Science.gov

Sample records for electrodynamic levitation system

  1. Dynamic circuit and Fourier series methods for moment calculation in electrodynamic repulsive magnetic levitation systems

    NASA Astrophysics Data System (ADS)

    Knowles, R.

    1982-07-01

    A general theory of moments for electrodynamic magnetic levitation systems has been developed using double Fourier series and dynamic circuit principles. Both employ Parseval's theorem using either wave constant derivatives or the polar waveconstant principle of the Fourier-Bessel/double Fourier series equivalence. A method for calculating angular derivatives of moments and forces is explained, and for all of these methods comparisons are made with experimental results obtained for single and split rail configurations. Extensions of dynamic circuit theory for tilted nonflat and circular magnets are also explained.

  2. Magnetic Levitation Experiments with the Electrodynamic Wheel

    NASA Astrophysics Data System (ADS)

    Cordrey, Vincent; Gutarra-Leon, Angel; Gaul, Nathan; Majewski, Walerian

    Our experiments explored inductive magnetic levitation using circular Halbach arrays with the strong variable magnetic field on the outer rim of the ring. Such a system is usually called an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We constructed two Electrodynamic Wheels with different diameters and demonstrated that the magnetic interactions produce both lift and drag forces on the EDW which can be used for levitation and propulsion of the EDW. The focus of our experiments is the direct measurement of lift and drag forces to compare with theoretical models using wheels of two different radii. Supported by Grants from the Virginia Academy of Science, Society of Physics Students, Virginia Community College System, and the NVCC Educational Foundation.

  3. Study on figure-eight-shaped coil electrodynamic suspension magnetic levitation systems without cross-connection

    SciTech Connect

    Ribani, P.L.; Urbano, N.

    2000-01-01

    Two figure-eight-shaped coils for electrodynamic suspension (EDS) magnetic levitation (MAGLEV) systems without cross-connection are proposed and analyzed. The guideway coils are positioned under the MAGLEV vehicle; they are parallel to the horizontal plane. The interaction of a magnetic module on the vehicle, composed of three or four superconducting (SC) coils, with a guideway module, comprised of two figure-eight coils, is studied by means of the dynamic circuit theory. The currents in the SC coils are supposed to be constant in time while they move as a rigid body, with a constant velocity. Some results are presented and compared with those for a standard side-wall cross-connected system.

  4. Laboratory Scale Prototype of a Low-Speed Electrodynamic Levitation System Based on a Halbach Magnet Array

    ERIC Educational Resources Information Center

    Iniguez, J.; Raposo, V.

    2009-01-01

    In this paper we analyse the behaviour of a small-scale model of a magnetic levitation system based on the Inductrack concept. Drag and lift forces acting on our prototype, moving above a continuous copper track, are studied analytically following a simple low-speed approach. The experimental results are in good agreement with the theoretical…

  5. Propulsion and Levitation with a Large Electrodynamic Wheel

    NASA Astrophysics Data System (ADS)

    Gaul, Nathan; Lane, Hannah

    We constructed an electrodynamic wheel using a motorized bicycle wheel with a radius of 12 inches and 36 one-inch cube magnets attached to the rim of the wheel. The radial magnetic field on the outside of the wheel was maximized by arranging the magnets into a series of Halbach arrays which amplify the field on one side of the array and reduce it on the other side. Rotating the wheel produces a rapidly oscillating magnetic field. When a conductive metal ``track'' is placed in this area of strong magnetic flux, eddy currents are produced in the track. These eddy currents create magnetic fields that interact with the magnetic fields from the electrodynamic wheel. The interaction of the magnetic fields produces lift and drag forces on the track which were measured with force gauges. Measurements were taken at a variety of wheel speeds, and the results were compared to the theoretical prediction that there should be a linear relationship between the lift and drag forces with increasing wheel speed. Partial levitation was achieved with the current electrodynamic wheel. In the future, the wheel will be upgraded to include 72 magnets rather than 36 magnets. This will double the frequency at which the magnetic field oscillates, increasing the magnetic flux. Electrodynamic wheels have applications to the transportation industry, since multiple electrodynamic wheels could be used on a vehicle to produce a lift and propulsion force over a conductive track.

  6. Lift to Drag Ratio Analysis in Magnetic Levitation with an Electrodynamic Wheel

    NASA Astrophysics Data System (ADS)

    Gutarra-Leon, Angel; Cordrey, Vincent; Majewski, Walerian

    Our experiments explored inductive magnetic levitation (MagLev) using simple permanent magnets and conductive tracks. Our investigations used a circular Halbach array with a 1 Tesla variable magnetic field on the outer rim of the ring. Such a system is usually called an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above or below a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields, which interact with the magnets of the EDW. We constructed a four-inch diameter Electrodynamic Wheel using twelve Neodymium permanent magnets and demonstrated that the magnetic interactions produce both lift and drag forces on the EDW. These forces can be used for levitation and propulsion of the EDW to produce magnetic levitation without coils and complex control circuitry. We achieved full levitation of the non-magnetic aluminum and copper plates. Our results confirm the expected behavior of lift to drag ratio as proportional to (L/R) ω, with L and R being the inductance and resistance of the track plate, and ω being the angular velocity of the magnetic flux. Supported by grants from the Virginia Academy of Science, Society of Physics Students, Virginia Community College System, and the NVCC Educational Foundation.

  7. Acoustic Levitation System

    NASA Technical Reports Server (NTRS)

    Gammell, P. M.; Wang, T. G.; Croonquist, A.; Lee, M. C.

    1985-01-01

    Dense materials, such as steel balls, continuously levitated with energy provided by efficient high-powered siren in combination with shaped reflector. Reflector system, consisting of curved top reflector and flat lower reflector, eliminates instability in spatial positioning of sample.

  8. Vibrating-chamber levitation systems

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Granett, D.; Lee, M. C. (Inventor)

    1985-01-01

    Systems are described for the acoustic levitation of objects, which enable the use of a sealed rigid chamber to avoid contamination of the levitated object. The apparatus includes a housing forming a substantially closed chamber, and means for vibrating the entire housing at a frequency that produces an acoustic standing wave pattern within the chamber.

  9. Vibrating-chamber levitation systems

    NASA Astrophysics Data System (ADS)

    Barmatz, M. B.; Granett, D.; Lee, M. C.

    1985-10-01

    Systems are described for the acoustic levitation of objects, which enable the use of a sealed rigid chamber to avoid contamination of the levitated object. The apparatus includes a housing forming a substantially closed chamber, and means for vibrating the entire housing at a frequency that produces an acoustic standing wave pattern within the chamber.

  10. Perspectives of an acoustic electrostatic/electrodynamic hybrid levitator for small fluid and solid samples

    NASA Astrophysics Data System (ADS)

    Lierke, E. G.; Holitzner, L.

    2008-11-01

    The feasibility of an acoustic-electrostatic hybrid levitator for small fluid and solid samples is evaluated. A proposed design and its theoretical assessment are based on the optional implementation of simple hardware components (ring electrodes) and standard laboratory equipment into typical commercial ultrasonic standing wave levitators. These levitators allow precise electrical charging of drops during syringe- or ink-jet-type deployment. The homogeneous electric 'Millikan field' between the grounded ultrasonic transducer and the electrically charged reflector provide an axial compensation of the sample weight in an indifferent equilibrium, which can be balanced by using commercial optical position sensors in combination with standard electronic PID position control. Radial electrostatic repulsion forces between the charged sample and concentric ring electrodes of the same polarity provide stable positioning at the centre of the levitator. The levitator can be used in a pure acoustic or electrostatic mode or in a hybrid combination of both subsystems. Analytical evaluations of the radial-axial force profiles are verified with detailed numerical finite element calculations under consideration of alternative boundary conditions. The simple hardware modification with implemented double-ring electrodes in ac/dc operation is also feasible for an electrodynamic/acoustic hybrid levitator.

  11. Electrodynamic tether system study

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The purpose of this program is to define an Electrodynamic Tether System (ETS) that could be erected from the space station and/or platforms to function as an energy storage device. A schematic representation of the ETS concept mounted on the space station is presented. In addition to the hardware design and configuration efforts, studies are also documented involving simulations of the Earth's magnetic fields and the effects this has on overall system efficiency calculations. Also discussed are some preliminary computer simulations of orbit perturbations caused by the cyclic/night operations of the ETS. System cost estimates, an outline for future development testing for the ETS system, and conclusions and recommendations are also provided.

  12. Analysis of an electrodynamic maglev system

    SciTech Connect

    Davey, K.

    1999-09-01

    Electrodynamic systems (EDS's) for maglev have an advantage over electromagnetic systems (EMS's) in that the stability is built into the system. EDS's induce the currents used for levitation and guidance, while EMS's impose those currents with controlled feedback. The movement of a magnet over properly designed EDS coils results in forces to keep the system fixed in the lowest energy or null flux spot. In the past such systems have been examined through two-dimensional boundary element techniques. An approximation to the full three-dimensional time harmonic problem is obtained through LaPlace transform theory after using boundary element methods to predict the mutual coupling of the magnets with the track coils. The analytic solution offers helpful design and operation guidelines.

  13. Study of Japanese electrodynamic-suspension maglev systems

    SciTech Connect

    He, J.L.; Rote, D.M.; Coffey, H.T.

    1994-04-01

    This report presents the results of a study of the Japanese MLU magnetic-levitation (maglev) system. The development of the MLU system is reviewed, and the dynamic circuit model then is introduced and applied to the figure-eight-shaped null-flux coil suspension system. Three different types of figure-eight-shaped null-flux suspension systems are discussed in detail: (1) the figure-eight-shaped null-flux coil suspension system without cross-connection; (2) the combined suspension and guidance system; and (3) the combined propulsion, levitation, and guidance system. The electrodynamic-suspension maglev systems developed in Japan seem to be very promising and could result in a commercial application in the near future.

  14. Compact rf heating and levitation systems for the NASA modular electromagnetic levitator

    NASA Technical Reports Server (NTRS)

    Fox, R. J.

    1990-01-01

    The levitator demonstrates levitation of a 5 mm diam aluminum sphere at 1 G using a small, compact rf levitator operating from a small 12-V battery. This system is designed to levitate and melt niobium in space; however, the small battery unit limits the power for melting operations.

  15. Closed loop electrostatic levitation system

    NASA Technical Reports Server (NTRS)

    Rhim, W. K.; Saffren, M. M.; Elleman, D. D. (Inventor)

    1985-01-01

    An electrostatic levitation system is described, which can closely control the position of objects of appreciable size. A plurality of electrodes surround the desired position of an electrostatically charged object, the position of the objects is monitored, and the voltages applied to the electrodes are varied to hold the object at a desired position. In one system, the object is suspended above a plate-like electrode which has a concave upper face to urge the object toward the vertical axis of the curved plate. An upper electrode that is also curved can be positioned above the object, to assure curvature of the field at any height above the lower plate. In another system, four spherical electrodes are positioned at the points of a tetrahedron, and the voltages applied to the electrodes are varied in accordance with the object position as detected by two sensors.

  16. Oscillation damping means for magnetically levitated systems

    DOEpatents

    Post, Richard F.

    2009-01-20

    The present invention presents a novel system and method of damping rolling, pitching, or yawing motions, or longitudinal oscillations superposed on their normal forward or backward velocity of a moving levitated system.

  17. Characteristics of an electromagnetic levitation system using a bulk superconductor

    SciTech Connect

    Senba, A.; Kitahara, H.; Ohsaki, H.; Masada, E.

    1996-09-01

    It is beneficial to apply a high-Tc bulk superconductor as a large flux source to an electromagnetic levitation system, which needs large amounts of levitation force. The authors made an attractive-type electromagnetic levitation system using a hybrid magnet that mainly consisted of bulk superconductor and control coils to confirm the principle of the levitation, and obtained characteristics of its system by both experiment and numerical analysis with magnetic circuit calculation. This is applicable to maglev transportation systems.

  18. Magnetic levitation self-regulating systems

    SciTech Connect

    Tozoni, O.

    1993-06-08

    A magnet levitation self-regulating system is described comprising monotypic magnetic devices combined together by rigid nonmagnetic couplers; said magnetic device comprising two cylindrical parts extended along a cylinder generatrix: a. an iron core having a symmetrical C-shaped cross section and an air gap between its core shoes; and b. a permanent magnet having a rectangular cross-section disposed in said air gap; wherein all the iron cores of said magnetic devices are fixed on a common foundation by a first plurality of rigid nonmagnetic couplers and formed a stator assembly; all the permanent magnets of said magnetic devices are connected together by a second plurality of rigid non-magnetic couplers and form a levitator assembly; said permanent magnets of said levitator generate an original magnetic field and magnetize the stator cores; said stator cores create a secondary magnetic field; both said original and secondary magnetic fields create a magnetic levitation force that provides a stable hovering of said levitator in a resulting magnetic field of said system.

  19. Electrostatic Liquid-Drop-Levitation System

    NASA Technical Reports Server (NTRS)

    Rhim, Won Kyu; Chung, San Kun; Hyson, Michael T.; Elleman, Daniel D.

    1988-01-01

    Electrostatic levitator has levitated drops of liquid up to 4 mm in diameter while maintaining spherical drop shapes. Stable levitation of spherical drops valuable in experiments involving super-cooling, solidification, and crystal growth.

  20. Knolle Magnetrans: A magnetically levitated train system

    NASA Astrophysics Data System (ADS)

    Knolle, Ernst G.

    1992-05-01

    The Knolle Magnetrans is a continuous transportation system featuring small cars traveling in rapid succession, levitated by permanent magnets in repulsion, and propelled by stationary linear induction motors. The vehicles' headway, speed, acceleration, and deceleration are designed into the system and mechanically enforced. Passengers board dynamically and controls consist of a simple on-off relay. This paper summarizes the system design goals, describes the system components and discusses related environmental issues.

  1. Knolle Magnetrans: A magnetically levitated train system

    NASA Technical Reports Server (NTRS)

    Knolle, Ernst G.

    1992-01-01

    The Knolle Magnetrans is a continuous transportation system featuring small cars traveling in rapid succession, levitated by permanent magnets in repulsion, and propelled by stationary linear induction motors. The vehicles' headway, speed, acceleration, and deceleration are designed into the system and mechanically enforced. Passengers board dynamically and controls consist of a simple on-off relay. This paper summarizes the system design goals, describes the system components and discusses related environmental issues.

  2. Temperature dependence of levitation force and its relaxation in a HTS levitation system

    NASA Astrophysics Data System (ADS)

    Zhou, Jun; Zhang, Xing-Yi; Zhou, You-He

    2010-03-01

    Using a modified Gifford-McMahon refrigerator to cool the cylindrical bulk YBaCuO superconductor within the region of 100-10 K, and using an updated high-temperature superconductor (HTS) maglev measurement system, the levitation force and its time relaxation at different temperatures between a YBaCuO bulk superconductor and a permanent magnet (PM) have been measured under zero-field cooling. It is found that decrease the cooling temperature of HTS can decrease the hysteresis of magnetization and increase the maximum levitation force of each hysteresis loop. For the relaxation of levitation force, if the temperature is continually lowered to 10 K after the relaxation measurement at given cooling temperature is performed for 600 s, the levitation force will continue to decrease sharply with the lowering of temperature even though it will get stable if the temperature is not lowered. Our results shown in this work are a benefit to the understanding of levitation systems.

  3. Effective method to control the levitation force and levitation height in a superconducting maglev system

    NASA Astrophysics Data System (ADS)

    Yang, Peng-Tao; Yang, Wan-Min; Wang, Miao; Li, Jia-Wei; Guo, Yu-Xia

    2015-11-01

    The influence of the width of the middle magnet in the permanent magnet guideways (PMGs) on the levitation force and the levitation height of single-domain yttrium barium copper oxide (YBCO) bulks has been investigated at 77 K under the zero field cooled (ZFC) state. It is found that the largest levitation force can be obtained in the system with the width of the middle magnet of the PMG equal to the size of the YBCO bulk when the gap between the YBCO bulk and PMG is small. Both larger levitation force and higher levitation height can be obtained in the system with the width of the middle magnet of the PMG larger than the size of the YBCO bulk. The stiffness of the levitation force between the PMG and the YBCO bulk is higher in the system with a smaller width of the middle magnet in the PMG. These results provide an effective way to control the levitation force and the levitation height for the superconducting maglev design and applications. Project supported by the National Natural Science Foundation of China (Grant Nos. 51342001 and 50872079), the Key-grant Project of Chinese Ministry of Education (Grant No. 311033), the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20120202110003), the Innovation Team in Shaanxi Province, China (Grant No. 2014KTC-18), and the Fundamental Research Funds for the Central Universities, China (Grant Nos. GK201101001 and GK201305014), and the Outstanding Doctoral Thesis Foundation Project of Shaanxi Normal University, China (Grant Nos. X2011YB08 and X2012YB05).

  4. Propulsion and stabilization system for magnetically levitated vehicles

    DOEpatents

    Coffey, Howard T.

    1993-06-29

    A propulsion and stabilization system for an inductive repulsion type magnetically levitated vehicle which is propelled and stabilized by a system which includes propulsion windings mounted above and parallel to vehicle-borne suspension magnets. A linear synchronous motor is part of the vehicle guideway and is mounted above and parallel to superconducting magnets attached to the magnetically levitated vehicle.

  5. Magnetic Levitation.

    ERIC Educational Resources Information Center

    Rossing, Thomas D.; Hull, John R.

    1991-01-01

    Discusses the principles of magnetic levitation presented in the physics classroom and applied to transportation systems. Topics discussed include three classroom demonstrations to illustrate magnetic levitation, the concept of eddy currents, lift and drag forces on a moving magnet, magnetic levitation vehicles, levitation with permanent magnets…

  6. Change in the coil distribution of electrodynamic suspension system

    NASA Technical Reports Server (NTRS)

    Tanaka, Hisashi

    1992-01-01

    At the Miyazaki Maglev Test Center, the initial test runs were completed using a system design that required the superconducting coils to be parallel with the ground levitation coils. Recently, the coil distribution was changed to a system such that the two types of coils were perpendicular to each other. Further system changes will lead to the construction of a side wall levitation system. It is hoped that the development will culminate in a system whereby a superconducting coil will maintain all the functions: levitation, propulsion, and guidance.

  7. The electrodynamic and hydrodynamic phenomena in magnetically-levitated molten droplets. I - Steady state behavior

    NASA Technical Reports Server (NTRS)

    Zong, Jin-Ho; Li, Benqiang; Szekely, Julian

    1992-01-01

    A mathematical formulation is given and computed results are presented describing the behavior of electromagnetically-levitated metal droplets under the conditions of microgravity. In the formulation the electromagnetic force field is calculated using a modification of the volume integral method and these results are then combined with the FIDAP code to calculate the steady state melt velocities. The specific computational results are presented for the conditions corresponding to the planned IML-2 Space Shuttle experiment, using the TEMPUS device, which has separate 'heating' and 'positioning' coils. While the computed results are necessarily specific to the input conditions, some general conclusions may be drawn from this work. These include the fact that for the planned TEMPUS experiments to positioning coils will produce only a weak melt circulation, while the heating coils are like to produce a mildly turbulent recirculating flow pattern within the samples. The computed results also allow us to assess the effect of sample size, material properties and the applied current on these phenomena.

  8. The electrodynamic and hydrodynamic phenomena in magnetically-levitated molten droplets. I - Steady state behavior

    NASA Astrophysics Data System (ADS)

    Zong, Jin-Ho; Li, Benqiang; Szekely, Julian

    1992-06-01

    A mathematical formulation is given and computed results are presented describing the behavior of electromagnetically-levitated metal droplets under the conditions of microgravity. In the formulation the electromagnetic force field is calculated using a modification of the volume integral method and these results are then combined with the FIDAP code to calculate the steady state melt velocities. The specific computational results are presented for the conditions corresponding to the planned IML-2 Space Shuttle experiment, using the TEMPUS device, which has separate 'heating' and 'positioning' coils. While the computed results are necessarily specific to the input conditions, some general conclusions may be drawn from this work. These include the fact that for the planned TEMPUS experiments to positioning coils will produce only a weak melt circulation, while the heating coils are like to produce a mildly turbulent recirculating flow pattern within the samples. The computed results also allow us to assess the effect of sample size, material properties and the applied current on these phenomena.

  9. Dual-keel electrodynamic maglev system

    SciTech Connect

    He, J.; Wang, Z.; Rote, D.M.; Coffey, H.T.; Hull, J.R.; Mulcahy, T.M.; Cai, Y.

    1995-12-31

    A propulsion and stabilization system with a plurality of superconducting magnetic devices affixed to the dual-keels of a vehicle, where the superconducting magnetic devices produce a magnetic field when energized. The system also includes a plurality of figure-eight shaped null-flux coils affixed to opposing vertical sides of slots in a guideway. The figure-eight shaped null-flux coils are vertically oriented, laterally cross-connected in parallel, longitudinally connected in series, and continue the length of the vertical slots providing levitation and guidance force. An external power source energizes the figure-eight shaped null-flux coils to create a magnetic traveling wave that interacts with the magnetic field produced by the superconducting magnets to impart motion to the vehicle.

  10. Dual-keel electrodynamic maglev system

    DOEpatents

    He, J.L.; Wang, Z.; Rote, D.M.; Coffey, H.T.; Hull, J.R.; Mulcahy, T.M.; Cal, Y.

    1996-12-24

    A propulsion and stabilization system is disclosed with a plurality of superconducting magnetic devices affixed to the dual-keels of a vehicle, where the superconducting magnetic devices produce a magnetic field when energized. The system also includes a plurality of figure-eight shaped null-flux coils affixed to opposing vertical sides of slots in a guideway. The figure-eight shaped null-flux coils are vertically oriented, laterally cross-connected in parallel, longitudinally connected in series, and continue the length of the vertical slots providing levitation and guidance force. An external power source energizes the figure-eight shaped null-flux coils to create a magnetic traveling wave that interacts with the magnetic field produced by the superconducting magnets to impart motion to the vehicle. 6 figs.

  11. Dual-keel electrodynamic maglev system

    DOEpatents

    He, Jianliang; Wang, Zian; Rote, Donald M.; Coffey, Howard T.; Hull, John R.; Mulcahy, Thomas M.; Cal, Yigang

    1996-01-01

    A propulsion and stabilization system with a plurality of superconducting magnetic devices affixed to the dual-keels of a vehicle, where the superconducting magnetic devices produce a magnetic field when energized. The system also includes a plurality of figure-eight shaped null-flux coils affixed to opposing vertical sides of slots in a guideway. The figure-eight shaped null-flux coils are vertically oriented, laterally cross-connected in parallel, longitudinally connected in series, and continue the length of the vertical slots providing levitation and guidance force. An external power source energizes the figure-eight shaped null-flux coils to create a magnetic traveling wave that interacts with the magnetic field produced by the superconducting magnets to impart motion to the vehicle.

  12. Dual-keel electrodynamic Maglev system

    SciTech Connect

    He, Jianliang; Rote, D.M.; Wang, Zian; Coffey, H.T.

    1995-12-31

    This paper introduces a new concept for an electrodynamic-suspension maglev system that has a dual-keel arrangement. Each keel consists of a row of superconducting magnets aboard the vehicle. The keels move in troughs in the guideway that are each lined with pairs of figure-eight-shaped null-flux coils. Each pair of null-flux coils is cross-connected to produce null-flux suspension and guidance force. The cross-connected figure-eight null-flux coils in each trough are also energized by a three-phase power supply to produce propulsive force. Preliminary analysis shows that the new system has many advantages over other EDS systems in terms of system performance and dynamic stability.

  13. Control and dynamics of an anti-friction levitation system

    NASA Technical Reports Server (NTRS)

    Ih, C.-H. C.; Vivian, H.; Ahmed, A.; Wang, S. J.

    1992-01-01

    A novel anti-friction levitator concept has been devised and analytically evaluated to overcome support bearing friction and thereby minimize the structural damping of the Large Spacecraft Control Laboratory (LSCL) experiment structure at JPL. A dynamic model and controller design have been developed for the new levitation system. Simulation results show excellent system performance even when the system is subjected to significant measurement noise and hardware saturation effects.

  14. Combination Solar Sail and Electrodynamic Tether Propulsion System

    NASA Technical Reports Server (NTRS)

    Johnson, Charles L. (Inventor); Matloff, Gregory L. (Inventor)

    2003-01-01

    A propulsion system for a spacecraft includes a solar sail system and an electrodynamic tether system is presented. The solar sail system is used to generate propulsion to propel the spacecraft through space using solar photons and the electrodynamic tether system is used to generate propulsion to steer the spacecraft into orbit and to perform orbital maneuvers around a planet using the planet's magnetic field. The electrodynamic tether system can also be used to generate power for the spacecraft using the planet's magnetic field.

  15. Coarse-fine residual gravity cancellation system with magnetic levitation

    NASA Technical Reports Server (NTRS)

    Salcudean, S. E.; Davis, H.; Chen, C. T.; Goertz, D. E.; Tryggvason, B. V.

    1992-01-01

    Aircraft flight along parabolic trajectories have been proposed and executed in order to achieve low cost, near free fall conditions of moderate duration. This paper describes a six degree of freedom experiment isolation system designed to cancel out residual accelerations due to mechanical vibrations and errors in aircraft trajectory. The isolation system consists of a fine motion magnetic levitator whose stator is transported by a conventional coarse motion stage. The levitator uses wide gap voice coil actuators and has the dual purpose of isolating the experiment platform from aircraft vibrations and actively cancelling residual accelerations through feedback control. The course motion stage tracks the levitated platform in order to keep the levitator's coils centered within their matching magnetic gaps. Aspects of system design, an analysis of the proposed control strategy and simulation results are presented. Feasibility experiments are also discussed.

  16. Eddy damping effect of additional conductors in superconducting levitation systems

    NASA Astrophysics Data System (ADS)

    Jiang, Zhao-Fei; Gou, Xiao-Fan

    2015-12-01

    Passive superconducting levitation systems consisting of a high temperature superconductor (HTSC) and a permanent magnet (PM) have demonstrated several fascinating applications such as the maglev system, flywheel energy storage. Generally, for the HTSC-PM levitation system, the HTSC with higher critical current density Jc can obtain larger magnetic force to make the PM levitate over the HTSC (or suspended below the HTSC), however, the process of the vibration of the levitated PM, provides very limited inherent damping (essentially hysteresis). To improve the dynamic stability of the levitated PM, eddy damping of additional conductors can be considered as the most simple and effective approach. In this article, for the HTSC-PM levitation system with an additional copper damper attached to the HTSC, we numerically and comprehensively investigated the damping coefficient c, damping ratio, Joule heating of the copper damper, and the vibration frequency of the PM as well. Furthermore, we comparatively studied four different arrangements of the copper damper, on the comprehensive analyzed the damping effect, efficiency (defined by c/VCu, in which VCu is the volume of the damper) and Joule heating, and finally presented the most advisable arrangement.

  17. Magnetic levitation system for moving objects

    DOEpatents

    Post, R.F.

    1998-03-03

    Repelling magnetic forces are produced by the interaction of a flux-concentrated magnetic field (produced by permanent magnets or electromagnets) with an inductively loaded closed electric circuit. When one such element moves with respect to the other, a current is induced in the circuit. This current then interacts back on the field to produce a repelling force. These repelling magnetic forces are applied to magnetically levitate a moving object such as a train car. The power required to levitate a train of such cars is drawn from the motional energy of the train itself, and typically represents only a percent or two of the several megawatts of power required to overcome aerodynamic drag at high speeds. 7 figs.

  18. Magnetic levitation system for moving objects

    DOEpatents

    Post, Richard F.

    1998-01-01

    Repelling magnetic forces are produced by the interaction of a flux-concentrated magnetic field (produced by permanent magnets or electromagnets) with an inductively loaded closed electric circuit. When one such element moves with respect to the other, a current is induced in the circuit. This current then interacts back on the field to produce a repelling force. These repelling magnetic forces are applied to magnetically levitate a moving object such as a train car. The power required to levitate a train of such cars is drawn from the motional energy of the train itself, and typically represents only a percent or two of the several megawatts of power required to overcome aerodynamic drag at high speeds.

  19. Damping in high-temperature superconducting levitation systems

    DOEpatents

    Hull, John R.

    2009-12-15

    Methods and apparatuses for improved damping in high-temperature superconducting levitation systems are disclosed. A superconducting element (e.g., a stator) generating a magnetic field and a magnet (e.g. a rotor) supported by the magnetic field are provided such that the superconducting element is supported relative to a ground state with damped motion substantially perpendicular to the support of the magnetic field on the magnet. Applying this, a cryostat housing the superconducting bearing may be coupled to the ground state with high damping but low radial stiffness, such that its resonant frequency is less than that of the superconducting bearing. The damping of the cryostat may be substantially transferred to the levitated magnetic rotor, thus, providing damping without affecting the rotational loss, as can be derived applying coupled harmonic oscillator theory in rotor dynamics. Thus, damping can be provided to a levitated object, without substantially affecting the rotational loss.

  20. Analysis of the combined maglev levitation, propulsion, and guidance system

    SciTech Connect

    He, J.L.; Coffey, H.T.; Rote, D.M.

    1995-03-01

    An analysis of a Japanese maglev system that uses only one set of coils in the guideway for combined levitation, propulsion, and guidance functions is presented. This preliminary study, using the dynamic circuit approach, indicates that the system is very promising.

  1. Technical background for a demonstration magnetic levitation system

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.

    1987-01-01

    A preliminary technical assessment of the feasibility of a demonstration Magnetic Levitation system, required to support aerodynamic models with a specified clear air volume around them, is presented. Preliminary calculations of required sizes of electromagnets and power supplies are made, indicating that the system is practical. Other aspects, including model position sensing and controller design, are briefly addressed.

  2. NASA MSFC Electrostatic Levitator (ESL) Rapid Quench System

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Craven, Paul D.

    2014-01-01

    Electrostatic levitation, a form of containerless processing, is an important tool in materials research. Levitated specimens are free from contact with a container; therefore, heterogeneous nucleation on container walls is not possible. This allows studies of deeply undercooled melts. Furthermore, studies of high-temperature, highly reactive materials are also possible. Studies of the solidification and crystallization of undercooled melts is vital to the understanding of microstructure development, particularly the formation of alloys with unique properties by rapid solidification. The NASA Marshall Space Flight Center (MSFC) Electrostatic Levitator (ESL) lab has recently been upgraded to allow for rapid quenching of levitated materials. The ESL Rapid Quench System uses a small crucible-like vessel that can be partially filled with a low melting point material, such as a Gallium alloy, as a quench medium. An undercooled sample can be dropped into the vessel to rapidly quench the sample. A carousel with nine vessels sits below the bottom electrode assembly. This system allows up to nine rapid quenches before having to break vacuum and remove the vessels. This new Rapid Quench System will allow materials science studies of undercooled materials and new materials development. In this presentation, the system is described and initial results are presented.

  3. On the force relaxation in the magnetic levitation system with a high-Tc superconductor

    NASA Astrophysics Data System (ADS)

    Smolyak, B. M.; Zakharov, M. S.

    2014-05-01

    The effect of magnetic flux creep on the lift force in a magnet/superconductor system was studied. It was shown experimentally that in the case of real levitation (when a levitating object bears only on a magnetic field) the suspension height and consequently the lift force did not change over a long period of time. When the levitating object is fixed for some time (i.e. a rigid constraint is imposed on it), the levitation height decreases after removal of the external constraint. It is assumed that free oscillations of the levitating object slow down the flux creep process, which is activated when these oscillations are suppressed.

  4. Effect of the active damper coil system on the lateral displacement of the magnetically levitated bogie

    SciTech Connect

    Ohashi, S.; Ohsaki, H.; Masada, E.

    1999-09-01

    Numerical simulation of the superconducting magnetically levitated bogie (JR Maglev) has been studied. The active damper coil system is introduced. In this levitation system, the interaction between levitation and guidance is strong. This active damper coil system is designed for reducing the vertical vibration of the bogie. Using the numerical simulation, its effect on the lateral displacement of the bogie is assessed. The active damper coil system for the vertical vibration is shown to works as a passive damper for the lateral vibration.

  5. New levitation scheme with AC superconducting magnet for EDS MAGLEV system

    SciTech Connect

    Kim, D.H.; Lee, J.K.; Hahn, S.Y.; Cha, G.

    1996-09-01

    This paper proposes a new magnetic levitation scheme which is able to generate levitation force for all speeds including a standstill. Auxiliary wheels which are needed in EDS MAGLEV vehicle can be eliminated. This scheme uses AC superconducting magnets to generate levitation force. In this paper, magnetic fields, forces and power dissipations generated by AC magnets moving above a conducting slab are calculated analytically. Results of calculation show characteristics of EDS system with AC magnet, such as levitation force and loss, are superior to those of EDS system with DC magnets for all speeds.

  6. Robust levitation control for maglev systems with guaranteed bounded airgap.

    PubMed

    Xu, Jinquan; Chen, Ye-Hwa; Guo, Hong

    2015-11-01

    The robust control design problem for the levitation control of a nonlinear uncertain maglev system is considered. The uncertainty is (possibly) fast time-varying. The system has magnitude limitation on the airgap between the suspended chassis and the guideway in order to prevent undesirable contact. Furthermore, the (global) matching condition is not satisfied. After a three-step state transformation, a robust control scheme for the maglev vehicle is proposed, which is able to guarantee the uniform boundedness and uniform ultimate boundedness of the system, regardless of the uncertainty. The magnitude limitation of the airgap is guaranteed, regardless of the uncertainty. PMID:26524957

  7. Electrodynamic Bare Tether Systems as a Thruster for the Momentum-Exchange/Electrodynamic Reboost(MXER)Project

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Krivorutsky, E. N.; Gallagher, D. L.

    2006-01-01

    The concept of electrodynamic tether propulsion has a number of attractive features and has been widely discussed for different applications. Different system designs have been proposed and compared during the last 10 years. In spite of this, the choice of proper design for any particular mission is a unique problem. Such characteristics of tether performance as system acceleration, efficiency, etc., should be calculated and compared on the basis of the known capability of a tether to collect electrical current. We discuss the choice of parameters for circular and tape tethers with regard to the Momentum-Exchange/Electrodynamic Reboost (MXER) tether project.

  8. Development of magnetically levitated high speed transport system in Japan

    SciTech Connect

    Sawada, Kazuo

    1996-07-01

    In Japan, huge passenger traffic moves through the Tokyo-Osaka corridor and the demand is mounting on one more high speed line besides the Tokaido Shinkansen. A magnetically levitated vehicle (JR Maglev) using superconducting magnets has been developed for the Tokyo-Osaka superspeed express. JR Maglev has many advantages over conventional rail systems. This paper describes the necessity of one more high speed line in this corridor, the reason the author chose Maglev, the scheme of this system, history of the development and outline of the new Yamanashi test line project.

  9. Characteristics on electodynamic suspension simulator with HTS levitation magnet

    NASA Astrophysics Data System (ADS)

    Lee, J.; Bae, D. K.; Sim, K.; Chung, Y. D.; Lee, Y.-S.

    2009-10-01

    High- Tc superconducting (HTSC) electrodynamic suspension (EDS) system basically consists of the HTSC levitation magnet and the ground conductor. The levitation force of EDS system is forms by the interaction between the moving magnetic field produced by the onboard levitation magnet and the induced magnetic field produced by eddy current in the ground conductor. This paper deals with the characteristics of the EDS simulators with high- Tc superconducting (HTS) levitation magnet. Two EDS simulator systems, rotating type EDS simulator and static type EDS simulator, were studied in this paper. The rotating type EDS simulator consists of a HTS levitation magnet and a 1.5 m diameter rotating ground conductor, a motor, the supporting structure and force measuring devices. In the static type EDS simulator, instead of moving magnetic field, AC current was applied to the fixed HTS levitation magnet to induce the eddy current. The static type EDS simulator consists of a HTS levitation magnet, a ground conductor, force measuring devices and supporting structure. The double-pancake type HTSC levitation magnet was designed, manufactured and tested in the EDS simulator.

  10. A review of dynamic characteristics of magnetically levitated vehicle systems

    SciTech Connect

    Cai, Y.; Chen, S.S.

    1995-11-01

    The dynamic response of magnetically levitated (maglev) ground transportation systems has important consequences for safety and ride quality, guideway design, and system costs. Ride quality is determined by vehicle response and by environmental factors such as humidity and noise. The dynamic response of the vehicles is the key element in determining ride quality, while vehicle stability is an important safety-related element. To design a guideway that provides acceptable ride quality in the stable region, vehicle dynamics must be understood. Furthermore, the trade-off between guideway smoothness and levitation and control systems must be considered if maglev systems are to be economically feasible. The link between the guideway and the other maglev components is vehicle dynamics. For a commercial maglev system, vehicle dynamics must be analyzed and tested in detail. This report, which reviews various aspects of the dynamic characteristics, experiments and analysis, and design guidelines for maglev systems, discusses vehicle stability, motion dependent magnetic force components, guideway characteristics, vehicle/ guideway interaction, ride quality, suspension control laws, aerodynamic loads and other excitations, and research needs.

  11. Damping and support in high-temperature superconducting levitation systems

    DOEpatents

    Hull, John R.; McIver, Carl R.; Mittleider, John A.

    2009-12-15

    Methods and apparatuses to provide improved auxiliary damping for superconducting bearings in superconducting levitation systems are disclosed. In a superconducting bearing, a cryostat housing the superconductors is connected to a ground state with a combination of a damping strip of material, a set of linkage arms to provide vertical support, and spring washers to provide stiffness. Alternately, the superconducting bearing may be supported by a cryostat connected to a ground state by posts constructed from a mesh of fibers, with the damping and stiffness controlled by the fiber composition, size, and mesh geometry.

  12. Levitation force relaxation under reloading in a HTS Maglev system

    NASA Astrophysics Data System (ADS)

    He, Qingyong; Wang, Jiasu; Wang, Suyu; Wang, Jiansi; Dong, Hao; Wang, Yuxin; Shao, Senhao

    2009-02-01

    The loading capacity of the high-temperature superconducting (HTS) Maglev vehicle is an important parameter in the practical application. It is closely related to the levitation force of the HTS bulk. Many papers reported that the levitation force showed the relaxation characteristic. Because different loads cause different levitation gaps and different applied magnetic fields, the levitation force relaxations under the different loads are not the same. In terms of cylindrical YBCO bulk levitated over the permanent magnetic guideway, the relationship between the levitation force relaxation and the reloading is investigated experimentally in this paper. The decrement, the decrement rate and the relaxation rate of the levitation force are calculated, respectively. This work might be helpful for studying the loading capacity of the HTS Maglev vehicle.

  13. Active damping control for electrodynamic suspension systems without mechanical transducers

    SciTech Connect

    Brunelli, B.; Casadei, D.; Serra, G.; Tani, A.

    1996-09-01

    In this paper an electrodynamic suspension system for maglev vehicles is analyzed, in which the active damping of the vertical oscillations is obtained without position, velocity and acceleration transducers. The damping effect is accomplished controlling the supply voltage of the damping coil to respond to current changes due to vertical oscillations. The stability of the suspension system is investigated by a linearized analysis of the model equations, emphasizing the influence of the voltage regulator parameters. The performance of the damping system, in terms of step response and ride quality, is also discussed.

  14. Evaluation of a six-DOF electrodynamic shaker system.

    SciTech Connect

    Gregory, Danny Lynn; Smallwood, David Ora

    2009-03-01

    The paper describes the preliminary evaluation of a 6 degree of freedom electrodynamic shaker system. The 8 by 8 inch (20.3 cm) table is driven by 12 electrodynamic shakers producing motion in all 6 rigid body modes. A small electrodynamic shaker system suitable for small component testing is described. The principal purpose of the system is to demonstrate the technology. The shaker is driven by 12 electrodynamic shakers each with a force capability of about 50 lbs (220 N). The system was developed through an informal cooperative agreement between Sandia National Laboratories, Team Corp. and Spectral Dynamics Corporation. Sandia provided the laboratory space and some development funds. Team provided the mechanical system, and Spectral Dynamics provided the control system. Spectral Dynamics was chosen to provide the control system partly because of their experience in MIMO control and partly because Sandia already had part of the system in house. The shaker system was conceived and manufactured by TEAM Corp. Figure 1 shows the overall system. The vibration table, electrodynamic shakers, hydraulic pumps, and amplifiers are all housed in a single cabinet. Figure 2 is a drawing showing how the electrodynamic shakers are coupled to the table. The shakers are coupled to the table through a hydraulic spherical pad bearing providing 5 degrees of freedom and one stiff degree of freedom. The pad bearing must be preloaded with a static force as they are unable to provide any tension forces. The horizontal bearings are preloaded with steel springs. The drawing shows a spring providing the vertical preload. This was changed in the final design. The vertical preload is provided by multiple strands of an O-ring material as shown in Figure 4. Four shakers provide excitation in each of the three orthogonal axes. The specifications of the shaker are outlined in Table 1. Four shakers provide inputs in each of the three orthogonal directions. By choosing the phase relationships

  15. Lyapunov Orbits in the Jupiter System Using Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Bokelmann, Kevin; Russell, Ryan P.; Lantoine, Gregory

    2013-01-01

    Various researchers have proposed the use of electrodynamic tethers for power generation and capture from interplanetary transfers. The effect of tether forces on periodic orbits in Jupiter-satellite systems are investigated. A perturbation force is added to the restricted three-body problem model and a series of simplifications allows development of a conservative system that retains the Jacobi integral. Expressions are developed to find modified locations of equilibrium positions. Modified families of Lyapunov orbits are generated as functions of tether size and Jacobi integral. Zero velocity curves and stability analyses are used to evaluate the dynamical properties of tether-modified orbits.

  16. Dynamic stability of electrodynamic maglev systems

    SciTech Connect

    Cai, Y.; Chen, S.S.; Mulcahy, T.M.; Rote, D.M.

    1997-01-01

    Because dynamic instabilities are not acceptable in any commercial maglev system, it is important to consider dynamic instability in the development of all maglev systems. This study considers the stability of maglev systems based on mathematical models and experimental data. Divergence and flutter are obtained for coupled vibration of a three-degree-of-freedom maglev vehicle on a guideway consisting of double L-shaped aluminum segments. The theory and analysis for motion-dependent magnetic-force-induced instability developed in this study provides basic stability characteristics and identifies future research needs for maglev systems.

  17. Output feedback control of a mechanical system using magnetic levitation.

    PubMed

    Beltran-Carbajal, F; Valderrabano-Gonzalez, A; Rosas-Caro, J C; Favela-Contreras, A

    2015-07-01

    This paper presents an application of a nonlinear magnetic levitation system to the problem of efficient active control of mass-spring-damper mechanical systems. An output feedback control scheme is proposed for reference position trajectory tracking tasks on the flexible mechanical system. The electromagnetically actuated system is shown to be a differentially flat nonlinear system. An extended state estimation approach is also proposed to obtain estimates of velocity, acceleration and disturbance signals. The differential flatness structural property of the system is then employed for the synthesis of the controller and the signal estimation approach presented in this work. Some experimental and simulation results are included to show the efficient performance of the control approach and the effective estimation of the unknown signals.

  18. Output feedback control of a mechanical system using magnetic levitation.

    PubMed

    Beltran-Carbajal, F; Valderrabano-Gonzalez, A; Rosas-Caro, J C; Favela-Contreras, A

    2015-07-01

    This paper presents an application of a nonlinear magnetic levitation system to the problem of efficient active control of mass-spring-damper mechanical systems. An output feedback control scheme is proposed for reference position trajectory tracking tasks on the flexible mechanical system. The electromagnetically actuated system is shown to be a differentially flat nonlinear system. An extended state estimation approach is also proposed to obtain estimates of velocity, acceleration and disturbance signals. The differential flatness structural property of the system is then employed for the synthesis of the controller and the signal estimation approach presented in this work. Some experimental and simulation results are included to show the efficient performance of the control approach and the effective estimation of the unknown signals. PMID:25707718

  19. Expansion joint for guideway for magnetic levitation transportation system

    DOEpatents

    Rossing, Thomas D.

    1993-01-01

    An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The sidewalls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging sidewalls so that the cuts have a substantially dove-tail shape.

  20. Expansion joint for guideway for magnetic levitation transportation system

    DOEpatents

    Rossing, T.D.

    1993-02-09

    An expansion joint that allows a guideway of a magnetic levitation transportation system to expand and contract while minimizing transients occurring in the magnetic lift and drag forces acting on a magnetic levitation vehicle traveling over the joint includes an upper cut or recess extending downwardly from the upper surface of the guideway and a non-intersecting lower cut or recess that extends upwardly from the lower surface of the guideway. The side walls of the cuts can be parallel to each other and the vertical axis of the guideway; the depth of the lower cut can be greater than the depth of the upper cut; and the overall combined lengths of the cuts can be greater than the thickness of the guideway from the upper to lower surface so that the cuts will overlap, but be spaced apart from each other. The distance between the cuts can be determined on the basis of the force transients and the mechanical behavior of the guideway. A second pair of similarly configured upper and lower cuts may be disposed in the guideway; the expansion joint may consist of two upper cuts and one lower cut; or the cuts may have non-parallel, diverging side walls so that the cuts have a substantially dove-tail shape.

  1. Superconducting bulk magnets for magnetic levitation systems

    NASA Astrophysics Data System (ADS)

    Fujimoto, H.; Kamijo, H.

    2000-06-01

    The major applications of high-temperature superconductors have mostly been confined to products in the form of wires and thin films. However, recent developments show that rare-earth REBa 2Cu 3O 7- x and light rare-earth LREBa 2Cu 3O 7- x superconductors prepared by melt processes have a high critical-current density at 77 K and high magnetic fields. These superconductors will promote the application of bulk high-temperature superconductors in high magnetic fields; the superconducting bulk magnet for the Maglev train is one possible application. We investigated the possibility of using bulk magnets in the Maglev system, and examined flux-trapping characteristics of multi-superconducting bulks arranged in array.

  2. System and Method for Obtaining Simultaneous Levitation and Rotation of a Ferromagnetic Object

    NASA Astrophysics Data System (ADS)

    Banerjee, Subrata; Sarkar, Mrinal Kanti; Ghosh, Arnab

    2016-06-01

    In this work a practical demonstration for simultaneous levitation and rotation for a ferromagnetic cylindrical object is presented. A hollow steel cylinder has been arranged to remain suspended stably under I-core electromagnet utilizing dc attraction type levitation principle and then arranged to rotate the levitated object around 1000 rpm speed based on eddy current based energy meter principle. Since the object is to be rotating during levitated condition the device will be frictionless, energy-efficient and robust. This technology may be applied to frictionless energy meter, wind turbine, machine tool applications, precision instruments and many other devices where easy energy-efficient stable rotation will be required. The cascade lead compensation control scheme has been applied for stabilization of unstable levitation system. The proposed device is successfully tested in the laboratory and experimental results have been produced.

  3. Spin pumping in electrodynamically coupled magnon-photon systems

    NASA Astrophysics Data System (ADS)

    Bai, Lihui

    The electronics industry is quickly approaching the limitation of Moore's Law due to Joule heating in high density-integrated devices. To achieve new higher-speed devices and reduce energy consumption, researchers are turning to spintronics where the intrinsic spin, rather than the charge of electrons, is used to carry information in devices. Advances in spintronics have led to the discovery of giant magnetoresistance (GMR), spin transfer torque etc. Another subject, cavity electrodynamics, promises a completely new quantum algorithm by studying the properties of a single electron interacting with photons inside of a cavity. By merging both spintronics and cavity electrodynamics, a new cutting edge field called Cavity Spintronics is forming, which draws on the advantages of both subjects to develop new spintronics devices utilizing light-matter interaction. In this work, we use electrical detection, in combination with microwave transmission, to investigate both resonant and nonresonant magnon-photon coupling in a microwave cavity at room temperature. Spin pumping in a dynamically coupled magnon-photon system is found to be distinctly different from previous experiments. Characteristic coupling features such as modes anticrossing, linewidth evolution, peculiar line shape, and resonance broadening are systematically measured and consistently analyzed by a theoretical model set on the foundation of classical electrodynamic coupling. Our experimental and theoretical approach paves the way for pursuing microwave coherent manipulation of pure spin current via the combination of spin pumping and magnon-photon coupling. Co-authored with M. Harder, C.-M. Hu from University of Manitoba, Y. P. Chen, J. Q. Xiao from University of Delaware, and X. Fan from Univeristy of Denver.

  4. Interaction between propulsion and levitation system in the HTSC-permanent magnet conveyance system

    NASA Astrophysics Data System (ADS)

    Ohashi, S.; Nishio, R.; Hashikawa, T.

    2010-11-01

    The magnetically levitated conveyance system has been developed. Pinning force of high temperature bulk superconductors (HTSC) are used for the levitation and the guidance of the carrier. The magnetic rail is set on the ground, and flux from the magnetic rail is pinned by HTSCs on the carrier body. To increase the load weight, the repulsive force of the permanent magnet is introduced. The hybrid levitation system is composed. The repulsive force by the permanent magnet between the load stage on the carrier and the magnetic rail on the ground is used to support the load weight. As the load stage is connected to the carrier body by the linear sliders, the mass of the load weight does not act on the carrier body. The interaction between the electromagnet and the permanent magnet under the load stage generates the propulsion force. The electromagnet is constructed by the air core coils, and excited only when the load stage passes. The interaction between the propulsion and the levitation system is investigated. Disturbance of the propulsion system on the levitation and the guidance force is measured. The results show the influence of the propulsion electromagnet on the pinning force is little, and this propulsion system works effectively.

  5. An advanced arrangement of the combined propulsion, levitation and guidance system of superconducting Maglev

    SciTech Connect

    Fujie, Junji

    1999-09-01

    The PLG (combined Propulsion, Levitation and Guidance) method was proposed for a more favorable Maglev ground coil system, combining the functions of propulsion, levitation, and guidance of the vehicle into one coil. Research and development is currently being conducted on this method. In this paper, the characteristics of a newly-structured system for the PLG method is examined. The discussed characteristics include propulsion, levitation-guidance, vehicle dynamics in the cases of problems with the superconducting magnets, and the magnetic field on board the vehicle.

  6. Levitation characteristics of a high-temperature superconducting Maglev system for launching space vehicles

    NASA Astrophysics Data System (ADS)

    Yang, Wenjiang; Liu, Yu; Chen, Xiaodong; Wen, Zheng; Duan, Yi; Qiu, Ming

    2007-05-01

    Maglev launch assist is viewed as an effective method to reduce the cost of space launch. The primary aerodynamic characteristics of the Maglev launch vehicle and the space vehicle are discussed by analyzing their aerodynamic shapes and testing a scale mode in a standard wind tunnel. After analyzing several popular Maglev systems, we present a no-controlling Maglev system with bulk YBaCuO high-temperature superconductors (HTSs). We tested a HTS Maglev system unit, and obtained the levitation force density of 3.3 N/cm2 and the lateral force density of 2.0 N/cm2. We also fabricated a freely levitated test platform to investigate the levitation characteristics of the HTS Maglev system in load changing processes. We found that the HTS system could provide the strong self-stable levitation performance due to the magnetic flux trapped in superconductors. The HTS Maglev system provided feasibility for application in the launch vehicle.

  7. A Superconducting Levitation Transport Model System for Dynamical and Didactical Studies

    NASA Astrophysics Data System (ADS)

    Rosenzweig, St.; Reich, E.; Neu, V.; Berger, D.; Peukert, K.; Holzapfel, B.; Schultz, L.; Pospiech, G.

    Superconducting levitation transport systems might become very attractive in the near future due to various reasons. The realisation of contactless systems allows e.g. extended maintenance-free operation with high efficiency since such a system only needs energy for cooling and propulsion. We established a small superconducting levitation transport model system called "SupraTrans Min" consisting of permanent magnetic rails and a levitated vehicle including four YBCO-bulk samples in a cryostat. The rail system consists of an oval shaped loop (2.90 m x 1.44 m), which was build up from individual linear and curved track modules. Inside the vehicle position variations of the superconductors are possible. By means of velocity, acceleration and temperature measurements different dynamical aspects of our complex levitation system can be investigated. We also show the broad applicability of the experimental setup for didactical studies in physics.

  8. The 13th International Conference on Magnetically Levitated Systems and Linear Drives MAGLEV 1993

    NASA Astrophysics Data System (ADS)

    This report contains short papers on research being conducted throughout the world on magnetically levitated systems, mainly consisting of trains, and magnetic linear drives. These papers have been index separately elsewhere on the data base.

  9. 13th International Conference on Magnetically Levitated Systems and Linear Drives

    SciTech Connect

    Not Available

    1993-09-01

    This report contains short papers on research being conducted throughout the world on magnetically levitated systems, mainly consisting of trains, and magnetic linear drives. These papers have been index separately elsewhere on the data base.

  10. Parametric study of an acoustic levitation system. [for thermophysical properties determination of nonmetal materials

    NASA Technical Reports Server (NTRS)

    Oran, W. A.; Berge, L. H.; Parker, H. W.

    1980-01-01

    The performance of an acoustic levitation system designed for the containerless processing of materials and consisting of a St. Clair generator and a reflector arranged in a six-axis configuration, is examined in order to define critical parameters of high-temperature systems and limitations of earth-based devices. The fields and forces along the axis of the system are measured and the forces are plotted versus body volume. It is found that for a range of shapes and sizes the levitation force is roughly proportional to body volume until the characteristic 'diameter' reaches a value of about lambda/2. A significant (i.e., factor of four) enhancement in the levitation force is obtained by curving the faces of the driver and reflector. In addition, the behavior of liquid materials in the acoustic fields is studied, and the radius at which the deformation of a levitated drop occurs is calculated.

  11. Relaxation transition due to different cooling processes in a superconducting levitation system

    NASA Astrophysics Data System (ADS)

    Zhou, You-He; Zhang, Xing-Yi; Zhou, Jun

    2008-06-01

    We present an experimental study of relaxation of vertical and horizontal force components in a high-temperature superconducting levitation system, with different initial cooling process after fixing the levitated body in an expected position statically. In the experiment, the bulk YBaCuO cylinder superconductor and the permanent magnet disk are employed. For a selected levitation height (LH) and a lateral displacement (LD) of the system, the experimental results show that the relaxations of the vertical and horizontal forces are strongly dependent on the initial cooling height (CH). With CH decreasing, the transition of the lateral force from repulsion to attraction is found as well as the changing characteristics with time from decrease to increase. Additionally, when LH is fixed at the CH, the transition phenomenon is also observed in the levitation force behavior and their relaxation under different LDs.

  12. Levitation and Guidance Characteristics of the Permanent magnet-HTSC Hybrid Magnetic Conveyance System

    NASA Astrophysics Data System (ADS)

    Ohashi, Shunsuke; Dodo, Daiki

    Hybrid magnetically levitated transportation system has been developed. The magnetic rail is set on the ground, and the carrier with permanent magnets and high-Tc superconductors (HTSC) levitates on the rail. In this system, pinning force of HTSC and repulsive force of permanent magnet is combined. Repulsive force of permanent magnet is introduced to support weight. Pinning force is used to support weight of the frame of the carrier and to achieve lateral stability of the carrier. To decrease influence of weight on the levitation gap of the carrier, the weight stage is fixed to the carrier frame by linear sliders, and moves freely for vertical direction. As a result, there is little influence on levitation gap of the carrier. Basic levitation and guidance characteristics of the system are shown. Repulsive force generates very large levitation force. It also generates unstable lateral force. Weight added to the carrier has some influence on lateral stability. Although lateral position recovery force by pinning effect decreases at a heavier weight, the carrier shows enough force to keep lateral stability.

  13. The detection of gravitational waves using electrodynamic system of Earth

    NASA Astrophysics Data System (ADS)

    Grunskaya, Lubov; Isakevich, Valiriy

    There is studied the interconnection of tide processes of geophysical and astrophysical origin with the Earth electromagnetic fields. There has been developed a programme-analytical system (PAS) to investigate signal structures in spectral and time series, caused by geophysical and astrophysical processes based on the method of eigen vectors. There were discovered frequencies in the electrical and geomagnetical field of ELF range with PAS, which coincide with the frequency of gravitational -wave radiation of a number of double stellar systems. In the electrical and geomagnetic field there was discovered a specific axion frequency VA=0.5*10-5 Hz belonging to the ELF range which was predicted by the theory. The problem of the anomalous behavior of the electrodynamic system response to the gravitational - wave affect is being discussed. On the basis of the rich experimental material have been investigated the frequencies of gravitational-wave radiation of a number of binary systems: J0700+6418, J1012+5307, J1537+1155, J1959+2048, J2130+1210, J1915+1606. The work is carried out with supporting of RFFI № 14-07-97510, State Task to Universities on 2014-2016.

  14. Influence of the lateral movement on the levitation and guidance force in the high-temperature superconductor maglev system

    NASA Astrophysics Data System (ADS)

    Song, Honghai; de Haas, Oliver; Beyer, Christoph; Krabbes, Gernot; Verges, Peter; Schultz, Ludwig

    2005-05-01

    After the levitation force relaxation was studied for different field-cooling height and working-levitation height, the high-temperature superconductor (HTS) bulk was horizontally moved in the lateral direction above the permanent magnet guideway. Both levitation and guidance force were collected by the measurement system at the same time. It was found that the decay of levitation force is dependent on both the maximum lateral displacement and the movement cycle times, while the guidance force hysteresis curve does not change after the first cycle. This work provided scientific analysis for the HTS maglev system design.

  15. High fidelity microelectromechanical system electrodynamic micro-speaker characterization

    NASA Astrophysics Data System (ADS)

    Sturtzer, E.; Shahosseini, I.; Pillonnet, G.; Lefeuvre, E.; Lemarquand, G.

    2013-06-01

    This paper deals with the heterogeneous characterization of a microelectromechanical system (MEMS) electrodynamic micro-speaker. This MEMS micro-speaker consists of an optimized silicon structure based on a very light but very stiff membrane. The mobile part is suspended using soft suspension beams, also made of silicon, which enable large out-of-plane displacement. The electromagnetic motor is composed of a micro-assembly permanent ring magnet and of a deposit mobile planar coil fixed on the top of the silicon membrane. Previous publications have presented the MEMS as theoretically able to produce high fidelity and high efficiency over a wide bandwidth. The present study intends to validate the electrical, the mechanical, and the acoustic performance improvements. The characterization of the microfabricated micro-speaker showed that the electric impedance is flat over the entire audio bandwidth. Some results validates the performance improvements in terms of audio quality as compared to state of the art of the MEMS micro-speakers, such as the high out-of-plane membrane displacement over ±400 μm, the 80 dBSPL sound pressure level at 10 cm, the 2% maximal distortion level, and the useful bandwidth from 335 Hz to cutoff frequency.

  16. Effect of reciprocating motions around working points on levitation force of superconductor-magnet system

    NASA Astrophysics Data System (ADS)

    Xu, Jimin; Zhang, Fei; Sun, Tao; Yuan, Xiaoyang; Zhang, Cuiping

    2016-09-01

    In order to simulate vibration around working points in practical operation of superconducting levitation system, magnet in a simple superconductor-magnet system are conducted reciprocating motions around static height in this study. Two YBCO cylindrical samples with different grain orientations are used to investigate the effect of reciprocating motions of magnet on superconducting magnetic force. The c-axis of sample S1 is perpendicular to the top surface while sample S2 is parallel to the top surface. The initial cooling processes for the superconductors include zero-field-cooled (ZFC) and filed-cooled (FC). Compared to the levitation force before reciprocating motions, the ZFC levitation force at static height becomes smaller after reciprocating while the FC force presents opposite phenomenon. It is found that levitation force at static height tends to be stable after several times of reciprocating under ZFC and FC conditions and its time-decay phenomenon is suppressed in some extent, which is meaningful for the practical application of superconducting levitation system. Based on vortex dynamic, some physical discussions are presented to the experimental results.

  17. Apparatus and method for reducing inductive coupling between levitation and drive coils within a magnetic propulsion system

    DOEpatents

    Post, Richard F.

    2001-01-01

    An apparatus and method is disclosed for reducing inductive coupling between levitation and drive coils within a magnetic levitation system. A pole array has a magnetic field. A levitation coil is positioned so that in response to motion of the magnetic field of the pole array a current is induced in the levitation coil. A first drive coil having a magnetic field coupled to drive the pole array also has a magnetic flux which induces a parasitic current in the levitation coil. A second drive coil having a magnetic field is positioned to attenuate the parasitic current in the levitation coil by canceling the magnetic flux of the first drive coil which induces the parasitic current. Steps in the method include generating a magnetic field with a pole array for levitating an object; inducing current in a levitation coil in response to motion of the magnetic field of the pole array; generating a magnetic field with a first drive coil for propelling the object; and generating a magnetic field with a second drive coil for attenuating effects of the magnetic field of the first drive coil on the current in the levitation coil.

  18. Preliminary characterization of a one-axis acoustic system. [acoustic levitation for space processing

    NASA Technical Reports Server (NTRS)

    Oran, W. A.; Reiss, D. A.; Berge, L. H.; Parker, H. W.

    1979-01-01

    The acoustic fields and levitation forces produced along the axis of a single-axis resonance system were measured. The system consisted of a St. Clair generator and a planar reflector. The levitation force was measured for bodies of various sizes and geometries (i.e., spheres, cylinders, and discs). The force was found to be roughly proportional to the volume of the body until the characteristic body radius reaches approximately 2/k (k = wave number). The acoustic pressures along the axis were modeled using Huygens principle and a method of imaging to approximate multiple reflections. The modeled pressures were found to be in reasonable agreement with those measured with a calibrated microphone.

  19. Improvement of the Levitation Characteristics in the Magnetic Bearing System Using HTSC-Permanent Magnet Hybrid Structure

    NASA Astrophysics Data System (ADS)

    Ohashi, Shunsuke

    Magnetic bearing using pining force of a permanent magnet and a high-temperature superconductor has been developed. Additional permanent magnet is introduced to increase the levitation force of the magnetic bearing. In this hybrid magnetic bearing system, levitation force is mainly given by the repulsive force of the permanent magnets, and stability for the lateral direction is given by pining force of the superconductor. The experimental device is developed. A ring type superconductor and a bulk one are examined. Levitation characteristics of the hybrid magnetic bearing are measured. A bulk superconductor shows better characteristics both levitation and lateral stability than ring one. Levitation force of the hybrid system becomes about twice as large as that of the no-hybrid one. Although repulsive force of the permanent magnet decreases lateral stability of the system, its influence becomes small by choosing adequate position of the permanent magnets and the superconductor.

  20. Performance analysis of the combined EDS maglev propulsion, levitation, and guidance system

    SciTech Connect

    He, J.L.; Coffey, H.T.; Rote, D.M.

    1993-10-01

    An analysis of the Japanese maglev system which uses only one set of coils in the guideway for combined levitation, propulsion, and guidance functions is presented in this paper. This preliminary study, using the dynamic circuit approach, indicates that the system is very promising.

  1. Robust dynamic sliding-mode control using adaptive RENN for magnetic levitation system.

    PubMed

    Lin, Faa-Jeng; Chen, Syuan-Yi; Shyu, Kuo-Kai

    2009-06-01

    In this paper, a robust dynamic sliding mode control system (RDSMC) using a recurrent Elman neural network (RENN) is proposed to control the position of a levitated object of a magnetic levitation system considering the uncertainties. First, a dynamic model of the magnetic levitation system is derived. Then, a proportional-integral-derivative (PID)-type sliding-mode control system (SMC) is adopted for tracking of the reference trajectories. Moreover, a new PID-type dynamic sliding-mode control system (DSMC) is proposed to reduce the chattering phenomenon. However, due to the hardware being limited and the uncertainty bound being unknown of the switching function for the DSMC, an RDSMC is proposed to improve the control performance and further increase the robustness of the magnetic levitation system. In the RDSMC, an RENN estimator is used to estimate an unknown nonlinear function of lumped uncertainty online and replace the switching function in the hitting control of the DSMC directly. The adaptive learning algorithms that trained the parameters of the RENN online are derived using Lyapunov stability theorem. Furthermore, a robust compensator is proposed to confront the uncertainties including approximation error, optimal parameter vectors, and higher order terms in Taylor series. Finally, some experimental results of tracking the various periodic trajectories demonstrate the validity of the proposed RDSMC for practical applications. PMID:19423437

  2. Electrostatic Levitator Electrodes

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Electrostatic levitation system inside Electrostatic Levitator (ESL) vacuum chamber. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  3. Electromagnetically levitated vibration isolation system for the manufacturing process of silicon monocrystals

    NASA Technical Reports Server (NTRS)

    Kanemitsu, Yoichi; Watanabe, Katsuhide; Yano, Kenichi; Mizuno, Takayuki

    1994-01-01

    This paper introduces a study on an Electromagnetically Levitated Vibration Isolation System (ELVIS) for isolation control of large-scale vibration. This system features no mechanical contact between the isolation table and the installation floor, using a total of four electromagnetic actuators which generate magnetic levitation force in the vertical and horizontal directions. The configuration of the magnet for the vertical direction is designed to prevent any generation of restoring vibratory force in the horizontal direction. The isolation system is set so that vibration control effects due to small earthquakes can be regulated to below 5(gal) versus horizontal vibration levels of the installation floor of up t 25(gal), and those in the horizontal relative displacement of up to 30 (mm) between the floor and levitated isolation table. In particular, studies on the relative displacement between the installation floor and the levitated isolation table have been made for vibration control in the horizontal direction. In case of small-scale earthquakes (Taft wave scaled: max. 25 gal), the present system has been confirmed to achieve a vibration isolation to a level below 5 gal. The vibration transmission ratio of below 1/10 has been achieved versus continuous micro-vibration (approx. one gal) in the horizontal direction on the installation floor.

  4. Mass determination with the magnetic levitation method—proposal for a new design of electromechanical system

    NASA Astrophysics Data System (ADS)

    Kajastie, H.; Riski, K.; Satrapinski, A.

    2009-06-01

    The method for realization of the kilogram using 'superconducting magnetic levitation' was re-evaluated at MIKES. The realization of the kilogram based on the traditional levitation method is limited by the imperfections of the superconducting materials and the indefinable dependence between supplied electrical energy and the gravitational potential energy of the superconducting mass. This indefiniteness is proportional to the applied magnetic field and is caused by increasing losses and trapped magnetic fluxes. A new design of an electromechanical system for the levitation method is proposed. In the proposed system the required magnetic field and the corresponding force are reduced, as the mass of the body (hanging from a mass comparator) is compensated by the reference weight on the mass comparator. The direction of the magnetic force can be upward (levitation force, when the body is over the coil) or downward (repulsive force, when the body is under the coil). The initial force to move the body from the coil is not needed and magnetic field sensitivity is increased, providing linearization of displacement versus applied current. This new construction allows a lower magnetic induction, reduces energy losses compared with previous designs of electromechanical system and reduces the corresponding systematic error.

  5. Study on control method of running velocity for the permanent magnet-HTSC hybrid magnetically levitated conveyance system

    NASA Astrophysics Data System (ADS)

    Nishio, R.; Ikeda, M.; Sasaki, R.; Ohashi, S.

    2011-11-01

    We have developed the magnetically levitated carrying system. In this system, pinning force of high temperature bulk super conductor (HTSC) is used for the levitation and guidance. Four HTSCs are installed on the carrier. The magnetic rail is set on the ground, and flux from the magnetic rail is pinned by HTSCs. To increase levitation force, repulsive force of the permanent magnet is used. The hybrid levitation system is composed. The permanent magnet is installed under the load stage of the carrier. Repulsive force by the permanent magnet between the load stage on the carrier and the magnetic rail on the ground is used to support the load weight. Levitation and guidance one by pinning effect of the YBaCuO HTSC in the carrier is used to levitate the carrier body. The load stage is separated from the carrier flame and can move freely for vertical direction levitation. For the propulsion system, electromagnet is installed on the surface of the magnetic rail. In this paper, control method of running velocity of the carrier is studied. Propulsion force is given as follows; Air core copper coils are installed on the magnetic rail. Interaction between current of these coils and permanent magnets on the carrier generates propulsion force. Running velocity is controlled by current of the propulsion coils. It is also changed by position of the carrier and the load weight. From the results, stability of the propulsion system is given, and propulsion characteristics are improved.

  6. Experiments with Electrodynamic Wheels

    NASA Astrophysics Data System (ADS)

    Gaul, Nathan; Corey, Daniel; Cordrey, Vincent; Majewski, Walerian

    2015-04-01

    Our experiments were involving inductive magnetic levitation. A Halbach array is a system in which a series of magnets is arranged in a manner such that the magnetic field is cancelled on one side of the array while strengthening the field on the other. We constructed two circular Halbach wheels, making the strong magnetic field on the outer rim of the ring. Such system is usually dubbed as an Electrodynamic Wheel (EDW). Rotating this wheel around a horizontal axis above a flat conducting surface should induce eddy currents in said surface through the variable magnetic flux. The eddy currents produce, in turn, their own magnetic fields which interact with the magnets of the EDW. We demonstrated that these interactions produce both drag and lift forces on the EDW which can theoretically be used for lift and propulsion of the EDW. The focus of our experiments is determining how to maximize the lift-to-drag ratio by the proper choice of the induction element. We will also describe our experiments with a rotating circular Halbach array having the strong magnetic field of about 1 T on the flat side of the ring, and acting as a hovercraft.

  7. Safety of high speed magnetic levitation transportation systems. Preliminary safety review of the transrapid maglev system

    NASA Astrophysics Data System (ADS)

    Dorer, R. M.; Hathaway, W. T.

    1990-11-01

    The safety of various magnetically levitated trains under development for possible implementation in the United States is of direct concern to the Federal Railroad Administration. Safety issues are addressed related to a specific maglev technology. The Transrapid maglev system was under development by the German Government over the last 10 to 15 years and was evolved into the current system with the TR-07 vehicle. A technically based safety review was under way over the last year by the U.S. Department of Transportation. The initial results of the review are presented to identify and assess potential maglev safety issues.

  8. Improved acoustic levitation apparatus

    NASA Technical Reports Server (NTRS)

    Berge, L. H.; Johnson, J. L.; Oran, W. A.; Reiss, D. A.

    1980-01-01

    Concave driver and reflector enhance and shape levitation forces in acoustic resonance system. Single-mode standing-wave pattern is focused by ring element situated between driver and reflector. Concave surfaces increase levitating forces up to factor of 6 as opposed to conventional flat surfaces, making it possible to suspend heavier objects.

  9. Optimization of guideway coil dimensions for a magnetic levitation system

    SciTech Connect

    Chen, Y.J.; Feng, J.

    1997-09-01

    A fast computer code that generates currents and forces for multiple magnetic levitation (MAGLEV) vehicle coils over a discrete guideway of arbitrary geometry has been developed, tested, and verified. A study of coil dimensions for overlapping loops, ladders, and discrete loops has been conducted to determine the optimal guideway design. A parameter known as figure of merit has been defined to assist in evaluating the level of merit for a particular track configuration. From this, it has been discovered that, for most cases, ladder tracks are a better configuration over both overlapping and discrete loops. On closer inspection, it was also discovered that an aspect ratio of unity for the dimensions of a ladder track yields the best overall results.

  10. Analysis of electrode system for generation of high-power electrodynamic flow

    NASA Astrophysics Data System (ADS)

    Rebrov, I. E.; Khomich, V. Yu.; Yamshchikov, V. A.

    2016-08-01

    A high-power electrodynamic flow in atmospheric air is numerically simulated and experimentally studied. An electrode system consisting of a cylindrical plasma emitter and a plane metal grid collector of ions is used to generate a flow with a speed of 2 m/s and a volume rate of 15 L/s.

  11. Electrodynamic pulsator

    SciTech Connect

    Myslinski, A.; Semeniuk, B.; Kasprzycka-Guttman, T. . Dept. of Chemistry)

    1993-11-01

    An electrodynamic pulsator, designed for the reciprocation of liquids in an pulsed extractor, is described. Application of the pulsator is illustrated by its performance in connection with a laboratory packed column used for extraction of citric acid from aqueous solutions by cyclohexanone. A schematic of the pulsator is shown. This pulsator was designed to avoid the indirect, stepwise, mechanical regulation systems used in pulsed extractors which employ an external device such as a piston pump.

  12. High temperature metal purification using a compact portable rf heating and levitation system on the wake shield

    NASA Technical Reports Server (NTRS)

    Hahs, C. A.

    1990-01-01

    The Wake Shield Facility (WSF) can provide an ideal vacuum environment for the purification of high temperature metals in space. The Modular Electromagnetic Levitator (MEL), will provide the opportunity to study undercooling of metals in space and allow to determine material properties in space. The battery powered rf levitation and heating system developed for the MEL demonstrated efficiency of 36 percent. This system is being considered to purify metals at temperatures below 3000 C.

  13. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, D.M.; He, J.; Johnson, L.R.

    1994-01-04

    A propulsion and stabilization system are described comprising a series of coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance, and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension. 8 figures.

  14. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, Donald M.; He, Jianliang; Johnson, Larry R.

    1994-01-01

    A propulsion and stabilization system comprising a series of FIG. 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the FIG. 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  15. Integrated null-flux suspension and multiphase propulsion system for magnetically-levitated vehicles

    DOEpatents

    Rote, D.M.; He, Jianliang; Johnson, L.R.

    1992-01-01

    This report discusses a propulsion and stabilization system comprising a series of figure 8 coils mounted vertically on the walls of the guideway to provide suspension, lateral guidance and propulsion of a magnetically levitated vehicle. This system further allows for altering the magnetic field effects by changing the relative position of the loops comprising the figure 8 coils either longitudinally and/or vertically with resulting changes in the propulsion, the vertical stability, and the suspension.

  16. Acoustic levitation

    SciTech Connect

    2012-09-12

    Scientists at Argonne National Laboratory have discovered a way to use sound waves to levitate individual droplets of solutions containing different pharmaceuticals. While the connection between levitation and drug development may not be immediately apparent, a special relationship emerges at the molecular level. Read more: http://www.anl.gov/articles/no-magic-show-real-world-levitation-inspire-better-pharmaceuticals

  17. Leidenfrost levitation: beyond droplets

    PubMed Central

    Hashmi, Ali; Xu, Yuhao; Coder, Benjamin; Osborne, Paul A.; Spafford, Jonathon; Michael, Grant E.; Yu, Gan; Xu, Jie

    2012-01-01

    Friction is a major inhibitor in almost every mechanical system. Enlightened by the Leidenfrost effect – a droplet can be levitated by its own vapor layer on a sufficiently hot surface – we demonstrate for the first time that a small cart can also be levitated by Leidenfrost vapor. The levitated cart can carry certain amount of load and move frictionlessly over the hot surface. The maximum load that the cart can carry is experimentally tested over a range of surface temperatures. We show that the levitated cart can be propelled not only by gravitational force over a slanted flat surface, but also self-propelled over a ratchet shaped horizontal surface. In the end, we experimentally tested water consumption rate for sustaining the levitated cart, and compared the results to theoretical calculations. If perfected, this frictionless Leidenfrost cart could be used in numerous engineering applications where relative motion exists between surfaces. PMID:23150770

  18. Leidenfrost levitation: beyond droplets.

    PubMed

    Hashmi, Ali; Xu, Yuhao; Coder, Benjamin; Osborne, Paul A; Spafford, Jonathon; Michael, Grant E; Yu, Gan; Xu, Jie

    2012-01-01

    Friction is a major inhibitor in almost every mechanical system. Enlightened by the Leidenfrost effect - a droplet can be levitated by its own vapor layer on a sufficiently hot surface - we demonstrate for the first time that a small cart can also be levitated by Leidenfrost vapor. The levitated cart can carry certain amount of load and move frictionlessly over the hot surface. The maximum load that the cart can carry is experimentally tested over a range of surface temperatures. We show that the levitated cart can be propelled not only by gravitational force over a slanted flat surface, but also self-propelled over a ratchet shaped horizontal surface. In the end, we experimentally tested water consumption rate for sustaining the levitated cart, and compared the results to theoretical calculations. If perfected, this frictionless Leidenfrost cart could be used in numerous engineering applications where relative motion exists between surfaces.

  19. Time-delay control of a magnetic levitated linear positioning system

    NASA Technical Reports Server (NTRS)

    Tarn, J. H.; Juang, K. Y.; Lin, C. E.

    1994-01-01

    In this paper, a high accuracy linear positioning system with a linear force actuator and magnetic levitation is proposed. By locating a permanently magnetized rod inside a current-carrying solenoid, the axial force is achieved by the boundary effect of magnet poles and utilized to power the linear motion, while the force for levitation is governed by Ampere's Law supplied with the same solenoid. With the levitation in a radial direction, there is hardly any friction between the rod and the solenoid. The high speed motion can hence be achieved. Besides, the axial force acting on the rod is a smooth function of rod position, so the system can provide nanometer resolution linear positioning to the molecule size. Since the force-position relation is highly nonlinear, and the mathematical model is derived according to some assumptions, such as the equivalent solenoid of the permanently magnetized rod, so there exists unknown dynamics in practical application. Thus 'robustness' is an important issue in controller design. Meanwhile the load effect reacts directly on the servo system without transmission elements, so the capability of 'disturbance rejection; is also required. With the above consideration, a time-delay control scheme is chosen and applied. By comparing the input-output relation and the mathematical model, the time-delay controller calculates an estimation of unmodeled dynamics and disturbances and then composes the desired compensation into the system. Effectiveness of the linear positioning system and control scheme are illustrated with simulation results.

  20. Optimization of levitation and guidance forces in a superconducting Maglev system

    NASA Astrophysics Data System (ADS)

    Yildizer, Irfan; Cansiz, Ahmet; Ozturk, Kemal

    2016-09-01

    Optimization of the levitation for superconducting Maglev systems requires effective use of vertical and guidance forces during the operation. In this respect the levitation and guidance forces in terms of various permanent magnet array configurations are analyzed. The arrangements of permanent magnet arrays interacting with the superconductor are configured for the purpose of increasing the magnetic flux density. According to configurations, modeling the interaction forces between the permanent magnet and the superconductor are established in terms of the frozen image model. The model is complemented with the analytical calculations and provides a reasonable agreement with the experiments. The agreement of the analytical calculation associated with the frozen image model indicates a strong case to establish an optimization, in which provides preliminary analysis before constructing more complex Maglev system.

  1. Electric generator using a triangular diamagnetic levitating rotor system.

    PubMed

    Ho, Joe Nhut; Wang, Wei-Chih

    2009-02-01

    This paper describes a feasibility study of creating a small low friction and low maintenance generator using a diamagnetically stabilized levitating rotor. The planar rotor described in this paper uses a triangular configuration of magnets that generates emf by passing over coils placed below the rotor. Equations were developed to predict the generated emf from coils with two different coil geometries. Additionally, this paper provides a method for estimating optimal coil size and position for the planar rotor presented for both segmental arc and circular coils to obtain maximum power output. Experiments demonstrated that the emf generated in the coils matches well with the predicted wave forms for each case, and the optimization theory gives good prediction to outcome of induced waveforms. For the segmental arc coil design, the induced emf was 1.7 mV at a radial frequency of 21.8 rad/s. For the circular coil design, the emf was 1.25 mV at a radial frequency of 28.1 rad/s. PMID:19256668

  2. Magnetic levitation systems for future aeronautics and space research and missions

    SciTech Connect

    Blankson, I.M.; Mankins, J.C.

    1996-02-01

    The objectives, advantages, and research needs for several applications of superconducting magnetic levitation to aerodynamics research, testing, and space-launch are discussed. Applications include very large-scale magnetic balance and suspension systems for high alpha testing, support interference-free testing of slender hypersonic propulsion/airframe integrated vehicles, and hypersonic maglev. Current practice and concepts are outlined as part of a unified effort in high magnetic fields R&D within NASA. Recent advances in the design and construction of the proposed ground-based Holloman test track (rocket sled) that uses magnetic levitation are presented. It is projected that ground speeds of up to Mach 8 to 11 at sea-level are possible with such a system. This capability may enable supersonic combustor tests as well as ramjet-to-scramjet transition simulation to be performed in clean air. Finally a novel space launch concept (Maglifter) which uses magnetic levitation and propulsion for a re-usable `first stage` and rocket or air-breathing combined-cycle propulsion for its second stage is discussed in detail. Performance of this concept is compared with conventional advanced launch systems and a preliminary concept for a subscale system demonstration is presented.

  3. Magnetic levitation systems for future aeronautics and space research and missions

    NASA Technical Reports Server (NTRS)

    Blankson, Isaiah M.; Mankins, John C.

    1996-01-01

    The objectives, advantages, and research needs for several applications of superconducting magnetic levitation to aerodynamics research, testing, and space-launch are discussed. Applications include very large-scale magnetic balance and suspension systems for high alpha testing, support interference-free testing of slender hypersonic propulsion/airframe integrated vehicles, and hypersonic maglev. Current practice and concepts are outlined as part of a unified effort in high magnetic fields R&D within NASA. Recent advances in the design and construction of the proposed ground-based Holloman test track (rocket sled) that uses magnetic levitation are presented. It is protected that ground speeds of up to Mach 8 to 11 at sea-level are possible with such a system. This capability may enable supersonic combustor tests as well as ramjet-to-scramjet transition simulation to be performed in clean air. Finally a novel space launch concept (Maglifter) which uses magnetic levitation and propulsion for a re-usable 'first stage' and rocket or air-breathing combined-cycle propulsion for its second stage is discussed in detail. Performance of this concept is compared with conventional advanced launch systems and a preliminary concept for a subscale system demonstration is presented.

  4. A new conveyor system based on a passive magnetic levitation unit having repulsive-type magnetic bearings

    NASA Astrophysics Data System (ADS)

    Ohji, T.; Ichiyama, S.; Amei, K.; Sakui, M.; Yamada, S.

    2004-05-01

    A magnetic repulsive-type conveyor system is proposed as a new application of repulsive-type magnetic bearings, which use repulsive forces between the stator and rotor permanent magnets. The proposed conveyer is composed by aligning many passive magnetic levitation units. Each unit also contains electromagnets to oscillate a levitator shaft in the radial direction. The way of generating vibration and rotation in the conveyance direction was examined by the various excitation methods.

  5. Electrodynamic Propulsion System Tether Experiment (T-REX)

    NASA Technical Reports Server (NTRS)

    Johnson, L.; Fujii, H. A.; Sanmartin, J. R.

    2010-01-01

    A Japanese-led international team is developing a suborbital test of orbital-motion-limited (OML) bare wire anode current collection for application to electrodynamic tether (EDT) propulsion. The tether is a tape with a width of 25 mm, thickness of 0.05 mm, and is 300 m in length. This will be the first space test of OML theory. The mission will launch in the summer of 2010 using an S520 Sounding Rocket. During ascent, and above approximately 100 km in attitude, the tape tether will be deployed at a rate of approximately8 m/s. Once deployed, the tape tether will serve as an anode, collecting ionospheric electrons. The electrons will be expelled into space by a hollow cathode device, thereby completing the circuit and allowing current to flow. The total amount of current collected will be used to assess the validity of OML theory. This paper will describe the objectives of the proposed mission, the technologies to be employed, and the application of the results to future space missions using EDTs for propulsion or power generation

  6. A new electromagnetic levitation system for rapid transit and high speed transportation

    SciTech Connect

    Wang, T.C.; Tzeng, Y.K. . Dept. of Electrical Engineering)

    1994-11-01

    A Maglev system using permanent and electromagnet is described. Such a system offers the advantages of high lift force to magnet weight ratio and nearly zero ohmic loss of its control winding. However, it is more difficult to control. Also, unlike the conventional electromagnetic levitation system, the control current is always maintained at zero value even with load variations. Analysis shows that the size and weight of this system are smaller by a factor of three compared to the conventional Maglev system. Basic design criteria and control strategy using variable structure control method are given, together with experimental results of a small model to verify its feasibility and good dynamic response.

  7. Space weather disturbances in the ionosphere-thermosphere-electrodynamics system at middle and low latitudes

    NASA Astrophysics Data System (ADS)

    Schunk, Robert

    2012-07-01

    It has been clearly established that the ionosphere-thermosphere-electrodynamics system can vary significantly from hour to hour and from day to day. The hour-to-hour variations are associated with weather disturbances, which can produce mesoscale (100-1000 km) structures and plasma irregularities. For the ionosphere, these weather disturbances include Traveling Ionospheric Disturbances (TIDs), sporadic E layers, He ^{+} layers in the topside ionosphere, descending intermediate layers, ridges of enhanced ionization (Storm Enhanced Densities), a 4-wave signature, spread-F, and equatorial plasma bubbles. For the thermosphere, the weather disturbances include upward propagating waves from the lower atmosphere (planetary, tidal and gravity waves), Traveling Atmospheric Disturbances (TADs) generated at high latitudes, storm-time O/N _{2} depletions, and neutral gas perturbations both at the terminator and in the regions containing equatorial plasma bubbles. The current state of our knowledge of weather disturbances in the middle and low latitude ionosphere-thermosphere-electrodynamics system will be reviewed.

  8. Photon antibunching and bunching in a ring-resonator waveguide quantum electrodynamics system.

    PubMed

    Chen, Zihao; Zhou, Yao; Shen, Jung-Tsung

    2016-07-15

    We numerically investigate the photonic state generation and its nonclassical correlations in a ring-resonator waveguide quantum electrodynamics system. Specifically, we discuss photon antibunching and bunching in various scenarios, including the imperfect resonator with backscattering and dissipations. Our numerical results indicate that an imperfect ring resonator with backscattering can enhance the quality of antibunching. In addition, we also identify the quantum photonic halo phenomenon in the photon scattering dynamics and the shoulder effect in the second-order correlation function. PMID:27420523

  9. Photon antibunching and bunching in a ring-resonator waveguide quantum electrodynamics system.

    PubMed

    Chen, Zihao; Zhou, Yao; Shen, Jung-Tsung

    2016-07-15

    We numerically investigate the photonic state generation and its nonclassical correlations in a ring-resonator waveguide quantum electrodynamics system. Specifically, we discuss photon antibunching and bunching in various scenarios, including the imperfect resonator with backscattering and dissipations. Our numerical results indicate that an imperfect ring resonator with backscattering can enhance the quality of antibunching. In addition, we also identify the quantum photonic halo phenomenon in the photon scattering dynamics and the shoulder effect in the second-order correlation function.

  10. Design and implementation of a 2-DOF PID compensation for magnetic levitation systems.

    PubMed

    Ghosh, Arun; Rakesh Krishnan, T; Tejaswy, Pailla; Mandal, Abhisek; Pradhan, Jatin K; Ranasingh, Subhakant

    2014-07-01

    This paper employs a 2-DOF (degree of freedom) PID controller for compensating a physical magnetic levitation system. It is shown that because of having a feedforward gain in the proposed 2-DOF PID control, the transient performance of the compensated system can be changed in a desired manner unlike the conventional 1-DOF PID control. It is also shown that for a choice of PID parameters, although the theoretical loop robustness is the same for both the compensated systems, in real-time, 2-DOF PID control may provide superior robustness if a suitable choice of the feedforward parameter is made. The results are verified through simulations and experiments. PMID:24947430

  11. Design approaches and parameters for magnetically levitated transport systems. [Null flux suspension (Maglev)

    SciTech Connect

    Danby, G.T.; Powell, J.R.

    1988-01-01

    Mechanically levitated transport system approaches are assessed with regard to thrust power needs, track cost, suspension stability, and safety. The null flux suspension appears as the favored approach, having the least thrust power requirements, highest stability, and lowest amount of track material. Various null flux configurations are described together with their operating parameters. The Linear Synchronous Motor (LSM) propulsion system is also described for propelling the suspended vehicles. Cryogenics and superconductivity aspects are discussed and the effect of high T/sub c/ superconductors evaluated. 13 refs., 16 figs., 2 tabs.

  12. Electrostatic Levitator Electrode Layout

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Schematic of Electrostatic Levitator (ESL) electrodes and controls system. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  13. Investigation of the stability of AC repulsive force levitation systems for low-speed maglev.

    SciTech Connect

    He, J. L.; Wang, Z.; Rote, D. M.; Winkelman, S.; Energy Systems

    1992-09-01

    Discusses the stability of an AC induction levitation system, focusing on the analysis and optimum design of the secondary conductor. Several improved secondary conductor geometries are considered. A theoretical model with numerical results, as well as experimental observations and data are presented. Theoretical and experimental results indicate that only marginal stability can be achieved with a single-plate secondary conductor. Modifications of the single plate can enhance its stability at rest, but this design suffers from longitudinal instabilities when propelled. It is concluded that a double-plate secondary conductor is stable in all six degrees of freedom.

  14. Levitation With a Single Acoustic Driver

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Gaspar, M. S.; Allen, J. L.

    1986-01-01

    Pair of reports describes acoustic-levitation systems in which only one acoustic resonance mode excited, and only one driver needed. Systems employ levitation chambers of rectangular and cylindrical geometries. Reports first describe single mode concept and indicate which modes used to levitate sample without rotation. Reports then describe systems in which controlled rotation of sample introduced.

  15. Self-adjusting control system of the electrodynamic velocity transducer for Mössbauer spectrometer

    NASA Astrophysics Data System (ADS)

    Zekhtser, M. Yu.; Revyakin, A. S.; Sarychev, D. A.

    2016-08-01

    The novel control system has been developed on the basis of motion equation for the moving part of the electrodynamic velocity transducer of Mössbauer spectrometer. The motion equation coefficients are the parameters of its vibrating system. The square of cyclic eigenfrequency and damping factor are automatically determined by the control software for the spectrometer using the express analysis of free damped oscillations before any measurements are taken. The control system does not require manual adjustment of the spectrometer before the experiment. It exhibits accuracy of self-tuning and high degree of Doppler modulation stability in long-term experiments, providing high quality Mössbauer spectra.

  16. Matching Impedances and Modes in Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.

    1985-01-01

    Temperature differences accommodated with tunable coupler. Report discusses schemes for coupling sound efficiently from cool outside atmosphere into hot acoustic-levitation chamber. Theoretical studies have practical implications for material-processing systems that employ acoustic levitation.

  17. Optimal pole arrangement design of a linear switched-reluctance machine for magnetic levitation and propulsion system

    SciTech Connect

    Liu, C.T.; Sheu, N.

    1996-09-01

    This paper provides an optimal pole arrangement design scheme of a linear switched-reluctance machine that is applicable for magnetic levitated vehicle (MAGLEV) system. The proposed low-cost machine structure will be able to supply both the levitation and the propulsion forces simultaneously. Minimum torque generation and smooth switch operation in the entire operation range have been selected as the design objectives subjected to the available machine bogie and electromagnet sizes. Comparison studies on the system electromagnetic and electromechanical characteristics will be provided to verify the adequacy of the proposed design scheme.

  18. Thermal properties of a cylindrical YBa2Cu3O x superconductor in a levitation system: triggered by nonlinear dynamics

    NASA Astrophysics Data System (ADS)

    Huang, Yi; Zhang, Xingyi; Zhou, You-He

    2016-07-01

    The vibration of a permanent magnet (PM) levitated upon a high temperature superconductor (HTS) shows anomalous motion under external disturbance. In this paper we construct a cantilevered beam experimental setup composed of a bulk PM and a thermally insulated cylindrical YBa2Cu3O x superconductor. When the levitation system is disturbed by vertical excitation, the thermal character of the superconductor surface could be measured directly. Our experiments on a clean and large single-domain superconductor show that a giant temperature spike appears once the levitated PM experiences period doubling oscillation. We develop a numerical simulation for the analysis of the nonlinear vibration of the levitated PM coupled with the nonlinear electromagnetic force between the PM and HTS, taking into account heat diffusion. Using this procedure, we explore the electromagnetic and thermal properties at the thermally insulated HTS surface when the levitated PM shows a period doubling vibration. We find a remarkable difference between the experimental results and simulation. In order to interpret this temperature difference, we suggest a type of flux motion triggered by the electromagnetic force when it is far larger than the pinning force of the superconductor. The quantitative approach is based on the analysis process of the partial flux jump as a result of the flux creep. Finally, the calculated result is shown to be very close to the experimental result.

  19. General theory based on fluctuational electrodynamics for van der Waals interactions in colloidal systems

    SciTech Connect

    Yannopapas, Vassilios

    2007-12-15

    A rigorous theory for the determination of the van der Waals interactions in colloidal systems is presented. The method is based on fluctuational electrodynamics and a multiple-scattering method which provides the electromagnetic Green's tensor. In particular, expressions for the Green's tensor are presented for arbitrary, finite collections of colloidal particles, for infinitely periodic or defected crystals, as well as for finite slabs of crystals. The presented formalism allows for ab initio calculations of the van der Waals interactions in colloidal systems since it takes fully into account retardation, many-body, multipolar, and near-field effects.

  20. Stability of magnetic tip/superconductor levitation systems

    NASA Astrophysics Data System (ADS)

    K. Alqadi, M.

    2015-11-01

    The vertical stability of a magnetic tip over a superconducting material is investigated by using the critical state and the frozen image models. The analytical expressions of the stiffness and the vibration frequency about the equilibrium position are derived in term of the geometrical parameters of the magnet/superconductor system. It is found that the stability of the system depends on the shape of the superconductor as well as its thickness.

  1. A Shaftless Magnetically Levitated Multifunctional Spacecraft Flywheel Storage System

    NASA Technical Reports Server (NTRS)

    Stevens, Ken; Thornton, Richard; Clark, Tracy; Beaman, Bob G.; Dennehy, Neil; Day, John H. (Technical Monitor)

    2002-01-01

    Presently many types of spacecraft use a Spacecraft Attitude Control System (ACS) with momentum wheels for steering and electrochemical batteries to provide electrical power for the eclipse period of the spacecraft orbit. Future spacecraft will use Flywheels for combined use in ACS and Energy Storage. This can be done by using multiple wheels and varying the differential speed for ACS and varying the average speed for energy storage and recovery. Technology in these areas has improved since the 1990s so it is now feasible for flywheel systems to emerge from the laboratory for spacecraft use. This paper describes a new flywheel system that can be used for both ACS and energy storage. Some of the possible advantages of a flywheel system are: lower total mass and volume, higher efficiency, less thermal impact, improved satellite integration schedule and complexity, simplified satellite orbital operations, longer life with lower risk, less pointing jitter, and greater capability for high-rate slews. In short, they have the potential to enable new types of missions and provide lower cost. Two basic types of flywheel configurations are the Flywheel Energy Storage System (FESS) and the Integrated Power and Attitude Control System (IPACS).

  2. Design, implementation, and testing of a single axis levitation system for the suspension of a platform.

    PubMed

    Banerjee, Subrata; Prasad, Dinkar; Pal, Jayanta

    2007-04-01

    This paper describes the design and implementation of a single axis DC attraction type suspension system, where a platform (vehicle structure) of around 14 kg mass is made to remain suspended at the desired operating gap under a ferromagnetic guide-way. The prototype has four electromagnetic actuators of attraction type and four inductive gap sensors, all located at the corners of the platform. The four actuators are controlled independently through four identical controllers, and the stable levitation of the platform is achieved through the single input and single output (SISO) control of each air-gap. The emphasis of this work is on the design and development of the switched mode power amplifier cum controller unit for the four actuators. The proposed single switch-based power circuit simplifies the overall hardware, and it can be extended to any number of magnet-coils. A cascade lead compensation control scheme utilizing an inner current loop and outer position loop has been designed and implemented for the stabilization of such a highly unstable and strongly nonlinear system. The prototype has been successfully tested, and stable levitation was demonstrated with the desired operating gap. PMID:17350630

  3. Acoustic Levitation With One Driver

    NASA Technical Reports Server (NTRS)

    Wang, T. G.; Rudnick, I.; Elleman, D. D.; Stoneburner, J. D.

    1985-01-01

    Report discusses acoustic levitation in rectangular chamber using one driver mounted at corner. Placement of driver at corner enables it to couple effectively to acoustic modes along all three axes. Use of single driver reduces cost, complexity and weight of levitation system below those of three driver system.

  4. Differential force balances during levitation

    NASA Astrophysics Data System (ADS)

    Todd, Paul

    The simplest arithmetic of inertial, buoyant, magnetic and electrokinetic levitation is explored in the context of a model living system with “acceleration-sensitive structures” in which motion, if allowed, produces a biological effect. The simple model is a finite-sized object enclosed within another finite-sized object suspended in an outer fluid (liquid or vapor) medium. The inner object has density and electrical and magnetic properties quantitatively different from those of the outer object and the medium. In inertial levitation (“weightlessness”) inertial accelerations are balanced, and the forces due to them are canceled in accordance with Newton’s third law. In the presence of inertial acceleration (gravity, centrifugal) motionlessness depends on a balance between the levitating force and the inertial force. If the inner and outer objects differ in density one or the other will be subjected to an unbalanced force when one object is levitated by any other force (buoyant, magnetic, electrokinetic). The requirements for motionlessness of the internal object in the presence of a levitating force are equality of density in the case of buoyant levitation, equality of magnetic susceptibility in the case of magnetic levitation, and equality of zeta potential and dielectric constant in the case of electrokinetic levitation. Examples of internal “acceleration-sensitive structures” are cellular organelles and the organs of advanced plants and animals. For these structures fundamental physical data are important in the interpretation of the effects of forces used for levitation.

  5. Single-photon filtering by a cavity quantum electrodynamics system

    SciTech Connect

    Koshino, Kazuki

    2008-02-15

    The nonlinear dynamics of a classical photon pulse in a cavity-QED system is investigated theoretically. It is shown that this system can work as a single-photon filter, which drastically suppresses the multiple-photon probability of the output. The output photon statistics is sensitive to the input pulse length. A suitable choice of pulse length produces a photon pulse with the single-photon probability of 0.32, while the multiple-photon probability is suppressed to 0.01.

  6. Interference control of nonlinear excitation in a multi-atom cavity quantum electrodynamics system.

    PubMed

    Yang, Guoqing; Tan, Zheng; Zou, Bichen; Zhu, Yifu

    2014-12-01

    We show that by manipulating quantum interference in a multi-atom cavity quantum electrodynamics (CQED) system, the nonlinear excitation of the cavity-atom polariton can be resonantly enhanced while the linear excitation is suppressed. Under the appropriate conditions, it is possible to selectively enhance or suppress the polariton excitation with two free-pace laser fields. We report on an experiment with cold Rb atoms in an optical cavity and present experimental results that demonstrate such interference control of the CQED excitation and its direct application to studies of all-optical switching and cross-phase modulation of the cavity-transmitted light.

  7. Thermocapillary Levitation of Nanoliter-Volume Droplets and Extension to Two-Phase Systems

    NASA Astrophysics Data System (ADS)

    Black, James; Neitzel, G. Paul

    2012-11-01

    The development of a novel method of droplet levitation to be employed in lab-on-a-chip (LOC) applications relies upon the mechanism of thermocapillary convection (due to the temperature dependence of surface tension) to drive a layer of lubricating gas between droplet and substrate. The fact that most droplets of interest in LOC applications are aqueous in nature, coupled with the fact that success in effecting thermocapillary transport in aqueous solutions has been limited, has led to the development of a technique for the controlled encapsulation of nanoliter-volume water droplets within a shell of inert silicone oil. Previously, microliter-volume single-phase silicone-oil droplets have been levitated. This work aims to extend this technique to nanoliter-volume single- and compound-phase oil and water droplets as well as ascertain how the fluid-fluid interface affects the internal convective currents driven by the surface flow in compound-phase systems. Supported by NASA and NSF.

  8. Electromagnet Weight Reduction in a Magnetic Levitation System for Contactless Delivery Applications

    PubMed Central

    Hong, Do-Kwan; Woo, Byung-Chul; Koo, Dae-Hyun; Lee, Ki-Chang

    2010-01-01

    This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM) and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG) algorithm is adopted in the kriging model. This paper’s procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results. PMID:22163572

  9. Electromagnet weight reduction in a magnetic levitation system for contactless delivery applications.

    PubMed

    Hong, Do-Kwan; Woo, Byung-Chul; Koo, Dae-Hyun; Lee, Ki-Chang

    2010-01-01

    This paper presents an optimum design of a lightweight vehicle levitation electromagnet, which also provides a passive guide force in a magnetic levitation system for contactless delivery applications. The split alignment of C-shaped electromagnets about C-shaped rails has a bad effect on the lateral deviation force, therefore, no-split positioning of electromagnets is better for lateral performance. This is verified by simulations and experiments. This paper presents a statistically optimized design with a high number of the design variables to reduce the weight of the electromagnet under the constraint of normal force using response surface methodology (RSM) and the kriging interpolation method. 2D and 3D magnetostatic analysis of the electromagnet are performed using ANSYS. The most effective design variables are extracted by a Pareto chart. The most desirable set is determined and the influence of each design variable on the objective function can be obtained. The generalized reduced gradient (GRG) algorithm is adopted in the kriging model. This paper's procedure is validated by a comparison between experimental and calculation results, which shows that the predicted performance of the electromagnet designed by RSM is in good agreement with the simulation results.

  10. Acoustic Translation of an Acoustically Levitated Sample

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Allen, J. L.

    1986-01-01

    Acoustic-levitation apparatus uses only one acoustic mode to move sample from one region of chamber to another. Sample heated and cooled quickly by translation between hot and cold regions of levitation chamber. Levitated sample is raised into furnace region by raising plunger. Frequency of sound produced by transducers adjusted by feedback system to maintain (102) resonant mode, which levitates sample midway between transducers and plunger regardless of plunger position.

  11. Electrodynamics of a compound system with relativistic corrections

    SciTech Connect

    Pachucki, Krzysztof

    2007-08-15

    The electromagnetic interaction of a moving compound charged system with leading relativistic corrections is studied. An effective Hamiltonian is obtained by using a set of canonical transformations, and it is demonstrated that the coupling of the total motion to internal degrees of freedom is uniquely determined by Lorentz covariance. Several known results such as the Roentgen term and the interaction of the spin with the electric field are recovered, and new results for various relativistic and recoil corrections are obtained.

  12. Electrodynamic System of Earth in Moon and Solar Tides Investigation

    NASA Astrophysics Data System (ADS)

    Grunskaya, Lubov; Isakevich, Valiriy

    Since 2000 there has been working the united system of monitoring of electrical and geomagnetic fields of ELF range of the atmosphere boundary surface layer at the spaced apart stations: Vladimir State physical experimental ground; the station of RAS Institute of Sun and Earth physics at Lake Baikal; the station in Paratunka (Kamchatka); the station in Obninsk. There has been developed a programme-analytical system (PAS) to investigate signal structures in spectral and time series, caused by geophysical and astrophysical processes based on the method of eigen vectors. There has been developed a programme and analytical system to investigate the signal structure in the spectral and time series caused by geophysical processes. There has been estimated the amplitude and investigated the properties of the Earth atmosphere boundary layer electrical field components localized spectrally at the frequencies of the moon and solar tides. There has been exposed a method of determination of relative and absolute amplitudes of the main components of the eigen series. There has been investigated coherence of the spectral components at the frequencies of solar and moon tides. The work is carried out with supporting of RFFI № 14-07-97510, State Task to Universities on 2014-2016.

  13. Classical electrodynamic systems interacting with classical electromagnetic random radiation

    NASA Astrophysics Data System (ADS)

    Cole, Daniel C.

    1990-02-01

    In the past, a few researchers have presented arguments indicating that a statistical equilibrium state of classical charged particles necessarily demands the existence of a temperature-independent, incident classical electromagnetic random radiation. Indeed, when classical electromagnetic zero-point radiation is included in the analysis of problems with macroscopic boundaries, or in the analysis of charged particles in linear force fields, then good agreement with nature is obtained. In general, however, this agreement has not been found to hold for charged particles bound in nonlinear force fields. The point is raised here that this disagreement arising for nonlinear force fields may be a premature conclusion on this classical theory for describing atomic systems, because past calculations have not directed strict attention to electromagnetic interactions between charges. This point is illustrated here by examining the classical hydrogen atom and showing that this problem has still not been adequately solved.

  14. Iterative methods for the solution of very large complex symmetric linear systems of equations in electrodynamics

    SciTech Connect

    Clemens, M.; Weiland, T.

    1996-12-31

    In the field of computational electrodynamics the discretization of Maxwell`s equations using the Finite Integration Theory (FIT) yields very large, sparse, complex symmetric linear systems of equations. For this class of complex non-Hermitian systems a number of conjugate gradient-type algorithms is considered. The complex version of the biconjugate gradient (BiCG) method by Jacobs can be extended to a whole class of methods for complex-symmetric algorithms SCBiCG(T, n), which only require one matrix vector multiplication per iteration step. In this class the well-known conjugate orthogonal conjugate gradient (COCG) method for complex-symmetric systems corresponds to the case n = 0. The case n = 1 yields the BiCGCR method which corresponds to the conjugate residual algorithm for the real-valued case. These methods in combination with a minimal residual smoothing process are applied separately to practical 3D electro-quasistatical and eddy-current problems in electrodynamics. The practical performance of the SCBiCG methods is compared with other methods such as QMR and TFQMR.

  15. Numerical simulations of the electrodynamic interactions between the Tethered-Satellite-System and space plasma

    NASA Technical Reports Server (NTRS)

    Vashi, Bharat I.

    1992-01-01

    The first Tethered-Satellite-System (TSS-1), scheduled for a flight in late 1992, is expected to provide relevant information related to the concept of generating an emf in a 20-km-long (or longer) conducting wire. This paper presents numerical simulations of the electrodynamic interactions between the TSS system and space plasma, using a 2D and 3D models of the system. The 2D case code simulates the motion of a long cylinder past a plasma, which is composed of electrons and H(+) ions. The system is solved by allowing the plasma to flow past the cylinder with an imposed magnetic field. The more complex 3D case is considered to study the dynamics in great detail. Results of 2D simulation show that the interaction of a satellite with plasma flowing perpendicularly to the magnetic field results in an enhancement in the current collection.

  16. Possibilities for Continuous Frequency Tuning in Terahertz Gyrotrons with Nontunable Electrodynamic Systems

    NASA Astrophysics Data System (ADS)

    Bratman, V. L.; Savilov, A. V.; Chang, T. H.

    2016-02-01

    Large ohmic losses in the cavities of terahertz gyrotrons may lead to the overlapping of the axial mode spectra. In a number of gyrotron experiments, this effect has been used to provide a fairly broadband frequency tuning by changing appropriately the operating magnetic field and/or accelerating voltage of the gyrotron. Similar to the systems with nonfixed axial structure of the RF electromagnetic field and low diffraction quality, which are due to weak reflections of the operating wave from the collector end of the electrodynamic system, this changing leads to a monotonic change in the axial index of the operating wave and transition from the gyrotron regime to the gyro-BWO regime. According to a theoretical comparison of these two methods performed on the basis of generalization of self-consistent gyrotron equations with allowance for variations in the axial electron momenta, low-reflection systems can provide a higher efficiency and monotonicity of the frequency tuning.

  17. Airborne chemistry: acoustic levitation in chemical analysis.

    PubMed

    Santesson, Sabina; Nilsson, Staffan

    2004-04-01

    This review with 60 references describes a unique path to miniaturisation, that is, the use of acoustic levitation in analytical and bioanalytical chemistry applications. Levitation of small volumes of sample by means of a levitation technique can be used as a way to avoid solid walls around the sample, thus circumventing the main problem of miniaturisation, the unfavourable surface-to-volume ratio. Different techniques for sample levitation have been developed and improved. Of the levitation techniques described, acoustic or ultrasonic levitation fulfils all requirements for analytical chemistry applications. This technique has previously been used to study properties of molten materials and the equilibrium shape()and stability of liquid drops. Temperature and mass transfer in levitated drops have also been described, as have crystallisation and microgravity applications. The airborne analytical system described here is equipped with different and exchangeable remote detection systems. The levitated drops are normally in the 100 nL-2 microL volume range and additions to the levitated drop can be made in the pL-volume range. The use of levitated drops in analytical and bioanalytical chemistry offers several benefits. Several remote detection systems are compatible with acoustic levitation, including fluorescence imaging detection, right angle light scattering, Raman spectroscopy, and X-ray diffraction. Applications include liquid/liquid extractions, solvent exchange, analyte enrichment, single-cell analysis, cell-cell communication studies, precipitation screening of proteins to establish nucleation conditions, and crystallisation of proteins and pharmaceuticals. PMID:14762640

  18. Self-formed cavity quantum electrodynamics in coupled dipole cylindrical-waveguide systems.

    PubMed

    Afshar V, S; Henderson, M R; Greentree, A D; Gibson, B C; Monro, T M

    2014-05-01

    An ideal optical cavity operates by confining light in all three dimensions. We show that a cylindrical waveguide can provide the longitudinal confinement required to form a two dimensional cavity, described here as a self-formed cavity, by locating a dipole, directed along the waveguide, on the interface of the waveguide. The cavity resonance modes lead to peaks in the radiation of the dipole-waveguide system that have no contribution due to the skew rays that exist in longitudinally invariant waveguides and reduce their Q-factor. Using a theoretical model, we evaluate the Q-factor and modal volume of the cavity formed by a dipole-cylindrical-waveguide system and show that such a cavity allows access to both the strong and weak coupling regimes of cavity quantum electrodynamics.

  19. An illuminated growth system for the study of Arabidopsis thaliana during diamagnetic levitation by a superconducting magnet

    NASA Astrophysics Data System (ADS)

    Lu, Y.; Ding, C.; Wang, J.; Shang, P.

    2015-01-01

    The effect of gravity on plant growth is an interesting topic in its own right, but it is also important because it impacts the possibility of long-term space travel. Plants may be grown in microgravity simulated by diamagnetic levitation within superconducting magnet, but this approach is limited by the size and other objective conditions of the superconducting magnet. Tremendous difficulties exist in evaluating the effects of simulated microgravity on plant seedling growth under lighting conditions. Therefore, we developed a lighting system and culturing system that can meet the demands of growing plant seedlings in a superconducting magnet. This system mainly consists of an illumination system, suitable containers and a method to cultivate Arabidopsis thaliana seedlings. In order to prove the suitability of this light-growing system, A. thaliana was cultured in a superconducting magnet for four days. The status of seedlings was recorded and total RNA was extracted for gene expression analysis. Our results showed that Arabidopsis seedlings could germinate and grow successfully in this light-growing system. In addition, it was observed that under diamagnetic levitation conditions, the seedling bended and gene expression of PGM and MOR1 decreased significantly compared to a control group. Nonetheless, there were no substantial differences between the diamagnetic levitation group and RPM group. Our results suggest that this light-growing system is expedient and beneficial for plants grown in a superconducting magnet. Our experiment also provides a way to utilize diamagnetic levitation in a superconducting magnet that simulates the conditions necessary to study plant physiology and biochemical responses in a microgravity environment.

  20. Multiparty Quantum Secret Sharing of Classical Message using Cavity Quantum Electrodynamic System

    NASA Astrophysics Data System (ADS)

    Han, Lian-Fang; Liu, Yi-Min; Zhang, Zhan-Jun

    2006-08-01

    An experimental feasible scheme of multiparty secret sharing of classical messages is proposed, based on a cavity quantum electrodynamic system. The secret messages are imposed on atomic Bell states initially in the sender's possession by local unitary operations. By swapping quantum entanglement of atomic Bell states, the secret messages are split into several parts and each part is distributed to a separate party. In this case, any subset of the entire party group can not read out the secret message but the entirety via mutual cooperations. In this scheme, to discriminate atomic Bell states, additional classical fields are employed besides the same highly-detuned single-mode cavities used to prepare atomic Bell states. This scheme is insensitive to the cavity decay and the thermal field, and usual joint Bell-state measurements are unnecessary.

  1. Flux-canceling electrodynamic maglev suspension. Part 1: Test fixture design and modeling

    SciTech Connect

    Thompson, M.T.; Thornton, R.D.; Kondoleon, A.

    1999-05-01

    The design and analysis of a scale-model suspension test facility for magnetic levitation (maglev) is discussed. The authors describe techniques for the design, construction, and testing of a prototype electrodynamic suspension (EDS) levitation system. The viability of future high-temperature superconducting magnet designs for maglev has been investigated with regard to their application to active secondary suspensions. In order to test the viability of a new flux-canceling EDS suspension, a 1/5-scale suspension magnet and guideway was constructed. The suspension was tested by using a high-speed rotating test wheel facility with linear peripheral speed of up to 84 m/s (300 km/h). A set of approximate design tools and scaling laws has been developed in order to evaluate forces and critical velocities in the suspension.

  2. Magnetic levitation of single cells.

    PubMed

    Durmus, Naside Gozde; Tekin, H Cumhur; Guven, Sinan; Sridhar, Kaushik; Arslan Yildiz, Ahu; Calibasi, Gizem; Ghiran, Ionita; Davis, Ronald W; Steinmetz, Lars M; Demirci, Utkan

    2015-07-14

    Several cellular events cause permanent or transient changes in inherent magnetic and density properties of cells. Characterizing these changes in cell populations is crucial to understand cellular heterogeneity in cancer, immune response, infectious diseases, drug resistance, and evolution. Although magnetic levitation has previously been used for macroscale objects, its use in life sciences has been hindered by the inability to levitate microscale objects and by the toxicity of metal salts previously applied for levitation. Here, we use magnetic levitation principles for biological characterization and monitoring of cells and cellular events. We demonstrate that each cell type (i.e., cancer, blood, bacteria, and yeast) has a characteristic levitation profile, which we distinguish at an unprecedented resolution of 1 × 10(-4) g ⋅ mL(-1). We have identified unique differences in levitation and density blueprints between breast, esophageal, colorectal, and nonsmall cell lung cancer cell lines, as well as heterogeneity within these seemingly homogenous cell populations. Furthermore, we demonstrate that changes in cellular density and levitation profiles can be monitored in real time at single-cell resolution, allowing quantification of heterogeneous temporal responses of each cell to environmental stressors. These data establish density as a powerful biomarker for investigating living systems and their responses. Thereby, our method enables rapid, density-based imaging and profiling of single cells with intriguing applications, such as label-free identification and monitoring of heterogeneous biological changes under various physiological conditions, including antibiotic or cancer treatment in personalized medicine. PMID:26124131

  3. Magnetic levitation of single cells

    PubMed Central

    Durmus, Naside Gozde; Tekin, H. Cumhur; Guven, Sinan; Sridhar, Kaushik; Arslan Yildiz, Ahu; Calibasi, Gizem; Davis, Ronald W.; Steinmetz, Lars M.; Demirci, Utkan

    2015-01-01

    Several cellular events cause permanent or transient changes in inherent magnetic and density properties of cells. Characterizing these changes in cell populations is crucial to understand cellular heterogeneity in cancer, immune response, infectious diseases, drug resistance, and evolution. Although magnetic levitation has previously been used for macroscale objects, its use in life sciences has been hindered by the inability to levitate microscale objects and by the toxicity of metal salts previously applied for levitation. Here, we use magnetic levitation principles for biological characterization and monitoring of cells and cellular events. We demonstrate that each cell type (i.e., cancer, blood, bacteria, and yeast) has a characteristic levitation profile, which we distinguish at an unprecedented resolution of 1 × 10−4 g⋅mL−1. We have identified unique differences in levitation and density blueprints between breast, esophageal, colorectal, and nonsmall cell lung cancer cell lines, as well as heterogeneity within these seemingly homogenous cell populations. Furthermore, we demonstrate that changes in cellular density and levitation profiles can be monitored in real time at single-cell resolution, allowing quantification of heterogeneous temporal responses of each cell to environmental stressors. These data establish density as a powerful biomarker for investigating living systems and their responses. Thereby, our method enables rapid, density-based imaging and profiling of single cells with intriguing applications, such as label-free identification and monitoring of heterogeneous biological changes under various physiological conditions, including antibiotic or cancer treatment in personalized medicine. PMID:26124131

  4. Diamagnetic Levitation Cantilever System for the Calibration of Normal Force Atomic Force Microscopy Measurements

    NASA Astrophysics Data System (ADS)

    Torres, Jahn; Yi, Jin-Woo; Murphy, Colin; Kim, Kyung-Suk

    2011-03-01

    In this presentation we report a novel technique for normal force calibration for Atomic Force Microcopy (AFM) adhesion measurements known as the diamagnetic normal force calibration (D-NFC) system. The levitation produced by the repulsion between a diamagnetic graphite sheet and a set of rare-earth magnets is used in order to produce an oscillation due to an unstable mechanical moment produced by a silicon cantilever supported on the graphite. The measurement of the natural frequency of this oscillation allows for the calculation of the stiffness of the system to three-digit accuracy. The D-NFC response was proven to have a high sensitivity for the structure of water molecules collected on its surface. This in turns allows for the study of the effects of coatings on the structure of surface water. This work was supported by the Coatings/Biofouling Program and the Maritime Sensing Program of the Office of Naval Research as well as the ILIR Program of the Naval Undersea Warfare Center DIVNPT.

  5. Electrodynamics panel presentation

    NASA Technical Reports Server (NTRS)

    Mccoy, J.

    1986-01-01

    The Plasma Motor Generator (PMG) concept is explained in detail. The PMG tether systems being used to calculate the estimated performance data is described. The voltage drops and current contact geometries involved in the operation of an electrodynamic tether are displayed illustrating the comparative behavior of hollow cathodes, electron guns, and passive collectors for current coupling into the ionosphere. The basic PMG design involving the massive tether cable with little or no satellite mass at the far end(s) are also described. The Jupiter mission and its use of electrodynamic tethers are given. The need for demonstration experiments is stressed.

  6. Acoustic levitation

    NASA Astrophysics Data System (ADS)

    Hansen, Uwe J.

    2005-09-01

    A speaker, driven by an amplified audio signal is used to set up a standing wave in a 3b-ft-long, 4-in.-diam transparent tube. Initially the tube is oriented horizontally, and Styrofoam packing peanuts accumulate near the pressure nodes. When the tube is turned to a position with the axis oriented vertically, the peanuts drop slightly, until the gravitational force on the peanuts is balanced by the force due to the sound pressure, at which point levitation is observed. Sound-pressure level measurements are used to map the air column normal mode pattern. Similarly, standing waves are established between an ultrasonic horn and a metal reflector and millimeter size Styrofoam balls are levitated.

  7. DuraHeart magnetically levitated centrifugal left ventricular assist system for advanced heart failure patients.

    PubMed

    Morshuis, Michiel; Schoenbrodt, Michael; Nojiri, Chisato; Roefe, Daniela; Schulte-Eistrup, Sebastian; Boergermann, Jochen; Gummert, Jan F; Arusoglu, Latif

    2010-03-01

    The implantable left ventricular assist system (LVAS) using pulsatile pump technology has become an established therapeutic option for advanced heart failure patients. However, there have been technological limitations in some older designs, including a high incidence of infection and mechanical failures associated with moving parts, and the large size of both implantable pump and percutaneous cable. A smaller rotary blood pump emerged as a possible alternative to a large pulsatile pump to overcome some of these limitations. The technological advancement that defines the third-generation LVAS was the elimination of all mechanical contacts between the impeller and the drive mechanism. The DuraHeart LVAS is the world's first third-generation implantable LVAS to obtain market approval (CE-mark), which combines a centrifugal pump and active magnetic levitation. The initial clinical experience with the DuraHeart LVAS in Europe demonstrated that it provided significantly improved survival (85% at 6 months and 79% at 1 year), reduced adverse event rates and long-term device reliability (freedom from device replacement at 2 years: 96 +/- 3%) over pulsatile LVAS. PMID:20214423

  8. Modeling the Ionosphere-Thermosphere-Electrodynamics System for Space Weather Specifications, Forecasts and Applications

    NASA Astrophysics Data System (ADS)

    Schunk, R. W.; Scherliess, L.; Eccles, V.; Gardner, L. C.; Sojka, J. J.; Zhu, L.; Pi, X.; Mannucci, A. J.; Butala, M. D.; Wilson, B. D.; Komjathy, A.; Wang, C.; Rosen, G.

    2015-12-01

    Significant progress has been made during the last two decades with regard to understanding, specifying, forecasting, and mitigating the impacts of space weather on numerous DoD and civilian activities. The progress has been made because of more and improved measurements, and advances in modeling the ionosphere-thermosphere-electrodynamics (I-T-E) system. With regard to modeling, the recent focus has been on ensemble modeling with both physics-based and data assimilation models. Our team has created a Multimodel Ensemble Prediction System (MEPS) that is composed of seven physics-based data assimilation models for the I-T-E system that cover the globe. Five different data assimilation models cover the mid-low latitude region, so that we can conduct ensemble modeling with physics-based data assimilation models in that domain. The data assimilation models can assimilate Total Electron Content (TEC) from a constellation of satellites, bottom-side electron density profiles from digisondes, and in situ plasma densities, occultations and ultraviolet emissions from satellites. We have performed MEPS model runs for selected storm and quiet periods, and for each period we have obtained ensemble model reconstructions with different data types and amounts in order to determine how the individual data assimilation models behave. These new and interesting results will be presented.

  9. The performance of induction levitators

    NASA Astrophysics Data System (ADS)

    Eastham, J. F.; Rodger, D.

    1984-09-01

    The present investigation is concerned with the performance of induction levitators, which are employed in vehicles for contactless transport systems, utilizing magnetic levitation (Maglev). A small model (38 cm long) of an induction levitator is shown. The armature consists of a laminated 'u' shaped iron yoke. Around the limbs of the yoke are wound two primary excitation coils carrying single phase 50 Hz current. Eddy currents, induced in the conducting secondary, produce a force of repulsion between secondary and yoke. A lateral stabilizing force can also be obtained. A description is presented of a study of the characteristics of these forces. Attention is given of a finite element model and the application of the Galerkin weighted residual technique, experimental and calculated results, and a design study of two single phase levitators for a 50 tonne Maglev vehicle.

  10. Development of the sonic pump levitator

    NASA Technical Reports Server (NTRS)

    Dunn, S. A.

    1985-01-01

    The process and mechanism involved in producing glass microballoons (GMBs) of acceptable quality for laser triggered inertial fusion through use of glass jet levitation and manipulation are considered. The gas jet levitation device, called sonic pumps, provides positioning by timely and appropriate application of gas mementum from one or more of six sonic pumps which are arranged orthogonally in opposed pairs about the levitation region and are activated by an electrooptical, computer controlled, feedback system. The levitation device was fabricated and its associated control systems were assembled into a package and tested in reduced gravity flight regime of the NASA KC-135 aircraft.

  11. Velocity damper for electromagnetically levitated materials

    SciTech Connect

    Fox, R.J.

    1992-12-31

    A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation.

  12. Velocity damper for electromagnetically levitated materials

    DOEpatents

    Fox, R.J.

    1994-06-07

    A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material is disclosed. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation. 1 fig.

  13. Velocity damper for electromagnetically levitated materials

    DOEpatents

    Fox, Richard J.

    1994-01-01

    A system for damping oscillatory and spinning motions induced in an electromagnetically levitated material. Two opposed field magnets are located orthogonally to the existing levitation coils for providing a DC quadrupole field (cusp field) around the material. The material used for generating the DC quadrupole field must be nonconducting to avoid eddy-current heating and of low magnetic permeability to avoid distorting the induction fields providing the levitation.

  14. Acoustic Levitator Maintains Resonance

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Gaspar, M. S.

    1986-01-01

    Transducer loading characteristics allow resonance tracked at high temperature. Acoustic-levitation chamber length automatically adjusted to maintain resonance at constant acoustic frequency as temperature changes. Developed for containerless processing of materials at high temperatures, system does not rely on microphones as resonance sensors, since microphones are difficult to fabricate for use at temperatures above 500 degrees C. Instead, system uses acoustic transducer itself as sensor.

  15. Quantum electrodynamical theory of high-efficiency excitation energy transfer in laser-driven nanostructure systems

    NASA Astrophysics Data System (ADS)

    Weeraddana, Dilusha; Premaratne, Malin; Gunapala, Sarath D.; Andrews, David L.

    2016-08-01

    A fundamental theory is developed for describing laser-driven resonance energy transfer (RET) in dimensionally constrained nanostructures within the framework of quantum electrodynamics. The process of RET communicates electronic excitation between suitably disposed emitter and detector particles in close proximity, activated by the initial excitation of the emitter. Here, we demonstrate that the transfer rate can be significantly increased by propagation of an auxiliary laser beam through a pair of nanostructure particles. This is due to the higher order perturbative contribution to the Förster-type RET, in which laser field is applied to stimulate the energy transfer process. We construct a detailed picture of how excitation energy transfer is affected by an off-resonant radiation field, which includes the derivation of second and fourth order quantum amplitudes. The analysis delivers detailed results for the dependence of the transfer rates on orientational, distance, and laser intensity factor, providing a comprehensive fundamental understanding of laser-driven RET in nanostructures. The results of the derivations demonstrate that the geometry of the system exercises considerable control over the laser-assisted RET mechanism. Thus, under favorable conformational conditions and relative spacing of donor-acceptor nanostructures, the effect of the auxiliary laser beam is shown to produce up to 70% enhancement in the energy migration rate. This degree of control allows optical switching applications to be identified.

  16. A portable Raman acoustic levitation spectroscopic system for the identification and environmental monitoring of algal cells.

    PubMed

    Wood, Bayden R; Heraud, Philip; Stojkovic, Slobodanka; Morrison, Danielle; Beardall, John; McNaughton, Don

    2005-08-01

    We report the coupling of a portable Raman spectrometer to an acoustic levitation device to enable environmental monitoring and the potential taxonomic identification of microalgae. Spectra of living cells were recorded at 785 nm using a fiber-optic probe coupled to a portable Raman spectrometer. The spectra exhibit an excellent signal-to-noise ratio and clearly show bands from chlorophyll a and beta-carotene. Spectra of levitated photobleached microalgae clearly show a reduction in chlorophyll a concentration relative to beta-carotene after 10 min of exposure to a quartz halogen lamp. Spectra recorded from levitated nitrogen-limited cells also show a significant reduction in bands associated with chlorophyll a, as compared to nitrogen-replete cells. To investigate the diagnostic capability of the technique, four species of microalgae were analyzed. Good quality spectra of all four species were obtained showing varying ratios of beta-carotene to chlorophyll. The combination of an acoustic levitation device and a portable Raman spectrometer shows potential as a taxonomic and environmental monitoring tool with direct application to field studies in remote environments. PMID:16053309

  17. On a modified electrodynamics.

    PubMed

    Reiss, H R

    2012-09-01

    A modification of electrodynamics is proposed, motivated by previously unremarked paradoxes that can occur in the standard formulation. It is shown by specific examples that gauge transformations exist that radically alter the nature of a problem, even while maintaining the values of many measurable quantities. In one example, a system with energy conservation is transformed to a system where energy is not conserved. The second example possesses a ponderomotive potential in one gauge, but this important measurable quantity does not appear in the gauge-transformed system. A resolution of the paradoxes comes from noting that the change in total action arising from the interaction term in the Lagrangian density cannot always be neglected, contrary to the usual assumption. The problem arises from the information lost by employing an adiabatic cutoff of the field. This is not necessary. Its replacement by a requirement that the total action should not change with a gauge transformation amounts to a supplementary condition for gauge invariance that can be employed to preserve the physical character of the problem. It is shown that the adiabatic cutoff procedure can also be eliminated in the construction of quantum transition amplitudes, thus retaining consistency between the way in which asymptotic conditions are applied in electrodynamics and in quantum mechanics. The 'gauge-invariant electrodynamics' of Schwinger is shown to depend on an ansatz equivalent to the condition found here for maintenance of the ponderomotive potential in a gauge transformation. Among the altered viewpoints required by the modified electrodynamics, in addition to the rejection of the adiabatic cutoff, is the recognition that the electric and magnetic fields do not completely determine a physical problem, and that the electromagnetic potentials supply additional information that is required for completeness of electrodynamics.

  18. Improvement of the propulsion force for HTSC-permanent magnet hybrid magnetically levitated carrying system by using the pinned flux of HTSC

    NASA Astrophysics Data System (ADS)

    Ikeda, M.; Sasaki, R.; Ueno, T.; Ohashi, S.

    Magnetically levitated carrying system has been developed. In this system, pinning force of high temperature bulk superconductor (HTSC) is used for the levitation and guidance. The magnetic rail is set on the ground, and flux from the magnetic rail is pinned by HTSCs. To increase levitation force, repulsive force of the permanent magnet is used. For the propulsion system, electromagnets are installed on the surface of the magnetic rail. Improvement of the propulsion force is studied. In the previous system, only flux of the permanent magnet of the carrier is used for propulsion. To increase propulsion force, that of the HTSC of the carrier is also used. Using this excitation method, the propulsion force is improved even though total number of the excited coil is the same.

  19. Sound Waves Levitate Substrates

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Wang, T. G.

    1982-01-01

    System recently tested uses acoustic waves to levitate liquid drops, millimeter-sized glass microballoons, and other objects for coating by vapor deposition or capillary attraction. Cylindrical contactless coating/handling facility employs a cylindrical acoustic focusing radiator and a tapered reflector to generate a specially-shaped standing wave pattern. Article to be processed is captured by the acoustic force field under the reflector and moves as reflector is moved to different work stations.

  20. Acoustic Levitation Containerless Processing

    NASA Technical Reports Server (NTRS)

    Whymark, R. R.; Rey, C. A.

    1985-01-01

    This research program consists of the development of acoustic containerless processing systems with applications in the areas of research in material sciences, as well as the production of new materials, solid forms with novel and unusual microstructures, fusion target spheres, and improved optical fibers. Efforts have been focused on the containerless processing at high temperatures for producing new kinds of glasses. Also, some development has occurred in the areas of containerlessly supporting liquids at room temperature, with applications in studies of fluid dynamics, potential undercooling of liquids, etc. The high temperature area holds the greatest promise for producing new kinds of glasses and ceramics, new alloys, and possibly unusual structural shapes, such as very uniform hollow glass shells for fusion target applications. High temperature acoustic levitation required for containerless processing has been demonstrated in low-g environments as well as in ground-based experiments. Future activities include continued development of the signals axis acoustic levitator.

  1. High-temperature metal purification using a compact, portable rf heating and levitation system on the wake shield

    NASA Technical Reports Server (NTRS)

    Hahs, C. A.

    1990-01-01

    The potential use of a compact, battery-operated rf levitator and heating system to purify high-temperature melting materials in space is described. The wake shield now being fabricated for the Space Vacuum Epitaxy Center will provide an Ultra-high vacuum (10(exp -14) Torr hydrogen, 10(exp -14) Torr helium, 10(exp -30) Torr oxygen). The use of the wake shield to purify Nb, Ti, W, Ir, and other metals to a purity level not achievable on earth is described.

  2. Electromagnetic Levitation of Silicon and Silicon-Iron Alloy Droplets

    NASA Astrophysics Data System (ADS)

    Wu, Paul; Yang, Yindong; Barati, Mansoor; McLean, Alex

    2014-09-01

    In this paper, the design of an electromagnetic levitation system and a technique for non-conductive silicon heating and conductive silicon levitation is described. The aim of the work is to describe the various parameters including coil design, applied power and specimen weight that govern the temperature of levitated silicon and silicon-iron alloy droplets.

  3. Solidification Studies from the Electrostatic Levitation System at the Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Rogers, Jan R.; Hyers, Robert W.; Robinson, Michael B.; Savage, Larry

    2000-01-01

    Electrostatic levitation (ESL) provides a means to study molten materials in a high-purity environment, free from contact with a container. Many phenomena important to materials science can be studied in the ESL. Solidification of metals, alloys and undercooled materials represent an important topic for research in the ESL. Recent studies of metals and alloys during solidification in the ESL are reported. Measurements include time, temperature and transformation of metallic glass-forming alloys, solidification velocities, and microstructure,

  4. Quantum levitation using metamaterials

    NASA Astrophysics Data System (ADS)

    Pappakrishnan, Venkatesh K.

    The emergence of an attractive vacuum force (Casimir force) between two purely dielectric materials can lead to an increase in the friction and the stiction effects in nanoscale devices, resulting in degradation or decreased performance. Thus, it is of high practical importance that the conditions for the reversal of the Casimir force from attractive to repulsive are identified. Although the repulsive Casimir force has been considered for high dielectric materials as an intermediate (between the plates) medium, so far no realistic system has been proposed that can demonstrate quantum levitation with air/vacuum as a host medium. Since air is the natural environment for almost all nano- and microscopic devices, it is therefore imperative to seek a better understanding of the nature of the Casimir force under such ambient conditions. In this thesis, the conditions for achieving quantum levitation at an arbitrary temperature are investigated by considering a simple configuration consisting of two parallel plates separated by air. The proposed parallel-plate designs are based on artificial nano-engineered electromagnetic materials commonly referred to as the electromagnetic metamaterials. In the case of an ideal system consisting of non-dispersive plates, we have uncovered the existence of six universal Casimir force types. We have also derived an explicit necessary condition for Casimir force reversal as a function of the non-retarded specular functions of the plates. By introducing a modification of the Lifshitz theory, we have performed an extensive investigation of the Casimir force for general dispersive magneto-dielectric plates. Simple necessary and sufficient conditions for force reversal have been derived that can serve as a useful tool in designing quantum levitation systems. Based on the sufficient condition, the complete parametric domain for the Casimir force repulsion has been identified. A strongly magnetic response for at least one of the plates is

  5. Adipose tissue engineering in three-dimensional levitation tissue culture system based on magnetic nanoparticles.

    PubMed

    Daquinag, Alexes C; Souza, Glauco R; Kolonin, Mikhail G

    2013-05-01

    White adipose tissue (WAT) is becoming widely used in regenerative medicine/cell therapy applications, and its physiological and pathological importance is increasingly appreciated. WAT is a complex organ composed of differentiated adipocytes, stromal mesenchymal progenitors known as adipose stromal cells (ASC), as well as endothelial vascular cells and infiltrating leukocytes. Two-dimensional (2D) culture that has been typically used for studying adipose cells does not adequately recapitulate WAT complexity. Improved methods for reconstruction of functional WAT ex vivo are instrumental for understanding of physiological interactions between the composing cell populations. Here, we used a three-dimensional (3D) levitation tissue culture system based on magnetic nanoparticle assembly to model WAT development and growth in organoids termed adipospheres. We show that 3T3-L1 preadipocytes remain viable in spheroids for a long period of time, while in 2D culture, they lose adherence and die after reaching confluence. Upon adipogenesis induction in 3T3-L1 adipospheres, cells efficiently formed large lipid droplets typical of white adipocytes in vivo, while only smaller lipid droplet formation is achievable in 2D. Adiposphere-based coculture of 3T3-L1 preadipocytes with murine endothelial bEND.3 cells led to a vascular-like network assembly concomitantly with lipogenesis in perivascular cells. Adipocyte-depleted stromal vascular fraction (SVF) of mouse WAT cultured in 3D underwent assembly into organoids with vascular-like structures containing luminal endothelial and perivascular stromal cell layers. Adipospheres made from primary WAT cells displayed robust proliferation and complex hierarchical organization reflected by a matricellular gradient incorporating ASC, endothelial cells, and leukocytes, while ASC quickly outgrew other cell types in adherent culture. Upon adipogenesis induction, adipospheres derived from the SVF displayed more efficient lipid droplet

  6. Adipose tissue engineering in three-dimensional levitation tissue culture system based on magnetic nanoparticles.

    PubMed

    Daquinag, Alexes C; Souza, Glauco R; Kolonin, Mikhail G

    2013-05-01

    White adipose tissue (WAT) is becoming widely used in regenerative medicine/cell therapy applications, and its physiological and pathological importance is increasingly appreciated. WAT is a complex organ composed of differentiated adipocytes, stromal mesenchymal progenitors known as adipose stromal cells (ASC), as well as endothelial vascular cells and infiltrating leukocytes. Two-dimensional (2D) culture that has been typically used for studying adipose cells does not adequately recapitulate WAT complexity. Improved methods for reconstruction of functional WAT ex vivo are instrumental for understanding of physiological interactions between the composing cell populations. Here, we used a three-dimensional (3D) levitation tissue culture system based on magnetic nanoparticle assembly to model WAT development and growth in organoids termed adipospheres. We show that 3T3-L1 preadipocytes remain viable in spheroids for a long period of time, while in 2D culture, they lose adherence and die after reaching confluence. Upon adipogenesis induction in 3T3-L1 adipospheres, cells efficiently formed large lipid droplets typical of white adipocytes in vivo, while only smaller lipid droplet formation is achievable in 2D. Adiposphere-based coculture of 3T3-L1 preadipocytes with murine endothelial bEND.3 cells led to a vascular-like network assembly concomitantly with lipogenesis in perivascular cells. Adipocyte-depleted stromal vascular fraction (SVF) of mouse WAT cultured in 3D underwent assembly into organoids with vascular-like structures containing luminal endothelial and perivascular stromal cell layers. Adipospheres made from primary WAT cells displayed robust proliferation and complex hierarchical organization reflected by a matricellular gradient incorporating ASC, endothelial cells, and leukocytes, while ASC quickly outgrew other cell types in adherent culture. Upon adipogenesis induction, adipospheres derived from the SVF displayed more efficient lipid droplet

  7. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOEpatents

    Coffey, H.T.

    1993-10-19

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle levitation. 3 figures.

  8. The Wonders of Levitation

    ERIC Educational Resources Information Center

    French, M. M. J.

    2010-01-01

    I discuss some interesting classroom demonstrations of diamagnetism and how this effect can produce levitation. The possibilities for hands-on demonstrations of diamagnetic and superconducting levitation are discussed. To conclude I discuss some practical uses for levitation in daily life. (Contains 6 figures.)

  9. Improvement of levitation force characteristics in magnetic levitation type seismic isolation device composed of HTS bulk and permanent magnet

    NASA Astrophysics Data System (ADS)

    Tsuda, M.; Kawasaki, T.; Yagai, T.; Hamajima, T.

    2008-02-01

    Magnetic levitation type seismic isolation device composed of HTS bulks and permanent magnets can theoretically remove horizontal vibration completely. It is, however, not easy to generate the large levitation force by using only the levitation system composed of HTS bulk and permanent magnet (HTS-PM system). We focused on a hybrid levitation system composed of the HTS-PM system and the PM-PM system composed of only permanent magnets and investigated the suitable arranging method of the hybrid system for improving levitation force and obtaining stable levitation. In order to clarify the most suitable permanent magnet arrangement in the PM-PM system for the levitation force improvement, repulsive force between permanent magnets was measured in various kinds of the PM-PM system. The maximum repulsive force per unit area in the PM-PM system was at least three times larger than the levitation force per unit area in the HTS-PM system, so that the levitation force in the hybrid system was larger than that of the HTS-PM system. Stable levitation was also achieved in the hybrid system. This is because repulsive force in the PM-PM system against horizontal displacement was much smaller than restoring force in the HTS-PM system.

  10. Isolation of crystallizing droplets by electrostatic levitation

    NASA Technical Reports Server (NTRS)

    Rhim, Won-Kyu; Chung, Sang K.

    1990-01-01

    The principles of electrostatic levitation where the positioning and stabilization of a sample are accomplished by applying appropriate electrostatic forces to a charged sample are outlined, and attention is focused on a feedback control algorithm, drop-launching method, and four-drop levitator. Drop levitation in 1-g is discussed, and crystal-growth experiments are presented. An experiment in which the protein concentration of a levitated drop is controlled by a feedback system is described. During levitation, the drop evaporation rate is controlled in a programmed way in order to acquire proper protein concentration levels for both nucleation and growth. The containerless approach of protein crystal growth when applied in the space environment is assessed.

  11. Gravity enhanced acoustic levitation method and apparatus

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Allen, J. L.; Granett, D. (Inventor)

    1985-01-01

    An acoustic levitation system is provided for acoustically levitating an object by applying a single frequency from a transducer into a resonant chamber surrounding the object. The chamber includes a stabilizer location along its height, where the side walls of the chamber are angled so they converge in an upward direction. When an acoustic standing wave pattern is applied between the top and bottom of the chamber, a levitation surface within the stabilizer does not lie on a horizontal plane, but instead is curved with a lowermost portion near the vertical axis of the chamber. As a result, an acoustically levitated object is urged by gravity towards the lowermost location on the levitation surface, so the object is kept away from the side walls of the chamber.

  12. Gravity enhanced acoustic levitation method and apparatus

    NASA Astrophysics Data System (ADS)

    Barmatz, M. B.; Allen, J. L.; Granett, D.

    1985-06-01

    An acoustic levitation system is provided for acoustically levitating an object by applying a single frequency from a transducer into a resonant chamber surrounding the object. The chamber includes a stabilizer location along its height, where the side walls of the chamber are angled so they converge in an upward direction. When an acoustic standing wave pattern is applied between the top and bottom of the chamber, a levitation surface within the stabilizer does not lie on a horizontal plane, but instead is curved with a lowermost portion near the vertical axis of the chamber. As a result, an acoustically levitated object is urged by gravity towards the lowermost location on the levitation surface, so the object is kept away from the side walls of the chamber.

  13. Improved Position Sensor for Feedback Control of Levitation

    NASA Technical Reports Server (NTRS)

    Hyers, Robert; Savage, Larry; Rogers, Jan

    2004-01-01

    An improved optoelectronic apparatus has been developed to provide the position feedback needed for controlling the levitation subsystem of a containerless-processing system. As explained, the advantage of this apparatus over prior optoelectronic apparatuses that have served this purpose stems from the use of an incandescent lamp, instead of a laser, to illuminate the levitated object. In containerless processing, a small object to be processed is levitated (e.g., by use of a microwave, low-frequency electromagnetic, electrostatic, or acoustic field) so that it is not in contact with the wall of the processing chamber or with any other solid object during processing. In the case of electrostatic or low-frequency electromagnetic levitation, real-time measurement of the displacement of the levitated object from its nominal levitation position along the vertical axis (and, in some cases, along one or two horizontal axes) is needed for feedback control of the levitating field.

  14. Mixing in colliding, ultrasonically levitated drops.

    PubMed

    Chainani, Edward T; Choi, Woo-Hyuck; Ngo, Khanh T; Scheeline, Alexander

    2014-02-18

    Lab-in-a-drop, using ultrasonic levitation, has been actively investigated for the last two decades. Benefits include lack of contact between solutions and an apparatus and a lack of sample cross-contamination. Understanding and controlling mixing in the levitated drop is necessary for using an acoustically levitated drop as a microreactor, particularly for studying kinetics. A pulsed electrostatic delivery system enables addition and mixing of a desired-volume droplet with the levitated drop. Measurement of mixing kinetics is obtained by high-speed video monitoring of a titration reaction. Drop heterogeneity is visualized as 370 nl of 0.25 M KOH (pH: 13.4) was added to 3.7 μL of 0.058 M HCl (pH: 1.24). Spontaneous mixing time is about 2 s. Following droplet impact, the mixed drop orbits the levitator axis at about 5 Hz during homogenization. The video's green channel (maximum response near 540 nm) shows the color change due to phenolphthalein absorption. While mixing is at least an order of magnitude faster in the levitated drop compared with three-dimensional diffusion, modulation of the acoustic waveform near the surface acoustic wave resonance frequency of the levitated drop does not substantially reduce mixing time. PMID:24460103

  15. Flowfield characteristics of an aerodynamic acoustic levitator

    NASA Astrophysics Data System (ADS)

    Yarin, A. L.; Brenn, G.; Keller, J.; Pfaffenlehner, M.; Ryssel, E.; Tropea, C.

    1997-11-01

    A droplet held in a single-axis ultrasonic levitator will principally sustain a certain external blowing along the levitation axis, which introduces the possibility of investigating heat and/or mass transfer from the droplet under conditions which are not too remote from those in spray systems. The focus of the present work is on the influence of the acoustic field on the external flow. More specifically, an axisymmetric submerged gas jet in an axial standing acoustic wave is examined, both in the absence and presence of a liquid droplet. Flow visualization is first presented to illustrate the global flow effects and the operating windows of jet velocities and acoustic powers which are suitable for further study. An analytic and numeric solution, based on the parabolic boundary layer equations are then given for the case of no levitated droplet, providing quantitative estimates of the acoustic field/flow interaction. Detailed velocity measurements using a laser Doppler anemometer verify the analytic results and extend these to the case of a levitated droplet. Some unresolved discrepancy remains in predicting the maximum velocity attainable before the droplet is blown out of the levitator. Two methods are developed to estimate the sound pressure level in the levitator by comparing flowfield patterns with analytic results. These results and observations are used to estimate to what extent acoustic aerodynamic levitators can be used in the future for investigating transport properties of individual droplets.

  16. Electrodynamics of Perfect Conductors

    NASA Astrophysics Data System (ADS)

    Fiolhais, Miguel C. N.; Essén, Hanno

    2013-05-01

    The most general electrodynamic equations of a perfect conducting state are obtained using a variational principle in a classical framework, following an approach by Pierre-Gilles de Gennes. London equations are derived as the time-independent case of these equations, corresponding to the magnetostatic minimal energy state of the perfect conducting system. For further confirmation, the same equations are also derived in the classical limit of the Coleman-Weinberg model, the most successful quantum macroscopic theory of superconductivity. The magnetic field expulsion is, therefore, a direct consequence of zero resistivity and not an exclusive property of superconductors.

  17. Electrostatic Levitator in Use

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Metal droplet levitated inside the Electrostatic Levitator (ESL). The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  18. Quantization of general linear electrodynamics

    SciTech Connect

    Rivera, Sergio; Schuller, Frederic P.

    2011-03-15

    General linear electrodynamics allow for an arbitrary linear constitutive relation between the field strength 2-form and induction 2-form density if crucial hyperbolicity and energy conditions are satisfied, which render the theory predictive and physically interpretable. Taking into account the higher-order polynomial dispersion relation and associated causal structure of general linear electrodynamics, we carefully develop its Hamiltonian formulation from first principles. Canonical quantization of the resulting constrained system then results in a quantum vacuum which is sensitive to the constitutive tensor of the classical theory. As an application we calculate the Casimir effect in a birefringent linear optical medium.

  19. Large charged drop levitation against gravity

    NASA Technical Reports Server (NTRS)

    Rhim, Won-Kyu; Chung, Sang Kun; Hyson, Michael T.; Trinh, Eugene H.; Elleman, Daniel D.

    1987-01-01

    A hybrid electrostatic-acoustic levitator that can levitate and manipulate a large liquid drop in one gravity is presented. To the authors' knowledge, this is the first time such large drops (up to 4 mm in diameter in the case of water) have been levitated against 1-gravity. This makes possible, for the first time, many new experiments both in space and in ground-based laboratories, such as 1)supercooling and superheating, 2) containerless crystal growth from various salt solutions or melts, 3) drop dynamics of oscillating or rotating liquid drops, 4) drop evaporation and Rayleigh bursting, and 5) containerless material processing in space. The digital control system, liquid drop launch process, principles of electrode design, and design of a multipurpose room temperature levitation chamber are described. Preliminary results that demonstrate drop oscillation and rotation, and crystal growth from supersaturated salt solutions are presented.

  20. The Inductrack concept: A new approach to magnetic levitation

    SciTech Connect

    Post, R.F.; Ryutov, D.

    1996-05-01

    This report describes theoretical and experimental investigations of a new approach to the problem of the magnetic levitation of a moving object. By contrast with previously studied levitation approaches, the Inductrack concept concept represents a simpler, potentially less expensive, and totally passive means of levitating a high-speed train. It may also be applicable to other areas where simpler magnetic levitation systems are needed, for example, high-speed test sleds for crash testing applications, or low-friction conveyer systems for industrial use.

  1. Electrodynamics sensor for the image reconstruction process in an electrical charge tomography system.

    PubMed

    Rahmat, Mohd Fua'ad; Isa, Mohd Daud; Rahim, Ruzairi Abdul; Hussin, Tengku Ahmad Raja

    2009-01-01

    Electrical charge tomography (EChT) is a non-invasive imaging technique that is aimed to reconstruct the image of materials being conveyed based on data measured by an electrodynamics sensor installed around the pipe. Image reconstruction in electrical charge tomography is vital and has not been widely studied before. Three methods have been introduced before, namely the linear back projection method, the filtered back projection method and the least square method. These methods normally face ill-posed problems and their solutions are unstable and inaccurate. In order to ensure the stability and accuracy, a special solution should be applied to obtain a meaningful image reconstruction result. In this paper, a new image reconstruction method - Least squares with regularization (LSR) will be introduced to reconstruct the image of material in a gravity mode conveyor pipeline for electrical charge tomography. Numerical analysis results based on simulation data indicated that this algorithm efficiently overcomes the numerical instability. The results show that the accuracy of the reconstruction images obtained using the proposed algorithm was enhanced and similar to the image captured by a CCD Camera. As a result, an efficient method for electrical charge tomography image reconstruction has been introduced.

  2. Magnetically levitated micro-machines

    NASA Astrophysics Data System (ADS)

    Pelrine, Ron; Busch-Vishniac, Ilene

    The use of magnetic levitation (maglev) as a microdrive has been studied. A wide variety of micromechanical systems are possible with maglev technology. Advantages for factory automation include very light and small manipulators, integration of transport with precision processes, and high tolerance for adverse environments. A prototype system using air-core electromagnets driving a permanent magnet manipulator has been built. Preliminary results include 2 degrees of freedom at + or - 1.5 micron relative accuracy and 15 moves/s.

  3. Acoustic Levitation With One Transducer

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B.

    1987-01-01

    Higher resonator modes enables simplification of equipment. Experimental acoustic levitator for high-temperature containerless processing has round cylindrical levitation chamber and only one acoustic transducer. Stable levitation of solid particle or liquid drop achieved by exciting sound in chamber to higher-order resonant mode that makes potential well for levitated particle or drop at some point within chamber.

  4. Matrix method for acoustic levitation simulation.

    PubMed

    Andrade, Marco A B; Perez, Nicolas; Buiochi, Flavio; Adamowski, Julio C

    2011-08-01

    A matrix method is presented for simulating acoustic levitators. A typical acoustic levitator consists of an ultrasonic transducer and a reflector. The matrix method is used to determine the potential for acoustic radiation force that acts on a small sphere in the standing wave field produced by the levitator. The method is based on the Rayleigh integral and it takes into account the multiple reflections that occur between the transducer and the reflector. The potential for acoustic radiation force obtained by the matrix method is validated by comparing the matrix method results with those obtained by the finite element method when using an axisymmetric model of a single-axis acoustic levitator. After validation, the method is applied in the simulation of a noncontact manipulation system consisting of two 37.9-kHz Langevin-type transducers and a plane reflector. The manipulation system allows control of the horizontal position of a small levitated sphere from -6 mm to 6 mm, which is done by changing the phase difference between the two transducers. The horizontal position of the sphere predicted by the matrix method agrees with the horizontal positions measured experimentally with a charge-coupled device camera. The main advantage of the matrix method is that it allows simulation of non-symmetric acoustic levitators without requiring much computational effort. PMID:21859587

  5. 2013 Problem 5: Levitation

    NASA Astrophysics Data System (ADS)

    Ruan, Qiyuan; Zeng, Pei; Zhou, Huijun; Wang, Sihui

    2015-10-01

    In this work, we reproduce the phenomenon through a preliminary experiment. The main factors to optimize the system are identified as the mass of the ball, the flow velocity and distribution of the airstream. We propose a Gaussian velocity distribution model to describe the flow velocity field model quantitatively which is supported by COMSOL simulation and experimental data. Through force analysis, the supporting forces that balance the gravity of the ball are identified. Equation for the tilt angle has been found, from which the optimal tilt angle can be calculated and compared to experimental data. Our research also shows that levitation is more stable without rotation. So the method we used to adjust the mass of the ball by injecting water is also effective in preventing rotation and enhance stability. The theoretical result for the optimal tilt angle is consistent with experimental data.

  6. 3D positional control of magnetic levitation system using adaptive control: improvement of positioning control in horizontal plane

    NASA Astrophysics Data System (ADS)

    Nishino, Toshimasa; Fujitani, Yasuhiro; Kato, Norihiko; Tsuda, Naoaki; Nomura, Yoshihiko; Matsui, Hirokazu

    2012-01-01

    The objective of this paper is to establish a technique that levitates and conveys a hand, a kind of micro-robot, by applying magnetic forces: the hand is assumed to have a function of holding and detaching the objects. The equipment to be used in our experiments consists of four pole-pieces of electromagnets, and is expected to work as a 4DOF drive unit within some restricted range of 3D space: the three DOF are corresponding to 3D positional control and the remaining one DOF, rotational oscillation damping control. Having used the same equipment, Khamesee et al. had manipulated the impressed voltages on the four electric magnetics by a PID controller by the use of the feedback signal of the hand's 3D position, the controlled variable. However, in this system, there were some problems remaining: in the horizontal direction, when translating the hand out of restricted region, positional control performance was suddenly degraded. The authors propose a method to apply an adaptive control to the horizontal directional control. It is expected that the technique to be presented in this paper contributes not only to the improvement of the response characteristic but also to widening the applicable range in the horizontal directional control.

  7. Modeling Ionospheric Electrodynamics (Invited)

    NASA Astrophysics Data System (ADS)

    Huba, J. D.

    2009-12-01

    We present modeling results of ionospheric electrodynamics using the 3D NRL ionosphere model SAMI3. Recently, SAMI3 has been upgraded to solve the potential equation that determines the electrostatic potential from the ionospheric conductances (Pedersen and Hall) and drivers: neutral wind, gravity, and parallel current systems. We present results showing the impact of different neutral wind models (e.g., HWM93, HWM07, TIMEGCM) on the dynamics of the low- to mid-latitude ionosphere, as well as the Region 1 and 2 current systems. We point out issues and concerns with obtaining an accurate specification of the global electric field within the context of existing models.(with J. Krall, G. Joyce, S. Slinker, and G. Crowley). Research supported by NASA and ONR

  8. The PROPEL Electrodynamic Tether Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Bilen, Sven G.; Johnson, C. Les; Wiegmann, Bruce M.; Alexander, Leslie; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael

    2012-01-01

    The PROPEL ("Propulsion using Electrodynamics") mission will demonstrate the operation of an electrodynamic tether propulsion system in low Earth orbit and advance its technology readiness level for multiple applications. The PROPEL mission has two primary objectives: first, to demonstrate the capability of electrodynamic tether technology to provide robust and safe, near-propellantless propulsion for orbit-raising, de-orbit, plane change, and station keeping, as well as to perform orbital power harvesting and formation flight; and, second, to fully characterize and validate the performance of an integrated electrodynamic tether propulsion system, qualifying it for infusion into future multiple satellite platforms and missions with minimal modification. This paper provides an overview of the PROPEL system and design reference missions; mission goals and required measurements; and ongoing PROPEL mission design efforts.

  9. Effect of the characteristics of a superconductor on the levitation properties of the magnet-superconductor system

    SciTech Connect

    Rudnev, I. A. Ermolaev, Yu. S.

    2007-07-15

    The results of the experimental and theoretical investigations of the magnetic levitation force appearing at the interaction of the multilayer superconducting block of the YBa{sub 2}Cu{sub 3}O{sub 7-x} melted textured ceramic and a permanent magnet are presented. The maximum repulsive force and maximum attractive force are determined as functions of the thickness of the superconducting block in the superconductor cooling regime in both zero and nonzero magnetic fields. The dependence of the levitation force on the geometric parameters and critical current of the superconductor is found.

  10. Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state

    NASA Astrophysics Data System (ADS)

    Sarabi, B.; Ramanayaka, A. N.; Burin, A. L.; Wellstood, F. C.; Osborn, K. D.

    2015-04-01

    Random tunneling two-level systems (TLSs) in dielectrics have been of interest recently because they adversely affect the performance of superconducting qubits. The coupling of TLSs to qubits has allowed individual TLS characterization, which has previously been limited to TLSs within (thin) Josephson tunneling barriers made from aluminum oxide. Here, we report on the measurement of an individual TLS within the capacitor of a lumped-element LC microwave resonator, which forms a cavity quantum electrodynamics (CQED) system and allows for individual TLS characterization in a different structure and material than demonstrated with qubits. Due to the reduced volume of the dielectric (80 μm3), even with a moderate dielectric thickness (250 nm), we achieve the strong coupling regime as evidenced by the vacuum Rabi splitting observed in the cavity spectrum. A TLS with a coherence time of 3.2 μs was observed in a film of silicon nitride as analyzed with a Jaynes-Cummings spectral model, which is larger than seen from superconducting qubits. As the drive power is increased, we observe an unusual but explicable set of continuous and discrete crossovers from the vacuum Rabi split transitions to the Glauber (coherent) state.

  11. Cavity quantum electrodynamics using a near-resonance two-level system: Emergence of the Glauber state

    SciTech Connect

    Sarabi, B.; Ramanayaka, A. N.; Burin, A. L.; Wellstood, F. C.; Osborn, K. D.

    2015-04-27

    Random tunneling two-level systems (TLSs) in dielectrics have been of interest recently because they adversely affect the performance of superconducting qubits. The coupling of TLSs to qubits has allowed individual TLS characterization, which has previously been limited to TLSs within (thin) Josephson tunneling barriers made from aluminum oxide. Here, we report on the measurement of an individual TLS within the capacitor of a lumped-element LC microwave resonator, which forms a cavity quantum electrodynamics (CQED) system and allows for individual TLS characterization in a different structure and material than demonstrated with qubits. Due to the reduced volume of the dielectric (80 μm{sup 3}), even with a moderate dielectric thickness (250 nm), we achieve the strong coupling regime as evidenced by the vacuum Rabi splitting observed in the cavity spectrum. A TLS with a coherence time of 3.2 μs was observed in a film of silicon nitride as analyzed with a Jaynes-Cummings spectral model, which is larger than seen from superconducting qubits. As the drive power is increased, we observe an unusual but explicable set of continuous and discrete crossovers from the vacuum Rabi split transitions to the Glauber (coherent) state.

  12. Acoustic-Levitation Chamber

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Granett, D.; Lee, M. C.

    1984-01-01

    Uncontaminated environments for highly-pure material processing provided within completely sealed levitation chamber that suspends particles by acoustic excitation. Technique ideally suited for material processing in low gravity environment of space.

  13. Studying Electrostatic Levitator Specimen

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Kevin Croat of Washington University in St. Louis, MO, examines samples processed in NASA/Marshall Space Flight Center's (MSFC)Electrostatic Levitator Facility. Croat is working with Prof. Kerneth Kelton in investigating undercooling of polytetrahedral phase-forming liquids.

  14. Electrodynamic Tether

    NASA Technical Reports Server (NTRS)

    Johnson, Charles L. (Inventor); Ballance, Judy L. (Inventor); Welzyn, Kenneth J. (Inventor); Vaughn, Jason A. (Inventor); Lorenzini, Enrico (Inventor); Schuler, Peter S. (Inventor)

    2006-01-01

    A tether system for providing thrust to or power subsystems of an artificial satellite in a low earth orbit. The tether has three main sections, an insulated section connected to the satellite, a conducting section connected to the insulating section for drawing in and releasing electrons from the space plasma and a non-conducting section for providing a tension to the other sections of the tether. An oxygen resistant coating is applied to the bare wire of the conducting section as well as the insulated wires of the insulated section that prevents breakdown during tether operations in the space plasma. The insulated and bare wire sections also surround a high tensile flexible polymer core to prevent any debris from breaking the tether during use.

  15. Livermore's 2004 R&D 100 Awards: Magnetically Levitated Train Takes Flight

    SciTech Connect

    Hazi, A

    2005-09-20

    within {+-}1 millimeter. Position sensors and electronic feedback systems are required to control the magnetic current and to compensate for the inherent instability. This requirement, plus the onboard source of emergency power required to ensure operational safety during a sudden power loss, increases the complexity of EMS trains. In contrast, in electrodynamic systems (EDS), large superconducting magnet coils mounted on the sides of the train generate high-intensity magnetic field poles. Interaction of the current between the coils and the track levitates the train. At operating speeds (above a liftoff speed of about 100 kilometers per hour), the magnetic levitation force balances the weight of the car at a stable position. EDS trains do not require the feedback control systems that EMS trains use to stabilize levitation. However, the superconducting magnetic coils must be kept at temperatures of only 5 kelvins, so costly electrically powered cryogenic equipment is required. Also, passengers, especially those with pacemakers, must be shielded from the high magnetic fields generated by the superconductors.

  16. Electrostatic Levitator Layout

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Electrostatic Levitator (ESL) general layout with captions. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  17. Electrostatic Levitator Layout

    NASA Technical Reports Server (NTRS)

    1998-01-01

    General oayout of Electrostatic Levitator (ESL). The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  18. Method and apparatus for shaping and enhancing acoustical levitation forces

    NASA Technical Reports Server (NTRS)

    Oran, W. A.; Berge, L. H.; Reiss, D. A.; Johnson, J. L. (Inventor)

    1980-01-01

    A method and apparatus for enhancing and shaping acoustical levitation forces in a single-axis acoustic resonance system wherein specially shaped drivers and reflectors are utilized to enhance to levitation force and better contain fluid substance by means of field shaping is described.

  19. Method and apparatus for shaping and enhancing acoustical levitation forces

    NASA Astrophysics Data System (ADS)

    Oran, W. A.; Berge, L. H.; Reiss, D. A.; Johnson, J. L.

    1980-08-01

    A method and apparatus for enhancing and shaping acoustical levitation forces in a single-axis acoustic resonance system wherein specially shaped drivers and reflectors are utilized to enhance to levitation force and better contain fluid substance by means of field shaping is described.

  20. Optics for five-dimensional measurement for correction of vertical displacement error due to attitude of floating body in superconducting magnetic levitation system

    SciTech Connect

    Shiota, Fuyuhiko; Morokuma, Tadashi

    2006-09-15

    An improved optical system for five-dimensional measurement has been developed for the correction of vertical displacement error due to the attitude change of a superconducting floating body that shows five degrees of freedom besides a vertical displacement of 10 mm. The available solid angle for the optical measurement is extremely limited because of the cryogenic laser interferometer sharing the optical window of a vacuum chamber in addition to the basic structure of the cryogenic vessel for liquid helium. The aim of the design was to develop a more practical as well as better optical system compared with the prototype system. Various artifices were built into this optical system and the result shows a satisfactory performance and easy operation overcoming the extremely severe spatial difficulty in the levitation system. Although the system described here is specifically designed for our magnetic levitation system, the concept and each artifice will be applicable to the optical measurement system for an object in a high-vacuum chamber and/or cryogenic vessel where the available solid angle for an optical path is extremely limited.

  1. The effects of a realistic hollow cathode plasma contactor model on the simulation of bare electrodynamic tether systems

    NASA Astrophysics Data System (ADS)

    Blash, Derek M.

    The region known as Low-Earth Orbit (LEO) has become populated with artificial satellites and space debris since humanities initial venture into the region. This has turned LEO into a hazardous region. Since LEO is very valuable to many different countries, there has been a push to prevent further buildup and talk of even deorbiting spent satellites and debris already in LEO. One of the more attractive concepts available for deorbiting debris and spent satellites is a Bare Electrodynamic Tether (BET). A BET is a propellantless propulsion technique in which two objects are joined together by a thin conducting material. When these tethered objects are placed in LEO, the tether sweeps across the magnetic field lines of the Earth and induces an electromotive force (emf) along the tether. Current from the space plasma is collected on the bare tether under the action of the induced emf, and this current interacts with the Earth's magnetic field to create a drag force that can be used to deorbit spent satellites and space debris. A Plasma Contactor (PC) is used to close the electrical circuit between the BET and the ionospheric plasma. The PC requires a voltage and, depending on the device, a gas flow to emit electrons through a plasma bridge to the ionospheric plasma. The PC also can require a plasma discharge electrode and a heater to condition the PC for operation. These parameters as well as the PC performance are required to build an accurate simulation of a PC and, therefore, a BET deorbiting system. This thesis focuses on the development, validation, and implementation of a simulation tool to model the effects of a realistic hollow cathode PC system model on a BET deorbit system.

  2. Magnetic levitation configuration incorporating levitation, guidance and linear synchronous motor

    DOEpatents

    Coffey, Howard T.

    1993-01-01

    A propulsion and suspension system for an inductive repulsion type magnetically levitated vehicle which is propelled and suspended by a system which includes propulsion windings which form a linear synchronous motor and conductive guideways, adjacent to the propulsion windings, where both combine to partially encircling the vehicle-borne superconducting magnets. A three phase power source is used with the linear synchronous motor to produce a traveling magnetic wave which in conjunction with the magnets propel the vehicle. The conductive guideway combines with the superconducting magnets to provide for vehicle leviation.

  3. Investigations of levitated helium drops

    NASA Astrophysics Data System (ADS)

    Whitaker, Dwight Lawrence

    1999-11-01

    We report on the development of two systems capable of levitating drops of liquid helium. Helium drops of ˜20 mum have been levitated with the radiation pressure from two counter-propagating Nd:YAG laser beams. Drops are produced with a submerged piezoelectric transducer, and could be held for up to three minutes in our optical trap. Calculations show that Brillouin and Raman scattering of the laser light in the liquid helium produces a negligible rate of evaporation of the drop. Evaporation caused by the enhanced vapor pressure of the curved drop surfaces appears to be a significant effect limiting the drop lifetimes. Helium drops as large as 2 cm in diameter have been suspended in the earth's gravitational field with a magnetic field. A commercial superconducting solenoid provides the necessary field, field-gradient product required to levitate the drops. Drops are cooled to 0.5 K with a helium-3 refrigerator, and can be held in the trap indefinitely. We have found that when two or more drops are levitated in the same magnetic trap, the drops often remain in a state of apparent contact without coalescing. This effect is a result of the evaporation of liquid from between the two drops, and is found to occur only for normal fluid drops. We can induce shape oscillations in charged, levitated drops with an applied ac electric field. We have measured the resonance frequencies and damping rates for the l = 2 mode of oscillation as function of temperature. We have also developed a theory to describe the small amplitude shape oscillations of a He II drop surrounded by its saturated vapor. In our theory, we have considered two sets of boundary conditions---one where the drop does not evaporate and another in which the liquid and vapor are in thermodynamic equilibrium. We have found that both solutions give a frequency that agrees well with experiment, but that the data for the damping rate agree better with the solution without evaporation.

  4. Stable And Oscillating Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B.; Garrett, Steven L.

    1988-01-01

    Sample stability or instability determined by levitating frequency. Degree of oscillation of acoustically levitated object along axis of levitation chamber controlled by varying frequency of acoustic driver for axis above or below frequency of corresponding chamber resonance. Stabilization/oscillation technique applied in normal Earth gravity, or in absence of gravity to bring object quickly to rest at nominal levitation position or make object oscillate in desired range about that position.

  5. Levitated Duct Fan (LDF) Aircraft Auxiliary Generator

    NASA Technical Reports Server (NTRS)

    Eichenberg, Dennis J.; Emerson, Dawn C.; Gallo, Christopher A.; Thompson, William K.

    2011-01-01

    This generator concept includes a novel stator and rotor architecture made from composite material with blades attached to the outer rotating shell of a ducted fan drum rotor, a non-contact support system between the stator and rotor using magnetic fields to provide levitation, and an integrated electromagnetic generation system. The magnetic suspension between the rotor and the stator suspends and supports the rotor within the stator housing using permanent magnets attached to the outer circumference of the drum rotor and passive levitation coils in the stator shell. The magnets are arranged in a Halbach array configuration.

  6. Variable-Position Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Stoneburner, J. D.; Jacobi, N.; Wang, T. G.

    1983-01-01

    Method of acoustic levitation supports objects at positions other than acoustic nodes. Acoustic force is varied so it balances gravitational (or other) force, thereby maintaining object at any position within equilibrium range. Levitation method applicable to containerless processing. Such objects as table-tennis balls, hollow plastic spheres, and balsa-wood spheres levitated in laboratory by new method.

  7. Levitation Technology in International Space Station Research

    NASA Technical Reports Server (NTRS)

    Guinart-Ramirez, Y.; Cooley, V. M.; Love, J. E.

    2016-01-01

    The International Space Station (ISS) is a unique multidisciplinary orbiting laboratory for science and technology research, enabling discoveries that benefit life on Earth and exploration of the universe. ISS facilities for containerless sample processing in Materials Science experiments include levitation devices with specimen positioning control while reducing containment vessel contamination. For example, ESA's EML (ElectroMagnetic Levitator), is used for melting and solidification of conductive metals, alloys, or semiconductors in ultra-high vacuum, or in high-purity gaseous atmospheres. Sample heating and positioning are accomplished through electromagnetic fields generated by a coil system. EML applications cover investigation of solidification and microstructural formation, evaluation of thermophysical properties of highly reactive metals (whose properties can be very sensitive to contamination), and examination of undercooled liquid metals to understand metastable phase convection and influence convection on structural changes. MSL utilization includes development of novel light-weight, high-performance materials. Another facility, JAXA's ELF (Electrostatic Levitation Furnace), is used to perform high temperature melting while avoiding chemical reactions with crucibles by levitating a sample through Coulomb force. ELF is capable of measuring density, surface tension, and viscosity of samples at high temperatures. One of the initial ELF investigations, Interfacial Energy-1, is aimed at clarification of interfacial phenomena between molten steels and oxide melts with industrial applications in control processes for liquid mixing. In addition to these Materials Science facilities, other ISS investigations that involve levitation employ it for biological research. For example, NASA's "Magnetic 3D Culturing and Bioprinting" investigation uses magnetic levitation for three-dimensional culturing and positioning of magnetized cells to generate spheroid assemblies

  8. Final Report: Levitated Dipole Experiment

    SciTech Connect

    Kesner, Jay; Mauel, Michael

    2013-03-10

    -field transport. We find levitation causes the central plasma density to increase dramatically and to significantly improve the confinement of thermal plasma [Boxer, Nature-Physics, v8, p. 949, 2010]. Several diagnostic systems have been used to measure plasma fluctuations, and these appear to represent low-frequency convection that may lead to adiabatic heating and strongly peaked pressure profiles. These experiments are remarkable, and the motivate wide-ranging studies of plasma found in space and confined for fusion energy. In the following report, we describe: (i) observations of the centrally-peaked density profile that appears naturally as a consequence of a strong turbulent pinch, (ii) observations of overall density and pressure increases that suggest large improvements to the thermal electron confinement time result occur during levitation, and (iii) the remarkable properties of low-frequency plasma fluctuations that cause magnetized plasma to "self-organize" into well-confined, centrally-peaked profiles that are relative to fusion and to space.

  9. Electrodynamics on extrasolar giant planets

    SciTech Connect

    Koskinen, T. T.; Yelle, R. V.; Lavvas, P.; Cho, J. Y-K.

    2014-11-20

    Strong ionization on close-in extrasolar giant planets (EGPs) suggests that their atmospheres may be affected by ion drag and resistive heating arising from wind-driven electrodynamics. Recent models of ion drag on these planets, however, are based on thermal ionization only and do not include the upper atmosphere above the 1 mbar level. These models are also based on simplified equations of resistive magnetohydrodynamics that are not always valid in extrasolar planet atmospheres. We show that photoionization dominates over thermal ionization over much of the dayside atmosphere above the 100 mbar level, creating an upper ionosphere dominated by ionization of H and He and a lower ionosphere dominated by ionization of metals such as Na, K, and Mg. The resulting dayside electron densities on close-in exoplanets are higher than those encountered in any planetary ionosphere of the solar system, and the conductivities are comparable to the chromosphere of the Sun. Based on these results and assumed magnetic fields, we constrain the conductivity regimes on close-in EGPs and use a generalized Ohm's law to study the basic effects of electrodynamics in their atmospheres. We find that ion drag is important above the 10 mbar level where it can also significantly alter the energy balance through resistive heating. Due to frequent collisions of the electrons and ions with the neutral atmosphere, however, ion drag is largely negligible in the lower atmosphere below the 10 mbar level for a reasonable range of planetary magnetic moments. We find that the atmospheric conductivity decreases by several orders of magnitude in the night side of tidally locked planets, leading to a potentially interesting large-scale dichotomy in electrodynamics between the day and night sides. A combined approach that relies on UV observations of the upper atmosphere, phase curve and Doppler measurements of global dynamics, and visual transit observations to probe the alkali metals can potentially be

  10. Development of the sonic pump levitation

    NASA Technical Reports Server (NTRS)

    Dunn, S. A.

    1984-01-01

    A prototype levitating/positioning device termed the Sonic Pump Levitator was designed, built and successfully tested in full gravity and in the reduced gravity of the parabolic flight regime of the KC-135. Positioning is achieved by timely and appropriate application of gas momentum from one or more of six sonic pumps. The sonic pumps, which are arranged orthogonally in opposed pairs about the levitation region, are activated by an electro-optical, computer controlled, feedback system. The sonic pump is a transducer which is capable of converting sound energy into a directed flow of gas. It consists of a loudspeaker whose face is sealed by a closure perforated by one or more orifices. The diaphragm of the loudspeaker is the only moving part of the sonic pump, no valves being needed. This very low inertia electromechanical device was developed to provide the short response time necessary to keep pace with the demands of computerized position keeping.

  11. Electrodynamic forces of the cross-connected figure-eight null-flux coil suspension system

    SciTech Connect

    He, J.L.; Rote, D.M.; Coffey, H.T.

    1993-01-01

    This paper analyzes the cross-connected figure-eight null-flux coil suspension system for maglev vehicles on the basis of dynamic circuit theory. The equivalent circuits and general magnetic force expressions for the system are developed. Simple analytical formulas for the magnetic force partitions on the basis of harmonic approximation are presented, and numerical results are also included.

  12. Sonic levitation apparatus

    NASA Technical Reports Server (NTRS)

    Dunn, S. A.; Pomplum, A. R.; Paquette, E. G.; Ethridge, E. C.; Johnson, J. L. (Inventor)

    1984-01-01

    A sonic levitation apparatus is disclosed which includes a sonic transducer which generates acoustical energy responsive to the level of an electrical amplifier. A duct communicates with an acoustical chamber to deliver an oscillatory motion of air to a plenum section which contains a collimated hole structure having a plurality of parallel orifices. The collimated hole structure converts the motion of the air to a pulsed. Unidirectional stream providing enough force to levitate a material specimen. Particular application to the production of microballoons in low gravity environment is discussed.

  13. Electrostatic Levitator Inspected

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Larry Savage, Dr. Jan Rogers, Dr. Michael Robinson (All NASA) and Doug Huie (Mevatec) inspect the Electrostatic Levitator (ESL) at NASA's Marshall Space Flight Center (MSFC). The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  14. Electrostatic Levitator (ESL) Undercooling

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Graph depicting Electrostatic Levitator (ESL) heating and cooling cycle to achieve undercooling of liquid metals. The ESL uses static electricity to suspend an object (about 3-4 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contracting the container or any instruments, conditions that would alter the readings. The electrostatic Levitator is one of several tools used in NASA's microgravity matierials sciences program.

  15. Electrostatic Levitator at Work

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A 3 mm drop of nickel-zirconium, heated to incandescence, hovers between electrically charged plates inside the Electrostatic Levitator (ESL). The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  16. Electrostatic Levitator Operations

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Dr. Jan Rogers and Dr. Michael Robinson operate the Electrostatic Levitator (ESL) at NASA's Marshall Space Flight Center (MSFC). The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  17. Electrostatic Levitator Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Optical ports ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (beam passes through the window at left), positioning lasers (one port is at center), and lamps to allow diagnostic instruments to view the sample. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  18. Electron spin control of optically levitated nanodiamonds in vacuum

    NASA Astrophysics Data System (ADS)

    Hoang, Thai; Ahn, Jonghoon; Bang, Jaehoon; Li, Tongcang

    2016-05-01

    Electron spins of diamond nitrogen-vacancy (NV) centers are important quantum resources for nanoscale sensing and quantum information. Combining such NV spin systems with levitated optomechanical resonators will provide a hybrid quantum system for many novel applications. Here we optically levitate a nanodiamond and demonstrate electron spin control of its built-in NV centers in low vacuum. We observe that the strength of electron spin resonance (ESR) is enhanced when the air pressure is reduced. To better understand this novel system, we also investigate the effects of trap power and measure the absolute internal temperature of levitated nanodiamonds with ESR after calibration of the strain effect.

  19. Recurrent Delocalization and Quasiequilibration of Photons in Coupled Systems in Circuit Quantum Electrodynamics.

    PubMed

    Hwang, Myung-Joong; Kim, M S; Choi, Mahn-Soo

    2016-04-15

    We explore the photon population dynamics in two coupled circuit QED systems. For a sufficiently weak intercavity photon hopping, as the photon-cavity coupling increases, the dynamics undergoes double transitions first from a delocalized to a localized phase and then from the localized to another delocalized phase. The latter delocalized phase is distinguished from the former one; instead of oscillating between the two cavities, the photons rapidly quasiequilibrate over the two cavities. These intriguing features are attributed to an interplay between two qualitatively distinctive nonlinear behaviors of the circuit QED systems in the utrastrong coupling regime, whose distinction has been widely overlooked. PMID:27127967

  20. Recurrent Delocalization and Quasiequilibration of Photons in Coupled Systems in Circuit Quantum Electrodynamics.

    PubMed

    Hwang, Myung-Joong; Kim, M S; Choi, Mahn-Soo

    2016-04-15

    We explore the photon population dynamics in two coupled circuit QED systems. For a sufficiently weak intercavity photon hopping, as the photon-cavity coupling increases, the dynamics undergoes double transitions first from a delocalized to a localized phase and then from the localized to another delocalized phase. The latter delocalized phase is distinguished from the former one; instead of oscillating between the two cavities, the photons rapidly quasiequilibrate over the two cavities. These intriguing features are attributed to an interplay between two qualitatively distinctive nonlinear behaviors of the circuit QED systems in the utrastrong coupling regime, whose distinction has been widely overlooked.

  1. Quantum electrodynamical time-dependent density functional theory for many-electron systems on a lattice

    NASA Astrophysics Data System (ADS)

    Farzanehpour, Mehdi; Tokatly, Ilya; Nano-Bio Spectroscopy Group; ETSF Scientific Development Centre Team

    2015-03-01

    We present a rigorous formulation of the time-dependent density functional theory for interacting lattice electrons strongly coupled to cavity photons. We start with an example of one particle on a Hubbard dimer coupled to a single photonic mode, which is equivalent to the single mode spin-boson model or the quantum Rabi model. For this system we prove that the electron-photon wave function is a unique functional of the electronic density and the expectation value of the photonic coordinate, provided the initial state and the density satisfy a set of well defined conditions. Then we generalize the formalism to many interacting electrons on a lattice coupled to multiple photonic modes and prove the general mapping theorem. We also show that for a system evolving from the ground state of a lattice Hamiltonian any density with a continuous second time derivative is locally v-representable. Spanish Ministry of Economy and Competitiveness (Grant No. FIS2013-46159-C3-1-P), Grupos Consolidados UPV/EHU del Gobierno Vasco (Grant No. IT578-13), COST Actions CM1204 (XLIC) and MP1306 (EUSpec).

  2. Method for identifying electromagnetically induced transparency in a tunable circuit quantum electrodynamics system

    NASA Astrophysics Data System (ADS)

    Liu, Qi-Chun; Li, Tie-Fu; Luo, Xiao-Qing; Zhao, Hu; Xiong, Wei; Zhang, Ying-Shan; Chen, Zhen; Liu, J. S.; Chen, Wei; Nori, Franco; Tsai, J. S.; You, J. Q.

    2016-05-01

    Electromagnetically induced transparency (EIT) has been realized in atomic systems, but fulfilling the EIT conditions for artificial atoms made from superconducting circuits is a more difficult task. Here we report an experimental observation of the EIT in a tunable three-dimensional transmon by probing the cavity transmission. To fulfill the EIT conditions, we tune the transmon to adjust its damping rates by utilizing the effect of the cavity on the transmon states. From the experimental observations, we clearly identify the EIT and Autler-Townes splitting (ATS) regimes as well as the transition regime in between. Also, the experimental data demonstrate that the threshold ΩAIC determined by the Akaike information criterion can describe the EIT-ATS transition better than the threshold ΩEIT given by the EIT theory.

  3. Levitation Kits Demonstrate Superconductivity.

    ERIC Educational Resources Information Center

    Worthy, Ward

    1987-01-01

    Describes the "Project 1-2-3" levitation kit used to demonstrate superconductivity. Summarizes the materials included in the kit. Discusses the effect demonstrated and gives details on how to obtain kits. Gives an overview of the documentation that is included. (CW)

  4. Levitation of superconducting composites

    NASA Technical Reports Server (NTRS)

    Chiang, C. K.; Turchinskaya, M.; Swartzendruber, L. J.; Shull, R. D.; Bennett, L. H.

    1991-01-01

    The inverse levitation of a high temperature superconductor polymer composite consisting of powdered quench melt growth Ba2YCu3O(7-delta) and cyanoacrylate is reported. Magnetic hysteresis loop measurements for the composite are compared to those measured for the bulk material prior to powdering. Differences in the flux pining capability between the two material forms are small but significant.

  5. Studying Electrostatic Levitator Specimen

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Prof. Kerneth Kelton of Washington University in St. Lous, MO, (L) and Dr. Michael Robinson of NASA's Marshall Space Flight Center (MSFC) examine a titanium-iron silicate (TiFeSiO)sample processed in MSFC's Electrostatic Levitator (ESL) Facility (background). Kelton is investigating undercooling of polytetrahedral phase-forming liquids.

  6. System engineering study of electrodynamic tether as a spaceborne generator and radiator of electromagnetic waves in the ULF/ELF frequency band

    NASA Technical Reports Server (NTRS)

    Estes, Robert D.

    1987-01-01

    An electrodynamic tether deployed from a satellite in low-Earth orbit can perform, if properly instrumented, as a partially self-powered generator of electromagnetic waves in the ULF/ELF band, potentially at power levels high enough to be of practical use. Two basic problems are examined. The first is that of the level of wave power that the system can be expected to generate in the ULF/ELF radiation band. The second major question is whether an electrodynamic tethered satellite system for transmitting waves can be made partially self-powering so that power requirements for drag compensation can be met within economical constraints of mass, cost, and complexity. The theoretical developments and the system applications study are presented. The basic design criteria, the drag-compensation method, the effects on the propagation paths from orbit to Earth surface of high-altitude nuclear debris patches, and the estimate of masses and sizes are covered. An outline of recommended analytical work, to be performed as a follow-on to the present study, is contained.

  7. Magnetically levitated space elevator to low-earth orbit.

    SciTech Connect

    Hull, J. R.; Mulcahy, T. M.

    2001-07-02

    The properties of currently available NbTi superconductor and carbon-fiber structural materials enable the possibility of constructing a magnetically levitated space elevator from the earth's surface up to an altitude of {approx} 200 km. The magnetic part of the elevator consists of a long loop of current-carrying NbTi, composed of one length that is attached to the earth's surface in an east-west direction and a levitated-arch portion. The critical current density of NbTi is sufficiently high that these conductors will stably levitate in the earth's magnetic field. The magnetic self-field from the loop increases the levitational force and for some geometries assists levitational stability. The 200-km maximum height of the levitated arch is limited by the allowable stresses of the structural material. The loop is cryogenically cooled with helium, and the system utilizes intermediate pumping and cooling stations along both the ground and the levitated portion of the loop, similar to other large terrestrial cryogenic systems. Mechanically suspended from the basic loop is an elevator structure, upon which mass can be moved between the earth's surface and the top of the loop by a linear electric motor or other mechanical or electrical means. At the top of the loop, vehicles may be accelerated to orbital velocity or higher by rocket motors, electromagnetic propulsion, or hybrid methods.

  8. First quantized electrodynamics

    SciTech Connect

    Bennett, A.F.

    2014-06-15

    The parametrized Dirac wave equation represents position and time as operators, and can be formulated for many particles. It thus provides, unlike field-theoretic Quantum Electrodynamics (QED), an elementary and unrestricted representation of electrons entangled in space or time. The parametrized formalism leads directly and without further conjecture to the Bethe–Salpeter equation for bound states. The formalism also yields the Uehling shift of the hydrogenic spectrum, the anomalous magnetic moment of the electron to leading order in the fine structure constant, the Lamb shift and the axial anomaly of QED. -- Highlights: •First-quantized electrodynamics of the parametrized Dirac equation is developed. •Unrestricted entanglement in time is made explicit. •Bethe and Salpeter’s equation for relativistic bound states is derived without further conjecture. •One-loop scattering corrections and the axial anomaly are derived using a partial summation. •Wide utility of semi-classical Quantum Electrodynamics is argued.

  9. Structure of Aristotelian electrodynamics

    NASA Astrophysics Data System (ADS)

    Jacobson, Ted

    2015-07-01

    Aristotelian electrodynamics (AE) describes the regime of a plasma with a very strong electric field that is not shorted out, with the charge current determined completely by pair production and the balance of the Lorentz 4-force against the curvature radiation reaction. Here it is shown how the principal null directions and associated eigenvalues of the field tensor govern AE, and how force-free electrodynamics arises smoothly from AE when the eigenvalues (and therefore the electric field in some frame) vanish. A criterion for validity of AE and force-free electrodynamics is proposed in terms of a pair of "field curvature scalars" formed from the first derivative of the principal null directions.

  10. Safety of high speed magnetic levitation transportation systems. Magnetic field testing of the TR07 Maglev vehicle and system. Volume 2: Appendices

    NASA Astrophysics Data System (ADS)

    Dietrich, Fred; Robertson, David; Steiner, George

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) emissions, both steady (dc) and produced by alternating current (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposures to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Appendices include catalogs and documents detailing magnetic field data files and their specifics (static fields, spectral waveforms, and temporal and spatial information) by location.

  11. Safety of high speed magnetic levitation transportation systems. Magnetic field testing of the TR07 Maglev vehicle and system. Volume 1: Analysis

    NASA Astrophysics Data System (ADS)

    Dietrich, Fred; Feero, William E.

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic field (EMF) emissions, both steady (dc) and produced by alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposure to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Analysis summarizes the experimental findings and compares results to common home, work, and power lines emissions for selected spectral bands.

  12. The Inductrack Approach to Magnetic Levitation

    SciTech Connect

    Post, R.F.; Ryutov, D.D.

    2000-04-19

    Concepts developed during research on passive magnetic bearing systems at the Lawrence Livermore National Laboratory gave rise to a new approach to magnetic levitation, the Inductrack. A passive induced-current system employing permanent magnets on the moving vehicle, the Inductrack maximizes levitation forces by a combination of two elements. First, the permanent magnets on the vehicle are arranged in a ''Halbach array,'' a magnet configuration that optimally produces a periodic magnetic field below the array, while canceling the field above the array. Second, the track is made up of close-packed shorted electrical circuits. These circuits couple optimally to the magnetic field of the Halbach array. As a result, levitating forces of order 40 metric tonnes per square meter of Halbach array can be generated, using NdFeB magnets whose weight is a few percent of the levitated weight. Being an induced-current system, the levitation requires motion of the vehicle above a low transition speed. For maglev applications this speed is a few kilometers per hour, walking speed. At rest or in the station auxiliary wheels are needed. The Inductrack is thus fail-safe, that is, drive system failure would only result in the vehicle slowing down and finally settling on its auxiliary wheels. On the basis of theoretical analyses a small model vehicle and a 20-meter-long track was built and tested at speeds of order 12 meters per second. A second model, designed to achieve 10-g acceleration levels and much higher speeds, is under construction under NASA sponsorship, en route to the design of maglev-based launchers for rockets. Some of the presently perceived practical problems of implementing full-scale maglev systems based on the Inductrack concept will be discussed.

  13. Gas levitator having fixed levitation node for containerless processing

    NASA Technical Reports Server (NTRS)

    Berge, L. H.; Oran, W. A.; Theiss, M. (Inventor)

    1981-01-01

    A method and apparatus is disclosed for levitating a specimen of material in a containerless environment at a stable nodal position independent of gravity. An elongated levitation tube has a contoured interior in the form of convergent section, constriction, and a divergent section in which the levitation node is created. A gas flow control means prevents separation of flow from the interior walls in the region of a specimen. The apparatus provides for levitating and heating the specimen simultaneously by combustion of a suitable gas mixture combined with an inert gas.

  14. A levitation instrument for containerless study of molten materials

    NASA Astrophysics Data System (ADS)

    Nordine, Paul C.; Merkley, Dennis; Sickel, Jeffrey; Finkelman, Steve; Telle, Rainer; Kaiser, Arno; Prieler, Robert

    2012-12-01

    A new aero-acoustic levitation instrument (AAL) has been installed at the Institute for Mineral Engineering at RWTH University in Aachen, Germany. The AAL employs acoustically stabilized gas jet levitation with laser-beam heating and melting to create a contact-free containerless environment for high temperature materials research. Contamination-free study of liquids is possible at temperatures in excess of 3000 °C and of undercooled liquids at temperatures far below the melting point. Digital control technology advances the art of containerless experiments to obtain long-term levitation stability, allowing new experiments in extreme temperature materials research and to study operation of the levitation instrument itself. Experiments with liquid Al2O3 at temperatures more than 3200 °C, 1200 °C above the melting point, and with liquid Y3Al5O12 far below the melting point are reported. Fast pyrometry and video recording instruments yield crystallization rates in undercooled liquid Al2O3 as a function of temperature. Levitation of dense liquid HfO2 at temperatures above 2900 °C is demonstrated. Capabilities are described for resonant frequency matching in the three-axis acoustic positioning system, acoustic control of sample spin, and position control of standing wave nodes to stabilize levitation under changing experimental conditions. Further development and application of the levitation technology is discussed based on the results of experiments and modeling of instrument operations.

  15. A levitation instrument for containerless study of molten materials.

    PubMed

    Nordine, Paul C; Merkley, Dennis; Sickel, Jeffrey; Finkelman, Steve; Telle, Rainer; Kaiser, Arno; Prieler, Robert

    2012-12-01

    A new aero-acoustic levitation instrument (AAL) has been installed at the Institute for Mineral Engineering at RWTH University in Aachen, Germany. The AAL employs acoustically stabilized gas jet levitation with laser-beam heating and melting to create a contact-free containerless environment for high temperature materials research. Contamination-free study of liquids is possible at temperatures in excess of 3000 °C and of undercooled liquids at temperatures far below the melting point. Digital control technology advances the art of containerless experiments to obtain long-term levitation stability, allowing new experiments in extreme temperature materials research and to study operation of the levitation instrument itself. Experiments with liquid Al(2)O(3) at temperatures more than 3200 °C, 1200 °C above the melting point, and with liquid Y(3)Al(5)O(12) far below the melting point are reported. Fast pyrometry and video recording instruments yield crystallization rates in undercooled liquid Al(2)O(3) as a function of temperature. Levitation of dense liquid HfO(2) at temperatures above 2900 °C is demonstrated. Capabilities are described for resonant frequency matching in the three-axis acoustic positioning system, acoustic control of sample spin, and position control of standing wave nodes to stabilize levitation under changing experimental conditions. Further development and application of the levitation technology is discussed based on the results of experiments and modeling of instrument operations. PMID:23278026

  16. Experimental study of streaming flows associated with ultrasonic levitators

    NASA Astrophysics Data System (ADS)

    Trinh, E. H.; Robey, J. L.

    1994-11-01

    Steady-state acoustic streaming flow patterns have been observed during the operation of a variety of resonant single-axis ultrasonic levitators in a gaseous environment and in the 20-37 kHz frequency range. Light sheet illumination and scattering from smoke particles have revealed primary streaming flows which display different characteristics at low and high sound pressure levels. Secondary macroscopic streaming cells around levitated samples are superimposed on the primary streaming flow pattern generated by the standing wave. These recorded flows are quite reproducible, and are qualitatively the same for a variety of levitator physical geometries. An onset of flow instability can also be recorded in nonisothermal systems, such as levitated spot-heated samples when the resonance conditions are not exactly satisfied. A preliminary qualitative interpretation of these experimental results is presented in terms of the superposition of three discrete sets of circulation cells operating on different spatial scales. These relevant length scales are the acoustic wavelength, the levitated sample size, and finally the acoustic boundary layer thickness. This approach fails, however, to explain the streaming flow-field morphology around liquid drops levitated on Earth. Observation of the interaction between the flows cells and the levitated samples also suggests the existence of a steady-state torque induced by the streaming flows.

  17. Simplified Rotation In Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Gaspar, M. S.; Trinh, E. H.

    1989-01-01

    New technique based on old discovery used to control orientation of object levitated acoustically in axisymmetric chamber. Method does not require expensive equipment like additional acoustic drivers of precisely adjustable amplitude, phase, and frequency. Reflecting object acts as second source of sound. If reflecting object large enough, close enough to levitated object, or focuses reflected sound sufficiently, Rayleigh torque exerted on levitated object by reflected sound controls orientation of object.

  18. Single mode levitation and translation

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B. (Inventor); Allen, James L. (Inventor)

    1988-01-01

    A single frequency resonance mode is applied by a transducer to acoustically levitate an object within a chamber. This process allows smooth movement of the object and suppression of unwanted levitation modes that would urge the object to a different levitation position. A plunger forms one end of the chamber, and the frequency changes as the plunger moves. Acoustic energy is applied to opposite sides of the chamber, with the acoustic energy on opposite sides being substantially 180 degrees out of phase.

  19. Electron spin control of optically levitated nanodiamonds in vacuum

    PubMed Central

    Hoang, Thai M.; Ahn, Jonghoon; Bang, Jaehoon; Li, Tongcang

    2016-01-01

    Electron spins of diamond nitrogen-vacancy (NV) centres are important quantum resources for nanoscale sensing and quantum information. Combining NV spins with levitated optomechanical resonators will provide a hybrid quantum system for novel applications. Here we optically levitate a nanodiamond and demonstrate electron spin control of its built-in NV centres in low vacuum. We observe that the strength of electron spin resonance (ESR) is enhanced when the air pressure is reduced. To better understand this system, we investigate the effects of trap power and measure the absolute internal temperature of levitated nanodiamonds with ESR after calibration of the strain effect. We also observe that oxygen and helium gases have different effects on both the photoluminescence and the ESR contrast of nanodiamond NV centres, indicating potential applications of NV centres in oxygen gas sensing. Our results pave the way towards a levitated spin–optomechanical system for studying macroscopic quantum mechanics. PMID:27432560

  20. Electron spin control of optically levitated nanodiamonds in vacuum.

    PubMed

    Hoang, Thai M; Ahn, Jonghoon; Bang, Jaehoon; Li, Tongcang

    2016-01-01

    Electron spins of diamond nitrogen-vacancy (NV) centres are important quantum resources for nanoscale sensing and quantum information. Combining NV spins with levitated optomechanical resonators will provide a hybrid quantum system for novel applications. Here we optically levitate a nanodiamond and demonstrate electron spin control of its built-in NV centres in low vacuum. We observe that the strength of electron spin resonance (ESR) is enhanced when the air pressure is reduced. To better understand this system, we investigate the effects of trap power and measure the absolute internal temperature of levitated nanodiamonds with ESR after calibration of the strain effect. We also observe that oxygen and helium gases have different effects on both the photoluminescence and the ESR contrast of nanodiamond NV centres, indicating potential applications of NV centres in oxygen gas sensing. Our results pave the way towards a levitated spin-optomechanical system for studying macroscopic quantum mechanics. PMID:27432560

  1. Electron spin control of optically levitated nanodiamonds in vacuum

    NASA Astrophysics Data System (ADS)

    Hoang, Thai M.; Ahn, Jonghoon; Bang, Jaehoon; Li, Tongcang

    2016-07-01

    Electron spins of diamond nitrogen-vacancy (NV) centres are important quantum resources for nanoscale sensing and quantum information. Combining NV spins with levitated optomechanical resonators will provide a hybrid quantum system for novel applications. Here we optically levitate a nanodiamond and demonstrate electron spin control of its built-in NV centres in low vacuum. We observe that the strength of electron spin resonance (ESR) is enhanced when the air pressure is reduced. To better understand this system, we investigate the effects of trap power and measure the absolute internal temperature of levitated nanodiamonds with ESR after calibration of the strain effect. We also observe that oxygen and helium gases have different effects on both the photoluminescence and the ESR contrast of nanodiamond NV centres, indicating potential applications of NV centres in oxygen gas sensing. Our results pave the way towards a levitated spin-optomechanical system for studying macroscopic quantum mechanics.

  2. Causality in Classical Electrodynamics

    ERIC Educational Resources Information Center

    Savage, Craig

    2012-01-01

    Causality in electrodynamics is a subject of some confusion, especially regarding the application of Faraday's law and the Ampere-Maxwell law. This has led to the suggestion that we should not teach students that electric and magnetic fields can cause each other, but rather focus on charges and currents as the causal agents. In this paper I argue…

  3. Quantum Electrodynamics: Theory

    ScienceCinema

    Lincoln, Don

    2016-07-12

    The Standard Model of particle physics is composed of several theories that are added together. The most precise component theory is the theory of quantum electrodynamics or QED. In this video, Fermilab’s Dr. Don Lincoln explains how theoretical QED calculations can be done. This video links to other videos, giving the viewer a deep understanding of the process.

  4. Electrostatic Levitator Vacuum Chambers

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Optical prots ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (the beam passes through the window at left), poisitioning lasers (one port is at center), and lamps (such as the deuterium arc lamp at right), and to allow diagnostic instruments to view the sample. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  5. Electrostatic Levitator Vacuum Chamber

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Optical prots ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (the beam passes through the window at left), poisitioning lasers (one port is at center), and lamps (arc lamp at right), and to allow diagnostic instruments to view the sample. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  6. Electrostatic Levitator Vaccum Chamber

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Optical ports ring the Electrostatic Levitator (ESL) vacuum chamber to admit light from the heating laser (the beam passes through the window at left), positioning lasers (one port is at center), and lamps (such as the deuterium arc lamp at right), and to allow diagnostic instruments to view the sample. The ESL uses static electricity to suspend an object (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials science program.

  7. Dimensionless Analysis and Numerical Modeling of Rebalancing Phenomena During Levitation

    NASA Astrophysics Data System (ADS)

    Gao, Lei; Shi, Zhe; Li, Donghui; McLean, Alexander; Chattopadhyay, Kinnor

    2016-06-01

    Electromagnetic levitation (EML) has proved to be a powerful tool for research activities in areas pertaining to materials physics and engineering. The customized EML setups in various fields, ranging from solidification to nanomaterial manufacturing, require the designing of stable levitation systems. Since the elevated droplet is opaque, the most effective way to research on EML is mathematical modeling. In the present study, a 3D model was built to investigate the rebalancing phenomenon causing instabilities during droplet melting. A mathematical model modified based on Hooke's law (spring) was proposed to describe the levitation system. This was combined with dimensionless analysis to investigate the generation of levitation forces as it will significantly affect the behavior of the spring model.

  8. Magnetically levitated micro-robotics

    NASA Astrophysics Data System (ADS)

    Pelrine, Ronald Edward

    The use of magnetic levitation (maglev) as a microrobot drive is examined theoretically and experimentally. Microrobots are small, programmable, multi-degree of freedom mechanical devices. Maglev drive appears capable of addressing a number of important microrobotics issues, including friction, wear, material transport, and ability to tolerate adverse environments. These issues, often involving problems beyond the technical feasibility of single microrobots, must be dealt with effectively in order to realize the goal of low cost, integrated, multi-manipulator systems operating on small scales. Maglev microrobot drive is compared with other possible microrobot drives, particularly electrostatic drive. Various magnetic levitation systems are examined next, showing the rich variety of possible maglev microrobots. Out of 48 physically distinct maglev drive systems, the focus is narrowed using the requirements of an integrated micro-factory (IMF). These requirements suggest that at the present level of technical development the maglev system of primary interest is one which uses air core electromagnets driving a permanent magnet manipulator. Various air core electromagnets are discussed, including planar electromagnets suitable for a high level of silicon integration. Several force/torque environments are considered, such as solid and liquid surfaces. These different environments primarily affect the control strategy's performance and requirements, such as the ability to operate in open loop modes. The analysis was used to build a number of experimental prototypes, including a planar type, 1-D manipulator transport path, and 4. degree of freedom microrobots capable of 0.5 micron resolutions. Finally, future trends in the field such as superconductive systems are discussed.

  9. Electrodynamic Tethers for Novel LEO Missions

    NASA Technical Reports Server (NTRS)

    Kantner, Michael; Hoyt, Robert; Scardera, Michael; Johnson, Charles

    2011-01-01

    The exponential increase of launch system size - and cost - with deltaV makes missions requiring large total impulse cost prohibitive. Northrop Grumman and partners have matured a fundamentally different method for generating propulsion using electrodynamic tethers (EDTs) that escapes the limitations of the rocket equation. With essentially unlimited delta V, we can perform new classes of missions that are currently unaffordable or unfeasible.

  10. Aerodynamic levitator for large-sized glassy material production.

    PubMed

    Yoda, Shinichi; Cho, Won-Seung; Imai, Ryoji

    2015-09-01

    Containerless aerodynamic levitation processing is a unique technology for the fabrication of bulk non-crystalline materials. Using conventional aerodynamic levitation, a high reflective index (RI) material (BaTi2O5 and LaO3/2-TiO2-ZrO2 system) was developed with a RI greater than approximately 2.2, which is similar to that of diamond. However, the glass size was small, approximately 3 mm in diameter. Therefore, it is essential to produce large sized materials for future optical materials applications, such as camera lenses. In this study, a new aerodynamic levitator was designed to produce non-crystalline materials with diameters larger than 6 mm. The concept of this new levitator was to set up a reduced pressure at the top of the molten samples without generating turbulent flow. A numerical simulation was also performed to verify the concept. PMID:26429456

  11. Aerodynamic levitator for large-sized glassy material production.

    PubMed

    Yoda, Shinichi; Cho, Won-Seung; Imai, Ryoji

    2015-09-01

    Containerless aerodynamic levitation processing is a unique technology for the fabrication of bulk non-crystalline materials. Using conventional aerodynamic levitation, a high reflective index (RI) material (BaTi2O5 and LaO3/2-TiO2-ZrO2 system) was developed with a RI greater than approximately 2.2, which is similar to that of diamond. However, the glass size was small, approximately 3 mm in diameter. Therefore, it is essential to produce large sized materials for future optical materials applications, such as camera lenses. In this study, a new aerodynamic levitator was designed to produce non-crystalline materials with diameters larger than 6 mm. The concept of this new levitator was to set up a reduced pressure at the top of the molten samples without generating turbulent flow. A numerical simulation was also performed to verify the concept.

  12. Experience on a cryogenic linear mechanism based on superconducting levitation

    NASA Astrophysics Data System (ADS)

    Serrano-Tellez, Javier; Romera-Juarez, Fernando; González-de-María, David; Lamensans, Mikel; Argelaguet-Vilaseca, Heribert; Pérez-Díaz, José-Luis; Sánchez-Casarrubios, Juan; Díez-Jiménez, Efrén.; Valiente-Blanco, Ignacio

    2012-09-01

    The instrumentation of many space missions requires operation in cryogenic temperatures. In all the cases, the use of mechanisms in this environment is a matter of concern, especially when long lifetime is required. With the aim of removing lifetime concerns and to benefit from the cryogenic environment, a cryogenic contactless linear mechanism has been developed. It is based on the levitation of a permanent magnet over superconductor disks. The mechanism has been designed, built, and tested to assess the performances of such technology. The levitation system solves the mechanical contact problems due to cold-welding effects, material degradation by fatigue, wearing, backlash, lubrication...etc, at cryogenic temperatures. In fact, the lower is the temperature the better the superconductor levitation systems work. The mechanism provides a wide stroke (18mm) and high resolution motion (1μm), where position is controlled by changing the magnetic field of its environment using electric-magnets. During the motion, the moving part of the mechanism levitates supported by the magnetic interaction with the high temperature type II superconductors after reaching the superconductor state down to 90K. This paper describes the results of the complete levitation system development, including extensive cryogenic testing to measure optically the motion range, resolution, run-outs and rotations in order to characterize the levitation mechanism and to verify its performance in a cryogenic environment.

  13. Hybrid Contactless Heating and Levitation

    NASA Technical Reports Server (NTRS)

    Lee, M. C.

    1985-01-01

    Acoustic and electromagnetic fields applied. In contactless processing apparatus, acoustic and electromagnetic levitating fields employed alternately or simultaneously with amplitude of each controlled to produce various combinations of heating, cooling, and levitation. Apparatus provides rapid heating and cooling or slow heating and cooling for such processes as nucleation, crystallization, incubation, deep undercooling, and heterogeneity control.

  14. Electromagnetic Levitation of a Disc

    ERIC Educational Resources Information Center

    Valle, R.; Neves, F.; de Andrade, R., Jr.; Stephan, R. M.

    2012-01-01

    This paper presents a teaching experiment that explores the levitation of a disc of ferromagnetic material in the presence of the magnetic field produced by a single electromagnet. In comparison to the classical experiment of the levitation of a sphere, the main advantage of the proposed laboratory bench is that the uniform magnetic field…

  15. Characterization of Acousto-Electric Cluster and Array Levitation and its Application to Evaporation

    NASA Technical Reports Server (NTRS)

    Robert E. Apfel; Zheng, Yibing

    2000-01-01

    An acousto-electric levitator has been developed to study the behavior of liquid drop and solid particle clusters and arrays. Unlike an ordinary acoustic levitator that uses only a standing acoustic wave to levitate a single drop or particle, this device uses an extra electric static field and the acoustic field simultaneously to generate and levitate charged drops in two-dimensional arrays in air without any contact to a solid surface. This cluster and array generation (CAG) instrument enables us to steadily position drops and arrays to study the behavior of multiple drop and particle systems such as spray and aerosol systems relevant to the energy, environmental, and material sciences.

  16. On generalized logarithmic electrodynamics

    NASA Astrophysics Data System (ADS)

    Kruglov, S. I.

    2015-02-01

    The generalized logarithmic electrodynamics with two parameters and is considered. The indexes of refraction of light in the external magnetic field are calculated. In the case we come to results obtained by Gaete and Helayël-Neto (Eur Phys J C 74:2816, 2014). The bound on the values of , was obtained from the Biréfringence Magnétique du Vide (BMV) experiment. The symmetrical Belinfante energy-momentum tensor and dilatation current are found.

  17. Extended symmetrical classical electrodynamics.

    PubMed

    Fedorov, A V; Kalashnikov, E G

    2008-03-01

    In this paper, we discuss a modification of classical electrodynamics in which "ordinary" point charges are absent. The modified equations contain additional terms describing the induced charges and currents. The densities of the induced charges and currents depend on the vector k and the vectors of the electromagnetic field, E and B . It is shown that the vectors E and B can be defined in terms of two four-potentials and the components of k are the components of a four-tensor of the third rank. The Lagrangian of the modified electrodynamics is defined. The conditions are derived at which only one four-potential determines the behavior of the electromagnetic field. It is also shown that static modified electrodynamics can describe the electromagnetic field in the inner region of an electric monopole. In the outer region of the electric monopole the electric field is governed by the Maxwell equations. It follows from boundary conditions at the interface between the inner and outer regions of the monopole that the vector k has a discrete spectrum. The electric and magnetic fields, energy, and angular momentum of the monopole are found for different eigenvalues of k .

  18. Adaptive control based on fast online algebraic identification and GPI control for magnetic levitation systems with time-varying input gain

    NASA Astrophysics Data System (ADS)

    Morales, R.; Sira-Ramírez, H.; Feliu, V.

    2014-08-01

    This paper considers the position tracking problem of a voltage-controlled magnetic levitation system (MLS) in the presence of modelling errors caused by uncertainties in the system's physical parameters. An adaptive control based on fast online algebraic parameter estimation and generalised proportional integral (GPI) output feedback control is considered as a control scheme candidate. The GPI controller guarantees an asymptotically exponentially stable behaviour of the controlled ball position and the possibilities of carrying out rest-to-rest trajectory tracking tasks. The nature of the control input gain in an MLS is that of a state-dependent time-varying gain, reflecting the nonlinear character of the magnetic force with regard to the distance and the properties of the metallic ball. The system gain has therefore been locally approximated using a periodically updated time polynomial function (of second degree), where the coefficients of the polynomial are estimated during a very short period of time. This estimation is achieved using the recently introduced algebraic online parameter estimation approach. The stability of the closed-loop system is demonstrated under the assumption that no external factors cause changes in the parameter during the time interval in which the stability is analysed. Finally, experimental results are presented for the controlled MLS demonstrating the excellent stabilisation and position tracking performance of the control system designed in the presence of significant nonlinearities and uncertainties of the underlying system.

  19. Manipulation of optically levitated particles

    NASA Astrophysics Data System (ADS)

    Isaksson, Oscar; Karlsteen, Magnus; Rostedt, Mats; Hanstorp, Dag

    2013-09-01

    The development of an experimental system in which optical levitation combined with Millikańs classical oil drop experiment will be presented. The focus of the apparatus is a glass cell (25x72x25 mm3) in which an oil drop is levitated using a vertically aligned laser beam. A laser power of about 0.9 W is needed to capture a drop, whereas typically 0.3 W is sufficient to maintain it in the trap. An alternating electric field is applied vertically across the cell, causing the drop to oscillate in the vertical direction. The amplitude of the oscillations depends on the strength of the electric field and the q/m ratio of the oil drop. The oscillations are observed by imaging scattered laser light onto either a screen or a position sensitive detector. The number of discrete charges on the drop can be reduced by exposing it to either UV-light or a radioactive source. The radius of the drop is measured by detecting the diffraction pattern produced when illuminated with a horizontally aligned He-Ne laser beam. The mass of the drop can then be determined since the density of the oil is known. Hence, absolute measurements of both the mass and the charge of the drop can be obtained. The goal of the experiment is to design a system which can be used to demonstrate several fundamental physical phenomena using the bare eye as the only detector. The experimental set-up will be further developed for studies of light scattering and spectroscopy of liquids and for studies of interactions between liquid drops.

  20. Densitometry By Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Trinh, Eugene H.

    1989-01-01

    "Static" and "dynamic" methods developed for measuring mass density of acoustically levitated solid particle or liquid drop. "Static" method, unknown density of sample found by comparison with another sample of known density. "Dynamic" method practiced with or without gravitational field. Advantages over conventional density-measuring techniques: sample does not have to make contact with container or other solid surface, size and shape of samples do not affect measurement significantly, sound field does not have to be know in detail, and sample can be smaller than microliter. Detailed knowledge of acoustic field not necessary.

  1. Electrodynamic Dust Shield Demonstrator

    NASA Technical Reports Server (NTRS)

    Stankie, Charles G.

    2013-01-01

    The objective of the project was to design and manufacture a device to demonstrate a new technology developed by NASA's Electrostatics and Surface Physics Laboratory. The technology itself is a system which uses magnetic principles to remove regolith dust from its surface. This project was to create an enclosure that will be used to demonstrate the effectiveness of the invention to The Office of the Chief Technologist. ONE of the most important challenges of space exploration is actually caused by something very small and seemingly insignificant. Dust in space, most notably on the moon and Mars, has caused many unforeseen issues. Dirt and dust on Earth, while a nuisance, can be easily cleaned and kept at bay. However, there is considerably less weathering and erosion in space. As a result, the microscopic particles are extremely rough and abrasive. They are also electrostatically charged, so they cling to everything they make contact with. This was first noted to be a major problem during the Apollo missions. Dust would stick to the spacesuits, and could not be wiped off as predicted. Dust was brought back into the spacecraft, and was even inhaled by astronauts. This is a major health hazard. Atmospheric storms and other events can also cause dust to coat surfaces of spacecraft. This can cause abrasive damage to the craft. The coating can also reduce the effectiveness of thermal insulation and solar panels.' A group of engineers at Kennedy Space Center's Electrostatics and Surface Physics Laboratory have developed a new technology, called the Electrodynamic Dust Shield, to help alleviate these problems. It is based off of the electric curtain concept developed at NASA in 1967. "The EDS is an active dust mitigation technology that uses traveling electric fields to transport electrostatically charged dust particles along surfaces. To generate the traveling electric fields, the EDS consists of a multilayer dielectric coating with an embedded thin electrode grid

  2. The effects of magnetization process on levitation characteristics of a superconducting bulk magnet

    NASA Astrophysics Data System (ADS)

    Jiang, J.; Gong, Y. M.; Li, Y. H.; Liang, G.; Yang, X. S.; Cheng, C. H.; Zhao, Y.

    2015-09-01

    In this paper, a bulk YBCO superconductor was magnetized in a chosen magnetic field generated from a superconducting magnet (SM) after field cooling process. The effects of magnetization process with different magnetization intensities on levitation forces and relaxation characteristics were investigated. From the results, it can be confirmed that the superconducting bulk magnet (SBM) magnetized with proper magnetization intensity was beneficial to improve the levitation characteristics of the magnetic levitation system. Nevertheless, when the magnetization intensity exceeded 0.85T, the levitation forces and the relaxation characteristics of the SBM attained saturation.

  3. Levitated micro-accelerometer.

    SciTech Connect

    Warne, Larry Kevin; Schmidt, Carrie Frances; Peterson, Kenneth Allen; Kravitz, Stanley H.; Renn, Rosemarie A.; Peter, Frank J.; Kinney, Ragon D.; Gilkey, Jeffrey C.

    2004-06-01

    The objective is a significant advancement in the state-of-the-art of accelerometer design for tactical grade (or better) applications. The design goals are <1 milli-G bias stability across environments and $200 cost. This quantum leap in performance improvement and cost reduction can only be achieved by a radical new approach, not incremental improvements to existing concepts. This novel levitated closed-loop accelerometer is implemented as a hybrid micromachine. The hybrid approach frees the designer from the limitations of any given monolithic process and dramatically expands the available design space. The design can be tailored to the dynamic range, resolution, bandwidth, and environmental requirements of the application while still preserving all of the benefits of monolithic MEMS fabrication - extreme precision, small size, low cost, and low power. An accelerometer was designed and prototype hardware was built, driving the successful development and refinement of several 'never been done before' fabrication processes. Many of these process developments are commercially valuable and are key enablers for the realization of a wide variety of useful micro-devices. While controlled levitation of a proof mass has yet to be realized, the overall design concept remains sound. This was clearly demonstrated by the stable and reliable closed-loop control of a proof mass at the test structure level. Furthermore, the hybrid MEMS implementation is the most promising approach for achieving the ambitious cost and performance targets. It is strongly recommended that Sandia remain committed to the original goal.

  4. Aerodynamic levitation : an approach to microgravity.

    SciTech Connect

    Glorieux, B.; Saboungi, M.-L.; Millot, F.; Enderby, J.; Rifflet, J.-C.

    2000-12-05

    Measurements of the thermophysical and structural properties of liquid materials at high temperature have undergone considerable development in the past few years. Following improvements in electromagnetic levitation, aerodynamic levitation associated with laser heating has shown promise for assessing properties of different molten materials (metals, oxides, and semiconductors), preserving sample purity over a wide range of temperatures and under different gas environments. The density, surface tension and viscosity are measured with a high-speed video camera and an image analysis system. Results on nickel and alumina show that small droplets can be considered in the first approximation to be under microgravity conditions. Using a non-invasive contactless technique recently developed to measure electrical conductivity, results have been extended to variety of materials ranging from liquid metals and liquid semiconductors to ionically conducting materials. The advantage of this technique is the feasibility of monitoring changes in transport occurring during phase transitions and in deeply undercooled states.

  5. Cavity cooling a single charged levitated nanosphere.

    PubMed

    Millen, J; Fonseca, P Z G; Mavrogordatos, T; Monteiro, T S; Barker, P F

    2015-03-27

    Optomechanical cavity cooling of levitated objects offers the possibility for laboratory investigation of the macroscopic quantum behavior of systems that are largely decoupled from their environment. However, experimental progress has been hindered by particle loss mechanisms, which have prevented levitation and cavity cooling in a vacuum. We overcome this problem with a new type of hybrid electro-optical trap formed from a Paul trap within a single-mode optical cavity. We demonstrate a factor of 100 cavity cooling of 400 nm diameter silica spheres trapped in vacuum. This paves the way for ground-state cooling in a smaller, higher finesse cavity, as we show that a novel feature of the hybrid trap is that the optomechanical cooling becomes actively driven by the Paul trap, even for singly charged nanospheres. PMID:25860743

  6. Superconducting magnetic levitation train project in Japan

    SciTech Connect

    Oshima, K.

    1981-09-01

    The superconducting magnetic levitated train of Japanese National Railways at Miyazaki achieved its experimental target speed of 500 km/hr by reaching the world record of 517 km/hr in December 1979. The development project of high speed linear motor propulsion train levitated by superconducting magnet, Maglev, was started in 1970 by constructing a new mass-transportation system in the 1980's. The test track in Miyazaki was constructed in 1977 with an inverted T-shape guideway of about 7 km, and vehicles were tested. Now a part of the guideway was changed to a U shape in 1980 and experiments of a new vehicle of a 2 or 3 car make-up with on-board refrigerators and capacity of carrying 2 persons were undertaken. It is expected that these tests will be finalized with a demonstration track of 40 km in the near future. 3 refs.

  7. Levitation forces in bearingless permanent magnet motors

    SciTech Connect

    Amrhein, W.; Silber, S.; Nenninger, K.

    1999-09-01

    Bearingless motors combine brushless AC-motors with active magnetic bearings by the integration of two separate winding systems (torque and radial levitation force windings with different pole pairs) in one housing. This paper gives an insight into the influences of the motor design on the levitation force and torque generation. It is shown that especially for machines with small air gaps it can be very important to choose the right design parameters. Increasing the permanent magnet height in order to increase the motor torque can result in a remarkable reduction of radial forces. The interrelationships are discussed on the basis of Maxwell and Lorentz forces acting upon the stator surface. The investigations are presented for a bearingless low cost motor, suited for pump, fan or blower applications. The presented motor needs only four coils for operation.

  8. Safety of high speed magnetic levitation transportation systems. Comparison of US and foreign safety requirements for application to US maglev systems. Final report, April 1991-August 1993

    SciTech Connect

    Bing, A.J.; Parker, J.D.; Pristach, G.S.; Behara, C.; Gabriel, D.

    1993-09-01

    The use of magnetically levitated (maglev) vehicles for high-speed guided ground transportation has been proposed for passenger operations in the United States. As a result, a need exists for the assessment for the safety implications of this new form of technology to ensure passenger safety. This report contains the results of a detailed review of safety requirements to evaluate their suitability to maglev operations in the U.S. environment.

  9. Electrodynamic force law controversy.

    PubMed

    Graneau, P; Graneau, N

    2001-05-01

    Cavalleri et al. [Phys. Rev. E 52, 2505 (1998); Eur. J. Phys. 17, 205 (1996)] have attempted to resolve the electrodynamic force law controversy. This attempt to prove the validity of either the Ampère or Lorentz force law by theory and experiment has revealed only that the two are equivalent when predicting the force on part of a circuit due to the current in the complete circuit. However, in our analysis of internal stresses, only Ampère's force law agrees with experiment. PMID:11415053

  10. Semi-classical Electrodynamics

    NASA Astrophysics Data System (ADS)

    Lestone, John

    2016-03-01

    Quantum electrodynamics is complex and its associated mathematics can appear overwhelming for those not trained in this field. We describe semi-classical approaches that can be used to obtain a more intuitive physical feel for several QED processes including electro-statics, Compton scattering, pair annihilation, the anomalous magnetic moment, and the Lamb shift, that could be taught easily to undergraduate students. Any physicist who brings their laptop to the talk will be able to build spread sheets in less than 10 minutes to calculate g/2 =1.001160 and a Lamb shift of 1057 MHz.

  11. Analysis and experimental study on the effect of a resonant tube on the performance of acoustic levitation devices

    NASA Astrophysics Data System (ADS)

    Jiang, Hai; Liu, Jianfang; Lv, Qingqing; Gu, Shoudong; Jiao, Xiaoyang; Li, Minjiao; Zhang, Shasha

    2016-09-01

    The influence of a resonant tube on the performance of acoustic standing wave-based levitation device (acoustic levitation device hereinafter) is studied by analyzing the acoustic pressure and levitation force of four types of acoustic levitation devices without a resonance tube and with resonance tubes of different radii R using ANSYS and MATLAB. Introducing a resonance tube either enhances or weakens the levitation strength of acoustic levitation device, depending on the resonance tube radii. Specifically, the levitation force is improved to a maximum degree when the resonance tube radius is slightly larger than the size of the reflector end face. Furthermore, the stability of acoustic levitation device is improved to a maximum degree by introducing a resonance tube of R=1.023λ. The experimental platform and levitation force measurement system of the acoustic levitation device with concave-end-face-type emitter and reflector are developed, and the test of suspended matters and liquid drops is conducted. Results show that the Φ6.5-mm steel ball is suspended easily when the resonance tube radius is 1.023λ, and the Φ5.5-mm steel ball cannot be suspended when the resonance tube radius is 1.251λ. The levitation capability of the original acoustic levitation device without a resonance tube is weakened when a resonance tube of R=1.251λ is applied. These results are consistent with the ANSYS simulation results. The levitation time of the liquid droplet with a resonance tube of R=1.023λ is longer than without a resonance tube. This result is also supported by the MATLAB simulation results. Therefore, the performance of acoustic levitation device can be improved by introducing a resonant tube with an appropriate radius.

  12. Microwave Dielectrophoretic Levitation In Microgravity

    NASA Technical Reports Server (NTRS)

    Watkins, John L.; Jackson, Henry W.; Barmatz, Martin B.

    1993-01-01

    Two reports propose use of dielectrophoresis in microwave resonant cavities to levitate samples of materials for containerless processing in microgravity in vacuum or in any suitable atmosphere. Also describe experiments undertaken to verify feasibility of proposal.

  13. Acoustic Levitation With Less Equipment

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Jacobi, N.

    1983-01-01

    Certain chamber shapes require fewer than three acoustic drivers. Levitation at center of spherical chamber attained using only one acoustic driver. Exitation of lowest spherical mode produces asymmetric acoustic potential well.

  14. Vertical Magnetic Levitation Force Measurement on Single Crystal YBaCuO Bulk at Different Temperatures

    NASA Astrophysics Data System (ADS)

    Celik, Sukru; Guner, Sait Baris; Ozturk, Kemal; Ozturk, Ozgur

    Magnetic levitation force measurements of HTS samples are performed with the use of liquid nitrogen. It is both convenient and cheap. However, the temperature of the sample cannot be changed (77 K) and there is problem of frost. So, it is necessary to build another type of system to measure the levitation force high Tc superconductor at different temperatures. In this study, we fabricated YBaCuO superconducting by top-seeding-melting-growth (TSMG) technique and measured vertical forces of them at FC (Field Cooling) and ZFC (Zero Field Cooling) regimes by using our new designed magnetic levitation force measurement system. It was used to investigate the three-dimensional levitation force and lateral force in the levitation system consisting of a cylindrical magnet and a permanent cylindrical superconductor at different temperatures (37, 47, 57, 67 and 77 K).

  15. Thermodynamic Studies of Levitated Microdroplets of Highly Supersaturated Electrolyte Solutions

    NASA Technical Reports Server (NTRS)

    Myerson, Allan S.; Izmailov, Alexander F.; Na, Han-Soo

    1996-01-01

    Highly supersaturated electrolyte solutions are studied by employing an electrodynamic levitator trap (ELT) technique. The ELT technique involves containerless suspension of a microdroplet thus eliminating dust, dirt, and container walls which normally cause heterogeneous nucleation. This allows very high supersaturations to be achieved. A theoretical study of the experimental results obtained for the water activity in microdroplets of various electrolyte solutions is based on the development of the Cahn-Hilliard formalism for electrolyte solutions. A correspondence of 96-99% between the theory and experiment for the all solutions studied was achieved and allowed the determination of an analytical expression for the spinodal concentration n(sub spin) and its calculation for various electrolyte solutions at 298 K.

  16. Modeling and analysis of a levitated droplet using lumped masses

    NASA Astrophysics Data System (ADS)

    Dupac, Mihai

    In the past twenty years important progresses in the theory and applications of electromagnetic levitation (ELM), now a well-established technique in metallurgy, has been achieved. This technique consists of placing a conductive sample in a time-varying magnetic field produced by a coil carrying a high frequency electric current. The electric current induces eddy currents in the sample. As a result of the interaction between the induced currents and the external magnetic field, a Lorentz force is produced and eddy currents heat or eventually melt the specimen by Joule effect, effects that are, in fact, the main purpose of ELM. If the applied current is strong enough, the electromagnetic forces can counterbalance the gravitational force to levitate the sample. The great advantage of EML process is that levitation creates a containerless environment and prevents against the contamination of the sample with any impurities from the container walls when the metal is processed by using the "traditional" melting method. The main problem that was faced during the ELM melting experiments performed at Space Power Institute at Auburn University was maintaining the stability of the levitated droplet. This dissertation proposes a lumped masses approach to study the stability problem. This lumped mass approach offers advantages for system control applications when compared to complex fluid mechanics models. Two-dimensional, three-dimensional and particles interactions models were proposed and implemented. A nonlinear dynamics approach was applied to decide from simulated data what type of time evolution is performed by the melted droplet. Lyapunov theory was considered to address the stability of levitated specimens. The equation of vertical motion and the surface oscillations of the levitated samples were studied. An advanced particle model was also proposed to study the vibrations of the levitated droplet.

  17. Magnetic levitation and MHD propulsion

    NASA Astrophysics Data System (ADS)

    Tixador, P.

    1994-04-01

    Magnetic levitation and MHD propulsion are now attracting attention in several countries. Different superconducting MagLev and MHD systems will be described concentrating on, above all, the electromagnetic aspect. Some programmes occurring throughout the world will be described. Magnetic levitated trains could be the new high speed transportation system for the 21st century. Intensive studies involving MagLev trains using superconductivity have been carried out in Japan since 1970. The construction of a 43 km long track is to be the next step. In 1991 a six year programme was launched in the United States to evaluate the performances of MagLev systems for transportation. The MHD (MagnetoHydroDynamic) offers some interesting advantages (efficiency, stealth characteristics, ...) for naval propulsion and increasing attention is being paid towards it nowadays. Japan is also up at the top with the tests of Yamato I, a 260 ton MHD propulsed ship. Depuis quelques années nous assistons à un redémarrage de programmes concernant la lévitation et la propulsion supraconductrices. Différents systèmes supraconducteurs de lévitation et de propulsion seront décrits en examinant plus particulièrement l'aspect électromagnétique. Quelques programmes à travers le monde seront abordés. Les trains à sustentation magnétique pourraient constituer un nouveau mode de transport terrestre à vitesse élevée (500 km/h) pour le 21^e siècle. Les japonais n'ont cessé de s'intéresser à ce système avec bobine supraconductrice. Ils envisagent un stade préindustriel avec la construction d'une ligne de 43 km. En 1991 un programme américain pour une durée de six ans a été lancé pour évaluer les performances des systèmes à lévitation pour le transport aux Etats Unis. La MHD (Magnéto- Hydro-Dynamique) présente des avantages intéressants pour la propulsion navale et un regain d'intérêt apparaît à l'heure actuelle. Le japon se situe là encore à la pointe des d

  18. Diamagnetically-stabilized levitation control of an intraluminal magnetic capsule.

    PubMed

    Lam, Michael; Mintchev, Martin P

    2008-01-01

    Controlled navigation promotes full utilization of capsule endoscopy for reliable real-time diagnosis in the gastrointestinal (GI) tract, but intermittent natural peristalsis can disturb the navigational control, destabilize the capsule and take it out of levitation. A real-size magnetic navigation system that can handle peristaltic forces of up to 1.5 N was designed utilizing the computer-aided design (CAD) system Maxwell 3D (Ansoft, Pittsburg, PA), and was verified using a small-size physical experimental setup. The proposed system contains a pair of 50-cm in diameter, 10,000-turns copper electromagnets with a 10-cm by 10-cm ferrous core driven by currents of up to 300 Amperes and can successfully maintain position control over the levitating capsule during peristalsis. The addition of Bismuth diamagnetic casing for stabilizing the levitating capsule was also studied. PMID:19163990

  19. Magnetic levitation technology and transportation strategies

    SciTech Connect

    Not Available

    1990-01-01

    This book contains the following topics: Benefits of magnetically levitated high speed transportation for the United States. Monorail MagLev, HSST magnetic levitation trains, past, present and future, a national vision for MagLev transit in America.

  20. Middle atmospheric electrodynamics

    NASA Technical Reports Server (NTRS)

    Kelley, M. C.

    1983-01-01

    A review is presented of the advances made during the last few years with respect to the study of the electrodynamics in the earth's middle atmosphere. In a report of the experimental work conducted, attention is given to large middle atmospheric electric fields, the downward coupling of high altitude processes into the middle atmosphere, and upward coupling of tropospheric processes into the middle atmosphere. It is pointed out that new developments in tethered balloons and superpressure balloons should greatly increase the measurement duration of earth-ionospheric potential measurements and of stratospheric electric field measurements in the next few years. Theoretical work considered provides an excellent starting point for study of upward coupling of transient and dc electric fields. Hays and Roble (1979) were the first to construct a model which included orographic features as well as the classical thunderstorm generator.

  1. Mesoscopic cavity quantum electrodynamics with quantum dots

    SciTech Connect

    Childress, L.; Soerensen, A.S.; Lukin, M.D.

    2004-04-01

    We describe an electrodynamic mechanism for coherent, quantum-mechanical coupling between spatially separated quantum dots on a microchip. The technique is based on capacitive interactions between the electron charge and a superconducting transmission line resonator, and is closely related to atomic cavity quantum electrodynamics. We investigate several potential applications of this technique which have varying degrees of complexity. In particular, we demonstrate that this mechanism allows design and investigation of an on-chip double-dot microscopic maser. Moreover, the interaction may be extended to couple spatially separated electron-spin states while only virtually populating fast-decaying superpositions of charge states. This represents an effective, controllable long-range interaction, which may facilitate implementation of quantum information processing with electron-spin qubits and potentially allow coupling to other quantum systems such as atomic or superconducting qubits.

  2. Radiative corrections in symmetrized classical electrodynamics

    PubMed

    Van Meter JR; Kerman; Chen; Hartemann

    2000-12-01

    The physics of radiation reaction for a point charge is discussed within the context of classical electrodynamics. The fundamental equations of classical electrodynamics are first symmetrized to include magnetic charges: a double four-potential formalism is introduced, in terms of which the field tensor and its dual are employed to symmetrize Maxwell's equations and the Lorentz force equation in covariant form. Within this framework, the symmetrized Dirac-Lorentz equation is derived, including radiation reaction (self-force) for a particle possessing both electric and magnetic charge. The connection with electromagnetic duality is outlined, and an in-depth discussion of nonlocal four-momentum conservation for the wave-particle system is given.

  3. Electrodynamics of planar Archimedean spiral resonator

    NASA Astrophysics Data System (ADS)

    Maleeva, N.; Averkin, A.; Abramov, N. N.; Fistul, M. V.; Karpov, A.; Zhuravel, A. P.; Ustinov, A. V.

    2015-07-01

    We present a theoretical and experimental study of electrodynamics of a planar spiral superconducting resonator of a finite length. The resonator is made in the form of a monofilar Archimedean spiral. By making use of a general model of inhomogeneous alternating current flowing along the resonator and specific boundary conditions on the surface of the strip, we obtain analytically the frequencies fn of resonances which can be excited in such system. We also calculate corresponding inhomogeneous RF current distributions ψ n ( r ) , where r is the coordinate across a spiral. We show that the resonant frequencies and current distributions are well described by simple relationships f n = f 1 n and ψ n ( r ) ≃ sin [ π n ( r / R e ) 2 ] , where n = 1 , 2... and Re is the external radius of the spiral. Our analysis of electrodynamic properties of spiral resonators' is in good agreement with direct numerical simulations and measurements made using specifically designed magnetic probe and laser scanning microscope.

  4. Pulsar electrodynamics: an unsolved problem

    NASA Astrophysics Data System (ADS)

    Melrose, D. B.; Yuen, R.

    2016-04-01

    > Pulsar electrodynamics is reviewed emphasizing the role of the inductive electric field in an oblique rotator and the incomplete screening of its parallel component by charges, leaving `gaps' with \\Vert \

  5. Timelike Momenta In Quantum Electrodynamics

    DOE R&D Accomplishments Database

    Brodsky, S. J.; Ting, S. C. C.

    1965-12-01

    In this note we discuss the possibility of studying the quantum electrodynamics of timelike photon propagators in muon or electron pair production by incident high energy muon or electron beams from presently available proton or electron accelerators.

  6. Experimental determination of the dynamics of an acoustically levitated sphere

    NASA Astrophysics Data System (ADS)

    Pérez, Nicolás; Andrade, Marco A. B.; Canetti, Rafael; Adamowski, Julio C.

    2014-11-01

    Levitation of solids and liquids by ultrasonic standing waves is a promising technique to manipulate materials without contact. When a small particle is introduced in certain areas of a standing wave field, the acoustic radiation force pushes the particle to the pressure node. This movement is followed by oscillations of the levitated particle. Aiming to investigate the particle oscillations in acoustic levitation, this paper presents the experimental and numerical characterization of the dynamic behavior of a levitated sphere. To obtain the experimental response, a small sphere is lifted by the acoustic radiation force. After the sphere lift, it presents a damped oscillatory behavior, which is recorded by a high speed camera. To model this behavior, a mass-spring-damper system is proposed. In this model, the acoustic radiation force that acts on the sphere is theoretically predicted by the Gor'kov theory and the viscous forces are modeled by two damping terms, one term proportional to the square of the velocity and another term proportional to the particle velocity. The proposed model was experimentally verified by using different values of sound pressure amplitude. The comparison between numerical and experimental results shows that the model can accurately describe the oscillatory behavior of the sphere in an acoustic levitator.

  7. Nanomagnetic Levitation 3-D Cultures of Breast and Colorectal Cancers

    PubMed Central

    Bumpers, Harvey L.; Janagama, Dasharatham G.; Manne, Upender; Basson, Marc D.; Katkoori, Venkat

    2014-01-01

    Background Innovative technologies for drug discovery and development, cancer models, stem cell research, tissue engineering, and drug testing in various cell-based platforms require an application similar to the in vivo system. Materials and Methods We developed for the first time nanomagnetically levitated three dimensional (3-D) cultures of breast cancer (BC) and colorectal cancer (CRC) cells using carbon encapsulated cobalt magnetic nanoparticles. BC and CRC xenografts grown in severe combined immunodeficient (SCID) mice were evaluated for N-cadherin and Epidermal growth factor receptor (EGFR) expressions. These phenotypes were compared with 2-D cultures and 3-D cultures grown in a gel matrix. Results The BC and CRC cells grown by magnetic levitation formed microtissues. The levitated cultures had high viability and were maintained in culture for long periods of time. It has been observed that N-cadherin and EGFR activities were highly expressed in the levitated 3-D tumor spheres and xenografts of CRC and BC cells. Conclusions Nanomagnetically levitated 3-D cultures tend to form stable microtissues of BC and CRC and may be more feasible for a range of applications in drug discovery or regenerative medicine. PMID:25617973

  8. Experimental determination of the dynamics of an acoustically levitated sphere

    SciTech Connect

    Pérez, Nicolás; Andrade, Marco A. B.; Canetti, Rafael; Adamowski, Julio C.

    2014-11-14

    Levitation of solids and liquids by ultrasonic standing waves is a promising technique to manipulate materials without contact. When a small particle is introduced in certain areas of a standing wave field, the acoustic radiation force pushes the particle to the pressure node. This movement is followed by oscillations of the levitated particle. Aiming to investigate the particle oscillations in acoustic levitation, this paper presents the experimental and numerical characterization of the dynamic behavior of a levitated sphere. To obtain the experimental response, a small sphere is lifted by the acoustic radiation force. After the sphere lift, it presents a damped oscillatory behavior, which is recorded by a high speed camera. To model this behavior, a mass-spring-damper system is proposed. In this model, the acoustic radiation force that acts on the sphere is theoretically predicted by the Gor'kov theory and the viscous forces are modeled by two damping terms, one term proportional to the square of the velocity and another term proportional to the particle velocity. The proposed model was experimentally verified by using different values of sound pressure amplitude. The comparison between numerical and experimental results shows that the model can accurately describe the oscillatory behavior of the sphere in an acoustic levitator.

  9. Electrodynamic Arrays Having Nanomaterial Electrodes

    NASA Technical Reports Server (NTRS)

    Trigwell, Steven (Inventor); Biris, Alexandru S. (Inventor); Calle, Carlos I. (Inventor)

    2013-01-01

    An electrodynamic array of conductive nanomaterial electrodes and a method of making such an electrodynamic array. In one embodiment, a liquid solution containing nanomaterials is deposited as an array of conductive electrodes on a substrate, including rigid or flexible substrates such as fabrics, and opaque or transparent substrates. The nanomaterial electrodes may also be grown in situ. The nanomaterials may include carbon nanomaterials, other organic or inorganic nanomaterials or mixtures.

  10. Observation of the Field, Current and Force Distributions in an Optimized Superconducting Levitation with Translational Symmetry

    NASA Astrophysics Data System (ADS)

    Ye, Chang-Qing; Ma, Guang-Tong; Liu, Kun; Wang, Jia-Su

    2016-08-01

    The superconducting levitation realized by immersing the high-temperature superconductors (HTSs) into nonuniform magnetic field is deemed promising in a wide range of industrial applications such as maglev transportation and kinetic energy storage. Using a well-established electromagnetic model to mathematically describe the HTS, we have developed an efficient scheme that is capable of intelligently and globally optimizing the permanent magnet guideway (PMG) with single or multiple HTSs levitated above for the maglev transportation applications. With maximizing the levitation force as the principal objective, we optimized the dimensions of a Halbach-derived PMG to observe how the field, current and force distribute inside the HTSs when the optimized situation is achieved. Using a pristine PMG as a reference, we have analyzed the critical issues for enhancing the levitation force through comparing the field, current and force distributions between the optimized and pristine PMGs. It was also found that the optimized dimensions of the PMG are highly dependent upon the levitated HTS. Moreover, the guidance force is not always contradictory to the levitation force and may also be enhanced when the levitation force is prescribed to be the principle objective, depending on the configuration of levitation system and lateral displacement.

  11. An electrostatic levitator for high-temperature containerless materials processing in 1-g

    NASA Astrophysics Data System (ADS)

    Rhim, Won-Kyu; Chung, Sang K.; Barber, Daniel; Man, Kin F.; Gutt, Gary; Rulison, Aaron; Spjut, R. Erik

    1993-10-01

    This article discusses recent developments in high-temperature electrostatic levitation technology for containerless processing of metals and alloys. Presented is the first demonstration of an electrostatic levitation technology which can levitate metals and alloys (2-4 mm diam spheres) in vacuum and of superheating-undercooling-recalescence cycles which can be repeated while maintaining good positioning stability. The electrostatic levitator (ESL) has several important advantages over the electromagnetic levitator. Most important is the wide range of sample temperature which can be achieved without affecting levitation. This article also describes the general architecture of the levitator, electrode design, position control hardware and software, sample heating, charging, and preparation methods, and operational procedures. Particular emphasis is given to sample charging by photoelectric and thermionic emission. While this ESL is more oriented toward ground-based operation, an extension to microgravity applications is also addressed briefly. The system performance was demonstrated by showing multiple superheating-undercooling-recalescence cycles in a zirconium sample (Tm=2128 K). This levitator, when fully matured, will be a valuable tool both in Earth-based and space-based laboratories for the study of thermophysical properties of undercooled liquids, nucleation kinetics, the creation of metastable phases, and access to a wide range of materials with novel properties.

  12. Controlling charge on levitating drops.

    PubMed

    Hilger, Ryan T; Westphall, Michael S; Smith, Lloyd M

    2007-08-01

    Levitation technologies are used in containerless processing of materials, as microscale manipulators and reactors, and in the study of single drops and particles. Presented here is a method for controlling the amount and polarity of charge on a levitating drop. The method uses single-axis acoustic levitation to trap and levitate a single, initially neutral drop with a diameter between 400 microm and 2 mm. This drop is then charged in a controllable manner using discrete packets of charge in the form of charged drops produced by a piezoelectric drop-on-demand dispenser equipped with a charging electrode. The magnitude of the charge on the dispensed drops can be adjusted by varying the voltage applied to the charging electrode. The polarity of the charge on the added drops can be changed allowing removal of charge from the trapped drop (by neutralization) and polarity reversal. The maximum amount of added charge is limited by repulsion of like charges between the drops in the trap. This charging scheme can aid in micromanipulation and the study of charged drops and particles using levitation. PMID:17580951

  13. Modeling and experimental study on near-field acoustic levitation by flexural mode.

    PubMed

    Liu, Pinkuan; Li, Jin; Ding, Han; Cao, Wenwu

    2009-12-01

    Near-field acoustic levitation (NFAL) has been used in noncontact handling and transportation of small objects to avoid contamination. We have performed a theoretical analysis based on nonuniform vibrating surface to quantify the levitation force produced by the air film and also conducted experimental tests to verify our model. Modal analysis was performed using ANSYS on the flexural plate radiator to obtain its natural frequency of desired mode, which is used to design the measurement system. Then, the levitation force was calculated as a function of levitation distance based on squeeze gas film theory using measured amplitude and phase distributions on the vibrator surface. Compared with previous fluid-structural analyses using a uniform piston motion, our model based on the nonuniform radiating surface of the vibrator is more realistic and fits better with experimentally measured levitation force. PMID:20040404

  14. The ElectroDynamic Delivery Experiment (EDDE)

    NASA Astrophysics Data System (ADS)

    Pearson, Jerome; Levin, Eugene; Oldson, John; Carroll, Joseph

    2001-02-01

    The ElectroDynamic Delivery Experiment (EDDE) is proposed for a space demonstration. EDDE consists of an autonomous space vehicle powered by lightweight solar arrays, a bi-directional electrodynamic tether, and batteries for power leveling. The EDDE vehicle can modify its orbit repeatedly without rocket fuel, and can change all six orbital parameters by modulating and reversing the current flow in the conducting tether. The base spacecraft is connected to the service module by a 6-km-long electrodynamic tether, and is designed for 2 kW of power and a total mass of 180 kg. Tether lifetime of several years is achieved with a two-strand caduceus, with the strands connected every few meters. Tether libration is minimized by mass distribution and by active current control. The vehicle and tether system concepts are developed, the operational envelopes are examined, and potential applications are evaluated. The EDDE vehicle is about twice as fast as ion rockets for high-inclination orbital plane changes, and has much higher maximum delta-V capability. A proof-of-concept experiment is proposed for a low-cost space demonstration. This on-orbit experiment could include additional secondary payloads; for example, EDDE could place low-ΔV, free-flying inspectors into arbitrary orbits from which they could approach selected objects without concern for tether dynamics or interference. .

  15. Large gap magnetic suspension system

    NASA Technical Reports Server (NTRS)

    Abdelsalam, Moustafa K.; Eyssa, Y. M.

    1991-01-01

    The design of a large gap magnetic suspension system is discussed. Some of the topics covered include: the system configuration, permanent magnet material, levitation magnet system, superconducting magnets, resistive magnets, superconducting levitation coils, resistive levitation coils, levitation magnet system, and the nitrogen cooled magnet system.

  16. Effect of permanent-magnet irregularities in levitation force measurements.

    SciTech Connect

    Hull, J. R.

    1999-10-14

    In the measurement of the levitation force between a vertically magnetized permanent magnet (PM) and a bulk high-temperature superconductor (HTS), PM domains with horizontal components of magnetization are shown to produce a nonnegligible contribution to the levitation force in most systems. Such domains are typically found in all PMs, even in those that exhibit zero net horizontal magnetic moment. Extension of this analysis leads to an HTS analog of Earnshaw's theorem, in which at the field-cooling position the vertical stiffness is equal to the sum of the horizontal stiffnesses, independent of angular distribution of magnetic moments within the PM.

  17. Optical sample-position sensing for electrostatic levitation

    NASA Technical Reports Server (NTRS)

    Sridharan, G.; Chung, S.; Elleman, D.; Whim, W. K.

    1989-01-01

    A comparative study is conducted for optical position-sensing techniques applicable to micro-G conditions sample-levitation systems. CCD sensors are compared with one- and two-dimensional position detectors used in electrostatic particle levitation. In principle, the CCD camera method can be improved from current resolution levels of 200 microns through the incorporation of a higher-pixel device and more complex digital signal processor interface. Nevertheless, the one-dimensional position detectors exhibited superior, better-than-one-micron resolution.

  18. Containerless processing using electromagnetic levitation

    NASA Technical Reports Server (NTRS)

    Gokhale, A. B.; Abbaschian, R.

    1990-01-01

    The theory and practice of containerless processing via electromagnetic (EM) levitation is reviewed briefly. The use of EM levitation for the processing of alloys is described with particular emphasis on the bulk melt supercooling phenomenon in a containerless environment. The various effects associated with rapid solidification via bulk melt supercooling are discussed with examples of Nb-Si alloys. It is suggested that a detailed analysis of such effects can be utilized to select the potentially most promising alloys for future space-based processing.

  19. Design and implementation of an efficient acoustically levitated drop reactor for in stillo measurements.

    PubMed

    Field, Christopher R; Scheeline, Alexander

    2007-12-01

    We present the details necessary for building an efficient acoustic drop levitator with reduced electrical power consumption and greater drop stability compared to previous designs. The system is optimized so that the levitated drop may be used as a chemical reactor. By introducing a temperature, pressure, and relative humidity sensor for feedback control of a linear actuator for adjusting resonator length, we have built a completely automated system capable of continuous levitation for extended periods of time. The result is a system capable of portable operation and interfacing with a variety of detection instrumentation for in stillo (in drop) measurements. PMID:18163744

  20. Diamagnetically stabilized levitation control of an intraluminal magnetic capsule.

    PubMed

    Lam, Michael; Mintchev, Martin

    2009-08-01

    Controlled navigation promotes full utilization of capsule endoscopy for reliable real-time diagnosis in the gastrointestinal (GI) tract, but intermittent natural peristalsis can disturb the navigational control, destabilize the capsule and take it out of levitation. The focus of the present work was to develop an economical and effective real-time magnetic capsule-guiding system that can operate in the presence of naturally existing peristalsis while retaining navigational control. A real-size magnetic navigation system that can handle peristaltic forces of up to 1.5 N was designed utilizing the computer-aided design (CAD) system Maxwell 3D (Ansoft, Pittsburg, PA) and was verified using a small-size physical experimental setup. The proposed system contains a pair of 50 cm diameter, 10,000-turn copper electromagnets with a 10 cm x 10 cm ferrous core driven by currents of up to 300 A and can successfully maintain position control over the levitating capsule during peristalsis. The addition of bismuth diamagnetic casing for stabilizing the levitating capsule was also studied. A modeled magnetic field around the diamagnetically cased permanent magnet was shown to be redistributed aligning its interaction with the external electromagnets, thus stabilizing the levitating capsule. In summary, a custom-designed diamagnetically facilitated capsule navigation system can successfully steer an intraluminal magnet-carrying capsule. PMID:19550023

  1. Electrodynamics of superconducting pnictide superlattices

    SciTech Connect

    Perucchi, A.; Pietro, P. Di; Capitani, F.; Lupi, S.; Lee, S.; Kang, J. H.; Eom, C. B.; Jiang, J.; Weiss, J. D.; Hellstrom, E. E.; Dore, P.

    2014-06-02

    It was recently shown that superlattices where layers of the 8% Co-doped BaFe{sub 2}As{sub 2} superconducting pnictide are intercalated with non superconducting ultrathin layers of either SrTiO{sub 3} or of oxygen-rich BaFe{sub 2}As{sub 2}, can be used to control flux pinning, thereby increasing critical fields and currents, without significantly affecting the critical temperature of the pristine superconducting material. However, little is known about the electron properties of these systems. Here, we investigate the electrodynamics of these superconducting pnictide superlattices in the normal and superconducting state by using infrared reflectivity, from THz to visible range. We find that multigap structure of these superlattices is preserved, whereas some significant changes are observed in their electronic structure with respect to those of the original pnictide. Our results suggest that possible attempts to further increase the flux pinning may lead to a breakdown of the pnictide superconducting properties.

  2. Vibrational Properties of High- Superconductors Levitated Above a Bipolar Permanent Magnetic Guideway

    NASA Astrophysics Data System (ADS)

    Liu, Lu; Wang, Jiasu

    2014-05-01

    A bipolar permanent magnetic guideway (PMG) has a unique magnetic field distribution profile which may introduce a better levitation performance and stability to the high- superconducting (HTS) maglev system. The dynamic vibration properties of multiple YBCO bulks arranged into different arrays positioned above a bipolar PMG and free to levitate were investigated. The acceleration and resonance frequencies were experimentally measured, and the stiffness and damping coefficients were evaluated for dynamic stability. Results indicate that the levitation stiffness is closely related to the field-cooling-height and sample positioning. The damping ratio was found to be low and nonlinear for the Halbach bipolar HTS-PMG system.

  3. Digital Controller For Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Tarver, D. Kent

    1989-01-01

    Acoustic driver digitally controls sound fields along three axes. Allows computerized acoustic levitation and manipulation of small objects for such purposes as containerless processing and nuclear-fusion power experiments. Also used for controlling motion of vibration-testing tables in three dimensions.

  4. Magnetic levitation of condensed hydrogen

    NASA Technical Reports Server (NTRS)

    Paine, C. G.; Seidel, G. M.

    1991-01-01

    Liquid and solid molecular hydrogen has been levitated using a pair of small superconducting solenoids. The hydrogen samples, up to 3 mm in dimension, were trapped in a magnetic potential having either a discrete minimum or a minimum in the form of a ring 1 cm in diameter. The hydrogen could be moved about in the magnetic trap by applying an electric field.

  5. Microwave Levitation Of Small Objects

    NASA Technical Reports Server (NTRS)

    Watkins, John L.; Jackson, Henry W.

    1991-01-01

    Microwave radiation in resonant cavities used to levitate small objects, according to proposal. Feedback control and atmosphere not needed. Technique conceived for use in experiments on processing of materials in low gravitation of outer space, also used in normal Earth gravitation, albeit under some limitations.

  6. Levitation of liquid sodium droplets

    SciTech Connect

    Roy, S.S.; Cramb, A.W.; Hoburg, J.F.; Lally, B.

    1995-12-01

    Droplets of liquid sodium ranging from 1.2 to 2.1 g, immersed in mineral oil, were levitated in an electromagnetic field. The experimental setup was designed and constructed to levitate small metal droplets at audio frequencies. The levitated droplet was found to be very stable inside the inductor, and the equilibrium shape attained by the droplet in the electromagnetic field was measured during the experiment. A surface coupled mathematical model was used to calculate the self-consistent equilibrium droplet shape of liquid sodium under the influence of an electromagnetic field. The predicted shapes of the metal droplet and the position of the droplet inside the inductor compare well with the experimental data. The idea of casting metals and alloys without any physical contact has generated a lot of interest in the metals industry, especially in the production of metals/alloys that are highly reactive and have a very high melting point. Containerless casting can be achieved by levitating or pushing the liquid metal from the surface of the container.

  7. International Space Station Electrodynamic Tether Reboost Study

    NASA Technical Reports Server (NTRS)

    Johnson, L.; Herrmann, M.

    1998-01-01

    The International Space Station (ISS) will require periodic reboost due to atmospheric aerodynamic drag. This is nominally achieved through the use of thruster firings by the attached Progress M spacecraft. Many Progress flights to the ISS are required annually. Electrodynamic tethers provide an attractive alternative in that they can provide periodic reboost or continuous drag cancellation using no consumables, propellant, nor conventional propulsion elements. The system could also serve as an emergency backup reboost system used only in the event resupply and reboost are delayed for some reason.

  8. About the Influence of the Magnetic Field Configuration on the Levitation Characteristics of the System Superconductor - Array of Magnets

    NASA Astrophysics Data System (ADS)

    Ermolaev, Yu. S.; Rudnev, I. A.

    2014-07-01

    Interaction of a superconductor with an array of magnets having different orientations of the magnetization vector is theoretically investigated. Based on a critical state model, the interaction force arising in the system superconductor - array of magnets is calculated by the method of finite elements. Optimal configurations of the magnetic system are established in which maximum values of both attractive and repulsive forces are created.

  9. Time-dependent Kohn-Sham approach to quantum electrodynamics

    SciTech Connect

    Ruggenthaler, M.; Mackenroth, F.; Bauer, D.

    2011-10-15

    We prove a generalization of the van Leeuwen theorem toward quantum electrodynamics, providing the formal foundations of a time-dependent Kohn-Sham construction for coupled quantized matter and electromagnetic fields. We circumvent the symmetry-causality problems associated with the action-functional approach to Kohn-Sham systems. We show that the effective external four-potential and four-current of the Kohn-Sham system are uniquely defined and that the effective four-current takes a very simple form. Further we rederive the Runge-Gross theorem for quantum electrodynamics.

  10. On the horizontal wobbling of an object levitated by near-field acoustic levitation.

    PubMed

    Kim, Cheol-Ho; Ih, Jeong-Guon

    2007-11-01

    A circular planar object can be levitated with several hundreds of microns by ultrasonic near-field acoustic levitation (NFAL). However, when both the sound source and the levitated object are circularly shaped and the center of the levitated object does not coincide with the source center, instability problem often occurs. When this happens, it becomes difficult to pick up or transport the object for the next process. In this study, when the center of the levitated object was offset from the source center, the moving direction of the levitated object was predicted by using the time averaged potential around the levitated object. The wobbling frequency of the levitated object was calculated by analyzing the nonlinear wobbling motion of the object. It was shown that the predicted wobbling frequencies agreed with measured ones well. Finally, a safe zone was suggested to avoid the unstable movement of an object. PMID:17590402

  11. Quantum electrodynamics effects on NMR magnetic shielding constants of He-like and Be-like atomic systems

    NASA Astrophysics Data System (ADS)

    Gimenez, Carlos A.; Kozioł, Karol; Aucar, Gustavo A.

    2016-03-01

    NMR shielding constants for He- and Be-like atomic systems of Ne, Ar, Kr, Xe, and Rn have been calculated at the random-phase-approximation level of approach, including an estimation of QED corrections within the polarization propagator formalism. We show that QED effects enhance electron correlation when Z becomes heavier, which happens with relativistic effects, and also that QED effects become smaller when going from more to less ionized systems. We studied two- and four-electron systems. Then such studies could easily be generalized to other many-electron systems. Results of calculations with our relatively simple model, which includes QED and electron correlation effects on the same theoretical grounds, have a summarized error in the range from 10% (for Ne) up to 24% (for Rn), so that our accuracy is a little lower than for calculations on H-like systems. Our findings should stimulate the development and/or the application of more rigorous formalisms to get more accurate QED corrections to response properties in many-electron systems.

  12. Space Station Reboost with Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Vas, Irwin E.; Kelly, Thomas J.; Scarl, Ethan A.

    1999-01-01

    This paper presents the results of a study of an electrodynamic tether system to reboost the International Space Station (ISS). One recommendation is to use a partially bare tether for electron collection. Locations are suggested as to where the tether system is to be attached at the space station. The effects of the tether system on the microgravity environment may actually be beneficial, because the system can neutralize aerodrag during quiescent periods and, if deployed from a movable boom, can permit optimization of laboratory positioning with respect to acceleration contours. Alternative approaches to tether deployment and retrieval are discussed. It is shown that a relatively short tether system, 7 km long, operating at a power level of 5 kW could provide cumulative savings or over a billion dollars during a 10-year period ending in 2012. This savings is the direct result of a reduction in the number or nights that would otherwise be required to deliver propellant for reboost, with larger cost savings for higher tether usage. In addition to economic considerations, an electrodynamic tether promises a practical backup system that could ensure ISS survival in the event of an (otherwise) catastrophic delay in propellant delivery.

  13. The Electrostatic Levitation Facility at NASA's Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Rogers, Jan R.; Hyers, Robert W.; Savage, Larry; Robinson, Michael B.; Rathz, Thomas J.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Containerless processing is an important area of research in materials science. Electrostatic levitation (ESL) represents an emerging technology which permits containerless processing in a vacuum environment. NASA's Marshall Space Flight Center (MSFC) established a levitation facility to provide a critical resource to the microgravity materials science research community to continue and enhance ground-based research in the support of the development of flight experiments during the transition to Space Station. During ESL processing, charged specimens are levitated in the electrostatic field produced by the system's electrodes. Three sets of positioning electrodes represent the heart of the MSFC system. Two dual-axis position sensitive detectors provide input for the PID control-loop computer. Sample position is maintained by adjusting the control voltages for the power supplies of the positioning electrodes. A UV source refreshes the charge on specimens during processing via the photoelectric effect. Lasers permit sample heating independent of positioning. The processing chamber typically operates under vacuum condition approximately = 10(exp -7) Torr. Electrostatic levitation provides a materials science research tool for investigations of refractory solids and melts. Topics of investigation include thermophysical properties, phase equilibria, metastable phase formation, undercooling and nucleation, time-temperature-transformation diagrams and other aspects of materials processing. Current capabilities and recent results of processing studies for metals, alloys and oxides will be reviewed.

  14. Magnetic levitation using high temperature superconducting pancake coils as composite bulk cylinders

    NASA Astrophysics Data System (ADS)

    Patel, A.; Hopkins, S. C.; Baskys, A.; Kalitka, V.; Molodyk, A.; Glowacki, B. A.

    2015-11-01

    Stacks of superconducting tape can be used as composite bulk superconductors for both trapped field magnets and for magnetic levitation. Little previous work has been done on quantifying the levitation force behavior between stacks of tape and permanent magnets. This paper reports the axial levitation force properties of superconducting tape wound into pancake coils to act as a composite bulk cylinder, showing that similar stable forces to those expected from a uniform bulk cylinder are possible. Force creep was also measured and simulated for the system. The geometry tested is a possible candidate for a rotary superconducting bearing. Detailed finite element modeling in COMSOL Multiphysics was also performed including a full critical state model for induced currents, with temperature and field dependent properties and 3D levitation force models. This work represents one of the most complete levitation force modeling frameworks yet reported using the H-formulation and helps explain why the coil-like stacks of tape are able to sustain levitation forces. The flexibility of geometry and consistency of superconducting properties offered by stacks of tapes, make them attractive for superconducting levitation applications.

  15. Inhomogeneities in particle composition of single, levitated aerosol particles observed by Mie resonance spectroscopy

    NASA Astrophysics Data System (ADS)

    Krieger, Ulrich; Lienhard, Daniel; Bastelberger, Sandra; Steimer, Sarah

    2014-05-01

    Recent observations have indicated that organic aerosol particles in the atmosphere may exist in an amorphous semi-solid or even solid (i.e. glassy) state, e.g. [1]. The influence of highly viscous and glassy states on the timescale of aerosol particle equilibration with respect to water vapor have been investigated for some model systems of atmospheric aerosol, e.g. [2,3]. In particular, it has been shown that the kinetics of the water absorption/desorption process is controlled entirely by liquid-phase diffusion of water molecules for a highly viscous aerosol particle. A liquid phase diffusion model based on numerically solving the non-linear diffusion equation predicts strong internal gradients in water concentration when condensed phase diffusion impedes the water uptake from the gas phase [2]. Here we observe and quantify the internal concentration gradients in single, levitated, micron size aerosol particles of aqueous shikimic acid using elastic Mie resonance spectroscopy. A single, aqueous particle is levitated in an electro-dynamic balance (for details see [2]), dried for several days at room temperature, cooled to the target temperature and exposed to a rapid change in relative humidity. In addition to measuring the elastically backscattered light of a "white light" LED source and recording the full spectrum with a spectrograph as in [2], we use a tunable diode laser (TDL) to scan high resolution TE- and TM spectra. This combination allows observing various Mie resonance mode orders simultaneously. Since we perform the experiment at low temperatures and low humidities the changes in the Mie-spectra due to water uptake are sufficiently slow to resolve the kinetics. Experimental Mie resonance spectra are inverted to concentration profiles of water within the particle by applying the numerical diffusion model [2] in conjunction with Mie calculations of multilayered spheres [4]. [1] A. Virtanen et al. (2010): An amorphous solid state of biogenic secondary

  16. Radial inhomogeneities in particle composition of single, levitated aerosol particles observed by Mie resonance spectroscopy (Invited)

    NASA Astrophysics Data System (ADS)

    Krieger, U. K.; Steimer, S.; Lienhard, D.; Bastelberger, S.

    2013-12-01

    Recent observations have indicated that organic aerosol particles in the atmosphere may exist in an amorphous semi-solid or even solid (i.e. glassy) state, e.g. [1]. The influence of highly viscous and glassy states on the timescale of aerosol particle equilibration with respect to water vapor have been investigated for some model systems of atmospheric aerosol, e.g. [2,3]. In particular, it has been shown that the kinetics of the water absorption/desorption process is controlled entirely by liquid-phase diffusion of water molecules for a highly viscous aerosol particle. A liquid phase diffusion model based on numerically solving the non-linear diffusion equation predicts strong internal gradients in water concentration when condensed phase diffusion impedes the water uptake from the gas phase [2]. Here we observe and quantify the internal concentration gradients in single, levitated, micron size aerosol particles of aqueous MBTCA (3-methyl-1,2,3-Butanetricarboxylic acid) and shikimic acid using elastic Mie resonance spectroscopy. A single, aqueous particle is levitated in an electro-dynamic balance (for details see [2]), dried for several days at room temperature, cooled to the target temperature and exposed to a rapid change in relative humidity. In addition to measuring the elastically backscattered light of a 'white light ' LED source and recording the full spectrum with a spectrograph as in [2], we use a tunable diode laser (TDL) to scan high resolution TE- and TM spectra. This combination allows observing various Mie resonance mode orders simultaneously. Since we perform the experiment at low temperatures and low humidities the changes in the Mie-spectra due to water uptake are sufficiently slow to resolve the kinetics. Experimental Mie resonance spectra are inverted to concentration profiles of water within the particle by applying the numerical diffusion model [2] in conjunction with Mie calculations of multilayered spheres [4]. Potential implications for

  17. Dust levitation about Itokawa's equator

    NASA Astrophysics Data System (ADS)

    Hartzell, C.; Zimmerman, M.; Takahashi, Y.

    2014-07-01

    Introduction: Electrostatic dust motion has been hypothesized to occur on the asteroids, due to the observations of the Eros dust ponds [1] and the potential presence of such a phenomenon on the Moon [2]. There are two phases of electrostatic dust motion: lofting and the subsequent trajectories. The feasibility of electrostatic dust lofting can be assessed by comparing the strength of the electrostatic force to the gravity and cohesion which hold the grain on to the surface [3--5]. The motion of the dust grains after they detach from the surface can be described as either ballistic, escaping, or levitating. We are interested in dust levitation because it could potentially redistribute grains on the surface of an asteroid (for instance, producing the Eros dust ponds) and it could also be hazardous to spacecraft. Specifically, levitating dust could obscure the observations of surface-based spacecraft or possibly trigger obstacle avoidance routines during landing. Dust Levitation: Dust levitation is defined as the altitude oscillation of grains prior to their redeposition on the surface of an asteroid. Levitation occurs about equilibria where the electrostatic and gravity forces on the grain are equal and opposite. An equilibrium state is defined as a position and charge for a specific grain size. We have previously identified equilibria using a 1D plasma model and a simple gravity model for Itokawa [6]. In this simple model, the largest grain that was capable of stable levitation above Itokawa was 3 microns (in radius) [6]. Additionally, we have shown that levitating dust grains follow the variation in the equilibria for a rotating asteroid (i.e., the grain continues to oscillate about an equilibrium state that approaches the surface) [7]. Due to the nonspherical shape of Itokawa, both the gravity and plasma environments are much more complicated than the 1D approximations made in our previous work. Thus, in order to accurately assess the feasibility of dust

  18. Rapid Quench in an Electrostatic Levitator

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.; Matson, Michael M.

    2016-01-01

    The Electrostatic Levitation (ESL) Laboratory at the NASA Marshall Space Flight Center (MSFC) is a unique facility for investigators studying high-temperature materials. The ESL laboratory’s main chamber has been upgraded with the addition of a rapid quench system. This system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy, as a quench medium. Thereby allowing rapid quenching of undercooled liquid metals. Up to eight quench vessels can be loaded into a wheel inside the chamber that is indexed with control software. The system has been tested successfully with samples of zirconium, iron-cobalt alloys, iron-chromium-nickel, titanium-zirconium-nickel alloys, and a silicon-cobalt alloy. This new rapid quench system will allow materials science studies of undercooled materials and new materials development. The system is described and some initial results are presented.

  19. Rapid Quench in an Electrostatic Levitator

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.; Matson, Douglas M.

    2016-01-01

    The Electrostatic Levitation (ESL) Laboratory at the NASA Marshall Space Flight Center (MSFC) is a unique facility for investigators studying high-temperature materials. The ESL laboratory's main chamber has been upgraded with the addition of a rapid quench system. This system allows samples to be dropped into a quench vessel that can be filled with a low melting point material, such as a gallium or indium alloy, as a quench medium. Thereby allowing rapid quenching of undercooled liquid metals. Up to eight quench vessels can be loaded into a wheel inside the chamber that is indexed with control software. The system has been tested successfully with samples of zirconium, iron-cobalt alloys, titanium-zirconium-nickel alloys, and a silicon-cobalt alloy. This new rapid quench system will allow materials science studies of undercooled materials and new materials development. In this presentation, the system is described and some initial results are presented.

  20. Acoustic wave levitation: Handling of components

    NASA Astrophysics Data System (ADS)

    Vandaele, Vincent; Delchambre, Alain; Lambert, Pierre

    2011-06-01

    Apart from contact micromanipulation, there exists a large variety of levitation techniques among which standing wave levitation will be proposed as a way to handle (sub)millimetric components. This paper will compare analytical formulas to calculate the order of magnitude of the levitation force. It will then describe digital simulation and experimental levitation setup. Stable levitation of various components (cardboard, steel washer, ball, ceramic capacity, water droplet) was shown along 5 degrees of freedom: The only degree of freedom that could not be mastered was the rotation about the symmetry axis of the acoustic field. More importantly, the present work will show the modification of the orientation of the radial force component in the presence of an object disturbing the acoustic field. This property can be used as a new feeding strategy as it means that levitating components are spontaneously pushed toward grippers in an acoustic plane standing wave.

  1. Subclassical fields and polarization in electrodynamics

    SciTech Connect

    Planat, Mathieu; Polonyi, Janos

    2010-08-15

    Expectation values of the electromagnetic field and the electric current are introduced at space-time resolution which belongs to the quantum domain. These allow us to approach some key features of classical electrodynamics from the underlying QED. One is the emergence of the radiation field in the retarded solution of the Maxwell equation, derived from an action principle. Another question discussed is the systematic derivation of the polarizability of a charge system. Furthermore, the decoherence and the consistency of the photon field are established by a perturbative calculation of the reduced density matrix for the electromagnetic field within the closed time path formalism.

  2. Path integral quantization of generalized quantum electrodynamics

    SciTech Connect

    Bufalo, R.; Pimentel, B. M.; Zambrano, G. E. R.

    2011-02-15

    In this paper, a complete covariant quantization of generalized electrodynamics is shown through the path integral approach. To this goal, we first studied the Hamiltonian structure of the system following Dirac's methodology and, then, we followed the Faddeev-Senjanovic procedure to obtain the transition amplitude. The complete propagators (Schwinger-Dyson-Fradkin equations) of the correct gauge fixation and the generalized Ward-Fradkin-Takahashi identities are also obtained. Afterwards, an explicit calculation of one-loop approximations of all Green's functions and a discussion about the obtained results are presented.

  3. Topological vortices in generalized Born-Infeld-Higgs electrodynamics

    NASA Astrophysics Data System (ADS)

    Casana, R.; Hora, E. da; Rubiera-Garcia, D.; Santos, C. dos

    2015-08-01

    A consistent BPS formalism to study the existence of topological axially symmetric vortices in generalized versions of the Born-Infeld-Higgs electrodynamics is implemented. Such a generalization modifies the field dynamics via the introduction of three nonnegative functions depending only in the Higgs field, namely, , , and . A set of first-order differential equations is attained when these functions satisfy a constraint related to the Ampère law. Such a constraint allows one to minimize the system's energy in such way that it becomes proportional to the magnetic flux. Our results provides an enhancement of the role of topological vortex solutions in Born-Infeld-Higgs electrodynamics. Finally, we analyze a set of models entailing the recovery of a generalized version of Maxwell-Higgs electrodynamics in a certain limit of the theory.

  4. Controlling Sample Rotation in Acoustic Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Stoneburner, J. D.

    1985-01-01

    Rotation of acoustically levitated object stopped or controlled according to phase-shift monitoring and control concept. Principle applies to square-cross-section levitation chamber with two perpendicular acoustic drivers operating at same frequency. Phase difference between X and Y acoustic excitation measured at one corner by measuring variation of acoustic amplitude sensed by microphone. Phase of driver adjusted to value that produces no rotation or controlled rotation of levitated object.

  5. Stability of equilibrium of a superconducting ring that levitates in the field of a fixed ring with constant current

    NASA Astrophysics Data System (ADS)

    Bishaev, A. M.; Bush, A. A.; Gavrikov, M. B.; Kamentsev, K. E.; Kozintseva, M. V.; Savel'ev, V. V.; Sigov, A. S.

    2015-11-01

    In order to develop a plasma trap with levitating superconducting magnetic coils, it is necessary to search for their stable levitating states. An analytical expression for the potential energy of a single superconducting ring that captures a fixed magnetic flux in the field of a fixed ring with constant current versus the coordinate of the free ring on the axis of the system, deviation angle of its axis from the axis of the system, and radial displacement of its plane is derived for uniform gravity field in the thin ring approximation. The calculated stable levitation states of the superconducting ring in the field of the ring with constant current are proven in experiments. The generalization of such an approach to the levitation of several rings makes it possible to search for stable levitation states of several coils that form a magnetic system of a multipole trap.

  6. Engineering squeezed states of microwave radiation with circuit quantum electrodynamics

    SciTech Connect

    Li Pengbo; Li Fuli

    2011-03-15

    We introduce a squeezed state source for microwave radiation with tunable parameters in circuit quantum electrodynamics. We show that when a superconducting artificial multilevel atom interacting with a transmission line resonator is suitably driven by external classical fields, two-mode squeezed states of the cavity modes can be engineered in a controllable fashion from the vacuum state via adiabatic following of the ground state of the system. This scheme appears to be robust against decoherence and is realizable with present techniques in circuit quantum electrodynamics.

  7. Acoustic Levitator With Furnace And Laser Heating

    NASA Technical Reports Server (NTRS)

    Barmatz, Martin B.; Stoneburner, James D.

    1991-01-01

    Acoustic-levitation apparatus incorporates electrical-resistance furnace for uniform heating up to temperature of about 1,000 degrees C. Additional local heating by pair of laser beams raise temperature of sample to more than 1,500 degrees C. High temperature single-mode acoustic levitator generates cylindrical-mode accoustic resonance levitating sample. Levitation chamber enclosed in electrical-resistance furnace. Infrared beams from Nd:YAG laser provide additional local heating of sample. Designed for use in containerless processing of materials in microgravity or in normal Earth gravity.

  8. Acoustic levitator for containerless measurements on low temperature liquids

    SciTech Connect

    Benmore, Chris J; Weber, Richard; Neuefeind, Joerg C; Rey, Charles A A

    2009-01-01

    A single-axis acoustic levitator was constructed and used to levitate liquid and solid drops at temperatures from -40 to +40 C. The levitator consisted of: (i) two acoustic transducers mounted on a rigid vertical support that was bolted to an optical breadboard, (ii) a acoustic power supply that controlled acoustic intensity, relative phase of the drive to the transducers, and could modulate the acoustic forces at frequencies up to 1kHz, (iii) a video camera, and (iv) a system for providing a stream of controlled temperature gas flow over the sample. The acoustic transducers were operated at their resonant frequency of ~ 22 kHz and could produce sound pressure levels up to 160 dB. The force applied by the acoustic field could be modulated using a frequency generator to excite oscillations in the sample. Sample temperature was controlled using a modified Cryostream Plus and measured using thermocouples and an infrared thermal imager. The levitator was installed at x-ray beamline 11 ID-C at the Advanced Photon Source and used to investigate the structure of supercooled liquids.

  9. Acoustic levitator for structure measurements on low temperature liquid droplets.

    PubMed

    Weber, J K R; Rey, C A; Neuefeind, J; Benmore, C J

    2009-08-01

    A single-axis acoustic levitator was constructed and used to levitate liquid and solid drops of 1-3 mm in diameter at temperatures in the range -40 to +40 degrees C. The levitator comprised (i) two acoustic transducers mounted on a rigid vertical support that was bolted to an optical breadboard, (ii) an acoustic power supply that controlled acoustic intensity, relative phase of the drive to the transducers, and could modulate the acoustic forces at frequencies up to 1 kHz, (iii) a video camera, and (iv) a system for providing a stream of controlled temperature gas flow over the sample. The acoustic transducers were operated at their resonant frequency of approximately 22 kHz and could produce sound pressure levels of up to 160 dB. The force applied by the acoustic field could be modulated to excite oscillations in the sample. Sample temperature was controlled using a modified Cryostream Plus and measured using thermocouples and an infrared thermal imager. The levitator was installed at x-ray beamline 11 ID-C at the Advanced Photon Source and used to investigate the structure of supercooled liquids.

  10. Acoustic levitator for structure measurements on low temperature liquid droplets.

    PubMed

    Weber, J K R; Rey, C A; Neuefeind, J; Benmore, C J

    2009-08-01

    A single-axis acoustic levitator was constructed and used to levitate liquid and solid drops of 1-3 mm in diameter at temperatures in the range -40 to +40 degrees C. The levitator comprised (i) two acoustic transducers mounted on a rigid vertical support that was bolted to an optical breadboard, (ii) an acoustic power supply that controlled acoustic intensity, relative phase of the drive to the transducers, and could modulate the acoustic forces at frequencies up to 1 kHz, (iii) a video camera, and (iv) a system for providing a stream of controlled temperature gas flow over the sample. The acoustic transducers were operated at their resonant frequency of approximately 22 kHz and could produce sound pressure levels of up to 160 dB. The force applied by the acoustic field could be modulated to excite oscillations in the sample. Sample temperature was controlled using a modified Cryostream Plus and measured using thermocouples and an infrared thermal imager. The levitator was installed at x-ray beamline 11 ID-C at the Advanced Photon Source and used to investigate the structure of supercooled liquids. PMID:19725664

  11. Cylindrical acoustic levitator/concentrator

    DOEpatents

    Kaduchak, Gregory; Sinha, Dipen N.

    2002-01-01

    A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

  12. Final Report: Levitated Dipole Experiment

    SciTech Connect

    Kesner, Jay; Mauel, Michael

    2013-03-10

    Since the very first experiments with the LDX, research progress was rapid and significant. Initial experiments were conducted with the high-field superconducting coil suspended by three thin rods. These experiments produced long-pulse, quasi-steady-state microwave discharges, lasting more than 10 s, having peak beta values of 20% [Garnier et al., Physics of Plasmas, 13 (2006) 056111]. High- beta, near steady-state discharges have been maintained in LDX for more than 20 seconds, and this capability made LDX the longest pulse fusion confinement experiment operating in the U.S. fusion program. A significant measure of progress in the LDX research program was the routine investigation of plasma confinement with a magnetically-levitated dipole and the resulting observations of confinement improvement. In both supported and levitated configurations, detailed measurements were made of discharge evolution, plasma dynamics and instability, and the roles of gas fueling, microwave power deposition profiles, and plasma boundary shape. High-temperature plasma was created by multi frequency electron cyclotron resonance heating at 2.45 GHz, 6.4 GHz, 10.5 GHz and 28 GHz allowing control of heating profiles. Depending upon neutral fueling rates, the LDX discharges contain a fraction of energetic electrons, with mean energies above 50 keV. Depending on whether or not the superconducting dipole was levitated or supported, the peak thermal electron temperature was estimated to exceed 500 eV and peak densities to approach 1e18 m-3. We have found that levitation causes a strong inwards density pinch [Boxer et al., Nature Physics, 6 (2010) 207] and we have observed the central plasma density increase dramatically indicating a significant improvement in the confinement of a thermal plasma species.

  13. Anisotropy Effect on Levitation Performance of Bulk High-Tc Superconductors Above a Permanent Magnet Guideway

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Liao, Xinglin; Jing, Hailian; Lin, Qunxu; Ma, Guangtong; Yen, Fei; Wang, Suyu; Wang, Jiasu

    The anisotropy properties of bulk high-temperature superconductors (HTSCs) are taken into consideration for the application of high-temperature superconducting (HTS) Maglev systems, which are especially based on the different flux-trapping capabilities as well as critical current density, Jc, values between the growth section boundary (GSB) and the growth sections (GS) in bulk superconductors. By adjusting the angle between the GSB of bulk HTSCs and the strongest magnetic field position of a permanent magnet guideway (PMG), the levitation force and its relaxation processes are compared at different field-cooling conditions. Experimental results show that the levitation capability and the suppression of levitation force decay can be enhanced by optimizing the GS/GSB alignment of every bulk HTSC above the PMG. Meanwhile, our conclusions may provide references to other HTS maglev systems with small levitation gaps, i.e., superconducting magnetic bearings.

  14. Application of an ultrasonic focusing radiator for acoustic levitation of submillimeter samples

    NASA Technical Reports Server (NTRS)

    Lee, M. C.

    1981-01-01

    An acoustic apparatus has been specifically developed to handle samples of submillimeter size in a gaseous medium. This apparatus consists of an acoustic levitation device, deployment devices for small liquid and solid samples, heat sources for sample heat treatment, acoustic alignment devices, a cooling system and data-acquisition instrumentation. The levitation device includes a spherical aluminum dish of 12 in. diameter and 0.6 in. thickness, 130 pieces of PZT transducers attached to the back side of the dish and a spherical concave reflector situated in the vicinity of the center of curvature of the dish. The three lowest operating frequencies for the focusing-radiator levitation device are 75, 105 and 163 kHz, respectively. In comparison with other levitation apparatus, it possesses a large radiation pressure and a high lateral positional stability. This apparatus can be used most advantageously in the study of droplets and spherical shell systems, for instance, for fusion target applications.

  15. Application of an ultrasonic focusing radiator for acoustic levitation of submillimeter samples

    SciTech Connect

    Lee, M.C.

    1981-01-01

    An acoustic apparatus has been specifically developed to handle samples of submillimeter size in a gaseous medium. This apparatus consists of an acoustic levitation device, deployment devices for small liquid and solid samples, heat sources for sample heat treatment, acoustic alignment devices, a cooling system and data-acquisition instrumentation. The levitation device includes a spherical aluminum dish of 12'' diameter and 0.6'' thickness, 130 pieces of PZT tranducers attached to the back side of the dish and a spherical concave reflector situated in the vicinity of the center of curvature of the dish. The three lowest operating frequencies for the focusing-radiator levitation device are 75, 105 and 163 kHz, respectively. In comparison with other levitation apparatus, it possesses a large radiation pressure and a high lateral positional stability. This apparatus can be used most advantageously in the study of droplets and spherical shell systems, for instance, for fusion target applications.

  16. Magnet levitation at your fingertips

    NASA Astrophysics Data System (ADS)

    Geim, A. K.; Simon, M. D.; Boamfa, M. I.; Heflinger, L. O.

    1999-07-01

    The stable levitation of magnets is forbidden by Earnshaw's theorem, which states that no stationary object made of magnets in a fixed configuration can be held in stable equilibrium by any combination of static magnetic or gravitational forces. Earnshaw's theorem can be viewed as a consequence of the Maxwell equations, which do not allow the magnitude of a magnetic field in a free space to possess a maximum, as required for stable equilibrium. Diamagnets (which respond to magnetic fields with mild repulsion) are known to flout the theorem, as their negative susceptibility results in the requirement of a minimum rather than a maximum in the field's magnitude. Nevertheless, levitation of a magnet without using superconductors is widely thought to be impossible. We find that the stable levitation of a magnet can be achieved using the feeble diamagnetism of materials that are normally perceived as being non-magnetic, so that even human fingers can keep a magnet hovering in mid-air without touching it.

  17. Apparent Paradoxes in Classical Electrodynamics: Relativistic Transformation of Force

    ERIC Educational Resources Information Center

    Kholmetskii, A. L.; Yarman, T.

    2007-01-01

    In this paper, we analyse a number of paradoxical teaching problems of classical electrodynamics, dealing with the relativistic transformation of force for complex macro systems, consisting of a number of subsystems with nonzero relative velocities such as electric circuits that change their shape in the course of time. (Contains 7 figures.)

  18. Study on the Levitation and Restoring Force Characteristics of the Improved HTS-permanent Magnet Hybrid Magnetic Bearing

    NASA Astrophysics Data System (ADS)

    Sugiyama, R.; Oguni, K.; Ohashi, S.

    We have developed the hybrid magnetic bearing using permanent magnets and high temperature bulk super conductor (HTS). In this system, the permanent magnet has ring type structure so that the permanent magnet and the HTS can be set to the stator. The pinning force of the HTS is used for the levitation and the guidance. Repulsive force of the permanent magnets was used in the conventional hybrid system. However the restoring force in the guidance direction of the conventional hybrid system decreases by the side slip force of the permanent magnets. In this research, attractive force of permanent magnets is used for increasing the load weight in the guidance direction. In this paper, influence of the hybrid system on the static characteristics of the rotor is studied. Three-dimensional numerical analysis of the linkage flux (in the levitation and the guidance direction) in the HTS is undertaken. The stator side permanent magnet increases the linkage flux of the levitation direction. Therefore in the hybrid system the linkage flux of the levitation direction increases. The levitation and restoring force of the rotor is measured. The levitation force of the hybrid system becomes smaller than that of the non-hybrid one by attractive force. The rotor in the hybrid system is supported by the pinning force and attractive force. The restoring force of the hybrid system becomes larger than that of the non-hybrid one because of increasing the linkage flux of the levitation direction.

  19. Dynamics of the bogie of a maglev system with guideway irregularities

    SciTech Connect

    Seki, Akio; Osada, Yutaka; Kitano, Junichi; Miyamoto, Shigeki

    1996-09-01

    This paper describes the stability of a bogie in the electrodynamic suspension system with superconducting magnets, especially in response to displacement of the levitation coils. The result of dynamic analysis indicates its stability with the displacement of coils which may happen most frequently; such as a longitudinal displacement and a vertical displacement. In addition, Cayley-Klein parameters are adopted for conversion of coordinates in this analysis in order to simplify it instead of Euler angles which are usually used in 3-dimensional analysis. All simulations in this paper are conducted with these parameters.

  20. Design, Fabrication and Levitation Experiments of a Micromachined Electrostatically Suspended Six-Axis Accelerometer

    PubMed Central

    Cui, Feng; Liu, Wu; Chen, Wenyuan; Zhang, Weiping; Wu, Xiaosheng

    2011-01-01

    A micromachined electrostatically suspended six-axis accelerometer, with a square plate as proof mass housed by a top stator and bottom stator, is presented. The device structure and related techniques concerning its operating principles, such as calculation of capacitances and electrostatic forces/moments, detection and levitation control of the proof mass, acceleration measurement, and structural parameters design, are described. Hybrid MEMS manufacturing techniques, including surface micromachining fabrication of thin film electrodes and interconnections, integration fabrication of thick nickel structures about 500 μm using UV-LIGA by successful removal of SU-8 photoresist mold, DRIE of silicon proof mass in thickness of 450 μm, microassembly and solder bonding, were employed to fabricate this prototype microdevice. A levitation experiment system for the fabricated microaccelerometer chip is introduced, and levitation results show that fast initial levitation within 10 ms and stable full suspension of the proof mass have been successfully demonstrated. PMID:22247662

  1. Passive levitation in alternating magnetic fields

    DOEpatents

    Romero, Louis; Christenson, Todd; Aronson, Eugene A.

    2009-06-16

    Stable levitation of an object in an alternating magnetic field can be achieved by eliminating coupling between the rotational and translational forces acting on the object. Stable levitation can also be achieved by varying the coupling between the rotational and translational forces acting on the object, while maintaining one or more of the rotational and translational forces steady in time.

  2. Passive levitation in alternating magnetic fields

    DOEpatents

    Romero, Louis; Christenson, Todd; Aronson, Eugene A.

    2010-09-14

    Stable levitation of an object in an alternating magnetic field can be achieved by eliminating coupling between the rotational and translational forces acting on the object. Stable levitation can also be achieved by varying the coupling between the rotational and translational forces acting on the object, while maintaining one or more of the rotational and translational forces steady in time.

  3. Off-Resonance Acoustic Levitation Without Rotation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Allen, J. L.

    1984-01-01

    Orthogonal acoustic-levitation modes excited at slightly different frequencies to control rotation. Rotation of object in square cross-section acoustic-levitation chamber stopped by detuning two orthogonal (x and y) excitation drivers in plane of square cross section. Detuning done using fundamental degenerate modes or odd harmonic modes.

  4. Acoustical-Levitation Chamber for Metallurgy

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Trinh, E.; Wang, T. G.; Elleman, D. D.; Jacobi, N.

    1983-01-01

    Sample moved to different positions for heating and quenching. Acoustical levitation chamber selectively excited in fundamental and second-harmonic longitudinal modes to hold sample at one of three stable postions: A, B, or C. Levitated object quickly moved from one of these positions to another by changing modes. Object rapidly quenched at A or C after heating in furnace region at B.

  5. Droplet Vaporization In A Levitating Acoustic Field

    NASA Technical Reports Server (NTRS)

    Ruff, G. A.; Liu, S.; Ciobanescu, I.

    2003-01-01

    Combustion experiments using arrays of droplets seek to provide a link between single droplet combustion phenomena and the behavior of complex spray combustion systems. Both single droplet and droplet array studies have been conducted in microgravity to better isolate the droplet interaction phenomena and eliminate or reduce the effects of buoyancy-induced convection. In most experiments involving droplet arrays, the droplets are supported on fibers to keep them stationary and close together before the combustion event. The presence of the fiber, however, disturbs the combustion process by introducing a source of heat transfer and asymmetry into the configuration. As the number of drops in a droplet array increases, supporting the drops on fibers becomes less practical because of the cumulative effect of the fibers on the combustion process. To eliminate the effect of the fiber, several researchers have conducted microgravity experiments using unsupported droplets. Jackson and Avedisian investigated single, unsupported drops while Nomura et al. studied droplet clouds formed by a condensation technique. The overall objective of this research is to extend the study of unsupported drops by investigating the combustion of well-characterized drop clusters in a microgravity environment. Direct experimental observations and measurements of the combustion of droplet clusters would provide unique experimental data for the verification and improvement of spray combustion models. In this work, the formation of drop clusters is precisely controlled using an acoustic levitation system so that dilute, as well as dense clusters can be created and stabilized before combustion in microgravity is begun. While the low-gravity test facility is being completed, tests have been conducted in 1-g to characterize the effect of the acoustic field on the vaporization of single and multiple droplets. This is important because in the combustion experiment, the droplets will be formed and

  6. Carl Neumann's Contributions to Electrodynamics

    NASA Astrophysics Data System (ADS)

    Schlote, Karl-Heinz

    2004-09-01

    I examine the publications of Carl Neumann (1832 1925) on electrodynamics, which constitute a major part of his work and which illuminate his approach to mathematical physics. I show how Neumann contributed to physics at an important stage in its development and how his work led to a polemic with Hermann Helmholtz (1821 1894). Neumann advanced and extended the ideas of the Königsberg school of mathematical physics. His investigations were aimed at founding a mathematically exact physical theory of electrodynamics, following the approach of Carl G.J. Jacobi (1804 1851) on the foundation of a physical theory as outlined in Jacobi’s lectures on analytical mechanics. Neumann’s work also shows how he clung to principles that impeded him in appreciating and developing new ideas such as those on field theory that were proposed by Michael Faraday (1791 1867) and James Clerk Maxwell (1831 1879).

  7. Acoustic levitation methods for density measurements

    NASA Technical Reports Server (NTRS)

    Trinh, E. H.; Hsu, C. J.

    1986-01-01

    The capability of ultrasonic levitators operating in air to perform density measurements has been demonstrated. The remote determination of the density of ordinary liquids as well as low density solid metals can be carried out using levitated samples with size on the order of a few millimeters and at a frequency of 20 kHz. Two basic methods may be used. The first one is derived from a previously known technique developed for acoustic levitation in liquid media, and is based on the static equilibrium position of levitated samples in the earth's gravitational field. The second approach relies on the dynamic interaction between a levitated sample and the acoustic field. The first technique appears more accurate (1 percent uncertainty), but the latter method is directly applicable to a near gravity-free environment such as that found in space.

  8. Dielectrophoretic levitation of droplets and bubbles

    NASA Technical Reports Server (NTRS)

    Jones, T. B.

    1982-01-01

    Uncharged droplets and bubbles can be levitated dielectrophoretically in liquids using strong, nonuniform electric fields. The general equations of motion for a droplet or bubble in an axisymmetric, divergence-free electrostatic field allow determination of the conditions necessary and sufficient for stable levitation. The design of dielectrophoretic (DEP) levitation electrode structures is simplified by a Taylor-series expansion of cusped axisymmetric electrostatic fields. Extensive experimental measurements on bubbles in insulating liquids verify the simple dielectrophoretic model. Other have extended dielectrophoretic levitation to very small particles in aqueous media. Applications of DEP levitation to the study of gas bubbles, liquid droplets, and solid particles are discussed. Some of these applications are of special interest in the reduced gravitational field of a spacecraft.

  9. Accelerator and electrodynamics capability review

    SciTech Connect

    Jones, Kevin W

    2010-01-01

    Los Alamos National Laboratory (LANL) uses capability reviews to assess the science, technology and engineering (STE) quality and institutional integration and to advise Laboratory Management on the current and future health of the STE. Capability reviews address the STE integration that LANL uses to meet mission requirements. The Capability Review Committees serve a dual role of providing assessment of the Laboratory's technical contributions and integration towards its missions and providing advice to Laboratory Management. The assessments and advice are documented in reports prepared by the Capability Review Committees that are delivered to the Director and to the Principal Associate Director for Science, Technology and Engineering (PADSTE). Laboratory Management will use this report for STE assessment and planning. LANL has defined fifteen STE capabilities. Electrodynamics and Accelerators is one of the seven STE capabilities that LANL Management (Director, PADSTE, technical Associate Directors) has identified for review in Fiscal Year (FY) 2010. Accelerators and electrodynamics at LANL comprise a blend of large-scale facilities and innovative small-scale research with a growing focus on national security applications. This review is organized into five topical areas: (1) Free Electron Lasers; (2) Linear Accelerator Science and Technology; (3) Advanced Electromagnetics; (4) Next Generation Accelerator Concepts; and (5) National Security Accelerator Applications. The focus is on innovative technology with an emphasis on applications relevant to Laboratory mission. The role of Laboratory Directed Research and Development (LDRD) in support of accelerators/electrodynamics will be discussed. The review provides an opportunity for interaction with early career staff. Program sponsors and customers will provide their input on the value of the accelerator and electrodynamics capability to the Laboratory mission.

  10. Some problems of classical electrodynamics

    NASA Astrophysics Data System (ADS)

    Ginzburg, I. F.

    2011-12-01

    In this lecture, I discuss issues that usually escape attention of students in electrodynamics. These are the questions of (1) what the photon observed in nature "looks like," (2) how an interference pattern arises from a source containing a lot of incoherently emitting atoms, and (3) how light "slows down" in a medium. Answers to these questions, if discussed at all, are scattered over various textbooks. Here, I follow our textbook [1].

  11. Safety of high-speed magnetic-levitation transportation systems. Magnetic-field testing of the TR07 maglev vehicle and system. Volume 1. Analysis. Final report Jun 91-Mar 92

    SciTech Connect

    Dietrich, F.; Feero, W.E.

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) emissions, both steady (dc) and produced by alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposures to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Volume I-Analysis summarizes the experimental findings and compares results to common home, work, and power lines emissions for selected spectral bands.

  12. Safety of high-speed magnetic-levitation transportation systems. Magnetic-field testing of the TR07 maglev vehicle and system. Volume 2. Appendices. Final report Jun 91-Mar 92

    SciTech Connect

    Dietrich, F.; Robertson, D.; Steiner, G.

    1992-04-01

    The safety of various magnetically levitated (maglev) and high speed rail (HSR) trains proposed for application in the United States is of direct concern to the Federal Railroad Administration (FRA). The characterization of electric and magnetic fields (EMF) emissions, both steady (dc) and produced by alternating currents (ac) at power frequency (50 Hz in Europe and 60 Hz in the U.S.) and other frequencies in the Extreme Low Frequency (ELF) range (3-3000 Hz), and associated public and worker exposures to EMF, are a growing health and safety concern worldwide. As part of a comprehensive safety assessment of the German TransRapid (TR-07) maglev system undertaken by the FRA, with technical support from the DOT/RSPA Volpe National Transportation System Center (VNTSC), magnetic field measurements were performed by Electric Research and Management, Inc. (ERM) at the Transrapid Test Facility (TVE) in Emsland, Germany in August, 1990. Volume II-Appendices catalogs and documents detailed magnetic field data files and their specifics (static fields, spectral waveforms, temporal and spatial information) by location.

  13. Polymeric Coatings for Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Vaughn, Jason A.; Kamenetzky, Rachel R.; Finckenor, Miria M.; Schuler, Peter

    2000-01-01

    Two polymeric coatings have been developed for the Propulsive Small Expendable Deployer System (ProSEDS) mission. ProSEDS is designed to provide an on-orbit demonstration of the electrodynamic propulsion capabilities of tethers in space. The ProSEDS experiment will be a secondary payload on a Delta II unmanned expendable booster scheduled for launch in August 2000. A 5-km conductive tether is attached to the Delta 11 second stage and collects current from the low Earth orbit (LEO) plasma to facilitate de-orbit of the spent stage. The conductive tether is attached to a 10-km non-conductive tether, the other end of which is attached to an endmass containing several scientific instruments. A bare metal tether would have the best conductivity but thermal concerns preclude this design. A conductive polymer developed by Triton Systems has been optimized for conductivity and thermo-optical properties. The current design for the ProSEDS conductive tether is seven strands of 28 AWG aluminum wire individually coated with 8.7 micrometers (0.35 mil) of an atomic oxygen-resistant conductive polymer composed of a mixture of 87% Clear Oxygen-Resistant polymer (COR) and 13% polyanaline (PANi), wrapped around a braided Kevlar (TM) 49 core. Extensive testing has been performed at the Marshall Space Flight Center (MSFC) to qualify this material for flight on ProSEDS. Atomic oxygen exposure was performed, with solar absorptance and infrared emittance measured before and after exposure. Conductivity was measured before and after atomic oxygen exposure. High voltage tests, up to 1500 V, of the current collecting ability of the COR/PANi have been completed. Approximately 160 meters of the conductive tether closest to the Delta 11 second stage is insulated to prevent any electron reconnection to the tether from the plasma contactor. The insulation is composed of polyimide overcoated with TOR-BP, another polymeric coating developed by Triton for this mission. TOR-BP acts as both insulator

  14. Low Frequency Vibration Energy Harvesting using Diamagnetically Stabilized Magnet Levitation

    NASA Astrophysics Data System (ADS)

    Palagummi, Sri Vikram

    Over the last decade, vibration-based energy harvesting has provided a technology push on the feasibility of self-powered portable small electronic devices and wireless sensor nodes. Vibration energy harvesters in general transduce energy by damping out the environmentally induced relative emotion through either a cantilever beam or an equivalent suspension mechanism with one of the transduction mechanisms, like, piezoelectric, electrostatic, electromagnetic or magnetostrictive. Two major challenges face the present harvesters in literature, one, they suffer from the unavoidable mechanical damping due to internal friction present in the systems, second, they cannot operate efficiently in the low frequency range (< 10 Hz), when most of the ambient vibrational energy is in this low frequency broadband range. Passive and friction free diamagnetically stabilized magnet levitation mechanisms which can work efficiently as a vibration energy harvester in the low frequency range are discussed in this work. First, a mono-stable vertical diamagnetic levitation (VDL) based vibration energy harvester (VEH) is discussed. The harvester consists of a lifting magnet (LM), a floating magnet (FM) and two diamagnetic plates (DPs). The LM balances out the weight of the FM and stability is brought about by the repulsive effect of the DPs, made of pyrolytic graphite. Two thick cylindrical coils, placed in grooves which are engraved in the DPs, are used to convert the mechanical energy into electrical energy. Experimental frequency response of the system is validated by the theoretical analysis which showed that the VEH works in a low frequency range but sufficient levitation gap was not achieved and the frequency response characteristic of the system was effectively linear. To overcome these challenges, the influence of the geometry of the FM, the LM, and the DP were parametrically studied to assess their effects on the levitation gap, size of the system and the natural frequency. For

  15. Study of a new passive magnetic levitation concept

    SciTech Connect

    Post, R.F.

    1995-03-01

    As a bonus from an existing LDRD-supported project (Electromechanical Battery Research and Development) a new concept for the magnetic levitation of a moving object evolved. To initiate a study of the merits of the concept mid-year ``seed money`` LDRD funding was provided. The FY94 activities resulted in a preliminary evaluation of the merits of this concept through calculations, laboratory measurements, and the design of a simple test model. There is now considerable international interest in the ``Maglev`` concept for highspeed trains. Wear, rolling friction, and speed limitations of conventional rail technology make this technology unsuitable for such trains, whence the use of magnetic levitation. In present Maglev trains, however, such as those constructed in Germany and Japan, servo-controlled magnetic systems are required, involving sensor and control circuitry and non-trivial on-board power requirements. In such systems the failure of a control system can have serious consequences, so that redundant systems may be required, thus adding to the cost and complexity. It would be highly desirable to replace the present ``active``, servo-controlled magnetic levitation systems with a totally passive one, one for which neither control circuits nor on-board power would be required. Failure of such a system could be made to be much more benign in its consequences than for servo-controlled ones, and the cost, particularly of the on-board equipment, might be greatly reduced.

  16. Capillary solitons on a levitated medium.

    PubMed

    Perrard, S; Deike, L; Duchêne, C; Pham, C-T

    2015-07-01

    A water cylinder deposited on a heated channel levitates on its own generated vapor film owing to the Leidenfrost effect. This experimental setup permits the study of the one-dimensional propagation of surface waves in a free-to-move liquid system. We report the observation of gravity-capillary waves under a dramatic reduction of gravity (up to a factor 30), leading to capillary waves at the centimeter scale. The generated nonlinear structures propagate without deformation and undergo mutual collisions and reflections at the boundaries of the domain. They are identified as Korteweg-de Vries solitons with negative amplitude and subsonic velocity. The typical width and amplitude-dependent velocities are in excellent agreement with theoretical predictions based on a generalized Korteweg-de Vries equation adapted to any substrate geometry. When multiple solitons are present, they interact and form a soliton turbulencelike spectrum.

  17. Nano-optomechanics with optically levitated nanoparticles

    NASA Astrophysics Data System (ADS)

    Neukirch, Levi P.; Vamivakas, A. Nick

    2015-01-01

    Nano-optomechanics is a vibrant area of research that continues to push the boundary of quantum science and measurement technology. Recently, it has been realised that the optical forces experienced by polarisable nanoparticles can provide a novel platform for nano-optomechanics with untethered mechanical oscillators. Remarkably, these oscillators are expected to exhibit quality factors approaching ?. The pronounced quality factors are a direct result of the mechanical oscillator being freed from a supporting substrate. This review provides an overview of the basic optical physics underpinning optical trapping and optical levitation experiments, it discusses a number of experimental approaches to optical trapping and finally outlines possible applications of this nano-optomechanics modality in hybrid quantum systems and nanoscale optical metrology.

  18. Capillary solitons on a levitated medium.

    PubMed

    Perrard, S; Deike, L; Duchêne, C; Pham, C-T

    2015-07-01

    A water cylinder deposited on a heated channel levitates on its own generated vapor film owing to the Leidenfrost effect. This experimental setup permits the study of the one-dimensional propagation of surface waves in a free-to-move liquid system. We report the observation of gravity-capillary waves under a dramatic reduction of gravity (up to a factor 30), leading to capillary waves at the centimeter scale. The generated nonlinear structures propagate without deformation and undergo mutual collisions and reflections at the boundaries of the domain. They are identified as Korteweg-de Vries solitons with negative amplitude and subsonic velocity. The typical width and amplitude-dependent velocities are in excellent agreement with theoretical predictions based on a generalized Korteweg-de Vries equation adapted to any substrate geometry. When multiple solitons are present, they interact and form a soliton turbulencelike spectrum. PMID:26274114

  19. Capillary solitons on a levitated medium

    NASA Astrophysics Data System (ADS)

    Perrard, S.; Deike, L.; Duchêne, C.; Pham, C.-T.

    2015-07-01

    A water cylinder deposited on a heated channel levitates on its own generated vapor film owing to the Leidenfrost effect. This experimental setup permits the study of the one-dimensional propagation of surface waves in a free-to-move liquid system. We report the observation of gravity-capillary waves under a dramatic reduction of gravity (up to a factor 30), leading to capillary waves at the centimeter scale. The generated nonlinear structures propagate without deformation and undergo mutual collisions and reflections at the boundaries of the domain. They are identified as Korteweg-de Vries solitons with negative amplitude and subsonic velocity. The typical width and amplitude-dependent velocities are in excellent agreement with theoretical predictions based on a generalized Korteweg-de Vries equation adapted to any substrate geometry. When multiple solitons are present, they interact and form a soliton turbulencelike spectrum.

  20. Contactless Calorimetry for Levitated Samples

    NASA Technical Reports Server (NTRS)

    Lee, M. C.; Dokko, W.

    1986-01-01

    Temperature and specific heat of hot sample measured with pyrometer in proposed experimental technique. Technique intended expecially for contactless calorimetry of such materials as undercooled molten alloys, samples of which must be levitated to prevent contamination and premature crystallization. Contactless calorimetry technique enables data to be taken over entire undercooling temperature range with only one sample. Technique proves valuable in study of undercooling because difference in specific heat between undercooled-liquid and crystalline phases at same temperature provides driving force to convert metastable undercooled phase to stable crystalline phase.

  1. Quantum Magnetomechanics: Ultrahigh-Q-Levitated Mechanical Oscillators

    NASA Astrophysics Data System (ADS)

    Cirio, M.; Brennen, G. K.; Twamley, J.

    2012-10-01

    Engineering nanomechanical quantum systems possessing ultralong motional coherence times allows for applications in precision quantum sensing and quantum interfaces, but to achieve ultrahigh motional Q one must work hard to remove all forms of motional noise and heating. We examine a magneto-meso-mechanical quantum system that consists of a 3D arrangement of miniature superconducting loops which is stably levitated in a static inhomogeneous magnetic field. The motional decoherence is predominantly due to loss from induced eddy currents in the magnetized sphere which provides the trapping field ultimately yielding Q˜109 with motional oscillation frequencies of several hundreds of kilohertz. By inductively coupling this levitating object to a nearby driven flux qubit one can cool its motion very close to the ground state and this may permit the generation of macroscopic entangled motional states of multiple clusters.

  2. Cavity cooling of an optically levitated submicron particle

    PubMed Central

    Kiesel, Nikolai; Blaser, Florian; Delić, Uroš; Grass, David; Kaltenbaek, Rainer; Aspelmeyer, Markus

    2013-01-01

    The coupling of a levitated submicron particle and an optical cavity field promises access to a unique parameter regime both for macroscopic quantum experiments and for high-precision force sensing. We report a demonstration of such controlled interactions by cavity cooling the center-of-mass motion of an optically trapped submicron particle. This paves the way for a light–matter interface that can enable room-temperature quantum experiments with mesoscopic mechanical systems. PMID:23940352

  3. Levitated Optomechanics for Fundamental Physics

    NASA Astrophysics Data System (ADS)

    Rashid, Muddassar; Bateman, James; Vovrosh, Jamie; Hempston, David; Ulbricht, Hendrik

    2015-05-01

    Optomechanics with levitated nano- and microparticles is believed to form a platform for testing fundamental principles of quantum physics, as well as find applications in sensing. We will report on a new scheme to trap nanoparticles, which is based on a parabolic mirror with a numerical aperture of 1. Combined with achromatic focussing, the setup is a cheap and readily straightforward solution to trapping nanoparticles for further study. Here, we report on the latest progress made in experimentation with levitated nanoparticles; these include the trapping of 100 nm nanodiamonds (with NV-centres) down to 1 mbar as well as the trapping of 50 nm Silica spheres down to 10?4 mbar without any form of feedback cooling. We will also report on the progress to implement feedback stabilisation of the centre of mass motion of the trapped particle using digital electronics. Finally, we argue that such a stabilised particle trap can be the particle source for a nanoparticle matterwave interferometer. We will present our Talbot interferometer scheme, which holds promise to test the quantum superposition principle in the new mass range of 106 amu. EPSRC, John Templeton Foundation.

  4. Charged drop levitators and their applications

    NASA Technical Reports Server (NTRS)

    Rhim, W. K.; Chung, S. K.; Hyson, M. T.; Elleman, D. D.

    1987-01-01

    An account is given of the charged drop levitation characteristics of two different devices: (1) a feedback-controlled electrostatic levitator able to lift a several mm-diameter drop in 1g conditions, which is applicable to drop dynamics, crystal growth, and supercooling/solidification experiments; and (2) a linear quadrupole levitator, whose advantages are demonstrated in light of the results obtained for the charged drop instability experiment. The cause of the premature drop burstings observed is suggested to be an electron avalanche in the surrounding gaseous medium rather than the Rayleigh limit.

  5. Analysis of SPAR 8 single-axis levitation experiment

    NASA Technical Reports Server (NTRS)

    Rush, J. E.; Schafer, C. F.; Holland, R. L.

    1981-01-01

    The melting and resolidification of SPAR 8 payload melting and resolidification of a glass specimen from the in a containerless condition and the retrieval and examination of the specimen from the. The absence of container contact was assured by use of a single-axis acoustic levitation system. However, the sample contacted a wire cage after being held without container contact by the acoustic field for only approximately 87 seconds. At this time, the sample was still molten and, therefore, flowed aroung the wire and continued to adhere to it. An analysis of why the sample did not remain levitated free of container contact is presented. The experiment is described, and experimental observations are discussed and analyzed.

  6. Three-dimensional cell culturing by magnetic levitation.

    PubMed

    Haisler, William L; Timm, David M; Gage, Jacob A; Tseng, Hubert; Killian, T C; Souza, Glauco R

    2013-10-01

    Recently, biomedical research has moved toward cell culture in three dimensions to better recapitulate native cellular environments. This protocol describes one method for 3D culture, the magnetic levitation method (MLM), in which cells bind with a magnetic nanoparticle assembly overnight to render them magnetic. When resuspended in medium, an external magnetic field levitates and concentrates cells at the air-liquid interface, where they aggregate to form larger 3D cultures. The resulting cultures are dense, can synthesize extracellular matrix (ECM) and can be analyzed similarly to the other culture systems using techniques such as immunohistochemical analysis (IHC), western blotting and other biochemical assays. This protocol details the MLM and other associated techniques (cell culture, imaging and IHC) adapted for the MLM. The MLM requires 45 min of working time over 2 d to create 3D cultures that can be cultured in the long term (>7 d). PMID:24030442

  7. A novel ultrasonic clutch using near-field acoustic levitation.

    PubMed

    Chang, Kuo-Tsi

    2004-10-01

    This paper investigates design, fabrication and drive of an ultrasonic clutch with two transducers. For the two transducers, one serving as a driving element of the clutch is connected to a driving shaft via a coupling, and the other serving as a slave element of the clutch is connected to a slave shaft via another coupling. The principle of ultrasonic levitation is first expressed. Then, a series-resonant inverter is used to generate AC voltages at input terminals of each transducer, and a speed measuring system with optic sensors is used to find the relationship between rotational speed of the slave shaft and applied voltage of each transducer. Moreover, contact surfaces of the two transducers are coupled by the frictional force when both the two transducers are not energized, and separated using the ultrasonic levitation when at least one of the two transducers is energized at high voltages at resonance. PMID:15358528

  8. Large- and Small-Scale Ring Current Electrodynamic Coupling

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.

    2003-01-01

    In this talk we will address the two primary issues of ring current (RC) electrodynamic coupling: 1. RC self-consistent magnetosphere-ionosphere coupling that includes calculation of the magnetospheric electric field (large scale electrodynamic coupling); and 2. RC self-consistent coupling with electromagnetic ion cyclotron (EMIC) waves (small scale electrodynamic coupling). Our study will be based on two RC models that we have recently developed in our group. The first model by Khazanov et al. [2002] couples the system of two kinetic equations: one equation which describes the RC ion dynamics and another equation which describes the energy density evolution of EMIC waves. The second model by Khazanov et al. [2003] deals with large scale electrodynamic coupling processes and provides a self-consistent simulation of RC ions and the magnetospheric electric field. There is presently no model that addresses both of these issues simultaneously in a self-consistent calculation. However, the need exists for such a model, because these two processes directly influence each other, with the mesoscale coupling changing the drift paths of the thermal and energetic particle populations in the inner magnetosphere, thereby changing the wave interactions, and the microscale coupling altering the pitch angle distributions and ionospheric conductivities (through increased precipitation), thus changing the field-aligned currents and electric potential structure. The initial thrust of the work will be the development of a combined kinetic model of micro- and meso-scale RC electrodynamic coupling processes and to examine their interactions with each other on a global scale.

  9. Electrodynamics at the highest energies

    SciTech Connect

    Klein, Spencer R.

    2002-06-17

    At very high energies, the bremsstrahlung and pair production cross sections exhibit complex behavior due to the material in which the interactions occur. The cross sections in dense media can be dramatically different than for isolated atoms. This writeup discusses these in-medium effects, emphasizing how the cross section has different energy and target density dependencies in different regimes. Data from SLAC experiment E-146 will be presented to confirm the energy and density scaling. Finally, QCD analogs of the electrodynamics effects will be discussed.

  10. Quantum Electrodynamics for Vector Mesons

    SciTech Connect

    Djukanovic, Dalibor; Schindler, Matthias R.; Scherer, Stefan; Gegelia, Jambul

    2005-07-01

    Quantum electrodynamics for {rho} mesons is considered. It is shown that, at the tree level, the value of the gyromagnetic ratio of the {rho}{sup +} is fixed to 2 in a self-consistent effective quantum field theory. Further, the mixing parameter of the photon and the neutral vector meson is equal to the ratio of electromagnetic and strong couplings, leading to the mass difference M{sub {rho}}{sub {sup 0}}-M{sub {rho}}{sub {sup {+-}}}{approx}1 MeV at tree order.

  11. A model of nonlinear electrodynamics

    SciTech Connect

    Kruglov, S.I.

    2015-02-15

    A new model of nonlinear electrodynamics with two parameters is investigated. We also consider a model with one dimensional parameter. It was shown that the electric field of a point-like charge is not singular at the origin and there is the finiteness of the static electric energy of point-like charged particle. We obtain the canonical and symmetrical Belinfante energy–momentum tensors and dilatation currents. It is demonstrated that the dilatation symmetry and dual symmetry are broken in the models suggested. We have calculated the static electric energy of point-like particles.

  12. Electrostatic Levitation of Fines on Asteroids

    NASA Astrophysics Data System (ADS)

    Lee, P.

    1995-09-01

    Electrostatic fields can develop at the surface of resistive asteroids exposed directly to solar radiation and to the solar wind. As on the Moon (e.g., [1-3]), the process may lead to the levitation and transport of charged grains, and contribute to winnowing asteroidal regoliths of their finest particle size fraction. Two commonly proposed mechanisms for the levitation of dust on the Moon are applied to asteroids. The first depends on global scale electrostatic fields and involves the development of a near-surface photoelectron layer over the asteroid's sunlit hemisphere [4,5] ; the second involves local fields near the terminator and particle charging by higher-energy photoelectron emission on the sunlit faces of blocks and other small-scale prominences [6,7]. Preliminary modeling results suggest that on a sufficiently resistive and slow-rotating asteroid at a heliocentric distance of 3 AU, the subsolar region evolves surface electrostatic fields of ~5 V/m^-1, while field intensities in the terminator zone may reach ~10^5 V/m^-1. Charged regolithic fines are easily levitated, their fate being a function of their charge and size. On a 20 km-radius chondritic main belt asteroid, particles up to ~100 microns across may be electro- statically accelerated to escape. Fines <=1 micron across are subject to radiation pressure and/or to solar wind drag as soon as they are lofted, and may be quickly entrained to escape even if initially launched at sub-escape velocities. Larger particles levitated in the sub-escape regime remain gravitationally bound to the asteroid and experience lateral transport along local electrostatic and gravity gradients. The particles may migrate across the asteroid's surface indefinitely or, more likely, until they settle in perenially shadowed areas and/or topographic lows (craters or grooves), thus smoothing the asteroid's topography and minimizing shadows. They will remain on the asteroid until ejected by impacts or until the particles are

  13. Fluidic electrodynamics: Approach to electromagnetic propulsion

    SciTech Connect

    Martins, Alexandre A.; Pinheiro, Mario J.

    2009-03-16

    We report on a new methodological approach to electrodynamics based on a fluidic viewpoint. We develop a systematic approach establishing analogies between physical magnitudes and isomorphism (structure-preserving mappings) between systems of equations. This methodological approach allows us to give a general expression for the hydromotive force, thus re-obtaining the Navier-Stokes equation departing from the appropriate electromotive force. From this ground we offer a fluidic approach to different kinds of issues with interest in propulsion, e.g., the force exerted by a charged particle on a body carrying current; the magnetic force between two parallel currents; the Magnus's force. It is shown how the intermingle between the fluid vector fields and electromagnetic fields leads to new insights on their dynamics. The new concepts introduced in this work suggest possible applications to electromagnetic (EM) propulsion devices and the mastery of the principles of producing electric fields of required configuration in plasma medium.

  14. Research on Orbital Plasma Electrodynamics (ROPE)

    NASA Technical Reports Server (NTRS)

    Intriligator, Devrie S.

    1998-01-01

    This final report summarizes some of the important scientific contributions to the Research on Orbital Plasma Electrodynamics (ROPE) investigation, to the Tethered Satellite System (TSS) mission, and to NASA that resulted from the work carried out under this contract at Carmel Research Center. These include Dr. Intriligator's participation in the PIT for the TSS-1R simulations and flight, her participation in ROPE team meetings and IWG meetings, her scientific analyses, and her writing and submitting technical papers to scientific journals. The scientific analyses concentrated on the characterization of energetic ions and their possible relation to pickup ion effects, correlation of particle and other effects (e.g., magnetic field, satellite surface), and collaboration with theorists including with ROPE co-investigators. In addition, scientific analyses were carried out of the effects due to satellite gas releases.

  15. Radio pulsar disk electrodynamics

    SciTech Connect

    Michel, F.C.

    1983-03-01

    We outline the macroscopic physics of a disk close to an isolated, magnetized, rotating neutron star. It seems likely that such systems are formed from time to time in the universe. The neutron star acts as a Faraday disk dynamo, and the disk acts as both a load and a neutral sheet, permitting the polar cap current to return to the neutron star and also splitting a dipolar magnetic field into two monopolar halves. Michel and Dessler have proposed that such systems are radio pulsars. The dominant energy loss is from the stellar wind torque (giving a deceleration index n = 7/3), and the next contribution is dissipation in the ''auroral'' zones, where the current returns to the star in a sheet about 5 cm thick. The latter is comparable to the observed radio luminosities and is in reasonable accord with the data. The disk itself may be a source of visible radiation comparable to that in pulsed radiofrequency emission. As the pulsar ages, the disk expands and narrows into a ring, the plausible consequence of which could be cessation of pulsed emission at periods of a few seconds.

  16. Eutectic growth under acoustic levitation conditions.

    PubMed

    Xie, W J; Cao, C D; Lü, Y J; Wei, B

    2002-12-01

    Samples of Pb-Sn eutectic alloy with a high density of 8.5 x 10(3) kg/m(3) are levitated with a single-axis acoustic levitator, and containerlessly melted and then solidified in argon atmosphere. High undercoolings up to 38 K are obtained, which results in a microstructural transition of "lamellas-broken lamellas-dendrites." This transition is further investigated in the light of the coupled zone for eutectic growth and the effects of ultrasound. The breaking of regular eutectic lamellas and suppression of gravity-induced macrosegregation of (Pb) and (Sn) dendrites are explained by the complicated internal flow inside the levitated drop, which is jointly induced by the shape oscillation, bulk vibration and rotation of the levitated drop. The ultrasonic field is also found to drive forced surface vibration, which subsequently excites capillary ripples and catalyzes nucleation on the sample surface. PMID:12513291

  17. Acoustic levitation in the presence of gravity

    NASA Technical Reports Server (NTRS)

    Collas, P.; Barmatz, M.; Shipley, C.

    1989-01-01

    The method of Gor'kov (1961) has been applied to derive general expressions for the total potential and force on a small spherical object in a resonant chamber in the presence of both acoustic and gravitational force fields. The levitation position is also determined in rectangular resonators for the simultaneous excitation of up to three acoustic modes, and the results are applied to the triple-axis acoustic levitator. The analysis is applied to rectangular, spherical, and cylindrical single-mode levitators that are arbitrarily oriented relative to the gravitational force field. Criteria are determined for isotropic force fields in rectangular and cylindrical resonators. It is demonstrated that an object will be situated within a volume of possible levitation positions at a point determined by the relative strength of the acoustic and gravitational fields and the orientation of the chamber relative to gravity.

  18. Towards hybrid circuit quantum electrodynamics with quantum dots

    NASA Astrophysics Data System (ADS)

    Viennot, Jérémie J.; Delbecq, Matthieu R.; Bruhat, Laure E.; Dartiailh, Matthieu C.; Desjardins, Matthieu M.; Baillergeau, Matthieu; Cottet, Audrey; Kontos, Takis

    2016-08-01

    Cavity quantum electrodynamics allows one to study the interaction between light and matter at the most elementary level. The methods developed in this field have taught us how to probe and manipulate individual quantum systems like atoms and superconducting quantum bits with an exquisite accuracy. There is now a strong effort to extend further these methods to other quantum systems, and in particular hybrid quantum dot circuits. This could turn out to be instrumental for a noninvasive study of quantum dot circuits and a realization of scalable spin quantum bit architectures. It could also provide an interesting platform for quantum simulation of simple fermion-boson condensed matter systems. In this short review, we discuss the experimental state of the art for hybrid circuit quantum electrodynamics with quantum dots, and we present a simple theoretical modeling of experiments.

  19. Electrodynamic radioactivity detector for microparticles

    NASA Astrophysics Data System (ADS)

    Ward, T. L.; Davis, E. J.; Jenkins, R. W., Jr.; McRae, D. D.

    1989-03-01

    A new technique for the measurement of the radioactive decay of single microparticles has been demonstrated. Although the experiments were made with droplets of order 20 μm in diameter, microparticles in the range 0.1-100 μm can be accommodated. An electrodynamic balance and combination light-scattering photometer were used to measure the charge-loss rate and size of a charged microsphere suspended in a laser beam by superposed ac and dc electrical fields. The charged particle undergoes charge loss in the partially ionized gas atmosphere which results from radioactive decay of 14C-tagged compounds, and the rate of charge loss is proportional to the rate of decay here. The charge on a particle was determined by measuring the dc voltage necessary to stably suspend the particle against gravity while simultaneously determining the droplet size by light-scattering techniques. The parameters which affect the operation of the electrodynamic balance as a radioactivity detector are examined, and the limits of its sensitivity are explored. Radioactivity levels as low as 120 pCi have been measured, and it appears that by reducing the background contamination inside our balance activity levels on the order of 10 pCi can be detected. This new technique has application in the measurement of activity levels and source discrimination of natural and man-made aerosols and smokes and is also useful for studies involving specifically labeled radio-chemical probes.

  20. Electrodynamic Tethers for Reboost of the International Space Station

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Herrmann, Melody; Vas, Irwin; Estes, Bob

    1999-01-01

    The International Space Station (ISS) will require periodic reboost due to atmospheric aerodynamic drag. This is nominally achieved through the use of thruster firings by the attached Progress M spacecraft. Many Progress flights to the ISS are required annually. Electrodynamic tethers provide an attractive alternative in that they can provide periodic reboost or continuous drag cancellation using no consumables, propellant nor conventional propulsion elements. The system could also serve as an emergency backup reboost system used only in the event resupply and reboost are delayed for some reason. The system also has direct application to spacecraft and upper stage propulsion. Electrodynamic tethers have been demonstrated in space previously with the Plasma Motor Generator (PMG) experiment and the Tethered Satellite System (TSS-IR). The advanced electrodynamic tether proposed for ISS reboost has significant advantages over previous systems in that hi-her thrust is achievable with significantly shorter tethers and without the need for an active current collection device, hence making the system simpler and much less expensive.

  1. Superferric magnets for fast levitated trains

    SciTech Connect

    Huson, F.R.; MacKay, W.W.; Miao, Y.; Pissanetzky, S. ); Xiang, Y. )

    1991-03-01

    This paper reports on the development of a technology for high-speed maglev transportation. The technology is based on self-shielded superferric magnets which provide guidance and levitation above 50 mph. A linear motor is used for propulsion. The levitation and guidance superconducting magnets are distributed along the entire length of the cars. The superferric magnet shields the fringe field within the car to less than 5 Gauss. Magnetic details and initial calculations of dynamics are presented.

  2. Equilibrium shapes of acoustically levitated drops

    NASA Astrophysics Data System (ADS)

    Trinh, E. H.; Hsu, C.-J.

    1986-05-01

    The quantitative determination of the shape of liquid drops levitated in an ultrasonic standing wave has provided experimental data on the radiation pressure-induced deformations of freely suspended liquids. Within the limits of small deviations from the spherical shape and small drop diameter relative to the acoustic wavelength, an existing approximate theory yields a good agreement with experimental evidence. The data were obtained for millimeter and submillimeter drops levitated in air under 1 g, where g is the sea level gravitational acceleration.

  3. Electrostatic Levitation for Studies of Additive Manufactured Materials

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.; Tramel, Terri

    2014-01-01

    The electrostatic levitation (ESL) laboratory at NASA's Marshall Space Flight Center is a unique facility for investigators studying high temperature materials. The laboratory boasts two levitators in which samples can be levitated, heated, melted, undercooled, and resolidified. Electrostatic levitation minimizes gravitational effects and allows materials to be studied without contact with a container or instrumentation. The lab also has a high temperature emissivity measurement system, which provides normal spectral and normal total emissivity measurements at use temperature. The ESL lab has been instrumental in many pioneering materials investigations of thermophysical properties, e.g., creep measurements, solidification, triggered nucleation, and emissivity at high temperatures. Research in the ESL lab has already led to the development of advanced high temperature materials for aerospace applications, coatings for rocket nozzles, improved medical and industrial optics, metallic glasses, ablatives for reentry vehicles, and materials with memory. Modeling of additive manufacturing materials processing is necessary for the study of their resulting materials properties. In addition, the modeling of the selective laser melting processes and its materials property predictions are also underway. Unfortunately, there is very little data for the properties of these materials, especially of the materials in the liquid state. Some method to measure thermophysical properties of additive manufacturing materials is necessary. The ESL lab is ideal for these studies. The lab can provide surface tension and viscosity of molten materials, density measurements, emissivity measurements, and even creep strength measurements. The ESL lab can also determine melting temperature, surface temperatures, and phase transition temperatures of additive manufactured materials. This presentation will provide background on the ESL lab and its capabilities, provide an approach to using the ESL

  4. Atmospheric electrodynamics in the U. S. - 1987-1990

    SciTech Connect

    Holzworth, R.H. )

    1991-01-01

    Atmospheric electrodynamics research is summarized, focusing on three general areas: the ionosphere as a source for middle atmospheric electrodynamics, regional and global scale electrodynamics, and thunderstorms and lightning. New or improved instrumentation techniques which have furthered atmospheric electrodynamics research are also discussed. 93 refs.

  5. Electrodynamic studies of upper and lower atmospheric coupling

    NASA Technical Reports Server (NTRS)

    Chiu, Y. T.; Cornwall, J. M.; Edgar, B. C.; Schulz, M.; Sharp, L. R.

    1981-01-01

    Theoretical interprotations and data interpretations of electrodynamical studies in upper and lower atmosphere coupling are reported. The following topics are discussed: (1) magnetosphere/ionosphere/atmosphere coupling in auroral electrodynamics; (2) middle atmosphere electrodynamics; (3) thermosphere troposphere coupling; and (4) tropospheric electrodynamics. Understanding of the near Earth space environment shows the interrelationships between various components of the Earth's atmosphere.

  6. Levitation and lateral forces between a point magnetic dipole and a superconducting sphere

    NASA Astrophysics Data System (ADS)

    H, M. Al-Khateeb; M, K. Alqadi; F, Y. Alzoubi; B, Albiss; M, K. Hasan (Qaseer; N, Y. Ayoub

    2016-05-01

    The dipole–dipole interaction model is employed to investigate the angular dependence of the levitation and lateral forces acting on a small magnet in an anti-symmetric magnet/superconducting sphere system. Breaking the symmetry of the system enables us to study the lateral force which is important in the stability of the magnet above a superconducting sphere in the Meissner state. Under the assumption that the lateral displacement of the magnet is small compared to the physical dimensions of our proposed system, analytical expressions are obtained for the levitation and lateral forces as a function of the geometrical parameters of the superconductor as well as the height, the lateral displacement, and the orientation of the magnetic moment of the magnet. The dependence of the levitation force on the height of the levitating magnet is similar to that in the symmetric magnet/superconducting sphere system within the range of proposed lateral displacements. It is found that the levitation force is linearly dependent on the lateral displacement whereas the lateral force is independent of this displacement. A sinusoidal variation of both forces as a function of the polar and azimuthal angles specifying the orientation of the magnetic moment is observed. The relationship between the stability and the orientation of the magnetic moment is discussed for different orientations.

  7. Levitation of iridium and liquid mercury by ultrasound.

    PubMed

    Xie, W J; Cao, C D; Lü, Y J; Wei, B

    2002-09-01

    Single-axis acoustic levitation of the heaviest solid (iridium, rho=22.6 g cm(-3)) and liquid (mercury, rho=13.6 g cm(-3) on the Earth is achieved by greatly enhancing both the levitation force and stability through optimizing the geometric parameters of the levitator. The acoustically levitated Pb-Sn eutectic alloy melt (rho=8.5 g cm(-3)) is highly undercooled by up to 38 K, which results in a microstructural transition of "lamellae-broken lamellae-dendrites." The drastic enhancement of levitation capability indicates a broader application range of single-axis acoustic levitation. PMID:12225198

  8. Velocity and rotation measurements in acoustically levitated droplets

    NASA Astrophysics Data System (ADS)

    Saha, Abhishek; Basu, Saptarshi; Kumar, Ranganathan

    2012-10-01

    The velocity scale inside an acoustically levitated droplet depends on the levitator and liquid properties. Using Particle Imaging Velocimetry (PIV), detailed velocity measurements have been made in a levitated droplet of different diameters and viscosity. The maximum velocity and rotation are normalized using frequency and amplitude of acoustic levitator, and droplet viscosity. The non-dimensional data are fitted for micrometer- and millimeter-sized droplets levitated in different levitators for different viscosity fluids. It is also shown that the rotational speed of nanosilica droplets at an advanced stage of vaporization compares well with that predicted by exponentially fitted parameters.

  9. [Acoustic Levitation Methods and Apparatus

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Jacobi, N. (Inventor)

    1982-01-01

    Methods are described for acoustically levitating objects within chambers of spherical and cylindrical shape. The wavelengths for chambers of particular dimensions are given, for generating standing wave patterns of any of a variety of modes within the chambers. For a spherical chamber the lowest resonant mode is excited by applying a wavelength of 3.02R, where R is the chamber radius. The two lowest pure radial modes for that chamber, are excited by applying wavelengths of 1.40R and 0.814R. For a cylindrical chamber of radius R, the lowest mode is at a wavelength of 3.41R, and the lowest pure radial modes are at wavelengths of 1.64R and 0.896R.

  10. Acoustic levitation methods and apparatus

    NASA Astrophysics Data System (ADS)

    Barmatz, M. B.; Jacobi, N.

    1982-03-01

    Methods are described for acoustically levitating objects within chambers of spherical and cylindrical shape. The wavelengths for chambers of particular dimensions are given, for generating standing wave patterns of any of a variety of modes within the chambers. For a spherical chamber the lowest resonant mode is excited by applying a wavelength of 3.02R, where R is the chamber radius. The two lowest pure radial modes for that chamber, are excited by applying wavelengths of 1.40R and 0.814R. For a cylindrical chamber of radius R, the lowest mode is at a wavelength of 3.41R, and the lowest pure radial modes are at wavelengths of 1.64R and 0.896R.

  11. Electrochemistry in an acoustically levitated drop.

    PubMed

    Chainani, Edward T; Ngo, Khanh T; Scheeline, Alexander

    2013-02-19

    Levitated drops show potential as microreactors, especially when radicals are present as reactants or products. Solid/liquid interfaces are absent or minimized, avoiding adsorption and interfacial reaction of conventional microfluidics. We report amperometric detection in an acoustically levitated drop with simultaneous ballistic addition of reactant. A gold microelectrode sensor was fabricated with a lithographic process; active electrode area was defined by a photosensitive polyimide mask. The microdisk gold working electrode of radius 19 μm was characterized using ferrocenemethanol in aqueous buffer. Using cyclic voltammetry, the electrochemically active surface area was estimated by combining a recessed microdisk electrode model with the Randles-Sevcik equation. Computer-controlled ballistic introduction of reactant droplets into the levitated drop was developed. Chronoamperometric measurements of ferrocyanide added ballistically demonstrate electrochemical monitoring using the microfabricated electrode in a levitated drop. Although concentration increases with time due to drop evaporation, the extent of concentration is predictable with a linear evaporation model. Comparison of diffusion-limited currents in pendant and levitated drops show that convection arising from acoustic levitation causes an enhancement of diffusion-limited current on the order of 16%. PMID:23351154

  12. Dusty Plasma Experiments Using an Electrodynamic Balance

    NASA Technical Reports Server (NTRS)

    Spann, J. F.; Abbas, M. M.; Suess, S. T.; Venturini, C. C.; Comfort, R. H.

    2000-01-01

    Knowledge of the formation, distribution, physical, chemical and optical characteristics of interstellar, interplanetary, and planetary dust grains provide valuable information about many issues dealing with the origin and formation of the solar system bodies, interplanetary and interstellar environments as well as various industrial processes. Understanding the microphysics of individual grains and their interaction with the surrounding environment is key to properly model various conditions and interpret existing data. The theory and models of individual dust grains are well developed for environments that vary from dense planetary atmospheres to dusty plasmas to diffuse environments such is interplanetary space. However, experimental investigations of individual dust grains in equilibrium are less common, perhaps due to the difficult of these experiments. Laboratory measurements of dust grains have primarily measured ensemble properties or transient properties of single grains. A technique developed in the 1950's for ion spectroscopy, known as a quadrupole trap or 'Paul Trap', has recently been used to investigate single micron-sized dust grains. This scaled ion trap called an electrodynamic balance has been used for atmospheric aerosol research. A description of this technique is provided. Recent results from experiments to investigate the equilibrium potential of dust grains exposed to far ultraviolet light or to -,in electron or ion beam are presented. This laboratory technique ]ends itself to many applications that relate to planetary atmospheres, heliospheric environments, pre-stellar and pre-planetary conditions, and industrial settings. Several planned experimental approaches are presented. Potential experiments to investigate the interaction of multiple dust grains using an electrodynamic balance are proposed.

  13. Electrostatic and electrodynamic response properties of nanostructures

    NASA Astrophysics Data System (ADS)

    Ayaz, Yuksel

    1999-11-01

    This thesis addresses the problem of nanostructure dielectric response to excitation by electric fields, both in the electrostatic c→infinity and the electrodynamic regimes. The nanostructures treated include planar quantum wells and quantum wires embedded in the vicinity of the bounding surface of the host semiconductor medium. Various cases are analyzed, including a single well or wire, a double well or wire, a lattice of N wells or wires and an infinite superlattice of wells or wires. The host medium is considered to have phonons and/or a bulk semiconductor plasma which interact with the plasmons of the embedded quantum wells or wires, and the host plasma is treated in both the local "cold" plasma regime and the nonlocal "hot" plasma regime. New hybridized quantum plasma collective modes emerge from these studies. The techniques employed here include the variational differential formulation of integral equations for the inverse dielectric function (in electrostatic case) and the dyadic Green's function (in the electrodynamic case) for the various systems described above. These integral equations are then solved in frequency-position representation by a variety of techniques depending on the geometrical features of the particular problem. Explicit closed form solutions for the inverse dielectric function or dyadic Green's function facilitate identification of the coupled collective modes in terms of their frequency poles, and the residues at the pole positions provide the relative amplitudes with which these normal modes respond to external excitation. Interesting features found include, for example, explicit formulas showing the transference of coupling of a two dimensional (2D) quantum well plasmon from a surface phonon to a bulk phonon as the 2D quantum well is displaced away from the bounding surface, deeper into the medium.

  14. Levitating states of superconducting rings in the field of a fixed ring with constant current

    NASA Astrophysics Data System (ADS)

    Bishaev, A. M.; Bush, A. A.; Gavrikov, M. B.; Denisyuk, A. I.; Kamentsev, K. E.; Kozintseva, M. V.; Savel'ev, V. V.; Sigov, A. S.

    2014-06-01

    We consider the possibility of designing a plasma trap with a magnetic system formed by super-conducting rings and coils levitating in the field of a fixed coaxial coil carrying constant current. An analytic dependence of the potential energy of such a system with one or two levitating superconducting rings having trapped preset magnetic fluxes on their coordinates in the uniform gravitational field is obtained in the thin ring approximation. Calculations performed in the Mathcad system show that equilibrium states of such a system exist for certain values of parameters. Levitating states of a single superconducting ring and two superconducting rings in the field of the coil with constant current are observed experimentally in positions corresponding to calculated values.

  15. Double row loop-coil configuration for high-speed electrodynamic maglev suspension, guidance, propulsion and guideway directional switching

    SciTech Connect

    He, J.; Rote, D.M.

    1994-12-31

    A stabilization and propulsion system comprising a series of loop-coils arranged in parallel rows wherein two rows form a magnetic rail. Levitation and lateral stability is provided when the induced field in the magnetic rails interacts with the superconducting magnets (SCM) mounted on the magnetic levitation vehicle. A multiphase propulsion system interconnects specific coils in a given magnetic rail and interacts with the SCM to produce a propulsion force to the vehicle.

  16. Stability of an electrodynamic suspension

    NASA Astrophysics Data System (ADS)

    Filatov, Alexei V.; Maslen, Eric H.; Gillies, George T.

    2002-09-01

    Previously, the authors have described a method of dynamically stabilized noncontact electromagnetic suspension of rotating bodies. The method makes use of the dynamic interaction between stationary and rotating sets of conductors and permanent magnets. The validity of this method has been demonstrated by building and testing a prototype in which noncontact suspension of a 3.2 kg rotor was achieved when it rotates at speeds above 18 Hz. A stability condition for that method of suspension was obtained with certain simplifying assumptions. One of these assumptions was that the inductive component of the stationary conductors is negligible. Here, we present modified stability conditions which take the inductance of the stationary conductors into consideration. One of the predicted effects is that nonzero inductance may cause significant reduction of the minimum stable levitation speed. Consequently, careful choice of the electrical properties of the stationary coils may significantly enhance the performance of the suspension.

  17. Electrodynamic Tether Propulsion and Power Generation at Jupiter

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Johnson, L.; Moore, J.; Bagenal, F.

    1998-01-01

    The results of a study performed to evaluate the feasibility and merits of using an electrodynamic tether for propulsion and power generation for a spacecraft in the Jovian system are presented. The environment of the Jovian system has properties which are particularly favorable for utilization of an electrodynamic tether. Specifically, the planet has a strong magnetic field and the mass of the planet dictates high orbital velocities which, when combined with the planet's rapid rotation rate, can produce very large relative velocities between the magnetic field and the spacecraft. In a circular orbit close to the planet, tether propulsive forces are found to be as high as 50 N and power levels as high as 1 MW.

  18. Electrodynamic Tether as a Thruster for LEO Mission Applications

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V; Krivorutsky, E. N.; Johnson, L.

    2006-01-01

    Electrodynamic tether propulsion has a number of attractive features and has been widely discussed for different low earth orbit applications. Despite the commonality of application, the choice of the proper design for any particular mission is a unique problem. The flight trajectory, duration, available power and voltage, and drag force should be taken into consideration with other mission requirements. Characteristics of tether performance such as system acceleration and electrical efficiency should be calculated and assessed based on the system's capability to collect electrical current. We discuss the choice of parameters for circular, tape, and grid-sphere tether anodes and their applicability to International Space Station (ISS) reboost and Momentum Exchange Electrodynamic Reboost (MXER) applications.

  19. Aspects of passive magnetic levitation based on high-T(sub c) superconducting YBCO thin films

    NASA Astrophysics Data System (ADS)

    Schoenhuber, P.; Moon, F. C.

    1995-04-01

    Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here we present fundamental studies on magnetic levitation employing cylindrical permanent magnets floating above high-T(sub c) superconducting YBCO thin films (thickness about 0.3 mu m). Experiments included free floating rotating magnets as well as well-established flexible beam methods. By means of the latter, we investigated levitation and drag force hysteresis as well as magnetic stiffness properties of the superconductor-magnet arrangement. In the case of vertical motion of the magnet, characteristic high symmetry of repulsive (approaching) and attractive (withdrawing) branches of the pronounced force-displacement hysteresis could be detected. Achievable force levels were low as expected but sufficient for levitation of permanent magnets. With regard to magnetic stiffness, thin films proved to show stiffness-force ratios about one order of magnitude higher than bulk materials. Phenomenological models support the measurements. Regarding the magnetic hysteresis of the superconductor, the Irie-Yamafuji model was used for solving the equation of force balance in cylindrical coordinates allowing for a macroscopic description of the superconductor magnetization. This procedure provided good agreement with experimental levitation force and stiffness data during vertical motion. For the case of (lateral) drag force basic qualitative characteristics could be recovered, too. It is shown that models, based on simple asymmetric magnetization of the superconductor, describe well asymptotic transition of drag forces after the change of the magnet motion direction. Virgin curves (starting from equilibrium, i.e. symmetric magnetization) are approximated by a linear approach already reported in literature only. This paper shows that basic properties of superconducting thin films allow for their application to magnetic levitation or - without need of levitation

  20. Aspects of passive magnetic levitation based on high-T(sub c) superconducting YBCO thin films

    NASA Technical Reports Server (NTRS)

    Schoenhuber, P.; Moon, F. C.

    1995-01-01

    Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here we present fundamental studies on magnetic levitation employing cylindrical permanent magnets floating above high-T(sub c) superconducting YBCO thin films (thickness about 0.3 mu m). Experiments included free floating rotating magnets as well as well-established flexible beam methods. By means of the latter, we investigated levitation and drag force hysteresis as well as magnetic stiffness properties of the superconductor-magnet arrangement. In the case of vertical motion of the magnet, characteristic high symmetry of repulsive (approaching) and attractive (withdrawing) branches of the pronounced force-displacement hysteresis could be detected. Achievable force levels were low as expected but sufficient for levitation of permanent magnets. With regard to magnetic stiffness, thin films proved to show stiffness-force ratios about one order of magnitude higher than bulk materials. Phenomenological models support the measurements. Regarding the magnetic hysteresis of the superconductor, the Irie-Yamafuji model was used for solving the equation of force balance in cylindrical coordinates allowing for a macroscopic description of the superconductor magnetization. This procedure provided good agreement with experimental levitation force and stiffness data during vertical motion. For the case of (lateral) drag force basic qualitative characteristics could be recovered, too. It is shown that models, based on simple asymmetric magnetization of the superconductor, describe well asymptotic transition of drag forces after the change of the magnet motion direction. Virgin curves (starting from equilibrium, i.e. symmetric magnetization) are approximated by a linear approach already reported in literature only. This paper shows that basic properties of superconducting thin films allow for their application to magnetic levitation or - without need of levitation

  1. Primordial magnetic fields and nonlinear electrodynamics

    SciTech Connect

    Kunze, Kerstin E.

    2008-01-15

    The creation of large scale magnetic fields is studied in an inflationary universe where electrodynamics is assumed to be nonlinear. After inflation ends electrodynamics becomes linear and thus the description of reheating and the subsequent radiation dominated stage are unaltered. The nonlinear regime of electrodynamics is described by Lagrangians having a power-law dependence on one of the invariants of the electromagnetic field. It is found that there is a range of parameters for which primordial magnetic fields of cosmologically interesting strengths can be created.

  2. Teleportation of atomic states via cavity quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Guerra, E. S.

    2004-12-01

    In this paper, we discuss a scheme of teleportation of atomic states. The experimental realization proposed makes use of cavity quatum electrodynamics involving the interaction of Rydberg atoms with a micromaser cavity prepared in a coherent state. We start presenting a scheme to prepare atomic Bell states via the interaction of atoms with a cavity. In our scheme the cavity and some atoms play the role of auxiliary systems used to achieve the teleportation.

  3. How to simply demonstrate diamagnetic levitation with pencil lead

    NASA Astrophysics Data System (ADS)

    Koudelkova, Vera

    2016-01-01

    A new simple arrangement how to demonstrate diamagnetic levitation is presented. It uses pencil lead levitating in a track built from neodymium magnets. This arrangement can also be used as a classroom experiment.

  4. How to Simply Demonstrate Diamagnetic Levitation with Pencil Lead

    ERIC Educational Resources Information Center

    Koudelkova, Vera

    2016-01-01

    A new simple arrangement how to demonstrate diamagnetic levitation is presented. It uses pencil lead levitating in a track built from neodymium magnets. This arrangement can also be used as a classroom experiment.

  5. Fluctuational electrodynamics of hyperbolic metamaterials

    SciTech Connect

    Guo, Yu; Jacob, Zubin

    2014-06-21

    We give a detailed account of equilibrium and non-equilibrium fluctuational electrodynamics of hyperbolic metamaterials. We show the unifying aspects of two different approaches; one utilizes the second kind of fluctuation dissipation theorem and the other makes use of the scattering method. We analyze the near-field of hyperbolic media at finite temperatures and show that the lack of spatial coherence can be attributed to the multi-modal nature of super-Planckian thermal emission. We also adopt the analysis to phonon-polaritonic super-lattice metamaterials and describe the regimes suitable for experimental verification of our predicted effects. The results reveal that far-field thermal emission spectra are dominated by epsilon-near-zero and epsilon-near-pole responses as expected from Kirchoff's laws. Our work should aid both theorists and experimentalists to study complex media and engineer equilibrium and non-equilibrium fluctuations for applications in thermal photonics.

  6. Theoretic and numerical analysis of diamagnetic levitation and its experimental verification

    NASA Astrophysics Data System (ADS)

    Ye, Zhitong; Duan, Zhiyong; Su, Yufeng

    2015-02-01

    Diamagnetic levitation system is studied in detail in this paper. From top to bottom, the diamagnetic levitation system is composed of a lifting magnet, a top pyrolytic graphite sheet, a floating magnet and a bottom pyrolytic graphite sheet. The gravity of the floating magnet is balanced by the attractive force between the lifting magnet and the floating magnet. And the floating magnet is stably levitated between the top and bottom graphite sheets due to their diamagnetism. The force exerted on the floating magnet is analyzed through theoretical and numerical methods, and at the same time the equilibrium position is obtained. Totally 11 groups of magnets are studied by COMSOL, in which the accumulative error is eliminated to improve the accuracy of finite element analysis(FEA). Corresponding experiments are carried out to verify the numerical results, and the error of equilibrium position is less than 10%, which shows that the FEA is precise enough to simulate the diamagnetic system. Motion characteristic is studied for group 6, in which the lifting magnet is a φ3/16"× 1/8" cylinder. For the floating magnet, the horizontal force versus the eccentric displacement and the vertical force versus the vertical displacement are calculated by COMSOL respectively. In the magnetic potential well of the lifting magnet, the floating magnet returns to the vertical central axis automatically, and the frequencies of the vertical and horizontal movements are between 4 and 5 Hz. The frequencies of the two directional movements can be tuned by the magnetic parameters of the lifting and floating magnets and the structure dimensions of the system. The method used to analyze the diamagnetic system is proved effective to design the diamagnetic levitation structure. Because of the contactless levitation of the floating magnet based on diamagnetism, the system is sensitive to very small input. This diamagnetic levitation structure is potential in micro-actuators and sensors.

  7. Continuum electrodynamics and the Abraham-Minkowski momentum controversy

    NASA Astrophysics Data System (ADS)

    Crenshaw, Michael E.

    2015-08-01

    Continuum electrodynamics is an axiomatic formal theory based on the macroscopic Maxwell equations and the constitutive relations. We apply the formal theory to a thermodynamically closed system consisting of an antireection coated block of dielectric situated in free-space and illuminated by a quasimonochromatic field. We show that valid theorems of the formal theory are proven false by relativity and by conservation laws. Then the axioms of the formal theory are proven false at a fundamental level of mathematical logic. We derive a new formal theory of continuum electrodynamics for macroscopic electric and magnetic fields in a four-dimensional at non-Minkowski material spacetime in which the speed of light is c/n.

  8. Dendrimer light-harvesting: intramolecular electrodynamics and mechanisms.

    PubMed

    Andrews, David L; Bradshaw, David S; Jenkins, Robert D; Rodríguez, Justo

    2009-12-01

    In the development of highly efficient materials for harvesting solar energy, there is an increasing focus on purpose-built dendrimers and allied multi-chromophore systems. A proliferation of antenna chromophores is not the only factor determining the sought light-harvesting efficiency; the internal geometry and photophysics of these molecules are also crucially important. In particular, the mechanisms by means of which radiant energy is ultimately trapped depends on an intricate interplay of electronic, structural, energetic and symmetry properties. To better understand these processes a sound theoretical representation of the intramolecular electrodynamics is required. A suitable formalism, based on quantum electrodynamics, readily delivers physical insights into the necessary excitation channelling processes, and it affords a rigorous basis for modelling the intramolecular flow of energy.

  9. Electrodynamic Maglev coil design and analysis

    SciTech Connect

    Davey, K.R.

    1997-09-01

    Electrodynamic Maglev systems are distinguished from electromagnetic systems in that the currents yielding lift and guidance forces are induced by the movement of the vehicle. Above a threshold speed, such a system is inherently stable, and has the additional benefit of having greater flexibility to system construction tolerances in that the magnet vertical position can change by as much as 5 cm. A stacked magnet design is considered which couples into a set of interleave coils which are interconnected in such a way as to yield both lift and guidance forces. A mutual coupling analysis is embraced wherein the mutual inductance between the permanent magnets on board the vehicle and the coils are computed using closed form analytical expressions for filaments. The derivatives of these expressions are then averaged to compute both the induced current and the forces on the coils as a function of the system geometry and speed. A full transient analysis must be performed to accurately account for entry and exit effects. The results are compared to those experimentally measured on a test track and extrapolations are offered to suggest future design considerations.

  10. Levitation performance of the magnetized bulk high- Tc superconducting magnet with different trapped fields

    NASA Astrophysics Data System (ADS)

    Liu, W.; Wang, J. S.; Liao, X. L.; Zheng, S. J.; Ma, G. T.; Zheng, J.; Wang, S. Y.

    2011-03-01

    To a high- Tc superconducting (HTS) maglev system which needs large levitation force density, the magnetized bulk high- Tc superconductor (HTSC) magnet is a good candidate because it can supply additional repulsive or attractive force above a permanent magnet guideway (PMG). Because the induced supercurrent within a magnetized bulk HTSC is the key parameter for the levitation performance, and it is sensitive to the magnetizing process and field, so the magnetized bulk HTSC magnets with different magnetizing processes had various levitation performances, not only the force magnitude, but also its force relaxation characteristics. Furthermore, the distribution and configuration of the induced supercurrent are also important factor to decide the levitation performance, especially the force relaxation characteristics. This article experimentally investigates the influences of different magnetizing processes and trapped fields on the levitation performance of a magnetized bulk HTSC magnet with smaller size than the magnetic inter-pole distance of PMG, and the obtained results are qualitatively analyzed by the Critical State Model. The test results and analyses of this article are useful for the suitable choice and optimal design of magnetized bulk HTSC magnets.

  11. Design of electrostatically levitated micromachined rotational gyroscope based on UV-LIGA technology

    NASA Astrophysics Data System (ADS)

    Cui, Feng; Chen, Wenyuan; Su, Yufeng; Zhang, Weiping; Zhao, Xiaolin

    2004-12-01

    The prevailing micromachined vibratory gyroscope typically has a proof mass connected to the substrate by a mechanical suspension system, which makes it face a tough challenge to achieve tactical or inertial grade performance levels. With a levitated rotor as the proof mass, a micromachined rotational gyroscope will potentially have higher performance than vibratory gyroscope. Besides working as a moment rebalance dual-axis gyroscope, the micromachined rotational gyroscope based on a levitated rotor can simultaneously work as a force balance tri-axis accelerometer. Micromachined rotational gyroscope based on an electrostatically levitated silicon micromachined rotor has been notably developed. In this paper, factors in designing a rotational gyro/accelerometer based on an electrostatically levitated disc-like rotor, including gyroscopic action of micro rotor, methods of stable levitation, micro displacement detection and control, rotation drive and speed control, vacuum packaging and microfabrication, are comprehensively considered. Hence a design of rotational gyro/accelerometer with an electroforming nickel rotor employing low cost UV-LIGA technology is presented. In this design, a wheel-like flat rotor is proposed and its basic dimensions, diameter and thickness, are estimated according to the required loading capability. Finally, its micromachining methods based on UV-LIGA technology and assembly technology are discussed.

  12. Levitation-melting technique for metals and alloys

    NASA Technical Reports Server (NTRS)

    Downey, J. W.

    1969-01-01

    Experimentation resulted in an improved levitation-melting technique for metals and alloys which quickly produces a completly homogeneous melt. Also developed were two levitation coils that permit a wide variety of metals to be levitated in the molten state and a helium quenching method which minimizes contamination and segregation.

  13. Acoustic Measurement Of Periodic Motion Of Levitated Object

    NASA Technical Reports Server (NTRS)

    Watkins, John L.; Barmatz, Martin B.

    1992-01-01

    Some internal vibrations, oscillations in position, and rotations of acoustically levitated object measured by use of microphone already installed in typical levitation chamber for tuning chamber to resonance and monitoring operation. Levitating acoustic signal modulated by object motion of lower frequency. Amplitude modulation detected and analyzed spectrally to determine amplitudes and frequencies of motions.

  14. Self-arraying of charged levitating droplets.

    PubMed

    Kauffmann, Paul; Nussbaumer, Jérémie; Masse, Alain; Jeandey, Christian; Grateau, Henri; Pham, Pascale; Reyne, Gilbert; Haguet, Vincent

    2011-06-01

    Diamagnetic levitation of water droplets in air is a promising phenomenon to achieve contactless manipulation of chemical or biochemical samples. This noncontact handling technique prevents contaminations of samples as well as provides measurements of interaction forces between levitating reactors. Under a nonuniform magnetic field, diamagnetic bodies such as water droplets experience a repulsive force which may lead to diamagnetic levitation of a single or few micro-objects. The levitation of several repulsively charged picoliter droplets was successfully performed in a ~1 mm(2) adjustable flat magnetic well provided by a centimeter-sized cylindrical permanent magnet structure. Each droplet position results from the balance between the centripetal diamagnetic force and the repulsive Coulombian forces. Levitating water droplets self-organize into satellite patterns or thin clouds, according to their charge and size. Small triangular lattices of identical droplets reproduce magneto-Wigner crystals. Repulsive forces and inner charges can be measured in the piconewton and the femtocoulomb ranges, respectively. Evolution of interaction forces is accurately followed up over time during droplet evaporation.

  15. Dynamics of acoustically levitated disk samples.

    PubMed

    Xie, W J; Wei, B

    2004-10-01

    The acoustic levitation force on disk samples and the dynamics of large water drops in a planar standing wave are studied by solving the acoustic scattering problem through incorporating the boundary element method. The dependence of levitation force amplitude on the equivalent radius R of disks deviates seriously from the R3 law predicted by King's theory, and a larger force can be obtained for thin disks. When the disk aspect ratio gamma is larger than a critical value gamma(*) ( approximately 1.9 ) and the disk radius a is smaller than the critical value a(*) (gamma) , the levitation force per unit volume of the sample will increase with the enlargement of the disk. The acoustic levitation force on thin-disk samples ( gammalevitation of a large water drop is to adjust the reflector-emitter interval H slightly above the resonant interval H(n) . The simulation shows that the drop is flattened and the central parts of its top and bottom surface become concave with the increase of sound pressure level, which agrees with the experimental observation. The main frequencies of the shape oscillation under different sound pressures are slightly larger than the Rayleigh frequency because of the large shape deformation. The simulated translational frequencies of the vertical vibration under normal gravity condition agree with the theoretical analysis. PMID:15600551

  16. Dynamics of acoustically levitated disk samples

    NASA Astrophysics Data System (ADS)

    Xie, W. J.; Wei, B.

    2004-10-01

    The acoustic levitation force on disk samples and the dynamics of large water drops in a planar standing wave are studied by solving the acoustic scattering problem through incorporating the boundary element method. The dependence of levitation force amplitude on the equivalent radius R of disks deviates seriously from the R3 law predicted by King’s theory, and a larger force can be obtained for thin disks. When the disk aspect ratio γ is larger than a critical value γ*(≈1.9) and the disk radius a is smaller than the critical value a*(γ) , the levitation force per unit volume of the sample will increase with the enlargement of the disk. The acoustic levitation force on thin-disk samples (γ⩽γ*) can be formulated by the shape factor f(γ,a) when a⩽a*(γ) . It is found experimentally that a necessary condition of the acoustic field for stable levitation of a large water drop is to adjust the reflector-emitter interval H slightly above the resonant interval Hn . The simulation shows that the drop is flattened and the central parts of its top and bottom surface become concave with the increase of sound pressure level, which agrees with the experimental observation. The main frequencies of the shape oscillation under different sound pressures are slightly larger than the Rayleigh frequency because of the large shape deformation. The simulated translational frequencies of the vertical vibration under normal gravity condition agree with the theoretical analysis.

  17. Self-arraying of charged levitating droplets.

    PubMed

    Kauffmann, Paul; Nussbaumer, Jérémie; Masse, Alain; Jeandey, Christian; Grateau, Henri; Pham, Pascale; Reyne, Gilbert; Haguet, Vincent

    2011-06-01

    Diamagnetic levitation of water droplets in air is a promising phenomenon to achieve contactless manipulation of chemical or biochemical samples. This noncontact handling technique prevents contaminations of samples as well as provides measurements of interaction forces between levitating reactors. Under a nonuniform magnetic field, diamagnetic bodies such as water droplets experience a repulsive force which may lead to diamagnetic levitation of a single or few micro-objects. The levitation of several repulsively charged picoliter droplets was successfully performed in a ~1 mm(2) adjustable flat magnetic well provided by a centimeter-sized cylindrical permanent magnet structure. Each droplet position results from the balance between the centripetal diamagnetic force and the repulsive Coulombian forces. Levitating water droplets self-organize into satellite patterns or thin clouds, according to their charge and size. Small triangular lattices of identical droplets reproduce magneto-Wigner crystals. Repulsive forces and inner charges can be measured in the piconewton and the femtocoulomb ranges, respectively. Evolution of interaction forces is accurately followed up over time during droplet evaporation. PMID:21500859

  18. Study on Transient Properties of Levitated Object in Near-Field Acoustic Levitation

    NASA Astrophysics Data System (ADS)

    Jia, Bing; Chen, Chao; Zhao, Chun-Sheng

    2011-12-01

    A new approach to the study on the transient properties of the levitated object in near-field acoustic levitation (NFAL) is presented. In this article, the transient response characteristics, including the levitated height of an object with radius of 24 mm and thickness of 5 mm, the radial velocity and pressure difference of gas at the boundary of clearance between the levitated object and radiating surface (squeeze film), is calculated according to several velocity amplitudes of radiating surface. First, the basic equations in fluid areas on Arbitrary Lagrange—Euler (ALE) form are numerically solved by using streamline upwind petrov galerkin (SUPG) finite elements method. Second, the formed algebraic equations and solid control equations are solved by using synchronous alternating method to gain the transient messages of the levitated object and gas in the squeeze film. Through theoretical and numerical analyses, it is found that there is a oscillation time in the transient process and that the response time does not simply increase with the increasing of velocity amplitudes of radiating surface. More investigations in this paper are helpful for the understanding of the transient properties of levitated object in NFAL, which are in favor of enhancing stabilities and responsiveness of levitated object.

  19. Observations on the Freezing of Supercooled Pollen Washing Water by a New Electrodynamic Balance

    NASA Astrophysics Data System (ADS)

    Tong, Haijie; Pope, Francis D.; Kalberer, Markus

    2014-05-01

    Primary biological particles can act as efficient ice nuclei (IN) by initiating freezing events at temperatures warmer than the homogenous freezing temperature [1, 2]. For example, pollen grain particles can trigger freezing events at temperatures as warm as -5 °C in the contact freezing mode [3]. More recently pollen residues, which are released by washing pollen grains in water, were also observed to act as efficient IN in the immersion mode [4, 5]. In this study we developed a new cold electrodynamic balance (CEDB) system and investigated the freezing properties of single particles of supercooled pollen washing water (SPWW). The EDB technique allows for a contact free measurement of freezing events. The phase of the particle (liquid or frozen solid) can be distinguished via measuring the Mie scattering signal from the particle. Furthermore the size of liquid (spherical) particles can be determined. The freezing events are characterized through the loss of the regular Mie scattering signal from the levitated droplet as it changes state from liquid to a frozen solid. The statistical freezing probabilities of SPWW were obtained in the temperature range: -15 to -40 °C. Each temperature measurement point consists of the analysis of 30-100 droplets. Preliminary conclusions are that SPWW is IN active in the immersion mode. Further discussion will focus on the temperature range of the IN activity, the important variables (other than temperature) for IN activity, other likely modes of IN activity, and the implications of these results in terms of the atmospheric relevance of SPWW. This study was supported by the NERC. We acknowledge Professor Jonathan Reid and James Davis from the University of Bristol for providing information of the design of the warm EDB system. References: [1] Möhler, O., et al. (2007) Biogeosciences, 4, 1059-1071. [2] Prenni, A. J., et al. (2009) Nat. Geosci., 2, 401-404. [3] Diehl, K., et al. (2002) Atmos. Res., 61, 125-133. [4] Pummer, B. G

  20. [Computer modeling of electrodynamic processes in SHF-based water disinfection and heating system as part of the spacecrew life support system].

    PubMed

    Klimarev, S I; Zaĭtsev, K A

    2012-01-01

    To optimize the design of SHF-based potable water disinfection and heating subsystem within the life support system (LSS), computer modeling of the super-high frequency electromagnetic field in SHF-based waveguide-coaxial and coaxial running water heaters was performed Software package CST Microwave Studio 2010 was used as the main instrument in the investigation. Results of the investigation can contribute to the development and prototyping of an HSF-based water heater as an integral part of advanced life support system for spacecrews

  1. Materials science investigations using electromagnetic levitation

    NASA Astrophysics Data System (ADS)

    Seidel, A.; Soellner, W.; Stenzel, C.

    2011-12-01

    EML on ISS allows levitating liquid samples both above and below their melting points for extended periods under ultra-high vacuum or ultra clean noble gas atmosphere. Various stimuli can be applied to the samples for dedicated experiment objectives. The heat input into the sample can be modulated to induce a thermal response of the sample, short heater pulses can be used to induce surface shape oscillations of the liquid sample, a custom made trigger needle can be driven into the undercooled sample to induce heterogeneous nucleation at a predefined temperature, touching of the sample by a dedicated chill cool plate or application of a forced gas flow can be used to increase the cooling rate of the sample or to simulate convection for reference experiments. Dedicated diagnostics elements are available to measure the physical properties of the sample. Sample temperature is measured by a pyrometer; two video units in orthogonal views provide both high spatial (up to 1 Megapixel and relative size resolution 2 * 10-4) and temporal (up to 30 kHz) resolution. Additional capabilities are under discussion which would allow to measure the electrical conductivity of the sample from electrical data of the rf coil system, and to determine the residual oxygen content of the process atmosphere.

  2. Non-US electrodynamic launchers research and development

    SciTech Connect

    Parker, J.V.; Batteh, J.H.; Greig, J.R.; Keefer, D.; McNab, I.R.; Zabar, Z.

    1994-11-01

    Electrodynamic launcher research and development work of scientists outside the United States is analyzed and assessed by six internationally recognized US experts in the field of electromagnetic and electrothermal launchers. The assessment covers five broad technology areas: (1) Experimental railguns; (2) Railgun theory and design; (3) Induction launchers; (4) Electrothermal guns; (5) Energy storage and power supplies. The overall conclusion is that non-US work on electrodynamic launchers is maturing rapidly after a relatively late start in many countries. No foreign program challenges the US efforts in scope, but it is evident that the United States may be surpassed in some technologies within the next few years. Until recently, published Russian work focused on hypervelocity for research purposes. Within the last two years, large facilities have been described where military-oriented development has been underway since the mid-1980s. Financial support for these large facilities appears to have collapsed, leaving no effective effort to develop practical launchers for military or civilian applications. Electrodynamic launcher research in Europe is making rapid progress by focusing on a single application, tactical launchers for the military. Four major laboratories, in Britain, France, Germany, and the Netherlands, are working on this problem. Though narrower in scope than the US effort, the European work enjoys a continuity of support that has accelerated its progress. The next decade will see the deployment of electrodynamic launcher technology, probably in the form of an electrothermal-chemical upgrade for an existing gun system. The time scale for deployment of electromagnetic launchers is entirely dependent on the level of research-and-development effort. If resources remain limited, the advantage will lie with cooperative efforts that have reasonably stable funding such as the present French-German program.

  3. Middle Atmosphere Electrodynamics (MAE). Middle atmospheric electrodynamics during MAP

    NASA Technical Reports Server (NTRS)

    Goldberg, R. A.

    1989-01-01

    The recent revival and strong motivation for research in middle atmospheric electrodynamics can be attributed, in large part, to the discovery of large (V/m) electric fields within the lower mesosphere during the decade prior to MAP. Subsequent rocket soundings appeared to verify the preliminary findings. During the MAP era, more sophisticated techniques have been employed to obtain measurements which respond positively to criticisms of earlier results, and which provide more insight regarding the character of the fields. The occurrence of mesospheric V/m electric fields now seems to require the presence of aerosols, of local winds and related dynamics, and of an atmospheric electrical conductivity less than 10(-10)S/m. Furthermore, new theoretical ideas describing the origin of the V/m fields are consistent with the measurements. The current status of results regarding V/m fields in the middle atmosphere is reviewed in light of the more widely accepted electric field structure for this region from rocket, balloon and modeling results.

  4. Electrodynamic Approach for Visualization of Sound Propagation in Solids

    NASA Astrophysics Data System (ADS)

    Völz, U.; Mrasek, H.; Matthies, K.; Wü; stenberg, H.; Kreutzbruck, M.

    2009-03-01

    The visualization of sound propagation in solids is vital for transducer adaptation and better understanding of complex test samples and their wave propagation modeling. In this work we present an electrodynamic technique detecting the grazing sound beam with a 10 mm-sized electrodynamic probe. The particle displacement along the sample's surface was then measured as a function of time and position. Adapting the electrodynamic probe and its coil alignment allows for measuring the displacement components in all three dimensions. Thus horizontal and vertical particle displacement with respect to the surface can be detected. A SNR of up to 40 dB could be achieved within ferromagnetic and high conductive chrome steel when using a shear wave generated by an angle beam probe. When dealing with nonconductive materials such as PMMA we obtained a reduced SNR of 12 dB. We report on measurements of the sound field in complex weld joints. One example shows a narrow gap weld joining a nickel alloy with a chrome steel. The weld of the 80 mm-thick test block shows a distinct anisotropic texture. The system enables us to visualize the wave propagation within the weld and indicates the reflection and scattering scenario and the energy losses due to both the anisotropic structure and material defects.

  5. Global ionospheric dynamics and electrodynamics during geomagnetic storms (Invited)

    NASA Astrophysics Data System (ADS)

    Mannucci, A. J.; Tsurutani, B.; Verkhoglyadova, O. P.; Komjathy, A.; Butala, M. D.

    2013-12-01

    Globally distributed total electron content (TEC) data has become an important tool for exploring the consequences of storm-time electrodynamics. Magnetosphere-ionosphere coupling during the main phase is responsible for the largest ionospheric effects observed during geomagnetic storms, mediated by global scale electrodynamics. Recent research using case studies reveals a complex picture of M-I coupling and its relationship to interplanetary drivers such as the solar wind electric field. Periods of direct coupling exist where the solar wind electric field is strongly correlated with prompt penetration electric fields, observed as enhanced vertical plasma drifts or an enhanced electrojet in the daytime equatorial ionosphere. Periods of decoupling between low latitude electric fields and the solar wind electric field are also observed, but the factors distinguishing these two types of response have not been clearly identified. Recent studies during superstorms suggest a role for the transverse (y-component) of the interplanetary magnetic field, which affects magnetospheric current systems and therefore may affect M-I coupling, with significant ionospheric consequences. Observations of the global ionospheric response to a range of geomagnetic storm intensities are presented. Scientific understanding of the different factors that affect electrodynamic aspects of M-I coupling are discussed.

  6. Levitation Performance of Two Opposed Permanent Magnet Pole-Pair Separated Conical Bearingless Motors

    NASA Technical Reports Server (NTRS)

    Kascak, Peter; Jansen, Ralph; Dever, Timothy; Nagorny, Aleksandr; Loparo, Kenneth

    2013-01-01

    In standard motor applications, rotor suspension with traditional mechanical bearings represents the most economical solution. However, in certain high performance applications, rotor suspension without contacting bearings is either required or highly beneficial. Examples include applications requiring very high speed or extreme environment operation, or with limited access for maintenance. This paper expands upon a novel bearingless motor concept, in which two motors with opposing conical air-gaps are used to achieve full five-axis levitation and rotation of the rotor. Force in this motor is created by deliberately leaving the motor s pole-pairs unconnected, which allows the creation of different d-axis flux in each pole pair. This flux imbalance is used to create lateral force. This approach is different than previous bearingless motor designs, which require separate windings for levitation and rotation. This paper examines the predicted and achieved suspension performance of a fully levitated prototype bearingless system.

  7. Raman acoustic levitation spectroscopy of red blood cells and Plasmodium falciparum trophozoites.

    PubMed

    Puskar, Ljiljana; Tuckermann, Rudolf; Frosch, Torsten; Popp, Jürgen; Ly, Vanalysa; McNaughton, Don; Wood, Bayden R

    2007-09-01

    Methods to probe the molecular structure of living cells are of paramount importance in understanding drug interactions and environmental influences in these complex dynamical systems. The coupling of an acoustic levitation device with a micro-Raman spectrometer provides a direct molecular probe of cellular chemistry in a containerless environment minimizing signal attenuation and eliminating the affects of adhesion to walls and interfaces. We show that the Raman acoustic levitation spectroscopic (RALS) approach can be used to monitor the heme dynamics of a levitated 5 microL suspension of red blood cells and to detect hemozoin in malaria infected cells. The spectra obtained have an excellent signal-to-noise ratio and demonstrate for the first time the utility of the technique as a diagnostic and monitoring tool for minute sample volumes of living animal cells. PMID:17713610

  8. Acoustic levitation of a large solid sphere

    NASA Astrophysics Data System (ADS)

    Andrade, Marco A. B.; Bernassau, Anne L.; Adamowski, Julio C.

    2016-07-01

    We demonstrate that acoustic levitation can levitate spherical objects much larger than the acoustic wavelength in air. The acoustic levitation of an expanded polystyrene sphere of 50 mm in diameter, corresponding to 3.6 times the wavelength, is achieved by using three 25 kHz ultrasonic transducers arranged in a tripod fashion. In this configuration, a standing wave is created between the transducers and the sphere. The axial acoustic radiation force generated by each transducer on the sphere was modeled numerically as a function of the distance between the sphere and the transducer. The theoretical acoustic radiation force was verified experimentally in a setup consisting of an electronic scale and an ultrasonic transducer mounted on a motorized linear stage. The comparison between the numerical and experimental acoustic radiation forces presents a good agreement.

  9. Conjunctions and Collision Avoidance with Electrodynamic Tethers

    NASA Astrophysics Data System (ADS)

    Levin, E.

    2013-09-01

    Electrodynamic propulsion technology is currently in development by NASA, ESA, and JAXA for the purpose of affordable removal of large debris objects from LEO. At the same time, the Naval Research Laboratory is preparing a 3U CubeSat with a 1-km electrodynamic tether for a flight demonstration of electrodynamic propulsion. This type of propulsion does not require fuel. The electrodynamic thrust is the Lorentz force acting on the electric current in a long conductor (tether) in the geomagnetic field. Electrons are collected from the ambient plasma on one end and emitted back into the plasma from the other end. The electric current loop is closed through the ionosphere, as demonstrated in two previous flights. The vehicle is solar powered. To support safe navigation of electrodynamic tethers, proper conjunction analysis and collision avoidance strategies are needed. The typical lengths of electrodynamic tethers for near-term applications are measured in kilometers, and the conjunction geometry is very different from the geometry of conjunctions between compact objects. It is commonly thought that the collision cross-section in a conjunction between a tether and a compact object is represented by the product of the tether length and the size of the object. However, rigorous analysis shows that this is not the case, and that the above assumption leads to grossly overestimated collision probabilities. The paper will present the results of a detailed mathematical analysis of the conjunction geometry and collision probabilities in close approaches between electrodynamic tethers and compact objects, such as satellites, rocket bodies, and debris fragments. Electrodynamic spacecraft will not require fuel, and therefore, can thrust constantly. Their orbit transfers can take many days, but can result in major orbit changes, including large rotations of the orbital plane, both in the inclination and the node. During these orbit transfers, the electrodynamic spacecraft will

  10. Conductive Tether Coating for Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Vaughn, Jason A.; Schuler, Pete

    2000-01-01

    The Propulsive Small Expendable Deployer System (ProSEDS), which is an on-orbit demonstration of the propulsion capabilities of electrodynamic tethers in space, is a secondary payload on a Delta 11 unmanned expendable booster. The ProSEDS tether consists of a 5 km bare electrodynamic tether and a 1 0-km non-conductive leader tether. Near the Delta 11, 160 m of the conductive tether is insulated to prevent plasma electron collection from the plasma contactor and for other science requirements. The remainder of the 5-km conductive tether is coated with a new conductive coating to collect plasma electrons. A bare metal tether easily collects electrons from the plasma, but thermal concerns preclude this design. A highly emissive conductive polymer developed by Triton Systems, Inc. has been optimized for both conductivity and thermo-optical properties. The current design for the ProSEDS conductive tether is seven individually coated strands of 28 AWG aluminum wire, coated with an atomic oxygen-resistant conductive polymer composed of a mixture of COR (Colorless Oxygen Resistant) and polyanaline (PANI) known as C-COR (Conductive-Colorless Oxygen Resistant). The conductive-coated wire strands are cold-welded to individually coated strands of the insulated tether. The insulated tether is coated with 1 mil of polyimide and an atomic oxygen resistant polymer TOR-BP. The insulated tether must stand off the entire voltage of the tether (1 200 V) at various times during the mission. All seven wires are twisted around a Kevlar-29 core using the Hi-wire design. Extensive testing has been performed at the Marshall Space Flight Center to qualify both the conductive coating and insulating coating for use on the ProSEDS tether. The conductive coating has been exposed to a plasma to verify the coatings ability to collect electrons from the space plasma from 0 to 1500 V, and to verify the coatings ability to collect electrons after atomic oxygen exposure. The insulated coating has been

  11. Particle manipulation by a non-resonant acoustic levitator

    NASA Astrophysics Data System (ADS)

    Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

    2015-01-01

    We present the analysis of a non-resonant acoustic levitator, formed by an ultrasonic transducer and a concave reflector. In contrast to traditional levitators, the geometry presented herein does not require the separation distance between the transducer and the reflector to be a multiple of half wavelength. The levitator behavior is numerically predicted by applying a numerical model to calculate the acoustic pressure distribution and the Gor'kov theory to obtain the potential of the acoustic radiation force that acts on a levitated particle. We also demonstrate that levitating particles can be manipulated by controlling the reflector position while maintaining the transducer in a fixed position.

  12. Particle manipulation by a non-resonant acoustic levitator

    SciTech Connect

    Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

    2015-01-05

    We present the analysis of a non-resonant acoustic levitator, formed by an ultrasonic transducer and a concave reflector. In contrast to traditional levitators, the geometry presented herein does not require the separation distance between the transducer and the reflector to be a multiple of half wavelength. The levitator behavior is numerically predicted by applying a numerical model to calculate the acoustic pressure distribution and the Gor'kov theory to obtain the potential of the acoustic radiation force that acts on a levitated particle. We also demonstrate that levitating particles can be manipulated by controlling the reflector position while maintaining the transducer in a fixed position.

  13. High T sub c superconducting levitation motor with a laser commutator

    SciTech Connect

    Weeks, D.E. )

    1990-01-01

    A high {ital T}{sub {ital c}} superconducting levitation bearing driven by an optically switched solenoid is described. The bearing uses flux pinning in the new high {ital T}{sub {ital c}} superconductors for stability. A simple liquid nitrogen supply system is described that greatly improves the ease with which high {ital T}{sub {ital c}} superconductors can be maintained at 77 K for extended periods of time in small styrofoam dishes. A force versus height curve is given and is used to determine the design limits of the levitation bearing. Alternate motor designs are discussed.

  14. Determining Equilibrium Position For Acoustical Levitation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Aveni, G.; Putterman, S.; Rudnick, J.

    1989-01-01

    Equilibrium position and orientation of acoustically-levitated weightless object determined by calibration technique on Earth. From calibration data, possible to calculate equilibrium position and orientation in presence of Earth gravitation. Sample not levitated acoustically during calibration. Technique relies on Boltzmann-Ehrenfest adiabatic-invariance principle. One converts resonant-frequency-shift data into data on normalized acoustical potential energy. Minimum of energy occurs at equilibrium point. From gradients of acoustical potential energy, one calculates acoustical restoring force or torque on objects as function of deviation from equilibrium position or orientation.

  15. Method and apparatus for acoustic levitation

    SciTech Connect

    Danley, T.J.; Merkley, D.R.; Rey, C.A.

    1991-08-06

    This patent describes a method for acoustically levitating an object along a first axis in a sound transmitting medium. It comprises providing a pair of independent opposed, spaced sound sources along the first axis, operating the sound sources at substantially the same frequency such that the sound waves from the respective sources interfere without use of reflective surfaces and creation of standing waves to create at least one well of acoustic energy between the interfering sound waves, and disposing the object into the one well to acoustically levitate the object.

  16. Dr. Jan Rogers with Electrostatic Levitator

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Dr. Jan Rogers, project scientist for the Electrostatic Levitator (ESL) at NASA's Marshall Space Flight Center(MSFC). The ESL uses static electricity to suspend an obejct (about 2-3 mm in diameter) inside a vacuum chamber while a laser heats the sample until it melts. This lets scientists record a wide range of physical properties without the sample contacting the container or any instruments, conditions that would alter the readings. The Electrostatic Levitator is one of several tools used in NASA's microgravity materials sciences program.

  17. Nonlinear electrodynamics and CMB polarization

    SciTech Connect

    Cuesta, Herman J. Mosquera; Lambiase, G. E-mail: lambiase@sa.infn.it

    2011-03-01

    Recently WMAP and BOOMERanG experiments have set stringent constraints on the polarization angle of photons propagating in an expanding universe: Δα = (−2.4±1.9)°. The polarization of the Cosmic Microwave Background radiation (CMB) is reviewed in the context of nonlinear electrodynamics (NLED). We compute the polarization angle of photons propagating in a cosmological background with planar symmetry. For this purpose, we use the Pagels-Tomboulis (PT) Lagrangian density describing NLED, which has the form L ∼ (X/Λ{sup 4}){sup δ−1} X, where X = ¼F{sub αβ}F{sup αβ}, and δ the parameter featuring the non-Maxwellian character of the PT nonlinear description of the electromagnetic interaction. After looking at the polarization components in the plane orthogonal to the (x)-direction of propagation of the CMB photons, the polarization angle is defined in terms of the eccentricity of the universe, a geometrical property whose evolution on cosmic time (from the last scattering surface to the present) is constrained by the strength of magnetic fields over extragalactic distances.

  18. Optimal Electrodynamic Tether Phasing Maneuvers

    NASA Technical Reports Server (NTRS)

    Bitzer, Matthew S.; Hall, Christopher D.

    2007-01-01

    We study the minimum-time orbit phasing maneuver problem for a constant-current electrodynamic tether (EDT). The EDT is assumed to be a point mass and the electromagnetic forces acting on the tether are always perpendicular to the local magnetic field. After deriving and non-dimensionalizing the equations of motion, the only input parameters become current and the phase angle. Solution examples, including initial Lagrange costates, time of flight, thrust plots, and thrust angle profiles, are given for a wide range of current magnitudes and phase angles. The two-dimensional cases presented use a non-tilted magnetic dipole model, and the solutions are compared to existing literature. We are able to compare similar trajectories for a constant thrust phasing maneuver and we find that the time of flight is longer for the constant thrust case with similar initial thrust values and phase angles. Full three-dimensional solutions, which use a titled magnetic dipole model, are also analyzed for orbits with small inclinations.

  19. Nanofriction in Cavity Quantum Electrodynamics.

    PubMed

    Fogarty, T; Cormick, C; Landa, H; Stojanović, Vladimir M; Demler, E; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics. PMID:26684118

  20. Nanofriction in Cavity Quantum Electrodynamics.

    PubMed

    Fogarty, T; Cormick, C; Landa, H; Stojanović, Vladimir M; Demler, E; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics.

  1. Nanofriction in Cavity Quantum Electrodynamics

    NASA Astrophysics Data System (ADS)

    Fogarty, T.; Cormick, C.; Landa, H.; Stojanović, Vladimir M.; Demler, E.; Morigi, Giovanna

    2015-12-01

    The dynamics of cold trapped ions in a high-finesse resonator results from the interplay between the long-range Coulomb repulsion and the cavity-induced interactions. The latter are due to multiple scatterings of laser photons inside the cavity and become relevant when the laser pump is sufficiently strong to overcome photon decay. We study the stationary states of ions coupled with a mode of a standing-wave cavity as a function of the cavity and laser parameters, when the typical length scales of the two self-organizing processes, Coulomb crystallization and photon-mediated interactions, are incommensurate. The dynamics are frustrated and in specific limiting cases can be cast in terms of the Frenkel-Kontorova model, which reproduces features of friction in one dimension. We numerically recover the sliding and pinned phases. For strong cavity nonlinearities, they are in general separated by bistable regions where superlubric and stick-slip dynamics coexist. The cavity, moreover, acts as a thermal reservoir and can cool the chain vibrations to temperatures controlled by the cavity parameters and by the ions' phase. These features are imprinted in the radiation emitted by the cavity, which is readily measurable in state-of-the-art setups of cavity quantum electrodynamics.

  2. Thickness dependence of the levitation performance of double-layer high-temperature superconductor bulks above a magnetic rail

    NASA Astrophysics Data System (ADS)

    Sun, R. X.; Zheng, J.; Liao, X. L.; Che, T.; Gou, Y. F.; He, D. B.; Deng, Z. G.

    2014-10-01

    A double-layer high-temperature superconductor (HTSC) arrangement was proposed and proved to be able to bring improvements to both levitation force and guidance force compared with present single-layer HTSC arrangement. To fully exploit the applied magnetic field by a magnetic rail, the thickness dependence of a double-layer HTSC arrangement on the levitation performance was further investigated in the paper. In this study, the lower-layer bulk was polished step by step to different thicknesses, and the upper-layer bulk with constant thickness was directly superimposed on the lower-layer one. The levitation force and the force relaxation of the double-layer HTSC arrangement were measured above a Halbach magnetic rail. Experimental result shows that a bigger levitation force and a less levitation force decay could be achieved by optimizing the thickness of the lower-layer bulk HTSC. This thickness optimization method could be applied together with former reported double-layer HTSC arrangement method with aligned growth sector boundaries pattern. This series of study on the optimized combination method do bring a significant improvement on the levitation performance of present HTS maglev systems.

  3. Spin-Up Instability of a Levitated Molten Drop in MHD-Flow Transition to Turbulence

    NASA Technical Reports Server (NTRS)

    Abedian, B.; Hyers, R. W.; Curreri, Peter A. (Technical Monitor)

    2002-01-01

    When an alternating magnetic field interacts with induced eddy currents in a conducting body, there will be a repulsive force between the body and the driving coil system generating the field. This repulsive force is the basis of electromagnetic levitation, which allows containerless processing of different materials. The eddy currents in the conducting body also generate Joule heating. Axial rotation of electromagnetically levitated objects is a common observation in levitation systems and often an undesirable side effect of such experiments on 1-g and -g. There have been recent efforts to use magnetic damping and suppress this tendency of body rotation. The first report of rotation in EML drops was attributed to a slight asymmetry of the shape and location of the levitation coils could change the axis and speed of rotation. Other theories of sample rotation include a frequency difference in the traveling electromagnetic waves and a phase difference in two different applied fields of the same frequency. All of these different mechanisms share the following characteristics: the torque is small, constant for constant field strength, and very weakly dependent on the sample's temperature and phase (solid or liquid). During experiments on the MSL-1 (First Microgravity Science Laboratory) mission of the Space Shuttle (STS-83 and STS-94, April and July 1997), a droplet of palladium-silicon alloy was electromagnetically levitated for viscosity measurements. For the non-deforming droplet, the resultant MHD flow inside the drop is inferred from motion of impurities on the surface. These observations indicate formation of a pair of co-rotating toroidal flow structures inside the spheroidal levitated drop that undergo secondary flow instabilities. As rise in the fluid temperature rises, the viscosity falls and the internal flow accelerates and becomes oscillatory; and beyond a point in the experiments, the surface impurities exhibit non-coherent chaotic motion signifying

  4. Resolution of a paradox in classical electrodynamics

    SciTech Connect

    Pinto, Fabrizio

    2006-05-15

    It is an early result of electrostatics in curved space that the gravitational mass of a charge distribution changes by an amount equal to U{sub es}/c{sup 2}, where U{sub es} is the internal electrostatic potential energy and c is the speed of light, if the system is supported at rest by external forces. This fact, independently rediscovered in recent years in the case of a simple dipole, confirms a very reasonable expectation grounded in the mass-energy equivalency equation. However, it is an unsolved paradox of classical electrodynamics that the renormalized mass of an accelerated dipole calculated from the self-forces due to the distortion of the Coulomb field differs in general from that expected from the energy correction, U{sub es}/c{sup 2}, unless the acceleration is transversal to the orientation of the dipole. Here we show that this apparent paradox disappears for any dipole orientation if the self-force is evaluated by means of Whittaker's exact solution for the field of the single charge in a homogeneous gravitational field described in the Rindler metric. The discussion is supported by computer algebra results, diagrams of the electric fields distorted by gravitation, and a brief analysis of the prospects for realistic experimentation. The gravitational correction to dipole-dipole interactions is also discussed.

  5. PT-symmetric quantum electrodynamics and unitarity.

    PubMed

    Milton, Kimball A; Abalo, E K; Parashar, Prachi; Pourtolami, Nima; Wagner, J

    2013-04-28

    More than 15 years ago, a new approach to quantum mechanics was suggested, in which Hermiticity of the Hamiltonian was to be replaced by invariance under a discrete symmetry, the product of parity and time-reversal symmetry, PT. It was shown that, if PT is unbroken, energies were, in fact, positive, and unitarity was satisfied. Since quantum mechanics is quantum field theory in one dimension--time--it was natural to extend this idea to higher-dimensional field theory, and in fact an apparently viable version of PT-invariant quantum electrodynamics (QED) was proposed. However, it has proved difficult to establish that the unitarity of the scattering matrix, for example, the Källén spectral representation for the photon propagator, can be maintained in this theory. This has led to questions of whether, in fact, even quantum mechanical systems are consistent with probability conservation when Green's functions are examined, since the latter have to possess physical requirements of analyticity. The status of PT QED will be reviewed in this paper, as well as the general issue of unitarity.

  6. Renormalizable Electrodynamics of Scalar and Vector Mesons. Part II

    DOE R&D Accomplishments Database

    Salam, Abdus; Delbourgo, Robert

    1964-01-01

    The "gauge" technique" for solving theories introduced in an earlier paper is applied to scalar and vector electrodynamics. It is shown that for scalar electrodynamics, there is no {lambda}φ*2φ2 infinity in the theory, while with conventional subtractions vector electrodynamics is completely finite. The essential ideas of the gauge technique are explained in section 3, and a preliminary set of rules for finite computation in vector electrodynamics is set out in Eqs. (7.28) - (7.34).

  7. Reducing Thermal Conduction In Acoustic Levitators

    NASA Technical Reports Server (NTRS)

    Lierke, Ernst G.; Leung, Emily W.; Bhat, Balakrishna T.

    1991-01-01

    Acoustic transducers containing piezoelectric driving elements made more resistant to heat by reduction of effective thermal-conductance cross sections of metal vibration-transmitting rods in them, according to proposal. Used to levitate small objects acoustically for noncontact processing in furnaces. Reductions in cross sections increase amplitudes of transmitted vibrations and reduce loss of heat from furnaces.

  8. Phase Modulation Stops Levitated Sample Rotation

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B.; Brown, J. H.

    1984-01-01

    Rotation of sample in acoustic levitator prevented by relatively simple phase-modulation scheme. Technique differs from older methods; no feedback control or observation of sample required, nor necessary to carefully tune or detune two oscillators to precise frequency differences from resonance.

  9. Magnetic Levitational Assembly for Living Material Fabrication.

    PubMed

    Tasoglu, Savas; Yu, Chu Hsiang; Liaudanskaya, Volha; Guven, Sinan; Migliaresi, Claudio; Demirci, Utkan

    2015-07-15

    Functional living materials with microscale compositional topographies are prevalent in nature. However, the creation of biomaterials composed of living micro building blocks, each programmed by composition, functionality, and shape, is still a challenge. A powerful yet simple approach to create living materials using a levitation-based magnetic method is presented. PMID:25872008

  10. Precise Fabrication of Electromagnetic-Levitation Coils

    NASA Technical Reports Server (NTRS)

    Ethridge, E.; Curreri, P.; Theiss, J.; Abbaschian, G.

    1985-01-01

    Winding copper tubing on jig ensures reproducible performance. Sequence of steps insures consistent fabrication of levitation-and-melting coils. New method enables technician to produce eight coils per day, 95 percent of them acceptable. Method employs precise step-by-step procedure on specially designed wrapping and winding jig.

  11. Blowing Polymer Bubbles in an Acoustic Levitator

    NASA Technical Reports Server (NTRS)

    Lee, M. C.

    1985-01-01

    In new manufacturing process, small gas-filled polymer shells made by injecting gas directly into acoustically levitated prepolymer drops. New process allows sufficient time for precise control of shell geometry. Applications foreseen in fabrication of deuterium/tritium-filled fusion targets and in pharmaceutical coatings. New process also useful in glass blowing and blow molding.

  12. Apparatus and method for aerodynamic levitation

    NASA Technical Reports Server (NTRS)

    Williamson, John W. (Inventor); al-Darwish, Mohamad M. (Inventor); Cashen, Grant E. (Inventor)

    1993-01-01

    An apparatus for the levitation of a liquid drop by a fluid flow comprising a profile generator, a fluid flow supply means operatively connected to the profile generator. The profile generator includes an elongate cylindrical shell in which is contained a profiling means for configuring the velocity profile of the fluid flow exiting the profile generator.

  13. Magnetic Levitational Assembly for Living Material Fabrication.

    PubMed

    Tasoglu, Savas; Yu, Chu Hsiang; Liaudanskaya, Volha; Guven, Sinan; Migliaresi, Claudio; Demirci, Utkan

    2015-07-15

    Functional living materials with microscale compositional topographies are prevalent in nature. However, the creation of biomaterials composed of living micro building blocks, each programmed by composition, functionality, and shape, is still a challenge. A powerful yet simple approach to create living materials using a levitation-based magnetic method is presented.

  14. Levitated crystals and quasicrystals of metamaterials

    SciTech Connect

    Wang, Zhehui; Morris, Christopher; Goree, John A

    2012-07-25

    New scientific and technological opportunities exist by marrying dusty plasma research with metamaterials. Specifically, by balancing control and self-assembly, certain laboratory plasmas can become a generic levitation platform for novel structure formation and nanomaterial synthesis. We propose to experimentally investigate two dimensional (2D) and three dimensional (3D) levitated structures of metamaterials and their properties. Such structures can self assemble in laboratory plasmas, similar to levitated dust crystals which were discovered in the mid 1990's. Laboratory plasma platform for metamaterial formation eliminates substrates upon which most metamaterials have to be supported. Three types of experiments, with similar setups, are discussed here. Levitated crystal structures of metamaterials using anisotropic microparticles are the most basic of the three. The second experiment examines whether quasicrystals of metamaterials are possible. Quasicrystals, discovered in the 1980's, possess so-called forbidden symmetries according to the conventional crystallography. The proposed experiment could answer many fundamental questions about structural, thermal and dynamical properties of quasicrystals. And finally, how to use nanoparticle coated microparticles to synthesize very long carbon nanotubes is also described. All of the experiments can fit inside a standard International Space Station locker with dimensions of 8-inch x 17-inch X 18-inch. Microgravity environment is deemed essential in particular for large 3D structures and very long carbon nanotube synthesis.

  15. Levitating a Magnet Using a Superconductive Material.

    ERIC Educational Resources Information Center

    Juergens, Frederick H.; And Others

    1987-01-01

    Presented are the materials and a procedure for demonstrating the levitation of a magnet above a superconducting material. The demonstration can be projected with an overhead projector for a large group of students. Kits to simplify the demonstration can be purchased from the Institute for Chemical Education of the University of Wisconsin-Madison.…

  16. The power of magnetic levitation-Part 2; Is magnetic transportation in the future

    SciTech Connect

    Moon, F.C. . Sibley School of Mechanical and Aerospace Engineering)

    1990-01-01

    This article discusses how new magnetic-levitation (MAGLEV) transportation technologies can be used to relieve airport congestion. New superconducting materials may improve the cost/benefits ratio for some MAGLEV systems. According to the author, postponement of research in MAGLEV technology in the United States will mean the loss of jobs and worsening trade balances near the end of the decade.

  17. Electrodynamics of the middle atmosphere: Superpressure balloon program

    NASA Technical Reports Server (NTRS)

    Holzworth, Robert H.

    1987-01-01

    In this experiment a comprehensive set of electrical parameters were measured during eight long duration flights in the southern hemisphere stratosphere. These flight resulted in the largest data set ever collected from the stratosphere. The stratosphere has never been electrodynamically sampled in the systematic manner before. New discoveries include short term variability in the planetary scale electric current system, the unexpected observation of stratospheric conductivity variations over thunderstorms and the observation of direct stratospheric conductivity variations following a relatively small solar flare. Major statistical studies were conducted of the large scale current systems, the stratospheric conductivity and the neutral gravity waves (from pressure and temperature data) using the entire data set.

  18. Flying Lessons: the Levitated Dipole Experiment without parallel losses

    NASA Astrophysics Data System (ADS)

    Garnier, D. T.; Mauel, M. E.; Bergmann, R. M.; Boxer, A. C.; Ellsworth, J. L.; Kesner, J.; Michael, P. C.; Woskov, P.

    2008-11-01

    The Levitated Dipole Experiment (LDX) is designed to study the closed field line dipole magnetic geometry where the plasma stability is provided by compressibility and where plasma convection may allow for τE> τp. Over the past year, LDX has operated with physical supports removed from the plasma such that no plasma losses occur along field lines and has accrued over 18 hours of flight time. We note several differences with supported operation. Improved confinement of the bulk plasma is observed with higher densities achieved with reduced neutral fueling. Fast particle confinement is also improved as we observe higher diamagnetic currents. We observe a larger stable operating space to the hot electron interchange mode, due to a denser stabilizing bulk plasma, and a broader profile of the radially diffusing hot electrons. We now observe low frequency modes leading to radial convection of plasma density. A new 10.5GHz heating system has lead to higher plasma density and stored energy, and greater flexibility in heating profile. Upgrades to diagnostics (to study convective modes), the levitation control system (to improve isolation from plasma diamagnetism), and heating systems are planned.

  19. ELECTRODYNAMICS à la HOŘAVA

    NASA Astrophysics Data System (ADS)

    Romero, Juan M.; Santiago, José A.; González-Gaxiola, O.; Zamora, Adolfo

    We study an electrodynamics consistent with anisotropic transformations of spacetime with an arbitrary dynamic exponent z. The equations of motion and conserved quantities are explicitly obtained. We show that the propagator of this theory can be regarded as a quantum correction to the usual propagator. Moreover, we obtain that both the momentum and angular momentum are not modified, but their conservation laws do change. We also show that in this theory the speed of light and the electric charge are modified with z. The magnetic monopole in this electrodynamics and its duality transformations are also investigated. For that we found that there exists a dual electrodynamics, with higher derivatives in the electric field, invariant under the same anisotropic transformations.

  20. Quantum gravitational contributions to quantum electrodynamics.

    PubMed

    Toms, David J

    2010-11-01

    Quantum electrodynamics describes the interactions of electrons and photons. Electric charge (the gauge coupling constant) is energy dependent, and there is a previous claim that charge is affected by gravity (described by general relativity) with the implication that the charge is reduced at high energies. However, that claim has been very controversial and the matter has not been settled. Here I report an analysis (free from the earlier controversies) demonstrating that quantum gravity corrections to quantum electrodynamics have a quadratic energy dependence that result in the electric charge vanishing at high energies, a result known as asymptotic freedom.

  1. On the slow dynamics of near-field acoustically levitated objects under High excitation frequencies

    NASA Astrophysics Data System (ADS)

    Ilssar, Dotan; Bucher, Izhak

    2015-10-01

    This paper introduces a simplified analytical model describing the governing dynamics of near-field acoustically levitated objects. The simplification converts the equation of motion coupled with the partial differential equation of a compressible fluid, into a compact, second order ordinary differential equation, where the local stiffness and damping are transparent. The simplified model allows one to more easily analyse and design near-field acoustic levitation based systems, and it also helps to devise closed-loop controller algorithms for such systems. Near-field acoustic levitation employs fast ultrasonic vibrations of a driving surface and exploits the viscosity and the compressibility of a gaseous medium to achieve average, load carrying pressure. It is demonstrated that the slow dynamics dominates the transient behaviour, while the time-scale associated with the fast, ultrasonic excitation has a small presence in the oscillations of the levitated object. Indeed, the present paper formulates the slow dynamics under an ultrasonic excitation without the need to explicitly consider the latter. The simplified model is compared with a numerical scheme based on Reynolds equation and with experiments, both showing reasonably good results.

  2. Thermophysical and structural measurements of liquid metallic alloys using electrostatic levitation

    NASA Astrophysics Data System (ADS)

    Bendert, James Christopher

    In the study of the glass transition, the properties of high temperature liquids in their equilibrium and supercooled states may provide clues to the question of why certain compositions form glasses more easily than others. In metallic alloys such measurements are difficult due to the high reactivity and high melting temperatures of these liquids. Levitation methods provide a solution this problem by isolating liquid alloys from their environments. Here, the techniques of data acquisition and analysis for thermophysical property measurements under electrostatic levitation are presented, with demonstrative examples from select compositions from the Cu-Zr system. The development of techniques and software for the analysis of X-ray diffraction data acquired using electrostatic levitation is also discussed and applied to amorphous Zr58.5Cu15.6Ni12.8Al10.3Nb 2.8. The results of systematic studies of density and viscosity as a function of temperature in Cu100-xZrx (x = 30-55) reveal maxima in thermal expansion coefficient and kinetic strength at the best compositions of the alloy system. Interpretation of these results predicted a temperature dependence of the thermal expansion coefficient on supercooling. This prediction was confirmed by high precision measurements of density in Zr58.5Cu 15.6Ni12.8Al10.3Nb2.8 and Zr57 Cu15.4Ni12.6Al10Nb5 on cooling through the glass transition during electrostatic levitation.

  3. Trapping and dynamics of levitated ice particles at low pressures

    NASA Astrophysics Data System (ADS)

    Kowalski, Nicholas; Xie, Bernard; Parker, Colin; Chin, Cheng

    2015-05-01

    We report on experimental methods for trapping ice particles in medium vacuum, at pressures between 5 Torr and 25 Torr. At appropriate conditions aggregate ice particles hover at short distances due to the Knudson compressor effect. Additionally particles can launch and levitate robustly for extended periods of time. First we describe the experimental setup used to produce levitation, including producing the temperature gradients across the chamber. Additionally we describe our procedure for generating and introducing ice into the experimental setup. We describe the conditions necessary for levitation, and the dependence of levitation on the experimental parameters. In addition, we report on the behavior of particles during levitation and ejection, including position and stability, by analyzing particle trajectories. This includes events in which simultaneously levitated particles collide and merge.

  4. Parametric study of single-axis acoustic levitation

    SciTech Connect

    Xie, W. J.; Wei, B.

    2001-08-06

    Remarkable enhancement of the single-axis acoustic levitation force is achieved by properly curving the surface and enlarging the section of the reflector so as to levitate high density material like tungsten ({rho}{sub s}=18.92g/cm{sup 3}). A two-cylinder model incorporating the boundary element method simulations is presented for systematic study of the relationship between levitation capabilities and geometric parameters. The model proves to be successful in predicting resonant modes and explaining deviation of the levitated samples near the reflector and driver. The dependence of levitation force on resonant mode, reflector section radius R{sub b} and curvature radius R is revealed and summarized, which agrees with the experiment in principle and suggests that a reflector with large R{sub b} and small R (when R{sub b}/{lambda}{>=}0.982) working under mode 1 assures better levitation capabilities. {copyright} 2001 American Institute of Physics.

  5. Theoretical and experimental examination of near-field acoustic levitation.

    PubMed

    Nomura, Hideyuki; Kamakura, Tomoo; Matsuda, Kazuhisa

    2002-04-01

    A planar object can be levitated stably close to a piston sound source by making use of acoustic radiation pressure. This phenomenon is called near-field acoustic levitation [Y. Hashimoto et al., J. Acoust. Soc. Am. 100, 2057-2061 (1996)]. In the present article, the levitation distance is predicted theoretically by numerically solving basic equations in a compressible viscous fluid subject to the appropriate initial and boundary conditions. Additionally, experiments are carried out using a 19.5-kHz piston source with a 40-mm aperture and various aluminum disks of different sizes. The measured levitation distance agrees well with the theory, which is different from a conventional theory, and the levitation distance is not inversely proportional to the square root of the surface density of the levitated disk in a strict sense. PMID:12002842

  6. Analysis of a Non-resonant Ultrasonic Levitation Device

    NASA Astrophysics Data System (ADS)

    Andrade, Marco A. B.; Pérez, Nicolás; Adamowski, Julio C.

    In this study, a non-resonant configuration of ultrasonic levitation device is presented, which is formed by a small diameter ultrasonic transducer and a concave reflector. The influence of different levitator parameters on the levitation performance is investigated by using a numerical model that combines the Gor'kov theory with a matrix method based on the Rayleigh integral. In contrast with traditional acoustic levitators, the non-resonant ultrasonic levitation device allows the separation distance between the transducer and the reflector to be adjusted continually, without requiring the separation distance to be set to a multiple of half-wavelength. It is also demonstrated, both numerically and experimentally, that the levitating particle can be manipulated by maintaining the transducer in a fixed position in space and moving the reflector in respect to the transducer.

  7. Parametric study of single-axis acoustic levitation

    NASA Astrophysics Data System (ADS)

    Xie, W. J.; Wei, B.

    2001-08-01

    Remarkable enhancement of the single-axis acoustic levitation force is achieved by properly curving the surface and enlarging the section of the reflector so as to levitate high density material like tungsten (ρs=18.92 g/cm3). A two-cylinder model incorporating the boundary element method simulations is presented for systematic study of the relationship between levitation capabilities and geometric parameters. The model proves to be successful in predicting resonant modes and explaining deviation of the levitated samples near the reflector and driver. The dependence of levitation force on resonant mode, reflector section radius Rb and curvature radius R is revealed and summarized, which agrees with the experiment in principle and suggests that a reflector with large Rb and small R (when Rb/λ⩾0.982) working under mode 1 assures better levitation capabilities.

  8. The role of tactile support in arm levitation.

    PubMed

    Peter, Burkhard; Piesbergen, Christoph; Lucic, Kristina; Staudacher, Melina; Hagl, Maria

    2013-10-01

    How many persons need tactile support à la Milton H. Erickson to achieve arm levitation during hypnosis? How do these differ from those who do not need it? Hypnotic arm levitation was suggested three times consecutively to 30 medium suggestible students. Sixteen succeeded without any tactile support; 7 needed it one or two times; 5 needed it every time; and 2 achieved no arm levitation at all. Participants without any tactile support went more quickly into deeper hypnosis, experienced more involuntariness, less effort, and had higher electrodermal activity. This greater physiological activity seems necessary for hypnotic arm levitation as a form of "attentive hypnosis" in contrast to "relaxation hypnosis." A change in verbal suggestion from "imagine a helium balloon" to "leave levitation to your unconscious mind" revealed no differences. Several issues resulting from this exploratory arm levitation study are discussed. The idea of different proprioceptive-kinesthetic abilities is introduced and the profound need of co-creating an individual suggestion is emphasized.

  9. Thermal levitation of 10 um size particles in low vacuum

    NASA Astrophysics Data System (ADS)

    Fung, Long Fung Frankie; Kowalski, Nicholas; Parker, Colin; Chin, Cheng

    2016-05-01

    We report on experimental methods for trapping 10 micron-sized ice, glass, ceramic and polyethylene particles with thermophoresis in medium vacuum, at pressures between 5 Torr and 25 Torr. Under appropriate conditions particles can launch and levitate robustly for up to an hour. We describe the experimental setup used to produce the temperature gradient necessary for the levitation, as well as our procedure for generating and introducing ice into the experimental setup. In addition to analyzing the conditions necessary for levitation, and the dependence of levitation on the experimental parameters, we report on the behavior of particles during levitation and ejection, including position and stability, under different pressures and temperatures. We also note a significant discrepancy between theory and data, suggesting the presence of other levitating forces.

  10. Diamagnetic levitation: Flying frogs and floating magnets (invited)

    NASA Astrophysics Data System (ADS)

    Simon, M. D.; Geim, A. K.

    2000-05-01

    Contrary to our intuition, apparently nonmagnetic substances can be levitated in a magnetic field and can stabilize free levitation of a permanent magnet. Most substances are weakly diamagnetic and the tiny forces associated with this property make the two types of levitation possible. Living things mostly consist of diamagnetic molecules (such as water and proteins) and components (such as bones) and therefore can be levitated and can experience low gravity. In this way, frogs have been able to fly in the throat of a high field magnet. Stable levitation of one magnet by another with no energy input is usually prohibited by Earnshaw's Theorem. However, the introduction of diamagnetic material at special locations can stabilize such levitation. A magnet can even be stably suspended between (diamagnetic) fingertips.

  11. Containerless Processing Studies in the MSFC Electrostatic Levitator

    NASA Technical Reports Server (NTRS)

    Rogers, J. R.; SanSoucie, M. P.

    2012-01-01

    Levitation or containerless processing represents an important tool in materials research. Levitated specimens are free from contact with a container, which permits studies of deeply undercooled melts, and high-temperature, highly reactive materials. Containerless processing provides data for studies of thermophysical properties, phase equilibria, metastable state formation, microstructure formation, undercooling, and nucleation. Levitation techniques include: acoustic, aero-acoustic, electromagnetic, and electrostatic. In microgravity, levitation can be achieved with greatly reduced positioning forces. Microgravity also reduces the effects of buoyancy and sedimentation in melts. The European Space Agency (ESA) and the German Aerospace Center (DLR) jointly developed an electromagnetic levitator facility (MSL-EML) for containerless materials processing in space. The MSL-EML will be accommodated in the European Columbus Facility on the International Space Station (ISS). The electrostatic levitator (ESL) facility at the Marshall Space Flight Center provides support for the development of containerless processing studies for the ISS. The capabilities of the facility and recent results will be discussed.

  12. Capabilities of electrodynamic shakers when used for mechanical shock testing

    NASA Technical Reports Server (NTRS)

    Keegan, W. B.

    1973-01-01

    The results of a research task to investigate the capabilities of electrodynamic vibrators (shakers) to perform mechanical shock tests are presented. The simulation method employed was that of developing a transient whose shock response spectrum matched the desired shock response spectrum. Areas investigated included the maximum amplitude capabilities of the shaker systems, the ability to control the shape of the resultant shock response spectrum, the response levels induced at frequencies outside the controlled bandwidth, and the nonlinearities in structural response induced by a change in test level.

  13. Space Environmental Testing of the Electrodynamic Dust Shield Technology

    NASA Technical Reports Server (NTRS)

    Calle, Carlos I.; Mackey, P. J.; Hogue, M. D.; Johansen, M .R.; Yim, H.; Delaune, P. B.; Clements, J. S.

    2013-01-01

    NASA's exploration missions to Mars and the moon may be jeopardized by dust that will adhere to surfaces of (a) Optical systems, viewports and solar panels, (b) Thermal radiators, (c) Instrumentation, and (d) Spacesuits. We have developed an active dust mitigation technology, the Electrodynamic Dust Shield, a multilayer coating that can remove dust and also prevents its accumulation Extensive testing in simulated laboratory environments and on a reduced gravity flight shows that high dust removal performance can be achieved Long duration exposure to the space environment as part of the MISSE-X payload will validate the technology for lunar missions.

  14. Hybrid circuit cavity quantum electrodynamics with a micromechanical resonator.

    PubMed

    Pirkkalainen, J-M; Cho, S U; Li, Jian; Paraoanu, G S; Hakonen, P J; Sillanpää, M A

    2013-02-14

    Hybrid quantum systems with inherently distinct degrees of freedom have a key role in many physical phenomena. Well-known examples include cavity quantum electrodynamics, trapped ions, and electrons and phonons in the solid state. In those systems, strong coupling makes the constituents lose their individual character and form dressed states, which represent a collective form of dynamics. As well as having fundamental importance, hybrid systems also have practical applications, notably in the emerging field of quantum information control. A promising approach is to combine long-lived atomic states with the accessible electrical degrees of freedom in superconducting cavities and quantum bits (qubits). Here we integrate circuit cavity quantum electrodynamics with phonons. Apart from coupling to a microwave cavity, our superconducting transmon qubit, consisting of tunnel junctions and a capacitor, interacts with a phonon mode in a micromechanical resonator, and thus acts like an atom coupled to two different cavities. We measure the phonon Stark shift, as well as the splitting of the qubit spectral line into motional sidebands, which feature transitions between the dressed electromechanical states. In the time domain, we observe coherent conversion of qubit excitation to phonons as sideband Rabi oscillations. This is a model system with potential for a quantum interface, which may allow for storage of quantum information in long-lived phonon states, coupling to optical photons or for investigations of strongly coupled quantum systems near the classical limit.

  15. Electromagnetic levitation coil fabrication technique for MSFC containerless processing facilities

    NASA Technical Reports Server (NTRS)

    Ethridge, E. C.; Theiss, J.; Curreri, P. A.; Abbaschian, G. J.

    1983-01-01

    A technique is described for more reproducible fabrication of electromagnetic levitation coils. A split mandrel was developed upon which the coil is wound. After fabrication the mandrel can be disassembled to remove it from the coil. Previously, a full day was required to fabricate a levitation coil and the success rate for a functional coil was only 50 percent. About eight coils may be completed in one day using the technique developed and 95 percent of them are good levitation coils.

  16. Optical levitation of a microdroplet containing a single quantum dot.

    PubMed

    Minowa, Yosuke; Kawai, Ryoichi; Ashida, Masaaki

    2015-03-15

    We demonstrate the optical levitation or trapping in helium gas of a single quantum dot (QD) within a liquid droplet. Bright single photon emission from the levitated QD in the droplet was observed for more than 200 s. The observed photon count rates are consistent with the value theoretically estimated from the two-photon-action cross section. This Letter presents the realization of an optically levitated solid-state quantum emitter. PMID:25768143

  17. Non-contact transportation using near-field acoustic levitation

    PubMed

    Ueha; Hashimoto; Koike

    2000-03-01

    Near-field acoustic levitation, where planar objects 10 kg in weight can levitate stably near the vibrating plate, is successfully applied both to non-contact transportation of objects and to a non-contact ultrasonic motor. Transporting apparatuses and an ultrasonic motor have been fabricated and their characteristics measured. The theory of near-field acoustic levitation both for a piston-like sound source and a flexural vibration source is also briefly described. PMID:10829622

  18. Lamb Shift in Nonrelativistic Quantum Electrodynamics.

    ERIC Educational Resources Information Center

    Grotch, Howard

    1981-01-01

    The bound electron self-energy or Lamb shift is calculated in nonrelativistic quantum electrodynamics. Retardation is retained and also an interaction previously dropped in other nonrelativistic approaches is kept. Results are finite without introducing a cutoff and lead to a Lamb shift in hydrogen of 1030.9 MHz. (Author/JN)

  19. Electrodynamics in One Dimension: Radiation and Reflection

    ERIC Educational Resources Information Center

    Asti, G.; Coisson, R.

    2011-01-01

    Problems involving polarized plane waves and currents on sheets perpendicular to the wavevector involve only one component of the fields, so it is possible to discuss electrodynamics in one dimension. Taking for simplicity linearly polarized sinusoidal waves, we can derive the field emitted by currents (analogous to dipole radiation in three…

  20. Linear Response Laws and Causality in Electrodynamics

    ERIC Educational Resources Information Center

    Yuffa, Alex J.; Scales, John A.

    2012-01-01

    Linear response laws and causality (the effect cannot precede the cause) are of fundamental importance in physics. In the context of classical electrodynamics, students often have a difficult time grasping these concepts because the physics is obscured by the intermingling of the time and frequency domains. In this paper, we analyse the linear…

  1. Testing Born-Infeld electrodynamics in waveguides.

    PubMed

    Ferraro, Rafael

    2007-12-01

    Waveguides can be employed to test nonlinear effects in electrodynamics. We solve Born-Infeld equations for TE waves in a rectangular waveguide. We show that the energy velocity acquires a dependence on the amplitude, and harmonic components appear as a consequence of the nonlinear behavior.

  2. Nonlinear quantum electrodynamics in vacuum and plasmas

    SciTech Connect

    Brodin, Gert; Lundin, Joakim; Marklund, Mattias

    2010-12-14

    We consider high field physics due to quantum electrodynamics, in particular those that can be studied in the next generation of laser facilities. Effective field theories based on the Euler-Heisenberg Lagrangian are briefly reviewed, and examples involving plasma- and vacuum physics are given.

  3. Quantum Hall effect in quantum electrodynamics

    SciTech Connect

    Penin, Alexander A.

    2009-03-15

    We consider the quantum Hall effect in quantum electrodynamics and find a deviation from the quantum-mechanical prediction for the Hall conductivity due to radiative antiscreening of electric charge in an external magnetic field. A weak dependence of the universal von Klitzing constant on the magnetic field strength, which can possibly be observed in a dedicated experiment, is predicted.

  4. Students' Difficulties with Vector Calculus in Electrodynamics

    ERIC Educational Resources Information Center

    Bollen, Laurens; van Kampen, Paul; De Cock, Mieke

    2015-01-01

    Understanding Maxwell's equations in differential form is of great importance when studying the electrodynamic phenomena discussed in advanced electromagnetism courses. It is therefore necessary that students master the use of vector calculus in physical situations. In this light we investigated the difficulties second year students at KU Leuven…

  5. Strong field electrodynamics of a thin foil

    SciTech Connect

    Bulanov, Sergei V.; Esirkepov, Timur Zh.; Kando, Masaki; Bulanov, Stepan S.; Rykovanov, Sergey G.; Pegoraro, Francesco

    2013-12-15

    Exact solutions describing the nonlinear electrodynamics of a thin double layer foil are presented. These solutions correspond to a broad range of problems of interest for the interaction of high intensity laser pulses with overdense plasmas, such as frequency upshifting, high order harmonic generation, and high energy ion acceleration.

  6. Single photon delayed feedback: a way to stabilize intrinsic quantum cavity electrodynamics.

    PubMed

    Carmele, Alexander; Kabuss, Julia; Schulze, Franz; Reitzenstein, Stephan; Knorr, Andreas

    2013-01-01

    We propose a scheme to control cavity quantum electrodynamics in the single photon limit by delayed feedback. In our approach a single emitter-cavity system, operating in the weak coupling limit, can be driven into the strong coupling-type regime by an external mirror: The external loop produces Rabi oscillations directly connected to the electron-photon coupling strength. As an expansion of typical cavity quantum electrodynamics, we treat the quantum correlation of external and internal light modes dynamically and demonstrate a possible way to implement a fully quantum mechanical time-delayed feedback. Our theoretical approach proposes a way to experimentally feedback control quantum correlations in the single photon limit.

  7. Levitation of a magnet by an alternating magnetic field

    NASA Astrophysics Data System (ADS)

    Gough, W.; Hunt, M. O.; Summerskill, W. S. H.

    2013-01-01

    An experiment is described in which a small strong cylindrical magnet is levitated by a vertical non-uniform alternating magnetic field. Surprisingly, no superimposed constant field is necessary, but the levitation can be explained when the vertical motion of the magnet is taken into account. The theoretical mean levitation force is (0.26 ± 0.06) N, which is in good agreement with the levitated weight of (0.239 ± 0.001) N. This experiment is suitable for an undergraduate laboratory, particularly as a final year project. Students have found it interesting, and it sharpens up knowledge of basic magnetism.

  8. Dependence of acoustic levitation capabilities on geometric parameters.

    PubMed

    Xie, W J; Wei, B

    2002-08-01

    A two-cylinder model incorporating boundary element method simulations is developed, which builds up the relationship between the levitation capabilities and the geometric parameters of a single-axis acoustic levitator with reference to wavelength. This model proves to be successful in predicting resonant modes of the acoustic field and explaining axial symmetry deviation of the levitated samples near the reflector and emitter. Concave reflecting surfaces of a spherical cap, a paraboloid, and a hyperboloid of revolution are investigated systematically with regard to the dependence of the levitation force on the section radius R(b) and curvature radius R (or depth D) of the reflector. It is found that the levitation force can be remarkably enhanced by choosing an optimum value of R or D, and the possible degree of this enhancement for spherically curved reflectors is the largest. The degree of levitation force enhancement by this means can also be facilitated by enlarging R(b) and employing a lower resonant mode. The deviation of the sample near the reflector is found likely to occur in case of smaller R(b), larger D, and a higher resonant mode. The calculated dependence of levitation force on R, R(b), and the resonant mode is also verified by experiment and finally demonstrated to be in good agreement with experimental results, in which considerably a strong levitation force is achieved to levitate an iridium sphere which has the largest density of 22.6 g/cm(3). PMID:12241309

  9. Aerodynamics of magnetic levitation (MAGLEV) trains

    NASA Technical Reports Server (NTRS)

    Schetz, Joseph A.; Marchman, James F., III

    1996-01-01

    High-speed (500 kph) trains using magnetic forces for levitation, propulsion and control offer many advantages for the nation and a good opportunity for the aerospace community to apply 'high tech' methods to the domestic sector. One area of many that will need advanced research is the aerodynamics of such MAGLEV (Magnetic Levitation) vehicles. There are important issues with regard to wind tunnel testing and the application of CFD to these devices. This talk will deal with the aerodynamic design of MAGLEV vehicles with emphasis on wind tunnel testing. The moving track facility designed and constructed in the 6 ft. Stability Wind Tunnel at Virginia Tech will be described. Test results for a variety of MAGLEV vehicle configurations will be presented. The last topic to be discussed is a Multi-disciplinary Design approach that is being applied to MAGLEV vehicle configuration design including aerodynamics, structures, manufacturability and life-cycle cost.

  10. Acoustic levitation and manipulation for space applications

    NASA Technical Reports Server (NTRS)

    Wang, T. G.

    1979-01-01

    A wide spectrum of experiments to be performed in space in a microgravity environment require levitation and manipulation of liquid or molten samples. A novel acoustic method has been developed at JPL for controlling liquid samples without physical contacts. This method utilizes the static pressure generated by three orthogonal acoustic standing waves excited within an enclosure. Furthermore, this method will allow the sample to be rotated and/or oscillated by modifying the phase angles and/or the amplitude of the acoustic field. This technique has been proven both in our laboratory and in a microgravity environment provided by KC-135 flights. Samples placed within our chamber driven at (1,0,0), (0,1,0), and (0,0,1), modes were indeed levitated, rotated, and oscillated.

  11. Sound field inside acoustically levitated spherical drop

    NASA Astrophysics Data System (ADS)

    Xie, W. J.; Wei, B.

    2007-05-01

    The sound field inside an acoustically levitated small spherical water drop (radius of 1mm) is studied under different incident sound pressures (amplitude p0=2735-5643Pa). The transmitted pressure ptr in the drop shows a plane standing wave, which varies mainly in the vertical direction, and distributes almost uniformly in the horizontal direction. The maximum of ptr is always located at the lowermost point of the levitated drop. Whereas the secondary maximum appears at the uppermost point if the incident pressure amplitude p0 is higher than an intermediate value (3044Pa), in which there exists a pressure nodal surface in the drop interior. The value of the maximum ptr lies in a narrow range of 2489-3173Pa, which has a lower limit of 2489Pa when p0=3044Pa. The secondary maximum of ptr is rather small and only remarkable at high incident pressures.

  12. Electrodynamic Balance for Studies of Cosmic Dust Particles

    NASA Technical Reports Server (NTRS)

    Spann, J. F.; Abbas, M. M.; Venturini, C. C.; Comfort, R. H.; Rose, M. Franklin (Technical Monitor)

    2000-01-01

    Knowledge of the formation and distribution of interstellar, interplanetary, and planetary dust grains, and their physical, chemical and optical characteristics provide valuable information about many issues dealing with the origin and formation of the solar system bodies, interplanetary and interstellar environments as well as various industrial processes. Understanding the microphysics of individual grains and their interaction with the surrounding, environment is key to properly model various conditions and interpret existing data. The theory and models of individual dust grains are well developed for environments that vary from dense planetary atmospheres to dusty plasmas to diffuse environments such as interplanetary space. However, experimental investigations of individual dust grains in equilibrium are less common, perhaps due to the difficulty of these experiments. Laboratory measurements of dust grains have primarily measured ensemble properties or transient properties of single grains. A technique developed in the 1950's for ion spectroscopy, generally referred to as a quadrupole trap has recently been employed as an electrodynamic balance to investigate single micron-sized dust grains and for atmospheric aerosol research. A description of the theoretical basis and the experimental setup of the electrodynamic balance being developed in our laboratory are given. This laboratory technique lends itself to many applications that relate to planetary atmospheres, heliospheric environments, pre-stellar and pre-planetary conditions, and industrial settings. We present results from some recent experiments carried out to investigate the equilibrium potential of dust grains exposed to far ultraviolet light or to an electron beam. Some future experiments using an electrodynamic balance to investigate the optical characteristics, and condensation process involving dust grains in various astrophysical environments are discussed.

  13. Electrostatic Levitation Furnace for the ISS

    NASA Technical Reports Server (NTRS)

    Murakami, Keiji; Koshikawa, Naokiyo; Shibasaki, Kohichi; Ishikawa, Takehiko; Okada, Junpei; Takada, Tetsuya; Arai, Tatsuya; Fujino, Naoki; Yamaura, Yukiko

    2012-01-01

    JAXA (Japan Aerospace Exploration Agency) has just started the development of Electrostatic Levitation Furnace to be launched in 2014 for the ISS. This furnace can control the sample position with electrostatic force and heat it above 2000 degree Celsius using semiconductor laser from four different directions. The announcement of Opportunity will be issued soon for this furnace. In this paper, we will show the specifications of this furnace and also the development schedule

  14. Levitational Image Cytometry with Temporal Resolution.

    PubMed

    Tasoglu, Savas; Khoory, Joseph A; Tekin, Huseyin C; Thomas, Clemence; Karnoub, Antoine E; Ghiran, Ionita C; Demirci, Utkan

    2015-07-01

    A simple, yet powerful magnetic-levitation-based device is reported for real-time, label-free separation, as well as high-resolution monitoring of cell populations based on their unique magnetic and density signatures. This method allows a wide variety of cellular processes to be studied, accompanied by transient or permanent changes in cells' fundamental characteristics as a biological material. PMID:26058598

  15. Sputter coating of microspherical substrates by levitation

    DOEpatents

    Lowe, A.T.; Hosford, C.D.

    Microspheres are substantially uniformly coated with metals or nonmetals by simltaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure comprising a parallel array of upwardly projecting individual gas outlets is machined out to form a dimple. Glass microballoons,, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

  16. Sputter coating of microspherical substrates by levitation

    DOEpatents

    Lowe, Arthur T.; Hosford, Charles D.

    1981-01-01

    Microspheres are substantially uniformly coated with metals or nonmetals by simultaneously levitating them and sputter coating them at total chamber pressures less than 1 torr. A collimated hole structure 12 comprising a parallel array of upwardly projecting individual gas outlets 16 is machined out to form a dimple 11. Glass microballoons, which are particularly useful in laser fusion applications, can be substantially uniformly coated using the coating method and apparatus.

  17. Flow visualization of acoustic levitation experiment

    NASA Technical Reports Server (NTRS)

    Baroth, ED

    1987-01-01

    Acoustic levitation experiments for space applications were performed. Holographic interferometry is being used to study the heat transfer rates on a heated rod enclosed in a 6 cu in chamber. Acoustic waves at levels up to 150 db increased the heating rates to the rod by factors of three to four. High speed real time holographic interferometry was used to measure the boundary layer on the heated rod. Data reduction and digitization of the interferograms are being implemented.

  18. Experimenting with a Superconducting Levitation Train

    ERIC Educational Resources Information Center

    Miryala, Santosh; Koblischka, M. R.

    2014-01-01

    The construction and operation of a prototype high-"Tc" superconducting train model is presented. The train is levitated by a melt-processed GdBa[subscript 2]Cu[subscript 3]O[subscript x] (Gd-123) superconducting material over a magnetic rail (track). The oval shaped track is constructed in S-N-S or PM3N configuration arranged on an iron…

  19. Spin stabilized magnetic levitation of horizontal rotors.

    SciTech Connect

    Romero, Louis Anthony

    2004-10-01

    In this paper we present an analysis of a new configuration for achieving spin stabilized magnetic levitation. In the classical configuration, the rotor spins about a vertical axis; and the spin stabilizes the lateral instability of the top in the magnetic field. In this new configuration the rotor spins about a horizontal axis; and the spin stabilizes the axial instability of the top in the magnetic field.

  20. Experiments for electromagnetic levitation in microgravity

    NASA Technical Reports Server (NTRS)

    Willnecker, R.; Egry, I.

    1990-01-01

    Containerless processing is a promising research tool for investigating the properties of undercooled melts and their solidification. For conducting samples RF-electromagnetic levitation offers the possibility to obtain large undercoolings by avoiding heterogeneous nucleation at container walls. On earth, however, strong magnetic fields are needed to compensate the gravitational force which imposes a lower limit on the available temperatures and on the accessible undercooling range. Under microgravity conditions the magnetic positioning fields can be minimized and hence, undercooling becomes feasible under ultra-high vacuum conditions and lower temperatures become accessible. In contrast to other undercooling and solidification techniques, electromagnetic levitation allows for diagnostic measurements during the early steps of nucleation and phase selection. Experiments cover a wide field of research topics: nucleation, directional solidification at high velocities, generation of metastable phases, evolution of microstructures, properties of undercooled liquids. Examples from these classes including experiments selected for the IML-2 mission are discussed with emphasis on technical requirements. An overview is given on the German TEMPUS (electromagnetic levitation facility) program.