WorldWideScience

Sample records for superconducting super collidermagnets

  1. The Superconducting Super Collider: A status report

    Energy Technology Data Exchange (ETDEWEB)

    Schwitters, R.F.

    1993-04-01

    The design of the Superconducting Super Collider (SSC) is briefly reviewed, including its key machine parameters. The scientific objectives are twofold: (1) investigation of high-mass, low-rate, rare phenomena beyond the standard model; and (2) investigation of processes within the domain of the standard model. Machine luminosity, a key parameter, is a function of beam brightness and current, and it must be preserved through the injector chain. Features of the various injectors are discussed. The superconducting magnet system is reviewed in terms of model magnet performance, including the highly successful Accelerator System String Test Various magnet design modifications are noted, reflecting minor changes in the collider arcs and improved installation procedures. The paper concludes with construction scenarios and priority issues for ensuring the earliest collider commissioning.

  2. Optical data transmission at the superconducting super collider

    Energy Technology Data Exchange (ETDEWEB)

    Leskovar, B. [Lawrence Berkeley Lab., CA (United States)

    1989-04-01

    Digital and analog data transmissions via fiber optics for the Superconducting Super Collider have been investigated. The state of the art of optical transmitters, low loss fiber waveguides, receivers and associated electronics components are reviewed and summarized. Emphasis is placed on the effects of the radiation environment on the performance of an optical data transmission system components. Also, the performance of candidate components of the wide band digital and analog transmission systems intended for deployment in the Superconducting Super Collider Detector is discussed.

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

    Science.gov (United States)

    Golner, Thomas M.; Mehta, Shirish P.

    2005-07-26

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

  4. Calibration beams at the SSC (Superconducting Super Collider)

    Energy Technology Data Exchange (ETDEWEB)

    Autin, A.; Edwards, H. (Superconducting Super Collider Lab., Dallas, TX (USA)); Bensinger, J.R. (Superconducting Super Collider Lab., Dallas, TX (USA) Brandeis Univ., Waltham, MA (USA)); Baller, B.; Browning, F.; Coleman, R.; Cooper, J.; Cossairt, D.; Kula, L.; Malensek, A.; Stefanski, R.; Stutte, L. (Fermi National Accelerator Lab., Batavia, IL (USA))

    1989-04-30

    This paper discusses the following topics on the Superconducting Super Collider: beam specification at calibration halls; high energy booster options with tunnels to surface; switchyard; six beams with high and low power options; switchyard optics for both high and low energy transport; secondary beams; wide band beams; radiation shielding; tagging system; and test and calibration halls.

  5. Audit of controls over Superconducting Super Collider Laboratory subcontractor expenditures

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-22

    In January 1989 the Department of Energy contracted with Universities Research Association, Inc. to design, construct, manage, operate, and maintain the Superconducting Super Collider Laboratory. Through Fiscal Year 1992, costs for subcontractor goods and services accounted for about 75 percent of the Superconducting Super Collider Laboratory expenditures. The Office of Inspector General evaluated the adequacy of controls in place to ensure that subcontractor costs were reasonable, as required by the contract. The following conclusions were drawn from the audit. The Superconducting Super Collider Laboratory did not consistently exercise prudent business judgment in making subcontractor expenditures. As a result, $60 million in expenditures already made and $128 million planned with commercial subcontractors were, in the authors opinion, unnecessary, excessive, or represented uncontrolled growth. The audit also found inadequate justifications, accountability, and cost controls over $143 million in expenditures made and $47 million planned with other Department of Energy laboratories. Improvements were needed in subcontract administration and internal controls, including appropriate audit coverage of the subcontracts. In addition, Department of Energy guidance concerning procurement actions between the laboratories needed to be established.

  6. Technology and materials for the Superconducting Super Collider (SSC) project

    Energy Technology Data Exchange (ETDEWEB)

    Shintomi, Takakazu; Ishimaru, Hajime; Unno, Yoshinobu; Arai, Yasuo; Watase, Yoshiyuki; Amako, Katsuya; Kondo, Takahiko (National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan))

    1992-08-01

    The Superconducting Super Collider (SSC) is the accelerator for the research on elementary particle physics, of which the construction was already begun in Texas, USA. Two proton rings comprising about 10,000 superconducting magnets are installed in an underground tunnel with the circumferential length of 87 km, and the proton-proton collision of superhigh energy is realized. This accelerator becomes the largest machine that mankind makes. In this report, among the high-tech and materials used for the SSC, superconducting magnets, super-high vacuum beam pipes, silicon semiconductor detector, the use of VLSI and superhigh density mounting and high speed, large quantity data processing system are taken up, and the outline of those is described. The SSC was planned for the elucidation of Higg's theory. The incidence accelerator group is composed of a linear accelerator and three booster synchrotrons. The particles generated by proton-proton collision are measured, and the discovery of new particles and the study on high energy physical phenomena are carried out. The construction of the accelerator and experimental equipment is carried out by international cooperation. (K.I.).

  7. Superconducting Super Collider: A step in the 21st century

    Science.gov (United States)

    McAshan, M.

    1991-08-01

    The development of superconducting materials and the development of helium temperature refrigeration technology have both been propelled by their wide application in large-scale scientific research. The development of materials and technology for the Tevatron proton storage ring at Fermi National Accelerator Laboratory, Batavia, IL USA, in the decade of the seventies provided the basis in the decade of the eighties, for example, for the use of superconducting helium-cooled whole-body magnets for magnetic resonance imaging in medical diagnosis. In the decade of the nineties a number of particle accelerators for high energy physics will be constructed in national and international laboratories around the world. These devices will employ superconductivity on an ambitious scale, and their operation will require more than double the amount of helium refrigeration capacity now installed worldwide. This large increase in the use of helium refrigeration will have a significant effect on the technology and on the industry that produces it. The largest of these accelerator projects is the Superconducting Super Collider (SSC) now under construction at a new laboratory near Dallas, TX USA. This report discusses the development of this cryogenic system for the SSC magnets.

  8. Control Surveys for Underground Construction of the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    Greening, W.J.Trevor; Robinson, Gregory L.; /Measurment Science Inc.; Robbins, Jeffrey S.; Ruland, Robert E.; /SLAC

    2005-08-16

    Particular care had to be taken in the design and implementation of the geodetic control systems for the Superconducting Super Collider (SSC) due to stringent accuracy requirements, the demanding tunneling schedule, long duration and large size of the construction effort of the project. The surveying requirements and the design and implementation of the surface and underground control scheme for the precise location of facilities which include approximately 120 km of bored tunnel are discussed. The methodology used for the densification of the surface control networks, the technique used for the transfer of horizontal and vertical control into the underground facilities, and the control traverse scheme employed in the tunnels is described.

  9. SSC (Superconducting Super Collider) dipole coil production tooling

    Energy Technology Data Exchange (ETDEWEB)

    Carson, J.A.; Barczak, E.J.; Bossert, R.C.; Brandt, J.S.; Smith, G.A.

    1989-03-01

    Superconducting Super Collider dipole coils must be produced to high precision to ensure uniform prestress and even conductor distribution within the collared coil assembly. Tooling is being prepared at Fermilab for the production of high precision 1M and 16.6M SSC dipole coils suitable for mass production. The design and construction methods builds on the Tevatron tooling and production experience. Details of the design and construction methods and measured coil uniformity of 1M coils will be presented. 4 refs., 10 figs.

  10. Control Surveys for Underground Construction of the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    Greening, W.J.Trevor; Robinson, Gregory L.; /Measurment Science Inc.; Robbins, Jeffrey S.; Ruland, Robert E.; /SLAC

    2005-08-16

    Particular care had to be taken in the design and implementation of the geodetic control systems for the Superconducting Super Collider (SSC) due to stringent accuracy requirements, the demanding tunneling schedule, long duration and large size of the construction effort of the project. The surveying requirements and the design and implementation of the surface and underground control scheme for the precise location of facilities which include approximately 120 km of bored tunnel are discussed. The methodology used for the densification of the surface control networks, the technique used for the transfer of horizontal and vertical control into the underground facilities, and the control traverse scheme employed in the tunnels is described.

  11. Preliminary report on the design of the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-01-01

    While a rather detailed Conceptual Design Report will be available in April, an Superconducting Super Collider (SSC) it is appropriate to give a preview, now that the primary parameters for the Conceptual Design Report have been put down. In this preview the leading two chapters give the historical and scientific-technical background for the SSC and deal at somelength with the physics issues to be explored by the SSC. A third chapter reviews briefly the engineering and accelerator physics foundations for the developing SSC design, while the fourth lists the primary design parameters and describes the overall design. The fifth chapter describes briefly the principal engineering systems that will appear in the Conceptual Design Report, including the rather extensive injector system required. A sixth and final chapter outlines the beginnings of a ``construction plan`` put together for the purposes of exploring practical schedules and defining the critical design, development and planning paths for the overall facility and its major sub-systems.

  12. Short sample testing facility for the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    Zbasnik, J.; Scanlan, R.; Taylor, C.; Peters, C.; Pope, W.; Royet, J. (Lawrence Berkeley Lab., CA (USA))

    1989-06-01

    In this paper we present the system requirements of the apparatus measuring the short sample critical current of the cable for the Superconducting Super Collider (SSC), and the current status of our development work. Key features of the system presented here are: a sample holder which clamps the samples sufficiently well such that no training quenches are required to perform critical current measurements and another which may allow for faster sample mounting; voltage tap boards using a printed-circuit technique which eliminates the necessity of soldering wires for the voltage measurements; a 1-m ling, 5-cm-bore dipole magnet with close-in iron designed to produce 7.5 T with a 6000 A excitation current; and an air-lock system that allows repeated sample changes without the magnet chamber being contaminated with air and other impurities. 7 refs., 6 figs.

  13. Safety aspects of superconducting magnets for Super-FRS

    CERN Document Server

    CERN. Geneva

    2016-01-01

    The Super Fragment Separator (Super FRS) is a two-stage in flight separator to be built next to the site of GSI, Darmstadt, Germany as part of FAIR (Facility for Anti-proton and Ion Research). Its purpose is to create and separate rare isotope beams and to enable the mass measurement also for very short lived nuclei. A superferric design with superconducting coils and standard iron yoke shaping the magnetic field was chosen for the magnets. The cooling will be by a liquid Helium bath. For the main dipoles only the coil is at cold for the multiplets (asemblies of quadrupoles and hgher order correctors) also the iron yoke will be in the bath. From a safety point of view the large He-volumes of more than 1000 l of the multiplets, the high design pressure of 20 bar, as well as the high inductances of the magnets up to 30 H are challenges to be considered in the design and definition of the testing procedures.

  14. Superconductivity

    CERN Document Server

    Thomas, D B

    1974-01-01

    A short general review is presented of the progress made in applied superconductivity as a result of work performed in connection with the high-energy physics program in Europe. The phenomenon of superconductivity and properties of superconductors of Types I and II are outlined. The main body of the paper deals with the development of niobium-titanium superconducting magnets and of radio-frequency superconducting cavities and accelerating structures. Examples of applications in and for high-energy physics experiments are given, including the large superconducting magnet for the Big European Bubble Chamber, prototype synchrotron magnets for the Super Proton Synchrotron, superconducting d.c. beam line magnets, and superconducting RF cavities for use in various laboratories. (0 refs).

  15. Current Reversal and Negative Conductance for a Super-Conducting Junctions Device

    Institute of Scientific and Technical Information of China (English)

    LI Jing-Hui

    2009-01-01

    In the paper, we study a super-conducting junctions device subject to an input periodic signal and a constant force. It is shown that, for this device, we can get current reversals for the current of the electron pairs versus the frequency of the periodic signal and negative conductance for the current of the electron pairs as a function of the constant force.

  16. Contracting practices for the underground construction of the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    This report was prepared by a specially appointed committee under the auspices of the National Academy of Sciences/National Research Council to address contracting and associated management issues essential to the successful execution of underground construction for the Superconducting Super Collider.

  17. Data acquisition and online processing requirements for experimentation at the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    Lankford, A.J.; Barsotti, E.; Gaines, I.

    1989-07-01

    Differences in scale between data acquisition and online processing requirements for detectors at the Superconducting Super Collider and systems for existing large detectors will require new architectures and technological advances in these systems. Emerging technologies will be employed for data transfer, processing, and recording. 9 refs., 3 figs.

  18. 2008 LHC Open Days: Super(-conducting) events and activities

    CERN Multimedia

    2008-01-01

    Superconductivity will be one of the central themes of the programme of events and discovery activities of the forthcoming LHC Open Days on 5 and 6 April. Visitors will be invited to take part in a range of activities, experiments and exchanges all about this amazing aspect of the LHC project. Why superconductivity? Simply because it’s the principle on which the very operation of the LHC is based. At the heart of the LHC magnets lie 7000 kilometres of superconducting cables, each strand containing between 6000 and 9000 filaments of the superconducting alloy niobium-titanium in a copper coating. These cables, cooled to a temperature close to absolute zero, are able to conduct electricity without resistance. 12000 amp currents - an intensity some 30000 times greater than that of a 100 watt light bulb - pass through the cables of the LHC magnets.   Programme:   BLDG 163 (Saturday 5 and Sunday 6 April): See weird and wonderful experiments with your own eyes In the workshop where the 2...

  19. Entangled States in a Single-Qubit Structure with SQUID Coupled with a Super-conducting Resonator

    Institute of Scientific and Technical Information of China (English)

    SONG Jian-Wen; LIANG Bao-Long; HAI Wen-Hua; WANG Ji-Suo; ZHONG Hong-Hua; MENG Xiang-Guo; LUO Xiao-Bing

    2008-01-01

    In this paper, the number-phase quantization scheme of the mesoscopic circuit, which consists of a single-qubit structure with superconducting quantum interference device coupled with a super-conducting resonator, is given. By introducing a unitary matrix and by means of spectral decomposition, the Hamiltonian operator of the system is exactly formulated in compact forms in spin-1/2 notation. The eigenvalues and the eigenstates of the system are investigated. It is found that using this system the entangled states can not only be prepared, but also be manipulated by tuning the magnetic flux through the super-conducting loop.

  20. Final Report - The Decline and Fall of the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    RIORDAN, MICHAEL

    2011-11-29

    In October 1993 the US Congress terminated the Superconducting Super Collider — at the time the largest pure-science project ever attempted, with a total cost estimated to exceed $10 billion. It was a stunning loss for the US highenergy physics community, which until that moment had perched for decades at the pinnacle of American science. Ever since 1993, this once-dominant scientific community has been in gradual decline. With the 2010 startup of research on the CERN Large Hadron Collider and the 2011 shutdown of the Fermilab Tevatron, world leadership in elementary-particle physics has crossed the Atlantic and returned to Europe.

  1. Shielding optimization studies for the detector systems of the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    Slater, C.O.; Lillie, R.A.; Gabriel, T.A.

    1994-09-01

    Preliminary shielding optimization studies for the Superconducting Super Collider`s Solenoidal Detector Collaboration detector system were performed at the Oak Ridge National Laboratory in 1993. The objective of the study was to reduce the neutron and gamma-ray fluxes leaving the shield to a level that resulted in insignificant effects on the functionality of the detector system. Steel and two types of concrete were considered as components of the shield, and the shield was optimized according to thickness, weight, and cost. Significant differences in the thicknesses, weights, and costs were noted for the three optimization parameters. Results from the study are presented.

  2. Appearance of Spatial-Temporal Noise in Super-conducting Junction and Its Effect on Transport of Electron Pairs

    Institute of Scientific and Technical Information of China (English)

    LI Jing-Hui

    2007-01-01

    Transport of electron pairs in super-conducting junction with spatial-temporal noise is investigated.We show that the spatial-temporal noise can produce the current of the electron pairs,which stems from a symmetry breaking of the system induced by the correlation of the spatial-temporal noise with the phase difference.It is found that there is a positive current for the electron pairs,exhibiting a peak with increasing the values of some parameters of the noises.The results provide a theoretical foundation for the further investigation of the super-conducting junction.

  3. A controller for 97 MHz super-conducting QWR for NSC LINAC booster

    Indian Academy of Sciences (India)

    Gopal Joshi; C I Sujo; Bhuban Sahu; Ashutosh Pandey; Ajith Kumar; Jitendra Karande

    2002-12-01

    A resonator controller has been implemented to stabilize the amplitude and phase of rf fields in the super-conducting resonators of NSC LINAC. Due to reduced losses these resonators have intrinsic band width of the order of 0.1 Hz at 97 MHz whereas the vibration-induced center frequency changes are of the order of a few tens of hertz. In the control strategy followed, the resonator is made the frequency selective part of an oscillator. The phase lock is achieved by dynamically adding a phase shift in the oscillator. A slow tuner minimizes the slow drifts in the resonator center frequency. In this paper we present the control strategy, implementation details and performance obtained with this controller.

  4. Tunnel visions the rise and fall of the Superconducting Super Collider

    CERN Document Server

    Riordan, Michael; Kolb, Adrienne W

    2015-01-01

    Starting in the 1950s, US physicists dominated the search for elementary particles; aided by the association of this research with national security, they held this position for decades. In an effort to maintain their hegemony and track down the elusive Higgs boson, they convinced President Reagan and Congress to support construction of the multibillion-dollar Superconducting Super Collider project in Texas-the largest basic-science project ever attempted. But after the Cold War ended and the estimated SSC cost surpassed ten billion dollars, Congress terminated the project in October 1993. Drawing on extensive archival research, contemporaneous press accounts, and over one hundred interviews with scientists, engineers, government officials, and others involved, Tunnel Visions tells the riveting story of the aborted SSC project. The authors examine the complex, interrelated causes for its demise, including problems of large-project management, continuing cost overruns, and lack of foreign contributions. In doi...

  5. 3D calculations of the Superconducting Super Collider (SSC) 3 Tesla magnet

    Energy Technology Data Exchange (ETDEWEB)

    Lari, R.J.

    1984-01-01

    A 20 TeV Superconducting Super Collider (SSC) proton accelerator is being proposed by the High Energy Physics Community. One proposal would consist of a ring of magnets 164 km in circumference with a field strength of 3 Tesla and would cost 2.7 billion dollars. The magnet consists of stacked steel laminations with superconducting coils. The desired field uniformity is obtained for all fields from 0.2 to 3 Tesla by using three (or more) different pole shapes. These three different laminations are stacked in the order 1-2-3-1-2-3-... creating a truly three dimensional geometry. A three laminated stack 1-2-3 with periodic boundary conditions at 1 and 3 was assigned about 5000 finite elements per lamination and solved using the computer program TOSCA. To check the TOSCA results, the field of each of the three different shaped laminations was calculated separately using periodic boundary conditions and compared to the two dimensional field calculations using TRIM. This was done for a constant permeability of 2000 and using the B-H table for fully annealed 1010 steel. The difference of the field calculations in the region of interest was always less than +-.2%

  6. SSC [Superconducting Super Collider] Project: Technical Training for the Future of Texas. Navarro College/Dallas Community College District. Final Report for Year One.

    Science.gov (United States)

    Orsak, Charles; McGlohen, Patti J.

    The Superconducting Super Collider Laboratory (SSCL) is a national lab for research on the fundamental forces and constituents of the universe. A major part of the research will involve an oval ring 54 miles in circumference through which superconducting magnets will steer two beams of protons in opposite directions. In response to the…

  7. A Bridge Too Far: The Demise of the Superconducting Super Collider, 1989-1993

    Science.gov (United States)

    Riordan, Michael

    2015-04-01

    In October 1993 the US Congress terminated the Superconducting Super Collider -- at over 10 billion the largest and costliest basic-science project ever attempted. It was a disastrous loss for the nation's once-dominant high-energy physics community, which has been slowly declining since then. With the 2012 discovery of the Higgs boson at CERN's Large Hadron Collider, Europe has assumed world leadership in this field. A combination of fiscal austerity, continuing SSC cost overruns, intense Congressional scrutiny, lack of major foreign contributions, waning Presidential support, and the widespread public perception of mismanagement led to the project's demise nearly five years after it had begun. Its termination occurred against the political backdrop of changing scientific needs as US science policy shifted to a post-Cold War footing during the early 1990s. And the growing cost of the SSC inevitably exerted undue pressure upon other worthy research, thus weakening its support in Congress and the broader scientific community. As underscored by the Higgs boson discovery, at a mass substantially below that of the top quark, the SSC did not need to collide protons at 40 TeV in order to attain its premier physics goal. The selection of this design energy was governed more by politics than by physics, given that Europeans could build the LHC by eventually installing superconducting magnets in the LEP tunnel under construction in the mid-1980s. In hindsight, there were good alternative projects the US high-energy physics community could have pursued that did not involve building a gargantuan, multibillion-dollar machine at a green-field site in Texas. Research supported by the National Science Foundation, Department of Energy, and the Richard Lounsbery Foundation.

  8. Summary of the Proceedings of the Super-Conductivity Technical Exchange Meeting

    Science.gov (United States)

    1980-04-01

    Contents: Large Superconductive Magnets; Superconductivity Activities at LASL; Superconductivity Studies at Argonne National Laboratory; CFFF MHD Magnet at Argonne National Laboratory; MHD Superconducting Magnets; Fermilab's Energy Saver; LCP and 12 Tesla Programs at ORNL; Division of Electric Energy System's Superconductivity Program; Development of Standards for Practical Superconductors; Casting of Dendritic Cu-Nb Alloys for Superconducting Wire; Review of Recent Developments of Multifilamentary Nb3Sn by 'in Situ' and Cold Powder Metallurgy Processes; Superconducting Magnet Facility at NRL; Airborne Superconductor Applications; High Pressure Synthesis Program at Benet Weapons Laboratory Watervliet Arsenal; CuCl; Stability and Exciton Population Percursive to Anomalous Diagmagnetism; Navy Superconductive Machinery Development Program; and Superconducting Materials Program at NRL.

  9. On chromoelectric (super)conductivity of the Yang–Mills vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Chernodub, M.N., E-mail: maxim.chernodub@lmpt.univ-tours.fr [CNRS, Laboratoire de Mathématiques et Physique Théorique, Université François-Rabelais Tours, Fédération Denis Poisson, Parc de Grandmont, 37200 Tours (France); Department of Physics and Astronomy, University of Gent, Krijgslaan 281, S9, B-9000 Gent (Belgium); Kalaydzhyan, Tigran [Department of Physics and Astronomy, Stony Brook University, Stony Brook, NY 11794-3800 (United States); Van Doorsselaere, Jos [CNRS, Laboratoire de Mathématiques et Physique Théorique, Université François-Rabelais Tours, Fédération Denis Poisson, Parc de Grandmont, 37200 Tours (France); Verschelde, Henri [Department of Physics and Astronomy, University of Gent, Krijgslaan 281, S9, B-9000 Gent (Belgium)

    2014-03-07

    We argue that in the Copenhagen (“spaghetti”) picture of the QCD vacuum the chromomagnetic flux tubes exhibit chromoelectric superconductivity. We show that the superconducting chromoelectric currents in the tubes may be induced by the topological charge density.

  10. On chromoelectronic (super)conductivity of the Yang-Mills vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Chernodub, M.N. [Tours Univ. (France). CNRS, Lab. de Mathematiques et Physique Theorique; Gent Univ. (Belgium). Dept. of Physics and Astronomy; Doorsselaere, Jos van; Verschelde, Henri [Gent Univ. (Belgium). Dept. of Physics and Astronomy; Kalaydzhyan, Tigran [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany). Theory Group; Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)

    2012-12-15

    We argue that in the Copenhagen (''spaghetti'') picture of the QCD vacuum the chromomagnetic flux tubes exhibit chromoelectric superconductivity. The superconducting chromoelectric currents in the tubes may be induced by the topological charge density.

  11. A model for correlating 4. 2-K performance with room-temperature mechanical characteristics in superconducting test dipole magnets for the Superconducting Super Collider (SSC)

    Energy Technology Data Exchange (ETDEWEB)

    Ige, O.O.; Lyon, R.H.; Iwasa, Y. (Francis Bitter National Magnet Laboratory Plasma Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States))

    1992-03-15

    The longitudinal attenuation of impact-generated pulses in ten superconducting dipole magnets was measured at room temperature. A lumped-parameter model was constructed for the collared dipole. Using the method of nonlinear least-squares, the model was used to estimate the internal damping in the main components of the dipoles and the coupling resistances between the components: collars, inner, and outer coils. A positive correlation was found between the collar-inner coil coupling resistance and the 4.2-K performance of the magnets: the higher the coupling resistance, the fewer the number of quenches required to reach design operating current. There was virtually no correlation between any of the other internal or coupling resistances and 4.2-K performance. These observations are explained in terms of frictional slip of the inner coil against the collars causing premature quenches. The magnets are more susceptible to quenches at the collar-inner coil interface than at the collar-outer coil interface because the inner coil is subject to higher fields and forces. The experiment is potentially useful as a technique for screening high-performance superconducting magnets such as Superconducting Super Collider (SSC) dipoles at room temperature.

  12. Superconductivity

    CERN Document Server

    Poole, Charles P; Farach, Horacio A

    1995-01-01

    Superconductivity covers the nature of the phenomenon of superconductivity. The book discusses the fundamental principles of superconductivity; the essential features of the superconducting state-the phenomena of zero resistance and perfect diamagnetism; and the properties of the various classes of superconductors, including the organics, the buckministerfullerenes, and the precursors to the cuprates. The text also describes superconductivity from the viewpoint of thermodynamics and provides expressions for the free energy; the Ginzburg-Landau and BCS theories; and the structures of the high

  13. Developmental condition and technical problems on electric insulation for super-conducting electric power machine

    Science.gov (United States)

    Motoyama, H.

    1989-05-01

    The present situations of superconducting electric power machines in the world and studied problems were investigated from viewpoint of the electric insulation. 50MVA generator (CRIE/Hitachi) or 120MVA generator (KWU/Siemens) where the dc superconducting technique was applied on field windings, are developed. As to Superconducting transformer, 220KVA transformer is trially manufactured and the conceptual design of 1,000MVA transformer is made by W.H. or Alstom. Future problems are the study of protecting method for the overvoltage to superconducting electric power machines and the study to prevent the quench for superconducting windings. The respective insulating characteristics of solid and liquid insulators become clear gradually under the cryogenic condition but a large part of insulating characteristics of composite insulator prepared by combination of both insulators are not clear, so that these problems must be clarified.

  14. Superconductivity

    Science.gov (United States)

    1989-07-01

    SUPERCONDUCTIVITY HIGH-POWER APPLICATIONS Electric power generation/transmission Energy storage Acoustic projectors Weapon launchers Catapult Ship propulsion • • • Stabilized...temperature superconductive shields could be substantially enhanced by use of high-Tc materials. 27 28 NRAC SUPERCONDUCTIVITY SHIP PROPULSION APPLICATIONS...motor shown in the photograph. As a next step in the evolution of electric-drive ship propulsion technology, DTRC has proposed to scale up the design

  15. Report of the Task Force on detector Research and Development for the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1986-06-01

    This report contains a: Report of the working group on tracking devices; report of the working group on calorimetry; report of the working group on muon, electron and hadron identification; report of the working group on electronics, triggering, data acquisition and computing; report of the working group on superconducting magnets; and report of the working group on Monte Carlo development.

  16. Technical design of a detector to be operated at the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    1992-04-01

    This report discusses the following topics on the Soleoidal Detector Collaboration: Summary and overview of the detector; physics and detector requirements; central tracking system; superconducting magnet; calorimetry; muon system; electronics; online computing; offline computing; safety; experimental facilities; installation; test and calibration beam plan; and cost and schedule summary.

  17. The feasibility of low-mass conductors for toroidal superconducting magnets for SSC (Superconducting Super Collider) detectors

    Energy Technology Data Exchange (ETDEWEB)

    Luton, J.N.

    1990-01-01

    An earlier study by Luton and Bonanos concluded that the design and fabrication of superconducting toroidal bending magnets would require a major effort but would be feasible. This study is an extension to examine the feasibility of low-mass conductors for such use. It included a literature search, consultations, with conductor manufacturers, and design calculations, but no experimental work. An unoptimized sample design that used a residual resistivity ratio for aluminum of 1360 and a current density of 3.5 kA/cm{sup 2} over the uninsulated conductor for a 4.5-T toroid with 1 GJ of stored energy obtained a hot-spot temperature of 120 K with a maximum dump voltage of 3.6 kV and 24% of the initial current inductively transferred into the shorted aluminum structure. The stability margin was 200 mJ/cm{sup 3} of cable space. Limiting the quench pressure to 360 atm to give conservative stresses in the sheath and assuming that the whole flow path quenched immediately resulted in helium taps that could be a kilometer apart if the flow friction factor were the same as that experienced in the Westinghouse (W) Large Coil Task (LCT) coil. This indicates that the 520-m conductor length of each of the 72 individual coil segments of a toroid would be a single flow path. If some practical uncertainties can be favorably resolved by producing and testing sample conductors, the use of a conductor with clad-aluminum stabilizer and extruded aluminum-alloy sheath should be feasible and economical. 9 refs., 3 figs.

  18. Superconductivity

    CERN Document Server

    Ketterson, John B

    2008-01-01

    Conceived as the definitive reference in a classic and important field of modern physics, this extensive and comprehensive handbook systematically reviews the basic physics, theory and recent advances in the field of superconductivity. Leading researchers, including Nobel laureates, describe the state-of-the-art in conventional and unconventional superconductors at a particularly opportune time, as new experimental techniques and field-theoretical methods have emerged. In addition to full-coverage of novel materials and underlying mechanisms, the handbook reflects continued intense research into electron-phone based superconductivity. Considerable attention is devoted to high-Tc superconductivity, novel superconductivity, including triplet pairing in the ruthenates, novel superconductors, such as heavy-Fermion metals and organic materials, and also granular superconductors. What’s more, several contributions address superconductors with impurities and nanostructured superconductors. Important new results on...

  19. Superconductivity

    CERN Document Server

    Poole, Charles P; Creswick, Richard J; Prozorov, Ruslan

    2014-01-01

    Superconductivity, Third Edition is an encyclopedic treatment of all aspects of the subject, from classic materials to fullerenes. Emphasis is on balanced coverage, with a comprehensive reference list and significant graphics from all areas of the published literature. Widely used theoretical approaches are explained in detail. Topics of special interest include high temperature superconductors, spectroscopy, critical states, transport properties, and tunneling. This book covers the whole field of superconductivity from both the theoretical and the experimental point of view. This third edition features extensive revisions throughout, and new chapters on second critical field and iron based superconductors.

  20. A blanket design, apparatus, and fabrication techniques for the mass production of multilayer insulation blankets for the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    Gonczy, J.D.; Boroski, W.N.; Niemann, R.C.; Otavka, J.G.; Ruschman, M.K.; Schoo, C.J.

    1989-09-01

    The multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) consists of full cryostat length assemblies of aluminized polyester film fabricated in the form of blankets and installed as blankets to the 4.5K cold mass and the 20K and 80K thermal radiation shields. Approximately 40,000 MLI blankets will be required in the 10,000 cryogenic devices comprising the SSC accelerator. Each blanket is nearly 17 meters long and 1.8 meters wide. This paper reports the blanket design, an apparatus, and the fabrication method used to mass produce pre-fabricated MLI blankets. Incorporated in the blanket design are techniques which automate quality control during installation of the MLI blankets in the SSC cryostat. The apparatus and blanket fabrication method insure consistency in the mass produced blankets by providing positive control of the dimensional parameters which contribute to the thermal performance of the MLI blanket. By virtue of the fabrication process, the MLI blankets have inherent features of dimensional stability three-dimensional uniformity, controlled layer density, layer-to-layer registration, interlayer cleanliness, and interlayer material to accommodate thermal contraction differences. 11 refs., 6 figs., 1 tab.

  1. Review of project definition studies of possible on-site uses of superconducting super collider assets and facilities. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-01

    This document reports on the results of a peer review and evaluation of studies made of potential uses of assets from the terminated Superconducting Super Collider (SSC) project. These project definition studies focused on nine areas of use of major assets and facilities at the SSC site near Waxahachie, Texas. The studies were undertaken as part of the effort to maximize the value of the investment made in the SSC and were supported by two sets of grants, one to the Texas National Research Laboratory Commission (TNRLC) and the second to various universities and other institutions for studies of ideas raised by a public call for expressions of interest. The Settlement Agreement, recently signed by the Department of Energy (DOE) and TNRLC, provides for a division of SSC property. As part of the goal of maximizing the value of the SSC investment, the findings contained in this report are thus addressed to officials in both the Department and TNRLC. In addition, this review had several other goals: to provide constructive feedback to those doing the studies; to judge the benefits and feasibility (including funding prospects) of the projects studied; and to help worthy projects become reality by matching projects with possible funding sources.

  2. Design and Fabrication of the Superconducting Horizontal Bend Magnet for the Super High Momentum Spectrometer at Jefferson Lab

    Energy Technology Data Exchange (ETDEWEB)

    Chouhan, Shailendra S. [Michigan State University; DeKamp, Jon [Michigan State University; Burkhart, E. E, [Michigan State University; Bierwagen, J. [Michigan State University; Song, H. [Michigan State University; Zeller, Albert F. [Michigan State University; Brindza, Paul D. [JLAB; Lassiter, Steven R. [JLAB; Fowler, Michael J. [JLAB; Sun, Qiuli (Eric) [JLAB

    2015-06-01

    A collaboration exists between NSCL and JLab to design and build JLab's Super High Momentum Spectrometer (SHMS) horizontal bend magnet that allows the bending of the 12 GeV/c particles horizontally by 3° to allow SHMS to reach angles as low as 5.5°. Two full size coils have been wound and are cold tested for both magnetic and structural properties. Each coil is built from 90 layers of single-turn SSC outer conductor cable. An initial test coil with one third the turns was fabricated to demonstrate that the unique saddle shape with fully contoured ends could be wound with Rutherford superconducting cable. Learned lessons during the trial winding were integrated into the two complete full-scale coils that are now installed in the helium vessel. The fabrication of the iron yoke, cold mass, and thermal shield is complete, and assembly of the vacuum vessel is in progress. This paper presents the process and progress along with the modified magnet design to reduce the fringe field in the primary beam region and also includes the impact of the changes on coil forces and coil restraint system.

  3. Review of project definition studies of possible on-site uses of superconducting super collider assets and facilities

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-12-01

    This document reports on the results of a peer review and evaluation of studies made of potential uses of assets from the terminated Superconducting Super Collider (SSC) project. These project definition studies focused on nine areas of use of major assets and facilities at the SSC site near Waxahachie, Texas. The studies were undertaken as part of the effort to maximize the value of the investment made in the SSC and were supported by two sets of grants, one to the Texas National Research Laboratory Commission (TNRLC) and the second to various universities and other institutions for studies of ideas raised by a public call for expressions of interest. The Settlement Agreement, recently signed by the Department of Energy (DOE) and TNRLC, provides for a division of SSC property. As part of the goal of maximizing the value of the SSC investment, the findings contained in this report are thus addressed to officials in both the Department and TNRLC. In addition, this review had several other goals: to provide constructive feedback to those doing the studies; to judge the benefits and feasibility (including funding prospects) of the projects studied; and to help worthy projects become reality by matching projects with possible funding sources.

  4. Report on the program of 4 K irradiation of insulating materials for the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    Spindel, A.

    1993-07-01

    This report is intended to serve as an aid to material selection. The results reported herein are the product of a careful investigation and can be used with confidence in their validity. The selection of materials based on this data, however, is not the responsibility of the author. This report will not approve or disapprove any specific material for use in the Super Collider. The author of this report does not assume any design responsibility or responsibility for material selection for any application. It is, therefore, very important that those with design responsibility use this report wisely. For this reason, the following informational guide to the material selection process has been provided. There are several issues to take into account when evaluating a material for radiation resistance. It is very important that the design criteria and operating loads for the application be known. For many applications the actual loading, and therefore required properties, are unknown. Certain materials have empirically been used successfully in a similar application and those materials have often been selected on that basis. Both percent degradation and the magnitude of the actual properties after irradiation need to be considered. Consider the scenario where two materials are being compared that both have acceptable properties after exposure to 10{sup 9} rads. It is preferable to choose the material with less degradation because degradation tends to be a threshold phenomena with properties declining rapidly with dose after a certain threshold dose. The properties of the initially strong material, therefore, will be extremely sensitive to dose in that dose range and slight magnet-to-magnet differences in dose may, depending on the application, lead to performance variations.

  5. Color superconductivity, BPS Z{sub k} strings and monopole confinement in N 2 and N = 4 super Yang-Mills theories

    Energy Technology Data Exchange (ETDEWEB)

    Kneipp, Marco A.C. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Dept. de Fisica Teorica; Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil). Coordenacao de Teoria de Campos e Particulas

    2004-12-01

    We review some recent developments on BPS string solutions and monopole confinement in the Higgs (or color) superconducting phase of N = 2 and N = 4 super Yang-Mills theories. In particular, the monopole magnetic fluxes are shown to be always integer linear combinations of string fluxes. Moreover, a bound for the threshold length of the string breaking is obtained. When the gauge group SU(N) is broken to Z{sub N}, the BPS string tension satisfies the Casimir scaling law. Furthermore, in the SU(3) case the string solutions are such that they allow the formation of a confining system with three monopoles. (author)

  6. A design of novel type superconducting magnet for super-high field functional magnetic resonance imaging by using the harmonic analysis method of magnetic vector potentials

    Institute of Scientific and Technical Information of China (English)

    俎栋林; 郭华; 宋枭禹; 包尚联

    2002-01-01

    The approach of expanding the magnetic scalar potential in a series of Legendre polynomials is suitable for designing a conventional superconducting magnetic resonance imaging magnet of distributed solenoidal configuration. Whereas the approach of expanding the magnetic vector potential in associated Legendre harmonics is suitable for designing a single-solenoid magnet that has multiple tiers, in which each tier may have multiple layers with different winding lengths. A set of three equations to suppress some of the lowest higher-order harmonics is found. As an example, a 4T single-solenoid magnetic resonance imaging magnet with 4 × 6 layers of superconducting wires is de signed The degree of homogeneity in the 0.5m diameter sphere volume is better than 5.8 ppm. The same degree of homogeneity is retained after optimal integralization of turns in each correction layer. The ratio Bm/Bo in the single-solenoid magnet is 30%lower than that in the conventional six-solenoid magnet. This tolerates higher rated superconducting current in the coil. The Lorentz force of the coil in the single-solenoid system is also much lower than in the six-solenoid system. This novel type of magnet possesses significant advantage over conventional magnets, especially when used as a super-high field functional magnetic resonance imaging magnet.

  7. Disbursement of $65 million to the State of Texas for construction of a Regional Medical Technology Center at the former Superconducting Super Collider Site, Waxahachie, Texas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    As part of a settlement agreement between the US DOE and the State of Texas, DOE proposes to transfer $65 million of federal funds to the Texas National Research Laboratory Commission (TNLRC) for construction of the Regional Medical Technology Center (RMTC) to be located in Ellis County, Texas. The RMTC would be a state-of-the-art medical facility for proton cancer therapy, operated by the State of Texas in conjunction with the University of Texas Southwestern Medical Center. The RMTC would use the linear accelerator assets of the recently terminated DOE Superconducting Super Collider Project to accelerate protons to high energies for the treatment of cancer patients. The current design provides for treatment areas, examination rooms, support laboratories, diagnostic imaging equipment, and office space as well as the accelerators (linac and synchrotron) and beam steering and shaping components. The potential environmental consequences of the proposed action are expected to be minor.

  8. Assessment of the impact of HTSCs on superconducting fault-current limiters. [High Temperature SuperConductors (HTSCs)

    Energy Technology Data Exchange (ETDEWEB)

    Giese, R.F. (Argonne National Lab., IL (United States)); Runde, M. (Energiforsyningens Forskningsinstitutt A/S, Trondheim (Norway))

    1993-01-01

    The possible impact of nitrogen-cooled superconductors on the desip and cost of superconducting fault-current limiters is assessed by considering the technical specifications such devices must meet and by comparing material properties of 77-K and 4-K superconductors. The main advantages of operating superconductors at 77 K are that the refrigeration operating cost is reduced by a factor of up to 25 and the refrigeration capital cost is reduced by a factor of up to 10. The heat capacity is several orders of magnitude Larger at 77 K and at 4 K. This phenomenon increases conductor stability against flux jumps but makes switching from the superconducting to the normal state slow and difficult. Therefore, a high critical current density, probably at least 10[sup 5] A/cm[sup 2], is required.

  9. Performance of a superconducting magnet system operated in the Super Omega Muon beam line at J-PARC

    Energy Technology Data Exchange (ETDEWEB)

    Makida, Yasuhiro; Ikedo, Yutaka; Ogitsu, Toru; Shimomura, Koichiro; Miyake, Yasuhiro; Yoshida, Makoto; Adachi, Taihei; Kadono, Ryosuke; Kawamura, Naritoshi; Strasser, Patric; Koda, Akihiro; Fujimori, Hiroshi; Nishiyama, Kusuo; Ohhata, Hirokatsu; Okamura, Takahiro; Okada, Ryutaro [J-PARC, KEK, Shirakata 203-1, Tokai, Naka, Ibaraki (Japan); Orikasa, Tomofumi [Keihin Product Operations, Toshiba, Suehiro 2-4, Tsurumi, Yokohama (Japan)

    2014-01-29

    A superconducting magnet system, which is composed of an 8 m long solenoid for transportation and 12 short solenoids for focusing, has been developed for Muon Science Establishment facility of J-PARC. The transport solenoid is composed of a 6 m straight section connected to a 45 degree curved section at each end. Muons of various momenta and of both electric charges are transported through the solenoid inner bore with an effective diameter of 0.3 m, where 2 T magnetic field is induced. There are 12 focusing solenoids with an effective bore diameter of 0.6 m and a length of 0.35 m arranged on a straight line at suitable intervals. The maximum central field of each focusing solenoid is 0.66 T. All solenoid coils are cooled by GM cryocoolers through their own conductions. The magnet system has been installed into the beam line in the summer of 2012, and its performance has been checked. Beam commissioning has been carried out since October 2012. During beam operation, temperature rise over 6 K in the transport solenoid due to a nuclear heating from the muon production target is observed at beam intensity of about 300 kW.

  10. Fingerprints of Mott Superconductivity

    Institute of Scientific and Technical Information of China (English)

    王强华

    2003-01-01

    We improve a previous theory of doped Mott insulators with duality between pairing and magnetism by a further duality transform. As the result we obtained a quantum Ginzburg-Landau theory describing the Cooper pair condensate and the dual of spin condensate. We address the superconductivity by doping a Mott insulator,which we call the Mott superconductivity. Some fingerprints of such novelty in cuprates are the scaling between neutron resonance energy and superfluid density, and the induced quantized spin moment by vortices or Zn impurity (together with circulating charge super-current to be checked by experiments).

  11. Applied superconductivity

    CERN Document Server

    Newhouse, Vernon L

    1975-01-01

    Applied Superconductivity, Volume II, is part of a two-volume series on applied superconductivity. The first volume dealt with electronic applications and radiation detection, and contains a chapter on liquid helium refrigeration. The present volume discusses magnets, electromechanical applications, accelerators, and microwave and rf devices. The book opens with a chapter on high-field superconducting magnets, covering applications and magnet design. Subsequent chapters discuss superconductive machinery such as superconductive bearings and motors; rf superconducting devices; and future prospec

  12. Superconducting transistor

    Science.gov (United States)

    Gray, Kenneth E.

    1979-01-01

    A superconducting transistor is formed by disposing three thin films of superconducting material in a planar parallel arrangement and insulating the films from each other by layers of insulating oxides to form two tunnel junctions. One junction is biased above twice the superconducting energy gap and the other is biased at less than twice the superconducting energy gap. Injection of quasiparticles into the center film by one junction provides a current gain in the second junction.

  13. Superconductivity and superconductive electronics

    Science.gov (United States)

    Beasley, M. R.

    1990-12-01

    The Stanford Center for Research on Superconductivity and Superconductive Electronics is currently focused on developing techniques for producing increasingly improved films and multilayers of the high-temperature superconductors, studying their physical properties and using these films and multilayers in device physics studies. In general the thin film synthesis work leads the way. Once a given film or multilayer structure can be made reasonably routinely, the emphasis shifts to studying the physical properties and device physics of these structures and on to the next level of film quality or multilayer complexity. The most advanced thin films synthesis work in the past year has involved developing techniques to deposit a-axis and c-axis YBCO/PBCO superlattices and related structures. The in-situ feature is desirable because no solid state reactions with accompanying changes in volume, morphology, etc., that degrade the quality of the film involved.

  14. Super Special Codes using Super Matrices

    CERN Document Server

    Kandasamy, W B Vasantha; Ilanthenral, K

    2010-01-01

    The new classes of super special codes are constructed in this book using the specially constructed super special vector spaces. These codes mainly use the super matrices. These codes can be realized as a special type of concatenated codes. This book has four chapters. In chapter one basic properties of codes and super matrices are given. A new type of super special vector space is constructed in chapter two of this book. Three new classes of super special codes namely, super special row code, super special column code and super special codes are introduced in chapter three. Applications of these codes are given in the final chapter.

  15. Superconducting Super Collider Laboratory : tunnel boring

    CERN Multimedia

    SSC Media Production

    1999-01-01

    This film will take you down into the tunnel, show you the technology involved in boring the tunnel, and show what the SSC fmeans to the U.S. in terms of scientific discovery, innovative collaborations with industry and stimulating the job base nation-wide.

  16. Super Factories

    Indian Academy of Sciences (India)

    D G Hitlin

    2006-11-01

    Heavy-flavor physics, in particular and physics results from the factories, currently provides strong constraints on models of physics beyond the Standard Model. A new generation of colliders, Super Factories, with 50 to 100 times the luminosity of existing colliders, can, in a dialog with LHC and ILC, provide unique clarification of new physics phenomena seen at those machines.

  17. Superconducting electronics

    NARCIS (Netherlands)

    Rogalla, Horst

    1994-01-01

    During the last decades superconducting electronics has been the most prominent area of research for small scale applications of superconductivity. It has experienced quite a stormy development, from individual low frequency devices to devices with high integration density and pico second switching

  18. The Super Patalan Numbers

    OpenAIRE

    Richardson, Thomas M.

    2014-01-01

    We introduce the super Patalan numbers, a generalization of the super Catalan numbers in the sense of Gessel, and prove a number of properties analagous to those of the super Catalan numbers. The super Patalan numbers generalize the super Catalan numbers similarly to how the Patalan numbers generalize the Catalan numbers.

  19. Superconducting Resonator Spectrometer for Millimeter- and Submillimeter-Wave Astrophysics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — "We propose to develop a novel ultra-compact spectrograph-on-a-chip for the submillimeter and millimeter waveband. SuperSpec uses planar lithographed superconducting...

  20. Manufacturing of superconductive silver/ceramic composites

    DEFF Research Database (Denmark)

    Seifi, Behrouz; Bech, Jakob Ilsted; Eriksen, Morten

    2000-01-01

    Manufacturing of superconducting metal/ceramic composites is a rather new discipline within materials forming processes. High Temperature SuperConductors, HTSC, are manufactured applying the Oxide-Powder-In-Tube process, OPIT. A ceramic powder containing lead, calcium, bismuth, strontium...... and current leading properties of the final superconducting fibres. The present work describes studies on alternative packing geometries and process parameters in the flat rolling operations. The aim is to obtain homogenous filaments with advantageous geometry and good texture while avoiding potential defects...

  1. Operation of a 400MHz NMR magnet using a (RE:Rare Earth)Ba2Cu3O7-x high-temperature superconducting coil: Towards an ultra-compact super-high field NMR spectrometer operated beyond 1GHz.

    Science.gov (United States)

    Yanagisawa, Y; Piao, R; Iguchi, S; Nakagome, H; Takao, T; Kominato, K; Hamada, M; Matsumoto, S; Suematsu, H; Jin, X; Takahashi, M; Yamazaki, T; Maeda, H

    2014-10-18

    High-temperature superconductors (HTS) are the key technology to achieve super-high magnetic field nuclear magnetic resonance (NMR) spectrometers with an operating frequency far beyond 1GHz (23.5T). (RE)Ba2Cu3O7-x (REBCO, RE: rare earth) conductors have an advantage over Bi2Sr2Ca2Cu3O10-x (Bi-2223) and Bi2Sr2CaCu2O8-x (Bi-2212) conductors in that they have very high tensile strengths and tolerate strong electromagnetic hoop stress, thereby having the potential to act as an ultra-compact super-high field NMR magnet. As a first step, we developed the world's first NMR magnet comprising an inner REBCO coil and outer low-temperature superconducting (LTS) coils. The magnet was successfully charged without degradation and mainly operated at 400MHz (9.39T). Technical problems for the NMR magnet due to screening current in the REBCO coil were clarified and solved as follows: (i) A remarkable temporal drift of the central magnetic field was suppressed by a current sweep reversal method utilizing ∼10% of the peak current. (ii) A Z2 field error harmonic of the main coil cannot be compensated by an outer correction coil and therefore an additional ferromagnetic shim was used. (iii) Large tesseral harmonics emerged that could not be corrected by cryoshim coils. Due to those harmonics, the resolution and sensitivity of NMR spectra are ten-fold lower than those for a conventional LTS NMR magnet. As a result, a HSQC spectrum could be achieved for a protein sample, while a NOESY spectrum could not be obtained. An ultra-compact 1.2GHz NMR magnet could be realized if we effectively take advantage of REBCO conductors, although this will require further research to suppress the effect of the screening current.

  2. Superconducting Microelectronics.

    Science.gov (United States)

    Henry, Richard W.

    1984-01-01

    Discusses superconducting microelectronics based on the Josephson effect and its advantages over conventional integrated circuits in speed and sensitivity. Considers present uses in standards laboratories (voltage) and in measuring weak magnetic fields. Also considers future applications in superfast computer circuitry using Superconducting…

  3. Computer protection plan for the Superconducing Super Collider Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Hunter, S.

    1992-04-15

    The purpose of this document is to describe the current unclassified computer security program practices, Policies and procedures for the Superconducting Super Collider Laboratory (SSCL). This document includes or references all related policies and procedures currently implemented throughout the SSCL. The document includes security practices which are planned when the facility is fully operational.

  4. Color superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Wilczek, F. [Institute for Advanced Study, Princeton, NJ (United States)

    1997-09-22

    The asymptotic freedom of QCD suggests that at high density - where one forms a Fermi surface at very high momenta - weak coupling methods apply. These methods suggest that chiral symmetry is restored and that an instability toward color triplet condensation (color superconductivity) sets in. Here I attempt, using variational methods, to estimate these effects more precisely. Highlights include demonstration of a negative pressure in the uniform density chiral broken phase for any non-zero condensation, which we take as evidence for the philosophy of the MIT bag model; and demonstration that the color gap is substantial - several tens of MeV - even at modest densities. Since the superconductivity is in a pseudoscalar channel, parity is spontaneously broken.

  5. SUPERCONDUCTING PHOTOCATHODES.

    Energy Technology Data Exchange (ETDEWEB)

    SMEDLEY, J.; RAO, T.; WARREN, J.; SEKUTOWICZ, LANGNER, J.; STRZYZEWSKI, P.; LEFFERS, R.; LIPSKI, A.

    2005-10-09

    We present the results of our investigation of lead and niobium as suitable photocathode materials for superconducting RF injectors. Quantum efficiencies (QE) have been measured for a range of incident photon energies and a variety of cathode preparation methods, including various lead plating techniques on a niobium substrate. The effects of operating at ambient and cryogenic temperatures and different vacuum levels on the cathode QE have also been studied.

  6. Measurement of the magnetically-induced QED birefringence of the vacuum and an improved search for laboratory axions: Technical report. Project definition study of the use of assets and facilities of the Superconducting Super Collider Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S.A.; Fairbank, W.M. Jr.; Toki, W.H. [Colorado State Univ., Fort Collins, CO (United States). Dept. of Physics; Hall, J.L. [Univ. of Colorado, Boulder, CO (United States). Joint Inst. for Lab. Astrophysics]|[National Inst. of Standards and Technology, Boulder, CO (United States); Kraushaar, P.F. Jr.; Jaffery, T.S. [Superconducting Super Collider Lab., Waxahachie, TX (United States)

    1994-10-31

    The Colorado State Collaboration has studied the feasibility of a high sensitivity QED birefringence/axion search measurement. The objective of this work is to measure, for the first time, the birefringence induced in the vacuum on a light beam travelling in a powerful magnetic field. The same experimental setup also allows a highly sensitive search for axion or axion-like particles. The experiment would combined custom-designed optical heterodyne interferometry with a string of six SSC prototype superconducting dipole magnets at the N-15 site of the SSC Laboratory. With these powerful laser tools, sensitivity advances of 10{sup 7} to 10{sup 9} over previous optical experiments will be possible. The proposed experiment will be able to measure the QED light-by-light scattering effect with a 0.5% accuracy. The increased sensitivity for the axion-two photon interaction will result in a bound on this process rivaling the results based on astrophysical arguments. In the technical report the authors address the scientific significance of these experiments and examine the limiting technical parameters which control their feasibility. The proposed optical/electronic scheme is presented in the context of a background of the known and projected systematic problems which will confront any serious attempt to make such measurements.

  7. SuperTools Test and Evaluation Plan

    Energy Technology Data Exchange (ETDEWEB)

    Mannos, Tom J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Mixed Signal ASIC Design

    2017-01-01

    Superconducting electronics (SCE) represents a potential path to efficient exascale computing for HPC and data center applications, but SCE-based circuit design lags far behind its CMOS equivalent. IARPA’s ongoing C3 program and its developing SuperTools program aim to jumpstart SCE R&D with the near-term goal of producing a high-speed, low-energy, 64-bit RISC processor using Josephson Junction based logic cells. SuperTools performers will develop software tools for efficient SCE design and accurate simulation and characterization of JJ-based circuits, which include the RSFQ, RQL, and AQFP logic families. T&E teams from NIST, MIT Lincoln Lab, Berkeley Lab, and Sandia National Labs will evaluate the tools and fabricate test circuits to compare with simulated results. The five-year, three-phase program includes 48 performer deliverables, three annual technical exchange meetings, and annual site visits.

  8. Super/subradiant second harmonic generation

    Science.gov (United States)

    Koganov, Gennady A.; Shuker, Reuben

    2017-04-01

    A scheme for active second harmonics generation is suggested. The system comprises N three-level atoms in ladder configuration, situated into a resonant cavity. The system generates the field whose frequency is twice the frequency of the pumping laser, and the field phase is locked to the phase of the pumping field. It is found that the system can lase in either superradiant or subradiant regime, depending on the number of atoms N. When N passes some critical value the transition from the super to subradiance occurs in a phase-transition-like manner. Stability study of the steady state supports this conclusion. For experimental realization of the super/subradiant second harmonics generation we propose semiconductor quantum well structures, superconducting quantum circuits, and evanescently coupled waveguides in which equally spaced levels relevant to this study exist.

  9. Itinerant Ferromagnetism and Superconductivity

    OpenAIRE

    Karchev, Naoum

    2004-01-01

    Superconductivity has again become a challenge following the discovery of unconventional superconductivity. Resistance-free currents have been observed in heavy-fermion materials, organic conductors and copper oxides. The discovery of superconductivity in a single crystal of $UGe_2$, $ZrZn_2$ and $URhGe$ revived the interest in the coexistence of superconductivity and ferromagnetism. The experiments indicate that: i)The superconductivity is confined to the ferromagnetic phase. ii)The ferromag...

  10. 100 years of superconductivity

    CERN Document Server

    Rogalla, Horst

    2011-01-01

    Even a hundred years after its discovery, superconductivity continues to bring us new surprises, from superconducting magnets used in MRI to quantum detectors in electronics. 100 Years of Superconductivity presents a comprehensive collection of topics on nearly all the subdisciplines of superconductivity. Tracing the historical developments in superconductivity, the book includes contributions from many pioneers who are responsible for important steps forward in the field.The text first discusses interesting stories of the discovery and gradual progress of theory and experimentation. Emphasizi

  11. Calculus super review

    CERN Document Server

    2012-01-01

    Get all you need to know with Super Reviews! Each Super Review is packed with in-depth, student-friendly topic reviews that fully explain everything about the subject. The Calculus I Super Review includes a review of functions, limits, basic derivatives, the definite integral, combinations, and permutations. Take the Super Review quizzes to see how much you've learned - and where you need more study. Makes an excellent study aid and textbook companion. Great for self-study!DETAILS- From cover to cover, each in-depth topic review is easy-to-follow and easy-to-grasp - Perfect when preparing for

  12. Algebra & trigonometry super review

    CERN Document Server

    2012-01-01

    Get all you need to know with Super Reviews! Each Super Review is packed with in-depth, student-friendly topic reviews that fully explain everything about the subject. The Algebra and Trigonometry Super Review includes sets and set operations, number systems and fundamental algebraic laws and operations, exponents and radicals, polynomials and rational expressions, equations, linear equations and systems of linear equations, inequalities, relations and functions, quadratic equations, equations of higher order, ratios, proportions, and variations. Take the Super Review quizzes to see how much y

  13. High field superconducting magnets

    Science.gov (United States)

    Hait, Thomas P. (Inventor); Shirron, Peter J. (Inventor)

    2011-01-01

    A superconducting magnet includes an insulating layer disposed about the surface of a mandrel; a superconducting wire wound in adjacent turns about the mandrel to form the superconducting magnet, wherein the superconducting wire is in thermal communication with the mandrel, and the superconducting magnet has a field-to-current ratio equal to or greater than 1.1 Tesla per Ampere; a thermally conductive potting material configured to fill interstices between the adjacent turns, wherein the thermally conductive potting material and the superconducting wire provide a path for dissipation of heat; and a voltage limiting device disposed across each end of the superconducting wire, wherein the voltage limiting device is configured to prevent a voltage excursion across the superconducting wire during quench of the superconducting magnet.

  14. Theory of superconductivity

    CERN Document Server

    Crisan, Mircea

    1989-01-01

    This book discusses the most important aspects of the theory. The phenomenological model is followed by the microscopic theory of superconductivity, in which modern formalism of the many-body theory is used to treat most important problems such as superconducting alloys, coexistence of superconductivity with the magnetic order, and superconductivity in quasi-one-dimensional systems. It concludes with a discussion on models for exotic and high temperature superconductivity. Its main aim is to review, as complete as possible, the theory of superconductivity from classical models and methods up t

  15. A New Interaction Region Design for the Super-B Factory

    Energy Technology Data Exchange (ETDEWEB)

    Sullivan, Michael; /SLAC; Bertsche, Kirk; /SLAC; Bettoni, Simona; /CERN; Paoloni, Eugenio; /INFN, Pisa; Raimondi, Pantaleo; /INFN, Rome; Vobly, Pavel; /Novosibirsk, IYF

    2012-07-06

    A final focus magnet design that uses super-ferric magnets is introduced for the SuperB interaction region. The baseline design has air-core super-conducting quadrupoles. This idea instead uses super-conducting wire in an iron yoke. The iron is in the shape of a Panofsky quadrupole and this allows two quadrupoles to be side-by-side with no intervening iron as long as the gradients of the two quads are equal. This feature allows us to move in as close as possible to the collision point and minimize the beta functions in the interaction region. The superferric design has advantages as well as drawbacks and we will discuss these in the paper.

  16. A New Interaction Region Design for the Super-B Factory

    CERN Document Server

    Sullivan, Michael; Bettoni, Simona; Paoloni, Eugenio; Raimondi, Pantaleo; Vobly, Pavel

    2010-01-01

    A final focus magnet design that uses super-ferric magnets is introduced for the SuperB interaction region. The baseline design has air-core super-conducting quadrupoles. This idea instead uses super-conducting wire in an iron yoke. The iron is in the shape of a Panofsky quadrupole and this allows two quadrupoles to be sideby- side with no intervening iron as long as the gradients of the two quads are equal. This feature allows us to move in as close as possible to the collision point and minimize the beta functions in the interaction region. The superferric design has advantages as well as drawbacks and we will discuss these in the pape

  17. Cryogenic distribution for radioactive secondary beam fragment separator (Super-FRS) of FAIR

    CERN Document Server

    Xiang, Y; Kauschke, M; Moritz, G; Quack, H

    2009-01-01

    We present the flow schemes for the superconducting dipoles, the superconducting multiplets (quadrupoles, hexapoles, octupoles and steering dipoles) and the corresponding feedboxes of the Super-FRS in the FAIR project. The system layout of the helium distribution for the whole separator including the three branches of the Super-FRS and the experiment caves is discussed as well. Based on the maximum cooling capacity specified for the refrigerator, the cold-down time of the multiplets which are characteristic of large cold mass (up to 37 Tons for each) has been investigated. The issues as operation conditions, quench protection and safety relief are also discussed.

  18. Super Tomboy Style

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Sparked by Super Girl, the androgynous look is in among Chinese youth On September 8, this year's top six contestants on the Super Girl television show, a singing contest for young women, stepped into the spotlight. Nearly none of them had long black hair or wore evening gowns, traditionally associated with beauty in China. Rather, they

  19. Simulations of Noise in Phase-Separated Transition-Edge Sensors for SuperCDMS

    CERN Document Server

    Anderson, A J; Pyle, M; Figueroa-Feliciano, E; McCarthy, K; Doughty, T; Cherry, M; Young, B

    2011-01-01

    We briefly review a simple model of superconducting-normal phase-separation in transition-edge sensors in the SuperCDMS experiment. After discussing some design considerations relevant to the TES in the detectors, we study noise sources in both the phase-separated and phase-uniform cases. Such simulations are valuable for optimizing the critical temperature and TES length of future SuperCDMS detectors.

  20. Transmission Level High Temperature Superconducting Fault Current Limiter

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Gary [SuperPower, Inc., Schenectady, NY (United States)

    2016-10-05

    The primary objective of this project was to demonstrate the feasibility and reliability of utilizing high temperature superconducting (HTS) materials in a Transmission Level Superconducting Fault Current Limiter (SFCL) application. During the project, the type of high temperature superconducting material used evolved from 1st generation (1G) BSCCO-2212 melt cast bulk high temperature superconductors to 2nd generation (2G) YBCO based high temperature superconducting tape. The SFCL employed SuperPower's “Matrix” technology that offers modular features to enable scale up to transmission voltage levels. The SFCL consists of individual modules that contain elements and parallel inductors that assist in carrying the current during the fault. A number of these modules are arranged in an m x n array to form the current limiting matrix.

  1. Transmission Level High Temperature Superconducting Fault Current Limiter

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, Gary [SuperPower, Inc., Schenectady, NY (United States)

    2016-10-05

    The primary objective of this project was to demonstrate the feasibility and reliability of utilizing high-temperature superconducting (HTS) materials in a Transmission Level Superconducting Fault Current Limiter (SFCL) application. During the project, the type of high-temperature superconducting material used evolved from 1st generation (1G) BSCCO-2212 melt cast bulk high-temperature superconductors to 2nd generation (2G) YBCO-based high-temperature superconducting tape. The SFCL employed SuperPower's “Matrix” technology, that offers modular features to enable scale up to transmission voltage levels. The SFCL consists of individual modules that contain elements and parallel inductors that assist in carrying the current during the fault. A number of these modules are arranged in an m x n array to form the current-limiting matrix.

  2. Simple Superconducting "Permanent" Electromagnet

    Science.gov (United States)

    Israelson, Ulf E.; Strayer, Donald M.

    1992-01-01

    Proposed short tube of high-temperature-superconducting material like YBa2Cu3O7 acts as strong electromagnet that flows as long as magnetic field remains below critical value and temperature of cylinder maintained sufficiently below superconducting-transition temperature. Design exploits maximally anisotropy of high-temperature-superconducting material.

  3. Basic principle of superconductivity

    OpenAIRE

    De Cao, Tian

    2007-01-01

    The basic principle of superconductivity is suggested in this paper. There have been two vital wrong suggestions on the basic principle, one is the relation between superconductivity and the Bose-Einstein condensation (BEC), and another is the relation between superconductivity and pseudogap.

  4. Nonlinear Super Integrable Couplings of Super Classical-Boussinesq Hierarchy

    Directory of Open Access Journals (Sweden)

    Xiuzhi Xing

    2014-01-01

    Full Text Available Nonlinear integrable couplings of super classical-Boussinesq hierarchy based upon an enlarged matrix Lie super algebra were constructed. Then, its super Hamiltonian structures were established by using super trace identity. As its reduction, nonlinear integrable couplings of the classical integrable hierarchy were obtained.

  5. Super-FRS Target Area Remote Handling: Scenario and Development

    Directory of Open Access Journals (Sweden)

    Luis Miguel Orona

    2013-11-01

    Full Text Available The Super-FRS, Superconducting Fragment Separator, is a unique machine that presents several challenging technical problems. One of these is regarding how to conduct maintenance in the target area where high levels of radiation will be generated and human access is forbidden. To address this problem the use of a remote maintenance system is foreseen. The objective of this paper is to develop a systems engineering (SE research and development (R&D approach suitable to develop the Super-FRS Target Area Remote Maintenance Systems (TARMS and the RH design adaptation of the components in the target area. The Super-FRS target area is described in detail in order to introduce the need for a remote maintenance system. Components in the target area are classified by adopting ITER RH maintenance classification. The general scenario of remote handling and the current target area remote maintenance system are described. Finally, the proposed systems engineering approach is presented.

  6. Super-resolution

    DEFF Research Database (Denmark)

    Nasrollahi, Kamal; Moeslund, Thomas B.

    2014-01-01

    Super-resolution, the process of obtaining one or more high-resolution images from one or more low-resolution observations, has been a very attractive research topic over the last two decades. It has found practical applications in many real world problems in different fields, from satellite...... the contributions of different authors to the basic concepts of each group. Furthermore, common issues in super-resolution algorithms, such as imaging models and registration algorithms, optimization of the cost functions employed, dealing with color information, improvement factors, assessment of super...

  7. Superconductivity in Medicine

    Science.gov (United States)

    Alonso, Jose R.; Antaya, Timothy A.

    2012-01-01

    Superconductivity is playing an increasingly important role in advanced medical technologies. Compact superconducting cyclotrons are emerging as powerful tools for external beam therapy with protons and carbon ions, and offer advantages of cost and size reduction in isotope production as well. Superconducting magnets in isocentric gantries reduce their size and weight to practical proportions. In diagnostic imaging, superconducting magnets have been crucial for the successful clinical implementation of magnetic resonance imaging. This article introduces each of those areas and describes the role which superconductivity is playing in them.

  8. Enhanced superconductivity of fullerenes

    Energy Technology Data Exchange (ETDEWEB)

    Washington, II, Aaron L.; Teprovich, Joseph A.; Zidan, Ragaiy

    2017-06-20

    Methods for enhancing characteristics of superconductive fullerenes and devices incorporating the fullerenes are disclosed. Enhancements can include increase in the critical transition temperature at a constant magnetic field; the existence of a superconducting hysteresis over a changing magnetic field; a decrease in the stabilizing magnetic field required for the onset of superconductivity; and/or an increase in the stability of superconductivity over a large magnetic field. The enhancements can be brought about by transmitting electromagnetic radiation to the superconductive fullerene such that the electromagnetic radiation impinges on the fullerene with an energy that is greater than the band gap of the fullerene.

  9. Superconducting microfabricated ion traps

    CERN Document Server

    Wang, Shannon X; Labaziewicz, Jaroslaw; Dauler, Eric; Berggren, Karl; Chuang, Isaac L

    2010-01-01

    We fabricate superconducting ion traps with niobium and niobium nitride and trap single 88Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the resistance and critical current using a 4-wire measurement on the trap structure, and observing change in the rf reflection. The lowest observed heating rate is 2.1(3) quanta/sec at 800 kHz at 6 K and shows no significant change across the superconducting transition, suggesting that anomalous heating is primarily caused by noise sources on the surface. This demonstration of superconducting ion traps opens up possibilities for integrating trapped ions and molecular ions with superconducting devices.

  10. Superconducting material development

    Science.gov (United States)

    1987-09-01

    A superconducting compound was developed that showed a transition to a zero-resistance state at 65 C, or 338 K. The superconducting material, which is an oxide based on strontium, barium, yttrium, and copper, continued in the zero-resistance state similar to superconductivity for 10 days at room temperature in the air. It was also noted that measurements of the material allowed it to observe a nonlinear characteristic curve between current and voltage at 65 C, which is another indication of superconductivity. The research results of the laboratory experiment with the superconducting material will be published in the August edition of the Japanese Journal of Applied Physics.

  11. Protective link for superconducting coil

    Science.gov (United States)

    Umans, Stephen D.

    2009-12-08

    A superconducting coil system includes a superconducting coil and a protective link of superconducting material coupled to the superconducting coil. A rotating machine includes first and second coils and a protective link of superconducting material. The second coil is operable to rotate with respect to the first coil. One of the first and second coils is a superconducting coil. The protective link is coupled to the superconducting coil.

  12. Time Transient Effects in Superconducting Magnets

    CERN Document Server

    AUTHOR|(CDS)2051280; Russenschuck, Stephan; Palumbo, Luigi

    2004-01-01

    The subject of this thesis is the study of time transient effects in super- conducting cables, with applications to accelerator magnets, and the development of a simulation code. The superconducting cables are modeled at the strand level as a lumped resistor, inductor generator circuit. The analysis in time domain of the circuit currents discloses the transient effects. The code developed can solve Rutherford type cable of any size, shape geometry under any exciting external field. The code has been implemented in Roxie where it is used to compute ramp dependent field error and heat losses.

  13. Manufacturing of superconductive silver/ceramic composites

    DEFF Research Database (Denmark)

    Seifi, Behrouz; Bech, Jakob Ilsted; Eriksen, Morten

    2000-01-01

    Manufacturing of superconducting metal/ceramic composites is a rather new discipline within materials forming processes. High Temperature SuperConductors, HTSC, are manufactured applying the Oxide-Powder-In-Tube process, OPIT. A ceramic powder containing lead, calcium, bismuth, strontium......, and copper oxides is inserted into a silver tube and reduced by multi-step drawing. These single-filaments are packed in a new silver tube thus forming a multi-filament containing e.g. 37 single-filaments, which is subsequently reduced by drawing and rolling to tapes approximately 0.2 mm thick by 3 mm wide...

  14. Superconductivity in transition metals.

    Science.gov (United States)

    Slocombe, Daniel R; Kuznetsov, Vladimir L; Grochala, Wojciech; Williams, Robert J P; Edwards, Peter P

    2015-03-13

    A qualitative account of the occurrence and magnitude of superconductivity in the transition metals is presented, with a primary emphasis on elements of the first row. Correlations of the important parameters of the Bardeen-Cooper-Schrieffer theory of superconductivity are highlighted with respect to the number of d-shell electrons per atom of the transition elements. The relation between the systematics of superconductivity in the transition metals and the periodic table high-lights the importance of short-range or chemical bonding on the remarkable natural phenomenon of superconductivity in the chemical elements. A relationship between superconductivity and lattice instability appears naturally as a balance and competition between localized covalent bonding and so-called broken covalency, which favours d-electron delocalization and superconductivity. In this manner, the systematics of superconductivity and various other physical properties of the transition elements are related and unified.

  15. NETL Super Computer

    Data.gov (United States)

    Federal Laboratory Consortium — The NETL Super Computer was designed for performing engineering calculations that apply to fossil energy research. It is one of the world’s larger supercomputers,...

  16. Super-resolution

    DEFF Research Database (Denmark)

    Nasrollahi, Kamal; Moeslund, Thomas B.

    2014-01-01

    and aerial imaging to medical image processing, to facial image analysis, text image analysis, sign and number plates reading, and biometrics recognition, to name a few. This has resulted in many research papers, each developing a new super-resolution algorithm for a specific purpose. The current......Super-resolution, the process of obtaining one or more high-resolution images from one or more low-resolution observations, has been a very attractive research topic over the last two decades. It has found practical applications in many real world problems in different fields, from satellite...... the contributions of different authors to the basic concepts of each group. Furthermore, common issues in super-resolution algorithms, such as imaging models and registration algorithms, optimization of the cost functions employed, dealing with color information, improvement factors, assessment of super...

  17. Super-Kamiokande

    Science.gov (United States)

    Magro, Lluís Martí

    2016-06-01

    The Super-Kamiokande experiment performs a large variety of studies, many of them in the neutrino sector. The archetypes are atmospheric neutrino (recently awarded with the Nobel prize for Mr. T. Kajita) and the solar neutrinos analyses. In these proceedings we report our latest results and present updates to indirect dark matter searches, our solar neutrino analysis and discuss the future upgrade of Super-Kamiokande by loading gadolinium into our ultra-pure water.

  18. The Super Girl Effect

    Institute of Scientific and Technical Information of China (English)

    WANG PEI

    2006-01-01

    @@ In recent years, Changsha,the capital city of Hunan Province, has become famous across China for its innovative TV channel, in particular the cultural phenomenon of the Super Girl talent show. And as far as culture goes, Hunan TV is merely a reflection of a renaissance happening in the city. Animation, music halls, drama festivals and a famous book market are just some of the city's cultural sectors that are benefiting from the fame and notoriety of the Super Girl show.

  19. The formation of super-rings

    CERN Document Server

    Tenorio-Tagle, G

    1980-01-01

    The author has calculated the collision of a small neutral cloud (surface density approximately 10/sup 19/ cm/sup -2/) with a constant density galactic disk. Through the collision, a large amount of energy is deposited in a small volume of the galaxy, resulting in a supersonic expansion of very hot (10/sup 6/-10/sup 7/K) gas into the Galaxy and out of the galactic disk. The expansion generates a large cavity (a super-ring) with physical characteristics (diameter, velocity of expansion, etc.) in agreement with the observations, and a large volume of hot low-density gas with properties similar to those of the observed coronal gas. (31 refs).

  20. Nonlinear Super Integrable Couplings of Super Dirac Hierarchy and Its Super Hamiltonian Structures

    Institute of Scientific and Technical Information of China (English)

    尤福财

    2012-01-01

    We construct nonlinear super integrable couplings of the super integrable Dirac hierarchy based on an enlarged matrix Lie superalgebra. Then its super Hamiltonian structure is furnished by super trace identity. As its reduction, we gain the nonlinear integrable couplings of the classical integrable Dirac hierarchy.

  1. Deforming super Riemann surfaces with gravitinos and super Schottky groups

    Energy Technology Data Exchange (ETDEWEB)

    Playle, Sam [Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino,Via P. Giuria 1, I-10125 Torino (Italy)

    2016-12-12

    The (super) Schottky uniformization of compact (super) Riemann surfaces is briefly reviewed. Deformations of super Riemann surface by gravitinos and Beltrami parameters are recast in terms of super Schottky group cohomology. It is checked that the super Schottky group formula for the period matrix of a non-split surface matches its expression in terms of a gravitino and Beltrami parameter on a split surface. The relationship between (super) Schottky groups and the construction of surfaces by gluing pairs of punctures is discussed in an appendix.

  2. Workshop on Calorimetery for the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, G.T.; /Fermilab

    1989-03-19

    The international workshop brought together 170 participants to further develop the SSC design and performance specifications of the LAr, Gas, Scintillation, Silicon, and Warm Liquid calorimeter technologies, and to develop the general topics of Requirements, Simulation, and Electronics. Progress was made across a broad front in all areas; at the feasibility level for some and In the fine structure for others. The meeting established areas of agreement, provided some general direction, and helped to quantify some differences at widely varying levels of detector technology development. The workshop helped to level the different understandings of the participants; increased the depth of the generalists and the breadth of the specialists. A high degree of group partitioning limited access to the detailed discussion within some detector groups. The communication was clearly necessary and rewarding, and seemed to meet or exceed the expectations of most participants. This report will deal with: the Liquid Argon detector and, to a lesser extent, the Requirements working groups, an update on uranIum material logistics, and a view of LAr calorimetry by others.

  3. Strain energy minimization in SSC (Superconducting Super Collider) magnet winding

    Energy Technology Data Exchange (ETDEWEB)

    Cook, J.M.

    1990-09-24

    Differential geometry provides a natural family of coordinate systems, the Frenet frame, in which to specify the geometric properties of magnet winding. By a modification of the Euler-Bernoulli thin rod model, the strain energy is defined with respect to this frame. Then it is minimized by a direct method from the calculus of variations. The mathematics, its implementation in a computer program, and some analysis of an SSC dipole by the program will be described. 16 refs.

  4. Elementary particle physics and the superconducting super collider.

    Science.gov (United States)

    Quigg, C; Schwitters, R F

    1986-03-28

    The present status and future prospects of elementary particle physics are reviewed, and some of the scientific questions that motivate the construction of a major new accelerator complex in the United States are summarized.

  5. Frontiers in Superconducting Materials

    CERN Document Server

    Narlikar, Anant V

    2005-01-01

    Frontiers in Superconducting Materials gives a state-of-the-art report of the most important topics of the current research in superconductive materials and related phenomena. It comprises 30 chapters written by renowned international experts in the field. It is of central interest to researchers and specialists in Physics and Materials Science, both in academic and industrial research, as well as advanced students. It also addresses electronic and electrical engineers. Even non-specialists interested in superconductivity might find some useful answers.

  6. Superconducting energy recovery linacs

    Science.gov (United States)

    Ben-Zvi, Ilan

    2016-10-01

    High-average-power and high-brightness electron beams from a combination of laser photocathode electron guns and a superconducting energy recovery linac (ERL) is an emerging accelerator science with applications in ERL light sources, high repetition rate free electron lasers , electron cooling, electron ion colliders and more. This paper reviews the accelerator physics issues of superconducting ERLs, discusses major subsystems and provides a few examples of superconducting ERLs.

  7. High-Temperature Superconductivity

    Science.gov (United States)

    Tanaka, Shoji

    2006-12-01

    A general review on high-temperature superconductivity was made. After prehistoric view and the process of discovery were stated, the special features of high-temperature superconductors were explained from the materials side and the physical properties side. The present status on applications of high-temperature superconductors were explained on superconducting tapes, electric power cables, magnets for maglev trains, electric motors, superconducting quantum interference device (SQUID) and single flux quantum (SFQ) devices and circuits.

  8. Fundamentals of Superconducting Nanoelectronics

    CERN Document Server

    Sidorenko, Anatolie

    2011-01-01

    This book demonstrates how the new phenomena in superconductivity on the nanometer scale (FFLO state, triplet superconductivity, Crossed Andreev Reflection, synchronized generation etc.) serve as the basis for the invention and development of novel nanoelectronic devices and systems. It demonstrates how rather complex ideas and theoretical models, like odd-pairing, non-uniform superconducting state, pi-shift etc., adequately describe the processes in real superconducting nanostructues and novel devices based on them. The book is useful for a broad audience of readers, researchers, engineers, P

  9. Superconductive imaging surface magnetometer

    Science.gov (United States)

    Overton, Jr., William C.; van Hulsteyn, David B.; Flynn, Edward R.

    1991-01-01

    An improved pick-up coil system for use with Superconducting Quantum Interference Device gradiometers and magnetometers involving the use of superconducting plates near conventional pick-up coil arrangements to provide imaging of nearby dipole sources and to deflect environmental magnetic noise away from the pick-up coils. This allows the practice of gradiometry and magnetometry in magnetically unshielded environments. One embodiment uses a hemispherically shaped superconducting plate with interior pick-up coils, allowing brain wave measurements to be made on human patients. another embodiment using flat superconducting plates could be used in non-destructive evaluation of materials.

  10. Superconducting optical modulator

    Science.gov (United States)

    Bunt, Patricia S.; Ference, Thomas G.; Puzey, Kenneth A.; Tanner, David B.; Tache, Nacira; Varhue, Walter J.

    2000-12-01

    An optical modulator based on the physical properties of high temperature superconductors has been fabricated and tested. The modulator was constructed form a film of Yttrium Barium Copper Oxide (YBCO) grown on undoped silicon with a buffer layer of Yttria Stabilized Zirconia. Standard lithographic procedures were used to pattern the superconducting film into a micro bridge. Optical modulation was achieved by passing IR light through the composite structure normal to the micro bridge and switching the superconducting film in the bridge region between the superconducting and non-superconducting states. In the superconducting state, IR light reflects from the superconducting film surface. When a critical current is passed through the micro bridge, it causes the film in this region to switch to the non-superconducting state allowing IR light to pass through it. Superconducting materials have the potential to switch between these two states at speeds up to 1 picosecond using electrical current. Presently, fiber optic transmission capacity is limited by the rate at which optical data can be modulated. The superconducting modulator, when combined with other components, may have the potential to increase the transmission capacity of fiber optic lines.

  11. Basic Study of Superconductive Actuator

    OpenAIRE

    涌井, 和也; 荻原, 宏康

    2000-01-01

    There are two kinds of electromagnetic propulsion ships : a superconductive electromagnetic propulsion ship and a superconductive electricity propulsion ship. A superconductive electromagnetic propulsion ship uses the electromagnetic force (Lorenz force) by the interaction between a magnetic field and a electric current. On the other hand, a superconductive electricity propulsion ship uses screws driven by a superconductive motor. A superconductive propulsion ship technique has the merits of ...

  12. Raspberry Pi super cluster

    CERN Document Server

    Dennis, Andrew K

    2013-01-01

    This book follows a step-by-step, tutorial-based approach which will teach you how to develop your own super cluster using Raspberry Pi computers quickly and efficiently.Raspberry Pi Super Cluster is an introductory guide for those interested in experimenting with parallel computing at home. Aimed at Raspberry Pi enthusiasts, this book is a primer for getting your first cluster up and running.Basic knowledge of C or Java would be helpful but no prior knowledge of parallel computing is necessary.

  13. SuperQuant

    DEFF Research Database (Denmark)

    Gorshkov, Vladimir; Verano-Braga, Thiago; Kjeldsen, Frank

    2015-01-01

    SuperQuant is a quantitative proteomics data processing approach that uses complementary fragment ions to identify multiple co-isolated peptides in tandem mass spectra allowing for their quantification. This approach can be applied to any shotgun proteomics data set acquired with high mass accura...... of the same proteins were close to the values typical for other precursor ion-based quantification methods. The raw data is deposited to ProteomeXchange (PXD001907). The developed node is available for testing at https://github.com/caetera/SuperQuantNode....

  14. Graphene: Carbon's superconducting footprint

    Science.gov (United States)

    Vafek, Oskar

    2012-02-01

    Graphene exhibits many extraordinary properties, but superconductivity isn't one of them. Two theoretical studies suggest that by decorating the surface of graphene with the right species of dopant atoms, or by using ionic liquid gating, superconductivity could yet be induced.

  15. Superconducting cavities for LEP

    CERN Multimedia

    1983-01-01

    Above: a 350 MHz superconducting accelerating cavity in niobium of the type envisaged for accelerating electrons and positrons in later phases of LEP. Below: a small 1 GHz cavity used for investigating the surface problems of superconducting niobium. Albert Insomby stays on the right. See Annual Report 1983 p. 51.

  16. Academic training: Applied superconductivity

    CERN Multimedia

    2007-01-01

    LECTURE SERIES 17, 18, 19 January from 11.00 to 12.00 hrs Council Room, Bldg 503 Applied Superconductivity : Theory, superconducting Materials and applications E. PALMIERI/INFN, Padova, Italy When hearing about persistent currents recirculating for several years in a superconducting loop without any appreciable decay, one realizes that we are dealing with a phenomenon which in nature is the closest known to the perpetual motion. Zero resistivity and perfect diamagnetism in Mercury at 4.2 K, the breakthrough during 75 years of several hundreds of superconducting materials, the revolution of the "liquid Nitrogen superconductivity"; the discovery of still a binary compound becoming superconducting at 40 K and the subsequent re-exploration of the already known superconducting materials: Nature discloses drop by drop its intimate secrets and nobody can exclude that the last final surprise must still come. After an overview of phenomenology and basic theory of superconductivity, the lectures for this a...

  17. "Super Roman Pots"

    CERN Multimedia

    CERN PhotoLab

    1975-01-01

    Remotely controlled re-entrant vacuum vessels, with very thin (0.17 mm) central windows, that will be installed in each downstream arm of intersection I-8. Detectors for a coming physics experiment, placed inside these "Super Roman Pots", can be moved very close to the circulating ISR beams.

  18. A Super Roman Pot

    CERN Multimedia

    1975-01-01

    Remotely controlled re-entrant vacuum vessels, with very thin (0.17 mm) central windows, that were installed in each downstream arm of the ISR intersection I-8. Detectors placed inside these Super Roman Pots could be moved very close to the circulating ISR beams. (See Annual Report 1974 p. 110.)

  19. Superconductivity in carbon nanomaterials

    Science.gov (United States)

    Dlugon, Katarzyna

    The purpose of this thesis is to explain the phenomenon of superconductivity in carbon nanomaterials such as graphene, fullerenes and carbon nanotubes. In the introductory chapter, there is a description of superconductivity and how it occurs at critical temperature (Tc) that is characteristic and different to every superconducting material. The discovery of superconductivity in mercury in 1911 by Dutch physicist Heike Kamerlingh Onnes is also mentioned. Different types of superconductors, type I and type II, low and high temperatures superconductors, as well as the BCS theory that was developed in 1957 by Bardeen, Cooper, and Schrieffer, are also described in detail. The BCS theory explains how Cooper's pairs are formed and how they are responsible for the superconducting properties of many materials. The following chapters explain superconductivity in doped fullerenes, graphene and carbon nanotubes, respectively. There is a thorough explanation followed by many examples of different types of carbon nanomaterials in which small changes in chemical structure cause significant changes in superconducting properties. The goal of this research was not only to take into consideration well known carbon based superconductors but also to search for the newest available materials such as the fullerene nanowhiskers discovered quite recently. There is also a presentation of fairly new ideas about inducing superconductivity in a monolayer of graphene which is more challenging than inducing superconductivity in graphite by simply intercalating metal atoms between its graphene sheets. An effort has been taken to look for any available information about carbon nanomaterials that have the potential to superconduct at room temperature, mainly because discovery of such materials would be a real revolution in the modern world, although no such materials have been discovered yet.

  20. In-situ spectroscopic studies and interfacial engineering on FeSe/oxide heterostructures:Insights on the interfacial superconductivity

    Institute of Scientific and Technical Information of China (English)

    彭瑞; 徐海超; 封东来

    2015-01-01

    The discovery of high temperature superconductivity in single-layer FeSe/SrTiO3 provides a new platform for ex-ploring superconductivity and pursuing higher Tc (superconducting transition temperature) through fabricating artificial heterostructures. In this paper, we review the recent progress in studying and tuning the interfacial superconductivity in single-layer FeSe, through the combined in-situ spectroscopic studies and atomic-scale engineering. By fabricating arti-ficial heterostructures, various interfacial factors were tuned, and the corresponding evolutions of electronic structure and superconducting gap behavior were investigated. These studies enrich the current understanding on the interfacial super-conductivity, and provide clues for further enhancing Tc through interface engineering.

  1. Superconductivity in aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Kubozono, Yoshihiro, E-mail: kubozono@cc.okayama-u.ac.jp [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Japan Science and Technology Agency, ACT-C, Kawaguchi 332-0012 (Japan); Goto, Hidenori; Jabuchi, Taihei [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Yokoya, Takayoshi [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Research Center of New Functional Materials for Energy Production, Storage and Transport, Okayama University, Okayama 700-8530 (Japan); Kambe, Takashi [Department of Physics, Okayama University, Okayama 700-8530 (Japan); Sakai, Yusuke; Izumi, Masanari; Zheng, Lu; Hamao, Shino; Nguyen, Huyen L.T. [Research Laboratory for Surface Science, Okayama University, Okayama 700-8530 (Japan); Sakata, Masafumi; Kagayama, Tomoko; Shimizu, Katsuya [Center of Science and Technology under Extreme Conditions, Osaka University, Osaka 560-8531 (Japan)

    2015-07-15

    Highlights: • Aromatic superconductor is one of core research subjects in superconductivity. Superconductivity is observed in certain metal-doped aromatic hydrocarbons. Some serious problems to be solved exist for future advancement of the research. This article shows the present status of aromatic superconductors. - Abstract: ‘Aromatic hydrocarbon’ implies an organic molecule that satisfies the (4n + 2) π-electron rule and consists of benzene rings. Doping solid aromatic hydrocarbons with metals provides the superconductivity. The first discovery of such superconductivity was made for K-doped picene (K{sub x}picene, five benzene rings). Its superconducting transition temperatures (T{sub c}’s) were 7 and 18 K. Recently, we found a new superconducting K{sub x}picene phase with a T{sub c} as high as 14 K, so we now know that K{sub x}picene possesses multiple superconducting phases. Besides K{sub x}picene, we discovered new superconductors such as Rb{sub x}picene and Ca{sub x}picene. A most serious problem is that the shielding fraction is ⩽15% for K{sub x}picene and Rb{sub x}picene, and it is often ∼1% for other superconductors. Such low shielding fractions have made it difficult to determine the crystal structures of superconducting phases. Nevertheless, many research groups have expended a great deal of effort to make high quality hydrocarbon superconductors in the five years since the discovery of hydrocarbon superconductivity. At the present stage, superconductivity is observed in certain metal-doped aromatic hydrocarbons (picene, phenanthrene and dibenzopentacene), but the shielding fraction remains stubbornly low. The highest priority research area is to prepare aromatic superconductors with a high superconducting volume-fraction. Despite these difficulties, aromatic superconductivity is still a core research target and presents interesting and potentially breakthrough challenges, such as the positive pressure dependence of T{sub c} that is clearly

  2. The superconducting spin valve and triplet superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Garifullin, I.A., E-mail: ilgiz_garifullin@yahoo.com [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Leksin, P.V.; Garif' yanov, N.N.; Kamashev, A.A. [Zavoisky Physical-Technical Institute, Kazan Scientific Center of Russian Academy of Sciences, 420029 Kazan (Russian Federation); Fominov, Ya.V. [L. D. Landau Institute for Theoretical Physics RAS, 119334 Moscow (Russian Federation); Moscow Institute of Physics and Technology, 141700 Dolgoprudny (Russian Federation); Schumann, J.; Krupskaya, Y.; Kataev, V.; Schmidt, O.G. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Büchner, B. [Leibniz Institute for Solid State and Materials Research IFW Dresden, D-01171 Dresden (Germany); Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden (Germany)

    2015-01-01

    A review of our recent results on the spin valve effect is presented. We have used a theoretically proposed spin switch design F1/F2/S comprising a ferromagnetic bilayer (F1/F2) as a ferromagnetic component, and an ordinary superconductor (S) as the second interface component. Based on it we have prepared and studied in detail a set of multilayers CoO{sub x}/Fe1/Cu/Fe2/S (S=In or Pb). In these heterostructures we have realized for the first time a full spin switch effect for the superconducting current, have observed its sign-changing oscillating behavior as a function of the Fe2-layer thickness and finally have obtained direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the magnetizations of the Fe1 and Fe2 layers. - Highlights: • We studied a spin switch design F1/F2/S. • We prepared a set of multilayers CoOx/Fe1/Cu/Fe2/S (S=In or Pb). • The full spin switch effect for the superconducting current was realized. • We observed its oscillating behavior as a function of the Fe2-layer thickness. • We obtained direct evidence for the long-range triplet superconductivity.

  3. Tunneling in superconducting structures

    Science.gov (United States)

    Shukrinov, Yu. M.

    2010-12-01

    Here we review our results on the breakpoint features in the coupled system of IJJ obtained in the framework of the capacitively coupled Josephson junction model with diffusion current. A correspondence between the features in the current voltage characteristics (CVC) and the character of the charge oscillations in superconducting layers is demonstrated. Investigation of the correlations of superconducting currents in neighboring Josephson junctions and the charge correlations in neighboring superconducting layers reproduces the features in the CVC and gives a powerful method for the analysis of the CVC of coupled Josephson junctions. A new method for determination of the dissipation parameter is suggested.

  4. Superconductivity in doped insulators

    Energy Technology Data Exchange (ETDEWEB)

    Emery, V.J. [Brookhaven National Lab., Upton, NY (United States); Kivelson, S.A. [California Univ., Los Angeles, CA (United States). Dept. of Physics

    1995-12-31

    It is shown that many synthetic metals, including high temperature superconductors are ``bad metals``, with such a poor conductivity that the usual meanfield theory of superconductivity breaks down because of anomalously large classical and quantum fluctuations of the phase of the superconducting order parameter. It is argued that the supression of a first order phase transition (phase separation) by the long-range Coulomb interaction leads to high temperature superconductivity accompanied by static or dynamical charge inhomogeneIty. Evidence in support of this picture for high temperature superconductors is described.

  5. Possible detection of super massive very slow GUTS monopole.

    Science.gov (United States)

    Khalil, A. E.

    A conceptual design idea for a detector of super massive very slow grand unified theories (GUTS) monopoles is discussed. The idea is based on the total stopping power due to the field energy generated by the supercurrents when a slowly moving monopole β ≍ 10-4 passes through a superconductor. The detector incorporates a superconducting Al disc with dimensions chosen for maximum phonon thermalization energy, surrounded by an array of plastic scintillators to provide a monopole trigger and cosmic ray veto. The integrated system acts as a velocity filter for very slow Dirac galactic monopoles.

  6. SuperSegger

    DEFF Research Database (Denmark)

    Stylianidou, Stella; Brennan, Connor; Nissen, Silas B

    2016-01-01

    -colonies with many cells, facilitating the analysis of cell-cycle dynamics in bacteria as well as cell-contact mediated phenomena. This package has a range of built-in capabilities for characterizing bacterial cells, including the identification of cell division events, mother, daughter, and neighboring cells......Many quantitative cell biology questions require fast yet reliable automated image segmentation to identify and link cells from frame-to-frame, and characterize the cell morphology and fluorescence. We present SuperSegger, an automated MATLAB-based image processing package well......-suited to quantitative analysis of high-throughput live-cell fluorescence microscopy of bacterial cells. SuperSegger incorporates machine-learning algorithms to optimize cellular boundaries and automated error resolution to reliably link cells from frame-to-frame. Unlike existing packages, it can reliably segment micro...

  7. NASA Super Pressure Balloon

    Science.gov (United States)

    Fairbrother, Debbie

    2017-01-01

    NASA is in the process of qualifying the mid-size Super Pressure Balloon (SPB) to provide constant density altitude flight for science investigations at polar and mid-latitudes. The status of the development of the 18.8 million cubic foot SPB capable of carrying one-tone of science to 110,000 feet, will be given. In addition, the operating considerations such as launch sites, flight safety considerations, and recovery will be discussed.

  8. Super-diversité

    NARCIS (Netherlands)

    Crul, M.R.J.; Schneider, J.; Lelie, F.

    2013-01-01

    Le concept de super-diversité, en cernant les conditions d'un scénario 'avenir optimiste, offre un nouvel éclairage au débat sur l'intégration. Nous sommes à la croisée des chemins. Cette étude comparative internationale montre qu'un avenir souriant se profile dans les villes qui donnent des chances

  9. Performing the Super Instrument

    DEFF Research Database (Denmark)

    Kallionpaa, Maria

    2016-01-01

    The genre of contemporary classical music has seen significant innovation and research related to new super, hyper, and hybrid instruments, which opens up a vast palette of expressive potential. An increasing number of composers, performers, instrument designers, engineers, and computer programmers...... provides the performer extensive virtuoso capabilities in terms of instrumental range, harmony, timbre, or spatial, textural, acoustic, technical, or technological qualities. The discussion will be illustrated by a composition case study involving augmented musical instrument electromagnetic resonator...

  10. Performing the Super Instrument

    DEFF Research Database (Denmark)

    Kallionpaa, Maria

    2016-01-01

    provides the performer extensive virtuoso capabilities in terms of instrumental range, harmony, timbre, or spatial, textural, acoustic, technical, or technological qualities. The discussion will be illustrated by a composition case study involving augmented musical instrument electromagnetic resonator......The genre of contemporary classical music has seen significant innovation and research related to new super, hyper, and hybrid instruments, which opens up a vast palette of expressive potential. An increasing number of composers, performers, instrument designers, engineers, and computer programmers...

  11. Characterising Super-Earths

    Directory of Open Access Journals (Sweden)

    Valencia D.

    2011-02-01

    Full Text Available The era of Super-Earths has formally begun with the detection of transiting low-mass exoplanets CoRoT-7b and GJ 1214b. In the path of characterising super-Earths, the first step is to infer their composition. While the discovery data for CoRoT-7b, in combination with the high atmospheric mass loss rate inferred from the high insolation, suggested that it was a rocky planet, the new proposed mass values have widened the possibilities. The combined mass range 1−10 M⊕ allows for a volatile-rich (and requires it if the mass is less than 4 M⊕ , an Earth-like or a super-Mercury-like composition. In contrast, the radius of GJ 1214b is too large to admit a solid composition, thus it necessarily to have a substantial gas layer. Some evidence suggests that within this gas layer H/He is a small but non-negligible component. These two planets are the first of many transiting low-mass exoplanets expected to be detected and they exemplify the limitations faced when inferring composition, which come from the degenerate character of the problem and the large error bars in the data.

  12. Super Fuzzy Matrices and Super Fuzzy Models for Social Scientists

    CERN Document Server

    Kandasamy, W B Vasantha; Amal, K

    2008-01-01

    This book introduces the concept of fuzzy super matrices and operations on them. This book will be highly useful to social scientists who wish to work with multi-expert models. Super fuzzy models using Fuzzy Cognitive Maps, Fuzzy Relational Maps, Bidirectional Associative Memories and Fuzzy Associative Memories are defined here. The authors introduce 13 multi-expert models using the notion of fuzzy supermatrices. These models are described with illustrative examples. This book has three chapters. In the first chaper, the basic concepts about super matrices and fuzzy super matrices are recalled. Chapter two introduces the notion of fuzzy super matrices adn their properties. The final chapter introduces many super fuzzy multi expert models.

  13. Super-quantum curves from super-eigenvalue models

    CERN Document Server

    Ciosmak, Paweł; Manabe, Masahide; Sułkowski, Piotr

    2016-01-01

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce $\\beta$-deformed version of those models, and derive differential equations for associated $\\alpha/\\beta$-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  14. Super-quantum curves from super-eigenvalue models

    Science.gov (United States)

    Ciosmak, Paweł; Hadasz, Leszek; Manabe, Masahide; Sułkowski, Piotr

    2016-10-01

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce β-deformed version of those models, and derive differential equations for associated α/ β-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  15. Super-quantum curves from super-eigenvalue models

    Energy Technology Data Exchange (ETDEWEB)

    Ciosmak, Paweł [Faculty of Mathematics, Informatics and Mechanics, University of Warsaw,ul. Banacha 2, 02-097 Warsaw (Poland); Hadasz, Leszek [M. Smoluchowski Institute of Physics, Jagiellonian University,ul. Łojasiewicza 11, 30-348 Kraków (Poland); Manabe, Masahide [Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Sułkowski, Piotr [Faculty of Physics, University of Warsaw,ul. Pasteura 5, 02-093 Warsaw (Poland); Walter Burke Institute for Theoretical Physics, California Institute of Technology,1200 E. California Blvd, Pasadena, CA 91125 (United States)

    2016-10-10

    In modern mathematical and theoretical physics various generalizations, in particular supersymmetric or quantum, of Riemann surfaces and complex algebraic curves play a prominent role. We show that such supersymmetric and quantum generalizations can be combined together, and construct supersymmetric quantum curves, or super-quantum curves for short. Our analysis is conducted in the formalism of super-eigenvalue models: we introduce β-deformed version of those models, and derive differential equations for associated α/β-deformed super-matrix integrals. We show that for a given model there exists an infinite number of such differential equations, which we identify as super-quantum curves, and which are in one-to-one correspondence with, and have the structure of, super-Virasoro singular vectors. We discuss potential applications of super-quantum curves and prospects of other generalizations.

  16. Superconducting wind turbine generators

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Mijatovic, Nenad; Seiler, Eugen

    2010-01-01

    , the main challenge of the superconducting direct drive technology is to prove that the reliability is superior to the alternative drive trains based on gearboxes or permanent magnets. A strategy of successive testing of superconducting direct drive trains in real wind turbines of 10 kW, 100 kW, 1 MW and 10...... offshore turbines of 8 and 10 MW have been determined from an up-scaling of an existing 5 MW turbine and the necessary properties of the superconducting drive train are discussed. We have found that the absence of the gear box is the main benefit and the reduced weight and size is secondary. However...... MW generator and it is concluded that the present production capacity of coated conductors must be increased by a factor of 36 by 2020, resulting in a ten times lower price of the tape in order to reach a realistic price level for the superconducting drive train....

  17. Magnetic and superconducting nanowires

    DEFF Research Database (Denmark)

    Piraux, L.; Encinas, A.; Vila, L.

    2005-01-01

    magnetic and superconducting nanowires. Using different approaches entailing measurements on both single wires and arrays, numerous interesting physical properties have been identified in relation to the nanoscopic dimensions of these materials. Finally, various novel applications of the nanowires are also...

  18. Superconductivity fundamentals and applications

    CERN Document Server

    Buckel, Werner

    2004-01-01

    This is the second English edition of what has become one of the definitive works on superconductivity in German -- currently in its sixth edition. Comprehensive and easy to understand, this introductory text is written especially with the non-specialist in mind. The authors, both long-term experts in this field, present the fundamental considerations without the need for extensive mathematics, describing the various phenomena connected with the superconducting state, with liberal insertion of experimental facts and examples for modern applications. While all fields of superconducting phenomena are dealt with in detail, this new edition pays particular attention to the groundbreaking discovery of magnesium diboride and the current developments in this field. In addition, a new chapter provides an overview of the elements, alloys and compounds where superconductivity has been observed in experiments, together with their major characteristics. The chapter on technical applications has been considerably expanded...

  19. Superconductivity and symmetry breaking

    Energy Technology Data Exchange (ETDEWEB)

    Sarasua, L.G., E-mail: sarasua@fisica.edu.uy [Instituto de Fisica, Facultad de Ciencias, Universidad de la Republica, Montevideo (Uruguay)

    2012-02-15

    In the present work we consider the relation between superconductivity and spontaneous gauge symmetry breaking (SGBS). We show that ODLRO does not require in principle SBGS, even in the presence of particle number fluctuations, by examining exact solutions of a fermionic pairing model. The criteria become equivalent if a symmetry breaking field is allowed, which can be attributed to the interaction with the environment. However, superconducting states without SBGS are not forbidden.

  20. Photoemission, Correlation and Superconductivity:

    Science.gov (United States)

    Abrecht, M.; Ariosa, D.; Cloëtta, D.; Pavuna, D.; Perfetti, L.; Grioni, M.; Margaritondo, G.

    We review some of the problems still affecting photoemission as a probe of high-temperature superconductivity, as well as important recent results concerning their solution. We show, in particular, some of the first important results on thin epitaxial films grown by laser ablation, which break the monopoly of cleaved BCSCO in this type of experiments. Such results, obtained on thin LSCO, may have general implications on the theory of high-temperature superconductivity.

  1. Emergent Higgsless Superconductivity

    Directory of Open Access Journals (Sweden)

    Cristina Diamantini M.

    2017-01-01

    Full Text Available We present a new Higgsless model of superconductivity, inspired from anyon superconductivity but P- and T-invariant and generalizable to any dimension. While the original anyon superconductivity mechanism was based on incompressible quantum Hall fluids as average field states, our mechanism involves topological insulators as average field states. In D space dimensions it involves a (D-1-form fictitious pseudovector gauge field which originates from the condensation of topological defects in compact lowenergy effective BF theories. There is no massive Higgs scalar as there is no local order parameter. When electromagnetism is switched on, the photon acquires mass by the topological BF mechanism. Although the charge of the gapless mode (2 and the topological order (4 are the same as those of the standard Higgs model, the two models of superconductivity are clearly different since the origins of the gap, reflected in the high-energy sectors are totally different. In 2D thi! s type of superconductivity is explicitly realized as global superconductivity in Josephson junction arrays. In 3D this model predicts a possible phase transition from topological insulators to Higgsless superconductors.

  2. Superconducting Fullerene Nanowhiskers

    Directory of Open Access Journals (Sweden)

    Yoshihiko Takano

    2012-04-01

    Full Text Available We synthesized superconducting fullerene nanowhiskers (C60NWs by potassium (K intercalation. They showed large superconducting volume fractions, as high as 80%. The superconducting transition temperature at 17 K was independent of the K content (x in the range between 1.6 and 6.0 in K-doped C60 nanowhiskers (KxC60NWs, while the superconducting volume fractions changed with x. The highest shielding fraction of a full shielding volume was observed in the material of K3.3C60NW by heating at 200 °C. On the other hand, that of a K-doped fullerene (K-C60 crystal was less than 1%. We report the superconducting behaviors of our newly synthesized KxC60NWs in comparison to those of KxC60 crystals, which show superconductivity at 19 K in K3C60. The lattice structures are also discussed, based on the x-ray diffraction (XRD analyses.

  3. High temperature interfacial superconductivity

    Science.gov (United States)

    Bozovic, Ivan [Mount Sinai, NY; Logvenov, Gennady [Port Jefferson Station, NY; Gozar, Adrian Mihai [Port Jefferson, NY

    2012-06-19

    High-temperature superconductivity confined to nanometer-scale interfaces has been a long standing goal because of potential applications in electronic devices. The spontaneous formation of a superconducting interface in bilayers consisting of an insulator (La.sub.2CuO.sub.4) and a metal (La.sub.1-xSr.sub.xCuO.sub.4), neither of which is superconducting per se, is described. Depending upon the layering sequence of the bilayers, T.sub.c may be either .about.15 K or .about.30 K. This highly robust phenomenon is confined to within 2-3 nm around the interface. After exposing the bilayer to ozone, T.sub.c exceeds 50 K and this enhanced superconductivity is also shown to originate from a 1 to 2 unit cell thick interfacial layer. The results demonstrate that engineering artificial heterostructures provides a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. The superconducting interface may be implemented, for example, in SIS tunnel junctions or a SuFET.

  4. The superconducting spin valve and triplet superconductivity

    Science.gov (United States)

    Garifullin, I. A.; Leksin, P. V.; Garif`yanov, N. N.; Kamashev, A. A.; Fominov, Ya. V.; Schumann, J.; Krupskaya, Y.; Kataev, V.; Schmidt, O. G.; Büchner, B.

    2015-01-01

    A review of our recent results on the spin valve effect is presented. We have used a theoretically proposed spin switch design F1/F2/S comprising a ferromagnetic bilayer (F1/F2) as a ferromagnetic component, and an ordinary superconductor (S) as the second interface component. Based on it we have prepared and studied in detail a set of multilayers CoOx/Fe1/Cu/Fe2/S (S=In or Pb). In these heterostructures we have realized for the first time a full spin switch effect for the superconducting current, have observed its sign-changing oscillating behavior as a function of the Fe2-layer thickness and finally have obtained direct evidence for the long-range triplet superconductivity arising due to noncollinearity of the magnetizations of the Fe1 and Fe2 layers.

  5. Operating modes of superconducting tunnel junction device

    Energy Technology Data Exchange (ETDEWEB)

    Maehata, Keisuke [Kyushu Univ., Fukuoka (Japan). Faculty of Engineering

    1998-07-01

    In the Electrotechnical Laboratory, an Nb type superconducting tunnel junction (STJ) device with 200 x 200 sq. micron in area and super high quality was manufactured. By using 55-fe source, response of this large area STJ to X-ray was measured. In this measurement, two action modes with different output wave height from front amplifier were observed. Then, in this study, current-voltage feature of the element in each action mode was analyzed to elucidate a mechanism to form such two action modes. The feature was analyzed by using first order approximate solution on cavity resonance mode of Sine-Gordon equation. From the analytical results, it could be supposed that direction and magnitude of effective magnetic field penetrating into jointed area changed by an induction current effect owing to impressing speed of the magnetic field, which brings two different current-voltage features to make possible to observe two action modes with different pulse wave height. (G.K.)

  6. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2004-01-01

    Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties...

  7. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2005-01-01

    This paper describes the application results of a previous and current EU-project on super insulating glazing based on monolithic silica aerogel. Prototypes measuring approx. 55´55 cm2 have been made with 15 mm evacuated aerogel between two layers of low-iron glass. Anti-reflective treatment...... of the glass and a heat-treatment of the aerogel increases the visible quality and the solar energy transmittance. A low-conductive rim seal solution with the required vacuum barrier properties has been developed along with a reliable assembly and evacuation process. The prototypes have a centre heat loss...

  8. Super-heptazethrene

    KAUST Repository

    Zeng, Wangdong

    2016-05-30

    The challenging synthesis of a laterally extended heptazethrene molecule, the super-heptazethrene derivative SHZ-CF3, is reported. This molecule was prepared using a strategy involving a multiple selective intramolecular Friedel–Crafts alkylation followed by oxidative dehydrogenation. Compound SHZ-CF3 exhibits an open-shell singlet diradical ground state with a much larger diradical character compared with the heptazethrene derivatives. An intermediate dibenzo-terrylene SHZ-2H was also obtained during the synthesis. This study provides a new synthetic method to access large-size quinoidal polycyclic hydrocarbons with unique physical properties.

  9. Design and comparative analysis of 10 MW class superconducting wind power generators according to different types of superconducting wires

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Hae-Jin, E-mail: haejin90@changwon.ac.kr [Changwon National University, 55306 Sarim-dong, Changwon 641-773 (Korea, Republic of); Kim, Gyeong-Hun; Kim, Kwangmin; Park, Minwon [Changwon National University, 55306 Sarim-dong, Changwon 641-773 (Korea, Republic of); Yu, In-Keun, E-mail: yuik@changwon.ac.kr [Changwon National University, 55306 Sarim-dong, Changwon 641-773 (Korea, Republic of); Kim, Jong-Yul [Korea Electrotechnology Research Institute, Changwon 641-120 (Korea, Republic of)

    2013-11-15

    Highlights: •10 MW SC wind power generators are designed using different types of SC wires. •SCSGs using YBCO and Bi-2223 wires are optimized by the modified Taguchi method. •The results demonstrate a proper type of SC wire for the optimal design of SCSG. -- Abstract: Wind turbine concepts can be classified into the geared type and the gearless type. The gearless type wind turbine is more attractive due to advantages of simplified drive train and increased energy yield, and higher reliability because the gearbox is omitted. In addition, this type resolves the weight issue of the wind turbine with the light weight of gearbox. However, because of the low speed operation, this type has disadvantage such as the large diameter and heavy weight of generator. Super-Conducting (SC) wind power generator can reduce the weight and volume of a wind power system. Properties of superconducting wire are very different from each company. This paper considers the design and comparative analysis of 10 MW class SC wind power generators according to different types of SC wires. Super-Conducting Synchronous Generators (SCSGs) using YBCO and Bi-2223 wires are optimized by an optimal method. The magnetic characteristics of the SCSGs are investigated using the finite elements method program. The optimized specifications of the SCSGs are discussed in detail, and the optimization processes can be used effectively to develop large scale wind power generation systems.

  10. Design and comparative analysis of 10 MW class superconducting wind power generators according to different types of superconducting wires

    Science.gov (United States)

    Sung, Hae-Jin; Kim, Gyeong-Hun; Kim, Kwangmin; Park, Minwon; Yu, In-Keun; Kim, Jong-Yul

    2013-11-01

    Wind turbine concepts can be classified into the geared type and the gearless type. The gearless type wind turbine is more attractive due to advantages of simplified drive train and increased energy yield, and higher reliability because the gearbox is omitted. In addition, this type resolves the weight issue of the wind turbine with the light weight of gearbox. However, because of the low speed operation, this type has disadvantage such as the large diameter and heavy weight of generator. Super-Conducting (SC) wind power generator can reduce the weight and volume of a wind power system. Properties of superconducting wire are very different from each company. This paper considers the design and comparative analysis of 10 MW class SC wind power generators according to different types of SC wires. Super-Conducting Synchronous Generators (SCSGs) using YBCO and Bi-2223 wires are optimized by an optimal method. The magnetic characteristics of the SCSGs are investigated using the finite elements method program. The optimized specifications of the SCSGs are discussed in detail, and the optimization processes can be used effectively to develop large scale wind power generation systems.

  11. Testing and Characterization of SuperCDMS Dark Matter Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Shank, Benjamin [Stanford Univ., CA (United States)

    2014-05-01

    The Cryogenic Dark Matter Search (SuperCDMS) relies on collection of phonons and charge carriers in semiconductors held at tens of milliKelvin as handles for detection of Weakly Interacting Massive Particles (WIMPs). This thesis begins with a brief overview of the direct dark matter search (Chapter 1) and SuperCDMS detectors (Chapter 2). In Chapter 3, a 3He evaporative refrigerator facility is described. Results from experiments performed in-house at Stanford to measure carrier transport in high-purity germanium (HPGe) crystals operated at sub-Kelvin temperatures are presented in Chapter 4. Finally, in Chapter 5 a new numerical model and a time-domain optimal filtering technique are presented, both developed for use with superconducting Transition Edge Sensors (TESs), that provide excellent event reconstruction for single particle interactions in detectors read out with superconducting W-TESs coupled to energy-collecting films of Al. This thesis is not intended to be read straight through. For those new to CDMS or dark matter searches, the first two chapters are meant to be a gentle introduction for experimentalists. They are by no means exhaustive. The remaining chapters each stand alone, with different audiences.

  12. Design, Fabrication and Testing of a Superconducting Fault Current Limiter (SFCL)

    Energy Technology Data Exchange (ETDEWEB)

    Gouge, M..; Schwenterly, S.W.; Hazelton, D. (SuperPower, Inc.)

    2011-06-15

    The purpose of this project was to conduct R&D on specified components and provide technical design support to a SuperPower team developing a high temperature superconducting Fault Current Limiter (SFCL). ORNL teamed with SuperPower, Inc. on a Superconductivity Partnerships with Industry (SPI) proposal for the SFCL that was submitted to DOE and approved in FY 2003. A contract between DOE and SuperPower, Inc. was signed on July 14, 2003 to design, fabricate and test the SFCL. This device employs high temperature superconducting (HTS) elements and SuperPower's proprietary technology. The program goal was to demonstrate a device that will address a broad range of the utility applications and meet utility industry requirements. This DOE-sponsored Superconductivity Partnership with Industry project would positively impact electric power transmission reliability and security by introducing a new element in the grid that can significantly mitigate fault currents and provide lower cost solutions for grid protection. The project will conduct R&D on specified components and provide technical design support to a SuperPower-led team developing a SFCL as detailed in tasks 1-5 below. Note the SuperPower scope over the broad SPI project is much larger than that shown below which indicates only the SuperPower tasks that are complementary to the ORNL tasks. SuperPower is the Project Manager for the SFCL program, and is responsible for completion of the project on schedule and budget. The scope of work for ORNL is to provide R&D support for the SFCL in the following four broad areas: (1) Assist with high voltage subsystem R&D, design, fabrication and testing including characterization of the general dielectric performance of LN2 and component materials; (2) Consult on cryogenic subsystem R&D, design, fabrication and testing; (3) Participate in project conceptual and detailed design reviews; and (4) Guide commercialization by participation on the Technical Advisory Board (TAB

  13. Nanoscience and Engineering in Superconductivity

    CERN Document Server

    Moshchalkov, Victor; Lang, Wolfgang

    2010-01-01

    For emerging energy saving technologies, superconducting materials with superior performance are needed. Such materials can be developed by manipulating the 'elementary building blocks' through nanostructuring. For superconductivity the 'elementary blocks' are Cooper pair and fluxon (vortex). This book presents new ways how to modify superconductivity and vortex matter through nanostructuring and the use of nanoscale magnetic templates. The basic nano-effects, vortex and vortex-antivortex patterns, vortex dynamics, Josephson phenomena, critical currents, and interplay between superconductivity

  14. Quantitative super-resolution microscopy

    NARCIS (Netherlands)

    Harkes, Rolf

    2016-01-01

    Super-Resolution Microscopy is an optical fluorescence technique. In this thesis we focus on single molecule super-resolution, where the position of single molecules is determined. Typically these molecules can be localized with a 10 to 30nm precision. This technique is applied in four different s

  15. A sourcebook of titanium alloy superconductivity

    CERN Document Server

    Collings, E W

    1983-01-01

    In less than two decades the concept of supercon­ In every field of science there are one or two ductivity has been transformed from a laboratory individuals whose dedication, combined with an innate curiosity to usable large-scale applications. In the understanding, permits them to be able to grasp, late 1960's the concept of filamentary stabilization condense, and explain to the rest of us what that released the usefulness of zero resistance into the field is all about. For the field of titanium alloy marketplace, and the economic forces that drive tech­ superconductivity, such an individual is Ted Collings. nology soon focused on niobium-titanium alloys. They His background as a metallurgist has perhaps given him are ductile and thus fabricable into practical super­ a distinct advantage in understanding superconduc­ conducting wires that have the critical currents and tivity in titanium alloys because the optimization of fields necessary for large-scale devices. More than superconducting parameters in ...

  16. Interface high-temperature superconductivity

    Science.gov (United States)

    Wang, Lili; Ma, Xucun; Xue, Qi-Kun

    2016-12-01

    Cuprate high-temperature superconductors consist of two quasi-two-dimensional (2D) substructures: CuO2 superconducting layers and charge reservoir layers. The superconductivity is realized by charge transfer from the charge reservoir layers into the superconducting layers without chemical dopants and defects being introduced into the latter, similar to modulation-doping in the semiconductor superlattices of AlGaAs/GaAs. Inspired by this scheme, we have been searching for high-temperature superconductivity in ultra-thin films of superconductors epitaxially grown on semiconductor/oxide substrates since 2008. We have observed interface-enhanced superconductivity in both conventional and unconventional superconducting films, including single atomic layer films of Pb and In on Si substrates and single unit cell (UC) films of FeSe on SrTiO3 (STO) substrates. The discovery of high-temperature superconductivity with a superconducting gap of ∼20 meV in 1UC-FeSe/STO has stimulated tremendous interest in the superconductivity community, for it opens a new avenue for both raising superconducting transition temperature and understanding the pairing mechanism of unconventional high-temperature superconductivity. Here, we review mainly the experimental progress on interface-enhanced superconductivity in the three systems mentioned above with emphasis on 1UC-FeSe/STO, studied by scanning tunneling microscopy/spectroscopy, angle-resolved photoemission spectroscopy and transport experiments. We discuss the roles of interfaces and a possible pairing mechanism inferred from these studies.

  17. Connectivity and superconductivity

    CERN Document Server

    Rubinstein, Jacob

    2000-01-01

    The motto of connectivity and superconductivity is that the solutions of the Ginzburg--Landau equations are qualitatively influenced by the topology of the boundaries, as in multiply-connected samples. Special attention is paid to the "zero set", the set of the positions (also known as "quantum vortices") where the order parameter vanishes. The effects considered here usually become important in the regime where the coherence length is of the order of the dimensions of the sample. It takes the intuition of physicists and the awareness of mathematicians to find these new effects. In connectivity and superconductivity, theoretical and experimental physicists are brought together with pure and applied mathematicians to review these surprising results. This volume is intended to serve as a reference book for graduate students and researchers in physics or mathematics interested in superconductivity, or in the Schrödinger equation as a limiting case of the Ginzburg--Landau equations.

  18. Large Superconducting Magnet Systems

    CERN Document Server

    Védrine, P.

    2014-07-17

    The increase of energy in accelerators over the past decades has led to the design of superconducting magnets for both accelerators and the associated detectors. The use of Nb−Ti superconducting materials allows an increase in the dipole field by up to 10 T compared with the maximum field of 2 T in a conventional magnet. The field bending of the particles in the detectors and generated by the magnets can also be increased. New materials, such as Nb3Sn and high temperature superconductor (HTS) conductors, can open the way to higher fields, in the range 13–20 T. The latest generations of fusion machines producing hot plasma also use large superconducting magnet systems.

  19. Failed theories of superconductivity

    CERN Document Server

    Schmalian, Joerg

    2010-01-01

    Almost half a century passed between the discovery of superconductivity by Kammerlingh Onnes and the theoretical explanation of the phenomenon by Bardeen, Cooper and Schrieffer. During the intervening years the brightest minds in theoretical physics tried and failed to develop a microscopic understanding of the effect. A summary of some of those unsuccessful attempts to understand superconductivity not only demonstrates the extraordinary achievement made by formulating the BCS theory, but also illustrates that mistakes are a natural and healthy part of the scientific discourse, and that inapplicable, even incorrect theories can turn out to be interesting and inspiring.

  20. Superconducting magnetic quadrupole

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.W.; Shepard, K.W.; Nolen, J.A.

    1995-08-01

    A design was developed for a 350 T/m, 2.6-cm clear aperture superconducting quadrupole focussing element for use in a very low q/m superconducting linac as discussed below. The quadrupole incorporates holmium pole tips, and a rectangular-section winding using standard commercially-available Nb-Ti wire. The magnet was modeled numerically using both 2D and 3D codes, as a basis for numerical ray tracing using the quadrupole as a linac element. Components for a prototype singlet are being procured during FY 1995.

  1. Superconducting racetrack booster for the ion complex of MEIC

    Energy Technology Data Exchange (ETDEWEB)

    Filatov, Yu [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); Moscow Inst. of Physics and Technology (MIPT), Moscow (Russian Federation); Kondratenko, A. M. [Science and Technique Laboratory ' Zaryad' , 630090, Novosibirsk, Russia; Kondratenko, M. A. [Science and Technique Laboratory ' Zaryad' , 630090, Novosibirsk, Russia; Kovalenko, A. [Joint Inst. for Nuclear Research (JINR), Dubna (Russian Federation); Derbenev, Yaroslav S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Lin, Fanglei [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Morozov, Vasiliy S. [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States); Zhang, Yuhong [Thomas Jefferson National Accelerator Facility (TJNAF), Newport News, VA (United States)

    2016-02-01

    The current design of the Medium-energy Electron-Ion Collider (MEIC) project at Jefferson lab features a single 8 GeV/c figure-8 booster based on super-ferric magnets. Reducing the circumference of the booster by switching to a racetrack design may improve its performance by limiting the space charge effect and lower its cost. We consider problems of preserving proton and deuteron polarizations in a superconducting racetrack booster. We show that using magnets based on hollow high-current NbTi composite superconducting cable similar to those designed at JINR for the Nuclotron guarantees preservation of the ion polarization in a racetrack booster up to 8 GeV/c. The booster operation cycle would be a few seconds that would improve the operating efficiency of the MEIC ion complex.

  2. Semiconductor-inspired design principles for superconducting quantum computing.

    Science.gov (United States)

    Shim, Yun-Pil; Tahan, Charles

    2016-03-17

    Superconducting circuits offer tremendous design flexibility in the quantum regime culminating most recently in the demonstration of few qubit systems supposedly approaching the threshold for fault-tolerant quantum information processing. Competition in the solid-state comes from semiconductor qubits, where nature has bestowed some very useful properties which can be utilized for spin qubit-based quantum computing. Here we begin to explore how selective design principles deduced from spin-based systems could be used to advance superconducting qubit science. We take an initial step along this path proposing an encoded qubit approach realizable with state-of-the-art tunable Josephson junction qubits. Our results show that this design philosophy holds promise, enables microwave-free control, and offers a pathway to future qubit designs with new capabilities such as with higher fidelity or, perhaps, operation at higher temperature. The approach is also especially suited to qubits on the basis of variable super-semi junctions.

  3. Semiconductor-inspired design principles for superconducting quantum computing

    Science.gov (United States)

    Shim, Yun-Pil; Tahan, Charles

    2016-03-01

    Superconducting circuits offer tremendous design flexibility in the quantum regime culminating most recently in the demonstration of few qubit systems supposedly approaching the threshold for fault-tolerant quantum information processing. Competition in the solid-state comes from semiconductor qubits, where nature has bestowed some very useful properties which can be utilized for spin qubit-based quantum computing. Here we begin to explore how selective design principles deduced from spin-based systems could be used to advance superconducting qubit science. We take an initial step along this path proposing an encoded qubit approach realizable with state-of-the-art tunable Josephson junction qubits. Our results show that this design philosophy holds promise, enables microwave-free control, and offers a pathway to future qubit designs with new capabilities such as with higher fidelity or, perhaps, operation at higher temperature. The approach is also especially suited to qubits on the basis of variable super-semi junctions.

  4. Investigation of Properties of Motion of Superconductive Electrons in Superconductors by Nonlinear Quantum Mechanical Theory

    Institute of Scientific and Technical Information of China (English)

    Xiao-Feng Pang

    2008-01-01

    The properties and rules of motion of superconductive electrons in steady and time-dependent non-equilibrium states of superconductors are studied by using the Ginzberg-Landau (GL) equations and nonlinear quantum theory. In the absence of external fields, the superconductive electrons move in the solitons with certain energy and velocity in a uniform system, The superconductive electron is still a soliton under action of an electromagnetic field, but its amplitude, phase and shape are changed. Thus we conclude that super- conductivity is a result of motion of soliton of superconductive electrons. Since soliton has the feature of motion for retaining its energy and form, thus a permanent current occurs in superconductor. From these solutions of GL equations under action of an electromagnetic field, we gain the structure of vortex lines-magnetic flux lines observed experimentally in type-II superconductors. In the time-dependent non- equilibrium states of superconductor, the motions of superconductive electrons exhibit still the soliton features, but the shape and amplitude have changed. In an invariant electric-field, it moves in a constant acceleration. In the medium with dissipation, the superconductive electron behaves still like a soliton, although its form, amplitude, and velocity are altered. Thus we have to convince that the superconductive electron is essentially a soliton in both non-equilibrium and equilibrium superconductors.

  5. Super insulating aerogel glazing

    DEFF Research Database (Denmark)

    Schultz, Jørgen Munthe; Jensen, Karsten Ingerslev; Kristiansen, Finn Harken

    2004-01-01

    Monolithic silica aerogel offers the possibility of combining super insulation and high solar energy transmittance, which has been the background for a previous and a current EU project on research and development of monolithic silica aerogel as transparent insulation in windows. Generally, windows...... form the weakest part of the thermal envelope with respect to heat loss coefficient, but on the other hand also play an important role for passive solar energy utilisation. For window orientations other than south, the net energy balance will be close to or below zero. However, the properties...... of aerogel glazing will allow for a positive net energy gain even for north facing vertical windows in a Danish climate during the heating season. This means that high quality daylight can be obtained even with additional energy gain. On behalf of the partners of the two EU projects, results related...

  6. Superatom representation of high-T{sub C} superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Panas, Itai, E-mail: itai@chalmers.se [Environmental Inorganic Chemistry, Division of Energy and Materials, Department of Chemistry and Biotechnology, Chalmers University of Technology, S-412 96 Gothenburg (Sweden)

    2012-10-15

    A 'super-atom' conceptual interface between chemistry and physics is proposed in order to assist in the search for higher T{sub C} superconductors. The plaquettes generating the checkerboard superstructure in the cuprates, the C{sub 60} molecules in K{sub 3}C{sub 60}, and the Mo{sub 6}S{sub 8}{sup 2-} clusters in Chevrel phase materials offer such candidate super-atoms. Thus, in the present study high-T{sub C} superconductivity HTSC is articulated as the entanglement of two disjoint electronic manifolds in the vicinity of a common Fermi energy. The resulting HTSC ground state couples near-degenerate protected local super-atom states to virtual magnons in an antiferromagnetic AFM embedding. The composite Cooper pairs emerge as the interaction particles for virtual magnons mediated 'self-coherent entanglement' of super-atom states. A Hueckel type resonating valence bond RVB formalism is employed in order to illustrate the real-space Cooper pairs as well as their delocalization and Bose Einstein condensation BEC on a ring of super-atoms. The chemical potential {mu}{sub BEC} for Cooper pairs joining the condensate is formulated in terms of the super-exchange interaction, and consequently the T{sub C} in terms of the Neel temperature. A rationale for the robustness of the HTSC ground state is proposed: achieving local maximum 'electron correlation entropy' at the expense of non-local phase rigidity.

  7. Improved photon counting efficiency calibration using superconducting single photon detectors

    Science.gov (United States)

    Gan, Haiyong; Xu, Nan; Li, Jianwei; Sun, Ruoduan; Feng, Guojin; Wang, Yanfei; Ma, Chong; Lin, Yandong; Zhang, Labao; Kang, Lin; Chen, Jian; Wu, Peiheng

    2015-10-01

    The quantum efficiency of photon counters can be measured with standard uncertainty below 1% level using correlated photon pairs generated through spontaneous parametric down-conversion process. Normally a laser in UV, blue or green wavelength range with sufficient photon energy is applied to produce energy and momentum conserved photon pairs in two channels with desired wavelengths for calibration. One channel is used as the heralding trigger, and the other is used for the calibration of the detector under test. A superconducting nanowire single photon detector with advantages such as high photon counting speed (optical spectroscopy, super resolution microscopy, deep space observation, and so on.

  8. Experimental program of the Super-FRS Collaboration at FAIR and developments of related instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Äystö, J. [Helsinki Institute of Physics, P.O. Box 64, 00014 Helsinki (Finland); Behr, K.-H. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Benlliure, J. [Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain); Bracco, A. [Dipartimento di Fisica, Università di Milano, 20133 Milano (Italy); Egelhof, P. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Fomichev, A. [Flerov Laboratory of Nuclear Reactions, JINR, 141980 Dubna (Russian Federation); Galès, S. [Institut de Physique Nucléaire Orsay, 91406 Orsay (France); Horia Hulubei National Institute of Physics and Nuclear Engineering, P.O. Box MG6, Bucharest (Romania); Geissel, H. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Justus-Liebig-Universität, 35392 Gießen (Germany); Grahn, T. [Helsinki Institute of Physics, P.O. Box 64, 00014 Helsinki (Finland); Department of Physics, University of Jyvaskyla, P.O. Box 35, 40014 Jyvaskyla (Finland); Grigorenko, L.V. [Flerov Laboratory of Nuclear Reactions, JINR, 141980 Dubna (Russian Federation); Harakeh, M.N. [KVI Center for Advanced Radiation Technology, University of Groningen, 9700 Groningen (Netherlands); Hayano, R. [Department of Physics, University of Tokyo, 113-0033 Tokyo (Japan); Heinz, S. [GSI Helmholtzzentrum für Schwerionenforschung, 64291 Darmstadt (Germany); Itahashi, K. [RIKEN Nishina Center, Wako, Saitama 351-0198 (Japan); Jokinen, A. [Helsinki Institute of Physics, P.O. Box 64, 00014 Helsinki (Finland); Department of Physics, University of Jyvaskyla, P.O. Box 35, 40014 Jyvaskyla (Finland); and others

    2016-06-01

    The physics program at the super-conducting fragment separator (Super-FRS) at FAIR, being operated in a multiple-stage, high-resolution spectrometer mode, is discussed. The Super-FRS will produce, separate and transport radioactive beams at high energies up to 1.5 AGeV, and it can be also used as a stand-alone experimental device together with ancillary detectors. Various combinations of the magnetic sections of the Super-FRS can be operated in dispersive, achromatic or dispersion-matched spectrometer ion-optical modes, which allow measurements of momentum distributions of secondary-reaction products with high resolution and precision. A number of unique experiments in atomic, nuclear and hadron physics are suggested with the Super-FRS as a stand-alone device, in particular searches for new isotopes, studies of hypernuclei, delta-resonances in exotic nuclei and spectroscopy of atoms characterized by bound mesons. Rare decay modes like multiple-proton or neutron emission and the nuclear tensor force observed in high-momentum regime can be also addressed. The in-flight radioactivity measurements as well as fusion, transfer and deep-inelastic reaction mechanisms with the slowed-down and energy-bunched fragment beams are proposed for the high-resolution and energy buncher modes at the Super-FRS.

  9. COMPARATIVE ANALYSIS OF ENERGY ACCUMULATION SYSTEMS AND DETERMINATION OF OPTIMAL APPLICATION AREAS FOR MODERN SUPER FLYWHEELS

    Directory of Open Access Journals (Sweden)

    M. A. Sokolov

    2014-07-01

    Full Text Available The paper presents a review and comparative analysis of late years native and foreign literature on various energy storage devices: state of the art designs, application experience in various technical fields. Comparative characteristics of energy storage devices are formulated: efficiency, quality and stability. Typical characteristics are shown for such devices as electrochemical batteries, super capacitors, pumped hydroelectric storage, power systems based on compressed air and superconducting magnetic energy storage systems. The advantages and prospects of high-speed super flywheels as means of energy accumulation in the form of rotational kinetic energy are shown. High output power of a super flywheels energy storage system gives the possibility to use it as a buffer source of peak power. It is shown that super flywheels have great life cycle (over 20 years and are environmental. A distinctive feature of these energy storage devices is their good scalability. It is demonstrated that super flywheels are especially effective in hybrid power systems that operate in a charge/discharge mode, and are used particularly in electric vehicles. The most important factors for space applications of the super flywheels are their modularity, high efficiency, no mechanical friction and long operating time without maintenance. Quick response to network disturbances and high power output can be used to maintain the desired power quality and overall network stability along with fulfilling energy accumulation needs.

  10. Superconducting Magnets for Particle Accelerators

    CERN Document Server

    Rossi, L

    2012-01-01

    Superconductivity has been the most influential technology in the field of accelerators in the last 30 years. Since the commissioning of the Tevatron, which demonstrated the use and operability of superconductivity on a large scale, superconducting magnets and rf cavities have been at the heart of all new large accelerators. Superconducting magnets have been the invariable choice for large colliders, as well as cyclotrons and large synchrotrons. In spite of the long history of success, superconductivity remains a difficult technology, requires adequate R&D and suitable preparation, and has a relatively high cost. Hence, it is not surprising that the development has also been marked by a few setbacks. This article is a review of the main superconducting accelerator magnet projects; it highlights the main characteristics and main achievements, and gives a perspective on the development of superconducting magnets for the future generation of very high energy colliders.

  11. Spin-orbit-coupled superconductivity.

    Science.gov (United States)

    Lo, Shun-Tsung; Lin, Shih-Wei; Wang, Yi-Ting; Lin, Sheng-Di; Liang, C-T

    2014-06-25

    Superconductivity and spin-orbit (SO) interaction have been two separate emerging fields until very recently that the correlation between them seemed to be observed. However, previous experiments concerning SO coupling are performed far beyond the superconducting state and thus a direct demonstration of how SO coupling affects superconductivity remains elusive. Here we investigate the SO coupling in the critical region of superconducting transition on Al nanofilms, in which the strength of disorder and spin relaxation by SO coupling are changed by varying the film thickness. At temperatures T sufficiently above the superconducting critical temperature T(c), clear signature of SO coupling reveals itself in showing a magneto-resistivity peak. When T superconductivity. By studying such magneto-resistivity peaks under different strength of spin relaxation, we highlight the important effects of SO interaction on superconductivity.

  12. AC/RF Superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Ciovati, Gianluigi [JLAB

    2015-02-01

    This contribution provides a brief introduction to AC/RF superconductivity, with an emphasis on application to accelerators. The topics covered include the surface impedance of normal conductors and superconductors, the residual resistance, the field dependence of the surface resistance, and the superheating field.

  13. Superconducting Technology Assessment

    Science.gov (United States)

    2005-08-01

    of Nb/Al- Nx /NbTiN junctions for SIS mixer applications,” IEEE Trans. Appl. Superconduct., vol. 11, pp. 76–79, Mar. 2001. [48] M. Gurvitch, W. A...Another connector developed by IBM for commercial applications using a dendritic interposer technology. A “beam-on-pad” approach developed by Siemens

  14. Hybrid superconducting neutron detectors

    Energy Technology Data Exchange (ETDEWEB)

    Merlo, V.; Lucci, M.; Ottaviani, I. [Dipartimento di Fisica, Università Tor Vergata, Via della Ricerca Scientifica, I-00133 Roma (Italy); Salvato, M.; Cirillo, M. [Dipartimento di Fisica, Università Tor Vergata, Via della Ricerca Scientifica, I-00133 Roma (Italy); CNR SPIN Salerno, Università di Salerno, Via Giovanni Paolo II, n.132, 84084 Fisciano (Italy); Scherillo, A. [Science and Technology Facility Council, ISIS Facility Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Celentano, G. [ENEA Frascati Research Centre, Via. E. Fermi 45, 00044 Frascati (Italy); Pietropaolo, A., E-mail: antonino.pietropaolo@enea.it [ENEA Frascati Research Centre, Via. E. Fermi 45, 00044 Frascati (Italy); Mediterranean Institute of Fundamental Physics, Via Appia Nuova 31, 00040 Marino, Roma (Italy)

    2015-03-16

    A neutron detection concept is presented that is based on superconductive niobium (Nb) strips coated by a boron (B) layer. The working principle of the detector relies on the nuclear reaction, {sup 10}B + n → α + {sup 7}Li, with α and Li ions generating a hot spot on the current-biased Nb strip which in turn induces a superconducting-normal state transition. The latter is recognized as a voltage signal which is the evidence of the incident neutron. The above described detection principle has been experimentally assessed and verified by irradiating the samples with a pulsed neutron beam at the ISIS spallation neutron source (UK). It is found that the boron coated superconducting strips, kept at a temperature T = 8 K and current-biased below the critical current I{sub c}, are driven into the normal state upon thermal neutron irradiation. As a result of the transition, voltage pulses in excess of 40 mV are measured while the bias current can be properly modulated to bring the strip back to the superconducting state, thus resetting the detector. Measurements on the counting rate of the device are presented and the basic physical features of the detector are discussed.

  15. Levitation Kits Demonstrate Superconductivity.

    Science.gov (United States)

    Worthy, Ward

    1987-01-01

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

  16. LEP superconducting cavity

    CERN Multimedia

    1995-01-01

    Engineers work in a clean room on one of the superconducting cavities for the upgrade to the LEP accelerator, known as LEP-2. The use of superconductors allow higher electric fields to be produced so that higher beam energies can be reached.

  17. Niobium superconducting cavity

    CERN Multimedia

    CERN PhotoLab

    1980-01-01

    This 5-cell superconducting cavity, made from bulk-Nb, stems from the period of general studies, not all directed towards direct use at LEP. This one is dimensioned for 1.5 GHz, the frequency used at CEBAF and also studied at Saclay (LEP RF was 352.2 MHz). See also 7908227, 8007354, 8209255, 8210054, 8312339.

  18. LHC Superconducting Magnets

    CERN Document Server

    Jean Leyder

    2000-01-01

    The LHC is the next step in CERN's quest to unravel the mysteries of the Universe. It will accelerate protons to energies never before achieved in laboratories, and to hold them on course it will use powerful superconducting magnets on an unprecedented scale.

  19. Coupled superconducting flux qubits

    NARCIS (Netherlands)

    Plantenberg, J.H.

    2007-01-01

    This thesis presents results of theoretical and experimental work on superconducting persistent-current quantum bits. These qubits offer an attractive route towards scalable solid-state quantum computing. The focus of this work is on the gradiometer flux qubit which has a special geometric design, t

  20. Superconducting Quantum Circuits

    NARCIS (Netherlands)

    Majer, J.B.

    2002-01-01

    This thesis describes a number of experiments with superconducting cir- cuits containing small Josephson junctions. The circuits are made out of aluminum islands which are interconnected with a very thin insulating alu- minum oxide layer. The connections form a Josephson junction. The current trough

  1. Checking BEBC superconducting magnet

    CERN Multimedia

    1974-01-01

    The superconducting coils of the magnet for the 3.7 m Big European Bubble Chamber (BEBC) had to be checked, see Annual Report 1974, p. 60. The photo shows a dismantled pancake. By December 1974 the magnet reached again the field design value of 3.5 T.

  2. Nonequilibrium superconducting detectors

    Science.gov (United States)

    Cristiano, R.; Ejrnaes, M.; Esposito, E.; Lisitskyi, M. P.; Nappi, C.; Pagano, S.; Perez de Lara, D.

    2006-03-01

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  3. Nonequilibrium superconducting detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, R [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Ejrnaes, M [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); INFN Sezione di Napoli, 80126 Naples (Italy); Esposito, E [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Lisitskyi, M P [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Nappi, C [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Pagano, S [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy); Dipartimento di Fisica, Universita di Salerno, 84081 Baronissi (Saudi Arabia) (Italy); Perez de Lara, D [CNR-Istituto di Cibernetica E. Caianiello, 80078 Pozzuoli (Namibia) (Italy)

    2006-03-15

    Nonequilibrium superconducting detectors exploit the early stages of the energy down cascade which occur after the absorption of radiation. They operate on a short temporal scale ranging from few microseconds down to tens of picoseconds. In such a way they provide fast counting capability, high time discrimination and also, for some devices, energy sensitivity. Nonequilibrium superconducting detectors are developed for their use both in basic science and in practical applications for detection of single photons or single ionized macromolecules. In this paper we consider two devices: distributed readout imaging detectors (DROIDs) based on superconducting tunnel junctions (STJs), which are typically used for high-speed energy spectroscopy applications, and hot-electron superconductive detectors (HESDs), which are typically used as fast counters and time discriminators. Implementation of the DROID geometry to use a single superconductor is discussed. Progress in the fabrication technology of NbN nanostructured HESDs is presented. The two detectors share the high sensitivity that makes them able to efficiently detect even single photons down to infrared energy.

  4. LHC superconducting strand

    CERN Multimedia

    Patrice Loiez

    1999-01-01

    This cross-section through a strand of superconducting matieral as used in the LHC shows the 8000 Niobium-Titanium filaments embedded like a honeycomb in copper. When cooled to 1.9 degrees above absolute zero in the LHC accelerator, these filaments will have zero resistance and so will carry a high electric current with no energy loss.

  5. Superconducting doped topological materials

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Satoshi, E-mail: sasaki@sanken.osaka-u.ac.jp [Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047 (Japan); Mizushima, Takeshi, E-mail: mizushima@mp.es.osaka-u.ac.jp [Department of Materials Engineering Science, Osaka University, Toyonaka, Osaka 560-8531 (Japan); Department of Physics, Okayama University, Okayama 700-8530 (Japan)

    2015-07-15

    Highlights: • Studies on both normal- and SC-state properties of doped topological materials. • Odd-parity pairing systems with the time-reversal-invariance. • Robust superconductivity in the presence of nonmagnetic impurity scattering. • We propose experiments to identify the existence of Majorana fermions in these SCs. - Abstract: Recently, the search for Majorana fermions (MFs) has become one of the most important and exciting issues in condensed matter physics since such an exotic quasiparticle is expected to potentially give rise to unprecedented quantum phenomena whose functional properties will be used to develop future quantum technology. Theoretically, the MFs may reside in various types of topological superconductor materials that is characterized by the topologically protected gapless surface state which are essentially an Andreev bound state. Superconducting doped topological insulators and topological crystalline insulators are promising candidates to harbor the MFs. In this review, we discuss recent progress and understanding on the research of MFs based on time-reversal-invariant superconducting topological materials to deepen our understanding and have a better outlook on both the search for and realization of MFs in these systems. We also discuss some advantages of these bulk systems to realize MFs including remarkable superconducting robustness against nonmagnetic impurities.

  6. Nonlinearities in Microwave Superconductivity

    OpenAIRE

    Ledenyov, Dimitri O.; Ledenyov, Viktor O.

    2012-01-01

    The research is focused on the modeling of nonlinear properties of High Temperature Superconducting (HTS) thin films, using Bardeen, Cooper, Schrieffer and Lumped Element Circuit theories, with purpose to enhance microwave power handling capabilities of microwave filters and optimize design of microwave circuits in micro- and nano- electronics.

  7. Coupled superconducting flux qubits

    NARCIS (Netherlands)

    Plantenberg, J.H.

    2007-01-01

    This thesis presents results of theoretical and experimental work on superconducting persistent-current quantum bits. These qubits offer an attractive route towards scalable solid-state quantum computing. The focus of this work is on the gradiometer flux qubit which has a special geometric design, t

  8. Applications of Superconductivity

    Science.gov (United States)

    Goodkind, John M.

    1971-01-01

    Presents a general review of current practical applications of the properties of superconducters. The devices are classified into groups according to the property that is of primary importance. The article is inteded as a first introduction for students and professionals. (Author/DS)

  9. Levitation Kits Demonstrate Superconductivity.

    Science.gov (United States)

    Worthy, Ward

    1987-01-01

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

  10. ISR Superconducting Quadrupoles

    CERN Multimedia

    1977-01-01

    Michel Bouvier is preparing for curing the 6-pole superconducting windings inbedded in the cylindrical wall separating liquid helium from vacuum in the quadrupole aperture. The heat for curing the epoxy glue was provided by a ramp of infrared lamps which can be seen above the slowly rotating cylinder. See also 7703512X, 7702690X.

  11. High temperature interface superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Gozar, A., E-mail: adrian.gozar@yale.edu [Yale University, New Haven, CT 06511 (United States); Bozovic, I. [Yale University, New Haven, CT 06511 (United States); Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2016-02-15

    Highlight: • This review article covers the topic of high temperature interface superconductivity. • New materials and techniques used for achieving interface superconductivity are discussed. • We emphasize the role played by the differences in structure and electronic properties at the interface with respect to the bulk of the constituents. - Abstract: High-T{sub c} superconductivity at interfaces has a history of more than a couple of decades. In this review we focus our attention on copper-oxide based heterostructures and multi-layers. We first discuss the technique, atomic layer-by-layer molecular beam epitaxy (ALL-MBE) engineering, that enabled High-T{sub c} Interface Superconductivity (HT-IS), and the challenges associated with the realization of high quality interfaces. Then we turn our attention to the experiments which shed light on the structure and properties of interfacial layers, allowing comparison to those of single-phase films and bulk crystals. Both ‘passive’ hetero-structures as well as surface-induced effects by external gating are discussed. We conclude by comparing HT-IS in cuprates and in other classes of materials, especially Fe-based superconductors, and by examining the grand challenges currently laying ahead for the field.

  12. Xinjiang Girl World Super Model

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Leading Chinese model Yue Mei won thetitle of World Super Model at the ’98 WorldSuper Model Competition held in FranceSeptember 6 - 17. Yue, a university studentfrom the Xinjiang Uygur AutonomousRegion, had won the top title at ’98 ChinaSuper Model Competition held in Beijingone month earier.After that, she underwentone month’s professional modeling trainingwith the New Silk Road ModelingManagement Company before setting off forthe world competition. In France, Yueimpressed the judges with her strikingfeatures, and display of oriental elegance and

  13. SuperB Progress Reports Accelerator

    CERN Document Server

    Biagini, Maria Enrica; Boscolo, M; Buonomo, B; Demma, T; Drago, A; Esposito, M; Guiducci, S; Mazzitelli, G; Pellegrino, L; Preger, M A; Raimondi, P; Ricci, R; Rotundo, U; Sanelli, C; Serio, M; Stella, A; Tomassini, S; Zobov, M; Bertsche, K; Brachman, A; Cai, Y; Chao, A; Chesnut, R; Donald, M.H; Field, C; Fisher, A; Kharakh, D; Krasnykh, A; Moffeit, K; Nosochkov, Y; Pivi, M; Seeman, J; Sullivan, M.K; Weathersby, S; Weidemann, A; Weisend, J; Wienands, U; Wittmer, W; Woods, M; Yocky, G; Bogomiagkov, A; Koop, I; Levichev, E; Nikitin, S; Okunev, I; Piminov, P; Sinyatkin, S; Shatilov, D; Vobly, P; Bosi, F; Liuzzo, S; Paoloni, E; Bonis, J; Chehab, R; Le Meur, G; Lepercq, P; Letellier-Cohen, F; Mercier, B; Poirier, F; Prevost, C; Rimbault, C; Touze, F; Variola, A; Bolzon, B; Brunetti, L; Jeremie, A; Baylac, M; Bourrion, O; De Conto, J M; Gomez, Y; Meot, F; Monseu, N; Tourres, D; Vescovi, C; Chanci, A; Napoly, O; Barber, D P; Bettoni, S; Quatraro, D

    2010-01-01

    This report details the present status of the Accelerator design for the SuperB Project. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

  14. SuperB Progress Report: Detector

    Energy Technology Data Exchange (ETDEWEB)

    Grauges, E.; /Barcelona U., ECM; Donvito, G.; Spinoso, V.; /INFN, Bari /Bari U.; Manghisoni, M.; Re, V.; Traversi, G.; /INFN, Pavia /Bergamo U., Ingengneria Dept.; Eigen, G.; Fehlker, D.; Helleve, L.; /Bergen U.; Carbone, A.; Di Sipio, R.; Gabrielli, A.; Galli, D.; Giorgi, F.; Marconi, U.; Perazzini, S.; Sbarra, C.; Vagnoni, V.; Valentinetti, S.; Villa, M.; Zoccoli, A.; /INFN, Bologna /Bologna U. /Caltech /Carleton U. /Cincinnati U. /INFN, CNAF /INFN, Ferrara /Ferrara U. /UC, Irvine /Taras Shevchenko U. /Orsay, LAL /LBL, Berkeley /UC, Berkeley /Frascati /INFN, Legnaro /Orsay, IPN /Maryland U. /McGill U. /INFN, Milan /Milan U. /INFN, Naples /Naples U. /Novosibirsk, IYF /INFN, Padua /Padua U. /INFN, Pavia /Pavia U. /INFN, Perugia /Perugia U. /INFN, Perugia /Caltech /INFN, Pisa /Pisa U. /Pisa, Scuola Normale Superiore /PNL, Richland /Queen Mary, U. of London /Rutherford /INFN, Rome /Rome U. /INFN, Rome2 /Rome U.,Tor Vergata /INFN, Rome3 /Rome III U. /SLAC /Tel Aviv U. /INFN, Turin /Turin U. /INFN, Padua /Trento U. /INFN, Trieste /Trieste U. /TRIUMF /British Columbia U. /Montreal U. /Victoria U.

    2012-02-14

    This report describes the present status of the detector design for SuperB. It is one of four separate progress reports that, taken collectively, describe progress made on the SuperB Project since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008.

  15. What's So Super about Superfoods?

    Science.gov (United States)

    ... with meals. The Skinny on Common Super Foods Salmon is a fatty fish that’s low in saturated ... soy nuts are high in polyunsaturated fat, fiber, vitamins and minerals but low in saturated fat. They ...

  16. Super Ministries,Better Administration

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ Chinese lawmakers on March 15th endorsed a State Counci l proposal for institutional overhaul of the tentral government,which involves the establishment of"super ministries"concerning energy,transport,industry and environmental protection.

  17. What are super-enhancers?

    Science.gov (United States)

    Pott, Sebastian; Lieb, Jason D

    2015-01-01

    The term 'super-enhancer' has been used to describe groups of putative enhancers in close genomic proximity with unusually high levels of Mediator binding, as measured by chromatin immunoprecipitation and sequencing (ChIP-seq). Here we review the identification and composition of super-enhancers, describe links between super-enhancers, gene regulation and disease, and discuss the functional significance of enhancer clustering. We also provide our perspective regarding the proposition that super-enhancers are a regulatory entity conceptually distinct from what was known before the introduction of the term. Our opinion is that there is not yet strong evidence that super-enhancers are a novel paradigm in gene regulation and that use of the term in this context is not currently justified. However, the term likely identifies strong enhancers that exhibit behaviors consistent with previous models and concepts of transcriptional regulation. In this respect, the super-enhancer definition is useful in identifying regulatory elements likely to control genes important for cell type specification.

  18. SQUID based cryogenic current comparator for measurements of the dark current of superconducting cavities

    Energy Technology Data Exchange (ETDEWEB)

    Vodel, W.; Nietzsche, S.; Neubert, R.; Nawrodt, R. [Friedrich Schiller Univ. Jena (Germany); Peters, A. [GSI Darmstadt (Germany); Knaack, K.; Wendt, M.; Wittenburg, K. [DESY Hamburg (Germany)

    2005-07-01

    The linear accelerator technology, based on super-conducting L-band (1.3 GHz) is currently under study at DESY (Hamburg, Germany). The two 10 km long main Linacs will be equipped with a total of nearly 20.000 cavities. The dark current due to the emission of electrons in these high gradient field super-conducting cavities is an unwanted particle source. A newly high performance SQUID based measurement system for detecting dark currents is proposed. It makes use of the Cryogenic Current Comparator principle and senses dark currents in the pA range with a measurement bandwidth of up to 70 kHz. The use of a cryogenic current comparator as dark current sensor has some important advantages: -) the measurement of the absolute value of the dark current, -) the non-dependence on the electron trajectories, -) the accurate absolute calibration with an additional wire loop, and -) extremely high resolution.

  19. Holography based super resolution

    Science.gov (United States)

    Hussain, Anwar; Mudassar, Asloob A.

    2012-05-01

    This paper describes the simulation of a simple technique of superresolution based on holographic imaging in spectral domain. The input beam assembly containing 25 optical fibers with different orientations and positions is placed to illuminate the object in the 4f optical system. The position and orientation of each fiber is calculated with respect to the central fiber in the array. The positions and orientations of the fibers are related to the shift of object spectrum at aperture plane. During the imaging process each fiber is operated once in the whole procedure to illuminate the input object transparency which gives shift to the object spectrum in the spectral domain. This shift of the spectrum is equal to the integral multiple of the pass band aperture width. During the operation of single fiber (ON-state) all other fibers are in OFF-state at that time. The hologram recorded by each fiber at the CCD plane is stored in computer memory. At the end of illumination process total 25 holograms are recorded by the whole fiber array and by applying some post processing and specific algorithm single super resolved image is obtained. The superresolved image is five times better than the band-limited image. The work is demonstrated using computer simulation only.

  20. Superconductivity an introduction

    CERN Document Server

    Kleiner, Reinhold

    2016-01-01

    The third edition of this proven text has been developed further in both scope and scale to reflect the potential for superconductivity in power engineering to increase efficiency in electricity transmission or engines. The landmark reference remains a comprehensive introduction to the field, covering every aspect from fundamentals to applications, and presenting the latest developments in organic superconductors, superconducting interfaces, quantum coherence, and applications in medicine and industry. Due to its precise language and numerous explanatory illustrations, it is suitable as an introductory textbook, with the level rising smoothly from chapter to chapter, such that readers can build on their newly acquired knowledge. The authors cover basic properties of superconductors and discuss stability and different material groups with reference to the latest and most promising applications, devoting the last third of the book to applications in power engineering, medicine, and low temperature physics. An e...

  1. Superconducting Accelerator Magnets

    CERN Document Server

    Mess, K H; Wolff, S

    1996-01-01

    The main topic of the book are the superconducting dipole and quadrupole magnets needed in high-energy accelerators and storage rings for protons, antiprotons or heavy ions. The basic principles of low-temperature superconductivity are outlined with special emphasis on the effects which are relevant for accelerator magnets. Properties and fabrication methods of practical superconductors are described. Analytical methods for field calculation and multipole expansion are presented for coils without and with iron yoke. The effect of yoke saturation and geometric distortions on field quality is studied. Persistent magnetization currents in the superconductor and eddy currents the copper part of the cable are analyzed in detail and their influence on field quality and magnet performance is investigated. Superconductor stability, quench origins and propagation and magnet protection are addressed. Some important concepts of accelerator physics are introduced which are needed to appreciate the demanding requirements ...

  2. Statistical mechanics of superconductivity

    CERN Document Server

    Kita, Takafumi

    2015-01-01

    This book provides a theoretical, step-by-step comprehensive explanation of superconductivity for undergraduate and graduate students who have completed elementary courses on thermodynamics and quantum mechanics. To this end, it adopts the unique approach of starting with the statistical mechanics of quantum ideal gases and successively adding and clarifying elements and techniques indispensible for understanding it. They include the spin-statistics theorem, second quantization, density matrices, the Bloch–De Dominicis theorem, the variational principle in statistical mechanics, attractive interaction, and bound states. Ample examples of their usage are also provided in terms of topics from advanced statistical mechanics such as two-particle correlations of quantum ideal gases, derivation of the Hartree–Fock equations, and Landau’s Fermi-liquid theory, among others. With these preliminaries, the fundamental mean-field equations of superconductivity are derived with maximum mathematical clarity based on ...

  3. Superconducting switch pack

    Energy Technology Data Exchange (ETDEWEB)

    Srivastava, V.C.; Wollan, J.J.

    1990-07-24

    This patent describes a superconducting switch pack at least one switch element. The switch element including a length of superconductive wire having a switching portion and two lead portions, the switching portion being between the lead portions; means for supporting the switching portion in a plane in a common mold; hardened resin means encapsulating the switching portion in the plane in a solid body; wherein the solid body has an exterior surface which is planar and substantially parallel with and spaced apart from the plane in which the switching portion is positioned. The exterior surface being exposed to the exterior of the switch pack and the resin means filling the space between the exterior surface and the plane of the switching portion so as to provide uninterrupted thermal communication between the plane of the switching portion and the exterior of the switch pack; and a heater element in thermal contact with the switching portion.

  4. Tunable superconducting nanoinductors

    Energy Technology Data Exchange (ETDEWEB)

    Annunziata, Anthony J; Santavicca, Daniel F; Frunzio, Luigi; Rooks, Michael J; Prober, Daniel E [Department of Applied Physics, Yale University, New Haven, CT 06511 (United States); Catelani, Gianluigi [Department of Physics, Yale University, New Haven, CT 06511 (United States); Frydman, Aviad, E-mail: anthony.annunziata@yale.edu, E-mail: daniel.prober@yale.edu [Department of Physics, Bar-Ilan University, Ramat Gan 52900 (Israel)

    2010-11-05

    We characterize inductors fabricated from ultra-thin, approximately 100 nm wide strips of niobium (Nb) and niobium nitride (NbN). These nanowires have a large kinetic inductance in the superconducting state. The kinetic inductance scales linearly with the nanowire length, with a typical value of 1 nH {mu}m{sup -1} for NbN and 44 pH {mu}m{sup -1} for Nb at a temperature of 2.5 K. We measure the temperature and current dependence of the kinetic inductance and compare our results to theoretical predictions. We also simulate the self-resonant frequencies of these nanowires in a compact meander geometry. These nanowire inductive elements have applications in a variety of microwave frequency superconducting circuits.

  5. Time ripe for superconductivity?

    Directory of Open Access Journals (Sweden)

    George Marsh

    2002-04-01

    But there is a crucial deadline and failure to meet it could send superconductivity back to the commercial shadows (at least outside the medical and scientific niches where it is a key enabler in analytical instruments, magnetic resonance imaging, and particle accelerators for another 30 years. Later this decade, the vintage infrastructure of dense copper conductors that supports power distribution in developed countries, in particular in the US, will become due for renewal. (Recent power problems in California were largely those of distribution infrastructure. At the same time, boosting capacity to serve the needs of increasingly affluent populations will pose a challenge. Superconductivity could provide the answer — if the technology matures in time and cost targets are met.

  6. Relativistic Model for two-band Superconductivity

    OpenAIRE

    Ohsaku, Tadafumi

    2003-01-01

    To understand the superconductivity in MgB2, several two-band models of superconductivity were proposed. In this paper, by using the relativistic fermion model, we clearize the effect of the lower band in the superconductivity.

  7. Models of high-Tc superconductivity and applications to electric generators and motors

    DEFF Research Database (Denmark)

    Sørensen, Mads Peter

    We present the Ginzburg Landau model for mesoscopic high-Tc superconductors of complex geometry. It is shown that giant vortices can form at boundary defects. The relation between total magnetic flux penetration through the superconductor and the externally applied field is established. This is i....... This is in turn used in modelling high-Tc superconducting generators proposed for windmills in the project SuperWind (http://www.superwind.dk)....

  8. Reproducible Operating Margins on a 72800-Device Digital Superconducting Chip (Open Access)

    Science.gov (United States)

    2015-10-28

    Reproducible operating margins on a 72800- device digital superconducting chip Quentin P Herr, Joshua Osborne, Micah J A Stoutimore, Harold Hearne...super- conducting-quantum-interference- device circuits [6–8] and even more directly using magnetic imaging [9]. For larger, digital circuits, flux...design and test of reciprocal quantum logic shift-register yield vehicles consisting of up to 72 800 Josephson junction devices per die, the largest

  9. The origins of macroscopic quantum coherence in high temperature superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Turner, Philip, E-mail: ph.turner@napier.ac.uk [Edinburgh Napier University, 10 Colinton Road, Edinburgh EH10 5DT (United Kingdom); Nottale, Laurent, E-mail: laurent.nottale@obspm.fr [CNRS, LUTH, Observatoire de Paris-Meudon, 5 Place Janssen, 92190 Meudon (France)

    2015-08-15

    Highlights: • We propose a new theoretical approach to superconductivity in p-type cuprates. • Electron pairing mechanisms in the superconducting and pseudogap phases are proposed. • A scale free network of dopants is key to macroscopic quantum coherence. - Abstract: A new, theoretical approach to macroscopic quantum coherence and superconductivity in the p-type (hole doped) cuprates is proposed. The theory includes mechanisms to account for e-pair coupling in the superconducting and pseudogap phases and their inter relations observed in these materials. Electron pair coupling in the superconducting phase is facilitated by local quantum potentials created by static dopants in a mechanism which explains experimentally observed optimal doping levels and the associated peak in critical temperature. By contrast, evidence suggests that electrons contributing to the pseudogap are predominantly coupled by fractal spin waves (fractons) induced by the fractal arrangement of dopants. On another level, the theory offers new insights into the emergence of a macroscopic quantum potential generated by a fractal distribution of dopants. This, in turn, leads to the emergence of coherent, macroscopic spin waves and a second associated macroscopic quantum potential, possibly supported by charge order. These quantum potentials play two key roles. The first involves the transition of an expected diffusive process (normally associated with Anderson localization) in fractal networks, into e-pair coherence. The second involves the facilitation of tunnelling between localized e-pairs. These combined effects lead to the merger of the super conducting and pseudo gap phases into a single coherent condensate at optimal doping. The underlying theory relating to the diffusion to quantum transition is supported by Coherent Random Lasing, which can be explained using an analogous approach. As a final step, an experimental program is outlined to validate the theory and suggests a new

  10. Topological confinement and superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Al-hassanieh, Dhaled A [Los Alamos National Laboratory; Batista, Cristian D [Los Alamos National Laboratory

    2008-01-01

    We derive a Kondo Lattice model with a correlated conduction band from a two-band Hubbard Hamiltonian. This mapping allows us to describe the emergence of a robust pairing mechanism in a model that only contains repulsive interactions. The mechanism is due to topological confinement and results from the interplay between antiferromagnetism and delocalization. By using Density-Matrix-Renormalization-Group (DMRG) we demonstrate that this mechanism leads to dominant superconducting correlations in aID-system.

  11. Unconventional superconductivity near inhomogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Poenicke, A.F.

    2008-01-25

    After the presentation of a quasi-classical theory the specific heat of Sr{sub 2}RuO{sub 4} is considered. Then tunneling spectroscopy on cuprate superconductors is discussed. Thereafter the subharmonic gap structure in d-wave superconductors is considered. Finally the application of the S-matrix in superconductivity is discussed with spin mixing, CrO{sub 2} as example, and an interface model. (HSI)

  12. Helical superconducting black holes.

    Science.gov (United States)

    Donos, Aristomenis; Gauntlett, Jerome P

    2012-05-25

    We construct novel static, asymptotically five-dimensional anti-de Sitter black hole solutions with Bianchi type-VII(0) symmetry that are holographically dual to superconducting phases in four spacetime dimensions with a helical p-wave order. We calculate the precise temperature dependence of the pitch of the helical order. At zero temperature the black holes have a vanishing entropy and approach domain wall solutions that reveal homogenous, nonisotropic dual ground states with an emergent scaling symmetry.

  13. Silicon superconducting quantum interference device

    Energy Technology Data Exchange (ETDEWEB)

    Duvauchelle, J. E.; Francheteau, A.; Marcenat, C.; Lefloch, F., E-mail: francois.lefloch@cea.fr [Université Grenoble Alpes, CEA - INAC - SPSMS, F-38000 Grenoble (France); Chiodi, F.; Débarre, D. [Université Paris-sud, CNRS - IEF, F-91405 Orsay - France (France); Hasselbach, K. [Université Grenoble Alpes, CNRS - Inst. Néel, F-38000 Grenoble (France); Kirtley, J. R. [Center for probing at nanoscale, Stanford University, Palo Alto, California 94305-4045 (United States)

    2015-08-17

    We have studied a Superconducting Quantum Interference Device (SQUID) made from a single layer thin film of superconducting silicon. The superconducting layer is obtained by heavily doping a silicon wafer with boron atoms using the gas immersion laser doping technique. The SQUID is composed of two nano-bridges (Dayem bridges) in a loop and shows magnetic flux modulation at low temperature and low magnetic field. The overall behavior shows very good agreement with numerical simulations based on the Ginzburg-Landau equations.

  14. Superconducting Qubit Optical Transducer (SQOT)

    Science.gov (United States)

    2015-08-05

    SECURITY CLASSIFICATION OF: The SQOT (Superconducting Qubit Optical Transducer ) project proposes to build a novel electro-optic system which can...Apr-2015 Approved for Public Release; Distribution Unlimited Final Report: "Superconducting Qubit Optical Transducer " (SQOT) The views, opinions and...journals: Number of Papers published in non peer-reviewed journals: Final Report: "Superconducting Qubit Optical Transducer " (SQOT) Report Title The

  15. Hybrid Superconducting Neutron Detectors

    CERN Document Server

    Merlo, V; Cirillo, M; Lucci, M; Ottaviani, I; Scherillo, A; Celentano, G; Pietropaolo, A

    2014-01-01

    A new neutron detection concept is presented that is based on superconductive niobium (Nb) strips coated by a boron (B) layer. The working principle of the detector relies on the nuclear reaction 10B+n $\\rightarrow$ $\\alpha$+ 7Li , with $\\alpha$ and Li ions generating a hot spot on the current-biased Nb strip which in turn induces a superconducting-normal state transition. The latter is recognized as a voltage signal which is the evidence of the incident neutron. The above described detection principle has been experimentally assessed and verified by irradiating the samples with a pulsed neutron beam at the ISIS spallation neutron source (UK). It is found that the boron coated superconducting strips, kept at a temperature T = 8 K and current-biased below the critical current Ic, are driven into the normal state upon thermal neutron irradiation. As a result of the transition, voltage pulses in excess of 40 mV are measured while the bias current can be properly modulated to bring the strip back to the supercond...

  16. Navy superconductivity efforts

    Science.gov (United States)

    Gubser, D. U.

    1990-04-01

    Both the new high temperature superconductors (HTS) and the low temperature superconductors (LTS) are important components of Navy's total plan to integrate superconductivity into field operational systems. Fundamental research is an important component of the total Navy program and focuses on the HTS materials. Power applications (ship propulsion, etc.) use LTS materials while space applications (MMW electronics, etc.) use HTS materials. The Space Experiment being conducted at NRL will involve space flight testing of HTS devices built by industry and will demonstrate the ability to engineer and space qualify these devices for systems use. Another important component of the Navy's effort is the development of Superconducting Quantum Interference Device (SQUID) magnetometers. This program will use LTS materials initially, but plans to implement HTS materials as soon as possible. Hybrid HTS/LTS systems are probable in many applications. A review of the status of the Navy's HTS materials research is given as well as an update on the Navy's development efforts in superconductivity, with particular emphasis on the related SDIO sponsored program on HTS applications.

  17. US Navy superconductivity program

    Science.gov (United States)

    Gubser, Donald U.

    1991-01-01

    Both the new high temperature superconductors (HTS) and the low temperature superconductors (LTS) are important components of the Navy's total plan to integrate superconductivity into field operational systems. Fundamental research is an important component of the total Navy program and focuses on the HTS materials. Power applications (ship propulsion) use LTS materials while space applications (millimeter wave electronics) use HTS materials. The Space Experiment to be conducted at NRL will involve space flight testing of HTS devices built by industry and will demonstrate the ability to engineer and space qualify these devices for systems use. Another important component of the Navy's effort is the development of Superconducting Quantum Interference Device (SQUID) magnetometers. This program will use LTS materials initially, but plans to implement HTS materials as soon as possible. Hybrid HTS/LTS systems are probable in many applications. A review of the status of the Navy's HTS materials research is given as well as an update on the Navy's development efforts in superconductivity.

  18. Navy superconductivity efforts

    Science.gov (United States)

    Gubser, D. U.

    1990-01-01

    Both the new high temperature superconductors (HTS) and the low temperature superconductors (LTS) are important components of Navy's total plan to integrate superconductivity into field operational systems. Fundamental research is an important component of the total Navy program and focuses on the HTS materials. Power applications (ship propulsion, etc.) use LTS materials while space applications (MMW electronics, etc.) use HTS materials. The Space Experiment being conducted at NRL will involve space flight testing of HTS devices built by industry and will demonstrate the ability to engineer and space qualify these devices for systems use. Another important component of the Navy's effort is the development of Superconducting Quantum Interference Device (SQUID) magnetometers. This program will use LTS materials initially, but plans to implement HTS materials as soon as possible. Hybrid HTS/LTS systems are probable in many applications. A review of the status of the Navy's HTS materials research is given as well as an update on the Navy's development efforts in superconductivity, with particular emphasis on the related SDIO sponsored program on HTS applications.

  19. Superconductivity in CVD diamond films.

    Science.gov (United States)

    Takano, Yoshihiko

    2009-06-24

    A beautiful jewel of diamond is insulator. However, boron doping can induce semiconductive, metallic and superconducting properties in diamond. When the boron concentration is tuned over 3 × 10(20) cm(-3), diamonds enter the metallic region and show superconductivity at low temperatures. The metal-insulator transition and superconductivity are analyzed using ARPES, XAS, NMR, IXS, transport and magnetic measurements and so on. This review elucidates the physical properties and mechanism of diamond superconductor as a special superconductivity that occurs in semiconductors.

  20. Unconventional superconductivity in honeycomb lattice

    Directory of Open Access Journals (Sweden)

    P Sahebsara

    2013-03-01

    Full Text Available   ‎ The possibility of symmetrical s-wave superconductivity in the honeycomb lattice is studied within a strongly correlated regime, using the Hubbard model. The superconducting order parameter is defined by introducing the Green function, which is obtained by calculating the density of the electrons ‎ . In this study showed that the superconducting order parameter appears in doping interval between 0 and 0.5, and x=0.25 is the optimum doping for the s-wave superconductivity in honeycomb lattice.

  1. Superconductivity in graphite intercalation compounds

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Robert P. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Weller, Thomas E.; Howard, Christopher A. [Department of Physics & Astronomy, University College of London, Gower Street, London WCIE 6BT (United Kingdom); Dean, Mark P.M. [Department of Condensed Matter Physics and Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States); Rahnejat, Kaveh C. [Department of Physics & Astronomy, University College of London, Gower Street, London WCIE 6BT (United Kingdom); Saxena, Siddharth S. [Cavendish Laboratory, University of Cambridge, Madingley Road, Cambridge CB3 0HE (United Kingdom); Ellerby, Mark, E-mail: mark.ellerby@ucl.ac.uk [Department of Physics & Astronomy, University College of London, Gower Street, London WCIE 6BT (United Kingdom)

    2015-07-15

    Highlights: • Historical background of graphite intercalates. • Superconductivity in graphite intercalates and its place in the field of superconductivity. • Recent developments. • Relevant modeling of superconductivity in graphite intercalates. • Interpretations that pertain and questions that remain. - Abstract: The field of superconductivity in the class of materials known as graphite intercalation compounds has a history dating back to the 1960s (Dresselhaus and Dresselhaus, 1981; Enoki et al., 2003). This paper recontextualizes the field in light of the discovery of superconductivity in CaC{sub 6} and YbC{sub 6} in 2005. In what follows, we outline the crystal structure and electronic structure of these and related compounds. We go on to experiments addressing the superconducting energy gap, lattice dynamics, pressure dependence, and how these relate to theoretical studies. The bulk of the evidence strongly supports a BCS superconducting state. However, important questions remain regarding which electronic states and phonon modes are most important for superconductivity, and whether current theoretical techniques can fully describe the dependence of the superconducting transition temperature on pressure and chemical composition.

  2. Korea's developmental program for superconductivity

    Science.gov (United States)

    Hong, Gye-Won; Won, Dong-Yeon; Kuk, Il-Hyun; Park, Jong-Chul

    1995-01-01

    Superconductivity research in Korea was firstly carried out in the late 70's by a research group in Seoul National University (SNU), who fabricated a small scale superconducting magnetic energy storage system under the financial support from Korea Electric Power Company (KEPCO). But a few researchers were involved in superconductivity research until the oxide high Tc superconductor was discovered by Bednorz and Mueller. After the discovery of YBaCuO superconductor operating above the boiling point of liquid nitrogen (77 K)(exp 2), Korean Ministry of Science and Technology (MOST) sponsored a special fund for the high Tc superconductivity research to universities and national research institutes by recognizing its importance. Scientists engaged in this project organized 'High Temperature Superconductivity Research Association (HITSRA)' for effective conducting of research. Its major functions are to coordinate research activities on high Tc superconductivity and organize the workshop for active exchange of information. During last seven years the major superconductivity research has been carried out through the coordination of HITSRA. The major parts of the Korea's superconductivity research program were related to high temperature superconductor and only a few groups were carrying out research on conventional superconductor technology, and Korea Atomic Energy Research Institute (KAERI) and Korea Electrotechnology Research Institute (KERI) have led this research. In this talk, the current status and future plans of superconductivity research in Korea will be reviewed based on the results presented in interim meeting of HITSRA, April 1-2, 1994. Taejeon, as well as the research activity of KAERI.

  3. Optimization of superconducting tiling pattern for superconducting bearings

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL)

    1996-01-01

    An apparatus and method for reducing magnetic field inhomogeneities which produce rotational loss mechanisms in high temperature superconducting magnetic bearings. Magnetic field inhomogeneities are reduced by dividing high temperature superconducting structures into smaller structures, and arranging the smaller structures into tiers which stagger the magnetic field maximum locations of the smaller structures.

  4. Electrically tuned super-capacitors

    CERN Document Server

    Chowdhury, Tazima S

    2015-01-01

    Fast charging and discharging of large amounts of electrical energy make super-capacitors ideal for short-term energy storage [1-5]. In its simplest form, the super-capacitor is an electrolytic capacitor made of an anode and a cathode immersed in an electrolyte. As for an ordinary capacitor, minimizing the charge separation distance and increasing the electrode area increase capacitance. In super-capacitors, charge separation is of nano-meter scale at each of the electrode interface (the Helmholtz double layer). Making the electrodes porous increases their effective surface area [6-8]. A separating layer between the anode and the cathode electrodes is used to minimize unintentional electrical discharge (Figure 1). Here we show how to increase the capacitance of super-capacitors by more than 45 percent when modifying the otherwise passive separator layer into an active diode-like structure. Active control of super-capacitors may increase their efficiency during charge and discharge cycles. Controlling ion flow...

  5. Quantization of super Teichmueller spaces

    Energy Technology Data Exchange (ETDEWEB)

    Aghaei, Nezhla

    2016-08-15

    The quantization of the Teichmueller spaces of Riemann surfaces has found important applications to conformal field theory and N=2 supersymmetric gauge theories. We construct a quantization of the Teichmueller spaces of super Riemann surfaces, using coordinates associated to the ideal triangulations of super Riemann surfaces. A new feature is the non-trivial dependence on the choice of a spin structure which can be encoded combinatorially in a certain refinement of the ideal triangulation. We construct a projective unitary representation of the groupoid of changes of refined ideal triangulations. Therefore, we demonstrate that the dependence of the resulting quantum theory on the choice of a triangulation is inessential. In the quantum Teichmueller theory, it was observed that the key object defining the Teichmueller theory has a close relation to the representation theory of the Borel half of U{sub q}(sl(2)). In our research we observed that the role of U{sub q}(sl(2)) is taken by quantum superalgebra U{sub q}(osp(1 vertical stroke 2)). A Borel half of U{sub q}(osp(1 vertical stroke 2)) is the super quantum plane. The canonical element of the Heisenberg double of the quantum super plane is evaluated in certain infinite dimensional representations on L{sup 2}(R) x C{sup 1} {sup vertical} {sup stroke} {sup 1} and compared to the flip operator from the Teichmueller theory of super Riemann surfaces.

  6. Super-Virasoro anomaly, super-Weyl anomaly and the super-Liouville action for 2D supergravity

    CERN Document Server

    Fujiwara, T; Suzuki, T; Fujiwara, Takanori; Igarashi, Hiroshi; Suzuki, Tadao

    1996-01-01

    The relation between super-Virasoro anomaly and super-Weyl anomaly in N=1 NSR superstring coupled with 2D supergravity is investigated from canonical theoretical view point. The WZW action canceling the super-Virasoro anomaly is explicitly constructed. It is super-Weyl invariant but nonlocal functional of 2D supergravity. The nonlocality can be remedied by the super-Liouvlle action, which in turn recovers the super-Weyl anomaly. The final gravitational effective action turns out to be local but noncovariant super-Liouville action, describing the dynamical behavior of the super-Liouville fields. The BRST invariance of this approach is examined in the superconformal gauge and in the light-cone gauge.

  7. The Super-Kamiokande Experiment

    CERN Document Server

    Walter, C W

    2008-01-01

    Super-Kamiokande is a 50 kiloton water Cherenkov detector located at the Kamioka Observatory of the Institute for Cosmic Ray Research, University of Tokyo. It was designed to study neutrino oscillations and carry out searches for the decay of the nucleon. The Super-Kamiokande experiment began in 1996 and in the ensuing decade of running has produced extremely important results in the fields of atmospheric and solar neutrino oscillations, along with setting stringent limits on the decay of the nucleon and the existence of dark matter and astrophysical sources of neutrinos. Perhaps most crucially, Super-Kamiokande for the first time definitively showed that neutrinos have mass and undergo flavor oscillations. This chapter will summarize the published scientific output of the experiment with a particular emphasis on the atmospheric neutrino results.

  8. Development of cooling systems for high-Tc superconducting sampler; Koon chodendo sanpura reikyaku shisutemu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Fujimoto, S. [Daikin Industries Ltd., Osaka (Japan). Air-Conditioning R and D Lab.; Kang, Y.M. [Daikin Industries Ltd., Osaka (Japan). ENvironmental Lab.

    2000-05-29

    The sampler applying the high speed responsibility of high temperature super-conducting Josephson junction and height of the critical current sensitivity is expected as means of accurately observing super speed digital signal waveform. The high temperature super-conducting element practically used in combination with a small sized refrigerator up to now is a microwave filter being a driven element and a SQUID being a low speed analog element. In this study, the element using high speed switching characteristic of the Josephson junction like sampler circuit is applied to two small refrigerating machines of Stirling refrigerating machine and GM type pulse tube refrigerating machine. As an example of the former, a system for observing super-speed digital waveform is introduced. In this system, Stirling refrigerating machine of 5W(at mark)80K class is used in order to obtain the cooling temperature below 40K for improving the performance of the high temperature superconductivity sampler. As an example of the latter, a current waveform measurement system is introduced. (NEDO)

  9. The Danish Superconducting Cable Project

    DEFF Research Database (Denmark)

    Tønnesen, Ole

    1997-01-01

    The design and construction of a superconducting cable is described. The cable has a room temperature dielectric design with the cryostat placed inside the electrical insulation.BSCCO 2223 superconducting tapes wound in helix form around a former are used as the cable conductor. Results from...

  10. Superconducting bearings for flywheel applications

    DEFF Research Database (Denmark)

    Abrahamsen, A.B.

    2001-01-01

    A literature study on the application of superconducting bearings in energy storage flywheel systems. The physics of magnetic levitation and superconductors are presented in the first part of the report, followed by a discussion of the literature found onthe applications of superconducting bearings...

  11. Microsphere Super-resolution Imaging

    CERN Document Server

    Wang, Zengbo

    2015-01-01

    Recently, it was discovered that microsphere can generate super-resolution focusing beyond diffraction limit. This has led to the development of an exciting super-resolution imaging technique -microsphere nanoscopy- that features a record resolution of 50 nm under white lights. Different samples have been directly imaged in high resolution and real time without labelling, including both non-biological (nano devices, structures and materials) and biological (subcellular details, viruses) samples. This chapter reviews the technique, which covers its background, fundamentals, experiments, mechanisms as well as the future outlook.

  12. Interactive Super Mario Bros Evolution

    DEFF Research Database (Denmark)

    Sørensen, Patrikk D.; Olsen, Jeppeh M.; Risi, Sebastian

    2016-01-01

    to encourage the evolution of desired behaviors. In this paper, we show how casual users can create controllers for \\emph{Super Mario Bros} through an interactive evolutionary computation (IEC) approach, without prior domain or programming knowledge. By iteratively selecting Super Mario behaviors from a set...... of candidates, users are able to guide evolution towards a variety of different behaviors, which would be difficult with an automated approach. Additionally, the user-evolved controllers perform similarly well as controllers evolved with a traditional fitness-based approach when comparing distance traveled...

  13. Quantisation of super Teichmueller theory

    Energy Technology Data Exchange (ETDEWEB)

    Aghaei, Nezhla [DESY Hamburg (Germany). Theory Group; Hamburg Univ. (Germany). Dept. of Mathematics; Pawelkiewicz, Michal; Techner, Joerg [DESY Hamburg (Germany). Theory Group

    2015-12-15

    We construct a quantisation of the Teichmueller spaces of super Riemann surfaces using coordinates associated to ideal triangulations of super Riemann surfaces. A new feature is the non-trivial dependence on the choice of a spin structure which can be encoded combinatorially in a certain refinement of the ideal triangulation. By constructing a projective unitary representation of the groupoid of changes of refined ideal triangulations we demonstrate that the dependence of the resulting quantum theory on the choice of a triangulation is inessential.

  14. Quantisation of super Teichmueller theory

    CERN Document Server

    Aghaei, Nezhla; Teschner, Joerg

    2015-01-01

    We construct a quantisation of the Teichmueller spaces of super Riemann surfaces using coordinates associated to ideal triangulations of super Riemann surfaces. A new feature is the non-trivial dependence on the choice of a spin structure which can be encoded combinatorially in a certain refinement of the ideal triangulation. By constructing a projective unitary representation of the groupoid of changes of refined ideal triangulations we demonstrate that the dependence of the resulting quantum theory on the choice of a triangulation is inessential.

  15. A superconducting magnetic gear

    Science.gov (United States)

    Campbell, A. M.

    2016-05-01

    A comparison is made between a magnetic gear using permanent magnets and superconductors. The objective is to see if there are any fundamental reasons why superconducting magnets should not provide higher power densities than permanent magnets. The gear is based on the variable permeability design of Attilah and Howe (2001 IEEE Trans. Magn. 37 2844-46) in which a ring of permanent magnets surrounding a ring of permeable pole pieces with a different spacing gives an internal field component at the beat frequency. Superconductors can provide much larger fields and forces but will saturate the pole pieces. However the gear mechanism still operates, but in a different way. The magnetisation of the pole pieces is now constant but rotates with angle at the beat frequency. The result is a cylindrical Halbach array which produces an internal field with the same symmetry as in the linear regime, but has an analytic solution. In this paper a typical gear system is analysed with finite elements using FlexPDE. It is shown that the gear can work well into the saturation regime and that the Halbach array gives a good approximation to the results. Replacing the permanent magnets with superconducting tapes can give large increases in torque density, and for something like a wind turbine a combined gear and generator is possible. However there are major practical problems. Perhaps the most fundamental is the large high frequency field which is inevitably present and which will cause AC losses. Also large magnetic fields are required, with all the practical problems of high field superconducting magnets in rotating machines. Nevertheless there are ways of mitigating these difficulties and it seems worthwhile to explore the possibilities of this technology further.

  16. Superconductivity in a chiral nanotube

    Science.gov (United States)

    Qin, F.; Shi, W.; Ideue, T.; Yoshida, M.; Zak, A.; Tenne, R.; Kikitsu, T.; Inoue, D.; Hashizume, D.; Iwasa, Y.

    2017-02-01

    Chirality of materials are known to affect optical, magnetic and electric properties, causing a variety of nontrivial phenomena such as circular dichiroism for chiral molecules, magnetic Skyrmions in chiral magnets and nonreciprocal carrier transport in chiral conductors. On the other hand, effect of chirality on superconducting transport has not been known. Here we report the nonreciprocity of superconductivity--unambiguous evidence of superconductivity reflecting chiral structure in which the forward and backward supercurrent flows are not equivalent because of inversion symmetry breaking. Such superconductivity is realized via ionic gating in individual chiral nanotubes of tungsten disulfide. The nonreciprocal signal is significantly enhanced in the superconducting state, being associated with unprecedented quantum Little-Parks oscillations originating from the interference of supercurrent along the circumference of the nanotube. The present results indicate that the nonreciprocity is a viable approach toward the superconductors with chiral or noncentrosymmetric structures.

  17. Japan. Superconductivity for Smart Grids

    Energy Technology Data Exchange (ETDEWEB)

    Hayakawa, K.

    2012-11-15

    Currently, many smart grid projects are running or planned worldwide. These aim at controlling the electricity supply more efficiently and more stably in a new power network system. In Japan, especially superconductivity technology development projects are carried out to contribute to the future smart grid. Japanese cable makers such as Sumitomo Electric and Furukawa Electric are leading in the production of high-temperature superconducting (HTS) power cables. The world's largest electric current and highest voltage superconductivity proving tests have been started this year. Big cities such as Tokyo will be expected to introduce the HTS power cables to reduce transport losses and to meet the increased electricity demand in the near future. Superconducting devices, HTS power cables, Superconducting Magnetic Energy Storage (SMES) and flywheels are the focus of new developments in cooperations between companies, universities and research institutes, funded by the Japanese research and development funding organization New Energy and Industrial Technology Development Organization (NEDO)

  18. Superconducting Pb stripline resonators in parallel magnetic field and their application for microwave spectroscopy

    Science.gov (United States)

    Ebensperger, Nikolaj G.; Thiemann, Markus; Dressel, Martin; Scheffler, Marc

    2016-11-01

    Planar superconducting microwave resonators are key elements in a variety of technical applications and also act as sensitive probes for microwave spectroscopy of various materials of interest in present solid state research. Here superconducting Pb is a suitable material as a basis for microwave stripline resonators. To utilize Pb stripline resonators in a variable magnetic field (e.g. in ESR measurements), the electrodynamics of such resonators in a finite magnetic field has to be fully understood. Therefore we performed microwave transmission measurements (with ample applied power to work in linear response) on superconducting Pb stripline resonators in a variable, parallel magnetic field. We determined surface resistance, penetration depth, as well as real and imaginary parts, {σ }1 and {σ }2, of the complex conductivity of superconducting Pb as a function of a magnetic field. Here we find features reminiscent of those in temperature-dependent measurements, such as a maximum in {σ }1 (coherence peak). At magnetic fields above the critical field of this type-I superconductor we still find a low-loss microwave response, which we assign to remaining superconductivity in the form of filaments within the Pb. Hysteresis effects are found in the quality factor of resonances once the swept magnetic field has exceeded the critical magnetic field. This is due to normal conducting areas that are pinned and can therefore persist in the superconducting phase. Besides zero-field-cooling we show an alternative way to eliminate these even at T\\lt {T}c. Based on our microwave data, we also determine the critical magnetic field and the critical temperature of Pb in a temperature range between 1.6 K and 6.5 K and magnetic fields up to 140 mT, showing good agreement with BCS predictions. We also study a Sn sample in a Pb resonator to demonstrate the applicability of superconducting Pb stripline resonators in the experimental study of other (super-)conducting materials in a

  19. The construction of orthodox super rpp semigroups

    Institute of Scientific and Technical Information of China (English)

    HE Yong; GUO Yuqi; Kar Ping Shum

    2004-01-01

    We define orthodox super rpp semigroups and study their semilattice decompositions. Standard representation theorem of orthodox super rpp semigroups whose subband of idempotents is in the varieties of bands described by an identity with at most three variables are obtained.

  20. Superconducting dipole electromagnet

    Science.gov (United States)

    Purcell, John R.

    1977-07-26

    A dipole electromagnet of especial use for bending beams in particle accelerators is wound to have high uniformity of magnetic field across a cross section and to decrease evenly to zero as the ends of the electromagnet are approached by disposing the superconducting filaments of the coil in the crescent-shaped nonoverlapping portions of two intersecting circles. Uniform decrease at the ends is achieved by causing the circles to overlap increasingly in the direction of the ends of the coil until the overlap is complete and the coil is terminated.

  1. 100 years of superconductivity

    CERN Multimedia

    Globe Info

    2011-01-01

    Public lecture by Philippe Lebrun, who works at CERN on applications of superconductivity and cryogenics for particle accelerators. He was head of CERN’s Accelerator Technology Department during the LHC construction period. Centre culturel Jean Monnet, route de Gex Tuesday 11 October from 8.30 p.m. to 10.00 p.m. » Suitable for all – Admission free - Lecture in French » Number of places limited For further information: +33 (0)4 50 42 29 37

  2. TOPICAL REVIEW: Superconducting bearings

    Science.gov (United States)

    Hull, John R.

    2000-02-01

    The physics and technology of superconducting bearings is reviewed. Particular attention is given to the use of high-temperature superconductors (HTSs) in rotating bearings. The basic phenomenology of levitational forces is presented, followed by a brief discussion of the theoretical models that can be used for conceptual understanding and calculations. The merits of various HTS bearing designs are presented, and the behaviour of HTS bearings in typical situations is discussed. The article concludes with a brief survey of various proposed applications for HTS bearings.

  3. Conventional and unconventional superconductivity

    Science.gov (United States)

    Fernandes, R. M.

    2012-02-01

    Superconductivity has been one of the most fruitful areas of research in condensed matter physics, bringing together researchers with distinct interests in a collaborative effort to understand from its microscopic basis to its potential for unprecedented technological applications. The concepts, techniques, and methods developed along its centennial history have gone beyond the realm of condensed matter physics and influenced the development of other fascinating areas, such as particle physics and atomic physics. These notes, based on a set of lectures given at the 2011 Advanced Summer School of Cinvestav, aim to motivate the young undergraduate student in getting involved in the exciting world of conventional and unconventional superconductors.

  4. Superconductivity from correlated hopping

    CERN Document Server

    Batista, C D; Aligia, A A

    1995-01-01

    We consider a chain described by a next-nearest-neighbor hopping combined with a nearest-neighbor spin flip. In two dimensions this three-body term arises from a mapping of the three-band Hubbard model for CuO$_2$ planes to a generalized $t-J$ model and for large O-O hopping favors resonance-valence-bond superconductivity of predominantly $d$-wave symmetry. Solving the ground state and low-energy excitations by analytical and numerical methods we find that the chain is a Luther-Emery liquid with correlation exponent $K_{\\rho} = (2-n)^2/2$, where $n$ is the particle density.

  5. Superconductivity in nanowires

    CERN Document Server

    Bezryadin, Alexey

    2012-01-01

    The importance and actuality of nanotechnology is unabated and will be for years to come. A main challenge is to understand the various properties of certain nanostructures, and how to generate structures with specific properties for use in actual applications in Electrical Engineering and Medicine.One of the most important structures are nanowires, in particular superconducting ones. They are highly promising for future electronics, transporting current without resistance and at scales of a few nanometers. To fabricate wires to certain defined standards however, is a major challenge, and so i

  6. Introduction to superconductivity

    CERN Document Server

    Rose-Innes, AC

    1978-01-01

    Introduction to Superconductivity differs from the first edition chiefly in Chapter 11, which has been almost completely rewritten to give a more physically-based picture of the effects arising from the long-range coherence of the electron-waves in superconductors and the operation of quantum interference devices. In this revised second edition, some further modifications have been made to the text and an extra chapter dealing with """"high-temperature"""" superconductors has been added. A vast amount of research has been carried out on these since their discovery in 1986 but the results, both

  7. Superconducting Electronic Film Structures

    Science.gov (United States)

    1991-02-14

    cubic, yttria stabilized, zirconia (YSZ) single crystals with (100) orientation and ao = 0.512 to 0.516 nm. Films were magnetron-sputtered... Crown by Solid-State and Vapor-Phase Epitaxy," IEEE Trans. Uagn. 25(2), 2538 (1989). 6. J. H. Kang, R. T. Kampwirth, and K. E. Gray, "Superconductivity...summarized in Fig. 1, are too high for SrTiO3 or yttria- stabilized zirconia (YSZ) to be used in rf applications. MgO, LaAIO 3 , and LaGaO3 have a tan 6

  8. Heavy fermion superconductivity

    Science.gov (United States)

    Brison, Jean-Pascal; Glémot, Loı̈c; Suderow, Hermann; Huxley, Andrew; Kambe, Shinsaku; Flouquet, Jacques

    2000-05-01

    The quest for a precise identification of the symmetry of the order parameter in heavy fermion systems has really started with the discovery of the complex superconducting phase diagram in UPt 3. About 10 years latter, despite numerous experiments and theoretical efforts, this is still not achieved, and we will quickly review the present status of knowledge and the main open question. Actually, the more forsaken issue of the nature of the pairing mechanism has been recently tackled by different groups with macroscopic or microscopic measurement, and significant progress have been obtained. We will discuss the results emerging from these recent studies which all support non-phonon-mediated mechanisms.

  9. Overview on superconducting photoinjectors

    CERN Document Server

    Arnold, A

    2011-01-01

    The success of most of the proposed energy recovery linac (ERL) based electron accelerator projects for future storage ring replacements (SRR) and high power IR–free-electron lasers (FELs) largely depends on the development of an appropriate source. For example, to meet the FEL specifications [J.W. Lewellen, Proc. SPIE Int. Soc. Opt. Eng. 5534, 22 (2004)] electron beams with an unprecedented combination of high brightness, low emittance (0.1 µmrad), and high average current (hundreds of mA) are required. An elegant way to create a beam of such quality is to combine the high beam quality of a normal conducting rf photoinjector with the superconducting technology, i.e., to build a superconducting rf photoinjector (SRF gun). SRF gun R&D programs based on different approaches have been launched at a growing number of institutes and companies (AES, Beijing University, BESSY, BNL, DESY, FZD, TJNAF, Niowave, NPS, Wisconsin University). Substantial progress was achieved in recent years and the first long term ...

  10. Overview of Superconducting Photoinjectors

    CERN Document Server

    Arnold, A

    2009-01-01

    The success of most of the proposed ERL based electron accelerator projects for future storage ring replacements (SRR) and high power IR-FELs is contingent upon the development of an appropriate source. Electron beams with an unprecedented combination of high brightness, low emittance (0.1 µm rad) and high average current (hundreds of mA) are required to meet the FEL specification [1]. An elegant way to create such an unique beam is to combine the high beam quality of a normal conducting RF photo injector with the superconducting technology to get a superconducting RF photo injector (SRF gun). SRF gun R&D programs based on different approaches are under investigation at a growing number of institutes and companies (AES, Beijing University, BESSY, BNL, DESY, FZD, JLab, Niowave, NPS, Wisconsin University). Lot of progress could be achieved during the last years and first long term operation was demonstrated at the FZD [2]. In the near future, this effort will lead to SRF guns, which are indispensab...

  11. Superconducting magnets for MRI

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.E.

    1984-08-01

    Three types of magnets are currently used to provide the background field required for magnet resonance imaging (MRI). (i) Permanent magnets produce fields of up to 0.3 T in volumes sufficient for imaging the head or up to 0.15 T for whole body imaging. Cost and simplicity of operation are advantages, but relatively low field, weight (up to 100 tonnes) and, to a small extent, instability are limitations. (ii) Water-cooled magnets provide fields of up to 0.25 T in volumes suitable for whole body imaging, but at the expense of power (up to 150 kW for 0.25 T) and water-cooling. Thermal stability of the field requires the maintenance of constant temperature through periods both of use and of quiescence. (iii) Because of the limitations imposed by permanent and resistive magnets, particularly on field strength, the superconducting magnet is now most widely used to provide background fields of up to 2 T for whole body MRI. It requires very low operating power and that only for refrigeration. Because of the constant low temperature, 4.2 K, at which its stressed structure operates, its field is stable. The following review deals principally with superconducting magnets for MRI. However, the sections on field analysis apply to all types of magnet and the description of the source terms of circular coils and of the principals of design of solenoids apply equally to resistive solenoidal magnets.

  12. Super-resolution Phase Tomography

    KAUST Repository

    Depeursinge, Christian

    2013-04-21

    Digital Holographic Microscopy (DHM) yields reconstructed complex wavefields. It allows synthesizing the aperture of a virtual microscope up to 2π, offering super-resolution phase images. Live images of micro-organisms and neurons with resolution less than 100 nm are presented.

  13. Super Rice Breeding in China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@I. Demand for super high yield rice in China   Rice is one of the main staple food in China. The performance of rice sector in production and yield had been very impressive in the last four decades. However, rice production and yield has stagnated since 1990.

  14. Super Girls Still Center Stage

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The TV singing contest continues to draw a devoted audience, but will its impact on Chinese culture fall away like a shooting star? Ask any teenage girl in China to name the finalists of last year's Super Girl show and chances are she will instantly come up with the three big names.She'll probable

  15. Analysis of Forensic Super Timelines

    Science.gov (United States)

    2012-06-14

    BIB .1  vii List of Figures Figure Page...Hacker disconnects from User’s system  User clicks off Screen Saver  User closes Solitaire program  User logs off system BIB .1...analysis- tapestry_33836. BIB .2 Guðjónsson, K. (2010). Mastering the super timeline with log2timeline. SANS Gold Paper accepted June 29,2010

  16. Superconducting Fault Current Limiter optimized design

    Science.gov (United States)

    Tixador, Pascal; Badel, Arnaud

    2015-11-01

    The SuperConducting Fault Current Limiter (SCFCL) appears as one of the most promising SC applications for the electrical grids. Despite its advantages and many successful field experiences the market of SCFCL has difficulties to take off even if the first orders for permanent operation in grids are taken. The analytical design of resistive SCFCL will be discussed with the objective to reduce the quantity of SC conductor (length and section) to be more cost-effective. For that the SC conductor must have a high resistivity in normal state. It can be achieved by using high resistivity alloy for shunt, such as Hastelloy®. One of the most severe constraint is that the SCFCL should operate safely for any faults, especially those with low prospective short-circuit currents. This constraint requires to properly design the thickness of the SC tape in order to limit the hot spot temperature. An operation at 65 K appears as very interesting since it decreases the SC cost at least by a factor 2 with a simple LN2 cryogenics. Taking into account the cost reduction in a near future, the SC conductor cost could be rather low, half a dollar per kV A.

  17. Superconducting Fault Current Limiter optimized design

    Energy Technology Data Exchange (ETDEWEB)

    Tixador, Pascal, E-mail: Pascal.Tixador@grenoble-inp.fr [Univ. Grenoble Alpes, G2Elab – Institut Néel, F-38000 Grenoble (France); CNRS, G2Elab – Institut Néel, F-38000 Grenoble (France); Badel, Arnaud [CNRS, G2Elab – Institut Néel, F-38000 Grenoble (France)

    2015-11-15

    Highlights: • A low cost design of YBCO Fault Current Limiter. • A high resistance conductor for reduced length. • An asymmetrical YBCO conductor (injection and AC losses). • A thickness suitable for non destructive hot spots. - Abstract: The SuperConducting Fault Current Limiter (SCFCL) appears as one of the most promising SC applications for the electrical grids. Despite its advantages and many successful field experiences the market of SCFCL has difficulties to take off even if the first orders for permanent operation in grids are taken. The analytical design of resistive SCFCL will be discussed with the objective to reduce the quantity of SC conductor (length and section) to be more cost-effective. For that the SC conductor must have a high resistivity in normal state. It can be achieved by using high resistivity alloy for shunt, such as Hastelloy®. One of the most severe constraint is that the SCFCL should operate safely for any faults, especially those with low prospective short-circuit currents. This constraint requires to properly design the thickness of the SC tape in order to limit the hot spot temperature. An operation at 65 K appears as very interesting since it decreases the SC cost at least by a factor 2 with a simple LN2 cryogenics. Taking into account the cost reduction in a near future, the SC conductor cost could be rather low, half a dollar per kV A.

  18. Superconductivity in doped Dirac semimetals

    Science.gov (United States)

    Hashimoto, Tatsuki; Kobayashi, Shingo; Tanaka, Yukio; Sato, Masatoshi

    2016-07-01

    We theoretically study intrinsic superconductivity in doped Dirac semimetals. Dirac semimetals host bulk Dirac points, which are formed by doubly degenerate bands, so the Hamiltonian is described by a 4 ×4 matrix and six types of k -independent pair potentials are allowed by the Fermi-Dirac statistics. We show that the unique spin-orbit coupling leads to characteristic superconducting gap structures and d vectors on the Fermi surface and the electron-electron interaction between intra and interorbitals gives a novel phase diagram of superconductivity. It is found that when the interorbital attraction is dominant, an unconventional superconducting state with point nodes appears. To verify the experimental signature of possible superconducting states, we calculate the temperature dependence of bulk physical properties such as electronic specific heat and spin susceptibility and surface state. In the unconventional superconducting phase, either dispersive or flat Andreev bound states appear between point nodes, which leads to double peaks or a single peak in the surface density of states, respectively. As a result, possible superconducting states can be distinguished by combining bulk and surface measurements.

  19. Meissner effect in superconducting microtraps

    Energy Technology Data Exchange (ETDEWEB)

    Cano, Daniel

    2009-04-30

    This thesis investigates the impact of the Meissner effect on magnetic microtraps for ultracold atoms near superconducting microstructures. This task has been accomplished both theoretically and experimentally. The Meissner effect distorts the magnetic fields near superconducting surfaces, thus altering the parameters of magnetic microtraps. Both computer simulations and experimental measurements demonstrate that the Meissner effect shortens the distance between the magnetic microtrap and the superconducting surface, reduces the magnetic-field gradients and dramatically lowers the trap depth. A novel numerical method for calculating magnetic fields in atom chips with superconducting microstructures has been developed. This numerical method overcomes the geometrical limitations of other calculation techniques and can solve superconducting microstructures of arbitrary geometry. The numerical method has been used to calculate the parameters of magnetic microtraps in computer-simulated chips containing thin-film wires. Simulations were carried out for both the superconducting and the normal-conducting state, and the differences between the two cases were analyzed. Computer simulations have been contrasted with experimental measurements. The experimental apparatus generates a magnetic microtrap for ultracold Rubidium atoms near a superconducting Niobium wire of circular cross section. The design and construction of the apparatus has met the challenge of integrating the techniques for producing atomic quantum gases with the techniques for cooling solid bodies to cryogenic temperatures. By monitoring the position of the atom cloud, one can observe how the Meissner effect influences the magnetic microtrap. (orig.)

  20. Operational Merits of Maritime Superconductivity

    Science.gov (United States)

    Ross, R.; Bosklopper, J. J.; van der Meij, K. H.

    The perspective of superconductivity to transfer currents without loss is very appealing in high power applications. In the maritime sector many machines and systems exist in the roughly 1-100 MW range and the losses are well over 50%, which calls for dramatic efficiency improvements. This paper reports on three studies that aimed at the perspectives of superconductivity in the maritime sector. It is important to realize that the introduction of superconductivity comprises two technology transitions namely firstly electrification i.e. the transition from mechanical drives to electric drives and secondly the transition from normal to superconductive electrical machinery. It is concluded that superconductivity does reduce losses, but its impact on the total energy chain is of little significance compared to the investments and the risk of introducing a very promising but as yet not proven technology in the harsh maritime environment. The main reason of the little impact is that the largest losses are imposed on the system by the fossil fueled generators as prime movers that generate the electricity through mechanical torque. Unless electric power is supplied by an efficient and reliable technology that does not involve mechanical torque with the present losses both normal as well as superconductive electrification of the propulsion will hardly improve energy efficiency or may even reduce it. One exception may be the application of degaussing coils. Still appealing merits of superconductivity do exist, but they are rather related to the behavior of superconductive machines and strong magnetic fields and consequently reduction in volume and mass of machinery or (sometimes radically) better performance. The merits are rather convenience, design flexibility as well as novel applications and capabilities which together yield more adequate systems. These may yield lower operational costs in the long run, but at present the added value of superconductivity rather seems more

  1. Spinon Superconductivity and Superconductivities Mediated by Spin-Waves and Phonons in Cuprates

    OpenAIRE

    Mourachkine, A.

    1998-01-01

    The disclosure of spinon superconductivity and superconductivity mediated by spin-waves in hole-doped Bi2212 cuprate raises the question about the origin of the superconductivity in other cuprates and specially in an electron-doped NCCO cuprate.

  2. Superconducting interfaces between insulating oxides.

    Science.gov (United States)

    Reyren, N; Thiel, S; Caviglia, A D; Kourkoutis, L Fitting; Hammerl, G; Richter, C; Schneider, C W; Kopp, T; Rüetschi, A-S; Jaccard, D; Gabay, M; Muller, D A; Triscone, J-M; Mannhart, J

    2007-08-31

    At interfaces between complex oxides, electronic systems with unusual electronic properties can be generated. We report on superconductivity in the electron gas formed at the interface between two insulating dielectric perovskite oxides, LaAlO3 and SrTiO3. The behavior of the electron gas is that of a two-dimensional superconductor, confined to a thin sheet at the interface. The superconducting transition temperature of congruent with 200 millikelvin provides a strict upper limit to the thickness of the superconducting layer of congruent with 10 nanometers.

  3. Antiferromagnetic hedgehogs with superconducting cores

    Energy Technology Data Exchange (ETDEWEB)

    Goldbart, P.M.; Sheehy, D.E. [Department of Physics and Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

    1998-09-01

    Excitations of the antiferromagnetic state that resemble antiferromagnetic hedgehogs at large distances but are predominantly superconducting inside a core region are discussed within the context of Zhang{close_quote}s SO(5)-symmetry-based approach to the physics of high-temperature superconducting materials. Nonsingular, in contrast with their hedgehog cousins in pure antiferromagnetism, these texture excitations are what hedgehogs become when the antiferromagnetic order parameter is permitted to {open_quotes}escape{close_quotes} into superconducting directions. The structure of such excitations is determined in a simple setting, and a number of their experimental implications are examined. {copyright} {ital 1998} {ital The American Physical Society}

  4. Superconducting cable connections and methods

    Energy Technology Data Exchange (ETDEWEB)

    van der Laan, Daniel Cornelis

    2017-09-05

    Superconducting cable connector structures include a terminal body (or other structure) onto which the tapes from the superconducting cable extend. The terminal body (or other structure) has a diameter that is sufficiently larger than the diameter of the former of the superconducting cable, so that the tapes spread out over the outer surface of the terminal body. As a result, gaps are formed between tapes on the terminal body (or other structure). Those gaps are filled with solder (or other suitable flowable conductive material), to provide a current path of relatively high conductivity in the radial direction. Other connector structures omit the terminal body.

  5. Domain wall description of superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Brito, F.A. [Departamento de Física, Universidade Federal de Campina Grande, Caixa Postal 10071, 58109-970 Campina Grande, Paraíba (Brazil); Freire, M.L.F. [Departamento de Física, Universidade Estadual da Paraíba, 58109-753 Campina Grande, Paraíba (Brazil); Mota-Silva, J.C. [Departamento de Física, Universidade Federal de Campina Grande, Caixa Postal 10071, 58109-970 Campina Grande, Paraíba (Brazil); Departamento de Física, Universidade Federal da Paraíba, Caixa Postal 5008, 58051-970 João Pessoa, Paraíba (Brazil)

    2014-01-20

    In the present work we shall address the issue of electrical conductivity in superconductors in the perspective of superconducting domain wall solutions in the realm of field theory. We take our set up made out of a dynamical complex scalar field coupled to gauge field to be responsible for superconductivity and an extra scalar real field that plays the role of superconducting domain walls. The temperature of the system is interpreted through the fact that the soliton following accelerating orbits is a Rindler observer experiencing a thermal bath.

  6. Super-translations and super-rotations at the horizon

    CERN Document Server

    Donnay, Laura; Gonzalez, Hernan A; Pino, Miguel

    2015-01-01

    We show that the asymptotic symmetries close to non-extremal black hole horizons are generated by an extension of super-translations. This group is generated by a semi-direct sum of Virasoro and abelian currents. The charges associated to the asymptotic Killing symmetries satisfy the same algebra. When considering the special case of the stationary black hole, the zero mode charges correspond to the angular momentum and the entropy at the horizon.

  7. Aspects of Color Superconductivity

    CERN Document Server

    Hong, D K

    2001-01-01

    I discuss some aspects of recent developments in color superconductivity in high density quark matter. I calculate the Cooper pair gap and the critical points at high density, where magnetic gluons are not screened. The ground state of high density QCD with three light flavors is shown to be a color-flavor locking state, which can be mapped into the low-density hadronic phase. The meson mass at the CFL superconductor is also calculated. The CFL color superconductor is bosonized, where the Fermi sea is identified as a $Q$-matter and the gapped quarks as topological excitations, called superqualitons, of mesons. Finally, as an application of color supercoductivity, I discuss the neutrino interactions in the CFL color superconductor.

  8. Superconducting Hadron Linacs

    CERN Document Server

    Ostroumov, Peter

    2013-01-01

    This article discusses the main building blocks of a superconducting (SC) linac, the choice of SC resonators, their frequencies, accelerating gradients and apertures, focusing structures, practical aspects of cryomodule design, and concepts to minimize the heat load into the cryogenic system. It starts with an overview of design concepts for all types of hadron linacs differentiated by duty cycle (pulsed or continuous wave) or by the type of ion species (protons, H-, and ions) being accelerated. Design concepts are detailed for SC linacs in application to both light ion (proton, deuteron) and heavy ion linacs. The physics design of SC linacs, including transverse and longitudinal lattice designs, matching between different accelerating–focusing lattices, and transition from NC to SC sections, is detailed. Design of high-intensity SC linacs for light ions, methods for the reduction of beam losses, preventing beam halo formation, and the effect of HOMs and errors on beam quality are discussed. Examples are ta...

  9. Superconducting energy storage

    Energy Technology Data Exchange (ETDEWEB)

    Giese, R.F.

    1993-10-01

    This report describes the status of energy storage involving superconductors and assesses what impact the recently discovered ceramic superconductors may have on the design of these devices. Our description is intended for R&D managers in government, electric utilities, firms, and national laboratories who wish an overview of what has been done and what remains to be done. It is assumed that the reader is acquainted with superconductivity, but not an expert on the topics discussed here. Indeed, it is the author`s aim to enable the reader to better understand the experts who may ask for the reader`s attention, support, or funding. This report may also inform scientists and engineers who, though expert in related areas, wish to have an introduction to our topic.

  10. Anyon Superconductivity of Sb

    Science.gov (United States)

    Maksoed, Wh-; Parengkuan, August

    2016-10-01

    In any permutatives to Pedro P. Kuczhynski from Peru, for anyon superconductivity sought EZ Kuchinskii et al.: ``Anion height dependence of Tc & d.o.s of Fe-based Superconductors'', 2010 as well as ``on the basis of electron microscopy & AFM measurements, these phenomena are quantified with focus on fractal dimension, particle perimeter & size of the side branch(tip width) in bert Stegemann et al.:Crystallization of Sb nanoparticles-Pattern Formation & Fractal Growth'', J.PhysChem B., 2004. For dendritic & dendrimer fractal characters shown further: ``antimony denrites were found to be composed of well-crystallized nanoflakes with size 20-4 nm''- Bou Zhau, et al., MaterialLetters, 59 (2005). The alkyl triisopropyl attached in TIPSb those includes in DNA, haemoglobin membrane/fixed-bed reactor for instance quotes in Dragony Fu, Nature Review Cancer, 12 (Feb 2012). Heartfelt Gratitudes to HE. Mr. Prof. Ir. Handojo.

  11. Superconductivity of columbium

    Energy Technology Data Exchange (ETDEWEB)

    Cook, D.B.; Zemansky, M.W.; Boorse, H.A.

    1950-11-15

    Isothermal critical magnetic field curves and zero field transitions for several annealed specimens of columbium have been measured by an a.c. mutual inductance method at temperatures from 5.1 deg K to the zero field transition temperature. The H-T curve was found to fit the usual parabolic relationship H = H{sub 0}(1-T(2)/T(2){sub 0}) with H{sub 0} = 8250 oersteds and T{sub 0} = 8.65 deg K. The initial slope of the curve was 1910 oersteds/deg. The electronic specific heat in the normal state calculated from the thermodynamic equations is 0.0375T and the approximate Debye characteristic temperature in the superconducting state, 67 deg K. Results on a different grade of columbium with a tantalum impurity of 0.4 percent, according to neutron scattering measurements, were in agreement, with the data obtained from columbium of 0.2 percent maximum tantalum impurity.

  12. Superconducting pulsed magnets

    CERN Document Server

    CERN. Geneva

    2006-01-01

    Lecture 1. Introduction to Superconducting Materials Type 1,2 and high temperature superconductors; their critical temperature, field & current density. Persistent screening currents and the critical state model. Lecture 2. Magnetization and AC Loss How screening currents cause irreversible magnetization and hysteresis loops. Field errors caused by screening currents. Flux jumping. The general formulation of ac loss in terms of magnetization. AC losses caused by screening currents. Lecture 3. Twisted Wires and Cables Filamentary composite wires and the losses caused by coupling currents between filaments, the need for twisting. Why we need cables and how the coupling currents in cables contribute more ac loss. Field errors caused by coupling currents. Lecture 4. AC Losses in Magnets, Cooling and Measurement Summary of all loss mechanisms and calculation of total losses in the magnet. The need for cooling to minimize temperature rise in a magnet. Measuring ac losses in wires and in magnets. Lecture 5. Stab...

  13. Overview on superconducting photoinjectors

    Directory of Open Access Journals (Sweden)

    A. Arnold

    2011-02-01

    Full Text Available The success of most of the proposed energy recovery linac (ERL based electron accelerator projects for future storage ring replacements (SRR and high power IR–free-electron lasers (FELs largely depends on the development of an appropriate source. For example, to meet the FEL specifications [J. W. Lewellen, Proc. SPIE Int. Soc. Opt. Eng. 5534, 22 (2004PSISDG0277-786X10.1117/12.557378] electron beams with an unprecedented combination of high brightness, low emittance (0.1  μmrad, and high average current (hundreds of mA are required. An elegant way to create a beam of such quality is to combine the high beam quality of a normal conducting rf photoinjector with the superconducting technology, i.e., to build a superconducting rf photoinjector (SRF gun. SRF gun R&D programs based on different approaches have been launched at a growing number of institutes and companies (AES, Beijing University, BESSY, BNL, DESY, FZD, TJNAF, Niowave, NPS, Wisconsin University. Substantial progress was achieved in recent years and the first long term operation was demonstrated at FZD [R. Xiang et al., in Proceedings of the 31st International Free Electron Laser Conference (FEL 09, Liverpool, UK (STFC Daresbury Laboratory, Warrington, 2009, p. 488]. In the near future SRF guns are expected to play an important role for linac-driven FEL facilities. In this paper we will review the concepts, the design parameters, and the status of the major SRF gun projects.

  14. Superconducting Aero Propulsion Motor Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Superconducting electric propulsion systems will yield improvements in total ownership costs due to the simplicity of electric drive when compared with gas turbine...

  15. Mixed-mu superconducting bearings

    Energy Technology Data Exchange (ETDEWEB)

    Hull, John R. (Hinsdale, IL); Mulcahy, Thomas M. (Western Springs, IL)

    1998-01-01

    A mixed-mu superconducting bearing including a ferrite structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet structure. The ferrite structure is levitated by said stationary permanent magnet structure.

  16. Superconductivity in all its states

    CERN Multimedia

    Globe Info

    2011-01-01

    Temporary exhibition at the Saint-Genis-Pouilly Tourist Office. For the 100th anniversary of its discovery, take a plunge into the amazing world of superconductivity. Some materials, when cooled down to extreme temperatures, acquire a remarkable property -  they become superconducting. Superconductivity is a rare example of a quantum effect that can be witnessed on the macroscopic scale and is today at the heart of much research. In laboratories, researchers try to gain a better understanding of its origins, study new superconducting materials, explore the phenomenon at the nanometric scale and pursue their indefatigable search for new applications. Monday to Friday: 09:00 a.m. to 12:00 and 2:30 p.m. to 6:30 p.m. Saturday: 10:00 a.m. to 12:00 noon » Open to all – Admission free For further information: +33 (0)4 50 42 29 37

  17. Search for superconductivity in micrometeorites.

    Science.gov (United States)

    Guénon, S; Ramírez, J G; Basaran, Ali C; Wampler, J; Thiemens, M; Taylor, S; Schuller, Ivan K

    2014-12-05

    We have developed a very sensitive, highly selective, non-destructive technique for screening inhomogeneous materials for the presence of superconductivity. This technique, based on phase sensitive detection of microwave absorption is capable of detecting 10(-12) cc of a superconductor embedded in a non-superconducting, non-magnetic matrix. For the first time, we apply this technique to the search for superconductivity in extraterrestrial samples. We tested approximately 65 micrometeorites collected from the water well at the Amundsen-Scott South pole station and compared their spectra with those of eight reference materials. None of these micrometeorites contained superconducting compounds, but we saw the Verwey transition of magnetite in our microwave system. This demonstrates that we are able to detect electro-magnetic phase transitions in extraterrestrial materials at cryogenic temperatures.

  18. Advanced Superconducting Test Accelerator (ASTA)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Superconducting Test Accelerator (ASTA) facility will be based on upgrades to the existing NML pulsed SRF facility. ASTA is envisioned to contain 3 to 6...

  19. Superconductivity in Layered Organic Metals

    Directory of Open Access Journals (Sweden)

    Jochen Wosnitza

    2012-04-01

    Full Text Available In this short review, I will give an overview on the current understanding of the superconductivity in quasi-two-dimensional organic metals. Thereby, I will focus on charge-transfer salts based on bis(ethylenedithiotetrathiafulvalene (BEDT-TTF or ET for short. In these materials, strong electronic correlations are clearly evident, resulting in unique phase diagrams. The layered crystallographic structure leads to highly anisotropic electronic as well as superconducting properties. The corresponding very high orbital critical field for in-plane magnetic-field alignment allows for the occurrence of the Fulde–Ferrell– Larkin–Ovchinnikov state as evidenced by thermodynamic measurements. The experimental picture on the nature of the superconducting state is still controversial with evidence both for unconventional as well as for BCS-like superconductivity.

  20. Advanced Superconducting Test Accelerator (ASTA)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Superconducting Test Accelerator (ASTA) facility will be based on upgrades to the existing NML pulsed SRF facility. ASTA is envisioned to contain 3 to...

  1. Cryogenic Systems and Superconductive Power

    Science.gov (United States)

    The report defines, investigates, and experimentally evaluates the key elements of a representative crogenic turborefrigerator subsystem suitable for providing reliable long-lived cryogenic refrigeration for a superconductive ship propulsion system.

  2. Recent advances in fullerene superconductivity

    CERN Document Server

    Margadonna, S

    2002-01-01

    Superconducting transition temperatures in bulk chemically intercalated fulleride salts reach 33 K at ambient pressure and in hole-doped C sub 6 sub 0 derivatives in field-effect-transistor (FET) configurations, they reach 117 K. These advances pose important challenges for our understanding of high-temperature superconductivity in these highly correlated organic metals. Here we review the structures and properties of intercalated fullerides, paying particular attention to the correlation between superconductivity and interfullerene separation, orientational order/disorder, valence state, orbital degeneracy, low-symmetry distortions, and metal-C sub 6 sub 0 interactions. The metal-insulator transition at large interfullerene separations is discussed in detail. An overview is also given of the exploding field of gate-induced superconductivity of fullerenes in FET electronic devices.

  3. The superconducting bending magnets 'CESAR'

    CERN Document Server

    Pérot, J

    1978-01-01

    In 1975, CERN decided to build two high precision superconducting dipoles for a beam line in the SPS north experimental area. The aim was to determine whether superconducting magnets of the required accuracy and reliability can be built and what their economies and performances in operation will be. Collaboration between CERN and CAE /SACLAY was established in order to make use of the knowledge and experience already acquired in the two laboratories. (0 refs).

  4. Y-Ba Superconducting Ceramics

    Science.gov (United States)

    Shunbao, Tian; Xiaofei, Li; Tinglian, Wen; Zuxiang, Lin; Shichun, Li; Huijun, Yu

    Polycrystalline Y-Ba-Cu-O superconducting materials have been studied. It was found that chemical composition and processing condition may play an important role in the final structure and superconducting properties. The density has been determined and compared with the calculated value according to the structure model reported by Bell Labs. The grain size and the morphology of the materials were observed by SEM.

  5. Composite conductor containing superconductive wires

    Energy Technology Data Exchange (ETDEWEB)

    Larson, W.L.; Wong, J.

    1974-03-26

    A superconductor cable substitute made by coworking multiple rods of superconductive niobium--titanium or niobium--zirconium alloy with a common copper matrix to extend the copper and rods to form a final elongated product which has superconductive wires distributed in a reduced cross-section copper conductor with a complete metallurgical bond between the normal-conductive copper and the superconductor wires contained therein is described. The superconductor cable can be in the form of a tube.

  6. Entanglement witnessing in superconducting beamsplitters

    Science.gov (United States)

    Soller, H.; Hofstetter, L.; Reeb, D.

    2013-06-01

    We analyse a large class of superconducting beamsplitters for which the Bell parameter (CHSH violation) is a simple function of the spin detector efficiency. For these superconducting beamsplitters all necessary information to compute the Bell parameter can be obtained in Y-junction setups for the beamsplitter. Using the Bell parameter as an entanglement witness, we propose an experiment which allows to verify the presence of entanglement in Cooper pair splitters.

  7. Superconductivity in domains with corners

    DEFF Research Database (Denmark)

    Bonnaillie-Noel, Virginie; Fournais, Søren

    2007-01-01

    We study the two-dimensional Ginzburg-Landau functional in a domain with corners for exterior magnetic field strengths near the critical field where the transition from the superconducting to the normal state occurs. We discuss and clarify the definition of this field and obtain a complete...... asymptotic expansion for it in the large $\\kappa$ regime. Furthermore, we discuss nucleation of superconductivity at the boundary....

  8. 伦敦SuperDesign展

    Institute of Scientific and Technical Information of China (English)

    柚子

    2011-01-01

    近日,英国伦敦Super Design展在伦敦Wakefield大街的The Dairy展厅如期举行。本次展览展出了来自包括知名设计师和新兴设计师的特别定制的工作室作品:到如今已经是第五个年头的伦敦Super Deslgn展,力图强发展,展出形式别出心裁、独树一帜,从一个崭新.活跃的角度集展示当代艺术。

  9. Super-stable Poissonian structures

    Science.gov (United States)

    Eliazar, Iddo

    2012-10-01

    In this paper we characterize classes of Poisson processes whose statistical structures are super-stable. We consider a flow generated by a one-dimensional ordinary differential equation, and an ensemble of particles ‘surfing’ the flow. The particles start from random initial positions, and are propagated along the flow by stochastic ‘wave processes’ with general statistics and general cross correlations. Setting the initial positions to be Poisson processes, we characterize the classes of Poisson processes that render the particles’ positions—at all times, and invariantly with respect to the wave processes—statistically identical to their initial positions. These Poisson processes are termed ‘super-stable’ and facilitate the generalization of the notion of stationary distributions far beyond the realm of Markov dynamics.

  10. Super-Kamiokande atmospheric neutrinos

    Energy Technology Data Exchange (ETDEWEB)

    Moriyama, S. [Kamioka Observatory, Institute for Cosmic Ray Research, University of Tokyo, Higashi Mozumi, Hida city, Gifu prefecture (Japan)

    2005-08-15

    Results on atmospheric neutrino analysis at Super-Kamiokande I is presented. The whole data set of atmospheric neutrino sample in Super-Kamiokande I is consistently explained with an assumption of pure {nu}{sub {mu}}-{nu}{sub {tau}} oscillations. The allowed range of parameters is 1.5x10{sup -3}<{delta}m{sup 2}<3.4x10{sup -3} eV{sup 2} and sin{sup 2}2{theta}>0.92 at 90% C.L. In the oscillation analysis, we improved the treatment of systematic errors so that they can be considered as independent. This makes possible to find which systematic errors have larger effect on the analysis results. Some sensitivity studies under several assumptions of improvements in systematic errors are presented.

  11. Recent developments in superconducting materials including ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Tachikawa, Kyoji

    1987-06-01

    This report describes the history of superconduction starting in 1911, when the superconducting phenomenon was first observed in murcury, until the recent discovery of superconducting materials with high critical temperatures. After outlining the BCS theory, basic characteristics are discussed including the critical temperature, magnetic field and current density to be reached for realizing the superconducting state. Various techniques for practical superconducting materials are discussed, including methods for producing extra fine multiconductor wires from such superconducting alloys as Nb-Ti, intermetallic Nb/sub 3/Sn compound and V/sub 3/Ga, as well as methods for producing wires of Nb/sub 3/Al, Nb/sub 3/(Al, Ge) and Nb/sub 3/Ge such as continuous melt quenching, electron beam irradiation, laser beam irradiation and chemical evaporation. Characteristics of superconducting ceramics are described, along with their applications including superconducting magnets and superconducting elements. (15 figs, 1 tab, 19 refs)

  12. The Era of Super Capitalism

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The world has entered the "super capitalism" era when one third of its economic activities are controlled by less than 3 percent of global financial capital. This year,a global economic recession,triggered by the U.S. subprime mortgage crisis,seems unavoidable. To tackle international financial problems,Tao Dong,Chief Economist for Asia at Credit Suisse First Boston in Hong Kong,shared his insights with China Business Journal. Excerpts follow.

  13. BEWARE OF...SUPER GLUES!!

    CERN Multimedia

    2006-01-01

    What happened? A number of accidents have occurred with the use of 'Super Glues'. Some individuals have suffered injuries - severe irritation, or skin bonded together - through getting glue on their face and in their eyes. What are the hazards associated with glues? 'Super Glues' (i.e. cyanoacrylates): Are harmful if swallowed and are chemical irritants to the eyes, respiratory system and skin. Present the risk of polymerization (hardening) leading to skin damage. Be careful ! 'Super Glues' can bond to skin and eyes in seconds. Note: Other glues, resins and hardeners are also chemicals and as such can cause serious damage to the skin, eyes, respiratory or digestive tract. (For example: some components can be toxic, harmful, corrosive, sensitizing agents, etc.). How to prevent accidents in the future? Read the Material Safety Data Sheet (MSDS) for all of the glues you work with. Check the label on the container to find out which of the materials you work with are hazardous. Wear the right Per...

  14. Super-Eccentric Migrating Jupiters

    CERN Document Server

    Socrates, Aristotle; Dong, Subo; Tremaine, Scott

    2011-01-01

    An important class of formation theories for hot Jupiters involves the excitation of extreme orbital eccentricity (e=0.99 or even larger) followed by tidal dissipation at periastron passage that eventually circularizes the planetary orbit at a period less than 10 days. In a steady state, this mechanism requires the existence of a significant population of super-eccentric (e>0.9) migrating Jupiters with long orbital periods and periastron distances of only a few stellar radii. For these super-eccentric planets, the periastron is fixed due to conservation of orbital angular momentum and the energy dissipated per orbit is constant, implying that the rate of change in semi-major axis a is \\dot a \\propto a^0.5 and consequently the number distribution satisfies dN/dlog a\\propto a^0.5. If this formation process produces most hot Jupiters, Kepler should detect several super-eccentric migrating progenitors of hot Jupiters, allowing for a test of high-eccentricity migration scenarios.

  15. SUPER-ECCENTRIC MIGRATING JUPITERS

    Energy Technology Data Exchange (ETDEWEB)

    Socrates, Aristotle; Katz, Boaz; Dong Subo; Tremaine, Scott [Institute for Advanced Study, Princeton, NJ 08540 (United States)

    2012-05-10

    An important class of formation theories for hot Jupiters involves the excitation of extreme orbital eccentricity (e = 0.99 or even larger) followed by tidal dissipation at periastron passage that eventually circularizes the planetary orbit at a period less than 10 days. In a steady state, this mechanism requires the existence of a significant population of super-eccentric (e > 0.9) migrating Jupiters with long orbital periods and periastron distances of only a few stellar radii. For these super-eccentric planets, the periastron is fixed due to conservation of orbital angular momentum and the energy dissipated per orbit is constant, implying that the rate of change in semi-major axis a is a-dot {proportional_to}a{sup 1/2} and consequently the number distribution satisfies dN/d log a{proportional_to}a{sup 1/2}. If this formation process produces most hot Jupiters, Kepler should detect several super-eccentric migrating progenitors of hot Jupiters, allowing for a test of high-eccentricity migration scenarios.

  16. Optimization of the AGS superconducting helical partial snake strength.

    Energy Technology Data Exchange (ETDEWEB)

    Lin,F.; Huang, H.; Luccio, A.U.; Roser, T.

    2008-06-23

    Two helical partial snakes, one super-conducting (a.k.a cold snake) and one normal conducting (a.k.a warm snake), have preserved the polarization of proton beam up to 65% in the Brookhaven Alternating Gradient Synchrotron (AGS) at the extraction energy from 85% at injection. In order to overcome spin resonances, stronger partial snakes would be required. However, the stronger the partial snake, the more the stable spin direction tilted producing a stronger horizontal intrinsic resonance. The balance between increasing the spin tune gap generated by the snakes and reducing the tilted stable spin direction has to be considered to maintain the polarization. Because the magnetic field of the warm snake has to be a constant, only the cold snake with a maximum 3T magnetic field can be varied to find out the optimum snake strength. This paper presents simulation results by spin tracking with different cold snake magnetic fields. Some experimental data are also analyzed.

  17. The road to superconducting spintronics

    Science.gov (United States)

    Eschrig, Matthias

    Energy efficient computing has become a major challenge, with the increasing importance of large data centres across the world, which already today have a power consumption comparable to that of Spain, with steeply increasing trend. Superconducting computing is progressively becoming an alternative for large-scale applications, with the costs for cooling being largely outweighed by the gain in energy efficiency. The combination of superconductivity and spintronics - ``superspintronics'' - has the potential and flexibility to develop into such a green technology. This young field is based on the observation that new phenomena emerge at interfaces between superconducting and other, competing, phases. The past 15 years have seen a series of pivotal predictions and experimental discoveries relating to the interplay between superconductivity and ferromagnetism. The building blocks of superspintronics are equal-spin Cooper pairs, which are generated at the interface between superconducting and a ferromagnetic materials in the presence of non-collinear magnetism. Such novel, spin-polarised Cooper pairs carry spin-supercurrents in ferromagnets and thus contribute to spin-transport and spin-control. Geometric Berry phases appear during the singlet-triplet conversion process in structures with non-coplanar magnetisation, enhancing functionality of devices, and non-locality introduced by superconducting order leads to long-range effects. With the successful generation and control of equal-spin Cooper pairs the hitherto notorious incompatibility of superconductivity and ferromagnetism has been not only overcome, but turned synergistic. I will discuss these developments and their extraordinary potential. I also will present open questions posed by recent experiments and point out implications for theory. This work is supported by the Engineering and Physical Science Research Council (EPSRC Grant No. EP/J010618/1).

  18. Watching the Birth of Super Star Clusters

    CERN Document Server

    Turner, J L; Turner, Jean L.; Beck, Sara C.

    2003-01-01

    Subarcsecond infrared and radio observations yield important information about the formation of super star clusters from their surrounding gas. We discuss the general properties of ionized and molecular gas near young, forming SSCs, as illustrated by the prototypical young forming super star cluster nebula in the dwarf galaxy, NGC 5253. This super star cluster appears to have a gravitationally bound nebula. The lack of molecular gas suggests a very high star formation efficiency, consistent with the formation of a large, bound star cluster.

  19. Superconductivity of lead

    Energy Technology Data Exchange (ETDEWEB)

    Boorse, H.A.; Cook, D.B.; Zemansky, W.M.

    1950-06-01

    Numerous determinations of the zero-field transition temperature of lead have been made. All of these observations except that of Daunt were made by the direct measurement of electrical resistance. Daunt`s method involved the shielding effect of persistent currents in a hollow cylinder. In the authors work on columbium to be described in a forthcoming paper an a.c. induction method was used for the measurement of superconducting transitions. The superconductor was mounted as a cylindrical core of a coil which functioned as the secondary of a mutual inductance. The primary coil was actuated by an oscillator which provided a maximum a.c. field within the secondary of 1.5 oersteds at a frequency of 1000 cycles per second. The secondary e.m.f. which was dependent for its magnitude on the permeability of the core was amplified, rectifie, and observed on a recording potentiometer. During the application of this method to the study of columbium it appeared that a further check on the zero-field transition temperature of lead would be worth while especially if agreement between results for very pure samples could be obtained using this method. Such result would help in establishing the lead transition temperature as a reasonably reproducible reference point in the region between 4 deg and 10 deg K.

  20. High temperature superconducting compounds

    Science.gov (United States)

    Goldman, Allen M.

    1992-11-01

    The major accomplishment of this grant has been to develop techniques for the in situ preparation of high-Tc superconducting films involving the use of ozone-assisted molecular beam epitaxy. The techniques are generalizable to the growth of trilayer and multilayer structures. Films of both the DyBa2Cu3O(7-x) and YBa2Cu3O(7-x) compounds as well as the La(2-x)Sr(x)CuO4 compound have been grown on the usual substrates, SrTiO3, YSZ, MgO, and LaAlO3, as well as on Si substrates without any buffer layer. A bolometer has been fabricated on a thermally isolated SiN substrate coated with YSZ, an effort carried out in collaboration with Honeywell Inc. The deposition process facilitates the fabrication of very thin and transparent films creating new opportunities for the study of superconductor-insulator transitions and the investigation of photo-doping with carriers of high temperature superconductors. In addition to a thin film technology, a patterning technology has been developed. Trilayer structures have been developed for FET devices and tunneling junctions. Other work includes the measurement of the magnetic properties of bulk single crystal high temperature superconductors, and in collaboration with Argonne National Laboratory, measurement of electric transport properties of T1-based high-Tc films.

  1. The Superconducting TESLA Cavities

    CERN Document Server

    Aune, B.; Bloess, D.; Bonin, B.; Bosotti, A.; Champion, M.; Crawford, C.; Deppe, G.; Dwersteg, B.; Edwards, D.A.; Edwards, H.T.; Ferrario, M.; Fouaidy, M.; Gall, P-D.; Gamp, A.; Gössel, A.; Graber, J.; Hubert, D.; Hüning, M.; Juillard, M.; Junquera, T.; Kaiser, H.; Kreps, G.; Kuchnir, M.; Lange, R.; Leenen, M.; Liepe, M.; Lilje, L.; Matheisen, A.; Möller, W-D.; Mosnier, A.; Padamsee, H.; Pagani, C.; Pekeler, M.; Peters, H-B.; Peters, O.; Proch, D.; Rehlich, K.; Reschke, D.; Safa, H.; Schilcher, T.; Schmüser, P.; Sekutowicz, J.; Simrock, S.; Singer, W.; Tigner, M.; Trines, D.; Twarowski, K.; Weichert, G.; Weisend, J.; Wojtkiewicz, J.; Wolff, S.; Zapfe, K.

    2000-01-01

    The conceptional design of the proposed linear electron-positron colliderTESLA is based on 9-cell 1.3 GHz superconducting niobium cavities with anaccelerating gradient of Eacc >= 25 MV/m at a quality factor Q0 > 5E+9. Thedesign goal for the cavities of the TESLA Test Facility (TTF) linac was set tothe more moderate value of Eacc >= 15 MV/m. In a first series of 27industrially produced TTF cavities the average gradient at Q0 = 5E+9 wasmeasured to be 20.1 +- 6.2 MV/m, excluding a few cavities suffering fromserious fabrication or material defects. In the second production of 24 TTFcavities additional quality control measures were introduced, in particular aneddy-current scan to eliminate niobium sheets with foreign material inclusionsand stringent prescriptions for carrying out the electron-beam welds. Theaverage gradient of these cavities at Q0 = 5E+9 amounts to 25.0 +- 3.2 MV/mwith the exception of one cavity suffering from a weld defect. Hence only amoderate improvement in production and preparation technique...

  2. Optimization of a Superconducting Magnetic Energy Storage Device via a CPU-Efficient Semi-Analytical Simulation

    CERN Document Server

    Dimitrov, I K; Solovyov, V F; Chubar, O; Li, Qiang

    2014-01-01

    Recent advances in second generation (YBCO) high temperature superconducting wire could potentially enable the design of super high performance energy storage devices that combine the high energy density of chemical storage with the high power of superconducting magnetic storage. However, the high aspect ratio and considerable filament size of these wires requires the concomitant development of dedicated optimization methods that account for both the critical current density and ac losses in type II superconductors. Here, we report on the novel application and results of a CPU-efficient semi-analytical computer code based on the Radia 3D magnetostatics software package. Our algorithm is used to simulate and optimize the energy density of a superconducting magnetic energy storage device model, based on design constraints, such as overall size and number of coils. The rapid performance of the code is pivoted on analytical calculations of the magnetic field based on an efficient implementation of the Biot-Savart...

  3. Superconductivity basics and applications to magnets

    CERN Document Server

    Sharma, R G

    2015-01-01

    This book presents the basics and applications of superconducting magnets. It explains the phenomenon of superconductivity, theories of superconductivity, type II superconductors and high-temperature cuprate superconductors. The main focus of the book is on the application to superconducting magnets to accelerators and fusion reactors and other applications of superconducting magnets. The thermal and electromagnetic stability criteria of the conductors and the present status of the fabrication techniques for future magnet applications are addressed. The book is based on the long experience of the author in studying superconducting materials, building magnets and numerous lectures delivered to scholars. A researcher and graduate student will enjoy reading the book to learn various aspects of magnet applications of superconductivity. The book provides the knowledge in the field of applied superconductivity in a comprehensive way.

  4. Two-Component Super AKNS Equations and Their Finite-Dimensional Integrable Super Hamiltonian System

    OpenAIRE

    Jing Yu; Jingwei Han

    2014-01-01

    Starting from a matrix Lie superalgebra, two-component super AKNS system is constructed. By making use of monononlinearization technique of Lax pairs, we find that the obtained two-component super AKNS system is a finite-dimensional integrable super Hamiltonian system. And its Lax representation and $r$ -matrix are also given in this paper.

  5. Two-Component Super AKNS Equations and Their Finite-Dimensional Integrable Super Hamiltonian System

    Directory of Open Access Journals (Sweden)

    Jing Yu

    2014-01-01

    Full Text Available Starting from a matrix Lie superalgebra, two-component super AKNS system is constructed. By making use of monononlinearization technique of Lax pairs, we find that the obtained two-component super AKNS system is a finite-dimensional integrable super Hamiltonian system. And its Lax representation and r-matrix are also given in this paper.

  6. Superconductive articles including cerium oxide layer

    Science.gov (United States)

    Wu, Xin D.; Muenchausen, Ross E.

    1993-01-01

    A ceramic superconductor comprising a metal oxide substrate, a ceramic high temperature superconductive material, and a intermediate layer of a material having a cubic crystal structure, said layer situated between the substrate and the superconductive material is provided, and a structure for supporting a ceramic superconducting material is provided, said structure comprising a metal oxide substrate, and a layer situated over the surface of the substrate to substantially inhibit interdiffusion between the substrate and a ceramic superconducting material deposited upon said structure.

  7. 4. MESOSCOPIC SUPERCONDUCTIVITY: Proximity Action theory of superconductive nanostructures

    Science.gov (United States)

    Skvortsov, M. A.; Larkin, A. I.; Feigel'man, M. V.

    2001-10-01

    We review a novel approach to the superconductive proximity effect in disordered normal-superconducting (N-S) structures. The method is based on the multicharge Keldysh action and is suitable for the treatment of interaction and fluctuation effects. As an application of the formalism, we study the subgap conductance and noise in two-dimensional N-S systems in the presence of the electron-electron interaction in the Cooper channel. It is shown that singular nature of the interaction correction at large scales leads to a nonmonotonuos temperature, voltage and magnetic field dependence of the Andreev conductance.

  8. Highlights from Super-Kamiokande

    Science.gov (United States)

    Okumura, Kimihiro

    2016-11-01

    Recent results from Super-Kamiokande experiment are reviewed in this paper; Neutrino mass hierarchy and CP violation in the lepton sector are investigated via νμ → νe oscillation of the atmospheric neutrinos. The event rate, correlation with solar activity, energy spectrum of the solar neutrinos are measured via electron elastic scattering interactions. Neutrino emission from the WIMP annihilation at the center of the Sun are searched in the GeV energy regions. New project, SK-Gd project, to enhance anti-neutrino identification capability, has been approved inside the collaboration group.

  9. Highlights from Super-Kamiokande

    Directory of Open Access Journals (Sweden)

    Okumura Kimihiro

    2016-01-01

    Full Text Available Recent results from Super-Kamiokande experiment are reviewed in this paper; Neutrino mass hierarchy and CP violation in the lepton sector are investigated via νμ → νe oscillation of the atmospheric neutrinos. The event rate, correlation with solar activity, energy spectrum of the solar neutrinos are measured via electron elastic scattering interactions. Neutrino emission from the WIMP annihilation at the center of the Sun are searched in the GeV energy regions. New project, SK-Gd project, to enhance anti-neutrino identification capability, has been approved inside the collaboration group.

  10. 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...

  11. Electric currents in REBaCuO superconducting tapes

    Science.gov (United States)

    Jirsa, M.; Rameš, M.; Ďuran, I.; Melíšek, T.; Kováč, P.; Viererbl, L.

    2017-04-01

    Magnetic induction and current transport techniques were employed to test the electromagnetic performance of 22 samples of superconducting REBaCuO tapes of several manufacturers with the aim to select the best candidates for wiring new generation superconducting magnets for fusion reactors. An extraordinary shape of pinning force density as a function of magnetic field was observed in ‘advanced pinning, AP’ SuperPower tapes. The induced currents enabled us to classify the tapes and show the best ones, at low temperatures and high magnetic fields on the one hand and at high temperatures and low magnetic fields on the other hand. Transport current experiments confirmed the results. Moreover, they provided information on current anisotropy, which appeared to be specific for each tape type. The present results formed a basis for the ongoing study of neutron irradiation impact on the tapes’ properties. The first experiment showed that neutron irradiation by the fluence of 2.1 E22 m‑2 either enhances, reduces, or has no effect on the tape’s properties, according to the tape pinning structure.

  12. Superconducting Metallic Glass Transition-Edge-Sensors

    Science.gov (United States)

    Hays, Charles C. (Inventor)

    2013-01-01

    A superconducting metallic glass transition-edge sensor (MGTES) and a method for fabricating the MGTES are provided. A single-layer superconducting amorphous metal alloy is deposited on a substrate. The single-layer superconducting amorphous metal alloy is an absorber for the MGTES and is electrically connected to a circuit configured for readout and biasing to sense electromagnetic radiation.

  13. Gifts from the superconducting curiosity shop

    Institute of Scientific and Technical Information of China (English)

    David Mandrus

    2011-01-01

    Superconductivity has just celebrated its 100th birthday,and yet despite its advanced age it has never been more alive.Given that most subfields of materials physics have a half-life of about seven years,what accounts for the enduring popularity of superconductivity? What is it about superconductivity that continues to fascinate?

  14. An overview of recent developments in high-temperature superconductivity

    Science.gov (United States)

    Falicov, L. M.

    1987-10-01

    The BCS theory, in all probability, will explain the properties of new superconducting oxide materials. However, a detailed account of why they have such an unusually high transition temperature will require much more work. The key to the answer to the theoretical questions may be found in the fact that all these materials are ceramics, i.e., bad conductors in their normal phase. In fact, they are 'almost insulators', with strange and varied magnetic properties. And although the lattice polarization will certainly play a role (as shown by the isotope effect), the detailed motion of the electrons and the short-range Coulomb repulsion may give the unusual characteristics which result in high transition temperatures. From the point of view of practical applications and their implications in our everyday life, much can be speculated: transmission lines without any power losses, levitated trains, super-super-computers, new and not-yet-invented devices. But all these innovations will require the solution of complicated (and expensive to solve) materials problems (brittle, hard to handle ceramics; unstable phases; low critical currents) as well as a cool-headed economic analysis which this author is unable to provide.

  15. LLNL superconducting magnets test facility

    Energy Technology Data Exchange (ETDEWEB)

    Manahan, R; Martovetsky, N; Moller, J; Zbasnik, J

    1999-09-16

    The FENIX facility at Lawrence Livermore National Laboratory was upgraded and refurbished in 1996-1998 for testing CICC superconducting magnets. The FENIX facility was used for superconducting high current, short sample tests for fusion programs in the late 1980s--early 1990s. The new facility includes a 4-m diameter vacuum vessel, two refrigerators, a 40 kA, 42 V computer controlled power supply, a new switchyard with a dump resistor, a new helium distribution valve box, several sets of power leads, data acquisition system and other auxiliary systems, which provide a lot of flexibility in testing of a wide variety of superconducting magnets in a wide range of parameters. The detailed parameters and capabilities of this test facility and its systems are described in the paper.

  16. Superconductivity, antiferromagnetism, and neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Tranquada, John M., E-mail: jtran@bnl.gov; Xu, Guangyong; Zaliznyak, Igor A.

    2014-01-15

    High-temperature superconductivity in both the copper-oxide and the iron–pnictide/chalcogenide systems occurs in close proximity to antiferromagnetically ordered states. Neutron scattering has been an essential technique for characterizing the spin correlations in the antiferromagnetic phases and for demonstrating how the spin fluctuations persist in the superconductors. While the nature of the spin correlations in the superconductors remains controversial, the neutron scattering measurements of magnetic excitations over broad ranges of energy and momentum transfers provide important constraints on the theoretical options. We present an overview of the neutron scattering work on high-temperature superconductors and discuss some of the outstanding issues. - Highlights: • High-temperature superconductivity is closely associated with antiferromagnetism. • Antiferromagnetic spin fluctuations coexist with the superconductivity. • Neutron scattering is essential for characterising the full spectrum of spin excitations.

  17. Sensing with Superconducting Point Contacts

    Directory of Open Access Journals (Sweden)

    Argo Nurbawono

    2012-05-01

    Full Text Available Superconducting point contacts have been used for measuring magnetic polarizations, identifying magnetic impurities, electronic structures, and even the vibrational modes of small molecules. Due to intrinsically small energy scale in the subgap structures of the supercurrent determined by the size of the superconducting energy gap, superconductors provide ultrahigh sensitivities for high resolution spectroscopies. The so-called Andreev reflection process between normal metal and superconductor carries complex and rich information which can be utilized as powerful sensor when fully exploited. In this review, we would discuss recent experimental and theoretical developments in the supercurrent transport through superconducting point contacts and their relevance to sensing applications, and we would highlight their current issues and potentials. A true utilization of the method based on Andreev reflection analysis opens up possibilities for a new class of ultrasensitive sensors.

  18. Domain wall description of superconductivity

    CERN Document Server

    Brito, F A; Silva, J C M

    2012-01-01

    In the present work we shall address the issue of electrical conductivity in superconductors in the perspective of superconducting domain wall solutions in the realm of field theory. We take our set up made out of a dynamical complex scalar field coupled to gauge field to be responsible for superconductivity and an extra scalar real field that plays the role of superconducting domain walls. The temperature of the system is interpreted as the parameter to move type I to type II domain walls. Alternatively, this means that the domain wall surface is suffering an acceleration as one goes from one type to another. On the other hand, changing from type I to type II state means a formation of a condensate what is in perfect sense of lowering the temperature around the superconductor. One can think of this scenario as an analog of holographic scenarios where this set up is replaced by a black hole near the domain wall.

  19. The Super Separator Spectrometer S3 and the associated detection systems: SIRIUS & LEB-REGLIS3

    Science.gov (United States)

    Déchery, F.; Savajols, H.; Authier, M.; Drouart, A.; Nolen, J.; Ackermann, D.; Amthor, A. M.; Bastin, B.; Berryhill, A.; Boutin, D.; Caceres, L.; Coffey, M.; Delferrière, O.; Dorvaux, O.; Gall, B.; Hauschild, K.; Hue, A.; Jacquot, B.; Karkour, N.; Laune, B.; Le Blanc, F.; Lecesne, N.; Lopez-Martens, A.; Lutton, F.; Manikonda, S.; Meinke, R.; Olivier, G.; Payet, J.; Piot, J.; Pochon, O.; Prince, V.; Souli, M.; Stelzer, G.; Stodel, C.; Stodel, M.-H.; Sulignano, B.; Traykov, E.; Uriot, D.

    2016-06-01

    The Super Separator Spectrometer (S3) facility is developed in the framework of the SPIRAL2 project [1]. S3 has been designed to extend the capability of the facility to perform experiments with extremely low cross sections, taking advantage of the very high intensity stable beams of the superconducting linear accelerator of SPIRAL2. It will mainly use fusion-evaporation reactions to reach extreme regions of the nuclear chart: new opportunities will be opened for super-heavy element studies and spectroscopy at and beyond the driplines. In addition to our previous article (Déchery et al. [2]) introducing the optical layout of the spectrometer and the expected performances, this article will present the current status of the main elements of the facility: the target station, the superconducting multipole, and the magnetic and electric dipoles, with a special emphasis on the status of the detection system SIRIUS and on the low-energy branch which includes the REGLIS3 system. S3 will also be a source of low energy radioactive isotopes for delivery to the DESIR facility.

  20. Stripes and superconductivity in cuprates

    Science.gov (United States)

    Tranquada, John M.

    2012-06-01

    Holes doped into the CuO2 planes of cuprate parent compounds frustrate the antiferromagnetic order. The development of spin and charge stripes provides a compromise between the competing magnetic and kinetic energies. Static stripe order has been observed only in certain particular compounds, but there are signatures which suggest that dynamic stripe correlations are common in the cuprates. Though stripe order is bad for superconducting phase coherence, stripes are compatible with strong pairing. Ironically, magnetic-field-induced stripe order appears to enhance the stability of superconducting order within the planes.

  1. Stripes and superconductivity in cuprates

    Energy Technology Data Exchange (ETDEWEB)

    Tranquada, John M., E-mail: jtran@bnl.gov [Condensed Matter Physics and Materials Science Dept., Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

    2012-06-01

    Holes doped into the CuO{sub 2} planes of cuprate parent compounds frustrate the antiferromagnetic order. The development of spin and charge stripes provides a compromise between the competing magnetic and kinetic energies. Static stripe order has been observed only in certain particular compounds, but there are signatures which suggest that dynamic stripe correlations are common in the cuprates. Though stripe order is bad for superconducting phase coherence, stripes are compatible with strong pairing. Ironically, magnetic-field-induced stripe order appears to enhance the stability of superconducting order within the planes.

  2. Large superconducting wind turbine generators

    DEFF Research Database (Denmark)

    Abrahamsen, Asger Bech; Magnusson, Niklas; Jensen, Bogi Bech

    2012-01-01

    and the rotation speed is lowered in order to limit the tip speed of the blades. The ability of superconducting materials to carry high current densities with very small losses might facilitate a new class of generators operating with an air gap flux density considerably higher than conventional generators...... and thereby having a smaller size and weight [1, 2]. A 5 MW superconducting wind turbine generator forms the basics for the feasibility considerations, particularly for the YBCO and MgB2 superconductors entering the commercial market. Initial results indicate that a 5 MW generator with an active weight of 34...

  3. COLOR SUPERCONDUCTIVITY, INSTANTONS AND PARITY (NON?)-CONSERVATION AT HIGH BARYON DENSITY-VOLUME 5.

    Energy Technology Data Exchange (ETDEWEB)

    GYULASSY,M.

    1997-11-11

    This one day Riken BNL Research Center workshop was organized to follow-up on the rapidly developing theoretical work on color super-conductivity, instanton dynamics, and possible signatures of parity violation in strong interactions that was stimulated by the talk of Frank Wilczek during the Riken BNL September Symposium. The workshop was held on November 11, 1997 at the center with over 30 participants. The program consisted of four talks on theory in the morning followed by two talks in the afternoon by experimentalists and open discussion. Krishna Rajagopal (MIT) first reviewed the status of the chiral condensate calculations at high baryon density within the instanton model and the percolation transition at moderate densities restoring chiral symmetry. Mark Alford (Princeton) then discussed the nature of the novel color super-conducting diquark condensates. The main result was that the largest gap on the order of 100 MeV was found for the 0{sup +} condensate, with only a tiny gap << MeV for the other possible 1{sup +}. Thomas Schaefer (INT) gave a complete overview of the instanton effects on correlators and showed independent calculations in collaboration with Shuryak (SUNY) and Velkovsky (BNL) confirming the updated results of the Wilczek group (Princeton, MIT). Yang Pang (Columbia) addressed the general question of how breaking of discrete symmetries by any condensate with suitable quantum numbers could be searched for experimentally especially at the AGS through longitudinal A polarization measurements. Nicholas Samios (BNL) reviewed the history of measurements on {Lambda} polarization and suggested specific kinematical variables for such analysis. Brian Cole (Columbia) showed recent E910 measurements of {Lambda} production at the AGS in nuclear collisions and focused on the systematic biases that must be considered when looking for small symmetry breaking effects. Lively discussions led by Robert Jaffe (MIT) focused especially on speculations on the still

  4. Performance evaluation of high-temperature superconducting current leads for electric utility SMES systems

    Science.gov (United States)

    Niemann, R. C.; Cha, Y. S.; Hull, J. R.; Rey, C. M.; Dixon, K. D.

    As part of the U.S. Department of Energy's Superconductivity Technology Program, Argonne National Laboratory and Babcock & Wilcox are developing high-temperature super-conductor (HTS) current leads for application to electric utility superconducting magnetic energy storage systems. A 16,000-A HTS lead has been designed and is being constructed. An evaluation program for component performance was conducted to confirm performance predictions and/or to qualify the design features for construction. Performance of the current lead assemblies will be evaluated in a test program that includes assembly procedures, tooling, and quality assurance; thermal and electrical performance; and flow and mechanical characteristics. Results of the evaluations to date are presented.

  5. Coupling erbium spins to a three-dimensional superconducting cavity at zero magnetic field

    CERN Document Server

    Chen, Yu-Hui; Longdell, Jevon J

    2015-01-01

    We experimentally demonstrate the coupling of an erbium doped crystal to a three-dimensional superconducting cavity of a $10^5$ $Q$-factor at zero magnetic field. A tunable loop-gap resonator is used to match the cavity frequency to the hyperfine transitions of an erbium sample. The observed spectrum differs from what predicted by the published spin Hamiltonian parameters. The narrow cavity linewidth also enables the observations of asymmetric lineshapes of these hyperfine transitions, which are understood as the super-hyperfine interactions between the erbium ions and their adjacent yttrium ions. Such a broadly tunable superconducting cavity architecture, from 1.6 GHz to 4.0 GHz in the current design, is promising in building hybrid quantum systems.

  6. Optical trapping with Super-Gaussian beams

    CSIR Research Space (South Africa)

    McLaren, M

    2013-04-01

    Full Text Available We outline the possibility of optical trapping and tweezing with Super-Gaussian beam profiles. We show that the trapping strength can be tuned continuously by adjusting the order of a Super-Gaussian beam, approaching that of a perfect Gaussian...

  7. Tetrahedral Units: For Dodecahedral Super-Structures

    CERN Document Server

    Ortiz, Y; Liebman, J F

    2016-01-01

    Different novel organic-chemical possibilities for tetrahedral building units are considered, with attention to their utility in constructing different super-structures. As a representative construction we consider the use of sets of 20 such identical tetrahedral units to form a super-dodecahedron.

  8. dbSUPER: a database of super-enhancers in mouse and human genome.

    Science.gov (United States)

    Khan, Aziz; Zhang, Xuegong

    2016-01-04

    Super-enhancers are clusters of transcriptional enhancers that drive cell-type-specific gene expression and are crucial to cell identity. Many disease-associated sequence variations are enriched in super-enhancer regions of disease-relevant cell types. Thus, super-enhancers can be used as potential biomarkers for disease diagnosis and therapeutics. Current studies have identified super-enhancers in more than 100 cell types and demonstrated their functional importance. However, a centralized resource to integrate all these findings is not currently available. We developed dbSUPER (http://bioinfo.au.tsinghua.edu.cn/dbsuper/), the first integrated and interactive database of super-enhancers, with the primary goal of providing a resource for assistance in further studies related to transcriptional control of cell identity and disease. dbSUPER provides a responsive and user-friendly web interface to facilitate efficient and comprehensive search and browsing. The data can be easily sent to Galaxy instances, GREAT and Cistrome web-servers for downstream analysis, and can also be visualized in the UCSC genome browser where custom tracks can be added automatically. The data can be downloaded and exported in variety of formats. Furthermore, dbSUPER lists genes associated with super-enhancers and also links to external databases such as GeneCards, UniProt and Entrez. dbSUPER also provides an overlap analysis tool to annotate user-defined regions. We believe dbSUPER is a valuable resource for the biology and genetic research communities.

  9. Interplay of spin-orbit coupling and superconducting correlations in germanium telluride thin films

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Vijay; Nguyen, Thuy-Anh; Mansell, Rhodri; Ritchie, David [Cavendish Laboratory, Department of Physics, University of Cambridge, J. J. Thomson Avenue, Cambridge, CB3 0HE (United Kingdom); Mussler, Gregor [Peter Gruenberg Institute (PGI-9), Forschungszentrum Juelich, 52425, Juelich (Germany)

    2016-03-15

    There is much current interest in combining superconductivity and spin-orbit coupling in order to induce the topological superconductor phase and associated Majorana-like quasiparticles which hold great promise towards fault-tolerant quantum computing. Experimentally these effects have been combined by the proximity-coupling of super-conducting leads and high spin-orbit materials such as InSb and InAs, or by controlled Cu-doping of topological insu-lators such as Bi{sub 2}Se{sub 3}. However, for practical purposes, a single-phase material which intrinsically displays both these effects is highly desirable. Here we demonstrate coexisting superconducting correlations and spin-orbit coupling in molecular-beam-epitaxy-grown thin films of GeTe. The former is evidenced by a precipitous low-temperature drop in the electrical resistivity which is quelled by a magnetic field, and the latter manifests as a weak antilocalisation (WAL) cusp in the magnetotransport. Our studies reveal several other intriguing features such as the presence of two-dimensional rather than bulk transport channels below 2 K, possible signatures of topological superconductivity, and unexpected hysteresis in the magnetotransport. Our work demonstrates GeTe to be a potential host of topological SC and Majorana-like excitations, and to be a versatile platform to develop quantum information device architectures. (copyright 2016 The Authors. Phys. Status Solidi RRL published by WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Ending Aging in Super Glassy Polymer Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Lau, CH; Nguyen, PT; Hill, MR; Thornton, AW; Konstas, K; Doherty, CM; Mulder, RJ; Bourgeois, L; Liu, ACY; Sprouster, DJ; Sullivan, JP; Bastow, TJ; Hill, AJ; Gin, DL; Noble, RD

    2014-04-16

    Aging in super glassy polymers such as poly(trimethylsilylpropyne) (PTMSP), poly(4-methyl-2-pentyne) (PMP), and polymers with intrinsic microporosity (PIM-1) reduces gas permeabilities and limits their application as gas-separation membranes. While super glassy polymers are initially very porous, and ultra-permeable, they quickly pack into a denser phase becoming less porous and permeable. This age-old problem has been solved by adding an ultraporous additive that maintains the low density, porous, initial stage of super glassy polymers through absorbing a portion of the polymer chains within its pores thereby holding the chains in their open position. This result is the first time that aging in super glassy polymers is inhibited whilst maintaining enhanced CO2 permeability for one year and improving CO2/N-2 selectivity. This approach could allow super glassy polymers to be revisited for commercial application in gas separations.

  11. Hierarchic Models of Turbulence, Superfluidity and Superconductivity

    CERN Document Server

    Kaivarainen, A

    2000-01-01

    New models of Turbulence, Superfluidity and Superconductivity, based on new Hierarchic theory, general for liquids and solids (physics/0102086), have been proposed. CONTENTS: 1 Turbulence. General description; 2 Mesoscopic mechanism of turbulence; 3 Superfluidity. General description; 4 Mesoscopic scenario of fluidity; 5 Superfluidity as a hierarchic self-organization process; 6 Superfluidity in 3He; 7 Superconductivity: General properties of metals and semiconductors; Plasma oscillations; Cyclotron resonance; Electroconductivity; 8. Microscopic theory of superconductivity (BCS); 9. Mesoscopic scenario of superconductivity: Interpretation of experimental data in the framework of mesoscopic model of superconductivity.

  12. Proposal of rectifier type superconducting fault current limiter with non-inductive reactor (SFCL)

    Science.gov (United States)

    Mohammad Salim, Khosru; Muta, Itsuya; Hoshino, Tsutomu; Nakamura, Taketsune; Yamada, Masato

    2004-03-01

    A rectifier type superconducting fault current limiter (SFCL) with non-inductive reactor has been proposed. The concept behind this SFCL is the appearance of high impedance during non-superconducting state of the coil. In a hybrid bridge circuit, two superconducting coils connected in anti-parallel: a trigger coil and a limiting coil. Both the coils are magnetically coupled with each other and have same number of turns. There is almost zero flux inside the core and therefore the total inductance is small during normal operation. At fault time when the trigger coil current reaches to a certain level, the trigger coil changes from superconducting state to normal state. This super-to-normal transition of the trigger coil changes the current ratio of the coils and therefore the flux inside the reactor is no longer zero. So, the equivalent impedance of both the coils increased thus limits the fault current. We have carried out computer simulation using EMTDC and observed the results. A preliminary experiment has already been performed using copper wired reactor with simulated super-to-normal transition resistance and magnetic switches. Both the simulation and preliminary experiment shows good results. The advantage of using hybrid bridge circuit is that the SFCL can also be used as circuit breaker. Two separate bridge circuit can be used for both trigger coil and the limiter coil. In such a case, the trigger coil can be shutdown immediately after the fault to reduce heat and thus reduce the recovery time. Again, at the end of fault when the SFCL needs to re-enter to the grid, turning off the trigger circuit in the two-bridge configuration the inrush current can be reduced. This is because the current only flows through the limiting coil. Another advantage of this type of SFCL is that no voltage sag will appear during load increasing time as long as the load current stays below the trigger current level.

  13. Superconductivity in highly disordered dense carbon disulfide.

    Science.gov (United States)

    Dias, Ranga P; Yoo, Choong-Shik; Struzhkin, Viktor V; Kim, Minseob; Muramatsu, Takaki; Matsuoka, Takahiro; Ohishi, Yasuo; Sinogeikin, Stanislav

    2013-07-16

    High pressure plays an increasingly important role in both understanding superconductivity and the development of new superconducting materials. New superconductors were found in metallic and metal oxide systems at high pressure. However, because of the filled close-shell configuration, the superconductivity in molecular systems has been limited to charge-transferred salts and metal-doped carbon species with relatively low superconducting transition temperatures. Here, we report the low-temperature superconducting phase observed in diamagnetic carbon disulfide under high pressure. The superconductivity arises from a highly disordered extended state (CS4 phase or phase III[CS4]) at ~6.2 K over a broad pressure range from 50 to 172 GPa. Based on the X-ray scattering data, we suggest that the local structural change from a tetrahedral to an octahedral configuration is responsible for the observed superconductivity.

  14. Phase slips in superconducting weak links

    Energy Technology Data Exchange (ETDEWEB)

    Kimmel, Gregory; Glatz, Andreas; Aranson, Igor S.

    2017-01-01

    Superconducting vortices and phase slips are primary mechanisms of dissipation in superconducting, superfluid, and cold-atom systems. While the dynamics of vortices is fairly well described, phase slips occurring in quasi-one- dimensional superconducting wires still elude understanding. The main reason is that phase slips are strongly nonlinear time-dependent phenomena that cannot be cast in terms of small perturbations of the superconducting state. Here we study phase slips occurring in superconducting weak links. Thanks to partial suppression of superconductivity in weak links, we employ a weakly nonlinear approximation for dynamic phase slips. This approximation is not valid for homogeneous superconducting wires and slabs. Using the numerical solution of the time-dependent Ginzburg-Landau equation and bifurcation analysis of stationary solutions, we show that the onset of phase slips occurs via an infinite period bifurcation, which is manifested in a specific voltage-current dependence. Our analytical results are in good agreement with simulations.

  15. A unified theory of superconductivity

    CERN Document Server

    Huang, Xiuqing

    2008-01-01

    In this work, we argue that the phonon-mediated BCS theory may be incorrect. Two kinds of glues, pairing (pseudogap) glue and superconducting glue, are suggested based on a real space Coulomb confinement effect. The scenarios provide a unified explanation of the pairing symmetry, pseudogap and superconducting states, spin--charge stripe order, magic doping fractions and vortex structures in conventional and unconventional (the high-Tc cuprates, MgB2 and the newly-discovered Fe-based family) superconductors. The theory agrees with the existence of a pseudogap in high-temperature superconductors, while no pseudogap feature could be observed in MgB2, iron-based and most of the conventional superconductors. Our results indicate that the superconducting phase can coexist with a triangular vortex lattice in pure MgB2 single crystal with a charge carrier density n=1.49*10^22/cm3. For iron-based superconductors, the relationship between the superconducting vortex phases and the optimal doping levels are analytically ...

  16. Power applications for superconducting cables

    DEFF Research Database (Denmark)

    Tønnesen, Ole; Hansen, Steen; Jørgensen, Preben

    2000-01-01

    High temperature superconducting (HTS) cables for use in electric ac power systems are under development around the world today. There are two main constructions under development: the room temperature dielectric design and the cryogenic dielectric design. However, theoretical studies have shown...

  17. Superconductivity by kinetic energy saving?

    NARCIS (Netherlands)

    Van der Marel, D; Molegraaf, HJA; Presura, C; Santoso, [No Value; Hewson, AC; Zlatic,

    2003-01-01

    A brief introduction is given in the generic microscopic framework of superconductivity. The consequences for the temperature dependence of the kinetic energy, and the correlation energy are discussed for two cases: The BCS scenario and the non-Fermi liquid scenario. A quantitative comparison is mad

  18. Superconducting cavity model for LEP

    CERN Multimedia

    1979-01-01

    A superconducting cavity model is being prepared for testing in a vertical cryostat.At the top of the assembly jig is H.Preis while A.Scharding adjusts some diagnostic equipment to the cavity. See also photo 7912501X.

  19. Superconductivity of small metal grains

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Renrong; CHEN; Zhiqian; ZHU; Shunquan

    2005-01-01

    The formulas of the energy gap and superconducting critical temperature appropriate for systems with both odd and even number of electrons are derived; the bases of the derivations are BCS theory and energy level statistics. Numerical results qualitatively agree with the experimental phenomena. i.e., the superconductivity of small metallic grains will first enhance then decrease to zero when the grain are getting smaller and smaller. The calculations indicate that the above phenomena happen in the metallic grains belonging to Gaussian Orthogonal Ensemble (GOE) and Gaussian Unitary ensemble (GUE) with zero spin; The superconductivity of small metallic grains in Gaussian Symplectic Ensemble (GSE) will monotonically decrease to zero with the decreasing of the grain size. The analyses suggest that the superconductivity enhancements come from pairing and the balance of the strengths between spin-orbital coupling and external magnetic field. In order to take the latter into account, it is necessary to include the level statistics given by Random Matrix Theory (RMT) in describing small metallic grains.

  20. Superconductivity by kinetic energy saving?

    NARCIS (Netherlands)

    Van der Marel, D; Molegraaf, HJA; Presura, C; Santoso, [No Value; Hewson, AC; Zlatic,

    2003-01-01

    A brief introduction is given in the generic microscopic framework of superconductivity. The consequences for the temperature dependence of the kinetic energy, and the correlation energy are discussed for two cases: The BCS scenario and the non-Fermi liquid scenario. A quantitative comparison is

  1. Discovering superconductivity an investigative approach

    CERN Document Server

    Ireson, Gren

    2012-01-01

    The highly-illustrated text will serve as excellent introduction for students, with and without a physics background, to superconductivity. With a strong practical, experimental emphasis, it will provide readers with an overview of the topic preparing them for more advanced texts used in more advanced undergraduate and post-graduate courses.

  2. Collaring of Po Superconducting Dipole

    CERN Multimedia

    1983-01-01

    The picture shows the placing of a stack of stainless steel collars around the superconducting coils.Pre-assembled collar stacks were placed under and on top of the coils,the collars interleaving as comb teeth. During the following collaring operation of compression under a press the collars were locked together by means of side wedges. See also photos 8211532X, 7903168

  3. Superconductivity resulting from antiferromagnetic states

    Energy Technology Data Exchange (ETDEWEB)

    Feng Shi-Ping (Department of Physics, Beijing Normal University (CN))

    1989-09-01

    When the dopping is low enough, the holes obey Bose statistics, Bose-Einstein condensation of these holes may lead to occurance of superconductivity. In this framework, we have calculated some physical quantities, the results are in qualitative agreement with experiments.

  4. Superconductivity by kinetic energy saving?

    NARCIS (Netherlands)

    Van der Marel, D; Molegraaf, HJA; Presura, C; Santoso, [No Value; Hewson, AC; Zlatic,

    2003-01-01

    A brief introduction is given in the generic microscopic framework of superconductivity. The consequences for the temperature dependence of the kinetic energy, and the correlation energy are discussed for two cases: The BCS scenario and the non-Fermi liquid scenario. A quantitative comparison is mad

  5. Nonlinear diffusion and superconducting hysteresis

    Energy Technology Data Exchange (ETDEWEB)

    Mayergoyz, I.D. [Univ. of Maryland, College Park, MD (United States)

    1996-12-31

    Nonlinear diffusion of electromagnetic fields in superconductors with ideal and gradual resistive transitions is studied. Analytical results obtained for linear and nonlinear polarizations of electromagnetic fields are reported. These results lead to various extensions of the critical state model for superconducting hysteresis.

  6. Fireballs from Superconducting Cosmic Strings

    CERN Document Server

    Gruzinov, Andrei

    2016-01-01

    Thermalized fireballs should be created by cusp events on superconducting cosmic strings. This simple notion allows to reliably estimate particle emission from the cusps in a given background magnetic field. With plausible assumptions about intergalactic magnetic fields, the cusp events can produce observable fluxes of high-energy photons and neutrinos with unique signatures.

  7. Fireballs from superconducting cosmic strings

    Science.gov (United States)

    Gruzinov, Andrei; Vilenkin, Alexander

    2017-01-01

    Thermalized fireballs should be created by cusp events on superconducting cosmic strings. This simple notion allows to reliably estimate particle emission from the cusps in a given background magnetic field. With plausible assumptions about intergalactic magnetic fields, the cusp events can produce observable fluxes of high-energy photons and neutrinos with unique signatures.

  8. Superconducting Qubits and Quantum Resonators

    NARCIS (Netherlands)

    Forn-Díaz, P.

    2010-01-01

    Superconducting qubits are fabricated "loss-free" electrical circuits on a chip with size features of tens of nanometers. If cooled to cryogenic temperatures below -273 °C they behave as quantum elements, similar to atoms and molecules. Such a qubit can be manipulated by fast-oscillating magnetic fi

  9. Tutorial on Superconducting Accelerator Magnets

    Science.gov (United States)

    Ball, M. J. Penny; Goodzeit, Carl L.

    1997-05-01

    A multimedia CD-ROM tutorial on the physics and engineering concepts of superconducting magnets for particle accelerators is being developed under a U.S. Dept. of Energy SBIR grant. The tutorial, scheduled for distribution this summer, is targeted to undergraduate junior or senior level science students. However, its unified presentation of the broad range of issues involved in the design of superconducting magnets for accelerators and the extensive detail about the construction process (including animations and video clips) will also be of value to staff of research institutes and industrial concerns with an interest in applied superconductivity or magnet development. The source material, which is based on the world-wide R and D programs to develop superconducting accelerator magnets, is organized in five units with the following themes: Introduction to magnets and accelerators; (2) Superconductors for accelerator magnets; (3) Magnetic design methods for accelerator magnets; (4) Electrical, mechanical, and cryogenic considerations for the final magnet package; (5) Performance characteristics and measurement methods. A detailed outline and examples will be shown.

  10. Demonstration of superconducting micromachined cavities

    Energy Technology Data Exchange (ETDEWEB)

    Brecht, T., E-mail: teresa.brecht@yale.edu; Reagor, M.; Chu, Y.; Pfaff, W.; Wang, C.; Frunzio, L.; Devoret, M. H.; Schoelkopf, R. J. [Department of Applied Physics, Yale University, New Haven, Connecticut 06511 (United States)

    2015-11-09

    Superconducting enclosures will be key components of scalable quantum computing devices based on circuit quantum electrodynamics. Within a densely integrated device, they can protect qubits from noise and serve as quantum memory units. Whether constructed by machining bulk pieces of metal or microfabricating wafers, 3D enclosures are typically assembled from two or more parts. The resulting seams potentially dissipate crossing currents and limit performance. In this letter, we present measured quality factors of superconducting cavity resonators of several materials, dimensions, and seam locations. We observe that superconducting indium can be a low-loss RF conductor and form low-loss seams. Leveraging this, we create a superconducting micromachined resonator with indium that has a quality factor of two million, despite a greatly reduced mode volume. Inter-layer coupling to this type of resonator is achieved by an aperture located under a planar transmission line. The described techniques demonstrate a proof-of-principle for multilayer microwave integrated quantum circuits for scalable quantum computing.

  11. Photon-detecting superconducting resonators

    NARCIS (Netherlands)

    Barends, R.

    2009-01-01

    One of the greatest challenges in astronomy is observing star and planetary formation, redshifted distant galaxies and molecular spectral ‘fingerprints’ in the far-infrared spectrum of light, using highly sensitive and large cameras. In this thesis we investigate superconducting resonators for

  12. Superconductivity: The persistence of pairs

    Energy Technology Data Exchange (ETDEWEB)

    Edelman, Alex; Littlewood, Peter

    2015-05-20

    Superconductivity stems from a weak attraction between electrons that causes them to form bound pairs and behave much like bosons. These so-called Cooper pairs are phase coherent, which leads to the astonishing properties of zero electrical resistance and magnetic flux expulsion typical of superconducting materials. This coherent state may be qualitatively understood within the Bose–Einstein condensate (BEC) model, which predicts that a gas of interacting bosons will become unstable below a critical temperature and condense into a phase of matter with a macroscopic, coherent population in the lowest energy state, as happens in 4He or cold atomic gases. The successful theory proposed by Bardeen, Cooper and Schrieffer (BCS) predicts that at the superconducting transition temperature Tc, electrons simultaneously form pairs and condense, with no sign of pairing above Tc. Theorists have long surmised that the BCS and BEC models are opposite limits of a single theory and that strong interactions or low density can, in principle, drive the system to a paired state at a temperature Tpair higher than Tc, making the transition to the superconducting state BEC-like (Fig. 1). Yet most superconductors to date are reasonably well described by BCS theory or its extensions, and there has been scant evidence in electronic materials for the existence of pairing independent of the full superconducting state (though an active debate rages over the cuprate superconductors). Writing in Nature, Jeremy Levy and colleagues have now used ingenious nanostructured devices to provide evidence for electron pairing1. Perhaps surprisingly, the material they have studied is a venerable, yet enigmatic, low-temperature superconductor, SrTiO3.

  13. Phonon modes of MgB2: super-lattice structures and spectral response.

    Science.gov (United States)

    Alarco, Jose A; Chou, Alison; Talbot, Peter C; Mackinnon, Ian D R

    2014-11-28

    Micrometre-sized MgB2 crystals of varying quality, synthesized at low temperature and autogenous pressure, are compared using a combination of Raman and infra-red (IR) spectroscopy. These data, which include new peak positions in both spectroscopies for high quality MgB2, are interpreted using DFT calculations on phonon behaviour for symmetry-related structures. Raman and IR activity additional to that predicted by point group analyses of the P6/mmm symmetry are detected. These additional peaks, as well as the overall shapes of calculated phonon dispersion (PD) models are explained by assuming a double super-lattice, consistent with a lower symmetry structure for MgB2. A 2× super-lattice in the c-direction allows a simple correlation of the pair breaking energy and the superconducting gap by activation of corresponding acoustic frequencies. A consistent physical interpretation of these spectra is obtained when the position of a phonon anomaly defines a super-lattice modulation in the a-b plane.

  14. Radiation protection design for the Super-FRS and SIS100 at the international FAIR facility

    Science.gov (United States)

    Kozlova, Ekaterina; Sokolov, Alexey; Radon, Torsten; Lang, Rupert; Conrad, Inna; Fehrenbacher, Georg; Weick, Helmut; Winkler, Martin

    2017-09-01

    The new accelerator SIS100 and the Super-FRS will be built at the international Facility for Antiprotons and Ion Research FAIR. The synchrotron SIS100 is a core part of the FAIR facility which serves for acceleration of ions like Uranium up to 2.7 GeV/u with intensities of 3x1011 particles per second or protons up to 30 GeV with intensities of 5x1012 particles per second. The Super-FRS is a superconducting fragment separator, it will be able to separate all kinds of nuclear projectile fragments of primary heavy ion beams including Uranium with energies up to 1.5 GeV/u and intensities up to 3x1011 particles per second. During operation activation of several components, especially the production target and the beam catchers will take place. For handling of highly activated components it is foreseen to have a hot cell with connected storage place. All calculations for the optimisation of the shielding design of the SIS100, the Super-FRS and the hot cell were performed using the Monte Carlo code FLUKA, results are presented.

  15. SuperB Progress Report for Physics

    Energy Technology Data Exchange (ETDEWEB)

    O' Leary, B.; /Aachen, Tech. Hochsch.; Matias, J.; Ramon, M.; /Barcelona, IFAE; Pous, E.; /Barcelona U.; De Fazio, F.; Palano, A.; /INFN, Bari; Eigen, G.; /Bergen U.; Asgeirsson, D.; /British Columbia U.; Cheng, C.H.; Chivukula, A.; Echenard, B.; Hitlin, D.G.; Porter, F.; Rakitin, A.; /Caltech; Heinemeyer, S.; /Cantabria Inst. of Phys.; McElrath, B.; /CERN; Andreassen, R.; Meadows, B.; Sokoloff, M.; /Cincinnati U.; Blanke, M.; /Cornell U., Phys. Dept.; Lesiak, T.; /Cracow, INP /DESY /Zurich, ETH /INFN, Ferrara /Frascati /INFN, Genoa /Glasgow U. /Indiana U. /Mainz U., Inst. Phys. /Karlsruhe, Inst. Technol. /KEK, Tsukuba /LBL, Berkeley /UC, Berkeley /Lisbon, IST /Ljubljana U. /Madrid, Autonoma U. /Maryland U. /MIT /INFN, Milan /McGill U. /Munich, Tech. U. /Notre Dame U. /PNL, Richland /INFN, Padua /Paris U., VI-VII /Orsay, LAL /Orsay, LPT /INFN, Pavia /INFN, Perugia /INFN, Pisa /Queen Mary, U. of London /Regensburg U. /Republica U., Montevideo /Frascati /INFN, Rome /INFN, Rome /INFN, Rome /Rutherford /Sassari U. /Siegen U. /SLAC /Southern Methodist U. /Tel Aviv U. /Tohoku U. /INFN, Turin /INFN, Trieste /Uppsala U. /Valencia U., IFIC /Victoria U. /Wayne State U. /Wisconsin U., Madison

    2012-02-14

    SuperB is a high luminosity e{sup +}e{sup -} collider that will be able to indirectly probe new physics at energy scales far beyond the reach of any man made accelerator planned or in existence. Just as detailed understanding of the Standard Model of particle physics was developed from stringent constraints imposed by flavour changing processes between quarks, the detailed structure of any new physics is severely constrained by flavour processes. In order to elucidate this structure it is necessary to perform a number of complementary studies of a set of golden channels. With these measurements in hand, the pattern of deviations from the Standard Model behavior can be used as a test of the structure of new physics. If new physics is found at the LHC, then the many golden measurements from SuperB will help decode the subtle nature of the new physics. However if no new particles are found at the LHC, SuperB will be able to search for new physics at energy scales up to 10-100 TeV. In either scenario, flavour physics measurements that can be made at SuperB play a pivotal role in understanding the nature of physics beyond the Standard Model. Examples for using the interplay between measurements to discriminate New Physics models are discussed in this document. SuperB is a Super Flavour Factory, in addition to studying large samples of B{sub u,d,s}, D and {tau} decays, SuperB has a broad physics programme that includes spectroscopy both in terms of the Standard Model and exotica, and precision measurements of sin{sup 2} {theta}{sub W}. In addition to performing CP violation measurements at the {Upsilon}(4S) and {phi}(3770), SuperB will test CPT in these systems, and lepton universality in a number of different processes. The multitude of rare decay measurements possible at SuperB can be used to constrain scenarios of physics beyond the Standard Model. In terms of other precision tests of the Standard Model, this experiment will be able to perform precision over

  16. The superB silicon vertex tracker

    Energy Technology Data Exchange (ETDEWEB)

    Rizzo, G., E-mail: giuliana.rizzo@pi.infn.i [INFN-Pisa and Universita di Pisa (Italy); Avanzini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Calderini, G.; Ceccanti, M.; Cenci, R.; Cervelli, A.; Crescioli, F.; Dell' Orso, M.; Forti, F.; Giannetti, P.; Giorgi, M.A. [INFN-Pisa and Universita di Pisa (Italy); Lusiani, A. [Scuola Normale Superiore and INFN-Pisa (Italy); Gregucci, S.; Mammini, P.; Marchiori, G.; Massa, M.; Morsani, F. [INFN-Pisa and Universita di Pisa (Italy)

    2010-05-21

    The SuperB asymmetric e{sup +}-e{sup -} collider has been designed to deliver a luminosity greater than 10{sup 36}cm{sup -2}s{sup -1} with moderate beam currents. Comparing to current B-Factories, the reduced center of mass boost of the SuperB machine requires improved vertex resolution to allow precision measurements sensitive to New Physics. We present the conceptual design of the silicon vertex tracker (SVT) for the SuperB detector with the present status of the R and D on the different options under study for its innermost Layer0.

  17. N=2 Super - $W_{3}$ Algebra and N=2 Super Boussinesq Equations

    CERN Document Server

    Ivanov, E; Malik, R P

    1995-01-01

    We study classical $N=2$ super-$W_3$ algebra and its interplay with $N=2$ supersymmetric extensions of the Boussinesq equation in the framework of the nonlinear realization method and the inverse Higgs - covariant reduction approach. These techniques have been previously applied by us in the bosonic $W_3$ case to give a new geometric interpretation of the Boussinesq hierarchy. Here we deduce the most general $N=2$ super Boussinesq equation and two kinds of the modified $N=2$ super Boussinesq equations, as well as the super Miura maps relating these systems to each other, by applying the covariant reduction to certain coset manifolds of linear $N=2$ super-$W_3^{\\infty}$ symmetry associated with $N=2$ super-$W_3$. We discuss the integrability properties of the equations obtained and their correspondence with the formulation based on the notion of the second hamiltonian structure.

  18. Repeat-PPM Super-Symbol Synchronization

    Science.gov (United States)

    Connelly, J.

    2016-11-01

    To attain a wider range of data rates in pulse position modulation (PPM) schemes with constrained pulse durations, the sender can repeat a PPM symbol multiple times, forming a super-symbol. In addition to the slot and symbol synchronization typically required for PPM, the receiver must also properly align the noisy super-symbols. We present a low-complexity approximation of the maximum-likelihood method for performing super-symbol synchronization without use of synchronization sequences. We provide simulation results demonstrating performance advantage when PPM symbols are spread by a pseudo-noise sequence, as opposed to simply repeating. Additionally, the results suggest that this super-symbol synchronization technique requires signal levels below those required for reliable communication. This validates that the PPM spreading approach proposed to CCSDS can work properly as part of the overall scheme.

  19. Axial Super-resolution Evanescent Wave Tomography

    CERN Document Server

    Pendharker, Sarang; Newman, Ward; Ogg, Stephen; Nazemifard, Neda; Jacob, Zubin

    2016-01-01

    Optical tomographic reconstruction of a 3D nanoscale specimen is hindered by the axial diffraction limit, which is 2-3 times worse than the focal plane resolution. We propose and experimentally demonstrate an axial super-resolution evanescent wave tomography (AxSET) method that enables the use of regular evanescent wave microscopes like Total Internal Reflection Fluorescence Microscope (TIRF) beyond surface imaging, and achieve tomographic reconstruction with axial super-resolution. Our proposed method based on Fourier reconstruction achieves axial super-resolution by extracting information from multiple sets of three-dimensional fluorescence images when the sample is illuminated by an evanescent wave. We propose a procedure to extract super-resolution features from the incremental penetration of an evanescent wave and support our theory by 1D (along the optical axis) and 3D simulations. We validate our claims by experimentally demonstrating tomographic reconstruction of microtubules in HeLa cells with an axi...

  20. Surface superconductivity in thin cylindrical Bi nanowire.

    Science.gov (United States)

    Tian, Mingliang; Wang, Jian; Ning, Wei; Mallouk, Thomas E; Chan, Moses H W

    2015-03-11

    The physical origin and the nature of superconductivity in nanostructured Bi remains puzzling. Here, we report transport measurements of individual cylindrical single-crystal Bi nanowires, 20 and 32 nm in diameter. In contrast to nonsuperconducting Bi nanoribbons with two flat surfaces, cylindrical Bi nanowires show superconductivity below 1.3 K. However, their superconducting critical magnetic fields decrease with their diameter, which is the opposite of the expected behavior for thin superconducting wires. Quasiperiodic oscillations of magnetoresistance were observed in perpendicular fields but were not seen in the parallel orientation. These results can be understood by a model of surface superconductivity with an enhanced surface-to-bulk volume in small diameter wires, where the superconductivity originates from the strained surface states of the nanowires due to the surface curvature-induced stress.

  1. Superconducting Josephson vortex flow transistors

    CERN Document Server

    Tavares, P A C

    2002-01-01

    The work reported in this thesis focuses on the development of high-temperature superconducting Josephson vortex-flow transistors (JVFTs). The JVFT is a particular type of superconducting transistor, i.e. an electromagnetic device capable of delivering gain while keeping the control and output circuits electrically isolated. Devices were fabricated from (100) YBa sub 2 Cu sub 3 O sub 7 sub - subdelta thin films grown by Pulsed Laser Deposition on 24 deg magnesium oxide and strontium titanate bicrystals. The design of the JVFTs was guided by numerical simulations and the devices were optimised for current gain. Improvements were made to the fabrication process in order to accurately pattern the small structures required. The devices exhibited current gains higher than 60 in liquid nitrogen. Gains measured at lower temperatures were significantly higher. As part of the work a data acquisition suite was developed for the characterisation of three-terminal devices and, in particular, of JVFTs.

  2. Superconductivity in the Tungsten Bronzes

    Science.gov (United States)

    Wu, Phillip; Ishii, Satoshi; Tanabe, Kenji; Munakata, Ko; Hammond, Robert H.; Tokiwa, Kazuyasu; Geballe, Theodore H.; Beasley, Malcolm R.

    2015-03-01

    Via pulsed laser deposition and post-annealing, high quality K-doped WO3-y films with reproducible transport properties are obtained. A home built two-coil mutual inductance setup is used to probe the behavior of the films in the superconducting and normal state. The inverse penetration depths and dissipation peaks are measured as a function of temperature and field. Separately, via thin film deposition techniques, we report for the first time stable crystalline hexagonal WO3 on substrates. In order to tune the physical properties of the undoped material, we utilized an ionic liquid gating technique. We observe an insulator-to-metal transition, showing the ionic liquid gate to be a viable technique to alter the electrical transport properties of this material. By comparing the alkali and ionic liquid gated WO3, we conclude with some remarks regarding how superconductivity arises in this system.

  3. Superconducting wires and fractional flux

    Science.gov (United States)

    Sá de Melo, C. A. R.

    1996-05-01

    The quantization of flux quanta in superconductors is revisited and analyzed in a new geometry. The system analyzed is a superconducting wire. The geometry is such that the superconducting wire winds N times around an insulating cylinder and that the wire has its end connected back to its beginning, thus producing an N-loop short circuited solenoid. The winding number N acts as a topological index that controls flux quantization. In this case, fractional flux quanta can be measured through the center of the insulating cylinder, provided that the cylinder radius is small enough. The Little-Parks experiment for an identical geometry is discussed. The period of oscillation of the transition temperature of the wire is found to vary as 1/N in units of flux Φ relative to the flux quantum Φ0. When a SQUID is made in such a geometry the maximal current through the SQUID varies with period Φ0/N.

  4. Mirror-enhanced super-resolution microscopy

    OpenAIRE

    2016-01-01

    Axial excitation confinement beyond the diffraction limit is crucial to the development of next-generation, super-resolution microscopy. STimulated Emission Depletion (STED) nanoscopy offers lateral super-resolution using a donut-beam depletion, but its axial resolution is still over 500 nm. Total internal reflection fluorescence microscopy is widely used for single-molecule localization, but its ability to detect molecules is limited to within the evanescent field of ~ 100 nm from the cell a...

  5. Improving the design and analysis of superconducting magnets for particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Ramesh Chandra [Univ. of Rajasthan, Jaipur (India). Dept. of Physics

    1996-11-01

    High energy particle accelerators are now the primary means of discovering the basic building blocks of matter and understanding the forces between them. In order to minimize the cost of building these machines, superconducting magnets are used in essentially all present day high energy proton and heavy ion colliders. The cost of superconducting magnets is typically in the range of 20--30% of the total cost of building such machines. The circulating particle beam goes through these magnets a large number of times (over hundreds of millions). The luminosity performance and life time of the beam in these machines depends significantly on the field quality in these magnets. Therefore, even a small error in the magnetic field shape may create a large cumulative effect in the beam trajectory to throw the particles of the magnet aperture. The superconducting accelerator magnets must, therefore, be designed and constructed so that these errors are small. In this thesis the research and development work will be described 3which has resulted in significant improvements in the field quality of the superconducting magnets for the Relativistic Heavy Ion Collider (RHIC). The design and the field quality improvements in the prototype of the main collider dipole magnet for the Superconducting Super Collider (SSC) will also be presented. RHIC will accelerate and collide two counter rotating beams of heavy ions up to 100 GeV/u and protons up to 250 GeV. It is expected that RHIC will create a hot, dense quark-gluon plasma and the conditions which, according to the Big Bang theory, existed in the early universe.

  6. Stripes and Superconductivity in Cuprates

    OpenAIRE

    Tranquada, John M.

    2011-01-01

    Holes doped into the CuO2 planes of cuprate parent compounds frustrate the antiferromagnetic order. The development of spin and charge stripes provides a compromise between the competing magnetic and kinetic energies. Static stripe order has been observed only in certain particular compounds, but there are signatures which suggest that dynamic stripe correlations are common in the cuprates. Though stripe order is bad for superconducting phase coherence, stripes are compatible with strong pair...

  7. Superconducting Qubits: A Short Review

    OpenAIRE

    Devoret, M. H.; Wallraff, A.; Martinis, J. M.

    2004-01-01

    Superconducting qubits are solid state electrical circuits fabricated using techniques borrowed from conventional integrated circuits. They are based on the Josephson tunnel junction, the only non-dissipative, strongly non-linear circuit element available at low temperature. In contrast to microscopic entities such as spins or atoms, they tend to be well coupled to other circuits, which make them appealling from the point of view of readout and gate implementation. Very recently, new designs ...

  8. Inelastic tunneling in superconducting junctions

    Energy Technology Data Exchange (ETDEWEB)

    Hlobil, Patrik Christian

    2016-06-10

    In this dissertation a theoretical formalism of elastic and inelastic tunneling spectroscopy is developed for superconductors. The underlying physical processes behind the different two tunneling channels and their implications for the interpretation of experimental tunneling data are investigated in detail, which can explain the background conductance seen in the cuprate and iron-based superconductors. Further, the properties of the emitted light from a superconducting LED are investigated.

  9. Stimulated Superconductivity at Strong Coupling

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Ning; Dong, Xi; Silverstein, Eva; Torroba, Gonzalo; /Stanford U., ITP /Stanford U., Phys. Dept. /SLAC

    2011-08-12

    Stimulating a system with time dependent sources can enhance instabilities, thus increasing the critical temperature at which the system transitions to interesting low-temperature phases such as superconductivity or superfluidity. After reviewing this phenomenon in non-equilibrium BCS theory (and its marginal fermi liquid generalization) we analyze the effect in holographic superconductors. We exhibit a simple regime in which the transition temperature increases parametrically as we increase the frequency of the time-dependent source.

  10. RF Characterization of Superconducting Samples

    CERN Document Server

    Junginger, T; Welsch, C

    2009-01-01

    At CERN a compact Quadrupole Resonator has been re-commissioned for the RF characterization of superconducting materials at 400 MHz. In addition the resonator can also be excited at multiple integers of this frequency. Besides Rs it enables determination of the maximum RF magnetic field, the thermal conductivity and the penetration depth of the attached samples, at different temperatures. The features of the resonator will be compared with those of similar RF devices and first results will be presented.

  11. Activities on RF superconductivity at DESY

    Energy Technology Data Exchange (ETDEWEB)

    Matheisen, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); TESLA Collaboration

    1996-01-01

    At DESY the HERA electron storage ring is supplied with normal and superconducting cavities. The superconducting system transfers up to 1 MW klystron power to the beam. Experiences are reported on luminosity and machine study runs. Since 1993 one major activity in the field of RF superconducting cavities is the installation of the TESLA Test Facility. Set-up of hardware and first tests of s.c. resonators are presented. (R.P.). 11 refs.

  12. Superconducting electron and hole lenses

    Science.gov (United States)

    Cheraghchi, H.; Esmailzadeh, H.; Moghaddam, A. G.

    2016-06-01

    We show how a superconducting region (S), sandwiched between two normal leads (N), in the presence of barriers, can act as a lens for propagating electron and hole waves by virtue of the so-called crossed Andreev reflection (CAR). The CAR process, which is equivalent to Cooper pair splitting into two N electrodes, provides a unique possibility of constructing entangled electrons in solid state systems. When electrons are locally injected from an N lead, due to the CAR and normal reflection of quasiparticles by the insulating barriers at the interfaces, sequences of electron and hole focuses are established inside another N electrode. This behavior originates from the change of momentum during electron-hole conversion beside the successive normal reflections of electrons and holes due to the barriers. The focusing phenomena studied here are fundamentally different from the electron focusing in other systems, such as graphene p-n junctions. In particular, due to the electron-hole symmetry of the superconducting state, the focusing of electrons and holes is robust against thermal excitations. Furthermore, the effects of the superconducting layer width, the injection point position, and barrier strength are investigated on the focusing behavior of the junction. Very intriguingly, it is shown that by varying the barrier strength, one can separately control the density of electrons or holes at the focuses.

  13. Attenuation in Superconducting Circular Waveguides

    Directory of Open Access Journals (Sweden)

    K. H. Yeap

    2016-09-01

    Full Text Available We present an analysis on wave propagation in superconducting circular waveguides. In order to account for the presence of quasiparticles in the intragap states of a superconductor, we employ the characteristic equation derived from the extended Mattis-Bardeen theory to compute the values of the complex conductivity. To calculate the attenuation in a circular waveguide, the tangential fields at the boundary of the wall are first matched with the electrical properties (which includes the complex conductivity of the wall material. The matching of fields with the electrical properties results in a set of transcendental equations which is able to accurately describe the propagation constant of the fields. Our results show that although the attenuation in the superconducting waveguide above cutoff (but below the gap frequency is finite, it is considerably lower than that in a normal waveguide. Above the gap frequency, however, the attenuation in the superconducting waveguide increases sharply. The attenuation eventually surpasses that in a normal waveguide. As frequency increases above the gap frequency, Cooper pairs break into quasiparticles. Hence, we attribute the sharp rise in attenuation to the increase in random collision of the quasiparticles with the lattice structure.

  14. Ballistic superconductivity in semiconductor nanowires

    Science.gov (United States)

    Zhang, Hao; Gül, Önder; Conesa-Boj, Sonia; Nowak, Michał P.; Wimmer, Michael; Zuo, Kun; Mourik, Vincent; de Vries, Folkert K.; van Veen, Jasper; de Moor, Michiel W. A.; Bommer, Jouri D. S.; van Woerkom, David J.; Car, Diana; Plissard, Sébastien R.; Bakkers, Erik P. A. M.; Quintero-Pérez, Marina; Cassidy, Maja C.; Koelling, Sebastian; Goswami, Srijit; Watanabe, Kenji; Taniguchi, Takashi; Kouwenhoven, Leo P.

    2017-07-01

    Semiconductor nanowires have opened new research avenues in quantum transport owing to their confined geometry and electrostatic tunability. They have offered an exceptional testbed for superconductivity, leading to the realization of hybrid systems combining the macroscopic quantum properties of superconductors with the possibility to control charges down to a single electron. These advances brought semiconductor nanowires to the forefront of efforts to realize topological superconductivity and Majorana modes. A prime challenge to benefit from the topological properties of Majoranas is to reduce the disorder in hybrid nanowire devices. Here we show ballistic superconductivity in InSb semiconductor nanowires. Our structural and chemical analyses demonstrate a high-quality interface between the nanowire and a NbTiN superconductor that enables ballistic transport. This is manifested by a quantized conductance for normal carriers, a strongly enhanced conductance for Andreev-reflecting carriers, and an induced hard gap with a significantly reduced density of states. These results pave the way for disorder-free Majorana devices.

  15. SuperHILAC Upgrade Project

    Energy Technology Data Exchange (ETDEWEB)

    Feinberg, B.; Brown, I.G.

    1986-06-01

    A high current MEtal Vapor Vacuum Arc (MEVVA) ion source is to be installed in the third injector (Abel) at the SuperHILAC, representing the first accelerator use of this novel ion source. The MEVVA source has produced over 1 A of uranium in all charge states, with typically more than 100 electrical mA (emA) of U/sup 5 +/. A substantial fraction of this high current, heavy ion beam must be successfully transported to the entrance of the Wideroe linac to approach the 10 emA space-charge output limit of the Wideroe. Calculations show that up to 50 emA of U/sup 5 +/ can be transported through the present high voltage column. A bouncer will be added to the Cockcroft-Walton supply to handle the increased beam current. The Low Energy Beam Transport line vacuum will be improved to reduce charge exchange, and the phase matching between the 23 MHz Wideroe and the 70 MHz Alvarez linacs will be improved by the addition of two 70 HMz bunchers. The installation of the MEVVA source along with the modifications described above are expected to result in a five-fold increase in beam delivered to Bevatron experiments, increasing the extracted uranium beam to 5 x 10/sup 7/ ions/pulse.

  16. Super-B Project Overview

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, M.E.; Boni, R.; Boscolo, M.; Demma, T.; Drago, A.; Guiducci, S.; Raimondi, P.; Tomassini, S.; Zobov, M.; /Frascati; Bertsche, K.; Donald, M.; Nosochkov, Y.; Novokhatski, A.; Seeman, J.; Sullivan, M.; Yocky, G.; Wienands, U.; Wittmer, W.; /SLAC; Koop, I.; Levichev, E.; Nikitin, S.; /Novosibirsk, IYF /KEK, Tsukuba /Pisa U. /CERN

    2010-08-26

    The SuperB project aims at the construction of an asymmetric very high luminosity B-Factory on the Frascati/Tor Vergata (Italy) area, providing a uniquely sensitive probe of New Physics in the flavour sector of the Standard Model. The luminosity goal of 10{sup 36} cm{sup -2} s{sup -1} can be reached with a new collision scheme with 'large Piwinski angle' (LPA) and the use of 'crab waist sextupoles' (CW). A LPA&CW Interaction Region (IR) has been successfully tested at the DA{Phi}NE {Phi}-Factory at LNF-Frascati in 2008. The LPA&CW scheme, together with very low {beta}*, will allow for operation with relatively low beam currents and reasonable bunch length, comparable to those of PEP-II and KEKB. In the High Energy Ring (HER), two spin rotators will bring longitudinally polarized beams into collision at the IP. The lattice has been designed with a very low intrinsic emittance and is quite compact, less than 2 km long. The tight focusing requires the final doublet quadrupoles to be very close to the IP and very compact. A Conceptual Design Report was published in March 2007, and beam dynamics and collective effects R&D studies are in progress in order to publish a Technical Design Report by the end of 2010.

  17. SUPER-B LATTICE STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Biagini, M.E.; Raimondi, P.; /Frascati; Piminov, P.; Sinyatkin, S.; /Novosibirsk, IYF; Nosochkov, Y.; Wittmer, W.; /SLAC

    2010-08-25

    The SuperB asymmetric e{sup +}e{sup -} collider is designed for 10{sup 36} cm{sup -2} s{sup -1} luminosity and beam energies of 6.7 and 4.18 GeV for e{sup +} and e{sup -} respectively. The High and Low Energy Rings (HER and LER) have one Interaction Point (IP) with 66 mrad crossing angle. The 1258 m rings fit to the INFN-LNF site at Frascati. The ring emittance is minimized for the high luminosity. The Final Focus (FF) chromaticity correction is optimized for maximum transverse acceptance and energy bandwidth. Included Crab Waist sextupoles suppress betatron resonances induced in the collisions with a large Piwinski angle. The LER Spin Rotator sections provide longitudinally polarized electron beam at the IP. The lattice is flexible for tuning the machine parameters and compatible with reusing the PEP-II magnets, RF cavities and other components. Details of the lattice design are presented.

  18. Studies of the Super VELO

    CERN Document Server

    AUTHOR|(CDS)2156302

    2016-01-01

    The Super VELO is the Run 5 upgrade of the VeloPix detector of the LHCb experiment. Its most challenging task is to cope with a luminosity increase of the factor 10. This study examines the potential physics performance of a detector based on the VeloPix design at high luminosity conditions. It is found that an unmodified VeloPix detector shows poor performance when exposed to 10x design luminosity, most gravely high ghost rates of 40 %. When applying basic assumptions about material changes such as cutting the silicon thickness by half and removing the RF foil, the ghost rate drops by 20 %. When using thin silicon and re-optimizing the tracking algorithm, the ghost rate can even be reduced by 60 %. Applying the additional modification of a pixel area size four times smaller, the ghost rate drops by 88 % and the IP resolution improves. Finally, in a dream scenario with thin silicon, smaller pixels and no RF foil, big gains in resolution and a ghost rate of less than 4 % can be achieved.

  19. Similarities between normal- and super-currents in topological insulator magnetic tunnel junctions

    Energy Technology Data Exchange (ETDEWEB)

    Soodchomshom, Bumned, E-mail: Bumned@hotmail.co [ThEP Center, Commission of Higher Education, 328 Si Ayuthaya Rd. Bangkok 10400 (Thailand); Chantngarm, Peerasak [Department of Electronics and Telecommunication Engineering, Faculty of Engineering, Pathumwan Institute of Technology, Bangkok 10330 (Thailand)

    2010-11-15

    This work compares the normal-current in a NM/Fi/NM junction with the super-current in a SC/Fi/SC junction, where both are topological insulator systems. NM and Fi are normal region and ferromagnetic region of thickness d with exchange energy m playing a role of the mass of the Dirac electrons and with the gate voltage V{sub G}, respectively. SC is superconducting region induced by a s-wave superconductor. We show that, interestingly, the critical super-current passing through a SC/Fi/SC junction behaves quite similar to the normal-current passing through a NM/Fi/NM junction. The normal-current and super-current exhibit N-peak oscillation, found when currents are plotted as a function of the magnetic barrier strength {chi} {approx} md/hv{sub F}. With the barrier strength Z {approx} V{sub G}d/hv{sub F}, the number of peaks N is determined through the relation Z {approx} N{pi} + {sigma}{pi} (with 0 < {sigma}{<=}1 for {chi} < Z). The normal- and the super-currents also exhibit oscillating with the same height for all of peaks, corresponding to the Dirac fermion tunneling behavior. These anomalous oscillating currents due to the interplay between gate voltage and magnetic field in the barrier were not found in graphene-based NM/Fi/NM and SC/Fi/SC junctions. This is due to the different magnetic effect between the Dirac fermions in topological insulator and graphene.

  20. Interfacing superconducting qubits and single optical photons

    CERN Document Server

    Das, Sumanta; Sørensen, Anders S

    2016-01-01

    We propose an efficient light-matter interface at optical frequencies between a superconducting qubit and a single photon. The desired interface is based on a hybrid architecture composed of an organic molecule embedded inside an optical waveguide and electrically coupled to a superconducting qubit far from the optical axis. We show that high fidelity, photon-mediated, entanglement between distant superconducting qubits can be achieved with incident pulses at the single photon level. Such low light level is highly sought for to overcome the decoherence of the superconducting qubit caused by absorption of optical photons.

  1. Anisotropic superconductivity driven by kinematic interaction

    Science.gov (United States)

    Ivanov, V. A.

    2000-11-01

    We have analysed the effect of kinematic pairing on the symmetry of superconducting order parameter for a square lattice in the frame of the strongly correlated Hubbard model. It is argued that in the first perturbation order the kinematic interaction renormalizes the Hubbard-I dispersions and provides at low doping the mixed singlet (s + s*)-wave superconductivity, giving way at higher doping to the triplet p-wave superconductivity. The obtained phase diagram depends only on the hopping integral parameter. The influence of the Coulomb repulsion on the kinematic superconducting pairing has been estimated. The (s + s*)-wave gap and the thermodynamic critical magnetic field have been derived.

  2. Superconducting fault current limiter for railway transport

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, L. M., E-mail: LMFisher@niitfa.ru; Alferov, D. F.; Akhmetgareev, M. R.; Budovskii, A. I.; Evsin, D. V.; Voloshin, I. F.; Kalinov, A. V. [National Technical Physics and Automation Research Institute (Russian Federation)

    2015-12-15

    A resistive switching superconducting fault current limiter (SFCL) for DC networks with voltage of 3.5 kV and nominal current of 2 kA is developed. The SFCL consists of two series-connected units: block of superconducting modules and high-speed vacuum breaker with total disconnection time not more than 8 ms. The results of laboratory tests of superconducting SFCL modules in current limiting mode are presented. The recovery time of superconductivity is experimentally determined. The possibility of application of SFCL on traction substations of Russian Railways is considered.

  3. Foreword: Focus on Superconductivity in Semiconductors

    Directory of Open Access Journals (Sweden)

    Yoshihiko Takano

    2008-01-01

    Full Text Available Since the discovery of superconductivity in diamond, much attention has been given to the issue of superconductivity in semiconductors. Because diamond has a large band gap of 5.5 eV, it is called a wide-gap semiconductor. Upon heavy boron doping over 3×1020 cm−3, diamond becomes metallic and demonstrates superconductivity at temperatures below 11.4 K. This discovery implies that a semiconductor can become a superconductor upon carrier doping. Recently, superconductivity was also discovered in boron-doped silicon and SiC semiconductors. The number of superconducting semiconductors has increased. In 2008 an Fe-based superconductor was discovered in a research project on carrier doping in a LaCuSeO wide-gap semiconductor. This discovery enhanced research activities in the field of superconductivity, where many scientists place particular importance on superconductivity in semiconductors.This focus issue features a variety of topics on superconductivity in semiconductors selected from the 2nd International Workshop on Superconductivity in Diamond and Related Materials (IWSDRM2008, which was held at the National Institute for Materials Science (NIMS, Tsukuba, Japan in July 2008. The 1st workshop was held in 2005 and was published as a special issue in Science and Technology of Advanced Materials (STAM in 2006 (Takano 2006 Sci. Technol. Adv. Mater. 7 S1.The selection of papers describe many important experimental and theoretical studies on superconductivity in semiconductors. Topics on boron-doped diamond include isotope effects (Ekimov et al and the detailed structure of boron sites, and the relation between superconductivity and disorder induced by boron doping. Regarding other semiconductors, the superconducting properties of silicon and SiC (Kriener et al, Muranaka et al and Yanase et al are discussed, and In2O3 (Makise et al is presented as a new superconducting semiconductor. Iron-based superconductors are presented as a new series of high

  4. Baryon number violation and nonperturbative weak processes at Superconducting Super Collider energies

    Science.gov (United States)

    Shuryak, E. V.; Verbaarschot, J. J. M.

    1992-04-01

    Baryon number violation and multiple production of W and Higgs bosons are described semiclassically in terms of the instanton-anti-instanton valley. We find (i) two saddle points, one describing reflection from a barrier and the other describing tunneling through it. We find (ii) a critical energy Ec~35 TeV where the cross section is suppressed as exp(-const/g2w), but the formulas are no longer valid; (iii) however, depending on the (still uncertain) Higgs bosson action, the cross section at this point may be large enough to be observable.

  5. A Bridge Too Far: The Demise of the Superconducting Super Collider

    CERN Document Server

    CERN. Geneva

    2016-01-01

    A combination of fiscal austerity, continuing SSC cost overruns, intense Congressional scrutiny, lack of major foreign contributions, waning Presidential support, and the widespread public perception of mismanagement led to the project’s demise nearly five years after it had begun. Its termination occurred against the political backdrop of changing scientific needs as US science policy shifted to a post-Cold War footing during the early 1990s. And the growing cost of the SSC inevitably exerted undue pressure upon other worthy research, thus weakening its support in Congress and the bro...

  6. Report of the DOE Review Committee on the baseline validation of the Superconducting Super Collider

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    The Secretary of Energy directed that an independent review of the current cost and schedule baseline for the SSC be conducted. The purpose of this independent review was to validate the current cost and schedule baseline and to ensure that the project status is accurate as currently reported. Through May 1993, approximately $1.5 billion of the baseline cost of $8.249 billion had been expended, with project completion forecasted on the baseline schedule as of September 1999. This report documents the findings of the SSC Baseline Validation Review Committee (the Committee). The report is organized into five parts. The first section is the Executive Summary. This introduction is followed by a discussion of the project progress/status as determined by the Committee. The next section describes the Committee`s estimate of the cost at completion for the SSC project, followed by an assessment of the adequacy of the business management systems currently being used to manage the project. The final section presents the Committee`s conclusions and recommendations. The main body of the report is followed by the subcommittee reports and appendices.

  7. Cryogenic instrumentation of an SSC (superconducting super collider) magnet test stand

    Energy Technology Data Exchange (ETDEWEB)

    McGuire, K.; Strait, J.; Kuchnir, M.; McInturff, A.

    1987-09-01

    This paper describes the system used to acquire cryogenic data for the testing of SSC magnets at the Fermilab Magnet Test Facility. An array of pressure transducers, resistance thermometers, vapor pressure thermometers, and signal conditioning circuits are used. Readings with time resolution appropriate for quench recording are obtained with a waveform digitizer and steady-state measurements are obtained with higher accuracy using a digital voltmeter. The waveform digitizer is clocked at a 400 Hz sampling rate and these readings are stored in local ring buffers. The system is modular and can be expanded to add more channels. The software for the acquisition, control, logging, and display of cryogenic data consist of two programs which run as separate tasks. These programs (as well as a third program which acquires quench and magnetic data) communicate and pass data using shared global resources. The acquired data are available for analysis via a nationwide DECnet network.

  8. Superconducting Super Collider site environmental report for calendar year 1991. Pre-operational

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-05-01

    This is the first annual SER prepared for the SSC project. It is a pre-operational report, intended primarily to describe the baseline characterization of the Ellis County, Texas site that has been developed subsequent to the Environmental Impact Statement (EIS) and the Supplemental Environmental impact Statement (SEIS). As such, the emphasis will be on environmental compliance efforts, including monitoring and mitigation programs. The SER also reports on the measures taken to meet the commitments made in the EIS and SEIS. These measures are detailed in the Mitigation Action Plan (MAP) (Department of Energy (DOE), 1991), which was prepared following the signing of the Record of Decision (ROD) to construct the SSC in Texas. The SER will continue to be preoperational until the first high-energy (20 trillion electron volt or TeV) protons collisions are observed, at which point the SSC will become operational. At that time, the SER will place more emphasis on the radiological monitoring program. This SER will report on actions taken in 1991 or earlier and briefly mention some of those planned for calendar year 1992. AU actions completed in 1992 will be addressed in the SER for calendar year 1992.

  9. Apparatus and method for controlling the temperature of the core of a super-conducting transformer

    Science.gov (United States)

    Golner, Thomas; Pleva, Edward; Mehta, Shirish

    2006-10-10

    An apparatus for controlling the temperature of a core of a transformer is provided that includes a core, a shield surrounding the core, a cast formed between the core and the shield, and tubing positioned on the shield. The cast directs heat from the core to the shield and cooling fluid is directed through the tubing to cool the shield.

  10. Improvement of superconducting cylindrical linear induction motor; Chodendo entogata tan'ichiji rinia yudo mota no tokusei kaizen

    Energy Technology Data Exchange (ETDEWEB)

    Kikuma, T.; Ishiyama, A. [Waseda Univ., Tokyo (Japan)

    2000-05-29

    For the purpose of examining the characteristics (effect of stability and ac loss by the higher harmonic wave etc.) of an alternating current superconductivity winding under a real machine operating environment of the super-conductive AC machine vessel, authors produced a cylindrical shortness first linear guiding motor (SCLIM) which used the NbTi/CuNi super-conducting cable for the first excitation winding experimentally. In this study, the evaluation of the start up thrust and operation confirmation of the quenching detection protection circuit were carried out using the produced SCLIM. In the quenching detection protection control circuit, the first excitation winding was divided into an internal layer and an outer layer, and both layers were excited in the 2 layer division and a quenching detection protection circuit was installed on the 2 layers respectively. The circuit of a part of fact by this of the phase in which the quench was generated and observed was cut off, and the operation would be able to be continued in part of the remainder of the phase and other two phases. Here, it is to cut off the quenched phase from the circuit, when the phase current becomes zero, and the other effect on the phase is held as small as possible. (NEDO)

  11. Robustness of s-wave pairing symmetry in iron-based superconductors and its implications for fundamentals of magnetically driven high-temperature superconductivity

    Science.gov (United States)

    Hu, Jiangping; Yuan, Jing

    2016-10-01

    Based on the assumption that the superconducting state belongs to a single irreducible representation of lattice symmetry, we propose that the pairing symmetry in all measured iron-based superconductors is generally consistent with the A 1 g s-wave. Robust s-wave pairing throughout the different families of iron-based superconductors at different doping regions signals two fundamental principles behind high- T c superconducting mechanisms: (i) the correspondence principle: the short-range magnetic-exchange interactions and the Fermi surfaces act collaboratively to achieve high- T c superconductivity and determine pairing symmetries; (ii) the magnetic-selection pairing rule: superconductivity is only induced by the magnetic-exchange couplings from the super-exchange mechanism through cation-anion-cation chemical bonding. These principles explain why unconventional high- T c superconductivity appears to be such a rare but robust phenomena, with its strict requirements regarding the electronic environment. The results will help us to identify new electronic structures that can support high- T c superconductivity.

  12. Topological superconductivity induced by ferromagnetic metal chains

    Science.gov (United States)

    Li, Jian; Chen, Hua; Drozdov, Ilya K.; Yazdani, A.; Bernevig, B. Andrei; MacDonald, A. H.

    2014-12-01

    Recent experiments have provided evidence that one-dimensional (1D) topological superconductivity can be realized experimentally by placing transition-metal atoms that form a ferromagnetic chain on a superconducting substrate. We address some properties of this type of system by using a Slater-Koster tight-binding model to account for important features of the electronic structure of the transition-metal chains on the superconducting substrate. We predict that topological superconductivity is nearly universal when ferromagnetic transition-metal chains form straight lines on superconducting substrates and that it is possible for more complex chain structures. When the chain is weakly coupled to the substrate and is longer than superconducting coherence lengths, its proximity-induced superconducting gap is ˜Δ ESO/J where Δ is the s -wave pair potential on the chain, ESO is the spin-orbit splitting energy induced in the normal chain state bands by hybridization with the superconducting substrate, and J is the exchange splitting of the ferromagnetic chain d bands. Because of the topological character of the 1D superconducting state, Majorana end modes appear within the gaps of finite length chains. We find, in agreement with the experiment, that when the chain and substrate orbitals are strongly hybridized, Majorana end modes are substantially reduced in amplitude when separated from the chain end by less than the coherence length defined by the p -wave superconducting gap. We conclude that Pb is a particularly favorable substrate material for ferromagnetic chain topological superconductivity because it provides both strong s -wave pairing and strong Rashba spin-orbit coupling, but that there is an opportunity to optimize properties by varying the atomic composition and structure of the chain. Finally, we note that in the absence of disorder, a new chain magnetic symmetry, one that is also present in the crystalline topological insulators, can stabilize multiple

  13. Super-multiplex vibrational imaging

    Science.gov (United States)

    Wei, Lu; Chen, Zhixing; Shi, Lixue; Long, Rong; Anzalone, Andrew V.; Zhang, Luyuan; Hu, Fanghao; Yuste, Rafael; Cornish, Virginia W.; Min, Wei

    2017-04-01

    potential of this 24-colour (super-multiplex) optical imaging approach for elucidating intricate interactions in complex biological systems.

  14. Static Measurements on HTS Coils of Fully Superconducting AC Electric Machines for Aircraft Electric Propulsion System

    Science.gov (United States)

    Choi, Benjamin B.; Hunker, Keith R.; Hartwig, Jason; Brown, Gerald V.

    2017-01-01

    The NASA Glenn Research Center (GRC) has been developing the high efficiency and high-power density superconducting (SC) electric machines in full support of electrified aircraft propulsion (EAP) systems for a future electric aircraft. A SC coil test rig has been designed and built to perform static and AC measurements on BSCCO, (RE)BCO, and YBCO high temperature superconducting (HTS) wire and coils at liquid nitrogen (LN2) temperature. In this paper, DC measurements on five SC coil configurations of various geometry in zero external magnetic field are measured to develop good measurement technique and to determine the critical current (Ic) and the sharpness (n value) of the super-to-normal transition. Also, standard procedures for coil design, fabrication, coil mounting, micro-volt measurement, cryogenic testing, current control, and data acquisition technique were established. Experimentally measured critical currents are compared with theoretical predicted values based on an electric-field criterion (Ec). Data here are essential to quantify the SC electric machine operation limits where the SC begins to exhibit non-zero resistance. All test data will be utilized to assess the feasibility of using HTS coils for the fully superconducting AC electric machine development for an aircraft electric propulsion system.

  15. Superconducting integrated submillimeter receiver for TELIS

    NARCIS (Netherlands)

    Koshelets, Valery P.; Ermakov, Andrey B.; Filippenko, Lyudmila V.; Khudchenko, Andrey V.; Kiselev, Oleg S.; Sobolev, Alexander S.; Torgashin, Mikhail Yu.; Yagoubov, Pavel A.; Hoogeveen, Ruud W. M.; Wild, Wolfgang

    2007-01-01

    In this report an overview of the results on the development of a single-chip superconducting integrated receiver for the Terahertz Limb Sounder (TELIS) balloon project intended to measure a variety of stratosphere trace gases is presented. The Superconducting Integrated Receiver (SIR) comprises in

  16. Insulation systems for superconducting transmission cables

    DEFF Research Database (Denmark)

    Tønnesen, Ole

    1996-01-01

    the electrical insulation is placed outside both the superconducting tube and the cryostat. The superconducting tube is cooled by liquid nitrogen which is pumped through the hollow part of the tube.2) The cryogenic dielectric design, where the electrical insulation is placed inside the cryostat and thus is kept...

  17. 17th International Conference on RF Superconductivity

    CERN Document Server

    2015-01-01

    RF superconductivity is the key technology of accelerators for particle physics, nuclear physics and light sources. SRF 2015 covered the latest advances in the science, technology, and applications of superconducting RF. There was also an industrial exhibit during the conference with the key vendors in the community available to discuss their capabilities and products.

  18. Superconducting magnets. Citations from NTIS data base

    Science.gov (United States)

    Reimherr, G. W.

    1980-10-01

    The cited reports discuss research on materials studies, theory, design and applications of superconducting magnets. Examples of applications include particle accelerators, MHD power generation, superconducting generators, nuclear fusion research devices, energy storage systems, and magnetic levitation. This updated bibliography contains 218 citations, 88 of which are new entries to the previous edition.

  19. Superconducting Materials, Magnets and Electric Power Applications

    Science.gov (United States)

    Crabtree, George

    2011-03-01

    The surprising discovery of superconductivity a century ago launched a chain of convention-shattering innovations and discoveries in superconducting materials and applications that continues to this day. The range of large-scale applications grows with new materials discoveries - low temperature NbTi and Nb3 Sn for liquid helium cooled superconducting magnets, intermediate temperature MgB2 for inexpensive cryocooled applications including MRI magnets, and high temperature YBCO and BSSCO for high current applications cooled with inexpensive liquid nitrogen. Applications based on YBCO address critical emerging challenges for the electricity grid, including high capacity superconducting cables to distribute power in urban areas; transmission of renewable electricity over long distances from source to load; high capacity DC interconnections among the three US grids; fast, self-healing fault current limiters to increase reliability; low-weight, high capacity generators enabling off-shore wind turbines; and superconducting magnetic energy storage for smoothing the variability of renewable sources. In addition to these grid applications, coated conductors based on YBCO deposited on strong Hastelloy substrates enable a new generation of all superconducting high field magnets capable of producing fields above 30 T, approximately 50% higher than the existing all superconducting limit based on Nb3 Sn . The high fields, low power cost and the quiet electromagnetic and mechanical operation of such magnets could change the character of high field basic research on materials, enable a new generation of high-energy colliding beam experiments and extend the reach of high density superconducting magnetic energy storage.

  20. Superconducting chip receivers for imaging application

    NARCIS (Netherlands)

    Shitov, SV; Koshelets, VP; Ermakov, AB; Filippenko, LV; Baryshev, AM; Luinge, W; Gao, [No Value

    1999-01-01

    Experimental details of a unique superconducting imaging array receiver are discussed. Each pixel contains an internally pumped receiver chip mounted on the back of the elliptical microwave lens. Each chip comprises a quasi-optical SIS mixer integrated with a superconducting flux-flow oscillator (FF

  1. Diagram of a LEP superconducting cavity

    CERN Multimedia

    1991-01-01

    This diagram gives a schematic representation of the superconducting radio-frequency cavities at LEP. Liquid helium is used to cool the cavity to 4.5 degrees above absolute zero so that very high electric fields can be produced, increasing the operating energy of the accelerator. Superconducting cavities were used only in the LEP-2 phase of the accelerator, from 1996 to 2000.

  2. 17th International Conference on RF Superconductivity

    CERN Document Server

    Laxdal, Robert E.; Schaa, Volker R.W.

    2015-01-01

    RF superconductivity is the key technology of accelerators for particle physics, nuclear physics and light sources. SRF 2015 covered the latest advances in the science, technology, and applications of superconducting RF. There was also an industrial exhibit during the conference with the key vendors in the community available to discuss their capabilities and products.

  3. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig; Sakai, S

    1998-01-01

    We derive an analytical solution for the Josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low-T-c systems with magnetic coupling between the superconducting layers. but many features of our results are more general, and thus an application...

  4. Research progresses shed light on superconductivity mechanism

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The spring of 2008 saw substantial breakthroughs in superconductivity research. Four groups of physicists, one after another, achieved remarkable progresses in the study of iron-based materials after the breakthrough made by H. Hosono's group in Japan, providing renewed insights into the fundamental mechanism of high-temperature superconductivity (HTSC), a perplexing enigma on the frontier of condensed matter physics.

  5. Josephson plasma resonance in superconducting multilayers

    DEFF Research Database (Denmark)

    Pedersen, Niels Falsig

    1999-01-01

    We derive an analytical solution for the josephson plasma resonance of superconducting multilayers. This analytical solution is derived mainly for low T-c systems with magnetic coupling between the superconducting layers, but many features of our results are more general, and thus an application...

  6. Interfacing superconducting qubits and single optical photons

    NARCIS (Netherlands)

    Das, Sumanta; Faez, Sanli; Sørensen, Anders S.

    2016-01-01

    We propose an efficient light-matter interface at optical frequencies between a superconducting qubit and a single photon. The desired interface is based on a hybrid architecture composed of an organic molecule embedded inside an optical waveguide and electrically coupled to a superconducting qubit

  7. Interaction between ionic lattices and superconducting condensates

    OpenAIRE

    2007-01-01

    The interaction of the ionic lattice with the superconducting condensate is treated in terms of the electrostatic force in superconductors. It is shown that this force is similar but not identical to the force suggested by the volume difference of the normal and superconducting states. The BCS theory shows larger deviations than the two-fluid model.

  8. Axial super-resolution evanescent wave tomography.

    Science.gov (United States)

    Pendharker, Sarang; Shende, Swapnali; Newman, Ward; Ogg, Stephen; Nazemifard, Neda; Jacob, Zubin

    2016-12-01

    Optical tomographic reconstruction of a three-dimensional (3D) nanoscale specimen is hindered by the axial diffraction limit, which is 2-3 times worse than the focal plane resolution. We propose and experimentally demonstrate an axial super-resolution evanescent wave tomography method that enables the use of regular evanescent wave microscopes like the total internal reflection fluorescence microscope beyond surface imaging and achieve a tomographic reconstruction with axial super-resolution. Our proposed method based on Fourier reconstruction achieves axial super-resolution by extracting information from multiple sets of 3D fluorescence images when the sample is illuminated by an evanescent wave. We propose a procedure to extract super-resolution features from the incremental penetration of an evanescent wave and support our theory by one-dimensional (along the optical axis) and 3D simulations. We validate our claims by experimentally demonstrating tomographic reconstruction of microtubules in HeLa cells with an axial resolution of ∼130  nm. Our method does not require any additional optical components or sample preparation. The proposed method can be combined with focal plane super-resolution techniques like stochastic optical reconstruction microscopy and can also be adapted for THz and microwave near-field tomography.

  9. Axial super-resolution evanescent wave tomography

    Science.gov (United States)

    Pendharker, Sarang; Shende, Swapnali; Newman, Ward; Ogg, Stephen; Nazemifard, Neda; Jacob, Zubin

    2016-12-01

    Optical tomographic reconstruction of a 3D nanoscale specimen is hindered by the axial diffraction limit, which is 2-3 times worse than the focal plane resolution. We propose and experimentally demonstrate an axial super-resolution evanescent wave tomography (AxSET) method that enables the use of regular evanescent wave microscopes like Total Internal Reflection Fluorescence Microscope (TIRF) beyond surface imaging, and achieve tomographic reconstruction with axial super-resolution. Our proposed method based on Fourier reconstruction achieves axial super-resolution by extracting information from multiple sets of three-dimensional fluorescence images when the sample is illuminated by an evanescent wave. We propose a procedure to extract super-resolution features from the incremental penetration of an evanescent wave and support our theory by 1D (along the optical axis) and 3D simulations. We validate our claims by experimentally demonstrating tomographic reconstruction of microtubules in HeLa cells with an axial resolution of $\\sim$130 nm. Our method does not require any additional optical components or sample preparation. The proposed method can be combined with focal plane super-resolution techniques like STORM and can also be adapted for THz and microwave near-field tomography.

  10. Superconductivity in compensated and uncompensated semiconductors.

    Science.gov (United States)

    Yanase, Youichi; Yorozu, Naoyuki

    2008-12-01

    We investigate the localization and superconductivity in heavily doped semiconductors. The crossover from the superconductivity in the host band to that in the impurity band is described on the basis of the disordered three-dimensional attractive Hubbard model for binary alloys. The microscopic inhomogeneity and the thermal superconducting fluctuation are taken into account using the self-consistent 1-loop order theory. The superconductor-insulator transition accompanies the crossover from the host band to the impurity band. We point out an enhancement of the critical temperature Tc around the crossover. Further localization of electron wave functions leads to the localization of Cooper pairs and induces the pseudogap. We find that both the doping compensation by additional donors and the carrier increase by additional acceptors suppress the superconductivity. A theoretical interpretation is proposed for the superconductivity in the boron-doped diamond, SiC, and Si.

  11. Superconductivity in compensated and uncompensated semiconductors

    Directory of Open Access Journals (Sweden)

    Youichi Yanase and Naoyuki Yorozu

    2008-01-01

    Full Text Available We investigate the localization and superconductivity in heavily doped semiconductors. The crossover from the superconductivity in the host band to that in the impurity band is described on the basis of the disordered three-dimensional attractive Hubbard model for binary alloys. The microscopic inhomogeneity and the thermal superconducting fluctuation are taken into account using the self-consistent 1-loop order theory. The superconductor-insulator transition accompanies the crossover from the host band to the impurity band. We point out an enhancement of the critical temperature Tc around the crossover. Further localization of electron wave functions leads to the localization of Cooper pairs and induces the pseudogap. We find that both the doping compensation by additional donors and the carrier increase by additional acceptors suppress the superconductivity. A theoretical interpretation is proposed for the superconductivity in the boron-doped diamond, SiC, and Si.

  12. Method for producing substrates for superconducting layers

    DEFF Research Database (Denmark)

    2013-01-01

    There is provided a method for producing a substrate (600) suitable for supporting an elongated superconducting element, wherein, e.g., a deformation process is utilized in order to form disruptive strips in a layered solid element, and where etching is used to form undercut volumes (330, 332......) between an upper layer (316) and a lower layer (303) of the layered solid element. Such relatively simple steps enable providing a substrate which may be turned into a superconducting structure, such as a superconducting tape, having reduced AC losses, since the undercut volumes (330, 332) may be useful...... for separating layers of material. In a further embodiment, there is placed a superconducting layer on top of the upper layer (316) and/or lower layer (303), so as to provide a superconducting structure with reduced AC losses....

  13. Superconducting Radio Frequency Technology: An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Peter Kneisel

    2003-06-01

    Superconducting RF cavities are becoming more often the choice for larger scale particle accelerator projects such as linear colliders, energy recovery linacs, free electron lasers or storage rings. Among the many advantages compared to normal conducting copper structures, the superconducting devices dissipate less rf power, permit higher accelerating gradients in CW operation and provide better quality particle beams. In most cases these accelerating cavities are fabricated from high purity bulk niobium, which has superior superconducting properties such as critical temperature and critical magnetic field when compared to other superconducting materials. Research during the last decade has shown, that the metallurgical properties--purity, grain structure, mechanical properties and oxidation behavior--have significant influence on the performance of these accelerating devices. This contribution attempts to give a short overview of the superconducting RF technology with emphasis on the importance of the material properties of the high purity niobium.

  14. STRIPES AND SUPERCONDUCTIVITY IN CUPRATE SUPERCONDUCTORS

    Energy Technology Data Exchange (ETDEWEB)

    TRANQUADA, J.M.

    2005-08-22

    One type of order that has been observed to compete with superconductivity in cuprates involves alternating charge and antiferromagnetic stripes. Recent neutron scattering studies indicate that the magnetic excitation spectrum of a stripe-ordered sample is very similar to that observed in superconducting samples. In fact, it now appears that there may be a universal magnetic spectrum for the cuprates. One likely implication of this universal spectrum is that stripes of a dynamic form are present in the superconducting samples. On cooling through the superconducting transition temperature, a gap opens in the magnetic spectrum, and the weight lost at low energy piles up above the gap; the transition temperature is correlated with the size of the spin gap. Depending on the magnitude of the spin gap with respect to the magnetic spectrum, the enhanced magnetic scattering at low temperature can be either commensurate or incommensurate. Connections between stripe correlations and superconductivity are discussed.

  15. Stripes and superconductivity in cuprate superconductors

    Science.gov (United States)

    Tranquada, J. M.

    2005-08-01

    One type of order that has been observed to compete with superconductivity in cuprates involves alternating charge and antiferromagnetic stripes. Recent neutron scattering studies indicate that the magnetic excitation spectrum of a stripe-ordered sample is very similar to that observed in superconducting samples. In fact, it now appears that there may be a universal magnetic spectrum for the cuprates. One likely implication of this universal spectrum is that stripes of a dynamic form are present in the superconducting samples. On cooling through the superconducting transition temperature, a gap opens in the magnetic spectrum, and the weight lost at low energy piles up above the gap; the transition temperature is correlated with the size of the spin gap. Depending on the magnitude of the spin gap with respect to the magnetic spectrum, the enhanced magnetic scattering at low temperature can be either commensurate or incommensurate. Connections between stripe correlations and superconductivity are discussed.

  16. Free-standing oxide superconducting articles

    Science.gov (United States)

    Wu, Xin D.; Muenchausen, Ross E.

    1993-01-01

    A substrate-free, free-standing epitaxially oriented superconductive film including a layer of a template material and a layer of a ceramic superconducting material is provided together with a method of making such a substrate-free ceramic superconductive film by coating an etchable material with a template layer, coating the template layer with a layer of a ceramic superconductive material, coating the layer of ceramic superconductive material with a protective material, removing the etchable material by an appropriate means so that the etchable material is separated from a composite structure including the template lay This invention is the result of a contract with the Department of Energy (Contract No. W-7405-ENG-36).

  17. Development of Superconducting Wind Turbine Generators

    DEFF Research Database (Denmark)

    Jensen, Bogi Bech; Mijatovic, Nenad; Abrahamsen, Asger Bech

    2012-01-01

    (HTS); and one is a fully superconducting generator based on MgB2. It is concluded that there is large commercial interest in superconducting machines, with an increasing patenting activity. Such generators are however not without their challenges. The superconductors have to be cooled down......In this paper the commercial activities in the field of superconducting machines, particularly superconducting wind turbine generators, are reviewed and presented. Superconducting generators have the potential to provide a compact and light weight drive train at high torques and slow rotational...... to somewhere between 4K and 50K, depending on what type of superconductor is employed, which poses a significant challenge both from a construction and operation point of view. The high temperature superconductors can facilitate a higher operation temperature and simplified cooling, but the current price...

  18. Tunable Broadband Radiation Generated Via Ultrafast Laser Illumination of an Inductively Charged Superconducting Ring.

    Science.gov (United States)

    Bulmer, John; Bullard, Thomas; Dolasinski, Brian; Murphy, John; Sparkes, Martin; Pangovski, Krste; O'Neill, William; Powers, Peter; Haugan, Timothy

    2015-12-11

    An electromagnetic transmitter typically consists of individual components such as a waveguide, antenna, power supply, and an oscillator. In this communication we circumvent complications associated with connecting these individual components and instead combine them into a non-traditional, photonic enabled, compact transmitter device for tunable, ultrawide band (UWB) radiation. This device is a centimeter scale, continuous, thin film superconducting ring supporting a persistent super-current. An ultrafast laser pulse (required) illuminates the ring (either at a point or uniformly around the ring) and perturbs the super-current by the de-pairing and recombination of Cooper pairs. This generates a microwave pulse where both ring and laser pulse geometry dictates the radiated spectrum's shape. The transmitting device is self contained and completely isolated from conductive components that are observed to interfere with the generated signal. A rich spectrum is observed that extends beyond 30 GHz (equipment limited) and illustrates the complex super-current dynamics bridging optical, THz, and microwave wavelengths.

  19. Quantum Memristors with Superconducting Circuits

    Science.gov (United States)

    Salmilehto, J.; Deppe, F.; di Ventra, M.; Sanz, M.; Solano, E.

    2017-02-01

    Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. For realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop suitable methods to quantify memory retention in the system.

  20. Superconductivity in Metals and Alloys

    Science.gov (United States)

    1963-02-01

    sintered material (Reed, Gatos , LaFleur, and Roddy, 1962). It has great importance for any materials work, since generalizations based only on stoichio...1961),Phys. Rev. Letters 6, 597. Goodman, B. B., (1962) IBM J. Research and Development 6, 63. Gor’kov, L. P., (1960), Soy . Phys. JETP 10, 998...34Superconductivity in Metals and Alloys-Technical Documentary Report No. ASD-TDR-62-269, Contract No. AF 33(616)-640 5. Reed, T. B., Gatos , H. C., LaFleur, W. j

  1. The crystallography of color superconductivity

    CERN Document Server

    Bowers, J A; Bowers, Jeffrey A.; Rajagopal, Krishna

    2003-01-01

    We describe the crystalline phase of color superconducting quark matter. This phase may occur in quark matter at densities relevant for compact star physics, with possible implications for glitch phenomena in pulsars. We use a Ginzburg-Landau approach to determine that the crystal has a face-centered-cubic (FCC) structure. Moreover, our results indicate that the phase is robust, with gaps, critical temperature, and free energy comparable to those of the color-flavor-locked (CFL) phase. Our calculations also predict ``crystalline superfluidity'' in ultracold gases of fermionic atoms.

  2. Superconductivity, antiferromagnetism, and neutron scattering

    Science.gov (United States)

    Tranquada, John M.; Xu, Guangyong; Zaliznyak, Igor A.

    2014-01-01

    High-temperature superconductivity in both the copper-oxide and the iron-pnictide/chalcogenide systems occurs in close proximity to antiferromagnetically ordered states. Neutron scattering has been an essential technique for characterizing the spin correlations in the antiferromagnetic phases and for demonstrating how the spin fluctuations persist in the superconductors. While the nature of the spin correlations in the superconductors remains controversial, the neutron scattering measurements of magnetic excitations over broad ranges of energy and momentum transfers provide important constraints on the theoretical options. We present an overview of the neutron scattering work on high-temperature superconductors and discuss some of the outstanding issues.

  3. Superconductivity a very short introduction

    CERN Document Server

    Blundell, Stephen

    2009-01-01

    Superconductivity is one of the most exciting areas of research in physics today. Outlining the history of its discovery, and the race to understand its many mysterious and counter-intuitive phenomena, this Very Short Introduction explains in accessible terms the theories that have been developed, and how they have influenced other areas of science, including the Higgs boson of particle physics and ideas about the early Universe. It is an engaging and informative accountof a fascinating scientific detective story, and an intelligible insight into some deep and beautiful ideas of physics

  4. Quantum Memristors with Superconducting Circuits

    Science.gov (United States)

    Salmilehto, J.; Deppe, F.; Di Ventra, M.; Sanz, M.; Solano, E.

    2017-01-01

    Memristors are resistive elements retaining information of their past dynamics. They have garnered substantial interest due to their potential for representing a paradigm change in electronics, information processing and unconventional computing. Given the advent of quantum technologies, a design for a quantum memristor with superconducting circuits may be envisaged. Along these lines, we introduce such a quantum device whose memristive behavior arises from quasiparticle-induced tunneling when supercurrents are cancelled. For realistic parameters, we find that the relevant hysteretic behavior may be observed using current state-of-the-art measurements of the phase-driven tunneling current. Finally, we develop suitable methods to quantify memory retention in the system. PMID:28195193

  5. Superconductive Signal-Processing Circuits

    Science.gov (United States)

    1994-08-01

    September 1991. 13. P. H. Xiao, E. Charbon , A. Sangiovanni-Vincentelli, T. Van Duzer,and S.W. Whiteley, "INDEX: An inductance extractor for superconducting...wideband analog-to-digital to a useful binary representation. In order to achieve an N-bit converter reported earlier [1]. The original design has been...rises, the SQUID Parameter Original Modified switches to the voltage state, and the output goes high. Ic(J1) 337 367 I tA S gaicGate: The comparator

  6. Fermionic models with superconducting circuits

    Energy Technology Data Exchange (ETDEWEB)

    Las Heras, Urtzi; Garcia-Alvarez, Laura; Mezzacapo, Antonio; Lamata, Lucas [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); Solano, Enrique [University of the Basque Country UPV/EHU, Department of Physical Chemistry, Bilbao (Spain); IKERBASQUE, Basque Foundation for Science, Bilbao (Spain)

    2015-12-01

    We propose a method for the efficient quantum simulation of fermionic systems with superconducting circuits. It consists in the suitable use of Jordan-Wigner mapping, Trotter decomposition, and multiqubit gates, be with the use of a quantum bus or direct capacitive couplings. We apply our method to the paradigmatic cases of 1D and 2D Fermi-Hubbard models, involving couplings with nearest and next-nearest neighbours. Furthermore, we propose an optimal architecture for this model and discuss the benchmarking of the simulations in realistic circuit quantum electrodynamics setups. (orig.)

  7. Terahertz superconducting plasmonic hole array

    CERN Document Server

    Tian, Zhen; Han, Jiaguang; Gu, Jianqiang; Xing, Qirong; Zhang, Weili

    2010-01-01

    We demonstrate thermally tunable superconductor hole array with active control over their resonant transmission induced by surface plasmon polaritons . The array was lithographically fabricated on high temperature YBCO superconductor and characterized by terahertz-time domain spectroscopy. We observe a clear transition from the virtual excitation of the surface plasmon mode to the real surface plasmon mode. The highly tunable superconducting plasmonic hole arrays may have promising applications in the design of low-loss, large dynamic range amplitude modulation, and surface plasmon based terahertz devices.

  8. Assessing resolution in super-resolution imaging.

    Science.gov (United States)

    Demmerle, Justin; Wegel, Eva; Schermelleh, Lothar; Dobbie, Ian M

    2015-10-15

    Resolution is a central concept in all imaging fields, and particularly in optical microscopy, but it can be easily misinterpreted. The mathematical definition of optical resolution was codified by Abbe, and practically defined by the Rayleigh Criterion in the late 19th century. The limit of conventional resolution was also achieved in this period, and it was thought that fundamental constraints of physics prevented further increases in resolution. With the recent development of a range of super-resolution techniques, it is necessary to revisit the concept of optical resolution. Fundamental differences in super-resolution modalities mean that resolution is not a directly transferrable metric between techniques. This article considers the issues in resolution raised by these new technologies, and presents approaches for comparing resolution between different super-resolution methods.

  9. Architectural Engineering to Super-Light Structures

    DEFF Research Database (Denmark)

    Castberg, Niels Andreas

    with architectural engineering as a starting point. The thesis is based on a two stringed hypothesis: Architectural engineering gives rise to better architecture and Super-Light Structures support and enables a static, challenging architecture. The aim of the thesis is to clarify architectural engineering's impact...... on the work process between architects and engineers in the design development. Using architectural engineering, Super-Light Structures are examined in an architectural context, and it is explained how digital tools can support architectural engineering and design of Super-Light Structures. The experiences...... to be subjects of examination for this thesis. The research results show that architectural engineering has a significant impact on a design process. The projects illustrate that simple explanations, underpinned by visualisations of the challenges between shape versus structure, often creates a shared...

  10. Breeding Super-Earths and Birthing Super-Puffs in Transitional Disks

    CERN Document Server

    Lee, Eve J

    2015-01-01

    The riddle posed by super-Earths (1-4$R_\\oplus$, 2-20$M_\\oplus$) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (up to 9) orders of magnitude, and super-Earths can still robustly emerge after $\\sim$0.1-1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The picture --- that close-in super-Earths form in a gas-poor (but not ga...

  11. High-gradient High-charge CW Superconducting RF gun with CsK2Sb photocathode

    CERN Document Server

    Pinayev, Igor; Tuozzolo, Joseph; Brutus, Jean Clifford; Belomestnykh, Sergey; Boulware, Chase; Folz, Charles; Gassner, David; Grimm, Terry; Hao, Yue; Jamilkowski, James; Jing, Yichao; Kayran, Dmitry; Mahler, George; Mapes, Michael; Miller, Toby; Narayan, Geetha; Sheehy, Brian; Rao, Triveni; Skaritka, John; Smith, Kevin; Snydstrup, Louis; Than, Yatming; Wang, Erdong; Wang, Gang; Xiao, Binping; Xin, Tianmu; Zaltsman, Alexander; Altinbas, Z; Ben-Zvi, Ilan; Curcio, Anthony; Di Lieto, Anthony; Meng, Wuzheng; Minty, Michiko; Orfin, Paul; Reich, Jonathan; Roser, Thomas; Smart, Loralie A; Soria, Victor; Theisen, Charles; Xu, Wencan; Wu, Yuan H; Zhao, Zhi

    2015-01-01

    High-gradient CW photo-injectors operating at high accelerating gradients promise to revolutionize many sciences and applications. They can establish the basis for super-bright monochromatic X-ray free-electron lasers, super-bright hadron beams, nuclear- waste transmutation or a new generation of microchip production. In this letter we report on our operation of a superconducting RF electron gun with a record-high accelerating gradient at the CsK2Sb photocathode (i.e. ~ 20 MV/m) generating a record-high bunch charge (i.e., 3 nC). We briefly describe the system and then detail our experimental results. This achievement opens new era in generating high-power electron beams with a very high brightness.

  12. Characterization of superconducting multilayers samples

    CERN Document Server

    Antoine, C Z; Berry, S; Bouat, S; Jacquot, J F; Villegier, J C; Lamura, G; Gurevich, A

    2009-01-01

    Best RF bulk niobium accelerating cavities have nearly reached their ultimate limits at rf equatorial magnetic field H  200 mT close to the thermodynamic critical field Hc. In 2006 Gurevich proposed to use nanoscale layers of superconducting materials with high values of Hc > HcNb for magnetic shielding of bulk niobium to increase the breakdown magnetic field inside SC RF cavities [1]. Depositing good quality layers inside a whole cavity is rather difficult but we have sputtered high quality samples by applying the technique used for the preparation of superconducting electronics circuits and characterized these samples by X-ray reflectivity, dc resistivity (PPMS) and dc magnetization (SQUID). Dc magnetization curves of a 250 nm thick Nb film have been measured, with and without a magnetron sputtered coating of a single or multiple stack of 15 nm MgO and 25 nm NbN layers. The Nb samples with/without the coating clearly exhibit different behaviors. Because SQUID measurements are influenced by edge an...

  13. Recent developments in superconducting receivers

    Science.gov (United States)

    Richards, Paul L.

    1990-09-01

    A description is given of recent work at Berkeley on superconducting mixers and detectors for infrared and millimeter wavelengths. The first report is a review article which summarizes the status of development of superconducting components for infrared and millimeter wave receivers. The next report describes accurate measurements and also theoretical modeling of an SIS quasiparticle waveguide mixer for W-band which uses very high quality Ta junctions. The best mixer noise is only 1.3 times the quantum limit. Both the mixer gain and the noise are in quantitative agreement with the quantum theory. Next, a report is given on measurements and theoretical modeling of the absorptivity (surface resistance) of high quality epitaxial films of the high Tc superconductor YBCO from 750 GHz to 21 THz. Finally, there are reports on the design and experimental performance of two different types of high Tc bolometric detectors. One is a conventional bolometer with a gold-black absorber. The other is an antenna coupled microbolometer.

  14. Superconducting rf development at ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Shepard, K.W.; Kedzie, M.; Clifft, B.E. [Argonne National Lab., IL (United States); Roy, A.; Potukuchi, P. [Nuclear Science Centre, New Delhi (India); Givens, J.; Potter, J.; Crandall, K. [AccSys Technology, Inc., Pleasanton, CA (United States); Added, N. [Sao Paulo Univ., SP (Brazil)

    1993-12-31

    The ATLAS superconducting heavy-ion linac began operation in 1978 and has operated nearly continuously since that time, while undergoing a series of upgrades and expansions, the most recent being the ``uranium upgrade`` completed earlier this year and described below. In its present configuration the ATLAS linac consists of an array of 64 resonant cavities operating from 48 to 145 MHz, which match a range of particle velocities .007 < {beta} = v/c < .2. The linac provides approximately 50 MV of effective accelerating potential for ions of q/m > 1/10 over the entire periodic table. Delivered beams include 5 {minus} 7 pnA of {sup 238}U{sup 39+} at 1535 MeV. At present more than 10{sup 6} cavity-hours of operation at surface electric fields of 15 MV/m have been accumulated. Superconducting structure development at ATLAS is aimed at improving the cost/performance of existing low velocity structures both for possible future ATLAS upgrades, and also for heavy-ion linacs at other institutions. An application of particular current interest is to develop structures suitable for accelerating radioactive ion beams. Such structures must accelerate very low charge to mass ratio beams and must also have very large transverse acceptance.

  15. DC superconducting fault current limiter

    Science.gov (United States)

    Tixador, P.; Villard, C.; Cointe, Y.

    2006-03-01

    There is a lack of satisfying solutions for fault currents using conventional technologies, especially in DC networks, where a superconducting fault current limiter could play a very important part. DC networks bring a lot of advantages when compared to traditional AC ones, in particular within the context of the liberalization of the electric market. Under normal operation in a DC network, the losses in the superconducting element are nearly zero and only a small, i.e. a low cost, refrigeration system is then required. The absence of zero crossing of a DC fault current favourably accelerates the normal zone propagation. The very high current slope at the time of the short circuit in a DC grid is another favourable parameter. The material used for the experiments is YBCO deposited on Al2O3 as well as YBCO coated conductors. The DC limitation experiments are compared to AC ones at different frequencies (50-2000 Hz). Careful attention is paid to the quench homogenization, which is one of the key issues for an SC FCL. The University of Geneva has proposed constrictions. We have investigated an operating temperature higher than 77 K. As for YBCO bulk, an operation closer to the critical temperature brings a highly improved homogeneity in the electric field development. The material can then absorb large energies without degradation. We present tests at various temperatures. These promising results are to be confirmed over long lengths.

  16. High Temperature Superconducting Underground Cable

    Energy Technology Data Exchange (ETDEWEB)

    Farrell, Roger, A.

    2010-02-28

    The purpose of this Project was to design, build, install and demonstrate the technical feasibility of an underground high temperature superconducting (HTS) power cable installed between two utility substations. In the first phase two HTS cables, 320 m and 30 m in length, were constructed using 1st generation BSCCO wire. The two 34.5 kV, 800 Arms, 48 MVA sections were connected together using a superconducting joint in an underground vault. In the second phase the 30 m BSCCO cable was replaced by one constructed with 2nd generation YBCO wire. 2nd generation wire is needed for commercialization because of inherent cost and performance benefits. Primary objectives of the Project were to build and operate an HTS cable system which demonstrates significant progress towards commercial progress and addresses real world utility concerns such as installation, maintenance, reliability and compatibility with the existing grid. Four key technical areas addressed were the HTS cable and terminations (where the cable connects to the grid), cryogenic refrigeration system, underground cable-to-cable joint (needed for replacement of cable sections) and cost-effective 2nd generation HTS wire. This was the world’s first installation and operation of an HTS cable underground, between two utility substations as well as the first to demonstrate a cable-to-cable joint, remote monitoring system and 2nd generation HTS.

  17. Three-flavor color superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Malekzadeh, H.

    2007-12-15

    I investigate some of the inert phases in three-flavor, spin-zero color-superconducting quark matter: the CFL phase (the analogue of the B phase in superfluid {sup 3}He), the A and A{sup *} phases, and the 2SC and sSC phases. I compute the pressure of these phases with and without the neutrality condition. Without the neutrality condition, after the CFL phase the sSC phase is the dominant phase. However, including the neutrality condition, the CFL phase is again the energetically favored phase except for a small region of intermediate densities where the 2SC/A{sup *} phase is favored. It is shown that the 2SC phase is identical to the A{sup *} phase up to a color rotation. In addition, I calculate the self-energies and the spectral densities of longitudinal and transverse gluons at zero temperature in color-superconducting quark matter in the CFL phase. I find a collective excitation, a plasmon, at energies smaller than two times the gap parameter and momenta smaller than about eight times the gap. The dispersion relation of this mode exhibits a minimum at some nonzero value of momentum, indicating a van Hove singularity. (orig.)

  18. KML Super Overlay to WMS Translator

    Science.gov (United States)

    Plesea, Lucian

    2007-01-01

    This translator is a server-based application that automatically generates KML super overlay configuration files required by Google Earth for map data access via the Open Geospatial Consortium WMS (Web Map Service) standard. The translator uses a set of URL parameters that mirror the WMS parameters as much as possible, and it also can generate a super overlay subdivision of any given area that is only loaded when needed, enabling very large areas of coverage at very high resolutions. It can make almost any dataset available as a WMS service visible and usable in any KML application, without the need to reformat the data.

  19. Super-resolution optical microscopy: multiple choices.

    Science.gov (United States)

    Huang, Bo

    2010-02-01

    The recent invention of super-resolution optical microscopy enables the visualization of fine features in biological samples with unprecedented clarity. It creates numerous opportunities in biology because vast amount of previously obscured subcellular processes now can be directly observed. Rapid development in this field in the past two years offers many imaging modalities that address different needs but they also complicates the choice of the 'perfect' method for answering a specific question. Here I will briefly describe the principles of super-resolution optical microscopy techniques and then focus on comparing their characteristics in various aspects of practical applications.

  20. Super resolution of images and video

    CERN Document Server

    Katsaggelos, Aggelos K

    2007-01-01

    This book focuses on the super resolution of images and video. The authors' use of the term super resolution (SR) is used to describe the process of obtaining a high resolution (HR) image, or a sequence of HR images, from a set of low resolution (LR) observations. This process has also been referred to in the literature as resolution enhancement (RE). SR has been applied primarily to spatial and temporal RE, but also to hyperspectral image enhancement. This book concentrates on motion based spatial RE, although the authors also describe motion free and hyperspectral image SR problems. Also exa

  1. Super-Laplacians and their symmetries

    Science.gov (United States)

    Howe, P. S.; Lindström, U.

    2017-05-01

    A super-Laplacian is a set of differential operators in superspace whose highestdimensional component is given by the spacetime Laplacian. Symmetries of super-Laplacians are given by linear differential operators of arbitrary finite degree and are determined by superconformal Killing tensors. We investigate these in flat superspaces. The differential operators determining the symmetries give rise to algebras which can be identified in many cases with the tensor algebras of the relevant superconformal Lie algebras modulo certain ideals. They have applications to Higher Spin theories.

  2. One-Step Realization of SWAP Gate with Superconducting Quantum-Interference Devices and Atoms in Cavity QED

    Institute of Scientific and Technical Information of China (English)

    ZHAN Zhi-Ming

    2008-01-01

    We put forward a simple scheme for one-step realization of a two-qubit SWAP gate with SQUIDs (super-conducting quantum-interference devices) in cavity QED via Raman transition. In this scheme, the cavity field is only virtually excited and thus the cavity decay is suppressed. The SWAP gate is realized by using only two lower flux states of the SQUID system and the excited state would not be excited. Therefore, the effect of decoherence caused from the levels of the SQUID system is possibly minimized. The scheme can also be used to implement the SWAP gate with atoms.

  3. New method for making super-plastic glasses

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ It was a long-cherished dream for materials scientists to find a nearly ideal metallic alloy with high strength and super-plasticity concurrently as a super-material both extremely strong and exceptionally hard for human use.

  4. Second invariant for two-dimensional classical super systems

    Indian Academy of Sciences (India)

    S C Mishra; Roshan Lal; Veena Mishra

    2003-10-01

    Construction of superpotentials for two-dimensional classical super systems (for ≥ 2) is carried out. Some interesting potentials have been studied in their super form and also their integrability.

  5. An integrable generalization of the super AKNS hierarchy and its bi-Hamiltonian formulation

    Science.gov (United States)

    Yu, Jing; Ma, Wen-Xiu; Han, Jingwei; Chen, Shouting

    2017-02-01

    Based on a Lie super-algebra B(0, 1), an integrable generalization of the super AKNS iso-spectral problem is introduced and its corresponding generalized super AKNS hierarchy is generated. By making use of the super-trace identity (or the super variational identity), the resulting super soliton hierarchy can be put into a super bi-Hamiltonian form. A generalized super AKNS soliton hierarchy with self-consistent sources is also presented.

  6. Explosive Super-eruptions: Problems and Prejudices

    Science.gov (United States)

    Self, S.

    2010-12-01

    A super-eruption is defined as one with a magma yield > 10^15 kg (magnitude (M) 8). The term has mainly been applied to large-scale, caldera and ignimbrite-forming explosive eruptions, but it can be applied to all eruptions that released > 10^15 kg of magma. For effusive volcanism, evidence suggests that individual eruptions of this size ( > ~ 370 km^3 of typical basalt or > 450 km^3 of rhyolite flood lava) arise only during periods of LIP formation. The super-eruption concept raises interesting questions about genesis and storage of magmas that feed these vast events. Deposits of major explosive eruptions are Plinian fallout, ignimbrite sheets, and co-ignimbrite ash fall. Based on earlier suggestions and evidence, widespread outflow ignimbrite (O), co-ignimbrite ash (A), and inter-caldera ignimbrite (I) are all major components of the total super-eruption deposit and may tend towards being subequal. In super-eruption deposits, the reported volume of vent-derived Plinian eruption column fallout is often a minor component of the total volume, yet in several cases (Oruanui, Taupo, 26 ka ago, M 8.1; Bishop Tuff, 760 ka, M 8.2; Bandelier (Otowi) Tuff, 1.6 Ma, M8) it is now recognized that vent-derived columns persisted for most of the eruption. Thus, distally, the ash-fall derived from co-ignimbrite ash clouds may be mixed with contemporaneous fallout from a vertical column. Some major ignimbrites have no reported associated Plinian deposit; the huge Young Toba Tuff (YTT, 74 ka, M 8.8) is a significant example. However, the very widespread Toba ash-fall deposit constitutes ~ 40 % of the total mass of magma erupted and is presumed to be co-ignimbrite. Timing of the onset of column collapse probably controls whether a recognizable Plinian deposit is laid down. All super-eruptions probably produce extensive fallout deposits, and this is generally of vent-derived and pyroclastic-flow-derived origin. Establishing the relationships between large-scale ignimbrites and their

  7. On super edge-graceful trees of diameter four

    CERN Document Server

    Krop, E; Raridan, C

    2011-01-01

    In "On the super edge graceful trees of even orders," Chung, Lee, Gao, and Schaffer posed the following problem: Characterize trees of diameter 4 which are super edge-graceful. In this paper, we provide super edge-graceful labelings for all caterpillars and even size lobsters of diameter 4 which permit such labelings. We also provide super edge-graceful labelings for several families of odd size lobsters of diameter 4.

  8. Superconductivity in Ca-doped graphene laminates

    Science.gov (United States)

    Chapman, J.; Su, Y.; Howard, C. A.; Kundys, D.; Grigorenko, A. N.; Guinea, F.; Geim, A. K.; Grigorieva, I. V.; Nair, R. R.

    2016-01-01

    Despite graphene’s long list of exceptional electronic properties and many theoretical predictions regarding the possibility of superconductivity in graphene, its direct and unambiguous experimental observation has not been achieved. We searched for superconductivity in weakly interacting, metal decorated graphene crystals assembled into so-called graphene laminates, consisting of well separated and electronically decoupled graphene crystallites. We report robust superconductivity in all Ca-doped graphene laminates. They become superconducting at temperatures (Tc) between ≈4 and ≈6 K, with Tc’s strongly dependent on the confinement of the Ca layer and the induced charge carrier concentration in graphene. We find that Ca is the only dopant that induces superconductivity in graphene laminates above 1.8 K among several dopants used in our experiments, such as potassium, caesium and lithium. By revealing the tunability of the superconducting response through doping and confinement of the metal layer, our work shows that achieving superconductivity in free-standing, metal decorated monolayer graphene is conditional on an optimum confinement of the metal layer and sufficient doping, thereby bringing its experimental realization within grasp. PMID:26979564

  9. Superconductivity in Ca-doped graphene laminates

    Science.gov (United States)

    Chapman, J.; Su, Y.; Howard, C. A.; Kundys, D.; Grigorenko, A. N.; Guinea, F.; Geim, A. K.; Grigorieva, I. V.; Nair, R. R.

    2016-03-01

    Despite graphene’s long list of exceptional electronic properties and many theoretical predictions regarding the possibility of superconductivity in graphene, its direct and unambiguous experimental observation has not been achieved. We searched for superconductivity in weakly interacting, metal decorated graphene crystals assembled into so-called graphene laminates, consisting of well separated and electronically decoupled graphene crystallites. We report robust superconductivity in all Ca-doped graphene laminates. They become superconducting at temperatures (Tc) between ≈4 and ≈6 K, with Tc’s strongly dependent on the confinement of the Ca layer and the induced charge carrier concentration in graphene. We find that Ca is the only dopant that induces superconductivity in graphene laminates above 1.8 K among several dopants used in our experiments, such as potassium, caesium and lithium. By revealing the tunability of the superconducting response through doping and confinement of the metal layer, our work shows that achieving superconductivity in free-standing, metal decorated monolayer graphene is conditional on an optimum confinement of the metal layer and sufficient doping, thereby bringing its experimental realization within grasp.

  10. Visualizing domain wall and reverse domain superconductivity.

    Science.gov (United States)

    Iavarone, M; Moore, S A; Fedor, J; Ciocys, S T; Karapetrov, G; Pearson, J; Novosad, V; Bader, S D

    2014-08-28

    In magnetically coupled, planar ferromagnet-superconductor (F/S) hybrid structures, magnetic domain walls can be used to spatially confine the superconductivity. In contrast to a superconductor in a uniform applied magnetic field, the nucleation of the superconducting order parameter in F/S structures is governed by the inhomogeneous magnetic field distribution. The interplay between the superconductivity localized at the domain walls and far from the walls leads to effects such as re-entrant superconductivity and reverse domain superconductivity with the critical temperature depending upon the location. Here we use scanning tunnelling spectroscopy to directly image the nucleation of superconductivity at the domain wall in F/S structures realized with Co-Pd multilayers and Pb thin films. Our results demonstrate that such F/S structures are attractive model systems that offer the possibility to control the strength and the location of the superconducting nucleus by applying an external magnetic field, potentially useful to guide vortices for computing application.

  11. 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...

  12. 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...

  13. Superconducting phase transition in STM tips

    Energy Technology Data Exchange (ETDEWEB)

    Eltschka, Matthias; Jaeck, Berthold; Assig, Maximilian; Etzkorn, Markus; Ast, Christian R. [Max Planck Institute for Solid State Research, Stuttgart (Germany); Kern, Klaus [Max Planck Institute for Solid State Research, Stuttgart (Germany); Ecole Polytechnique Federale de Lausanne (Switzerland)

    2015-07-01

    The superconducting properties of systems with dimensions comparable to the London penetration depth considerably differ from macroscopic systems. We have studied the superconducting phase transition of vanadium STM tips in external magnetic fields. Employing Maki's theory we extract the superconducting parameters such as the gap or the Zeeman splitting from differential conductance spectra. While the Zeeman splitting follows the theoretical description of a system with s=1/2 and g=2, the superconducting gaps as well as the critical fields depend on the specific tip. For a better understanding of the experimental results, we solve a one dimensional Usadel equation modeling the superconducting tip as a cone with the opening angle α in an external magnetic field. We find that only a small region at the apex of the tip is superconducting in high magnetic fields and that the order of the phase transition is directly determined by α. Further, the spectral broadening increases with α indicating an intrinsic broadening mechanism due to the conical shape of the tip. Comparing these calculations to our experimental results reveals the order of the superconducting phase transition of the STM tips.

  14. Superconductivity in Ca-doped graphene laminates.

    Science.gov (United States)

    Chapman, J; Su, Y; Howard, C A; Kundys, D; Grigorenko, A N; Guinea, F; Geim, A K; Grigorieva, I V; Nair, R R

    2016-03-16

    Despite graphene's long list of exceptional electronic properties and many theoretical predictions regarding the possibility of superconductivity in graphene, its direct and unambiguous experimental observation has not been achieved. We searched for superconductivity in weakly interacting, metal decorated graphene crystals assembled into so-called graphene laminates, consisting of well separated and electronically decoupled graphene crystallites. We report robust superconductivity in all Ca-doped graphene laminates. They become superconducting at temperatures (Tc) between ≈4 and ≈6 K, with Tc's strongly dependent on the confinement of the Ca layer and the induced charge carrier concentration in graphene. We find that Ca is the only dopant that induces superconductivity in graphene laminates above 1.8 K among several dopants used in our experiments, such as potassium, caesium and lithium. By revealing the tunability of the superconducting response through doping and confinement of the metal layer, our work shows that achieving superconductivity in free-standing, metal decorated monolayer graphene is conditional on an optimum confinement of the metal layer and sufficient doping, thereby bringing its experimental realization within grasp.

  15. Now arriving at platform 1.. SUPER TRAIN

    CERN Multimedia

    Matthews, Robert

    2008-01-01

    Superconducting materials hold the secret to new high-speed trains and are likely to be thw solution to the pending energy crisis. But they've been around for almost a cnetury, so what are we still waiting for asks. (4 pages)_

  16. Advances in the Design of the SuperB Final Doublet

    Energy Technology Data Exchange (ETDEWEB)

    Paoloni, E.; Carmignani, N.; Pilo, F.; /Pisa U. /INFN, Pisa; Bettoni, S.; /CERN; Fabbricatore, P.; Farinon, S.; Musenich, R.; /INFN, Genoa; Bosi, F.; /INFN, Pisa; Biagini, M.E.; Raimondi, P.; /Frascati; Sullivan, M.; /SLAC

    2012-04-26

    SuperB is an asymmetric energy e{sup +}e{sup -} collider operating at the {Upsilon}(4S) peak with a design peak luminosity of 10{sup 36} Hz/cm{sup 2} to be built in Italy in the very near future. The design luminosity is almost a factor hundred higher than that of the present generation comparable facilities. To get the design luminosity a novel collision scheme, the so called 'large Piwinski angle with crab waist', has been designed. The scheme requires a short focus final doublet to reduce the vertical beta function down to {beta}*{sub y} = 0.2mm at the interaction point (IP). The final doublet will be composed by a set of permanent and superconducting (SC) quadrupoles. The SC quadrupole doublets QD0/QF1 will be placed as close to the IP as possible. This layout is critical because the space available for the doublets is very small. An advanced design of the quadrupole has been developed, based on the so-called helical coil concept. The paper discusses the design concept, the construction and the results of test of a model of the superconducting quadrupole based on NbTi technology. Future developments are also presented.

  17. The structure of the super-W∞(λ) algebra

    NARCIS (Netherlands)

    Bergshoeff, E.; Wit, B. de; Vasiliev, M.

    1991-01-01

    We give a comprehensive treatment of the super-W∞(λ) algebra, an extension of the super-Virasoro algebra that contains generators of spin s ≥ ½. The parameter λ defines the embedding of the Virasoro subalgebra. We describe how to obtain the super-W∞(λ) algebra from the associative algebra of

  18. The cold wars a history of superconductivity

    CERN Document Server

    Matricon, Jean

    1994-01-01

    Among the most peculiar of matter¡¦s behaviors is superconductivity„oelectric current without resistance. Since the 1986 discovery that superconductivity is possible at temperatures well above absolute zero, research into practical applications has flourished. The Cold Wars tells the history of superconductivity, providing perspective on the development of the field and its relationship with the rest of physics. Superconductivity offers an excellent example of the evolution of physics in the twentieth century: the science itself, its foundations, and its social context. The authors also introduce the reader to the fascinating scientific personalities, including 2003 Nobel Prize winners Alexei Alexeievich Abrikosov and Vitali Ginzburg, and political struggles behind this research.

  19. Dimensionality of high temperature superconductivity in oxides

    Science.gov (United States)

    Chu, C. W.

    1989-01-01

    Many models have been proposed to account for the high temperature superconductivity observed in oxide systems. Almost all of these models proposed are based on the uncoupled low dimensional carrier Cu-O layers of the oxides. Results of several experiments are presented and discussed. They suggest that the high temperature superconductivity observed cannot be strictly two- or one-dimensional, and that the environment between the Cu-O layers and the interlayer coupling play an important role in the occurrence of such high temperature superconductivity. A comment on the very short coherence length reported is also made.

  20. Downsized superconducting magnetic energy storage systems

    Science.gov (United States)

    Palmer, David N.

    Scaled-down superconductive magnetic energy storage systems (DSMES) and superconductive magnetic energy power sources (SMEPS) are proposed for residential, commercial/retail, industrial off-peak and critical services, telephone and other communication systems, computer operations, power back-up/energy storages, power sources for space stations, and in-field military logistics/communication systems. Recent advances in high-Tc superconducting materials technology are analyzed. DSMES/SMEPS concepts are presented, and design, materials, and systems requirements are discussed. Problems ar identified, and possible solutions are offered. Comparisons are made with mechanical and primary and secondary energy storage and conversion systems.

  1. Proximity Action theory of superconductive nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Skvortsov, M A; Larkin, A I; Feigel' man, M V [L D Landau Institute for Theoretical Physics, Russian Academy of Sciences, ul. Kosygina 2, 117940 Moscow (Russian Federation)

    2001-10-01

    We review a novel approach to the superconductive proximity effect in disordered normal-superconducting (N-S) structures. The method is based on the multicharge Keldysh action and is suitable for the treatment of interaction and fluctuation effects. As an application of the formalism, we study the subgap conductance and noise in two-dimensional N-S systems in the presence of the electron-electron interaction in the Cooper channel. It is shown that singular nature of the interaction correction at large scales leads to a nonmonotonuos temperature, voltage and magnetic field dependence of the Andreev conductance. (4. mesoscopic superconductivity)

  2. Energizer keep going: 100 years of superconductivity

    Institute of Scientific and Technical Information of China (English)

    Pengcheng Dai; Xing-jiang Zhou; Dao-xin Yao

    2011-01-01

    It has been 100 years since Heike Kamerlingh Onnes discovered superconductivity on April 8,1911.Amazingly,this field is still very active and keeps booming,like a magic.A lot of new phenomena and materials have been found,and superconductors have been used in many different fields to improve our lives.Onnes won the Nobel Prize for this incredible discovery in 1913 and used the word superconductivity for the first time.Onnes believed that quantum mechanics would explain the effect,but he could not produce a theory at that time.Now we know superconductivity is a macroscopic quantum phenomenon.

  3. Magnetism and superconductivity in heavy fermion systems

    Energy Technology Data Exchange (ETDEWEB)

    Flouquet, J. (DRFMC, C.E.N.G., 38 - Grenoble (France)); Brison, J.P.; Hasselbach, K.; Taillefer, L. (C.N.R.S., 38 - Grenoble (France)); Behnia, K.; Jaccard, D. (DPMC, Geneva Univ. (Switzerland)); Visser, A. de (Natuurkundig Lab., Univ. van Amsterdam (Netherlands))

    1991-12-01

    The normal and superconducting properties of heavy fermion compounds are reviewed. The discussion is focus on the three uranium compounds: UBe{sub 13}, UPt{sub 3} and URu{sub 2}Si{sub 2}. Special attention is given: 1) to unusual (H.T) superconducting phase diagram as discovered in UPt{sub 3} where two successive superconducting phases seem to occur in zero magnetic field; 2) to the role of long range ordering as found in URu{sub 2}Si{sub 2} and UPt{sub 3}. (orig.).

  4. DC Characterization of the Coaxial Superconducting Cable

    Science.gov (United States)

    Šouc, J.; Gömöry, F.; Vojenčiak, M.; Frolek, L.; Isfort, D.; Ehrenberg, J.; Bock, J.

    2008-01-01

    Coaxial cable model with superconducting core and superconducting shield conductor was constructed and tested in DC regime. While the core was already examined in our previous works, in this contribution the detailed study of the superconducting shield conductor in DC conditions is presented. It consists of 16 ReBCO coated tapes with critical current 35 A each connected in parallel. Using shunts with known values placed in series the currents in individual tapes were possible to measure. Distribution of the total cable current into the individual tapes was monitored and its influence on critical current of the cable is discussed.

  5. Thermodynamic Green functions in theory of superconductivity

    Directory of Open Access Journals (Sweden)

    N.M.Plakida

    2006-01-01

    Full Text Available A general theory of superconductivity is formulated within the thermodynamic Green function method for various types of pairing mediated by phonons, spin fluctuations, and strong Coulomb correlations in the Hubbard and t-J models. A rigorous Dyson equation for matrix Green functions is derived in terms of a self-energy as a many-particle Green function. By applying the noncrossing approximation for the self-energy, a closed self-consistent system of equations is obtained, similar to the conventional Eliashberg equations. A brief discussion of superconductivity mediated by kinematic interaction with an estimation of a superconducting transition temperature in the Hubbard model is given.

  6. Super ready: how a regional approach to Super Bowl EMS paid off.

    Science.gov (United States)

    Clancy, Terry; Cortacans, Henry P

    2014-07-01

    The Super Bowl and its associated activities represent one of the largest special events in the world. Super Bowl XLVIII was geographically unique because the NFL's and Super Bowl Host Committee's activities, venues and events encompassed two states and fell across numerous jurisdictions within six counties (Bergen, Hudson, Morris, Essex, Middlesex, and Manhattan).This Super Bowl was the first to do this. EMS was one of the largest operational components during this event. Last and most important, it is the people and relationships that make any planning initiative and event a success. Sit down and have a cup a coffee with your colleagues, partners and neighbors in and out of state to discuss your planning initiatives. Do it early-it will make your efforts less painful should an event of this magnitude come to a city near you!

  7. Acoustic Design of Super-light Structures

    DEFF Research Database (Denmark)

    Christensen, Jacob Ellehauge; Hertz, Kristian Dahl; Brunskog, Jonas

    aggregate (leca) along with a newly developed technology called pearl-chain reinforcement, which is a system for post-tensioning. Here, it is shown how to combine these technologies within a precast super-light slab element, while honoring the requirements of a holistic design. Acoustic experiments...

  8. Folded shapes with Super-Light Structures

    DEFF Research Database (Denmark)

    Castberg, Niels Andreas; Hertz, Kristian Dahl

    2012-01-01

    The use of folded shapes in structures has become more common, but it still costs problems because of construction issues and bending moments. The present paper deals with how the newly patented structural concept Super-Light structures (SLS) can be used to create folded shapes. SLS gives lighter...

  9. Single Image Super Resolution via Sparse Reconstruction

    NARCIS (Netherlands)

    Kruithof, M.C.; Eekeren, A.W.M. van; Dijk, J.; Schutte, K.

    2012-01-01

    High resolution sensors are required for recognition purposes. Low resolution sensors, however, are still widely used. Software can be used to increase the resolution of such sensors. One way of increasing the resolution of the images produced is using multi-frame super resolution algorithms. Limita

  10. Conformal anomaly of super Wilson loop

    Energy Technology Data Exchange (ETDEWEB)

    Belitsky, A.V., E-mail: andrei.belitsky@asu.edu [Department of Physics, Arizona State University, Tempe, AZ 85287-1504 (United States)

    2012-09-11

    Classically supersymmetric Wilson loop on a null polygonal contour possesses all symmetries required to match it onto non-MHV amplitudes in maximally supersymmetric Yang-Mills theory. However, to define it quantum mechanically, one is forced to regularize it since perturbative loop diagrams are not well defined due to presence of ultraviolet divergences stemming from integration in the vicinity of the cusps. A regularization that is adopted by practitioners by allowing one to use spinor helicity formalism, on the one hand, and systematically go to higher orders of perturbation theory is based on a version of dimensional regularization, known as Four-Dimensional Helicity scheme. Recently it was demonstrated that its use for the super Wilson loop at one loop breaks both conformal symmetry and Poincare supersymmetry. Presently, we exhibit the origin for these effects and demonstrate how one can undo this breaking. The phenomenon is alike the one emerging in renormalization group mixing of conformal operators in conformal theories when one uses dimensional regularization. The rotation matrix to the diagonal basis is found by means of computing the anomaly in the Ward identity for the conformal boost. Presently, we apply this ideology to the super Wilson loop. We compute the one-loop conformal anomaly for the super Wilson loop and find that the anomaly depends on its Grassmann coordinates. By subtracting this anomalous contribution from the super Wilson loop we restore its interpretation as a dual description for reduced non-MHV amplitudes which are expressed in terms of superconformal invariants.

  11. Super-Kamiokande worth full restoration

    CERN Multimedia

    Mishima, I

    2002-01-01

    While prospects are good that the SuperKamiokande facility will be partially repaired after an accident last November, the government has yet to confirm whether it will spend the estimated 2.5 billion yen needed for a full-scale restoration (1 page).

  12. Structural optimization of super-repellent surfaces

    DEFF Research Database (Denmark)

    Cavalli, Andrea; Bøggild, Peter; Okkels, Fridolin

    2013-01-01

    Micro-patterning is an effective way to achieve surfaces with extreme liquid repellency. This technique does not rely on chemical coatings and is therefore a promising concept for application in food processing and bio-compatibile coatings. This super-repellent behaviour is obtained by suspending...

  13. Facile preparation of super durable superhydrophobic materials.

    Science.gov (United States)

    Wu, Lei; Zhang, Junping; Li, Bucheng; Fan, Ling; Li, Lingxiao; Wang, Aiqin

    2014-10-15

    The low stability, complicated and expensive fabrication procedures seriously hinder practical applications of superhydrophobic materials. Here we report an extremely simple method for preparing super durable superhydrophobic materials, e.g., textiles and sponges, by dip coating in fluoropolymers (FPs). The morphology, surface chemical composition, mechanical, chemical and environmental stabilities of the superhydrophobic textiles were investigated. The results show how simple the preparation of super durable superhydrophobic textiles can be! The superhydrophobic textiles outperform their natural counterparts and most of the state-of-the-art synthetic superhydrophobic materials in stability. The intensive mechanical abrasion, long time immersion in various liquids and repeated washing have no obvious influence on the superhydrophobicity. Water drops are spherical in shape on the samples and could easily roll off after these harsh stability tests. In addition, this simple dip coating approach is applicable to various synthetic and natural textiles and can be easily scaled up. Furthermore, the results prove that a two-tier roughness is helpful but not essential with regard to the creation of super durable superhydrophobic textiles. The combination of microscale roughness of textiles and materials with very low surface tension is enough to form super durable superhydrophobic textiles. According to the same procedure, superhydrophobic polyurethane sponges can be prepared, which show high oil absorbency, oil/water separation efficiency and stability. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Pavement behaviour under the super single tyre

    CSIR Research Space (South Africa)

    Viljoen, AW

    1982-06-01

    Full Text Available Pavement behaviour under the super single tyre (SST) was investigated and compared with that under a conventional dual tyre (CDT). Contact areas and contact pressures over a range of loading conditions were measured and compared. Two approaches were...

  15. Typhoon effects on super-tall buildings

    Science.gov (United States)

    Li, Q. S.; Xiao, Y. Q.; Wu, J. R.; Fu, J. Y.; Li, Z. N.

    2008-06-01

    Full-scale measurement is considered to be the most reliable method for evaluating wind effects on buildings and structures. This paper presents selected results of wind characteristics and structural responses measured from four super-tall buildings, The Center (350 m high, 79 floors) in Hong Kong, Di Wang Tower (384 m high, 78 floors) in Shenzhen, CITIC Plaza Tower (391 m high, 80 floors) in Guangzhou and Jin Mao Building (421 m high, 88 floors) in Shanghai, during the passages of three typhoons. The field data such as wind speed, wind direction and acceleration responses, etc., were continuously measured from the super-tall buildings during the typhoons. Detailed analysis of the field data was conducted to investigate the characteristics of typhoon-generated wind and wind-induced vibrations of these super-tall buildings under typhoon conditions. The dynamic characteristics of the tall buildings were determined from the field measurements and comparisons with those calculated from the finite element (FE) models of the structures were made. Furthermore, the full-scale measurements were compared with wind tunnel results to evaluate the accuracy of the model test results and the adequacy of the techniques used in the wind tunnel tests. The results presented in this paper are expected to be of considerable interest and of use to researchers and professionals involved in designing super-tall buildings.

  16. Searching for Frozen Super Earth via Microlensing

    Science.gov (United States)

    Batista, V.; Beaulieu, J. P.; Cassan, A.; Coutures, C.; Donatowicz, J.; Fouqué, P.; Kubas, D.; Marquette, J. B.

    2009-04-01

    Microlensing planet hunt is a unique method to probe efficiently for frozen Super Earth orbiting the most common stars of our galaxy. It is nicely complementing the parameter space probed by very high accuracy radial velocity measurements and future space based detections of low mass transiting planets. In order to maximize the planet catch, the microlensing community is engaged in a total cooperation among the different groups (OGLE, MicroFUN, MOA, PLANET/RoboNET) by making the real time data available, and mutual informing/reporting about modeling efforts. Eight planets have been published so far by combinations of the different groups, 4 Jovian analogues, one Neptune and two Super Earth. Given the microlensing detection efficiency, it suggests that these Neptunes/Super Earths may be quite common. Using networks of dedicated 1-2m class telescopes, the microlensing community has entered a new phase of planet discoveries, and will be able to provide constraints on the abundance of frozen Super-Earths in the near future. Statistics about Mars to Earth mass planets, extending to the habitable zone will be achieved with space based wide field imagers (EUCLID) at the horizon 2017.

  17. Folded shapes with Super-Light Structures

    DEFF Research Database (Denmark)

    Castberg, Niels Andreas; Hertz, Kristian Dahl

    2012-01-01

    The use of folded shapes in structures has become more common, but it still costs problems because of construction issues and bending moments. The present paper deals with how the newly patented structural concept Super-Light structures (SLS) can be used to create folded shapes. SLS gives lighter...

  18. Advantages of super-light structures

    DEFF Research Database (Denmark)

    Hertz, Kristian Dahl

    2009-01-01

    Super-light structures with pearl-chain reinforcement is a new revolutionary technology that opens possibilities of building load-bearing structures much cheaper and with several other advantages compared to traditional constructions of concrete and steel. Some benefits are: 1 Half price or less. 2...

  19. Super-resolution near field imaging device

    DEFF Research Database (Denmark)

    2014-01-01

    Super-resolution imaging device comprising at least a first and a second elongated coupling element, each having a first transverse dimension at a first end and a second transverse dimension at a second end and being adapted for guiding light between their respective first and second ends, each...

  20. BREEDING SUPER-EARTHS AND BIRTHING SUPER-PUFFS IN TRANSITIONAL DISKS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eve J.; Chiang, Eugene, E-mail: evelee@berkeley.edu, E-mail: echiang@astro.berkeley.edu [Department of Astronomy, University of California Berkeley, Berkeley, CA 94720-3411 (United States)

    2016-02-01

    The riddle posed by super-Earths (1–4R{sub ⊕}, 2–20M{sub ⊕}) is that they are not Jupiters: their core masses are large enough to trigger runaway gas accretion, yet somehow super-Earths accreted atmospheres that weigh only a few percent of their total mass. We show that this puzzle is solved if super-Earths formed late, as the last vestiges of their parent gas disks were about to clear. This scenario would seem to present fine-tuning problems, but we show that there are none. Ambient gas densities can span many (in one case up to 9) orders of magnitude, and super-Earths can still robustly emerge after ∼0.1–1 Myr with percent-by-weight atmospheres. Super-Earth cores are naturally bred in gas-poor environments where gas dynamical friction has weakened sufficiently to allow constituent protocores to gravitationally stir one another and merge. So little gas is present at the time of core assembly that cores hardly migrate by disk torques: formation of super-Earths can be in situ. The basic picture—that close-in super-Earths form in a gas-poor (but not gas-empty) inner disk, fed continuously by gas that bleeds inward from a more massive outer disk—recalls the largely evacuated but still accreting inner cavities of transitional protoplanetary disks. We also address the inverse problem presented by super-puffs: an uncommon class of short-period planets seemingly too voluminous for their small masses (4–10R{sub ⊕}, 2–6M{sub ⊕}). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ∼1 AU where nebular gas is colder, less dense, and therefore less opaque. Unlike super-Earths, which can form in situ, super-puffs probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit greater water content. We close by confronting observations and itemizing remaining questions.

  1. SuperB A High-Luminosity Asymmetric $e^+ e^-$ Super Flavour Factory : Conceptual Design Report

    CERN Document Server

    Bona, M.; Grauges Pous, E.; Colangelo, P.; De Fazio, F.; Palano, A.; Manghisoni, M.; Re, V.; Traversi, G.; Eigen, G.; Venturini, M.; Soni, N.; Bruschi, M.; De Castro, S.; Faccioli, P.; Gabrieli, A.; Giacobbe, B.; Semprini Cesare, N.; Spighi, R.; Villa, M.; Zoccoli, A.; Hearty, C.; McKenna, J.; Soni, A.; Khan, A.; Barniakov, A.Y.; Barniakov, M.Y.; Blinov, V.E.; Druzhinin, V.P.; Golubev, V.B.; Kononov, S.A.; Koop, I.A.; Kravchenko, E.A.; Levichev, E.B.; Nikitin, S.A.; Onuchin, A.P.; Piminov, P.A.; Serednyakov, S.I.; Shatilov, D.N.; Skovpen, Y.I.; Solodov, E.A.; Cheng, C.H.; Echenard, B.; Fang, F.; Hitlin, D.J.; Porter, F.C.; Asner, D.M.; Pham, T.N.; Fleischer, R.; Giudice, G.F.; Hurth, T.; Mangano, M.; Mancinelli, G.; Meadows, B.T.; Schwartz, A.J.; Sokoloff, M.D.; Soffer, A.; Beard, C.D.; Haas, T.; Mankel, R.; Hiller, G.; Ball, P.; Pappagallo, M.; Pennington, M.R.; Gradl, W.; Playfer, S.; Abada, A.; Becirevic, D.; Descotes-Genon, S.; Pene, O.; Andreotti, D.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabresi, R.; Cecchi, A.; Cibinetto, G.; Franchini, P.; Luppi, E.; Negrini, M.; Petrella, A.; Piemontese, L.; Prencipe, E.; Santoro, V.; Stancari, G.; Anulli, F.; Baldini-Ferroli, R.; Biagini, M.E.; Boscolo, M.; Calcaterra, A.; Drago, A.; Finocchiaro, G.; Guiducci, S.; Isidori, G.; Pacetti, S.; Patteri, P.; Peruzzi, I.M.; Piccolo, M.; Preger, M.A.; Raimondi, P.; Rama, M.; Vaccarezza, C.; Zallo, A.; Zobov, M.; De Sangro, R.; Buzzo, A.; Lo Vetere, M.; Macri, M.; Monge, M.R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Matias, J.; Panduro Vazquez, W.; Borzumati, F.; Eyges, V.; Prell, S.A.; Pedlar, T.K.; Korpar, S.; Pestonik, R.; Staric, M.; Neubert, M.; Denig, A.G.; Nierste, U.; Agoh, T.; Ohmi, K.; Ohnishi, Y.; Fry, J.R.; Touramanis, C.; Wolski, A.; Golob, B.; Krizan, P.; Flaecher, H.; Bevan, A.J.; Di Lodovico, F.; George, K.A.; Barlow, R.; Lafferty, G.; Jawahery, A.; Roberts, D.A.; Simi, G.; Patel, P.M.; Robertson, S.H.; Lazzaro, A.; Palombo, F.; Kaidalov, A.; Buras, A.J.; Tarantino, C.; Buchalla, G.; Sanda, A.I.; D'Ambrosio, G.; Ricciardi, G.; Bigi, I.; Jessop, C.P.; Losecco, J.M.; Honscheid, K.; Arnaud, N.; Chehab, R.; Fedala, Y.; Polci, F.; Roudeau, P.; Sordini, V.; Soskov, V.; Stocchi, A.; Variola, A.; Vivoli, A.; Wormser, G.; Zomer, F.; Bertolin, A.; Brugnera, R.; Gagliardi, N.; Gaz, A.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Bonneaud, G.R.; Lombardo, V.; Calderini, G.; Ratti, L.; Speziali, V.; Biasini, M.; Covarelli, R.; Manoni, E.; Servoli, L.; Angelini, C.; Batignani, G.; Bettarini, S.; Bosi, F.; Carpinelli, M.; Cenci, R.; Cervelli, A.; Dell'Orso, M.; Forti, F.; Giannetti, P.; Giorgi, M.; Lusiani, A.; Marchiori, G.; Massa, M.; Mazur, M.A.; Morsani, F.; Neri, N.; Paoloni, E.; Raffaelli, F.; Rizzo, G.; Walsh, J.; Braun, V.; Lenz, A.; Adams, G.S.; Danko, I.Z.; Baracchini, E.; Bellini, F.; Cavoto, G.; D'Orazio, A.; Del Re, D.; Di Marco, E.; Faccini, R.; Ferrarotto, F.; Gaspero, Mario; Jackson, P.; Martinelli, G.; Mazzoni, M.A.; Morganti, Silvio; Piredda, G.; Renga, F.; Silvestrini, L.; Voena, C.; Catani, L.; Di Ciaccio, A.; Messi, R.; Santovetti, E.; Satta, A.; Ciuchini, M.; Lubicz, V.; Wilson, F.F.; Godang, R.; Chen, X.; Liu, H.; Park, W.; Purohit, M.; Trivedi, A.; White, R.M.; Wilson, J.R.; Allen, M.T.; Aston, D.; Bartoldus, R.; Brodsky, S.J.; Cai, Y.; Coleman, J.; Convery, M.R.; DeBarger, S.; Dingfelder, J.C.; Dubois-Felsmann, G.P.; Ecklund, S.; Fisher, A.S.; Haller, G.; Heifets, S.A.; Kaminski, J.; Kelsey, M.H.; Kocian, M.L.; Leith, D.W.G.S.; Li, N.; Luitz, S.; Luth, V.; MacFarlane, D.; Messner, R.; Muller, D.R.; Nosochkov, Y.; Novokhatski, A.; Pivi, M.; Ratcliff, B.N.; Roodman, A.; Schwiening, J.; Seeman, J.; Snyder, A.; Sullivan, M.; Va'Vra, J.; Wienands, U.; Wisniewski, W.; Stoeck, H.; Cheng, H.Y.; Li, H.N.; Keum, Y.Y.; Gronau, M.; Grossman, Y.; Bianchi, F.; Gamba, D.; Gambino, P.; Marchetto, F.; Menichetti, Ezio A.; Mussa, R.; Pelliccioni, M.; Dalla Betta, G.F.; Bomben, M.; Bosisio, L.; Cartaro, C.; Lanceri, L.; Vitale, L.; Azzolini, V.; Bernabeu, J.; Lopez-March, N.; Martinez-Vidal, F.; Milanes, D.A.; Oyanguren, A.; Paradisi, P.; Pich, A.; Sanchis-Lozano, M.A.; Kowalewski, Robert V.; Roney, J.M.; Back, J.J.; Gershon, T.J.; Harrison, P.F.; Latham, T.E.; Mohanty, G.B.; Petrov, A.A.; Pierini, M.; INFN

    2007-01-01

    The physics objectives of SuperB, an asymmetric electron-positron collider with a luminosity above 10^36/cm^2/s are described, together with the conceptual design of a novel low emittance design that achieves this performance with wallplug power comparable to that of the current B Factories, and an upgraded detector capable of doing the physics in the SuperB environment.

  2. Properties of Super-Poisson Processes and Super-Random Walks with Spatially Dependent Branching Rates

    Institute of Scientific and Technical Information of China (English)

    Yan Xia REN

    2008-01-01

    The global supports of super-Poisson processes and super-random walks with a branching mechanism ψ(z)=z2 and constant branching rate are known to be noncompact. It turns out that, for any spatially dependent branching rate, this property remains true. However, the asymptotic extinction property for these two kinds of superprocesses depends on the decay rate of the branching-rate function at infinity.

  3. A generalized super AKNS hierarchy associated with Lie superalgebra sl(2|1) and its super bi-Hamiltonian structure

    Science.gov (United States)

    Han, Jingwei; Yu, Jing

    2017-03-01

    Starting from a 3 × 3 matrix-valued spectral problem associated with a Lie superalgebra sl(2|1), a generalized super Ablowitz-Kaup-Newell-Segur (AKNS) hierarchy is derived. The resulting super AKNS hierarchy has a super bi-Hamiltonian structure by the supertrace identity.

  4. Super SI燃烧方式试验研究%Super SI Combustion Mode

    Institute of Scientific and Technical Information of China (English)

    沈义涛; 吕世亮; 尹琪; 杨嘉林; 高卫民

    2011-01-01

    The super spark ignition (Super SI) combustion mode, which was the ignition combustion of lean mixture at the temperature of close spontaneous combustion, was researched and its combustion characteristic and feasibility were analyzed.The results indicate that the increase of intake temperature can reduce the cyclic variation of Pmi obviously, shorten the combustion duration and extend the lean limit of SI combustion under the condition of lean mixture. Accordingly, Super SI combustion has the advantages of high thermal efficiency and controllable combustion process.%研究了Super Spark Ignition(Super SI)燃烧方式,即稀薄混合气在近自燃温度状态下点燃燃烧,分析了这种燃烧方式的可行性和燃烧特性.研究结果表明,混合气稀薄时提高发动机的进气温度可显著降低平均指示压力(pmi)的循环波动,缩短燃烧持续期,拓展点燃燃烧的稀薄极限;Super SI燃烧方式具有热效率高、燃烧过程可控的优点.

  5. The 2015 super-resolution microscopy roadmap

    Science.gov (United States)

    Hell, Stefan W.; Sahl, Steffen J.; Bates, Mark; Zhuang, Xiaowei; Heintzmann, Rainer; Booth, Martin J.; Bewersdorf, Joerg; Shtengel, Gleb; Hess, Harald; Tinnefeld, Philip; Honigmann, Alf; Jakobs, Stefan; Testa, Ilaria; Cognet, Laurent; Lounis, Brahim; Ewers, Helge; Davis, Simon J.; Eggeling, Christian; Klenerman, David; Willig, Katrin I.; Vicidomini, Giuseppe; Castello, Marco; Diaspro, Alberto; Cordes, Thorben

    2015-11-01

    Far-field optical microscopy using focused light is an important tool in a number of scientific disciplines including chemical, (bio)physical and biomedical research, particularly with respect to the study of living cells and organisms. Unfortunately, the applicability of the optical microscope is limited, since the diffraction of light imposes limitations on the spatial resolution of the image. Consequently the details of, for example, cellular protein distributions, can be visualized only to a certain extent. Fortunately, recent years have witnessed the development of ‘super-resolution’ far-field optical microscopy (nanoscopy) techniques such as stimulated emission depletion (STED), ground state depletion (GSD), reversible saturated optical (fluorescence) transitions (RESOLFT), photoactivation localization microscopy (PALM), stochastic optical reconstruction microscopy (STORM), structured illumination microscopy (SIM) or saturated structured illumination microscopy (SSIM), all in one way or another addressing the problem of the limited spatial resolution of far-field optical microscopy. While SIM achieves a two-fold improvement in spatial resolution compared to conventional optical microscopy, STED, RESOLFT, PALM/STORM, or SSIM have all gone beyond, pushing the limits of optical image resolution to the nanometer scale. Consequently, all super-resolution techniques open new avenues of biomedical research. Because the field is so young, the potential capabilities of different super-resolution microscopy approaches have yet to be fully explored, and uncertainties remain when considering the best choice of methodology. Thus, even for experts, the road to the future is sometimes shrouded in mist. The super-resolution optical microscopy roadmap of Journal of Physics D: Applied Physics addresses this need for clarity. It provides guidance to the outstanding questions through a collection of short review articles from experts in the field, giving a thorough

  6. Coherent controlization using superconducting qubits.

    Science.gov (United States)

    Friis, Nicolai; Melnikov, Alexey A; Kirchmair, Gerhard; Briegel, Hans J

    2015-01-01

    Coherent controlization, i.e., coherent conditioning of arbitrary single- or multi-qubit operations on the state of one or more control qubits, is an important ingredient for the flexible implementation of many algorithms in quantum computation. This is of particular significance when certain subroutines are changing over time or when they are frequently modified, such as in decision-making algorithms for learning agents. We propose a scheme to realize coherent controlization for any number of superconducting qubits coupled to a microwave resonator. For two and three qubits, we present an explicit construction that is of high relevance for quantum learning agents. We demonstrate the feasibility of our proposal, taking into account loss, dephasing, and the cavity self-Kerr effect.

  7. Pairing theory of striped superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Loder, Florian; Kampf, Arno P.; Kopp, Thilo; Graser, Siegfried [Center for Electronic Correlations and Magnetism, Institute of Physics, Augsburg (Germany)

    2011-07-01

    Striped high-T{sub c} superconductors such as La{sub 7/8}Ba{sub 1/8}CuO{sub 4} show a fascinating competition between spin and charge order on the one hand and superconductivity on the other. A theory for these systems therefore has to capture both the spin correlations in an antiferromagnet and the pair-correlation of a superconductor. For this purpose we have developed an effective Hartree-Fock theory by merging electron pairing with finite center-of-mass momentum and antiferromagnetism. We show that this theory reproduces the key experimental features such as the formation of the antiferromagnetic stripe patterns at 7/8 band filling or the quasi one-dimensional electronic structure observed by photoemission spectroscopy.

  8. Advanced Manufacturing of Superconducting Magnets

    Science.gov (United States)

    Senti, Mark W.

    1996-01-01

    The development of specialized materials, processes, and robotics technology allows for the rapid prototype and manufacture of superconducting and normal magnets which can be used for magnetic suspension applications. Presented are highlights of the Direct Conductor Placement System (DCPS) which enables automatic design and assembly of 3-dimensional coils and conductor patterns using LTS and HTS conductors. The system enables engineers to place conductors in complex patterns with greater efficiency and accuracy, and without the need for hard tooling. It may also allow researchers to create new types of coils and patterns which were never practical before the development of DCPS. The DCPS includes a custom designed eight-axis robot, patented end effector, CoilCAD(trademark) design software, RoboWire(trademark) control software, and automatic inspection.

  9. Feeding helium to superconducting magnets

    CERN Multimedia

    1979-01-01

    The photo shows two of the 3 superconducting magnets (two MBS dipoles (CESAR) of 150 mm bore and 4.5 T, and one quadrupole (CASTOR) of 90 mm bore and 54 T/m) which were installed in the hall EHN1 (Annual Report 1978 p. 134) and ran until 1985. They formed a section of the beam H6 travelling from target T4 (down the bottom of the photo) towards the NA30 setup followed by the NA11 setup. The two big transversal pipelines are the quench lines of the two magnets (on the right, one quadrupole and one dipole, the other dipole lays down the photo and is not visible). The Jura side of the hall is on the right.

  10. Towards inducing superconductivity into graphene

    Science.gov (United States)

    Efetov, Dmitri K.

    Graphenes transport properties have been extensively studied in the 10 years since its discovery in 2004, with ground-breaking experimental observations such as Klein tunneling, fractional quantum Hall effect and Hofstadters butterfly. Though, so far, it turned out to be rather poor on complex correlated electronic ground states and phase transitions, despite various theoretical predictions. The purpose of this thesis is to help understanding the underlying theoretical and experimental reasons for the lack of strong electronic interactions in graphene, and, employing graphenes high tunability and versatility, to identify and alter experimental parameters that could help to induce stronger correlations. In particular graphene holds one last, not yet experimentally discovered prediction, namely exhibiting intrinsic superconductivity. With its vanishingly small Fermi surface at the Dirac point, graphene is a semi-metal with very weak electronic interactions. Though, if it is doped into the metallic regime, where the size of the Fermi surface becomes comparable to the size of the Brillouin zone, the density of states becomes sizeable and electronic interactions are predicted to be dramatically enhanced, resulting in competing correlated ground states such as superconductivity, magnetism and charge density wave formation. Following these predictions, this thesis first describes the creation of metallic graphene at high carrier doping via electrostatic doping techniques based on electrolytic gates. Due to graphenes surface only properties, we are able to induce carrier densities above n>1014 cm-2 (epsilonF>1eV) into the chemically inert graphene. While at these record high carrier densities we yet do not observe superconductivity, we do observe fundamentally altered transport properties as compared to semi-metallic graphene. Here, detailed measurements of the low temperature resistivity reveal that the electron-phonon interactions are governed by a reduced, density

  11. Durability Evaluation of Superconducting Magnets

    Science.gov (United States)

    Inoue, Akihiko; Ogata, Masafumi; Nakauchi, Masahiko; Asahara, Tetsuo; Herai, Toshiki; Nishikawa, Yoichi

    2006-06-01

    It is one of the most essential things to verify the durability of devices and components of JR-Maglev system to realize the system into the future inauguration. Since the load requirements were insufficient in terms of the durability under vibrations under mere running tests carried out on Yamanashi Maglev Test Line hereinafter referred to YMTL, we have developed supplemental method with bench tests. Superconducting magnets hereinafter referred to SCM as used in the experimental running for the last seven years on the YMTL were brought to Kunitachi Technical Research Institute; we conducted tests to evaluate the durability of SCM up to a period of the service life in commercial use. The test results have indicated that no irregularity in each part of SCM proving that SCM are sufficiently durable for the practical application.

  12. Nonclassical correlations in superconducting circuits

    Energy Technology Data Exchange (ETDEWEB)

    Migliore, Rosanna [Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo (Italy); CNR-INFM, UdR CNISM di Palermo, Palermo (Italy); Scala, Matteo [Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo (Italy); Departamento de Optica, Facultad de Fisica, Universidad Complutense, Madrid (Spain); Guccione, Marina; Sanchez-Soto, Luis L. [Dipartimento di Scienze Fisiche ed Astronomiche, Universita di Palermo (Italy); Messina, Antonino [Departamento de Optica, Facultad de Fisica, Universidad Complutense, Madrid (Spain)

    2009-05-15

    A key step on the road map to solid-state quantum information processing (and to a deeper understanding of many counterintuitive aspects of quantum mechanics) is the generation and manipulation of nonclassical correlations between different quantum systems. Within this framework, we analyze the possibility of generating maximally entangled states in a system of two superconducting flux qubits, as well as the effectof their own environments on the entanglement dynamics. The analysis reported here confirms that the phenomena of sudden birth and sudden death of the entanglement do not depend on the particular measure of the entanglement adopted (copyright 2009 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  13. Gapless superconductivity and string theory

    CERN Document Server

    Khlebnikov, S

    2014-01-01

    Coexistence of superconducting and normal components in nanowires at currents below the critical (a "mixed" state) would have important consequences for the nature and range of potential applications of these systems. From the theoretical perspective, it represents a genuine interaction effect, not seen in the mean-field theory. Here we consider properties of such a state in the gravity dual of a strongly coupled superconductor constructed from D3 and D5 branes. We find numerically uniform gapless solutions containing both components but argue that they are unstable against phase separation, as their free energies are not convex. We speculate on the possible nature of the resulting non-uniform sate ("emulsion") and draw analogies between that state and the familiar mixed state of a type II superconductor in a magnetic field.

  14. Superconducting magnets and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Williams, J.E.C. (Massachusetts Inst. of Tech., Cambridge, MA (USA). Francis Bitter National Magnet Lab.)

    1989-08-01

    Superconducting magnets are now being used in applications as diverse as medical imaging, fusion research, and power conditioning. The steady improvement in the understanding of instability and quenching has allowed increases in current density and compactness of winding. The reduction in winding size that has thus followed has allowed the construction of economic magnets for imaging, for acceleration, and for high-resolution spectrometers. Large magnets for fusion and energy applications have been made possible by composite conductors containing large fractions of copper or aluminum. The advent of high-temperature superconductors may hold the promise, eventually, of very-high-field magnets. Meanwhile low-temperature superconductors capable of generating fields up to 30 T have been developed.

  15. An experimental superconducting helical undulator

    Energy Technology Data Exchange (ETDEWEB)

    Caspi, S.; Taylor, C. [Lawrence Berkeley Lab., CA (United States)

    1995-12-31

    Improvements in the technology of superconducting magnets for high energy physics and recent advancements in SC materials with the artificial pinning centers (APC){sup 2}, have made a bifilar helical SC device an attractive candidate for a single-pass free electron laser (FEL){sup 3}. Initial studies have suggested that a 6.5 mm inner diameter helical device, with a 27 mm period, can generate a central field of 2-2.5 Tesla. Additional studies have also suggested that with a stored energy of 300 J/m, such a device can be made self-protecting in the event of a quench. However, since the most critical area associated with high current density SC magnets is connected with quenching and training, a short experimental device will have to be built and tested. In this paper we discuss technical issues relevant to the construction of such a device, including a conceptual design, fields, and forces.

  16. More superconductivity questions than answers.

    Science.gov (United States)

    Robinson, A L

    1987-07-17

    Although making liquid nitrogen-temperature superconductors is easy enough that high school science projects already feature them, researchers still have little idea how the new ceramic oxides work and therefore little guidance for improving them. At the International Workshop on Novel Mechanisms of Superconductivity, held from 22 to 26 June in Berkeley, California, theorists reviewed a host of competing explanations of how these materials come by their remarkable properties, but they could not, get far in sifting through the candidates for the best one. One cause of the unsettled situation is that theorists have not yet pushed their models far enough to make many specific predictions about physical properties and therefore to provide a reason to choose one theory over another. But experimental data for comparison with theory are lacking, too. For example, experimentalists are just now succeeding in being able to grow single crystals and thin films of the ceramic oxide superconductors, whose properties were shown at the workshop to be highly anisotropic. Measurements already made on the polycrystalline sintered material available up to now are difficult to interpret and therefore need to be repeated on good-quality crystals and films, where the variation of properties with crystallographic orientation can be mapped out. Given the high level of Japanese activity in the field, it was surprising that no researchers from industrial laboratories in Japan presented their findings at the workshop. In the light of a budding international competition in commercializing superconductors, some American scientists interpreted the absence as an attempt to protect proprietary advances. A more pleasant surprise was the attendance of a delegation of six Soviet scientists, although one of the fathers of superconductivity theory, Vitaly Ginzburg of the P.N.Lebedev Institute of Physics in Moscow, who was expected, did not come.

  17. The Solution Construction of Heterotic Super-Liouville Model

    Institute of Scientific and Technical Information of China (English)

    YANG Zhan-Ying; ZHEN Yi

    2001-01-01

    We investigate the heterotic super-Liouville model on the base of the basic Lie super-algebra Osp(1|2).Using the super extension of Leznov-Saveliev analysis and Drinfeld Sokolov linear system, we construct the explicit solution of the heterotic super-Liouville system in component form. We also show that the solutions are local and periodic by calculating the exchange relation of the solution. Finally starting from the action of heterotic super-Liou ville model, we obtain the conserved current and conserved charge which possessed the BR ST properties.

  18. High Tc superconducting small loop antenna

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Z.; Mehler, M.J.; Maclean, T.S.M.; Lancaster, M.J.; Gough, C.E. (Univ. of Birmingham (UK)); Alford, N. (I.C.I. Advanced Materials Div., Runcorn (UK))

    1989-12-01

    The improvement in the radiation efficiency of an electrically small loop antenna is analysed when it is fabricated from a superconductor, and experimental results for a liquid nitrogen cooled, ceramic superconducting loop at 450MHz are presented. (orig.).

  19. Superconducting inductive displacement detection of a microcantilever

    Energy Technology Data Exchange (ETDEWEB)

    Vinante, A., E-mail: anvinante@fbk.eu [Istituto di Fotonica e Nanotecnologie, CNR - Fondazione Bruno Kessler, I-38123 Povo, Trento (Italy)

    2014-07-21

    We demonstrate a superconducting inductive technique to measure the displacement of a micromechanical resonator. In our scheme, a type I superconducting microsphere is attached to the free end of a microcantilever and approached to the loop of a dc Superconducting Quantum Interference Device (SQUID) microsusceptometer. A local magnetic field as low as 100 μT, generated by a field coil concentric to the SQUID, enables detection of the cantilever thermomechanical noise at 4.2 K. The magnetomechanical coupling and the magnetic spring are in good agreement with image method calculations assuming pure Meissner effect. These measurements are relevant to recent proposals of quantum magnetomechanics experiments based on levitating superconducting microparticles.

  20. Superconducting gap structure of FeSe.

    Science.gov (United States)

    Jiao, Lin; Huang, Chien-Lung; Rößler, Sahana; Koz, Cevriye; Rößler, Ulrich K; Schwarz, Ulrich; Wirth, Steffen

    2017-03-07

    The microscopic mechanism governing the zero-resistance flow of current in some iron-based, high-temperature superconducting materials is not well understood up to now. A central issue concerning the investigation of these materials is their superconducting gap symmetry and structure. Here we present a combined study of low-temperature specific heat and scanning tunnelling microscopy measurements on single crystalline FeSe. The results reveal the existence of at least two superconducting gaps which can be represented by a phenomenological two-band model. The analysis of the specific heat suggests significant anisotropy in the gap magnitude with deep gap minima. The tunneling spectra display an overall "U"-shaped gap close to the Fermi level away as well as on top of twin boundaries. These results are compatible with the anisotropic nodeless models describing superconductivity in FeSe.