD)

    1990-03-27T23:59:59.000Z

    A triggerable, high voltage, high current, spark gap switch for use in pu power systems. The device comprises a pair of electrodes in a high pressure hydrogen environment that is triggered by introducing an arc between one electrode and a trigger pin. Unusually high repetition rates may be obtained by undervolting the switch, i.e., operating the trigger at voltages much below the self-breakdown voltage of the device.

  20. Method for high resolution magnetic resonance analysis using magic angle technique

    DOE Patents [OSTI]

    Wind, Robert A.; Hu, Jian Zhi

    2003-12-30T23:59:59.000Z

    A method of performing a magnetic resonance analysis of a biological object that includes placing the object in a main magnetic field (that has a static field direction) and in a radio frequency field; rotating the object at a frequency of less than about 100 Hz around an axis positioned at an angle of about 54.degree.44' relative to the main magnetic static field direction; pulsing the radio frequency to provide a sequence that includes a phase-corrected magic angle turning pulse segment; and collecting data generated by the pulsed radio frequency. The object may be reoriented about the magic angle axis between three predetermined positions that are related to each other by 120.degree.. The main magnetic field may be rotated mechanically or electronically. Methods for magnetic resonance imaging of the object are also described.