Science.gov

Sample records for electrodynamic levitation system

  1. 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.

  2. 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.

  3. 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…

  4. Convertible electrodynamic levitator trap to quasielectrostatic levitator for microparticle nucleation studies

    NASA Astrophysics Data System (ADS)

    Arnold, S.; Goddard, N. L.; Wotherspoon, N.

    1999-02-01

    This article describes an apparatus for obtaining nucleation data from a levitated solution microdroplet, automatically. A particularly novel feature is that it uses an electrodynamic levitator trap (ELT) which converts to a quasielectrostatic levitator (QEL), at any time during an experiment. The conversion is accomplished by using asymmetrically applied potentials on the ELT structure. With this modification one can trap a particle in the ELT mode and then convert to the QEL mode for automatic operation. By eliminating the need for the alternating gradient forces which are intrinsic to the ELT, the system in its QEL mode is shielded from unwanted noise and parametric instabilities associated with the ELT's alternating potential. To test the system theoretically, we calculate the effect which molecular collisions have on the positional variance in a spherical void QEL. Following this, we describe the components of our servosystem, and demonstrate the robustness of our design by following the nucleation of a solution droplet as the ambient relative humidity is reduced by evacuation.

  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. Compact magnetic levitation transportation system

    SciTech Connect

    Suppes, G.J.

    1992-09-15

    This patent describes a magnetic levitation transportation system, it comprises: vehicle loading and unloading stations, at least one primary pair of laterally spaced rails comprises of magnetically interactive material extending between the vehicle loading and unloading stations, a vehicle of a size, a magnetic levitation means, energy conversion means for energizing the magnetic levitation means on the vehicle and for maintaining the speed and acceleration of the vehicle during travel, braking control means for creating a net braking force on the vehicle in a braking condition, and speed control means on the vehicle for accelerating and decelerating the vehicle.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Levitation dynamics of a collection of charged droplets in an electrodynamic balance

    NASA Astrophysics Data System (ADS)

    Singh, Mohit; Mayya, Y. S.; Gaware, Jitendra; Thaokar, Rochish M.

    2017-02-01

    The study explores the stable levitation and self-organization of charged multi-drop assemblies in a large sized quadrupole trap both experimentally and through numerical simulations. The trap is benchmarked by comparing single drop levitation experiments with numerical simulations. Important observation and findings of the study are: (i) long time stabilization and formation of patterns of droplet collections over a range of operating parameters (ii) Numerical prediction of polygonal patterns for few drop (2 to 8) systems and lattice structures for many drop (>10) systems, (iii) Numerical prediction of Non-dependence of the inter-drop spacing on droplet charge for similarly charged drops, consistent with earlier analytical formulations [Aardahl et al., J. Aerosol Sci. 28, 1491-1505 (1997)], (iv) numerical observation of two drops oscillations with a secular frequency distinctly higher than the single drop Dehmelt frequency (v) Simulations of a systematic transition from disordered to coulombic crystals with mean size increasing with the number of levitated drops (N) as ˜N0.29. The experimental observations on different patterns and lattice spacings are closely reproduced by simulations.

  16. 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.

  17. 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.

  18. MSFC Electrostatic Levitator (ESL) Rapid Quench System

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Craven, Paul D.; Rogers, Jan R.

    2014-01-01

    The NASA Marshall Space Flight Center (MSFC) Electrostatic Levitator (ESL) Laboratory 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, all without the interference of a container or data-gathering instrument. The ESL 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. Thereby allowing rapid quenching of undercooled liquid metals. Up to 8 quench vessels can be loaded into the quench wheel, which is indexed with LabVIEW control software. This allows up to 8 samples to be rapidly quenched before having to open the chamber. The system has been tested successfully on several zirconium samples. Future work will be done with other materials using different quench mediums. Microstructural analysis will also be done on successfully quench samples.

  19. 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).

  20. 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.

  1. 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…

  2. A simple levitation system using wireless power supply system and Lorentz force

    NASA Astrophysics Data System (ADS)

    Oka, Koichi; Tanaka, Masako

    2016-09-01

    A new type of magnetic levitation mechanism has been proposed. The feature of this mechanism is using wireless power supply system and Lorentz forces for levitation. The stability of levitation is performed by passive control by magnetic flux configuration between permanent magnets and active control of electromagnets. In this paper, the concept of levitation mechanism is introduced, FEM analyses for levitation force and wireless power supply performance is examined. In concept two types of levitation systems which are different on the point of active control directions are introduced. In FEM analyses, the required current for levitation and the directions of generating forces are calculated. In the study of wireless power supply system, the required voltage for the levitation is expected. Finally the feasibility of the proposed levitation system will be verified.

  3. Corridor guided transport system utilizing permanent magnet levitation

    SciTech Connect

    Geraghty, J.J.; Poland, A.P.; Lombardi, J.A.

    1995-07-01

    The invention relates to a corridor guided transport system including a guided goods conveyance container utilizing permanent magnet levitation. The transport system of the invention eliminates the need for the wheel and track arrangement presently required by known and utilized conventional train systems and also required by some conventional magnetic levitation transport systems and, as a result, is safer to operate and maintain than either of these known transportation systems.

  4. Electrodynamic tether system study: Extended study

    NASA Technical Reports Server (NTRS)

    1988-01-01

    This document is the final report of a study performed by Ball Space Systems Division (BSSD) for the NASA Johnson Space Center under an extension to contract NAS9-17666. The tasks for the extended study were as follows: (1) Define an interface between the Electrodynamic Tether System (ETS) and the Space Station (SS); (2) Identify growth paths for the 100 kW ETS defined in the original study to a 200 kW level of performance; (3) Quantify orbit perturbations caused by cyclic day/night operations of a Plasma Motor/Generator (PMG) on the SS and explore methods of minimizing these effects; (4) Define the analyses, precursor technology, ground tests, and precursor demonstrations leading up to a demonstration mission for an electrodynamic tether system that would be capable of producing maneuvering thrust levels of 25 newtons; and (5) Propose a development schedule for the demonstration mission and preliminary cost estimates.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Electrodynamic forces in tethered satellite systems. Part 1: System control

    NASA Astrophysics Data System (ADS)

    Netzer, Ehud; Kane, Thomas R.

    1994-10-01

    Part 1 of this work deals with the use of electrodynamic forces for control of tethered satellite system. A system formed by two massive end-bodies connected to each other by a current carrying tether is to be kept in an earth-pointing orientation by means of joint actions of thrusters on one of the end-bodies and electrodynamic forces acting on the tether.

  10. 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.

  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

    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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Magnetic levitation/suspension system by high-temperature superconducting materials

    SciTech Connect

    Chen, I.; Hsu, J.; Jamn, G.; Lin, C.E.; Wu, M.K.

    1997-04-01

    Recently, with the advance of materials processing techniques, such as top-seeding and melt-texturing (TSMT) method, very large single-grained Y-Ba-Cu-O (YBCO) samples up to several centimeters in diameter can be produced. Each sample is capable of levitating over kilograms of weight. A HTS magnetic levitation (MagLev) transportation prototype has been constructed at National Cheng-Kung University (NCKU) to validate the concept of HTS-MagLev system based on Meissner effect. This HTS-MagLev is an inherent stable levitation system, unlike traditional MagLev system that requires sensors and feedback circuits to dynamically adjust its unstable levitation position. In this report, the results of various magnetic levitation parameters, such as different permanent magnet configurations, relative levitation stability, levitation force, etc., as well as magnetic field intensity and distribution will be discussed. {copyright} {ital 1997 American Institute of Physics.}

  19. Implementing quantum electrodynamics with ultracold atomic systems

    NASA Astrophysics Data System (ADS)

    Kasper, V.; Hebenstreit, F.; Jendrzejewski, F.; Oberthaler, M. K.; Berges, J.

    2017-02-01

    We discuss the experimental engineering of model systems for the description of quantum electrodynamics (QED) in one spatial dimension via a mixture of bosonic 23Na and fermionic 6Li atoms. The local gauge symmetry is realized in an optical superlattice, using heteronuclear boson–fermion spin-changing interactions which preserve the total spin in every local collision. We consider a large number of bosons residing in the coherent state of a Bose–Einstein condensate on each link between the fermion lattice sites, such that the behavior of lattice QED in the continuum limit can be recovered. The discussion about the range of possible experimental parameters builds, in particular, upon experiences with related setups of fermions interacting with coherent samples of bosonic atoms. We determine the atomic system’s parameters required for the description of fundamental QED processes, such as Schwinger pair production and string breaking. This is achieved by benchmark calculations of the atomic system and of QED itself using functional integral techniques. Our results demonstrate that the dynamics of one-dimensional QED may be realized with ultracold atoms using state-of-the-art experimental resources. The experimental setup proposed may provide a unique access to longstanding open questions for which classical computational methods are no longer applicable.

  20. Analysis of a high Tc superconducting levitation system with vibration isolation control

    SciTech Connect

    Nagaya, Kosuke

    1996-03-01

    This paper presents a method for controlling vibrations of a levitated high Tc superconducting body subjected to base disturbances. To have the control forces, an actuator consisting of a permanent magnet with an electromagnet was presented. The analytical solution for calculating levitation forces due to the permanent magnet and the control currents in the electromagnet was obtained. The levitation forces obtained coincide with the previously published results. The equation of motion of the levitated body subjected to base disturbances under the control was presented. Nonlinear vibrations of the body were first discussed; then the method of vibration isolation control using the direct disturbance cancellation combining the velocity feedback control was investigated. Numerical calculations were carried out for the levitation forces, with respect to the levitated body subjected to harmonic or pulse base excitations. It was clarified that the present method is valid for controlling nonlinear systems like the magnetic levitated superconducting body.

  1. Quantized levitation states of superconducting multiple-ring systems

    SciTech Connect

    Haley, S.B.; Fink, H.J.

    1996-02-01

    The quantized levitation, trapped, and suspension states of a magnetic microsphere held in equilibrium by two fixed superconducting (SC) microrings are calculated by minimizing the free energy of the system. Each state is a discrete function of two independent fluxoid quantum numbers of the rings. When the radii of the SC rings are of the same order as the Ginzburg-Landau coherence length {xi}({ital T}), the system exhibits a small set of gravity and temperature-dependent levels. The levels of a weakly magnetized particle are sensitive functions of the gravitational field, indicating potential application as an accelerometer, and for trapping small magnetic particles in outer space or on Earth. The equilibrium states of a SC ring levitated by another SC ring are also calculated. {copyright} {ital 1996 The American Physical Society.}

  2. Air jet levitation furnace system for observing glass microspheres during heating and melting

    NASA Technical Reports Server (NTRS)

    Ethridge, E. C.; Dunn, S. L.

    1982-01-01

    A collimated hole structure air jet levitation system has been developed which can be used to levitate hollow glass microspheres used in inertial confinement fusion studies. An ellipsoidal furnace has been added to the system to provide a heating source. A video camera and a 16 mm movie camera connected to a microsphere system provide real time observation as well as permanent documentation of the experiments. Microspheres have been levitated at temperatures over 1400 C for over 10 minutes at a time.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Robustness and control of a magnetically levitated transportation system

    NASA Astrophysics Data System (ADS)

    Oleszczuk, Grzegorz

    2006-04-01

    Electromagnetic suspension of Magnetic Levitation Vehicles (Maglev) has been studied for many years as an alternative to wheel-on rail transportation systems. In this work, design and implementation of control systems for a Maglev laboratory experiment and a Maglev vehicle under development at Old Dominion University are described. Both plants are modeled and simulated with consideration of issues associated with system non-linearity, structural flexibility and electromagnetic force modeling. Discussion concerning different control strategies, namely centralized and decentralized approaches are compared and contrasted in this work. Different types of electromagnetic non-linearities are considered and described to establish a convenient method for modeling such a system. It is shown how a Finite Element structural model can be incorporated into the system to obtain transfer function notation. Influence of the dynamic interaction between the Maglev track and the Maglev vehicle is discussed and supported by both analytical results and theoretical examples. Finally, several control laws designed to obtain stable and robust levitation are explored in detail.

  8. 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.

  9. 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.

  10. 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.

  11. 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

    2017-02-01

    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.

  12. Mechanical resonance characteristics of a high-{Tc} superconducting levitation system

    SciTech Connect

    Sugiura, Toshihiko; Fujimori, Hideki

    1996-05-01

    This research deals with dynamic response of a permanent magnet freely levitated above an excited high-{Tc} superconductor. Evaluation of dynamic characteristics is required in mechanical design of high-{Tc} superconducting levitation systems. Their dynamics is coupled with Type-II superconducting phenomena. By a numerical approach based on some macroscopic models they evaluate mechanical resonance characteristics of a superconducting levitation system. Numerical results show some nonlinear properties and effect of the flux flow in Type-II superconductor, which are observed in experiments or predicted by analyses.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Gravito-electrodynamics and the structure of planetary ring systems

    NASA Technical Reports Server (NTRS)

    Mendis, D. A.

    1984-01-01

    Recent spacecraft observations of the Saturnian and Jovian ring systems have highlighted a plethora of interesting new phenomena associated with those regions containing fine (micron and sub-micron sized) dust. Recognizing that these dust grains, by virtue of being immersed within the planetary magnetospheres, are electrostatically charged to the point that they experience comparable gravitational and electric forces, a new 'gravito-electrodynamic' theory has been developed to describe their dynamics. This theory has been successful in explaining all these phenomena in a systematic way. In this review, the basic model and its range of validity are outlined, and its application to the Saturnian and Jovian ring systems are discussed.

  19. Amplitude and frequency dependence of hysteresis loss in a magnet-superconductor levitation system

    NASA Astrophysics Data System (ADS)

    Yang, Z. J.; Hull, J. R.; Mulcahy, T. M.; Rossing, T. D.

    1995-08-01

    Using an electromagnetically controlled mechanical pendulum, we measured the energy loss for different amplitudes in a magnetic levitation system that contained high temperature superconductors (HTSs). Two procedures were followed to measure losses at 77 K for frequencies of 93.8 mHz to 80 Hz. In the first procedure, the distance between the permanent magnet and the HTS levitator was the same as that during (field) cooling. In the second procedure, the magnet was lowered (after cooling) closer to the HTS levitator before the measurements were performed. The experimental data show that these two procedures give essentially the same results at the same distance despite different cooling (and magnetization) histories for melt-textured YBaCuO levitators, and the frequency-independent energy loss is a power-law function of amplitude. We attribute the energy loss to magnetic hysteresis in the superconductor.

  20. Magnetic Characteristics of Electromagnetic Levitation System for Short Radius Curve Track

    NASA Astrophysics Data System (ADS)

    Nomiyama, Takuma; Kakinoki, Toshio; Yamaguchi, Hitoshi; Jifuku, Yorito; Mochizuki, Takuro

    A magnetically levitated (MAGLEV) vehicle using electro-magnets and iron rails generates lateral guiding force naturally by controlling levitation force to maintain the air gaps between the magnets and the iron rails. A MAGLEV system without guide magnets offers simple design and cost advantages. But such a system has little lateral damping force. In order to improve damping characteristics, an experimental apparatus using salient-pole type magnets and laminated iron rails was made. The iron cores were placed in two rows. The levitation coils surrounded both of the magnet iron cores and the damping coils surrounded every magnet cores separately. The damping coils were excited by currents proportional to the lateral displacement velocity. According to a step response experiment, the lateral motion dissipated after a cycle or two of the swing. The self-inductance of the levitation coil of the magnet almost unchanged against variation of the lateral displacement. The influence of damping current on the levitation was very small. In this paper electromagnetic characteristics of the levitation system are shown.

  1. Translational and rotational dynamic analysis of a superconducting levitation system

    NASA Astrophysics Data System (ADS)

    Cansiz, A.; Hull, J. R.; Gundogdu, Ö.

    2005-07-01

    The rotational dynamics of a disc-shaped permanent magnet rotor levitated over a high temperature superconductor was studied experimentally and theoretically. The interaction between the rotor magnet and the superconductor was modelled by assuming the magnet to be a magnetic dipole and the superconductor a diamagnet. In the magnetomechanical analysis of the superconductor part, the frozen image concept was combined with the diamagnetic image, and the damping in the system was neglected. The interaction potential of the system is the combination of magnetic and gravitational potentials. From the dynamical analysis the equations of motion of the permanent magnet were stated as a function of lateral, vertical, tilt, precision and rotating angles. The vibration behaviour and correlation of the vibration of one direction with that of another were determined with a numerical calculation based on the Runge-Kutta method. The various vibrational frequencies identified were vertical, radial, tilt, precession and rotation. The tests performed for experimental verifications were translational and rotational. The permanent magnet was 'spun up' under vacuum conditions to analyse the dynamics of the free 'spin down' behaviour of the permanent magnet.

  2. Spin Pumping in Electrodynamically Coupled Magnon-Photon Systems

    NASA Astrophysics Data System (ADS)

    Bai, Lihui; Harder, M.; Chen, Y. P.; Fan, X.; Xiao, J. Q.; Hu, C.-M.

    2015-06-01

    We use electrical detection, in combination with microwave transmission, to investigate both resonant and nonresonant magnon-photon coupling 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.

  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. Development of an Acoustic Levitation Linear Transportation System Based on a Ring-type Structure.

    PubMed

    Thomas, Gilles; Andrade, Marco Aurelio; Adamowski, Julio; Silva, Emilio

    2017-02-23

    A linear acoustic levitation transportation system based on a ring-type vibrator is presented. The system is composed by two 21 kHz Langevin transducers connected to a ring-shaped structure formed by two semicircular sections and two flat plates. In this system, a flexural standing wave is generated along the ring structure, producing an acoustic standing wave between the vibrating ring and a plane reflector located at a distance of approximately a half wavelength from the ring. The acoustic standing wave in air has a series of pressure nodes, where small particles can be levitated and transported. The ring-type transportation system was designed and analyzed by using the Finite Element Method (FEM). Additionally, a prototype was built and the acoustic levitation and transport of a small polystyrene particle was demonstrated.

  5. 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.

  6. 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.

  7. Effect of size on levitation force in a magnet/superconductor system

    NASA Astrophysics Data System (ADS)

    Yang, Z. J.; Hull, J. R.

    1996-03-01

    We consider a model system consisting of an infinitely long magnetic dipole line placed symmetrically above an infinitely long superconducting strip. Using the Meissner effect of superconductors, we derive analytical expressions of the levitation forces acting on the dipole line. At lowest-order approximation, we discuss the possible application of our model system to estimate the upper limit of the levitation forces in some magnetic bearing systems. In one example, the model correctly calculated the vertical vibration frequency of an experimental superconducting bearing.

  8. 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.

  9. 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.

  10. Levitation force of small clearance superconductor-magnet system under non-coaxial condition

    NASA Astrophysics Data System (ADS)

    Xu, Jimin; Jin, Yingze; Yuan, Xiaoyang; Miao, Xusheng

    2017-03-01

    A novel superconducting tilting-pad bearing was proposed for the advanced research of reusable liquid hydrogen turbopump in liquid rocket. The bearing is a combination of superconducting magnetic bearing and hydrodynamic fluid-film bearing. Since the viscosity of cryogenic fuel to activate superconducting state and form hydrodynamic fluid-film is very low, bearing clearance will be very small. This study focuses on the investigation of superconducting levitation force in this kind of small clearance superconductor-magnet system. Based on Bean critical state model and three-dimensional finite element method, an analysis method is presented to obtain the levitation force under such situation. Since the complicated operational conditions and structural arrangement for application in liquid rocket, center lines of bulk superconductor and magnet rotor will usually be in non-coaxial state. Superconducting levitation forces in axial direction and radial direction under non-coaxial situation are also analyzed by the presented method.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Spontaneous and nonphotochemical laser-induced nucleation in levitated supersaturated microdroplets

    NASA Astrophysics Data System (ADS)

    Fang, Ke

    Research of nucleation in levitated supersaturated microdroplets was conducted in this dissertation. An unconventional crystallization system, levitated microdroplets, was utilized in this research. The microdroplet was levitated by an electrodynamic balance (EDB) constructed inside a vacuum chamber. EDB has the advantage of creating a containerless environment for the crystallization system. Spontaneous nucleation in levitated microdroplets was investigated. Spontaneous nucleation of aqueous microdroplets was caused by reducing the ambient relative humidity (RH) surrounding the solution droplets. Different polymorphs of glutaric acid and malonic acid are nucleated in levitated microdroplets when injected into a chamber maintained at different initial RH values. Effect of surfactant as additive is also investigated. A site-dependent evaporation-driven crystallization theory is established to explain the spontaneous nucleation phenomena in levitated aqueous microdroplets. Levitated microdroplets containing a solute and an organic solvent were also investigated. The crystallization behavior of glutaric acid methanol solutions and ethanol solutions was observed. ROY, a deca-polymorphic compound, was also studied from its DMSO solution microdroplets. Non-photochemical laser induced nucleation (NPLIN) was observed in levitated microdroplets of supersaturated potassium chloride (KCl) aqueous solution. A focused green (532 nm) pulsed laser with 1 ns pulse width was used to induce nucleation. Nucleation of levitated KCl microdroplet with high supersaturation was observed upon laser irradiation. A laser-induced charge loss phenomenon was also observed. A hypothesis of laser-induced electrostriction and corona discharge is discussed. Analysis with classical nucleation theory suggests that the NPLIN results in levitated microdroplets are consistent with previously published data on bulk samples.

  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. 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.

  18. Calculation of the induced currents and forces for a hybrid magnetic levitation system

    SciTech Connect

    Albertz, D.; Dappen, S.; Henneberger, G.

    1997-03-01

    This paper presents the calculation of the induced currents and forces for a 3D non-linear eddy current field problem with ferromagnetic moving conductors. The {rvec A}, V-{rvec A} formulation is used in combination with four different gauging methods to stabilize the solution process. To consider non-rectangular shapes of geometries tetrahedral elements were employed. The computation procedure is applied to a hybrid magnetic levitation system of a contactless and frictionless conveyance system.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. Nearly time-optimal feedback control of a magnetically levitated photolithography positioning system

    SciTech Connect

    Redmond, J.

    1993-12-31

    This paper focuses on the development of an approximate time-optimal feedback strategy for conducting rest-to-rest maneuvers of a magnetically levitated table. Classical switching curves are modified to account for the complexities of magnetic actuation as well as the coupling of the rigid body modes through the control. A smooth blend of time-optimal and proportional-derivative controls is realized near the destination point to correct for inaccuracies produced by the approximate time-optimal strategy. Detailed computer simulations of the system indicate that this hybrid control strategy provides a significant reduction in settling time as compared to proportional-derivative control alone.

  11. 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.

  12. Development of ultrasonically levitated drops as microreactors for study of enzyme kinetics and potential as a universal portable analysis system

    NASA Astrophysics Data System (ADS)

    Scheeline, A.; Pierre, Z.; Field, C. R.; Ginsberg, M. D.

    2009-05-01

    Development of microfluidics has focused on carrying out chemical synthesis and analysis in ever-smaller volumes of solution. In most cases, flow systems are made of either quartz, glass, or an easily moldable polymer such as polydimethylsiloxane (Whitesides 2006). As the system shrinks, the ratio of surface area to volume increases. For studies of either free radical chemistry or protein chemistry, this is undesirable. Proteins stick to surfaces, biofilms grow on surfaces, and radicals annihilate on walls (Lewis et al. 2006). Thus, under those circumstances where small amounts of reactants must be employed, typical microfluidic systems are incompatible with the chemistry one wishes to study. We have developed an alternative approach. We use ultrasonically levitated microliter drops as well mixed microreactors. Depending on whether capillaries (to form the drop) and electrochemical sensors are in contact with the drop or whether there are no contacting solids, the ratio of solid surface area to volume is low or zero. The only interface seen by reactants is a liquid/air interface (or, more generally, liquid/gas, as any gas may be used to support the drop). While drop levitation has been reported since at least the 1940's, we are the second group to carry out enzyme reactions in levitated drops, (Weis; Nardozzi 2005) and have fabricated the lowest power levitator in the literature (Field; Scheeline 2007). The low consumption aspects of ordinary microfluidics combine with a contact-free determination cell (the levitated drop) that ensures against cross-contamination, minimizes the likelihood of biofilm formation, and is robust to changes in temperature and humidity (Lide 1992). We report kinetics measurements in levitated drops and explain how outgrowths of these accomplishments will lead to portable chemistry/biology laboratories well suited to detection of a wide range of chemical and biological agents in the asymmetric battlefield environment.

  13. 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).

  14. 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.

  15. 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.

  16. Flux line depinning in a magnet-superconductor levitation system

    NASA Astrophysics Data System (ADS)

    Terentiev, A. N.; Hull, J. R.; De Long, L. E.

    The AC loss characteristics of a magnet-superconductor system were studied with the magnet fixed to the free end of an oscillating cantilever located near a stationary melt-textured YBCO pellet. Below a threshold AC field amplitude ≈2 Oe, the dissipation of the oscillator is amplitude-independent, characteristic of a linear, non-hysteretic regime. Above threshold, dissipation increases with amplitude, reflecting the depinning and hysteretic motion of flux lines. The threshold AC field is an order of magnitude higher than that measured for the same YBCO material via AC susceptometry in a uniform DC magnetic field. A partial lock-in of flux lines between YBCO ab planes is proposed as the mechanism for the substantial increase of the depinning threshold.

  17. Cold atoms as a coolant for levitated optomechanical systems

    NASA Astrophysics Data System (ADS)

    Ranjit, Gambhir; Montoya, Cris; Geraci, Andrew A.

    2015-01-01

    Optically trapped dielectric objects are well suited for reaching the quantum regime of their center-of-mass motion in an ultrahigh-vacuum environment. We show that ground-state cooling of an optically trapped nanosphere is achievable when starting at room temperature, by sympathetic cooling of a cold-atomic gas optically coupled to the nanoparticle. Unlike cavity cooling in the resolved-sideband limit, this system requires only a modest cavity finesse and it allows the cooling to be turned off, permitting subsequent observation of strongly coupled dynamics between the atoms and sphere. Nanospheres cooled to their quantum ground state could have applications in quantum information science or in precision sensing.

  18. Radial stiffness improvement of a flywheel system using multi-surface superconducting levitation

    NASA Astrophysics Data System (ADS)

    Basaran, Sinan; Sivrioglu, Selim

    2017-03-01

    The goal of this research study is the maximization of the levitation force in a flywheel system by the use of more than one permanent magnet with a single ring-shaped HTS material. An analytical model for the radial stiffness of the ring HTS-PM is derived using the frozen image approach. The experimental works are carried out for different polarizations of the permanent magnets, and radial stiffness values are obtained from the radial force measurements. The rotational test of the flywheel system is also realized for different cases. Finally, natural frequencies of the flywheel superconducting magnetic bearing system are experimentally obtained for different combinations of the permanent magnets using a frequency analyzer.

  19. Electrostatic Levitator (ESL)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Dr. Rulison of Space System LORAl working with the Electrostatic Levitation (ESL) prior to the donation. Space System/LORAL donated the electrostatic containerless processing system to NASA's Marshall Space Flight Center (MSFC). The official hand over took place in July 1998.

  20. 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.

  1. Gas viscosity measurement with diamagnetic-levitation viscometer based on electromagnetically spinning system

    NASA Astrophysics Data System (ADS)

    Shimokawa, Y.; Matsuura, Y.; Hirano, T.; Sakai, K.

    2016-12-01

    Utilizing a graphite-disk probe attached with a thin aluminum disk, we have developed a friction-free viscosity measurement system. The probe is levitated above a NdFeB magnet because of diamagnetic effect and rotated by an electromagnetically induced torque. The probe is absolutely free form mechanical friction, and therefore, the accurate measurements of the viscosity of gases can be achieved. To demonstrate the accuracy and sensitivity of our method, we measured the viscosity of 8 kinds of gases and its temperature change from 278 K to 318 K, and we confirmed a good agreement between the obtained values and literature values. This paper demonstrates that our method has the ability to measure the fluid viscosity in the order of μPa ṡ s.

  2. Gas viscosity measurement with diamagnetic-levitation viscometer based on electromagnetically spinning system.

    PubMed

    Shimokawa, Y; Matsuura, Y; Hirano, T; Sakai, K

    2016-12-01

    Utilizing a graphite-disk probe attached with a thin aluminum disk, we have developed a friction-free viscosity measurement system. The probe is levitated above a NdFeB magnet because of diamagnetic effect and rotated by an electromagnetically induced torque. The probe is absolutely free form mechanical friction, and therefore, the accurate measurements of the viscosity of gases can be achieved. To demonstrate the accuracy and sensitivity of our method, we measured the viscosity of 8 kinds of gases and its temperature change from 278 K to 318 K, and we confirmed a good agreement between the obtained values and literature values. This paper demonstrates that our method has the ability to measure the fluid viscosity in the order of μPa ⋅ s.

  3. Optical-response properties in levitated optomechanical systems beyond the low-excitation limit

    NASA Astrophysics Data System (ADS)

    Nie, Wenjie; Chen, Aixi; Lan, Yueheng

    2016-02-01

    We investigate the optical-response properties of a levitated optomechanical cavity coupled to a higher order excited atomic medium. The cavity field driven through the atom-field interaction is responsible for trapping a dielectric nanosphere, whose steady-state position is biased by the Coulomb force between the nanosphere and the cavity wall. We show that the phenomena of optomechanically induced transparency (OMIT) and amplification can be generated from the output probe field in the presence of an effective optomechanical coupling between the nanosphere and the cavity field. Further, the width of the transparency window increases with increasing strength of the effective optomechanical coupling, which is controlled easily by varying the Coulomb interaction and the radius of the nanosphere. In particular, when the higher order excitation of the atomic medium is included, a large driving of the atomic ensemble but a relatively small atom-field detuning can be applied to help observe the OMIT behavior in the hybrid system.

  4. 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.

  5. 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.

  6. Switching delayed feedback control for an electrodynamic tether system in an inclined elliptic orbit

    NASA Astrophysics Data System (ADS)

    Kojima, Hirohisa; Sugimoto, Tetsuro

    2010-04-01

    The chaotic librational motion of a tether system in elliptic orbit has been studied and controlled by delayed feedback control up to date. Contrary to the past literatures that addressed the periodic stability of tether systems, this paper studies the local stability of in-plane/out-of-plane motion of electrodynamic tether (EDT) systems in elliptic orbits with respect to the true anomaly. From the viewpoint of the local stability of tether systems, in this paper, provided that the electric current is used only for controlling the librational motion, a new simple delayed feedback control, named "switching delayed-feedback control (SDFC)" is proposed, which combines a delayed-feedback control (DFC) and variable structure system (VSS) concept. The effectiveness of the proposed method to stabilize the librational in-plane/out-of-plane periodic motion of an electrodynamic tether system in an inclined elliptic orbit with high eccentricity was demonstrated, and compared with that of the traditional delayed-feedback controllers by numerical simulations.

  7. 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.

  8. Transient response of an electrodynamic tether system in the ionosphere: TSS-1 first results

    NASA Astrophysics Data System (ADS)

    BiléN, Sven G.; Gilchrist, Brian E.; Bonifazi, Carlo; Melchioni, Enrico

    1995-09-01

    The electrical transient response of an electrodynamic tether system in low earth orbit has been investigated experimentally and by computer simulation. Our experimental results come from the first Tethered Satellite System (TSS-1) mission flown on the space shuttle in 1992. During this mission a tethered satellite was deployed to a distance of 267 m above the shuttle using a conducting, insulated cable. It is shown by computer simulation that the electrical transient response of the system is due to a combination of both the tether electrical circuit and the interaction of the tether system with the space plasma. In general, ground measurements showed that the TSS-1 electrical circuit is approximately second order and underdamped. However, it was found that on-orbit transient decay as well as the symmetry of transient oscillations could be dramatically altered, following closely with ionospheric plasma density variations. Combined electrical circuit and plasma interaction modeling shows that these differences can be explained by accounting for ion and electron current collection capabilities of the tether end connections with the space plasma. These results have implications for the use of electrodynamic tethers for high current switched applications including direct generation of low-frequency electromagnetic signals and high electrical power generation as well as detection of natural electric field transient signatures.

  9. 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.

  10. Study on electrodynamic sensor of multi-modality system for multiphase flow measurement

    NASA Astrophysics Data System (ADS)

    Deng, Xiang; Chen, Dixiang; Yang, Wuqiang

    2011-12-01

    Accurate measurement of multiphase flows, including gas/solids, gas/liquid, and liquid/liquid flows, is still challenging. In principle, electrical capacitance tomography (ECT) can be used to measure the concentration of solids in a gas/solids flow and the liquid (e.g., oil) fraction in a gas/liquid flow, if the liquid is non-conductive. Electrical resistance tomography (ERT) can be used to measure a gas/liquid flow, if the liquid is conductive. It has been attempted to use a dual-modality ECT/ERT system to measure both the concentration profile and the velocity profile by pixel-based cross correlation. However, this approach is not realistic because of the dynamic characteristics and the complexity of multiphase flows and the difficulties in determining the velocities by cross correlation. In this paper, the issues with dual modality ECT/ERT and the difficulties with pixel-based cross correlation will be discussed. A new adaptive multi-modality (ECT, ERT and electro-dynamic) sensor, which can be used to measure a gas/solids or gas/liquid flow, will be described. Especially, some details of the electrodynamic sensor of multi-modality system such as sensing electrodes optimum design, electrostatic charge amplifier, and signal processing will be discussed. Initial experimental results will be given.

  11. Study on electrodynamic sensor of multi-modality system for multiphase flow measurement.

    PubMed

    Deng, Xiang; Chen, Dixiang; Yang, Wuqiang

    2011-12-01

    Accurate measurement of multiphase flows, including gas/solids, gas/liquid, and liquid/liquid flows, is still challenging. In principle, electrical capacitance tomography (ECT) can be used to measure the concentration of solids in a gas/solids flow and the liquid (e.g., oil) fraction in a gas/liquid flow, if the liquid is non-conductive. Electrical resistance tomography (ERT) can be used to measure a gas/liquid flow, if the liquid is conductive. It has been attempted to use a dual-modality ECT/ERT system to measure both the concentration profile and the velocity profile by pixel-based cross correlation. However, this approach is not realistic because of the dynamic characteristics and the complexity of multiphase flows and the difficulties in determining the velocities by cross correlation. In this paper, the issues with dual modality ECT/ERT and the difficulties with pixel-based cross correlation will be discussed. A new adaptive multi-modality (ECT, ERT and electro-dynamic) sensor, which can be used to measure a gas/solids or gas/liquid flow, will be described. Especially, some details of the electrodynamic sensor of multi-modality system such as sensing electrodes optimum design, electrostatic charge amplifier, and signal processing will be discussed. Initial experimental results will be given.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  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

    2014-05-05

    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. Superconductor and magnet levitation devices

    NASA Astrophysics Data System (ADS)

    Ma, K. B.; Postrekhin, Y. V.; Chu, W. K.

    2003-12-01

    using superconductor magnet levitation, focusing more on issues specific to the application. We note that applications of superconductor magnet levitation devices tend to be most attractive in situations where energy conservation is critical. The most advanced in development are flywheel kinetic energy storage systems incorporating superconductor magnet bearings. Variations in the designs to enhance the performance in some specific regards are examined case by case. Next we present a reaction wheel for attitude control on small satellites, similar in overall design to the flywheel kinetic energy storage systems, but with subtle differences in details of emphasis, due to the difference in purpose and environment. Finally, we take a brief look at the case of vibration isolation devices as an example of a rectilinear modification of the more familiar rotational bearing applications.

  20. Large-scale maximal entanglement and Majorana bound states in coupled circuit quantum electrodynamic systems

    NASA Astrophysics Data System (ADS)

    Hwang, Myung-Joong; Choi, Mahn-Soo

    2013-03-01

    We study the effect of ultrastrong cavity-qubit coupling on the low-lying excitations of a chain of coupled circuit quantum electrodynamic (QED) systems. We show that, in the presence of the onsite ultrastrong coupling, the photon hopping between cavities can be mapped to the Ising interaction between the lowest two levels of individual circuit QED of the chain. Based on our mapping, we predict two nearly degenerate ground states whose wave functions involve maximal entanglement between the macroscopic quantum states of the cavities and the states of qubits and identify that they are mathematically equivalent to Majorana bound states. Further, we devise a scheme for the dispersive measurement of the ground states using an additional resonator attached to one end of the circuit QED chain. Finally, we discuss the effects of disorders and local noises on the coherence of the ground states.

  1. Electrodynamic thermogravimetric analyzer

    NASA Astrophysics Data System (ADS)

    Spjut, R. Erik; Bar-Ziv, Ezra; Sarofim, Adel F.; Longwell, John P.

    1986-08-01

    The design and operation of a new device for studying single-aerosol-particle kinetics at elevated temperatures, the electrodynamic thermogravimetric analyzer (EDTGA), was examined theoretically and experimentally. The completed device consists of an electrodynamic balance modified to permit particle heating by a CO2 laser, temperature measurement by a three-color infrared-pyrometry system, and continuous weighing by a position-control system. In this paper, the position-control, particle-weight-measurement, heating, and temperature-measurement systems are described and their limitations examined.

  2. Controlled levitation of a large magnet above superconductors

    SciTech Connect

    Takamori, T.; Boland, J.J.; Dove, D.B. )

    1990-07-01

    The levitation of a permanent magnet over a type-II superconductor may be modified and controlled by the addition of a variable magnetic field to the magnet-superconductor system. Using this scheme, levitation of a magnet of significantly larger mass was established by the direct interaction of the additonal field with the levitating magnet.

  3. 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.

  4. 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,

  5. 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.

  6. Collective Electrodynamics

    NASA Astrophysics Data System (ADS)

    Mead, Carver A.

    2002-08-01

    In this book Carver Mead offers a radically new approach to the standard problems of electromagnetic theory. Motivated by the belief that the goal of scientific research should be the simplification and unification of knowledge, he describes a new way of doing electrodynamics--collective electrodynamics--that does not rely on Maxwell's equations, but rather uses the quantum nature of matter as its sole basis. Collective electrodynamics is a way of looking at how electrons interact, based on experiments that tell us about the electrons directly. (As Mead points out, Maxwell had no access to these experiments.) The results Mead derives for standard electromagnetic problems are identical to those found in any text. Collective electrodynamics reveals, however, that quantities that we usually think of as being very different are, in fact, the same--that electromagnetic phenomena are simple and direct manifestations of quantum phenomena. Mead views his approach as a first step toward reformulating quantum concepts in a clear and comprehensible manner. The book is divided into five sections: magnetic interaction of steady currents, propagating waves, electromagnetic energy, radiation in free space, and electromagnetic interaction of atoms. In an engaging preface, Mead tells how his approach to electromagnetic theory was inspired by his interaction with Richard Feynman. Carver A. Mead is the Gordon and Betty Moore Professor of Engineering and Applied Science, Emeritus, at the California Institute of Technology. He won the 1999 Lemelson-MIT Prize for Invention and Innovation.

  7. 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.

  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. 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

  10. Nanogravity gradiometer based on a sharp optical nonlinearity in a levitated particle optomechanical system

    NASA Astrophysics Data System (ADS)

    Liu, Jian; Zhu, Ka-Di

    2017-02-01

    In the present paper, we provide a scheme to probe the gradient of gravity at the nanoscale in a levitated nanomechanical resonator coupled to a cavity via two-field optical control. The enhanced sharp peak on the probe spectrum will suffer a distinct shift with the nonuniform force being taken into consideration. The nonlinear optics with very narrow bandwidth (10-8 Hz ) resulting from the extremely high-quality factor will lead to a superresolution of 10-20 N /m for the measurement of gravity gradient. The improved sensitivity may offer new opportunities for detecting Yukawa moduli forces and Kaluza-Klein gravitons in extra dimensions.

  11. Remote sensing of the electrodynamic coupling between thunderstorm systems and the mesophere/lower ionosphere

    NASA Astrophysics Data System (ADS)

    Reising, Steven Craig

    In the past few years, dramatic experimental evidence has emerged, showing that tropospheric lightning discharges modify the mesosphere and the lower ionosphere through heating and ionization, producing gamma-ray bursts and optical emissions known as Sprites, blue jets, and elves. These processes may have long-term effects such as increased production of mesospheric and stratospheric nitrogen oxides (NOy) and persistent heating of ionospheric electrons. To determine the effects of this electrodynamic coupling, the global occurrence rate of Sprites needs to be known. Since optical monitoring of Sprite occurrence on large spatial scales is not practical, a continuous proxy indicator for Sprite occurrence is needed. Sprites are intense, transient luminous events in the mesosphere and lower ionosphere above thunderstorm systems. They extend from ~40 to ~90 km in altitude, are primarily red in color, and develop to full brightness in a few ms. Sprites are nearly uniquely associated with a subset of positive cloud-to-ground lightning fiashes, but the peak current of each flash, measured by the National Lightning Detection Network, is not sufficient to determine the likelihood of Sprite occurrence. In this work, remote sensing of the electrodynamic coupling between thunderstorms and the middle atmosphere is accomplished by measurement of radio atmospherics in the ELF (extremely low frequency, here 15 Hz-1.5 kHz) and VLF (very low frequency, here 1.5-22 kHz) ranges. Radio atmospherics ('sferics'), the electromagnetic signatures of each lightning discharge, propagate efficiently in the waveguide bounded by the Earth's surface and the ionosphere. Novel digital signal processing techniques allow automated detection of individual sferics and the determination of their arrival azimuth with /pm1o precision at Palmer Station, Antarctica, a source-to-receiver distance of ~12,000 km. Broadband measurements of sferics performed near Ft. Collins, Colorado, ~500 km from the source

  12. 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.

  13. 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.

  14. 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.

  15. Quantum theory of an electromagnetic observer: Classically behaving macroscopic systems and the emergence of the classical world in quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Plimak, L. I.; Ivanov, Misha; Aiello, A.; Stenholm, S.

    2015-08-01

    Quantum electrodynamics under conditions of distinguishability of interacting matter entities, and of controlled actions and back-actions between them, is considered. Such "mesoscopic quantum electrodynamics" is shown to share its dynamical structure with the classical stochastic electrodynamics. In formal terms, we demonstrate that all general relations of the mesoscopic quantum electrodynamics may be recast in a form lacking Planck's constant. Mesoscopic quantum electrodynamics is therefore subject to "doing quantum electrodynamics while thinking classically," allowing one to substitute essentially classical considerations for quantum ones without any loss in generality. Implications of these results for the quantum measurement theory are discussed.

  16. Magnetic levitation in linear propulsion machines

    SciTech Connect

    Schieber, D.

    1984-03-01

    A simple magnetic levitation system is analyzed. The results obtained yield insight into the lift-thrust mechanism and demonstrate, through the magnetic Reynolds number, the interplay of the electric and geometric parameters. 7 references.

  17. 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.

  18. 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.

  19. Electrodynamics of chiral matter

    NASA Astrophysics Data System (ADS)

    Qiu, Zebin; Cao, Gaoqing; Huang, Xu-Guang

    2017-02-01

    Many-body systems with chiral fermions can exhibit novel transport phenomena that violate parity and time-reversal symmetries, such as the chiral magnetic effect, the anomalous Hall effect, and the anomalous generation of charge. Based on the Maxwell-Chern-Simons electrodynamics, we examine some electromagnetic and optical properties of such systems including the electrostatics, the magnetostatics, the propagation of electromagnetic waves, the novel optical effects, etc.

  20. Entropy concepts in classical electrodynamics

    NASA Astrophysics Data System (ADS)

    Cole, Daniel C.

    2002-11-01

    Aspects of entropy and related thermodynamic analyses are discussed here that have been deduced in recent years in the area of classical electrodynamics. A motivating factor for most of this work has been an attempted theory of nature often called, "stochastic electrodynamics" (SED). This theory involves classical electrodynamics (Maxwell's equations plus the relativistic version of Newton's second law of motion for particles), but with the consideration that motion and fluctuations should not necessarily be assumed to reduce to zero at temperature T = 0. Both fairly subtle and rather blatant assumptions were often imposed in early thermodynamic analyses of electrodynamic systems that prevented the analyses from being sufficiently general to account for these "zero-point" properties, which hindered classical physics from being able to better account for quantum mechanical phenomena observed in nature. In turn, such thermodynamic considerations have helped motivate many of the key ideas of SED.

  1. Substorm electrodynamics

    NASA Technical Reports Server (NTRS)

    Stern, David P.

    1990-01-01

    The present one-dimensional model analysis of substorm electrodynamics proceeds from the standard scenario in which the plasma sheet collapses into a neutral sheet, and magnetic merging occurs between the two tail lobes; plasma flows into the neutral sheet from the lobes and the sides, undergoing acceleration in the dawn-dusk direction. The process is modified by the tendency of the accelerated plasma to unbalance charge neutrality, leading to an exchange of electrons with the ionosphere in order to maintain neutrality. The cross-tail current is weakened by the diversion: this reduces the adjacent lobe-field intensity, but without notable effects apart from a slight expansion of the tail boundary.

  2. Proposal and FEM analysis of superconductive magnetic gradient levitation

    SciTech Connect

    Ohsaki, Hiroyuki

    1995-11-01

    A magnetic levitation system that enables a stable levitation even at a standstill without active control has been studied by numerical analysis of electromagnetic field. The new superconductive magnetic levitation system consists of superconducting coils and iron rails, and its principle of levitation is based on a magnetic gradient in space, which is obtained by the flux-conservation characteristic of superconducting coils. A two-dimensional FEM program was used for analysis of electromagnetic force characteristics in a two-dimensional plane and the distribution of coil current. These results show the two-dimensional stability of the system.

  3. 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.

  4. 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.

  5. Magnetic levitation experiments in Sendai

    NASA Astrophysics Data System (ADS)

    Mogi, I.; Takahashi, K.; Awaji, S.; Watanabe, K.; Motokawa, M.

    2006-11-01

    A levitating apple in a hybrid magnet implies the presence of microgravity conditions under gradient magnetic fields. However, several unique behaviors were found, the orientation of levitating rice grains, the alignment of levitating bismuth particles, and the thermal convection in water under the levitation conditions. These are unlikely under the microgravity conditions in the space and are characteristic of the magnetic levitation. On the basis of the understanding of such behaviors, the magnetic levitation was applied to containerless materials processing, and such an attempt resulted in the development of a magnetic levitation furnace.

  6. High temperature acoustic levitator

    NASA Technical Reports Server (NTRS)

    Barmatz, M. B. (Inventor)

    1984-01-01

    A system is described for acoustically levitating an object within a portion of a chamber that is heated to a high temperature, while a driver at the opposite end of the chamber is maintained at a relatively low temperature. The cold end of the chamber is constructed so it can be telescoped to vary the length (L sub 1) of the cold end portion and therefore of the entire chamber, so that the chamber remains resonant to a normal mode frequency, and so that the pressure at the hot end of the chamber is maximized. The precise length of the chamber at any given time, is maintained at an optimum resonant length by a feedback loop. The feedback loop includes an acoustic pressure sensor at the hot end of the chamber, which delivers its output to a control circuit which controls a motor that varies the length (L) of the chamber to a level where the sensed acoustic pressure is a maximum.

  7. Electromagnetic levitation applications

    SciTech Connect

    Bayazitoglu, Y.

    1996-11-01

    At high temperatures, most materials react with the walls of their containers. This inevitably leads to material contamination and property degradation. Therefore, it becomes difficult to process materials to the required degree of purity and/or measure their properties at high temperatures. Levitation melting has been used on earth and microgravity since to circumvent this problem. In this paper, first a broad survey of the work done in electromagnetic levitation since its invention is given. Then the heat generation due to an alternating magnetic field is studied. Finally, the application of levitation melting in the determination of thermal diffusivity, emissivity, surface tension and viscosity of liquid metals is presented.

  8. 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.

  9. Electrostatic Levitator Operations

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Dr. Jan Rogers (left) and Larry Savage (foreground) of the Science Directorate at NASA's Marshall Space Flight Center are joined by Dr. Richard Weber (Center) and April Hixon of Containerless Research Inc. of Evanston, Ill., in conducting an experiment run of the Electrostatic Levitator (ESL) using insulating materials. Materials researchers use unique capability of the facility to levitate and study the properties of various materials important in manufacturing processes.

  10. 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.

  11. 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.

  12. Characterizing electrodynamic shakers

    SciTech Connect

    Smallwood, D.O.

    1996-12-31

    An electrodynamic shaker is modeled as a mixed electrical/mechanical system with an experimentally derived two port network characterization. The model characterizes the shaker in a manner that the performance of the shaker with a mounted load (test item and fixture) can be predicted. The characterization depends on the measurements of shaker input voltage and current, and on the acceleration of the shaker armature with several mounted loads. The force into the load is also required, and can be measured directly or inferred from the load apparent mass.

  13. 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.

  14. Magnetic levitation servo for flexible assembly automation

    SciTech Connect

    Tsuda, Masahiro; Higuchi, Toshiro )

    1992-08-01

    This article develops an application of magnetic levitation for actuation and force sensing and calls such a system magnetic levitation servo to distinguish from conventional suspension-only systems. Flexible assembly automation is a technical and engineering challenge to be accomplished promptly. For this purpose, the authors have developed a Magnetically end-effector-levitating Instrument for a Skilled-Task-undertaking Expert Robot (MEISTER) by applying magnetic levitation servo. The MEISTER is located between a wrist and an end effector in a manipulator to levitate and control the end effector by magnetic forces without any mechanical contact. This friction-free and backlash-free mechanism enables precision control of multi-DOFs and permits the MEISTER to have three versatilely functional properties: (1) programmable compliance: the compliance and viscous damping of supporting an end effector are magnetically changeable by software; (2) precision multi-DOF actuation: the position and attitude of an end effector can be accurately controlled without friction or backlash by changing magnetic forces; and (3) multi-axis force sensing: external forces and moments acting on an end effector can be computed by the MEISTER without any additional sensory equipment from the force equivalent equation. By using these functional properties, the MEISTER can correct a minute misalignment between a couple of mating parts to automate precision insertion.

  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. 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.

  17. 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.

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

    SciTech Connect

    Coffey, H.T.

    1992-12-31

    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.

  19. 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.

  20. A Simple, Inexpensive Acoustic Levitation Apparatus

    NASA Astrophysics Data System (ADS)

    Schappe, R. Scott; Barbosa, Cinthya

    2017-01-01

    Acoustic levitation uses a resonant ultrasonic standing wave to suspend small objects; it is used in a variety of research disciplines, particularly in the study of phase transitions and materials susceptible to contamination, or as a stabilization mechanism in microgravity environments. The levitation equipment used for such research is quite costly; we wanted to develop a simple, inexpensive system to demonstrate this visually striking example of standing waves. A search of the literature produced only one article relevant to creating such an apparatus, but the authors' approach uses a test tube, which limits the access to the standing wave. Our apparatus, shown in Fig. 1, can levitate multiple small (1-2 mm) pieces of expanded polystyrene (Styrofoam) using components readily available to most instructors of introductory physics. Acoustic levitation occurs in small, stable equilibrium locations where the weight of the object is balanced by the acoustic radiation force created by an ultrasonic standing wave; these locations are slightly below the pressure nodes. The levitation process also creates a horizontal restoring force. Since the pressure nodes are also velocity antinodes, this transverse stability may be analogous to the effect of an upward air stream supporting a ball.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Electromagnetic suspension and levitation techniques

    NASA Astrophysics Data System (ADS)

    Jayawant, B. V.

    1988-04-01

    A comprehensive account is given of state-of-the-art and prospective electromagnetic and electromechanical suspension/levitation technologies, using both conventional and superconducting materials, with a view both to their performance improvements over differently grounded technologies and their economic feasibility. In addition to passenger-carrying vehicles, controlled DC electromagnet technologies have been applied to frictionless magnetic bearings, flow meters, conveyor systems, high-speed machine tool spindles, ultracentrifuges, turboalternators, corrosive-liquid pumps, gas compressors, high-vacuum pumps, and energy storage flywheels. Attention is given to the commercial prospects for devices based on superconducting magnets.

  12. Magnetic levitation for hard superconductors

    SciTech Connect

    Kordyuk, A.A.

    1998-01-01

    An approach for calculating the interaction between a hard superconductor and a permanent magnet in the field-cooled case is proposed. The exact solutions were obtained for the point magnetic dipole over a flat ideally hard superconductor. We have shown that such an approach is adaptable to a wide practical range of melt-textured high-temperature superconductors{close_quote} systems with magnetic levitation. In this case, the energy losses can be calculated from the alternating magnetic field distribution on the superconducting sample surface. {copyright} {ital 1998 American Institute of Physics.}

  13. 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.

  14. Dynamics and control of high precision magnetically levitated vibration isolation systems

    NASA Technical Reports Server (NTRS)

    Youcef-Toumi, K.; Yeh, T-J.

    1992-01-01

    Vibration control of flexible structures has received a great deal of interest in recent years. Several authors have investigated this topic in the areas of robot manipulators, space structures, and flexible rotors. Key issues associated with the dynamics and control of vibration isolation systems are addressed. Among other important issues to consider in the control of such systems, the location and number of actuators and sensors are essential to effectively control and suppress vibration. We first address the selection of proper actuator and sensor locations leading to a controllable and observable system. The Rayleigh-Ritz modal analysis method is used to develop a lumped-parameter model of a flexible vibration isolation table top. This model is then used to investigate the system's controllability and observability including the coupling effects introduced by the magnetic bearing. This analysis results in necessary and sufficient conditions for proper selection of actuator and sensor locations. These locations are also important for both controller system's complexity and stability of point of views. A favorable pole-zero plot of the open loop transfer functions is presented. Necessary and sufficient conditions for reducing the controller complexity are derived. The results are illustrated by examples using approximate mode shape functions.

  15. The choice of the principle of functioning of the system of magnetic levitation for the device of high-performance testing of powder permanent magnets

    NASA Astrophysics Data System (ADS)

    Shaykhutdinov, D. V.; Gorbatenko, N. I.; Narakidze, N. D.; Vlasov, A. S.; Stetsenko, I. A.

    2017-02-01

    The present article focuses on permanent magnets quality control problems. High-performance direct-flow type systems for the mechanical engineering production processes are considered. The main lack of the existing high-performance direct-flow type systems is a completing phase of movement of a tested product when the movement is oscillatory and abrupt braking may be harmful for high fragility samples. A special system for permanent magnets control is offered. The system realizes the magnetic levitation of a test sample. Active correction of the electric current in magnetizing coils as the basic functioning principle of this system is offered. The system provides the required parameters of the movement of the test sample by using opposite connection of magnetizing coils. This new technique provides aperiodic nature of the movement and limited acceleration with saving of high accuracy and required timeframe of the installation in the measuring position.

  16. 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)

  17. Report of the Electrodynamic Interactions Panel

    NASA Technical Reports Server (NTRS)

    Stone, N. H.; Taylor, R. S.; Benford, S.; Binsack, J. H.; Dobrowolny, M.; Finnegan, P.; Grossi, M. D.; Hudson, M.; Intriligator, D.; Kaminskas, R.

    1985-01-01

    A wide range of opportunities is provided by the electrodynamic tether to more fully understand the generation of waves in plasmas, the behavior of field aligned currents, the behavior of large body-space plasma interactions, and for process simulation, using the electrodynamic tether to study processes and phenomena relevant to solar system and astrophysics plasma physics. The electrodynamic tether offers a means of study and experimentation in space which will provide a rich yield in new scientific results and will enhance the understanding of space plasma physics. It also has promising technological applications (e.g., the generation of electrical power and thrust) which may be highly significant to future space operations.

  18. A new repulsive magnetic levitation approach using permanent magnets and air-core electromagnets

    SciTech Connect

    Wang, I.Y.A.; Busch-Vishniac, I. . Dept. of Mechanical Engineering)

    1994-07-01

    This paper introduces a new repulsive magnetic levitation approach using permanent magnets and air-core electromagnets as primary actuating components. The permanent magnets, which are attached to the bottom of a carrier, are repulsively levitated above and by oblong shaped electromagnets, which constitute one part of the guide tracks. Due to the lateral unstable nature of repulsive levitation, the stability of the levitated permanent magnets is regulated by another part of the guide tracks, electromagnetic stabilizers, which are strands of straight wires running through the entire length of the guide tracks above the levitation coils. A state feedback controller with integral compensator is designed for the stability control. The entire levitation system is divided into three subsystems: levitation, stabilization and propulsion. Al the control works with respect to each subsystem are executed extrinsic to the carrier, i.e., there is no electrical circuit on board the carrier.

  19. A containerless levitation setup for liquid processing in a superconducting magnet.

    PubMed

    Lu, Hui-Meng; Yin, Da-Chuan; Li, Hai-Sheng; Geng, Li-Qiang; Zhang, Chen-Yan; Lu, Qin-Qin; Guo, Yun-Zhu; Guo, Wei-Hong; Shang, Peng; Wakayama, Nobuko I

    2008-09-01

    Containerless processing of materials is considered beneficial for obtaining high quality products due to the elimination of the detrimental effects coming from the contact with container walls. Many containerless processing methods are realized by levitation techniques. This paper describes a containerless levitation setup that utilized the magnetization force generated in a gradient magnetic field. It comprises a levitation unit, a temperature control unit, and a real-time observation unit. Known volume of liquid diamagnetic samples can be levitated in the levitation chamber, the temperature of which is controlled using the temperature control unit. The evolution of the levitated sample is observed in real time using the observation unit. With this setup, containerless processing of liquid such as crystal growth from solution can be realized in a well-controlled manner. Since the levitation is achieved using a superconducting magnet, experiments requiring long duration time such as protein crystallization and simulation of space environment for living system can be easily succeeded.

  20. Electrodynamic Tethers for Spacecraft Propulsion

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Estes, Robert D.; Lorenzini, Enrico; Martinez-Sanchez, Manuel; Sanmartin, Juan; Vas, Irwin

    1998-01-01

    Relatively short electrodynamic tethers can use solar power to 'push' against a planetary magnetic field to achieve propulsion without the expenditure of propellant. The groundwork has been laid for this type of propulsion. NASA began developing tether technology for space applications in the 1960's. Important recent milestones include retrieval of a tether in space (TSS-1, 1992), successful deployment of a 20-km-long tether in space (SEDS-1, 1993), and operation of an electrodynamic tether with tether current driven in both directions-power and thrust modes (PMG, 1993). The planned Propulsive Small Expendable Deployer System (ProSEDS) experiment will demonstrate electrodynamic tether thrust during its flight in early 2000. ProSEDS will use the flight-proven Small Expendable Deployer System (SEDS) to deploy a 5 km bare copper tether from a Delta II upper stage to achieve approximately 0.4 N drag thrust, thus deorbiting the stage. The experiment will use a predominantly 'bare' tether for current collection in lieu of the endmass collector and insulated tether approach used on previous missions. Theory and ground-based plasma chamber testing indicate that the bare tether is a highly-efficient current collector. The flight experiment is a precursor to utilization of the technology on the International Space Station for reboost application and the more ambitious electrodynamic tether upper stage demonstration mission which will be capable of orbit raising, lowering and inclination changes - all using electrodynamic thrust. In addition, the use of this type of propulsion may be attractive for future missions at Jupiter and any other planetary body with a magnetosphere.

  1. Depinning of flux lines and AC losses in magnet-superconductor levitation system

    SciTech Connect

    Terentiev, A. N.; Hull, J. R.; De Long, L. E.

    1999-11-29

    The AC loss characteristics of a magnet-superconductor system were studied with the magnet fixed to the free end of an oscillating cantilever located near a stationary melt-textured YBCO pellet. Below a threshold AC field amplitude {approx}2Oe, the dissipation of the oscillator is amplitude-independent, characteristic of a linear, non-hysteretic regime. Above threshold,dissipation increases with amplitude, reflecting the depinning and hysteretic motion of flux lines. The threshold AC field is an order of magnitude higher than that measured for the same YBCO material via AC susceptometry in a uniform DC magnetic field, A partial lock-in of flux lines between YBCO ab planes is proposed as the mechanism for the substantial increase of the depinning threshold.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

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

    PubMed

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

    2016-07-19

    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.

  12. 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.

  13. 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.

  14. Approximate boundary conditions in a circular conductor and their application to nonlinear vibration analyses of high-Tc superconducting levitation system

    SciTech Connect

    Nagaya, Kosuke; Shuto, Syunsuke

    1996-05-01

    When a levitated superconductor vibrates, the levitation force has nonlinear relationship among an air gap, amplitude, and frequency, so the usual static analysis for levitation forces is invalid. There are two phenomena of a flux creep and flux flow when the conductor vibrates in a magnetic field. The present article provides an analytical result for the levitation forces of a thick superconducting disc with consideration of the phenomena and effects of flux variations on the critical current. It is significantly difficult to have the analytical result of levitation force by using the exact boundary conditions. This paper presents approximate boundary conditions which give an appropriate result. To validate the proposed boundary conditions, eddy currents in a conductor are first discussed, then the superconductor is discussed. Numerical results for the levitation forces were obtained and compared with the previously published experimental data. The levitation force becomes a restoring force having the nonlinear relationship, so it is difficult to solve vibrations. The present article gives a simplified method for solving nonlinear vibration problems for the levitated conductor. Numerical calculations were carried out for some typical examples.

  15. Optimal Control of Electrodynamic Tethers

    DTIC Science & Technology

    2008-06-01

    method.46 Even though the derivation that produced Eq. (11) required integration over a hypothetical integer number of revolutions, the optimizer ... approach to multi-revolution, long time scale optimal control of an electrodynamic tether is investigated for a tethered satellite system in Low Earth...time scale approach is used to capture the effects of the Earth’s rotating tilted magnetic field. Optimal control solutions are achieved using a

  16. The design considerations for a superconducting magnetic bearing system

    NASA Astrophysics Data System (ADS)

    Cansiz, Ahmet; Yildizer, Irfan

    2014-09-01

    In this paper a high temperature superconducting magnetic bearing is studied with various design considerations. The design of the bearing consists of a rotor with 7.5 kg mass. The stable levitation of the rotor is provided with the Evershed type and superconducting components. The dynamic stability of the rotor is strengthened with the electromagnetic and electrodynamic levitation techniques. The force on the rotor is predicted in terms of semi-analytical frozen image model. The designed driving system sustains stable levitation during the rotation of the rotor and achieves higher rotational speed than that of the torque driver. The results indicate that the designed rotor and driving system have potential solutions for the development of the superconducting flywheel energy storage.

  17. 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…

  18. Magnetic levitation of a flexible steel plate with a vibration suppressing magnet

    SciTech Connect

    Hayashiya, H.; Araki, N.; Paddison, J.E.; Ohsaki, H.; Masada, E.

    1996-09-01

    In the steel making process, the application of a magnetic levitation to the steel plate conveyance is expected. The advantages brought by introducing contactless support of a steel plate are improved quality of products, reduced maintenance cost of installations, increased productivity, and quieter operation. Here, a magnetic levitation system that has a vibration suppressing electromagnet which use only the velocity of the levitated object for the control has been studied. The proposed system has advantages of the stale levitation of a flexible steel plate which moves with time under the fixed electromagnets. The simulation of levitated plate`s response using finite element method and the magnetic levitation experiments using such a vibration suppressing magnet were carried out. The results show the vibration suppressing magnet is able to control the low frequency natural vibration effectively, and a notch filter is able to avoid the excitation of the high frequency natural vibration.

  19. 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.

  20. Self-sensing active magnetic levitation

    SciTech Connect

    Vischer, D.; Bleuler, H. )

    1993-03-01

    Magnetic bearing technology is now rapidly being introduced to industrial applications. The most popular configuration applied is the classical' one of gap sensor, current control, current-amplifier and magnetic coil. Here the authors present a magnetic levitation method which combines all the known advantages of active magnetic bearing in a self-sensing configuration. The novel method realizes stable and well damped levitation without any sensor hardware at the rotor. This is achieved by using the coil voltage of the magnetic bearing as system input (voltage instead of current amplifiers) and the current as system output. It is demonstrated that the resulting system is observable and controllable in the sense of control theory, allowing a magnetic bearing to be stabilized with a simple linear controller using current measurements alone. Several self-sensing bearings have been constructed. Their performance is comparable to systems with sensors, but hardware requirements and costs are substantially reduced. Experimental results are included.

  1. Understanding hygroscopic growth and phase transformation of aerosols using single particle Raman spectroscopy in an electrodynamic balance.

    PubMed

    Lee, Alex K Y; Ling, T Y; Chan, Chak K

    2008-01-01

    Hygroscopic growth is one of the most fundamental properties of atmospheric aerosols. By absorbing or evaporating water, an aerosol particle changes its size, morphology, phase, chemical composition and reactivity and other parameters such as its refractive index. These changes affect the fate and the environmental impacts of atmospheric aerosols, including global climate change. The ElectroDynamic Balance (EDB) has been widely accepted as a unique tool for measuring hygroscopic properties and for investigating phase transformation of aerosols via single particle levitation. Coupled with Raman spectroscopy, an EDB/Raman system is a powerful tool that can be used to investigate both physical and chemical changes associated with the hygroscopic properties of individually levitated particles under controlled environments. In this paper, we report the use of an EDB/Raman system to investigate (1) contact ion pairs formation in supersaturated magnesium sulfate solutions; (2) phase transformation in ammonium nitrate/ammonium sulfate mixed particles; (3) hygroscopicity of organically coated inorganic aerosols; and (4) heterogeneous reactions altering the hygroscopicity of organic aerosols.

  2. Comprehensive comparison of the levitation performance of bulk YBaCuO arrays above two different types of magnetic guideways

    NASA Astrophysics Data System (ADS)

    Deng, Zigang; Qian, Nan; Che, Tong; Jin, Liwei; Si, Shuaishuai; Zhang, Ya; Zheng, Jun

    2016-12-01

    The permanent magnet guideway (PMG) is an important part of high temperature superconducting (HTS) maglev systems. So far, two types of PMG, the normal PMG and Halbach-type PMG, are widely applied in present maglev transportation systems. In this paper, the levitation performance of high temperature superconductor bulks above the two PMGs was synthetically compared. Both static levitation performance and dynamic response characteristics were investigated. Benefiting from the reasonable magnetic field distribution, the Halbach-type PMG is able to gain larger levitation force, greater levitation force decay during the same relaxation time, bigger resonance frequency and dynamic stiffness for the bulk superconductor levitation unit compared with the normal PMG. Another finding is that the Halbach-type PMG is not sensitive to the levitation performance of the bulk levitation unit with different arrays. These results are helpful for the practical application of HTS maglev systems.

  3. 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

  4. 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.

  5. 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.

  6. A vibration energy harvester using diamagnetic levitation

    NASA Astrophysics Data System (ADS)

    Palagummi, S.; Yuan, F. G.

    2013-04-01

    In this paper a novel electromagnetic vibration type energy harvester which uses a diamagnetic levitation system is conceptualized, designed, fabricated, and tested. The harvester uses two diamagnetic plates made of pyrolytic graphite between which a cylindrical magnet levitates passively. Two archimedean spiral coils are placed in grooves which are engraved in the pyrolytic graphite plates, used to convert the mechanical energy into electrical energy efficiently. The geometric configurations of coils are selected based on the field distribution of the magnet to enhance the efficiency of the harvester. A thorough theoretical analysis is done to compare with the experiment results. At an input power of 103.45 μW and at a frequency of 2.7 Hz, the harvester generated a power of 0.744 μW at an efficiency of 0.72 %. Both theoretical and experimental results show that this new energy harvesting system is efficient and can capture low frequency broadband spectra.

  7. 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.

  8. A hybrid electromagnetic-acoustic levitator for the containerless processing of undercooled melts

    NASA Technical Reports Server (NTRS)

    Hmelo, Anthony B.; Banerjee, Sharbari; Wang, Taylor G.

    1992-01-01

    The hybrid, acoustic-EM levitator discussed provides a small lifting force independently of its EM component by exciting an acoustic resonance that serves as a pressure node at the position of the EM-levitated specimen. The system also stabilizes and damps chaotic oscillations during specimen positioning, and can excite forced oscillations of levitated molten metals for drop-physics and thermophysical property measurements. Attention is given to the character and function of the atmosphere in the levitator. Noncontact temperature measurement is via single-color optical pyrometer.

  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. 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.

  11. 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.

  12. 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.

  13. Design, implementation and control of a magnetic levitation device

    NASA Astrophysics Data System (ADS)

    Shameli, Ehsan

    Magnetic levitation technology has shown a great deal of promise for micromanipulation tasks. Due to the lack of mechanical contact, magnetic levitation systems are free of problems caused by friction, wear, sealing and lubrication. These advantages have made magnetic levitation systems a great candidate for clean room applications. In this thesis, a new large gap magnetic levitation system is designed, developed and successfully tested. The system is capable of levitating a 6.5(gr) permanent magnet in 3D space with an air gap of approximately 50(cm) with the traveling range of 20x20x30 mm3. The overall positioning accuracy of the system is 60mum. With the aid of finite elements method, an optimal geometry for the magnetic stator is proposed. Also, an energy optimization approach is utilized in the design of the electromagnets. In order to facilitate the design of various controllers for the system, a mathematical model of the magnetic force experienced by the levitated object is obtained. The dynamic magnetic force model is determined experimentally using frequency response system identification. The response of the system components including the power amplifiers, and position measurement system are also considered in the development of the force model. The force model is then employed in the controller design for the magnetic levitation device. Through a modular approach, the controller design for the 3D positioning system is started with the controller design for the vertical direction, i.e. z, and then followed by the controller design in the horizontal directions, i.e. x and y. For the vertical direction, several controllers such as PID, feed forward and feedback linearization are designed and their performances are compared. Also a control command conditioning method is introduced as a solution to increase the control performance and the results of the proposed controller are compared with the other designs. Experimental results showed that for the magnetic

  14. 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.

  15. Electrodynamics, wind and temperature

    NASA Technical Reports Server (NTRS)

    Schmidlin, F. J.

    1988-01-01

    This RTOP provides for correlative meteorological wind and temperature measurements with atmospheric electrodynamic measurements. Meteorological rocketsondes were launched as part of a number of electrodynamic investigations in Alaska, Norway, Peru, Sweden, and at the Wallops Flight Facility, Wallops Island, Virginia. Measurements obtained as part of the MAC/Epsilon campaign during October 1987 from Andoya, Norway, were in conjunction with electric field, ion mobility, conductivity, and energy deposition studies. The measurements obtained between 30 and 90 km are to evaluate and correlate changes in the atmospheric electrical structure caused by the neutral wind and temperature, or changes in the neutral atmosphere resulting from electrical anomalies.

  16. The tethered satellite electrodynamics experiment project

    NASA Technical Reports Server (NTRS)

    Price, John M.

    1988-01-01

    NASA and Italy's PSN have undertaken the Tethered Satellite Electrodynamics Experiment, in which two tethered bodies will be equipped with data-collecting scientific instruments, as the first stage of the development of the Tethered Satellite System that can be deployed by the Space Shuttle. The experiment will give attention to the electromagnetic interaction between the satellite/tether/orbiter system and the ambient space plasma, and should demonstrate the operation of both satellite- and Shuttle-borne electrodynamic instruments with a conductive tether.

  17. 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.

  18. Torsional Optomechanics of a Levitated Nonspherical Nanoparticle

    NASA Astrophysics Data System (ADS)

    Hoang, Thai M.; Ma, Yue; Ahn, Jonghoon; Bang, Jaehoon; Robicheaux, F.; Yin, Zhang-Qi; Li, Tongcang

    2016-09-01

    An optically levitated nanoparticle in vacuum is a paradigm optomechanical system for sensing and studying macroscopic quantum mechanics. While its center-of-mass motion has been investigated intensively, its torsional vibration has only been studied theoretically in limited cases. Here we report the first experimental observation of the torsional vibration of an optically levitated nonspherical nanoparticle in vacuum. We achieve this by utilizing the coupling between the spin angular momentum of photons and the torsional vibration of a nonspherical nanoparticle whose polarizability is a tensor. The torsional vibration frequency can be 1 order of magnitude higher than its center-of-mass motion frequency, which is promising for ground state cooling. We propose a simple yet novel scheme to achieve ground state cooling of its torsional vibration with a linearly polarized Gaussian cavity mode. A levitated nonspherical nanoparticle in vacuum will also be an ultrasensitive nanoscale torsion balance with a torque detection sensitivity on the order of 10-29 N m /√{Hz } under realistic conditions.

  19. 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.

  20. 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…

  1. Quantum Electrodynamics: Theory

    SciTech Connect

    Lincoln, Don

    2016-03-30

    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.

  2. 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.

  3. Observation of vacuum-enhanced electron spin resonance of optically levitated nanodiamonds

    NASA Astrophysics Data System (ADS)

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

    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. Our results show that optical levitation of nanodiamonds in vacuum not only can improve the mechanical quality of its oscillation, but also enhance the ESR contrast, which pave the way towards a novel levitated spin-optomechanical system for studying macroscopic quantum mechanics. The results also indicate potential applications of NV centers in gas sensing.

  4. Circuit quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Bishop, Lev Samuel

    Circuit Quantum Electrodynamics (cQED), the study of the interaction between superconducting circuits behaving as artificial atoms and 1-dimensional transmission-line resonators, has shown much promise for quantum information processing tasks. For the purposes of quantum computing it is usual to approximate the artificial atoms as 2-level qubits, and much effort has been expended on attempts to isolate these qubits from the environment and to invent ever more sophisticated control and measurement schemes. Rather than focussing on these technological aspects of the field, this thesis investigates the opportunities for using these carefully engineered systems for answering questions of fundamental physics. The low dissipation and small mode volume of the circuits allows easy access to the strong-coupling regime of quantum optics, where one can investigate the interaction of light and matter at the level of single atoms and photons. A signature of strong coupling is the splitting of the cavity transmission peak into a pair of resolvable peaks when a single resonant atom is placed inside the cavity---an effect known as vacuum Rabi splitting. The cQED architecture is ideally suited for going beyond this linear response effect. This thesis shows that increasing the drive power results in two unique nonlinear features in the transmitted heterodyne signal: the supersplitting of each vacuum Rabi peak into a doublet, and the appearance of additional peaks with the characteristic n spacing of the Jaynes-Cummings ladder. These constitute direct evidence for the coupling between the quantized microwave field and the anharmonic spectrum of a superconducting qubit acting as an artificial atom. This thesis also addresses the idea of Bell tests, which are experiments that aim to disprove certain types of classical theories, presenting a proposed method for preparing maximally entangled 3-qubit states via a 'preparation by measurement' scheme using an optimized filter on the time

  5. 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

  6. 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).

  7. 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.

  8. Magnetically levitated space elevator to low-earth orbit

    NASA Astrophysics Data System (ADS)

    Hull, John R.; Mulcahy, Thomas M.; Niemann, Ralph C.

    2002-05-01

    The properties of currently available NbTi superconductors 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 ≈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 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. A preliminary economic analysis estimates the cost to orbit at <30/kg when amortized over ten years with a large volume of traffic; estimated construction cost is well within the ability of many industrial nations.

  9. Electrodynamics in Giant Planet Atmospheres

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

    The atmospheres of close-in extrasolar giant planets such as HD209458b are strongly ionized by the UV flux of their host stars. We show that photoionization on such planets creates a dayside ionosphere that extends from the thermosphere to the 100 mbar level. The resulting peak electron density near the 1 mbar level is higher than that encountered in any planetary ionosphere of the solar system, and the model conductivity is in fact comparable to the atmospheres of Sun-like stars. As a result, the momentum and energy balance in the upper atmosphere of HD209458b and similar planets can be strongly affected by ion drag and resistive heating arising from wind-driven electrodynamics. Despite much weaker ionization, electrodynamics is nevertheless also important on the giant planets of the solar system. We use a generic framework to constrain the conductivity regimes on close-in extrasolar planets, and compare the results with conductivites based on the same approach for Jupiter and Saturn. By using a generalized Ohm's law and assumed magnetic fields, we then demonstrate the basic effects of wind-driven ion drag in giant planet atmospheres. Our results show that ion drag is often significant in the upper atmosphere where it can also substantially alter the energy budget through resistive heating.

  10. 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.

  11. 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.

  12. Coil optimization for electromagnetic levitation using a genetic like algorithm

    NASA Astrophysics Data System (ADS)

    Royer, Z. L.; Tackes, C.; LeSar, R.; Napolitano, R. E.

    2013-06-01

    The technique of electromagnetic levitation (EML) provides a means for thermally processing an electrically conductive specimen in a containerless manner. For the investigation of metallic liquids and related melting or freezing transformations, the elimination of substrate-induced nucleation affords access to much higher undercooling than otherwise attainable. With heating and levitation both arising from the currents induced by the coil, the performance of any EML system depends on controlling the balance between lifting forces and heating effects, as influenced by the levitation coil geometry. In this work, a genetic algorithm is developed and utilized to optimize the design of electromagnetic levitation coils. The optimization is targeted specifically to reduce the steady-state temperature of the stably levitated metallic specimen. Reductions in temperature of nominally 70 K relative to that obtained with the initial design are achieved through coil optimization, and the results are compared with experiments for aluminum. Additionally, the optimization method is shown to be robust, generating a small range of converged results from a variety of initial starting conditions. While our optimization criterion was set to achieve the lowest possible sample temperature, the method is general and can be used to optimize for other criteria as well.

  13. High levitation pressures with cage-cooled superconductors

    NASA Astrophysics Data System (ADS)

    Hull, John R.; Komori, Mochimitsu

    2002-05-01

    We present an analysis of and experimental results from a levitational system comprising a stationary, bulk high-temperature superconductor (HTS) and a levitated component (rotor) that consists of a cylindrical permanent magnet surrounded by an annular HTS. The rotor is cooled below the critical temperature of the HTS while surrounded by a ferromagnetic cage. When the ferromagnetic cage is removed, the flux from the permanent magnet is essentially excluded from the interior of the HTS. When brought into proximity with the HTS stator, the cage-cooled rotor experiences a levitational force. The levitational force may be calculated by applying magnetic circuit theory. Such calculations indicate that for a sufficiently high critical current density, the levitational pressure may exceed that between the permanent magnet and its mirror image. We constructed a rotor from an NdFeB permanent magnet and YBCO bulk HTS with a critical current density of ≈5 kA cm-2. A soft ferromagnetic steel cage was constructed in segments. The critical current density of the stator HTS was also ≈5 kA cm-2. Experimental results obtained with the cage-cooled rotor and stationary HTS show a significant increase in force over that of an equivalent PM rotor and stationary HTS.

  14. 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.

  15. Electrodynamics of Pulsar Magnetospheres

    NASA Astrophysics Data System (ADS)

    Cerutti, Benoît; Beloborodov, Andrei M.

    2016-12-01

    We review electrodynamics of rotating magnetized neutron stars, from the early vacuum model to recent numerical experiments with plasma-filled magnetospheres. Significant progress became possible due to the development of global particle-in-cell simulations which capture particle acceleration, emission of high-energy photons, and electron-positron pair creation. The numerical experiments show from first principles how and where electric gaps form, and promise to explain the observed pulsar activity from radio waves to gamma-rays.

  16. Accretion disk electrodynamics

    NASA Technical Reports Server (NTRS)

    Coroniti, F. V.

    1985-01-01

    Accretion disk electrodynamic phenomena are separable into two classes: (1) disks and coronas with turbulent magnetic fields; (2) disks and black holes which are connected to a large-scale external magnetic field. Turbulent fields may originate in an alpha-omega dynamo, provide anomalous viscous transport, and sustain an active corona by magnetic buoyancy. The large-scale field can extract energy and angular momentum from the disk and black hole, and be dynamically configured into a collimated relativistic jet.

  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. 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

    2017-01-01

    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.

  19. Implementation Options for the PROPEL Electrodynamic Tether Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Bilen, Sven G.; Johnson, Les; Gilchrist, Brian E.; Hoyt, Robert P.; Elder, Craig H.; Fuhrhop, Keith P.; Scadera, Michael P.; Stone, Nobie H.

    2014-01-01

    The PROPEL flight mission concept will demonstrate the safe use of an electrodynamic tether for generating thrust. PROPEL is being designed to be a versatile electrodynamic-tether system for multiple end users and to be flexible with respect to platform. As such, several implementation options are being explored, including a comprehensive mission design for PROPEL with a mission duration of six months; a space demonstration mission concept design with configuration of a pair of tethered satellites, one of which is the Japanese H-II Transfer Vehicle; and an ESPA-based system. We report here on these possible implementation options for PROPEL. electrodynamic tether; PROPEL demonstration mission; propellantless propulsion

  20. 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.

  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. Magnetic levitation, suspension, and superconductivity: Macroscopic and mesoscopic

    SciTech Connect

    Haley, S.B.; Fink, H.J.

    1996-02-01

    The levitation state of a large magnetic sphere held in equilibrium above a thick superconducting layer in the Meissner state is a single temperature-independent state as long as the maximum magnetic field at the superconducting (SC) surface does not exceed the critical field {ital H}{sub {ital c}}({ital T}). In contrast, a magnetic microsphere trapped by a superconducting microring exhibits very different behavior. When the radius {ital b} of the SC ring is of the same order as the Ginzburg-Landau coherence length {xi}({ital T}), the system exhibits, in general, a small set of distinct, quantized, temperature-dependent levitation and suspension states. For certain discrete values of {ital b} the flux in the ring is quantized, and the levitation and suspension heights are temperature independent. An abrupt temperature induced transition in the suspension height is also found for a special set of parameters. {copyright} {ital 1996 The American Physical Society.}

  3. Compound Droplet Levitation for Lab-on-a-Chip

    NASA Astrophysics Data System (ADS)

    Black, James; Neitzel, G. Paul

    2016-11-01

    A fluid transport mechanism utilizing thermocapillarity has been previously shown to successfully levitate and translate both microliter- and nanoliter-volume droplets of silicone oil. The surface flow required to drive levitation and transport has not been achieved for aqueous droplets, and encapsulation of samples within a layer of silicone oil is necessary. A droplet-on-demand generator capable of producing nanoliter-volume compound droplets has been developed and previously reported. The work presented here discusses efforts to demonstrate the applicability of this microfluidic transport mechanism to lab-on-a-chip systems. We elaborate on translation speeds of single-phase, nanoliter-volume, silicone-oil droplets. Compound droplets of varying compositions of oil and water are then generated, captured, levitated, and merged to explore the composition limits thereof. Work supported by NSF and NASA.

  4. 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.

  5. Low gravity on earth by magnetic levitation of biological material.

    PubMed

    Valles, James M; Guevorkian, Karine

    2002-07-01

    The use of a magnetic field gradient levitation apparatus as a tool for investigating gravisensing mechanisms in biological systems and as a low gravity simulator for biological systems is described. The basic principles are described. Differences between its application to pure materials and the heterogeneous materials of biological materials are emphasized.

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

    NASA Astrophysics Data System (ADS)

    Hull, John R.

    2000-06-01

    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 non-negligible 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 analogue of Earnshaw's theorem, in which the vertical stiffness is equal to the sum of the horizontal stiffness at the field-cooling position, independent of the angular distribution of magnetic moments within the PM.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Magnetic levitation and stiffness in melt-textured Y-Ba-Cu-O

    NASA Astrophysics Data System (ADS)

    Hull, J. R.; Mulcahy, T. M.; Salama, K.; Selvamanickam, V.; Weinberger, B. R.; Lynds, L.

    1992-09-01

    Magnetic levitation and stiffness have been measured in several systems composed of a permanent magnet elastically suspended above a stationary melt-textured sample of Y-Ba-Cu-O. The levitation force and vertical stiffness have been calculated on the basis of magnetization measurements of the same system, and the calculated results showed excellent agreement with the experimental measurements. Based on the force and magnetization measurements, it is predicted that the same Y-Ba-Cu-O material configured in a geometry suitable for magnetic bearings could produce a levitation pressure of 100-400 kPa at 20 K.

  13. Magnetic levitation and stiffness in melt-textured Y-Ba-Cu-O

    SciTech Connect

    Hull, J.R.; Mulcahy, T.M. ); Salama, K.; Selvamanickam, V. ); Weinberger, B.R.; Lynds, L. )

    1992-09-01

    Magnetic levitation and stiffness have been measured in several systems composed of a permanent magnet elastically suspended above a stationary melt-textured sample of Y-Ba-Cu-O. The levitation force and vertical stiffness have been calculated on the basis of magnetization measurements of the same system, and the calculated results showed excellent agreement with the experimental measurements. Based on the force and magnetization measurements, it is predicted that the same Y-Ba-Cu-O material configured in a geometry suitable for magnetic bearings could produce a levitation pressure of 100--400 kPa at 20 K.

  14. Novel gas-dynamic levitation scheme for noncontact coating of spherical ICF targets

    SciTech Connect

    Kim, K.; Feng, Q.

    1995-12-01

    A novel gas-dynamic levitation technique has been developed to facilitate noncontact coating of spherical ICF targets. Using this technique three metal balls 450 {mu}m, 650 {mu}m and 950 {mu}m in diameter were levitated very stably for several hours, with the balls rotating continuously. Unlike the conventional gas-dynamic levitation scheme in which a single gas-emitting fixture, placed below an object, lifts it up and contains it in a confined volume, the present scheme relies on two fixtures, one placed under and the other above the object. The bottom fixture, as is with the conventional scheme, is a gas emitter; however, the top one is a gas collector shaping the flow field around the object so as to confine the object near the axis of symmetry of the levitation system. As a result, the present system exhibits excellent stability and robustness, and is immune to such external disturbances as nonuniform temperature fields and air currents, and small changes in the levitation gas pressure. The apparatus is inexpensive to fabricate and simple to operate. The details of the apparatus and the preliminary data demonstrating the capability of the levitation scheme are presented. A target coating method, compatible with the present target levitation scheme and suitable for uniform coating of ICF targets, is indicated. 6 refs., 5 figs.

  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. 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

  17. 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.

  18. 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.

  19. ELSA- The European Levitated Spherical Actruator

    NASA Astrophysics Data System (ADS)

    Ruiz, M.; Serin, J.; Telteu-Nedelcu, D.; De La Vallee Poussin, H.; Onillon, E.; Rossini, L.

    2014-08-01

    The reaction sphere is a magnetic bearing spherical actuator consisting of a permanent magnet spherical rotor that can be accelerated in any direction. It consists of an 8-pole permanent magnet spherical rotor that is magnetically levitated and can be accelerated about any axis by a 20-pole stator with electromagnets. The spherical actuator is proposed as a potential alternative to traditional momentum exchange devices such as reaction wheels (RWs) or control moment gyroscopes (CMGs). This new actuator provides several benefits such as reduced mass and power supply allocated to the attitude and navigation unit, performance gain, and improved reliability due to the absence of mechanical bearings. The paper presents the work done on the levitated spherical actuator and more precisely the electrical drive including its control unit and power parts. An elegant breadboard is currently being manufactured within the frame of an FP7 project. This project also comprises a feasibility study to show the feasibility of integrating such a system on a flight platform and to identify all the challenges to be solved in terms of technology or components to be developed.

  20. Time-symmetric electrodynamics and quantum measurement

    NASA Astrophysics Data System (ADS)

    Pegg, D. T.

    The application of the Wheeler-Feynman theory of time-symmetric electrodynamics to obtain definite answers to questions concerning the objective existence of quantum states in an optical EPR type of experiment is discussed. This theory allows the influence of the detector on the system being studied to be taken into account. The result is an entirely fresh understanding of experiments of the Kocher-Commins type.

  1. The Foundations of Linear Stochastic Electrodynamics

    NASA Astrophysics Data System (ADS)

    Peña, L. De La; Cetto, A. M.

    2006-03-01

    An analysis is briefly presented of the possible causes of the failure of stochastic electrodynamics (SED) when applied to systems with nonlinear forces, on the basis that the main principles of the theory are correct. In light of this analysis, an alternative approach to the theory is discussed, whose postulates allow to establish contact with quantum mechanics in a natural way. The ensuing theory, linear SED, confirms the essential role of the vacuum particle interaction as the source of quantum phenomena.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. EMC Test Report Electrodynamic Dust Shield

    NASA Technical Reports Server (NTRS)

    Carmody, Lynne M.; Boyette, Carl B.

    2014-01-01

    This report documents the Electromagnetic Interference E M I evaluation performed on the Electrodynamic Dust Shield (EDS) which is part of the MISSE-X System under the Electrostatics and Surface Physics Laboratory at Kennedy Space Center. Measurements are performed to document the emissions environment associated with the EDS units. The purpose of this report is to collect all information needed to reproduce the testing performed on the Electrodynamic Dust Shield units, document data gathered during testing, and present the results. This document presents information unique to the measurements performed on the Bioculture Express Rack payload; using test methods prepared to meet SSP 30238 requirements. It includes the information necessary to satisfy the needs of the customer per work order number 1037104. The information presented herein should only be used to meet the requirements for which it was prepared.

  7. 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.

  8. Large gap control in electromagnetic levitation.

    PubMed

    Banerjee, Subrata; Prasad, Dinkar; Pal, Jayanta

    2006-04-01

    This paper describes design and implementation of a single axis dc attraction type electromagnetic suspension system where an electromagnet of 2.6 kg mass is levitated over a large gap under a fixed ferromagnetic guide-way. The electromagnet exhibits nonlinear force-current-distance characteristics, and if controllers are to be designed by using linear analysis, the air-gap is restricted to a small region around the chosen nominal operating point. In this work, an attempt has been made to increase the operating range of an electromagnetic suspension system by using the concept of piecewise linear control where the nonlinear force-current-airgap relationships of the magnetic suspension system have been successively linearized at several operating points with a suitable controller designed for each operating point. A novel analog switching scheme has been designed and implemented to automatically switch to the relevant controller depending on the actual air-gap.

  9. Submersion Quenching of Undercooled Liquid Metals in an Electrostatic Levitator

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.

    2016-01-01

    The NASA Marshall Space Flight Center (MSFC) electrostatic levitation (ESL) laboratory has a long history of providing materials research and thermophysical property data. The laboratory has recently added a new capability, 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. Thereby allowing rapid quenching of undercooled liquid metals and alloys. This is the first submersion quench system inside an electrostatic levitator. The system has been tested successfully with samples of zirconium, iron-cobalt alloys, titanium-zirconium-nickel alloys, and silicon-cobalt alloys. This rapid quench system will allow materials science studies of undercooled materials and new materials development, including studies of metastable phases and transient microstructures. In this presentation, the system is described and some initial results are presented.

  10. 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.

  11. Two applications of axion electrodynamics

    NASA Technical Reports Server (NTRS)

    Wilczek, Frank

    1987-01-01

    The equations of axion electrodynamics are studied. Variations in the axion field can give rise to peculiar distributions of charge and current. These effects provide a simple understanding of the fractional electric charge on dyons and of some recently discovered oddities in the electrodynamics of antiphase boundaries in PbTe. Some speculations regarding the possible occurrence of related phenomena in other solids are presented.

  12. Cavity opto-mechanics using an optically levitated nanosphere

    PubMed Central

    Chang, D. E.; Regal, C. A.; Papp, S. B.; Wilson, D. J.; Ye, J.; Painter, O.; Kimble, H. J.; Zoller, P.

    2010-01-01

    Recently, remarkable advances have been made in coupling a number of high-Q modes of nano-mechanical systems to high-finesse optical cavities, with the goal of reaching regimes in which quantum behavior can be observed and leveraged toward new applications. To reach this regime, the coupling between these systems and their thermal environments must be minimized. Here we propose a novel approach to this problem, in which optically levitating a nano-mechanical system can greatly reduce its thermal contact, while simultaneously eliminating dissipation arising from clamping. Through the long coherence times allowed, this approach potentially opens the door to ground-state cooling and coherent manipulation of a single mesoscopic mechanical system or entanglement generation between spatially separate systems, even in room-temperature environments. As an example, we show that these goals should be achievable when the mechanical mode consists of the center-of-mass motion of a levitated nanosphere. PMID:20080573

  13. Magnetically levitated autoparametric broadband vibration energy harvesting

    NASA Astrophysics Data System (ADS)

    Kurmann, L.; Jia, Y.; Manoli, Y.; Woias, P.

    2016-11-01

    Some of the lingering challenges within the current paradigm of vibration energy harvesting (VEH) involve narrow operational frequency range and the inevitable non-resonant response from broadband noise excitations. Such VEHs are only suitable for limited applications with fixed sinusoidal vibration, and fail to capture a large spectrum of the real world vibration. Various arraying designs, frequency tuning schemes and nonlinear vibratory approaches have only yielded modest enhancements. To fundamentally address this, the paper proposes and explores the potentials in using highly nonlinear magnetic spring force to activate an autoparametric oscillator, in order to realize an inherently broadband resonant system. Analytical and numerical modelling illustrate that high spring nonlinearity derived from magnetic levitation helps to promote the 2:1 internal frequency matching required to activate parametric resonance. At the right internal parameters, the resulting system can intrinsically exhibit semi-resonant response regardless of the bandwidth of the input vibration, including broadband white noise excitation.

  14. Active Control of Magnetically Levitated Bearings

    SciTech Connect

    BARNEY, PATRICK S.; LAUFFER, JAMES P.; REDMOND, JAMES M.; SULLIVAN, WILLIAM N.

    2001-03-01

    This report summarizes experimental and test results from a two year LDRD project entitled Real Time Error Correction Using Electromagnetic Bearing Spindles. This project was designed to explore various control schemes for levitating magnetic bearings with the goal of obtaining high precision location of the spindle and exceptionally high rotational speeds. As part of this work, several adaptive control schemes were devised, analyzed, and implemented on an experimental magnetic bearing system. Measured results, which indicated precision positional control of the spindle was possible, agreed reasonably well with simulations. Testing also indicated that the magnetic bearing systems were capable of very high rotational speeds but were still not immune to traditional structural dynamic limitations caused by spindle flexibility effects.

  15. 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.

  16. A Simple, Inexpensive Acoustic Levitation Apparatus

    ERIC Educational Resources Information Center

    Schappe, R. Scott; Barbosa, Cinthya

    2017-01-01

    Acoustic levitation uses a resonant ultrasonic standing wave to suspend small objects; it is used in a variety of research disciplines, particularly in the study of phase transitions and materials susceptible to contamination, or as a stabilization mechanism in microgravity environments. The levitation equipment used for such research is quite…

  17. Passive levitation in alternating magnetic fields

    SciTech Connect

    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.

  18. Modeling superconductor degradation using magnetic levitation

    SciTech Connect

    Sriram, M.A.; Ponce, L.; Murr, L.E. . Department of Metallurgical and Materials Engineering)

    1991-03-18

    Corrosion of YBa{sub 2}Cu{sub 3}O{sub 7{minus}{ital x}} pellets has been studied using magnetic levitation. Pellets compressed at green compaction pressures of 120--200 MPa were exposed to water and air and the levitation heights were measured over a period of more than a month. A model based on diffusion as a rate-controlling step has been proposed. Levitation height normalized with respect to the initial levitation height was used as the modeling parameter. The experiments indicate that the normalized levitation height decreased with time up to a certain level called the saturation leviation, beyond which there is no change in the levitation height. Samples in air degraded faster than samples in water. The initial period of degradation before saturation fits the proposed model well and therefore appears to be diffusion controlled. The saturation levitation shows a dependence on the green compaction pressure. It has been proposed that corrosion (degrading reactions) is due to open porosities which are closed by the reaction products, thus causing a saturation in the levitation height dependent on the porosities.

  19. Passive levitation in alternating magnetic fields

    SciTech Connect

    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.

  20. 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

  1. Nonlinear restoring forces and geometry influence on stability in near-field acoustic levitation

    NASA Astrophysics Data System (ADS)

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

    2011-04-01

    Stability is a key factor in near-field acoustic levitation (NFAL), which is a popular method for noncontact transportation of surface-sensitive objects. Since the physical principle of NFAL is based on nonlinear vibration and nonuniform pressure distribution of a plate resonator, traditional linearized stability analysis cannot address this problem correctly. We have performed a theoretical analysis on the levitation stability using a nonlinear squeeze film model including inertia effects and entrance pressure drop, and obtained nonlinear effective restoring force and moment. It was found that the nonuniform pressure distribution is mode-dependent, which determines the stability of the levitation system. Based on the theoretical understanding, we have designed a NFAL resonator with tapered cross section, which can provide higher stability for the levitating object than the rectangular cross-section resonator.

  2. Design, fabrication and levitation experiments of a micromachined electrostatically suspended six-axis accelerometer.

    PubMed

    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.

  3. 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

  4. Magnetic levitation experiments in Tohoku University

    NASA Astrophysics Data System (ADS)

    Motokawa, M.; Mogi, I.; Tagami, M.; Hamai, M.; Watanabe, K.; Awaji, S.

    1998-12-01

    Magnetic levitation experiments of some diamagnetic materials in high magnetic fields have been done by using a hybrid magnet of Tohoku University. Water located near the edge of the water-cooled magnet, for example, becomes a globe and levitates when a field at the center of the magnet is above 20.5 T. As the first application of water levitation, we tried to make an ice crystal at the levitating condition and it turned out that the crystallization process shows complicated and strange behavior at supercooled -10°C. Synthesis of a dendrite ice crystal was also tried and it was first found that the directions of growing branches are different. But this effect seems to be not due to the levitation effect but due to the orientation effect.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. Summary Presentation of the Electrodynamics Interactions Panel

    NASA Technical Reports Server (NTRS)

    Stone, N. H.

    1985-01-01

    Technological and scientific uses of electrodynamic tethers in space are considered. Areas of concern for such applications of electrodynamic tethers are enumerated. Thrust and power generation using tethers are discussed.

  10. 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.

  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. Plasma contactors for electrodynamic tether

    NASA Technical Reports Server (NTRS)

    Patterson, Michael J.; Wilbur, Paul J.

    1986-01-01

    The role plasma contactors play in effective electrodynamic tether operation is discussed. Hollow cathodes and hollow cathode-based plasma sources have been identified as leading candidates for the electrodynamic tether plasma contactor. Present experimental efforts to evaluate the suitability of these devices as plasma contactors, conducted concurrently at NASA Lewis Research Center and Colorado State University, are reviewed. These research programs include the definition of preliminary plasma contactor designs, and the characterization of their operation both as electron emitters and electron collectors to and from a simulated space plasma. Results indicate that ampere-level electron currents, sufficient for electrodynamic tether operation, can be exchanged between hollow cathode-based plasma contactors and a dilute plasma.

  13. Electrodynamics payloads for small rockets

    NASA Technical Reports Server (NTRS)

    Croskey, C. L.; Hale, L. C.; Mitchell, J. D.; Mccarthy, S. P.; Goodnow, K. J.; Li, C.; Goldberg, R. A.

    1992-01-01

    Totally integrated design facilitates electrical cleanliness and light weight, which are necessary in subsonic parachute-borne payloads for electrodynamics investigations. 'Blunt' probes measure ion conductivity, as do Gerdien condensers. Recent finite-element computer analyses combining flow and electrodynamics have resolved problems in determining ion densities and mobilities from Gerdien data. Three-axis electric fields are measured with deployable boom-mounted electrodes from dc through VLF. Splitting the cylindrical payload with an insulator and measuring the current between halves has provided a vertical Maxwell current detector mechanically rigid enough to measure, at ELF, energy related to coupling. A nose tip 'Smith' probe turbulence measurement is usually performed on ascent. Other instrumentation, such as photo-ionization sources and X-ray detectors, can also be included. These electrodynamic measurement payloads are about one meter in length and have a mass of about 9 kg. They can be launched with an Orion-class or smaller vehicle.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. Time-optimal control of the magnetically levitated photolithography platen

    SciTech Connect

    Redmond, J.; Tucker, S.

    1995-01-01

    This report summarizes two approaches to time-optimal control of a nonlinear magnetically levitated platen. The system of interest is a candidate technology for next-generation photolithography machines used in the manufacture of integrated circuits. The dynamics and the variable peak control force of the electro-magnetic actuators preclude the direct application of classical time-optimal control methodologies for determining optimal rest-to-rest maneuver strategies. Therefore, this study explores alternate approaches using a previously developed computer simulation. In the first approach, conservative estimates of the available control forces are used to generate suboptimal switching curves. In the second approach, exact solutions are determined iteratively and used as a training set for an artificial neural network. The trained network provides optimal actuator switching times that incorporate the full nonlinearities of the magnetic levitation actuators. Sample problems illustrate the effectiveness of these techniques as compared to traditional proportional-derivative control.

  19. 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).

  20. 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.

  1. 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.

  2. A diamagnetically stabilized horizontally levitated electromagnetic vibration energy harvester

    NASA Astrophysics Data System (ADS)

    Palagummi, S.; Zou, J.; Yuan, F. G.

    2015-04-01

    This article investigates a horizontal diamagnetic levitation (HDL) system for vibration energy harvesting. In this configuration, two large magnets, alias lifting magnets, are arranged co-axially at a distance such that in between them a magnet, alias floating magnet, is passively levitated at a laterally offset equilibrium position. The levitation is stabilized in the horizontal direction by two diamagnetic plates made of pyrolytic graphite placed on each side of the floating magnet. This HDL configuration permits large amplitude vibration of the floating magnet and exploits the ability to tailor the geometry to meet specific applications due to its frequency tuning capability. Theoretical modeling techniques are discussed followed by an experimental setup to validate it. At an input root mean square (RMS) acceleration of 0.0434 m/s2 (0.0044 grms) and at a resonant frequency of 1.2 Hz, the prototype generated a RMS power of 3.6 μW with an average system efficiency of 1.93%. Followed by the validation, parametric studies on the geometry of the components are undertaken to show that with the optimized parameters the efficiency can be further enhanced.

  3. 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.

  4. 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.

  5. Quantum Electrodynamical Shifts in Multivalent Heavy Ions

    NASA Astrophysics Data System (ADS)

    Tupitsyn, I. I.; Kozlov, M. G.; Safronova, M. S.; Shabaev, V. M.; Dzuba, V. A.

    2016-12-01

    The quantum electrodynamics (QED) corrections are directly incorporated into the most accurate treatment of the correlation corrections for ions with complex electronic structure of interest to metrology and tests of fundamental physics. We compared the performance of four different QED potentials for various systems to access the accuracy of QED calculations and to make a prediction of highly charged ion properties urgently needed for planning future experiments. We find that all four potentials give consistent and reliable results for ions of interest. For the strongly bound electrons, the nonlocal potentials are more accurate than the local potential.

  6. Quantum Electrodynamical Shifts in Multivalent Heavy Ions.

    PubMed

    Tupitsyn, I I; Kozlov, M G; Safronova, M S; Shabaev, V M; Dzuba, V A

    2016-12-16

    The quantum electrodynamics (QED) corrections are directly incorporated into the most accurate treatment of the correlation corrections for ions with complex electronic structure of interest to metrology and tests of fundamental physics. We compared the performance of four different QED potentials for various systems to access the accuracy of QED calculations and to make a prediction of highly charged ion properties urgently needed for planning future experiments. We find that all four potentials give consistent and reliable results for ions of interest. For the strongly bound electrons, the nonlocal potentials are more accurate than the local potential.

  7. NEW APPROACHES: High temperature superconductor levitation motor

    NASA Astrophysics Data System (ADS)

    Abd-Shukor, R.; Lee, K. H.

    1998-01-01

    We show how it is possible to construct a high temperature superconductor levitation motor in an introductory physics laboratory. It is suitable for classroom demonstration and uses a simple yet efficient cooling method.

  8. Electrostatic Levitation Technique for Investigations of Physical Properties of Liquid States

    NASA Astrophysics Data System (ADS)

    Okada, Junpei; Ishikawa, Takehiko; Paradis, Paul-Francois; Yoda, Shinichi

    Electrostatic levitator (ESL) levitates a charged sample in a high vacuum using computer con-trolled electrostatic fields [1]. It can levitate materials such as metals, semiconductors, and some insulators. Sample temperature can be varied over a wide range, and samples can be deeply undercooled. We have been engaged in the research and development of the electro-static levitation technique with the aim of performing levitation dissolution experiments in the International Space Station (ISS). Our device for the electrostatic levitation dissolution test has been developed for experiments on the ISS. To this end, the system is designed to be compact and portable so that it can be launched by rocket and used for experiments in the limited space on the ISS. Accordingly, the device can be installed not just on the ISS or our research laboratory, but also in various external sites. We devised a plan to install the electrostatic levitation system in a site other than the ISS to study atomic structure and electron structure of ultra-high-temperature liquids. We mounted our system on third generation synchrotron radiation facility "SPring-8" in Japan, to investigate the atomic and electron structures of high-temperature liquids. The SPring-8 is an experimental facility that allows use of the most powerful X-rays in the world. We conducted a variety of experiments on ultra-high-temperature liquids using SPring-8. The X-ray is ideal for exploring atomic structure and electron structure. Since the X-ray is an electromagnetic wave, it interacts with electrons. In addition, most electrons gather around the atomic nucleus. By close analysis of the scattered x-rays, we can determine its atomic structure and electron structure in detail. In this talk, we introduce an x-ray Compton scattering and x-ray Raman scattering measurements on liquid aluminum and silicon. [1] W. -K. Rhim, et al, Rev. Sci. Instrum. (1985) 56 307.

  9. Magnetic Levitation and Noncoalescence of Liquid Helium

    SciTech Connect

    Weilert, M.; Whitaker, D.; Maris, H.; Seidel, G.

    1996-12-01

    We describe experiments in which drops of liquid helium-4, as large as 2cm in diameter, are magnetically levitated. 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. It appears that this effect is caused by the slow evaporation of liquid from the drops. {copyright} {ital 1996 The American Physical Society.}

  10. 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.

  11. 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

  12. Improved Plasma Properties in RT-1 with a Levitated Coil

    NASA Astrophysics Data System (ADS)

    Saitoh, Haruhiko; Yoshida, Zensho; Ogawa, Yuichi; Morikawa, Junji; Watanabe, Sho; Yano, Yoshihisa; Suzuki, Junko

    2007-11-01

    Ring Trap-1 (RT-1) is a novel device to confine plasmas in a magnetosphere-like configuration generated by a superconducting internal conductor. The ring coil is excited with a permanent current of Ic=250kAT that is magnetically levitated in the chamber to minimize disturbances to the plasmas. The main scientific objective of RT-1 is to realize self-organized states of flowing plasmas with a very high beta value, where the thermal pressure of plasmas is balanced by the hydrodynamic pressure of a fast flow (S. M. Mahajan & Z. Yoshida, PRL 81, 4863 (1998), Z. Yoshida & S. M. Mahajan, PRL 88, 095001 (2002)). We have started a series of initial plasma experiments since 2006, and in this study, we focused on the improvements of plasma properties by the coil levitation. Hydrogen plasmas were generated by an 8.2GHz ECH system. When the coil was levitated, a line integrated electron density increased to ne=4x10^17m-2 and the peak density was close to the O-mode cut off density of the microwave. The beta value of the plasma was ˜3% and the pressure was mainly sustained by a high energy component of electrons. The magnetic surface configuration of RT-1 is also suitable for the confinement of non-neutral plasmas. Experiments on electron plasmas were conducted in RT-1 expanding the previous work in a normal conducting device.

  13. 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.

  14. Sample handling and chemical kinetics in an acoustically levitated drop microreactor.

    PubMed

    Pierre, Zakiah N; Field, Christopher R; Scheeline, Alexander

    2009-10-15

    Accurate measurement of enzyme kinetics is an essential part of understanding the mechanisms of biochemical reactions. The typical means of studying such systems use stirred cuvettes, stopped-flow apparatus, microfluidic systems, or other small sample containers. These methods may prove to be problematic if reactants or products adsorb to or react with the container's surface. As an alternative approach, we have developed an acoustically-levitated drop reactor eventually intended to study enzyme-catalyzed reaction kinetics related to free radical and oxidative stress chemistry. Microliter-scale droplet generation, reactant introduction, maintenance, and fluid removal are all important aspects in conducting reactions in a levitated drop. A three capillary bundle system has been developed to address these needs. We report kinetic measurements for both luminol chemiluminescence and the reaction of pyruvate with nicotinamide adenine dinucleotide, catalyzed by lactate dehydrogenase, to demonstrate the feasibility of using a levitated drop in conjunction with the developed capillary sample handling system as a microreactor.

  15. 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

  16. On spacetime structure and electrodynamics

    NASA Astrophysics Data System (ADS)

    Ni, Wei-Tou

    2016-10-01

    Electrodynamics is the most tested fundamental physical theory. Relativity arose from the completion of Maxwell-Lorentz electrodynamics. Introducing the metric gij as gravitational potential in 1913, versed in general (coordinate-)covariant formalism in 1914 and shortly after the completion of general relativity, Einstein put the Maxwell equations in general covariant form with only the constitutive relation between the excitation and the field dependent on and connected by the metric in 1916. Further clarification and developments by Weyl in 1918, Murnaghan in 1921, Kottler in 1922 and Cartan in 1923 together with the corresponding developments in electrodynamics of continuous media by Bateman in 1910, Tamm in 1924, Laue in 1952 and Post in 1962 established the premetric formalism of electrodynamics. Since almost all phenomena electrodynamics deal with have energy scales much lower than the Higgs mass energy and intermediate boson energy, electrodynamics of continuous media should be applicable and the constitutive relation of spacetime/vacuum should be local and linear. What is the key characteristic of the spacetime/vacuum? It is the Weak Equivalence Principle I (WEP I) for photons/wave packets of light which states that the spacetime trajectory of light in a gravitational field depends only on its initial position and direction of propagation, and does not depend on its frequency (energy) and polarization, i.e. nonbirefringence of light propagation in spacetime/vacuum. With this principle it is proved by the author in 1981 in the weak field limit, and by Lammerzahl and Hehl in 2004 together with Favaro and Bergamin in 2011 without assuming the weak-field condition that the constitutive tensor must be of the core metric form with only two additional degrees of freedom — the pseudoscalar (Abelian axion or EM axion) degree of freedom and the scalar (dilaton) degree of freedom (i.e. metric with axion and dilaton). In this paper, we review this connection and the

  17. Physical properties of core-concrete systems: Al2O3-ZrO2 molten materials measured by aerodynamic levitation

    NASA Astrophysics Data System (ADS)

    Ohishi, Yuji; Kargl, F.; Nakamori, F.; Muta, Hiroaki; Kurosaki, Ken; Yamanaka, Shinsuke

    2017-04-01

    During a molten core-concrete interaction, molten oxides consisting of molten core materials (UO2 and ZrO2) and concrete (Al2O3, SiO2, CaO) are formed. Reliable data on the physical properties of the molten oxides will allow us to accurately predict the progression of a nuclear reactor core meltdown accident. In this study, the viscosities and densities of molten (ZrO2)x(Al2O3)1-x (x = 0.356 and 0.172) were measured using an aerodynamic levitation technique. The densities of two small samples were estimated from their masses and their volumes (calculated from recorded images of the molten samples). The droplets were forced to oscillate using speakers, and their viscosities were evaluated from the damping behaviors of their oscillations. The results showed that the viscosity of molten (ZrO2)x(Al2O3)1-x compared to that of pure molten Al2O3 is 25% lower for x = 0.172, while it is unexpectedly 20% higher for x = 0.356.

  18. 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.)

  19. 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.

  20. 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.

  1. 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).

  2. Photon propagator for axion electrodynamics

    SciTech Connect

    Itin, Yakov

    2007-10-15

    The axion modified electrodynamics is usually used as a model for description of possible violation of Lorentz invariance in field theory. The low-energy manifestation of Lorentz violation can hopefully be observed in experiments with electromagnetic waves. It justifies the importance of studying how a small axion addition can modify the wave propagation. Although a constant axion does not contribute to the dispersion relation at all, even a slowly varying axion field destroys the light cone structure. In this paper, we study the wave propagation in the axion modified electrodynamics in the framework of the premetric approach. In addition to the modified dispersion relation, we derive the axion generalization of the photon propagator in Feynman and Landau gauge. Our consideration is free of the usual restriction to the constant gradient axion field. It is remarkable that the axion modified propagator is Hermitian. Consequently, the dissipation effects are absent even in the phenomenological model considered here.

  3. Electrodynamics and Spacetime Geometry: Foundations

    NASA Astrophysics Data System (ADS)

    Cabral, Francisco; Lobo, Francisco S. N.

    2016-11-01

    We explore the intimate connection between spacetime geometry and electrodynamics. This link is already implicit in the constitutive relations between the field strengths and excitations, which are an essential part of the axiomatic structure of electromagnetism, clearly formulated via integration theory and differential forms. We review the foundations of classical electromagnetism based on charge and magnetic flux conservation, the Lorentz force and the constitutive relations. These relations introduce the conformal part of the metric and allow the study of electrodynamics for specific spacetime geometries. At the foundational level, we discuss the possibility of generalizing the vacuum constitutive relations, by relaxing the fixed conditions of homogeneity and isotropy, and by assuming that the symmetry properties of the electro-vacuum follow the spacetime isometries. The implications of this extension are briefly discussed in the context of the intimate connection between electromagnetism and the geometry (and causal structure) of spacetime.

  4. Pyroshock testing-electrodynamic shakers

    NASA Astrophysics Data System (ADS)

    Smallwood, David O.

    2002-05-01

    Far field pyroshock (accelerations less than a few hundred grams, and bandwidths less than a few kHz) can be simulated on electrodynamic shakers. Typically, the specification is in terms of the shock response spectrum (SRS). Wave forms are synthesized which will match the required SRS. The process is not unique, as many wave forms can have essentially the same SRS. Sometimes additional restrictions are placed on the synthesized wave form. Most common are restrictions on the duration of the wave form. The process of synthesizing wave forms, which will match an SRS and conform to the limitations of electrodynamic shakers, will be described. The methods used to reproduce these wave forms on the shaker will then be discussed.

  5. Electrodynamics and Spacetime Geometry: Foundations

    NASA Astrophysics Data System (ADS)

    Cabral, Francisco; Lobo, Francisco S. N.

    2017-02-01

    We explore the intimate connection between spacetime geometry and electrodynamics. This link is already implicit in the constitutive relations between the field strengths and excitations, which are an essential part of the axiomatic structure of electromagnetism, clearly formulated via integration theory and differential forms. We review the foundations of classical electromagnetism based on charge and magnetic flux conservation, the Lorentz force and the constitutive relations. These relations introduce the conformal part of the metric and allow the study of electrodynamics for specific spacetime geometries. At the foundational level, we discuss the possibility of generalizing the vacuum constitutive relations, by relaxing the fixed conditions of homogeneity and isotropy, and by assuming that the symmetry properties of the electro-vacuum follow the spacetime isometries. The implications of this extension are briefly discussed in the context of the intimate connection between electromagnetism and the geometry (and causal structure) of spacetime.

  6. Microscopic thermodynamics with levitated nanoparticles (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Gieseler, Jan; Jain, Vijay; Moritz, Clemens; Dellago, Christoph; Quidant, Romain; Novotny, Lukas

    2016-09-01

    Micsospheres trapped in liquid by so called optical tweezers have been established as useful tools to study microscopic thermodynamics. Since the sphere is in direct contact with the liquid, it is strongly coupled to the thermal bath and its dynamics is dominated by thermal fluctuations. In contrast, here we use an optically trapped nanoparticle in vacuum to study fluctuations of a system that is coupled only weakly to the thermal bath. The weak coupling allows us to resolve the ballistic dynamics and to control its motion via modulation of the trapping beam, thereby preparing it in a highly non-thermal state. We develop a theory for the effective Hamiltonian that describes the system dynamics in this state and show that all the relevant parameters can be controlled in situ. This tunability allows us to study classical fluctuation theorems for different effective Hamiltonians and for varying coupling to the thermal bath ranging over several orders of magnitude. The ultimate goal, however, is to completely suppress the effect of the thermal bath and to prepare the levitated nanoparticle in a quantum mechanical state. Our most recent result indicate that this regime is now within reach.

  7. 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.

  8. Quantum electrodynamics for vector mesons.

    PubMed

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

    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+ 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(rho0)-M(rho+/-) approximately 1 MeV at tree order.

  9. Asymptotic structure of electrodynamics revisited

    NASA Astrophysics Data System (ADS)

    Herdegen, Andrzej

    2017-03-01

    We point out that recently published analyses of null and timelike infinity and long-range structures in electrodynamics to large extent rediscover results present in the literature. At the same time, some of the conclusions these recent works put forward may prove controversial. In view of these facts, we find it desirable to revisit the analysis taken up more than two decades ago, starting from earlier works on null infinity by other authors.

  10. Spacecraft Solar Sails Containing Electrodynamic Tethers

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Matloff, Greg

    2005-01-01

    A report discusses a proposal to use large, lightweight solar sails embedded with electrodynamic tethers (essentially, networks of wires) to (1) propel robotic spacecraft to distant planets, then (2) exploit the planetary magnetic fields to capture the spacecraft into orbits around the planets. The purpose of the proposal is, of course, to make it possible to undertake long interplanetary missions without incurring the large cost and weight penalties of conventional rocket-type propulsion systems. Through transfer of momentum from reflected solar photons, a sail would generate thrust outward from the Sun. Upon arrival in the vicinity of a planet, the electrodynamic tethers would be put to use: Motion of the spacecraft across the planetary magnetic field would induce electric currents in the tether wires, giving rise to an electromagnetic drag force that would be exploited to brake the spacecraft for capture into orbit. The sail with embedded tethers would be made to spin to provide stability during capture. Depending upon the requirements of a particular application, it could be necessary to extend the tether to a diameter greater than that of the sail.

  11. 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

  12. Critical Researches on General Electrodynamics

    NASA Astrophysics Data System (ADS)

    Ritz, Walter; Fritzius, Robert

    1980-11-01

    Electric and electrodynamic phenomena have acquired in the course of these last years more and more importance. They include Optics, the laws of radiation and the innumerable molecular phenomena associated with the presence of charged centers, ions and electrons. Finally, with the notion of electromagnetic mass, Mechanics itself seems obliged to become a chapter of General Electrodynamics. In the form given to it by H. A. Lorentz, Maxwell's theory would thus become the turning point towards a new conception of nature, where the laws of electrodynamics, considered as primary, would contain the laws of motion as special cases and would play the fundamental role in the physical theories which, until now, have belonged to Mechanics. Under these circumstances, it is plainly desirable to have a rigorous criticism of the foundations of this theory, to give it the degree of clarity and precision that Mechanics itself reached only recently after much controversy. It is in order to ask which hypotheses are essential and can be deduced from observations, which others are logically useless or can be discarded without experience ceasing to be adequately represented, and finally, which are those which can be, and should be rejected; a question which is asked principally in regard to absolute motion.

  13. Using high-temperature superconductors for levitation applications

    NASA Astrophysics Data System (ADS)

    Hull, John R.

    1999-07-01

    Melt-textured, bulk high-temperature superconductors are finding increasing uses in superconducting bearings, flywheel energy storage, and other levitational applications. This article reviews the use of these materials in magnetic-levitation applications. The behavior of levitational force, stiffness, damping, and rotational losses is discussed.

  14. Using high-temperature superconductors for levitation applications.

    SciTech Connect

    Hull, J. R.; Energy Technology

    1999-07-01

    Melt-textured, bulk high-temperature superconductors are finding increasing uses in superconducting bearings, flywheel energy storage, and other levitational applications. This article reviews the use of these materials in magnetic-levitation applications. The behavior of levitational force, stiffness, damping, and rotational losses is discussed.

  15. Surface tension effects in levitated helium drops

    NASA Astrophysics Data System (ADS)

    Vicente, Carlos Luis

    We report our investigations of surface tension driven flows in magnetically levitated 4He drops. By levitating helium drops in a magnetic trap we are able to observe the free surface of drops as they undergo shape oscillations. We also study the dynamics of the free surface during the process of coalescence. Our experimental method allows us to excite shape oscillations in the levitated helium drops and measure their normal mode frequencies. By measuring the frequency of the fundamental (l = 2) mode, we obtain new measurements of the surface tension of helium for temperatures between 1.5 and 0.5 K. Our measurements extrapolate to a value of 0.375 erg cm -2 at T = 0 K. Our results agree with the capillary wave measurements of Roche et al., and Atkins and Narahra. We study how the shape of the trap used to levitate the drops influences the resonant frequency of the l = 2 mode. Measurements of the frequency spectrum were performed using different trap potentials. We have calculated the resonant frequencies for the trap shapes produced by different magnet coil currents. We compare our measurements of the resonant frequencies at various magnet currents with these theoretical predictions and find good agreement. We describe experiments to study the coalescence of He II drops levitated in a magnetic trap. Using a high speed CCD camera, we have produced movies of drops coalescing at temperatures as low as 0.7 K. We examine some interesting features of the motion during and following coalescence.

  16. The effect of acoustically levitated objects on the dynamics of ultrasonic actuators

    NASA Astrophysics Data System (ADS)

    Ilssar, D.; Bucher, I.

    2017-03-01

    This paper presents a comprehensive model, coupling a piezoelectric actuator operating at ultrasonic frequencies to a near-field acoustically levitated object through a compressible thin layer of gas such that the combined dynamic response of the system can be predicted. The latter is derived by introducing a simplified model of the nonlinear squeezed layer of gas and a variational model of the solid structure and the piezoelectric elements. Since the harmonic forces applied by the entrapped fluid depend on the levitated object's height and vertical motion, the latter affects the impedance of the driving surface, affecting the natural frequencies, damping ratios, and amplification of the actuator. Thus, the developed model is helpful when devising a resonance tracking algorithm aimed to excite a near-field acoustic levitation based apparatus optimally. Validation of the suggested model was carried out using a focused experimental setup geared to eliminate the effects that were already verified in the past. In agreement with the model, the experimental results showed that the natural frequency and damping ratio of a designated mode decrease monotonically with the levitated object's average height, whereas the amplification of the mode increases with the levitation height.

  17. Electrodynamic Tether Propulsion for Spacecraft and Upper Stages

    NASA Technical Reports Server (NTRS)

    Johnson, Les; Gilchrist, Brian; Estes, Robert D.; Lorenzini, Rnrico; Martinez-Sanchez, Manuel; Sanmartin, Juan

    1998-01-01

    Relatively short electrodynamic tethers can use solar power to 'push' against a planetary magnetic field to achieve propulsion without the expenditure of propellant. The groundwork has been laid for this type of propulsion. Important recent milestones include retrieval of a tether in space (TSS-1, 1992), successful deployment of a 20-km-long tether in space (SEDS-1, 1993), and operation of an electrodynamic tether with tether current driven in both directions (PMG, 1993). The planned Propulsive Small Expendable Deployer System (ProSEDS) experiment will use the flight-proven Small Expendable Deployer System (SEDS) to deploy a 5 km bare copper tether from a Delta II upper stage to achieve approximately 0.4 N drag thrust, thus deorbiting the stage. The experiment will use a predominantly 'bare' tether for current collection in lieu of the endmass collector and insulated tether approach used on previous missions. The flight experiment is a precursor to utilization of the technology on the International Space Station for reboost and the electrodynamic tether upper stage demonstration mission which will be capable of orbit raising, lowering and inclination changes, all using electrodynamic thrust. In addition, the use of this type of propulsion may be attractive for future missions at Jupiter.

  18. Continuous Variable Teleportation Within Stochastic Electrodynamics

    NASA Astrophysics Data System (ADS)

    Carmichael, H. J.; Nha, Hyunchul

    2004-12-01

    Stochastic electrodynamics provides a local realistic interpretation of the continuous variable teleportation of coherent light. Time-domain simulations illustrate broadband features of the teleportation process.

  19. Energy harvesting from the nonlinear oscillations of magnetic levitation

    NASA Astrophysics Data System (ADS)

    Mann, B. P.; Sims, N. D.

    2009-01-01

    This paper investigates the design and analysis of a novel energy harvesting device that uses magnetic levitation to produce an oscillator with a tunable resonance. The governing equations for the mechanical and electrical domains are derived to show the designed system reduces to the form of a Duffing oscillator under both static and dynamic loads. Thus, nonlinear analyses are required to investigate the energy harvesting potential of this prototypical nonlinear system. Theoretical investigations are followed by a series of experimental tests that validate the response predictions. The motivating hypothesis for the current work was that nonlinear phenomenon could be exploited to improve the effectiveness of energy harvesting devices.

  20. Free boundary problems in electromagnetic levitation melting and continuous casting

    NASA Astrophysics Data System (ADS)

    Gagnoud, A.; Leclercq, I.

    1988-01-01

    Two applications of the melting in cold crucibles are presented: continuous casting and levitation melting. These processes are typical examples of coupled phenomena. A free boundary problem has to be solved to determine the equilibrium shape of molten metal with respect to the electrical and geometrical parameters of the system. The magnetic field distribution is calculated by using a boundary integral method. The free surface can be deduced from a global analysis, that is based on the minimization of the total energy of the system. The derivation with respect to the domain leads to a rapid convergence toward the solution.

  1. Simulation Results Related to Stochastic Electrodynamics

    NASA Astrophysics Data System (ADS)

    Cole, Daniel C.

    2006-01-01

    Stochastic electrodynamics (SED) is a classical theory of nature advanced significantly in the 1960s by Trevor Marshall and Timothy Boyer. Since then, SED has continued to be investigated by a very small group of physicists. Early investigations seemed promising, as SED was shown to agree with quantum mechanics (QM) and quantum electrodynamics (QED) for a few linear systems. In particular, agreement was found for the simple harmonic electric dipole oscillator, physical systems composed of such oscillators and interacting electromagnetically, and free electromagnetic fields with boundary conditions imposed such as would enter into Casimir-type force calculations. These results were found to hold for both zero-point and non-zero temperature conditions. However, by the late 1970s and then into the early 1980s, researchers found that when investigating nonlinear systems, SED did not appear to provide agreement with the predictions of QM and QED. A proposed reason for this disagreement was advocated by Boyer and Cole that such nonlinear systems are not sufficiently realistic for describing atomic and molecular physical systems, which should be fundamentally based on the Coulombic binding potential. Analytic attempts on these systems have proven to be most difficult. Consequently, in recent years more attention has been placed on numerically simulating the interaction of a classical electron in a Coulombic binding potential, with classical electromagnetic radiation acting on the classical electron. Good agreement was found for this numerical simulation work as compared with predictions from QM. Here this worked is reviewed and possible directions are discussed. Recent simulation work involving subharmonic resonances for the classical hydrogen atom is also discussed; some of the properties of these subharmonic resonances seem quite interesting and unusual.

  2. 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.

  3. Linear stochastic electrodynamics: Looking for the physics behind quantum theory

    NASA Astrophysics Data System (ADS)

    de la Peña, Luis; Cetto, Ana María

    1999-03-01

    In this chapter, which covers part of the course given at ELAF, a straight-forward procedure is presented that leads from the basic postulates of stochastic electrodynamics to the usual formalism of quantum theory. The theory thus developed is called linear stochastic electrodynamics, to underline that one of its basic features is the (asymptotic) linear response of atomic systems to the background field. The chapter starts with a brief discussion of some open questions in quantum theory and of the possibility to find an answer to them by resorting to the zeropoint radiation field as the source of the quantum behavior of matter. The basic properties of this field are discussed, and a brief enumeration is made of some of the positive results and vital shortcomings of standard stochastic electrodynamics. After identifying the source of these shortcomings in the assumption that the background field is not altered by its interaction with matter, linear stochastic electrodynamics is developed and shown to lead, under certain approximations, to a consistent picture of both matter and field quantization. In the concluding part, it is shown that also the electron spin can be considered to be generated by the interaction of the particle with the zeropoint field; in particular, the two-valuedness of the spin projection is associated with the existence of just two independent states of polarization of the field.

  4. 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.

  5. A Low-Profile Design for the Noncontact Ultrasonically Levitated Stage

    NASA Astrophysics Data System (ADS)

    Ide, Takeshi; Friend, James Robert; Nakamura, Kentaro; Ueha, Sadayuki

    2005-06-01

    In this paper, we propose a new low-profile design for a linear bearing based on Near-Field Acoustic Levitation (NFAL). Two flat beams at a 45° angle are used as a guide rail, and a slider is levitated by ultrasonic bending vibrations excited along the beams. The beams are excited by a pair of Langevin transducers with “+”-shaped vibration direction converters (L-L converters) to install the transducers in the same plane of the beam and to lower the total height of the setup. First, the design of the vibration converter is described. Then, a two-phase driving system to excite a traveling wave is investigated theoretically and experimentally. The levitation characteristics and the sliding performance of the prototype stage are measured and discussed.

  6. Magnetohydrodynamic stability in the electromagnetic levitation of horizontal molten-metal sheets

    NASA Astrophysics Data System (ADS)

    Hull, John R.; Wiencek, Tom; Rote, Donald M.

    1989-06-01

    High-frequency electromagnetic (EM) fields are investigated for the levitation of thin horizontal sheets of liquid metal. A magnetic configuration is analyzed in which inductance stabilization provides global stability and magnetic flux compression provides local stability. Stability analysis indicates that frequencies greater than about 24 kHz are desirable to stably levitate 6 mm thick steel. For stability in systems without active feedback, a conducting screen is required below the metal, with a gap between the screen and the molten metal of no more than twice the metal thickness. Experiments in which 10 kHz EM fields were used to statically levitate sheets of molten tin indicate that dominant magnetohydrodynamic instabilities are of the Rayleigh-Taylor type and correspond to theory.

  7. 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.

  8. 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.

  9. Progress in absolute determination of {Phi}{sub 0} using superconducting magnetic levitation

    SciTech Connect

    Shiota, F.; Miki, Y.; Nuzu, Y.

    1994-12-31

    Superconducting magnetic levitation system for the determination of Magnetic Flux Quantum has been improved significantly in flux-up system using Josephson voltage. Studies are also in progress to improve mechanical measurement relevant to the floating body toward sub-ppm level uncertainty.

  10. Levitation apparatus for structural studies of high temperature liquids using synchrotron radiation

    SciTech Connect

    Krishnan, S.; Felten, J.J.; Rix, J.E.; Weber, J.K.; Nordine, P.C.; Beno, M.A.; Ansell, S.; Price, D.L.

    1997-09-01

    A new levitation apparatus coupled to a synchrotron-derived x-ray source has been developed to study the structure of liquids at temperatures up to 3000 K. The levitation apparatus employs conical nozzle levitation using aerodynamic forces to stably position solid and liquid specimens at high temperatures. A 270 W CO{sub 2} laser was used to heat the specimens to desired temperatures. Two optical pyrometers were used to record the specimen temperature, heating curves, and cooling curves. Three video cameras and a video recorder were employed to obtain and record specimen views in all three dimensions. The levitation assembly was supported on a three-axis translation stage to facilitate precise positioning of the specimen in the synchrotron radiation beam. The levitation system was enclosed in a vacuum chamber with Be windows, connections for vacuum and gas flow, ports for pyrometry, video, and pressure measurements. The vacuum system included automatic pressure control and multi-channel gas flow control. A phosphor screen coupled to a high-resolution video microscope provided images of the x-ray beam and specimen shadow which were used to establish the specimen position. The levitation apparatus was integrated with x-ray diffractometers located at X-6B and X-25 beamlines at the National Synchrotron Light Source. X-ray structural measurements have been obtained on a number of materials including Al{sub 2}O{sub 3}, Ni, Si, Ge, and other metallic and ceramic materials in the liquid state. {copyright} {ital 1997 American Institute of Physics. }

  11. Nano-optomechanics with a levitated nanoparticle (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Quidant, Romain; Mestres, Pau; Ricci, Francesco; Rica, Raul

    2016-09-01

    In this talk we first introduce the use of a levitated nanoparticle in vacuum as a nano-optomechanical system with unprecedented performances. Subsequently, we focus on our efforts in cooling its motion towards mechanical ground state at room temperature. In particular, we present an experiment that combines active parametric feedback cooling with passive resolved side band cooling. We first demonstrate systematic transfer of a single trapped nanoparticle from a load lock to the main vacuum chamber hosting a high-finesse optical cavity and report our latest advances in cooling.

  12. Homogeneous Quantum Electrodynamic Turbulence.

    DTIC Science & Technology

    1992-10-01

    classical Noether invariants of the system. Then the numerical method will be described, and numerical results will be presented. 2 In addition to...is also achieved by scattering particles whose ’interaction time’ is at least 10-21 seconds, i.e., ’resonant’ particles. 3. Noether Invariants The...well, fluctuating no more than 0.04 % during the run. 10 Thus, the Noether invariants of nomalization (i. e., total charge, probability, or particle

  13. 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.

  14. 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.

  15. Universe acceleration and nonlinear electrodynamics

    NASA Astrophysics Data System (ADS)

    Kruglov, S. I.

    2015-12-01

    A new model of nonlinear electrodynamics with a dimensional parameter β coupled to gravity is considered. We show that an accelerated expansion of the universe takes place if the nonlinear electromagnetic field is the source of the gravitational field. A pure magnetic universe is investigated, and the magnetic field drives the universe to accelerate. In this model, after the big bang, the universe undergoes inflation and the accelerated expansion and then decelerates approaching Minkowski spacetime asymptotically. We demonstrate the causality of the model and a classical stability at the deceleration phase.

  16. Electrodynamic Tethers for Spacecraft Propulsion

    NASA Technical Reports Server (NTRS)

    Johnson, Les

    2009-01-01

    Electrodynamic (Drag) Tether Thrust Principles: a) Uses both solar energy and consumes no propellant. b) Tether's orbital velocity v (approx. 7500 m/s) through North-pointing geomagnetic field B(sub north) (0.18 - 0.32 Gauss) induces voltage (35 - 160 V/km) in tether. c) Return current is through surrounding plasma. d) Current I produces a drag thrust force F on the tether. e) Magnetic force F from current I through insulated tether of length l: F = lI x B(sub north).

  17. Macroscopic quantum electrodynamics and duality.

    PubMed

    Buhmann, Stefan Yoshi; Scheel, Stefan

    2009-04-10

    We discuss under what conditions the duality between electric and magnetic fields is a valid symmetry of macroscopic quantum electrodynamics. It is shown that Maxwell's equations in the absence of free charges satisfy duality invariance on an operator level, whereas this is not true for Lorentz forces and atom-field couplings in general. We prove that derived quantities such as Casimir forces, local-field corrected decay rates, as well as van der Waals potentials are invariant with respect to a global exchange of electric and magnetic quantities. This exact symmetry can be used to deduce the physics of new configurations on the basis of already established ones.

  18. 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.

  19. 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.

  20. Quantum dot spectroscopy using cavity quantum electrodynamics.

    PubMed

    Winger, Martin; Badolato, Antonio; Hennessy, Kevin J; Hu, Evelyn L; Imamoğlu, Ataç

    2008-11-28

    We show how cavity quantum electrodynamics using a tunable photonic crystal nanocavity in the strong-coupling regime can be used for single quantum dot spectroscopy. From the distinctive avoided crossings observed in the strongly coupled system we can identify the neutral and single positively charged exciton as well as the biexciton transitions. Moreover we are able to investigate the fine structure of those transitions and to identify a novel cavity mediated mixing of bright and dark exciton states, where the hyperfine interactions with lattice nuclei presumably play a key role. These results are enabled by a deterministic coupling scheme which allowed us to achieve unprecedented coupling strengths in excess of 150 microeV.

  1. Electrodynamics of the Getaway Tether Experiment

    NASA Technical Reports Server (NTRS)

    Greene, Michael; Baginski, Michael; Wheelock, Douglas

    1989-01-01

    An electrodynamic circuit model of the interaction of a pair of small tethered satellites and the ionosphere is developed and analyzed. The system under study, the Getaway Tether Experiment (GATE), is composed of two small satellites and 1 km of insulated conducting tether. The nonlinear model has elements representing the emission, collection, and resistive flow of charge through an electrically conductive tether, plasma contactors, and the ionosphere. The circuit model is incorporated into a dynamic orbital simulation to predict mission performance. Simulation results show the feasibility to bilaterally transfer energy between stored electrical energy and orbital momentum. A transient model is also developed using the circuit model and a string of N lumped-parameter modules, each consisting of resistance, capacitance, and induced potential for the tether. Transients are shown via simulation to occur over millisecond intervals.

  2. A numerical simulation of auroral ionospheric electrodynamics

    NASA Technical Reports Server (NTRS)

    Mallinckrodt, A. J.

    1985-01-01

    A computer simulation of auroral ionospheric electrodynamics in the altitude range 80 to 250 km has been developed. The routine will either simulate typical electron precipitation profiles or accept observed data. Using a model background ionosphere, ion production rates are calculated from which equilibrium electron densities and the Hall and Pedersen conductivities may be determined. With the specification of suitable boundary conditions, the entire three-dimensional current system and electric field may be calculated within the simulation region. The results of the application of the routine to a typical inverted-V precipitation profile are demonstrated. The routine is used to explore the observed anticorrelation between electric field magnitude and peak energy in the precipitating electron spectrum of an auroral arc.

  3. Aspects of passive magnetic levitation based on high-T{sub c} superconducting YBCO thin films

    SciTech Connect

    Schoenhuber, P.; Moon, F.C.

    1995-04-01

    Passive magnetic levitation systems reported in the past were mostly confined to bulk superconducting materials. Here the authors 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, the authors 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.

  4. 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

  5. Hiding levitating objects above a ground plane

    NASA Astrophysics Data System (ADS)

    Zhang, Jingjing; Luo, Yu; Mortensen, Niels Asger

    2010-09-01

    An approach to hiding objects levitating above a conducting sheet is suggested in this paper. The proposed device makes use of isotropic negative-refractive-index materials without extreme material parameters, and creates an illusion of a remote conducting sheet. Numerical simulations are performed to investigate the performance of this cloak in two-dimensional and three-dimensional cases.

  6. 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.

  7. 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.…

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. Subcycle quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Riek, C.; Sulzer, P.; Seeger, M.; Moskalenko, A. S.; Burkard, G.; Seletskiy, D. V.; Leitenstorfer, A.

    2017-01-01

    Squeezed states of electromagnetic radiation have quantum fluctuations below those of the vacuum field. They offer a unique resource for quantum information systems and precision metrology, including gravitational wave detectors, which require unprecedented sensitivity. Since the first experiments on this non-classical form of light, quantum analysis has been based on homodyning techniques and photon correlation measurements. These methods currently function in the visible to near-infrared and microwave spectral ranges. They require a well-defined carrier frequency, and photons contained in a quantum state need to be absorbed or amplified. Quantum non-demolition experiments may be performed to avoid the influence of a measurement in one quadrature, but this procedure comes at the expense of increased uncertainty in another quadrature. Here we generate mid-infrared time-locked patterns of squeezed vacuum noise. After propagation through free space, the quantum fluctuations of the electric field are studied in the time domain using electro-optic sampling with few-femtosecond laser pulses. We directly compare the local noise amplitude to that of bare (that is, unperturbed) vacuum. Our nonlinear approach operates off resonance and, unlike homodyning or photon correlation techniques, without absorption or amplification of the field that is investigated. We find subcycle intervals with noise levels that are substantially less than the amplitude of the vacuum field. As a consequence, there are enhanced fluctuations in adjacent time intervals, owing to Heisenberg’s uncertainty principle, which indicate generation of highly correlated quantum radiation. Together with efforts in the far infrared, this work enables the study of elementary quantum dynamics of light and matter in an energy range at the boundary between vacuum and thermal background conditions.

  13. Subcycle quantum electrodynamics.

    PubMed

    Riek, C; Sulzer, P; Seeger, M; Moskalenko, A S; Burkard, G; Seletskiy, D V; Leitenstorfer, A

    2017-01-18

    Squeezed states of electromagnetic radiation have quantum fluctuations below those of the vacuum field. They offer a unique resource for quantum information systems and precision metrology, including gravitational wave detectors, which require unprecedented sensitivity. Since the first experiments on this non-classical form of light, quantum analysis has been based on homodyning techniques and photon correlation measurements. These methods currently function in the visible to near-infrared and microwave spectral ranges. They require a well-defined carrier frequency, and photons contained in a quantum state need to be absorbed or amplified. Quantum non-demolition experiments may be performed to avoid the influence of a measurement in one quadrature, but this procedure comes at the expense of increased uncertainty in another quadrature. Here we generate mid-infrared time-locked patterns of squeezed vacuum noise. After propagation through free space, the quantum fluctuations of the electric field are studied in the time domain using electro-optic sampling with few-femtosecond laser pulses. We directly compare the local noise amplitude to that of bare (that is, unperturbed) vacuum. Our nonlinear approach operates off resonance and, unlike homodyning or photon correlation techniques, without absorption or amplification of the field that is investigated. We find subcycle intervals with noise levels that are substantially less than the amplitude of the vacuum field. As a consequence, there are enhanced fluctuations in adjacent time intervals, owing to Heisenberg's uncertainty principle, which indicate generation of highly correlated quantum radiation. Together with efforts in the far infrared, this work enables the study of elementary quantum dynamics of light and matter in an energy range at the boundary between vacuum and thermal background conditions.

  14. 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.

  15. 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.

  16. 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.

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

    NASA Technical Reports Server (NTRS)

    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.

  18. 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.

  19. 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.

  20. Electrodynamics of ionospheric weather over low latitudes

    NASA Astrophysics Data System (ADS)

    Abdu, Mangalathayil Ali

    2016-12-01

    The dynamic state of the ionosphere at low latitudes is largely controlled by electric fields originating from dynamo actions by atmospheric waves propagating from below and the solar wind-magnetosphere interaction from above. These electric fields cause structuring of the ionosphere in wide ranging spatial and temporal scales that impact on space-based communication and navigation systems constituting an important segment of our technology-based day-to-day lives. The largest of the ionosphere structures, the equatorial ionization anomaly, with global maximum of plasma densities can cause propagation delays on the GNSS signals. The sunset electrodynamics is responsible for the generation of plasma bubble wide spectrum irregularities that can cause scintillation or even disruptions of satellite communication/navigation signals. Driven basically by upward propagating tides, these electric fields can suffer significant modulations from perturbation winds due to gravity waves, planetary/Kelvin waves, and non-migrating tides, as recent observational and modeling results have demonstrated. The changing state of the plasma distribution arising from these highly variable electric fields constitutes an important component of the ionospheric weather disturbances. Another, often dominating, component arises from solar disturbances when coronal mass ejection (CME) interaction with the earth's magnetosphere results in energy transport to low latitudes in the form of storm time prompt penetration electric fields and thermospheric disturbance winds. As a result, drastic modifications can occur in the form of layer restructuring (Es-, F3 layers etc.), large total electron content (TEC) enhancements, equatorial ionization anomaly (EIA) latitudinal expansion/contraction, anomalous polarization electric fields/vertical drifts, enhanced growth/suppression of plasma structuring, etc. A brief review of our current understanding of the ionospheric weather variations and the

  1. Magnetic Signals of High-Temperature Superconductor Bulk During the Levitation Force Measurement Process

    NASA Astrophysics Data System (ADS)

    Huang, Huan; Zheng, Jun; Qian, Nan; Che, Tong; Zheng, Botian; Jin, Liwei; Deng, Zigang

    2017-02-01

    In order to study the commonly neglected magnetic field information in the course of levitation force measurement process in a superconducting maglev system, a multipoint magnetic field measurement platform was employed to acquire magnetic signals of a bulk high-Tc superconductor on both the top and the bottom surface. Working conditions including field cooling (FC) and zero field cooling were investigated for these vertical down and up motions above a permanent magnet guideway performed on a HTS maglev measurement system. We have discussed the magnetic flux variation process based on the Bean model. A magnetic hysteresis effect similar to the levitation force hysteresis loop of the bulk superconductor was displayed and analyzed in this paper. What is more valuable, there exists some available magnetic flux on the top surface of the bulk superconductor, and the proportion is as high as 62.42% in the FC condition, which provides an experimental hint to design the superconductor bulk and the applied field for practical use in a more efficient way. In particular, this work reveals real-time magnetic flux variation of the bulk superconductor in the levitation application, which is the other important information in contrast to the macroscopic levitation and guidance force investigations in previous studies, and it enriches the existing research methods. The results are significant for understanding the magnetic characteristic of superconductors, and they can contribute to optimize the present HTS maglev system design.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. Modeling storm-time electrodynamics of the low-latitude ionosphere thermosphere system: Can long lasting disturbance electric fields be accounted for?

    NASA Astrophysics Data System (ADS)

    Maruyama, Naomi; Sazykin, Stanislav; Spiro, Robert W.; Anderson, David; Anghel, Adela; Wolf, Richard A.; Toffoletto, Frank R.; Fuller-Rowell, Timothy J.; Codrescu, Mihail V.; Richmond, Arthur D.; Millward, George H.

    2007-07-01

    Storm-time ionospheric disturbance electric fields are studied for two large geomagnetic storms, March 31, 2001 and April 17 18, 2002, by comparing low-latitude observations of ionospheric plasma drifts with results from numerical simulations based on a combination of first-principles models. The simulation machinery combines the Rice convection model (RCM), used to calculate inner magnetospheric electric fields, and the coupled thermosphere ionosphere plasmasphere electrodynamics (CTIPe) model, driven, in part, by RCM-computed electric fields. Comparison of model results with measured or estimated low-latitude vertical drift velocities (zonal electric fields) shows that the coupled model is capable of reproducing measurements under a variety of conditions. In particular, our model results suggest, from theoretical grounds, a possibility of long-lasting penetration of magnetospheric electric fields to low latitudes during prolonged periods of enhanced convection associated with southward-directed interplanetary magnetic field, although the model probably overestimates the magnitude and duration of such penetration during extremely disturbed conditions. During periods of moderate disturbance, we found surprisingly good overall agreement between model predictions and data, with penetration electric fields accounting for early main phase changes and oscillations in low-latitude vertical drift, while the disturbance dynamo mechanism becomes increasingly important later in the modeled events. Discrepancies between the model results and the observations indicate some of the difficulties in validating these combined numerical models, and the limitations of the available experimental data.

  12. 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.

  13. 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.

  14. Stop of magnetic flux movement in levitating superconductor

    NASA Astrophysics Data System (ADS)

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

    2017-01-01

    A phenomenon of magnetic relaxation stopping in a levitating superconductor was studied. It was experimentally shown that magnetic flux creep (diffusion of flux lines to regions with lower vortex density) is absent in magnetic suspension of the superconductor. Magnetic relaxation arises, when a rigid constraint that fixes a position of the superconductor relative to a magnet is imposed on a levitating object. It is assumed that oscillations of magnetic structure, which is due to free oscillations of the levitating superconductor, stop magnetic relaxation.

  15. Dendrimer light-harvesting: intramolecular electrodynamics and mechanisms.

    PubMed

    Andrews, David L; Bradshaw, David S; Jenkins, Robert D; Rodríguez, Justo

    2009-12-07

    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.

  16. Symmetries of field equations of axion electrodynamics

    NASA Astrophysics Data System (ADS)

    Nikitin, A. G.; Kuriksha, Oksana

    2012-07-01

    The group classification of models of axion electrodynamics with arbitrary self-interaction of axionic field is carried out. It is shown that extensions of the basic Poincaré invariance of these models appear only for constant and exponential interactions. The related conservation laws are discussed. The maximal continuous symmetries of the 3d Chern-Simons electrodynamics and Carroll-Field-Jackiw electrodynamics are presented. Using the Inönü-Wigner contraction the nonrelativistic limit of equations of axion electrodynamics is found. Exact solutions for the electromagnetic and axion fields are discussed including those which describe propagation with group velocities faster than the speed of light. However these solutions are causal since the corresponding energy velocities are subluminal.

  17. Undercooling of acoustically levitated molten drops

    NASA Technical Reports Server (NTRS)

    Ohsaka, K.; Trinh, E. H.; Glicksman, M. E.

    1990-01-01

    It was observed that the acoustically levitated molten SCN (succinonitrile) drops can generally be undercooled to a degree where the impurities in the drop are responsible for the nucleation of the solid phase. However, it was also observed that ultrasound occasionally terminates undercooling of the levitated drops by initiating the nucleation of the solid at an undercooling level which is lower than that found for the nucleation catalyzed by the impurities in the drop. This premature nucleation can be explained by thermodynamic considerations which predict an increase in effective undercooling of the liquid upon the collapse of cavities. Pre-existing gas microbubbles which grow under the influence of ultrasound are suggested as the source of cavitation. The highly undercooled SCN drops can be utilized to measure the growth velocity of the solid in the deeply undercooled region including the hypercooled region.

  18. 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.

  19. Lie algebras of classical and stochastic electrodynamics

    NASA Astrophysics Data System (ADS)

    Neto, J. J. Soares; Vianna, J. D. M.

    1994-03-01

    The Lie algebras associated with infinitesimal symmetry transformations of third-order differential equations of interest to classical electrodynamics and stochastic electrodynamics have been obtained. The structure constants for a general case are presented and the Lie algebra for each particular application is easily achieved. By the method used here it is not necessary to know the explicit expressions of the infinitesimal generators in order to determine the structure constants of the Lie algebra.

  20. Finite Element Analysis of the Vertical Levitation Force in an Electrostatic MEMS Comb Drive Actuator

    NASA Astrophysics Data System (ADS)

    Wooldridge, J.; Blackburn, J.; Muniz-Piniella, A.; Stewart, M.; Shean, T. A. V.; Weaver, P. M.; Cain, M. G.

    2013-11-01

    A vertical levitation electrostatic comb drive actuator was manufactured for the purpose of measuring piezoelectric coefficients in small-scale materials and devices. Previous modelling work on comb drive levitation has focussed on control of the levitation in standard poly-silicon devices in order to minimize effects on lateral modes of operation required for the accelerometer and gyroscope applications. The actuator developed in this study was manufactured using a 20 μm electroplated Ni process with a 25 μm trench created beneath the released structure through chemical wet etching. A finite element analysis using ZINC was used to model electrostatic potential around a cross section of one static and one movable electrode, from which the net levitation force per unit electrode was calculated. The model was first verified using the electrode geometry from previously studied systems, and then used to study the variation of force as a function of decreasing substrate-electrode distance. With the top electrode surfaces collinear the calculated force density is 0.00651 epsilon0V2Mμm-1, equivalent to a total force for the device of 36.4 μN at an applied voltage of VM=100 V, just 16% larger than the observed value. The measured increase in force with distance was smaller than predicted with the FEA, due to the geometry of the device in which the electrodes at the anchored ends of the supporting spring structure displace by a smaller amount than those at the centre.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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…

  6. Electromyographic investigation of hypnotic arm levitation: differences between voluntary arm elevation and involuntary arm levitation.

    PubMed

    Peter, Burkhard; Schiebler, Philipp; Piesbergen, Christoph; Hagl, Maria

    2012-01-01

    Thirty-three volunteers were randomly exposed to 3 conditions: hypnotic arm levitation, holding up the arm voluntarily without hypnosis, and imagined arm lifting without hypnosis. Trapezius, deltoid, extensor digitorum, flexor digitorum profundus, biceps brachii, and triceps brachii muscles were measured. Strain and muscle activity during lifting and holding up the right arm for 3 minutes were used as dependent variables. During hypnotic arm levitation, the total muscle activity was lower than during holding it up voluntarily (p < .01); the activity in the deltoid was 27% lower (p < .001). Without hypnosis, the muscle activity showed a positive correlation with strain. However, there was no such correlation in the hypnotic condition. Apparently, it is possible to reduce strain and to objectively measure muscle activity in an uplifted arm through hypnotic arm levitation.

  7. 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.

  8. Regolith Levitation on Small Fast Rotating Asteroids

    NASA Astrophysics Data System (ADS)

    Campo Bagatin, Adriano; Moreno, Fernando; Molina, Antonio

    2014-11-01

    A number of NEAs larger than few hundred meters are found with relatively high spin rates (from ~2.2 to less than 4 hr, depending on composition). On those bodies, local acceleration near their equator may be directed outwards, as in the case of the primaries of binary asteroids Didymos and 1996 FG3. They both are potential targets of future space missions. What are the effects of high spin states on regolith material at low asteroidal latitudes?NEAs come from the asteroid belt and are believed to be mostly gravitational aggregates at D > 0.5 - 1 km due to their former collisional evolution history (Campo Bagatin et al, 2001). Once in the inner Solar System, NEAs may undergo spin up evolution through YORP causing their components to disperse, shed mass or fission and eventually form binary, multiple systems or asteroid pairs (Walsh et al, 2008, Jacobson and Scheers, 2010, Pravec et al, 2009 and 2010). The end state of those events is often an object spinning above any Chandrasekhar stability limit, kept together by friction (Holsapple, 2007) and sometimes characterized by an equatorial “bulge”, as shown by radar images (Ostro et al, 2006).The centrifugal force acting on surface particles at equatorial latitudes may overcome the gravitational pull of the asteroid itself, and particles may leave its suface. Centrifugal is an apparent contact force, and as soon as particles lift off they mainly move under the gravitational field of the asteroid and the satellite, they may levitate for some time, land on the surface and repeat this cycle over and over. We are studying the motion of particles in the 1 μm to 10 cm range in the non-inertial reference frame of the rotating primary, accounting for centrifugal and Coriolis apparent forces as well as the gravitational fields of the primary, the secondary, the Sun and the radiation forces by the Sun itself. The main features of this effect are presented in the case of Didymos and 1996 FG3.

  9. 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.

  10. 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.

  11. Radiation and matter: Electrodynamics postulates and Lorenz gauge

    NASA Astrophysics Data System (ADS)

    Bobrov, V. B.; Trigger, S. A.; van Heijst, G. J.; Schram, P. P.

    2016-11-01

    In general terms, we have considered matter as the system of charged particles and quantized electromagnetic field. For consistent description of the thermodynamic properties of matter, especially in an extreme state, the problem of quantization of the longitudinal and scalar potentials should be solved. In this connection, we pay attention that the traditional postulates of electrodynamics, which claim that only electric and magnetic fields are observable, is resolved by denial of the statement about validity of the Maxwell equations for microscopic fields. The Maxwell equations, as the generalization of experimental data, are valid only for averaged values. We show that microscopic electrodynamics may be based on postulation of the d'Alembert equations for four-vector of the electromagnetic field potential. The Lorenz gauge is valid for the averages potentials (and provides the implementation of the Maxwell equations for averages). The suggested concept overcomes difficulties under the electromagnetic field quantization procedure being in accordance with the results of quantum electrodynamics. As a result, longitudinal and scalar photons become real rather than virtual and may be observed in principle. The longitudinal and scalar photons provide not only the Coulomb interaction of charged particles, but also allow the electrical Aharonov-Bohm effect.

  12. 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

  13. A CCD based approach to high-precision size and refractive index determination of levitated microdroplets using Fraunhofer diffraction

    SciTech Connect

    Barnes, M.D.; Lermer, N.; Whitten, W.B.; Ramsey, J.M.

    1997-06-01

    We describe a fast and convenient method of high precision size and refractive index determination of electrodynamically levitated microdroplets using Fraunhofer diffraction. The diffraction data were obtained with a 16-bit, unintensified charge coupled device (CCD) camera, and converted into angle-resolved elastic scattering intensity patterns by means of a carefully determined set of transformation parameters. The angular scattering patterns were analyzed without any {ital a priori} estimate of the droplet size and only a nominal estimate ({approx}2{percent}) of the refractive index. Experimental angular scattering patterns were fit to calculated patterns from Mie theory using a graded step-size and scaling algorithm and optimized with respect to both droplet diameter and refractive index (real part only) with a precision of {le}3 parts in 10{sup 4} and 1 part in 10{sup 3}, respectively. Potential application to quantitative fluorescence and Raman spectroscopy, as well as mixture analysis in microdroplets is discussed. {copyright} {ital 1997 American Institute of Physics.}

  14. Diffusion in nanoporous phases: size dependence and levitation effect.

    PubMed

    Yashonath, S; Ghorai, Pradip Kr

    2008-01-24

    Self-diffusivity, D, of diffusants in widely differing mediums such as liquids (e.g., solution), porous solids (e.g., guests in zeolites), or ions in polar solvents exhibit strong size dependence. We discuss the nature of the size dependence observed in these systems. Altogether, different theoretical approaches have been proposed to understand the nature of size dependence of D not only across these widely differing systems but even in just one medium or class of systems such as, for example, ions in polar solvents. But molecular dynamics investigations in the past decade have shown that the size dependence of self-diffusion in guest-porous solids could have origins in the mutual cancellation of forces that occurs when the size of the diffusant is comparable to the size of the void. The effect leading to the maximum in D is known as the levitation effect (LE). Such a cancellation is a consequence of symmetry. This effect exists in all porous solids irrespective of the geometrical and topological details of the pore network provided by the solid. Recent studies show that the levitation effect and size-dependent diffusivity maximum exists for uncharged solutes in solvents. One of the consequences of this is the breakdown in the Stokes-Einstein relationship over a certain range of solute-solvent size ratio. Experimental measurements of ionic conductivity over the past hundred years have found the existence of a size-dependent diffusivity maximum leading to violation of the Walden's rule for ions in polar solvents. Molecular dynamics simulations and experimental data suggest that even this maximum has its origin in LE. Simulation studies of impurity atom diffusion in close-packed solids as well as ions in superionic and other solids suggest the existence of a size-dependent diffusivity maximum in these materials as well. The levitation effect is a universal effect leading to a maximum in diffusivity of a diffusant in a variety of condensed matter phases. The only

  15. Nonlinear Dynamics and Strong Cavity Cooling of Levitated Nanoparticles

    NASA Astrophysics Data System (ADS)

    Fonseca, P. Z. G.; Aranas, E. B.; Millen, J.; Monteiro, T. S.; Barker, P. F.

    2016-10-01

    Optomechanical systems explore and exploit the coupling between light and the mechanical motion of macroscopic matter. A nonlinear coupling offers rich new physics, in both quantum and classical regimes. We investigate a dynamic, as opposed to the usually studied static, nonlinear optomechanical system, comprising a nanosphere levitated in a hybrid electro-optical trap. The cavity offers readout of both linear-in-position and quadratic-in-position (nonlinear) light-matter coupling, while simultaneously cooling the nanosphere, for indefinite periods of time and in high vacuum. We observe the cooling dynamics via both linear and nonlinear coupling. As the background gas pressure was lowered, we observed a greater than 1000-fold reduction in temperature before temperatures fell below readout sensitivity in the present setup. This Letter opens the way to strongly coupled quantum dynamics between a cavity and a nanoparticle largely decoupled from its environment.

  16. Magnetic coupling by using levitation characteristics of YBCO superconductors

    NASA Astrophysics Data System (ADS)

    Ishigaki, H.; Ito, H.; Itoh, M.; Hida, A.; Takahata, R.

    1993-03-01

    A mechanical system which uses high lateral restoring forces of high-Tc materials as the driving force for a magnetic coupling is proposed. As the basic study of the superconducting magnetic coupling, the relationship between the lateral restoring force and levitation force, transmitted torque characteristics as a function of a twisting angle and clearance, and damping characteristics of the coupling were examined. Superiorities of the coupling such as high damping coefficients and high stability against time and twisting angle were revealed. A magnetic force sensor system was used to evaluate the superconducting characteristics of materials, and nonuniform distribution of repulsive force was observed for the YBCO pellet fabricated by the melt-powder-melt-growth process. The improvement of the homogeneity was achieved by compensating for the composition rate which had changed during the quenching process.

  17. Applications of Electromagnetic Levitation and Development of Mathematical Models: A Review of the Last 15 Years (2000 to 2015)

    NASA Astrophysics Data System (ADS)

    Gao, Lei; Shi, Zhe; Li, Donghui; Zhang, Guifang; Yang, Yindong; McLean, Alexander; Chattopadhyay, Kinnor

    2016-02-01

    Electromagnetic levitation (EML) is a contact-less, high-temperature technique which has had extensive application with respect to the investigation of both thermophysical and thermochemical properties of liquid alloy systems. The varying magnetic field generates an induced current inside the metal droplet, and interactions are created which produce both the Lorentz force that provides support against gravity and the Joule heating effect that melts the levitated specimen. Since metal droplets are opaque, transport phenomena inside the droplet cannot be visualized. To address this aspect, several numerical modeling techniques have been developed. The present work reviews the applications of EML techniques as well as the contributions that have been made by the use of mathematical modeling to improve understanding of the inherent processes which are characteristic features of the levitation system.

  18. Electrodynamic arrow of time and cosmology

    NASA Astrophysics Data System (ADS)

    Radecke, Hans-Dieter

    Simplified mathematical models were used for the examination of the relationship between the arrows of time of electrodynamics and cosmology. The model of a 1-D harmonic oscillator, coupled to a scalar field, was first used. The combined system of coupled differential equations could be exactly resolved and allowed an examination of the field solution type, with regard to retard and advance in the framework of the cosmological geometry of the standard model, by which a closed universe was taken as a basis. It was shown that the oscillation radiation was clearly retarded at the big bang, and clearly advanced at the final explosion. In order to interpolate between these asymptotical boundary values, it was necessary to consider the radiation absorption of the cosmical medium. The general behavior of the considered system solutions showed that only the retarded radiation prevailed at big bang. Because of the cosmical absorption, its amplitude was completely attenuated to zero, before the universe heat death was installed. The advanced field amplitude is to be preceived after the universe contraction beginning and swings to a maximal value which is reached at the final explosion.

  19. Global electrodynamics from superpressure balloons

    NASA Astrophysics Data System (ADS)

    Holzworth, R. H.; Hu, H.

    1995-08-01

    Electric field and conductivity measurements in the stratosphere between November 1992 and March 1993 have been made using superpressure balloons in the southern hemisphere. Over 400 payload-days of data have been made during a record setting experiment called ELBBO (Extended Life Balloon Borne Observatories). This experiment resulted in 4 flights aloft simultaneously for over 2 months including one flight which lasted over 4 months. Electrodynamical coupling between the atmosphere and ionosphere is studied using the measured electric fields, and a simple empirical model of the stratospheric conductivity. Altitude profiles of conductivity have been obtained from several superpressure balloon flights using the large end-of-flight altitude swings on the last few days of each flight (as the balloon begins to loose superpressure). Coupling between the fields and atmospheric inertial waves has been observed. Effects and dynamics of the global circuit suggest that standard models are missing significant phenomena. Large scale ionospheric convection activity has been studied from the polar cap to the middle latitudes. Cusp latitude fields have been continuously measured for many days in a row.

  20. 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.

  1. 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.

  2. Nanofriction in Cavity Quantum Electrodynamics.

    PubMed

    Fogarty, T; Cormick, C; Landa, H; Stojanović, Vladimir M; Demler, E; Morigi, Giovanna

    2015-12-04

    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.

  3. Nonlocal electrodynamics in Weyl semimetals

    NASA Astrophysics Data System (ADS)

    Rosenstein, B.; Kao, H. C.; Lewkowicz, M.

    2017-02-01

    Recently synthesized three-dimensional materials with Dirac spectrum exhibit peculiar electric transport qualitatively different from its two-dimensional analog, graphene. By neglecting impurity scattering, the real part of the conductivity is strongly frequency dependent, while the imaginary part is nonzero unlike in undoped, clean graphene. The Coulomb interaction between electrons is unscreened as in a dielectric and hence is long range. We demonstrate that the interaction correction renders the electrodynamics nonlocal on a mesoscopic scale. The longitudinal conductivity σL and the transverse conductivity σT are different in the long-wavelength limit and consequently the standard local Ohm's law description does not apply. This leads to several remarkable effects in optical response. The p -polarized light generates in these materials bulk plasmons as well as the transversal waves. At a specific frequency the two modes coincide, a phenomenon impossible in a local medium. For any frequency there is a Brewster angle where total absorption occurs, turning the Weyl semimetals opaque. The effect of the surface, including the Fermi arcs, is discussed.

  4. 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.

  5. Chern-Simons quantum electrodynamics

    NASA Astrophysics Data System (ADS)

    Clancy, John Paul

    The first two chapters provide background information for the dissertation. In the first chapter, a brief history of Chern-Simons quantum field theories is given and motivation for studying these models is given by examining their physical properties and their mathematical difficulties. The second chapter gives a brief overview of quantum field theory, by presenting the Garding-Wightman formalism and the necessary modifications for studying quantum gauge field theories. Finally, the mathematical tools used in the following chapters are described. In the third chapter, Chern-Simons Quantum Electrodynamics is presented and its main features are developed. The gauge field is canonically quantized and the underlying indefinite metric is identified. Next, the physical subspace is characterized by functions that are analytic in harmonic oscillator coordinates. This property is used to show an equivalence between the Gauss vectors, gauge invariance, and positivity with respect to the indefinite metric. The fourth chapter presents the Euclidean formulation of this model, where the covariance for the free gauge field is calculated, and shown to generate a complex, Gaussian measure describing a real, random process. Next, a path-space formula on the Gauss vectors is developed, from which it follows that the physical vectors satisfy the Osterwalder-Schrader positivity requirement.

  6. Global electrodynamics from superpressure balloons

    NASA Technical Reports Server (NTRS)

    Holzworth, R. H.; Hu, H.

    1995-01-01

    Electric field and conductivity measurements in the stratosphere between November 1992 and March 1993 have been made using superpressure balloons in the southern hemisphere. Over 400 payload-days of data have been made during a record setting experiment called ELBBO (Extended Life Balloon Borne Observatories). This experiment resulted in 4 flights aloft simultaneously for over 2 months including one flight which lasted over 4 months. Electrodynamical coupling between the atmosphere and ionosphere is studied using the measured electric fields, and a simple empirical model of the stratospheric conductivity. Altitude profiles of conductivity have been obtained from several superpressure balloon flights using the large end-of-flight altitude swings on the last few days of each flight (as the balloon begins to loose superpressure). Coupling between the fields and atmospheric inertial waves has been observed. Effects and dynamics of the global circuit suggest that standard models are missing significant phenomena. Large scale ionospheric convection activity has been studied from the polar cap to the middle latitudes. Cusp latitude fields have been continuously measured for many days in a row.

  7. Spin-stabilized magnetic levitation without vertical axis of rotation

    DOEpatents

    Romero, Louis; Christenson, Todd; Aaronson, Gene

    2009-06-09

    The symmetry properties of a magnetic levitation arrangement are exploited to produce spin-stabilized magnetic levitation without aligning the rotational axis of the rotor with the direction of the force of gravity. The rotation of the rotor stabilizes perturbations directed parallel to the rotational axis.

  8. Method for obtaining large levitation pressure in superconducting magnetic bearings

    DOEpatents

    Hull, J.R.

    1997-08-05

    A method and apparatus are disclosed for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap. 4 figs.

  9. Method for obtaining large levitation pressure in superconducting magnetic bearings

    DOEpatents

    Hull, J.R.

    1996-10-08

    A method and apparatus are disclosed for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap. 4 figs.

  10. Method for obtaining large levitation pressure in superconducting magnetic bearings

    DOEpatents

    Hull, John R.

    1996-01-01

    A method and apparatus for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap.

  11. Method for obtaining large levitation pressure in superconducting magnetic bearings

    DOEpatents

    Hull, John R.

    1997-01-01

    A method and apparatus for compressing magnetic flux to achieve high levitation pressures. Magnetic flux produced by a magnetic flux source travels through a gap between two high temperature superconducting material structures. The gap has a varying cross-sectional area to compress the magnetic flux, providing an increased magnetic field and correspondingly increased levitation force in the gap.

  12. Modeling of and experiments on electromagnetic levitation for materials processing

    NASA Astrophysics Data System (ADS)

    Hyers, Robert W.

    Electromagnetic levitation (EML) is an important experimental technique for research in materials processing. It has been applied for many years to a wide variety of research areas, including studies of nucleation and growth, phase selection, reaction kinetics, and thermophysical property measurements. The work presented here contributes to a more fundamental understanding of three aspects of levitation systems: modeling of electromagnetic effects, modeling of fluid flow characteristics, and experiments to measure surface tension and viscosity in microgravity. In this work, the interaction between the electromagnetic field and the sample were modeled, and experiments to measure the surface tension and viscosity of liquid metal droplets were performed. The models use a 2-D axisymmetric formulation, and use the method of mutual inductances to calculate the currents induced in the sample. The magnetic flux density was calculated from the Biot-Savart law, and the force distribution obtained. Parametric studies of the total force and induced heating on the sample were carried out, as well as a study of the influence of different parameters on the internal flows in a liquid droplet. The oscillating current frequency has an important effect on the feasible operating range of an EML system. Optimization of both heating and positioning are discussed, and the use of frequencies far from those in current use for levitation of small droplets provides improved results. The dependences of the force and induced power on current, frequency, sample conductivity, and sample size are given. A model coupling the magnetic force calculations to a commercial finite-element fluid dynamics program is used to characterize the flows in a liquid sample, including transitions in the flow pattern. The dependence of fluid flow velocity on positioning force, sample viscosity, and oscillating current frequency is presented. These models were applied to the design of thermophysical property

  13. Middle atmosphere electrodynamics: Report of the Workshop on the Role of the Electrodynamics of the Middle Atmosphere on Solar Terrestrial Coupling

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The middle atmosphere (MA), which is defined as the region bounded below by the tropopause near 10 km and above by the mesopause near 90 to 100 km, is regarded as a passive medium through which electric fields and currents are transmitted from sources above and below. A scientific background is given for: sources of MA electric fields; MA conductivity and currents; and MA plasma characteristics. Recommendations are given for research in MA electrodynamics in the following areas: (1) MA electrodynamical parameters; (2) models and supportive laboratory measurements; and (3) investigation of specific problems in the coupled systems.

  14. Acoustic levitation for high temperature containerless processing in space

    NASA Technical Reports Server (NTRS)

    Rey, C. A.; Sisler, R.; Merkley, D. R.; Danley, T. J.

    1990-01-01

    New facilities for high-temperature containerless processing in space are described, including the acoustic levitation furnace (ALF), the high-temperature acoustic levitator (HAL), and the high-pressure acoustic levitator (HPAL). In the current ALF development, the maximum temperature capabilities of the levitation furnaces are 1750 C, and in the HAL development with a cold wall furnace they will exceed 2000-2500 C. The HPAL demonstrated feasibility of precursor space flight experiments on the ground in a 1 g pressurized-gas environment. Testing of lower density materials up to 1300 C has also been accomplished. It is suggested that advances in acoustic levitation techniques will result in the production of new materials such as ceramics, alloys, and optical and electronic materials.

  15. The measurement of heats of solution of high melting metallic systems in an electromagnetic levitation field. Ph.D. Thesis - Tech. Univ. Berlin - 1979

    NASA Technical Reports Server (NTRS)

    Frohberg, M. G.; Betz, G.

    1982-01-01

    A method was tested for measuring the enthalpies of mixing of liquid metallic alloying systems, involving the combination of two samples in the electromagnetic field of an induction coil. The heat of solution is calculated from the pyrometrically measured temperature effect, the heat capacity of the alloy, and the heat content of the added sample. The usefulness of the method was tested experimentally with iron-copper and niobium-silicon systems. This method should be especially applicable to high-melting alloys, for which conventional measurements have failed.

  16. Long term dynamics and optimal control of nano-satellite deorbit using a short electrodynamic tether

    NASA Astrophysics Data System (ADS)

    Zhong, R.; Zhu, Z. H.

    2013-10-01

    This paper studies the long term dynamics and optimal control of a nano-satellite deorbit by a short electrodynamic tether. The long term deorbit process is discretized into intervals and within each interval a two-phase optimal control law is proposed to achieve libration stability and fast deorbit simultaneously. The first-phase formulates an open-loop fast-deorbit control trajectory by a simplified model that assumes the slow-varying orbital elements of electrodynamic tethered system as constant and ignores perturbation forces other than the electrodynamic force. The second phase tracks the optimal trajectory derived in the first phase by a finite receding horizon control method while considering a full dynamic model of electrodynamic tether system. Both optimal control problems are solved by direct collocation method base on the Hermite-Simpson discretization schemes with coincident nodes. The resulting piecewise nonlinear programing problems in the sequential intervals reduces the problem size and improve the computational efficiency, which enable an on-orbit control application. Numerical results for deorbit control of a short electrodynamic tethered nano-satellite system in both equatorial and highly inclined orbits demonstrate the efficiency of the proposed control method. An optimal balance between the libration stability and a fast deorbit of satellite with minimum control efforts is achieved.

  17. 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.

  18. Battery cars on superconducting magnetically levitated carriers: One commuting solution

    NASA Astrophysics Data System (ADS)

    Briggs, B. Mike; Oman, Henry

    1992-05-01

    Commuting to work in an urban-suburban metropolitan environment is becoming an unpleasant time-wasting process. We applied the technology of communication management to this commuting problem. Communication management is a system-engineering tool that produced today's efficient telephone network. The resulting best commuting option is magnetically levitated carriers of two-passenger, battery-powered, personally-owned local-travel cars. A commuter drives a car to a nearby station, selects a destination, drives on a waiting carrier, and enters an accelerating ramp. A central computer selects an optimum 100 miles-per-hour trunk route, considering existing and forecast traffic; assigns the commuter a travel slot, and subsequently orders switching-station actions. The commuter uses the expensive facilities for only a few minutes during each trip. The cost of travel could be less than 6 cents per mile.

  19. Green chemistry and nanofabrication in a levitated Leidenfrost drop

    PubMed Central

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-01-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal–polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials. PMID:24169567

  20. Green chemistry and nanofabrication in a levitated Leidenfrost drop

    NASA Astrophysics Data System (ADS)

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-10-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal-polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials.

  1. Green chemistry and nanofabrication in a levitated Leidenfrost drop.

    PubMed

    Abdelaziz, Ramzy; Disci-Zayed, Duygu; Hedayati, Mehdi Keshavarz; Pöhls, Jan-Hendrik; Zillohu, Ahnaf Usman; Erkartal, Burak; Chakravadhanula, Venkata Sai Kiran; Duppel, Viola; Kienle, Lorenz; Elbahri, Mady

    2013-01-01

    Green nanotechnology focuses on the development of new and sustainable methods of creating nanoparticles, their localized assembly and integration into useful systems and devices in a cost-effective, simple and eco-friendly manner. Here we present our experimental findings on the use of the Leidenfrost drop as an overheated and charged green chemical reactor. Employing a droplet of aqueous solution on hot substrates, this method is capable of fabricating nanoparticles, creating nanoscale coatings on complex objects and designing porous metal in suspension and foam form, all in a levitated Leidenfrost drop. As examples of the potential applications of the Leidenfrost drop, fabrication of nanoporous black gold as a plasmonic wideband superabsorber, and synthesis of superhydrophilic and thermal resistive metal-polymer hybrid foams are demonstrated. We believe that the presented nanofabrication method may be a promising strategy towards the sustainable production of functional nanomaterials.

  2. Casimir-Polder shifts on quantum levitation states

    NASA Astrophysics Data System (ADS)

    Crépin, P.-P.; Dufour, G.; Guérout, R.; Lambrecht, A.; Reynaud, S.

    2017-03-01

    An ultracold atom above a horizontal mirror experiences quantum reflection from the attractive Casimir-Polder interaction, which holds it against gravity and leads to quantum levitation states. We analyze this system by using a Liouville transformation of the Schrödinger equation and a Langer coordinate adapted to problems with a classical turning point. Reflection on the Casimir-Polder attractive well is replaced by reflection on a repulsive wall, and the problem is then viewed as an ultracold atom trapped inside a cavity with gravity and Casimir-Polder potentials acting, respectively, as top and bottom mirrors. We calculate numerically Casimir-Polder shifts of the energies of the cavity resonances and propose an approximate treatment which is precise enough to discuss spectroscopy experiments aimed at tests of the weak-equivalence principle on antihydrogen. We also discuss the lifetimes by calculating complex energies associated with cavity resonances.

  3. Nonlinear dynamics and cavity cooling of levitated nanoparticles

    NASA Astrophysics Data System (ADS)

    Fonseca, P. Z. G.; Aranas, E. B.; Millen, J.; Monteiro, T. S.; Barker, P. F.

    2016-09-01

    We investigate a dynamic nonlinear optomechanical system, comprising a nanosphere levitated in a hybrid electro-optical trap. An optical cavity offers readout of both linear-in-position and quadratic-in-position (nonlinear) light-matter coupling, whilst simultaneously cooling the nanosphere, for indefinite periods of time and in high vacuum. Through the rich sideband structure displayed by the cavity output we can observe cooling of the linear and non-linear particle's motion. Here we present an experimental setup which allows full control over the cavity resonant frequencies, and shows cooling of the particle's motion as a function of the detuning. This work paves the way to strong-coupled quantum dynamics between a cavity and a mesoscopic object largely decoupled from its environment.

  4. Scattering-free optical levitation of a cavity mirror.

    PubMed

    Guccione, G; Hosseini, M; Adlong, S; Johnsson, M T; Hope, J; Buchler, B C; Lam, P K

    2013-11-01

    We demonstrate the feasibility of levitating a small mirror using only radiation pressure. In our scheme, the mirror is supported by a tripod where each leg of the tripod is a Fabry-Perot cavity. The macroscopic state of the mirror is coherently coupled to the supporting cavity modes allowing coherent interrogation and manipulation of the mirror motion. The proposed scheme is an extreme example of the optical spring, where a mechanical oscillator is isolated from the environment and its mechanical frequency and macroscopic state can be manipulated solely through optical fields. We model the stability of the system and find a three-dimensional lattice of trapping points where cavity resonances allow for buildup of optical field sufficient to support the weight of the mirror. Our scheme offers a unique platform for studying quantum and classical optomechanics and can potentially be used for precision gravitational field sensing and quantum state generation.

  5. Containerless processing at high temperatures using acoustic levitation

    NASA Technical Reports Server (NTRS)

    Rey, C. A.; Merkley, D. R.; Hampton, S.; Devos, J.; Mapes-Riordan, D.; Zatarski, M.

    1991-01-01

    Advanced techniques are presented which facilitate the development of inert or reducing atmospheres in excess of 2000 K in order to improve processing of containerless capabilities at higher temperatures and to provide more contamination-free environments. Recent testing, in the laboratory and aboard the NASA KC-135 aircraft, of a high-temperature acoustic positioner demonstrated the effectiveness of a specimen motion damping system and of specimen spin control. It is found that stable positioning can be achieved under ambient and heated conditions, including the transient states of heat-up and cool-down. An incorporated high-temperature levitator was found capable of processing specimens of up to 6-mm diameter in a high-purity environment without the contaminating effects of a container at high temperatures and with relative quiescence.

  6. Battery cars on superconducting magnetically levitated carriers: One commuting solution

    NASA Technical Reports Server (NTRS)

    Briggs, B. Mike; Oman, Henry

    1992-01-01

    Commuting to work in an urban-suburban metropolitan environment is becoming an unpleasant time-wasting process. We applied the technology of communication management to this commuting problem. Communication management is a system-engineering tool that produced today's efficient telephone network. The resulting best commuting option is magnetically levitated carriers of two-passenger, battery-powered, personally-owned local-travel cars. A commuter drives a car to a nearby station, selects a destination, drives on a waiting carrier, and enters an accelerating ramp. A central computer selects an optimum 100 miles-per-hour trunk route, considering existing and forecast traffic; assigns the commuter a travel slot, and subsequently orders switching-station actions. The commuter uses the expensive facilities for only a few minutes during each trip. The cost of travel could be less than 6 cents per mile.

  7. Mass Spectrometry of Acoustically Levitated Droplets

    PubMed Central

    Westphall, Michael S.; Jorabchi, Kaveh; Smith, Lloyd M.

    2008-01-01

    Containerless sample handling techniques such as acoustic levitation offer potential advantages for mass spectrometry, by eliminating surfaces where undesired adsorption/desorption processes can occur. In addition, they provide a unique opportunity to study fundamental aspects of the ionization process as well as phenomena occurring at the air–droplet interface. Realizing these advantages is contingent, however, upon being able to effectively interface levitated droplets with a mass spectrometer, a challenging task that is addressed in this report. We have employed a newly developed charge and matrix-assisted laser desorption/ionization (CALDI) technique to obtain mass spectra from a 5-μL acoustically levitated droplet containing peptides and an ionic matrix. A four-ring electrostatic lens is used in conjunction with a corona needle to produce bursts of corona ions and to direct those ions toward the droplet, resulting in droplet charging. Analyte ions are produced from the droplet by a 337-nm laser pulse and detected by an atmospheric sampling mass spectrometer. The ion generation and extraction cycle is repeated at 20 Hz, the maximum operating frequency of the laser employed. It is shown in delayed ion extraction experiments that both positive and negative ions are produced, behavior similar to that observed for atmospheric pressure matrix-assisted laser absorption/ionization. No ion signal is observed in the absence of droplet charging. It is likely, although not yet proven, that the role of the droplet charging is to increase the strength of the electric field at the surface of the droplet, reducing chargere combination after ion desorption. PMID:18582090

  8. 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).

  9. Quantum electrodynamics and fundamental constants

    NASA Astrophysics Data System (ADS)

    Wundt, Benedikt Johannes Wilhelm

    The unprecedented precision achieved both in the experimental measurements as well as in the theoretical description of atomic bound states make them an ideal study object for fundamental physics and the determination of fundamental constants. This requires a careful study of the effects from quantum electrodynamics (QED) on the interaction between the electron and the nucleus. The two theoretical approaches for the evaluation of QED corrections are presented and discussed. Due to the presence of two energy scales from the binding potential and the radiation field, an overlapping parameter has to be used in both approaches in order to separate the energy scales. The different choices for the overlapping parameter in the two methods are further illustrated in a model example. With the nonrelativistic theory, relativistic corrections in order ( Zalpha)2 to the two-photon decay rate of ionic states are calculated, as well as the leading radiative corrections of alpha( Zalpha)2ln[(Zalpha)-2 ]. It is shown that the corrections is gauge-invariant under a "hybrid" gauge transformation between Coulomb and Yennie gauge. Furthermore, QED corrections for Rydberg states in one-electron ions are investigated. The smallness of the corrections and the absence of nuclear size corrections enable very accurate theoretical predictions. Measuring transition frequencies and comparing them to the theoretical predictions, QED theory can be tested more precisely. In turn, this could yield a more accurate value for the Rydberg constant. Using a transition in a nucleus with a well determined mass, acting as a reference, a comparison to transition in other nuclei can even allow to determined nuclear masses. Finally, in order to avoid an additional uncertainty in nuclei with non zero nuclear spin, QED self-energy corrections to the hyperfine structure up to order alpha(Zalpha)2Delta EHFS are determined for highly excited Rydberg states.

  10. Superconductive levitated armatures for electromagnetic launchers

    SciTech Connect

    Jasper, L.J.

    1988-03-14

    An electromagnetic railgun launcher and armature. The armature is made from superconducting material and is levitated between the rails of the launcher by the Meissner effect. The Meissner effect is created by cooling the armature and subjecting it to a magnetic field. The armature configuration has a closed-loop topology and defines two planes - one plane coincides with the plane of the rails; the other plane is oblique to the first. The armature configuration, when placed between the rails receives an unbalanced Lorentz force which accelerates the armature.

  11. Secondary lift for magnetically levitated vehicles

    DOEpatents

    Cooper, Richard K.

    1976-01-01

    A high-speed terrestrial vehicle that is magnetically levitated by means of magnets which are used to induce eddy currents in a continuous electrically conductive nonferromagnetic track to produce magnetic images that repel the inducing magnet to provide primary lift for the vehicle. The magnets are arranged so that adjacent ones have their fields in opposite directions and the magnets are spaced apart a distance that provides a secondary lift between each magnet and the adjacent magnet's image, the secondary lift being maximized by optimal spacing of the magnets.

  12. Superconducting bearings with levitation control configurations

    SciTech Connect

    Flom, Y.; Royston, J.D.

    1992-05-26

    This patent describes a superconducting rotating assembly. It comprises first and second bearing means comprising a material exhibiting superconducting properties; a rotatable member having two extremities aligned along a common axis; magnet means at each extremity; means for maintaining each the bearing means at a temperature where the superconducting properties are manifest; means for rotating the rotatable member; means for sensing the position of the rotatable member relative to each the bearing means; and means for controlling the levitation forces exerted on the rotatable member by each the bearing means.

  13. Rotation of ultrasonically levitated glycerol drops

    NASA Technical Reports Server (NTRS)

    Biswas, A.; Leung, E. W.; Trinh, E. H.

    1991-01-01

    Ultrasonic levitation is used to suspend single millimeter-size glycerol drops in a rectangular chamber. Audio-frequency laterally standing waves set up in the chamber are used to torque the suspended drops. The shape evolution of the drop under the combined effect of centrifugal forces and the acoustic radiation stress, along with its angular velocity are monitored, using video imaging and light scattering techniques. The results show good qualitative agreement with the theoretically predicted shape evolution as a function of angular velocity.

  14. Stochastic Electrodynamics: A Road to Quantum Gravity

    NASA Astrophysics Data System (ADS)

    Lavenda, B. H.

    A formal analogy exists between electrodynamic and gravitational phenomena: the Coulomb potential is analogous to the Newton potential and both possess fine structure constants. There are no singularities in Nature; uncertainties in the measurement of small distances are accounted for by an extreme value probability distribution for smallest value of the radial coordinate. Quantum electrodynamic phenomena can simply be accounted for by a stochastic generalization of the Bohr model which we will then carry over to the quantum Kepler model. Both in quantum electrodynamics and gravitation all characteristic scales are related by simple powers of the fine structure constants. A new uncertainty relation between momentum and inverse separation between particles is derived. Electromagnetic and gravitational radiation phenomena are analyzed and compared.

  15. 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.

  16. An Investigation of Metallurgical Reactions with Levitated Droplets

    NASA Astrophysics Data System (ADS)

    Wu, Chao-Peng Paul

    The study of gas-metal interactions has industrial significance in metallurgical processes. Despite the vast production volume, the high temperature kinetics of these processes are far from fully understood. The difficulty in accounting for the effects brought by the large temperature gradients that commonly exist between gas and liquid metal phases remains a major challenge. It is therefore essential to understand and quantify the influence of these conditions on mass transfer during metallurgical reactions. In the production of stainless steel, one of the main objectives is to minimize oxidative loss of valuable alloying elements such as chromium during the decarburization process. Carbon dioxide has a lower oxidizing potential compared to oxygen gas, and could provide a potential solution to the problem of alloy loss during the oxidation refining of stainless steel. From an economic standpoint, in order to fully utilize the advantages associated with using CO2 as an alternative oxidant, decarburization should be carried out with alloy melts having high initial carbon contents. As a consequence of these considerations, an understanding of the oxidation kinetics of high carbon melts containing chromium is of fundamental importance in facilitating the implementation of a carbon dioxide based refining process. In the present thesis, several specific experimental investigations were carried out, using electromagnetic levitation, to study the decarburization of Fe-Cr-Csat alloys by carbon dioxide. However, a significant discrepancy was found between the measured decarburization rates and those predicted from models based on conventional formulations for evaluating mass transport behaviour. Although the well-established models offer accurate predictions for systems with small temperature gradients, evidence suggests that they are not suitable for the system in question. As a result of this work, new dimensionless equations for mass transport have been developed, to

  17. Quantum gravitational contributions to quantum electrodynamics.

    PubMed

    Toms, David J

    2010-11-04

    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.

  18. Four-dimensional black holes with scalar hair in nonlinear electrodynamics

    NASA Astrophysics Data System (ADS)

    Barrientos, José; González, P. A.; Vásquez, Yerko

    2016-12-01

    We consider a gravitating system consisting of a scalar field minimally coupled to gravity with a self-interacting potential and a U(1) nonlinear electromagnetic field. Solving analytically and numerically the coupled system for both power-law and Born-Infeld type electrodynamics, we find charged hairy black hole solutions. Then we study the thermodynamics of these solutions and we find that at a low temperature the topological charged black hole with scalar hair is thermodynamically preferred, whereas the topological charged black hole without scalar hair is thermodynamically preferred at a high temperature for power-law electrodynamics. Interestingly enough, these phase transitions occur at a fixed critical temperature and do not depend on the exponent p of the nonlinear electrodynamics.

  19. Smart-Phone Based Magnetic Levitation for Measuring Densities.

    PubMed

    Knowlton, Stephanie; Yu, Chu Hsiang; Jain, Nupur; Ghiran, Ionita Calin; Tasoglu, Savas

    2015-01-01

    Magnetic levitation, which uses a magnetic field to suspend objects in a fluid, is a powerful and versatile technology. We develop a compact magnetic levitation platform compatible with a smart-phone to separate micro-objects and estimate the density of the sample based on its levitation height. A 3D printed attachment is mechanically installed over the existing camera unit of a smart-phone. Micro-objects, which may be either spherical or irregular in shape, are suspended in a paramagnetic medium and loaded in a microcapillary tube which is then inserted between two permanent magnets. The micro-objects are levitated and confined in the microcapillary at an equilibrium height dependent on their volumetric mass densities (causing a buoyancy force toward the edge of the microcapillary) and magnetic susceptibilities (causing a magnetic force toward the center of the microcapillary) relative to the suspending medium. The smart-phone camera captures magnified images of the levitating micro-objects through an additional lens positioned between the sample and the camera lens cover. A custom-developed Android application then analyzes these images to determine the levitation height and estimate the density. Using this platform, we were able to separate microspheres with varying densities and calibrate their levitation heights to known densities to develop a technique for precise and accurate density estimation. We have also characterized the magnetic field, the optical imaging capabilities, and the thermal state over time of this platform.

  20. Smart-Phone Based Magnetic Levitation for Measuring Densities

    PubMed Central

    Knowlton, Stephanie; Yu, Chu Hsiang; Jain, Nupur

    2015-01-01

    Magnetic levitation, which uses a magnetic field to suspend objects in a fluid, is a powerful and versatile technology. We develop a compact magnetic levitation platform compatible with a smart-phone to separate micro-objects and estimate the density of the sample based on its levitation height. A 3D printed attachment is mechanically installed over the existing camera unit of a smart-phone. Micro-objects, which may be either spherical or irregular in shape, are suspended in a paramagnetic medium and loaded in a microcapillary tube which is then inserted between two permanent magnets. The micro-objects are levitated and confined in the microcapillary at an equilibrium height dependent on their volumetric mass densities (causing a buoyancy force toward the edge of the microcapillary) and magnetic susceptibilities (causing a magnetic force toward the center of the microcapillary) relative to the suspending medium. The smart-phone camera captures magnified images of the levitating micro-objects through an additional lens positioned between the sample and the camera lens cover. A custom-developed Android application then analyzes these images to determine the levitation height and estimate the density. Using this platform, we were able to separate microspheres with varying densities and calibrate their levitation heights to known densities to develop a technique for precise and accurate density estimation. We have also characterized the magnetic field, the optical imaging capabilities, and the thermal state over time of this platform. PMID:26308615

  1. Inverse Leidenfrost Effect: Levitating Drops on Liquid Nitrogen.

    PubMed

    Adda-Bedia, M; Kumar, S; Lechenault, F; Moulinet, S; Schillaci, M; Vella, D

    2016-05-03

    We explore the interaction between a liquid drop (initially at room temperature) and a bath of liquid nitrogen. In this scenario, heat transfer occurs through film-boiling: a nitrogen vapor layer develops that may cause the drop to levitate at the bath surface. We report the phenomenology of this inverse Leidenfrost effect, investigating the effect of the drop size and density by using an aqueous solution of a tungsten salt to vary the drop density. We find that (depending on its size and density) a drop either levitates or instantaneously sinks into the bulk nitrogen. We begin by measuring the duration of the levitation as a function of the radius R and density ρd of the liquid drop. We find that the levitation time increases roughly linearly with drop radius but depends weakly on the drop density. However, for sufficiently large drops, R ≥ Rc(ρd), the drop sinks instantaneously; levitation does not occur. This sinking of a (relatively) hot droplet induces film-boiling, releasing a stream of vapor bubbles for a well-defined length of time. We study the duration of this immersed-drop bubbling finding similar scalings (but with different prefactors) to the levitating drop case. With these observations, we study the physical factors limiting the levitation and immersed-film-boiling times, proposing a simple model that explains the scalings observed for the duration of these phenomena, as well as the boundary of (R,ρd) parameter space that separates them.

  2. Initial Plasma Experiment in the Levitated Ring Trap RT-1

    NASA Astrophysics Data System (ADS)

    Saitoh, H.; Yoshida, Z.; Ogawa, Y.; Morikawa, J.; Watanabe, S.; Yano, Y.; Suzuki, J.

    2006-10-01

    Studies on toroidal flowing plasma have started in a superconductor levitated coil device, Ring Trap 1 (RT-1) [1]. RT-1 generates a magnetosphere-like dipole magnetic field configuration that enables various kinds of experiments related to flowing plasmas. The main purpose of the Ring Trap Experiment is to explore a new high-b relaxation state of plasmas predicted by two-fluid relaxation theory of flowing plasmas [2]. Magnetic surface configuration of RT-1 also enables stable pure-magnetic trap of non-neutral plasmas [3], which is potentially suitable for the confinement of charged particles including anti-matters. As an initial experiment, hydrogen plasma is produced by electron cyclotron heating using 8.2GHz microwave generated by a klystron with the maximum power of 100kW for 1s pulse operation. The high-Tc superconductor (Bi-2223) ring with a total coil current of 250kAT is magnetically levitated in a vacuum chamber using a PID feedback control system. The field strength in the trap region is 0.03T to 0.3T. Diagnostics for the RT-1 experiment includes spectroscopy, soft X-ray pulse-height analysis with Si (Li) detector, magnetic probes, and Langmuir probes for edge plasma measurement. The initial experimental results and basic plasma parameters of RT-1 will be presented in the meeting. 1. Z. Yoshida et al., Plasma Fusion Res. 1, 008 (2006). 2. Z. Yoshida and S. M. Mahajan, Phys. Rev. Lett. 88, 095001 (2002). 3. Z. Yoshida, et al., in Nonneutral Plasma Physics III, IV.

  3. Threshold Gravity Determination and Artificial Gravity Studies Using Magnetic Levitation

    NASA Technical Reports Server (NTRS)

    Ramachandran, N.; Leslie, F.

    2005-01-01

    What is the threshold gravity (minimum gravity level) required for the nominal functioning of the human system? What dosage is required (magnitude and duration)? Do human cell lines behave differently in microgravity in response to an external stimulus? The critical need for a variable gravity simulator is emphasized by recent experiments on human epithelial cells and lymphocytes on the Space Shuttle clearly showing that cell growth and function are markedly different from those observed terrestrially. Those differences are also dramatic between cells grown in space and those in Rotating Wall Vessels (RWV), or NASA bioreactor often used to simulate microgravity, indicating that although morphological growth patterns (three dimensional growth) can be successfully simulated using RWVs, cell function performance is not reproduced - a critical difference. If cell function is dramatically affected by gravity off-loading, then cell response to stimuli such as radiation, stress, etc. can be very different from terrestrial cell lines. Yet, we have no good gravity simulator for use in study of these phenomena. This represents a profound shortcoming for countermeasures research. We postulate that we can use magnetic levitation of cells and tissue, through the use of strong magnetic fields and field gradients, as a terrestrial microgravity model to study human cells. Specific objectives of the research are: 1. To develop a tried, tested and benchmarked terrestrial microgravity model for cell culture studies; 2. Gravity threshold determination; 3. Dosage (magnitude and duration) of g-level required for nominal functioning of cells; 4. Comparisons of magnetic levitation model to other models such as RWV, hind limb suspension, etc. and 5. Cellular response to reduced gravity levels of Moon and Mars.

  4. Terrestrial Microgravity Model and Threshold Gravity Simulation sing Magnetic Levitation

    NASA Technical Reports Server (NTRS)

    Ramachandran, N.

    2005-01-01

    What is the threshold gravity (minimum gravity level) required for the nominal functioning of the human system? What dosage is required? Do human cell lines behave differently in microgravity in response to an external stimulus? The critical need for such a gravity simulator is emphasized by recent experiments on human epithelial cells and lymphocytes on the Space Shuttle clearly showing that cell growth and function are markedly different from those observed terrestrially. Those differences are also dramatic between cells grown in space and those in Rotating Wall Vessels (RWV), or NASA bioreactor often used to simulate microgravity, indicating that although morphological growth patterns (three dimensional growth) can be successiblly simulated using RWVs, cell function performance is not reproduced - a critical difference. If cell function is dramatically affected by gravity off-loading, then cell response to stimuli such as radiation, stress, etc. can be very different from terrestrial cell lines. Yet, we have no good gravity simulator for use in study of these phenomena. This represents a profound shortcoming for countermeasures research. We postulate that we can use magnetic levitation of cells and tissue, through the use of strong magnetic fields and field gradients, as a terrestrial microgravity model to study human cells. Specific objectives of the research are: 1. To develop a tried, tested and benchmarked terrestrial microgravity model for cell culture studies; 2. Gravity threshold determination; 3. Dosage (magnitude and duration) of g-level required for nominal functioning of cells; 4. Comparisons of magnetic levitation model to other models such as RWV, hind limb suspension, etc. and 5. Cellular response to reduced gravity levels of Moon and Mars.

  5. Terrestrial Microgravity Model and Threshold Gravity Simulation using Magnetic Levitation

    NASA Technical Reports Server (NTRS)

    Ramachandran, N.

    2005-01-01

    What is the threshold gravity (minimum gravity level) required for the nominal functioning of the human system? What dosage is required? Do human cell lines behave differently in microgravity in response to an external stimulus? The critical need for such a gravity simulator is emphasized by recent experiments on human epithelial cells and lymphocytes on the Space Shuttle clearly showing that cell growth and function are markedly different from those observed terrestrially. Those differences are also dramatic between cells grown in space and those in Rotating Wall Vessels (RWV), or NASA bioreactor often used to simulate microgravity, indicating that although morphological growth patterns (three dimensional growth) can be successfully simulated using RWVs, cell function performance is not reproduced - a critical difference. If cell function is dramatically affected by gravity off-loading, then cell response to stimuli such as radiation, stress, etc. can be very different from terrestrial cell lines. Yet, we have no good gravity simulator for use in study of these phenomena. This represents a profound shortcoming for countermeasures research. We postulate that we can use magnetic levitation of cells and tissue, through the use of strong magnetic fields and field gradients, as a terrestrial microgravity model to study human cells. Specific objectives of the research are: 1. To develop a tried, tested and benchmarked terrestrial microgravity model for cell culture studies; 2. Gravity threshold determination; 3. Dosage (magnitude and duration) of g-level required for nominal functioning of cells; 4. Comparisons of magnetic levitation model to other models such as RWV, hind limb suspension, etc. and 5. Cellular response to reduced gravity levels of Moon and Mars. The paper will discuss experiments md modeling work to date in support of this project.

  6. Introduction to electrodynamics for microwave linear accelerators

    SciTech Connect

    Whittum, D.H.

    1998-04-01

    This collection of notes and exercises is intended as a workbook to introduce the principles of microwave linear accelerators, starting with the underlying foundation in electrodynamics. The author reviewed Maxwell's equations, the Lorentz force law, and the behavior of fields near a conducting boundary. The author goes on to develop the principles of microwave electronics, including waveguide modes, circuit equivalence, shunt admittance of an iris, and voltage standing-wave ratio. The author constructed an elementary example of a waveguide coupled to a cavity, and examined its behavior during transient filling of the cavity, and in steady-state. He goes on to examine a periodic line. Then he examined the problem of acceleration in detail, studying first the properties of a single cavity-waveguide-beam system and developing the notions of wall Q, external Q, [R/Q], shunt impedance, and transformer ratio. He then examined the behavior of such a system on and off resonance, on the bench, and under conditions of transient and steady-state beam-loading. This work provides the foundation for the commonly employed circuit equivalents and the basic scalings for such systems. Following this he examined the coupling of two cavities, powered by a single feed, and goes on to consider structures constructed from multiple coupled cavities. The basic scalings for constant impedance and constant gradient traveling-wave structures are set down, including features of steady-state beam-loading, and the coupled-circuit model. Effects of uniform and random detuning are derived. These notes conclude with a brief outline of some problems of current interest in accelerator research.

  7. Rotational dynamics of levitated graphite flakes

    NASA Astrophysics Data System (ADS)

    Nagornykh, Pavel; Coppock, Joyce; Kane, Bruce

    Trapping of charged graphene multilayer flakes in a quadrupole ion trap provides a unique method of characterization of 2D materials via complete separation of the flake and the environment. As the ability to cool the center-of-mass temperature of the flakes levitated in high vacuum was shown in the previous work, in this talk we concentrate on probing the internal dynamics of the spinning flake. A 671 nm circularly polarized laser was used to provide a spinning torque to the levitated micron-sized flakes, while a linear 532 nm laser, oriented orthogonal to the first one, acted as a light source. We have studied the effects of 671 nm laser power on measured frequency spectra at pressures of 10-7 -10-9 Torr, where spinning frequencies of greater than 6 MHz have been achieved. Frequency decay data was collected by turning the laser on and off, which allowed us to estimate damping ratios from the flake deceleration. The spectra measured during the spinning acceleration showed multiple harmonics and other non-commensurate frequencies. We compare the observed frequencies to the behavior expected from a rigid body and from a membrane under the centrifugal tension.

  8. Microgravity simulation by diamagnetic levitation: effects of a strong gradient magnetic field on the transcriptional profile of Drosophila melanogaster

    PubMed Central

    2012-01-01

    Background Many biological systems respond to the presence or absence of gravity. Since experiments performed in space are expensive and can only be undertaken infrequently, Earth-based simulation techniques are used to investigate the biological response to weightlessness. A high gradient magnetic field can be used to levitate a biological organism so that its net weight is zero. Results We have used a superconducting magnet to assess the effect of diamagnetic levitation on the fruit fly D. melanogaster in levitation experiments that proceeded for up to 22 consecutive days. We have compared the results with those of similar experiments performed in another paradigm for microgravity simulation, the Random Positioning Machine (RPM). We observed a delay in the development of the fruit flies from embryo to adult. Microarray analysis indicated changes in overall gene expression of imagoes that developed from larvae under diamagnetic levitation, and also under simulated hypergravity conditions. Significant changes were observed in the expression of immune-, stress-, and temperature-response genes. For example, several heat shock proteins were affected. We also found that a strong magnetic field, of 16.5 Tesla, had a significant effect on the expression of these genes, independent of the effects associated with magnetically-induced levitation and hypergravity. Conclusions Diamagnetic levitation can be used to simulate an altered effective gravity environment in which gene expression is tuned differentially in diverse Drosophila melanogaster populations including those of different age and gender. Exposure to the magnetic field per se induced similar, but weaker, changes in gene expression. PMID:22296880

  9. The near-field acoustic levitation of high-mass rotors.

    PubMed

    Hong, Z Y; Lü, P; Geng, D L; Zhai, W; Yan, N; Wei, B

    2014-10-01

    Here we demonstrate that spherical rotors with 40 mm diameter and 0-1 kg mass can be suspended more than tens of micrometers away from an ultrasonically vibrating concave surface by near-field acoustic radiation force. Their rotating speeds exceed 3000 rpm. An acoustic model has been developed to evaluate the near-field acoustic radiation force and the resonant frequencies of levitation system. This technique has potential application in developing acoustic gyroscope.

  10. The near-field acoustic levitation of high-mass rotors

    SciTech Connect

    Hong, Z. Y.; Lü, P.; Geng, D. L.; Zhai, W.; Yan, N.; Wei, B.

    2014-10-15

    Here we demonstrate that spherical rotors with 40 mm diameter and 0-1 kg mass can be suspended more than tens of micrometers away from an ultrasonically vibrating concave surface by near-field acoustic radiation force. Their rotating speeds exceed 3000 rpm. An acoustic model has been developed to evaluate the near-field acoustic radiation force and the resonant frequencies of levitation system. This technique has potential application in developing acoustic gyroscope.

  11. Atomic fluorescence study of high temperature aerodynamic levitation

    NASA Technical Reports Server (NTRS)

    Nordine, P. C.; Schiffman, R. A.; Sethi, D. S.

    1982-01-01

    Ultraviolet laser induced atomic fluorescence has been used to characterize supersonic jet aerodynamic levitation experiments. The levitated specimen was a 0.4 cm sapphire sphere that was separately heated at temperatures up to 2327 K by an infrared laser. The supersonic jet expansion and thermal gradients in the specimen wake were studied by measuring spatial variations in the concentration of atomic Hg added to the levitating argon gas stream. Further applications of atomic fluorescence in containerless experiments, such as ideal gas fluorescence thermometry and containerless process control are discussed.

  12. Note: Attenuation motion of acoustically levitated spherical rotor

    NASA Astrophysics Data System (ADS)

    Lü, P.; Hong, Z. Y.; Yin, J. F.; Yan, N.; Zhai, W.; Wang, H. P.

    2016-11-01

    Here we observe the attenuation motion of spherical rotors levitated by near-field acoustic radiation force and analyze the factors that affect the duration time of free rotation. It is found that the rotating speed of freely rotating rotor decreases exponentially with respect to time. The time constant of exponential attenuation motion depends mainly on the levitation height, the mass of rotor, and the depth of concave ultrasound emitter. Large levitation height, large mass of rotor, and small depth of concave emitter are beneficial to increase the time constant and hence extend the duration time of free rotation.

  13. Studies of the Stability and Dynamics of Levitated Drops

    NASA Technical Reports Server (NTRS)

    Anikumar, A.; Lee, Chun Ping; Wang, T. G.

    1996-01-01

    This is a review of our experimental and theoretical studies relating to equilibrium and stability of liquid drops, typically of low viscosity, levitated in air by a sound field. The major emphasis here is on the physical principles and understanding behind the stability of levitated drops. A comparison with experimental data is also given, along with some fascinating pictures from high-speed photography. One of the aspects we shall deal with is how a drop can suddenly burst in an intense sound field; a phenomenon which can find applications in atomization technology. Also, we are currently investigating the phenomenon of suppression of coalescence between drops levitated in intense acoustic fields.

  14. Emergent Electrodynamics of Skyrmions in Chiral Magnets

    NASA Astrophysics Data System (ADS)

    Pfleiderer, Christian

    2013-03-01

    Skyrmions are particle-like states of continuous fields named after the English particle physicist Tony Skyrme. Their existence has long been considered in nuclear matter, quantum Hall systems, liquid crystals, superfluid 3He and ultracold atoms. As their defining property they support a topological winding number of 1. In magnetic materials spin configurations with a non-vanishing topological winding number, driven by the interplay of magnetic anisotropies, dipolar interactions and geometrical frustration, have been known for a long time. This is contrasted by the recent discovery of skyrmion lattices in chiral magnets, i.e., long-range magnetic order in which each magnetic unit cell contains a skyrmion and thus a non-zero winding number. As a practical consequence, the non-zero topological winding number implies that the conduction electrons in the presence of a skyrmion experience changes of Berry phase, that correspond precisely to one quantum of emergent magnetic flux. In transport measurements this leads directly to a topological Hall signal. Moreover, tiny electric current densities are already sufficient to generate a motion of the skyrmions first observed indirectly in neutron scattering. Since each skyrmion supports one quantum of emergent magnetic flux the motion of the skyrmions induces an emergent electric field consistent with Faradays law of induction that may also be observed experimentally. The excellent theoretical description of the skyrmion lattices observed so far in metals, doped semiconductors and insulators suggests that they represent a rather universal phenomenon to be expected in a wide range of systems supporting chiral spin interactions. Taken together with the first insights into their emergent electrodynamics, skyrmion lattices in chiral magnets develop into a new area of condensed matter magnetism offering insights relevant for applications.

  15. 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.

  16. 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.

  17. Magnetic levitation assisted aircraft take-off and landing (feasibility study - GABRIEL concept)

    NASA Astrophysics Data System (ADS)

    Rohacs, Daniel; Rohacs, Jozsef

    2016-08-01

    The Technology Roadmap 2013 developed by the International Air Transport Association envisions the option of flying without an undercarriage to be in operation by 2032. Preliminary investigations clearly indicate that magnetic levitation technology (MagLev) might be an appealing solution to assist the aircraft take-off and landing. The EU supported research project, abbreviated as GABRIEL, was dealing with (i) the concept development, (ii) the identification, evaluation and selection of the deployable magnetic levitation technology, (iii) the definition of the core system elements (including the required aircraft modifications, the ground-based system and airport elements, and the rendezvous control system), (iv) the analysis of the safety and security aspects, (v) the concept validation and (vi) the estimation of the proposed concept impact in terms of aircraft weight, noise, emission, cost-benefit). All results introduced here are compared to a medium size hypothetic passenger aircraft (identical with an Airbus A320). This paper gives a systematic overview of (i) the applied methods, (ii) the investigation of the possible use of magnetic levitation technology to assist the commercial aircraft take-off and landing processes and (iii) the demonstrations, validations showing the feasibility of the radically new concept. All major results are outlined.

  18. 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.

  19. System for Controlling a Magnetically Levitated Rotor

    NASA Technical Reports Server (NTRS)

    Morrison, Carlos R. (Inventor)

    2006-01-01

    In a rotor assembly having a rotor supported for rotation by magnetic bearings, a processor controlled by software or firmware controls the generation of force vectors that position the rotor relative to its bearings in a "bounce" mode in which the rotor axis is displaced from the principal axis defined between the bearings and a "tilt" mode in which the rotor axis is tilted or inclined relative to the principal axis. Waveform driven perturbations are introduced to generate force vectors that excite the rotor in either the "bounce" or "tilt" modes.

  20. 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…

  1. 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…

  2. Quantum electrodynamics with complex fermion mass

    SciTech Connect

    McKellar, B.J.H. . School of Physics); Wu, D.D. . School of Physics Academia Sinica, Beijing, BJ . Inst. of High Energy Physics Superconducting Super Collider Lab., Dallas, TX )

    1991-08-01

    The quantum electrodynamics (QED) with a complex fermion mass -- that is, a fermion mass with a chiral phase -- is restudied, together with its chirally rotated version. We show how fake electric dipole moment can be obtained and how to avoid it. 10 refs.

  3. 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.

  4. 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…

  5. 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.

  6. 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.

  7. 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)

  8. Strong field electrodynamics of a thin foil

    NASA Astrophysics Data System (ADS)

    Bulanov, S. S.; Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Rykovanov, S.; Pegoraro, F.; Schroeder, C. B.; Esarey, E.; Leemans, W. P.

    2017-03-01

    A new one-dimensional analytical model of a thin double layer foil interaction with a laser pulse is presented. It is based on one-dimensional electrodynamics. This model can be used for the study of high intensity laser pulse interactions with overdense plasmas, leading to frequency upshifting, high order harmonic generation, and ion acceleration in different regimes.

  9. Implementing a Remote Laboratory Experience into a Joint Engineering Degree Program: Aerodynamic Levitation of a Beach Ball

    ERIC Educational Resources Information Center

    Jernigan, S. R.; Fahmy, Y.; Buckner, G. D.

    2009-01-01

    This paper details a successful and inexpensive implementation of a remote laboratory into a distance control systems course using readily available hardware and software. The physical experiment consists of a beach ball and a dc blower; the control objective is to make the height of the aerodynamically levitated beach ball track a reference…

  10. Measurement and calculation of levitation forces between magnets and granular superconductors

    NASA Technical Reports Server (NTRS)

    Johansen, T. H.; Bratsberg, H.; Baziljevich, M.; Hetland, P. O.; Riise, A. B.

    1995-01-01

    Recent developments indicate that exploitation of the phenomenon of magnetic levitation may become one of the most important near-term applications of high-T(sub c) superconductivity. Because of this, the interaction between a strong permanent magnet(PM) and bulk high-T(sub c) superconductor (HTSC) is currently a subject of much interest. We have studied central features of the mechanics of PM-HTSC systems of simple geometries. Here we report experimental results for the components of the levitation force, their associated stiffness and mechanical ac-loss. To analyze the observed behavior a theoretical framework based on critical-state considerations is developed. It will be shown that all the mechanical properties can be explained consistently at a quantitative level wing a minimum of model parameters.

  11. Effect of temperature variations on equilibrium distances in levitating parallel dielectric plates interacting through Casimir forces

    NASA Astrophysics Data System (ADS)

    Esteso, Victoria; Carretero-Palacios, Sol; Míguez, Hernán

    2016-04-01

    We study at thermal equilibrium the effect of temperature deviations around room temperature on the equilibrium distance (deq) at which thin films made of Teflon, silica, or polystyrene immersed in glycerol levitate over a silicon substrate due to the balance of Casimir, gravity, and buoyancy forces. We find that the equilibrium nature (stable or unstable) of deq is preserved under temperature changes, and provide simple rules to predict whether the new equilibrium position will occur closer to or further from the substrate at the new temperature. These rules depend on the static permittivities of all materials comprised in the system ( ɛ0 ( m ) ) and the equilibrium nature of deq. Our designed dielectric configuration is excellent for experimental observation of thermal effects on the Casimir force indirectly detected through the tunable equilibrium distances (with slab thickness and material properties) in levitation mode.

  12. Measurement and calculation of levitation forces between magnets and granular superconductors

    SciTech Connect

    Johansen, T.H.; Bratsberg, H.; Baziljevich, M.; Hetland, P.O.; Riise, A.B.

    1995-04-01

    Recent developments indicate that exploitation of the phenomenon of magnetic levitation may become one of the most important near-term applications of high-T{sub c} superconductivity. Because of this, the interaction between a strong permanent magnet (PM) and bulk high-T{sub c} superconductor (HTSC) is currently a subject of much interest. The authors have studied central features of the mechanics of PM-HTSC systems of simple geometries. Here they report experimental results for the components of the levitation force, their associated stiffness and mechanical ac-loss. To analyze the observed behavior a theoretical framework based on critical-state considerations is developed. It will be shown that all the mechanical properties can be explained consistently at a quantitative level using a minimum of model parameters.

  13. On analytical study of holographic superconductors with Born-Infeld electrodynamics

    NASA Astrophysics Data System (ADS)

    Lai, Chuyu; Pan, Qiyuan; Jing, Jiliang; Wang, Yongjiu

    2015-10-01

    Based on the Sturm-Liouville eigenvalue problem, Banerjee et al. proposed a perturbative approach to analytically investigate the properties of the (2 + 1)-dimensional superconductor with Born-Infeld electrodynamics (Banerjee et al., 2013) [29]. By introducing an iterative procedure, we will further improve the analytical results and the consistency with the numerical findings, and can easily extend the analytical study to the higher-dimensional superconductor with Born-Infeld electrodynamics. We observe that the higher Born-Infeld corrections make it harder for the condensation to form but do not affect the critical phenomena of the system. Our analytical results can be used to back up the numerical computations for the holographic superconductors with various condensates in Born-Infeld electrodynamics.

  14. Analysis of the particle stability in a new designed ultrasonic levitation device.

    PubMed

    Baer, Sebastian; Andrade, Marco A B; Esen, Cemal; Adamowski, Julio Cezar; Schweiger, Gustav; Ostendorf, Andreas

    2011-10-01

    The use of acoustic levitation in the fields of analytical chemistry and in the containerless processing of materials requires a good stability of the levitated particle. However, spontaneous oscillations and rotation of the levitated particle have been reported in literature, which can reduce the applicability of the acoustic levitation technique. Aiming to reduce the particle oscillations, this paper presents the analysis of the particle stability in a new acoustic levitator device. The new acoustic levitator consists of a piezoelectric transducer with a concave radiating surface and a concave reflector. The analysis is conducted by determining numerically the axial and lateral forces that act on the levitated object and by measuring the oscillations of a sphere particle by a laser Doppler vibrometer. It is shown that the new levitator design allows to increase the lateral forces and reduce significantly the lateral oscillations of the levitated object.

  15. Magnetic and levitation characteristics of bulk high-temperature superconducting magnets above a permanent magnet guideway

    NASA Astrophysics Data System (ADS)

    Zheng, Jun; Zheng, Botian; He, Dabo; Sun, Ruixue; Deng, Zigang; Xu, Xun; Dou, Shixue

    2016-09-01

    Due to the large levitation force or the large guidance force of bulk high-temperature superconducting magnets (BHTSMs) above a permanent magnet guideway (PMG), it is reasonable to employ pre-magnetized BHTSMs to replace applied-magnetic-field-cooled superconductors in a maglev system. There are two combination modes between the BHTSM and the PMG, distinguished by the different directions of the magnetization. One is the S-S pole mode, and the other is the S-N pole mode combined with a unimodal PMG segment. A multi-point magnetic field measurement platform was employed to acquire the magnetic field signals of the BHTSM surface in real time during the pre-magnetization process and the re-magnetization process. Subsequently, three experimental aspects of levitation, including the vertical movement due to the levitation force, the lateral movement due to the guidance force, and the force relaxation with time, were explored above the PMG segment. Moreover, finite element modeling by COMSOL Multiphysics has been performed to simulate the different induced currents and the potentially different temperature rises with different modes inside the BHTSM. It was found that the S-S pole mode produced higher induced current density and a higher temperature rise inside the BHTSM, which might escalate its lateral instability above the PMG. The S-N pole mode exhibits the opposite characteristics. In general, this work is instructive for understanding and connecting the magnetic flux, the inner current density, the levitation behavior, and the temperature rise of BHTSMs employed in a maglev system.

  16. Repulsive magnetic levitation-based ocean wave energy harvester with variable resonance: Modeling, simulation and experiment

    NASA Astrophysics Data System (ADS)

    Masoumi, Masoud; Wang, Ya

    2016-10-01

    This paper investigates a magnetic levitation characteristic used in a vibration based energy harvester, called repulsive magnetic scavenger (RMS). The RMS is capable of harvesting ocean wave energy with a unique repelling permanent magnet array, which provides a stronger and more uniform magnetic field, compared to its attracting magnetic counterparts. The levitating magnets are stacked together around a threaded rod so that the same pole is facing each other. Two fixed magnets placed with one at each end of the RMS provides a collocated harvesting and braking mechanism in the face of high amplitude vibrations. Magnets in the levitated magnet stack are separated by pole pieces which are made of metals to intensify the magnetic field strength. The effect of the thickness and the use of different materials with different permeability for pole pieces is also studied to obtain an optimal energy harvesting efficiency. Moreover, the procedure to find the restoring force applied to the levitating magnet stack is demonstrated. Then, the Duffing vibration equation of the harvester is solved and the frequency response function is calculated for various force amplitudes and electrical damping so as to investigate the effect of these parameters on the response of the system. Furthermore, the effect of the maximum displacement of the moving magnet stack on the natural frequency of the device is studied. And finally, Faraday's law is employed to estimate the output voltage and power of the system under the specified input excitation force. Experiments show that the output emf voltage of the manufactured prototype reaches up to 42 V for an excitation force with the frequency of 9 Hz and the maximum amplitude of 3.4 g.

  17. Single photon delayed feedback: a way to stabilize intrinsic quantum cavity electrodynamics.

    PubMed

    Carmele, Alexander; Kabuss, Julia; Schulze, Franz; Reitzenstein, Stephan; Knorr, Andreas

    2013-01-04

    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.

  18. Some Quantum Experiments from the Point of View of Stochastic Electrodynamics

    NASA Astrophysics Data System (ADS)

    Špička, V.; Mareš, J. J.; Hubík, P.; Krištofik, J.

    2007-09-01

    Stochastic electrodynamics (SED), an alternative theory to quantum phenomena based on laws of classical physics is shortly reviewed and compared with quantum electrodynamics. Experiments supporting the existence of zero-point fluctuating radiation field, the key concept of SED, are discussed. Relation between measurements of the black-body radiation spectrum and noise is analysed to define conditions under which the zero-point component of radiation or noise can be observed. Further, it is shown that stability of weakly localized orbits, measured in disordered solid state systems, can be explained by the presence of zero-point fluctuations of vacuum.

  19. Predictions of quantum mechanics and stochastic electrodynamics in travelling wave second harmonic generation

    NASA Astrophysics Data System (ADS)

    Olsen, M. K.; Dechoum, K.; Plimak, L. I.

    2001-04-01

    We show that stochastic electrodynamics and quantum mechanics give quantitatively different predictions for the quantum nondemolition (QND) correlations in travelling wave second harmonic generation. Using phase space methods and stochastic integration, we calculate correlations in both the positive-P and truncated Wigner representations, the latter being equivalent to the semi-classical theory of stochastic electrodynamics. We show that the semi-classical results are different in the regions where the system performs best in relation to the QND criteria, and that they significantly overestimate the performance in these regions.

  20. An efficient low frequency horizontal diamagnetic levitation mechanism based vibration energy harvester

    NASA Astrophysics Data System (ADS)

    Palagummi, S.; Yuan, F. G.

    2016-04-01

    This article identifies and studies key parameters that characterize a horizontal diamagnetic levitation (HDL) mechanism based low frequency vibration energy harvester with the aim of enhancing performance metrics such as efficiency and volume figure of merit (FoMv). The HDL mechanism comprises of three permanent magnets and two diamagnetic plates. Two of the magnets, aka lifting magnets, are placed co-axially at a distance such that each attract a centrally located magnet, aka floating magnet, to balance its weight. This floating magnet is flanked closely by two diamagnetic plates which stabilize the levitation in the axial direction. The influence of the geometry of the floating magnet, the lifting magnet and the diamagnetic plate are parametrically studied to quantify their effects on the size, stability of the levitation mechanism and the resonant frequency of the floating magnet. For vibration energy harvesting using the HDL mechanism, a coil geometry and eddy current damping are critically discussed. Based on the analysis, an efficient experimental system is setup which showed a softening frequency response with an average system efficiency of 25.8% and a FoMv of 0.23% when excited at a root mean square acceleration of 0.0546 m/s2 and at frequency of 1.9 Hz.