WorldWideScience

Sample records for current carrying wires

  1. Calibration of magnetic force microscopy tips by using nanoscale current-carrying parallel wires

    International Nuclear Information System (INIS)

    Kebe, Th.; Carl, A.

    2004-01-01

    Experimental results on the characterization of commercially available magnetic force microscopy (MFM) thin film tips as a function of an external magnetic field are presented. Magnetic stray fields with a definitive z-component (perpendicular to the substrate) and a magnetic field strength of up to H z =±45 Oe are produced with current carrying parallel nanowires with a thickness of t=60 nm, which are fabricated by electron-beam lithography. The magnetic fields are generated by electrical dc-currents of up to ±6 mA which are directed antiparallel through the nanowires. The geometry and the dimensions of the nanowires are systematically varied by choosing different wire widths w as well as separations b between the parallel wires for two different sets of samples. On the one hand, the wire width w is varied within 380 nm< w<2460 nm while the separation b≅450 nm between the wires is kept constant. On the other hand the separation b between the parallel wires is varied within 120 nm< b<5100 nm, while the wire width w=960 nm is kept constant. For all the geometrical configurations of parallel wires the resulting magnetic contrast is imaged by MFM at various tip lift-heights. By treating the MFM tip as a point probe, the analysis of the image contrast as a function of both the magnetic field strength and the tip lift height allows one to quantitatively determine the effective magnetic dipole and monopole moments of the tip as well as their imaginary locations within the real physical tip. Our systematic study quantitatively relates the above point-probe parameters to (i) the dimensions of the parallel wires and (ii) to the characteristic decay length of the z-component of the magnetic field of parallel wires. From this the effective tip-volume of the real thin film tip is determined which is relevant in MFM-imaging. Our results confirm the reliability of earlier tip calibration schemes for which nanofabricated current carrying rings were used instead of parallel

  2. On the Behaviour of Current-Carrying Wire-Conductors and Bucking of a Column

    DEFF Research Database (Denmark)

    Ganji, S. S.; Barari, Amin; Fereidoon, A.

    2013-01-01

    This paper applies approximate analytical methods namely Iteration Perturbation Method (IPM), variational approach (VA) and Parameter Expanding Method (PEM) to Single-Degree-Of-Freedom (SDOF) nonlinear oscillation systems. Some numerical cases as dynamic behavior of current-carrying wire-conductors...

  3. Forces on a current-carrying wire in a magnetic field: the macro-micro connection

    DEFF Research Database (Denmark)

    Avelar Sotomaior Karam, Ricardo; Kneubil, Fabiana; Robilotta, Manoel

    2017-01-01

    The classic problem of determining the force on a current-carrying wire in a magnetic field is critically analysed. A common explanation found in many introductory textbooks is to represent the force on the wire as the sum of the forces on charge carriers. In this approach neither the nature...... of the forces involved nor their application points are fully discussed. In this paper we provide an alternative microscopic explanation that is suitable for introductory electromagnetism courses at university level. By considering the wire as a superposition of a positive and a negative cylindrical charge...

  4. On the possibility of a relativistic correction to the E and B fields around a current-carrying wire

    International Nuclear Information System (INIS)

    Folman, Ron

    2013-01-01

    It is well known that electric and magnetic fields may change when they are observed from different frames of reference. For example, the motion of a charged probe particle moving parallel to a current-carrying wire would be described by utilizing different electric or magnetic fields, depending on from which frame of reference the system is observed and described. To describe the situation in all frames by utilizing the theory of relativity, one has to first describe the situation in one particular frame, and this choice in the case of a current-carrying wire is the topic of this paper. Specifically, I consider the question of in which frame the current carrying wire is neutral. The importance of relaxation processes is emphasized. As an example, I examine a specific alternative to the standard choice, and consider its theoretical and experimental validity. An outcome of alternative approaches is that in the rest frame of a wire, running a current introduces also an electric field by giving rise to a minute charge. Present day experimental sensitivities, specifically those of cold ions, may be able to differentiate between the observable signatures predicted by the different approaches.

  5. Charged Particle Dynamics in the Magnetic Field of a Long Straight Current-Carrying Wire

    Science.gov (United States)

    Prentice, A.; Fatuzzo, M.; Toepker, T.

    2015-01-01

    By describing the motion of a charged particle in the well-known nonuniform field of a current-carrying long straight wire, a variety of teaching/learning opportunities are described: 1) Brief review of a standard problem; 2) Vector analysis; 3) Dimensionless variables; 4) Coupled differential equations; 5) Numerical solutions.

  6. Reply to 'Comment on 'Lorentz contraction and current-carrying wires''

    International Nuclear Information System (INIS)

    Van Kampen, Paul

    2010-01-01

    This reply answers the issues raised in the Comment on my paper (van Kampen 2008 Eur. J. Phys. 29 879-83). The error of applying a single Lorentz transformation to a wire segment is discussed in some detail. (letters and comments)

  7. Processing and critical currents of high-Tc superconductor wires

    International Nuclear Information System (INIS)

    Krauth, H.; Heine, K.; Tenbrink, J.

    1991-01-01

    High-Tc superconductors are expected to have a major impact on magnet and energy technology. For technical applications they have to fulfill the requirement of carrying sufficient current at a critical current density of the order of 10 5 A/cm 2 at operating temperature and magnetic field. At 77 K these values have not been achieved yet in bulk material or wires due to weak link problems and flux creep effects. Progress made so far and remaining problems will be discussed in detail concentrating on problems concerning development of technical wires. In Bi-based materials technically interesting critical current densities could be achieved at 4.2 K in fields above 20 T (1,2), rendering possible the use of such material for very high field application. (orig.)

  8. The Way of Reducing Current Values in Optical Ground Wires at Asymmetrical Faults on Overhead Transmission Lines

    Directory of Open Access Journals (Sweden)

    Egamnazarov Georgiy

    2016-12-01

    Full Text Available Given the fact that the installing costs of an optical ground wire on overhead lines directly depend on its cross-section, which in turn depends on the level of fault current it should withstand, in order to reduce these current values in the optical ground wire, I suggested performing its isolated descents from the end towers of the line with its transition to an optical cable. The research was carried out on the example of a 500 kV overhead line in the National Electric Power Grid. The Method of Symmetrical Components for calculating asymmetrical fault currents was not used; therefore, calculations were carried out on the base of presenting the line as a multi-wire system for the considered case as a five-wire system (optical ground wire, steel ground wire, and three phase wires. Such approach allows taking into account the initial asymmetry of the line parameters and modeling any kind of asymmetrical faults. The analyses of calculated results were performed. The conclusive evidence that the optical ground wire isolated descents from the end towers of the line give the possibility of reducing the level of maximal fault current distribution values in it and therefore its cross section, is presented.

  9. A simulation of a multifilamentary wire carrying a transport current in an AC applied field

    International Nuclear Information System (INIS)

    Rem, P.C.; Hartmann, R.A.; Dijkstra, D.; Van Beckum, F.P.H.; Van de Klundert, L.J.M.

    1986-01-01

    The problem of calculating the current distribution in a multi-filamentary wire subjected to a time-dependent field becomes difficult as soon as the non-linearity due to the saturation of layers of filaments can be neglected no more. Such a problem can be solved approximately if the shape of the boundaries between unsaturated regions can be prescribed on the basis of general considerations such as symmetry arguments. For cases involving both a transport current and an applied field, however, little is known about the boundaries and their time-dependence behaviour. For such cases a brute force numerical calculation may provide an answer. The results presented below were calculated for a combination of DC transport current and AC applied field

  10. Technology development and commercial production of current-carrying elements on the basis of Nb3Sn superconductor

    International Nuclear Information System (INIS)

    Nikulin, A.D.; Shikov, A.K.; Davydov, I.I.

    1995-01-01

    A description of a current carrying element intended for Tokamak-15 magnetic system is presented. The element is produced from multicore wires with superconducting Nb 3 Sn cores and calculated for 8.5 kA critical current in magnetic field of 8 T. Main processing procedures of its manufacturing are shown. Extrusion conditions needed for production of composite bronze-niobium rods and multicore wire 1.5 mm in diameter with 14641 niobium cores are determined. Heat treatment used results in formation of Nb 3 Sn intermetallics and assures maximal current-carrying capacity of 910-920 A in 8 T magnetic field. 15 refs., 9 figs

  11. Two ways to model voltage-current curves of adiabatic MgB2 wires

    International Nuclear Information System (INIS)

    Stenvall, A; Korpela, A; Lehtonen, J; Mikkonen, R

    2007-01-01

    Usually overheating of the sample destroys attempts to measure voltage-current curves of conduction cooled high critical current MgB 2 wires at low temperatures. Typically, when a quench occurs a wire burns out due to massive heat generation and negligible cooling. It has also been suggested that high n values measured with MgB 2 wires and coils are not an intrinsic property of the material but arise due to heating during the voltage-current measurement. In addition, quite recently low n values for MgB 2 wires have been reported. In order to find out the real properties of MgB 2 an efficient computational model is required to simulate the voltage-current measurement. In this paper we go back to basics and consider two models to couple electromagnetic and thermal phenomena. In the first model the magnetization losses are computed according to the critical state model and the flux creep losses are considered separately. In the second model the superconductor resistivity is described by the widely used power law. Then the coupled current diffusion and heat conduction equations are solved with the finite element method. In order to compare the models, example runs are carried out with an adiabatic slab. Both models produce a similar significant temperature rise near the critical current which leads to fictitiously high n values

  12. Superconducting wire for the T-15 toroidal magnet

    International Nuclear Information System (INIS)

    Klimenko, E.Yu.; Kruglov, V.S.; Martovetskij, N.N.

    1987-01-01

    Main characteristics of a wire designed for the T-15 toroidal superconducting magnet production are given. The wire with circulation cooling is a twist of 11 niobium-tin wires 1.5 mm in diameter, joined electrolytically by two copper tubes with 3 mm inside diameter. The wire is capable to carry 10 kA current in the 8.5 T induction field. Wire features and structures promote to receive high structural current density in winding: diffuseness of superconducting-to-normal transition increases wire stability, screw symmetry od a current-carrying core provides wire resistance to pulse longitudinal field effect at plasma current disruption, low bronze thermal conductivity in a twist increases stability to outside pulse perturbations

  13. Load carrying capacity of shear wall t-connections reinforced with high strength wire ropes

    DEFF Research Database (Denmark)

    Jørgensen, Henrik B.; Bryndom, Thor; Larsen, Michael

    2016-01-01

    -friendly solution. The wire ropes have no bending stiffness and therefore allow for an easier vertical installation of the wall elements. During the last 10 – 15 years, a number of shear tests on plane wire rope connections have been carried out. However, to the best knowledge of the authors, tests on wire rope......Traditionally, U-bar loop connections with keyed joints have been used in vertical shear connections between precast concrete wall elements. However, in the recent years, connections with looped high strength wire ropes instead of U-bar loops have proven to be a much more construction...... connections for assembly of precast elements in different planes, such as T- and L-connections, have not yet been published. This paper presents the results of a large test series recently conducted at the University of Southern Denmark to study the shear behaviour of high strength wire rope T...

  14. Load Carrying Capacity of Shear Wall T-Connections Reinforced with High Strength Wire Ropes

    DEFF Research Database (Denmark)

    Jørgensen, Henrik Brøner; Bryndum, Thor; Larsen, Michael

    2017-01-01

    Traditionally, U-bar loop connections with keyed joints have been used in vertical shear connections between precast concrete wall elements. However, in the recent years, connections with looped high strength wire ropes instead of U-bar loops have proven to be a much more construction-friendly so......Traditionally, U-bar loop connections with keyed joints have been used in vertical shear connections between precast concrete wall elements. However, in the recent years, connections with looped high strength wire ropes instead of U-bar loops have proven to be a much more construction......-friendly solution. The wire ropes have no bending stiffness and therefore allow for an easier vertical installation of the wall elements. During the last 10 – 15 years, a number of shear tests on plane wire rope connections have been carried out. However, to the best knowledge of the authors, tests on wire rope...... connections for assembly of precast elements in different planes, such as T- and L-connections, have not yet been published. This paper presents the results of a large test series recently conducted at the University of Southern Denmark to study the shear behaviour of high strength wire rope T...

  15. Critical current studies on fine filamentary NbTi accelerator wires

    International Nuclear Information System (INIS)

    Garber, M.; Sabatini, R.L.; Sampson, W.B.; Suenaga, M.

    1986-01-01

    The magnets for the Superconducting Super Collider, a high energy proton colliding beam accelerator, require a superconductor with very high current density (> 2400 A/mm 2 at 5 T) and very small filaments ( about 2μ m in diameter). Previous work has shown that by controling the formation of Cu 4 Ti compound particles on the filament surfaces it is possible to make fine filamentary NbTi wire with high critical current density. The performance of multi-filamentary wire is characterized by the current density and the quantity ''n'' which describes the superconducting-normal transition. Micrographs of wires having high J /SUB c/ and high n show smooth, uniform filaments. Recently wires of very high critical current and high n have been produced in experimental quantities by commercial manufacturers

  16. Critical current studies on fine filamentary NbTi accelerator wires

    International Nuclear Information System (INIS)

    Garber, M.; Suenaga, M.; Sampson, W.B.; Sabatini, R.L.

    1985-01-01

    The magnets for the Superconductig Super Collider, a high energy proton colliding beam accelerator, require a superconductor with very high current density (>2400 A/mm 2 at 5 T) and very small filaments (approx. 2μm in diameter). Previous work has shown that by controlling the formation of Cu 4 Ti compound particles on the filament surfaces it is possible to make fine filamentary NbTi wire with high critical current density. The performance of multi-filamentary wire is characterized by the current density and the quantity ''n'' which describes the superconducting-normal transition. Micrographs of wires having high J/sub c/ and high n show smooth, uniform filaments. Recently wires of very high critical current and high n have been produced in experimental quantities by commercial manufactures

  17. A.C. losses in current-carrying superconductors

    International Nuclear Information System (INIS)

    Reuver, J.L. de.

    1985-01-01

    The feasibility of superconductors for alternating current use depends on successful reduction of losses. Moreover, the demand for large field amplitudes is a stimulation for investigating the nature of a.c. losses (e.g. in the set of poloidal coils in a TOKAMAK). In this thesis, measurements are performed at a.c. superconductivity. Attention is given to various external field conditions as well as to self-field instability. Measurements are performed on different types of wires. A type of wire is searched for with both low losses and a good stabilization under self-field conditions. (G.J.P.)

  18. Evidence for length-dependent wire expansion, filament dedensification and consequent degradation of critical current density in Ag-alloy sheathed Bi-2212 wires

    International Nuclear Information System (INIS)

    Malagoli, A; Lee, P J; Jiang, J; Trociewitz, U P; Hellstrom, E E; Larbalestier, D C; Ghosh, A K; Scheuerlein, C; Di Michiel, M

    2013-01-01

    It is well known that longer Bi-2212 conductors have significantly lower critical current density (J c ) than shorter ones, and recently it has become clear that a major cause of this reduction is internal gas pressure generated during heat treatment, which expands the wire diameter and dedensifies the Bi-2212 filaments. Here we report on the length-dependent expansion of 5–240 cm lengths of state-of-the-art, commercial Ag alloy sheathed Bi-2212 wire after full and some partial heat treatments. Detailed image analysis along the wire length shows that the wire diameter increases with distance from the ends, longer samples often showing evident damage and leaks provoked by the internal gas pressure. Comparison of heat treatments carried out just below the melting point and with the usual melt process makes it clear that melting is crucial to developing high internal pressure. The decay of J c away from the ends is directly correlated to the local wire diameter increase, which decreases the local Bi-2212 filament mass density and lowers J c , often by well over 50%. It is clear that control of the internal gas pressure is crucial to attaining the full J c of these very promising round wires and that the very variable properties of Bi-2212 wires are due to the fact that this internal gas pressure has so far not been well controlled. (paper)

  19. Measurement of weak electric currents in copper wire phantoms using MRI: influence of susceptibility enhancement.

    Science.gov (United States)

    Huang, Ruiwang; Posnansky, Oleg; Celik, Abdullah; Oros-Peusquens, Ana-Maria; Ermer, Veronika; Irkens, Marco; Wegener, H-Peter; Shah, N Jon

    2006-08-01

    The use of magnetic resonance imaging (MRI)-based methods for the direct detection of neuronal currents is a topic of intense investigation. Much experimental work has been carried out with the express aim of establishing detection thresholds and sensitivity to flowing currents. However, in most of these experiments, magnetic susceptibility enhancement was ignored. In this work, we present results that show the influence of a susceptibility artefact on the detection threshold and sensitivity. For this purpose, a novel phantom, consisting of a water-filled cylinder with two wires of different materials connected in series, was constructed. Magnitude MR images were acquired from a single slice using a gradient-echo echo planar imaging (EPI) sequence. The data show that the time course of the detected MR signal magnitude correlates very well with the waveform of the input current. The effect of the susceptibility artefacts arising from the two different wires was examined by comparing the magnitudes of the MR signals at different voxel locations. Our results indicate the following: (1) MR signal enhancement arising from the magnetic susceptibility effect influences the detection sensitivity of weak current; (2) the detection threshold and sensitivity are phantom-wire dependent; (3) sub-mu A electric current detection in a phantom is possible on a 1.5-T MR scanner in the presence of susceptibility enhancement.

  20. Electrical short circuit and current overload tests on aircraft wiring

    Science.gov (United States)

    Cahill, Patricia

    1995-01-01

    The findings of electrical short circuit and current overload tests performed on commercial aircraft wiring are presented. A series of bench-scale tests were conducted to evaluate circuit breaker response to overcurrent and to determine if the wire showed any visible signs of thermal degradation due to overcurrent. Three types of wire used in commercial aircraft were evaluated: MIL-W-22759/34 (150 C rated), MIL-W-81381/12 (200 C rated), and BMS 1360 (260 C rated). A second series of tests evaluated circuit breaker response to short circuits and ticking faults. These tests were also meant to determine if the three test wires behaved differently under these conditions and if a short circuit or ticking fault could start a fire. It is concluded that circuit breakers provided reliable overcurrent protection. Circuit breakers may not protect wire from ticking faults but can protect wire from direct shorts. These tests indicated that the appearance of a wire subjected to a current that totally degrades the insulation looks identical to a wire subjected to a fire; however the 'fire exposed' conductor was more brittle than the conductor degraded by overcurrent. Preliminary testing indicates that direct short circuits are not likely to start a fire. Preliminary testing indicated that direct short circuits do not erode insulation and conductor to the extent that ticking faults did. Circuit breakers may not safeguard against the ignition of flammable materials by ticking faults. The flammability of materials near ticking faults is far more important than the rating of the wire insulation material.

  1. Fast commutation of high current in double wire array Z-pinch loads

    International Nuclear Information System (INIS)

    Davis, J.; Gondarenko, N.A.; Velikovich, A.L.

    1997-01-01

    A dynamic model of multi-MA current commutation in a double wire array Z-pinch load is proposed and studied theoretically. Initially, the load is configured as nested concentric wire arrays, with the current driven through the outer array and imploding it. Once the outer array or the annular plasma shell formed from it approaches the inner array, the imploded plasma might penetrate through the gaps between the wires, but the azimuthal magnetic field is trapped due to both the high conductivity of the inner wires and the inductive coupling between the two parts of the array, causing a rapid switching of the total current to the inner part of the array. copyright 1997 American Institute of Physics

  2. Heat Transfer Analysis in Wire Bundles for Aerospace Vehicles

    Science.gov (United States)

    Rickman, S. L.; Iamello, C. J.

    2016-01-01

    Design of wiring for aerospace vehicles relies on an understanding of "ampacity" which refers to the current carrying capacity of wires, either, individually or in wire bundles. Designers rely on standards to derate allowable current flow to prevent exceedance of wire temperature limits due to resistive heat dissipation within the wires or wire bundles. These standards often add considerable margin and are based on empirical data. Commercial providers are taking an aggressive approach to wire sizing which challenges the conventional wisdom of the established standards. Thermal modelling of wire bundles may offer significant mass reduction in a system if the technique can be generalized to produce reliable temperature predictions for arbitrary bundle configurations. Thermal analysis has been applied to the problem of wire bundles wherein any or all of the wires within the bundle may carry current. Wire bundles present analytical challenges because the heat transfer path from conductors internal to the bundle is tortuous, relying on internal radiation and thermal interface conductance to move the heat from within the bundle to the external jacket where it can be carried away by convective and radiative heat transfer. The problem is further complicated by the dependence of wire electrical resistivity on temperature. Reduced heat transfer out of the bundle leads to higher conductor temperatures and, hence, increased resistive heat dissipation. Development of a generalized wire bundle thermal model is presented and compared with test data. The steady state heat balance for a single wire is derived and extended to the bundle configuration. The generalized model includes the effects of temperature varying resistance, internal radiation and thermal interface conductance, external radiation and temperature varying convective relief from the free surface. The sensitivity of the response to uncertainties in key model parameters is explored using Monte Carlo analysis.

  3. Niobium Titanium and Copper wire samples

    CERN Multimedia

    2009-01-01

    Two wire samples, both for carrying 13'000Amperes. I sample is copper. The other is the Niobium Titanium wiring used in the LHC magnets. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9’000 niobium–titanium filaments ten times finer than a hair. The cables carry up to 12’500 amps and must withstand enormous electromagnetic forces. At full field, the force on one metre of magnet is comparable ...

  4. Current Capacity of Ag/Bi-2223 Wires for Rotating Electric Machinery

    International Nuclear Information System (INIS)

    Hussennether, Volker; Leghissa, Martino; Neumueller, Heinz-Werner

    2006-01-01

    With focus on the application in rotating electric machines we measured the dependence of current capacity of Ag/Bi-2223 wires on temperature and magnetic field. Even for wires stemming from a single manufacturer we observe a significant spread of wire properties. We study different temperature and magnetic field dependence by a parallel path model which allows for a quantitative analysis. The implications of experiments and modelling are discussed with regard to the further wire development and for application within windings

  5. Progress in American Superconductor’s HTS wire and optimization for fault current limiting systems

    Energy Technology Data Exchange (ETDEWEB)

    Malozemoff, Alexis P., E-mail: amalozemoff@amsc.com

    2016-11-15

    Highlights: • AMSC HTS wire critical current needed for rotating machinery is doubled by 16 MeV Au irradiation. • Nonuniformity of HTS wires in power devices causes hot spot formation during power system faults. • Lower normal-state resistivity and critical current lower HTS wire hot spot heating during faults. • HTS wire hot spot heating in HTS cables during faults must stay below lN{sub 2} bubble nucleation point. • HTS wire can be designed to meet hot spot heating limits in fault current limiting cables. - Abstract: American Superconductor has developed composite coated conductor tape-shaped wires using high temperature superconductor (HTS) on a flexible substrate with laminated metal stabilizer. Such wires enable many applications, each requiring specific optimization. For example, coils for HTS rotating machinery require increased current density J at 25–50 K. A collaboration with Argonne, Brookhaven and Los Alamos National Laboratories and several universities has increased J using an optimized combination of precipitates and ion irradiation defects in the HTS. Major commercial opportunities also exist to enhance electric power grid resiliency by linking substations with distribution-voltage HTS power cables [10]. Such links provide alternative power sources if one substation's transmission-voltage power is compromised. But they must also limit fault currents which would otherwise be increased by such distribution-level links. This can be done in an HTS cable, exploiting the superconductor-to-resistive transition when current exceeds the wires’ critical J. A key insight is that such transitions are usually nonuniform; so the wire must be designed to prevent localized hot spots from damaging the wire or even generating gas bubbles in the cable causing dielectric breakdown. Analysis shows that local heating can be minimized by increasing the composite tape's total thickness, decreasing its total resistance in the normal state and

  6. Atom chips in the real world: the effects of wire corrugation

    OpenAIRE

    Schumm , Thorsten; Estève , Jérôme; Aussibal , Christine; Figl , Cristina; Trebbia , Jean-Baptiste; Nguyen , Hai; Mailly , Dominique; Bouchoule , Isabelle; Westbrook , Christoph I; Aspect , Alain

    2005-01-01

    International audience; We present a detailed model describing the effects of wire corrugation on the trapping potential experienced by a cloud of atoms above a current carrying micro wire. We calculate the distortion of the current distribution due to corrugation and then derive the corresponding roughness in the magnetic field above the wire. Scaling laws are derived for the roughness as a function of height above a ribbon shaped wire. We also present experimental data on micro wire traps u...

  7. Soldered Contact and Current Risetime Effects on Negative Polarity Wire Array Z-pinches

    International Nuclear Information System (INIS)

    Chalenski, D. A.; Kusse, B. R.; Greenly, J. B.; Blesener, I. C.; McBride, R. D.; Hammer, D. A.; Knapp, P. F.

    2009-01-01

    The Cornell University COBRA pulser is a nominal 1 MA machine, capable of driving up to 32 wire cylindrical Z-pinch arrays. COBRA can operate with variable current risetimes ranging from 100 ns to 200 ns (short and long pulse, respectively). Wires are typically strung with a ''press'' contact to the electrode hardware, where the wire is loosely pulled against the hardware and held there to establish electrical contact. The machine is normally negative, but a bolt-on convolute can be used to modify the current path and effectively produce positive polarity operation at the load.Previous research with single wires on a 1-5 kA pulser has shown that soldering the wire, thereby improving the wire/electrode contact, and operating in positive polarity can improve the energy deposition into the wire and enhance wire core expansion. Negative polarity showed no difference. Previous experiments on the negative polarity, 20 MA, 100 ns Z accelerator have shown that improving the contact improved the x-ray yield.Cornell data were collected on 16-wire Aluminum Z-pinch arrays in negative polarity. Experiments were conducted with both short and long current pulses with soldered and no-soldered wire/electrode contacts. The initiation, ablation, implosion and stagnation phases were compared for these four conditions. Time dependent x-ray signals were measured using diodes and diamond detectors. An inductive voltage monitor was used to infer minimum current radius achieved, as defined by a uniform shell of current moving radially inward, producing a time dependent inductance. Total energy data were collected with a metal-strip bolometer. Self-emission data were collected by an XUV 4-frame camera and an optical streak camera.In negative polarity and with short pulses, soldering appeared to produce a smaller radius pinch and decrease variations in the x-ray pulse shape. The bolometer, laser backlighter, 4-frame and streak cameras showed negligible differences in the initiation ablation

  8. Electrothermal Action of the Pulse of the Current of a Short Artificial-Lightning Stroke on Test Specimens of Wires and Cables of Electric Power Objects

    Science.gov (United States)

    Baranov, M. I.; Rudakov, S. V.

    2018-03-01

    The authors have given results of investigations of the electrothermal action of aperiodic pulses of temporal shape 10/350 μs of the current of a short artificial-lightning stroke on test specimens of electric wires and cables with copper and aluminum cores and sheaths with polyvinylchloride and polyethylene insulations of power circuits of industrial electric power objects. It has been shown that the thermal stability of such wires and cables is determined by the action integral of the indicated current pulse. The authors have found the maximum permissible and critical densities of this pulse in copper and aluminum current-carrying parts of the wires and cables. High-current experiments conducted under high-voltage laboratory conditions on a unique generator of 10/350 μs pulses of an artificial-lightning current with amplitude-time parameters normalized according to the existing requirements of international and national standards and with tolerances on them have confirmed the reliability of the proposed calculated estimate for thermal lightning resistance of cabling and wiring products.

  9. Electrothermal Action of the Pulse of the Current of a Short Artificial-Lightning Stroke on Test Specimens of Wires and Cables of Electric Power Objects

    Science.gov (United States)

    Baranov, M. I.; Rudakov, S. V.

    2018-05-01

    The authors have given results of investigations of the electrothermal action of aperiodic pulses of temporal shape 10/350 μs of the current of a short artificial-lightning stroke on test specimens of electric wires and cables with copper and aluminum cores and sheaths with polyvinylchloride and polyethylene insulations of power circuits of industrial electric power objects. It has been shown that the thermal stability of such wires and cables is determined by the action integral of the indicated current pulse. The authors have found the maximum permissible and critical densities of this pulse in copper and aluminum current-carrying parts of the wires and cables. High-current experiments conducted under high-voltage laboratory conditions on a unique generator of 10/350 μs pulses of an artificial-lightning current with amplitude-time parameters normalized according to the existing requirements of international and national standards and with tolerances on them have confirmed the reliability of the proposed calculated estimate for thermal lightning resistance of cabling and wiring products.

  10. Evaluation on current-limiting performance of the YBCO thin-film wire considering electric coupling condition

    International Nuclear Information System (INIS)

    Du, H.-I.; Han, B.-S.; Kim, Y.-J.; Lee, D.-H.; Song, S.-S.; Han, T.-H.; Han, S.-C.

    2011-01-01

    The basic way to improve the performance of a superconducting current limiter is to apply and evaluate a superconducting device that is appropriate to the superconducting current limiter. Among the many types of superconducting devices, the YBCO thin film wire has excellent current-limiting performance that is appropriate for actual system application. For the application of the YBCO thin film wire to superconducting current limiters, its current-limiting performance as a unit device must be accurately evaluated, and measures to improve its current-limiting performance must be sought. Accordingly, to evaluate the current-limiting performance of the YBCO thin film wire, this study was conducted to evaluate its resistance-increasing trend, V max , T r , I max , I qt , and current-limiting rate as a unit device, after which the electric coupling condition that consists of a core and windings was used to evaluate the current-limiting performance of the YBCO thin film wire.

  11. INVESTIGATION OF PROPERTIES OF CURRENT COLLECTOR ELEMENTS AND THEIR EFFECT ON THE PERFORMANCE OF TRIBOSYSTEM «CONTACT WIRE - CURRENT COLLECTOR ELEMENT»

    Directory of Open Access Journals (Sweden)

    Yu. L. Bolshakov

    2015-11-01

    method for sorting the coal current collector inserts and the use of a special scheme for equipping pantograph slide. It will allow optimizing their work, knowing the limitations for edges in exploitation and the type of the objective function that should be achieved. The proposed measures can reduce the intensity of the electrical and mechanical wear of materials friction pair «contact wirecurrent collector inserts». The use of specialized research facility for the study of the friction pair, will allow carrying out the studies to determine the intensity of wear of contact surfaces of the pair of friction and the coefficient of friction at various external factors.

  12. Characterization of NbTi multifilamentary superconducting wires

    International Nuclear Information System (INIS)

    Vellego, G.

    1988-01-01

    Pirelli is developing superconducting mulfilamentary NbTi wires, with current carrying capacities of up to 500 A, for use in magnetic resonance imaging (MRI) systems and in small research magnets. Pirelli and IFUSP have developed a system for assessing wire performance, whose quality is comparable to the equivalent systems at the Brookhaven National Laboratory (BNL) and at the National Bureau of Standards (NBS). In particular, a high sensitivity is required for critical current measurements, so that the modern criteria for definition of critical current can be used. These involve conductor resistivities of the order of 10 -12 ohm-cm. The methods of measurements of critical current in applied magnetic fields, of residual resistance ratio and of copper to superconductor ratio are described. The results of the first tests performed in Pirelli wires and in wires of other manufacturers are described. These include tests on a NBS standard reference material. These results are of the same quality as results obtained at BNL or NBS on the same wires. So this system can be very useful throughout the Pirelli program. (author) [pt

  13. Critical current density and wire fabrication of high-TC superconductors

    International Nuclear Information System (INIS)

    Schlabach, T.D.; Jin, S.; Sherwood, R.C.; Tiefel, T.H.

    1989-01-01

    In this paper, some of the recent investigations of wire fabrication techniques and critical current behavior in high T c superconductors will be reviewed. In spite of the tremendous interest and research effort, the progress toward major applications of the bulk high-temperature superconductors has been impeded by, among other thins, the low critical currents and their severe deterioration in weak magnetic fields. Significant advances, however, have been made in understanding the causes of the problem as well as in improving the current-carrying capacity through proper microstructural control such as the melt-textured-growth in Y-Ba-Cu-O. The low density of effective flux-pinning sites in bulk Y-Ba-Cu-O limits J c at 77K in high magnetic fields to about 10 4 A/cm 2 even in the absence of weak links. Magnetization measurements on Bi-Sr-Ca-Cu-O and Tl-Ba-Ca-Cu-O at 77K by various researchers indicate even weaker flux pinning capabilities in these materials than in Y-Ba-Cu-O. The challenge in the future is to obtain suitable flux-pinning defects by choosing the right processing and chemistry changes

  14. Comparative study on the critical current performance of Bi-2223/Ag and YBCO wires in low magnetic fields at liquid nitrogen temperature

    International Nuclear Information System (INIS)

    Feng, F.; Qu, T.-M.; Gu, C.; Xin, Y.; Gong, W.-Z.; Wu, W.; Han, Z.

    2011-01-01

    Highlights: → The I c values of Bi-2223/Ag and YBCO wires in low fields at 77 K were compared. → The performance of Bi-2223/Ag in low parallel fields was better than that of YBCO. → The phenomenon mentioned above can be verified by the published literature datum. → A new aspect was brought to understand the transport properties of HTS wires. - Abstract: A comparative study on the critical current performance of Bi-2223/Ag and YBCO coated conductor wires in low magnetic fields at liquid nitrogen temperature was carried out in this work. Five commercial high temperature superconductor wires from different manufacturers were collected. Their critical currents were measured in magnetic fields, ranging from 0 to 0.4 T. On contrary to the common conception, the Bi-2223/Ag samples had better performance than YBCO coated conductor samples in the magnetic fields parallel to the wide surface of superconducting wires within the experimental scope. We also found similar results by collecting the concerned datum from the published literatures to confirm our measurement results. At the present stage, this fact made that the Bi-2223/Ag wires might be the preferred choice for the applications with mainly low parallel fields involved, unless other considerations were prioritized.

  15. Atom chips in the real world: the effects of wire corrugation

    Science.gov (United States)

    Schumm, T.; Estève, J.; Figl, C.; Trebbia, J.-B.; Aussibal, C.; Nguyen, H.; Mailly, D.; Bouchoule, I.; Westbrook, C. I.; Aspect, A.

    2005-02-01

    We present a detailed model describing the effects of wire corrugation on the trapping potential experienced by a cloud of atoms above a current carrying micro wire. We calculate the distortion of the current distribution due to corrugation and then derive the corresponding roughness in the magnetic field above the wire. Scaling laws are derived for the roughness as a function of height above a ribbon shaped wire. We also present experimental data on micro wire traps using cold atoms which complement some previously published measurements [CITE] and which demonstrate that wire corrugation can satisfactorily explain our observations of atom cloud fragmentation above electroplated gold wires. Finally, we present measurements of the corrugation of new wires fabricated by electron beam lithography and evaporation of gold. These wires appear to be substantially smoother than electroplated wires.

  16. Magnetic microscopy for characterization of local critical current in iron-sheathed MgB2 wires

    International Nuclear Information System (INIS)

    Higashikawa, K.; Yamamoto, A.; Kiss, T.; Ye, S.; Matsumoto, A.; Kumakura, H.

    2014-01-01

    Highlights: • We developed a characterization method of local critical current in MgB 2 wires. • Local homogeneity was visualized by the scanning Hall-probe microscopy (SHPM). • Local critical current value was quantified with the aid of the finite element method (FEM). • MgB 2 wire still has inhomogeneous distribution in local critical current. • Higher potential than that estimated by the four-probe transport method was suggested. - Abstract: We have developed a characterization method of local critical current in iron-sheathed MgB 2 wires. Local homogeneity was visualized by the scanning Hall-probe microscopy (SHPM). The value of local critical current was quantified with the aid of the finite element method (FEM) considering the ferromagnetic properties of the iron sheath. The results suggested that MgB 2 wires fabricated by internal Mg diffusion processes still have large longitudinal inhomogeneity and much higher potential than that estimated by the four-probe transport method. This will be very important information for making a correct strategy for further development of MgB 2 wires

  17. The effects of insulating coatings and current prepulse on tungsten planar wire array Z-pinches

    Energy Technology Data Exchange (ETDEWEB)

    Li, M., E-mail: limo@nint.ac.cn; Li, Y. [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Shaanxi 710049 (China); State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Sheng, L.; Wang, L. P.; Zhao, C.; Yuan, Y.; Zhang, X. J.; Zhang, M.; Peng, B. D.; Zhang, J. H.; Zhang, S. G.; Qiu, M. T. [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect, Northwest Institute of Nuclear Technology, Xi' an 710024 (China); Li, X. W. [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Shaanxi 710049 (China)

    2015-12-15

    This paper presents experimental results on the effects of insulating coatings and current prepulse on tungsten planar wire array Z-pinches on ∼100 ns main current facility. Optical framing images indicated that without a current prepulse the wire ablation process was asymmetrical and the implosion was zippered. The x-ray peak power was ∼320 GW. By using insulating coatings on the wire surface the asymmetry remained, and the processes of ablation and implosion were delayed by ∼30 ns. The x-ray burst was narrow and decreased to ∼200 GW. When current prepulses were used on both standard and insulated wire arrays, implosion symmetry was improved and the x-ray burst was improved (to ∼520 GW peak power). In addition, there was a strong emitting precursor column for insulated loads with the current prepulse.

  18. Cutting techniques of reinforced concrete by wire sawing

    International Nuclear Information System (INIS)

    Miyao, Hidehiko; Komatsu, Junji; Kamiyama, Yoshinori; Yasoshima, Harunori; Kukino, Yoshinori; Yamamoto, Yuichi; Miyazaki, Takashi; Aritomi, Masanori

    1995-01-01

    The Research Association for Nuclear Facility Decommissioning (RANDEC) has been carrying out demonstration tests to improve current technologies for decommissioning. The conceptual dismantling system has been studied and basic cutting tests have been carried out by wire sawing. In terms of waste management and dismantling efficiency, the diamond wire saw cutting method has advantages for cutting radioactive concrete in large blocks. A conceptual design for a dismantling system for various concrete shieldings of nuclear facilities has been developed and diamond wire sawing has been designed and manufactured. The basic cutting tests by wire sawing have been carried out to obtain quantitative data, in addition to the conceptual design of a dismantling system for biological shielding of various power reactors (PWR, BWR, GCR) and cell walls of nuclear fuel cycle facilities. On the basis of the conceptual dismantling system and quantitative cutting performance data, wire sawing equipment has been manufactured for use in nuclear facilities. This study was performed on consignment for the Science and Technology Agency of Japan. (author)

  19. A tentative opinion of modeling plasma formation in metallic wire Z pinch

    International Nuclear Information System (INIS)

    Ding Ning

    2002-01-01

    Numerous experiments in both single wire and in wire arrays have attracted much attention. For the wire array Z-pinch implosions the plasma formation in the metallic wire Z pinches is a key question. By means of analyzing a number of single-wire and multi-wire experiments, two models to describe the behavior of a wire array Z-pinch in initial phase are suggested. In this phase each wire carries a rising current and behaves independently in a way similar to that found in single wire Z-pinch experiments in which a comparable current in one wire is employed. Based on one- or/and two-dimensional magnetohydrodynamics (MHD) theory, one model is used to simulate the electrical explosion stage of the metallic wire, another is used to simulate the wire-plasma formation stage

  20. Large critical current density improvement in Bi-2212 wires through the groove-rolling process

    International Nuclear Information System (INIS)

    Malagoli, A; Bernini, C; Braccini, V; Romano, G; Putti, M; Chaud, X; Debray, F

    2013-01-01

    Recently there has been a growing interest in Bi-2212 superconductor round wire for high magnetic field use despite the fact that an increase of the critical current is still needed to boost its successful use in such applications. Recent studies have demonstrated that the main obstacle to current flow, especially in long wires, is the residual porosity inside these powder-in-tube processed conductors that develops from bubble agglomeration when the Bi-2212 melts. In this work we tried to overcome this issue affecting the wire densification by changing the deformation process. Here we show the effects of groove rolling versus the drawing process on the critical current density J C and on the microstructure. In particular, groove-rolled multifilamentary wires show a J C increased by a factor of about 3 with respect to drawn wires prepared with the same Bi-2212 powder and architecture. We think that this approach in the deformation process is able to produce the required improvements both because the superconducting properties are enhanced and because it makes the fabrication process faster and cheaper. (paper)

  1. Development of (Nb,Ta3Sn multifilamentary superconductor wire for high current applications

    Directory of Open Access Journals (Sweden)

    Durval Rodrigues Jr.

    2000-10-01

    Full Text Available The optimization of the energy generated by a MagnetoHydroDynamic (MHD channel using a superconducting magnet demands the optimization of the magnetic field of the system and of the critical points on the magnet winding. This work must include the development of a high performance superconductor wire suitable for this system. Aiming to the construction of improved performance MHD channel, it was developed a low cost superconductor wire, with the required characteristics. The wire was made using a technology compatible with the assembling steps and heat treatment conditions of the MHD superconducting magnets fabrication. It was used the internal Sn method in Nb-7.5wt%Ta tube to fabricate a 271-filament wire with a diameter of 0.81 mm and a Cu/nonCu ratio of 2.3. The wire was heat treated at 200 °C to diffuse the Sn into the Cu shell, producing bronze, followed by the final reaction at temperatures ranging from 670 °C to 730 °C during 25 to 150 h, to produce (Nb,Ta3Sn. The superconducting wire characterization was made measuring the critical current Ic versus the applied magnetic field in the range of 5 to 20 T, the critical temperature Tc and the residual resistivity ratio (RRR. The wire transported critical currents above those available in commercial superconducting wires. These values of Ic are higher than the expected values for the optimization of the MHD channel.

  2. Second-Generation High-Temperature Superconductor Wires for the Electric Power Grid

    Science.gov (United States)

    Malozemoff, A. P.

    2012-08-01

    Superconductors offer major advantages for the electric power grid, including high current and power capacity, high efficiency arising from the lossless current flow, and a unique current-limiting functionality arising from a superconductor-to-resistive transition. These advantages can be brought to bear on equipment such as underground power cables, fault current limiters, rotating machinery, transformers, and energy storage. The first round of significant commercial-scale superconductor power-equipment demonstrations, carried out during the past decade, relied on a first-generation high-temperature superconductor (HTS) wire. However, during the past few years, with the recent commercial availability of high-performance second-generation HTS wires, power-equipment demonstrations have increasingly been carried out with these new wires, which bring important advantages. The foundation is being laid for commercial expansion of this important technology into the power grid.

  3. Experimental study on manufacturing of grits-spiral- distribution electroplated wire saw

    Directory of Open Access Journals (Sweden)

    Yufei GAO

    2016-12-01

    Full Text Available In order to obtain high performance electroplating diamond wire saw, experimental studies are conducted for development of grits-spiral-distribution electroplated diamond wire saw using sand-suspend electroplating method. The influences of pre-plating cathode current density, grits electro-embedding cathode current density and time on composite deposite coating appearance and grits distribution of wire saw are analyzed, and the sawing experiment is carried out by using the trial wire saw. The results show that good bonding strength between the coating and the steel wire can be obtained when the adopted cathode current density is 5.0 A/dm2 at pre-plating stage; good coating and girts distribution can be obtained when the adopted cathode current density is 5.0 A/dm2 and the electroplating time is 7~8 min at grits electro-embedding stage. By winding insulation wire on the surface of steel wire and reasonably selecting technological parameters before pre-plating can make the diamond wire saw with grits-spiral-distribution on surface, and the new type of wire saw has a better crumbs-clearing effect in wire sawing process.

  4. A. C. losses in current-carrying superconductors

    Energy Technology Data Exchange (ETDEWEB)

    De Reuver, J L

    1985-01-01

    After a description of some basic concepts of superconductivity and the applied wire types, the basic measuring technique is dealt with. The performed measurements are given. The modification of the measuring technique will be explained. The prior interest is the theoretical description and the agreement between theory and experiment. Attention to various external field conditions is given, and to the self-field instability. Apart from theoretical considerations, measurements have been performed on types of wire which are less conventional. The intention is to contribute to the search for a type of wire with both low losses and a good stabilization under self-field conditions. The evaluation and conclusions concentrate on the developed measuring techniques, significant contributions to the theoretical verification and the proposed alternative wire configuration. (J.C.R.)

  5. 46 CFR 183.340 - Cable and wiring requirements.

    Science.gov (United States)

    2010-10-01

    ... a manner as to avoid chafing and other damage. The use of plastic tie wraps must be limited to... requirements. (a) If individual wires, rather than cable, are used in systems greater than 50 volts, the wire... current carrying capacity for the circuit in which they are used; (2) Be installed in a manner to avoid or...

  6. Persistent Spin Current in a Hard-Wall Confining Quantum Wire with Weak Dresselhaus Spin-Orbit Coupling

    Institute of Scientific and Technical Information of China (English)

    FU Xi; ZHOU Guang-Hui

    2009-01-01

    We investigate theoretically the spin current in a quantum wire with weak Dresselhaus spin-orbit coupling connected to two normal conductors.Both the quantum wire and conductors are described by a hard-wall confining potential.Using the electron wave-functions in the quantum wire and a new definition of spin current, we have calculated the elements of linear spin current density jTs,xi and jTs,yi(I = x, y, z).We lind that the elements jTs,xx and jTs,yy have a antisymmetrical relation and the element jTs,yz has the same amount level jTs,xx and jTs,yy.We also find a net linear spin current density, which has peaks at the center of quantum wire.The net linear spin current can induce a linear electric field, which may imply a way of spin current detection.

  7. A High-Sensitivity Current Sensor Utilizing CrNi Wire and Microfiber Coils

    Directory of Open Access Journals (Sweden)

    Xiaodong Xie

    2014-05-01

    Full Text Available We obtain an extremely high current sensitivity by wrapping a section of microfiber on a thin-diameter chromium-nickel wire. Our detected current sensitivity is as high as 220.65 nm/A2 for a structure length of only 35 μm. Such sensitivity is two orders of magnitude higher than the counterparts reported in the literature. Analysis shows that a higher resistivity or/and a thinner diameter of the metal wire may produce higher sensitivity. The effects of varying the structure parameters on sensitivity are discussed. The presented structure has potential for low-current sensing or highly electrically-tunable filtering applications.

  8. Load carrying capacity of keyed joints reinforced with high strength wire rope loops

    DEFF Research Database (Denmark)

    Jørgensen, Henrik B.; Hoang, Linh Cao

    2015-01-01

    friendly shear connection can be obtained by replacing the U-bars with high strength looped wire ropes. The wire ropes have the advantage of being flexible (they have virtually no bending stiffness) which makes installation of wall elements much easier. The looped wire ropes are usually pre-installed in so......-called wire boxes which are embedded in the precast wall elements. Once the joint is grouted with mortar, the boxes will function as shear keys and the overlapping wire loops will function as transverse reinforcement that replaces the U-bars. This paper presents a rigid-plastic upper bound model to determine...... the shear capacity of wire loop connections. Tests have shown that the shear capacity of such joints – due to the relatively high tensile strength of the wire ropes - is more prone to be governed by fracture of the joint mortar in combination with yielding of the locking bar. To model this type of failure...

  9. Persistent Spin Current in a Hard-Wall Confining Quantum Wire with Weak Dresselhaus Spin-Orbit Coupling

    International Nuclear Information System (INIS)

    Fu Xi; Zhou Guanghui

    2009-01-01

    We investigate theoretically the spin current in a quantum wire with weak Dresselhaus spin-orbit coupling connected to two normal conductors. Both the quantum wire and conductors are described by a hard-wall confining potential. Using the electron wave-functions in the quantum wire and a new definition of spin current, we have calculated the elements of linear spin current density j s,xi T and j s,yi T (i = x, y, z). We find that the elements j T s,xx and j T s,yy have a antisymmetrical relation and the element j T s,yz has the same amount level as j s,xx T and j s,yy T . We also find a net linear spin current density, which has peaks at the center of quantum wire. The net linear spin current can induce a linear electric field, which may imply a way of spin current detection.

  10. Strain induced irreversible critical current degradation in highly dense Bi-2212 round wire

    CERN Document Server

    Bjoerstad, R; Rikel, M.O.; Ballarino, A; Bottura, L; Jiang, J; Matras, M; Sugano, M; Hudspeth, J; Di Michiel, M

    2015-01-01

    The strain induced critical current degradation of overpressure processed straight Bi 2212/Ag wires has been studied at 77 K in self-field. For the first time superconducting properties, lattice distortions, composite wire stress and strain have been measured simultaneously in a high energy synchrotron beamline. A permanent Ic degradation of 5% occurs when the wire strain exceeds 0.60%. At a wire strain of about 0.65% a drastic n value and Ic reduction occur, and the composite stress and the Bi-2212 lattice parameter reach a plateau, indicating Bi-2212 filament fracturing. The XRD measurements show that Bi-2212 exhibits linear elastic behaviour up to the irreversible strain limit.

  11. Reduction of Gas Bubbles and Improved Critical Current Density in Bi-2212 Round Wire by Swaging

    CERN Document Server

    Jiang, J; Huang, Y; Hong, S; Parrell, J; Scheuerlein, C; Di Michiel, M; Ghosh, A; Trociewitz, U; Hellstrom, E; Larbalestier, D

    2013-01-01

    Bi-2212 round wire is made by the powder-in-tube technique. An unavoidable property of powder-in-tube conductors is that there is about 30% void space in the as-drawn wire. We have recently shown that the gas present in the as-drawn Bi-2212 wire agglomerates into large bubbles and that they are presently the most deleterious current limiting mechanism. By densifying short 2212 wires before reaction through cold isostatic pressing (CIPping), the void space was almost removed and the gas bubble density was reduced significantly, resulting in a doubled engineering critical current density (JE) of 810 A/mm2 at 5 T, 4.2 K. Here we report on densifying Bi-2212 wire by swaging, which increased JE (4.2 K, 5 T) from 486 A/mm2 for as-drawn wire to 808 A/mm2 for swaged wire. This result further confirms that enhancing the filament packing density is of great importance for making major JE improvement in this round-wire magnet conductor.

  12. Comparative study of microcontroller controlled four-wire voltage and current source shunt active power filters

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, S.

    2009-07-01

    During the past two decades, active power filters have increasingly grown their popularity as a viable method for improving electric power quality. The main reasons for this have been the advent of fast self-commutating solid-state devices, the progression of digital technology and the improved sensor technology. Four-wire active power filters provide an efficient solution for improving the quality of supply in grounded three-phase systems or three-phase systems with neutral conductors, which are commonly used for powering residential, office and public buildings. Four-wire active power filters are applicable in compensating current harmonics, reactive power, neutral current and load phase imbalance.This thesis presents a comparative study of microcontroller controlled four-wire voltage and current source shunt active power filters. The study includes two voltage source topologies and a current source topology with two different dc-link energy storage structures, which are compared on the basis of their filtering properties, filtering performance and efficiency. The obtained results are used for determining the suitability of current source technology for four-wire active power filtering and finding the most viable four-wire shunt active power filter topology. One commonly recognized disadvantage of the current source active power filter has always been the bulky dc-link inductor. To reduce the size of the dc-link inductor, an alternative dc-link structure for current source active power filters was introduced in the late 80's. The hybrid energy storage consists of both inductive and capacitive energy storage elements, two diodes and two controllable semiconductor switching devices. Since the capacitive element is used as a main storage unit, the inductance of the dc-link inductor can be considerably reduced. However, the original dc current control method proposed is not able to utilize the full potential of the hybrid energy storage and the inductance

  13. Calculation of the Critical Current Reduction in a Brittle Round Multifilamentary Wire due to External Forces

    NARCIS (Netherlands)

    ten Haken, Bernard; Godeke, A.; ten Kate, Herman H.J.

    1994-01-01

    A simple model is presented that can describe the electro-mechanical state of a multifilamentary wire. An elastic cylinder model is used to derive the strain state analytically. Axial and transverse forces came a position dependent critical current density in the wire. The integral critical current

  14. Effect of wire shape on wire array discharge

    International Nuclear Information System (INIS)

    Shimomura, N.; Tanaka, Y.; Yushita, Y.; Nagata, M.; Teramoto, Y.; Katsuki, S.; Akiyama, H.

    2001-01-01

    Although considerable investigations have been reported on z-pinches to achieve nuclear fusion, little attention has been given from the point of view of how a wire array consisting of many parallel wires explodes. Instability existing in the wire array discharge has been shown. In this paper, the effect of wire shape in the wire array on unstable behavior of the wire array discharge is represented by numerical analysis. The claws on the wire formed in installation of wire may cause uniform current distribution on wire array. The effect of error of wire diameter in production is computed by Monte Carlo Method. (author)

  15. Effect of wire shape on wire array discharge

    Energy Technology Data Exchange (ETDEWEB)

    Shimomura, N.; Tanaka, Y.; Yushita, Y.; Nagata, M. [University of Tokushima, Department of Electrical and Electronic Engineering, Tokushima (Japan); Teramoto, Y.; Katsuki, S.; Akiyama, H. [Kumamoto University, Department of Electrical and Computer Engineering, Kumamoto (Japan)

    2001-09-01

    Although considerable investigations have been reported on z-pinches to achieve nuclear fusion, little attention has been given from the point of view of how a wire array consisting of many parallel wires explodes. Instability existing in the wire array discharge has been shown. In this paper, the effect of wire shape in the wire array on unstable behavior of the wire array discharge is represented by numerical analysis. The claws on the wire formed in installation of wire may cause uniform current distribution on wire array. The effect of error of wire diameter in production is computed by Monte Carlo Method. (author)

  16. Novel magnetic wire fabrication process by way of nanoimprint lithography for current induced magnetization switching

    Science.gov (United States)

    Asari, Tsukasa; Shibata, Ryosuke; Awano, Hiroyuki

    2017-05-01

    Nanoimprint lithography (NIL) is an effective method to fabricate nanowire because it does not need expensive systems and this process is easier than conventional processes. In this letter, we report the Current Induced Magnetization Switching (CIMS) in perpendicularly magnetized Tb-Co alloy nanowire fabricated by NIL. The CIMS in Tb-Co alloy wire was observed by using current pulse under in-plane external magnetic field (HL). We successfully observed the CIMS in Tb-Co wire fabricated by NIL. Additionally, we found that the critical current density (Jc) for the CIMS in the Tb-Co wire fabricated by NIL is 4 times smaller than that fabricated by conventional lift-off process under HL = 200Oe. These results indicate that the NIL is effective method for the CIMS.

  17. Current-driven vortex domain wall motion in wire-tube nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Espejo, A. P. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); Institute of Nanostructure and Solid State Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg (Germany); Vidal-Silva, N. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); López-López, J. A. [Departamento de Física, Universidad Técnica Federico Santa María, Av. España 1680, Valparaíso (Chile); Goerlitz, D.; Nielsch, K. [Institute of Nanostructure and Solid State Physics, University of Hamburg, Jungiusstrasse 11, D-20355 Hamburg (Germany); Escrig, J. [Departamento de Física, Universidad de Santiago de Chile (USACH), Av. Ecuador 3493, 9170124 Santiago (Chile); Center for the Development of Nanoscience and Nanotechnology (CEDENNA), Av. Ecuador 3493, 9170124 Santiago (Chile)

    2015-03-30

    We have investigated the current-driven domain wall motion in nanostructures comprised of a pair of nanotube and nanowire segments. Under certain values of external magnetic fields, it is possible to pin a vortex domain wall in the transition zone between the wire and tube segments. We explored the behavior of this domain wall under the action of an electron flow applied in the opposite direction to the magnetic field. Thus, for a fixed magnetic field, it is possible to release a domain wall pinned simply by increasing the intensity of the current density, or conversely, for a fixed current density, it is possible to release the domain wall simply decreasing the magnetic external field. When the domain wall remains pinned due to the competition between the current density and the magnetic external field, it exhibits a oscillation frequency close to 8 GHz. The amplitude of the oscillations increases with the current density and decreases over time. On the other hand, when the domain wall is released and propagated through the tube segment, this shows the standard separation between a steady and a precessional regime. The ability to pin and release a domain wall by varying the geometric parameters, the current density, or the magnetic field transforms these wire-tube nanostructures in an interesting alternative as an on/off switch nano-transistor.

  18. Effect of stress on the critical current of NbTi multifilamentary composite wire

    International Nuclear Information System (INIS)

    Ekin, J.W.; Fickett, F.R.; Clark, A.F.

    1977-01-01

    Superconducting composites within large-scale magnets can be subjected to high stresses. These stresses arise from several sources, chief among them being the winding tension and prestressing during construction of the magnet, the thermomechanical forces incurred during thermal cycling to cryogenic temperatures, and especially in large-scale systems, the magnetomechanical forces generated when the magnet is energized. Typically, data on the critical-current characteristics of superconducting composites are obtained on wires that are in an unstressed state. Very little is known, however, about how the critical current behaves in wires experiencing stresses of the type described above. To measure these effects, short sample critical current tests were made under conditions simultaneously simulating the mechanical and magnetic environments of high-field superconducting magnets. The program was initiated both to form a basis for the fundamental understanding of stress effects on superconductor stability and to provide engineering data for optimizing design and construction of high-field magnets. The preliminary results indicate that NbTi multifilamentary superconducting composite wires are not characterized by a single critical current vs. field curve, but rather by a family of curves, each corresponding to a different operating stress level

  19. Development of MgB2 superconductor wire with high critical current

    International Nuclear Information System (INIS)

    Kim, Chan Joong; Jun, Byung Hyuk; Park, Soon Dong; Kim, Nam Kyu; Kim, Yi Jeong; Yi, Ji Hye; Lee, Ji Hyun; Tan, Kai Sin

    2009-07-01

    The MgB 2 superconductor with smaller grain size could improve its critical properties by providing flux pinning centers with high grain boundary density. The effects of C doping such as charcoal, paper ash and glycerin on the superconducting properties was investigated for in situ processed MgB 2 samples using low purity semi-crystalline B powder. The results show a decrease in Tc and an enhancement of Jc at high fields for the C-doped samples as compared to the un-doped samples. A combined process of a mechanical ball milling and liquid glycerin (C 3 H 8 O 3 ) treatment of B powder has been conducted to enhance the superconducting properties of MgB 2 . The mechanical ball milling was effective for grain refinement, and a lattice disorder was easily achieved by glycerin addition. With the combined process, the critical properties was further increased due to a higher grain boundary density and a greater C substitution. To get fine grain structure of MgB 2 with high critical current properties, mechanical milling for as-received B powder and low temperature solid-state reaction of 550 or 600 .deg. C were attempted to in situ powder-in-tube processed MgB 2 /Fe wires. The critical current properties of the MgB 2 wires using the milled B powder were enhanced due to a smaller grain size and an increased volume of the superconducting phase. The solid-state reaction of a low temperature process for the samples using the milled B powder resulted in a poorer crystallinity with a smaller grain size, which improved superconducting properties. We established the system to measure the transport current properties of the MgB 2 wires. The field dependence of the transport Jc was evaluated for the MgB 2 wires heat-treated at different heat treatment conditions using ball-milled and glycerin-treated B powder. The MgB 2 magnet was developed and the AC loss of MgB 2 wire was also investigated. A conduction cooling device to cool the MgB 2 coil down to 4 K has been fabricated and the

  20. Development of Ti-sheathed MgB2 wires with high critical current density

    International Nuclear Information System (INIS)

    Liang, G; Fang, H; Hanna, M; Yen, F; Lv, B; Alessandrini, M; Keith, S; Hoyt, C; Tang, Z; Salama, K

    2006-01-01

    Working towards developing lightweight superconducting magnets for future space and other applications, we have successfully fabricated mono-core Ti-sheathed MgB 2 wires by the powder-in-tube method. The wires were characterized by magnetization, electrical resistivity, x-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry measurements. The results indicate that the Ti sheath does not react with the magnesium and boron, and the present wire rolling process can produce MgB 2 wires with a superconducting volume fraction of at least 64% in the core. Using the Bean model, it was found that at 5 K, the magnetic critical current densities, J c , measured in magnetic fields of 0, 5, and 8 T are about 4.2 x 10 5 , 3.6 x 10 4 , and 1.4 x 10 4 A cm -2 , respectively. At 20 K and 0 T, the magnetic J c is about 2.4 x 10 5 A cm -2 . These results show that at zero and low fields, the values of the magnetic J c for Ti-sheathed MgB 2 wires are comparable with the best results available for the Fe-sheathed MgB 2 wires. At high fields, however, the J c for Ti-sheathed MgB 2 wires appears higher than that for the Fe-sheathed MgB 2 wires

  1. Novel magnetic wire fabrication process by way of nanoimprint lithography for current induced magnetization switching

    Directory of Open Access Journals (Sweden)

    Tsukasa Asari

    2017-05-01

    Full Text Available Nanoimprint lithography (NIL is an effective method to fabricate nanowire because it does not need expensive systems and this process is easier than conventional processes. In this letter, we report the Current Induced Magnetization Switching (CIMS in perpendicularly magnetized Tb-Co alloy nanowire fabricated by NIL. The CIMS in Tb-Co alloy wire was observed by using current pulse under in-plane external magnetic field (HL. We successfully observed the CIMS in Tb-Co wire fabricated by NIL. Additionally, we found that the critical current density (Jc for the CIMS in the Tb-Co wire fabricated by NIL is 4 times smaller than that fabricated by conventional lift-off process under HL = 200Oe. These results indicate that the NIL is effective method for the CIMS.

  2. The status of commercial and developmental HTS wires

    Energy Technology Data Exchange (ETDEWEB)

    Masur, L.J.; Buczek, D.; Harley, E.; Kodenkandath, T.; Li, X.; Lynch, J.; Nguyen, N.; Rupich, M.; Schoop, U.; Scudiere, J.; Siegal, E.; Thieme, C.; Verebelyi, D.; Zhang, W.; Kellers, J

    2003-10-15

    This paper provides an update on the development, performance and application of first and second generation high temperature superconductor (HTS) wires fabricated at American Superconductor (AMSC). First generation, multifilamentary composite wire is available commercially today in different viable product forms. This conductor carries 140 x the current of copper of the same cross-section, and is robust enough to stand tough industrial requirements. Second generation HTS wires, having a coated conductor composite architecture, are under development today and achieved substantial progress recently. AMSC's first generation wire will continue as the workhorse of the industry for the next 3-4 years while AMSC's second generation coated conductor wire is on track to be reproducible, uniform, scalable, and low cost. This paper provides a product differentiation with a view on the application of HTS wire in the electric power sector. Basic engineering data is reviewed that shall aid the engineer in the selection of the HTS wire product.

  3. Application of Copper Cladding Aluminum Composites in UHV Portable Earthing and Short-circuiting Wires

    Directory of Open Access Journals (Sweden)

    Zhu Jianjun

    2018-01-01

    Full Text Available Aiming at the heavy weight and inconvenience when carrying and installing copper earthing wires on the UHV transmission lines, in this paper, we present the use of copper clad aluminum(CCA composite materials as a lightweight method for UHV earthing wire conductor. Theoretical calculations and tests of the fusing current in a short time for copper and CCA material are conducted. The results show that the theoretical value of the earthing wire conductor's fusing current corresponds with the test value on condition of the conductor cross section greater than 4mm2 as well as fusing time less than 1.5s. The CCA-10 earthing wires get 36.2% weight reduction compared with copper wires.

  4. Experimental testing and modelling of a resistive type superconducting fault current limiter using MgB2 wire

    International Nuclear Information System (INIS)

    Smith, A C; Pei, X; Oliver, A; Husband, M; Rindfleisch, M

    2012-01-01

    A prototype resistive superconducting fault current limiter (SFCL) was developed using single-strand round magnesium diboride (MgB 2 ) wire. The MgB 2 wire was wound with an interleaved arrangement to minimize coil inductance and provide adequate inter-turn voltage withstand capability. The temperature profile from 30 to 40 K and frequency profile from 10 to 100 Hz at 25 K were tested and reported. The quench properties of the prototype coil were tested using a high current test circuit. The fault current was limited by the prototype coil within the first quarter-cycle. The prototype coil demonstrated reliable and repeatable current limiting properties and was able to withstand a potential peak current of 372 A for one second without any degradation of performance. A three-strand SFCL coil was investigated and demonstrated scaled-up current capacity. An analytical model to predict the behaviour of the prototype single-strand SFCL coil was developed using an adiabatic boundary condition on the outer surface of the wire. The predicted fault current using the analytical model showed very good correlation with the experimental test results. The analytical model and a finite element thermal model were used to predict the temperature rise of the wire during a fault. (paper)

  5. Single Wire Detector Performance Over One Year of Operation

    CERN Document Server

    Hervas Aguilar, David Alberto

    2014-01-01

    Abstract When ionizing radiation passes through gas chambers in single wire detectors gas molecules separate into ions and electrons. By applying a strong localized electric field near the single wire an avalanche of electrons is created and it can be collected. The current produced in the wire is then proportional to the energy of the particle detected. Nevertheless, many factors can contribute to detector aging effects which are visible in a loss of gain caused by deposition of contaminants on the collecting wire. This study consists on novel data analysis techniques used to process large amounts of data produced by two simultaneously running single wire detectors. Aging effects are analyzed while environmental fluctuations are corrected for. A series of scripts carry out data filtering, data matching, corrections, and finally trend plotting by using ROOT’s extensive libraries developed at CERN.

  6. Magnetoacoustic waves in current-carrying plasmas

    International Nuclear Information System (INIS)

    Brennan, M.H.

    1980-04-01

    The results of theoretical and experimental investigations of the characteristics of magnetoacoustic waves in non-uniform, current-carrying plasmas are reviewed. Dissipative MHD and collisionless theories are considered. Also discussed is the use of magnetoacoustic waves in plasma diagnostics and plasma heating

  7. Studies of implosion processes of nested tungsten wire-array Z-pinch

    International Nuclear Information System (INIS)

    Ning Cheng; Ding Ning; Liu Quan; Yang Zhenhua

    2006-01-01

    Nested wire-array is a kind of promising structured-load because it can improve the quality of Z-pinch plasma and enhance the radiation power of X-ray source. Based on the zero-dimensional model, the assumption of wire-array collision, and the criterion of optimized load (maximal load kinetic energy), optimization of the typical nested wire-array as a load of Z machine at Sandia Laboratory was carried out. It was shown that the load has been basically optimized. The Z-pinch process of the typical load was numerically studied by means of one-dimensional three-temperature radiation magneto-hydrodynamics (RMHD) code. The obtained results reproduce the dynamic process of the Z-pinch and show the implosion trajectory of nested wire-array and the transfer process of drive current between the inner and outer array. The experimental and computational X-ray pulse was compared, and it was suggested that the assumption of wire-array collision was reasonable in nested wire-array Z-pinch at least for the current level of Z machine. (authors)

  8. Comparison and analysis of the efficiency of heat exchange of copper rod and copper wires current lead

    International Nuclear Information System (INIS)

    Fang, J.; Yu, T.; Li, Z.M.; Wei, B.; Qiu, M.; Zhang, H.J.

    2013-01-01

    Highlights: •An optimized design of HTS binary current leads is proposed. •Temperature distributions of two different current leads are calculated. •Experiments are done to certify the calculated temperature distributions. •The experiments proved that the copper wires increase security margins. -- Abstract: Current leads are the key components that connect the low-temperature and high temperature parts of the cryogenic system. Owing to the wide range of temperatures, current leads are the main sources of heat leakage. Since the HTS tapes have no resistance and the generated Joule heat is almost zero, HTS binary current leads can reduce heat leakage compared to the conventional leads. However, heat will still be generated and conducted to the cryogenic system through the copper parts of the HTS current leads. In order to reduce heat leakage by the copper parts of the HTS current leads, this paper presents an optimized design of the copper parts of HTS binary current leads. Inside the leads, the copper wires were applied as an alternative to the copper rod without changing the overall dimensions. Firstly, the differential function of heat transfer was derived. By solving the function, the optimum number of the copper wires and the temperature distribution of two different current leads were gotten. Then the experiment of the temperature distribution was done, and the experimental results were basically the same with the calculative results. The simulation and related experiments proved that the copper wire can increase security margins and reduce maximum temperatures under the same shunt current

  9. Comparison and analysis of the efficiency of heat exchange of copper rod and copper wires current lead

    Energy Technology Data Exchange (ETDEWEB)

    Fang, J., E-mail: fangseer@sina.com [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); Yu, T. [School of Electrical Engineering, Beijing Jiaotong University, Beijing (China); Li, Z.M.; Wei, B.; Qiu, M.; Zhang, H.J. [China Electric Power Research Institute, Haidian District, Beijing (China)

    2013-11-15

    Highlights: •An optimized design of HTS binary current leads is proposed. •Temperature distributions of two different current leads are calculated. •Experiments are done to certify the calculated temperature distributions. •The experiments proved that the copper wires increase security margins. -- Abstract: Current leads are the key components that connect the low-temperature and high temperature parts of the cryogenic system. Owing to the wide range of temperatures, current leads are the main sources of heat leakage. Since the HTS tapes have no resistance and the generated Joule heat is almost zero, HTS binary current leads can reduce heat leakage compared to the conventional leads. However, heat will still be generated and conducted to the cryogenic system through the copper parts of the HTS current leads. In order to reduce heat leakage by the copper parts of the HTS current leads, this paper presents an optimized design of the copper parts of HTS binary current leads. Inside the leads, the copper wires were applied as an alternative to the copper rod without changing the overall dimensions. Firstly, the differential function of heat transfer was derived. By solving the function, the optimum number of the copper wires and the temperature distribution of two different current leads were gotten. Then the experiment of the temperature distribution was done, and the experimental results were basically the same with the calculative results. The simulation and related experiments proved that the copper wire can increase security margins and reduce maximum temperatures under the same shunt current.

  10. Effects of Mass Ablation on the Scaling of X-Ray Power with Current in Wire-Array Z Pinches

    International Nuclear Information System (INIS)

    Lemke, R. W.; Sinars, D. B.; Waisman, E. M.; Cuneo, M. E.; Yu, E. P.; Haill, T. A.; Hanshaw, H. L.; Brunner, T. A.; Jennings, C. A.; Stygar, W. A.; Desjarlais, M. P.; Mehlhorn, T. A.; Porter, J. L.

    2009-01-01

    X-ray production by imploding wire-array Z pinches is studied using radiation magnetohydrodynamics simulation. It is found that the density distribution created by ablating wire material influences both x-ray power production, and how the peak power scales with applied current. For a given array there is an optimum ablation rate that maximizes the peak x-ray power, and produces the strongest scaling of peak power with peak current. This work is consistent with trends in wire-array Z pinch x-ray power scaling experiments on the Z accelerator

  11. Current status of high-T{sub c} wire

    Energy Technology Data Exchange (ETDEWEB)

    Vase, Per [Nordic Superconductor Technologies A/S, Priorparken 685, DK 2605 Broendby (Denmark); Fluekiger, Rene [Departement de Physique de la Matiere Condensee, Universite de Geneve (Switzerland); Leghissa, Martino [Siemens AG, Corporate Technology, Erlangen (Germany); Glowacki, Bartek [Department of Material Science and Metallurgy, University of Cambridge, Cambridge CB2 3QZ (United Kingdom)

    2000-07-01

    This paper is the result of the work of a SCENET (The European Network for Superconductivity) material working group's efforts on giving values for present and future expected performance of high-temperature superconducting (HTS) wires and tapes. The purpose of the work is to give input to the design of HTS applications like power cables, motors, current leads, magnets, transformers and generators. The current status performance values are supposed to be used in the design of today's prototypes and the future values for the design of fully commercial HTS applications of the future. We focus on what is expected to be the relevant parameters for HTS application design. The most successful technique by far for making HTS tapes has been on the (Bi, Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} (Bi-2223) material by the powder-in-tube (PIT) technique and this paper therefore focuses on giving the current status and expected future performance for Bi-2223 tapes. (author)

  12. Structural and phase transformations in zinc and brass wires under heating with high-density current pulse

    Energy Technology Data Exchange (ETDEWEB)

    Pervikov, A. V. [Laboratory of Physical Chemistry of Ultrafine Materials, Institute of Strength Physics and Materials Science, 2/4, pr. Akademicheskii, 634021 Tomsk, Russia and Department of High Voltage Electrophysics and High Current Electronics, Tomsk Polytechnic University, 30 Lenin Avenue, 634050 Tomsk (Russian Federation)

    2016-06-15

    The work is focused on revealing the mechanism of structure and phase transformations in the metal wires under heating with a high-density current pulse (the electric explosion of wires, EEWs). It has been demonstrated on the example of brass and zinc wires that the transition of a current pulse with the density of j ≈ 3.3 × 10{sup 7} A/cm{sup 2} results in homogeneous heating of the crystalline structure of the metal/alloy. It has been determined that under heating with a pulse of high-density current pulse, the electric resistance of the liquid phases of zinc and brass decreases as the temperature increases. The results obtained allow for a conclusion that the presence of the particles of the condensed phase in the expanding products of EEW is the result of overheating instabilities in the liquid metal.

  13. Origin of current-induced forces in an atomic gold wire: A first-principles study

    DEFF Research Database (Denmark)

    Brandbyge, Mads; Stokbro, Kurt; Taylor, Jeremy Philip

    2003-01-01

    We address the microscopic origin of the current-induced forces by analyzing results of first principles density functional calculations of atomic gold wires connected to two gold electrodes with different electrochemical potentials. We find that current induced forces are closely related...

  14. Experimental studies of the quench behaviour of MgB{sub 2} superconducting wires for fault current limiter applications

    Energy Technology Data Exchange (ETDEWEB)

    Ye Lin [Interdisciplinary Research Center (IRC) in Superconductivity, Cavendish Laboratory/Department of Engineering, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Majoros, M [Laboratories for Applied Superconductivity and Magnetism, Ohio State University, Columbus, OH 43210 (United States); Campbell, A M [Interdisciplinary Research Center (IRC) in Superconductivity, Cavendish Laboratory/Department of Engineering, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Coombs, T [Interdisciplinary Research Center (IRC) in Superconductivity, Cavendish Laboratory/Department of Engineering, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Astill, D [Interdisciplinary Research Center (IRC) in Superconductivity, Cavendish Laboratory/Department of Engineering, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Harrison, S [Scientific Magnetics, Culham Science Centre, Culham, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Husband, M [Strategic Research Center (SRC)-Electrical Engineering, Rolls-Royce plc, Derby DE24 8BJ (United Kingdom); Rindfleisch, M [Hyper Tech Research Inc., Columbus, OH 43212 (United States); Tomsic, M [Hyper Tech Research Inc., Columbus, OH 43212 (United States)

    2007-07-15

    Various MgB{sub 2} wires with different sheath materials provided by Hyper Tech Research Inc., have been tested in the superconducting fault current limiter (SFCL) desktop tester at 24-26 K in a self-field. Samples 1 and 2 are similarly fabricated monofilamentary MgB{sub 2} wires with a sheath of CuNi, except that sample 2 is doped with SiC and Mg addition. Sample 3 is a CuNi sheathed multifilamentary wire with Cu stabilization and Mg addition. All the samples with Nb barriers have the same diameter of 0.83 mm and superconducting fractions ranging from 15% to 27% of the total cross section. They were heat-treated at temperatures of 700 deg. C for a hold time of 20-40 min. Current limiting properties of MgB{sub 2} wires subjected to pulse overcurrents have been experimentally investigated in an AC environment in the self-field at 50 Hz. The quench currents extracted from the pulse measurements were in a range of 200-328 A for different samples, corresponding to an average engineering critical current density (J{sub e}) of around 4.8 x 10{sup 4} A cm{sup -2} at 25 K in the self-field, based on the 1 {mu}V cm{sup -1} criterion. This work is intended to compare the quench behaviour in the Nb-barrier monofilamentary and multifilamentary MgB{sub 2} wires with CuNi and Cu/CuNi sheaths. The experimental results can be applied to the design of fault current limiter applications based on MgB{sub 2} wires.

  15. Measurement of 3-Axis Magnetic Fields Induced by Current Wires Using a Smartphone in Magnetostatics Experiments

    Science.gov (United States)

    Setiawan, B.; Septianto, R. D.; Suhendra, D.; Iskandar, F.

    2017-01-01

    This paper describes the use of an inexpensive smartphone's magnetic sensor to measure magnetic field components (B[subscript x], B[subscript y] and B[subscript z]) induced by current wires in magnetostatic experiments. The variable parameters used to measure the magnetic sensor's capabilities were: the geometrical shapes of the wire, current…

  16. Current's Fluctuations through Molecular Wires Composed of Thiophene Rings.

    Science.gov (United States)

    Ojeda Silva, Judith Helena; Cortés Peñaranda, Juan Camilo; Gómez Castaño, Jovanny A; Duque, Carlos Alberto

    2018-04-11

    We study theoretically the electronic transport and quantum fluctuations in single-molecule systems using thiophene rings as integrated elementary functions, as well as the dependence of these properties with the increase of the coupled rings, i.e., as a quantum wire. In order to analyze the current flow through these molecular systems, the thiophene rings are considered to be connected to metal contacts, which, in general terms, will be related to the application of voltages (bias voltages or gate voltages) to generate non-equilibrium behavior between the contacts. Due to the nonlinear behavior that is generated when said voltages are applied, it is possible to observe quantum fluctuations in the transport properties of these molecular wires. For the calculation of the transport properties, we applied a tight-binding approach using the Landauer-Büttiker formalism and the Fischer-Lee relationship, by means of a semi-analytic Green's function method within a real-space renormalization (decimation procedure). Our results showed an excellent agreement with results using a tight-binding model with a minimal number of parameters reported so far for these molecular systems.

  17. Electron transport in quantum wires: possible current instability mechanism

    International Nuclear Information System (INIS)

    Sablikov, V.A.

    2001-01-01

    The electrons nonlinear and dynamic transition in quantum wires connecting the electron reservoirs, are studies with an account of the Coulomb interaction distribution of electron density between the reservoirs and the wire. It is established that there exist two processes, leading to electrical instability in such structure. One of them is expressed in form of multistability of the charge accumulated in the wire, and negative differential conductivity. The other one is connected with origination of negative dynamic conductivity in the narrow frequency range near the resonance frequency of the charge waves on the wire length [ru

  18. INFLUENCE OF DRAWING SPEED ON THE TEMPERATURE AND DEFLECTED MODE IN WIRE OF HIGH-CARBON STEEL

    Directory of Open Access Journals (Sweden)

    M. N. Vereshchagin

    2008-01-01

    Full Text Available The calculation of deflected mode and temperature fields with the help of the method of finite elements for zones of wire deformation in dies for current and new technology of drawing of wire with diameter 0,41 mm is carried out.

  19. 1 mil gold bond wire study.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  20. General relativistic galvano-gravitomagnetic effect in current carrying conductors

    International Nuclear Information System (INIS)

    Ahmedov, B.J.

    1998-11-01

    The analogy between general relativity and electromagnetism suggests that there is a galvano-gravitomagnetic effect, which is the gravitational analogue of the Hall effect. This new effect takes place when a current carrying conductor is placed in a gravitomagnetic field and the conduction electrons moving inside the conductor are deflected transversally with respect to the current flow. In connection with this galvano-gravitomagnetic effect, we explore the possibility of using current carrying conductors for detecting the gravitomagnetic field of the Earth. (author)

  1. Load carrying capacity of keyed joints reinforced with high strength wire rope loops

    OpenAIRE

    Jørgensen, Henrik B.; Hoang, Linh Cao

    2015-01-01

    Vertical shear connections between precast concrete wall elements are usually made as keyed joints reinforced with overlapping U-bars. The overlapping U-bars form a cylindrical core in which the locking bar is placed and the connection is subsequently grouted with mortar. A more construction friendly shear connection can be obtained by replacing the U-bars with high strength looped wire ropes. The wire ropes have the advantage of being flexible (they have virtually no bending stiffness) which...

  2. Reducing condition number by appropriate current decomposition on a multiplet of several wires

    CSIR Research Space (South Africa)

    Lysko, AA

    2011-07-01

    Full Text Available This paper discusses a numerical investigation in connection with the dependency of the condition number of the impedance matrix on the decomposition of current on a junction with several attached wires (multiplet). It is shown that the condition...

  3. Diagnostics for exploding wires (abstract)

    International Nuclear Information System (INIS)

    Moosman, B.; Bystritskii, V.; Wessel, F.J.; Van Drie, A.

    1999-01-01

    Two diagnostics, capable of imaging fast, high temperature, plasmas were used on exploding wire experiments at UC Irvine. An atmospheric pressure nitrogen laser (λ=337.1 nm) was used to generate simultaneous shadow and shearing interferogram images with a temporal resolution of ∼1 ns and a spatial resolution of 10 μm. An x-ray backlighter imaged the exploding wire 90 degree with respect to the laser and at approximately the same instant in time. The backlighter spatial resolution as determined by geometry and film resolution was 25 μm. Copper wires of diameters (25, 50, and 100 μm) and steel wire d=25 μm were exploded in vacuum (10 -5 Torr) at a maximum current level of 12 kA, by a rectified marx bank at a voltage of 50 kV and a current rise time (quarter period) of 900 ns. Copper wires which were cleaned and then resistively heated under vacuum to incandescence for several hours prior to high current initiation, exhibited greater expansion velocities at peak current than wires which had not been heated prior to discharge. Axial variations on the surface of the wire observed with the laser were found to correlate with bulk axial mass differences from x-ray backlighting. High electron density, measured near the opaque surface of the exploding wire, suggests that much of the current is shunted outward away from the bulk of the wire. copyright 1999 American Institute of Physics

  4. Hotspot relaxation dynamics in a current-carrying superconductor

    Science.gov (United States)

    Marsili, F.; Stevens, M. J.; Kozorezov, A.; Verma, V. B.; Lambert, Colin; Stern, J. A.; Horansky, R. D.; Dyer, S.; Duff, S.; Pappas, D. P.; Lita, A. E.; Shaw, M. D.; Mirin, R. P.; Nam, S. W.

    2016-03-01

    We experimentally studied the dynamics of optically excited hotspots in current-carrying WSi superconducting nanowires as a function of bias current, bath temperature, and excitation wavelength. We observed that the hotspot relaxation time depends on bias current, temperature, and wavelength. We explained this effect with a model based on quasiparticle recombination, which provides insight into the quasiparticle dynamics of superconductors.

  5. Current distribution in conducting nanowire networks

    Science.gov (United States)

    Kumar, Ankush; Vidhyadhiraja, N. S.; Kulkarni, Giridhar U.

    2017-07-01

    Conducting nanowire networks find diverse applications in solar cells, touch-screens, transparent heaters, sensors, and various related transparent conducting electrode (TCE) devices. The performances of these devices depend on effective resistance, transmittance, and local current distribution in these networks. Although, there have been rigorous studies addressing resistance and transmittance in TCE, not much attention is paid on studying the distribution of current. Present work addresses this compelling issue of understanding current distribution in TCE networks using analytical as well as Monte-Carlo approaches. We quantified the current carrying backbone region against isolated and dangling regions as a function of wire density (ranging from percolation threshold to many multiples of threshold) and compared the wired connectivity with those obtained from template-based methods. Further, the current distribution in the obtained backbone is studied using Kirchhoff's law, which reveals that a significant fraction of the backbone (which is believed to be an active current component) may not be active for end-to-end current transport due to the formation of intervening circular loops. The study shows that conducting wire based networks possess hot spots (extremely high current carrying regions) which can be potential sources of failure. The fraction of these hot spots is found to decrease with increase in wire density, while they are completely absent in template based networks. Thus, the present work discusses unexplored issues related to current distribution in conducting networks, which are necessary to choose the optimum network for best TCE applications.

  6. A comparison study of exploding a Cu wire in air, water, and solid powders

    Science.gov (United States)

    Han, Ruoyu; Wu, Jiawei; Ding, Weidong; Zhou, Haibin; Qiu, Aici; Wang, Yanan

    2017-11-01

    In this paper, an experimental study on exploding a copper wire in air, water, incombustible powders, and energetic materials is performed. We examined the effects of the surrounding media on the explosion process and its related phenomena. Experiments were first carried out with copper wire explosions driven by microsecond timescale pulsed currents in air, water, and the half-half case. Then, the copper wires were exploded in air, water, SiO2 powders, quartz sand, NaCl powders, and energetic-material cylinders, respectively. Our experimental results indicated that the explosion process was significantly influenced by the surrounding media, resulting in noticeable differences in energy deposition, optical emission, and shock waves. In particular, incombustible powders could throttle the current flow completely when a fine wire was adopted. We also found that an air or incombustible-powder layer could drastically attenuate the shock wave generated by a wire explosion. As for energetic-material loads, obvious discrepancies were found in voltage/current waveforms from vaporization when compared with a wire explosion in air/water, which meant the metal vapor/liquid drops play a significant role in the ignition process.

  7. The role of MgO content in ex situ MgB2 wires

    DEFF Research Database (Denmark)

    Kovac, P.; Hugek, I.; Meligek, T.

    2004-01-01

    An experimental study of the effect of MgO content in the MgB2 powder used for ex situ made composite wires was carried out. Two single-core MgB2/Fe/Cu wires were made using commercial MgB2 powders from Alfa Aesar containing different fraction of MgO. Critical temperature and critical currents of...

  8. One century of Kirschner wires and Kirschner wire insertion techniques : A historical review

    NARCIS (Netherlands)

    Franssen, Bas B. G. M.; Schuurman, Arnold H.; Van der Molen, Aebele Mink; Kon, Moshe

    A century ago, in 1909, Martin Kirschner (1879-942) introduced a smooth pin, presently known as the Kirschner wire (K-wire). The K-wire was initiallly used for skeletal traction and is now currently used for many different goals. The development of the K-wire and its insertion devices were mainly

  9. Current distribution and giant magnetoimpedance in composite wires with helical magnetic anisotropy

    International Nuclear Information System (INIS)

    Buznikov, N.A.; Antonov, A.S.; Granovsky, A.B.; Kim, C.G.; Kim, C.O.; Li, X.P.; Yoon, S.S.

    2006-01-01

    The giant magnetoimpedance effect in composite wires consisting of a non-magnetic inner core and soft magnetic shell is studied theoretically. It is assumed that the magnetic shell has a helical anisotropy. The current and field distributions in the composite wire are found by means of a simultaneous solution of Maxwell equations and the Landau-Lifshitz equation. The expressions for the diagonal and off-diagonal impedance are obtained for low and high frequencies. The dependences of the impedance on the anisotropy axis angle and the shell thickness are analyzed. Maximum field sensitivity is shown to correspond to the case of the circular anisotropy in the magnetic shell. It is demonstrated that the optimum shell thickness to obtain maximum impedance ratio is equal to the effective skin depth in the magnetic material

  10. Current distribution and giant magnetoimpedance in composite wires with helical magnetic anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Buznikov, N.A. [Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences, Moscow 125412 (Russian Federation) and Research Center for Advanced Magnetic Materials, Chungnam National University, Daeduk Science Town, Daejeon 305-764 (Korea, Republic of)]. E-mail: n_buznikov@mail.ru; Antonov, A.S. [Institute for Theoretical and Applied Electrodynamics, Russian Academy of Sciences, Moscow 125412 (Russian Federation); Granovsky, A.B. [Faculty of Physics, M.V. Lomonosov Moscow State University, Moscow 119992 (Russian Federation); Kim, C.G. [Research Center for Advanced Magnetic Materials, Chungnam National University, Daeduk Science Town, Daejeon 305-764 (Korea, Republic of)]. E-mail: cgkim@cnu.ac.kr; Kim, C.O. [Research Center for Advanced Magnetic Materials, Chungnam National University, Daeduk Science Town, Daejeon 305-764 (Korea, Republic of); Li, X.P. [Department of Mechanical Engineering and Division of Bioengineering, National University of Singapore, Singapore 119260 (Singapore); Yoon, S.S. [Research Center for Advanced Magnetic Materials, Chungnam National University, Daeduk Science Town, Daejeon 305-764 (Korea, Republic of); Department of Physics, Andong National University, Andong 760-749 (Korea, Republic of)

    2006-01-15

    The giant magnetoimpedance effect in composite wires consisting of a non-magnetic inner core and soft magnetic shell is studied theoretically. It is assumed that the magnetic shell has a helical anisotropy. The current and field distributions in the composite wire are found by means of a simultaneous solution of Maxwell equations and the Landau-Lifshitz equation. The expressions for the diagonal and off-diagonal impedance are obtained for low and high frequencies. The dependences of the impedance on the anisotropy axis angle and the shell thickness are analyzed. Maximum field sensitivity is shown to correspond to the case of the circular anisotropy in the magnetic shell. It is demonstrated that the optimum shell thickness to obtain maximum impedance ratio is equal to the effective skin depth in the magnetic material.

  11. Anisotropy of energy losses in high-current Z-pinches produced by the implosion of cylindrical tungsten wire arrays

    Science.gov (United States)

    Aleksandrov, V. V.; Volkov, G. S.; Grabovski, E. V.; Gritsuk, A. N.; Lakhtyushko, N. I.; Medovshchikov, S. F.; Oleinik, G. M.; Svetlov, E. V.

    2014-02-01

    Results are presented from measurements of the anisotropy of energy losses in high-current Z-pinches produced by the implosion of wire arrays at the ANGARA-5-1 facility at load currents of up to 4MA. The energy losses were measured in the radial direction and along the pinch axis from the anode side. The main diagnostics were time-integrated thermocouple calorimeters, nanosecond X-ray diodes (XRDs) with different filters, and a foil radiation calorimeter with a time resolution of 2 μs. The azimuthal anisotropy of energy losses was measured for different wire array configurations and different shapes of the high-voltage electrode. The presence of strong initial azimuthal inhomogeneity of the wire mass distribution (sectioned arrays), as well as the use of conical electrodes instead of plane ones, does not increase the azimuthal inhomogeneity of the total energy losses. For cylindrical wire arrays, energy losses in the radial direction are compared with those along the pinch axis. According to XRD and calorimetric measurements, the radiation yield per unit solid angle along the pinch axis is two to three times lower than that in the radial direction. In the axial direction, the energy flux density of the expanding plasma is two to three times lower than the radiation intensity. The measured radiation yield across the pinch is 2.5-5 kJ/sr, while that along the pinch axis is 1-2 kJ/sr. The results obtained by means of XRDs agree to within measurement errors with those obtained using the radiation calorimeter. It is found that the energy per unit solid angle carried by the expanding plasma in the radial direction does not exceed 10% of the soft X-ray yield. Analysis of the structure of time-integrated pinhole images and signals from the radial and axial XRDs shows that radiation emitted in the radial direction from the hot central region of the pinch is partially screened by the less dense surrounding plasma halo, whereas radiation emitted in the axial direction is a

  12. Electron beam additive manufacturing with wire - Analysis of the process

    Science.gov (United States)

    Weglowski, Marek St.; Błacha, Sylwester; Pilarczyk, Jan; Dutkiewicz, Jan; Rogal, Łukasz

    2018-05-01

    The electron beam additive manufacturing process with wire is a part of global trend to find fast and efficient methods for producing complex shapes elements from costly metal alloys such as stainless steels, nickel alloys, titanium alloys etc. whose production by other conventional technologies is unprofitable or technically impossible. Demand for additive manufacturing is linked to the development of new technologies in the automotive, aerospace and machinery industries. The aim of the presented work was to carried out research on electron beam additive manufacturing with a wire as a deposited (filler) material. The scope of the work was to investigate the influence of selected technological parameters such as: wire feed rate, beam current, travelling speed, acceleration voltage on stability of the deposition process and geometric dimensions of the padding welds. The research revealed that, at low beam currents, the deposition process is unstable. The padding weld reinforcement is non-uniform. Irregularity of the width, height and straightness of the padding welds can be observed. At too high acceleration voltage and beam current, burn-through of plate and excess penetration weld can be revealed. The achieved results and gained knowledge allowed to produce, based on EBAM with wire process, whole structure from stainless steel.

  13. Plasma dynamics in aluminium wire array Z-pinch implosions

    International Nuclear Information System (INIS)

    Bland, S.N.

    2001-01-01

    The wire array Z-pinch is the world's most powerful laboratory X-ray source. An achieved power of ∼280TW has generated great interest in the use of these devices as a source of hohlraum heating for inertial confinement fusion experiments. However, the physics underlying how wire array Z-pinches implode is not well understood. This thesis presents the first detailed measurements of plasma dynamics in wire array experiments. The MAGPIE generator, with currents of up to 1.4MA, 150ns 10-90% rise-time, was used to implode arrays of 16mm diameter typically containing between 8 and 64 15μm aluminium wires. Diagnostics included: end and side-on laser probing with interferometry, schlieren and shadowgraphy channels; radial and axial streak photography; gated X-ray imaging; XUV and hard X-ray spectrometry; filtered XRDs and diamond PCDs; and a novel X-ray backlighting system to probe high density plasma. It was found that the plasma formed from the wires consisted of cold, dense cores, which ablated producing hot, low density coronal plasma. After an initial acceleration around the cores, coronal plasma streams flowed force-free towards the axis, with an instability wavelength determined by the core size. At ∼50% of the implosion time, the streams collided on axis forming a precursor plasma which appeared to be uniform, stable, and inertially confined. The existence of core-corona structure significantly affected implosion dynamics. For arrays with <64 wires, the wire cores remained in their original positions until ∼80% of the implosion time before accelerating rapidly. At 64 wires a transition in implosion trajectories to 0-D like occurred indicating a possible merger of current carrying plasma close to the cores - the cores themselves did not merge. During implosion, the cores initially developed uncorrelated instabilities that then transformed into a longer wavelength global mode of instability. The study of nested arrays (2 concentric arrays, one inside the other

  14. Correction of high-voltage pulse front by means of exploding wires

    International Nuclear Information System (INIS)

    Azarkevich, E.I.; Zajtsev, N.I.; Kotov, Yu.A.

    1979-01-01

    A method of correcting the poWer pulse fronts shaped during the discharge of the Akradiev-Marx generator on active load has been suggested with a view to shaping power high-voltage pulses on the diode of a high-current electron accelerator. Thish correction is carried oUt by means of the current breaker on the base of electrically exploding wires. The breaker consists of four copper wires of 0.12 mm diameter, and 940 mm length. A current pulse of 32 kA amplitude, duration of 2.7 μs with a front of 100 ns was obtained by the use of the current breaker when forming the pulse in the electron accelerator power supply at load of 12 Ohm. The correction resulted in a nearly 20-fold reduction of the front duration

  15. Development of a short sample test facility for evaluating superconducting wires

    International Nuclear Information System (INIS)

    Singh, M.R.; Kulkarni, D.G.; Sahni, V.C.; Ravikumar, G.; Patel, K.L.

    2002-01-01

    In this paper we describe a short sample test facility we have set up at Bhabha Atomic Research Centre (BARC). This facility has been used to measure critical currents of NbTi/Cu composite superconducting wires by recording V versus I data at 4.2 K. It offers sample current as large as 1500 A and a transverse magnetic field up to 7.4 T. A power law, V ∼I n( H) is fitted to the resistive transition region to estimate the exponent n, which is a measure of the uniformity of superconducting filaments in composite wires. It is observed that inadequate thermal stabilization of sample wire results in thermal runaway, which limits the V-I data to∼ 2μ V . This in turn affects the reliability of estimated filament uniformity. To mitigate this problem, we have used a sample holder made of OFHC-Cu which enhances thermal stabilization of the sample. With this sample holder, the results of measurements carried out on wires developed by the Atomic Fuel Division, BARC show a high filament uniformity (n ∼ 58). (author)

  16. Uniaxial Strain Induced Critical Current Degradation of Ag-Sheathed Bi-2212 Round Wire

    NARCIS (Netherlands)

    Dai, Chao; Qin, Jinggang; Liu, Bo; Liu, Peihang; Wu, Yu; Nijhuis, Arend; Zhou, Chao; Li, Chenshan; Hao, Qingbin; Liu, Sheng

    2018-01-01

    The critical current degradation of Bi-2212 Ag-sheathed round wire subjected to uniaxial strain was studied at 4.2 K in 14 T background field. The strains applied on the sample are both tension and compression. The additional tensile strain caused by the difference in thermal expansion between the

  17. Soft X-ray radiation power characteristics of tungsten wire arrays on Yang accelerator

    International Nuclear Information System (INIS)

    Zhang Siqun; Ouyang Kai; Huang Xianbin; Dan Jiakun; Zhou Rongguo; Yang Liang

    2013-01-01

    A series of experiments were carried out to research the X-ray radiation characteristics of tungsten wire arrays on Yang accelerator. In those experiments, we charged the Marx generator of 60 kV, and the load current of 0.85-1.00 MA, the rise time of 75-90 ns (10%-90%). A soft X-ray scintillator powermeter which responded flatly to 50-1800 eV X-rays was used to measure the power of soft X-ray emitted from implosion plasma. In this paper, we present the measuring results of time-resolved soft X-ray radiation power, and discuss the radiation characteristics of implosion plasma by analyzing the correlations of soft X-ray radiant power and the diameter, length, wire number of the tungsten wire arrays. The optimizing wire array configuration parameters on Yang are as follows: 8 mm array diameter, 15 mm wire length, and 24 wire number. We also present the radiant power difference in radial and axial directions of the wire arrays. (authors)

  18. Filament to filament bridging and its influence on developing high critical current density in multifilamentary Bi2Sr2CaCu2Ox round wires

    International Nuclear Information System (INIS)

    Shen, T; Jiang, J; Kametani, F; Trociewitz, U P; Larbalestier, D C; Schwartz, J; Hellstrom, E E

    2010-01-01

    Increasing the critical current density (J c ) of the multifilamentary round wire Ag/Bi 2 Sr 2 CaCu 2 O x (2212) requires understanding its complicated microstructure, in which extensive bridges between filaments are prominent. In this first through-process quench study of 2212 round wire, we determined how its microstructure develops during a standard partial-melt process and how filament bridging occurs. We found that filaments can bond together in the melt state. As 2212 starts to grow on subsequent cooling, we observed that two types of 2212 bridges form. One type, which we call Type-A bridges, forms within filaments that bonded in the melt; Type-A bridges are single grains that span multiple bonded filaments. The other type, called Type-B bridges, form between discrete filaments through 2212 outgrowths that penetrate into the Ag matrix and intersect with other 2212 outgrowths from adjacent filaments. We believe the ability of these two types of bridges to carry inter-filament current is intrinsically different: Type-A bridges are high- J c inter-filament paths whereas Type-B bridges contain high-angle grain boundaries and are typically weak linked. Slow cooling leads to more filament bonding, more Type-A bridges and a doubling of J c without changing the flux pinning. We suggest that Type-A bridges create a 3D current flow that is vital to developing high J c in multifilamentary 2212 round wire.

  19. Use of microsecond current prepulse for dramatic improvements of wire array Z-pinch implosion

    International Nuclear Information System (INIS)

    Calamy, H.; Lassalle, F.; Loyen, A.; Zucchini, F.; Chittenden, J. P.; Hamann, F.; Maury, P.; Georges, A.; Bedoch, J. P.; Morell, A.

    2008-01-01

    The Sphinx machine [F. Lassalle et al., 'Status on the SPHINX machine based on the 1microsecond LTD technology'] based on microsecond linear transformer driver (LTD) technology is used to implode an aluminium wire array with an outer diameter up to 140 mm and maximum current from 3.5 to 5 MA. 700 to 800 ns implosion Z-pinch experiments are performed on this driver essentially with aluminium. Best results obtained before the improvement described in this paper were 1-3 TW radial total power, 100-300 kJ total yield, and 20-30 kJ energy above 1 keV. An auxiliary generator was added to the Sphinx machine in order to allow a multi microsecond current to be injected through the wire array load before the start of the main current. Amplitude and duration of this current prepulse are adjustable, with maxima ∼10 kA and 50 μs. This prepulse dramatically changes the ablation phase leading to an improvement of the axial homogeneity of both the implosion and the final radiating column. Total power was multiplied by a factor of 6, total yield by a factor of 2.5 with a reproducible behavior. This paper presents experimental results, magnetohydrodynamic simulations, and analysis of the effect of such a long current prepulse

  20. Sample of superconducting wiring from the LHC

    CERN Multimedia

    The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. Magnet coils are made of copper-clad niobium–titanium cables — each wire in the cable consists of 9’000 niobium–titanium filaments ten times finer than a hair. The cables carry up to 12’500 amps and must withstand enormous electromagnetic forces. At full field, the force on one metre of magnet is comparable to the weight of a jumbo jet. Coil winding requires great care to prevent movements as the field changes. Friction can create hot spots wh...

  1. Current scaling of radiated power for 40-mm diameter single wire arrays on Z

    Science.gov (United States)

    Nash, T. J.; Cuneo, M. E.; Spielman, R. B.; Chandler, G. A.; Leeper, R. J.; Seaman, J. F.; McGurn, J.; Lazier, S.; Torres, J.; Jobe, D.; Gilliland, T.; Nielsen, D.; Hawn, R.; Bailey, J. E.; Lake, P.; Carlson, A. L.; Seamen, H.; Moore, T.; Smelser, R.; Pyle, J.; Wagoner, T. C.; LePell, P. D.; Deeney, C.; Douglas, M. R.; McDaniel, D.; Struve, K.; Mazarakis, M.; Stygar, W. A.

    2004-11-01

    In order to estimate the radiated power that can be expected from the next-generation Z-pinch driver such as ZR at 28 MA, current-scaling experiments have been conducted on the 20 MA driver Z. We report on the current scaling of single 40 mm diameter tungsten 240 wire arrays with a fixed 110 ns implosion time. The wire diameter is decreased in proportion to the load current. Reducing the charge voltage on the Marx banks reduces the load current. On one shot, firing only three of the four levels of the Z machine further reduced the load current. The radiated energy scaled as the current squared as expected but the radiated power scaled as the current to the 3.52±0.42 power due to increased x-ray pulse width at lower current. As the current is reduced, the rise time of the x-ray pulse increases and at the lowest current value of 10.4 MA, a shoulder appears on the leading edge of the x-ray pulse. In order to determine the nature of the plasma producing the leading edge of the x-ray pulse at low currents further shots were taken with an on-axis aperture to view on-axis precursor plasma. This aperture appeared to perturb the pinch in a favorable manner such that with the aperture in place there was no leading edge to the x-ray pulses at lower currents and the radiated power scaled as the current squared ±0.75. For a full-current shot we will present x-ray images that show precursor plasma emitting on-axis 77 ns before the main x-ray burst.

  2. Limiting currents in superconducting composites

    International Nuclear Information System (INIS)

    Keilin, V.E.; Romanovskii, V.R.

    1992-01-01

    In this paper the results of numerical and analytical calculations of the process of current charging into a round superconducting composite with properties homogenized over cross-section are presented. In the numerical solution taken was into account a common proceeding of the thermal and electromagnetic processes. A wire with real volt-ampere characteristics approximated by exponential dependence was considered. The calculations carried out at various rates of current charging, voltampere characteristics, matrix materials, heat transfer coefficients and other parameters showed: the existence of characteristic limiting value of current below which the wire remains in a superconducting state if the current charging ceases and above which changes into a normal state; this current is somewhat less than a quench current; the existence of finite value for limiting current at any low heat transfer from a surface. The analytical solution of the problem is given. It permitted to write the stability criterion from which the dependence of limiting currents on initial parameters follows. The wire nonisothermality, its heat capacity, thermal and electric conductivities are taken into account additionally, as compared to results published earlier

  3. Cold atoms in microscopic traps: from wires to chips

    International Nuclear Information System (INIS)

    Cassettari, D.

    2000-05-01

    This thesis reports on the experimental demonstration of magnetic guides, traps and beam splitters for neutral atoms using current carrying wires. A straight wire allows to create two basic guide configurations: the magnetic field generated by the wire alone produces a guide where atoms in a strong field seeking state perform orbits around the wire (Kepler guide); by adding an external magnetic field, atoms in a weak field seeking state are guided at the location where the external field and the field generated by the wire cancel out (side guide). Furthermore, bending the wire in various shapes allows to modify the side guide potential and hence to create a large variety of three dimensional traps. A relevant property of these potentials is that higher trapping gradients are obtained by decreasing the current flowing in the wires. As the trap is compressed, it also moves closer to the wire. This feature has allowed us to create microscopic potentials by using thin wires designed on a surface (atom chip) by means of high resolution microfabrication techniques. Wires mounted on a surface have the advantage of being more robust and able to sustain larger currents due to their thermal coupling with the substrate. In our experiment we have developed methods to load these traps and guides with laser cooled atoms. Our first investigations have been performed with free standing wires which we have used to study the Kepler guide, the side guide and a three dimensional Ioffe-Pritchard trap. In the latter we have achieved the trapping parameters required in the experiments with Bose-Einstein condensates with much reduced power consumption. In a second time we have replaced the free standing wires with an atom chip, which we have used to compress the atomic cloud in potentials with trap frequencies above 100 kHz and ground state sizes below 100 nm. Such potentials are especially interesting for quantum information proposals of performing quantum gate operations with controlled

  4. EVALUATION OF INDUCTANCE WITH ELECTRICAL WIRES

    Directory of Open Access Journals (Sweden)

    V. Kudry

    2016-08-01

    Full Text Available In this paper proved the possibility of developing passive electronic inductive elements based replace metal wire that is wound inductor, the wire is made of electret. The relative permeability of the electret S  10 000, several orders of magnitude greater than the permeability of conventional insulation materials, i < 10, resulting current in the wire acquires properties bias current. The essence of innovation is to replace the source of of magnetic induction flow that pervades the core of the coil. According to the theory of electrodynamics, current bias, in contrast to conduction current, generated no movement of charge along the wire, but the change of the charge in the local volume.Equivalence bias current and conduction current is manifested in the possibility of forming a magnetic field. The flow through magnetic induction coil core regardless of the current it generates, creates voltage at its ends.The paper also shows the numeric characteristics that determine the effective frequency range, specified the reason why electric a wire with і < 10 can not generate magnetic flux through the core and serve as a passive reactive component.

  5. Low-Cost Superconducting Wire for Wind Generators: High Performance, Low Cost Superconducting Wires and Coils for High Power Wind Generators

    Energy Technology Data Exchange (ETDEWEB)

    None

    2012-01-01

    REACT Project: The University of Houston will develop a low-cost, high-current superconducting wire that could be used in high-power wind generators. Superconducting wire currently transports 600 times more electric current than a similarly sized copper wire, but is significantly more expensive. The University of Houston’s innovation is based on engineering nanoscale defects in the superconducting film. This could quadruple the current relative to today’s superconducting wires, supporting the same amount of current using 25% of the material. This would make wind generators lighter, more powerful and more efficient. The design could result in a several-fold reduction in wire costs and enable their commercial viability of high-power wind generators for use in offshore applications.

  6. Enhanced transport currents in Cu-sheathed MgB{sub 2} wires

    Energy Technology Data Exchange (ETDEWEB)

    Eisterer, M; Weber, H W [Atomic Institute of the Austrian Universities, Vienna (Austria); Glowacki, B A [Department of Materials Science and Metallurgy, University of Cambridge, Cambridge (United Kingdom); Pacific Northwest National Laboratory, Richland, WA (United States); Greenwood, L R [Pacific Northwest National Laboratory, Richland, WA (United States); Majoros, M [Interdisciplinary Research Centre in Superconductivity, University of Cambridge, Cambridge (United Kingdom)

    2002-07-01

    Copper-sheathed MgB{sub 2} wires, prepared by an in-situ process, were exposed to neutron radiation in order to introduce defects into the superconductor. The high level of disorder (4.6x10{sup -2} dpa) leads to a decrease of the transition temperature by more than 4 K, but to an increase of the slope of the irreversibility line, thus resulting in higher irreversibility fields at low temperatures. The transport currents are significantly enhanced at 4.2 K for fields above 2 T. (author)

  7. Towards plant wires

    OpenAIRE

    Adamatzky, Andrew

    2014-01-01

    In experimental laboratory studies we evaluate a possibility of making electrical wires from living plants. In scoping experiments we use lettuce seedlings as a prototype model of a plant wire. We approximate an electrical potential transfer function by applying direct current voltage to the lettuce seedlings and recording output voltage. We analyse oscillation frequencies of the output potential and assess noise immunity of the plant wires. Our findings will be used in future designs of self...

  8. Electro-mechanical characterization of MgB2 wires for the Superconducting Link Project at CERN

    Science.gov (United States)

    Konstantopoulou, K.; Ballarino, A.; Gharib, A.; Stimac, A.; Garcia Gonzalez, M.; Perez Fontenla, A. T.; Sugano, M.

    2016-08-01

    In previous years, the R & D program between CERN and Columbus Superconductors SpA led to the development of several configurations of MgB2 wires. The aim was to achieve excellent superconducting properties in high-current MgB2 cables for the HL-LHC upgrade. In addition to good electrical performance, the superconductor shall have good mechanical strength in view of the stresses during operation (Lorenz forces and thermal contraction) and handling (tension and bending) during cabling and installation at room temperature. Thus, the study of the mechanical properties of MgB2 wires is crucial for the cable design and its functional use. In the present work we report on the electro-mechanical characterization of ex situ processed composite MgB2 wires. Tensile tests (critical current versus strain) were carried out at 4.2 K and in a 3 T external field by means of a purpose-built bespoke device to determine the irreversible strain limit of the wire. The minimum bending radius of the wire was calculated taking into account the dependence of the critical current with the strain and it was then used to obtain the minimum twist pitch of MgB2 wires in the cable. Strands extracted from cables having different configurations were tested to quantify the critical current degradation. The Young’s modulus of the composite wire was measured at room temperature. Finally, all measured mechanical parameters will be used to optimize an 18-strand MgB2 cable configuration.

  9. Magnetization reversal process and nonlinear magneto-impedance in Cu/NiFe and Nb/NiFe composite wires

    Energy Technology Data Exchange (ETDEWEB)

    Antonov, A.S.; Buznikov, N.A. E-mail: n_buznikov@mail.ru; Granovsky, A.B.; Iakubov, I.T.; Prokoshin, A.F.; Rakhmanov, A.L.; Yakunin, A.M

    2002-08-01

    The magnetization reversal of Cu/NiFe and Nb/NiFe composite wires carrying AC current is studied. The frequency spectrum of a voltage induced in a pick-up coil wound around the wire is analyzed. The frequency spectrum is shown to consist of even harmonics within a wide range of AC current amplitudes and longitudinal DC magnetic fields. The strong dependencies of the harmonic amplitudes on the DC field are found. The results obtained may be of importance for the design of weak magnetic field sensors.

  10. Magnetization reversal process and nonlinear magneto-impedance in Cu/NiFe and Nb/NiFe composite wires

    International Nuclear Information System (INIS)

    Antonov, A.S.; Buznikov, N.A.; Granovsky, A.B.; Iakubov, I.T.; Prokoshin, A.F.; Rakhmanov, A.L.; Yakunin, A.M.

    2002-01-01

    The magnetization reversal of Cu/NiFe and Nb/NiFe composite wires carrying AC current is studied. The frequency spectrum of a voltage induced in a pick-up coil wound around the wire is analyzed. The frequency spectrum is shown to consist of even harmonics within a wide range of AC current amplitudes and longitudinal DC magnetic fields. The strong dependencies of the harmonic amplitudes on the DC field are found. The results obtained may be of importance for the design of weak magnetic field sensors

  11. The relationship between critical current and microstructure of internal tin wire

    International Nuclear Information System (INIS)

    Dietderich, D.R.; Hassenzahl, W.V.; Morris, J.W. Jr.

    1986-01-01

    Prior work on internal tin wire has shown that an increase in critical current results when the Nb 3 Sn reaction temperatures (650-730 0 C) are preceded by low temperature diffusion heat treatments that distribute the tin. These heat treatments produce a more uniform tin distribution through the niobium filament array before substantial Nb 3 Sn formation has occurred. Heat treatments as long as 19 days have been proposed as the optimal heat treatment for the conductor. However, it is possible to substantially reduce the low temperature heat treatment time while retaining the same high critical current. The success of shortened heat treatments may be interpreted on the basis of the Cu-Sn reaction, diffusion kinetics and the Nb 3 Sn growth kinetics

  12. Minimisation of the wire position uncertainties of the new CERN vacuum wire scanner

    CERN Document Server

    AUTHOR|(CDS)2069346; Barjau Condomines, A

    In the next years the luminosity of the LHC will be significantly increased. This will require a much higher accuracy of beam profile measurement than actually achievable by the current wire scanner. The new fast wire scanner is foreseen to measure small emittance beams throughout the LHC injector chain, which demands a wire travelling speed up to 20 ms-1 and position measurement accuracy of the order of a few microns. The vibrations of the mechanical parts of the system, and particularly the vibrations of the thin carbon wire, were identified as the major error sources of wire position uncertainty. Therefore the understanding of the wire vibrations is a high priority for the design and operation of the new device. This document presents the work performed to understand the main causes of the wire vibrations observed in one of the existing wire scanner and the new proposed design.

  13. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  14. Sensitive and simple method for measuring wire tensions

    International Nuclear Information System (INIS)

    Atac, M.; Mishina, M.

    1982-08-01

    Measuring tension of wires in drift chambers and multiwire proportional chambers after construction is an important process because sometimes wires get loose after soldering, crimping or glueing. One needs to sort out wires which have tensions below a required minimum value to prevent electrostatic instabilities. There have been several methods reported on this subject in which the wires were excited either with sinusoidal current under magnetic field or with sinusoidal voltage electrostatically coupled to the wire, searching for a resonating frequency with which the wires vibrate mechanically. Then the vibration is detected either visually, optically or with magnetic pick-up directly touching the wires. Any of these is only applicable to the usual multiwire chamber which has open access to the wire plane. They also need fairly large excitation currents to induce a detectable vibration to the wires. Here we report a very simple method that can be used for any type of wire chamber or proportional tube system for measuring wire tension. Only a very small current is required for the wire excitation to obtain a large enough signal because it detects the induced emf voltage across a wire. A sine-wave oscillator and a digital voltmeter are sufficient devices aside from a permanent magnet to provide the magnetic field around the wire. A useful application of this method to a large system is suggested

  15. Tensile Strain Dependence of Critical Current for RHQ-Nb3Al Wires

    OpenAIRE

    Jin, Xinzhe; Oguro, Hidetoshi; Nakamoto, Tatsushi; Awaji, Satoshi; Ogitsu, Toru; Tsuchiya, Kiyosumi; Yamamoto, Akira; Kikuchi, Akihiro; Takeuchi, Takao

    2011-01-01

    KEK and NIMS have been jointly developing Nb3Al superconducting wire with a rapid heating and quenching (RHQ) method towards high field accelerator magnets in the Large Hadron Collider (LHC) luminosity upgrade. A15-type superconductors such as Nb3Al and Nb3Sn exhibit strain dependence with respect to their critical currents. Therefore, a thorough understanding of strain behavior is necessary for high field accelerator magnet development, which will be critical for the luminosity upgrade of th...

  16. Electromagnetic Behaviour of Metallic Wire Structures

    CERN Document Server

    Chui, S T

    2013-01-01

    Despite the recent development and interest in the photonics of metallic wire structures, the relatively simple concepts and physics often remain obscured or poorly explained to those who do not specialize in the field. Electromagnetic Behaviour of Metallic Wire Structures provides a clear and coherent guide to understanding these phenomena without excessive numerical calculations.   Including both background material and detailed derivations of the various different formulae applied, Electromagnetic Behaviour of Metallic Wire Structures describes how to extend basic circuit theory relating to voltages, currents, and resistances of metallic wire networks to include situations where the currents are no longer spatially uniform along the wire. This lays a foundation for a deeper understanding of the many new phenomena observed in meta-electromagnetic materials.   Examples of applications are included to support this new approach making Electromagnetic Behaviour of Metallic Wire Structures a comprehensive and ...

  17. Using active power filter to compensate the current component of asymmetrical non-linear load in the four wire network

    Directory of Open Access Journals (Sweden)

    Руслан Володимирович Власенко

    2016-07-01

    Full Text Available Electricity quality improving is extremely relevant nowadays. With such industrial loads as induction motors, induction furnaces, welding machines, controlled or uncontrolled rectifiers, frequency converters and others reactive power, harmonics and unbalance are generated in power grid. Reactive power, higher harmonic currents and asymmetry loads influence the functioning of electric devices and electrical mains. An effective technical solution is the use of new compensating devices, that is active power filters. The emergence of consumers with a unit capacity of four wire networks requires a new approach to building system control active power filter. When designing the active power filter control system the current flowing in the neutral wire must be taken into account. To assess the power balance in the four wire active power filter, scientists have proposed to apply pqr theory of power based on the Clarke transformation. There are different topologies of three-phase four wire active power filters. A visual simulation of Matlab / Simulink model with an active power filter based on pqr theory of power has been created. A method of pulse width modulation with four control channels was used as pulses forming systems with transistor keys. Operating conditions of three-phase four wire active power filter with asymmetry, non-sinosoidal voltage source and asymmetric load have been studied. The correction taking into account the means improving the active power filter has been offered as pqr theory of power does not take into account non-sinosoidal voltage

  18. Experimental study on underwater electrical explosion of a copper wire

    International Nuclear Information System (INIS)

    Zhou Qing; Zhang Jun; Tan Xiangyu; Ren Baozhong; Zhang Qiaogen

    2010-01-01

    Through analyzing the physical process of underwater electrical wire explosion, electrical wire explosions with copper wires were investigated underwater using pulsed voltage in the time scale of a few microseconds. A self-integrating Rogowsky coil and a voltage divider were used for current and voltage at the wire load, respectively. The shock wave pressure is measured with a piezoelectric pressure probe at the same distance. The current rise rate was adjusted by changing the applied voltage, circuit inductance, length and diameter of copper wire. The change of the current rise rate had a great effect on the process of underwater electrical wire explosion with copper wires. At last, the effect of discharge voltage, circuit inductance, length and diameter of copper wire were obtained on the explosion voltage and current as well as shock wave pressure. (authors)

  19. ''Water bath'' effect during the electrical underwater wire explosion

    International Nuclear Information System (INIS)

    Oreshkin, V. I.; Chaikovsky, S. A.; Ratakhin, N. A.; Grinenko, A.; Krasik, Ya. E.

    2007-01-01

    The results of a simulation of underwater electrical wire explosion at a current density >10 9 A/cm 2 , total discharge current of ∼3 MA, and rise time of the current of ∼100 ns are presented. The electrical wire explosion was simulated using a one-dimensional radiation-magnetohydrodynamic model. It is shown that the radiation of the exploded wire produces a thin conducting plasma shell in the water in the vicinity of the exploding wire surface. It was found that this plasma shell catches up to 30% of the discharge current. Nevertheless, it was shown that the pressure and temperature of the wire material remain unchanged as compared with the idealized case of the electrical wire explosion in vacuum. This result is explained by a 'water bath' effect

  20. Influence of an ac magnetic field and induced magnetic anisotropy on the surface magnetoimpedance tensor in an amorphous wire

    International Nuclear Information System (INIS)

    Chen, A P; Zhukova, V; Zhukov, A; Dominguez, L; Chizhik, A; Blanco, J M; Gonzalez, J

    2004-01-01

    The influence of an ac magnetic field and the induced magnetic anisotropy (by field annealing and torsion annealing) on the magnetoimpedance (MI) tensor in an amorphous wire has been analysed. The experimental measurements were carried out in an amorphous wire of composition (Co 0.94 Fe 0.06 ) 72.5 Si 12.5 B 15 , with a negative, nearly zero magnetostriction constant, excited either by an ac circular, h φ , or an axial, h z , magnetic field created by an ac electric current passing along the wire or through an exciting coil mounted on the wire, respectively. The ac current amplitude was changed from 7.5 to 40 mA and the current frequency f was varied from 1.5 to 20 MHz. The induced magnetic anisotropies modify the MI response drastically. The field annealed sample shows a unique peak of the MI effect, while the torsion annealed sample presents an asymmetric giant magnetoimpedance ratio associated with the induced magnetic anisotropy which provokes such thermal treatments

  1. Cryogenic deuterium Z-pinch and wire array Z-pinch studies at Imperial College

    International Nuclear Information System (INIS)

    Haines, M.G.; Aliaga-Rossel, R.; Beg, N.F.

    2001-01-01

    Z-pinch experiments using cryogenic deuterium fibre loads have been carried out on the MAGPIE generator at currents up to 1.4MA. M=0 instabilities in the corona caused plasma expansion and disruption before the plasma could enter the collisionless Large ion Larmor radius regime. For the last 12 months we have studied Aluminium wire array implosions using laser probing, optical streaks and gated X-ray images. Plasma from the wires in accelerated to the axis as radial plasma streams with uncorrelated m=0 instabilities superimposed. Later in the discharge a global Rayleigh-Taylor (R-T) instability develops. Single and double aluminium and tungsten wire shots were conducted at 150kA. 2-D and 3-D simulations and a heuristic model of wire arrays will be presented along with theories on the combined MHD/R-T instability and sheared axial flow generation by large ion Larmor radius effects. (author)

  2. Cryogenic deuterium Z-pinch and wire array Z-pinch studies at imperial college

    International Nuclear Information System (INIS)

    Haines, M.G.; Aliaga-Rossel, R.; Beg, F.N.

    1999-01-01

    Z-pinch experiments using cryogenic deuterium fibre loads have been carried out on the MAGPIE generator at currents up to 1.4MA. M=0 instabilities in the corona caused plasma expansion and disruption before the plasma could enter the collisionless Large ion Larmor radius regime. For the last 12 months we have studied Aluminium wire array implosions using laser probing, optical streaks and gated X-ray images. Plasma from the wires in accelerated to the axis as radial plasma streams with uncorrelated m=0 instabilities superimposed. Later in the discharge a global Rayleigh-Taylor (R-T) instability develops. Single and double aluminium and tungsten wire shots were conducted at 150kA. 2-D and 3-D simulations and a heuristic model of wire arrays will be presented along with theories on the combined MHD/R-T instability and sheared axial flow generation by large ion Larmor radius effects. (author)

  3. Investigation of method for Stainless Steel Welding Wire as a Replacement for Arc Wire Comsumables

    Directory of Open Access Journals (Sweden)

    Koiprasert, H.

    2005-01-01

    Full Text Available Arc spraying as a coating method is being employed in various industrial applications as a part of maintenance service, and also as a surface engineering technique for many machine parts and components. The major cost in producing the arc spray coating is, however, based on the cost of the arc wire comsumables. This project was carried out to investigate the use of the commercially-available gas metal arc welding wire (GMAW wire as a cheaper alternative to the special-purpose arc wire comsumables. The wire material chosen for this early study is the 316L stainless steel, due to its popularity in many applications as a built-up coating for worn parts. The physical properties of the coatings produced from the two sets of 316L stainless steel wire were determined to be different in the percentage of porosity and the oxide content. The mechanical properties, including the tensile bond strength and the wear rate of the coatings produced from the two types of sprayed wire, were also different. This will, in turn, result in a slight difference in the performance of thecoatings.

  4. Transport properties of different BSCCO wires

    International Nuclear Information System (INIS)

    Metra, P.; Gherardi, L.; Vellego, G.; Masini, R.; Zannella, S.

    1990-01-01

    This paper reports on two classes of solver sheathed BSCCO wires and laminates were prepared from 2223 (Pb substituted) and 2212 powders, respectively, by the powder in tube method. By suitable heat treatments (sintering and annealing below the melting temperature for 2223, melting + annealing for 2212), we obtained sample wires with Tc of ∼110 and ∼85 K respectively, comparable Jc at 77 K (∼10 3 A/cm 2 ), and dramatically different transport behavior. Measurements of critical current at different temperatures and as a function of applied magnetic field were carried out, to characterize the two classes of samples, together with other electrical testing (e.g. d.c. susceptibility) and structural analyses. The granular nature of the higher Tc BSCCO, qualitatively similar to the one of YBCO, was well documented. The melt-processed material showed no apparent granularity, but very strong field dependence of Jc at high temperature. The effect of mechanical deformation on Jc was also investigated by bending samples on different diameters before and after heat treatment. Wires and tapes with 2212 were found to be bendable on very small diameters before treatment, but also the 2223 filled samples were shown to accept significant deformation before sintering

  5. Development of a 10 m quasi-isotropic strand assembled from 2G wires

    Science.gov (United States)

    Kan, Changtao; Wang, Yinshun; Hou, Yanbing; Li, Yan; Zhang, Han; Fu, Yu; Jiang, Zhe

    2018-03-01

    Quasi-isotropic strands made of second generation (2G) high temperature superconducting (HTS) wires are attractive to applications of high-field magnets at low temperatures and power transmission cables at liquid nitrogen temperature in virtue of their high current carrying capability and well mechanical property. In this contribution, a 10 m length quasi-isotropic strand is manufactured and successfully tested in liquid nitrogen to verify the feasibility of an industrial scale production of the strand by the existing cabling technologies. The strand with copper sheath consists of 72 symmetrically assembled 2G wires. The uniformity of critical properties of long quasi-isotropic strands, including critical current and n-value, is very important for their using. Critical currents as well as n-values of the strand are measured every 1 m respectively and compared with the simulation results. Critical current and n-value of the strand are calculated basing on the self-consistent model solved by the finite element method (FEM). Effects of self-field on the critical current and n-value distributions in wires of the strand are analyzed in detail. The simulation results show good agreement with the experimental data and the 10 m quasi-isotropic strand has good critical properties uniformity.

  6. Magnetoimpedance effect of the Ni80Fe20/Cu composite wires: The influence of DC current imposed on the Cu base

    Directory of Open Access Journals (Sweden)

    Delu Chen

    2014-06-01

    Full Text Available In this paper, the copper composite wires of 75 μm in diameter with a sputtered layer of Ni80Fe20 permalloy were prepared, with a DC current applied to the basal Cu terminals during the fabrication process. The influence of the DC current on the magnetic configuration and Magneto-Impedance (MI effect was studied. The results indicate that both the current amplitude and actuation duration have significant effect on the magnetic properties of the Ni80Fe20 layer. With appropriate current applied, the induced magnetic field leads to a circumferential magnetic domain structure and reduces significantly the equivalent anisotropy field of Ni80Fe20 layer. Then, the GMI ratio of the composite wires was significantly increased. A maximum GMI of 194.8% can be reached when the current was fixed at 100 mA and the Ni80Fe20 thickness is 780 nm. If the Ni80Fe20 thickness is above 780 nm, the coercivity of the coating layer increases while the GMI ratio of the composite wire reduces, since the magnetic anisotropy of the Ni80Fe20 layer varies from circumferential to longitudinal. The results were explained combining the thermal and magnetic effects of current.

  7. Vibrating wire for beam profile scanning

    Directory of Open Access Journals (Sweden)

    S. G. Arutunian

    1999-12-01

    Full Text Available A method that measures the transverse profile (emittance of the bunch by detecting radiation arising at the scattering of the bunch on scanning wire is widely used. In this work information about bunch scattering is obtained by measuring the oscillation frequency of the tightened scanning wire. In such a way, the system of radiation (or secondary particles extraction and measurement can be removed. The entire unit consists of a compact fork with tightened wire and a scanning system. Normal oscillation frequency of a wire depends on wire tension, its geometric parameters, and, in a second approximation, its elastic characteristics. Normal oscillations are generated by interaction of an alternating current through the wire with magnetic field of a permanent magnet. In this case, it is suggested that the magnetic field of the accelerator (field of dipole magnets or quadrupole magnets be used for excitation of oscillations. The dependence of oscillation frequency on beam scattering is determined by several factors, including changes of wire tension caused by transverse force of the beam and influence of beam self-field. Preliminary calculations show that the influence of wire heating will dominate. We have studied strain gauges on the basis of vibrating wire from various materials (tungsten, beryl bronze, and niobium zirconium alloys. A scheme of normal oscillation generation by alternating current in autogeneration circuit with automatic frequency adjustment was selected. A special method of wire fixation and elimination of transverse degrees of freedom allows us to achieve relative stability better than 10^{-5} during several days at a relative resolution of 10^{-6}. Experimental results and estimates of wire heating of existing scanners show that the wire heats up to a few hundred grades, which is enough for measurements. The usage of wire of micrometer thickness diminishes the problem of wire thermalization speed during the scanning of the bunch.

  8. The control of stainless steel tubes and wires of small diameter by the Eddy current method

    International Nuclear Information System (INIS)

    Stossel, A.; Gallet, G.

    1978-01-01

    Stainless steel tubes and wires with an outer diameter greater than 1 mm were studied by Eddy currents. The sensor characteristics and the detection of defects in function of frequency are presented together with the results obtained in the detection of dimensional and metallurgical defects [fr

  9. Necking down of sausages in current-carrying plasma pinches

    International Nuclear Information System (INIS)

    Trubnikov, B.A.; Zhdanov, S.K.

    1986-01-01

    The evolution of long-wave perturbations is shown to be equivalent, for various unstable media, to the dynamics of a gas with a negative adiabatic index γ. This evolution is described (for various values at N) by the quasi-Chaplygin system of equations Several examples of such media are considered, including a ''Chaplygin gas'' (N = 3), drops on a ceiling or ''solitons which have broken'' (N = 0), necks in a current-carrying plasma pinch with a skin effect, for both incompressible and compressible models (N = 2), and the breakup of liquid jets into drops (N = 3/2). A principle for selecting evolutionary solutions corresponding to the absence of perturbations in the limit t → -∞ is formulated. In the cases N = 0 and N = 2, a hodograph transformation reduces system (1) to a magnetostatic equation (ΔA)/sub phi/ = -(4π/c)j/sub phi/ and all the instability modes are equivalent to multipoles of circular currents which are localized on a circle. Exact solutions are given for periodic and isolated (localized) perturbations. The breakup of a medium into distinct blobs, in particular, the rupture of necks in a current-carrying plasma pinch, is demonstrated

  10. Current diffusion in a superconduting composite with a smeared I-V characteristic

    International Nuclear Information System (INIS)

    Keilin, V.E.; Romanovskii, V.R.

    1992-01-01

    Results are presented from numerical and analytical calculations of current injection into a superconducting composite of circular cross section with homogeneous properties throughout the cross section. A wire with an I-V characteristic approximated by an exponential dependence is examined. In the numerical solution, the joint occurrence of thermal and electromagnetic processes is taken into account. The calculations carried out for different current injection rates, parameters of the I-V characteristics, and heat transfer coefficients revealed: the existence of a characteristic limit current, below which the wire remains in a superconducting state after termination of current injection and above which the wire undergoes a transition to the normal state; this is somewhat below the cut-off current; the existence of a finite current at any small yet finite surface heat transfer coefficient. An analytical solution of the problem, based of the derived stability criterion, has made if possible to write an approximate relation between the limit currents and the initial parameters. Unlike previously reported results, this study takes into account the tolerable overheating of the wire, which depends on the depth of current flow, the specific heat of the wire, and its thermal and electrical conductivities

  11. Towards a non-wired simulator for reliability analysis

    International Nuclear Information System (INIS)

    Jurvillier, I.; Laviron, A.; Blin, A.

    1991-11-01

    This paper outlines the objectives and preliminary results of a research programme aiming to increase the advantages of electronic simulators used for reliability studies of complex systems. Research work has resulted in the design of a device based on an electronic simulator capable of carrying out all types of simulation without the drawback of wiring, as is currently the case. Its performance levels as regards speed are comparable to those of wired simulators and this is its main advantage over studies made on a computer. In addition, the simulator is connected to a computer which greatly increases system flexibility and user-friendliness. The first results obtained illustrate what characteristics can be expected of such a system, both as regards the anticipated computation time and the extended processing capabilities (such as the study of common cause failures). (author) [fr

  12. Towards a non-wired simulator for reliability analysis

    International Nuclear Information System (INIS)

    Blin, A.; Laviron, A.; Jurvillier, I.

    1991-08-01

    This paper outlines the objectives and preliminary results of a research programme aiming to increase the advantages of electronic simulators used for reliability studies of complex systems. Research work has resulted in the design of a device based on an electronic simulator capable of carrying out all types of simulation without the drawback of wiring, as is currently the case. Its performance levels as regards speed are comparable to those of wired simulators and this is its main advantage over studies made on a computer. In addition, the simulator is connected to a computer which greatly increases system flexibility and user-friendliness. The first results obtained illustrate what characteristics can be expected of such a system, both as regards the anticipated computation time and the extended processing capabilities (such as the study of common cause failures)

  13. Electrodeposition of nickel nano wire arrays

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Kok Kuan Ying; Ng Inn Khuan; Nurazila Mat Zali; Siti Salwa Zainal Abidin

    2010-01-01

    Synthesis, characterization and assembly of one-dimensional nickel nano wires prepared by template directed electrodeposition are discussed in this paper. Parallel arrays of high aspect ratio nickel nano wires were electrodeposited using electrolytes with different cations and pH. The nano wires were characterized using X-ray diffractometry and scanning electron microscopy. It was found that the orientations of the electro deposited Ni nano wires were governed by the deposition current and the electrolyte conditions. Free standing nickel nano wires can be obtained by dissolving the template. Due to the magnetic nature of the nano wires, magnetic alignment was employed to assemble and position the free standing nano wires in the device structure. (author)

  14. Development of wire wrapping technology for FBR fuel pin

    International Nuclear Information System (INIS)

    Nogami, Tetsuya; Seki, Nobuo; Sawayama, Takeo; Ishibashi, Takashi

    1991-01-01

    For the FBR fuel assembly, the spacer wire is adopted to maintain the space between fuel pins. The developments have been carried out to achieve automatically wire wrapping with high precision. Based on the fundamental technology developed through the mock-up test operation, Joyo 'MK-I', fuel pin fabrication was started using partially mechanized wire wrapping machine in 1973. In 1978, an automated wire wrapping machine for Joyo 'MK-II' was developed by the adoption of some improvements for the wire inserting system to end plug hole and the precision of wire pitch. On the bases of these experiences, fully automated wire wrapping machine for 'Monju' fuel pin was installed at Plutonium Fuel Production Facility (PFPF) in 1987. (author)

  15. Modern trends of aircraft fly-by-wire systems

    Directory of Open Access Journals (Sweden)

    С. С. Юцкевич

    2013-07-01

    Full Text Available Specifics of civil aviation modern transport aircraft fly-by-wire control systems are described. A comparison of the systems-level hardware and software, expressed through modes of guidance, provision of aircraft Airbus A-320, Boeing B-777, Tupolev Tu-214, Sukhoi Superjet SSJ-100 are carried out. The possibility of transition from mechanical control wiring to control through fly-by-wire system in the backup channel is shown.

  16. Improvements of fabrication processes and enhancement of critical current densities in (Ba,K)Fe2As2 HIP wires and tapes

    Science.gov (United States)

    Pyon, Sunseng; Suwa, Takahiro; Tamegai, Tsuyoshi; Takano, Katsutoshi; Kajitani, Hideki; Koizumi, Norikiyo; Awaji, Satoshi; Zhou, Nan; Shi, Zhixiang

    2018-05-01

    We fabricated (Ba,K)Fe2As2 superconducting wires and tapes using the powder-in-tube method and hot isostatic pressing (HIP). HIP wires and tapes showed a high value of transport critical current density (J c) exceeding 100 kAcm‑2 at T = 4.2 K and the self-field. Transport J c in the HIP wire reached 38 kAcm‑2 in a high magnetic field of 100 kOe. This value is almost twice larger than the previous highest value of J c among round wires using iron-based superconductors. Enhancement of J c in the wires and tapes was caused by improvement of the drawing process, which caused degradation of the core, formation of microcracks, weak links between grains, and random orientation of grains. Details of the effect of the improved fabrication processes on the J c are discussed.

  17. Towards plant wires.

    Science.gov (United States)

    Adamatzky, Andrew

    2014-08-01

    In experimental laboratory studies we evaluate a possibility of making electrical wires from living plants. In scoping experiments we use lettuce seedlings as a prototype model of a plant wire. We approximate an electrical potential transfer function by applying direct current voltage to the lettuce seedlings and recording output voltage. We analyse oscillation frequencies of the output potential and assess noise immunity of the plant wires. Our findings will be used in future designs of self-growing wetware circuits and devices, and integration of plant-based electronic components into future and emergent bio-hybrid systems. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  18. Unsupervised Classification of Surface Defects in Wire Rod Production Obtained by Eddy Current Sensors

    Directory of Open Access Journals (Sweden)

    Sergio Saludes-Rodil

    2015-04-01

    Full Text Available An unsupervised approach to classify surface defects in wire rod manufacturing is developed in this paper. The defects are extracted from an eddy current signal and classified using a clustering technique that uses the dynamic time warping distance as the dissimilarity measure. The new approach has been successfully tested using industrial data. It is shown that it outperforms other classification alternatives, such as the modified Fourier descriptors.

  19. ROOT Analysis of 2004 H8 Test Beam Data & Studies of MDT Sense Wire Displacements

    CERN Document Server

    2004-01-01

    Tests are being carried out at the CERN H8 Test Facility on the subdetectors of ATLAS. Using MUTRAK, a tool developed by Dan Levin, data from test muon beam runs are converted to PAW plots and ntuples for easy analysis. ROOT classes are currently being developed to convert the PAW output of MUTRAK to ROOT files for more detailed analysis. Also studies are currently underway to understand the effect of sense wire displacements in Monitored Drift Tubes on drift time spectra. Concurrent tests using simulations in GARFIELD and Cosmic Ray MDT experiments are underway to study wire sags which may be up to 480 micrometers due to gravitational and electrostatic forces .

  20. Development of a new type of three-component composite superconducting wire

    International Nuclear Information System (INIS)

    Onishi, T.

    1977-01-01

    A new type of multifilamentary composite superconducting wire is described. This wire consists of seven filaments, each of which is a fine tubular Nb 50% Ti wire, filled with high purity aluminium and embedded in a cupronickel matrix. The results of experiments carried out on the stability and ac losses of this wire are presented. (author)

  1. Temperature Diffusion Distribution of Electric Wire Deteriorated by Overcurrent

    Science.gov (United States)

    Choi, Chung-Seog; Kim, Hyang-Kon; Kim, Dong-Woo; Lee, Ki-Yeon

    This study presents thermal diffusion distribution of the electric wires when overcurrent is supplied to copper wires. And then, this study intends to provide a basis of knowledge for analyzing the causes of electric accidents through hybrid technology. In the thermal image distribution analysis of the electric wire to which fusing current was supplied, it was found that less heat was accumulated in the thin wires because of easier heat dispersion, while more heat was accumulated in the thicker wires. The 3-dimensional thermal image analysis showed that heat distribution was concentrated at the center of the wire and the inclination of heat distribution was steep in the thicker wires. When 81A was supplied to 1.6mm copper wire for 500 seconds, the surface temperature of wire was maximum 46.68°C and minimum 30.87°C. It revealed the initial characteristics of insulation deterioration that generates white smoke without external deformation. In the analysis with stereoscopic microscope, the surface turned dark brown and rough with the increase of fusing current. Also, it was known that exfoliation occurred when wire melted down with 2 times the fusing current. With the increase of current, we found the number of primary arms of the dendrite structure to be increased and those of the secondary and tertiary arms to be decreased. Also, when the overcurrent reached twice the fusing current, it was found that columnar composition, observed in the cross sectional structure of molten wire, appeared and formed regular directivity. As described above, we could present the burning pattern and change in characteristics of insulation and conductor quantitatively. And we could not only minimize the analysis error by combining the information but also present the scientific basis in the analysis of causes of electric accidents, mediation of disputes on product liability concerning the electric products.

  2. Optimization of electron beam crosslinking of wire and cable insulation

    International Nuclear Information System (INIS)

    Zimek, Z.; Przybytniak, G.; Nowicki, A.

    2011-01-01

    Complete text of publication follows. The computer simulations based on Monte Carlo method and the ModeCEB software program were carried out in connection with EB radiation set-up for crosslinking of electrical wire and cable insulation, located at the Center for Radiation Research and Technology of the Institute of Nuclear Chemistry and Technology. The theoretical predictions for absorbed dose distribution in irradiated electrical wire and cable insulation caused by scanned EB were compared to the experimental results of irradiation which were carried out in the experimental set-up based on ILU 6 electron accelerator, which is characterized by the following parameters: Electron energy 0.5-2.0 MeV; Average beam current 40-10 mA, pulse duration 400 μs; Width of scanning up to 80 cm; Scan frequency up to 50 Hz. The computer simulation of the dose distributions in two-sided irradiation system by a scanned electron beam in multilayer circular objects was performed for different process parameters; electrical wire and cable geometry (thickness of insulation layers and cupper wire diameter), type of polymer isolation, electron energy, energy spread, geometry of electron beam and electrical wire and cable distribution at irradiation zone. The geometry of electron beam distribution in irradiation zone was measured using TVA and PVC foil dosimeters for electron energy range available in ILU 6 accelerator. The temperature rise of irradiated electrical wire and irradiation homogeneity were evaluated for different experimental conditions to optimize process parameters. The obtained results of computer simulation were supported by experimental data of dose distribution based on gel-fraction measurements. Such agreement indicates that computer simulation ModeCEB is correct and sufficient for modelling of absorbed dose distribution in multi-layer circular objects irradiated with scanned electron beams. Acknowledgement: The R and D activities are supported by the European

  3. Basic study of HTS magnet using 2G wires for maglev train

    International Nuclear Information System (INIS)

    Ogata, M.; Miyazaki, Y.; Hasegawa, H.; Sasakawa, T.; Nagashima, K.

    2010-01-01

    There are several advantages by applying a high-temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the I c measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of I c characteristics for the small race track-shaped superconducting coil.

  4. Preliminary study of HTS magnet using 2G wires for maglev train

    International Nuclear Information System (INIS)

    Ogata, Masafumi; Miyazaki, Yoshiki; Hasegawa, Hitoshi; Sasakawa, Takashi; Nagashima, Ken

    2010-01-01

    There are several advantages by applying a high temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the I c measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of I c characteristics for the small race track-shaped superconducting coil.

  5. Basic study of HTS magnet using 2G wires for maglev train

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, M., E-mail: ogata@rtri.or.j [Railway Technical Research Institute, 2-8-38, Hikari-cho, Kokubunji-shi, Tokyo 185-8540 (Japan); Miyazaki, Y.; Hasegawa, H.; Sasakawa, T.; Nagashima, K. [Railway Technical Research Institute, 2-8-38, Hikari-cho, Kokubunji-shi, Tokyo 185-8540 (Japan)

    2010-11-01

    There are several advantages by applying a high-temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the I{sub c} measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of I{sub c} characteristics for the small race track-shaped superconducting coil.

  6. Preliminary study of HTS magnet using 2G wires for maglev train

    Energy Technology Data Exchange (ETDEWEB)

    Ogata, Masafumi; Miyazaki, Yoshiki; Hasegawa, Hitoshi; Sasakawa, Takashi; Nagashima, Ken, E-mail: ogata@rtri.or.j [Railway Technical Research Institute, Hikari-cho 2-8-38, Kokubunji-shi, Tokyo (Japan)

    2010-06-01

    There are several advantages by applying a high temperature superconducting wire to an on-board superconducting magnet for the maglev train. At first, an increase of thermal capacity of superconducting coils contributes a stability of the superconducting state of the coils. In addition, a reliability of superconducting magnet improves by simplification of the magnet structure. And the weight of the superconducting magnet and the energy consumption of the on-board cryocooler will decrease. Therefore, we examined the possibility on application of the 2G wire with a high critical current density in a high magnetic field. We performed numerical analysis regarding the weight of a superconducting magnet and the energy consumption of an on-board cryocooler in consideration of the characteristics of the 2G wire. Furthermore, we have carried out the I{sub c} measurement for the commercial 2G wires under various experimental conditions such as temperature, magnetic field strength and angle. We also performed the trial manufacture and evaluation of I{sub c} characteristics for the small race track-shaped superconducting coil.

  7. Effect of discrete wires on the implosion dynamics of wire array Z pinches

    International Nuclear Information System (INIS)

    Lebedev, S. V.; Beg, F. N.; Bland, S. N.; Chittenden, J. P.; Dangor, A. E.; Haines, M. G.; Kwek, K. H.; Pikuz, S. A.; Shelkovenko, T. A.

    2001-01-01

    A phenomenological model of wire array Z-pinch implosions, based on the analysis of experimental data obtained on the mega-ampere generator for plasma implosion experiments (MAGPIE) generator [I. H. Mitchell , Rev. Sci. Instrum. 67, 1533 (1996)], is described. The data show that during the first ∼80% of the implosion the wire cores remain stationary in their initial positions, while the coronal plasma is continuously jetting from the wire cores to the array axis. This phase ends by the formation of gaps in the wire cores, which occurs due to the nonuniformity of the ablation rate along the wires. The final phase of the implosion starting at this time occurs as a rapid snowplow-like implosion of the radially distributed precursor plasma, previously injected in the interior of the array. The density distribution of the precursor plasma, being peaked on the array axis, could be a key factor providing stability of the wire array implosions operating in the regime of discrete wires. The modified ''initial'' conditions for simulations of wire array Z-pinch implosions with one-dimension (1D) and two-dimensions (2D) in the r--z plane, radiation-magnetohydrodynamic (MHD) codes, and a possible scaling to a larger drive current are discussed

  8. Wire Array Photovoltaics

    Science.gov (United States)

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  9. Effects of MgO impurities and micro-cracks on the critical current density of Ti-sheathed MgB2 wires

    International Nuclear Information System (INIS)

    Liang, G.; Alessandrini, M.; Yen, F.; Hanna, M.; Fang, H.; Hoyt, C.; Lv, B.; Zeng, J.; Salama, K.

    2007-01-01

    Ti-sheathed monocore MgB 2 wires with improved magnetic critical current density (J c ) have been fabricated by in situ powder-in-tube (PIT) method and characterized by magnetization, X-ray diffraction, scanning electron microscopy and electrical resistivity measurements. For the best wire, the magnetic J c values at 5 K and fields of 2 T, 5 T, and 8 T are 4.1 x 10 5 A/cm 2 , 7.8 x 10 4 A/cm 2 , and 1.4 x 10 4 A/cm 2 , respectively. At 20 K and fields of 0.5 T and 3 T, the J c values are about 3.6 x 10 5 A/cm 2 and 3.1 x 10 4 A/cm 2 , respectively, which are much higher than those of the Fe-sheathed mono-core MgB 2 wires fabricated with the same in situ PIT process and under the same fabricating conditions. It appears that the overall J c for the average Ti-sheathed wires is comparable to that of the Fe-sheathed wires. Our X-ray diffraction and scanning electron microscopy analysis indicates that J c in the Ti-sheathed MgB 2 wires can be strongly suppressed by MgO impurities and micro-cracks

  10. Impedance Characterisation of the SPS Wire Scanner

    CERN Document Server

    AUTHOR|(CDS)2091911; Prof. Sillanpää, Mika

    As a beam diagnostic tool, the SPS wire scanner interacts with the proton bunches traversing the vacuum pipes of the Super Proton Synchrotron particle accelerator. Following the interaction, the bunches decelerate or experience momentum kicks off-axis and couple energy to the cavity walls, resonances and to the diagnostic tool, the scanning wire. The beam coupling impedance and, in particular, the beam induced heating of the wire motivate the characterisation and redesign of the SPS wire scanner. In this thesis, we characterise RF-wise the low frequency modes of the SPS wire scanner. These have the highest contribution to the impedance. We measure the cavity modes in terms of resonance frequency and quality factor by traditional measurement techniques and data analysis. We carry out a 4-port measurement to evaluate the beam coupling to the scanning wire, that yields the spectral heating power. If combined with the simulations, one is able to extract the beam coupling impedance and deduce the spectral dissipa...

  11. Inductor Design Comparison of Three-wire and Four-wire Three-phase Voltage Source Converters in Power Factor Correction Applications

    DEFF Research Database (Denmark)

    Kouchaki, Alireza; Nymand, Morten

    2015-01-01

    This paper studies the inductor design for three-wire and four-wire power factor correction converter (PFC). Designing the efficient inductor for this converter (regardless of connecting the midpoint to the ground) requires a comprehensive knowledge of the inductor current and voltage behavior....... This paper investigates how changing three-wire PFC to four-wire counterpart influences the inductor design in terms of size, losses, and overall efficiency of the converter. Therefore, the inductor current and voltage waveforms are analyzed and generalized in both cases for one switching cycle to build...... a foundation for comparison. Accordingly, the analyses are able to interpret the differences between both configurations and explain the core losses and the copper losses of inductors, especially those caused by the high frequency ac current ripple. Finally, two inductors are designed for a 5 kW PFC...

  12. A statistical rationale for establishing process quality control limits using fixed sample size, for critical current verification of SSC superconducting wire

    International Nuclear Information System (INIS)

    Pollock, D.A.; Brown, G.; Capone, D.W. II; Christopherson, D.; Seuntjens, J.M.; Woltz, J.

    1992-03-01

    The purpose of this paper is to demonstrate a statistical method for verifying superconducting wire process stability as represented by I c . The paper does not propose changing the I c testing frequency for wire during Phase 1 of the present Vendor Qualification Program. The actual statistical limits demonstrated for one supplier's data are not expected to be suitable for all suppliers. However, the method used to develop the limits and the potential for improved process through their use, may be applied equally. Implementing the demonstrated method implies that the current practice of testing all pieces of wire from each billet, for the purpose of detecting manufacturing process errors (i.e. missing a heat-treatment cycle for a part of the billet, etc.) can be replaced by other less costly process control measures. As used in this paper process control limits for critical current are quantitative indicators of the source manufacturing process uniformity. The limits serve as alarms indicating the need for manufacturing process investigation

  13. Josephson junctions of multiple superconducting wires

    Science.gov (United States)

    Deb, Oindrila; Sengupta, K.; Sen, Diptiman

    2018-05-01

    We study the spectrum of Andreev bound states and Josephson currents across a junction of N superconducting wires which may have s - or p -wave pairing symmetries and develop a scattering matrix based formalism which allows us to address transport across such junctions. For N ≥3 , it is well known that Berry curvature terms contribute to the Josephson currents; we chart out situations where such terms can have relatively large effects. For a system of three s -wave or three p -wave superconductors, we provide analytic expressions for the Andreev bound-state energies and study the Josephson currents in response to a constant voltage applied across one of the wires; we find that the integrated transconductance at zero temperature is quantized to integer multiples of 4 e2/h , where e is the electron charge and h =2 π ℏ is Planck's constant. For a sinusoidal current with frequency ω applied across one of the wires in the junction, we find that Shapiro plateaus appear in the time-averaged voltage across that wire for any rational fractional multiple (in contrast to only integer multiples in junctions of two wires) of 2 e /(ℏ ω ) . We also use our formalism to study junctions of two p -wave and one s -wave wires. We find that the corresponding Andreev bound-state energies depend on the spin of the Bogoliubov quasiparticles; this produces a net magnetic moment in such junctions. The time variation of these magnetic moments may be controlled by an external voltage applied across the junction. We discuss experiments which may test our theory.

  14. Eddy current quality control of soldered current-carrying busbar splices of superconducting magnets

    CERN Document Server

    Kogan, L; Savary, F; Principe, R; Datskov, V; Rozenfel'd, E; Khudjakov, B

    2015-01-01

    The eddy current technique associated with a U-shaped transducer is studied for the quality control of soldered joints between superconducting busbars ('splices'). Two other quality control techniques, based on X-rays and direct measurement of the electrical resistance, are also studied for comparison. A comparative analysis of the advantages and disadvantages of these three methods in relation to the quality control of soldered superconducting busbar cables enclosed in copper shells is used for benchmarking. The results of inspections with the U-shaped eddy current transducer carried out on several sample joints presenting different types of soldering defects show the potential of this type of nondestructive (ND) quality control technique.

  15. Influence of particle size of Mg powder on the microstructure and critical currents of in situ powder-in-tube processed MgB_2 wires

    International Nuclear Information System (INIS)

    Kumakura, Hiroaki; Ye, Shujun; Matsumoto, Akiyoshi; Nitta, Ryuji

    2016-01-01

    We fabricated in situ powder-in-tube(PIT) MgB_2 wires using three kinds of Mg powders with particle size of ∼45 μm, ∼150 μm and 212∼600 μm. Mg particles were elongated to filamentary structure in the wires during cold drawing process. Especially, long Mg filamentary structure was obtained for large Mg particle size of 212∼600 μm. Critical current density, J_c, increased with increasing Mg particle size for 1 mm diameter wires. This is due to the development of filamentary structure of high density MgB_2 superconducting layer along the wires. This MgB_2 structure is similar to that of the internal Mg diffusion (IMD) processed MgB_2 wires. However, J_c of the wires fabricated with 212∼600 μm Mg particle size decreased and the scattering of J_c increased with decreasing wire diameter, while the J_c of the wires with ∼45 μm Mg particle was almost independent of the wire diameter. The cross sectional area reduction of the Mg particles during the wire drawing is smaller than that of the wire. When using large size Mg particle, the number of Mg filaments in the wire cross section is small. These two facts statistically lead to the larger scattering of Mg areal fraction in the wire cross section with proceeding of wire drawing process, resulting in smaller volume fraction of MgB_2 in the wire and lower J_c with larger scattering along the wire. SiC nano powder addition is effective in increasing J_c for all Mg particle sizes. (author)

  16. Fast wire scanner for intense electron beams

    Directory of Open Access Journals (Sweden)

    T. Moore

    2014-02-01

    Full Text Available We have developed a cost-effective, fast rotating wire scanner for use in accelerators where high beam currents would otherwise melt even carbon wires. This new design uses a simple planetary gear setup to rotate a carbon wire, fixed at one end, through the beam at speeds in excess of 20  m/s. We present results from bench tests, as well as transverse beam profile measurements taken at Cornell’s high-brightness energy recovery linac photoinjector, for beam currents up to 35 mA.

  17. Communication and Wiring in the Cortical Connectome

    Directory of Open Access Journals (Sweden)

    Julian eBudd

    2012-10-01

    Full Text Available In cerebral cortex, the huge mass of axonal wiring that carries information between near and distant neurons is thought to provide the neural substrate for cognitive and perceptual function. The goal of mapping the connectivity of cortical axons at different spatial scales, the cortical connectome, is to trace the paths of information flow in cerebral cortex. To appreciate the relationship between the connectome and cortical function, we need to discover the nature and purpose of the wiring principles underlying cortical connectivity. A popular explanation has been that axonal length is strictly minimized both within and between cortical regions. In contrast, we have hypothesized the existence of a multi-scale principle of cortical wiring where to optimise communication there is a trade-off between spatial (construction and temporal (routing costs. Here, using recent evidence concerning cortical spatial networks we critically evaluate this hypothesis at neuron, local circuit, and pathway scales. We report three main conclusions. First, the axonal and dendritic arbor morphology of single neocortical neurons may be governed by a similar wiring principle, one that balances the conservation of cellular material and conduction delay. Second, the same principle may be observed for fibre tracts connecting cortical regions. Third, the absence of sufficient local circuit data currently prohibits any meaningful assessment of the hypothesis at this scale of cortical organization. To avoid neglecting neuron and microcircuit levels of cortical organization, the connectome framework should incorporate more morphological description. In addition, structural analyses of temporal cost for cortical circuits should take account of both axonal conduction and neuronal integration delays, which appear mostly of the same order of magnitude. We conclude the hypothesized trade-off between spatial and temporal costs may potentially offer a powerful explanation for

  18. Analysis of critical current-bend strain relationships in composite Nb3Sn superconducting wires

    International Nuclear Information System (INIS)

    Luhman, T.; Welch, D.O.

    1979-01-01

    In order to be used successfully in fusion magnets, Nb 3 Sn conductors must meet several mechanical strain criteria, including tolerance to bending strains encountered during magnet construction. Since Nb 3 Sn is extremely brittle much information has been generated regarding the sensitivity of these conductros to tensile strain. A recent comparison of critical current-bend and tensile test data indicates that the strain required to initiate compound cracking during bending is significantly less than the strain required to do so by tensile of critical current on bending strains in monofilamentary Nb 3 Sn wires is calculated and compared with experimental data. The calculation takes into account a shift in the composite's neutral axis which occurs during bending. The analysis correctly predicts the observed depdndence of the critical current on bending strains

  19. Seeded perturbations in wire array Z-Pinches

    International Nuclear Information System (INIS)

    Robinson, Allen Conrad; Fedin, Dmitry; Kantsyrev, Victor Leonidovich; Wunsch, Scott Edward; Oliver, Bryan Velten; Lebedev, Sergey V.; Coverdale, Christine Anne; Ouart, Nicholas D.; LePell, Paul David; Safronova, Alla S.; Shrestha, I.; McKenney, John Lee; Ampleford, David J.; Rapley, J.; Bott, S.C.; Palmer, J.B.A.; Sotnikov, Vladimir Isaakovich; Bland, Simon Nicholas; Ivanov, Vladimir V.; Chittenden, Jeremy Paul; Jones, B.; Garasi, Christopher Joseph; Hall, Gareth Neville; Yilmaz, M. Faith; Mehlhorn, Thomas Alan; Deeney, Christopher; Pokala, S.; Nalajala, V.

    2005-01-01

    Controlled seeding of perturbations is employed to study the evolution of wire array z-pinch implosion instabilities which strongly impact x-ray production when the 3D plasma stagnates on axis. Wires modulated in radius exhibit locally enhanced magnetic field and imploding bubble formation at discontinuities in wire radius due to the perturbed current path. Wires coated with localized spectroscopic dopants are used to track turbulent material flow. Experiments and MHD modeling offer insight into the behavior of z-pinch instabilities.

  20. Processing of flexible high-Tc superconducting wires

    International Nuclear Information System (INIS)

    Lee, B.I.; Modi, V.

    1989-01-01

    Wires superconducting at temperatures above 77 K are produced by using YBa 2 Cu 3 O 7 materials. Flexibility was obtained by support from prefabricated fibers or a metallic coating on the extruded YBa 2 Cu 3 O 7 wires. The microstructure, the T c and the critical current densities of the wires were determined. Processing variables and steps are described

  1. Method and apparatus to trigger superconductors in current limiting devices

    Science.gov (United States)

    Yuan, Xing; Hazelton, Drew Willard; Walker, Michael Stephen

    2004-10-26

    A method and apparatus for magnetically triggering a superconductor in a superconducting fault current limiter to transition from a superconducting state to a resistive state. The triggering is achieved by employing current-carrying trigger coil or foil on either or both the inner diameter and outer diameter of a superconductor. The current-carrying coil or foil generates a magnetic field with sufficient strength and the superconductor is disposed within essentially uniform magnetic field region. For superconductor in a tubular-configured form, an additional magnetic field can be generated by placing current-carrying wire or foil inside the tube and along the center axial line.

  2. MATHEMATICAL FORMULATION OF PLASTIC CHARACTERISTICS OF WIRE OF STEEL 70 AT HIGH-SPEED WIRE DRAWING

    Directory of Open Access Journals (Sweden)

    Yu. L. Bobarikin

    2011-01-01

    Full Text Available The carried out numerical experiments subject to initial and boundary conditions indicate that mathematical model of elastic-plastic characteristics of steel 90 can be used for numerical calculations of wire drawing routes for this grade of steel.

  3. ABCXYZ: vector potential (A) and magnetic field (B) code (C) for Cartesian (XYZ) geometry using general current elements

    International Nuclear Information System (INIS)

    Anderson, D.V.; Breazeal, J.; Finan, C.H.; Johnston, B.M.

    1976-01-01

    ABCXYZ is a computer code for obtaining the Cartesian components of the vector potential and the magnetic field on an observed grid from an arrangement of current-carrying wires. Arbitrary combinations of straight line segments, arcs, and loops are allowed in the specification of the currents. Arbitrary positions and orientations of the current-carrying elements are also allowed. Specification of the wire diameter permits the computation of well-defined fields, even in the interiors of the conductors. An optical feature generates magnetic field lines. Extensive graphical and printed output is available to the user including contour, grid-line, and field-line plots. 12 figures, 1 table

  4. Wear behavior of Cu-Ag-Cr alloy wire under electrical sliding

    International Nuclear Information System (INIS)

    Jia, S.G.; Liu, P.; Ren, F.Z.; Tian, B.H.; Zheng, M.S.; Zhou, G.S.

    2005-01-01

    The wear behavior of a Cu-Ag-Cr alloy contact wire against a copper-base sintered alloy strip was investigated. Wear tests were conducted under laboratory conditions with a special sliding wear apparatus that simulated train motion under electrical current conditions. The initial microstructure of the Cu-Ag-Cr alloy contact wire was analyzed by transmission electron microscopy. Worn surfaces of the Cu-Ag-Cr alloy wire were analyzed by scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDS). The results indicate that the wear rate of the Cu-Ag-Cr wire increased with increasing electrical current and sliding. Within the studied range of electrical current, the wear rate increases with increasing electrical current and sliding speed. Compared with the Cu-Ag contact wire under the same testing conditions, the Cu-Ag-Cr alloy wire has much better wear resistance. Adhesive, abrasive, and electrical erosion wear are the dominant mechanisms during the electrical sliding processes

  5. Wire Scanner Motion Control Card

    CERN Document Server

    Forde, S E

    2006-01-01

    Scientists require a certain beam quality produced by the accelerator rings at CERN. The discovery potential of LHC is given by the reachable luminosity at its interaction points. The luminosity is maximized by minimizing the beam size. Therefore an accurate beam size measurement is required for optimizing the luminosity. The wire scanner performs very accurate profile measurements, but as it can not be used at full intensity in the LHC ring, it is used for calibrating other profile monitors. As the current wire scanner system, which is used in the present CERN accelerators, has not been made for the required specification of the LHC, a new design of a wire scanner motion control card is part of the LHC wire scanner project. The main functions of this card are to control the wire scanner motion and to acquire the position of the wire. In case of further upgrades at a later stage, it is required to allow an easy update of the firmware, hence the programmable features of FPGAs will be used for this purpose. The...

  6. Stabilization of magnetohydrodynamic instabilities in a current-carrying stellarator

    International Nuclear Information System (INIS)

    Matsuoka, K.; Miyamoto, K.

    1979-02-01

    Stable profiles against MHD instabilities are given in a cylindrical current-carrying stellarator. The comparison theorem, i.e., guiding principle for stabilization, is obtained in the same way as in a tokamak. As the external rotational transform due to an l = 2 helical field increases, MHD properties in a stellarator are improved than in a tokamak and the minimum value of q(a) which provides simultaneous stabilization of MHD modes can be lowered less than 2 even without a conducting shell. In an l = 3 stellarator, however, as shown from the Euler equation, the configuration becomes more unstable than in a tokamak and strong tailoring of the current profile is necessary in order to stabilize MHD modes. (author)

  7. The wire array Z-pinch: an efficient x-ray source for ICF and a new ion heating mechanism

    Science.gov (United States)

    Haines, M. G.

    2008-10-01

    The Z-pinch provides an efficient x-ray source for driving a hohlraum for inertial confinement fusion. The basic physics of wire-array implosions is reviewed. It can be understood in several sequential stages. Firstly, the wires heat and form a surrounding vapour which ionizes, causing the current to transfer to this lower resistance. The J×B global force leads to ejection of this plasma towards the axis to form a precursor plasma. The wire cores continue to ablate due to the heat flux from the Joule-heated nearby plasma. The cooling of this plasma by the wire-cores leads to a low magnetic Reynolds number so that the precursor plasma carries little or no current. When gaps appear in the liquid/vapour cores the plasma temperature and Reynolds number rise and this plasma accelerates in towards the axis carrying the current. This is the main implosion, and it sweeps up earlier ablated plasma, which acts to reduce Rayleigh-Taylor growth. At stagnation, the ion kinetic energy is thermalized and equipartition heats the electrons, which then radiate in a 5 ns pulse. In some conditions the energy radiated by soft x-rays exceeds the ion kinetic energy by a factor of 3 or 4. A theory has been developed to explain this in which fine-scale, fast growing m= 0 MHD instabilities grow to saturation, viscous dissipation of which leads to ion heating, followed by equipartition. World record ion temperatures of 2-3 billion Kelvin were predicted, and measured at Sandia National Laboratory. Lastly, progress in capsule implosions and in application to inertial fusion energy is reported.

  8. Experiments with a Gas-Puff-On-Wire-Array Load on the GIT-12 Generator for Al K-shell Radiation Production at Microsecond Implosion Times

    International Nuclear Information System (INIS)

    Shishlov, Alexander V.; Baksht, Rina B.; Chaikovsky, Stanislav A.; Fedunin, Anatoly V.; Fursov, Fedor I.; Kovalchuk, Boris M.; Kokshenev, Vladimir A.; Kurmaev, Nikolai E.; Labetsky, Aleksey Yu.; Oreshkin, Vladimir I.; Rousskikh, Alexander G.; Lassalle, Francis; Bayol, Frederic

    2006-01-01

    Results of the experiments carried out on the GIT-12 generator at the current level of 3.5 MA and the Z-pinch implosion times from 700 ns to 1.1 μs are presented. A multi-shell (triple-shell) load configuration with the outer gas puffs (neon) and the inner wire array (aluminum) was used in the experiments. In the course of the research, implosion dynamics of the triple-shell z-pinch was studied, and the radiation yield in the spectral range of neon and aluminum K-lines have been measured. Optimization of the inner wire array parameters aimed at obtaining the maximum aluminum K-shell radiation yield has been carried out. As a result of optimization of the gas-puff-on-wire-array Z-pinch load, the aluminum K-shell radiation yield (hv> 1.55 keV) up to 4 kJ/cm in the radiation pulse with FWHM less than 30 ns has been obtained. Comparison of the experimental results with the results of preliminary 1D RMHD simulations allows a conclusion that at least 2/3 of the generator current is switched from a gas puff to an aluminum wire array. The radiation yield in the spectral range of neon K-lines (0.92-1.55 keV) increases considerably in the shots with the inner wire array in comparison with the shots carried out with the outer gas puffs only. The radiation yield in the spectral range above 1 keV registered in the experiments reached 10 kJ/cm. The presence of a high portion of the neon plasma inside an inner wire array can limit the radiation yield in the spectral range above 1.55 keV

  9. Design of Two Feeder Three Phase Four Wire Distribution System Utilizing Multi Converter UPQC with Fuzzy Logic Controller

    Directory of Open Access Journals (Sweden)

    Chandra Babu Paduchuri

    2014-01-01

    Full Text Available This paper proposes the instantaneous p-q theory based fuzzy logic controller (FLC for multi converter unified power quality conditioner (MC-UPQC to mitigate power quality issues in two feeders three-phase four-wire distribution systems. The proposed system is extended system of the existing one feeder three-phase four-wire distribution system, which is operated with UPQC. This system is employed with three voltage source converters, which are connected commonly to two feeder distribution systems. The performance of this proposed system used to compensate voltage sag, neutral current mitigation and compensation of voltage and current harmonics under linear and nonlinear load conditions. The neutral current flowing in series transformers is zero in the implementation of the proposed system. The simulation performance analysis is carried out using MATLAB.

  10. Effect of impurities on the steady component of the current in a quantum wire under the joint action of ac and dc fields

    International Nuclear Information System (INIS)

    Zav'yalov, D. V.; Kryuchkov, S. V.

    2008-01-01

    The current flowing along a cylindrical quantum wire with a superlattice in the case of the simultaneous application of dc and ac fields is calculated. It is assumed that the wire contains impurity centers, whose ionization results in the generation of nonequilibrium carriers in the conduction band. It is found that the dependence of the steady component of the current on the ac-field frequency is a step-like function. It is shown that the distance between steps depends on the conduction miniband width and the transverse quantum confinement parameters and is independent of the impurity-level depth.

  11. Anisotropy of ultraviolet radiation of high current discharge in a plasma of exploding wire

    International Nuclear Information System (INIS)

    Bogolyubskij, S.L.

    1987-01-01

    The experiments on exploding thin wires in a diode of a high current generator of relativistic electron beams ''Triton'' have demonstrated that the presence of a hot plasma corona and a colder and denser core is typical for appearing radiation coolled Z-pinch. It is found that for 5-10 ns ultraviolet radiation emmitted by plasma channel has a pronounced axial directivity conditioned by quanta with the energy in the 60-120 eV range. Control experiments have shown that this effect is not connected with various near-electrode phenomena

  12. Energy transformation in Z-pinch and plasma focus discharges with wire and wire-in-liner loads

    International Nuclear Information System (INIS)

    Kubes, Pavel; Kravarik, Jozef; Klir, Daniel; Scholz, Marek; Paduch, Marian; Tomaszewski, Krzysztof; Karpinski, Leslaw; Bakshaev, Yury L.; Blinov, Peter I.; Chernenko, Andrey S.; Dan'ko, Sergey A.; Korolev, Valery D.; Shashkov, Andrey Y.; Tumanov, Victor I.

    2002-01-01

    The results of the study of the Z-pinch and plasma-focus plasmas at presence of the axial C, Al, or Cu wires of sufficient high diameter are discussed in this paper. The wire was positioned on the top of the inner electrode of the PF 1000 plasma focus (1.8 MA, IPPLM Warsaw), or at the axis with or without the tungsten or alumine wire array load at the S-300 facility (3 MA, RRC Kurchatov Institute, Moscow), and at the axis of the small Z-pinch Z-150 (50 kA, CTU Prague). The plasma corona around the wire was generated both by the current going through the wires and by the implosion of the wire array or of the current sheath. The experiments showed interesting results often observed in some shots of Z-pinch type discharges - existence of helical structures, two relatively long and stable pinch phases, oscillation of pinch diameter, and back return of the plasma exploding from the pinch. All these observed phenomena can be evolved by spontaneous self-generation and transformation of the axial magnetic field in the pinch during the plasma implosion and explosion. A configuration of axial and azimuthal magnetic field confines the plasma and later transforms or dissipates during a few tens or hundreds ns. A fast transformation of internal magnetic fields can induce a sufficiently high electric field for generation of keV particles and radiation. Study and usage of Z-pinch discharges is connected with solving of two principal problems, limitation of instability development and a way of generation of high energy particles and radiation. The first problem is partially solved by the faster increase of the current, by better cylindrical symmetry of the load and plasma, by higher density of the plasma or by the presence of a stronger magnetized plasma

  13. Transient Analysis of Lumped Circuit Networks Loaded Thin Wires By DGTD Method

    KAUST Repository

    Li, Ping

    2016-03-31

    With the purpose of avoiding very fine mesh cells in the proximity of a thin wire, the modified telegrapher’s equations (MTEs) are employed to describe the thin wire voltage and current distributions, which consequently results in reduced number of unknowns and augmented Courant-Friedrichs-Lewy (CFL) number. As hyperbolic systems, both the MTEs and the Maxwell’s equations are solved by the discontinuous Galerkin time-domain (DGTD) method. In realistic situations, the thin wires could be either driven or loaded by circuit networks. The thin wire-circuit interface performs as a boundary condition for the thin wire solver, where the thin wire voltage and current used for the incoming flux evaluation involved in the DGTD analyzed MTEs are not available. To obtain this voltage and current, an auxiliary current flowing through the thin wire-circuit interface is introduced at each interface. Corresponding auxiliary equations derived from the invariable property of characteristic variable for hyperbolic systems are developed and solved together with the circuit equations established by the modified nodal analysis (MNA) modality. Furthermore, in order to characterize the field and thin wire interactions, a weighted electric field and a volume current density are added into the MTEs and Maxwell-Ampere’s law equation, respectively. To validate the proposed algorithm, three representative examples are presented.

  14. Transient Analysis of Lumped Circuit Networks Loaded Thin Wires By DGTD Method

    KAUST Repository

    Li, Ping; Shi, Yifei; Jiang, Li Jun; Bagci, Hakan

    2016-01-01

    With the purpose of avoiding very fine mesh cells in the proximity of a thin wire, the modified telegrapher’s equations (MTEs) are employed to describe the thin wire voltage and current distributions, which consequently results in reduced number of unknowns and augmented Courant-Friedrichs-Lewy (CFL) number. As hyperbolic systems, both the MTEs and the Maxwell’s equations are solved by the discontinuous Galerkin time-domain (DGTD) method. In realistic situations, the thin wires could be either driven or loaded by circuit networks. The thin wire-circuit interface performs as a boundary condition for the thin wire solver, where the thin wire voltage and current used for the incoming flux evaluation involved in the DGTD analyzed MTEs are not available. To obtain this voltage and current, an auxiliary current flowing through the thin wire-circuit interface is introduced at each interface. Corresponding auxiliary equations derived from the invariable property of characteristic variable for hyperbolic systems are developed and solved together with the circuit equations established by the modified nodal analysis (MNA) modality. Furthermore, in order to characterize the field and thin wire interactions, a weighted electric field and a volume current density are added into the MTEs and Maxwell-Ampere’s law equation, respectively. To validate the proposed algorithm, three representative examples are presented.

  15. The effect of Birkeland currents on magnetic field topology

    Science.gov (United States)

    Peroomian, Vahe; Lyons, Larry R.; Schulz, Michael

    1996-01-01

    A technique was developed for the inclusion of large scale magnetospheric current systems in magnetic field models. The region 1 and 2 Birkeland current systems are included in the source surface model of the terrestrial magnetosphere. The region 1 and 2 Birkeland currents are placed in the model using a series of field aligned, infinitely thin wire segments. The normal component of the magnetic field from these currents is calculated on the surface of the magnetopause and shielded using image current carrying wires placed outside of the magnetosphere. It is found that the inclusion of the Birkeland currents in the model results in a northward magnetic field in the near-midnight tail, leading to the closure of previously open flux in the tail, and a southward magnetic field in the flanks. A sunward shift in the separatrix is observed.

  16. submitter Dynamical Models of a Wire Scanner

    CERN Document Server

    Barjau, Ana; Dehning, Bernd

    2016-01-01

    The accuracy of the beam profile measurements achievable by the current wire scanners at CERN is limited by the vibrations of their mechanical parts. In particular, the vibrations of the carbon wire represent the major source of wire position uncertainty which limits the beam profile measurement accuracy. In the coming years, due to the Large Hadron Collider (LHC) luminosity upgrade, a wire traveling speed up to 20 $m s^{−1}$ and a position measurement accuracy of the order of 1 μm will be required. A new wire scanner design based on the understanding of the wire vibration origin is therefore needed. We present the models developed to understand the main causes of the wire vibrations observed in an existing wire scanner. The development and tuning of those models are based on measurements and tests performed on that CERN proton synchrotron (PS) scanner. The final model for the (wire + fork) system has six degrees-of-freedom (DOF). The wire equations contain three different excitation terms: inertia...

  17. Progress in electrical and mechanical properties of rectangular MgB2 wires

    International Nuclear Information System (INIS)

    Kovac, P; Melisek, T; Kopera, L; Husek, I; Polak, M; Kulich, M

    2009-01-01

    Critical current densities and mechanical resistance of MgB 2 wires made by the rectangular wire-in-tube technique (RWIT) have been studied. Wires prepared from different precursor powders and variable sheath materials are compared. The best electrical performance (10 4 A cm -2 at 11.3 T) was measured for the wire with mechanically alloyed powder doped by SiC. While the critical current densities, J c , at 4.2 K are considerably influenced by the powder used, the differences at 20 K are much smaller. Flattened wires show different levels of critical current anisotropy influenced by the precursor powder used. Stress-strain characteristics and critical current degradation are strongly affected by the applied metallic materials and also by the filament's strength. The highest irreversible strain ε irr = 0.55% was measured for Ti/Cu/Monel sheathed wire with filaments from mechanically alloyed powder.

  18. Experimental study of parallel multi-tungsten wire Z-pinch

    International Nuclear Information System (INIS)

    Huang Xianbin; China Academy of Engineering Physics, Mianyang; Lin Libin; Yang Libing; Deng Jianjun; Gu Yuanchao; Ye Shican; Yue Zhengpu; Zhou Shaotong; Li Fengping; Zhang Siqun

    2005-01-01

    The study of three parallel tungsten wire loads and five parallel tungsten wire loads implosion experiment on accelerator 'Yang' are reported. Tungsten wires (φ17 μm) with separation of 1 mm were used. The pinch was driven by a 350 kA peak current, 80 ns 10%-90% rise time. By means of pinhole camera and X-ray diagnostics technology, a non-uniform plasma column is formed among the wires and soft X-ray pulse are observed. the change of load current are analyzed, the development of sausage instability and kink instability, 'hot spot' effect and dispersion spot for plasma column are also discussed. (authors)

  19. Wire-rope emplacement of diagnostics systems

    International Nuclear Information System (INIS)

    Burden, W.L.

    1982-01-01

    The study reported here was initiated to determine if, with the Cable Downhole System (CDS) currently under development, there is an advantage to using continuous wire rope to lower the emplacement package to the bottom of the hole. A baseline design using two wire ropes as well as several alternatives are discussed in this report. It was concluded that the advantages of the wire-rope emplacement system do not justify the cost of converting to such a system, especially for LLNL's maximum emplacement package weights

  20. Application of wire sawing method to decommissioning of high level activated concrete

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Hideki; Nishimura, Youichi [Tokyo Electric Power Co., Tokyo (Japan); Watanabe, Morishige; Yamashita Yoshitaka

    1999-07-01

    Wire sawing method is proposed as an effective cutting method for the dismantling of high level activated concrete of a nuclear power plant. The cutting test with wire sawing method discussed in this paper was carried out to obtain the data such as the cutting rate, the volume of concrete dust and the time of cutting and related work. The cutting test consisted of two parts; 'Fundamental test' and 'mock-up test.' In the fundamental test, we carried out the cutting test with small concrete blocks simulating the high level activated concrete of Boiling Water Reactor (BWR) and Pressurized Water Reactor (PWR). Through the test, the following data were obtained: the cutting rate of wire sawing, the volume of generated concrete dust and the grading distribution of suspended particulate. We also studied the life of wire and the relations between the wire tension, the wire rotating speed, the steel ratio and the cutting rate. In the mock-up test, we carried out the test with large concrete blocks simulating the part of the reactor shield wall of BWR and the biological shield wall of PWR. Through the mock-up test, we made clear that it is possible that the large test blocks with high re-bar ratio and a steel plate (steel plates) were cut smoothly by the wire sawing method. In the test, the following data were obtained; the cutting rate, the time of the cutting and related work and the remote controllability of cutting machines. (author)

  1. Application of wire sawing method to decommissioning of high level activated concrete

    International Nuclear Information System (INIS)

    Hasegawa, Hideki; Nishimura, Youichi; Watanabe, Morishige; Yamashita Yoshitaka

    1999-01-01

    Wire sawing method is proposed as an effective cutting method for the dismantling of high level activated concrete of a nuclear power plant. The cutting test with wire sawing method discussed in this paper was carried out to obtain the data such as the cutting rate, the volume of concrete dust and the time of cutting and related work. The cutting test consisted of two parts; 'Fundamental test' and 'mock-up test.' In the fundamental test, we carried out the cutting test with small concrete blocks simulating the high level activated concrete of Boiling Water Reactor (BWR) and Pressurized Water Reactor (PWR). Through the test, the following data were obtained: the cutting rate of wire sawing, the volume of generated concrete dust and the grading distribution of suspended particulate. We also studied the life of wire and the relations between the wire tension, the wire rotating speed, the steel ratio and the cutting rate. In the mock-up test, we carried out the test with large concrete blocks simulating the part of the reactor shield wall of BWR and the biological shield wall of PWR. Through the mock-up test, we made clear that it is possible that the large test blocks with high re-bar ratio and a steel plate (steel plates) were cut smoothly by the wire sawing method. In the test, the following data were obtained; the cutting rate, the time of the cutting and related work and the remote controllability of cutting machines. (author)

  2. Magnetization and critical currents of NbTi wires with fine filaments

    International Nuclear Information System (INIS)

    Ghosh, A.K.; Sampson, W.B.

    1985-01-01

    In high energy accelerators such as the SSC, the magnetization of the superconductor is an important component in determining the harmonic fields at injection (approx.0.3T). In an effort to reduce these residual fields, interest has focused on NbTi conductors with fine filaments which are expected to have a reduced magnetization as dictated by the critical state model. With this in view, the magnetization and critical currents were measured at 4.3K for a set of NbTi wires with filament diameters, d, ranging from 1.0 to 5.0 microns. The data show that, although the magnetization scales linearly with d, it does not do so with the product J/sub c/d for d less than 3 μm. However, at these d values, the critical transport current density, J/sub c/ of NbTi was observed to decrease rapidly as a function of d. The origin of this J/sub c/ degradation and its effect on the scaling of magnetization within the framework of the critical state model is explored. We also examine the question of the observed asymmetry of the hysteretic magnetization

  3. Modelling aluminium wire bond reliability in high power OMP devices

    NARCIS (Netherlands)

    Kregting, R.; Yuan, C.A.; Xiao, A.; Bruijn, F. de

    2011-01-01

    In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is

  4. Current Harmonics Cancellation in Three-Phase Four-Wire Systems by Using a Four-Branch Star Filtering Topology

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Candela, J. I.; Luna, A.

    2009-01-01

    This paper presents a new solution for filtering current harmonics in three-phase four-wire networks. The original four-branch star (FBS) filter topology presented in this paper is characterized by a particular layout of single-phase inductances and capacitors, without using any transformer......, a specific implementation of a three-phase four-wire hybrid power filter is presented as an illustrative application of the filtering topology. An extensive evaluation using simulation and experimental results from a DSP-based laboratory prototype is conducted in order to verify and validate the good...... only passive components are employed, or as a hybrid filter, when its behavior is improved by integrating a power converter into the filter structure. The paper analyzes the proposed topology, and derives fundamental concepts about the control of the resulting hybrid power filter. From this analysis...

  5. Multifilamentary Cu-Nb3Sn superconductor wires

    International Nuclear Information System (INIS)

    Rodrigues, D.; Pinatti, D.G.

    1990-01-01

    This paper reports on one of the main technological problems concerning Nb 3 Sn superconducting wires production which is the optimization of heat treatments for the formation of the A-15 intermetallic compound. At the present work, Nb 3 Sn superconducting wire is produced by solid-liquid diffusion method which increases considerably the critical current values of the superconductor. Through this method, niobium, copper and Sn 7% wt Cu alloy are kept in the pure state. Thus, the method dispenses intermediate heat treatments of recrystallization during the manufacturing process of the wire. After the wire was ready, optimization work of heat treatments was accomplished aiming to obtain its best superconducting characteristics, Measurement of critical temperature, critical current versus magnetic field, normal and at room temperature resistivity were performed, as well as scanning electron microscopy for determination of Nb 3 Sn layers and transmission electron microscopy measurements of redetermining the grain sizes in Nb 3 Sn formed in each treatment. It was obtained critical current densities of 1.8 x 10 6 A/cm 2 in the Nb 3 Sn layer, at 10 Teslas and 4.2 K. The samples were analyzed by employing the superconducting collective flux pinning theories and a satisfactory agreement between the experimental and theoretical data was attained. The production process and the small size of the filaments used made a successful optimization of the wire possible

  6. Chaotic behavior of current-carrying plasmas in external periodic oscillations

    Energy Technology Data Exchange (ETDEWEB)

    Ohno, Noriyasu; Tanaka, Masayoshi; Komori, Akio; Kawai, Yoshinobu

    1989-01-01

    A set of cascading bifurcations and a chaotic state in the presence of an external periodic oscillation are experimentally investigated in a current-carrying plasma. The measured bifurcation sequence leading to chaos, which is controlled by changing plasma densities and the frequencies of external oscillations, is in qualitative agreement with a theory which describes anharmonic systems in periodic fields. (author).

  7. Observation of minor collapse of current-carrying plasma in LHD

    International Nuclear Information System (INIS)

    Narushima, Yoshiro; Sakakibara, Satoru; Watanabe, Kiyomasa

    2006-01-01

    A minor collapse observed in current-carrying plasma has been investigated in Large Helical Device (LHD). The magnetic configuration with high central rotational transform has ι/2π=1 surface at the core region and is relatively unstable for the m/n=1/1 mode (here, m and n are the poloidal and toroidal mode number, respectively). When the beam-driven current exceeds a certain value, the m/n=1/1 mode grows with a growth time of ∼30 ms and causes a sudden drop of the plasma stored energy and the electron temperature, and it also limits the plasma current itself. A local flattening in an electron temperature profile appears just after the minor collapse. The mode does not rotate and stays at the same spatial location. The possibility of pressure- and current-driven magneto-hydro dynamics (MHD) instabilities is discussed. (author)

  8. LANSCE wire scanning diagnostics device mechanical design

    International Nuclear Information System (INIS)

    Rodriguez Esparza, Sergio

    2010-01-01

    The Los Alamos Neutron Science Center (LANSCE) is one of the major experimental science facilities at the Los Alamos National Laboratory (LANL). The core of LANSCE's work lies in the operation of a powerful linear accelerator, which accelerates protons up to 84% the speed oflight. These protons are used for a variety of purposes, including materials testing, weapons research and isotopes production. To assist in guiding the proton beam, a series of over one hundred wire scanners are used to measure the beam profile at various locations along the half-mile length of the particle accelerator. A wire scanner is an electro-mechanical device that moves a set of wires through a particle beam and measures the secondary emissions from the resulting beam-wire interaction to obtain beam intensity information. When supplemented with data from a position sensor, this information is used to determine the cross-sectional profile of the beam. This measurement allows beam operators to adjust parameters such as acceleration, beam steering, and focus to ensure that the beam reaches its destination as effectively as possible. Some of the current wire scanners are nearly forty years old and are becoming obsolete. The problem with current wire scanners comes in the difficulty of maintenance and reliability. The designs of these wire scanners vary making it difficult to keep spare parts that would work on all designs. Also many of the components are custom built or out-dated technology and are no longer in production.

  9. LANSCE wire scanning diagnostics device mechanical design

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Esparza, Sergio [Los Alamos National Laboratory

    2010-01-01

    The Los Alamos Neutron Science Center (LANSCE) is one of the major experimental science facilities at the Los Alamos National Laboratory (LANL). The core of LANSCE's work lies in the operation of a powerful linear accelerator, which accelerates protons up to 84% the speed oflight. These protons are used for a variety of purposes, including materials testing, weapons research and isotopes production. To assist in guiding the proton beam, a series of over one hundred wire scanners are used to measure the beam profile at various locations along the half-mile length of the particle accelerator. A wire scanner is an electro-mechanical device that moves a set of wires through a particle beam and measures the secondary emissions from the resulting beam-wire interaction to obtain beam intensity information. When supplemented with data from a position sensor, this information is used to determine the cross-sectional profile of the beam. This measurement allows beam operators to adjust parameters such as acceleration, beam steering, and focus to ensure that the beam reaches its destination as effectively as possible. Some of the current wire scanners are nearly forty years old and are becoming obsolete. The problem with current wire scanners comes in the difficulty of maintenance and reliability. The designs of these wire scanners vary making it difficult to keep spare parts that would work on all designs. Also many of the components are custom built or out-dated technology and are no longer in production.

  10. Corrosion resistance of premodeled wires made of stainless steel used for heart electrotherapy leaders

    International Nuclear Information System (INIS)

    Przondziono, J; Szatka, W; Walke, W; Młynarski, R

    2012-01-01

    The purpose of the study is to evaluate resistance to electrochemical corrosion of wire made of X10CrNi18-8 stainless steel designed for use in cardiology treatment. The influence of strain formed in the premodeling process and methods of wire surface preparation to corrosive resistance in artificial plasma solution were analysed. Wire corrosion tests were carried out in the solution of artificial plasma. Resistance to electrochemical corrosion was evaluated on the ground of recorded curves of anodic polarization by means of potentiodynamic method. Potentiodynamic tests carried out enabled to determine how the resistance to pitting corrosion of wire changes, depending on strain formed in the premodeling process as well as on the method of wire surface preparation. For evaluation of phenomena occurring on the surface of tested steel, electrochemical impedance spectroscopy (EIS) was applied. Deterioration of corrosive properties of wire along with the increase in the formed strain hardening was observed.

  11. Single-electron states near a current-carrying core

    International Nuclear Information System (INIS)

    Masale, M.

    2004-01-01

    The energy spectrum of an electron confined near a current-carrying core is obtained as a function of the azimuthal applied magnetic field within the effective-mass approximation. The double degeneracy of the non-zero electron's axial wave number (k z ) states is lifted by the current-induced magnetic field while that of the non-zero azimuthal quantum number (m) states is preserved. A further analysis is the evaluations of the oscillator strengths for optical transitions involving the lowest-order pair of the electron's energy subbands within the dipole approximation. The radiation field is taken as that of elliptically polarized light incident along the core axis. In this polarization and within the dipole approximation, the allowed transitions are only those governed by the following specific selection rules. The azimuthal quantum numbers of the initial and final states must differ by unity while the electron's axial wave number is conserved. The azimuthal magnetic field is also found to lift the multiple degeneracies of the k z ≠0 interaction integrals as well as those of the oscillator strengths for optical transitions

  12. Characterising mechanical transmission wire ropes’ typical failure modes

    Directory of Open Access Journals (Sweden)

    Edgar Espejo

    2007-01-01

    Full Text Available The National University of Colombia’s Engineering School’s AFIS research group has helped several public and private institutions during the last five years in analysing the causes of failures presented in elevation and trans- port machinery leading to expensive consequences and even the loss of life. A group of typical wire rope failure modes have been identified, along with their common causes. These are presented in this work to offer help to our industry’s engineers and technicians, allowing them to identify possible risk situations in their routine work regarding the wire ropes which they use and approaches for carrying out wire rope failure analysis.

  13. Improvement of cold wire drawing process by electropulsing

    OpenAIRE

    Sánchez Egea, Antonio José; González Rojas, Hernan Alberto; Jorba Peiró, Jordi

    2015-01-01

    The electroplastic effects on wire drawing process assisted with different short time current pulses configurations are investigated experimentally. The current pulses were induced to a specimen during the drawing process. The studied material is the 308L stainless steel. Current densities of 185 A/mm2, frequencies range from 140 to 350 Hz and pulse duration range from 100 to 250 μs were used in the electrically‐assisted wire drawing process. Frequency and pulse duration are...

  14. Ferromagnetic artificial pinning centers in multifilamentary superconducting wires

    International Nuclear Information System (INIS)

    Wang, J.Q.; Rizzo, N.D.; Prober, D.E.

    1997-01-01

    The authors fabricated multifilamentary NbTi wires with ferromagnetic (FM) artificial pinning centers (APCs) to enhance the critical current density (J c ) in magnetic fields. They used a bundle and draw technique to process the APC wires with either Ni or Fe as the pinning centers. Both wires produced higher J c in the high field range (5-9 T) than previous non-magnetic APC wires similarly processed, even though the authors have not yet optimized pin percentage. Using a magnetometer they found that the pins remained ferromagnetic for the wires with maximum J c . However, they did observe a substantial loss of FM material for the wires where the pin diameter approached 3 nm. Thus, they expect further enhancement of J c with better pin quality

  15. Transport critical current density and microstructure in extruded YBa2Cu3O7-x wires processed by zone melting

    International Nuclear Information System (INIS)

    Shi, D.; Krishnan, H.; Hong, J.M.; Miller, D.; McGinn, P.J.; Chen, W.H.; Xu, M.; Chen, J.G.; Fang, M.M.; Welp, U.; Lanagan, M.T.; Goretta, K.C.; Dusek, J.T.; Picciolo, J.J.; Balachandran, U.

    1990-01-01

    YBa 2 Cu 3 O 7-x compounds were extruded into long wires with the diameter of 1 mm after sintering. The sintered wires were subsequently zone melted to develop a highly textured microstructure. Magnetization experiments at 77 K indicated a J c value of 1x10 5 A/cm 2 at 1 T. Transport measurements at 77 K showed a greatly enhanced field dependence of the critical current density. Transmission electron microscopy revealed an important grain-boundary feature which eliminated the weak-link behavior. Large amounts of dislocations have also been found in the zone-melted sample which may contribute to flux pinning in the system

  16. Fabrication of seven-core multi-filamentary MgB2 wires with high critical current density by an internal Mg diffusion process

    International Nuclear Information System (INIS)

    Togano, K; Hur, J M; Matsumoto, A; Kumakura, H

    2009-01-01

    We found that the reaction between a Mg core and a B powder layer in an internal Mg diffusion (IMD)-processed multi-filamentary wire can proceed rapidly even at a furnace temperature lower than the melting point of Mg (650 deg. C), resulting in the formation of a reacted layer with a fine composite structure and, hence, excellent in-field critical current properties. The multi-filamentary wire is composed of an outermost Cu-Ni sheath and seven filaments with a Ta sheath, a Mg core, and B+SiC powder filled in the space between the Ta sheath and the Mg core. Heat treatment at 645 deg. C for 1 h produced a reacted layer with dense composite structure along the inner wall of the Ta sheath and a hole at the center of each core. This reaction probably initiated from the heat generation at the B/Mg interface, resulting in a temperature rise of the Mg core and the occurrence of liquid Mg infiltration. The J c value at 4.2 K for the reacted layer exceeds 10 5 cm -2 at 9 T, which is the highest reported so far for MgB 2 wire, including powder-in-tube (PIT)-processed wires. These results indicate that the IMD process can compete in terms of practical wire fabrication with the conventional PIT process.

  17. HTS Wire Development Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  18. Slice of LHC dipole wiring

    CERN Multimedia

    Dipole model slice made in 1994 by Ansaldo. The high magnetic fields needed for guiding particles around the Large Hadron Collider (LHC) ring are created by passing 12’500 amps of current through coils of superconducting wiring. At very low temperatures, superconductors have no electrical resistance and therefore no power loss. The LHC is the largest superconducting installation ever built. The magnetic field must also be extremely uniform. This means the current flowing in the coils has to be very precisely controlled. Indeed, nowhere before has such precision been achieved at such high currents. 50’000 tonnes of steel sheets are used to make the magnet yokes that keep the wiring firmly in place. The yokes constitute approximately 80% of the accelerator's weight and, placed side by side, stretch over 20 km!

  19. Progress on MOD/RABiTSTM 2G HTS wire

    International Nuclear Information System (INIS)

    Rupich, M.W.; Zhang, W.; Li, X.; Kodenkandath, T.; Verebelyi, D.T.; Schoop, U.; Thieme, C.; Teplitsky, M.; Lynch, J.; Nguyen, N.; Siegal, E.; Scudiere, J.; Maroni, V.; Venkataraman, K.; Miller, D.; Holesinger, T.G.

    2004-01-01

    The development of the second generation (2G) high temperature superconducting wire has advanced beyond initial laboratory demonstrations and is now focused on developing and testing high critical current conductor designs required for commercial applications. The approach pursued at American Superconductor for 2G wire manufacturing is based on the combination of the RABiTS TM substrate-buffer technology with metal organic deposition (MOD) of the YBCO layer. This MOD/RABiTS TM approach has been demonstrated in 10 m lengths with critical currents of up to 184 A/cm-width (∼2.3 MA/cm 2 ) and in short length with critical currents of up to 270 A/cm-width (∼3.4 MA/cm 2 ). In addition to a high critical current, the superconducting wire must also meet stringent mechanical and electrical stability requirements that vary by application. Commercially viable architectures designed to meet these specifications have been fabricated and tested. Wires manufactured by this process have been successfully tested in prototype cable and coil applications

  20. The influence of strain introduced by differential thermal contraction on the critical current of Nb3Sn supercontractors

    International Nuclear Information System (INIS)

    Pasztor, G.; Jakob, B.

    1992-01-01

    The NET Team initiated in 1988 a development program for a high current cable-in-conduit superconductor planned for fusion magnets. The basic strand chosen for the cable was a Nb 3 Sn wire of TWCA made by the MJR method. The electrical testing of the stand and sub-cables was carried out at several European Laboratories including PSI (Paul Scherrer Institute). The inter-laboratory comparison of the results revealed large differences in the measured critical currents of the strands. Obviously, each laboratory performed the measurement of critical current in its own way, and as a result some discrepancies in the measured values were inevitable. No standard technique of measuring critical current has been developed for Nb 3 Sn wires. The main source of difficulty arises from the strain sensitivity of Nb 3 Sn. It has been shown that the sample holder material and geometry as well as the bonding method of the specimen to its holder have important effects on the critical current measurements. It was found recently that the reaction mandrel material significantly influences the current-carrying capacity of Nb 3 Sn wires. The aim of this paper is to improve current understanding of the effect of sample configuration on critical current in Nb 3 Sn multifilamentary wires. The present study confirms the important role of reaction mandrel material on critical current. Based on comparative critical current measurements of straight and coil samples, an attempt is made to find the sample configuration which eliminates the strain induced in the specimen

  1. AC magnetic transport on heterogeneous ferromagnetic wires and tubes

    International Nuclear Information System (INIS)

    Sinnecker, J.P.; Pirota, K.R.; Knobel, M.; Kraus, L.

    2002-01-01

    The AC current density radial distribution is calculated on heterogeneous composite materials with cylindrical geometry. The composites have an inner core and thin outer shell that can be either from the same material (homogenous material like simple wires) or from different materials with different physical properties. The case in which a non-magnetic inner core is surrounded by a magnetic layer, like electrodeposited wires, is mainly studied. The effect of frequency and applied magnetic field is simulated. The current density distribution as a function of frequency and applied field, as well as the total current over the inner core and outer shells are calculated. The results agree substantially well with the experimentally observed data for simple electrodeposited wires

  2. Nano-/micro metallic wire synthesis on Si substrate and their characterization

    International Nuclear Information System (INIS)

    Kaur, Jaskiran; Kaur, Harmanmeet; Singh, Surinder; Kanjilal, Dinakar; Chakarvarti, Shiv Kumar

    2014-01-01

    Nano-/micro wires of copper are grown on semiconducting Si substrate using the template method. It involves the irradiation of 8 um thick polymeric layer coated on Si with150 MeV Ni ion beam at a fluence of 2E8. Later, by using the simple technique of electrodeposition, copper nano-/micro wires were grown via template synthesis. Synthesized wires were morphologically characterized using SEM and electrical characterization was carried out by finding I-V plot

  3. Comparison of growth texture in round Bi2212 and flat Bi2223 wires and its relation to high critical current density development

    OpenAIRE

    Kametani, F.; Jiang, J.; Matras, M.; Abraimov, D.; Hellstrom, E. E.; Larbalestier, D. C.

    2015-01-01

    Why Bi2Sr2CaCu2Ox (Bi2212) allows high critical current density Jc in round wires rather than only in the anisotropic tape form demanded by all other high temperature superconductors is important for future magnet applications. Here we compare the local texture of state-of-the-art Bi2212 and Bi2223 ((Bi,Pb)2Sr2Ca2Cu3O10), finding that round wire Bi2212 generates a dominant a-axis growth texture that also enforces a local biaxial texture (FWHM

  4. Development and manufacture of ultra-fine NbTi filament wires at ALSTHOM

    International Nuclear Information System (INIS)

    Hoang, G.K.; Laumond, Y.; Sabrie, J.L.; Dubots, P.

    1986-01-01

    Ultra-fine NbTi filament wires have been developed and manufactured by ALSTHOM. It is now possible to produce industrial copper -copper-nickel matrix wires with 0.6 mu m NbTi filaments for use in 50 / 60 Hz machines. Smaller filaments with diameters down to 0.08 mu m have been obtained with 254 100 filament wire samples. Studies are now being carried out on copper matrix conductors to reduce the filament diameter. The first results show that it is possible to obtain submicron filaments even in copper matrix wires

  5. Sharp burnout failure observed in high current-carrying double-walled carbon nanotube fibers

    Science.gov (United States)

    Song, Li; Toth, Geza; Wei, Jinquan; Liu, Zheng; Gao, Wei; Ci, Lijie; Vajtai, Robert; Endo, Morinobu; Ajayan, Pulickel M.

    2012-01-01

    We report on the current-carrying capability and the high-current-induced thermal burnout failure modes of 5-20 µm diameter double-walled carbon nanotube (DWNT) fibers made by an improved dry-spinning method. It is found that the electrical conductivity and maximum current-carrying capability for these DWNT fibers can reach up to 5.9 × 105 S m - 1 and over 1 × 105 A cm - 2 in air. In comparison, we observed that standard carbon fiber tended to be oxidized and burnt out into cheese-like morphology when the maximum current was reached, while DWNT fiber showed a much slower breakdown behavior due to the gradual burnout in individual nanotubes. The electron microscopy observations further confirmed that the failure process of DWNT fibers occurs at localized positions, and while the individual nanotubes burn they also get aligned due to local high temperature and electrostatic field. In addition a finite element model was constructed to gain better understanding of the failure behavior of DWNT fibers.

  6. Superconducting wires and methods of making thereof

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xingchen; Sumption, Michael D.; Peng, Xuan

    2018-03-13

    Disclosed herein are superconducting wires. The superconducting wires can comprise a metallic matrix and at least one continuous subelement embedded in the matrix. Each subelement can comprise a non-superconducting core, a superconducting layer coaxially disposed around the non-superconducting core, and a barrier layer coaxially disposed around the superconducting layer. The superconducting layer can comprise a plurality of Nb.sub.3Sn grains stabilized by metal oxide particulates disposed therein. The Nb.sub.3Sn grains can have an average grain size of from 5 nm to 90 nm (for example, from 15 nm to 30 nm). The superconducting wire can have a high-field critical current density (J.sub.c) of at least 5,000 A/mm.sup.2 at a temperature of 4.2 K in a magnetic field of 12 T. Also described are superconducting wire precursors that can be heat treated to prepare superconducting wires, as well as methods of making superconducting wires.

  7. Resistance microwelding of 316L stainless steel wire to block

    DEFF Research Database (Denmark)

    Friis, Kasper Storgaard; Khan, M.I.; Bay, Niels

    2011-01-01

    The excellent corrosion resistance of low carbon vacuum melted 316 stainless steel coupled with its non-magnetic properties makes it ideal for biomedical applications. The typical joint geometry for microcomponents, such as medical implants, includes joining of fine wire to a larger block. However......, this type of joint has received little attention in the current literature. The present study was conducted to examine the microstructure and mechanical properties of low carbon vacuum melted 316 stainless steel wire welded to a larger block. Results revealed solid state bonding occurring at low currents......, while fusion bonding occurred at higher currents. This was due to the highly asymmetrical heat generation resulting in almost complete melting of the wire before the initiation of interfacial melting. This is a distinctly different bonding mechanism compared to previous studies on crossed wire joints....

  8. Fluorescent silver nanoparticles via exploding wire technique

    Indian Academy of Sciences (India)

    Pure silver nanoparticles in double distilled water were generated via simple physical method using pure (99.9%) silver wires with 0.2 mm diameter. These wires have been exploded in water by bringing them into sudden contact with pure (99.9%) silver plate when subjected to a potential difference of 36 V DC. High current.

  9. Ozone generation by negative direct current corona discharges in dry air fed coaxial wire-cylinder reactors

    International Nuclear Information System (INIS)

    Yehia, Ashraf; Mizuno, Akira

    2013-01-01

    An analytical study was made in this paper for calculating the ozone generation by negative dc corona discharges. The corona discharges were formed in a coaxial wire-cylinder reactor. The reactor was fed by dry air flowing with constant rates at atmospheric pressure and room temperature, and stressed by a negative dc voltage. The current-voltage characteristics of the negative dc corona discharges formed inside the reactor were measured in parallel with concentration of the generated ozone under different operating conditions. An empirical equation was derived from the experimental results for calculating the ozone concentration generated inside the reactor. The results, that have been recalculated by using the derived equation, have agreed with the experimental results over the whole range of the investigated parameters, except in the saturation range for the ozone concentration. Therefore, the derived equation represents a suitable criterion for expecting the ozone concentration generated by negative dc corona discharges in dry air fed coaxial wire-cylinder reactors under any operating conditions in range of the investigated parameters.

  10. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  11. Characterization of LH induced current carrying fast electrons in JET

    Energy Technology Data Exchange (ETDEWEB)

    Ramponi, G.; Airoldi, A. [Consiglio Nazionale delle Ricerche, Milan (Italy). Lab. di Fisica del Plasma; Bartlett, D.; Brusati, M.; Froissard, P.; Gormezano, C.; Rimini, F.; Silva, R.P. da; Tanzi, C.P. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking

    1992-12-31

    Lower Hybrid Current Drive (LHCD) experiments have recently been made at JET by coupling up to 2.4 MW of RF power at 3.7 GHz, with a power spectrum centered at n{sub ||} = 1.8 {+-} 0.2 corresponding to a resonating electron energy of about 100 keV via Electron Landau Damping. The Current Drive (CD) efficiency has been observed to increase when LH and ICRH power are applied simultaneously to the plasma, suggesting that a part of the fast magnetosonic wave is absorbed on the LH-generated fast electrons. An important problem of CD experiments in tokamaks is the determination of the radial distribution of the driven current and the characterization in the momentum space of the current carrying fast electrons by using appropriate diagnostic tools. For this purpose, a combined analysis of the Electron Cyclotron Emission (ECE) and of the Fast Electron Bremsstrahlung (FEB) measurements has been made, allowing the relevant parameters of the suprathermal electrons to be estimated. (author) 5 refs., 5 figs., 2 tabs.

  12. Characterization of LH induced current carrying fast electrons in JET

    International Nuclear Information System (INIS)

    Ramponi, G.; Airoldi, A.; Bartlett, D.; Brusati, M.; Froissard, P.; Gormezano, C.; Rimini, F.; Silva, R.P. da; Tanzi, C.P.

    1992-01-01

    Lower Hybrid Current Drive (LHCD) experiments have recently been made at JET by coupling up to 2.4 MW of RF power at 3.7 GHz, with a power spectrum centered at n || = 1.8 ± 0.2 corresponding to a resonating electron energy of about 100 keV via Electron Landau Damping. The Current Drive (CD) efficiency has been observed to increase when LH and ICRH power are applied simultaneously to the plasma, suggesting that a part of the fast magnetosonic wave is absorbed on the LH-generated fast electrons. An important problem of CD experiments in tokamaks is the determination of the radial distribution of the driven current and the characterization in the momentum space of the current carrying fast electrons by using appropriate diagnostic tools. For this purpose, a combined analysis of the Electron Cyclotron Emission (ECE) and of the Fast Electron Bremsstrahlung (FEB) measurements has been made, allowing the relevant parameters of the suprathermal electrons to be estimated. (author) 5 refs., 5 figs., 2 tabs

  13. Wire breakage in SLC wire profile monitors

    International Nuclear Information System (INIS)

    Field, C.; McCormick, D.; Raimondi, P.; Ross, M.

    1998-05-01

    Wire scanning beam profile monitors are used at the Stanford Linear Collider (SLC) for emittance preservation control and beam optics optimization. Twenty such scanners have proven most useful for this purpose and have performed a total of 1.5 million scans in the 4 to 6 years since their installation. Most of the essential scanners are equipped with 20 to 40 microm tungsten wires. SLC bunch intensities and sizes often exceed 2 x 10 7 particles/microm 2 (3C/m 2 ). The authors believe that this has caused a number of tungsten wire failures that appear at the ends of the wire, near the wire support points, after a few hundred scans are accumulated. Carbon fibers, also widely used at SLAC, have been substituted in several scanners and have performed well. In this paper, the authors present theories for the wire failure mechanism and techniques learned in reducing the failures

  14. Monitoring and evaluation of wire mesh forming life

    Science.gov (United States)

    Enemuoh, Emmanuel U.; Zhao, Ping; Kadlec, Alec

    2018-03-01

    Forming tables are used with stainless steel wire mesh conveyor belts to produce variety of products. The forming tables will typically run continuously for several days, with some hours of scheduled downtime for maintenance, cleaning and part replacement after several weeks of operation. The wire mesh conveyor belts show large variation in their remaining life due to associated variations in their nominal thicknesses. Currently the industry is dependent on seasoned operators to determine the replacement time for the wire mesh formers. The drawback of this approach is inconsistency in judgements made by different operators and lack of data knowledge that can be used to develop decision making system that will be more consistent with wire mesh life prediction and replacement time. In this study, diagnostic measurements about the health of wire mesh former is investigated and developed. The wire mesh quality characteristics considered are thermal measurement, tension property, gage thickness, and wire mesh wear. The results show that real time thermal sensor and wear measurements would provide suitable data for the estimation of wire mesh failure, therefore, can be used as a diagnostic parameter for developing structural health monitoring (SHM) system for stainless steel wire mesh formers.

  15. Investigation of domain wall motion in RE-TM magnetic wire towards a current driven memory and logic

    Energy Technology Data Exchange (ETDEWEB)

    Awano, Hiroyuki

    2015-06-01

    Current driven magnetic domain wall (DW) motions of ferri-magnetic TbFeCo wires have been investigated. In the case of a Si substrate, the critical current density (Jc) of DW motion was successfully reduced to 3×10{sup 6} A/cm{sup 2}. Moreover, by using a polycarbonate (PC) substrate with a molding groove of 600 nm width, the Jc was decreased to 6×10{sup 5} A/cm{sup 2}. In order to fabricate a logic in memory, a current driven spin logics (AND, OR, NOT) have been proposed and successfully demonstrated under the condition of low Jc. These results indicate that TbFeCo nanowire is an excellent candidate for next generation power saving memory and logic.

  16. Bubble Formation within Filaments of Melt-Processed Bi2212 wires and its strongly negative effect on the Critical Current Density

    CERN Document Server

    Kametani, F; Jiang, J; Scheuerlein, C; Malagoli, A; Di Michiel, M; Huang, Y; Miao, H; Parrell, J A; Hellstrom, E E; Larbalestier, D C

    2011-01-01

    Most studies of Bi2Sr2CaCu2Ox (Bi2212) show that the critical current density Jc is limited by the connectivity of the filaments, but what determines the connectivity is still elusive. Here we report on the role played by filament porosity in limiting Jc. By a microstructural investigation of wires quenched from the melt state, we find that porosity in the unreacted wire agglomerates into bubbles that segment the Bi2212 melt within the filaments into discrete sections. These bubbles do not disappear during subsequent processing because they are only partially filled by Bi2212 grains as the Bi2212 forms on cooling. Correlating the microstructure of quenched wires to their final, fully processed Jc values shows an inverse relation between Jc and bubble density. Bubbles are variable between conductors and perhaps from sample to sample, but they occur frequently and almost completely fill the filament diameter, so they exert a strongly variable but always negative effect on Jc. Bubbles reduce the continuous Bi221...

  17. X-ray backlighting of two-wire Z-pinch plasma using X-pinch

    International Nuclear Information System (INIS)

    Tong, Zhao; Xiao-Bing, Zou; Ran, Zhang; Xin-Xin, Wang

    2010-01-01

    Two 50-μm Mo wires in parallel used as a Z-pinch load are electrically exploded with a pulsed current rising to 275 kA in 125 ns and their explosion processes are backlighted using an X-pinch as an x-ray source. The backlighting images show clearly the processes similar to those occurring in the initial stages of a cylindrical wire-array Z-pinch, including the electric explosion of single wires characterised by the dense wire cores surrounded by a low-density coronal plasma, the expansion of the exploding wire, the sausage instability (m = 0) in the coronal plasma around each wire, the motion of the coronal plasma as well as the wire core toward the current centroid, the formation of the precursor plasma column with a twist structure something like that of higher mode instability, especially the kink instability (m = 1). (fluids, plasmas and electric discharges)

  18. Mechanical optimisation of a high-precision fast wire scanner at CERN

    CERN Document Server

    Samuelsson, Sebastian; Veness, Raymond

    Wire scanners are instruments used to measure the transverse beam prole in particle accelerators by passing a thin wire through the particle beam. To avoid the issues of vacuum leakage through the bellows and wire failure related to current designs of wire scanners, a new concept for a wire scanner has been developed at CERN. This design has all moving parts inside the beam vacuum and has a nominal wire scanning speed of 20 m/s. The demands on the design associated with this together with the high precision requirements create a need for\

  19. Deformation of current-carrying jets by nonviscous electrically conducting fluid

    International Nuclear Information System (INIS)

    Morozova, V.I.

    1986-01-01

    The change in the form of the transverse cross section of the jet under the action of the current flowing along it is investigated. The reults of computations for solitary current carrying jets of square and rectangular cross sections, and for systems of six and twelve azimuthally periodic jets with currents alternating in direction, are shown in figures. A solitary jet with square transverse cross section at the initial instant executes a periodic motion involving transition from square cross section, through circular, back to square rotated by 45 0 with respect to the initial section, and later going through circular cross section and returning to the initial position is shown in a figure. Other figures show similar deformations occuring with a solitary rectangular cross section, and deformations of the systems of jets which are accompanied by their radial separation. The authors note that the present formulation uses only geometric criteria of similarity; therefore the dependences of the deformations on time, presented in figures, are universal

  20. Recent development of drastically innovative BSCCO wire (DI-BISCCO)

    International Nuclear Information System (INIS)

    Kikuchi, M.; Kato, T.; Ohkura, K.; Ayai, N.; Fujikami, J.; Fujino, K.; Kobayashi, S.; Ueno, E.; Yamazaki, K.; Yamade, S.; Hayashi, K.; Sato, K.; Nagai, T.; Matsui, Y.

    2006-01-01

    Up to this day, Ag-sheathed Bi2223 superconducting wires have been widely investigated and the long wires about 1000 m have been produced by using powder-in-tube (PIT) method on a commercial basis in the various facilities or companies. Although the wires are used for some applications such as HTS cables, magnets, motor and so on, the Bi2223 wires not only require much more improvements of the superconducting properties such as critical current, mechanical properties, but also longer and more uniform wires. Recently, the performances of Bi2223 wires have been drastically improved by using Controlled Over Pressure (CT-OP) sintering process. CT-OP process increased critical current (I c ) by more than 60% at 77 K and self field and improved the mechanical strength by more than 70%. The maximum I c was increased up to 166 A. These drastic improvements were caused by the higher density of Bi2223 filament up to almost 100% and better connectivity of the Bi2223 grains. The dense structure of the Bi2223 filaments prevents the ballooning phenomenon which is caused by the gasification of the trapped liquid nitrogen during temperature rise. Additionally, higher uniformity and higher production yield of long length wire were also achieved by exterminating defects during sintering. These high performance levels in CT-OP wires have contributed commercial level applications. We call as Drastically Innovative BSCCO (DI-BSCCO)

  1. Wire Array Solar Cells: Fabrication and Photoelectrochemical Studies

    Science.gov (United States)

    Spurgeon, Joshua Michael

    Despite demand for clean energy to reduce our addiction to fossil fuels, the price of these technologies relative to oil and coal has prevented their widespread implementation. Solar energy has enormous potential as a carbon-free resource but is several times the cost of coal-produced electricity, largely because photovoltaics of practical efficiency require high-quality, pure semiconductor materials. To produce current in a planar junction solar cell, an electron or hole generated deep within the material must travel all the way to the junction without recombining. Radial junction, wire array solar cells, however, have the potential to decouple the directions of light absorption and charge-carrier collection so that a semiconductor with a minority-carrier diffusion length shorter than its absorption depth (i.e., a lower quality, potentially cheaper material) can effectively produce current. The axial dimension of the wires is long enough for sufficient optical absorption while the charge-carriers are collected along the shorter radial dimension in a massively parallel array. This thesis explores the wire array solar cell design by developing potentially low-cost fabrication methods and investigating the energy-conversion properties of the arrays in photoelectrochemical cells. The concept was initially investigated with Cd(Se, Te) rod arrays; however, Si was the primary focus of wire array research because its semiconductor properties make low-quality Si an ideal candidate for improvement in a radial geometry. Fabrication routes for Si wire arrays were explored, including the vapor-liquid-solid growth of wires using SiCl4. Uniform, vertically aligned Si wires were demonstrated in a process that permits control of the wire radius, length, and spacing. A technique was developed to transfer these wire arrays into a low-cost, flexible polymer film, and grow multiple subsequent arrays using a single Si(111) substrate. Photoelectrochemical measurements on Si wire array

  2. Seeded perturbations in wire array z-pinches

    International Nuclear Information System (INIS)

    Robinson, Allen Conrad; Kantsyrev, Victor Leonidovich; Wunsch, Scott Edward; Oliver, Bryan Velten; Lebedev, Sergey V.; Safronova, Alla S.; Maxwell, J.; McKenney, John Lee; Ampleford, David J.; Rapley, J.; Bott, S.C.; Palmer, J.B.A.; Bland, Simon Nicholas; Jones, Brent Manley; Chittenden, Jeremy Paul; Garasi, Christopher Joseph; Hall, Gareth Neville; Mehlhorn, Thomas Alan; Deeney, Christopher

    2004-01-01

    The impact of 3D structure on wire array z-pinch dynamics is a topic of current interest, and has been studied by the controlled seeding of wire perturbations. First, Al wires were etched at Sandia, creating 20% radial perturbations with variable axial wavelength. Observations of magnetic bubble formation in the etched regions during experiments on the MAGPIE accelerator are discussed and compared to 3D MHD modeling. Second, thin NaF coatings of 1 mm axial extent were deposited on Al wires and fielded on the Zebra accelerator. Little or no axial transport of the NaF spectroscopic dopant was observed in spatially resolved K-shell spectra, which places constraints on particle diffusivity in dense z-pinch plasmas. Finally, technology development for seeding perturbations is discussed

  3. Numerical modelling of ozone production in a wire-cylinder corona discharge and comparison with a wire-plate corona discharge

    International Nuclear Information System (INIS)

    Wang Pengxiang; Chen Junhong

    2009-01-01

    The effect of electrode configuration on ozone production in the direct-current corona discharge of dry and humid air is studied by a numerical model that combines the electron distribution in the corona plasma, plasma chemistry and transport phenomena. Two electrode configurations are considered: wire-cylinder discharge with air flowing along the wire axis and wire-plate discharge with air flowing transverse to the wire. The ozone distributions in both types of discharges are compared. For both electrode configurations, the ozone production rate is higher in the negative corona than in the positive corona and it decreases with an increase in relative humidity. More importantly, the detailed ozone distribution in the neighbourhood of the discharge wire, together with the ozone kinetics, reveals the possible difference in the ozone production from the two discharges. With the same operating conditions and sufficiently short flow residence time, the ozone production rate is nearly the same for both electrode configurations. When the flow residence time is longer than the characteristic time for homogeneous ozone destruction, the net ozone production is higher in the wire-cylinder discharge than in the wire-plate discharge due to relatively less ozone destruction.

  4. Numerical modelling of ozone production in a wire-cylinder corona discharge and comparison with a wire-plate corona discharge

    Science.gov (United States)

    Wang, Pengxiang; Chen, Junhong

    2009-02-01

    The effect of electrode configuration on ozone production in the direct-current corona discharge of dry and humid air is studied by a numerical model that combines the electron distribution in the corona plasma, plasma chemistry and transport phenomena. Two electrode configurations are considered: wire-cylinder discharge with air flowing along the wire axis and wire-plate discharge with air flowing transverse to the wire. The ozone distributions in both types of discharges are compared. For both electrode configurations, the ozone production rate is higher in the negative corona than in the positive corona and it decreases with an increase in relative humidity. More importantly, the detailed ozone distribution in the neighbourhood of the discharge wire, together with the ozone kinetics, reveals the possible difference in the ozone production from the two discharges. With the same operating conditions and sufficiently short flow residence time, the ozone production rate is nearly the same for both electrode configurations. When the flow residence time is longer than the characteristic time for homogeneous ozone destruction, the net ozone production is higher in the wire-cylinder discharge than in the wire-plate discharge due to relatively less ozone destruction.

  5. Electromagnetic densification of MgB2/Cu wires

    International Nuclear Information System (INIS)

    Woźniak, M; Glowacki, B A

    2014-01-01

    Electromagnetic compaction of in situ MgB 2 /Cu wire has been achieved using a custom-built 200 J device. The monofilament core packing density was increased by 8% and up to 31% for unreacted and reacted wires respectively. The higher density of the MgB 2 core resulted in a critical current density increase of up to 75% in comparison to that for cold-drawn-only wire. Applying this treatment to a wire with Cu powder additions to the core and with an optimized heat treatment resulted in one of the highest ever reported values of J c for MgB 2 /Cu wires of 6.83 × 10 3  A cm −2 at 4.2 K and 6 T. (paper)

  6. Thermosonic wire bonding of IC devices using palladium wire

    International Nuclear Information System (INIS)

    Shze, J.H.; Poh, M.T.; Tan, R.M.

    1996-01-01

    The feasibility of replacing gold wire by palladium wire in thermosonic wire bonding of CMOS and bipolar devices are studied in terms of the manufacturability, physical, electrical and assembly performance. The results that palladium wire is a viable option for bonding the bipolar devices but not the CMOS devices

  7. Self-impedances of finite and infinite wires with earth-return

    International Nuclear Information System (INIS)

    Koglin, H.J.; Meyer, E.P.

    1981-01-01

    The electromagnetic field for a thin wire of finite length, embedded in a homogeneous earth of infinite extent in all directions, is given. The distribution of the electric field intensity close to the wire is examined. The mathematical model for the finite wire is expanded by substituting a spheroidal earth-electrode at each end. The external self-impedance of the wire between the earth-electrodes is calculated by integrating the electric field intensity along a presupposed radius. Especially in the case of short wires the results show considerable deviations to the known depth of current penetration as compared to that of an infinitely long wire. By considering the approximations used for short wires in this model, one can draw conclusions on the external self-impedance for short wires above, on and under the earth's surface. (orig.) [de

  8. Analysis of electrical explosion of wire systems for the production of ...

    Indian Academy of Sciences (India)

    Abstract. Nanoscience and nanotechnology continue to grow as fields of scien- ... material in large quantities, and development of nanoparticles characterization meth- ods. Exploding wire method is one such method for the production of metal and metal ... the voltage across the wire and the current flowing through the wire.

  9. Insulation effect on thermal stability of Coated Conductors wires in liquid nitrogen

    Science.gov (United States)

    Rubeli, Thomas; Dutoit, Bertrand; Martynova, Irina; Makarevich, Artem; Molodyk, Alexander; Samoilenkov, Sergey

    2017-02-01

    Superconducting wires are not perfectly homogeneous in term of critical current as well as stabilization. In resistive fault current limiter applications this could lead to hot spots if the fault current is only slightly above the nominal current of the device. Increasing stabilization by using thicker silver coating for example may prevent this problem but this method implies longer wire length to maintain the same impedance during a fault. Very efficient cooling in another way to prevent hot spots, this can be achieved in nucleate boiling regime. Optimal insulation can be used to prevent film boiling regime, staying in nucleate boiling regime in a much broader temperature range. In this work a novel technique is used to monitor in real time the temperature of the wire during the quench. Using this method several increasing insulation thicknesses are tested, measuring for each the heat exchange rate to the nitrogen bath. Exchange rate measurements are made in quasistatic regime and during the re-cooling of the wire. SuperOx wires provided with different insulation thicknesses exhibit an excellent stability, far above a bare wire. On the other side, for very thick insulations the stability gain is lost. Re-cooling speeds dependency on insulation thicknesses is measured too.

  10. Alignment tools used to locate a wire and a laser beam in the VISA undulator project

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Z.; Ruland, R.; Dix, B.; Arnett, D. [Stanford Linear Accelerator Center, Menlo Park, CA (United States)

    1999-07-01

    Within the framework of the LCLS (Linac Coherent Light Source), a small experiment VISA (Visual to Infrared SASE (Self Amplified Stimulated Emission) Amplifier) is being performed at Brookhaven National Laboratory. VISA consists of four wiggler segments, each 0.99 m long. The four segments are required to be aligned to the beam axis with an rms error less than 50 {mu}m. This very demanding alignment is carried out in two steps. First the segments are fiducialized using a pulsed wire system. Then the wiggler segments are placed along a reference laser beam which coincides with the electron beam axis. In the wiggler segment fiducialization, a wire is stretched through a wiggler segment and a current pulse is sent down the wire. The deflection of the wire is monitored. The deflection gives information about the electron beam trajectory. The wire is moved until its x position, the coordinate without wire sag, is on the ideal beam trajectory. (The y position is obtained by rotating the wiggler 90 deg C.) Once the wire is on the ideal beam trajectory, the wire's location is measured relative to tooling balls on the wiggler segment. To locate the wire, a device was constructed which measures the wire position relative to tooling balls on the device. The device is called the wire finder. It will be discussed in this paper. To place the magnets along the reference laser beam, the position of the laser beam must be determined. A device which can locate the laser beam relative to tooling balls was constructed and is also discussed in this paper. This device is called the laser finder. With a total alignment error budget less than 50 {mu}m, both the fiducialization and magnet placement must be performed with errors much smaller than 50 {mu}m. It is desired to keep the errors from the wire finder and laser finder at the few {mu}m level. (authors)

  11. Polarimetry and Schlieren diagnostics of underwater exploding wires

    Science.gov (United States)

    Fedotov-Gefen, A. V.; Krasik, Ya. E.

    2009-11-01

    Nondisturbing laser-probing polarimetry (based on the Faraday and Kerr effects) and Schlieren diagnostics were used in the investigation of underwater electrical wire explosion. Measuring the polarization plane rotation angle of a probing laser beam due to the Faraday effect allows one to determine an axially resolved current flowing through the exploding wire, unlike commonly used current probes. This optical method of measuring current yields results that match those obtained using a current viewing resistor within an accuracy of 10%. The same optical setup allows simultaneous space-resolved measurement of the electric field using the Kerr effect. It was shown that the maximal amplitude of the electric field in the vicinity of the high-voltage electrode is ˜80 kV/cm and that the radial electric field is <1 MV/cm during the wire explosion. Finally, it was shown that the use of Schlieren diagnostics allows one to obtain qualitatively the density distribution behind the shock wave front, which is important for the determination of the energy transfer from the discharge channel to the generated water flow.

  12. Polarimetry and Schlieren diagnostics of underwater exploding wires

    International Nuclear Information System (INIS)

    Fedotov-Gefen, A. V.; Krasik, Ya. E.

    2009-01-01

    Nondisturbing laser-probing polarimetry (based on the Faraday and Kerr effects) and Schlieren diagnostics were used in the investigation of underwater electrical wire explosion. Measuring the polarization plane rotation angle of a probing laser beam due to the Faraday effect allows one to determine an axially resolved current flowing through the exploding wire, unlike commonly used current probes. This optical method of measuring current yields results that match those obtained using a current viewing resistor within an accuracy of 10%. The same optical setup allows simultaneous space-resolved measurement of the electric field using the Kerr effect. It was shown that the maximal amplitude of the electric field in the vicinity of the high-voltage electrode is ∼80 kV/cm and that the radial electric field is <1 MV/cm during the wire explosion. Finally, it was shown that the use of Schlieren diagnostics allows one to obtain qualitatively the density distribution behind the shock wave front, which is important for the determination of the energy transfer from the discharge channel to the generated water flow.

  13. STRENGTHENING OF A REINFORCED CONCRETE BRIDGE WITH PRESTRESSED STEEL WIRE ROPES

    Directory of Open Access Journals (Sweden)

    Kexin Zhang

    2017-10-01

    Full Text Available This paper describes prestressed steel wire ropes as a way to strengthen a 20-year-old RC T-beam bridge. High strength, low relaxation steel wire ropes with minor radius, high tensile strain and good corrosion resistance were used in this reinforcement. The construction process for strengthening with prestressed steel wire ropes—including wire rope measuring, extruding anchor heads making, anchorage installing, tensioning steel wire ropes and pouring mortar was described. Ultimate bearing capacity of the bridge after strengthening was discussed based on the concrete structure theory. The flexural strength of RC T-beam bridges strengthened with prestressed steel wire ropes was governed by the failure of concrete crushing. To investigate effectiveness of the strengthening method, fielding-load tests were carried out before and after strengthening. The results of concrete strain and deflection show that the flexural strength and stiffness of the strengthened beam are improved. The crack width measurement also indicates that this technique could increase the durability of the bridge. Thus, this strengthened way with prestressed steel wire rope is feasible and effective.

  14. 29 CFR 1910.304 - Wiring design and protection.

    Science.gov (United States)

    2010-07-01

    ... contacts effectively grounded except for receptacles mounted on portable and vehicle-mounted generators in... types of current (ac or dc) on the same premises shall be of such design that the attachment plugs used... premises wiring shall be grounded as follows: (i) All 3-wire dc systems shall have their neutral conductor...

  15. Vibration of signal wires in wire detectors under irradiation

    International Nuclear Information System (INIS)

    Bojko, I.R.; Shelkov, G.A.; Dodonov, V.I.; Ignatenko, M.A.; Nikolenko, M.Yu.

    1995-01-01

    Radiation-induced vibration of signal wires in wire detectors is found and explained. The phenomenon is based on repulsion of a signal wire with a positive potential and a cloud of positive ions that remains after neutralization of the electron part of the avalanche formed in the course of gas amplification. Vibration with a noticeable amplitude may arise from fluctuations of repulsive forces, which act on the wire and whose sources are numerous ion clusters. A formula is obtained which allows wire oscillations to be estimated for all types of wire detectors. Calculation shows that oscillations of signal wires can be substantial for the coordinate accuracy of a detector working in the limited streamer mode at fluxes over 10 5 particles per second per wire. In the proportional mode an average oscillation amplitude can be as large as 20-30 μm at some detector parameters and external radiation fluxes over 10 5 . The experimental investigations show that the proposed model well describes the main features of the phenomenon. 6 refs., 8 figs

  16. Onset temperatures in hot wire Ignition of AN-Based emulsions

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Sek Kwan [Orica Mining Services, Quebec (Canada); Turcotte, Richard [Canadian Explosive Research Laboratory, Ottawa (Canada)

    2009-02-15

    Hot wire ignition experiments were carried out recently at the Canadian Explosives Research Laboratory on a few emulsion formulations. The data indicate that there is a pressure-dependent onset temperature beyond which the wire temperature increases at an accelerated rate. In order to explain this observation and to detect this temperature more consistently, particularly at low pressures, the data are reanalysed by comparing the experimental wire temperature with that predicted from theory for the heating of an inert material. For this purpose, an analytical theory from the literature is reviewed and the numerical solution developed in this report is described. The latter can deal with more general solutions with variable thermal properties and chemical reactions in the condensed medium surrounding the wire. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  17. 3D MHD Simulations of Radial Wire Array Z-pinches

    International Nuclear Information System (INIS)

    Niasse, N.; Chittenden, J. P.; Bland, S. N.; Suzuki-Vidal, F. A.; Hall, G. N.; Lebedev, S. V.; Calamy, H.; Zucchini, F.; Lassalle, F.; Bedoch, J. P.

    2009-01-01

    Recent experiments carried out on the MAGPIE (1 MA, 250 ns), OEDIPE (730 kA, 1.5 μs) and SPHINX (4 MA, 700 ns)[1] facilities have shown the relatively high level of scalability of the Radial Wire Array Z-pinches. These configurations where the wires stretch radially outwards from a central cathode offer numerous advantages over standard cylindrical arrays. In particular, imploding in a very stable and compact way, they seem suitable for coupling to small scale hohlraums. Making use of the 3D resistive magneto-hydrodynamic code GORGON[2] developed at Imperial College, the dynamic of the radial wire arrays is investigated. Influence of the cathode hotspots and wires angle on the x-ray emissions is also discussed. Comparison with experiments is offered to validate the numerical studies.

  18. Progress in second-generation HTS wire development and manufacturing

    International Nuclear Information System (INIS)

    Selvamanickam, V.; Chen, Y.; Xiong, X.; Xie, Y.; Zhang, X.; Rar, A.; Martchevskii, M.; Schmidt, R.; Lenseth, K.; Herrin, J.

    2008-01-01

    2007 has marked yet another year of continued rapid progress in developing and manufacturing high-performance, long-length second-generation (2G) HTS wires at high speeds. Using ion beam assisted deposition (IBAD) MgO and associated buffer sputtering processes, SuperPower has now exceeded piece lengths of 1000 m of fully buffered tape reproducibly with excellent in-plane texture of 6-7 degrees and uniformity of about 2%. These kilometer lengths are produced at high speeds of about 350 m/h of 4 mm wide tape. In combination with metal organic chemical vapor deposition (MOCVD), 2G wires up to single piece lengths to 790 m with a minimum critical current value of 190 A/cm corresponding to a Critical current x Length performance of 150,100 Am have been achieved. Tape speeds up to 180 m/h have been reached MOCVD while maintaining critical currents above 200 A/cm in 100+ m lengths. Thick film MOCVD technology has been transitioned to Pilot manufacturing system where a minimum critical current of 320 A/cm has been demonstrated over a length of 155 m processed at a speed of 70 m/h in 4 mm width. Finally, nearly 10,000 m of 2G wire has been produced, exhaustively tested, and delivered to the Albany Cable project. The average minimum critical current of the wire delivered in 225 segments of 43-44 m is 70 A in 4 mm widths. A 30 m cable has been fabricated with this wire by Sumitomo Electric and has been installed in the power grid of National Grid in downtown Albany and is the world's first 2G device installed in the grid

  19. Noise in the wire: The real impact of wire resistance for the Johnson(-like) noise based secure communicator

    International Nuclear Information System (INIS)

    Kish, Laszlo B.; Scheuer, Jacob

    2010-01-01

    We re-evaluate the impact of wire resistance on the noise voltage and current in the Johnson(-like) noise based secure communicator, correcting the result presented in [J. Scheuer, A. Yariv, Phys. Lett. A 359 (2006) 737]. The analysis shown here is based on the fluctuation-dissipation and the linear response theorems. The results indicate that the impact of wire resistance in practical communicators is significantly lower than the previous estimation.

  20. Study of a plasma of exploding wires at the 'Mirage' installation

    International Nuclear Information System (INIS)

    Zlotnikov, D.M.; Noskin, E.V.; Ramzaev, D.Yu.; Skoryupin, V.A.

    1989-01-01

    An interest to the explosion of thin conductors in diodes of high-current accelerators relates to the possibility of obtaining plasma with extremum (n e ∼10 23 , T e ∼1 keV) parameters being a powerful source of linear X-ray. Besides, works are stimulated by the possibility of ignition of thermonuclear reaction in intakes of z-pinch. The results of investigation of explosion dynamics of Al wires at the 'Mirazh' accelerator are presented in this paper. Wire explosion dynamics (diameter 35 μm, length 1.6 cm) is investigated using two X-ray electron optical transducers of an open type connected with a skeleton mode with pause interval ∼10 ns and time of exposition ∼5 ns. Proceeding from the initial resistance of wire (∼0.50 hm) and parameters of pre-impulse of installation U<300 V, τ < or approx.1.2 μs, it is possible to conclude that the explosion of wire occurs at the beginning of main current pulse. In the early period of time (up to 30 ns) inconsiderable spreadind of wire diameter occurs, that is confirmed by diagrams of an electron optical transducer. Further explosion dynamics and development of intakes to a great extent depend on current distribution along the wire cross section

  1. Anodic Aluminum Oxide Templates for Nano wires Array Fabrication

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Kok, K.Y.; Ng, I.K.

    2011-01-01

    This paper reports on the process developed to fabricate anodic aluminium oxide (AAO) templates suitable for the fabrication of nano wire arrays. Anodization process has been used to fabricate the AAO templates with pore diameters ranging from 15 nm to 30 nm. Electrodeposition of parallel arrays of high aspect ratio nickel nano wires were demonstrated using these fabricated AAO templates. The nano wires produced were characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that the orientations of the electrodeposited nickel nano wires were governed by the deposition current and electrolyte conditions. (author)

  2. Interferometer for electron density measurement in exploding wire plasma

    International Nuclear Information System (INIS)

    Batra, Jigyasa; Jaiswar, Ashutosh; Kaushik, T.C.

    2016-12-01

    Mach-Zehnder Interferometer (MZI) has been developed for measuring electron density profile in pulsed plasmas. MZI is to be used for characterizing exploding wire plasmas for correlating electron density dynamics with x-rays emission. Experiments have been carried out for probing electron density in pulsed plasmas produced in our laboratory like in spark gap and exploding wire plasmas. These are microsecond phenomenon. Changes in electron density have been registered in interferograms with the help of a streak camera for specific time window. Temporal electron density profiles have been calculated by analyzing temporal fringe shifts in interferograms. This report deals with details of MZI developed in our laboratory along with its theory. Basic introductory details have also been provided for exploding wire plasmas to be probed. Some demonstrative results of electron density measurements in pulsed plasmas of spark gap and single exploding wires have been described. (author)

  3. Torsion-induced magnetoimpedance in nanocrystalline Fe-based wires

    International Nuclear Information System (INIS)

    Santos, J.D.; Olivera, J.; Alvarez, P.; Sanchez, T.; Perez, M.J.; Sanchez, M.L.; Gorria, P.; Hernando, B.

    2007-01-01

    The magnetic field influence on the real and imaginary parts of axial-diagonal (ζ zz ) and off-diagonal (ζ φz ) components of the surface magnetoimpedance (MI) tensor has been studied in amorphous and nanocrystalline Fe 73.5 Si 13.5 B 9 Cu 1 Nb 3 wires. Twisted and untwisted wires were annealed at a temperature near to that of primary crystallization. The MI response has been measured at 1MHz and 5mA rms drive current in all the samples. Even though the higher values for both components of the MI tensor are achieved for the untwisted annealed wire, the most interesting features are observed in the torsion annealed wire

  4. Energy dissipation of composite multifilamentary superconductors for high-current ramp-field magnet applications

    International Nuclear Information System (INIS)

    Gung, C.Y.

    1993-01-01

    Energy dissipation, which is also called AC loss, of a composite multifilamentary superconducting wire is one of the most fundamental concerns in building a stable superconducting magnet. Characterization and reduction of AC losses are especially important in designing a superconducting magnet for generating transient magnetic fields. The goal of this thesis is to improve the understanding of AC-loss properties of superconducting wires developed for high-current ramp-field magnet applications. The major tasks include: (1) building an advanced AC-loss measurement system, (2) measuring AC losses of superconducting wires under simulated pulse magnet operations, (3) developing an analytical model for explaining the new AC-loss properties found in the experiment, and (4) developing a computational methodology for comparing AC losses of a superconducting wire with those of a cable for a superconducting pulse magnet. A new experimental system using an isothermal calorimetric method was designed and constructed to measure the absolute AC losses in a composite superconductor. This unique experimental setup is capable of measuring AC losses of a brittle Nb 3 Sn wire carrying high AC current in-phase with a large-amplitude pulse magnetic field. Improvements of the accuracy and the efficiency of this method are discussed. Three different types of composite wire have been measured: a Nb 3 Sn modified jelly-roll (MJR) internal-tin wire used in a prototype ohmic heating coil, a Nb 3 Sn internal-tin wire developed for a fusion reactor ohmic heating coil, and a NbTi wire developed for the magnets in a particle accelerator. The cross sectional constructions of these wires represent typical commercial wires manufactured for pulse magnet applications

  5. Surface cleaning of metal wire by atmospheric pressure plasma

    International Nuclear Information System (INIS)

    Nakamura, T.; Buttapeng, C.; Furuya, S.; Harada, N.

    2009-01-01

    In this study, the possible application of atmospheric pressure dielectric barrier discharge plasma for the annealing of metallic wire is examined and presented. The main purpose of the current study is to examine the surface cleaning effect for a cylindrical object by atmospheric pressure plasma. The experimental setup consists of a gas tank, plasma reactor, and power supply with control panel. The gas assists in the generation of plasma. Copper wire was used as an experimental cylindrical object. This copper wire was irradiated with the plasma, and the cleaning effect was confirmed. The result showed that it is possible to remove the tarnish which exists on the copper wire surface. The experiment reveals that atmospheric pressure plasma is usable for the surface cleaning of metal wire. However, it is necessary to examine the method for preventing oxidization of the copper wire.

  6. Cold atoms near surfaces: designing potentials by sculpturing wires

    International Nuclear Information System (INIS)

    Della Pietra, Leonardo; Aigner, Simon; Hagen, Christoph vom; Lezec, Henri J; Schmiedmayer, Joerg

    2005-01-01

    The magnetic trapping potentials for atoms on atom chips are determined by the current flow pattern in the chip wires. By modifying the wire shape using focused ion beam nano-machining we can design specialized current flow patterns and therefore micro-design the magnetic trapping potentials. We give designs for a barrier, a quantum dot, and a double well or double barrier and show preliminary experiments with ultra cold atoms in these designed potentials

  7. Wire Chamber

    CERN Multimedia

    Magnetoscriptive readout wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  8. Wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  9. Hot wire TIG temper bead welding for nuclear repairs

    International Nuclear Information System (INIS)

    Lambert, J.A.; Gilston, P.F.

    1989-08-01

    A preliminary assessment has been carried out to determine the suitability of the hot wire tungsten inert gas (TIG) welding process for the repair of thick section, ferritic steel nuclear pressure vessels. The objective has been to identify a hot wire TIG temper bead procedure, suitable for repairs without post weld heat treatment. This procedure involves depositing two weld layers with carefully selected welding parameters such that overlapping thermal cycles produce a refined and tempered heat affected zone, HAZ, microstructure. (author)

  10. A two-dimensional finite element method to calculate the AC loss in superconducting cables, wires and coated conductors

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Z; Jiang, Y; Pei, R; Coombs, T A [Electronic, Power and Energy Conversion Group, Engineering Department, University of Cambridge, CB2 1PZ (United Kingdom); Ye, L [Department of Electrical Power Engineering, CAU, P. O. Box 210, Beijing 100083 (China); Campbell, A M [Interdisciplinary Research Centre in Superconductivity, University of Cambridge, CB3 0HE (United Kingdom)], E-mail: Zh223@cam.ac.uk

    2008-02-15

    In order to utilize HTS conductors in AC electrical devices, it is very important to be able to understand the characteristics of HTS materials in the AC electromagnetic conditions and give an accurate estimate of the AC loss. A numerical method is proposed in this paper to estimate the AC loss in superconducting conductors including MgB{sub 2} wires and YBCO coated conductors. This method is based on solving a set of partial differential equations in which the magnetic field is used as the state variable to get the current and electric field distributions in the cross sections of the conductors and hence the AC loss can be calculated. This method is used to model a single-element and a multi-element MgB{sub 2} wires. The results demonstrate that the multi-element MgB{sub 2} wire has a lower AC loss than a single-element one when carrying the same current. The model is also used to simulate YBCO coated conductors by simplifying the superconducting thin tape into a one-dimensional region where the thickness of the coated conductor can be ignored. The results show a good agreement with the measurement.

  11. External wire-frame fixation of digital skin grafts: a non-invasive alternative to the K-wire insertion method.

    Science.gov (United States)

    Huang, Chenyu; Ogawa, Rei; Hyakusoku, Hiko

    2014-08-01

    The current skin graft fixation methods for digits, including the Kirschner wire insertion technique, can be limited by inadequate or excessive fixation and complications such as infection or secondary injuries. Therefore, the external wire-frame fixation method was invented and used for skin grafting of digits. This study aimed to investigate external wire-frame fixation of digital skin grafts as a non-invasive alternative to the K-wire insertion method. In 2005-2012, 15 patients with burn scar contractures on the hand digits received a skin graft that was then fixed with an external wire frame. The intra-operative time needed to make the wire frame, the postoperative time to frame and suture removal, the graft survival rate, the effect of contracture release and the complications were recorded. In all cases, the contracture release was 100%. The complete graft survival rate was 98.6%. Four patients had epithelial necrosis in wire-frame fixation is simple, minimally invasive and a custom-made technique for skin grafting of the fingers. It was designed for its potential benefits and the decreased risk it poses to patients with scar contractures on their fingers. It can be implemented in three phases of grafting, does not affect the epiphyseal line or subsequent finger growth and is suitable for children with multi-digit involvement. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  12. Autowaves in an active two-wire line with exponential current-voltage characteristics

    International Nuclear Information System (INIS)

    Zhuravlev, V. M.

    2006-01-01

    Nonlinear wave processes in two-wire lines containing an active element with an exponential current-voltage characteristic (CVC) similar to that of a p-n junction are investigated. These lines are models of systems that are encountered in various physical and biological applications, such as biological membranes and semiconductor devices. It is shown that such systems may operate in different modes each of which has different dispersion and dissipation properties and, as a consequence, is described by autowave processes of different types. The behavior of a system in all basic modes is analyzed. For each mode, exact solutions to relevant equations are found and their differential conservation laws and intrinsic symmetries are investigated. One of common properties of such equations is the presence of a special superposition principle that describes the discrete structure of excitations in a line that consist of individual elementary excitations. It is shown that autopulses may be generated in such systems

  13. Comparing the thermal stability of NbTi and Nb3Sn wires

    International Nuclear Information System (INIS)

    Breschi, M; Trevisani, L; Bottura, L; Devred, A; Trillaud, F

    2009-01-01

    The investigation of quenching in low temperature superconducting wires is of great relevance for a proper design of superconductive cables and magnets. This paper reports the experimental results of a vast measurement campaign of quench induced by laser pulses on NbTi and Nb 3 Sn wires in pool boiling helium I. A comparison of the quench behavior of two typical NbTi and Nb 3 Sn wires is shown from different standpoints. Different qualitative behaviors of the voltage traces recorded during quenches and recoveries on NbTi and Nb 3 Sn wires are reported and analyzed. It is shown that the Nb 3 Sn wire exhibits a quench or no-quench behavior, whereas quenches and recoveries are exhibited by the NbTi wire. The two wires are also compared by considering the behaviors of the two main parameters describing quench, i.e. quench energies and quench velocities, with respect to operating current, pulse duration, and magnetic field. It is shown that the Nb 3 Sn wire exhibits a 'kink' of the quench energy versus current curve that makes the quench energy of Nb 3 Sn lower than that of NbTi at some intermediate current levels. Both the qualitative differences of the voltage traces and the different behaviors of quench energies and velocities are interpreted through a coupled electromagnetic-thermal model, with special emphasis on the detailed description of heat exchange with liquid helium.

  14. Investigation of wire motion in superconducting magnets

    International Nuclear Information System (INIS)

    Ogitsu, T.; Tsuchiya, K.; Devred, A.

    1990-09-01

    The large Lorentz forces occuring during the excitation of superconducting magnets can provoke sudden motions of wire, which eventually release enough energy to trigger a quench. These wire motions are accompanied by two electromagnetic effects: an induced emf along the moved wire, and a local change in flux caused by the minute dislocation of current. Both effects cause spikes in the coil voltage. Voltage data recorded during the excitation of a superconducting quadrupole magnet which early exhibit such events are here reported. Interpretations of the voltage spikes in terms of energy release are also presented, leading to insights on the spectrum of the disturbances which occur in real magnets. 15 refs

  15. Retrograde Intubation in Temporomandibular Joint Ankylosis-A Double Guide Wire Technique

    Directory of Open Access Journals (Sweden)

    Vitha K Dhulkhed

    2008-01-01

    Full Text Available Intubating a patient with temporomandibular joint ankylosis is always a challenge particularly when fibreoptic laryngo-scope is not available. In a 20-year-old male patient we successfully carried out endotracheal intubation with 7 mm portex cuffed PVC tube with the help of two flexible J tipped guide wires. One guide wire was passed into the airway from cricothyroid puncture site and another from subcricoid site. Both were brought out through the nose. The first guide wire was used for retracting the epiglottis and the second as a guide for passing the endotracheal tube.

  16. Progress on MOD/RABiTS{sup TM} 2G HTS wire

    Energy Technology Data Exchange (ETDEWEB)

    Rupich, M.W.; Zhang, W.; Li, X.; Kodenkandath, T.; Verebelyi, D.T.; Schoop, U.; Thieme, C.; Teplitsky, M.; Lynch, J.; Nguyen, N.; Siegal, E.; Scudiere, J.; Maroni, V.; Venkataraman, K.; Miller, D.; Holesinger, T.G

    2004-10-01

    The development of the second generation (2G) high temperature superconducting wire has advanced beyond initial laboratory demonstrations and is now focused on developing and testing high critical current conductor designs required for commercial applications. The approach pursued at American Superconductor for 2G wire manufacturing is based on the combination of the RABiTS{sup TM} substrate-buffer technology with metal organic deposition (MOD) of the YBCO layer. This MOD/RABiTS{sup TM} approach has been demonstrated in 10 m lengths with critical currents of up to 184 A/cm-width ({approx}2.3 MA/cm{sup 2}) and in short length with critical currents of up to 270 A/cm-width ({approx}3.4 MA/cm{sup 2}). In addition to a high critical current, the superconducting wire must also meet stringent mechanical and electrical stability requirements that vary by application. Commercially viable architectures designed to meet these specifications have been fabricated and tested. Wires manufactured by this process have been successfully tested in prototype cable and coil applications.

  17. Nonlinear calculation of the M=1 internal kink instability in current carrying stellarators

    International Nuclear Information System (INIS)

    Wakatani, M.

    1978-02-01

    Nonlinear properties of the m = 1 internal kink mode are shown in a low β current carrying stellarator. The effects of the external helical magnetic fields are considered through a rotational transform and the magnetic surface is assumed to be circular. Magnetic surfaces inside the iota sub(h) + iota sub(σ) = 1 surface shift and deform non-circularly, while magnetic surfaces outside the iota sub(h) + iota sub(σ) = 1 are not disturbed, where iota sub(h) is a rotational transform due to helical magnetic fields and iota sub(σ) is due to a plasma current. Many higher harmonics are excited after the fundamental mode saturates. When the external helical magnetic fields are lowered, the m = 1 tearing mode similar to that in a low β tokamak grows and magnetic islands appear near the iota sub(h) + iota sub(σ) = 1 surface. For adequate helical magnetic fields, the current carrying stellarator becomes stable against both the m = 1 internal kink mode and the m = 1 tearing mode, without lowering the rotational transform. (auth.)

  18. Absorption of short-pulse electromagnetic energy by a resistively loaded straight wire

    International Nuclear Information System (INIS)

    Miller, E.K.; Deadrick, F.J.; Landt, J.A.

    1975-01-01

    Absorption of short-pulse electromagnetic energy by a resistively loaded straight wire is examined. Energy collected by the wire, load energy, peak load currents, and peak load voltages are found for a wide range of parameters, with particular emphasis on nuclear electromagnetic pulse (EMP) phenomena. A series of time-sequenced plots is used to illustrate pulse propagation on wires when loads and wire ends are encountered

  19. Production of diamond wire by Cu15 v-% Nb 'in situ' process

    International Nuclear Information System (INIS)

    Filgueira, M.; Pinatti, D.G.

    2001-01-01

    Diamond wires are cutting tools used in the slabbing of dimension stones, such as marbles and granites, as well as in cutting of concrete structures. This tool consists of a steel cable on which diamond annular segments (pearls) are mounted with spacing between them. This work has developed a new technological route to obtain the diamond wires, whose fabrication involves metal forming processes such as rotary forging and wire drawing, copper tubes restacking, and thermal treatments of sintering and recrystallization. It was idealized the use of Cu 15v% Nb composite wires as the high tensile strength cable, covered with an external cutting rope made of bronze 4wt% diamond composite, along the overall wire surface. Investigations were carried out on the mechanical behavior and on the microstructural evolution of the Cu 15 vol % Nb wires, which showed ultimate tensile strength (UTS) of 960 MPa and deformation of approximately 3,0 %. The cutting external rope of 1.84 mm in diameter showed UTS = 230 MPa. On the microstructural side aspect it was observed that the diamond crystals were uniformly distributed throughout the tool bulk in the several processing steps. Cutting tests were carried out starting with an external diamond rope of 1.93 mm in diameter, which cut a marble sectional area of 1188 cm 2 , and the tool degraded to a final diameter of 1.23 mm. For marble the 'in situ' wire showed a probable performance 4 times higher than the diamond saws, however their probable performance was about 5 to 8 times less than the conventional diamond wires due to the low abrasion resistance of the bronze matrix and the low adhesion between the pair bronze-diamond. (author)

  20. Eliminating a Major Cause of Wire Drawing Breakage in A-15 High-Field Superconductors

    International Nuclear Information System (INIS)

    Austen, Alfred R.

    2003-01-01

    Eliminating a Major Cause of Wire Drawing Breakage in A-15 High-Field Superconductors Phase 1 Summary Purpose of the research: The Phase 1 goal was to make a significant improvement in the wire drawing technology used for difficult to draw superconductor precursor composites. Many ductile Nb-Al and Nb-Sn precursor wire composites have experienced the onset of wire drawing breakage at about 1.5 mm diameter. Phase 1 focused on evaluating the role that precision rigid guidance of the wire into the drawing die and the hydrostatic stress state at the die entrance played in preventing wire breakage. Research carried out: The research performed depended upon the construction of both a mechanical wire guide and a hydrostatic pressure stiffened wire guidance system. Innovare constructed the two wire guidance systems and tested them for their ability to reduce wire drawing breakage. One set of hardware provided rigid alignment of the wires to their wire drawing die axes within 0.35 degrees using ''hydrostatic pressure stiffening'' to enable the precision guidance strategy to be implemented for these highly flexible small diameter wires. This apparatus was compared to a guide arrangement that used short span mechanical guide alignment with a misalignment limit of about 0.75 degrees. Four A-15 composite wires with breakage histories were drawn to evaluate the use of these wire guiding systems to reduce and/or eliminate wire breakage. Research findings and results: In Phase 1, a breakthrough in wire drawing technology for A-15 superconductor composites was achieved by dramatically limiting or eliminating breakage in four different A-15 composite precursor wire designs during the drawing of these very desirable composites that previously could not be drawn to near final size. Research results showed that the proposed Phase 1 mechanical wire guides were sufficiently effective and successful in eliminating breakage when used along with other advanced wire drawing technology to

  1. Mesoscopic NbSe3 wires

    International Nuclear Information System (INIS)

    Zant, H.S.J. van der; Kalwij, A.; Mantel, O.C.; Markovic, N.

    1999-01-01

    We have fabricated wire structures with (sub)micron sizes in the charge-density wave conductor NbSe 3 . Electrical transport measurements include complete mode-locking on Shapiro steps and show that the patterning has not affected the CDW material. Our mesoscopic wires show strong fluctuation and hysteresis effects in the low-temperature current-voltage characteristics, as well as a strong reduction of the phase-slip voltage. This reduction can not be explained with existing models. We suggest that single phase-slip events are responsible for a substantial reduction of the CDW strain in micron-sized systems. (orig.)

  2. Progress in second-generation HTS wire development and manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Selvamanickam, V. [SuperPower, Inc., 450 Duane Avenue, Schenectady, NY 12304 (United States)], E-mail: vselva@superpower-inc.com; Chen, Y.; Xiong, X.; Xie, Y.; Zhang, X.; Rar, A.; Martchevskii, M.; Schmidt, R.; Lenseth, K.; Herrin, J. [SuperPower, Inc., 450 Duane Avenue, Schenectady, NY 12304 (United States)

    2008-09-15

    2007 has marked yet another year of continued rapid progress in developing and manufacturing high-performance, long-length second-generation (2G) HTS wires at high speeds. Using ion beam assisted deposition (IBAD) MgO and associated buffer sputtering processes, SuperPower has now exceeded piece lengths of 1000 m of fully buffered tape reproducibly with excellent in-plane texture of 6-7 degrees and uniformity of about 2%. These kilometer lengths are produced at high speeds of about 350 m/h of 4 mm wide tape. In combination with metal organic chemical vapor deposition (MOCVD), 2G wires up to single piece lengths to 790 m with a minimum critical current value of 190 A/cm corresponding to a Critical current x Length performance of 150,100 Am have been achieved. Tape speeds up to 180 m/h have been reached MOCVD while maintaining critical currents above 200 A/cm in 100+ m lengths. Thick film MOCVD technology has been transitioned to Pilot manufacturing system where a minimum critical current of 320 A/cm has been demonstrated over a length of 155 m processed at a speed of 70 m/h in 4 mm width. Finally, nearly 10,000 m of 2G wire has been produced, exhaustively tested, and delivered to the Albany Cable project. The average minimum critical current of the wire delivered in 225 segments of 43-44 m is 70 A in 4 mm widths. A 30 m cable has been fabricated with this wire by Sumitomo Electric and has been installed in the power grid of National Grid in downtown Albany and is the world's first 2G device installed in the grid.

  3. AC loss characteristics of Bi2223/Ag sheathed tape wires subjected to mechanical strains and stresses

    International Nuclear Information System (INIS)

    Tsukamoto, Osami; Li, Z

    2007-01-01

    The influence of uniaxial tensile stress-strain on the AC loss characteristics of multifilamentary Bi2223/Ag sheathed tape wires was investigated. The uniaxial tensile stress-strain was applied to the sample wire in liquid nitrogen at atmospheric pressure, and the AC losses (transport, magnetization and total losses) were measured by an electric method. Two kinds of wire, oxide-dispersion strengthened Ag-alloy sheathed and Ag-alloy sheathed wires, were tested. The stress-strain curves of the tested wires were divided in three regions, i.e. elastic deformation, continuous plastic deformation and serrated-like plastic deformation regions, though the ranges of those regions were different for different kinds of wire. In the elastic and continuous plastic regions, the stress-strain curve was smooth and continuous, and in the serrated-like plastic region, the curve was rough. In the serrated-like plastic region, the wires kept elongating, while increase of the tensile stress was suspended. Dependences of the critical currents on the stress-strain were generally as follows. While decreases of the wire critical currents were in the range of less than 4% of the original values of the no-stress condition, the critical currents of the wires were reversible, that is, the critical currents recovered the original values at zero stress when the stress were released, regardless of whether the wires were in the elastic or continuous plastic region. In the continuous plastic region, the critical currents decreased up to 10%-15% of the original values and the critical currents were irreversible when the degradations of the critical currents exceeded about 4%. In the serrated-like plastic regions, the critical currents were more severely degraded. The AC loss characteristics of the wires are different in those regions. In the elastic and continuous plastic regions, the absolute values of AC losses were dependent on the stress-strain. However, the dependences of those normalized

  4. Electrochemically deposited BiTe-based nano wires for thermoelectric applications

    International Nuclear Information System (INIS)

    Inn-Khuan, N.; Kuan-Ying, K.; Che Zuraini Che Abdul Rahman; Nur Ubaidah Saidin; Suhaila Hani Ilias; Thye-Foo, C.

    2013-01-01

    Full-text: Nano structured materials systems such as thin-films and nano wires (NWs) are promising for thermoelectric power generation and refrigeration compared to traditional counterparts in bulk, due to their enhanced thermoelectric figures-of-merit. BiTe and its derivative compounds, in particular, are well-known for their near-room temperature thermoelectric performance. In this work, both the binary and ternary BiTe-based nano wires namely, BiTe and BiSbTe, were synthesized using template-assisted electrodeposition. Diameters of the nano wires were controlled by the pore sizes of the anodised alumina (AAO) templates used. Systematic study on the compositional change as a function of applied potential was carried out via Linear Sweep Voltametry (LSV). Chemical compositions of the nano wires were studied using Energy Dispersive X-ray Spectrometry (EDXS) and their microstructures evaluated using diffraction and imaging techniques. Results from chemical analysis on the nano wires indicated that while the Sb content in BiSbTe nano wires increased with more negative deposition potentials, the formation of Te 0 and Bi 2 Te 3 were favorable at more positive potentials. (author)

  5. Superconducting wire for Lawrence Livermore National Laboratory in U.S.A

    International Nuclear Information System (INIS)

    Inoue, Itaru; Ikeda, Masaru; Tanaka, Yasuzo; Meguro, Shinichiro

    1985-01-01

    In Lawrence Livermore National Laboratory in USA, the development of a mirror type nuclear fusion reactor is carried out, and for plasma confinement, superconducting magnets are used. For the axicell coil generating a 12 T magnetic field in one of these magnets, Nb 3 Sn superconducting wires are to be used, and after the completion, it will be the largest magnet in the world as high magnetic field superconducting magnets. Furukawa Electric Co., Ltd. has completed the delivery of Nb 3 Sn superconducting wires used for this purpose. Since the Nb 3 Sn superconducting wires are very brittle, attention was paid to the manufacture to satisfy the required characteristics, and it was able to obtain the good reputation that the product was highly homogeneous as the superconducting wires of this type. In this paper, the design, manufacture and various characteristics of these superconducting wires are reported. The Nb 3 Sn superconducting wires were manufactured on industrial scale of 8 tons. The features of these Nb 3 Sn wires are the compound structure with semi-hard copper for low temperature stability and strengthening. (Kako, I.)

  6. Optimization of electron beam crosslinking of wire and cable insulation

    International Nuclear Information System (INIS)

    Zimek, Zbigniew; Przybytniak, Grażyna; Nowicki, Andrzej

    2012-01-01

    The computer simulations based on Monte Carlo (MC) method and the ModeCEB software were carried out in connection with electron beam (EB) radiation set-up for crosslinking of electric wire and cable insulation. The theoretical predictions for absorbed dose distribution in irradiated electric insulation induced by scanned EB were compared to the experimental results of irradiation that was carried out in the experimental set-up based on ILU 6 electron accelerator with electron energy 0.5–2.0 MeV. The computer simulation of the dose distributions in two-sided irradiation system by a scanned electron beam in multilayer circular objects was performed for various process parameters, namely electric wire and cable geometry (thickness of insulation layers and copper wire diameter), type of polymer insulation, electron energy, energy spread and geometry of electron beam, electric wire and cable layout in irradiation zone. The geometry of electron beam distribution in the irradiation zone was measured using CTA and PVC foil dosimeters for available electron energy range. The temperature rise of the irradiated electric wire and irradiation homogeneity were evaluated for different experimental conditions to optimize technological process parameters. The results of computer simulation are consistent with the experimental data of dose distribution evaluated by gel-fraction measurements. Such conformity indicates that ModeCEB computer simulation is reliable and sufficient for optimization absorbed dose distribution in the multi-layer circular objects irradiated with scanned electron beams. - Highlights: ► We model wire and cables irradiation process by Monte Carlo simulations. ► We optimize irradiation configuration for various process parameters. ► Temperature rise and irradiation homogeneity were evaluated. ► Calculation (dose) and experimental (gel-fraction) results were compared. ► Computer simulation was found reliable and sufficient for process optimization.

  7. A new route to process diamond wires

    Directory of Open Access Journals (Sweden)

    Marcello Filgueira

    2003-06-01

    Full Text Available We propose an original route to process diamond wires, denominated In Situ Technology, whose fabrication involves mechanical conformation processes, such as rotary forging, copper tubes restacking, and thermal treatments, such as sintering and recrystallisation of a bronze 4 wt.% diamond composite. Tensile tests were performed, reaching an ultimate tensile strength (UTS of 230 MPa for the diameter of Æ = 1.84 mm. Scanning electron microscopy showed the diamond crystals distribution along the composite rope during its manufacture, as well as the diamond adhesion to the bronze matrix. Cutting tests were carried out with the processed wire, showing a probable performance 4 times higher than the diamond sawing discs, however its probable performance was about 5 to 8 times less than the conventional diamond wires (pearl system due to the low abrasion resistance of the bronze matrix, and low adhesion between the pair bronze-diamond due to the use of not metallised diamond single crystals.

  8. Optimization of arc-start performance by wire-feeding control for GMA welding

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Jong Gu; Ryu, Gyeong Su; Rhee, Se Hun [Hanyang University, Seoul (Korea, Republic of); Kim, Dong Cheol; Kang, Mun Jin [Korea Institute of Industrial Technology, Incheon (Korea, Republic of); Park, Young Whan [Pukyong National University, Busan (Korea, Republic of)

    2013-02-15

    The wire feeding system for gas metal arc welding usually consists of a wire feeder and a torch. In many industries, the distance between the wire feeder and the torch is generally 3 m to 5 m. In a conventional wire feeder, a direct current (DC) motor is used for wire feeding. However, a significant problem with this system is the impossibility of feedback control because of inner or outer impedance. In this paper, a digital wire feeder was developed by using a DC encoder motor and a push-pull torch. An optimized wire-feeding system was also developed by experiment. The welding process was observed using a high-speed camera. The resulting wire-feeding system exhibits low spatter generation and arc stability.

  9. Control for the Three-Phase Four-Wire Four-Leg APF Based on SVPWM and Average Current Method

    Directory of Open Access Journals (Sweden)

    Xiangshun Li

    2015-01-01

    Full Text Available A novel control method is proposed for the three-phase four-wire four-leg active power filter (APF to realize the accurate and real-time compensation of harmonic of power system, which combines space vector pulse width modulation (SVPWM with triangle modulation strategy. Firstly, the basic principle of the APF is briefly described. Then the harmonic and reactive currents are derived by the instantaneous reactive power theory. Finally simulation and experiment are built to verify the validity and effectiveness of the proposed method. The simulation results show that the response time for compensation is about 0.025 sec and the total harmonic distortion (THD of the source current of phase A is reduced from 33.38% before compensation to 3.05% with APF.

  10. Electrical and microstructural characterization of silver sheathed high Tc superconductors wires and ribbons

    International Nuclear Information System (INIS)

    Chaffron, L.; Regnier, P.; Schmirgeld, L.; Maurice, F.; Aguillon, C.; Senoussi, S.

    1991-01-01

    High Tc superconductors wires and ribbons were prepared according to the powder in tube method. It is shown that the electrical performances of the so prepared superconductors can be considerably improved, first by increasing as much as possible the density of the green body before sintering, and afterwards by melt texturing the sintered conductors. Some measurements of the transport critical current density of our conductors as a function of their diameter or their thickness are then presented and compared with indirect values obtained via the Bean method. The highest transport Jc measured in the present study, before melt texturing, are: 2250 and 5100 A/cm 2 at 77 and 63 K respectively, for a 50 μm thick silver sheathed ribbon. These figures compare nicely with the values of the intergranular critical current densities determined from magnetic measurements which are: 2100 and 5000 A/cm 2 at the same temperatures, and 40000 A/cm 2 at 4.2 K. Much higher intergranular values, in the range of 10 5 A/cm 2 were obtained after melt texturing the wires. Finally, microstructural characterizations carried out by X-ray diffraction, electron microprobe analysis and transmission electron microscopy are reported and discussed

  11. Investigation about the Chrome Steel Wire Arc Spray Process and the Resulting Coating Properties

    Science.gov (United States)

    Wilden, J.; Bergmann, J. P.; Jahn, S.; Knapp, S.; van Rodijnen, F.; Fischer, G.

    2007-12-01

    Nowadays, wire-arc spraying of chromium steel has gained an important market share for corrosion and wear protection applications. However, detailed studies are the basis for further process optimization. In order to optimize the process parameters and to evaluate the effects of the spray parameters DoE-based experiments had been carried out with high-speed camera shoots. In this article, the effects of spray current, voltage, and atomizing gas pressure on the particle jet properties, mean particle velocity and mean particle temperature and plume width on X46Cr13 wire are presented using an online process monitoring device. Moreover, the properties of the coatings concerning the morphology, composition and phase formation were subject of the investigations using SEM, EDX, and XRD-analysis. These deep investigations allow a defined verification of the influence of process parameters on spray plume and coating properties and are the basis for further process optimization.

  12. Technology development of fabrication NbTi and Nb3 Sn superconducting wires

    International Nuclear Information System (INIS)

    Rodrigues Junior, D.; Bormio, C.; Baldan, C.A.; Ramos, M.J.; Pinatti, D.G.

    1988-01-01

    The technology development of NbTi and Nb 3 Sn superconducting wires are studied, mentioning the use of fluxes capture theory in the sizing of wires fabrication. The fabrication process, the thermal treatment and the experimental datas of critical temperature and current of Nb 3 Sn wires are described. (C.G.C.) [pt

  13. Development and manufacturing of bronze-processed Ta-added Nb3Sn wires for the ITER

    International Nuclear Information System (INIS)

    Kikuchi, Kenichi; Seidou, Masahiro; Iwaki, Genzou; Sakai, Syuuji; Moriai, Hidezumi; Nishi, Masataka; Yoshida, Kiyoshi; Isono, Takaaki; Tsuji, Hiroshi.

    1997-01-01

    Development work to produce a high-performance Nb 3 Sn superconducting wire for the center solenoid coil of the ITER was carried out. The effects of concurrently adding Ti and Ta to bronze-processed Nb 3 Sn wires were examined. In addition, a high-Sn-concentration bronze matrix was applied. Then, the relation between hysteresis loss and filament diameter was examined. Moreover, the cause of wire breakage during processing was elucidated. As a result, a reliable manufacturing process for high-performance Nb 3 Sn superconducting wire was established. (author)

  14. Analysis of thermal characteristics of electrical wiring for load groups in cattle barns.

    Science.gov (United States)

    Kim, Doo Hyun; Yoo, Sang-Ok; Kim, Sung Chul; Hwang, Dong Kyu

    2015-01-01

    The purpose of the current study is to analyze the thermal characteristics of electrical wirings depending on the number of operating load by connecting four types of electrical wirings that are selected by surveying the conditions for the electric fans, automatic waterers and halogen warm lamps that were installed in cattle barns in different years. The conditions of 64 cattle barns were surveyed and an experimental test was conducted at a cattle barn. The condition-survey covered inappropriate design, construction and misuse of electrical facility, including electrical wiring mostly used, and the mode of load current was evaluated. The survey showed that the mode of load current increased as the installation year of the fans, waterers and halogen lamps became older. Accordingly, the cattle barn manager needed to increase the capacity of the circuit breaker, which promoted the degradation of insulation of the electrical wires' sheath and increased possibility for electrical fires in the long-run. The test showed that the saturation temperature of the wire insulated sheath increased depending on the installation year of the load groups, in case of VCTFK and VFF electric wires, therefore, requiring their careful usage in the cattle barns.

  15. F-8 Digital Fly-by-Wire (DFBW) in flight over snow capped mountains

    Science.gov (United States)

    1973-01-01

    is more efficient because it is lighter and takes up less space than the hydraulic systems it replaced. This either reduces the fuel required to fly or increases the number of passengers or pounds of cargo the aircraft can carry. Digital fly-by-wire is currently used in a variety of aircraft ranging from F/A-18 fighters to the Boeing 777. The DFBW research program is considered one of the most significant and most successful NASA aeronautical programs since the inception of the agency. F-8 aircraft were built originally for the U.S. Navy by LTV Aerospace of Dallas, Texas. The aircraft had a wingspan of 35 feet, 2 inches; was 54 feet, 6 inches long; and was powered by a Pratt & Whitney J57 turbojet engine.

  16. Advances in second generation high temperature superconducting wire manufacturing and R and D at American Superconductor Corporation

    Energy Technology Data Exchange (ETDEWEB)

    Rupich, Martin W; Li Xiaoping; Thieme, Cees; Sathyamurthy, Srivatsan; Fleshler, Steven; Tucker, David; Thompson, Elliot; Schreiber, Jeff; Lynch, Joseph; Buczek, David; DeMoranville, Ken; Inch, James; Cedrone, Paul; Slack, James, E-mail: mrupich@amsc.co [American Superconductor Corporation, 64 Jackson Road, Devens, MA 01434-4020 (United States)

    2010-01-15

    The RABiTS(TM)/MOD-YBCO (rolling assisted biaxially textured substrate/metal-organic deposition of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}) route has been established as a low-cost manufacturing process for producing high performance second generation (2G) wire. American Superconductor Corporation (AMSC) has used this approach to establish a production scale manufacturing line based on a wide-web manufacturing process. This initial production line is currently capable of producing 2G wire in lengths to 500 m with critical currents exceeding 250 A cm{sub width}{sup -1} at 77 K, in the self-field. The wide-web process, combined with slitting and lamination processes, allows customization of the 2G wire width and stabilizer composition to meet application specific wire requirements. The production line is currently supplying 2G wire for multiple cable, fault current limiter and coil applications. Ongoing R and D is focused on the development of thicker YBCO layers and improved flux pinning centers. This paper reviews the history of 2G wire development at AMSC, summarizes the current capability of the 2G wire manufacturing at AMSC, and describes future R and D improvements.

  17. Pin Wire Coating Trip Report

    International Nuclear Information System (INIS)

    Spellman, G P

    2004-01-01

    A meeting to discuss the current pin wire coating problems was held at the Reynolds plant in Los Angeles on 2MAR04. The attendance list for Reynolds personnel is attached. there was an initial presentation which gave a brief history and the current status of pin wire coating at Reynolds. There was a presentation by Lori Primus on the requirements and issues for the coating. There was a presentation by Jim Smith of LANL on the chemistry and to some extent process development done to date. There was a long session covering what steps should be taken in the short term and, to a lesser extent, the long term. The coating currently being used is a blend of two polymers, polyethersulfone and polyparabanic acid (PPA) and some TiO2 filler. This system was accepted and put into production when the pin wire coating was outsourced to another company in 1974. When that company no longer was interested, the wire coating was brought in-house to Reynolds. At that time polyparabanic acid was actually a commercial product available from Exxon under the trade name Tradlon. However, it appears that the material used at Reynolds was synthesized locally. Also, it appears that a single large batch was synthesized in that time period and used up to 1997 when the supply ran out. The reason for the inclusion of TiO2 is not known although it does act as a rheological thickener. However, a more controlled thickening can be obtained with materials such as fumed silica. This material would have less likelihood of causing point imperfections in the coatings. Also, the mixing technique being used for all stages of the process is a relatively low shear ball mill process and the author recommends a high shear process such as a three roll paint mill, at least for the final mixing. Since solvent is added to the powder at Reynolds, it may be that they need to have the paint mill there

  18. Critical current density analysis of ex situ MgB2 wire by in-field and temperature Hall probe imaging

    International Nuclear Information System (INIS)

    Bartolome, E; Granados, X; Cambel, V; Fedor, J; Kovac, P; Husek, I

    2005-01-01

    The irreversible magnetic behaviour at different temperatures of an ex situ Fe-alloy/MgB 2 wire, exhibiting a granular compositional distribution, was studied using an in-field, high resolution Hall probe imaging system. Quantitative information about the local current density was obtained by solving the Biot-Savart inversion problem. The flux penetration and current distribution maps obtained can be attributed to a inhomogeneous compositional 'plum-cake-like' system, consisting of large, isolated MgB 2 agglomerations embedded in a matrix of finely distributed MgB 2 +MgO. The critical current densities within the grains and their evolution with the applied magnetic field and temperature have been obtained, and compared to the mean J c (H,T) in the matrix

  19. A high resolution wire scanner beam profile monitor with a microprocessor data acquisition system

    International Nuclear Information System (INIS)

    Cutler, R.I.; Mohr, D.L.; Whittaker, J.K.; Yoder, N.R.

    1983-01-01

    A beam profile monitor has been constructed for the NBS-LANL Racetrack Microtron. The monitor consists of two perpendicular 30 μm diameter carbon wires that are driven through an electron beam by a pneumatic actuator. A long-lifetime, electroformed nickel bellows is used for the linear-motion vacuum feedthrough. Secondary emission current from the wires and a signal from a transducer measuring the position of the wires are simultaneously digitized by a microprocessor to yield beam current density profiles in two dimensions. The wire scanner is designed for use with both pulsed and cw beams

  20. Flow pattern assessment in tubes with wire coil inserts in laminar and transition regimes

    International Nuclear Information System (INIS)

    Garcia, A.; Solano, J.P.; Vicente, P.G.; Viedma, A.

    2007-01-01

    The paper presents an analysis of the flow mechanisms in tubes with wire coils using hydrogen bubble visualization and PIV techniques. Results have been contrasted with experimental data on pressure drop. The relation between the observed flow patterns and the friction factor has been analysed. The experimental analysis that has been carried out allows one to state that at low Reynolds numbers (Re < 400) the flow in tubes with wire coils is basically similar to the flow in smooth tubes. At Reynolds numbers between 500 and 700 and in short pitch wire coils a recirculating flow appears. The insertion of wires coils in a smooth tube accelerates significantly the transition to turbulence. This is produced at Reynolds numbers between 700 and 1000 depending on the wire pitch

  1. Superconducting critical-current densities of commercial multifilamentary Nb3Sn(Ti) wires made by the bronze process

    International Nuclear Information System (INIS)

    Suenaga, M.; Tsuchiya, K.; Higuchi, N.; Tachikawa, K.

    1985-01-01

    Superconducting critical-current densities Jsub(c) in fields up to 24 T and at 4.2 and 1.8 K were measured for a number of commercial Nb 3 Sn wires which were alloyed with Ti. The best values of Jsub(c) at 20 T and at 4.2 and 1.8 K were 78 and 156 A mm -2 , respectively. In order to achieve these high current densities at H>20 T, it was shown that nonuniformity of the filaments had to be minimized. It was also shown that the grain size of Nb 3 Sn is not very important in determining Jsub(c) at these high magnetic fields, and that achieving high values of critical magnetic field Hsub(c2) is more important than small grain size. (author)

  2. Detection of a buried wire with two resistively loaded wire antennas

    NARCIS (Netherlands)

    Vossen, S.H.J.A.; Tijhuis, A.G.; Lepelaars, E.S.A.M.; Zwamborn, A.P.M.

    2002-01-01

    The use of two identical straight thin-wire antennas for the detection of a buried wire is analyzed with the aid of numerical calculations. The buried wire is located below an interface between two homogeneous half-spaces. The detection setup, which is formed by a transmitting and a receiving wire,

  3. Flux pinning in bronze-processed Nb3Sn wires

    International Nuclear Information System (INIS)

    Suenaga, M.; Welch, D.O.

    1980-01-01

    The scaling law derived by Kramer for magnetic flux pinning in high magnetic fields was examined for its applicability to the magnetic field dependence of critical-current densities in the bronze processed monofilamentary Nb 3 Sn wires. From this it was concluded that: (1) its prediction for the form of the dependence of critical current on magnetic field and grain size [/J vector /sub c/ x H vector/ approx. h/sup 1/2/(1-h) 2 (1-a 0 √rho) -2 ] was found to be very good in most cases including wires with very small Nb 3 Sn grains (approx. 400 A). It was found very useful in comparison of J/sub c/ for different wires and in extrapolating to obtain H/sub c2/ for these wires. (2) However, it could not account consistently for the anisotropy in critical current of a tape which was measured with H applied perpendicular and parallel to the tape face. (3) The values of kappa 1 which were determined with the scaling law were too small by a factor of 2 to 3, and the trend in the variation with heat-treating time was opposite to that which is reasonably to be expected. That the behavior of kappa 1 is thus seriously in contradiction with the expected behavior for Nb 3 Sn suggests basic faults in the derivation of the scaling equation for critical currents at high magnetic fields

  4. wire chamber

    CERN Multimedia

    1985-01-01

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  5. Wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  6. wire chamber

    CERN Multimedia

    Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  7. Manchester Coding Option for SpaceWire: Providing Choices for System Level Design

    Science.gov (United States)

    Rakow, Glenn; Kisin, Alex

    2014-01-01

    This paper proposes an optional coding scheme for SpaceWire in lieu of the current Data Strobe scheme for three reasons. First reason is to provide a straightforward method for electrical isolation of the interface; secondly to provide ability to reduce the mass and bend radius of the SpaceWire cable; and thirdly to provide a means for a common physical layer over which multiple spacecraft onboard data link protocols could operate for a wide range of data rates. The intent is to accomplish these goals without significant change to existing SpaceWire design investments. The ability to optionally use Manchester coding in place of the current Data Strobe coding provides the ability to DC balanced the signal transitions unlike the SpaceWire Data Strobe coding; and therefore the ability to isolate the electrical interface without concern. Additionally, because the Manchester code has the clock and data encoded on the same signal, the number of wires of the existing SpaceWire cable could be optionally reduced by 50. This reduction could be an important consideration for many users of SpaceWire as indicated by the already existing effort underway by the SpaceWire working group to reduce the cable mass and bend radius by elimination of shields. However, reducing the signal count by half would provide even greater gains. It is proposed to restrict the data rate for the optional Manchester coding to a fixed data rate of 10 Megabits per second (Mbps) in order to make the necessary changes simple and still able to run in current radiation tolerant Field Programmable Gate Arrays (FPGAs). Even with this constraint, 10 Mbps will meet many applications where SpaceWire is used. These include command and control applications and many instruments applications with have moderate data rate. For most NASA flight implementations, SpaceWire designs are in rad-tolerant FPGAs, and the desire to preserve the heritage design investment is important for cost and risk considerations. The

  8. Quality analysis of superconducting wire and cable for SSC dipole magnets

    International Nuclear Information System (INIS)

    Pollock, D.A.

    1992-01-01

    This paper reports that a critical component of the SSC collider dipole magnets is superconducting cable. The uniformity and reliability requirements for the dipoles place stringent demands on the cable. These needs have been defined as various contract requirements in the material specifications for NbTi alloy, superconducting wire and cable. A supplied qualification program is being started by the SSCL with industry to establish reliable sources of superconductor cable. Key to this qualification program is the establishment by industry of detailed process methods and controls for wire and cable manufacture. To monitor conductor performance, a computer database is being developed by the SSCL Magnet Systems Division Quality Assurance Department. The database is part of a program for ensuring superconductor uniformity by focusing on the understanding and control of variation. A statistical and graphical summary of current data for key performance variables will be presented in light of the specification requirement for uniformity. Superconductor material characteristics to be addressed will include Wire Critical Current (I c ), Copper Ratio (Cu:SC), Wire Diameter, Wire Piece Length, and Cable Dimensional Control

  9. Effect of transverse compression on I/sub c/ of Nb3Sn multifilamentary wire

    International Nuclear Information System (INIS)

    Specking, W.; Goldacker, W.; Fluekiger, R.

    1988-01-01

    The effect of transverse compressive stress on critical current in bronze processed Nb 3 Sn multifilamentary wires was measured at 13.5 T. For the same wire the critical current was more sensitive to this stress than to axial stress. An increase in this stress first caused a slight enhancement of the critical current followed by a drastic decrease of 50 percent at a stress equal to 100 MPa. X-ray diffraction under transverse compression revealed a decrease in the spacing between the lattice planes parallel to the wire axis. This provided a physical basis for the initial enhancement of the critical current under transverse compressive stress

  10. Fabrication details for wire wrapped fuel assembly components

    International Nuclear Information System (INIS)

    Bosy, B.J.

    1978-09-01

    Extensive hydraulic testing of simulated LMFBR blanket and fuel assemblies is being carried out under this MIT program. The fabrication of these test assemblies has involved development of manufacturing procedures involving the wire wrapped pins and the flow housing. The procedures are described in detail in the report

  11. Chemistry of radiation damage to wire chambers

    International Nuclear Information System (INIS)

    Wise, J.

    1992-08-01

    Proportional counters are used to study aspects of radiation damage to wire chambers (wire aging). Principles of low-pressure, rf plasma chemistry are used to predict the plasma chemistry in electron avalanches (1 atm, dc). (1) Aging is studied in CF 4 /iC 4 H 10 gas mixtures. Wire deposits are analyzed by Auger electron spectroscopy. An apparent cathode aging process resulting in loss of gain rather than in a self-sustained current is observed in CF 4 -rich gases. A four-part model considering plasma polymerization of the hydrocarbon, etching of wire deposits by CF 4 , acceleration of deposition processes in strongly etching environments, and reactivity of the wire surface is developed to understand anode wire aging in CF 4 /iC 4 H 10 gases. Practical guidelines suggested by the model are discussed. (2) Data are presented to suggest that trace amounts of Freons do not affect aging rates in either dimethyl ether or Ar/C 2 H 6 . Apparent loss of gain is explained by attachment of primary electrons to a continuously increasing concentration of Freon 11 (CCl 3 F) in the counter gas. An increase in the concentration of Freon 11 in dimethyl ether is caused by a distillation process in the gas supply bottle and is a natural consequence of the unequal volatilities of the two compounds

  12. Expansion of plasma of electrically exploding single copper wire under 4.5 kA-9.5 kA/wire

    International Nuclear Information System (INIS)

    Li Yexun; Yang Libing; Sun Chengwei

    2003-01-01

    The experimental system for electrically exploding single metal wire has been designed and manufactured. Expansion of the dense plasma column formed from an electrically exploding Cu wire of diameter 30 μm has been studied with a high-speed photographer to obtain the time-dependent radius (R-t) curve. The experimental results demonstrate that the mean expansion rate of the dense plasma column is 1.94 μm/ns, 2.6 μm/ns and 3.75 μm/ns according to the peak pulse current 4.5 kA, 7 kA and 9.5 kA respectively. The results can be beneficial to giving a profound understanding of the early stage of wire-array Z-pinch physics and to improvement on their design

  13. 49 CFR 236.74 - Protection of insulated wire; splice in underground wire.

    Science.gov (United States)

    2010-10-01

    ... underground wire. 236.74 Section 236.74 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RULES, STANDARDS, AND INSTRUCTIONS GOVERNING... wire; splice in underground wire. Insulated wire shall be protected from mechanical injury. The...

  14. 49 CFR 234.241 - Protection of insulated wire; splice in underground wire.

    Science.gov (United States)

    2010-10-01

    ... underground wire. 234.241 Section 234.241 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION GRADE CROSSING SIGNAL SYSTEM SAFETY... of insulated wire; splice in underground wire. Insulated wire shall be protected from mechanical...

  15. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  16. Distributed resistance model for the analysis of wire-wrapped rod bundles

    International Nuclear Information System (INIS)

    Ha, K. S.; Jung, H. Y.; Kwon, Y. M.; Jang, W. P.; Lee, Y. B.

    2003-01-01

    A partial flow blockage within a fuel assembly in liquid metal reactor may result in localized boiling or a failure of the fuel cladding. Thus, the precise analysis for the phenomenon is required for a safe design of LMR. MATRA-LMR code developed by KAERI models the flow distribution in an assembly by using the wire forcing function to consider the effects of wire-wrap spacers, which is important to the analysis for flow blockage. However, the wire forcing function does not have the capabilities of analysis when the flow blockage is occurred. And thus this model was altered to the distributed resistance model and the validation calculation was carried out against to the experiment of FFM 2A

  17. Composite ceramic superconducting wires for electric motor applications

    Science.gov (United States)

    Halloran, John W.

    1990-07-01

    Several types of HTSC wire have been produced and two types of HTSC motors are being built. Hundreds of meters of Ag- clad wire were fabricated from YBa2Cu3O(7-x) (Y-123) and Bi2Ca2Sr2Cu3O10 (BiSCCO). The dc homopolar motor coils are not yet completed, but multiple turns of wire have been wound on the coil bobbins to characterize the superconducting properties of coiled wire. Multifilamentary conductors were fabricated as cables and coils. The sintered polycrystalline wire has self-field critical current densities (Jc) as high as 2800 A/sq cm, but the Jc falls rapidly with magnetic field. To improve Jc, sintered YBCO wire is melt textured with a continuous process which has produced textures wire up to 0.5 meters long with 77K transport Jc above 11, 770 A/sq cm2 in self field and 2100 A/sq cm2 at 1 telsa. The Emerson Electric dc homopolar HTSC motor has been fabricated and run with conventional copper coils. A novel class of potential very powerful superconducting motors have been designed to use trapped flux in melt textures Y-123 as magnet replicas in an new type of permanent magnet motor. The stator element and part of the rotor of the first prototype machine exist, and the HTSC magnet replica segments are being fabricated.

  18. Beam Position and Phase Monitor - Wire Mapping System

    International Nuclear Information System (INIS)

    Watkins, Heath A.; Shurter, Robert B.; Gilpatrick, John D.; Kutac, Vincent G.; Martinez, Derwin

    2012-01-01

    The Los Alamos Neutron Science Center (LANSCE) deploys many cylindrical beam position and phase monitors (BPPM) throughout the linac to measure the beam central position, phase and bunched-beam current. Each monitor is calibrated and qualified prior to installation to insure it meets LANSCE requirements. The BPPM wire mapping system is used to map the BPPM electrode offset, sensitivity and higher order coefficients. This system uses a three-axis motion table to position the wire antenna structure within the cavity, simulating the beam excitation of a BPPM at a fundamental frequency of 201.25 MHz. RF signal strength is measured and recorded for the four electrodes as the antenna position is updated. An effort is underway to extend the systems service to the LANSCE facility by replacing obsolete electronic hardware and taking advantage of software enhancements. This paper describes the upgraded wire positioning system's new hardware and software capabilities including its revised antenna structure, motion control interface, RF measurement equipment and Labview software upgrades. The main purpose of the wire mapping system at LANSCE is to characterize the amplitude response versus beam central position of BPPMs before they are installed in the beam line. The wire mapping system is able to simulate a beam using a thin wire and measure the signal response as the wire position is varied within the BPPM aperture.

  19. Vibrating-Wire, Supercooled Liquid Water Content Sensor Calibration and Characterization Progress

    Science.gov (United States)

    King, Michael C.; Bognar, John A.; Guest, Daniel; Bunt, Fred

    2016-01-01

    NASA conducted a winter 2015 field campaign using weather balloons at the NASA Glenn Research Center to generate a validation database for the NASA Icing Remote Sensing System. The weather balloons carried a specialized, disposable, vibrating-wire sensor to determine supercooled liquid water content aloft. Significant progress has been made to calibrate and characterize these sensors. Calibration testing of the vibrating-wire sensors was carried out in a specially developed, low-speed, icing wind tunnel, and the results were analyzed. The sensor ice accretion behavior was also documented and analyzed. Finally, post-campaign evaluation of the balloon soundings revealed a gradual drift in the sensor data with increasing altitude. This behavior was analyzed and a method to correct for the drift in the data was developed.

  20. One hundred fold increase in current carrying capacity in a carbon nanotube-copper composite

    Science.gov (United States)

    Subramaniam, Chandramouli; Yamada, Takeo; Kobashi, Kazufumi; Sekiguchi, Atsuko; Futaba, Don N.; Yumura, Motoo; Hata, Kenji

    2013-07-01

    Increased portability, versatility and ubiquity of electronics devices are a result of their progressive miniaturization, requiring current flow through narrow channels. Present-day devices operate close to the maximum current-carrying-capacity (that is, ampacity) of conductors (such as copper and gold), leading to decreased lifetime and performance, creating demand for new conductors with higher ampacity. Ampacity represents the maximum current-carrying capacity of the object that depends both on the structure and material. Here we report a carbon nanotube-copper composite exhibiting similar conductivity (2.3-4.7 × 105Scm-1) as copper (5.8 × 105Scm-1), but with a 100-times higher ampacity (6 × 108Acm-2). Vacuum experiments demonstrate that carbon nanotubes suppress the primary failure pathways in copper as observed by the increased copper diffusion activation energy (~2.0eV) in carbon nanotube-copper composite, explaining its higher ampacity. This is the only material with both high conductivity and high ampacity, making it uniquely suited for applications in microscale electronics and inverters.

  1. Study on ac losses of HTS coil carrying ac transport current

    International Nuclear Information System (INIS)

    Dai Taozhen; Tang Yuejin; Li Jingdong; Zhou Yusheng; Cheng Shijie; Pan Yuan

    2005-01-01

    Ac loss has an important influence on the thermal performances of HTS coil. It is necessary to quantify ac loss to ascertain its impact on coil stability and for sizing the coil refrigeration system. In this paper, we analyzed in detail the ac loss components, hysteresis loss, eddy loss and flux flow loss in the pancake HTS coil carrying ac transport current by finite element method. We also investigated the distribution of the ac losses in the coil to study the effects of magnetic field distribution on ac losses

  2. THE STRUCTURE ANALYTICAL RESEARCH OF POROUS PERMEABLE WIRE MATERIAL (in Russian

    Directory of Open Access Journals (Sweden)

    Andrzej JAKUBOWSKI

    2016-04-01

    Full Text Available The details of making technology of porous permeable material with use of wire are allowed to carry out the analytical research of structure and structural characteristics of wire winding body. Its permit for prognostication the final proper-ties of material, that is produced by the following deformation treatment (diameter reduction. Due to the regular orga-nized arrangement of wire, the coil of winding body is considered as a multispan continuous beam, but a contact of coils – as interaction of two cylinders. Possibility of exactly calculation of the contacts between coils is allowed to go over the single fragment displacements into deformation of whole winding body. During research of deformation processes in regards of winding body geometry and used wire mechanical properties, the structural characteristics of porous permea-ble wire material are expected. The optimal number of winding layers, eliminating the distortion of organized final struc-ture, is established. The material pressure–compactness relation is obtained in order to control the technological condi-tions of winding and drafting for guarantee the product required properties.

  3. Properties of stabilized MgB2 composite wire with Ti barrier

    International Nuclear Information System (INIS)

    Kovac, P; Husek, I; Melisek, T; Holubek, T

    2007-01-01

    Stabilized four-filament in situ MgB 2 /Ti/Cu/Monel composite wire was produced by the rectangular wire-in-tube (RWIT) technique. 10 wt% of nanosize SiC was added into the Mg-B powder mixture, which was packed into the Ti/Cu and Monel tubes, respectively. The assembled composite was two-axially rolled into wire and/or tape form and sintered at temperatures of 650-850 deg. C/0.5 h. Stabilized MgB 2 wire with Ti barrier is studied in terms of field-dependent transport critical current density, effects of filament size reduction and thermal stability

  4. Experimental and numerical investigations of wire bending by linear winding of rectangular tooth coils

    Science.gov (United States)

    Komodromos, A.; Tekkaya, A. E.; Hofmann, J.; Fleischer, J.

    2018-05-01

    Since electric motors are gaining in importance in many fields of application, e.g. hybrid electric vehicles, optimization of the linear coil winding process greatly contributes to an increase in productivity and flexibility. For the investigation of the forming behavior of the winding wire the material behavior is characterized in different experimental setups. Numerical examinatons of the linear winding process are carried out in a case study for a rectangular bobbin in order to analyze the influence of forming parameters on the resulting properties of the wound coil. Besides the numerical investigation of the linear winding method by using the finite element method (FEM), a multi-body dynamics (MBD) simulation is carried out. The multi-body dynamics simulation is necessary to represent the movement of the bodies as well as the connection of the components during winding. The finite element method is used to represent the material behavior of the copper wire and the plastic strain distribution within the wire. It becomes clear that the MBD simulation is not sufficient for analyzing the process and the wire behavior in its entirety. Important parameters that define the final coil properties cannot be analyzed in the manner of a precise manifestation, e.g. the clearance between coil bobbin and wire as well as the wire deformation behavior in form of a diameter reduction which negatively affects the ohmic resistance. Finally, the numerical investigations are validated experimentally by linear winding tests.

  5. Pulsed currents carried by whistlers. IV. Electric fields and radiation excited by an electrode

    International Nuclear Information System (INIS)

    Stenzel, R.L.; Urrutia, J.M.; Rousculp, C.L.

    1995-01-01

    Electromagnetic properties of current pulses carried by whistler wave packets are obtained from a basic laboratory experiment. While the magnetic field and current density are described in the preceding companion paper (Part III), the present analysis starts with the electric field. The inductive and space charge electric field contributions are separately calculated in Fourier space from the measured magnetic field and Ohm's law along B 0 . Inverse Fourier transformation yields the total electric field in space and time, separated into rotational and divergent contributions. The space-charge density in whistler wave packets is obtained. The cross-field tensor conductivity is determined. The frozen-in condition is nearly satisfied, E+v e xB congruent 0. The dissipation is obtained from Poynting's theorem. The waves are collisionally damped; Landau damping is negligible. A radiation resistance for the electrode is determined. Analogous to Poynting's theorem, the transport of helicity is analyzed. Current helicity is generated by a flow of helicity between pulses traveling in opposite directions which carry opposite signs of helicity. Helicity is dissipated by collisions. These observations complete a detailed description of whistler/current pulses which can occur in various laboratory and space plasmas. copyright 1995 American Institute of Physics

  6. Non-contact current and voltage sensor

    Science.gov (United States)

    Carpenter, Gary D; El-Essawy, Wael; Ferreira, Alexandre Peixoto; Keller, Thomas Walter; Rubio, Juan C; Schappert, Michael A

    2014-03-25

    A detachable current and voltage sensor provides an isolated and convenient device to measure current passing through a conductor such as an AC branch circuit wire, as well as providing an indication of an electrostatic potential on the wire, which can be used to indicate the phase of the voltage on the wire, and optionally a magnitude of the voltage. The device includes a housing that contains the current and voltage sensors, which may be a ferrite cylinder with a hall effect sensor disposed in a gap along the circumference to measure current, or alternative a winding provided through the cylinder along its axis and a capacitive plate or wire disposed adjacent to, or within, the ferrite cylinder to provide the indication of the voltage.

  7. Flux pinning and inhomogeneity in magnetic nanoparticle doped MgB2/Fe wires

    Science.gov (United States)

    Novosel, Nikolina; Pajić, Damir; Mustapić, Mislav; Babić, Emil; Shcherbakov, Andrey; Horvat, Joseph; Skoko, Željko; Zadro, Krešo

    2010-06-01

    The effects of magnetic nanoparticle doping on superconductivity of MgB2/Fe wires have been investigated. Fe2B and SiO2-coated Fe2B particles with average diameters 80 and 150 nm, respectively, were used as dopands. MgB2 wires with different nanoparticle contents (0, 3, 7.5, 12 wt.%) were sintered at temperature 750°C. The magnetoresistivity and critical current density Jc of wires were measured in the temperature range 2-40 K in magnetic field B doped wires decreases quite rapidly with doping level (~ 0.5 K per wt.%). This results in the reduction of the irreversibility fields Birr(T) and critical current densities Jc(B,T) in doped samples (both at low (5 K) and high temperatures (20 K)). Common scaling of Jc(B,T) curves for doped and undoped wires indicates that the main mechanism of flux pinning is the same in both types of samples. Rather curved Kramer's plots for Jc of doped wires imply considerable inhomogeneity.

  8. Comparing Thermal Stability of NbTi and Nb$_3$Sn Wires

    CERN Document Server

    Breschi, M; Bottura, L; Devred, A; Trillaud, F

    2009-01-01

    The investigation of quenching in low temperature superconducting wires is of great relevance for a proper design of superconductive cables and magnets. This paper reports the experimental results of a vast measurement campaign of quench induced by laser pulses on NbTi and Nb$_{3}$Sn wires in pool boiling Helium I. A comparison of the quench behavior of two typical NbTi and Nb$_{3}$Sn wires is shown from different standpoints. Different qualitative behaviors of the voltage traces recorded during quenches and recoveries on NbTi and Nb$_{3}$Sn wires are reported and analyzed. It is shown that the Nb$_{3}$Sn wire exhibits a quench or no-quench behavior, whereas quenches and recoveries are exhibited by the NbTi wire. The two wires are also compared considering the behaviors of the two main parameters describing quench, i.e. quench energies and quench velocities, with respect to operation current and pulse duration and magnetic field. It is shown that the Nb$_{3}$Sn wire exhibits a ‘kink’ of the quench energy ...

  9. Microstructural and crystallographic imperfections of MgB2 superconducting wire and their correlation with the critical current density

    Science.gov (United States)

    Shahabuddin, Mohammed; Alzayed, Nasser S.; Oh, Sangjun; Choi, Seyong; Maeda, Minoru; Hata, Satoshi; Shimada, Yusuke; Hossain, Md Shahriar Al; Kim, Jung Ho

    2014-01-01

    A comprehensive study of the effects of structural imperfections in MgB2 superconducting wire has been conducted. As the sintering temperature becomes lower, the structural imperfections of the MgB2 material are increased, as reflected by detailed X-ray refinement and the normal state resistivity. The crystalline imperfections, caused by lattice disorder, directly affect the impurity scattering between the π and σ bands of MgB2, resulting in a larger upper critical field. In addition, low sintering temperature keeps the grain size small, which leads to a strong enhancement of pinning, and thereby, enhanced critical current density. Owing to both the impurity scattering and the grain boundary pinning, the critical current density, irreversibility field, and upper critical field are enhanced. Residual voids or porosities obviously remain in the MgB2, however, even at low sintering temperature, and thus block current transport paths.

  10. PS wire chamber

    CERN Multimedia

    1970-01-01

    A wire chamber used at CERN's Proton Synchrotron accelerator in the 1970s. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  11. Estimates of the field-aligned current density in current-carrying filaments using auroral zone ground-based observations

    Directory of Open Access Journals (Sweden)

    M. A. Danielides

    Full Text Available We described the ground signatures of dynamic substorm features as observed by the imaging riometer, magnetometers and all-sky camera (ASC at Kilpisjärvi, Finland on 5 and 25 October 1999 during the late evening hours. The magnetometer data was consistent with the motion of up-ward field-aligned currents (FACs associated with absorption patches moving within the field of view of the riometer. We used riometer data in order to estimate the intensity of FACs associated with these local current-carrying filaments. It is shown that during these events, the estimated FAC intensity exceeds a threshold value that corresponds to the excitation of the low-frequency turbulence in the upper ionosphere. As a result, a quasi-oscillating regime of anomalous resistivity on the auroral field lines can give rise to the burst-like electron acceleration responsible for simultaneously observed auroral forms and bursts of Pi1B pulsations.

    Key words. Ionosphere (active experiments; auroral ionosphere; electric fields and currents

  12. B218 Weld Filler Wire Characterization for Al-Li Alloy 2195

    Science.gov (United States)

    Bjorkman, Gerry; Russell, Carolyn

    2000-01-01

    NASA Marshall Space Flight Center, Lockheed Martin Space Systems- Michoud Operations, and McCook Metals have developed an aluminum-copper weld filler wire for fusion welding aluminum lithium alloy 2195. The aluminum-copper based weld filler wire has been identified as B218, a McCook Metals designation. B218 is the result of six years of weld filler wire development funded by NASA, Lockheed Martin, and McCook Metals. The filler wire chemistry was developed to produce enhanced 2195 weld and repair weld mechanical properties over the 4043 aluminum-silicon weld filler wire, which is currently used to weld 2195 on the Super Lightweight External Tank for the NASA Space Shuttle Program. An initial characterization was performed consisting of a repair weld evaluation using B218 and 4043 weld filler wires. The testing involved room temperature and cryogenic repair weld tensile testing along with fracture toughness testing. From the testing, B218 weld filler wire produce enhanced repair weld tensile strength, ductility, and fracture properties over 4043. B218 weld filler wire has proved to be a superior weld filler wire for welding aluminum lithium alloy 2195 over 4043.

  13. Simulation of current generation in a 3-D plasma model

    International Nuclear Information System (INIS)

    Tsung, F.S.; Dawson, J.M.

    1996-01-01

    Two wires carrying current in the same direction will attract each other, and two wires carrying current in the opposite direction will repel each other. Now, consider a test charge in a plasma. If the test charge carries current parallel to the plasma, then it will be pulled toward the plasma core, and if the test charge carries current anti-parallel to the plasma, then it will be pushed to the edge. The electromagnetic coupling between the plasma and a test charge (i.e., the A parallel circ v parallel term in the test charge's Hamiltonian) breaks the symmetry in the parallel direction, and gives rise to a diffusion coefficient which is dependent on the particle's parallel velocity. This is the basis for the open-quotes preferential lossclose quotes mechanism described in the work by Nunan et al. In our previous 2+1/2 D work, in both cylindrical and toroidal geometries, showed that if the plasma column is centrally fueled, then an initial current increases steadily. The results in straight, cylindrical plasmas showed that self generated parallel current arises without trapped particle or neoclassical diffusion, as assumed by the bootstrap theory. It suggests that the fundamental mechanism seems to be the conservation of particles canonical momenta in the direction of the ignorable coordinate. We have extended the simulation to 3D to verify the model put forth. A scalable 3D EM-PIC code, with a localized field-solver, has been implemented to run on a large class of parallel computers. On the 512-node SP2 at Cornell Theory Center, we have benchmarked the 2+1/2 D calculations using 32 grids in the previously ignored direction, and a 100-fold increase in the number of particles. Our preliminary results show good agreements between the 2+1/2 D and the 3D calculations. We will present our 3D results at the meeting

  14. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  15. Replacement of corrosion protection chromate primers and paints used in cryogenic applications on the Space Shuttle with wire arc sprayed aluminum coatings

    Science.gov (United States)

    Daniel, R. L.; Sanders, H. L.; Zimmerman, F. R.

    1995-01-01

    With the advent of new environmental laws restricting volatile organic compounds and hexavalent chrome emissions, 'environmentally safe' thermal spray coatings are being developed to replace the traditional corrosion protection chromate primers. A wire arc sprayed aluminum coating is being developed for corrosion protection of low pressure liquid hydrogen carrying ducts on the Space Shuttle Main Engine. Currently, this hardware utilizes a chromate primer to provide protection against corrosion pitting and stress corrosion cracking induced by the cryogenic operating environment. The wire are sprayed aluminum coating has been found to have good potential to provide corrosion protection for flight hardware in cryogenic applications. The coating development, adhesion test, corrosion test and cryogenic flexibility test results will be presented.

  16. Mechanical and metallurgical changes on 308L wires drawn by electropulses

    OpenAIRE

    Sánchez Egea, Antonio José; González Rojas, Hernan Alberto; Celentano, Diego Javier; Jorba Peiró, Jordi

    2015-01-01

    The electroplastic effects resulting from different electropulses configurations on a wire drawing process are investigated experimentally and numerically. Electropulses are induced into 308L stainless steel while it is simultaneously wire drawn. A current density of 185 A/mm2, a frequency range from 140 to 355 Hz and a pulse duration range from 100 to 250 µs are combined to electrically assist the wire drawing process. The electropulsing influence is studied in several mechanical parameters,...

  17. Structural and phase studies of stainless wire after electroplastic drawing

    International Nuclear Information System (INIS)

    Troitskij, O.A.; Baldokhin, Yu.V.; Kir'yanchev, N.E.; Ryzhkov, V.G.; Kalugin, V.D.; Sokolov, N.V.; Klekovkin, A.A.; Klevtsur, S.A.

    1983-01-01

    Structural and phase properties of the 12Kh18N10T steel wire are studied after usual and electroplastic drawing from 0.40 up to 0.11 mm with 18-22% reduction per pass with passing 250 A/mm 2 electric current. The earlier made observation on a sharp decrease in content of deformation-induced martensite of α-phase takes place in the wire from stainless metastable austenitic steel as a result of electroplastic drawing. Distribution of the remained α-phase by the wire cross section is established

  18. Results of the Fermilab wire production program

    International Nuclear Information System (INIS)

    Strauss, B.P.; Remsbottom, R.H.; Reardon, P.J.; Curtis, C.W.; McDonald, W.K.

    1976-01-01

    In examining the various schedules of wire drawing and heat treating, the Critchlow type of schedule provided the highest and most uniform data from billet to billet. It consists of a long anneal at 400 +- 20 0 C at a cold work point giving about 99 percent reduction in area from the extrusion size. Several quick copper anneals at 300 0 C may be interspersed to aid in fabrication. A final anneal at finished size both peaks up the resistivity ratio of the copper as well as the critical current of the alloy by moving dislocations to subcell walls. Using this method, critical currents of 1.7 x 10 5 A/cm 2 could be maintained in all billets. The copper cladding and sinking method looks promising and should save production costs. In spite of this, it was important to attain good packing density in the billets to assure uniform filament pattern and reduce breakage in wire drawing. Overall, a procedure was found for fabricating wire in large production lots that would be acceptable for constructing dipole magnets. It is felt that this method could be peaked up with time

  19. Influences of Corrosive Sulfur on Copper Wires and Oil-Paper Insulation in Transformers

    Directory of Open Access Journals (Sweden)

    Jian Li

    2011-10-01

    Full Text Available Oil-impregnated paper is widely used in power transmission equipment as a reliable insulation. However, copper sulphide deposition on oil-paper insulation can lead to insulation failures in power transformers. This paper presents the influences of copper sulfur corrosion and copper sulphide deposition on copper wires and oil-paper insulation in power transformers. Thermal aging tests of paper-wrapped copper wires and bare copper wires in insulating oil were carried out at 130 °C and 150 °C in laboratory. The corrosive characteristics of paper-wrapped copper wires and bare copper wires were analyzed. Dielectric properties of insulation paper and insulating oil were also analyzed at different stages of the thermal aging tests using a broadband dielectric spectrometer. Experiments and analysis results show that copper sulfide deposition on surfaces of copper wires and insulation paper changes the surface structures of copper wires and insulation paper. Copper sulfur corrosion changes the dielectric properties of oil-paper insulation, and the copper sulfide deposition greatly reduces the electrical breakdown strength of oil-paper insulation. Metal passivator is capable of preventing copper wires from sulfur corrosion. The experimental results are helpful for investigations for fault diagnosis of internal insulation in power transformers.

  20. Single and nested tungsten-wire-array dynamics and applications to inertial confinement fusion

    Science.gov (United States)

    Cuneo, Michael

    2005-10-01

    Wire array z-pinches show great promise as x-ray sources for indirect-drive inertial confinement fusion (ICF). The double z-pinch hohlraum, for example, has produced capsule radiation drive symmetric to within 3%. This ICF concept will require that each of two 20-mm-diam arrays scale to x-ray powers ˜1 PW, to drive high-yield (>0.2 GJ) capsules to ignition. High-yield fusion will also require a temporally shaped radiation pulse to drive a low-entropy capsule implosion. Recently, improved understanding of high current (11-19 MA) single and nested wire-array dynamics has enabled significant progress towards these goals. As at lower currents, a single wire array (and both the outer and inner arrays of a nested system) shows a wire ablation phase, axial modulation of the ablation rate, a larger ablation rate for larger diameter wires, trailing mass and trailing current. These processes and others produce a broad mass profile that may impact the optimization of x-ray output for single and nested arrays. Our new insights into wire array physics have led to 20-mm-diam single and nested arrays with peak powers of 150-190 TW at implosion times of 55-90 ns, increased from 60-120 TW at 95-110 ns, improving power scaling. Radiation pulse shapes required for 3-shock isentropic compression of high-yield ICF capsules have also been demonstrated with nested wire arrays operating in current-transfer mode. In collaboration with: D.B. Sinars, R.A. Vesey, E.M. Waisman, W.A. Stygar, D.E. Bliss, S.V. Lebedev, J.P. Chittenden, P.V. Sasorov, R.W. Lemke, E.P. Yu, B.B. Afeyan, G.R. Bennett, M.G. Mazarakis, M.R. Lopez, M.E. Savage, J.L. Porter, T.A. Mehlhorn.

  1. Developing and Testing SpaceWire Devices and Networks

    Science.gov (United States)

    Parkes, Steve; Mills, Stuart

    2014-08-01

    SpaceWire is a data-handling network for use on-board spacecraft, which connects together instruments, mass- memory, processors, downlink telemetry, and other on- board sub-systems [1]. SpaceWire is simple to implement and has some specific characteristics that help it support data-handling applications in space: high-speed, low-power, simplicity, relatively low implementation cost, and architectural flexibility making it ideal for many space missions. SpaceWire provides high-speed (2 Mbits/s to 200 Mbits/s), bi- directional, full-duplex data-links, which connect together SpaceWire enabled equipment. Data-handling networks can be built to suit particular applications using point-to-point data-links and routing switches.Since the SpaceWire standard was published in January 2003, it has been adopted by ESA, NASA, JAXA and RosCosmos for many missions and is being widely used on scientific, Earth observation, commercial and other spacecraft. High-profile missions using SpaceWire include: Gaia, ExoMars rover, Bepi- Colombo, James Webb Space Telescope, GOES-R, Lunar Reconnaissance Orbiter and Astro-H.The development and testing of the SpaceWire links and networks used on these and many other spacecraft currently under development, requires a comprehensive array of test equipment. In this paper the requirements for test equipment fulfilling key test functions are outlined and then equipment that meets these requirements is described. Finally the all-important software that operates with the test equipment is introduced.

  2. Hybrid simulations of Z-Pinches in support of wire array implosion experiments at NTF

    International Nuclear Information System (INIS)

    Sotnikov, Vladimir Isaakovich; Oliver, Bryan Velten; Ivanov, Vladimir V.; LePell, Paul David; Fedin, Dmitry; Kantsyrev, Victor Leonidovich; Coverdale, Christine Anne; Travnicek, P.; Deeney, Christopher; Hellinger, P.; Jones, B.; Leboeuf, J.N.; Cowan, Thomas E.; Safronova, Alla S.

    2005-01-01

    Three-dimensional hybrid simulation of a plasma current-carrying column reveal two different regimes of sausage and kink instability development. In the first regime, with small Hall parameter, development of instabilities leads to the appearance of large-scale axial perturbations and eventually to bending of the plasma column. In the second regime, with a four-times-larger Hall parameter, small-scale perturbations dominate and no bending of the plasma column is observed. Simulation results are compared with laser probing experimental data obtained during wire array implosions on the Zebra pulse power generator at the Nevada Terawatt Facility.

  3. Studying superconducting Nb3Sn wire

    CERN Multimedia

    AUTHOR|(CDS)2099575

    2015-01-01

    Studying superconducting Nb3Sn wire. From the current experience from LHC and HL-LHC we know that the performance requirements for Nb3Sn conductor for future circular collider are challenging and should exceed that of present state-of-the-art materials.

  4. Studying superconducting Nb$_{3}$Sn wire

    CERN Multimedia

    AUTHOR|(CDS)2099575

    2015-01-01

    Studying superconducting Nb$_{3}$Sn wire. From the current experience from LHC and HL-LHC we know that the performance requirements for Nb$_{3}$Sn conductor for future circular collider are challenging and should exceed that of present state-of-the-art materials.

  5. Base Information Transport Infrastructure Wired (BITI Wired)

    Science.gov (United States)

    2016-03-01

    2016 Major Automated Information System Annual Report Base Information Transport Infrastructure Wired (BITI Wired) Defense Acquisition Management...Combat Information Transport System program was restructured into two pre-Major Automated Information System (pre-MAIS) components: Information...Major Automated Information System MAIS OE - MAIS Original Estimate MAR – MAIS Annual Report MDA - Milestone Decision Authority MDD - Materiel

  6. Load-Deflection and Friction Properties of PEEK Wires as Alternative Orthodontic Wires.

    Science.gov (United States)

    Tada, Yoshifumi; Hayakawa, Tohru; Nakamura, Yoshiki

    2017-08-09

    Polyetheretherketone (PEEK) is now attracting attention as an alternative to metal alloys in the dental field. In the present study, we evaluated the load-deflection characteristics of PEEK wires in addition to their frictional properties. Three types of PEEK wires are used: two sizes of rectangular shape, 0.016 × 0.022 in² and 0.019 × 0.025 in² (19-25PEEK), and rounded shape, diameter 0.016 in (16PEEK). As a control, Ni-Ti orthodontic wire, diameter 0.016 in, was used. The three-point bending properties were evaluated in a modified three-point bending system for orthodontics. The static friction between the orthodontic wire and the bracket was also measured. The load-deflection curves were similar among Ni-Ti and PEEK wires, except for 16PEEK with slot-lid ligation. The bending force of 19-25PEEK wire was comparable with that of Ni-Ti wire. 19-25PEEK showed the highest load at the deflection of 1500 μm ( p 0.05). No significant difference was seen in static friction between all three PEEK wires and Ni-Ti wire ( p > 0.05). It is suggested that 19-25PEEK will be applicable for orthodontic treatment with the use of slot-lid ligation.

  7. An investigation into preparation of silver sheathed superconducting wires with a high critical temperature

    International Nuclear Information System (INIS)

    Chaffron, Laurent

    1992-01-01

    We have shown that the critical current density of YBaCuO superconducting wires prepared using 'powder in tube' method is limited by the following principal factors: - cracks and porosity arising from the shrinkage of the powder during sintering, - irregularities in the wire section, - presence of secondary phases in the phase diagram of the three oxides, - incomplete re-oxidation at the centre of the wire, - insufficient, or complete lack of, texture in the wire, - presence of amorphous, non superconducting phase across the grains that blocks grain boundary migration. We have reduced the deleterious effects due to the first four factors by modifying prior nature of the powder, by reinforcing the sheath and by modifying the thermal treatments. We also used creep sintering to produce a strong texture; however, our study shows that texture, though necessary, is not a sufficient condition for a high current. This is because the latter is limited by the presence of the amorphous phase at too many grain boundaries. Finally, we have obtained wires in which grain boundaries are clean and which have very high critical currents by melting the wire in a thermal gradient and by passing it through the gradient very slowly. Such a technique, however, is too slow for producing superconductors. (author) [fr

  8. An Icepak-PSpice Co-Simulation Method to Study the Impact of Bond Wires Fatigue on the Current and Temperature Distribution of IGBT Modules under Short-Circuit

    DEFF Research Database (Denmark)

    Wu, Rui; Iannuzzo, Francesco; Wang, Huai

    2014-01-01

    Bond wires fatigue is one of the dominant failure mechanisms of IGBT modules. Prior-art research mainly focuses on its impact on the end-of-life failure, while its effect on the short-circuit capability of IGBT modules is still an open issue. This paper proposes a new electro-thermal simulation...... approach enabling analyze the impact of the bond wires fatigue on the current and temperature distribution on IGBT chip surface under short-circuit. It is based on an Icepack-PSpice co-simulation by taking the advantage of both a finite element thermal model and an advanced PSpice-based multi-cell IGBT...

  9. A platform for exploding wires in different media

    Science.gov (United States)

    Han, Ruoyu; Wu, Jiawei; Qiu, Aici; Zhou, Haibin; Wang, Yanan; Yan, Jiaqi; Ding, Weidong

    2017-10-01

    A platform SWE-2 used for single wire explosion experiments has been designed, established, and commissioned. This paper describes the design and initial experiments of SWE-2. In summary, two pulsed current sources based on pulse capacitors and spark gaps are adopted to drive sub-microsecond and microsecond time scale wire explosions in a gaseous/liquid medium, respectively. In the initial experiments, a single copper wire was exploded in air, helium, and argon with a 0.1-0.3 MPa ambient pressure as well as tap water with a 283-323 K temperature, 184-11 000 μ S/cm conductivity, or 0.1-0.9 MPa hydrostatic pressure. In addition, the diagnostic system is introduced in detail. Energy deposition, optical emission, and shock wave characteristics are briefly discussed based on experimental results. The platform was demonstrated to operate successfully with a single wire load. These results provide the potential for further applications of this platform, such as plasma-matter interactions, shock wave effects, and reservoir simulations.

  10. Magnesium diboride(MgB2) wires for applications

    International Nuclear Information System (INIS)

    Patel, Dipak; Kim, Jung Ho

    2016-01-01

    Field and temperature dependence of the critical current density, Jc, were measured for both un-doped and carbon doped MgB 2 /Nb/Monel wires manufactured by Hyper Tech Research, Inc. In particular, carbon incorporation into the MgB 2 structure using malic acid additive and a chemical solution method can be advantageous because of the highly uniform mixing between the carbon and boron powders. At 4.2 K and 10 T, Jc was estimated to be 25,000 - 25,300 Acm -2 for the wire sintered at 600 degrees C for 4 hours. The irreversibility field, Birr, of the malic acid doped wire was approximately 21.0 - 21.8 T, as obtained from a linear extrapolation of the J-B characteristic. Interestingly enough, the Jc of the malic acid doped sample exceeds 10 5 Acm -2 at 6 T and 4.2 K, which is comparable to that of commercial Nb-Ti wires

  11. Quench detection method for 2G HTS wire

    International Nuclear Information System (INIS)

    Marchevsky, M; Xie, Y-Y; Selvamanickam, V

    2010-01-01

    2G HTS conductors are increasingly used in various commercial applications and their thermal and electrical stability is an important reliability factor. Detection and prevention of quenches in 2G wire-based cables and solenoids has proven to be a difficult engineering task. This is largely due to a very slow normal zone propagation in coated conductors that leads to formation of localized hotspots while the rest of the conductor remains in the superconducting state. We propose an original method of quench and hotspot detection for 2G wires and coils that is based upon local magnetic sensing and takes advantage of 2G wire planar geometry. We demonstrate our technique experimentally and show that its sensitivity is superior to the known voltage detection scheme. A unique feature of the method is its capability to remotely detect instant degradation of the wire critical current even before a normal zone is developed within the conductor. Various modifications of the method applicable to practical device configurations are discussed.

  12. Quench detection method for 2G HTS wire

    Energy Technology Data Exchange (ETDEWEB)

    Marchevsky, M; Xie, Y-Y; Selvamanickam, V, E-mail: maxmarche@gmail.co, E-mail: yxie@superpower-inc.co [SuperPower, Inc., 450 Duane Avenue, Schenectady, NY 12304 (United States)

    2010-03-15

    2G HTS conductors are increasingly used in various commercial applications and their thermal and electrical stability is an important reliability factor. Detection and prevention of quenches in 2G wire-based cables and solenoids has proven to be a difficult engineering task. This is largely due to a very slow normal zone propagation in coated conductors that leads to formation of localized hotspots while the rest of the conductor remains in the superconducting state. We propose an original method of quench and hotspot detection for 2G wires and coils that is based upon local magnetic sensing and takes advantage of 2G wire planar geometry. We demonstrate our technique experimentally and show that its sensitivity is superior to the known voltage detection scheme. A unique feature of the method is its capability to remotely detect instant degradation of the wire critical current even before a normal zone is developed within the conductor. Various modifications of the method applicable to practical device configurations are discussed.

  13. Laser Annealing on the Surface Treatment of Thin Super Elastic NiTi Wire

    Science.gov (United States)

    Samal, S.; Heller, L.; Brajer, J.; Tyc, O.; Kadrevek, L.; Sittner, P.

    2018-05-01

    Here the aim of this research is annealing the surface of NiTi wire for shape memory alloy, super-elastic wire by solid state laser beam. The laser surface treatment was carried out on the NiTi wire locally with fast, selective, surface heat treatment that enables precisely tune the localized material properties without any precipitation. Both as drawn (hard) and straight annealing NiTi wire were considered for laser annealing with input power 3 W, with precisely focusing the laser beam height 14.3 % of the Z-axis with a spot size of 1 mm. However, straight annealing wire is more interest due to its low temperature shape setting behavior and used by companies for stent materials. The variable parameter such as speed of the laser scanning and tensile stress on the NiTi wire were optimized to observe the effect of laser response on the sample. Superelastic, straight annealed NiTi wires (d: 0.10 mm) were held prestrained at the end of the superelastic plateau (ε: 5 ∼6.5 %) above the superelastic region by a tensile machine ( Mitter: miniature testing rig) at room temperature (RT). Simultaneously, the hardness of the wires along the cross-section was performed by nano-indentation (NI) method. The hardness of the NiTi wire corresponds to phase changes were correlated with NI test. The laser induced NiTi wire shows better fatigue performance with improved 6500 cycles.

  14. Pulsed taut-wire measurement of the magnetic alignment of the ITS induction cells

    International Nuclear Information System (INIS)

    Melton, J.G.; Burns, M.J.; Honaberger, D.J.

    1993-01-01

    The mechanical and magnetic alignment of the first eight induction-cell, solenoid magnets of the Integrated Test Stand (ITS) for the Dual-Axis Radiographic Hydrodynamic Test (DARHT) facility were measured by observing the deflection of a fine, taut wire carrying a pulsed current. To achieve the required alignment (less than 0.25 mm offset and less than 5 mrad tilt), the magnet design uses quadrufilar windings and iron field-smoothing rings. After detailed measurements of each solenoid magnet, the cells are assembled and then mechanically aligned using a laser and an alignment target moved along the cell centerline. After the cells are in final position, the pulsed wire method is used to verify the magnetic alignment. The measurements show an average offset of the magnetic axes from the mechanical axis of 0. 15 mm, with a maximum offset of 0.3 mm. The average tilt of the magnetic axis was 0.7 mrad with a maximum tilt of 1.4 mrad. Tilts are corrected to less than 0.3 mrad, using dipole trim magnets assembled into each cell. Correction is limited noise

  15. Adhesion strength study of IBAD-MOCVD-based 2G HTS wire using a peel test

    International Nuclear Information System (INIS)

    Zhang, Y.; Hazelton, D.W.; Knoll, A.R.; Duval, J.M.; Brownsey, P.; Repnoy, S.; Soloveichik, S.; Sundaram, A.; McClure, R.B.; Majkic, G.; Selvamanickam, V.

    2012-01-01

    A peel test was used to study the adhesion strength of a commercial grade 2G HTS wire which features a characteristic multilayer structure with the rare earth-based MOCVD superconducting film deposited on an IBAD-MgO template. The peel test could be carried out at various peeling angles (from 90° to 180°) and the peel strength of a wire was defined as the steady-state peeling load determined from a load-displacement curve. The test results had good reproducibility and accuracy, making the test a reliable and useful method for studying the adhesion strength of the wire. By characterizing the peeled surfaces the weakest interface in a wire could be identified. The peel strength data of the wire was analyzed together with the performance of the experimental magnet coils fabricated using the wire. The effect of the silver contact layer annealing on the peel strength is discussed.

  16. Development of Nb3Sn AC superconducting wire. Pt. 2

    International Nuclear Information System (INIS)

    Kasahara, Hobun; Torii, Shinji; Akita, Shirabe; Ueda, Kiyotaka; Kubota, Yoji; Yasohama, Kazuhiko; Kobayashi, Hisayasu; Ogasawara, Takeshi.

    1993-01-01

    For the realization of superconducting power apparatus, it is important that the development of highly stable superconducting cables. Nb 3 Sn wire has higher critical temperature than NbTi wire. Therefore, it is possible to make highly stable superconducting wires. In this report, we examine a manufacturing process of Ac Nb 3 Sn wire. This manufacturing process has four times higher critical current density than conventional processes. We have made a 400 kVA class AC coil with React and Wind method. The loss density of this coil was 20MW/m 3 at just before the quench. In this case, the temperature of cable increased about 3.8 K. This means that the Nb 3 Sn coil has a very high stability. (author)

  17. Structural, magnetic and electrical transport properties in cold-drawn thin Fe-rich wires

    International Nuclear Information System (INIS)

    Garcia, C.; Chizhik, A.; Val, J.J. del; Zhukov, A.; Blanco, J.M.; Gonzalez, J.

    2005-01-01

    Microstructural (X-ray diffraction), magnetic properties (hysteresis loop), electrical resistivity, magneto-impedance and stress impedance effects have been investigated in cold-drawn Fe 77.5 B 15 Si 7.5 amorphous wire. Initial amorphous wire (obtained by the in-rotating-water technique) with diameter of 125 μm was submitted to cold-drawn process decreasing the diameter to 50 μm. Such cold-drawn wire was treated by current annealing (currents of 190, 210, 220 and 230 mA during times between 1 and 45 min) for tailoring the magnetic and electrical transport properties. A qualitative analysis of the magnetoimpedance and stress impedance effects is given by considering the influence of the magnetoelastic anisotropy and frequency of the AC driving electrical current on the circular permeability

  18. Wire-array initiation and interwire-plasma merger concerns in PBFA-Z tungsten z-pinch implosions

    Energy Technology Data Exchange (ETDEWEB)

    Sanford, T.W.L.; Spielman, R.B.; Allshouse, G.O. [Sandia National Labs., Albuquerque, NM (United States)] [and others

    1997-12-31

    Experiments with annular wire-array loads to generate high quality, high-power, z-pinch implosions on Saturn have shown the importance of maintaining azimuthal symmetry and how the individual wire plasmas merge to form a plasma shell. Here the authors discuss the impact of current symmetry, current prepulse, interwire spacing, and wire size on generating high-quality, high-power, z-pinch implosions on PBFA-Z, with annular tungsten wire loads. B-dot monitors measured the current as a function of azimuth in the MITLs and 4.5 cm upstream of the load. Bolometers and filtered XRDs and PCDs, spanning the energy range {approximately} 0 eV to 6 keV, monitored the temporal characteristics of the radiation. Time-integrated and time-resolved, filtered, fast-framing, x-ray pinhole cameras, and a crystal spectrometer monitored the spatial and spectral structure of the radiation. The radial dynamics of single-wire plasmas from the solid-state, using the measured current, was calculated by 1D radiation magnetohydrodynamics code (RMHC) and used as input to an xy RMHC. These calculations together with 2D RMHC simulations in the rz plane are discussed and correlated with the measurements.

  19. Wire-array initiation and interwire-plasma merger concerns in PBFA-Z tungsten z-pinch implosions

    International Nuclear Information System (INIS)

    Sanford, T.W.L.; Spielman, R.B.; Allshouse, G.O.

    1997-01-01

    Experiments with annular wire-array loads to generate high quality, high-power, z-pinch implosions on Saturn have shown the importance of maintaining azimuthal symmetry and how the individual wire plasmas merge to form a plasma shell. Here the authors discuss the impact of current symmetry, current prepulse, interwire spacing, and wire size on generating high-quality, high-power, z-pinch implosions on PBFA-Z, with annular tungsten wire loads. B-dot monitors measured the current as a function of azimuth in the MITLs and 4.5 cm upstream of the load. Bolometers and filtered XRDs and PCDs, spanning the energy range ∼ 0 eV to 6 keV, monitored the temporal characteristics of the radiation. Time-integrated and time-resolved, filtered, fast-framing, x-ray pinhole cameras, and a crystal spectrometer monitored the spatial and spectral structure of the radiation. The radial dynamics of single-wire plasmas from the solid-state, using the measured current, was calculated by 1D radiation magnetohydrodynamics code (RMHC) and used as input to an xy RMHC. These calculations together with 2D RMHC simulations in the rz plane are discussed and correlated with the measurements

  20. Non-destructive X-ray examination of weft knitted wire structures

    Science.gov (United States)

    Obermann, M.; Ellouz, M.; Aumann, S.; Martens, Y.; Bartelt, P.; Klöcker, M.; Kordisch, T.; Ehrmann, A.; Weber, M. O.

    2016-07-01

    Conductive yarns or wires are often integrated in smart textiles to enable data or energy transmission. In woven fabrics, these conductive parts are fixed at defined positions and thus protected from external loads. Knitted fabrics, however, have relatively loose structures, resulting in higher impacts of possible mechanical forces on the individual yarns. Hence, metallic wires with smaller diameters in particular are prone to break when integrated in knitted fabrics. In a recent project, wires of various materials including copper, silver and nickel with diameters varying between 0.05 mm and 0.23 mm were knitted in combination with textile yarns. Hand flat knitting machines of appropriate gauges were used to produce different structures. On these samples, non-destructive examinations, using an industrial X-ray system Seifert x|cube (225 kV) equipped with a minifocus X-ray tube, were carried out, directly after knitting as well as after different mechanical treatments (tensile, burst, and washing tests). In this way, structural changes of the stitch geometry could be visualized before failure. In this paper, the loop geometries in the knitted fabrics are depicted depending on knitted structures, wire properties and the applied mechanical load. Consequently, it is shown which metallic wires and yarns are most suitable to be integrated into knitted smart textiles.

  1. Theory of wire number scaling in wire-array Z pinches

    International Nuclear Information System (INIS)

    Desjarlais, M.P.; Marder, B.M.

    1999-01-01

    Pulsed-power-driven Z pinches, produced by imploding cylindrical arrays of many wires, have generated very high x-ray radiation powers (>200 TW) and energies (2 MJ). Experiments have revealed a steady improvement in Z-pinch performance with increasing wire number at fixed total mass and array radius. The dominant mechanism acting to limit the performance of these devices is believed to be the Rayleigh-Taylor instability which broadens the radially imploding plasma sheath and consequently reduces the peak radiation power. A model is presented which describes an amplification over the two-dimensional Rayleigh-Taylor growth rate brought about by kink-like forces on the individual wires. This amplification factor goes to zero as the number of wires approaches infinity. This model gives results which are in good agreement with the experimental data and provides a scaling for wire-array Z pinches. copyright 1999 American Institute of Physics

  2. Investigations of current limiting properties of the MgB{sub 2} wires subjected to pulse overcurrents in the benchtop tester

    Energy Technology Data Exchange (ETDEWEB)

    Ye Lin [Interdisciplinary Research Center (IRC) in Superconductivity, Department of Engineering, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Majoros, M [Laboratories for Applied Superconductivity and Magnetism, Ohio State University, Columbus, OH 43210 (United States); Campbell, A M [Interdisciplinary Research Center (IRC) in Superconductivity, Department of Engineering, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Coombs, T [Interdisciplinary Research Center (IRC) in Superconductivity, Department of Engineering, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Harrison, S [Scientific Magnetics, Culham Science Centre, Culham, Abingdon, Oxfordshire OX14 3DB (United Kingdom); Sargent, P [Diboride Conductors Ltd, Cambridge CB1 3QJ (United Kingdom); Haslett, M [Diboride Conductors Ltd, Cambridge CB1 3QJ (United Kingdom); Husband, M [Strategic Research Center (SRC)-Electrical Engineering, Rolls-Royce Plc., Derby DE24 8BJ (United Kingdom)

    2007-04-15

    A laboratory scale desktop test system including a cryogenic system, an AC pulse generation system and a real time data acquisition program in LabView/DAQmx, has been developed to evaluate the quench properties of MgB{sub 2} wires as an element in a superconducting fault current limiter under pulse overcurrents at 25 K in self-field conditions. The MgB{sub 2} samples started from a superconducting state and demonstrated good current limiting properties characterized by a fast transition to the normal state during the first half of the cycle and a continuously limiting effect in the subsequent cycles without burnouts. The experimental and numerical simulation results on the quench behaviour indicate the feasibility of using MgB{sub 2} for future superconducting fault current limiter (SFCL) applications.

  3. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  4. THERMO-MECHANICALLY PROCESSED ROLLED WIRE FOR HIGH-STRENGTH ON-BOARD WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    Full Text Available It is shown that at twisting of wire of diameter 1,83 mm, produced by direct wire drawing of thermomechanically processed rolled wire of diameter 5,5 mm of steel 90, metal stratification is completely eliminated at decrease of carbon, manganese and an additional alloying of chrome.

  5. Preparation of Electrospun Polymer Fibers Using a Copper Wire Electrode in a Capillary Tube

    Science.gov (United States)

    Shinbo, Kazunari; Onozuka, Shintaro; Hoshino, Rikiya; Mizuno, Yoshinori; Ohdaira, Yasuo; Baba, Akira; Kato, Keizo; Kaneko, Futao

    2010-04-01

    Polymer fibers were prepared by an electrospinning method utilizing a copper wire electrode in a capillary tube. The morphology of electrospun poly(vinyl alcohol) (PVA) fibers was observed, and was found to be dependent on the wire electrode tip position in the capillary tube, the concentration of the polymer solution, the distance between the electrodes, and the applied voltage. By using the wire electrode, the experimental setup is simple and the distance between the electrodes and the applied voltage can be easily reduced. Furthermore, the preparation of poly(3-hexylthiophene) (P3HT) fibers was carried out. P3HT fibers were successfully prepared by mixing poly(ethylene oxide) (PEO) in P3HT solution. Orientation control was also carried out by depositing the fibers on a rotating collector electrode, and the alignment of the P3HT:PEO fibers was confirmed. Anisotropy of the optical absorption spectra was also observed for the aligned fibers.

  6. Modelling of drawing and rolling of high carbon flat wires

    International Nuclear Information System (INIS)

    Bobadilla, C.; Persem, N.; Foissey, S.

    2007-01-01

    In order to meet customer requirements, it is necessary to develop new flat wires with a high tensile strength and a high width/thickness ratio. These products are manufactured from wire rod. The first step is to draw the wire until we have the required mechanical properties and required surface area of the section. After this, the wire is rolled from a round to a rectangular section. During the flat rolling process it can be reduced by more than 50%. Then the wire is exposed to a high level of stress during this process. Modelling allows us to predetermine this stress level, taking into account the final dimensions and the mechanical properties, thus optimising both rolling and drawing process. Forge2005 was used in order to simulate these processes. The aim of this study is to determine the value of residual stresses after drawing and so to optimise rolling. Indeed, the highest stress values are reached at this step of the process by changing the section of the wire from a round to a rectangular one. In order to evaluate the stress value accuracy for high strain levels, a behaviour law has been identified. This is a result of tensile tests carried out at each step of the drawing process. Finally, a multi-axial damage criterion was implemented using Forge2005. The optimisation of the rolling is directly linked to the minimisation of this criterion

  7. Emissions from heavy current carrying high density plasma and their diagnostics

    International Nuclear Information System (INIS)

    Hirano, Katsumi

    1987-06-01

    Workshop on ''Emissions from heavy current carrying high density plasma and diagnostics'' was held at Institute of Plasma Physics, Nagoya University on 3. and 4. December 1986 under a collaborating research Program. The workshop was attended by 43 researchers from 19 labolatories. A total of 22 papers were submitted and are presented in these proceedings. The largest group of papers was that on soft X-ray emission. It seems this topic is a foremost interest for groups which engaged in research of the Z pinch and the plasma focus. A variety of problems in pinched dense plasmas, namely spectroscopy, diagnostics, pinch dynamics, and related engineering aspects were also discussed. (author)

  8. Wire rope superconducting cable for diurnal load leveling SMES

    International Nuclear Information System (INIS)

    Costello, G.A.

    1980-01-01

    The design of a wire rope cable for a superconducting magnetic energy storage (SMES) unit is discussed. The superconducting wires in the rope permit the passage of large currents in the relatively small conductors of the windings and hence cause large electromagnetic forces to act on the rope. The diameter of the rope, from a strength point of view, can be considerably reduced by supporting the rope at various points along its length

  9. Adhesion strength study of IBAD-MOCVD-based 2G HTS wire using a peel test

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y., E-mail: yzhang@superpower-inc.com [SuperPower Inc., 450 Duane Avenue, Schenectady, NY 12304 (United States); Hazelton, D.W.; Knoll, A.R.; Duval, J.M.; Brownsey, P.; Repnoy, S.; Soloveichik, S.; Sundaram, A.; McClure, R.B. [SuperPower Inc., 450 Duane Avenue, Schenectady, NY 12304 (United States); Majkic, G.; Selvamanickam, V. [University of Houston, 4800 Calhoun Road, Houston, TX 77204 (United States)

    2012-02-15

    A peel test was used to study the adhesion strength of a commercial grade 2G HTS wire which features a characteristic multilayer structure with the rare earth-based MOCVD superconducting film deposited on an IBAD-MgO template. The peel test could be carried out at various peeling angles (from 90 Degree-Sign to 180 Degree-Sign) and the peel strength of a wire was defined as the steady-state peeling load determined from a load-displacement curve. The test results had good reproducibility and accuracy, making the test a reliable and useful method for studying the adhesion strength of the wire. By characterizing the peeled surfaces the weakest interface in a wire could be identified. The peel strength data of the wire was analyzed together with the performance of the experimental magnet coils fabricated using the wire. The effect of the silver contact layer annealing on the peel strength is discussed.

  10. Basic characteristics of thin wire arc plasma

    International Nuclear Information System (INIS)

    Urushihara, K.; Endoh, N.; Ono, S.; Teii, S.; Ishimura, T.

    1998-01-01

    The investigated plasma was generated by applying an electric current of about 50 A to a copper wire of 48 μm diameter in air. The development in time of emission spectra was measured and relative line intensity ratios were used to determine the temperature. The extension of the plasma was measured with a movable electrostatic probe which was placed next to the thin wire, and the electron density was estimated using the known electron mobility. The electron temperature was typically about 8000 K. On the other hand, the electron density tended to decrease with time from about 3.10 16 cm -3

  11. Microstructural and crystallographic imperfections of MgB{sub 2} superconducting wire and their correlation with the critical current density

    Energy Technology Data Exchange (ETDEWEB)

    Shahabuddin, Mohammed; Alzayed, Nasser S. [Department of Physics and Astronomy, College of Science, P. O. Box 2455, King Saud University, Riyadh 11451 (Saudi Arabia); Oh, Sangjun [Materials Research Team, National Fusion Research Institute, Yueeong, Daejeon 305-333 (Korea, Republic of); Choi, Seyong [Busan Center, Korea Basic Science Institute, Geumjeong, Busan 609-735 (Korea, Republic of); Maeda, Minoru [Department of Physics, College of Science and Technology, Nihon University, 1-8 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Hata, Satoshi; Shimada, Yusuke [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, 6-1 Kasugakoen, Kasuga, Fukuoka 816-8580 (Japan); Hossain, Md Shahriar Al [Institute for Superconducting and Electronic Materials, University of Wollongong, North Wollongong, New South Wales 2500 (Australia); Kim, Jung Ho, E-mail: jhk@uow.edu.au [Department of Physics and Astronomy, College of Science, P. O. Box 2455, King Saud University, Riyadh 11451 (Saudi Arabia); Institute for Superconducting and Electronic Materials, University of Wollongong, North Wollongong, New South Wales 2500 (Australia)

    2014-01-15

    A comprehensive study of the effects of structural imperfections in MgB{sub 2} superconducting wire has been conducted. As the sintering temperature becomes lower, the structural imperfections of the MgB{sub 2} material are increased, as reflected by detailed X-ray refinement and the normal state resistivity. The crystalline imperfections, caused by lattice disorder, directly affect the impurity scattering between the π and σ bands of MgB{sub 2}, resulting in a larger upper critical field. In addition, low sintering temperature keeps the grain size small, which leads to a strong enhancement of pinning, and thereby, enhanced critical current density. Owing to both the impurity scattering and the grain boundary pinning, the critical current density, irreversibility field, and upper critical field are enhanced. Residual voids or porosities obviously remain in the MgB{sub 2}, however, even at low sintering temperature, and thus block current transport paths.

  12. One-dimensional curved wire chamber for powder x-ray crystallography

    International Nuclear Information System (INIS)

    Ortendahl, D.; Perez-Mendez, V.; Stoker, J.; Beyermann, W.

    1978-01-01

    A xenon filled single anode wire chamber with delay line readout has been constructed for use in powder x-ray crystallography using 8 to 20 keV x-rays. The entire chamber including the anode wire and the delay line which forms part of the cathode plane is a section of a circular arc whose center is the powder specimen. The anode wire--38 μm gold-plated tungsten--is suspended in a circular arc by the interaction of a current flowing through it and magnetic field provided by two permanent magnets, above and below the wire, extending along the active length of the chamber. When filled with xenon to 3 atmospheres the chamber has uniform sensitivity in excess of 80% at 8 keV and a spatial resolution better than 0.3 mm

  13. A vibrating wire parallel to a high temperature superconducting slab. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Saif, A G; El-sabagh, M A [Department of Mathematic and Theoretical physics, Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt)

    1996-03-01

    The power losses problem for an idealized high temperature type II superconducting system of a simple geometry is studied. This system is composed of a vibrating normal conducting wire (two wires) carrying a direct current parallel to an uniaxial anisotropic type II superconducting slab (moving slab). First, the electromagnetic equation governing the dynamics of this system, and its solutions are obtained. Secondly, a modified anisotropic london equation is developed to study these systems in the case of the slab moving. Thirdly, it is found that, the power losses is dependent on the frequency, london penetration depth, permeability, conductivity, velocity, and the distance between the normal conductors and the surfaces of the superconducting slab. Moreover, the power losses decreases as the distance between the normal conductors and the surface of the superconducting slab decreases; and increases as the frequency, the london penetration depth, permeability, conductivity, and velocity are increased. These losses along the versor of the anisotropy axis is increased as {lambda}{sub |}| increases. Moreover, it is greater than the power losses along the crystal symmetry direction. In the isotropic case as well as the slab thickness tends to infinity, agreement with previous results are obtained. 2 figs.

  14. The role of nano-contacts in electrical transport through a molecular wire

    International Nuclear Information System (INIS)

    Shokri, Ali A.; Mardaani, M.

    2006-01-01

    Theoretical studies on electrical transport in a nano-device which consisting of two semi-infinite cubic leads with finite cross-sections separated by a typical molecular wire (MW) are carried out by including the effect of single and multiple contacts. The calculations are based on the tight-binding model and Green's function method in the coherent regime. In order to calculate the effect of contact coupling on molecular wire transport, we derive a theoretical formula based on the nearest and next nearest neighbor coupling strengths between the MW and the surface atoms in the simple cubic leads. This approach can be generalized to other leads with different lattice structure. The results show small changes in the transport properties with changing next nearest neighbor coupling strength. Some asymmetry is noted in the strong multiple contact limit. Also, we observe that with enlarging the cross-section size of leads, the current density increases and then leads to the quantum unit of conductance. Hence, our derived formalism can be used for devices attached to macroscopic surfaces. The theoretical results obtained, can be a base for developments in designing nano-electronic devices

  15. Effect of Flow Direction on the Extinction Limit for Flame Spread over Wire Insulation in Microgravity

    DEFF Research Database (Denmark)

    Nagachi, Masashi; Mitsui, Fumiya; Citerne, Jean-Marie

    Experiments to determine the Limiting Oxygen Concentration (LOC) of a flame spread over electric wire insulation were carried out in microgravity provided by parabolic flights. The difference between the LOC in opposed and concurrent flows was evidenced. Polyethylene insulated Copper (Cu) wires...... and polyethylene insulated Nickel-Chrome (NiCr) wires with inner core diameter of 0.50 mm and insulation thickness of 0.30 mm were examined with external flow velocities ranging from 50mm/s to 200mm/s. The results for the Copper wires show that with increasing external flow velocity, the LOC monotonically...... decreased for the concurrent flow conditions and the LOC first decreased and then increased (“U” trend) for the opposed flow conditions. Similar trends were found in the experiments with NiCr wires. Also, in terms of the minimum LOC value, the minimum LOC was comparable for both wire types in both flow...

  16. Studies of IBL wire bonds operation in a ATLAS-like magnetic field.

    CERN Document Server

    Alvarez Feito, D; Mandelli, B

    2015-01-01

    At the Large Hadron Collider (LHC) experiments, most of silicon detectors use wire bonds to connect front-end chips and sensors to circuit boards for the data and service trans- missions. These wire bonds are operated in strong magnetic field environments and if time varying currents pass through them with frequencies close to their mechanical resonance frequency, strong resonant oscillations may occur. Under certain conditions, this effect can lead to fatigue stress and eventually breakage of wire bonds. During the first LHC Long Shutdown, the ATLAS Pixel Detector has been upgraded with the addition of a fourth innermost layer, the Insertable B-Layer (IBL), which has more than 50000 wire bonds operated in the ATLAS 2 T magnetic field. The results of systematic studies of operating wire bonds under IBL-like conditions are presented. Two different solutions have been investigated to minimize the oscillation amplitude of wire bonds.

  17. Prediction of multi performance characteristics of wire EDM process using grey ANFIS

    Science.gov (United States)

    Kumanan, Somasundaram; Nair, Anish

    2017-09-01

    Super alloys are used to fabricate components in ultra-supercritical power plants. These hard to machine materials are processed using non-traditional machining methods like Wire cut electrical discharge machining and needs attention. This paper details about multi performance optimization of wire EDM process using Grey ANFIS. Experiments are designed to establish the performance characteristics of wire EDM such as surface roughness, material removal rate, wire wear rate and geometric tolerances. The control parameters are pulse on time, pulse off time, current, voltage, flushing pressure, wire tension, table feed and wire speed. Grey relational analysis is employed to optimise the multi objectives. Analysis of variance of the grey grades is used to identify the critical parameters. A regression model is developed and used to generate datasets for the training of proposed adaptive neuro fuzzy inference system. The developed prediction model is tested for its prediction ability.

  18. Reliability Criteria for Thick Bonding Wire.

    Science.gov (United States)

    Dagdelen, Turker; Abdel-Rahman, Eihab; Yavuz, Mustafa

    2018-04-17

    Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al) and aluminum coated copper (CucorAl) wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire.

  19. Reliability Criteria for Thick Bonding Wire

    Science.gov (United States)

    Yavuz, Mustafa

    2018-01-01

    Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al) and aluminum coated copper (CucorAl) wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire. PMID:29673194

  20. Stress effects on multifilamentary Nb3Sn wire

    International Nuclear Information System (INIS)

    Bartlett, R.J.; Taylor, R.D.; Thompson, J.D.

    1979-01-01

    Critical current I/sub c/ measurements were obtained on highly stabilized mf Nb 3 Sn wires as a function of heat treatment, stress, temperature, and applied magnetic field. The ratio of the area of the copper to bronze core-niobium tube is about 8, and the filaments are concentrated in the inner 30% of the wire cross section. Values of I/sub c/ and T/sub c/ were determined for samples subjected to a wide range of heat treatments. Diffusion reaction times and temperatures in the ranges 16 to 128 hr and 700 to 750 0 C provided a number of mf Nb 3 Sn wires having similar I/sub c/ characteristics. To some extent the residual compressive loading on the Nb 3 Sn wires varied with the particular heat treatment. This loading arises primarily from the differential contraction of the remaining bronze and the Nb 3 Sn layer when cooled from the reaction temperature to the operating temperature. It was found that, by controlled bending or stretching of the wires, whereby some of the strain in the Nb 3 Sn is relieved, the I/sub c/ at 14 K is increased by as much as 30% and the critical temperature is increased by up to 1 K

  1. Sample of superconducting wiring (Niobium Titanium)

    CERN Multimedia

    About NbTi cable: The cable consists of 36 strands of superconducting wire, each strand has a diameter of 0.825 mm and houses 6300 superconducting filaments of niobium-titanium (Nb-Ti, a superconducting alloy). Each filament has a diameter of about 0.006 mm, i.e. 10 times smaller than a typical human hair. The filaments are embedded in a high-purity copper matrix. Copper is a normal conducting material. The filaments are in the superconductive state when the temperature is below about -263ºC (10.15 K). When the filaments leave the superconductive state, the copper acts as conductor transports the electrical current. Each strand of The NbTi cable (at superconducting state) has a current density of up to above 2000 A/mm2 at 9 T and -271ºC (2.15 K). A cable transport a current of about 13000 A at 10 T and -271ºC (2.15 K). About LHC superconducting wiring: The high magnetic fields needed for the LHC can only be reached using superconductors. At very low temperatures, superconductors have no electrical resistan...

  2. Sample of superconducting wiring (Niobium Titanium)

    CERN Multimedia

    About NbTi cable: The cable consists of 36 strands of superconducting wire, each strand has a diameter of 0.825 mm and houses 6300 superconducting filaments of niobium-titanium (Nb-Ti, a superconducting alloy). Each filament has a diameter of about 0.006 mm, i.e. 10 times smaller than a typical human hair. The filaments are embedded in a high-purity copper matrix. Copper is a normal conducting material. The filaments are in the superconductive state when the temperature is below about -263ºC (10.15 K). When the filaments leave the superconductive state, the copper acts as conductor transports the electrical current. Each strand of The NbTi cable (at superconducting state) has a current density of up to above 2000 A/mm2 at 9 T and -271ºC (2.15 K). A cable transport a current of about 13000 A at 10 T and -271ºC (2.15 K). About LHC superconducting wiring: The high magnetic fields needed for the LHC can only be reached using superconductors. At very low temperatures, superconductors have no electrical resista...

  3. Vibrating wire apparatus for periodic magnetic structure measurement

    International Nuclear Information System (INIS)

    Temnykh, A.B.

    2003-01-01

    Devices with periodic magnetic structures such as wigglers and undulators are often key elements in synchrotron radiation sources. In applications where the coherence of the emitted radiation is important, magnetic field errors distorting the periodicity of the field can significantly reduce the performance of the devices. Thus, the measurement, localization, and correction of the field errors can be a critical issue. This article presents a new method for magnetic field measurements in periodic magnetic structures. The method uses a vibrating taut wire passing through the magnetic structure, and it involves measurements of the amplitudes and phases of the standing waves excited on the wire by the Lorentz force between an AC current in the wire and the surrounding magnetic field. For certain arrangements of the wire, vibrations in the wire will be excited by only non-periodic magnetic field component, i.e., by the error field. By measuring the phase and amplitude of these waves, one can reconstruct the error field distribution and then correct it. The method was tested on a permanent magnet wiggler with 19.8 cm period and a peak field of ∼7000G. It demonstrated ∼0.6G RMS sensitivity, δB rms /B rms ∼1.2x10 -4 and spatial resolution sufficient to identify poles generating the field error. Good agreement was found between field error measurements obtained with the vibrating wire method and with traditional Hall probe field mapping

  4. Reliability Criteria for Thick Bonding Wire

    Directory of Open Access Journals (Sweden)

    Turker Dagdelen

    2018-04-01

    Full Text Available Bonding wire is one of the main interconnection techniques. Thick bonding wire is widely used in power modules and other high power applications. This study examined the case for extending the use of traditional thin wire reliability criteria, namely wire flexure and aspect ratio, to thick wires. Eleven aluminum (Al and aluminum coated copper (CucorAl wire samples with diameter 300 μm were tested experimentally. The wire response was measured using a novel non-contact method. High fidelity FEM models of the wire were developed and validated. We found that wire flexure is not correlated to its stress state or fatigue life. On the other hand, aspect ratio is a consistent criterion of thick wire fatigue life. Increasing the wire aspect ratio lowers its critical stress and increases its fatigue life. Moreover, we found that CucorAl wire has superior performance and longer fatigue life than Al wire.

  5. Effect of Cu4Ti compound formation on the characteristics of NbTi accelerator magnet wire

    International Nuclear Information System (INIS)

    Garber, M.; Suenaga, M.; Sampson, W.B.; Sabatini, R.L.

    1985-01-01

    High critical current density, J/sub c/ > 2500 A/mm 2 , and small filament diameter, d approx. 3 μm, are required in multifilamentary NbTi wire used for superconducting accelerator magnets. Wires obtained from various commercial sources had J/sub c/'s in the range 1000 to 2800 A/mm 2 amd d's in the range 1 to 23 μm. The filaments were examined by means of scanning electron microscopy in order to determine the reason for the variation in J/sub c/. It was found that the filaments in high J/sub c/ wires had clean smooth surfaces and uniform cross section along their lengths. Filaments in low J/sub c/ wires show formation of Cu 4 Ti compound particles on their surfaces and large variations in cross section. The lower critical current measured in these wires is believed to be largely due to this effect. The superconducting-normal state transition is relatively wide in these wires

  6. High Resolution Eddy-Current Wire Testing Based on a Gmr Sensor-Array

    Science.gov (United States)

    Kreutzbruck, Marc; Allweins, Kai; Strackbein, Chris; Bernau, Hendrick

    2009-03-01

    Increasing demands in materials quality and cost effectiveness have led to advanced standards in manufacturing technology. Especially when dealing with high quality standards in conjunction with high throughput quantitative NDE techniques are vital to provide reliable and fast quality control systems. In this work we illuminate a modern electromagnetic NDE approach using a small GMR sensor array for testing superconducting wires. Four GMR sensors are positioned around the wire. Each GMR sensor provides a field sensitivity of 200 pT/√Hz and a spatial resolution of about 100 μm. This enables us to detect under surface defects of 100 μm in size in a depth of 200 μm with a signal-to-noise ratio of better than 400. Surface defects could be detected with a SNR of up to 10,000. Besides this remarkably SNR the small extent of GMR sensors results in a spatial resolution which offers new visualisation techniques for defect localisation, defect characterization and tomography-like mapping techniques. We also report on inverse algorithms based on either a Finite Element Method or an analytical approach. These allow for accurate defect localization on the urn scale and an estimation of the defect size.

  7. Dorgan's lateral cross-wiring of supracondylar fractures of the humerus in children: A retrospective review.

    LENUS (Irish Health Repository)

    Queally, Joseph M

    2010-06-01

    The currently accepted treatment for displaced supracondylar humeral fractures in children is closed reduction and fixation with percutaneous Kirschner wires. The purpose of this study was to retrospectively review a novel cross-wiring technique where the cross-wire configuration is achieved solely from the lateral side, thereby reducing the risk of ulnar nerve injury.

  8. Evolution of ion-acoustic potential well in a current-carrying plasma

    International Nuclear Information System (INIS)

    Maslov, V.I.

    1990-01-01

    Properties and evolution of nonlinear correlated collective disturbance of potential well in current-carrying limited plasma are described. Study shows, that potential well intensifies while exchanging energy with resonance electrons reflecting from it with distribution unstable function. In this case, electron deficiency occurs ahead of the well and electron excess - behined it due to asymmetry, relatively to well velocity, of distribution function of electrons injected at boundaries, in velocity space and due to their reflection from well. Quasineutrality is reduced by self-congruent formation of potential jump within well range. With amplitude growth at its essential values the well is braked. Similar pattern of localized disturbance evolution was observed during numerical and laboratory experiments

  9. Influence of tensile stress and frequency on the longitudinal magnetic hysteresis of amorphous wires

    International Nuclear Information System (INIS)

    Torres, Carlos; Maria Munoz, Jose; Hernandez-Gomez, Pablo; Francisco, Carlos de

    2010-01-01

    This work studies the longitudinal magnetic hysteresis of amorphous wires with different Fe or Co compositions through an external magnetic field in the axial direction. Measurements have been carried out with the help of a digitally processed system in the 50 Hz-1 kHz frequency range. In addition, the influence of different tensile stresses has been also analyzed. The results show that both parameters change considerably the magnetic hysteresis of the wires but in a different way depending on their composition. This behaviour has been interpreted in terms of the different domain distribution associated with the opposite sign of the magnetostriction for Fe and Co-based wires, respectively.

  10. Dynamic resistance of a high-T c coated conductor wire in a perpendicular magnetic field at 77 K

    Science.gov (United States)

    Jiang, Zhenan; Toyomoto, Ryuki; Amemiya, Naoyuki; Zhang, Xingyou; Bumby, Chris W.

    2017-03-01

    Superconducting high-T c coated conductor (CC) wires comprise a ceramic thin film with a large aspect ratio. This geometry can lead to significant dissipative losses when exposed to an alternating magnetic field. Here we report experimental measurements of the ‘dynamic resistance’ of commercially available SuperPower and Fujikura CC wires in an AC perpendicular field. The onset of dynamic resistance occurs at a threshold field amplitude, which is determined by the total DC transport current and the penetration field of the conductor. We show that the field-dependence of the normalised magnetisation loss provides an unambiguous value for this threshold field at zero transport current. From this insight we then obtain an expression for the dynamic resistance in perpendicular field. This approach implies a linear relationship between dynamic resistance and applied field amplitude, and also between threshold field and transport current and this is consistent with our experimental data. The analytical expression obtained yields values that closely agree with measurements obtained across a wide range of frequencies and transport currents, and for multiple CC wires produced by different wire manufacturers and with significantly differing dimensions and critical currents. We further show that at high transport currents, the measured DC resistance includes an additional nonlinear term which is due to flux-flow resistance incurred by the DC transport current. This occurs once the field-dependent critical current of the wire falls below the DC transport current for part of each field cycle. Our results provide an effective and simple approach to calculating the dynamic resistance of a CC wire, at current and field magnitudes consistent with those expected in superconducting machines.

  11. 1998 wire development workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development.

  12. 1998 wire development workshop proceedings

    International Nuclear Information System (INIS)

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development

  13. Magnesium diboride(MgB{sub 2}) wires for applications

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Dipak; Kim, Jung Ho [Institute for Superconducting and Electronic Materials, Australian Institute for Innovative Materials, University of Wollongong, North Wollongong (Australia)

    2016-03-15

    Field and temperature dependence of the critical current density, Jc, were measured for both un-doped and carbon doped MgB{sub 2}/Nb/Monel wires manufactured by Hyper Tech Research, Inc. In particular, carbon incorporation into the MgB{sub 2} structure using malic acid additive and a chemical solution method can be advantageous because of the highly uniform mixing between the carbon and boron powders. At 4.2 K and 10 T, Jc was estimated to be 25,000 - 25,300 Acm{sup -2} for the wire sintered at 600 degrees C for 4 hours. The irreversibility field, Birr, of the malic acid doped wire was approximately 21.0 - 21.8 T, as obtained from a linear extrapolation of the J-B characteristic. Interestingly enough, the Jc of the malic acid doped sample exceeds 10{sup 5} Acm{sup -2} at 6 T and 4.2 K, which is comparable to that of commercial Nb-Ti wires.

  14. Does the insertion of a gel-based marker at stereotactic breast biopsy allow subsequent wire localizations to be carried out under ultrasound guidance?

    International Nuclear Information System (INIS)

    McMahon, M.A.; James, J.J.; Cornford, E.J.; Hamilton, L.J.; Burrell, H.C.

    2011-01-01

    Aim: To investigate whether the insertion of a gel-based marker at the time of stereotactic breast biopsy allows subsequent preoperative localization to be performed under ultrasound guidance. Materials and methods: One hundred consecutive women who underwent either a 10 G stereotactic vacuum-assisted breast biopsy or 14 G stereotactic core biopsy with marker placement, followed by wire localization and surgical excision were identified. All had mammographic abnormalities not initially visible with ultrasound. The method of preoperative localization was recorded and its success judged with reference to the wire position on the post-procedure films relative to the mammographic abnormality and the marker. Histopathology data were reviewed to ensure the lesion had been adequately excised. Results: Eighty-three women (83%) had a successful ultrasound-guided wire localization. Successful ultrasound-guided localization was more likely after stereotactic vacuum biopsy (86%) compared to stereotactic core biopsy (68%), although this did not quite reach statistical significance (p = 0.06). Conclusion: The routine placement of a gel-based marker after stereotactic breast biopsy facilitates preoperative ultrasound-guided localization.

  15. Influence of Ta and Ti Doping on the High Field Performance of (Nb, Ta, Ti)3Sn Multifilamentary Wires based on Osprey Bronze with High Tin Content

    International Nuclear Information System (INIS)

    Abaecherli, V; Uglietti, D; Lezza, P; Seeber, B; Fluekiger, R; Cantoni, M; Buffat, P-A

    2006-01-01

    Ta and Ti are the most widely used additions for technical Nb 3 Sn multifilamentary superconductors. These elements are known to influence grain growth, grain morphology and chemical composition in the A15 layer, hence the current carrying properties of the wires over a wide magnetic field range. So far only few studies tried to compare systematically Ta and Ti doped and undoped Nb 3 Sn wires in the frame of the same work, down to a nanometric scale. We present an investigation on several multifilamentary (Nb, Ta, Ti) 3 Sn bronze route wires, fabricated at a laboratory scale, with various amounts of additives. The wires consist of fine filaments embedded in a Cu-Sn or Cu-Sn-Ti Osprey bronze with > 15 wt.% Sn and an external Cu stabilization. Microstructural observations are compared with the results of J c and n values measured up to 21 T at 4.2 and 2.2 K, and for longitudinal strains up to 0.5%. Non-Cu J c values up to 300 Amm -2 and n values up to 50 at 17 T and 4.2 K show clearly that wires with Ti addition to the bronze have a better performance with respect to wires with Ti additions to the filaments

  16. Right wire in orthodontics: a review

    OpenAIRE

    Ali, Hashim

    2015-01-01

    Quality of orthodontic wire such as stiffness, hardness, resiliency, elasticity and working range are important determinants of the effectivenes of tooth movement. Commonly used types of orthodontic arch wire:1) stainless steel(ss) wire, 2) conventional nickel- titanium (NiTi)alloy wire,3) improved super elastic NiTi- alloy wire( also called low hysteresis(LH)wire), and titanium molybdenum alloy(TMA) wire.

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

    International Nuclear Information System (INIS)

    Campbell, Scott; Holesinger, Terry; Huang, Ybing

    2012-01-01

    The performance demands on modern particle accelerators generate a relentless push towards higher field magnets. In turn, advanced high field magnet development places increased demands on superconducting materials. Nb3Sn conductors have been used to achieve 16 T in a prototype dipole magnet and are thought to have the capability for ∼18 T for accelerator magnets (primarily dipoles but also higher order multipole magnets). However there have been suggestions and proposals for such magnets higher than 20 T. The High Energy Physics Community (HEP) has identified important new physics opportunities that are enabled by extremely high field magnets: 20 to 50 T solenoids for muon cooling in a muon collider (impact: understanding of neutrinos and dark matter); and 20+ T dipoles and quadrupoles for high energy hadron colliders (impact: discovery reach far beyond present). This proposal addresses the latest SBIR solicitation that calls for grant applications that seek to develop new or improved superconducting wire technologies for magnets that operate at a minimum of 12 Tesla (T) field, with increases up to 15 to 20 T sought in the near future (three to five years). The long-term development of accelerator magnets with fields greater than 20 T will require superconducting wires having significantly better high-field properties than those possessed by current Nb 3 Sn or other A15 based wires. Given the existing materials science base for Bi-2212 wire processing, we believe that Bi 2 Sr 2 CaCu 2 O y (Bi-2212) round wires can be produced in km-long piece lengths with properties suitable to meet both the near term and long term needs of the HEP community. The key advance will be the translation of this materials science base into a robust, high-yield wire technology. While the processing and application of A15 materials have advanced to a much higher level than those of the copper oxide-based, high T c (HTS) counterparts, the HTS materials have the very significant advantage

  18. Application of irradiated wire

    International Nuclear Information System (INIS)

    Uda, I.; Kozima, K.; Suzuki, S.; Tada, S.; Torisu, S.; Veno, K.

    1984-01-01

    Rubber insulated wires are still useful for internal wiring in motor vehicles and electrical equipment because of flexibility and toughness. Irradiated cross-linked rubber materials have been successfully introduced for use with fusible link wire and helically coiled cord

  19. Dissipation in a Quantum Wire: Fact and Fantasy

    International Nuclear Information System (INIS)

    Das, Mukunda P.; Green, Frederick

    2008-01-01

    Where, and how, does energy dissipation of electrical energy take place in a ballistic wire? Fully two decades after the advent of the transmissive phenomenology of electrical conductance, this deceptively simple query remains unanswered. We revisit the quantum kinetic basis of dissipation and show its power to give a definitive answer to our query. Dissipation leaves a clear, quantitative trace in the non-equilibrium current noise of a quantum point contact; this signature has already been observed in the laboratory. We then highlight the current state of accepted understandings in the light of well-known yet seemingly contradictory measurements. The physics of mesoscopic transport rests not in coherent carrier transmission through a perfect and dissipationless metallic channel, but explicitly in their dissipative inelastic scattering at the wire's interfaces and adjacent macroscopic leads.

  20. Cockpit canopy shattering using exploding wire techniques

    International Nuclear Information System (INIS)

    Novac, B M; Smith, I R; Downs, P R; Marston, P; Fahey, D

    2007-01-01

    This paper presents the principal experimental results provided by a preliminary investigation into the possibility of using exploding wire (EW) techniques to shatter the plastic cockpit canopy of a modern jet aircraft. The data provided forms the basis for a qualitative understanding of the physics of interaction between the plasma produced by an EW and the surrounding elasto-plastic material in which the wire is embedded. To optimize the shock-wave 'clean cutting' effect, the significance of the material, the dimensions of the exploding wire and the amplitude of the current and voltage pulses are all considered. This leads to important conclusions concerning both the characteristics of the EW and the optimum arrangement of the electrical circuit, with the single most important optimization factor being the peak electrical power input to the EW, rather than the dissipated Joule energy. A full-scale system relevant to an actual cockpit canopy shattering is outlined and relevant results are presented and discussed

  1. Curved anode wire chambers for x-ray diffraction applications

    International Nuclear Information System (INIS)

    Perez-Mendez, V.; Wiedenbeck, P.; Wagner, C.N.J.; Woelfel, E.

    1983-01-01

    Curved position sensitive proportional detectors are described. The first has a radius of curvature of 135 mm and a 60 0 angular range. The second has a radius of curvature of 360 mm and a 45 0 angular range. For high quantum efficiency for x-ray energies up to 60 keV, a relatively large x-ray path and high gas pressure are required. The anode wires are suspended in circular arcs by the interaction of a current flowing through them and a magnetic field provided by two permanent magnets placed above and below the wire running parallel to it over the full length of the curved chambers. Anode wire stability under the combined action of the magnetic and electrostatic forces is discussed

  2. Control of core structure in MgB{sub 2} wire through tailoring boron powder

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, Minoru, E-mail: maeda.minoru70@nihon-u.ac.jp [Department of Physics, College of Science and Technology, Nihon University, 1-8-14 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Uchiyama, Daisuke [Department of Physics, College of Science and Technology, Nihon University, 1-8-14 Kanda-Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Hossain, Md Shahriar Al; Ma, Zongqing [Institute for Superconducting and Electronic Materials, University of Wollongong, North Wollongong, New South Wales 2500 (Australia); Shahabuddin, Mohammed [Department of Physics and Astronomy, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Kim, Jung Ho, E-mail: jhk@uow.edu.au [Institute for Superconducting and Electronic Materials, University of Wollongong, North Wollongong, New South Wales 2500 (Australia)

    2015-07-05

    Highlights: • The typical void structure in the wire is obtained by using large-sized B powder. • In contrast, void alignment can be achieved by using fine B powder. • The sintering at lower temperatures improves the critical current density in fields. - Abstract: A common fabrication process for MgB{sub 2} wire, namely, the in situ powder-in-tube process, forms numerous voids within the wire core, and void formation cannot be completely avoided. The orientation is, however, known to be aligned more or less along the current-flow direction when ductile coarse magnesium powder is used as a precursor, and further tailoring approaches could open up the way to improving the transport critical current density. Herein, we have used boron powders with different particle sizes, in combination with the coarse magnesium powder, and evaluated their size effects on the phase composition, microstructure, and transport properties. A mixture of the coarse magnesium powder with large-sized boron powder in the wire core, after cold working and sintering, forms a granular morphology. In contrast, an aligned core appears during the reduction process for wire which is prepared by using fine boron powder. The sintering process, especially at a low temperature, where magnesium evaporation hardly occurs, yields an aligned structure, mainly consisting of MgB{sub 2} phase, along the wire direction. These findings demonstrate that the initial size of the starting materials is critical for the tailored structure.

  3. Effects of load voltage on voltage breakdown modes of electrical exploding aluminum wires in air

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jian; Li, Xingwen, E-mail: xwli@mail.xjtu.edu.cn; Yang, Zefeng; Wang, Kun; Chao, Youchuang; Shi, Zongqian; Jia, Shenli; Qiu, Aici [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Xi' an 710049 (China)

    2015-06-15

    The effects of the load voltage on the breakdown modes are investigated in exploding aluminum wires driven by a 1 kA, 0.1 kA/ns pulsed current in air. From laser probing images taken by laser shadowgraphy, schlieren imaging, and interferometry, the position of the shockwave front, the plasma channel, and the wire core edge of the exploding product can be determined. The breakdown mode makes a transition from the internal mode, which involves breakdown inside the wire core, to the shunting mode, which involves breakdown in the compressed air, with decreasing charging voltage. The breakdown electrical field for a gaseous aluminum wire core of nearly solid density is estimated to be more than 20 kV/cm, while the value for gaseous aluminum of approximately 0.2% solid density decreases to 15–20 kV/cm. The breakdown field in shunting mode is less than 20 kV/cm and is strongly affected by the vaporized aluminum, the desorbed gas, and the electrons emitted from the wire core during the current pause. Ohmic heating during voltage collapses will induce further energy deposition in the current channel and thus will result in different expansion speeds for both the wire core and the shockwave front in the different modes.

  4. Frequency- and axial-field-dependent circular magnetization reversal in a stress-annealed Fe-based nanocrystalline wire

    International Nuclear Information System (INIS)

    Li, Y.F.; Vazquez, M.; Yin, S.Z.

    2009-01-01

    Absract: After suitable annealing under a tensile stress, Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 amorphous wire becomes the nano-structured material together with a transverse anisotropy field H k =-3.2 kA/m. Its circular permeability, μ=μ'-jμ'', was determined from the measurements of the impedance, as a function of the frequency (f=333-33,333 Hz) and amplitude (I AC =0.1-100 mA) of AC current and the axially applied DC field (H=0-89 kA/m). We found that the circular technical magnetization of this sample carried out by the spontaneous domain nucleation process. The influences of the AC current frequency and the axial DC field on the circular magnetization have been studied

  5. Aluminum Lithium Alloy 2195 Fusion Welding Improvements with New Filler Wire

    Science.gov (United States)

    Russell, C.

    2001-01-01

    The objective of this research was to assess the B218 weld filler wire for Super Lightweight External Tank production, which could improve current production welding and repair productivity. We took the following approaches: (1) Perform a repair weld quick look evaluation between 4043/B218 and B218/B218 weld filler wire combinations and evaluation tensile properties for planished and unplanished conditions; and (2) Perform repair weld evaluation on structural simulation panel using 4043-B218 and B218/B218 weld filler wire combinations and evaluation tensile and simulated service fracture properties for planished and unplanished conditions.

  6. Wire core reactor for NTP

    International Nuclear Information System (INIS)

    Harty, R.B.

    1991-01-01

    The development of the wire core system for Nuclear Thermal Propulsion (NTP) that took place from 1963 to 1965 is discussed. A wire core consists of a fuel wire with spacer wires. It's an annular flow core having a central control rod. There are actually four of these, with beryllium solid reflectors on both ends and all the way around. Much of the information on the concept is given in viewgraph form. Viewgraphs are presented on design details of the wire core, the engine design, engine weight vs. thrust, a technique used to fabricate the wire fuel element, and axial temperature distribution

  7. Thermoelectric Mechanism and Interface Characteristics of Cyanide-Free Nanogold-Coated Silver Wire

    Science.gov (United States)

    Tseng, Yi-Wei; Hung, Fei-Yi; Lui, Truan-Sheng

    2016-01-01

    Traditional bath-plated gold contains a cyanide complex, which is an environmental hazard. In response, our study used a green plating process to produce cyanide-free gold-coated silver (cyanide-free ACA) bonding wire that has been proven to be a feasible alternative to gold bonding wire in semiconductor packaging. In this work, ACA wire annealed at 550°C was found to have stable microstructure and superior mechanical properties. Intermetallic compounds Ag2Al and AuAl2 grew from Ag-Au balls and Al pads after aging at 175°C for 500 h. After current testing, ACA wire was found to have improved electrical properties due to equiaxed grain growth. The gold nanolayer on the Ag surface increased the oxidation resistance. These results provide insights regarding the reliability of ACA wire in advanced bonding processes.

  8. Development of Powder-in-Tube Processed Iron Pnictide Wires and Tapes

    KAUST Repository

    Ma, Yanwei

    2011-06-01

    The development of PIT fabrication process of iron pnictide superconducting wires and tapes has been reviewed. Silver was found to be the best sheath material, since no reaction layer was observed between the silver sheath and the superconducting core. The grain connectivity of iron pnictide wires and tapes has been markedly improved by employing Ag or Pb as dopants. At present, critical current densities in excess of 3750 A /cm 2 (I c = 37.5 A) at 4.2 K have been achieved in Ag-sheathed SrKFeAs wires prepared with the above techniques, which is the highest value obtained in iron-based wires and tapes so far. Moreover, Ag-sheathed Sm-1111 superconducting tapes were successfully prepared by PIT method at temperatures as low as ̃ 900 °C, instead of commonly used temperatures of ̃ 1200 °C. These results demonstrate the feasibility of producing superconducting pnictide composite wires, even grain boundary properties require much more attention. © 2010 IEEE.

  9. Nanosecond electrical explosion of thin aluminum wire in vacuum: experimental and computational investigations

    International Nuclear Information System (INIS)

    Cochrane, Kyle Robert; Struve, Kenneth William; Rosenthal, Stephen Edgar; McDaniel, Dillon Heirman; Sarkisov, Gennady Sergeevich; Deeney, Christopher

    2004-01-01

    The experimental and computational investigations of nanosecond electrical explosion of thin Al wire in vacuum are presented. We have demonstrated that increasing the current rate leads to increased energy deposited before voltage collapse. Laser shadowgrams of the overheated Al core exhibit axial stratification with a ∼100 (micro)m period. The experimental evidence for synchronization of the wire expansion and light emission with voltage collapse is presented. Two-wavelength interferometry shows an expanding Al core in a low-ionized gas condition with increasing ionization toward the periphery. Hydrocarbons are indicated in optical spectra and their influence on breakdown physics is discussed. The radial velocity of low-density plasma reaches a value of ∼100 km/s. The possibility of an overcritical phase transition due to high pressure is discussed. 1D MHD simulation shows good agreement with experimental data. MHD simulation demonstrates separation of the exploding wire into a high-density cold core and a low-density hot corona as well as fast rejection of the current from the wire core to the corona during voltage collapse. Important features of the dynamics for wire core and corona follow from the MHD simulation and are discussed.

  10. A One Chip Hardened Solution for High Speed SpaceWire System Implementations. Session: Components

    Science.gov (United States)

    Marshall, Joseph R.; Berger, Richard W.; Rakow, Glenn P.

    2007-01-01

    An Application Specific Integrated Circuit (ASIC) that implements the SpaceWire protocol has been developed in a radiation hardened 0.25 micron CMOS technology. This effort began in March 2003 as a joint development between the NASA Goddard Space Flight Center (GSFC) and BAE Systems. The BAE Systems SpaceWire ASIC is comprised entirely of reusable core elements, many of which are already flight-proven. It incorporates a router with 4 SpaceWire ports and two local ports, dual PC1 bus interfaces, a microcontroller, 32KB of internal memory, and a memory controller for additional external memory use. The SpaceWire cores are also reused in other ASICs under development. The SpaceWire ASIC is planned for use on the Geostationary Operational Environmental Satellites (GOES)-R, the Lunar Reconnaissance Orbiter (LRO) and other missions. Engineering and flight parts have been delivered to programs and users. This paper reviews the SpaceWire protocol and those elements of it that have been built into the current and next SpaceWire reusable cores and features within the core that go beyond the current standard and can be enabled or disabled by the user. The adaptation of SpaceWire to BAE Systems' On Chip Bus (OCB) for compatibility with the other reusable cores will be reviewed and highlighted. Optional configurations within user systems and test boards will be shown. The physical implementation of the design will be described and test results from the hardware will be discussed. Application of this ASIC and other ASICs containing the SpaceWire cores and embedded microcontroller to Plug and Play and reconfigurable implementations will be described. Finally, the BAE Systems roadmap for SpaceWire developments will be updated, including some products already in design as well as longer term plans.

  11. Water Desalination with Wires

    NARCIS (Netherlands)

    Porada, S.; Sales, B.B.; Hamelers, H.V.M.; Biesheuvel, P.M.

    2012-01-01

    We show the significant potential of water desalination using a novel capacitive wire-based technology in which anode/cathode wire pairs are constructed from coating a thin porous carbon electrode layer on top of electrically conducting rods (or wires). By alternately dipping an array of electrode

  12. Evolution of cementite morphology in pearlitic steel wire during wet wire drawing

    DEFF Research Database (Denmark)

    Zhang, Xiaodan; Godfrey, Andrew; Hansen, Niels

    2010-01-01

    The evolution of the cementite phase during wet wire drawing of a pearlitic steel wire has been followed as a function of strain. Particular attention has been given to a quantitative characterization of changes in the alignment and in the dimensions of the cementite phase. Scanning electron...... microscope observations show that cementite plates become increasingly aligned with the wire axis as the drawing strain is increased. Measurements in the transmission electron microscope show that the cementite deforms plastically during wire drawing , with the average thickness of the cementite plates...... decreasing from 19 nm (ε = 0) to 2 nm (ε = 3.7) in correspondence with the reduction in wire diameter. The deformation of the cementite is strongly related to plastic deformation in the ferrite, with coarse slip steps, shear bands and cracks in the cementite plates/particles observed parallel to either {110...

  13. Breakdown processes in wire chambers, prevention and rate capability

    International Nuclear Information System (INIS)

    Atac, M.

    1983-01-01

    Breakdowns were optically and electronically observed in drift tubes and drift chambers. They occur at a critical gain for given intensity in a gas mixture when ultraviolet photons are not completely quenched. It was observed that the breakdowns depended critically on average current for a given gas mixture independent of the size of the drift tubes used. Using 4.6% ethyl alcohol vapor mixed into 50/50 argon ethane gas, breakdown are eliminated up to 7 /sub μ/A average current drawn by pulses on a 1 cm section of an anode wire under an intense source. Pulses with an avalanche size of 10 6 electron rates above 10 6 pulses per centimeter per wire may be obtained with the elimination of breakdowns

  14. Breakdown processes in wire chambers, prevention and rate capability

    International Nuclear Information System (INIS)

    Atac, M.

    1982-01-01

    Breakdowns were optically and electronically observed in drift tubes and drift chambers. They occur at a critical gain for given intensity in a gas mixture when ultraviolet photons are not completely quenched. It was observed that the breakdowns depended critically on average current for a given gas mixture independent of the size of the drift tubes used. Using 4.6% ethyl alcohol vapor mixed into 50/50 argon ethane gas, breakdowns are eliminated up to 7 μA average current drawn by pulses on a 1 cm section of an anode wire under an intense source. Pulses with an avalanche size of 10 6 electron rates above 10 6 pulses per centimeter per wire may be obtained with the elimination of breakdowns

  15. Electrical Crystallization Mechanism and Interface Characteristics of Nano wire Zn O/Al Structures Fabricated by the Solution Method

    International Nuclear Information System (INIS)

    Tseng, Y.W.; Hung, F.Y.; Lui, T.Sh.; Chen, Y.T.; Xiao, R.S.; Chen, K.J.

    2012-01-01

    Both solution nano wire Zn O and sputtered Al thin film on SiO 2 as the wire-film structure and the Al film were a conductive channel for electrical-induced crystallization (EIC). Direct current (DC) raised the temperature of the Al film and improved the crystallization of the nano structure. The effects of EIC not only induced Al atomic interface diffusion, but also doped Al on the roots of Zn O wires to form aluminum doped zinc oxide (AZO)/Zn O wires. The Al doping concentration and the distance of the Zn O wire increased with increasing the electrical duration. Also, the electrical current-induced temperature was ∼211 degree C (solid-state doped process) and so could be applied to low-temperature optoelectronic devices.

  16. Experimental investigation on the energy deposition and morphology of the electrical explosion of copper wire in vacuum

    International Nuclear Information System (INIS)

    Shi, Zongqian; Shi, Yuanjie; Wang, Kun; Jia, Shenli

    2016-01-01

    This paper presents the experimental results of the electrical explosion of copper wires in vacuum using negative nanosecond-pulsed current with magnitude of 1–2 kA. The 20 μm-diameter copper wires with different lengths are exploded with three different current rates. A laser probe is applied to construct the shadowgraphy and interferometry diagnostics to investigate the distribution and morphology of the exploding product. The interference phase shift is reconstructed from the interferogram, by which the atomic density distribution is calculated. Experimental results show that there exist two voltage breakdown modes depending on the amount of the specific energy deposition. For the strong-shunting mode, shunting breakdown occurs, leading to the short-circuit-like current waveform. For the weak-shunting mode with less specific energy deposition, the plasma generated during the voltage breakdown is not enough to form a conductive plasma channel, resulting in overdamped declining current waveform. The influence of the wire length and current rate on the characteristics of the exploding wires is also analyzed.

  17. Experimental investigation on the energy deposition and morphology of the electrical explosion of copper wire in vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Zongqian; Shi, Yuanjie; Wang, Kun; Jia, Shenli [State Key Laboratory of Electrical Insulation and Power Equipment, Xi' an Jiaotong University, Shanxi 710049 (China)

    2016-03-15

    This paper presents the experimental results of the electrical explosion of copper wires in vacuum using negative nanosecond-pulsed current with magnitude of 1–2 kA. The 20 μm-diameter copper wires with different lengths are exploded with three different current rates. A laser probe is applied to construct the shadowgraphy and interferometry diagnostics to investigate the distribution and morphology of the exploding product. The interference phase shift is reconstructed from the interferogram, by which the atomic density distribution is calculated. Experimental results show that there exist two voltage breakdown modes depending on the amount of the specific energy deposition. For the strong-shunting mode, shunting breakdown occurs, leading to the short-circuit-like current waveform. For the weak-shunting mode with less specific energy deposition, the plasma generated during the voltage breakdown is not enough to form a conductive plasma channel, resulting in overdamped declining current waveform. The influence of the wire length and current rate on the characteristics of the exploding wires is also analyzed.

  18. Understanding Irreversible Degradation of Nb3Sn Wires with Fundamental Fracture Mechanics

    Energy Technology Data Exchange (ETDEWEB)

    Zhai, Yuhu [PPPL; Calzolaio, Ciro [Univ of Geneva; Senatore, Carmine [Univ of Geneva

    2014-08-01

    Irreversible performance degradation of advanced Nb3Sn superconducting wires subjected to transverse or axial mechanical loading is a critical issue for the design of large-scale fusion and accelerator magnets such as ITER and LHC. Recent SULTAN tests indicate that most cable-in-conduit conductors for ITER coils made of Nb3Sn wires processed by various fabrication techniques show similar performance degradation under cyclic loading. The irreversible degradation due to filament fracture and local strain accumulation in Nb3Sn wires cannot be described by the existing strand scaling law. Fracture mechanic modeling combined with X-ray diffraction imaging of filament micro-crack formation inside the wires under mechanical loading may reveal exciting insights to the wire degradation mechanisms. We apply fundamental fracture mechanics with a singularity approach to study influence of wire filament microstructure of initial void size and distribution to local stress concentration and potential crack propagation. We report impact of the scale and density of the void structure on stress concentration in the composite wire materials for crack initiation. These initial defects result in an irreversible degradation of the critical current beyond certain applied stress. We also discuss options to minimize stress concentration in the design of the material microstructure for enhanced wire performance for future applications.

  19. Superconductivity of powder-in-tube MgB{sub 2} wires

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, B A; Evetts, J E [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge, CB3 OHE (United Kingdom); Department of Materials Science and Metallurgy, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Majoros, M [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge, CB3 OHE (United Kingdom); Institute of Electrical Engineering, Slovak Academy of Science, Dubravska Cesta 9, Bratislava (Slovakia); Vickers, M [Department of Materials Science and Metallurgy, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Shi, Y [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge, CB3 OHE (United Kingdom); McDougall, I [Oxford Instruments Plc, Eynsham, OX8 ITL (United Kingdom)

    2001-04-01

    A new class of 'powder-in-tube' Mg-B superconducting conductors has been prepared using two different methods: an in situ technique where an Mg + 2B mixture was used as a central conductor core and reacted in situ to form MgB{sub 2}, and an ex situ technique where fully reacted MgB{sub 2} powder was used to fill the metal tube. Conductors were prepared using silver, copper and bimetallic silver/stainless steel tubes. Wires manufactured by the in situ technique, diffusing Mg to B particles experienced {approx}25.5% decrease in density from the initial value after cold deformation, due to the phase transformation from Mg + 2({beta}-B){yields}MgB{sub 2} all with hexagonal structure. A comparative study of the intergranular current and grain connectivity in wires was conducted by AC susceptibility measurements and direct four point transport measurements. Using a SQUID magnetometer, magnetization versus magnetic field (M-H) curves of the round wires before and after sintering and reactive diffusion were measured at 5 K and in magnetic fields up to 5 T to define the J{sub cmag}. The direct current measurements were performed in self field at 4.2 K. A comparison between zero-field-cooled (ZFC) and field-cooled (FC) susceptibility measurements for sintered Ag/MgB{sub 2}, and reacted Cu/Mg + 2B conductors revealed systematic differences in the flux pinning in the wires which is in very good agreement with direct high transport current measurements. (author)

  20. Superconductivity of powder-in-tube MgB{sub 2} wires

    Energy Technology Data Exchange (ETDEWEB)

    Glowacki, B.A.; Evetts, J.E. [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge, CB3 OHE (United Kingdom); Department of Materials Science and Metallurgy, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Majoros, M. [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge, CB3 OHE (United Kingdom); Institute of Electrical Engineering, Slovak Academy of Science, Dubravska Cesta 9, Bratislava (Slovakia); Vickers, M. [Department of Materials Science and Metallurgy, Pembroke Street, Cambridge, CB2 3QZ (United Kingdom); Shi, Y. [IRC in Superconductivity, University of Cambridge, Madingley Road, Cambridge, CB3 OHE (United Kingdom); McDougall, I. [Oxford Instruments Plc, Eynsham, OX8 ITL (United Kingdom)

    2001-04-01

    A new class of 'powder-in-tube' Mg-B superconducting conductors has been prepared using two different methods: an in situ technique where an Mg + 2B mixture was used as a central conductor core and reacted in situ to form MgB{sub 2}, and an ex situ technique where fully reacted MgB{sub 2} powder was used to fill the metal tube. Conductors were prepared using silver, copper and bimetallic silver/stainless steel tubes. Wires manufactured by the in situ technique, diffusing Mg to B particles experienced {approx}25.5% decrease in density from the initial value after cold deformation, due to the phase transformation from Mg + 2({beta}-B){yields}MgB{sub 2} all with hexagonal structure. A comparative study of the intergranular current and grain connectivity in wires was conducted by AC susceptibility measurements and direct four point transport measurements. Using a SQUID magnetometer, magnetization versus magnetic field (M-H) curves of the round wires before and after sintering and reactive diffusion were measured at 5 K and in magnetic fields up to 5 T to define the J{sub cmag}. The direct current measurements were performed in self field at 4.2 K. A comparison between zero-field-cooled (ZFC) and field-cooled (FC) susceptibility measurements for sintered Ag/MgB{sub 2}, and reacted Cu/Mg + 2B conductors revealed systematic differences in the flux pinning in the wires which is in very good agreement with direct high transport current measurements. (author)

  1. The development of natural-draught cooling towers of prestressed wire-rope network construction of aerodynamic design

    International Nuclear Information System (INIS)

    Braun, R.; Jasch, E.

    1975-01-01

    Natural-draught cooling towers carried to a height of up to 200 m will be required for the dissipation of the residual heat from the thermal processes of large-capacity power stations to be erected in future. The structural problems involved in such large-size towers can be overcome by using prestressed wire-rope network construction. A structural concept is discussed which proposes to use a cooling tower shell constructed of a prestressed, planked wire-rope network of circular hyperbolic form carried by a spacer ring attached to the central mast. Comments are given on the ensuing problems of aerodynamics, stress-strength assessment, and erection. (orig.) [de

  2. Scaleup of powder metallurgy processed Nb-Al multifilamentary wire

    International Nuclear Information System (INIS)

    Thieme, C.; Foner, S.; Otubo, J.; Pourrahimi, S.; Schwartz, B.; Zhang, H.

    1983-01-01

    Power metallurgy processed Nb-Al superconducting wires were fabricated from billets up to 45 mm o.d. with nominal areal reduction ratios, R, up to 2 X 10 5 , Nb powder sizes from 40 to 300 μm from various sources, Al powder sizes from 9 to 75 μm, Al concentrations from 3 to 25 wt % Al and with a wide range of heat treatments. All the compacts used tap density powder in a Cu tube and swaging and/or rod rolling and subsequent wire drawing. Both single strand and bundled wires were made. Overall critical current densities, J /SUB c/, of 2 X 10 4 A/cm 2 at 14 T and 10 4 A/cm 2 at 16 T were achieved for 6 to 8 wt % Al in Nb

  3. Synthesis of chemical vapor deposition graphene on tantalum wire for supercapacitor applications

    International Nuclear Information System (INIS)

    Li, Mingji; Guo, Wenlong; Li, Hongji; Xu, Sheng; Qu, Changqing; Yang, Baohe

    2014-01-01

    Highlights: • The capacitance of graphene/tantalum (Ta) wire electrodes is firstly reported. • Graphene was grown on the Ta surface by hot-filament chemical vapor deposition. • Graphene/Ta wire structure is favorable for fast ion and electron transfer. • The graphene/Ta wire electrode shows high capacitive properties. - Abstract: This paper studies the synthesis and electrochemical characterization of graphene/tantalum (Ta) wires as high-performance electrode material for supercapacitors. Graphene on Ta wires is prepared by the thermal decomposition of methane under various conditions. The graphene nanosheets on the Ta wire surface have an average thickness of 1.3–3.4 nm and consist typically of a few graphene monolayers, and TaC buffer layers form between the graphene and Ta wire. A capacitor structure is fabricated using graphene/Ta wire with a length of 10 mm and a diameter of 0.6 mm as the anode and Pt wire of the same size as the cathode. The electrochemical behavior of the graphene/Ta wires as supercapacitor electrodes is characterized by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy in 1 M Na 2 SO 4 aqueous electrolyte. The as-prepared graphene/Ta electrode has highest capacitance of 345.5 F g −1 at current density of 0.5 A g −1 . The capacitance remains at about 84% after 1000 cycles at 10 A g −1 . The good electrochemical performance of the graphene/Ta wire electrode is attributed to the unique nanostructural configuration, high electrical conductivity, and large specific surface area of the graphene layer. This suggests that graphene/Ta wire electrode materials have potential applications in high-performance energy storage devices

  4. Diameter dependent failure current density of gold nanowires

    International Nuclear Information System (INIS)

    Karim, S; Maaz, K; Ali, G; Ensinger, W

    2009-01-01

    Failure current density of single gold nanowires is investigated in this paper. Single wires with diameters ranging from 80 to 720 nm and length 30 μm were electrochemically deposited in ion track-etched single-pore polycarbonate membranes. The maximum current density was investigated while keeping the wires embedded in the polymer matrix and ramping up the current until failure occurred. The current density is found to increase with diminishing diameter and the wires with a diameter of 80 nm withstand 1.2 x 10 12 A m -2 before undergoing failure. Possible reasons for these results are discussed in this paper.

  5. Precipitation formation in recrystallized nickel-plated non-sag tungsten wire

    International Nuclear Information System (INIS)

    Lai, Z.H.

    1994-01-01

    It is well established that some metals, such as palladium and nickel, can easily penetrate into tungsten by fast diffusion via crystal defects such as grain boundaries and dislocations. As a result of the fast penetration of these so called activators the recrystallization temperature of heavily drawn non-sag tungsten wire can be lower from about 2,000 C to about 1,000 C, thus the application of the tungsten wire, serving as reinforcement material in metal matrix composites used at high temperatures, is limited. An interesting question is in which form these activators exist in the recrystallized tungsten wire. It is generally believed that W-Ni intermediate compounds could form in the recrystallized material, presumably at grain boundaries. The free energy difference between the pure tungsten fibbers and the precipitating W(Ni) solid solution was suggested as the chemical driving force which governed the recrystallization process. The presence of nickel in small particles had also been observed in recrystallized grains of nickel plated tungsten wires using scanning electron microscopy (SEM) and secondary ion mass spectroscopy. These particles were considered to be nickel rich precipitates. However, a detailed investigation of the precipitation process has not been reported. In the present work an investigation of the structure, composition and distribution of nickel rich particles precipitated in recrystallized grains of nickel plated heavily drawn non-sage tungsten wires was carried out using analytical electron microscopy (AEM)

  6. Using wire shaping techniques and holographic optics to optimize deposition characteristics in wire-based laser cladding.

    Science.gov (United States)

    Goffin, N J; Higginson, R L; Tyrer, J R

    2016-12-01

    In laser cladding, the potential benefits of wire feeding are considerable. Typical problems with the use of powder, such as gas entrapment, sub-100% material density and low deposition rate are all avoided with the use of wire. However, the use of a powder-based source material is the industry standard, with wire-based deposition generally regarded as an academic curiosity. This is because, although wire-based methods have been shown to be capable of superior quality results, the wire-based process is more difficult to control. In this work, the potential for wire shaping techniques, combined with existing holographic optical element knowledge, is investigated in order to further improve the processing characteristics. Experiments with pre-placed wire showed the ability of shaped wire to provide uniformity of wire melting compared with standard round wire, giving reduced power density requirements and superior control of clad track dilution. When feeding with flat wire, the resulting clad tracks showed a greater level of quality consistency and became less sensitive to alterations in processing conditions. In addition, a 22% increase in deposition rate was achieved. Stacking of multiple layers demonstrated the ability to create fully dense, three-dimensional structures, with directional metallurgical grain growth and uniform chemical structure.

  7. On the improved adhesion of NiTi wires embedded in polyester and vinylester resins

    Directory of Open Access Journals (Sweden)

    Mattia Merlin

    2015-01-01

    Full Text Available This paper discusses the effect of different surface treatments on shape memory alloy wires embedded in PolyEster (PE and VinylEster (VE polymeric matrices. In particular, two types of chemical etching and a chemical bonding with a silane coupling agent have been performed on the surfaces of the wires. Pull-out tests have been carried out on samples made from a specifically designed Teflon mould. Considering the best results of the pull-out tests obtained with PE resin, the debonding induced by strain recovery of 4%, 5% and 6% pre-strained NiTi wires has been evaluated with the wires being subjected to different surface treatment conditions and then being embedded in the PE matrix. The results prove that the wires functionalised and embedded in the PE resin show the maximum pull-out forces and the highest interfacial adhesion. Finally, it has been found that debonding induced by strain recovery is strongly related to the propagation towards the radial direction of sharp cracks at the debonding region.

  8. Evolution of cementite morphology in pearlitic steel wire during wet wire drawing

    International Nuclear Information System (INIS)

    Zhang Xiaodan; Godfrey, Andrew; Hansen, Niels; Huang Xiaoxu; Liu Wei; Liu Qing

    2010-01-01

    The evolution of the cementite phase during wet wire drawing of a pearlitic steel wire has been followed as a function of strain. Particular attention has been given to a quantitative characterization of changes in the alignment and in the dimensions of the cementite phase. Scanning electron microscope observations show that cementite plates become increasingly aligned with the wire axis as the drawing strain is increased. Measurements in the transmission electron microscope show that the cementite deforms plastically during wire drawing , with the average thickness of the cementite plates decreasing from 19 nm (ε = 0) to 2 nm (ε = 3.7) in correspondence with the reduction in wire diameter. The deformation of the cementite is strongly related to plastic deformation in the ferrite, with coarse slip steps, shear bands and cracks in the cementite plates/particles observed parallel to either {110} α or {112} α slip plane traces in the ferrite.

  9. Corrosion of Wires on Wooden Wire-Bound Packaging Crates

    Science.gov (United States)

    Samuel L. Zelinka; Stan Lebow

    2015-01-01

    Wire-bound packaging crates are used by the US Army to transport materials. Because these crates may be exposed to harsh environments, they are dip-treated with a wood preservative (biocide treatment). For many years, zinc-naphthenate was the most commonly used preservative for these packaging crates and few corrosion problems with the wires were observed. Recently,...

  10. A Prototype Wire Position Monitoring System

    International Nuclear Information System (INIS)

    Wang, Wei

    2010-01-01

    The Wire Position Monitoring System (WPM) will track changes in the transverse position of LCLS Beam Position Monitors (BPMs) to 1(micro)m over several weeks. This position information will be used between applications of beam based alignment to correct for changes in component alignment. The WPM system has several requirements. The sensor range must be large enough so that precision sensor positioning is not required. The resolution needs to be small enough so that the signal can be used to monitor motion to 1(micro)m. The system must be stable enough so that system drift does not mimic motion of the component being monitored. The WPM sensor assembly consists of two parts, the magnetic sensor and an integrated lock-in amplifier. The magnetic sensor picks up a signal from the alternating current in a stretched wire. The voltage v induced in the sensor is proportional to the wire displacement from the center of the sensor. The integrated lock-in amplifier provides a DC output whose magnitude is proportional to the AC signal from the magnetic sensor. The DC output is either read on a digital voltmeter or digitized locally and communicated over a computer interface.

  11. Etching of anode wire deposits with CF4/isobutane (80:20) avalanches

    International Nuclear Information System (INIS)

    Openshaw, R.; Henderson, R.S.; Faszer, W.; Salomon, M.

    1991-01-01

    An ionization exposure of 0.5 C per cm of wire in a gas mixture of CF 4 /isobutane (80:20) is shown to reverse anode wire damage in single-wire chambers. Several chambers aged in argon/ethane (50:50) and argon/ethane/ethanol (50:50:0.2) and having pulse height reduction of 25-30% have recovered pulse heights and currents to greater than 98% of their initial values. Inspection of the anode wires indicates that the thick deposits caused by the exposure in argon/ethane have been removed. Auger electron spectroscopy reveals only a thin residual layer containing primarily carbon and oxygen. This etching ability of CF 4 /isobutane (80:20) avalanches may explain the extremely good ageing characteristics previously reported for this mixture. (orig.)

  12. Underwater electrical wire explosion: Shock wave from melting being overtaken by shock wave from vaporization

    Science.gov (United States)

    Li, Liuxia; Qian, Dun; Zou, Xiaobing; Wang, Xinxin

    2018-05-01

    The shock waves generated by an underwater electrical wire explosion were investigated. A microsecond time-scale pulsed current source was used to trigger the electrical explosion of copper wires with a length of 5 cm and a diameter of 200 μm. The energy-storage capacitor was charged to a relatively low energy so that the energy deposited onto the wire was not large enough to fully vaporize the whole wire. Two shock waves were recorded with a piezoelectric gauge that was located at a position of 100 mm from the exploding wire. The first and weak shock wave was confirmed to be the contribution from wire melting, while the second and stronger shock wave was the contribution from wire vaporization. The phenomenon whereby the first shock wave generated by melting being overtaken by the shock wave due to vaporization was observed.

  13. A design and construction of wire drive mechanical barrier system on the medium dose brachytherapy for cervical cancer

    International Nuclear Information System (INIS)

    Nur Khasan; Tri Harjanto; Ari Satmoko

    2012-01-01

    A design and construction of wire drive mechanical barrier system on the medium dose brachytherapy for cervical cancer has been done as a complete system for security of both mechanically and electrically during the operation of the device as a whole. The design and construction were carried out by paying attention to the length of wire dimensions, the diameter of the roller drum for wire, the process of wire rolling and delivery path length of the radioactive source or also the checker. The length dimension of wire or delivery path length with a diameter of drum rollers which is converted into 2 pieces of limiting the size of the circular line on the gear system is integrated with the limit switch/divider electrically. By using this barrier the security and certainty of the wire rolling and delivery process are assured, either wire of radioactive sources or also wire of checker. The materials or components used are aluminum for gear system and limit switches for electrical systems. The result of the construction is a set of equipment that is used to complete a safety facility operating on the wire drive module of medium dose brachytherapy for cervical cancer. (author)

  14. Graphene-on-diamond devices with increased current-carrying capacity: carbon sp2-on-sp3 technology.

    Science.gov (United States)

    Yu, Jie; Liu, Guanxiong; Sumant, Anirudha V; Goyal, Vivek; Balandin, Alexander A

    2012-03-14

    Graphene demonstrated potential for practical applications owing to its excellent electronic and thermal properties. Typical graphene field-effect transistors and interconnects built on conventional SiO(2)/Si substrates reveal the breakdown current density on the order of 1 μA/nm(2) (i.e., 10(8) A/cm(2)), which is ~100× larger than the fundamental limit for the metals but still smaller than the maximum achieved in carbon nanotubes. We show that by replacing SiO(2) with synthetic diamond, one can substantially increase the current-carrying capacity of graphene to as high as ~18 μA/nm(2) even at ambient conditions. Our results indicate that graphene's current-induced breakdown is thermally activated. We also found that the current carrying capacity of graphene can be improved not only on the single-crystal diamond substrates but also on an inexpensive ultrananocrystalline diamond, which can be produced in a process compatible with a conventional Si technology. The latter was attributed to the decreased thermal resistance of the ultrananocrystalline diamond layer at elevated temperatures. The obtained results are important for graphene's applications in high-frequency transistors, interconnects, and transparent electrodes and can lead to the new planar sp(2)-on-sp(3) carbon-on-carbon technology. © 2012 American Chemical Society

  15. Analogue Between Dynamic Hamiltonian-Operators of a Mesoscopic Ring Carrying Persistent Current and a Josephson Junction

    International Nuclear Information System (INIS)

    Fan Hongyi; Wang Jisuo

    2006-01-01

    By making the analogy between the operator Hamiltonians of a mesoscopic ring carrying the persistent current and a Josephson junction we have introduced a phase operator and entangled state representation to establish a theoretical formalism for the ring system.

  16. Fabrication and properties of multifilamentary MgB 2 wires by in-situ powder-in-tube process

    Science.gov (United States)

    Wang, Q. Y.; Jiao, G. F.; Liu, G. Q.; Xiong, X. M.; Yan, S. C.; Zhang, P. X.; Sulpice, A.; Mossang, E.; Feng, Y.; Yan, G.

    2010-11-01

    We have fabricated the long TiC-doped MgB2 wires with 6 filaments by in-situ powder-in-tube method using Nb as the barrier and copper as the stabilizer. To improve the strength of wires, the Nb-core was used as the central filament. The transport engineering critical current density (Jce) of the samples sintered at different temperature were measured, which reaches 2.5 × 104 A/cm2 at 4.2 K, 5 T. 100 m MgB2 wires with different diameter were wound into coils and the transport critical current (Ic) of the coil were measured at 30 K in self-field. The Jce value 100 m coil achieves 1.1 × 104 A/cm2 in 1.2 mm wire. The reasons leading to the enhancement of high field Jce were discussed. The results show a good potential to fabricate high performance MgB2 wires and tapes at ambient pressure on an industrial scale.

  17. Forming Refractory Insulation On Copper Wire

    Science.gov (United States)

    Setlock, J.; Roberts, G.

    1995-01-01

    Alternative insulating process forms flexible coat of uncured refractory insulating material on copper wire. Coated wire formed into coil or other complex shape. Wire-coating apparatus forms "green" coat on copper wire. After wire coiled, heating converts "green" coat to refractory electrical insulator. When cured to final brittle form, insulating material withstands temperatures above melting temperature of wire. Process used to make coils for motors, solenoids, and other electrical devices to be operated at high temperatures.

  18. The effect of copper additions in the synthesis of in situ MgB2 Cu-sheathed wires

    International Nuclear Information System (INIS)

    Woźniak, M.; Hopkins, S.C.; Gajda, D.; Glowacki, B.A.

    2012-01-01

    The powder-in-tube (PIT) technique has been used to fabricate copper-sheathed magnesium diboride (MgB 2 ) wires using an insitu reaction method. The effect of copper powder additions, magnesium-boron molar ratio and heat treatment is studied by SEM, XRD, transport critical current I c (B) and resistivity ρ(T, B) measurements. The results show that addition of copper powder to the core of the wire accelerates the formation of MgB 2 and hence increases its amount and greatly decreases the amount of Mg-Cu intermetallic phases present in the core of the wire after heat treatment. Excess magnesium proved to be effective in compensating for Mg loss due to interdiffusion with the Cu of the wire sheath and resulted in less unreacted boron in the core for wires without added Cu, but seems to oppose the accelerated formation of MgB 2 in Cu added wires. The highest critical current density, 2.8 × 10 4 A cm -2 at 3 T and 4.2 K, was achieved for a wire with a stoichiometric Mg:B ratio and 3 at.% added copper powder heat treated at 700 °C for 5 min.

  19. Current situation and development tendency of thermal spraying materials in China

    Institute of Scientific and Technical Information of China (English)

    YU; Yue-guang

    2005-01-01

    The current situations of thermal spraying materials in China are described in this paper.The thermal spraying technology in China has a great progress over tens of years. More than one hundred varieties of material products serve thermal spraying producing now. They belong to three kinds, powders,wires and rods. Technologies for producing alloy, ceramic and composite powders, alloy and cored wires,and oxide ceramic rods are applied to large-scale production. Many research and development works on advanced materials for thermal spraying are carrying out recent years. They show that the general tendencies of thermal spraying materials in China are composite or low-impurity component, ultrafine or nanosized microstructure, high properties, and specialized and systematized applications. Thermal spraying materials have great prospects with the development of saving society in China.

  20. The Effect of Annealing on the Elastic Modulus of Orthodontic Wires

    Science.gov (United States)

    Higginbottom, Kyle

    Introduction: Nickel Titanium orthodontic wires are currently used in orthodontic treatment due to their heat activated properties and their delivery of constant force. The objective of this study was to determine the effect of annealing on the elastic modulus of Nickel Titanium, Stainless Steel and Beta-titanium (TMA) wires. Different points along the wire were tested in order to determine how far from the annealed ends the elastic modulus of the wires was affected. Methods: Eighty (80) orthodontic wires consisting of 4 equal groups (SS/TMA/Classic NitinolRTM/Super Elastic NitinolRTM) were used as the specimens for this study. All wires were measured and marked at 5mm measurements, and cut into 33.00mm sections. The wires were heated with a butane torch until the first 13.00mm of the wires were red hot. Load deflection tests using an InstronRTM universal testing machine were run at 5mm distances from the end of the wire that had been annealed. The change in elastic modulus was then determined. Results: There was a significant difference (F = 533.001, p = 0.0005) in the change in elastic modulus for the four distances. There was also a significant difference (F = 57.571, p = 0.0005) in the change in elastic modulus for the four wire types. There was a significant interaction (F = 19.601, p = 0.005) between wire type and distance, however this interaction negated the differences between the wires. Conclusion: 1) There are significant differences in the changes in elastic modulus between the areas of the wires within the annealed section and those areas 5mm and 10mm away from the annealed section. The change in elastic modulus within the annealed section was significantly greater at 8 mm than it was at 13mm, and this was significantly greater than 18mm and 23mm (5mm and 10mm beyond the annealed section). However, there was no statistical difference in the change in elastic modulus between 5mm and 10mm away from the annealed section (18mm and 23mm respectively). 2

  1. Wire chambers: Trends and alternatives

    Energy Technology Data Exchange (ETDEWEB)

    Regler, Meinhard

    1992-05-15

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!.

  2. Synthesis of chemical vapor deposition graphene on tantalum wire for supercapacitor applications

    Energy Technology Data Exchange (ETDEWEB)

    Li, Mingji, E-mail: limingji@163.com [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Guo, Wenlong [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China); Li, Hongji, E-mail: hongjili@yeah.net [Tianjin Key Laboratory of Organic Solar Cells and Photochemical Conversion, School of Chemistry and Chemical Engineering, Tianjin University of Technology, Tianjin 300384 (China); Xu, Sheng [School of Precision Instrument and Optoelectronics Engineering, Tianjin University, Tianjin 300072 (China); Qu, Changqing; Yang, Baohe [Tianjin Key Laboratory of Film Electronic and Communicate Devices, School of Electronics Information Engineering, Tianjin University of Technology, Tianjin 300384 (China)

    2014-10-30

    Highlights: • The capacitance of graphene/tantalum (Ta) wire electrodes is firstly reported. • Graphene was grown on the Ta surface by hot-filament chemical vapor deposition. • Graphene/Ta wire structure is favorable for fast ion and electron transfer. • The graphene/Ta wire electrode shows high capacitive properties. - Abstract: This paper studies the synthesis and electrochemical characterization of graphene/tantalum (Ta) wires as high-performance electrode material for supercapacitors. Graphene on Ta wires is prepared by the thermal decomposition of methane under various conditions. The graphene nanosheets on the Ta wire surface have an average thickness of 1.3–3.4 nm and consist typically of a few graphene monolayers, and TaC buffer layers form between the graphene and Ta wire. A capacitor structure is fabricated using graphene/Ta wire with a length of 10 mm and a diameter of 0.6 mm as the anode and Pt wire of the same size as the cathode. The electrochemical behavior of the graphene/Ta wires as supercapacitor electrodes is characterized by cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy in 1 M Na{sub 2}SO{sub 4} aqueous electrolyte. The as-prepared graphene/Ta electrode has highest capacitance of 345.5 F g{sup −1} at current density of 0.5 A g{sup −1}. The capacitance remains at about 84% after 1000 cycles at 10 A g{sup −1}. The good electrochemical performance of the graphene/Ta wire electrode is attributed to the unique nanostructural configuration, high electrical conductivity, and large specific surface area of the graphene layer. This suggests that graphene/Ta wire electrode materials have potential applications in high-performance energy storage devices.

  3. An experimental comparison of three wire beam electrode based methods for determining corrosion rates and patterns

    International Nuclear Information System (INIS)

    Tan, Y.-J.

    2005-01-01

    Laboratory experiments have been carried out to examine the advantages and limitations of three wire beam electrode (WBE) based techniques, including the noise resistance R n -WBE method, the overpotential-galvanic current method, and the galvanic current method, in determining corrosion rates and patterns. These techniques have been applied simultaneously to several selected corrosion systems of different characteristics. It has been found that the R n -WBE method has advantages over other WBE based methods when applying to WBE surfaces under uniform corrosion. However, the R n -WBE method has been found to be unsuitable for low noise level corrosion systems. It has also been found that both R n -WBE and overpotential-galvanic current methods are similarly applicable to WBE surfaces under nonuniform corrosion. However, the galvanic current method has been found to be suitable only for WBE surfaces under highly localised corrosion. Some related issues regarding R n calculation such as trend removal and its effects on corrosion mapping have also been discussed

  4. Experimental study on imploding characteristics of wire-array Z pinches on Qiangguang-1 facility

    Institute of Scientific and Technical Information of China (English)

    Wang Zhen; Xu Rong-Kun; Yang Jian-Lun; Hua Xin-Sheng; Li Lin-Bo; Xu Ze-Ping; Ning Jia-Min; Song Feng-Jun

    2007-01-01

    To investigate the imploding characteristics of cylindrical wire array,experiments with load current varying from 1.5MA to 1.7MA were carried out on the Qiangguang-1 facility.The complicated temporal-spatial distribution of x-ray radiation was measured by the one-dimensional (1D) x-ray imaging system.Other diagnostic equipments including the x-ray power meter(XRPM) and the time-integrated pinhole camera were used to record time-resolved x-ray power pulse and pinhole x-ray images.Analysis shows that the fast leading edge of the local x-ray radiation pulse is of primary importance in sharpening x-ray power pulse rather than the temporal synchrony and the spatial uniformity of implosion.Experimental results indicated that the better axial imploding synchrony,the faster the increase of X-ray power for an array consisting of 32 tungsten wires of 5μm diameter than for the others,and the higher the x-ray radiation power with maximal convergence ratio (r0/r1) of 10.5.A 'zipper-like' effect of x-ray radiation extending from the cathode Was also observed.

  5. Life cycle assessment of the application of nanoclays in wire coating

    International Nuclear Information System (INIS)

    Tellaetxe, A; Blázquez, M; Unzueta, I; Arteche, A; Egizabal, A; Ermini, V; Rose, J; Chaurand, P

    2012-01-01

    A life cycle assessment (LCA) is carried out to compare nanoclay-reinforced polymer wire coatings with conventional ones. While the conventional wire coatings contain standard halogen free retardants, in reinforced coatings, montmorillonite (nanoclay) is incorporated into electric cable linings as a rheological agent for an increased resistance to fire. In addition, a reduced load of standard halogen free retardants is obtained. The synergistic effect of the montmorillonite on traditional flame retardant additives (by the formation of a three-dimensional char network) can lead to a revolution in wire production. The application of nanoclays contributes also to anti-dripping effect and flexibility increase. Some producers have already started commercializing wire with nanotechnology-based coating; in the short term the use of nanoclay in wire coating production will probably reach a significant market share replacing traditional formulations. The main aim of this study is to compare the environmental impacts along the life cycle of a traditional wire coating (mineral flame retardants like ATH or MDH in a polymer matrix) with the nanoclay-reinforced wire coating, where the montmorillonite replaces a low percentage of the mineral flame retardant. The system boundaries of the study include the following unit processes: nanoclay production, thermoplastic material and mineral flame retardants production, cable coating manufacturing by extrusion and different end of life scenarios (recycling, incineration and landfill disposal). Whereas nanoreinforced composites have shown and increased fire retardance, the addition of nanomaterials seems to have no significant relevance in the environmental assessment. However, the lack of nano-specific characterization factors for nanomaterials and emission rates associated to the different life cycle stages -mainly in the extrusion and use phase, where accidental combustions can take place- still remains a challenge for realistic life

  6. Review of wire chamber aging

    International Nuclear Information System (INIS)

    Va'Vra, J.

    1986-02-01

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

  7. MgB2 superconducting wires basics and applications

    CERN Document Server

    2016-01-01

    The compendium gives a complete overview of the properties of MgB2 (Magnesium Diboride), a superconducting compound with a transition temperature of Tc = 39K, from the fundamental properties to the fabrication of multifilamentary wires and to the presentation of various applications. Written by eminent researchers in the field, this indispensable volume not only discusses superconducting properties of MgB2 compounds, but also describes known preparation methods of thin films and of bulk samples obtained under high pressure methods. A unique selling point of the book is the detailed coverage of various applications based on MgB2, starting with MRI magnets and high current cables, cooled by Helium (He) vapor. High current cables cooled by liquid hydrogen are also highlighted as an interesting alternative due to the shrinking He reserves on earth. Other pertinent subjects comprise permanent magnets, ultrafine wires for space applications and wind generator projects.

  8. A highly crystalline single Au wire network as a high temperature transparent heater

    Science.gov (United States)

    Rao, K. D. M.; Kulkarni, Giridhar U.

    2014-05-01

    A transparent conductor which can generate high temperatures finds important applications in optoelectronics. In this article, a wire network made of Au on quartz is shown to serve as an effective high temperature transparent heater. The heater has been fabricated by depositing Au onto a cracked sacrificial template. The highly interconnected Au wire network thus formed exhibited a transmittance of ~87% in a wide spectral range with a sheet resistance of 5.4 Ω □-1. By passing current through the network, it could be joule heated to ~600 °C within a few seconds. The extraordinary thermal performance and stability owe much to the seamless junctions present in the wire network. Furthermore, the wire network gets self-annealed through joule heating as seen from its increased crystallinity. Interestingly, both transmittance and sheet resistance improved following annealing to 92% and 3.2 Ω □-1, respectively. A transparent conductor which can generate high temperatures finds important applications in optoelectronics. In this article, a wire network made of Au on quartz is shown to serve as an effective high temperature transparent heater. The heater has been fabricated by depositing Au onto a cracked sacrificial template. The highly interconnected Au wire network thus formed exhibited a transmittance of ~87% in a wide spectral range with a sheet resistance of 5.4 Ω □-1. By passing current through the network, it could be joule heated to ~600 °C within a few seconds. The extraordinary thermal performance and stability owe much to the seamless junctions present in the wire network. Furthermore, the wire network gets self-annealed through joule heating as seen from its increased crystallinity. Interestingly, both transmittance and sheet resistance improved following annealing to 92% and 3.2 Ω □-1, respectively. Electronic supplementary information (ESI) available: Optical micrographs, EDAX, XRD, SEM and TEM images of Au metal wires. See DOI: 10.1039/c4nr00869c

  9. Functional model of a high-current high-voltage superconducting switches

    International Nuclear Information System (INIS)

    Menke, Kh.; Shishov, Yu.A.

    1977-01-01

    Considered are problems of superconducting switches (SS) for energy extraction from magnets at a current of several kiloamperes and a voltage of several kilovolts with a time for transition to the normal state of <0.5 ms. SS is made of a wire of 0.5 mm diameter containing 19 strands of Nb-Ti alloy of 65 μm diameter. The wire matrix was etched out, 19 wires of 4.5 m length were braided together. On each of three groups of wires a heater wire of constantan of 0.12 mm diameter and 6 m length was wound. A second heater intended for slow heating during current feeding into the magnet, is wound over the braid. The wires and heaters are parallel connected and impregnated by an epoxy compound. The following main parameters were obtained in SS testing: critical current of 920 A, resistance in the normal state of 2.5 Ohm, and minimum delay time of 0.2 ms at a nominal current of 0.8 of the critical one

  10. Etching of anode wire deposits with CF4/isobutane (80:20) avalanches

    International Nuclear Information System (INIS)

    Openshaw, R.; Henderson, R.S.; Faszer, W.; Salomon, M.

    1990-11-01

    An ionization exposure of 0.5 coulombs per cm of wire in a gas mixture of CF 4 /isobutane (80:20) is shown to reverse anode wire damage in single-wire chambers. Several chambers aged in argon/ethane (50:50) and argon/ethane/ethanol (50:50:0.2) and having pulse height reductions of 25-30% have recovered pulse heights and currents to greater than 98% of their initial values. Inspection of the anode wires indicates that the thick deposits caused by the exposure in argon/ethane have been removed. Auger electron spectroscopy reveals only a thin residual layer containing primarily carbon and oxygen. This etching ability of CF 4 /isobutane (80:20) avalanches may explain the extremely good ageing characteristics previously reported for this mixture. (Author) (13 refs., 3 tabs., 11 figs.)

  11. Wire chambers: Trends and alternatives

    International Nuclear Information System (INIS)

    Regler, Meinhard

    1992-01-01

    The subtitle of this year's Vienna Wire Chamber Conference - 'Recent Trends and Alternative Techniques' - signalled that it covered a wide range of science and technology. While an opening Vienna talk by wire chamber pioneer Georges Charpak many years ago began 'Les funerailles des chambres a fils (the burial of wire chambers)', the contrary feeling this year was that wire chambers are very much alive!

  12. 2d-LCA - an alternative to x-wires

    Science.gov (United States)

    Puczylowski, Jaroslaw; Hölling, Michael; Peinke, Joachim

    2014-11-01

    The 2d-Laser Cantilever Anemometer (2d-LCA) is an innovative sensor for two-dimensional velocity measurements in fluids. It uses a micostructured cantilever made of silicon and SU-8 as a sensing element and is capable of performing mesurements with extremly high temporal resolutions up to 150 kHz. The size of the cantilever defines its spatial resolution, which is in the order of 150 μm only. Another big feature is a large angular range of 180° in total. The 2d-LCA has been developed as an alternative measurement method to x-wires with the motivation to create a sensor that can operate in areas where the use of hot-wire anemometry is difficult. These areas include measurements in liquids and in near-wall or particle-laden flows. Unlike hot-wires, the resolution power of the 2d-LCA does not decrease with increasing flow velocity, making it particularly suitable for measurements in high speed flows. Comparative measurements with the 2d-LCA and hot-wires have been carried out in order to assess the performance of the new anemometer. The data of both measurement techniques were analyzed using the same stochastic methods including a spectral analysis as well as an inspection of increment statistics and structure functions. Furthermore, key parameters, such as mean values of both velocity components, angles of attack and the characteristic length scales were determined from both data sets. The analysis reveals a great agreement between both anemometers and thus confirms the new approach.

  13. Material and biofilm load of K wires in toe surgery: titanium versus stainless steel.

    Science.gov (United States)

    Clauss, Martin; Graf, Susanne; Gersbach, Silke; Hintermann, Beat; Ilchmann, Thomas; Knupp, Markus

    2013-07-01

    Recurrence rates for toe deformity correction are high and primarily are attributable to scar contractures. These contractures may result from subclinical infection. We hypothesized that (1) recurrence of toe deformities and residual pain are related to low-grade infections from biofilm formation on percutaneous K wires, (2) biofilm formation is lower on titanium (Ti) K wires compared with stainless steel (SS) K wires, and (3) clinical outcome is superior with the use of Ti K wires compared with SS K wires. In this prospective nonrandomized, comparative study, we investigated 135 lesser toe deformities (61 patients; 49 women; mean ± SD age, 60 ± 15 years) temporarily fixed with K wires between August 2010 and March 2011 (81 SS, 54 Ti). K wires were removed after 6 weeks. The presence of biofilm-related infections was analyzed by sonication. High bacterial loads (> 500 colony-forming units [CFU]/mL) were detected on all six toes requiring revision before 6 months. Increased bacterial load was associated with pain and swelling but not recurrence of the deformity. More SS K wires had greater than 100 CFU/mL bacteria than Ti K wires. For K wires with a bacterial count greater than 100 CFU/mL, toes with Ti K wires had a lower recurrence rate, less pain, and less swelling than toes with SS K wires. Ti K wires showed superior clinical outcomes to SS K wires. This appears to be attributable to reduced infection rates. Although additional study is needed, we currently recommend the use of Ti K wires for the transfixation of toe deformities. Level II, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

  14. Electromagnetic characteristic of twin-wire indirect arc welding

    Science.gov (United States)

    Shi, Chuanwei; Zou, Yong; Zou, Zengda; Wu, Dongting

    2015-01-01

    Traditional welding methods are limited in low heat input to workpiece and high welding wire melting rate. Twin-wire indirect arc(TWIA) welding is a new welding method characterized by high melting rate and low heat input. This method uses two wires: one connected to the negative electrode and another to the positive electrode of a direct-current(DC) power source. The workpiece is an independent, non-connected unit. A three dimensional finite element model of TWIA is devised. Electric and magnetic fields are calculated and their influence upon TWIA behavior and the welding process is discussed. The results show that with a 100 A welding current, the maximum temperature reached is 17 758 K, arc voltage is 14.646 V while maximum current density was 61 A/mm2 with a maximum Lorene force of 84.5 μN. The above mentioned arc parameters near the cathode and anode regions are far higher than those in the arc column region. The Lorene force is the key reason for plasma velocity direction deviated and charged particles flowed in the channel formed by the cathode, anode and upper part of arc column regions. This led to most of the energy being supplied to the polar and upper part of arc column regions. The interaction between electric and magnetic fields is a major determinant in shaping TWIA as well as heat input on the workpiece. This is a first study of electromagnetic characteristics and their influences in the TWIA welding process, and it is significant in both a theoretical and practical sense.

  15. Charpak hemispherical wire chamber

    CERN Multimedia

    1970-01-01

    pieces. Mesures are of the largest one. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  16. AC over-current characteristics of YBCO coated conductor with copper stabilizer layer considering insulation layer

    International Nuclear Information System (INIS)

    Du, H.-I.; Kim, M.-J.; Kim, Y.-J.; Lee, D.-H.; Han, B.-S.; Song, S.-S.

    2010-01-01

    Compared with the first-generation BSCCO wire, the YBCO thin-film wire boasts low material costs and high J c and superior magnetic-field properties, among other strengths. Meanwhile, the previous BSCCO wire material for superconducting cables has been researched on considerably with regard to its post-wire quenching characteristics during the application of an alternating over-current. In this regard, the promising YBCO thin-film wire has yet to be further researched on. Moreover, still lacking is research on the YBCO thin-film wire with insulating layers, which is essential in the manufacture of superconducting cables, along with the testing of the application of an alternating over-current to the wire. In this study, YBCO thin-film wires with copper-stabilizing layers were used in testing alternating over-current application according to the presence or absence of insulating layers and to the thickness of such layers, to examine the post-quenching wire resistance increase and quenching trends. The YBCO thin-film wire with copper-stabilizing layers has a critical temperature of 90 K and a critical current of 85 A rms . Moreover, its current application cycle is 5.5 cycles, and its applied currents are 354, 517, 712, and 915 A peak . These figures enabled the YBCO thin-film wires with copper-stabilizing layers to reach 90, 180, 250, and 300 K, respectively, in this study. These temperatures serve as a relative reference to examine the post-quenching wire properties following the application of an alternating over-current.

  17. Influence of the ac magnetic field frequency on the magnetoimpedance of amorphous wire

    International Nuclear Information System (INIS)

    Chen, A P; Garcia, C; Zhukov, A; Dominguez, L; Blanco, J M; Gonzalez, J

    2006-01-01

    Experimental and theoretical studies on the influence of ac magnetic field frequency on the axial diagonal (ζ zz ) and off-diagonal (ζ Φz ) components of the magnetoimpedance (MI) tensor in (Co 0.94 Fe 0.06 ) 72.5 Si 12.5 B 15 amorphous wires have been performed. The frequency (f) of an ac current flowing along the wire was varied from 1 to 20 MHz with the current amplitude less than 15 mA. In order to enhance the ζ Φz component, the amorphous wire was submitted to torsion annealing for developing and preserving a helical magnetic anisotropy in the surface of the wire. The experimental measurements show that the value of the impedance is proportional to the square-root of the ac current frequency, √f, in the vicinity of H ex K and this increase is due to the contribution of the resistance (real part of the impedance). The measurements also indicate that the peaks of the MI curve shift slightly towards higher field values with increasing f. In a theoretical study the magnetoimpedance expressions ζ zz and ζ Φz have been deduced using the Faraday law in combination with the solutions of the Maxwell and Landau-Lifshitz-Gilbert (LLG) equations. By analysing quantitatively the spectra of ζ zz and ζ Φz , the phenomenon of the shift in the peaks of the MI curve with f has been considered as a characteristic of the helical anisotropy in the domain structure of the wire surface

  18. AC dielectrophoresis alignment of single-walled carbon nano tubes (SWNTS) and palladium nano wires for hydrogen gas sensor

    International Nuclear Information System (INIS)

    Nur Ubaidah Saidin; Nur Ubaidah Saidin; Ying, K.K.; KKhuan, N.I.; Mohammad Hafizuddin Jumali

    2013-01-01

    Full-text: Using AC electric field, nano wires or nano tubes can be aligned, chained or accelerated in a direction parallel to the applied field, oriented or concentrated onto designated locations as well as dispersed in controlled manner under high efficiencies. In this work, systematic study on the alignment of nano wires/ nano tubes across the 3 μm-gaps between pairs of micro fabricated gold electrodes was carried out using AC dielectrophoresis technique. Densities and alignment of the nano wires/ nano tubes across the gaps of the electrodes were controlled by the applied AC field strengths and frequencies on the electrodes. Good alignments of SWNTs and Pd nano wires were achieved at an applied frequency of 5 MHz and a field strength as high as 25 V pp for Pd nano wires compared to only 2 V pp for SWNTs. The aligned nano wires/ nano tubes will be functioned as sensor elements for hydrogen gas sensing. (author)

  19. Wire-number effects on high-power annular z-pinches and some characteristics at high wire number

    Energy Technology Data Exchange (ETDEWEB)

    SANFORD,THOMAS W. L.

    2000-05-23

    Characteristics of annular wire-array z-pinches as a function of wire number and at high wire number are reviewed. The data, taken primarily using aluminum wires on Saturn are comprehensive. The experiments have provided important insights into the features of wire-array dynamics critical for high x-ray power generation, and have initiated a renaissance in z-pinches when high numbers of wires are used. In this regime, for example, radiation environments characteristic of those encountered during the early pulses required for indirect-drive ICF ignition on the NIF have been produced in hohlraums driven by x-rays from a z-pinch, and are commented on here.

  20. Wire-number effects on high-power annular z-pinches and some characteristics at high wire number

    International Nuclear Information System (INIS)

    SANFORD, THOMAS W. L.

    2000-01-01

    Characteristics of annular wire-array z-pinches as a function of wire number and at high wire number are reviewed. The data, taken primarily using aluminum wires on Saturn are comprehensive. The experiments have provided important insights into the features of wire-array dynamics critical for high x-ray power generation, and have initiated a renaissance in z-pinches when high numbers of wires are used. In this regime, for example, radiation environments characteristic of those encountered during the early pulses required for indirect-drive ICF ignition on the NIF have been produced in hohlraums driven by x-rays from a z-pinch, and are commented on here

  1. Wire Position Monitoring with FPGA based Electronics

    International Nuclear Information System (INIS)

    Eddy, N.; Lysenko, O.

    2009-01-01

    This fall the first Tesla-style cryomodule cooldown test is being performed at Fermilab. Instrumentation department is preparing the electronics to handle the data from a set of wire position monitors (WPMs). For simulation purposes a prototype pipe with a WMP has been developed and built. The system is based on the measurement of signals induced in pickups by 320 MHz signal carried by a wire through the WPM. The wire is stretched along the pipe with a tensioning load of 9.07 kg. The WPM consists of four 50 (Omega) striplines spaced 90 o apart. FPGA based digitizer scans the WPM and transmits the data to a PC via VME interface. The data acquisition is based on the PC running LabView. In order to increase the accuracy and convenience of the measurements some modifications were required. The first is implementation of an average and decimation filter algorithm in the integrator operation in the FPGA. The second is the development of alternative tool for WPM measurements in the PC. The paper describes how these modifications were performed and test results of a new design. The last cryomodule generation has a single chain of seven WPMs (placed in critical positions: at each end, at the three posts and between the posts) to monitor a cold mass displacement during cooldown. The system was developed in Italy in collaboration with DESY. Similar developments have taken place at Fermilab in the frame of cryomodules construction for SCRF research. This fall preliminary cryomodule cooldown test is being performed. In order to prepare an appropriate electronic system for the test a prototype pipe with a WMP has been developed and built, figure 1. The system is based on the measurement of signals induced in pickups by 320 MHz signal carried by a wire through the WPM. The 0.5 mm diameter Cu wire is stretched along the pipe with a tensioning load of 9.07 kg and has a length of 1.1 m. The WPM consists of four 50 (Omega) striplines spaced 90 o apart. An FPGA based digitizer

  2. The effect of different annealing treatments on magneto-impedance in Finemet wires

    International Nuclear Information System (INIS)

    Hernando, B.; Olivera, J.; Alvarez, P.; Santos, J.D.; Sanchez, M.L.; Perez, M.J.; Sanchez, T.; Gorria, P.

    2006-01-01

    In this paper, we analyze the behaviour of Fe-rich wires that have been submitted to a current annealing, with and without an applied torsional stress. The structural relaxation and induced anisotropies achieved in the samples produce different effects in the magneto-impedance and torsion impedance response, in comparison with the as-quenched wire, due to the different domain structure and magnetization processes involved

  3. Enhancing the x-ray output of a single-wire explosion with a gas-puff based plasma opening switch

    Science.gov (United States)

    Engelbrecht, Joseph T.; Ouart, Nicholas D.; Qi, Niansheng; de Grouchy, Philip W.; Shelkovenko, Tatiana A.; Pikuz, Sergey A.; Banasek, Jacob T.; Potter, William M.; Rocco, Sophia V.; Hammer, David A.; Kusse, Bruce R.; Giuliani, John L.

    2018-02-01

    We present experiments performed on the 1 MA COBRA generator using a low density, annular, gas-puff z-pinch implosion as an opening switch to rapidly transfer a current pulse into a single metal wire on axis. This gas-puff on axial wire configuration was studied for its promise as an opening switch and as a means of enhancing the x-ray output of the wire. We demonstrate that current can be switched from the gas-puff plasma into the wire, and that the timing of the switch can be controlled by the gas-puff plenum backing pressure. X-ray detector measurements indicate that for low plenum pressure Kr or Xe shots with a copper wire, this configuration can offer a significant enhancement in the peak intensity and temporal distribution of radiation in the 1-10 keV range.

  4. Expansion of a multicomponent current-carrying plasma jet into vacuum

    International Nuclear Information System (INIS)

    Krasov, V. I.; Paperny, V. L.

    2017-01-01

    An expression for the ion−ion coupling in a multicomponent plasma jet is derived for an arbitrary ratio between the thermal and relative velocities of the components. The obtained expression is used to solve the problem on the expansion of a current-carrying plasma microjet emitted from the cathode surface into vacuum. Two types of plasmas with two ion components are analyzed: (i) plasma in which the ion components of equal masses are in the charge states Z 1 = +1 and Z 2 = +2 and (ii) plasma with ions in equal charge states but with the mass ratio m 1 /m 2 = 2. It is shown that, for such plasmas, the difference between the velocities of the plasma components remains substantial (about 10% of the average jet velocity in case (i) and 15% in case (ii)) at distances of several centimeters from the emission center, where it can be measured experimentally, provided that its initial value at the emitting cathode surface exceeds a certain threshold. This effect is investigated as a function of the mass ratio and charge states of the ion components.

  5. Review of effects of dielectric coatings on electrical exploding wires and Z pinches

    Science.gov (United States)

    Wu, Jian; Li, Xingwen; Li, Mo; Li, Yang; Qiu, Aici

    2017-10-01

    As the most powerful x-ray source in the laboratories, the wire array Z pinches have been of great relevance to inertial confinement fusions, laboratory astrophysics, and other high-energy density applications. In order to produce x-ray with greater power and higher efficiency, the dynamics of wire array has been investigated extensively, and various methods have been proposed to improve the implosion quality of the wire array. This review focuses on the experimental and theoretical investigations regarding the effects of the dielectric coatings on electrical exploding wires and Z pinches. Since the early 2000, the electrical wire explosion related to the first stage of the wire array Z pinches has been studied extensively, and the results indicated that the dielectric coatings can significantly increase the joule energy deposition into a wire in the initial stage, and even the corona free explosion of tungsten wires can be achieved. Recently, there is an increasing interest in the dynamics of insulated wire array Z pinches. By applying dielectric coatings, the ablation process is suppressed, the x-ray start time is delayed, and the possibility of multi-peak radiation is decreased. This review is organized by the evolution dynamics of wire array Z pinches, and a broad introduction to relevant scientific concepts and various other applications are presented. According to the current research status, the challenges, opportunities and further developments of Z pinch loads using dielectric coatings are proposed to further promote the researches and their applications.

  6. Review of effects of dielectric coatings on electrical exploding wires and Z pinches

    International Nuclear Information System (INIS)

    Wu, Jian; Li, Mo; Li, Yang; Li, Xingwen; Qiu, Aici

    2017-01-01

    As the most powerful x-ray source in the laboratories, the wire array Z pinches have been of great relevance to inertial confinement fusions, laboratory astrophysics, and other high-energy density applications. In order to produce x-ray with greater power and higher efficiency, the dynamics of wire array has been investigated extensively, and various methods have been proposed to improve the implosion quality of the wire array. This review focuses on the experimental and theoretical investigations regarding the effects of the dielectric coatings on electrical exploding wires and Z pinches. Since the early 2000, the electrical wire explosion related to the first stage of the wire array Z pinches has been studied extensively, and the results indicated that the dielectric coatings can significantly increase the joule energy deposition into a wire in the initial stage, and even the corona free explosion of tungsten wires can be achieved. Recently, there is an increasing interest in the dynamics of insulated wire array Z pinches. By applying dielectric coatings, the ablation process is suppressed, the x-ray start time is delayed, and the possibility of multi-peak radiation is decreased. This review is organized by the evolution dynamics of wire array Z pinches, and a broad introduction to relevant scientific concepts and various other applications are presented. According to the current research status, the challenges, opportunities and further developments of Z pinch loads using dielectric coatings are proposed to further promote the researches and their applications. (topical review)

  7. ELECTROMECHANICAL TRANSIENT PROCESSES DURING SUPPLY VOLTAGE CHANGING IN THE SYSTEM OF POLYMER INSULATION COVERING OF THE CURRENT-CARRYING CORE OF ULTRA HIGH VOLTAGE CABLES

    Directory of Open Access Journals (Sweden)

    V. M. Zolotaryov

    2018-04-01

    Full Text Available Aim. The article is devoted to the analysis of the electromechanical transient processes in a system of three frequency-controlled electric drives based on asynchronous motors that control current-carrying core motion, as well as to the study of the effect of such processes on the modes applying three-layer polymer insulation to the current-carrying core. Technique. The study was conducted based on the concepts of electromechanics, electromagnetic field theory, mathematical physics, mathematical modeling. Results. A mathematical model has been developed to analyze transients in an electromechanical system consisting of three frequency-controlled electric drives providing current-carrying core motion of ultra-high voltage cables in an inclined extrusion line. The coordination of the electromechanical parameters of the system drives has been carried out and the permissible changes in the supply voltage at the limiting mass while moving current-carrying core of ultra-high voltage cables with applied polymer insulation have been estimated. Scientific novelty. For the first time it is determined that with the limiting mass of the current-carrying core, the electromechanical system allows to stabilize the current-carrying core speed with the required accuracy at short-term decreases in the supply voltage by no more than 27 % of its amplitude value. It is also shown that this system is resistant to short-term increases in voltage by 32 % for 0.2 s. Practical significance. Using the developed model, it is possible to calculate the change in the configuration and speed of the slack current-carrying core when applying polymer insulation, depending on the specific mass of the current-carrying core per unit length, its tension at the bottom, the torque of the traction motor and the supply voltage to achieve stable operation of the system and accurate working of the set parameters.

  8. Self-Catalyzed CdTe Wires

    Directory of Open Access Journals (Sweden)

    Tom Baines

    2018-04-01

    Full Text Available CdTe wires have been fabricated via a catalyst free method using the industrially scalable physical vapor deposition technique close space sublimation. Wire growth was shown to be highly dependent on surface roughness and deposition pressure, with only low roughness surfaces being capable of producing wires. Growth of wires is highly (111 oriented and is inferred to occur via a vapor-solid-solid growth mechanism, wherein a CdTe seed particle acts to template the growth. Such seed particles are visible as wire caps and have been characterized via energy dispersive X-ray analysis to establish they are single phase CdTe, hence validating the self-catalysation route. Cathodoluminescence analysis demonstrates that CdTe wires exhibited a much lower level of recombination when compared to a planar CdTe film, which is highly beneficial for semiconductor applications.

  9. A low-power high-flow shape memory alloy wire gas microvalve

    International Nuclear Information System (INIS)

    Gradin, Henrik; Braun, Stefan; Stemme, Göran; Van der Wijngaart, Wouter; Clausi, Donato; Peirs, Jan; Reynaerts, Dominiek

    2012-01-01

    In this paper the use of shape memory alloy (SMA) wire actuators for high gas flow control is investigated. A theoretical model for effective gas flow control is presented and gate microvalve prototypes are fabricated. The SMA wire actuator demonstrates the robust flow control of more than 1600 sccm at a pressure drop of 200 kPa. The valve can be successfully switched at over 10 Hz and at an actuation power of 90 mW. Compared to the current state-of-the-art high-flow microvalves, the proposed solution benefits from a low-voltage actuator with low overall power consumption. This paper demonstrate that SMA wire actuators are well suited for high-pressurehigh-flow applications. (paper)

  10. Fabrication of a smart air intake structure using shape memory alloy wire embedded composite

    International Nuclear Information System (INIS)

    Jung, Beom-Seok; Kim, Min-Saeng; Kim, Ji-Soo; Kim, Yun-Mi; Lee, Woo-Yong; Ahn, Sung-Hoon

    2010-01-01

    Shape memory alloys (SMAs) have been actively studied in many fields utilizing their high energy density. Applying SMA wire-embedded composite to aerospace structures, such as air intake of jet engines and guided missiles, is attracting significant attention because it could generate a comparatively large actuating force. In this research, a scaled structure of SMA wire-embedded composite was fabricated for the air intake of aircraft. The structure was composed of several prestrained Nitinol (Ni-Ti) SMA wires embedded in intersection -shape glass fabric reinforced plastic (GFRP), and it was cured at room temperature for 72 h. The SMA wire-embedded GFRP could be actuated by applying electric current through the embedded SMA wires. The activation angle generated from the composite structure was large enough to make a smart air intake structure.

  11. Stress distribution and lattice distortions in Nb3Sn multifilament wires under uniaxial tensile loading at 4.2 K

    International Nuclear Information System (INIS)

    Scheuerlein, C; Flükiger, R; Kadar, J; Bordini, B; Ballarino, A; Bottura, L; Di Michiel, M; Buta, F; Seeber, B; Senatore, C; Siegrist, T; Besara, T

    2014-01-01

    The lattice parameter changes in three types of Nb 3 Sn superconducting wires during uniaxial stress–strain measurements at 4.2 K have been measured by high-energy synchrotron x-ray diffraction. The nearly-stress-free Nb 3 Sn lattice parameter has been determined using extracted filaments, and the elastic strain in the axial and transverse wire directions in the different wire phases has been calculated. The mechanical properties of the PIT and RRP wire are mainly determined by the properties of Nb 3 Sn and unreacted Nb. This is in contrast to the bronze route wire, where the matrix can carry substantial loads. In straight wires the axial Nb 3 Sn pre-strain is strongest in the bronze route wire, its value being smaller in the PIT and RRP wires. A strong reduction of the non-Cu elastic modulus of about 30% is observed during cool-down from ambient temperature to 4.2 K. The Nb 3 Sn Poisson ratio at 4.2 K measured in the untwisted bronze route wire is 0.35. The present study also shows that the process route has a strong influence on the Nb 3 Sn texture. (paper)

  12. Practical wiring in SI units

    CERN Document Server

    Miller, Henry A

    2013-01-01

    Practical Wiring, Volume 1 is a 13-chapter book that first describes some of the common hand tools used in connection with sheathed wiring. Subsequent chapters discuss the safety in wiring, cables, conductor terminations, insulating sheathed wiring, conductor sizes, and consumer's control equipments. Other chapters center on socket outlets, plugs, lighting subcircuits, lighting accessories, bells, and primary and secondary cells. This book will be very valuable to students involved in this field of interest.

  13. Wire EDM for Refractory Materials

    Science.gov (United States)

    Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

    1982-01-01

    In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

  14. Audio wiring guide how to wire the most popular audio and video connectors

    CERN Document Server

    Hechtman, John

    2012-01-01

    Whether you're a pro or an amateur, a musician or into multimedia, you can't afford to guess about audio wiring. The Audio Wiring Guide is a comprehensive, easy-to-use guide that explains exactly what you need to know. No matter the size of your wiring project or installation, this handy tool provides you with the essential information you need and the techniques to use it. Using The Audio Wiring Guide is like having an expert at your side. By following the clear, step-by-step directions, you can do professional-level work at a fraction of the cost.

  15. Hot fuel examination facility element spacer wire-wrap machine

    International Nuclear Information System (INIS)

    Tobias, D.A.; Sherman, E.K.

    1989-01-01

    Nondestructive examinations of irradiated experimental fuel elements conducted in the Argonne National Laboratory Hot Fuel Examination Facility/North (HFEF/N) at the Idaho National Engineering Laboratory include laser and contact profilometry (element diameter measurements), electrical eddy-current testing for cladding and thermal bond defects, bow and length measurements, neutron radiography, gamma scanning, remote visual exam, and photography. Profilometry was previously restricted to spiral profilometry of the element to prevent interference with the element spacer wire wrapped in a helix about the Experimental Breeder Reactor II (EBR-II)-type fuel element from end to end. By removing the spacer wire prior to conducting profilometry examination, axial profilometry techniques may be used, which are considerably faster than spiral techniques and often result in data acquisition more important to experiment sponsors. Because the element must often be reinserted into the nuclear reactor (EBR-II) for additional irradiation, however, the spacer wire must be reinstalled on the highly irradiated fuel element by remote means after profilometry of the wireless elements. The element spacer wire-wrap machine developed at HFEF is capable of helically wrapping fuel elements with diameters up to 1.68 cm (0.660 in.) and 2.44-m (96-in.) lengths. The machine can accommodate almost any desired wire pitch length by simply inserting a new wrapper gear module

  16. Localization of intraductal mass through the ostium of the duct using wire guided ductography technique

    International Nuclear Information System (INIS)

    Aslam, M.

    2014-01-01

    To localize intraductal mass (Papilloma) before surgery Materials Guide wire 10-15 cm length of 2/3-0 Prolene/Surgipro Plastic 26G to 20G I/V cannulas Kopans breast lesion localization hook wire Disposable syringe heaving 2ml non-ionic contrast High intensity light and magnified glass. Methods: Prepare patient in sitting or lying position adjust high intensity light clean the nipple with antiseptic lotion. Elicit the discharge with gentle periareolar pressure or ask the patient to bring the discharge. If the opening with discharge is not clearly visualize use magnified glass or loop. Slowly inserted the wire into the duct orifice, it should pass freely into the duct. Introduce the 26G I/V plastic cannula coaxially over the guide wire and remove the guide wire. Gently inject 0.2-0.4 ml contrast, remove and the syringe and apply stopper. The cannula stopper assembly is secured to the breast with tape. Magnified craniocaudal view of the breast is taken, the 26G cannula removed and bigger length 22/20G cannula gradually passed over the guide wire according to distance of lesion from the ostium. Intraductal mass location is verified the hook wire is replaced with guide wire, the position of hook confirmed by mammographic film. The wire is cut 2cms from the nipple and pt. send to operation theater Results:Hook localization has been successfully carried out in six patients. Conclusion:This is a new method of localization of intraductal mass it enables the surgeon to do microductectomy with minimal cosmetic effects to the breast. (author)

  17. K-wire and tension band wire fixation in treating sternoclavicular joint dislocation

    Directory of Open Access Journals (Sweden)

    CHEN Qing-yu

    2011-02-01

    Full Text Available 【Abstract】Objective: To evaluate the feasibility and therapeutic effect of treating sternoclavicular joint dislocation by K-wire and tension band wire fixation, and to improve the safety and stability of this technique. Methods: This study consisted of 9 cases, 6 males and 3 females with the mean age of 25 years (range, 9-62 years. The causes were traffic accident in 7 cases, falling in 1 case and fight in 1 case. The duration from injury to operation was 2 hours to 7 days. There were 5 left dislocations and 4 right dislocations; 8 anterior dislocations and 1 posterior dislocation, including one combined with left scapular fracture and one with left olecranon fracture. Open reduction and internal fixation using K-wires and tension band wires were performed to treat dislocations. Results: All patients were followed up for 6 to 24 months, 10 months on average. According to Rockwood’s rating scale on postoperative sternoclavicular joint, 8 cases achieved excellent outcomes with an average score of 13.88, and the rest case achieved a good outcome with the score of 12. Anatomical reduction was obtained in all cases. There were no such postoperative complications as severe infection, injury to blood vessel and nerve, failure of fixation, etc. Patients were all satisfied with the anatomical reduction and functional recovery. Conclusions: The technique of K-wire and tension band wire fixation is safe, simple, effective, less invasive and has been successfully used in orthopedic surgery. It is effective in treating sternoclavicular joint dislocation though it has some disadvantages. Key words: Sternoclavicular joint; Dislocations; Bone wires; Fracture fixation, internal

  18. Generation of a subgigagauss magnetic field by pinching the plasma channel of exploded-wire

    International Nuclear Information System (INIS)

    Bogolyubsky, S.L.

    1990-01-01

    An interest in the dense pinches produced in the explosion of thin wires in the diodes of high current-nanosecond-REB-generators is provided by an opportunity to obtain high temperature-dense plasma configurations as an object of fusion studies and that in the spectroscopy of multi-charged ions. One needs to have a micrometer size of the Z-pinch neck to ignite the fusion reaction. The plasma channel pinching of the wires exploded by a megaampere current to a micrometer size of its neck can provide gigagauss magnetic fields. An important aspect of a given study is verification of an opportunity to obtain the radiation collapse of the plasma channel due to an exploded wire along its whole length up to the kA because of a line radiation cut-off due to the Braginsky-Pease current reduction to 150-200 from the plasma with left-angle Z right-angle much-gt 1. This paper presents experimental studies in this field, with the currents 0.2 MA, 0.5 MA, 1.2 MA

  19. Roebel assembled coated conductor cables (RACC): Ac-Losses and current carrying potential

    Science.gov (United States)

    Frank, A.; Heller, R.; Goldacker, W.; Kling, A.; Schmidt, C.

    2008-02-01

    Low ac-loss HTS cables for transport currents well above 1 kA are required for application in transformers and generators and are taken into consideration for future generations of fusion reactor coils. Coated conductors (CC) are suitable candidates for high field application at an operation temperature in the range 50-77 K. Ac-field applications require cables with low ac-losses and hence twisting of the individual strands. We solved this problem using the Roebel technique. Short lengths of Roebel bar cables were prepared from industrial DyBCO and YBCO-CC. Meander shaped tapes of 4 or 5 mm width with twist pitches of 123 or 127 mm were cut from the 10 or 12 mm wide CC tapes using a specially designed tool. Eleven or twelve of these strands were assembled to a cable. The electrical and mechanical connection of the tapes was achieved using a silver powder filled conductive epoxy resin. Ac-losses of a short sample in an external ac-field were measured as a function of frequency and field amplitude as well as the coupling current decay time constant. We discuss the results in terms of available theories and compare measured time constants in transverse field with measured coupling losses. Finally the potential of this cable type for ac-use is discussed with respect to ac-losses and current carrying capability.

  20. Roebel assembled coated conductor cables (RACC): Ac-Losses and current carrying potential

    International Nuclear Information System (INIS)

    Frank, A; Heller, R; Goldacker, W; Kling, A; Schmidt, C

    2008-01-01

    Low ac-loss HTS cables for transport currents well above 1 kA are required for application in transformers and generators and are taken into consideration for future generations of fusion reactor coils. Coated conductors (CC) are suitable candidates for high field application at an operation temperature in the range 50-77 K. Ac-field applications require cables with low ac-losses and hence twisting of the individual strands. We solved this problem using the Roebel technique. Short lengths of Roebel bar cables were prepared from industrial DyBCO and YBCO-CC. Meander shaped tapes of 4 or 5 mm width with twist pitches of 123 or 127 mm were cut from the 10 or 12 mm wide CC tapes using a specially designed tool. Eleven or twelve of these strands were assembled to a cable. The electrical and mechanical connection of the tapes was achieved using a silver powder filled conductive epoxy resin. Ac-losses of a short sample in an external ac-field were measured as a function of frequency and field amplitude as well as the coupling current decay time constant. We discuss the results in terms of available theories and compare measured time constants in transverse field with measured coupling losses. Finally the potential of this cable type for ac-use is discussed with respect to ac-losses and current carrying capability

  1. Quantized acoustoelectric current in the presence of large tunneling counterflow

    DEFF Research Database (Denmark)

    Gloos, K.; Utko, P.; Hansen, Jørn Bindslev

    2004-01-01

    A surface acoustic wave drives an electrical current through a short quantum wire. A second tunneling current is injected by biasing one side of the quantum wire. These two contributions to the total current, which flow in opposite directions, are controlled almost independently by the gate...... and the bias voltage, respectively. We have observed the quantization of the acoustoelectric current at up to ten times larger counterflowing tunneling currents. At large tunneling currents the acoustoelectric current can be strongly suppressed. However, this does not seem to be due to an electrostatic...... interaction between the two currents, but is probably caused by the complex potential landscape in the narrow channel of the quantum wire....

  2. Quantized acoustoelectric current in the presence of large tunneling counterflow

    International Nuclear Information System (INIS)

    Gloos, K.; Utko, P.; Lindelof, P.E.; Hansen, J. Bindslev

    2004-01-01

    A surface acoustic wave drives an electrical current through a short quantum wire. A second tunneling current is injected by biasing one side of the quantum wire. These two contributions to the total current, which flow in opposite directions, are controlled almost independently by the gate and the bias voltage, respectively. We have observed the quantization of the acoustoelectric current at up to ten times larger counterflowing tunneling currents. At large tunneling currents the acoustoelectric current can be strongly suppressed. However, this does not seem to be due to an electrostatic interaction between the two currents, but is probably caused by the complex potential landscape in the narrow channel of the quantum wire

  3. A comparison of a 'J' wire and a straight wire in successful antegrade cannulation of the superficial femoral artery

    International Nuclear Information System (INIS)

    Gay, D.A.T.; Edwards, A.J.; Puckett, M.A.; Roobottom, C.A.

    2005-01-01

    AIMS: To evaluate the success of two different types of wire in common use in their ability to successfully cannulate the superficial femoral artery (SFA) using antegrade puncture. METHODS: 50 consecutive patients in whom antegrade infra-inguinal intervention was planned, underwent common femoral arterial puncture and then cannulation with either a standard 3 mm 'J' wire or a floppy tipped straight wire (William Cook--Europe). The frequency with which each type of wire entered the SFA or profunda femoris artery without image guidance was recorded. Further analysis was also made of the success of manipulation of the wire into the SFA following profunda cannulation and the use of alternative guide wires. RESULTS: In 19 out of 25 (76%) patients the 'J' wire correctly entered the SFA without image guidance. Only 5 out of 25 (25%) of straight wires entered the SFA with the initial pass (p<0.0001). Following further manipulation with the same wire all except 1 'J' wire was successfully negotiated into the SFA. The same was true for only 9 of the remaining straight wires with 11 patients requiring an alternative guide wire. CONCLUSIONS: When performing antegrade cannulation of the SFA a 'J' wire is more likely to be successful than a straight guide wire

  4. Dry diamond wire sawing techniques to be used in an active environment

    International Nuclear Information System (INIS)

    Loftus, S.

    2003-01-01

    Dry diamond wire sawing techniques usable in an active environment has the following benefits: - Reduced personnel exposure time due the remote control and operation of the cutting equipment, the operator is positioned outside the active cell when controlling the equipment; - The equipment will be reusable with only the diamond cutting wire and the drive wheel rubber inserts coming into contact with potentially contaminated material; - The reduced impact on the existing ventilation systems from fumes or particulate blinding in-cell filters. - No dismantling work has to be carried out on the object to make it suitable for cutting using diamond wire cutting; - The diamond wire is the only piece of equipment subject to short-term replacement due to wear. The paper presents the following issues: The project the equipment is to be used on; -The equipment to be used; - Cutting machine support frame; - Drive units; - Wire coolant device. The seconds part of the paper deals with in-active cutting trials. To produce a strategy for cutting up a vessel in an active facility, the cutting technique proposed for size reducing the vessel to be tested implies establishing its suitability before developing the cutting rig that will be used for the actual task. A mock-up of the vessel was manufactured and size reduced using an existing cutting rig located at the supplies works. This sets out and records the results of the trials performed to functionally demonstrate the adequacy of using a diamond wire to cut the vessel into several pieces. The trials were performed at Diamant Boart test facility in Brussels.The objectives of the vessel cutting trials were: - To assess if a double skinned mock-up of the vessel can be cut successfully, dry, using Diamant Boart diamond wire cooled using liquid nitrogen; - To optimise the cutting process to achieve maximum cutting speed, minimum nitrogen usage and optimise wire life; - To identify any changes to the cutting rig, heat exchanger or

  5. Heat treatment control of Bi-2212 coils: I. Unravelling the complex dependence of the critical current density of Bi-2212 wires on heat treatment

    Science.gov (United States)

    Shen, Tengming; Li, Pei; Ye, Liyang

    2018-01-01

    A robust and reliable heat treatment is crucial for developing superconducting magnets from several superconductors especially Bi-2212. An improper heat treatment may significantly reduce the critical current density Jc of a Bi-2212 superconducting coil, even to zero, since the Jc of Bi-2212 wires is sensitive to parameters of its heat treatment (partial melt processing). To provide an essential database for heat treating Bi-2212 coils, the dependence of Jc on heat treatment is studied systematically in 11 industrial Bi-2212 wires, revealing several common traits shared between these wires and outlier behaviors. The dependence of the Jc of Bi-2212 on heat treatment is rather complex, with many processing parameters affecting Jc, including the peak processing temperature Tp, the time at the peak temperature tp, the time in the melt tmelt, the rate at which Bi-2212 melt is initially cooled CR1, the rate at which the solidification of Bi-2212 melt occurs CR2, and the temperature Tq at which the cooling rate switches from CR1 to CR2. The role of these parameters is analyzed and clarified, in the perspective of heat treating a coil. Practical advices on heat treatment design are given. The ability of a Bi-2212 coil to follow the prescribed recipe decreases with increasing coil sizes. The size of a coil that can be properly heat treated is determined.

  6. Passive fault current limiting device

    Science.gov (United States)

    Evans, Daniel J.; Cha, Yung S.

    1999-01-01

    A passive current limiting device and isolator is particularly adapted for use at high power levels for limiting excessive currents in a circuit in a fault condition such as an electrical short. The current limiting device comprises a magnetic core wound with two magnetically opposed, parallel connected coils of copper, a high temperature superconductor or other electrically conducting material, and a fault element connected in series with one of the coils. Under normal operating conditions, the magnetic flux density produced by the two coils cancel each other. Under a fault condition, the fault element is triggered to cause an imbalance in the magnetic flux density between the two coils which results in an increase in the impedance in the coils. While the fault element may be a separate current limiter, switch, fuse, bimetal strip or the like, it preferably is a superconductor current limiter conducting one-half of the current load compared to the same limiter wired to carry the total current of the circuit. The major voltage during a fault condition is in the coils wound on the common core in a preferred embodiment.

  7. PEEK (polyether-ether-ketone)-coated nitinol wire: Film stability for biocompatibility applications

    Science.gov (United States)

    Sheiko, Nataliia; Kékicheff, Patrick; Marie, Pascal; Schmutz, Marc; Jacomine, Leandro; Perrin-Schmitt, Fabienne

    2016-12-01

    High quality biocompatible poly-ether-ether-ketone (PEEK) coatings were produced on NiTi shape memory alloy wires using dipping deposition from colloidal aqueous PEEK dispersions after substrate surface treatment. The surface morphology and microstructure were investigated by Scanning Electron Microscopy at every step of the process from the as-received Nitinol substrate to the ultimate PEEK-coated NiTi wire. Nanoscratch tests were carried out to access the adhesive behavior of the polymer coated film to the NiTi. The results indicate that the optimum process conditions in cleaning, chemical etching, and electropolishing the NiTi, were the most important and determining parameters to be achieved. Thus, high quality PEEK coatings were obtained on NiTi wires, straight or curved (even with a U-shape) with a homogeneous microstructure along the wire length and a uniform thickness of 12 μm without any development of cracks or the presence of large voids. The biocompatibility of the PEEK coating film was checked in fibrobast cultured cells. The coating remains stable in biological environment with negligible Ni ion release, no cytotoxicity, and no delamination observed with time.

  8. The Analysis of the High Speed Wire Drawing Process of High Carbon Steel Wires Under Hydrodynamic Lubrication Conditions

    Directory of Open Access Journals (Sweden)

    Suliga M.

    2015-04-01

    Full Text Available In this work the analysis of the wire drawing process in hydrodynamic dies has been done. The drawing process of φ5.5 mm wire rod to the final wire of φ1.7 mm was conducted in 12 passes, in drawing speed range of 5-25 m/s. For final wires of φ1.7 mm the investigation of topography of wire surface, the amount of lubricant on the wire surface and the pressure of lubricant in hydrodynamic dies were determined. Additionally, in the work selected mechanical properties of the wires have been estimated.

  9. Stabilized superconductive wires

    International Nuclear Information System (INIS)

    Randall, R.N.; Wong, J.

    1976-01-01

    A stable, high field, high current conductor is produced by packing multiple, multi-layer rods of a bronze core and niobium or vanadium inner jacket and copper outer jacket into a pure copper tube or other means for forming a pure copper matrix, sealing, working the packed tube to a wire, and by diffusion, heat treating to form a type II superconducting, Beta-Wolfram structure, intermetallic compound as a layer within each of several filaments derived from the rods. The layer of Beta-Wolfram structure compound may be formed in less than 2 h of diffusion heat treatment in a thickness of 0.5--2μ

  10. Corrosion resistance of a laser spot-welded joint of NiTi wire in simulated human body fluids.

    Science.gov (United States)

    Yan, Xiao-Jun; Yang, Da-Zhi

    2006-04-01

    The purpose of this study was to investigate corrosion resistance of a laser spot-welded joint of NiTi alloy wires using potentiodynamic tests in Hank's solution at different PH values and the PH 7.4 NaCl solution for different Cl- concentrations. Scanning electron microscope observations were carried out before and after potentiodynamic tests. The composition of a laser spot-welded joint and base metal were characterized by using an electron probe microanalyzer. The results of potentiodynamic tests showed that corrosion resistance of a laser spot-welded joint of NiTi alloy wire was better than that of base metal, which exhibited a little higher breakdown potential and passive range, and a little lower passive current density. Corrosion resistances of a laser spot-welded joint and base metal decreased with increasing of the Cl- concentration and PH value. The improvement of corrosion resistance of the laser spot-welded joint was due to the decrease of the surface defects and the increase of the Ti/Ni ratio. (c) 2005 Wiley Periodicals, Inc.

  11. Melt quality induced failure of electrical conductor (EC grade aluminum wires

    Directory of Open Access Journals (Sweden)

    Khaliq A.

    2017-01-01

    Full Text Available The failure of electrical conductor grade (EC aluminum during wire drawing process was investigated. The fractured aluminum wires were subjected to Scanning Electron Microscopy (SEM and Energy Dispersive X-ray (EDX analyses for an initial examination. Thermodynamic analyses of molten aluminum interaction with refractories was also carried out using FactSage at 710°C to predict the stable phases. The SEM/EDX analyses has revealed the inclusions in aluminum matrix. The typical inclusions observed were Al2O3, Al3C4 (Al-Carbide and oxides of refractories elements (Al, Mg, Si and O that have particle size ranging up to 5 μm. The transition metal boride particles were not identified during SEM/EDX analyses these might be too fine to be detected with this microscope. The overall investigation suggested that the possible cause of this failure is second phase particles presence as inclusions in the aluminum matrix, and this was associated with the poor quality of melt. During wire drawing process, these inclusions were pulled out of the aluminum matrix by the wiredrawing forces to produce micro-voids which led to ductile tearing and final fracture of wires. It was recommended to use ceramic foam filters to segregate inclusions from molten aluminum.

  12. Experimental investigation of powerful pulse current generators based on capacitive storage and explosive magnetic generators

    Science.gov (United States)

    Shurupov, A. V.; Zavalova, V. E.; Kozlov, A. V.; Shurupov, M. A.; Povareshkin, M. N.; Kozlov, A. A.; Shurupova, N. P.

    2018-01-01

    Experimental models of microsecond duration powerful generators of current pulses on the basis of explosive magnetic generators and voltage impulse generator have been developed for the electromagnetic pulse effects on energy facilities to verify their stability. Exacerbation of voltage pulse carried out through the use of electro explosive current interrupter made of copper wires with diameters of 80 and 120 μm. Experimental results of these models investigation are represented. Voltage fronts about 100 ns and the electric field strength of 800 kV/m are registered.

  13. PEEK (polyether-ether-ketone)-coated nitinol wire: Film stability for biocompatibility applications

    Energy Technology Data Exchange (ETDEWEB)

    Sheiko, Nataliia [Institut Charles Sadron, C.N.R.S. UPR 22, Université de Strasbourg, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2 (France); Kékicheff, Patrick, E-mail: patrick.kekicheff@ics-cnrs.unistra.fr [Institut Charles Sadron, C.N.R.S. UPR 22, Université de Strasbourg, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2 (France); Marie, Pascal; Schmutz, Marc; Jacomine, Leandro [Institut Charles Sadron, C.N.R.S. UPR 22, Université de Strasbourg, 23 rue du Loess, BP 84047, 67034 Strasbourg Cedex 2 (France); Perrin-Schmitt, Fabienne [Faculté de Médecine, INSERM, UMR-S 1121, “Biomaterials and Bioengineering”, Université de Strasbourg, 11 rue Humann, 67085 Strasbourg Cedex (France)

    2016-12-15

    Highlights: • A thin (12 μm) homogeneous PEEK film without any defects or voids is deposited on NiTi wires. • The coating remains stable in biological environment with negligible Ni ion release and no cytotoxicity. • Large pressure (>2 GPa) can only disrupt the coating film as shown by nanoscratch tests. • Coated spring wires sustain mechanical stress in continuous cycles of axial compression/stretching for >7 million cycles. - Abstract: High quality biocompatible poly-ether-ether-ketone (PEEK) coatings were produced on NiTi shape memory alloy wires using dipping deposition from colloidal aqueous PEEK dispersions after substrate surface treatment. The surface morphology and microstructure were investigated by Scanning Electron Microscopy at every step of the process from the as-received Nitinol substrate to the ultimate PEEK-coated NiTi wire. Nanoscratch tests were carried out to access the adhesive behavior of the polymer coated film to the NiTi. The results indicate that the optimum process conditions in cleaning, chemical etching, and electropolishing the NiTi, were the most important and determining parameters to be achieved. Thus, high quality PEEK coatings were obtained on NiTi wires, straight or curved (even with a U-shape) with a homogeneous microstructure along the wire length and a uniform thickness of 12 μm without any development of cracks or the presence of large voids. The biocompatibility of the PEEK coating film was checked in fibrobast cultured cells. The coating remains stable in biological environment with negligible Ni ion release, no cytotoxicity, and no delamination observed with time.

  14. PEEK (polyether-ether-ketone)-coated nitinol wire: Film stability for biocompatibility applications

    International Nuclear Information System (INIS)

    Sheiko, Nataliia; Kékicheff, Patrick; Marie, Pascal; Schmutz, Marc; Jacomine, Leandro; Perrin-Schmitt, Fabienne

    2016-01-01

    Highlights: • A thin (12 μm) homogeneous PEEK film without any defects or voids is deposited on NiTi wires. • The coating remains stable in biological environment with negligible Ni ion release and no cytotoxicity. • Large pressure (>2 GPa) can only disrupt the coating film as shown by nanoscratch tests. • Coated spring wires sustain mechanical stress in continuous cycles of axial compression/stretching for >7 million cycles. - Abstract: High quality biocompatible poly-ether-ether-ketone (PEEK) coatings were produced on NiTi shape memory alloy wires using dipping deposition from colloidal aqueous PEEK dispersions after substrate surface treatment. The surface morphology and microstructure were investigated by Scanning Electron Microscopy at every step of the process from the as-received Nitinol substrate to the ultimate PEEK-coated NiTi wire. Nanoscratch tests were carried out to access the adhesive behavior of the polymer coated film to the NiTi. The results indicate that the optimum process conditions in cleaning, chemical etching, and electropolishing the NiTi, were the most important and determining parameters to be achieved. Thus, high quality PEEK coatings were obtained on NiTi wires, straight or curved (even with a U-shape) with a homogeneous microstructure along the wire length and a uniform thickness of 12 μm without any development of cracks or the presence of large voids. The biocompatibility of the PEEK coating film was checked in fibrobast cultured cells. The coating remains stable in biological environment with negligible Ni ion release, no cytotoxicity, and no delamination observed with time.

  15. Study Of The Wet Multipass Drawing Process Applied On High Strength Thin Steel Wires

    Science.gov (United States)

    Thimont, J.; Felder, E.; Bobadilla, C.; Buessler, P.; Persem, N.; Vaubourg, JP.

    2011-05-01

    Many kinds of high strength thin steel wires are involved in so many applications. Most of the time, these wires are made of a pearlitic steel grade. The current developments mainly concern the wire last drawing operation: after a patenting treatment several reduction passes are performed on a slip-type multipass drawing machine. This paper focuses on modeling this multipass drawing process: a constitutive law based on the wire microstructure evolutions is created, a mechanical study is performed, a set of experiments which enables determining the process friction coefficients is suggested and finally the related analytical model is introduced. This model provides several general results about the process and can be used in order to set the drawing machines.

  16. submitter Electromagnetism in a Multiconnected Universe

    CERN Document Server

    Mertens, Tom

    2016-01-01

    Our raw intuition tells us that the topology of the universe shouldn′t affect the behavior of a current-carrying wire, but when the wire wraps all the way around a multiconnected space, our intuition is wrong. While an infinitely long perfectly conducting wire in Euclidean space may carry a constant current, a simple application of the Ampère–Maxwell circuital law shows that the analogous wire in a 3-torus may not. Instead, we find that the current spontaneously oscillates, and the wire acts like an antenna, gradually radiating away its energy.

  17. Development of exploding wire ion source for intense pulsed heavy ion beam accelerator

    International Nuclear Information System (INIS)

    Ochiai, Y.; Murata, T.; Ito, H.; Masugata, K.

    2012-01-01

    A Novel exploding wire type ion source device is proposed as a metallic ion source of intense pulsed heavy ion beam (PHIB) accelerator. In the device multiple shot operations is realized without breaking the vacuum. The basic characteristics of the device are evaluated experimentally with an aluminum wire of diameter 0.2 mm, length 25 mm. Capacitor bank of capacitance 3 μF, charging voltage 30 kV was used and the wire was successfully exploded by a discharge current of 15 kA, rise time 5.3 μs. Plasma flux of ion current density around 70 A/cm 2 was obtained at 150 mm downstream from the device. The drift velocity of ions evaluated by a time-of-flight method was 2.7x10 4 m/sec, which corresponds to the kinetic energy of 100 eV for aluminum ions. From the measurement of ion current density distribution ion flow is found to be concentrated to the direction where ion acceleration gap is placed. From the experiment the device is found to be acceptable for applying PHIB accelerator. (author)

  18. Broadband spectroscopy of magnetic response in a nano-scale magnetic wire

    International Nuclear Information System (INIS)

    Yamaguchi, A.; Motoi, K.; Miyajima, H.; Utsumi, Y.

    2014-01-01

    We measure the broadband spectra of magnetic response in a single layered ferromagnetic nano-scale wire in order to investigate the size effect on the ferromagnetic resonance. We found that the resonance frequency difference between 300-nm- and 5-μm-wide wires was varied by about 5 GHz due to the shape anisotropy. Furthermore, we experimentally detected the magnetization precession induced by the thermal fluctuation via the rectification of a radio-frequency (rf) current by incorporating an additional direct current (dc) by using Wheatstone bridge circuit. Our investigation renders that the shape anisotropy is of great importance to control the resonance frequency and to provide thermal stability of the microwave devices. - Highlights: • We describe an experimental investigation of the magnetic response of a single layered ferromagnetic nano-scale wire. • We present the conventional broadband microwave spectroscopy with a vector network analyzer and rectifying spectroscopy obtained with a Wheatstone bridge technique. • The investigation enables us to characterize the size effect on the ferromagnetic response and also to detect the magnetization precession induced by the thermal fluctuations

  19. Developing a reliable signal wire attachment method for rail.

    Science.gov (United States)

    2014-11-01

    The goal of this project was to develop a better attachment method for rail signal wires to improve the reliability of signaling : systems. EWI conducted basic research into the failure mode of current attachment methods and developed and tested a ne...

  20. Experimental study of surface insulated-standard hybrid tungsten planar wire array Z-pinches at “QiangGuang-I” facility

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Liang; Peng, Bodong; Yuan, Yuan; Zhang, Mei; Zhao, Chen; Zhao, Jizhen; Wang, Liangping [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Northwest Institute of Nuclear Technology), Xi' an 710024 (China); Li, Yang, E-mail: liyang@nint.ac.cn; Li, Mo [State Key Laboratory of Intense Pulsed Radiation Simulation and Effect (Northwest Institute of Nuclear Technology), Xi' an 710024 (China); Xi' an Jiaotong University, Xi' an 710049 (China)

    2016-01-15

    The experimental results of the insulated-standard hybrid wire array Z pinches carried out on “QiangGuang-I” facility at Northwest Institute of Nuclear Technology were presented and discussed. The surface insulating can impose a significant influence on the dynamics and radiation characteristics of the hybrid wire array Z pinches, especially on the early stage (t/t{sub imp} < 0.6). The expansion of insulated wires at the ablation stage is suppressed, while the streams stripped from the insulated wires move faster than that from the standard wires. The foot radiation of X-ray is enhanced by increment of the number of insulated wires, 19.6 GW, 33.6 GW, and 68.6 GW for shots 14037S, 14028H, and 14039I, respectively. The surface insulation also introduces nonhomogeneity along the single wire—the streams move much faster near the electrodes. The colliding boundary of the hybrid wire array Z pinches is bias to the insulated side approximately 0.6 mm.

  1. RANS based CFD methodology for a real scale 217-pin wire-wrapped fuel assembly of KAERI PGSFR

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Jae-Ho, E-mail: jhjeong@kaeri.re.kr [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseoung-gu, Daejeon (Korea, Republic of); Song, Min-Seop [Department of Nuclear Engineering, Seoul National University, 559 Gwanak-ro, Gwanak-gu, Seoul (Korea, Republic of); Lee, Kwi-Lim [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseoung-gu, Daejeon (Korea, Republic of)

    2017-03-15

    Highlights: • This paper presents a suitable way for a practical RANS based CFD methodology which is applicable to real scale 217-pin wire-wrapped fuel assembly of KAERI PGSFR. • A key point of differentiation of the RANS based CFD methodology in this study is adapting an innovative grid generation method using a fortran based in-house code with a GGI function in a general-purpose commercial CFD code, CFX. • The RANS based CFD methodology is implemented with high resolution scheme and SST turbulence model in the 7-pin 37-pin, and 127-pin wire-wrapped fuel assembly of PNC and JNC. Furthermore, the RANS based CFD methodology can be successfully extended to the real scale 217-pin wire-wrapped fuel bundles of KAERI PGSFR. • Three-dimensional thermal-hydraulic characteristics have been also investigated briefly. - Abstract: This paper presents a suitable way for a practical RANS (Reynolds Averaged Navier-Stokes simulation) based CFD (Computational Fluid Dynamics) methodology which is applicable to real scale 217-pin wire-wrapped fuel assembly of KAERI (Korea Atomic Energy Research Institute) PGSFR (Prototype Gen-IV Sodium-cooled Fast Reactor). The main purpose of the current study is to support license issue for the KAERI PGSFR core safety and to elucidate thermal-hydraulic characteristics in a 217-pin wire-wrapped fuel assembly of KAERI PGSFR. A key point of differentiation of the RANS based CFD methodology in this study is adapting an innovative grid generation method using a fortran based in-house code with a GGI (General Grid Interface) function in a general-purpose commercial CFD code, CFX. The innovative grid generation method with GGI function can achieve to simulate a real wire shape with minimizing cell skewness. The RANS based CFD methodology is implemented with high resolution scheme in convection term and SST (Shear Stress Transport) turbulence model in the 7-pin 37-pin, and 127-pin wire-wrapped fuel assembly of PNC (Power reactor and Nuclear fuel

  2. Welding wire pressure sensor assembly

    Science.gov (United States)

    Morris, Timothy B. (Inventor); Milly, Peter F., Sr. (Inventor); White, J. Kevin (Inventor)

    1994-01-01

    The present invention relates to a device which is used to monitor the position of a filler wire relative to a base material being welded as the filler wire is added to a welding pool. The device is applicable to automated welding systems wherein nonconsumable electrode arc welding processes are utilized in conjunction with a filler wire which is added to a weld pool created by the electrode arc. The invention senses pressure deviations from a predetermined pressure between the filler wire and the base material, and provides electrical signals responsive to the deviations for actuating control mechanisms in an automatic welding apparatus so as to minimize the pressure deviation and to prevent disengagement of the contact between the filler wire and the base material.

  3. Effect of Sodium Fluoride Mouthwash on the Frictional Resistance of Orthodontic Wires

    Directory of Open Access Journals (Sweden)

    Allahyar Geramy

    2017-12-01

    Full Text Available Objectives: The friction between the brackets and orthodontic wire during sliding mechanics inflicts difficulties such as decreasing the applied force and tooth movement and also the loss of anchorage. Therefore, many studies have focused on the factors that affect the friction. The purpose of this study was to assess the effect of 0.05% sodium fluoride mouthwash on the friction between orthodontic brackets and wire.Materials and Methods: Four types of orthodontic wires including rectangular standard stainless steel (SS, titanium molybdenum alloy (TMA, nickel-titanium (NiTi and copper-nickel-titanium (Cu-NiTi were selected. In each group, half of the samples were immersed in 0.05% sodium fluoride mouthwash and the others were immersed in artificial saliva for 10 hours. An elastomeric ligature was used for ligating the wires to brackets. The frictional test was performed in a universal testing machine at the speed of 10 mm/minute. Two-way ANOVA was used for statistical analysis of the friction rate.Results: The friction rate was significantly higher after immersion in 0.05% sodium fluoride mouthwash in comparison with artificial saliva (P=0.00. Cu-NiTi wire showed the highest friction value followed by TMA, NiTi and SS wires.  Conclusions: According to the results of the current study, 0.05% sodium fluoride mouthwash increased the frictional characteristics of all the evaluated orthodontic wires.

  4. Non-contact current and voltage sensor having detachable housing incorporating multiple ferrite cylinder portions

    Science.gov (United States)

    Carpenter, Gary D.; El-Essawy, Wael; Ferreira, Alexandre Peixoto; Keller, Thomas Walter; Rubio, Juan C.; Schappert, Michael A.

    2016-04-26

    A detachable current and voltage sensor provides an isolated and convenient device to measure current passing through a conductor such as an AC branch circuit wire, as well as providing an indication of an electrostatic potential on the wire, which can be used to indicate the phase of the voltage on the wire, and optionally a magnitude of the voltage. The device includes a housing formed from two portions that mechanically close around the wire and that contain the current and voltage sensors. The current sensor is a ferrite cylinder formed from at least three portions that form the cylinder when the sensor is closed around the wire with a hall effect sensor disposed in a gap between two of the ferrite portions along the circumference to measure current. A capacitive plate or wire is disposed adjacent to, or within, the ferrite cylinder to provide the indication of the voltage.

  5. Controlling Cu–Sn mixing so as to enable higher critical current densities in RRP® Nb3Sn wires

    Science.gov (United States)

    Sanabria, Charlie; Field, Michael; Lee, Peter J.; Miao, Hanping; Parrell, Jeff; Larbalestier, David C.

    2018-06-01

    Dipole magnets for the proposed Future Circular Collider (FCC) demand specifications significantly beyond the limits of all existing Nb3Sn wires, in particular a critical current density (J c) of more than 1500 A mm‑2 at 16 T and 4.2 K with an effective filament diameter (D eff) of less than 20 μm. The restacked-rod-process (RRP®) is the technology closest to meeting these demands, with a J c (16 T) of up to 1400 A mm‑2, residual resistivity ratio > 100, for a sub-element size D s of 58 μm (which in RRP® wires is essentially the same as D eff). An important present limitation of RRP® is that reducing the sub-element size degrades J c to as low as 900 A mm‑2 at 16 T for D s = 35 μm. To gain an understanding of the sources of this J c degradation, we have made a detailed study of the phase evolution during the Cu–Sn ‘mixing’ stages of the wire heat treatment that occur prior to Nb3Sn formation. Using extensive microstructural quantification, we have identified the critical role that the Sn–Nb–Cu ternary phase (Nausite) can play. The Nausite forms as a well-defined ring between the Sn source and the Cu/Nb filament pack, and acts as an osmotic membrane in the 300 °C–400 °C range—greatly inhibiting Sn diffusion into the Cu/Nb filament pack while supporting a strong Cu counter-diffusion from the filament pack into the Sn core. This converts the Sn core into a mixture of the low melting point (408 °C) η phase (Cu6Sn5) and the more desirable ε phase (Cu3Sn), which decomposes at 676 °C. After the mixing stages, when heated above 408 °C towards the Nb3Sn reaction, any residual η liquefies to form additional irregular Nausite on the inside of the membrane. All Nausite decomposes into NbSn2 on further heating, and ultimately transforms into coarse-grain (and often disconnected) Nb3Sn which has little contribution to current transport. Understanding this critical Nausite reaction pathway has allowed us to simplify the mixing heat treatment to

  6. Multifilament Cable Wire versus Conventional Wire for Sternal Closure in Patients Undergoing Major Cardiac Surgery

    Directory of Open Access Journals (Sweden)

    You Na Oh

    2015-08-01

    Full Text Available Background: Stainless steel wiring remains the most popular technique for primary sternal closure. Recently, a multifilament cable wiring system (Pioneer Surgical Technology Inc., Marquette, MI, USA was introduced for sternal closure and has gained wide acceptance due to its superior resistance to tension. We aimed to compare conventional steel wiring to multifilament cable fixation for sternal closure in patients undergoing major cardiac surgery. Methods: Data were collected retrospectively on 1,354 patients who underwent sternal closure after major cardiac surgery, using either the multifilament cable wiring system or conventional steel wires between January 2009 and October 2010. The surgical outcomes of these two groups of patients were compared using propensity score matching based on 18 baseline patient characteristics. Results: Propensity score matching yielded 392 pairs of patients in the two groups whose baseline profiles showed no significant differences. No significant differences between the two groups were observed in the rates of early mortality (2.0% vs. 1.3%, p=0.578, major wound complications requiring reconstruction (1.3% vs. 1.3%, p>0.99, minor wound complications (3.6% vs. 2.0%, p=0.279, or mediastinitis (0.8% vs. 1.0%, p=1.00. Patients in the multifilament cable group had fewer sternal bleeding events than those in the conventional wire group, but this tendency was not statistically significant (4.3% vs. 7.4%, p=0.068. Conclusion: The surgical outcomes of sternal closure using multifilament cable wires were comparable to those observed when conventional steel wires were used. Therefore, the multifilament cable wiring system may be considered a viable option for sternal closure in patients undergoing major cardiac surgery.

  7. Multifilament Cable Wire versus Conventional Wire for Sternal Closure in Patients Undergoing Major Cardiac Surgery.

    Science.gov (United States)

    Oh, You Na; Ha, Keong Jun; Kim, Joon Bum; Jung, Sung-Ho; Choo, Suk Jung; Chung, Cheol Hyun; Lee, Jae Won

    2015-08-01

    Stainless steel wiring remains the most popular technique for primary sternal closure. Recently, a multifilament cable wiring system (Pioneer Surgical Technology Inc., Marquette, MI, USA) was introduced for sternal closure and has gained wide acceptance due to its superior resistance to tension. We aimed to compare conventional steel wiring to multifilament cable fixation for sternal closure in patients undergoing major cardiac surgery. Data were collected retrospectively on 1,354 patients who underwent sternal closure after major cardiac surgery, using either the multifilament cable wiring system or conventional steel wires between January 2009 and October 2010. The surgical outcomes of these two groups of patients were compared using propensity score matching based on 18 baseline patient characteristics. Propensity score matching yielded 392 pairs of patients in the two groups whose baseline profiles showed no significant differences. No significant differences between the two groups were observed in the rates of early mortality (2.0% vs. 1.3%, p=0.578), major wound complications requiring reconstruction (1.3% vs. 1.3%, p>0.99), minor wound complications (3.6% vs. 2.0%, p=0.279), or mediastinitis (0.8% vs. 1.0%, p=1.00). Patients in the multifilament cable group had fewer sternal bleeding events than those in the conventional wire group, but this tendency was not statistically significant (4.3% vs. 7.4%, p=0.068). The surgical outcomes of sternal closure using multifilament cable wires were comparable to those observed when conventional steel wires were used. Therefore, the multifilament cable wiring system may be considered a viable option for sternal closure in patients undergoing major cardiac surgery.

  8. Expansion of a multicomponent current-carrying plasma jet into vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Krasov, V. I.; Paperny, V. L., E-mail: paperny@math.isu.runnet.ru [Irkutsk State University (Russian Federation)

    2017-03-15

    An expression for the ion−ion coupling in a multicomponent plasma jet is derived for an arbitrary ratio between the thermal and relative velocities of the components. The obtained expression is used to solve the problem on the expansion of a current-carrying plasma microjet emitted from the cathode surface into vacuum. Two types of plasmas with two ion components are analyzed: (i) plasma in which the ion components of equal masses are in the charge states Z{sub 1}= +1 and Z{sub 2}= +2 and (ii) plasma with ions in equal charge states but with the mass ratio m{sub 1}/m{sub 2} = 2. It is shown that, for such plasmas, the difference between the velocities of the plasma components remains substantial (about 10% of the average jet velocity in case (i) and 15% in case (ii)) at distances of several centimeters from the emission center, where it can be measured experimentally, provided that its initial value at the emitting cathode surface exceeds a certain threshold. This effect is investigated as a function of the mass ratio and charge states of the ion components.

  9. Electromechanical characterization of superconducting wires and tapes at 77 K

    CERN Document Server

    Bjoerstad, Roger

    The strain dependency of the critical current in state-of-the-art cuprate high-temperature superconductors (HTS) has been characterized. A universal test machine (UTM) combined with a critical current measurement system has been used to characterize the mechanical and the superconducting properties of conductors immersed in an open liquid nitrogen dewar. A set-up has been developed in order to perform simultaneous measurements of the superconductor lattice parameter changes, critical current, as well as the stress and strain at 77 K in self-field in a high energy synchrotron beamline. The HTS tapes and wires studied were based on YBCO, Bi-2223 and Bi-2212. The YBCO tapes were produced by SuperPower and American Superconductors (AMSC). Two types of Bi-2223 tapes, HT and G, were produced by Sumitomo Electric Industries (SEI). The Bi-2212 wires were produced by Oxford Superconducting Technology (OST) using Nexans granulate precursor, before undergoing a specialized over pressure (OP) processing and heat treatmen...

  10. Modified coaxial wire method for measurement of transfer impedance of beam position monitors

    Science.gov (United States)

    Kumar, Mukesh; Babbar, L. K.; Deo, R. K.; Puntambekar, T. A.; Senecha, V. K.

    2018-05-01

    The transfer impedance is a very important parameter of a beam position monitor (BPM) which relates its output signal with the beam current. The coaxial wire method is a standard technique to measure transfer impedance of the BPM. The conventional coaxial wire method requires impedance matching between coaxial wire and external circuits (vector network analyzer and associated cables). This paper presents a modified coaxial wire method for bench measurement of the transfer impedance of capacitive pickups like button electrodes and shoe box BPMs. Unlike the conventional coaxial wire method, in the modified coaxial wire method no impedance matching elements have been used between the device under test and the external circuit. The effect of impedance mismatch has been solved mathematically and a new expression of transfer impedance has been derived. The proposed method is verified through simulation of a button electrode BPM using cst studio suite. The new method is also applied to measure transfer impedance of a button electrode BPM developed for insertion devices of Indus-2 and the results are also compared with its simulations. Close agreement between measured and simulation results suggests that the modified coaxial wire setup can be exploited for the measurement of transfer impedance of capacitive BPMs like button electrodes and shoe box BPM.

  11. Modified coaxial wire method for measurement of transfer impedance of beam position monitors

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar

    2018-05-01

    Full Text Available The transfer impedance is a very important parameter of a beam position monitor (BPM which relates its output signal with the beam current. The coaxial wire method is a standard technique to measure transfer impedance of the BPM. The conventional coaxial wire method requires impedance matching between coaxial wire and external circuits (vector network analyzer and associated cables. This paper presents a modified coaxial wire method for bench measurement of the transfer impedance of capacitive pickups like button electrodes and shoe box BPMs. Unlike the conventional coaxial wire method, in the modified coaxial wire method no impedance matching elements have been used between the device under test and the external circuit. The effect of impedance mismatch has been solved mathematically and a new expression of transfer impedance has been derived. The proposed method is verified through simulation of a button electrode BPM using cst studio suite. The new method is also applied to measure transfer impedance of a button electrode BPM developed for insertion devices of Indus-2 and the results are also compared with its simulations. Close agreement between measured and simulation results suggests that the modified coaxial wire setup can be exploited for the measurement of transfer impedance of capacitive BPMs like button electrodes and shoe box BPM.

  12. A New Understanding of the Heat Treatment of Nb-Sn Superconducting Wires

    Science.gov (United States)

    Sanabria, Charlie

    Enhancing the beam energy of particle accelerators like the Large Hadron Collider (LHC), at CERN, can increase our probability of finding new fundamental particles of matter beyond those predicted by the standard model. Such discoveries could improve our understanding of the birth of universe, the universe itself, and/or many other mysteries of matter--that have been unresolved for decades--such as dark matter and dark energy. This is obviously a very exciting field of research, and therefore a worldwide collaboration (of universities, laboratories, and the industry) is attempting to increase the beam energy in the LHC. One of the most challenging requirements for an energy increase is the production of a magnetic field homogeneous enough and strong enough to bend the high energy particle beam to keep it inside the accelerating ring. In the current LHC design, these beam bending magnets are made of Nb Ti superconductors, reaching peak fields of 8 T. However, in order to move to higher fields, future magnets will have to use different and more advanced superconducting materials. Among the most viable superconductor wire technologies for future particle accelerator magnets is Nb3Sn, a technology that has been used in high field magnets for many decades. However, Nb3Sn magnet fabrication has an important challenge: the fact the wire fabrication and the coil assembly itself must be done using ductile metallic components (Nb, Sn, and Cu) before the superconducting compound (Nb3 Sn) is activated inside the wires through a heat treatment. The studies presented in this thesis work have found that the heat treatment schedule used on the most advanced Nb3Sn wire technology (the Restacked Rod Process wires, RRPRTM) can still undergo significant improvements. These improvements have already led to an increase of the figure of merit of these wires (critical current density) by 28%.

  13. Clinical bending of nickel titanium wires

    Directory of Open Access Journals (Sweden)

    Stephen Chain

    2015-01-01

    Full Text Available Since the evolution and the involvement of Nickel Titanium wires in the field of Orthodontics. The treatment plan has evolved with the use of low force Nickel Titanium wires. Because of their high springback, low stiffness, they are the key initial wires in leveling and alignment but have poor formability. Since poor formability limits its ability to create variable arch forms thus; limits the form of treatment. We have devised a method to bend the Nickel Titanium wires to help in our inventory but also customized the wire according to the treatment.

  14. Energy Deposition in a Septum Wire

    CERN Document Server

    Ferioli, G; Knaus, P; Koopman, J; CERN. Geneva. SPS and LHC Division

    2001-01-01

    The present note describes a machine development (MD) aimed to confirm experimentally the need for protection of the extraction wire septum ZS in SPS long straight section LSS6 during LHC operation. Single wires identical to the ones mounted on the extraction septum were fixed on a fast wire scanner and put into the beam path. The beam heated the wire until it broke after a measured number of turns. The maximum single shot intensity the septum wires could withstand was thus calculated and compared with simulation results.

  15. First steps towards cube textured nickel profile wires for YBCO-coated conductors

    International Nuclear Information System (INIS)

    Eickemeyer, J.; Gueth, A.; Freudenberger, J.; Holzapfel, B.; Schultz, L.

    2011-01-01

    The cube texture as a typical sheet texture can also be formed by cold drawing and recrystallization in profile wires. Cube textured Ni profile wires containing up to 96.2% cube oriented grains in the central region were obtained. Forthcoming investigations are promising to get a textured substrate wire for YBCO-coated conductors. Cube textured nickel alloy tapes prepared by cold rolling and annealing (RABiTS method) represent a standard metallic substrate for superconductor coatings of the YBa 2 Cu 3 O 7-δ (YBCO) type. These tapes have a width to thickness ratio of about 30-100. However, a value of close to one is optimal concerning low energetic losses under alternating current applications. First experiments on micro-alloyed nickel prove that the cube texture as a typical sheet texture can also be formed in profile wires with a rectangular cross-section after cold drawing and recrystallization treatment.

  16. Influence of self-field on the critical current of Bi-2223/Ag tapes

    International Nuclear Information System (INIS)

    Lehtonen, Jorma; Korpela, Aki; Nah, Wansoo; Kang, Joonsun; Kovac, Pavol; Melisek, Tibor

    2004-01-01

    The knowledge of critical current density in a superconducting wire is essential in order to compute AC losses. In HTS tapes the critical current density is difficult to estimate from the measured critical current because self-field tends to reduce the current carrying capacity. In this paper the critical current is measured with a single sample and with two similar samples connected in antiparallel in order to compensate the self-field. Both types of measurement are simulated with finite element method. The simulations help to understand the relation between the measured critical current and material properties. The results suggest that in a high quality tape the self-field effect reduced the measured critical current ∼25% if compared to the real critical current at the zero external field

  17. Feasibility studies on the direct wire readout on wire scanners in electron accelerators

    International Nuclear Information System (INIS)

    Markert, Michael

    2010-10-01

    This bachelor thesis deals essentially with the signal processing of a so-called wire scanner, a special monitor, which comes to application in the beam diagnostics of particle accelerators. In this direct wire readout the voltage signal, which is induced by the particle beam in the measurement wire of the wire scanner, shall be directly read out. The aim of this thesis is to show fundamental considerations and perform studies, which study, whether and how in the future by means of a suited data transmission as well as readout electronics conclusion on the most important parameters of the beam, like position and profile, are possible. The measurement system presented here is divided in three main components: Signal measurement, signal preparation, and signal stretching. A suited test facility was developed and is presented in detail, in which then all components, like for instance the transmission cables, the wire-scanner fork, and the developed measurement circuit, are studied, which are of importance for a faultless signal transmission and presentation. Extensive measurements on the single components, as well as calculations for the signal transmission on and in the wire scanner were performed, whereby a good agreement could be found. Thereafter a comparison and a selection of the component used in this project were made. Furthermore improvement proposals, new constructions, and outlooks are presented, which could be of importance in further works.

  18. An interconnecting bus power optimization method combining interconnect wire spacing with wire ordering

    International Nuclear Information System (INIS)

    Zhu Zhang-Ming; Hao Bao-Tian; En Yun-Fei; Yang Yin-Tang; Li Yue-Jin

    2011-01-01

    On-chip interconnect buses consume tens of percents of dynamic power in a nanometer scale integrated circuit and they will consume more power with the rapid scaling down of technology size and continuously rising clock frequency, therefore it is meaningful to lower the interconnecting bus power in design. In this paper, a simple yet accurate interconnect parasitic capacitance model is presented first and then, based on this model, a novel interconnecting bus optimization method is proposed. Wire spacing is a process for spacing wires for minimum dynamic power, while wire ordering is a process that searches for wire orders that maximally enhance it. The method, i.e., combining wire spacing with wire ordering, focuses on bus dynamic power optimization with a consideration of bus performance requirements. The optimization method is verified based on various nanometer technology parameters, showing that with 50% slack of routing space, 25.71% and 32.65% of power can be saved on average by the proposed optimization method for a global bus and an intermediate bus, respectively, under a 65-nm technology node, compared with 21.78% and 27.68% of power saved on average by uniform spacing technology. The proposed method is especially suitable for computer-aided design of nanometer scale on-chip buses. (interdisciplinary physics and related areas of science and technology)

  19. K-wire and tension band wire fixation in treating sternoclavicular joint dislocation.

    Science.gov (United States)

    Chen, Qing-yu; Cheng, Shao-wen; Wang, Wei; Lin, Zhong-qin; Zhang, Wei; Kou, Dong-quan; Shen, Yue; Ying, Xiao-zhou; Cheng, Xiao-jie; Lv, Chuan-zhu; Peng, Lei

    2011-02-01

    To evaluate the feasibility and therapeutic effect of treating sternoclavicular joint dislocation by K-wire and tension band wire fixation, and to improve the safety and stability of this technique. This study consisted of 9 cases, 6 males and 3 females with the mean age of 25 years (range, 9-62 years). The causes were traffic accident in 7 cases, falling in 1 case and fight in 1 case. The duration from injury to operation was 2 hours to 7 days. There were 5 left dislocations and 4 right dislocations; 8 anterior dislocations and 1 posterior dislocation, including one combined with left scapular fracture and one with left olecranon fracture. Open reduction and internal fixation using K-wires and tension band wires were performed to treat dislocations. All patients were followed up for 6 to 24 months, 10 months on average. According to Rockwood's rating scale on postoperative sternoclavicular joint, 8 cases achieved excellent outcomes with an average score of 13.88, and the rest case achieved a good outcome with the score of 12. Anatomical reduction was obtained in all cases. There were no such postoperative complications as severe infection, injury to blood vessel and nerve, failure of fixation, etc. Patients were all satisfied with the anatomical reduction and functional recovery. The technique of K-wire and tension band wire fixation is safe, simple, effective, less invasive and has been successfully used in orthopedic surgery. It is effective in treating sternoclavicular joint dislocation though it has some disadvantages.

  20. Voltage current characteristics of type III superconductors

    International Nuclear Information System (INIS)

    Dorofejev, G.L.; Imenitov, A.B.; Klimenko, E.Y.

    1980-01-01

    An adequate description of voltage-current characteristics is important in order to understand the nature of high critical current for the electrodynamic construction of type-III superconductors and for commercial superconductor specification. Homogeneous monofilament and multifilament Nb-Ti, Nb-Zr,Nb 3 Sn wires were investigated in different ranges of magnetic field, temperature and current. The shape of the voltage-current characteristics of multifilament wires, and the parameter's dependence on temperature and magnetic field may be explained qualitatively by the longitudinal heterogeneous nature of the filaments. A method of attaining the complete specification of the wire's electro-physical properties is proposed. It includes the traditional description of a critical surface (i.e. the surface corresponding to a certain conventional effective resistivity in T,B,J-space) and a description of any increasing parameter that depends on B and T. (author)