National Library of Energy BETA

Sample records for nanofabricated superconducting rf

  1. Nano-fabricated superconducting radio-frequency composites, method for producing nano-fabricated superconducting rf composites

    DOE Patents [OSTI]

    Norem, James H.; Pellin, Michael J.

    2013-06-11

    Superconducting rf is limited by a wide range of failure mechanisms inherent in the typical manufacture methods. This invention provides a method for fabricating superconducting rf structures comprising coating the structures with single atomic-layer thick films of alternating chemical composition. Also provided is a cavity defining the invented laminate structure.

  2. Nb-Pb superconducting RF gun

    SciTech Connect (OSTI)

    J. Sekutowicz; J. Iversen; G. Kreps; W.D. Moller; W. Singer; X. Singer; I. Ben-Zvi; A. Burrill; J. Smedley; T. Rao; M. Ferrario; P. Kneisel; J. Langner; P. Strzyzewski; R. Lefferts; A. Lipski; K. Szalowski; K. Ko; L. Xiao

    2006-04-14

    We report on the status of an electron RF-gun made of two superconductors: niobium and lead. The presented design combines the advantages of the RF performance of bulk niobium superconducting cavities and the reasonably high quantum efficiency of lead, as compared to other superconducting metals. The concept, mentioned in a previous paper, follows the attractive approach of all niobium superconducting RF-gun as it has been proposed by the BNL group. Measured values of quantum efficiency for lead at various photon energies, analysis of recombination time of photon-broken Cooper pairs for lead and niobium, and preliminary cold test results are discussed in this paper.

  3. Superfluid helium cryogenic systems for superconducting RF cavities...

    Office of Scientific and Technical Information (OSTI)

    (STF) for R and D of the International Linear Collider (ILC) project and the compact Energy Recovery Linac (cERL), employ superconducting RF cavities made of pure niobium,...

  4. Realization and modeling of rf superconducting quantum interference device metamaterials

    E-Print Network [OSTI]

    M. Trepanier; Daimeng Zhang; Oleg Mukhanov; Steven M. Anlage

    2013-10-28

    We have prepared meta-atoms based on radio frequency superconducting quantum interference devices (RF SQUIDs) and examined their tunability with dc magnetic field, rf current, and temperature. RF SQUIDs are superconducting split ring resonators in which the usual capacitance is supplemented with a Josephson junction, which introduces strong nonlinearity in the rf properties. We find excellent agreement between the data and a model which regards the Josephson junction as the resistively and capacitively-shunted junction. A magnetic field tunability of 80 THz/Gauss at 12 GHz is observed, a total tunability of 56$%$ is achieved, and a unique electromagnetically-induced transparency feature at intermediate excitation powers is demonstrated for the first time. An RF SQUID metamaterial is shown to have qualitatively the same behavior as a single RF SQUID with regards to DC flux and temperature tuning.

  5. Investigation of Microscopic Materials Limitations of Superconducting RF Cavities

    SciTech Connect (OSTI)

    Anlage, Steven

    2014-07-23

    The high-field performance of SRF cavities is often limited by breakdown events below the intrinsic limiting surface fields of Nb, and there is abundant evidence that these breakdown events are localized in space inside the cavity. Also, there is a lack of detailed understanding of the causal links between surface treatments and ultimate RF performance at low temperatures. An understanding of these links would provide a clear roadmap for improvement of SRF cavity performance, and establish a cause-and-effect ‘RF materials science’ of Nb. We propose two specific microscopic approaches to addressing these issues. First is a spatially-resolved local microwave-microscope probe that operates at SRF frequencies and temperatures to discover the microscopic origins of breakdown, and produce quantitative measurements of RF critical fields of coatings and films. Second, RF Laser Scanning Microscopy (LSM) has allowed visualization of RF current flow and sources of nonlinear RF response in superconducting devices with micro-meter spatial resolution. The LSM will be used in conjunction with surface preparation and characterization techniques to create definitive links between physical and chemical processing steps and ultimate cryogenic microwave performance. We propose to develop RF laser scanning microscopy of small-sample Nb pieces to establish surface-processing / RF performance relations through measurement of RF current distributions on micron-length scales and low temperatures.

  6. STATUS OF THE SPALLATION NEUTRON SOURCE SUPERCONDUCTING RF FACILITIES

    SciTech Connect (OSTI)

    Stout, Daniel S [ORNL] [ORNL; Assadi, Saeed [ORNL] [ORNL; Campisi, Isidoro E [ORNL] [ORNL; Casagrande, Fabio [ORNL] [ORNL; Crofford, Mark T [ORNL] [ORNL; DeVan, Bill [ORNL] [ORNL; Hardek, Thomas W [ORNL] [ORNL; Henderson, Stuart D [ORNL] [ORNL; Howell, Matthew P [ORNL] [ORNL; Kang, Yoon W [ORNL] [ORNL; Geng, Xiaosong [ORNL] [ORNL; Stone Jr, William C [ORNL] [ORNL; Strong, William Herb [ORNL] [ORNL; Williams, Derrick C [ORNL] [ORNL; Wright, Paul Alan [ORNL] [ORNL

    2007-01-01

    The Spallation Neutron Source (SNS) project was completed with only limited superconducting RF (SRF) facilities installed as part of the project. A concerted effort has been initiated to install the infrastructure and equipment necessary to maintain and repair the superconducting Linac, and to support power upgrade research and development (R&D). Installation of a Class10/100/10,000 cleanroom and outfitting of the test cave with RF, vacuum, controls, personnel protection and cryogenics systems is underway. A horizontal cryostat, which can house a helium vessel/cavity and fundamental power coupler for full power, pulsed testing, is being procured. Equipment for cryomodule assembly and disassembly is being procured. This effort, while derived from the experience of the SRF community, will provide a unique high power test capability as well as long term maintenance capabilities. This paper presents the current status and the future plans for the SNS SRF facilities.

  7. Design of Superconducting Parallel Bar Deflecting and Crabbing rf Structures

    SciTech Connect (OSTI)

    Jean Delayen, Haipeng Wang

    2009-05-01

    A new concept for a deflecting and crabbing rf structure based on half-wave resonant lines was introduced recently*. It offers significant advantages to existing designs and, because of it compactness, allows low frequency operation. This concept has been further refined and optimized for superconducting implementation. Results of this optimization and application to a 400 MHz crabbing cavity and a 499 MHz deflecting cavity are presented.

  8. BNl 703 MHz superconducting RF cavity testing

    SciTech Connect (OSTI)

    Sheehy, B.; Altinbas, Z.; Burrill, A.; Ben-Zvi, I.; Gassner, D.; Hahn, H.; Hammons, L.; Jamilkowski, J.; Kayran, D.; Kewisch, J.; Laloudakis, N.; Lederle, D.; Litvinenko, V.; McIntyre, G.; Pate, D.; Phillips, D.; Schultheiss, C.; Seda,T.; Than, R.; Xu, W.; Zaltsman, A.; Schultheiss, T.

    2011-03-28

    The BNL 5-cell, 703 MHz superconducting accelerating cavity has been installed in the high-current ERL experiment. This experiment will function as a proving ground for the development of high-current machines in general and is particularly targeted at beam development for an electron-ion collider (eRHIC). The cavity performed well in vertical tests, demonstrating gradients of 20 MV/m and a Q{sub 0} of 1e10. Here we will present its performance in the horizontal tests, and discuss technical issues involved in its implementation in the ERL.

  9. A new microphonics measurement method for superconducting RF cavities

    SciTech Connect (OSTI)

    Gao,Zheng; He,Yuan; Chang,Wei; Powers, Tom [JLAB; Yue,Wei-ming; Zhu,Zheng-long; Chen,Qi

    2014-09-01

    Mechanical vibrations of the superconducting cavity, also known as microphonics, cause shifts in the resonant frequency of the cavity. In addition to requiring additional RF power, these frequency shifts can contribute to errors in the closed loop phase and amplitude regulation. In order to better understand these effects, a new microphonics measurement method was developed, and the method was successfully used to measure microphonics on the half-wave superconducting cavity when it was operated in a production style cryostat. The test cryostat held a single ?=0.1 half-wave cavity which was operated at 162.5 MHz [1] and [2]. It's the first time that the National Instruments PXIe-5641R intermediate frequency transceiver has been used for microphonics measurements in superconducting cavities. The new microphonics measurement method and results will be shown and analyzed in this paper.

  10. Superconducting DC and RF Properties of Ingot Niobium

    SciTech Connect (OSTI)

    Pashupati Dhakal, Gianluigi Ciovati, Peter Kneisel, Ganapati Rao Myneni

    2011-07-01

    The thermal conductivity, DC magnetization and penetration depth of large-grain niobium hollow cylindrical rods fabricated from ingots, manufactured by CBMM subjected to chemical and heat treatment were measured. The results confirm the influence of chemical and heat-treatment processes on the superconducting properties, with no significant dependence on the impurity concentrations in the original ingots. Furthermore, RF properties, such as the surface resistance and quench field of the niobium rods were measured using a TE{sub 011} cavity. The hollow niobium rod is the center conductor of this cavity, converting it to a coaxial cavity. The quench field is limited by the critical heat flux through the rods' cooling channel.

  11. 1.3 GHz superconducting RF cavity program at Fermilab

    SciTech Connect (OSTI)

    Ginsburg, C.M.; Arkan, T.; Barbanotti, S.; Carter, H.; Champion, M.; Cooley, L.; Cooper, C.; Foley, M.; Ge, M.; Grimm, C.; Harms, E.; /Fermilab

    2011-03-01

    At Fermilab, 9-cell 1.3 GHz superconducting RF (SRF) cavities are prepared, qualified, and assembled into cryomodules (CMs) for Project X, an International Linear Collider (ILC), or other future projects. The 1.3 GHz SRF cavity program includes targeted R&D on 1-cell 1.3 GHz cavities for cavity performance improvement. Production cavity qualification includes cavity inspection, surface processing, clean assembly, and one or more cryogenic low-power CW qualification tests which typically include performance diagnostics. Qualified cavities are welded into helium vessels and are cryogenically tested with pulsed high-power. Well performing cavities are assembled into cryomodules for pulsed high-power testing in a cryomodule test facility, and possible installation into a beamline. The overall goals of the 1.3 GHz SRF cavity program, supporting facilities, and accomplishments are described.

  12. Cerenkov Radiator Driven by a Superconducting RF Electron Gun

    SciTech Connect (OSTI)

    Poole, B R; Harris, J R

    2011-03-07

    The Naval Postgraduate School (NPS), Niowave, Inc., and Boeing have recently demonstrated operation of the first superconducting RF electron gun based on a quarter wave resonator structure. In preliminary tests, this gun has produced 10 ps long bunches with charge in excess of 78 pC, and with beam energy up to 396 keV. Initial testing occurred at Niowave's Lansing, MI facility, but the gun and diagnostic beam line are planned for installation in California in the near future. The design of the diagnostic beam line is conducive to the addition of a Cerenkov radiator without interfering with other beam line operations. Design and simulations of a Cerenkov radiator, consisting of a dielectric lined waveguide will be presented. The dispersion relation for the structure is determined and the beam interaction is studied using numerical simulations. The characteristics of the microwave radiation produced in both the short and long bunch regimes will be presented.

  13. Sensitivity of Niobium Superconducting RF Cavities to Magnetic Field

    E-Print Network [OSTI]

    Gonnella, Dan

    2015-01-01

    Future particle accelerators such as the the SLAC "Linac Coherent Light Source-II" (LCLS-II) and the proposed Cornell Energy Recovery Linac (ERL) require hundreds of superconducting RF (SRF) cavities operating in continuous wave (CW) mode. In order to achieve economic feasibility of projects such as these, the cavities must achieve a very high intrinsic quality factor (Q0). In order to reach these high Q0's in the case of LCLS-II, nitrogen-doping has been proposed as a cavity preparation technique. When dealing with Q0's greater than 1x10^10, the effects of ambient magnetic field on Q0 become significant. Here we show that the sensitivity that a cavity has to ambient magnetic field is highly dependent on the cavity preparation. Specifically, standard electropolished and 120C baked cavities show a sensitivity of ~0.8 and ~0.6 nOhm/mG trapped, respectively, while nitrogen-doped cavities show a sensitivity of ~2 to 5 nOhm/mG trapped. Less doping results in weaker sensitivity. This difference in sensitivities is ...

  14. Dependence of the microwave surface resistance of superconducting niobium on the magnitude of the rf field

    SciTech Connect (OSTI)

    Romanenko, A.; Grassellino, A. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)] [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States)

    2013-06-24

    Utilizing difference in temperature dependencies we decoupled Bardeen-Cooper-Schrieffer (BCS) and residual components of the microwave surface resistance of superconducting niobium at all rf fields up to B{sub rf}{approx}115 mT. We reveal that the residual resistance decreases with field at B{sub rf} Less-Than-Or-Equivalent-To 40 mT and strongly increases in chemically treated niobium at B{sub rf}>80 mT. We find that BCS surface resistance is weakly dependent on field in the clean limit, whereas a strong and peculiar field dependence emerges after 120 Degree-Sign C vacuum baking.

  15. Realization and Modeling of Metamaterials Made of rf Superconducting Quantum-Interference Devices

    E-Print Network [OSTI]

    Anlage, Steven

    ,5], cloaking [6,7], transformation optics [8,9], and perfect absorption [10]. Most of the applications invoking in space (e.g., for cloaking or transformation optics) or that can be tuned and reconfigured after for digital rf receivers [25,26]. Superconducting metamaterials have been proposed to address all three

  16. Superconducting RF Lab Facility Upgrades at Los Alamos

    SciTech Connect (OSTI)

    Katonak, D.J.; Rusnak, B.

    1999-03-01

    Research and testing of multi-cell superconducting cavities demands extensive contamination control resources to achieve high-cavity fields. Facility upgrades at Los Alamos National Laboratory (LANL) included the modernization of test equipment, expanding and modernizing cleanroom facilities, improving safety, and expanding the high-pressure rinse cleaning process equipment. Each upgrade was integrated into the facility to enable users to assemble prototype cryomodules. The scope of the upgrades, the new installed capability, and budget and schedule for certain aspects of the project are discussed in this paper.

  17. Superconducting RF cavity R&D for future accelerators

    E-Print Network [OSTI]

    C. M. Ginsburg

    2009-10-22

    High-beta superconducting radiofrequency (SRF) elliptical cavities are being developed for several accelerator projects including Project X, the European XFEL, and the International Linear Collider (ILC). Fermilab has recently established an extensive infrastructure for SRF cavity R&D for future accelerators, including cavity surface processing and testing and cavity assembly into cryomodules. Some highlights of the global effort in SRF R&D toward improving cavity performance, and Fermilab SRF cavity R&D in the context of global projects are reviewed.

  18. Precision vector control of a superconducting RF cavity driven by an injection locked magnetron

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

    Chase, B.; Pasquinelli, R.; Cullerton, E.; Varghese, P.

    2015-03-01

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons [1]. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs - compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRFmore »cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.« less

  19. Precision Vector Control of a Superconducting RF Cavity driven by an Injection Locked Magnetron

    E-Print Network [OSTI]

    Brian Chase; Ralph Pasquinelli; Ed Cullerton; Philip Varghese

    2014-11-21

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

  20. Precision Vector Control of a Superconducting RF Cavity driven by an Injection Locked Magnetron

    E-Print Network [OSTI]

    Chase, Brian; Cullerton, Ed; Varghese, Philip

    2015-01-01

    The technique presented in this paper enables the regulation of both radio frequency amplitude and phase in narrow band devices such as a Superconducting RF (SRF) cavity driven by constant power output devices i.e. magnetrons. The ability to use low cost high efficiency magnetrons for accelerator RF power systems, with tight vector regulation, presents a substantial cost savings in both construction and operating costs compared to current RF power system technology. An operating CW system at 2.45 GHz has been experimentally developed. Vector control of an injection locked magnetron has been extensively tested and characterized with a SRF cavity as the load. Amplitude dynamic range of 30 dB, amplitude stability of 0.3% r.m.s, and phase stability of 0.26 degrees r.m.s. has been demonstrated.

  1. Construction and Test of a Novel Superconducting RF Electron gun

    SciTech Connect (OSTI)

    Bisognano, Joseph J.

    2014-04-16

    The University of Wisconsin-Madison has completed installation of a superconducting electron gun. Its concept was optimized to be the source for a CW free electron laser facility with multiple megahertz repetition rate end stations. This VHF superconducting configuration holds the promise of the highest performance for CW injectors. Initial commissioning efforts show that the cavity can achieve gradients of 35 MV/m at the cathode position. With the cathode inserted CW operation has been achieved at 20 MV/m with good control of microphonics, negligible dark current, and Q0 > 3×109 at 4 K. Bunch charges of ~100 pC have been delivered, and first simple beam measurements made. These preliminary results are very encouraging for production of 100s pC bunches with millimeter-milliradian or smaller normalized emittances. Plans are in place to carry out more definitive studies to establish the full capabilities. However, since the grant was not renewed, the electron gun is currently mothballed, and without supplemental fund the opportunity for further work will be lost.

  2. Design of a horizontal test cryostat for superconducting RF cavities for the FREIA facility at Uppsala University

    SciTech Connect (OSTI)

    Chevalier, N. R.; Thermeau, J.-P.; Bujard, P.; Junquera, T. [Accelerators and Cryogenic Systems (ACS), 86 rue de Paris, 91400 Orsay (France); Hermansson, L.; Kern, R. Santiago; Ruber, R. [Uppsala University, Department of Physics and Astronomy, 75120 Uppsala (Sweden)

    2014-01-29

    Uppsala University is constructing a large scale facility, called FREIA (Facility for Research Instrumentation and Accelerator Development). FREIA includes a helium liquefier and an accelerator test facility and has the capacity to test superconducting radio-frequency (RF) cavities with the same RF system and RF power level as in an accelerator. A central element of FREIA is a horizontal test cryostat connected in closed loop to a helium liquefier. This cryostat can house two fully equipped (tuners, piezo, power coupler, helium tank) superconducting cavities to perform full RF high power tests and operate at temperatures between 1.8 K and 4.2 K. The cryostat is designed to accommodate a large array of superconducting cavities and magnets, among which the European Spallation Source (ESS) type spoke and high-? elliptical cavities as well as TESLA/ILC type elliptical cavities. The present status of the project and the design of the cryostat are reported.

  3. A Survey of Pressure Vessel Code Compliance for Superconducting RF Cryomodules

    SciTech Connect (OSTI)

    Peterson, Thomas; Klebaner, Arkadiy; Nicol, Tom; Theilacker, Jay; /Fermilab; Hayano, Hitoshi; Kako, Eiji; Nakai, Hirotaka; Yamamoto, Akira; /KEK, Tsukuba; Jensch, Kay; Matheisen, Axel; /DESY; Mammosser, John; /Jefferson Lab

    2011-06-07

    Superconducting radio frequency (SRF) cavities made from niobium and cooled with liquid helium are becoming key components of many particle accelerators. The helium vessels surrounding the RF cavities, portions of the niobium cavities themselves, and also possibly the vacuum vessels containing these assemblies, generally fall under the scope of local and national pressure vessel codes. In the U.S., Department of Energy rules require national laboratories to follow national consensus pressure vessel standards or to show ''a level of safety greater than or equal to'' that of the applicable standard. Thus, while used for its superconducting properties, niobium ends up being treated as a low-temperature pressure vessel material. Niobium material is not a code listed material and therefore requires the designer to understand the mechanical properties for material used in each pressure vessel fabrication; compliance with pressure vessel codes therefore becomes a problem. This report summarizes the approaches that various institutions have taken in order to bring superconducting RF cryomodules into compliance with pressure vessel codes. In Japan, Germany, and the U.S., institutions building superconducting RF cavities integrated in helium vessels or procuring them from vendors have had to deal with pressure vessel requirements being applied to SRF vessels, including the niobium and niobium-titanium components of the vessels. While niobium is not an approved pressure vessel material, data from tests of material samples provide information to set allowable stresses. By means of procedures which include adherence to code welding procedures, maintaining material and fabrication records, and detailed analyses of peak stresses in the vessels, or treatment of the vacuum vessel as the pressure boundary, research laboratories around the world have found methods to demonstrate and document a level of safety equivalent to the applicable pressure vessel codes.

  4. Proc. of the workshop on pushing the limits of RF superconductivity.

    SciTech Connect (OSTI)

    Kim, K-J., Eyberger, C., editors

    2005-04-13

    For three days in late September last year, some sixty experts in RF superconductivity from around the world came together at Argonne to discuss how to push the limits of RF superconductivity for particle accelerators. It was an intense workshop with in-depth presentations and ample discussions. There was added excitement due to the fact that, a few days before the workshop, the International Technology Recommendation Panel had decided in favor of superconducting technology for the International Linear Collider (ILC), the next major high-energy physics accelerator project. Superconducting RF technology is also important for other large accelerator projects that are either imminent or under active discussion at this time, such as the Rare Isotope Accelerator (RIA) for nuclear physics, energy recovery linacs (ERLs), and x-ray free-electron lasers. For these accelerators, the capability in maximum accelerating gradient and/or the Q value is essential to limit the length and/or operating cost of the accelerators. The technological progress of superconducting accelerators during the past two decades has been truly remarkable, both in low-frequency structures for acceleration of protons and ions as well as in high-frequency structures for electrons. The requirements of future accelerators demand an even higher level of performance. The topics of this workshop are therefore highly relevant and timely. The presentations given at the workshop contained authoritative reviews of the current state of the art as well as some original materials that previously had not been widely circulated. We therefore felt strongly that these materials should be put together in the form of a workshop proceeding. The outcome is this report, which consists of two parts: first, a collection of the scholarly papers prepared by some of the participants and second, copies of the viewgraphs of all presentations. The presentation viewgraphs, in full color, are also available from the Workshop Presentations link on the workshop's web page at http://www.aps.anl.gov/conferences/RFSCLimits/. I would like to thank all of the participants for their lively contributions to the workshop and to these proceedings, and Helen Edwards and Hasan Padamsee for their help in developing the workshop program. I also thank Cathy Eyberger, Kelly Jaje, and Renee Lanham for working very hard to take care of the administrative details, in particular Cathy for editing this report.

  5. Status and Plans for a Superconducting RF Accelerator Test Facility at Fermilab

    SciTech Connect (OSTI)

    Leibfritz, J.; Andrews, R.; Baffes, C.M.; Carlson, K.; Chase, B.; Church, M.D.; Harms, E.R.; Klebaner, A.L.; Kucera, M.; Martinez, A.; Nagaitsev, S.; /Fermilab

    2012-05-01

    The Advanced Superconducting Test Accelerator (ASTA) is being constructed at Fermilab. The existing New Muon Lab (NML) building is being converted for this facility. The accelerator will consist of an electron gun, injector, beam acceleration section consisting of 3 TTF-type or ILC-type cryomodules, multiple downstream beam lines for testing diagnostics and conducting various beam tests, and a high power beam dump. When completed, it is envisioned that this facility will initially be capable of generating a 750 MeV electron beam with ILC beam intensity. An expansion of this facility was recently completed that will provide the capability to upgrade the accelerator to a total beam energy of 1.5 GeV. Two new buildings were also constructed adjacent to the ASTA facility to house a new cryogenic plant and multiple superconducting RF (SRF) cryomodule test stands. In addition to testing accelerator components, this facility will be used to test RF power systems, instrumentation, and control systems for future SRF accelerators such as the ILC and Project-X. This paper describes the current status and overall plans for this facility.

  6. Conceptual Design for Replacement of the DTL and CCL with Superconducting RF Cavities in the Spallation Neutron Source Linac

    SciTech Connect (OSTI)

    Champion, Mark S; Doleans, Marc; Kim, Sang-Ho

    2013-01-01

    The Spallation Neutron Source Linac utilizes normal conducting RF cavities in the low energy section from 2.5 MeV to 186 MeV. Six Drift Tube Linac (DTL) structures accelerate the beam to 87 MeV, and four Coupled Cavity Linac (CCL) structures provide further acceleration to 186 MeV. The remainder of the Linac is comprised of 81 superconducting cavities packaged in 23 cryomodules to provide final beam energy of approximately 1 GeV. The superconducting Linac has proven to be substantially more reliable than the normal conducting Linac despite the greater number of stations and the complexity associated with the cryogenic plant and distribution. A conceptual design has been initiated on a replacement of the DTL and CCL with superconducting RF cavities. The motivation, constraints, and conceptual design are presented.

  7. Cryogenic Test of a 750 MHz Superconducting RF Dipole Crabbing Cavity

    SciTech Connect (OSTI)

    Castilla, Alejandro [ODU; Delayen, Jean R. [ODU, JLAB; Park, HyeKyoung [JLAB

    2014-07-01

    A superconducting rf dipole cavity has been designed to address the challenges of a high repetition rate (750 MHz), high current for both electron/ion species (0.5/3 A per bunch), and large crossing angle (50 mrad) at the interaction points (IPs) crabbing system for the Medium Energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The cavity prototype built at Niowave, Inc. has been tested at the Jefferson Lab facilities. In this work we present a detailed analysis of the prototype cavity performance at 4 K and 2 K, corroborating the absence of hard multipacting barriers that could limit the desired transverse fields, along with the surface resistance (Rs) temperature dependency.

  8. Plasma processing of large curved surfaces for superconducting rf cavity modification

    SciTech Connect (OSTI)

    Upadhyay, J; Im, Do; Popovi??, S; Valente-Feliciano, A -M; Phillips, L; Vuskovic, L

    2014-12-01

    Plasma based surface modification of niobium is a promising alternative to wet etching of superconducting radio frequency (SRF) cavities. The development of the technology based on Cl2/Ar plasma etching has to address several crucial parameters which influence the etching rate and surface roughness, and eventually, determine cavity performance. This includes dependence of the process on the frequency of the RF generator, gas pressure, power level, the driven (inner) electrode configuration, and the chlorine concentration in the gas mixture during plasma processing. To demonstrate surface layer removal in the asymmetric non-planar geometry, we are using a simple cylindrical cavity with 8 ports symmetrically distributed over the cylinder. The ports are used for diagnosing the plasma parameters and as holders for the samples to be etched. The etching rate is highly correlated with the shape of the inner electrode, radio-frequency (RF) circuit elements, chlorine concentration in the Cl2/Ar gas mixtures, residence time of reactive species and temperature of the cavity. Using cylindrical electrodes with variable radius, large-surface ring-shaped samples and d.c. bias implementation in the external circuit we have demonstrated substantial average etching rates and outlined the possibility to optimize plasma properties with respect to maximum surface processing effect.

  9. Development of a CW Superconducting RF Booster Cryomodule for Future Light Sources

    SciTech Connect (OSTI)

    Grimm, Terry L; Bogle, Andrew; Deimling, Brian; Hollister, Jerry; II, Randall Jecks; Kolka, Ahren; Romel, Chandra

    2009-04-13

    Future light sources based on seeded free electron lasers (FEL) have the potential to increase the soft xray flux by several orders of magnitude with short bunch lengths to probe electron structure and dynamics. A low emittance, high rep-rate radio frequency (RF) photocathode electron gun will generate the electron beam that will require very stringent beam control and manipulation through the superconducting linear accelerator to maintain the high brightness required for an x-ray FEL. The initial or booster cavities of the superconducting radio frequency (SRF) linear accelerator will require stringent control of transverse kicks and higher order modes (HOM) during the beam manipulation and conditioning that is needed for emittance exchange and bunch compression. This SBIR proposal will develop, fabricate and test a continuous-wave SRF booster cryomodule specifically for this application. Phase I demonstrated the technical feasibility of the project by completing the preliminary SRF cavity and cryomodule design and its integration into an R&D test stand for beam studies at Lawrence Berkeley National Laboratory (LBNL). The five-cell bulk niobium cavities operate at 750 MHz, and generate 10 MV each with strong HOM damping and special care to eliminate transverse kicks due to couplers. Due to continuous-wave operation at fairly modest beam currents and accelerating gradients the complexity of the two cavity cryomodule is greatly reduced compared to an ILC type system. Phase II will finalize the design, and fabricate and test the booster cryomodule. The cryomodule consists of two five-cell cavities that will accelerate megahertz bunch trains with nano-coulomb charge. The accelerating gradient is a very modest 10 MV/m with peak surface fields of 20 MV/m and 42.6 mT. The cryogenic system operates at 2 K with a design dynamic load of 20 W and total required cryogenic capacity of 45 W. The average beam current of up to 1 mA corresponds to a beam power of 10 kW per 5- cell cavity and will require 20 kW of RF power for transmission, control and regulation. The RF power will be supplied by a commercial tetrode. Cryogenic tests will be carried out at LBNL to make use of their test facilities, cryogenics and laser systems, and for future use with beam. Demonstration of this new type of booster cryomodule will open many new applications of SRF linear accelerators.

  10. Mechanical design of 56 MHz superconducting RF cavity for RHIC collider

    SciTech Connect (OSTI)

    Pai, C.; Ben-Zvi, I.; Burrill, A.; Chang, X.; McIntyre, G.; Than, Y.; Tuozzolo, J.; Wu, Q.

    2011-03-28

    A 56 MHz Superconducting RF Cavity operating at 4.4K is being constructed for the RHIC collider. This cavity is a quarter wave resonator with beam transmission along the centerline. This cavity will increase collision luminosity by providing a large longitudinal bucket for stored bunches of RHIC ion beam. The major components of this assembly are the niobium cavity with the mechanical tuner, its titanium helium vessel and vacuum cryostat, the support system, and the ports for HOM and fundamental dampers. The cavity and its helium vessel must meet equivalent safety with the ASME pressure vessel code and it must not be sensitive to frequency shift due to pressure fluctuations from the helium supply system. Frequency tuning achieved by a two stage mechanical tuner is required to meet performance parameters. This tuner mechanism pushes and pulls the tuning plate in the gap of niobium cavity. The tuner mechanism has two separate drive systems to provide both coarse and fine tuning capabilities. This paper discusses the design detail and how the design requirements are met.

  11. INTEGRATED SYSTEMS NANOFABRICATION CLEANROOM NEW USER APPLICATION

    E-Print Network [OSTI]

    Jalali. Bahram

    INTEGRATED SYSTEMS NANOFABRICATION CLEANROOM NEW USER APPLICATION interest in using the CNSI Integrated Systems Nanofabrication Cleanroom (ISNC). We ask you to carefully

  12. Cold RF test and associated mechanical features correlation of a TESLA-style 9-cell superconducting niobium cavity built in China

    SciTech Connect (OSTI)

    Dai, Jing; Quan, Sheng-Wen; Zhang, Bao-Cheng; Lin, Lin; Hao, Jian-Kui; Zhu, Feng; Xu, Wen-Can; He, Fei-Si; Jin, Song; Wang, Fang; Liu, Ke-Xin; Geng, R L

    2012-02-01

    The RF performance of a 1.3 GHz 9-cell superconducting niobium cavity was evaluated at cryogenic temperatures following surface processing by using the standard ILC-style recipe. The cavity is a TESLA-style 9-cell superconducting niobium cavity, with complete end group components including a higher order mode coupler, built in China for practical applications. An accelerating gradient of 28.6 MV/m was achieved at an unloaded quality factor of 4 x 10{sup 9}. The morphological property of mechanical features on the RF surface of this cavity was characterized through optical inspection. Correlation between the observed mechanical features and the RF performance of the cavity is attempted.

  13. The Design of a Five-Cell Superconducting RF Module with a PBG Coupler Cell

    SciTech Connect (OSTI)

    Arsenyev, Sergey A [Los Alamos National Laboratory; Simakov, Evgenya I [Los Alamos National Laboratory

    2012-08-29

    We discuss the problem of incorporating a Photonic Band Gap (PBG) cell into a superconducting accelerating module of 5 cells designed for the operational frequency of 2.1 GHz. The reason for using a PBG cell is to provide a good accelerating mode confinement and good Higher Order Mode (HOM) suppression. PBG cell can potentially be used for placing HOM and fundamental mode couplers. However, because of the naturally higher ratio of the peak magnetic field to the accelerating field in the PBG cell, it should be designed to operate at a lower accelerating gradient than the other cells of the module. This ensures that the probability of quench in the PBG cell would be no higher than in other elliptical cells of the structure.

  14. DEPOSITION OF NIOBIUM AND OTHER SUPERCONDUCTING MATERIALS WITH HIGH POWER IMPULSE MAGNETRON SPUTTERING: CONCEPT AND FIRST RESULTS

    E-Print Network [OSTI]

    Anders, Andre

    2013-01-01

    Workshop on RF Superconductivity, DESY, Hamburg, Germany,Gennaro, Physica C: Superconductivity 441 (2006) 130. [10]the Limits of RF Superconductivity, Padua, Italy, 2010. [12

  15. Comparative Simulation Studies of Multipacting in Higher-Order-Mode Couplers of Superconducting RF Cavities

    SciTech Connect (OSTI)

    Li, Y. M. [Peking University, Beijing (China); Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Liu, Kexin [Peking University, Beijing (China); Geng, Rongli [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2014-02-01

    Multipacting (MP) in higher-order-mode (HOM) couplers of the International Linear Collider (ILC) baseline cavity and the Continuous Electron Beam Accelerator Facility (CEBAF) 12 GeV upgrade cavity is studied by using the ACE3P suites, developed by the Advanced Computations Department at SLAC. For the ILC cavity HOM coupler, the simulation results show that resonant trajectories exist in three zones, corresponding to an accelerating gradient range of 0.6?1.6 MV/m, 21?34 MV/m, 32?35 MV/m, and > 40MV/m, respectively. For the CEBAF 12 GeV upgrade cavity HOM coupler, resonant trajectories exist in one zone, corresponding to an accelerating gradient range of 6?13 MV/m. Potential implications of these MP barriers are discussed in the context of future high energy pulsed as well as medium energy continuous wave (CW) accelerators based on superconducting radio frequency cavities. Frequency scaling of MP?s predicted in HOM couplers of the ILC, CBEAF upgrade, SNS and FLASH third harmonic cavity is given and found to be in good agreement with the analytical result based on the parallel plate model.

  16. Population inversion induced by Landau--Zener transition in a strongly driven rf superconducting quantum interference device

    E-Print Network [OSTI]

    Sun, Guozhu; Wen, Xueda; Wang, Yiwen; Cong, Shanhua; Chen, Jian; Kang, Lin; Xu, Weiwei; Yu, Yang; Han, Siyuan; Wu, Peiheng

    2009-03-09

    Microwave resonances between discrete macroscopically distinct quantum states with single photon and multiphoton absorption are observed in a strongly driven radio frequency superconducting quantum interference device flux qubit. The amplitude...

  17. Nanofabrication

    DOE Patents [OSTI]

    Tuominen, Mark; Bal, Mustafa; Russell, Thomas P.; Ursache, Andrei

    2007-03-13

    Pathways to rapid and reliable fabrication of three-dimensional nanostructures are provided. Simple methods are described for the production of well-ordered, multilevel nanostructures. This is accomplished by patterning block copolymer templates with selective exposure to a radiation source. The resulting multi-scale lithographic template can be treated with post-fabrication steps to produce multilevel, three-dimensional, integrated nanoscale media, devices, and systems.

  18. Nanofabrication

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory ofDid you notHeatMaRIEdioxide capture CS SeminarsNREL Private AreaDOEFacility

  19. Advanced nanofabrication of thermal emission devices

    E-Print Network [OSTI]

    Hurley, Fergus (Fergus Gerard)

    2008-01-01

    Nanofabricated thermal emission devices can be used to modify and modulate blackbody thermal radiation. There are many areas in which altering thermal radiation is extremely useful, especially in static power conversion, ...

  20. Micro/nanofabricated environments for synthetic biology

    SciTech Connect (OSTI)

    Collier, Pat [ORNL; Simpson, Michael L [ORNL

    2011-01-01

    A better understanding of how confinement, crowding and reduced dimensionality modulate reactivity and reaction dynamics will aid in the rational and systematic discovery of functionality in complex biological systems. Artificial micro- and nanofabricated structures have helped elucidate the effects of nanoscale spatial confinement and segregation on biological behavior, particularly when integrated with microfluidics, through precise control in both space and time of diffusible signals and binding interactions. Examples of nanostructured interfaces for synthetic biology include the development of cell-like compartments for encapsulating biochemical reactions, nanostructured environments for fundamental studies of diffusion, molecular transport and biochemical reaction kinetics, and regulation of biomolecular interactions as functions of micro- and nanofabricated topological constraints.

  1. 986 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 13, NO. 2, JUNE 2003 Effects of Pulse Shape on rf SQUID Quantum Gates

    E-Print Network [OSTI]

    Chu, Shih-I

    986 IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 13, NO. 2, JUNE 2003 Effects of Pulse for conventional computers. Among the many approaches, building quantum computers with the use of superconducting up. Furthermore, superconducting qubits can be driven by pulsed microwaves to perform various 1-bit

  2. Superconducting microfabricated ion traps

    E-Print Network [OSTI]

    Shannon X. Wang; Yufei Ge; Jaroslaw Labaziewicz; Eric Dauler; Karl Berggren; Isaac L. Chuang

    2010-12-14

    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.

  3. Nanofabrication & Devices | Argonne National Laboratory

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines lightGeospatialDevelopment of09SponsorNanobioPortalNanofabrication

  4. Nanofabrication on unconventional substrates using transferred hard masks

    E-Print Network [OSTI]

    Li, Luozhou

    A major challenge in nanofabrication is to pattern unconventional substrates that cannot be processed for a variety of reasons, such as incompatibility with spin coating, electron beam lithography, optical lithography, or ...

  5. Bilayer membrane interactions with nanofabricated scaffolds

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

    Collier, Patrick C.

    2015-07-29

    Membrane function is facilitated by lateral organization within the lipid bilayer, including phase-separation of lipids into more ordered domains (lipid rafts) and anchoring of the membrane to a cytoskeleton. These features have proven difficult to reproduce in model membrane systems such as black lipid membranes, unilamellar vesicles and supported bilayers. However, advances in micro/nanofabrication have resulted in more realistic synthetic models of membrane-cytoskeleton interactions that can help uncover the design rules responsible for biological membrane formation and organization. This review will focus on describing micro-/nanostructured scaffolds that can emulate the connections of a cellular membrane to an underlying “cytoskeleton”. Thismore »includes molecular-based scaffolds anchored to a solid substrate through surface chemistry, solid-state supports modified by material deposition, lithography and etching, the creation of micro/nanoporous arrays, integration with microfluidics, and droplet-based bilayers at interfaces.Model systems such as these are increasing our understanding of structure and organization in cell membranes, and how they result in the emergence of functionality at the nanoscale.« less

  6. WAFER TEST CAVITY -Linking Surface Microstructure to RF Performance: a ‘Short-­?Sample Test Facility’ for characterizing superconducting materials for SRF cavities.

    SciTech Connect (OSTI)

    Pogue, Nathaniel; Comeaux, Justin; McIntyre, Peter

    2014-05-30

    The Wafer Test cavity was designed to create a short sample test system to determine the properties of the superconducting materials and S?I?S hetero?structures. The project, funded by ARRA, was successful in accomplishing several goals to achieving a high gradient test system for SRF research and development. The project led to the design and construction of the two unique cavities that each severed unique purposes: the Wafer test Cavity and the Sapphire Test cavity. The Sapphire Cavity was constructed first to determine the properties of large single crystal sapphires in an SRF environment. The data obtained from the cavity greatly altered the design of the Wafer Cavity and provided the necessary information to ascertain the Wafer Test cavity’s performance.

  7. Longitudinal beam dynamics with rf noise

    SciTech Connect (OSTI)

    Shih, H.J.; Ellison, J.A.; Cogburn, R.; Newberger, B.S.

    1993-06-01

    The Dome-Krinsky-Wang (DKW) diffusion-inaction theory for rf-noise-induced emittance dilution is reviewed and related to recent work on the approximation of stochastic processes by Markov processes. An accurate and efficient numerical procedure is developed to integrate the diffusion equation of the DKW theory. Tracking simulations are undertaken to check the validity of the theory in the parameter range of the Superconducting Super Collider (SSC) and to provide additional information. The study of effects of rf noise is applied to two problems of interest at the SSC: (1) determination of noise tolerance levels in the rf system, and (2) feasibility of beam extraction using crystal channeling.

  8. Upgrade of the cryogenic CERN RF test facility

    SciTech Connect (OSTI)

    Pirotte, O.; Benda, V.; Brunner, O.; Inglese, V.; Maesen, P.; Vullierme, B.; Koettig, T.

    2014-01-29

    With the large number of superconducting radiofrequency (RF) cryomodules to be tested for the former LEP and the present LHC accelerator a RF test facility was erected early in the 1990’s in the largest cryogenic test facility at CERN located at Point 18. This facility consisted of four vertical test stands for single cavities and originally one and then two horizontal test benches for RF cryomodules operating at 4.5 K in saturated helium. CERN is presently working on the upgrade of its accelerator infrastructure, which requires new superconducting cavities operating below 2 K in saturated superfluid helium. Consequently, the RF test facility has been renewed in order to allow efficient cavity and cryomodule tests in superfluid helium and to improve its thermal performances. The new RF test facility is described and its performances are presented.

  9. The LHC Low Level RF

    E-Print Network [OSTI]

    Baudrenghien, Philippe; Molendijk, John Cornelis; Olsen, Ragnar; Rohlev, Anton; Rossi, Vittorio; Stellfeld, Donat; Valuch, Daniel; Wehrle, Urs

    2006-01-01

    The LHC RF consists of eight 400 MHz superconducting cavities per ring, with each cavity independently powered by a 300 kW klystron, via a circulator. The challenge for the Low Level is to cope with very high beam current (more than 1 A RF component) and achieve excellent beam lifetime (emittance growth time in excess of 25 hours). Each cavity has an associated Cavity Controller rack consisting of two VME crates which implement high gain RF Feedback, a Tuner Loop with a new algorithm, a Klystron Ripple Loop and a Conditioning system. In addition each ring has a Beam Control system (four VME crates) which includes a Frequency Program, Phase Loop, Radial Loop and Synchronization Loop. A Longitudinal Damper (dipole and quadrupole mode) acting via the 400 MHz cavities is included to reduce emittance blow-up due to filamentation from phase and energy errors at injection. Finally an RF Synchronization system implements the bunch into bucket transfer from the SPS into each LHC ring. When fully installed in 2007, the...

  10. Superconducting Spintronics

    E-Print Network [OSTI]

    Linder, Jacob; Robinson, Jason W. A.

    2015-04-02

    device functionality. Traditional studies which combine spintronics and superconductivity have mainly focused on the injection of spin-polarized quasiparticles into superconducting materials. However, a complete synergy between superconducting...

  11. Fundamental Research in Superconducting RF Cavity Design

    SciTech Connect (OSTI)

    Georg Hoffstaetter

    2012-11-13

    This is a 3-year SRF R&D proposal with two main goals: 1) to benefit near term high gradient SRF applications by understanding the causes of quench at high fields in present-day niobium cavities 2) to open the long-range prospects for SRF applications by experimentally verifying the recent exciting theoretical predication for new cavity materials such as Nb3Sn and MgB2. These predictions shwo that ultimately gradients of 100Mv/m to 200MV/m may become possible as material imperfections are overcome.

  12. Superconducting RF, the History, Challenges and Promise

    ScienceCinema (OSTI)

    Hasan Padamsee

    2010-01-08

    After a short survey of on-going accelerator applications, I will discuss future applications prospects for this enabling technology, both near term and long term. A selection of technology highlights will serve as an introduction to outstanding issues for all types of applications, from pulsed high gradient to CW medium gradient. Finally I will touch upon the limits of niobium and the prospects of new materials. The talk will be targeted at a general audience.

  13. SUPERCONDUCTING DEVICES

    E-Print Network [OSTI]

    Clarke, John

    2014-01-01

    communications. References Superconductor Applications: ~on all aspects of superconducting devices. IEEE Trans.on all aspects vf superconducting devices. The IBM Journal

  14. TESLA-FEL Report 2005-06 DIGITAL LOW LEVEL RF CONTROL SYSTEM FOR THE DESY TTF

    E-Print Network [OSTI]

    TESLA-FEL Report 2005-06 DIGITAL LOW LEVEL RF CONTROL SYSTEM FOR THE DESY TTF VUV-FEL LINAC Valeri Electron Laser (VUV-FEL) Linac each klystron supplies RF power to up to 32 cavities. The superconducting. The VUV-FEL Linac RF control system employs a completely digital feedback system to provide flexibility

  15. Chip-Scale Nanofabrication of Single Spins and Spin Arrays in Diamond

    SciTech Connect (OSTI)

    Toyli, David M.; Weis, Christoph D.; Fuchs, D.; Schenkel, Thomas; Awschalom, David D.

    2010-07-02

    We demonstrate a technique to nanofabricate nitrogen vacancy (NV) centers in diamond based on broad-beam nitrogen implantation through apertures in electron beam lithography resist. This method enables high-throughput nanofabrication of single NV centers on sub-100-nm length scales. Secondary ion mass spectroscopy measurements facilitate depth profiling of the implanted nitrogen to provide three-dimensional characterization of the NV center spatial distribution. Measurements of NV center coherence with on-chip coplanar waveguides suggest a pathway for incorporating this scalable nanofabrication technique in future quantum applications.

  16. Recycler barrier RF buckets

    SciTech Connect (OSTI)

    Bhat, C.M.; /Fermilab

    2011-03-01

    The Recycler Ring at Fermilab uses a barrier rf systems for all of its rf manipulations. In this paper, I will give an overview of historical perspective on barrier rf system, the longitudinal beam dynamics issues, aspects of rf linearization to produce long flat bunches and methods used for emittance measurements of the beam in the RR barrier rf buckets. Current rf manipulation schemes used for antiproton beam stacking and longitudinal momentum mining of the RR beam for the Tevatron collider operation are explained along with their importance in spectacular success of the Tevatron luminosity performance.

  17. Beam dynamics studies for transverse electromagnetic mode type rf deflectors

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

    Ahmed, Shahid; Krafft, Geoffrey A.; Deitrick, Kirsten; De Silva, Subashini U.; Delayen, Jean R.; Spata, Mike; Tiefenback, Michael; Hofler, Alicia; Beard, Kevin

    2012-02-01

    We have performed three-dimensional simulations of beam dynamics for transverse electromagnetic mode (TEM) type rf deflectors: normal and superconducting. The compact size of these cavities as compared to the conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a single cell superconducting structure is enough to produce the required vertical displacement at the target point. Both the normal and superconducting structures show very small emittance dilution due to the verticalmore »kick of the beam.« less

  18. Beam dynamics studies for transverse electromagnetic mode type rf deflectors

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

    Ahmed, Shahid; Krafft, Geoffrey A.; Deitrick, Kirsten; De Silva, Subashini U.; Delayen, Jean R.; Spata, Mike; Tiefenback, Michael; Hofler, Alicia; Beard, Kevin

    2012-02-01

    We have performed three-dimensional simulations of beam dynamics for transverse electromagnetic mode (TEM) type rf deflectors: normal and superconducting. The compact size of these cavities as compared to the conventional TM110 type structures is more attractive particularly at low frequency. Highly concentrated electromagnetic fields between the parallel bars provide strong electrical stability to the beam for any mechanical disturbance. An array of six 2-cell normal conducting cavities or a single cell superconducting structure is enough to produce the required vertical displacement at the target point. Both the normal and superconducting structures show very small emittance dilution due to the vertical kick of the beam.

  19. RF power recovery feedback circulator

    DOE Patents [OSTI]

    Sharamentov, Sergey I. (Bolingbrook, IL)

    2011-03-29

    A device and method for improving the efficiency of RF systems having a Reflective Load. In the preferred embodiment, Reflected Energy from a superconducting resonator of a particle accelerator is reintroduced to the resonator after the phase of the Reflected Energy is aligned with the phase of the Supply Energy from a RF Energy Source. In one embodiment, a Circulator is used to transfer Reflected Energy from the Reflective Load into a Phase Adjuster which aligns the phase of the Reflected Energy with that of the Supply Energy. The phase-aligned energy is then combined with the Supply Energy, and reintroduced into the Reflective Load. In systems having a constant phase shift, the Phase Adjuster may be designed to shift the phase of the Reflected Energy by a constant amount using a Phase Shifter. In systems having a variety (variable) phase shifts, a Phase Shifter controlled by a phase feedback loop comprising a Phase Detector and a Feedback Controller to account for the various phase shifts is preferable.

  20. RF Power Generation in LHC

    E-Print Network [OSTI]

    Brunner, O C; Valuch, D

    2003-01-01

    The counter-rotating proton beams in the Large Hadron Collider (LHC) will be captured and then accelerated to their final energies of 2 x 7 TeV by two identical 400 MHz RF systems. The RF power source required for each beam comprises eight 300 kW klystrons. The output power of each klystron is fed via a circulator and a waveguide line to the input coupler of a single-cell super-conducting (SC) cavity. Four klystrons are powered by a 100 kV, 40A AC/DC power converter, previously used for the operation of the LEP klystrons. A five-gap thyratron crowbar protects the four klystrons in each of these units. The technical specification and measured performance of the various high-power elements are discussed. These include the 400MHz/300kW klystrons with emphasis on their group delay and the three-port circulators, which have to cope with peak reflected power levels up to twice the simultaneously applied incident power of 300 kW. In addition, a novel ferrite loaded waveguide absorber, used as termination for port No...

  1. High power RF systems for the BNL ERL project

    SciTech Connect (OSTI)

    Zaltsman, A.; Lambiase, R.

    2011-03-28

    The Energy Recovery Linac (ERL) project, now under construction at Brookhaven National Laboratory, requires two high power RF systems. The first RF system is for the 703.75 MHz superconducting electron gun. The RF power from this system is used to drive nearly half an Ampere of beam current to 2 MeV. There is no provision to recover any of this energy so the minimum amplifier power is 1 MW. It consists of 1 MW CW klystron, transmitter and power supplies, 1 MW circulator, 1 MW dummy load and a two-way power splitter. The second RF system is for the 703.75 MHz superconducting cavity. The system accelerates the beam to 54.7 MeV and recovers this energy. It will provide up to 50 kW of CW RF power to the cavity. It consists of 50 kW transmitter, circulator, and dummy load. This paper describes the two high power RF systems and presents the test data for both.

  2. Rf Feedback free electron laser

    DOE Patents [OSTI]

    Brau, Charles A. (Los Alamos, NM); Swenson, Donald A. (Los Alamos, NM); Boyd, Jr., Thomas J. (Los Alamos, NM)

    1981-01-01

    A free electron laser system and electron beam system for a free electron laser which use rf feedback to enhance efficiency. Rf energy is extracted from an electron beam by decelerating cavities and returned to accelerating cavities using rf returns such as rf waveguides, rf feedthroughs, etc. This rf energy is added to rf klystron energy to lower the required input energy and thereby enhance energy efficiency of the system.

  3. Superconducting Cable

    DOE Patents [OSTI]

    Hughey, Raburn L. (Franklin, GA); Sinha, Uday K. (Carrollton, GA); Reece, David S. (Carrollton, GA); Muller, Albert C. (Eidson, TN)

    2005-03-08

    In order to provide a flexible oxide superconducting cable which is reduced in AC loss, tape-shaped superconducting wires covered with a stabilizing metal are wound on a flexible former. The superconducting wires are preferably laid on the former at a bending strain of not more than 0.2%. In laying on the former, a number of tape-shaped superconducting wires are laid on a core member in a side-by-side manner, to form a first layer. A prescribed number of tape-shaped superconducting wires are laid on top of the first layer in a side-by-side manner, to form a second layer. The former may be made of a metal, plastic, reinforced plastic, polymer, or a composite and provides flexibility to the superconducting wires and the cable formed therewith.

  4. Superconducting Cable

    DOE Patents [OSTI]

    Hughey, Raburn L. (Franklin, GA); Sinha, Uday K. (Carrollton, GA); Reece, David S. (Carrollton, GA); Muller, Albert C. (Eidson, TN)

    2005-07-22

    In order to provide a flexible oxide superconducting cable which is reduced in AC loss, tape-shaped superconducting wires covered with a stabilizing metal are wound on a flexible former. The superconducting wires are preferably laid on the former at a bending strain of not more than 0.2%. In laying on the former, a number of tape-shaped superconducting wires are laid on a core member in a side-by-side manner, to form a first layer. A prescribed number of tape-shaped superconducting wires are laid on top of the first layer in a side-by-side manner, to form a second layer. The former may be made of a metal, plastic, reinforced plastic, polymer, or a composite and provides flexibility to the superconducting wires and the cable formed therewith.

  5. The superconducting solenoid magnets for MICE

    SciTech Connect (OSTI)

    Green, Michael A.

    2002-12-22

    The Muon Ionization Cooling Experiment (MICE) is a channel of superconducting solenoid magnets. The magnets in MICE are around the RF cavities, absorbers (liquid or solid) and the primary particle detectors [1], [2]. The MICE superconducting solenoid system consists of eighteen coils that are grouped in three types of magnet assemblies. The cooling channel consists of two complete cell of an SFOFO cooling channel. Each cell consists of a focusing coil pair around an absorber and a coupling coil around a RF cavity that re-accelerates the muons to their original momentum. At the ends of the experiment are uniform field solenoids for the particle detectors and a set of matching coils used to match the muon beam to the cooling cells. Three absorbers are used instead of two in order to shield the detectors from dark currents generated by the RF cavities at high operating acceleration gradients.

  6. Superconducting structure

    DOE Patents [OSTI]

    Kwon, Chuhee (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM)

    2003-04-01

    A superconductive structure including a dielectric oxide substrate, a thin buffer layer of a superconducting material thereon; and, a layer of a rare earth-barium-copper oxide superconducting film thereon the thin layer of yttrium-barium-copper oxide, the rare earth selected from the group consisting of samarium, gadolinium, ytterbium, erbium, neodymium, dysprosium, holmium, lutetium, a combination of more than one element from the rare earth group and a combination of one or more elements from the rare earth group with yttrium, the buffer layer of superconducting material characterized as having chemical and structural compatibility with the dielectric oxide substrate and the rare earth-barium-copper oxide superconducting film is provided.

  7. Superconducting Structure

    DOE Patents [OSTI]

    Kwon, Chuhee (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM)

    2005-09-13

    A superconductive structure including a dielectric oxide substrate, a thin buffer layer of a superconducting material thereon; and, a layer of a rare earth-barium-copper oxide superconducting film thereon the thin layer of yttrium-barium-copper oxide, the rare earth selected from the group consisting of samarium, gadolinium, ytterbium, erbium, neodymium, dysprosium, holmium, lutetium, a combination of more than one element from the rare earth group and a combination of one or more elements from the rare earth group with yttrium, the buffer layer of superconducting material characterized as having chemical and structural compatibility with the dielectric oxide substrate and the rare earth-barium-copper oxide superconducting film is provided.

  8. Deposition and atomic force microscopy of individual phthalocyanine polymers between nanofabricated electrodes

    E-Print Network [OSTI]

    Dekker, Cees

    Deposition and atomic force microscopy of individual phthalocyanine polymers between nanofabricated of cellulose using the Langmuir­Blodgett deposition technique. Atomic force microscopy was used to study- layer of an insulating molecule.6 We show that this method leads to a controlled deposition and strong

  9. High Power RF Test Facility at the SNS

    SciTech Connect (OSTI)

    Y.W. Kang; D.E. Anderson; I.E. Campisi; M. Champion; M.T. Crofford; R.E. Fuja; P.A. Gurd; S. Hasan; K.-U. Kasemir; M.P. McCarthy; D. Stout; J.Y. Tang; A.V. Vassioutchenko; M. Wezensky; G.K. Davis; M. A. Drury; T. Powers; M. Stirbet

    2005-05-16

    RF Test Facility has been completed in the SNS project at ORNL to support test and conditioning operation of RF subsystems and components. The system consists of two transmitters for two klystrons powered by a common high voltage pulsed converter modulator that can provide power to two independent RF systems. The waveguides are configured with WR2100 and WR1150 sizes for presently used frequencies: 402.5 MHz and 805 MHz. Both 402.5 MHz and 805 MHz systems have circulator protected klystrons that can be powered by the modulator capable of delivering 11 MW peak and 1 MW average power. The facility has been equipped with computer control for various RF processing and complete dual frequency operation. More than forty 805 MHz fundamental power couplers for the SNS superconducting linac (SCL) cavities have been RF conditioned in this facility. The facility provides more than 1000 ft2 floor area for various test setups. The facility also has a shielded cave area that can support high power tests of normal conducting and superconducting accelerating cavities and components.

  10. SUPERCONDUCTING MAGNETIC ENERGY STORAGE

    E-Print Network [OSTI]

    Hassenzahl, W.

    2011-01-01

    and R. W . BOOIll, "Superconductive Energy Storage Inducand H. A. Peterson, "Superconductive E nergy S torage forMeeting, Janua ry N. Mohan, "Superconductive Energy S torage

  11. Superconducting phase qubits

    E-Print Network [OSTI]

    Martinis, John M.

    2009-01-01

    frequency noise in dc superconducting quantum interfer- enceeld enhancement of superconductivity in ultranarrow wires.Transformed dissipation in superconducting quantum circuits.

  12. Superconductivity for Electric Systems

    E-Print Network [OSTI]

    Superconductivity Program Oak Ridge National Laboratory For: Department of Energy Office of Electricity Delivery and Energy Reliability ­ Superconductivity for Electric Systems #12;3 Control Milestones and Status ControlSuperconductivity for Electric Systems Superconductivity Program Quarterly Progress Report

  13. Shielded RF Lattice Chris Rogers,

    E-Print Network [OSTI]

    McDonald, Kirk

    Shielded RF Lattice Chris Rogers, Accelerator Science and Technology Centre (ASTeC), Rutherford Appleton Laboratory #12;Shielded RF Status Shielded RF Lattice was developed until ~ April 2010 April make the same decision for RDR Time to dust the design off #12;Shielded RF - Reminder Increase cell

  14. Assessment of Alternative RF Linac Structures for APT

    SciTech Connect (OSTI)

    1997-03-26

    The APT program has been examining both normal and superconducting variants of the APT linac for the past two years. A decision on which of the two will be the selected technology will depend upon several considerations including the results of ongoing feasibility experiments, the performance and overall attractiveness of each of the design concepts, and an assessment of the system-level features of both alternatives. The primary objective of the Assessment of Alternative RF Linac Structures for APT study reported herein was to assess and compare, at the system-level, the performance, capital and life cycle costs, reliability/availability/maintainability (RAM) and manufacturing schedules of APT RF linear accelerators based upon both superconducting and normal conducting technologies. A secondary objective was to perform trade studies to explore opportunities for system optimization, technology substitution and alternative growth pathways and to identify sensitivities to design uncertainties.

  15. Comparison of electromagnetic, thermal and mechanical calculations with rf test results in rf-dipole deflecting/crabbing cavities

    SciTech Connect (OSTI)

    Park, HyeKyoung [JLAB, ODU; De Silva, Subashini U. [ODU; Delayen, Jean R. [ODU, JLAB

    2013-12-01

    The current requirements of higher gradients and strict dimensional constraints in the emerging applications have required the designing of compact deflecting and crabbing rf structures. The superconducting rf-dipole cavity is one of the first novel compact designs with attractive properties such as higher gradients, higher shunt impedance and widely separated higher order modes. The recent tests performed on proof-of-principle designs of the rf-dipole geometry at 4.2 K and 2.0 K in the vertical test area at Jefferson Lab have proven the designs to achieve higher gradients with higher intrinsic quality factors and easily processed multipacting conditions. The cavity characteristics, such as pressure sensitivity and Lorentz force detuning, were studied using ANSYS before the fabrication. These characteristics were measured during the cavity test. The comparison between the simulation and the measurement provides insight how the simulation can be used for design and fabrication of future cavities.

  16. Rf2a and rf2b transcription factors

    DOE Patents [OSTI]

    Beachy, Roger N. (St. Louis, MO); Petruccelli, Silvana (La Plata, AR); Dai, Shunhong (St. Louis, MO)

    2007-10-02

    A method of activating the rice tungro bacilliform virus (RTBV) promoter in vivo is disclosed. The RTBV promoter is activated by exposure to at least one protein selected from the group consisting of Rf2a and Rf2b.

  17. Superconducting magnets

    SciTech Connect (OSTI)

    Not Available

    1994-08-01

    This report discusses the following topics on superconducting magnets: D19B and -C: The next steps for a record-setting magnet; D20: The push beyond 10 T: Beyond D20: Speculations on the 16-T regime; other advanced magnets for accelerators; spinoff applications; APC materials development; cable and cabling-machine development; and high-{Tc} superconductor at low temperature.

  18. Nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging

    DOE Patents [OSTI]

    Fukushima, Eiichi (Los Alamos, NM); Roeder, Stephen B. W. (La Mesa, CA); Assink, Roger A. (Albuquerque, NM); Gibson, Atholl A. V. (Bryan, TX)

    1986-01-01

    An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio-frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

  19. RF test bench automation Description

    E-Print Network [OSTI]

    Dobigeon, Nicolas

    RF test bench automation Description: Callisto would like to implement automated RF test bench. Three RF test benches have to be studied and automated: LNA noise temperature test bench LNA gain phase of the test benches and an implementation of the automation phase. Tasks: Noise temperature

  20. Highly efficient electron vortex beams generated by nanofabricated phase holograms Vincenzo Grillo, Gian Carlo Gazzadi, Ebrahim Karimi, Erfan Mafakheri, Robert W. Boyd, and Stefano Frabboni

    E-Print Network [OSTI]

    Boyd, Robert W.

    Highly efficient electron vortex beams generated by nanofabricated phase holograms Vincenzo Grillo membranes using electron-beam lithography J. Vac. Sci. Technol. B 31, 06F402 (2013); 10.1063/1.4810917 Ion and electron beam nanofabrication of the which-way double-slit experiment in a transmission

  1. (Final Draft) Superconducting

    E-Print Network [OSTI]

    ANDAND (Final Draft) Achieving Advanced Electrical Wires From Superconducting Coatings Prepared and Development Roadmap to Achieve Electrical Wire Advancements from Superconducting Coatings (Final Draft) Edited

  2. SUPERCONDUCTING MAGNETIC ENERGY STORAGE

    E-Print Network [OSTI]

    Hassenzahl, W.

    2011-01-01

    Superconducting 30-MJ Energy Storage Coil", Proc. 19 80 ASC,Superconducting Magnetic Energy Storage Plant", IEEE Trans.SlIperconducting Magnetic Energy Storage Unit", in Advances

  3. Model for biological communication in a nanofabricated cell-mimic driven by stochastic resonance

    SciTech Connect (OSTI)

    Karig, David K [ORNL; Siuti, Piro [ORNL; Dar, Roy D. [University of Tennessee, Knoxville (UTK); Retterer, Scott T [ORNL; Doktycz, Mitchel John [ORNL; Simpson, Michael L [ORNL

    2011-01-01

    Cells offer natural examples of highly efficient networks of nanomachines. Accordingly, both intracellular and intercellular communication mechanisms in nature are looked to as a source of inspiration and instruction for engineered nanocommunication. Harnessing biological functionality in this manner requires an interdisciplinary approach that integrates systems biology, synthetic biology, and nanofabrication. Recent years have seen the amassing of a tremendous wealth of data from the sequencing of new organisms and from high throughput expression experiments. At the same time, a deeper fundamental understanding of individual cell function has been developed, as exemplified by the growth of fields such as noise biology, which seeks to characterize the role of noise in gene expression. The availability of well characterized biological components coupled with a deeper understanding of cell function has led to efforts to engineer both living cells and to create bio-like functionality in non-living substrates in the field of synthetic biology. Here, we present a model system that exemplifies the synergism between these realms of research. We propose a synthetic gene network for operation in a nanofabricated cell mimic array that propagates a biomolecular signal over long distances using the phenomenon of stochastic resonance. Our system consists of a bacterial quorum sensing signal molecule, a bistable genetic switch triggered by this signal, and an array of nanofabricated cell mimic wells that contain the genetic system. An optimal level of noise in the system helps to propagate a time-varying AHL signal over long distances through the array of mimics. This noise level is determined both by the system volume and by the parameters of the genetic network. Our proposed genetically driven stochastic resonance system serves as a testbed for exploring the potential harnessing of gene expression noise to aid in the transmission of a time-varying molecular signal.

  4. Racetrack microtron rf system

    SciTech Connect (OSTI)

    Tallerico, P.J.; Keffeler, D.R.

    1985-01-01

    The rf system for the National Bureau of Standards (NBS)/Los Alamos cw racetrack microtron is described. The low-power portion consists of five 75-W amplifers that drive two input ports in each of two chopper deflection cavities and one port in the prebuncher cavity. A single 500-kW klystron drives four separate 2380-MHz cavity sections: the two main accelerator sections, a capture section, and a preaccelerator section. The phases and amplitudes in all cavities are controlled by electronic or electromechanical controls. The 1-MW klystron power supply and crowbar system were purchased as a unit; several modifications are described that improve power-supply performance. The entire rf system has been tested and shipped to the NBS, and the chopper-buncher system has been operated with beam at the NBS. 5 refs., 2 figs.

  5. Superconducting wires

    SciTech Connect (OSTI)

    Lanagan, M.T.; Poeppel, R.B.; Singh, J.P.; Dos Santos, D.I.; Lumpp, J.K.; Dusek, J.T.; Goretta, K.C.

    1988-06-01

    The requirement of high critical current density has prompted extensive research on ceramic processing of high-T/sub c/ superconductors. An overview of wire fabrication techniques and the limitations they impose on component design will be presented. The effects of processing on microstructure and critical current density will also be discussed. Particle alignment has been observed in extruded samples which is attributed to high shear stresses during plastic forming. Composites of superconductor and silver in several configurations have been made with little deleterious effect on the superconducting properties. 35 refs., 2 figs., 1 tab.

  6. Superconductivity for Electric Systems

    E-Print Network [OSTI]

    1 Superconductivity for Electric Systems Superconductivity Program Quarterly Progress Report For the Period October 1, 2006, to December 31, 2006 #12;2 Superconductivity Program Quarterly Progress Report Superconductivity Program Oak Ridge National Laboratory For U.S. Department of Energy Office of Electricity Delivery

  7. Superconductivity for Electric Systems

    E-Print Network [OSTI]

    Superconductivity for Electric Systems Superconductivity Program Quarterly Progress Report For the Period April 1, 2007, to June 30, 2007 #12;2 Superconductivity Program Quarterly Progress Report Superconductivity Program Oak Ridge National Laboratory For: Department of Energy Office of Electricity Delivery

  8. LANL ACTIVITIES IN THE FIELD OF RF SUPERCONDUCTIVITY.

    SciTech Connect (OSTI)

    Tajima, Tsuyoshi; Jason, Andy; Kelley, Patrick J.; Krawczyk, Frank L.; Liu, Jianfei; Schrage, Dale L.; Shapiro, Alan H.; Findikoglu, Alp T.; Peterson,, Dean E.

    2003-07-29

    This report briefly summarizes activities, including: tests of elliptical cavities; design and testing of high-power couplers and cryomodules; design, procurement, and tests of 2-gap spoke cavities. It also summarizes critical technology issues.

  9. Fiber Optic Based Thermometry System for Superconducting RF Cavities

    SciTech Connect (OSTI)

    Dr. Kochergin, Vladimir [Microxact Inc.] [Microxact Inc.

    2013-05-06

    Thermometry is recognized as the best technique to identify and characterize losses in SRF cavities. The most widely used and reliable apparatus for temperature mapping at cryogenic temperatures is based on carbon resistors (RTDs). The use of this technology on multi-cell cavities is inconvenient due to the very large number of sensors required to obtain sufficient spatial resolution. Recent developments make feasible the use of multiplexible fiber optic sensors for highly distributed temperature measurements. However, sensitivity of multiplexible cryogenic temperature sensors was found extending only to 12K at best and thus was not sufficient for SRF cavity thermometry. During the course of the project the team of MicroXact, JLab and Virginia Tech developed and demonstrated the multiplexible fiber optic sensor with adequate response below 20K. The demonstrated temperature resolution is by at least a factor of 60 better than that of the best multiplexible fiber optic temperature sensors reported to date. The clear path toward at least 10times better temperature resolution is shown. The first to date temperature distribution measurements with ~2.5mm spatial resolution was done with fiber optic sensors at 2K to4K temperatures. The repeatability and accuracy of the sensors were verified only at 183K, but at this temperature both parameters significantly exceeded the state of the art. The results of this work are expected to find a wide range of applications, since the results are enabling the whole new testing capabilities, not accessible before.

  10. Superfluid helium cryogenic systems for superconducting RF cavities at KEK

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback System inStatusand carbon(Journal Article) | SciTech

  11. Ion source with external RF antenna

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Ji, Qing; Wilde, Stephen

    2005-12-13

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source.

  12. QUENCHES IN LARGE SUPERCONDUCTING MAGNETS

    E-Print Network [OSTI]

    Eberhard, P.H.

    2010-01-01

    QUENCHES IN LARGE SUPERCONDUCTING MAGNETS. P. H. Eberhard,Study of an Unprotected Superconducting Coil Going Normal,"Method for Testing Superconducting Magnets," LBL Physics

  13. RF power generation

    E-Print Network [OSTI]

    Carter, R G

    2011-01-01

    This paper reviews the main types of r.f. power amplifiers which are, or may be, used for particle accelerators. It covers solid-state devices, tetrodes, inductive output tubes, klystrons, magnetrons, and gyrotrons with power outputs greater than 10 kW c.w. or 100 kW pulsed at frequencies from 50 MHz to 30 GHz. Factors affecting the satisfactory operation of amplifiers include cooling, matching and protection circuits are discussed. The paper concludes with a summary of the state of the art for the different technologies.

  14. A New First-Principles Calculation of Field-Dependent RF Surface Impedance of BCS Superconductor

    SciTech Connect (OSTI)

    Xiao, Binping; Reece, Charles E.

    2014-02-01

    There is a need to understand the intrinsic limit of radiofrequency (RF) surface impedance that determines the performance of superconducting RF cavities in particle accelerators. Here we present a field-dependent derivation of Mattis-Bardeen theory of the RF surface impedance of BCS superconductors based on the shifted density of states resulting from coherently moving Cooper pairs. Our theoretical prediction of the effective BCS RF surface resistance (Rs) of niobium as a function of peak surface magnetic field amplitude agrees well with recently reported record low loss resonant cavity measurements from JLab and FNAL with carefully, yet differently, prepared niobium material. The surprising reduction in resistance with increasing field is explained to be an intrinsic effect.

  15. A photocathode rf gun design for a mm-wave linac-based FEL

    SciTech Connect (OSTI)

    Nassiri, A.; Berenc, T,; Foster, J.; Waldschmidt, G.; Zhou, J.

    1995-07-01

    In recent years, advances in the rf gun technology have made it possible to produce small beam emittances suitable for short period microundulators which take advantage of the low emittance beam to reduce the wavelength of FELs. At the Advanced Photon Source, we are studying the design of a compact 50-MeV superconducting mm-wave linac-based FEL for the production of short wavelengths ({approximately}300 nm) to carry out FEL demonstration experiments. The electron source considered for the linac is a 30- GHz, 3 1/2-cell {pi}-mode photocathode rf gun. For cold model rf measurements a 15-GHz prototype structure was fabricated. Here we report on the design, numerical modelling and the initial cold-model rf measurement results on the 15-GHz prototype structure.

  16. CAMD Nanofabrication

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L OBransenBusiness networkingFleetPuget Dr.Home :: Research ::

  17. CAMD Nanofabrication

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room News PublicationsAudits &Bradbury Science Museum6 Shares ofDOE/WIPP-97-2238AMonument

  18. Improved nuclear magnetic resonance apparatus having semitoroidal rf coil for use in topical NMR and NMR imaging

    DOE Patents [OSTI]

    Fukushima, E.; Roeder, S.B.W.; Assink, R.A.; Gibson, A.A.V.

    1984-01-01

    An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, so as to enable NMR measurements to be taken from selected regions inside an object, particularly including human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other interaction of the electric field with the sample.

  19. Superconducting cavity transducer for resonant gravitational radiation antennas

    E-Print Network [OSTI]

    R. Ballantini; M. Bassan; A. Chincarini; G. Gemme; R. Parodi; R. Vaccarone

    2006-02-15

    Parametric transducers, such as superconducting rf cavities, can boost the bandwidth and sensitivity of the next generation resonant antennas, thanks to a readily available technology. We have developed a fully coupled dynamic model of the system "antenna--transducer" and worked out some estimates of signal--to--noise ratio and the stability conditions in various experimental configurations. We also show the design and the prototype of a rf cavity which, together with a suitable read--out electronic, will be used as a test bench for the parametric transducer.

  20. Commissioning of the LHC Low Level RF System Remote Configuration Tools

    SciTech Connect (OSTI)

    Van Winkle, Daniel; /SLAC; Fox, John; /SLAC; Mastorides, Themis; /SLAC; Rivetta, Claudio; /SLAC; Baudrenghien, Philippe; /CERN; Butterworth, Andrew; /CERN; Molendijk, John; /CERN

    2010-08-26

    The LHC Low Level RF system (LLRF) is a complex multi-loop system used to regulate the superconductive cavity gap voltage as well as to reduce the impedance presented by RF stations to the beam. The RF system can have a profound impact on the stability of the beam; a mis-configured RF system has the potential of causing longitudinal instabilities, beam diffusion and beam loss. To configure the RF station for operation, a set of parameters in the LLRF multi-loop system have to be defined. Initial system commissioning as well as ongoing operation requires a consistent method of computer based remote measurement and model-based design of each RF station feedback system. This paper describes the suite of Matlab tools used for configuring the LHC RF system during the start up in Nov2009-Feb2010. We present a brief overview of the tool, examples of commissioning results, and basics of the model-based design algorithms. This work complements our previous presentation, where the algorithms and methodology followed in the tools were described.

  1. Nanomanipulation and nanofabrication with multi-probe STM: From individual atoms to nanowires

    SciTech Connect (OSTI)

    Qin, Shengyong; Kim, Tae Hwan; Wang, Zhouhang; Li, An-Ping

    2012-01-01

    The wide variety of nanoscale structures and devices demands novel tools for handling, assembly, and fabrication at nanoscopic positioning precision. The manipulation tools should allow for in situ characterization and testing of fundamental building blocks, such as nanotubes and nanowires, as they are built into functional devices. In this paper, a bottom-up technique for nanomanipulation and nanofabrication is reported by using a 4-probe scanning tunneling microscope (STM) combined with a scanning electron microscope (SEM). The applications of this technique are demonstrated in a variety of nanosystems, from manipulating individual atoms to bending, cutting, breaking carbon nanofibers, and constructing nanodevices for electrical characterizations. The combination of the wide field of view of SEM, the atomic position resolution of STM, and the flexibility of multiple scanning probes is expected to be a valuable tool for rapid prototyping in the nanoscience and nanotechnology.

  2. Superconducting microfabricated ion traps

    E-Print Network [OSTI]

    Wang, Shannon Xuanyue

    We fabricate superconducting ion traps with niobium and niobium nitride and trap single [superscript 88]Sr ions at cryogenic temperatures. The superconducting transition is verified and characterized by measuring the ...

  3. Superconducting quantum circuits theory and application

    E-Print Network [OSTI]

    Deng, Xiuhao

    2015-01-01

    viii General theory of Superconducting cavity coupled to2.4 Decoherence in superconductingProposed circuit for superconducting qubits . . . . .

  4. Superconducting magnet

    DOE Patents [OSTI]

    Satti, John A. (Naperville, IL)

    1980-01-01

    A superconducting magnet designed to produce magnetic flux densities of the order of 4 to 5 Webers per square meter is constructed by first forming a cable of a plurality of matrixed superconductor wires with each wire of the plurality insulated from each other one. The cable is shaped into a rectangular cross-section and is wound with tape in an open spiral to create cooling channels. Coils are wound in a calculated pattern in saddle shapes to produce desired fields, such as dipoles, quadrupoles, and the like. Wedges are inserted between adjacent cables as needed to maintain substantially radial placement of the long dimensions of cross sections of the cables. After winding, individual strands in each of the cables are brought out to terminals and are interconnected to place all of the strands in series and to maximize the propagation of a quench by alternating conduction from an inner layer to an outer layer and from top half to bottom half as often as possible. Individual layers are separated from others by spiraled aluminum spacers to facilitate cooling. The wound coil is wrapped with an epoxy tape that is cured by heat and then machined to an interference fit with an outer aluminum pipe which is then affixed securely to the assembled coil by heating it to make a shrink fit. In an alternate embodiment, one wire of the cable is made of copper or the like to be heated externally to propagate a quench.

  5. RF breakdown experiments at SLAC

    SciTech Connect (OSTI)

    Laurent, L. [University of California Davis, Davis, California 95616 (United States); Vlieks, A.; Pearson, C.; Caryotakis, G.; Luhmann, N.C. [Stanford Linear Accelerator Center, Menlo Park, California 94025 (United States)

    1999-05-01

    RF breakdown is a critical issue in the conditioning of klystrons, accelerator sections, and rf components for the next linear collider (NLC), as well as other high gradient accelerators and high power microwave sources. SLAC is conducting a series of experiments using an X-band traveling wave ring to characterize the processes and trigger mechanisms associated with rf breakdown. The goal of the research is to identify materials, processes, and manufacturing methods that will increase the breakdown threshold and minimize the time required for conditioning. {copyright} {ital 1999 American Institute of Physics.}

  6. Basic principle of superconductivity

    E-Print Network [OSTI]

    Tian De Cao

    2009-11-10

    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.

  7. Experimental Advanced Superconducting Tokamak

    E-Print Network [OSTI]

    ASIPP Experimental Advanced Superconducting Tokamak (EAST) Design, Fabrication and Assembly Weng of the project is to develop an advanced superconducting tokamak · Explore and demonstrate of steady magnets Total weight 38.7 tons, Total flux swing 10 VS Magnet system Superconducting coils; CIC conductor

  8. Superconducting Power Generation

    E-Print Network [OSTI]

    Mario Rabinowitz

    2003-02-20

    The superconducting ac generator has the greatest potential for large-scale commercial application of superconductivity that can benefit the public. Electric power is a vital ingredient of modern society, and generation may be considered to be the vital ingredient of a power system. This articles gives background, and an insight into the physics and engineering of superconducting power generation.

  9. Multipole Field Effects for the Superconducting Parallel-Bar Deflecting/Crabbing Cavities

    SciTech Connect (OSTI)

    De Silva, Payagalage Subashini Uddika [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States) and Old Dominion University, Norfolk, VA (United States); Delayen, Jean Roger [Old Dominion University, Norfolk, VA (United States)

    2012-09-01

    The superconducting parallel-bar deflecting/crabbing cavity is currently being considered as one of the design options in rf separation for the Jefferson Lab 12 GeV upgrade and for the crabbing cavity for the proposed LHC luminosity upgrade. Knowledge of multipole field effects is important for accurate beam dynamics study of rf structures. The multipole components can be accurately determined numerically using the electromagnetic surface field data in the rf structure. This paper discusses the detailed analysis of those components for the fundamental deflecting/crabbing mode and higher order modes in the parallel-bar deflecting/crabbing cavity.

  10. Unbalanced field RF electron gun

    DOE Patents [OSTI]

    Hofler, Alicia

    2013-11-12

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.

  11. Intelligent Radio Frequency (RF) Monitoring 

    E-Print Network [OSTI]

    Kimbrough, B.

    2010-01-01

    ? Regulatory fines Location 8 ?Expect many enjoyable experiences!? David M. Armstrong Continuous RF Monitoring RELIEF VALVE MONITORING The solution?? 9 ?Expect many enjoyable experiences!? David M. Armstrong Continuous RF Monitoring TEMPERATURE...?Armstrong? WiHART?Device Non?Armstrong? WiHART?Device Non?Armstrong? WiHART?Device Open Mesh Wireless Structure STEAM TRAP MONITORING RELIEF VALVE MONITORING TEMPERATURE MONITORING GATEWAY 14 ?Expect many enjoyable experiences!? David M. Armstrong...

  12. Protective link for superconducting coil

    DOE Patents [OSTI]

    Umans, Stephen D. (Belmont, MA)

    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.

  13. Superconducting 112 MHz QWR electron gun

    SciTech Connect (OSTI)

    Belomestnykh, S.; Ben-Zvi, I.; Boulware, C.H.; Chang, X.; Grimm, T.L.; Rao, T.; Siegel, B.; Skaritka, J.; Than, R.; Winowski, M.; Wu, Q.; Xin, T.; Xue, L.

    2011-07-25

    Brookhaven National Laboratory and Niowave, Inc. have designed and fabricated a superconducting 112 MHz quarter-wave resonator (QWR) electron gun. The first cold test of the QWR cryomodule has been completed at Niowave. The paper describes the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule. Future experiments include studies of different photocathodes and use for the coherent electron cooling proof-of-principle experiment. Two cathode stalk options, one for multi-alkali photocathodes and the other one for a diamond-amplified photocathode, are discussed. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was proposed at BNL for electron cooling hadron beams in RHIC. QWRs can be made sufficiently compact even at low RF frequencies (long wavelengths). The long wavelength allows to produce long electron bunches, thus minimizing space charge effects and enabling high bunch charge. Also, such guns should be suitable for experiments requiring high average current electron beams. A 112 MHz QWR gun was designed, fabricated, and cold-tested in collaboration between BNL and Niowave. This is the lowest frequency SRF gun ever tested successfully. In this paper we describe the gun design and fabrication, present the cold test results, and outline our plans. This gun will also serve as a prototype for a future SRF gun to be used for coherent electron cooling of hadrons in eRHIC.

  14. Broadband sample holder for microwave spectroscopy of superconducting qubits

    SciTech Connect (OSTI)

    Averkin, A. S.; Karpov, A.; Glushkov, E.; Abramov, N. [National University of Science and Technology (MISIS), Leninskiy prosp. 4, Moscow, 119049 (Russian Federation); Shulga, K. [National University of Science and Technology (MISIS), Leninskiy prosp. 4, Moscow, 119049 (Russian Federation); Russian Quantum Center (RQC), 100 Novaya St., Skolkovo, Moscow region, 143025 (Russian Federation); Huebner, U. [Leibniz Institute of Photonic Technology (IPHT), PO Box 100239, D-07702 Jena (Germany); Il'ichev, E. [Russian Quantum Center (RQC), 100 Novaya St., Skolkovo, Moscow region, 143025 (Russian Federation); Leibniz Institute of Photonic Technology (IPHT), PO Box 100239, D-07702 Jena (Germany); Ustinov, A. V. [National University of Science and Technology (MISIS), Leninskiy prosp. 4, Moscow, 119049 (Russian Federation); Russian Quantum Center (RQC), 100 Novaya St., Skolkovo, Moscow region, 143025 (Russian Federation); Physikalisches Institut, Karlsruhe Institute of Technology (KIT), D-76131 Karlsruhe (Germany)

    2014-10-15

    We present a practical design and implementation of a broadband sample holder suitable for microwave experiments with superconducting integrated circuits at millikelvin temperatures. Proposed design can be easily integrated in standard dilution cryostats, has flat pass band response in a frequency range from 0 to 32 GHz, allowing the RF testing of the samples with substrate size up to 4 × 4 mm{sup 2}. The parasitic higher modes interference in the holder structure is analyzed and prevented via design considerations. The developed setup can be used for characterization of superconducting parametric amplifiers, bolometers, and qubits. We tested the designed sample holder by characterizing of a superconducting flux qubit at 20 mK temperature.

  15. AC Loss Analysis on the Superconducting Coupling Magnet in MICE

    E-Print Network [OSTI]

    Wu, Hong

    2009-01-01

    of Cryogenics and Superconductivity Technology, Harbinof cryogenics and superconductivity engineering technologyof Cryogenics and Superconductivity Technology, “Engineering

  16. Phase modulation in RF tag

    DOE Patents [OSTI]

    Carrender, Curtis Lee; Gilbert, Ronald W.

    2007-02-20

    A radio frequency (RF) communication system employs phase-modulated backscatter signals for RF communication from an RF tag to an interrogator. The interrogator transmits a continuous wave interrogation signal to the RF tag, which based on an information code stored in a memory, phase-modulates the interrogation signal to produce a backscatter response signal that is transmitted back to the interrogator. A phase modulator structure in the RF tag may include a switch coupled between an antenna and a quarter-wavelength stub; and a driver coupled between the memory and a control terminal of the switch. The driver is structured to produce a modulating signal corresponding to the information code, the modulating signal alternately opening and closing the switch to respectively decrease and increase the transmission path taken by the interrogation signal and thereby modulate the phase of the response signal. Alternatively, the phase modulator may include a diode coupled between the antenna and driver. The modulating signal from the driver modulates the capacitance of the diode, which modulates the phase of the response signal reflected by the diode and antenna.

  17. Philosophy 26 High Temperature Superconductivity

    E-Print Network [OSTI]

    Callender, Craig

    Philosophy 26 High Temperature Superconductivity By Ohm's Law, resistance will dim. Low temperature superconductivity was discovered in 1911 by Heike was explained by BCS theory. BCS theory explains superconductivity microscopically

  18. Ion bombardment in RF photoguns

    SciTech Connect (OSTI)

    Pozdeyev,E.; Kayran, D.; Litvinenko, V. N.

    2009-05-04

    A linac-ring eRHIC design requires a high-intensity CW source of polarized electrons. An SRF gun is viable option that can deliver the required beam. Numerical simulations presented elsewhere have shown that ion bombardment can occur in an RF gun, possibly limiting lifetime of a NEA GaAs cathode. In this paper, we analytically solve the equations of motion of ions in an RF gun using the ponderomotive potential of the Rf field. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper discusses possible mitigation techniques that can reduce the rate of ion bombardment.

  19. Cryogenic vacuumm RF feedthrough device

    DOE Patents [OSTI]

    Wu, Genfa (Yorktown, VA); Phillips, Harry Lawrence (Hayes, VA)

    2008-12-30

    A cryogenic vacuum rf feedthrough device comprising: 1) a probe for insertion into a particle beam; 2) a coaxial cable comprising an inner conductor and an outer conductor, a dielectric/insulating layer surrounding the inner conductor, the latter being connected to the probe for the transmission of higher mode rf energy from the probe; and 3) a high thermal conductivity stub attached to the coaxial dielectric about and in thermal contact with the inner conductor which high thermal conductivity stub transmits heat generated in the vicinity of the probe efficiently and radially from the area of the probe and inner conductor all while maintaining useful rf transmission line characteristics between the inner and outer coaxial conductors.

  20. Klystron equalization for RF feedback

    SciTech Connect (OSTI)

    Corredoura, P.

    1993-01-01

    The next generation of colliding beam storage rings support higher luminosities by significantly increasing the number of bunches and decreasing the spacing between respective bunches. The heavy beam loading requires large RF cavity detuning which drives several lower coupled bunch modes very strongly. One technique which has proven to be very successful in reducing the coupled bunch mode driving impedance is RF feedback around the klystron-cavity combination. The gain and bandwidth of the feedback loop is limited by the group delay around the feedback loop. Existing klystrons on the world market have not been optimized for this application and contribute a large portion of the total loop group delay. This paper describes a technique to reduce klystron group delay by adding an equalizing filter to the klystron RF drive. Such a filter was built and tested on a 500 kill klystron as part of the on going PEP-II R&D effort here at SLAC.

  1. Klystron equalization for RF feedback

    SciTech Connect (OSTI)

    Corredoura, P.

    1993-01-01

    The next generation of colliding beam storage rings support higher luminosities by significantly increasing the number of bunches and decreasing the spacing between respective bunches. The heavy beam loading requires large RF cavity detuning which drives several lower coupled bunch modes very strongly. One technique which has proven to be very successful in reducing the coupled bunch mode driving impedance is RF feedback around the klystron-cavity combination. The gain and bandwidth of the feedback loop is limited by the group delay around the feedback loop. Existing klystrons on the world market have not been optimized for this application and contribute a large portion of the total loop group delay. This paper describes a technique to reduce klystron group delay by adding an equalizing filter to the klystron RF drive. Such a filter was built and tested on a 500 kill klystron as part of the on going PEP-II R D effort here at SLAC.

  2. Negative ion source with external RF antenna

    DOE Patents [OSTI]

    Leung, Ka-Ngo; Hahto, Sami K.; Hahto, Sari T.

    2007-02-13

    A radio frequency (RF) driven plasma ion source has an external RF antenna, i.e. the RF antenna is positioned outside the plasma generating chamber rather than inside. The RF antenna is typically formed of a small diameter metal tube coated with an insulator. An external RF antenna assembly is used to mount the external RF antenna to the ion source. The RF antenna tubing is wound around the external RF antenna assembly to form a coil. The external RF antenna assembly is formed of a material, e.g. quartz, which is essentially transparent to the RF waves. The external RF antenna assembly is attached to and forms a part of the plasma source chamber so that the RF waves emitted by the RF antenna enter into the inside of the plasma chamber and ionize a gas contained therein. The plasma ion source is typically a multi-cusp ion source. A converter can be included in the ion source to produce negative ions.

  3. Superconductive imaging surface magnetometer

    DOE Patents [OSTI]

    Overton, Jr., William C. (Los Alamos, NM); van Hulsteyn, David B. (Santa Fe, NM); Flynn, Edward R. (Los Alamos, NM)

    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.

  4. Superconducting VAR control

    DOE Patents [OSTI]

    Boenig, Heinrich J. (Los Alamos, NM); Hassenzahl, William V. (Piedmont, CA)

    1982-01-01

    Static VAR control means employing an asymmetrically controlled Graetz bridge and a superconducting direct current coil having low losses and low cost characteristics.

  5. Alexei Abrikosov and Superconductivity

    Office of Scientific and Technical Information (OSTI)

    quantum liquids. ... Superconductivity is the ability of some materials to conduct electricity without resistance when they are chilled to extremely low temperatures....

  6. Search for: superconduct* | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    superconduct* Find + Advanced Search Advanced Search All Fields: superconduct* Title: Full Text: Bibliographic Data: Creator Author: Name Name ORCID Search Authors Type: All...

  7. SciTech Connect: superconduct*

    Office of Scientific and Technical Information (OSTI)

    superconduct* Find + Advanced Search Term Search Semantic Search Advanced Search All Fields: superconduct* Semantic Semantic Term Title: Full Text: Bibliographic Data: Creator ...

  8. Note on RF Photo-Cathode Gun

    E-Print Network [OSTI]

    Kim, Kwang-Je

    2010-01-01

    Emittances in Laser-Driven RF Guns", Proc. 1988 Linear Acc.Palmer, "Preliminary Study of Gun Emittance Correction", BNLLaser-Driven RF Electron Guns", Nuc1. ln stt. Meth. , A275,

  9. High-Power Rf Load

    DOE Patents [OSTI]

    Tantawi, Sami G. (San Mateo, CA); Vlieks, Arnold E. (Livermore, CA)

    1998-09-01

    A compact high-power RF load comprises a series of very low Q resonators, or chokes [16], in a circular waveguide [10]. The sequence of chokes absorb the RF power gradually in a short distance while keeping the bandwidth relatively wide. A polarizer [12] at the input end of the load is provided to convert incoming TE.sub.10 mode signals to circularly polarized TE.sub.11 mode signals. Because the load operates in the circularly polarized mode, the energy is uniformly and efficiently absorbed and the load is more compact than a rectangular load. Using these techniques, a load having a bandwidth of 500 MHz can be produced with an average power dissipation level of 1.5 kW at X-band, and a peak power dissipation of 100 MW. The load can be made from common lossy materials, such as stainless steel, and is less than 15 cm in length. These techniques can also produce loads for use as an alternative to ordinary waveguide loads in small and medium RF accelerators, in radar systems, and in other microwave applications. The design is easily scalable to other RF frequencies and adaptable to the use of other lossy materials.

  10. RF digital-to-analog converter

    DOE Patents [OSTI]

    Conway, Patrick H. (Rancho Palos Verdes, CA); Yu, David U. L. (Rancho Palos Verdes, CA)

    1995-01-01

    A digital-to analogue converter for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration.

  11. RF digital-to-analog converter

    DOE Patents [OSTI]

    Conway, P.H.; Yu, D.U.L.

    1995-02-28

    A digital-to-analog converter is disclosed for producing an RF output signal proportional to a digital input word of N bits from an RF reference input, N being an integer greater or equal to 2. The converter comprises a plurality of power splitters, power combiners and a plurality of mixers or RF switches connected in a predetermined configuration. 18 figs.

  12. Introduction Final Cooling Channel -High Frequency RF

    E-Print Network [OSTI]

    McDonald, Kirk

    Outline Introduction Final Cooling Channel - High Frequency RF Muon Collider Final Cooling Hisham Sayed February 27, 2014 1 / 10 #12;Outline Introduction Final Cooling Channel - High Frequency RF Table of Contents 1 Introduction 2 Final Cooling Channel - High Frequency RF 2 / 10 #12;Outline Introduction Final

  13. BROADBAND LOW ACTUATIONVOLTAGE RF'MEM SWITCHES

    E-Print Network [OSTI]

    Shen, Shyh-Chiang

    (RF) Microelectromechanical (MEM) switches have been thought of as one of the most attractive devicesBROADBAND LOW ACTUATIONVOLTAGE RF'MEM SWITCHES Shyh-ChiangShen,David Caruth, and Milton Feng of Illinois at Urbana-Champaign,IL61801-2355 ABSTRACT- We demonstrate a sub-lovolts RF MEM switch built

  14. Superconducting Magnet Division

    E-Print Network [OSTI]

    Gupta, Ramesh

    Superconducting Magnet Division Permanent Magnet Designs with Large Variations in Field Strength the residual field of the magnetized bricks by concentrating flux lines at the iron pole. Low Field Design Medium Field Design Superconducting Magnet Division Dipole and Quadrupole Magnets for RHIC e

  15. Superconductivity of magnesium diboride

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

    Bud’ko, Sergey L.; Canfield, Paul C.

    2015-07-15

    Over the past 14 years MgB2 has gone from a startling discovery to a promising, applied superconductor. In our article we present a brief overview of the synthesis and the basic superconducting properties of this remarkable compound. Specifically, the effect of pressure, substitutions and neutron irradiation on superconducting properties are discussed.

  16. RF and structural characterization of new SRF films

    SciTech Connect (OSTI)

    A.-M. Valente-Feliciano,H. L. Phillips,C. E. Reece,X. Zhao,D. Gu,R. Lukaszew,B. Xiao,K. Seo

    2009-09-01

    In the past years, energetic vacuum deposition methods have been developed in different laboratories to improve Nb/Cu technology for superconducting cavities. Jefferson Lab is pursuing energetic condensation deposition via Electron Cyclotron Resonance. As part of this study, the influence of the deposition energy on the material and RF properties of the Nb thin film is investigated. The film surface and structure analyses are conducted with various techniques like X-ray diffraction, Transmission Electron Microscopy, Auger Electron Spectroscopy and RHEED. The microwave properties of the films are characterized on 50 mm disk samples with a 7.5 GHz surface impedance characterization system. This paper presents surface impedance measurements in correlation with surface and material characterization for Nb films produced on copper substrates with different bias voltages and also highlights emerging opportunities for developing multilayer SRF films with a new deposition system.

  17. National RF Test Facility as a multipurpose development tool

    SciTech Connect (OSTI)

    McManamy, T.J.; Becraft, W.R.; Berry, L.A.; Blue, C.W.; Gardner, W.L.; Haselton, H.H.; Hoffman, D.J.; Loring, C.M. Jr.; Moeller, F.A.; Ponte, N.S.

    1983-01-01

    Additions and modifications to the National RF Test Facility design have been made that (1) focus its use for technology development for future large systems in the ion cyclotron range of frequencies (ICRF), (2) expand its applicability to technology development in the electron cyclotron range of frequencies (ECRF) at 60 GHz, (3) provide a facility for ELMO Bumpy Torus (EBT) 60-GHz ring physics studies, and (4) permit engineering studies of steady-state plasma systems, including superconducting magnet performance, vacuum vessel heat flux removal, and microwave protection. The facility will continue to function as a test bed for generic technology developments for ICRF and the lower hybrid range of frequencies (LHRF). The upgraded facility is also suitable for mirror halo physics experiments.

  18. Superconducting Radiofrequency (SRF) Accelerator Cavities

    ScienceCinema (OSTI)

    Reece, Charlie

    2014-05-22

    Charlie Reece, an accelerator technology scientist, explains how superconducting radiofrequency accelerator cavities work.

  19. Decrease of the surface resistance in superconducting niobium resonator cavities by the microwave field

    SciTech Connect (OSTI)

    Ciovati, Gianluigi; Dhakal, Pashupati; Gurevich, Alexander V.

    2014-03-03

    Measurements of the quality factor, Q, of Nb superconducting microwave resonators often show that Q increases by {approx_equal} 10%–30% with increasing radio-frequency (rf) field, H, up to {approx} 15-20 mT. Recent high temperature heat treatments can amplify this rf field-induced increase of Q up to {approx_equal} 50%–100% and extend it to much higher fields, but the mechanisms of the enhancement of Q(H) remain unclear. Here, we suggest a method to reveal these mechanisms by measuring temperature dependencies of Q at different rf field amplitudes. We show that the increase of Q(H) does not come from a field dependent quasi-particles activation energy or residual resistance, but rather results from the smearing of the density of state by the rf field.

  20. 6.763 Applied Superconductivity, Fall 2001

    E-Print Network [OSTI]

    Orlando, Terry P.

    Phenomenological approach to superconductivity, with emphasis on superconducting electronics. Electrodynamics of superconductors, London's model, and flux quantization. Josephson Junctions and superconducting quantum ...

  1. Superconducting solenoids for the MICE channel

    E-Print Network [OSTI]

    2003-01-01

    IEEE Transactions on Applied Superconductivity 13, No. 2 S.SUPERCONDUCTING SOLENOIDS FOR THE MICE CHANNEL* M. A. Green,describes the channel of superconducting solenoids for the

  2. Cancellation of RF Coupler-Induced Emittance Due to Astigmatism

    E-Print Network [OSTI]

    Dowell, David H

    2015-01-01

    It is well-known that the electron beam quality required for applications such as FELs and ultra-fast electron diffraction can be degraded by the asymmetric fields introduced by the RF couplers of superconducting linacs. This effect is especially troublesome in the injector where the low energy beam from the gun is captured into the first high gradient accelerator section. Unfortunately modifying the established cavity design is expensive and time consuming, especially considering that only one or two sections are needed for an injector. Instead, it is important to analyze the coupler fields to understand their characteristics and help find less costly solutions for their cancellation and mitigation. This paper finds the RF coupler-induced emittance for short bunches is mostly due to the transverse spatial sloping or tilt of the field, rather than the field's time-dependence. It is shown that the distorting effects of the coupler can be canceled with a static (DC) quadrupole lens rotated about the z-axis.

  3. RF System Modeling for the CEBAF Energy Upgrade

    SciTech Connect (OSTI)

    Tomasz Plawski, J. Hovater

    2009-05-01

    An RF system model, based on MATLAB/SIMULINK, has been developed for analyzing the basic characteristics of the low level RF (LLRF) control system being designed for the CEBAF 12 GeV Energy Upgrade. In our model, a typical passband cavity representation is simplified to in-phase and quadrature (I&Q) components. Lorentz Force and microphonic detuning are incorporated as a new quadrature carrier frequency (frequency modulation). Beam is also represented as in-phase and quadrature components and superpositioned with the cavity field vector. Signals pass through two low pass filters, where the cutoff frequency is equal to half of the cavity bandwidth, then they are demodulated using the same detuning frequency. Because only baseband I&Q signals are calculated, the simulation process is very fast when compared to other controller-cavity models. During the design process we successfully analyzed gain requirements vs. field stability for different superconducting cavity microphonic backgrounds and Lorentz Force coefficients. Moreover, we were able to evaluate different types of a LLRF system’s control algorithm: GDR (Generator Driven Resonator) and SEL (Self Excited Loop) [1] as well as klystron power requirements for different cavities and beam loads.

  4. The SPEAR3 RF System

    SciTech Connect (OSTI)

    McIntosh, P.

    2005-01-18

    SPEAR2 was upgraded in 2003, to a new 3rd Generation Light Source (3GLS)-SPEAR3, enabling users to take better advantage of almost 100x higher brightness and flux density over its predecessor. As part of the upgrade, the SPEAR2 RF system has been revamped from its original configuration of one 200 kW klystron feeding a single 358.5 MHz, 5-cell aluminum cavity; to a 1.2 MW klystron feeding four 476.3 MHz, HOM damped copper cavities. The system installation was completed in late November 2003 and the required accelerating voltage of 3.2 MV (800 kV/cavity) was very rapidly achieved soon after. This paper details the SPEAR3 RF system configuration and its new operating requirements, highlighting its installation and subsequent successful operation.

  5. Introduction to Color Superconductivity

    E-Print Network [OSTI]

    G. Nardulli

    2006-10-23

    At high nuclear density and small temperature, due to the asymptotic freedom property of Quantum ChromoDynamics and to the existence of an attractive channel in the color interaction, diquark condensates might be formed. Since these condensates break the color gauge symmetry, this phenomenon has the name of color superconductivity. In the last few years this has become a very active field of research. While a direct experimental test is still missing, color superconductivity might have implications in astrophysics because for some compact stars, e.g. pulsars, the baryon densities necessary for color superconductivity can probably be reached.

  6. Superconducting active impedance converter

    DOE Patents [OSTI]

    Ginley, David S. (Albuquerque, NM); Hietala, Vincent M. (Placitas, NM); Martens, Jon S. (Albuquerque, NM)

    1993-01-01

    A transimpedance amplifier for use with high temperature superconducting, other superconducting, and conventional semiconductor allows for appropriate signal amplification and impedance matching to processing electronics. The amplifier incorporates the superconducting flux flow transistor into a differential amplifier configuration which allows for operation over a wide temperature range, and is characterized by high gain, relatively low noise, and response times less than 200 picoseconds over at least a 10-80 K. temperature range. The invention is particularly useful when a signal derived from either far-IR focal plane detectors or from Josephson junctions is to be processed by higher signal/higher impedance electronics, such as conventional semiconductor technology.

  7. Low jitter RF distribution system

    DOE Patents [OSTI]

    Wilcox, Russell; Doolittle, Lawrence; Huang, Gang

    2012-09-18

    A timing signal distribution system includes an optical frequency stabilized laser signal amplitude modulated at an rf frequency. A transmitter box transmits a first portion of the laser signal and receive a modified optical signal, and outputs a second portion of the laser signal and a portion of the modified optical signal. A first optical fiber carries the first laser signal portion and the modified optical signal, and a second optical fiber carries the second portion of the laser signal and the returned modified optical signal. A receiver box receives the first laser signal portion, shifts the frequency of the first laser signal portion outputs the modified optical signal, and outputs an electrical signal on the basis of the laser signal. A detector at the end of the second optical fiber outputs a signal based on the modified optical signal. An optical delay sensing circuit outputs a data signal based on the detected modified optical signal. An rf phase detect and correct signal circuit outputs a signal corresponding to a phase stabilized rf signal based on the data signal and the frequency received from the receiver box.

  8. Power Dependence of the RF Surface Resistance of MgB2 Superconductor.

    SciTech Connect (OSTI)

    Tajima, T.; Findikoglu, A. T.; Jason, A. J.; Krawczyk, F. L.; Mueller, F. M.; Shapiro, A. H.; Geng, R. L.; Padamsee, Hasan,; Romanenko, A.; Moeckly, B. H.

    2005-01-01

    Magnesium diboride (MgB{sub 2}) is a superconducting material that has a transition temperature (T{sub c}) of {approx}40 K, which is {approx}30 K higher than niobium (Nb) that has been used for most superconducting RF cavities in the past decades. Last year, it was demonstrated that the RF surface resistance of MgB{sub 2} can be lower than Nb at 4 K. One of the problems with other high-T{sub c} materials such as YBCO was its rapid increase in RF surface resistance with higher surface magnetic fields. Recently, we have shown that MgB2 shows little increase in the surface resistance up to {approx}120 Oe, equivalent of an accelerating field of {approx}3 MV/m. The highest field tested was limited by available power. This result is encouraging and has made us consider fabrication of a cavity coated with MgB{sub 2} and test it. Also, there is a potential that this material has a higher critical magnetic field that enables the cavity to run at a higher gradient than Nb cavities in addition to the possibility of operation at higher temperatures.

  9. Single electron beam rf feedback free electron laser

    DOE Patents [OSTI]

    Brau, C.A.; Stein, W.E.; Rockwood, S.D.

    1981-02-11

    A free electron laser system and electron beam system for a free electron laser which uses rf feedback to enhance efficiency are described. Rf energy is extracted from a single electron beam by decelerating cavities and energy is returned to accelerating cavities using rf returns, such as rf waveguides, rf feedthroughs, resonant feedthroughs, etc. This rf energy is added to rf klystron energy to reduce the required input energy and thereby enhance energy efficiency of the system.

  10. Superconducting thermoelectric generator

    DOE Patents [OSTI]

    Metzger, J.D.; El-Genk, M.S.

    1996-01-01

    An apparatus and method for producing electricity from heat. The present invention is a thermoelectric generator that uses materials with substantially no electrical resistance, often called superconductors, to efficiently convert heat into electrical energy without resistive losses. Preferably, an array of superconducting elements is encased within a second material with a high thermal conductivity. The second material is preferably a semiconductor. Alternatively, the superconducting material can be doped on a base semiconducting material, or the superconducting material and the semiconducting material can exist as alternating, interleaved layers of waferlike materials. A temperature gradient imposed across the boundary of the two materials establishes an electrical potential related to the magnitude of the temperature gradient. The superconducting material carries the resulting electrical current at zero resistivity, thereby eliminating resistive losses. The elimination of resistive losses significantly increases the conversion efficiency of the thermoelectric device.

  11. Superconducting thermoelectric generator

    DOE Patents [OSTI]

    Metzger, J.D.; El-Genk, M.S.

    1998-05-05

    An apparatus and method for producing electricity from heat is disclosed. The present invention is a thermoelectric generator that uses materials with substantially no electrical resistance, often called superconductors, to efficiently convert heat into electrical energy without resistive losses. Preferably, an array of superconducting elements is encased within a second material with a high thermal conductivity. The second material is preferably a semiconductor. Alternatively, the superconducting material can be doped on a base semiconducting material, or the superconducting material and the semiconducting material can exist as alternating, interleaved layers of waferlike materials. A temperature gradient imposed across the boundary of the two materials establishes an electrical potential related to the magnitude of the temperature gradient. The superconducting material carries the resulting electrical current at zero resistivity, thereby eliminating resistive losses. The elimination of resistive losses significantly increases the conversion efficiency of the thermoelectric device. 4 figs.

  12. Superconducting thermoelectric generator

    DOE Patents [OSTI]

    Metzger, John D. (Eaton's Neck, NY); El-Genk, Mohamed S. (Albuquerque, NM)

    1998-01-01

    An apparatus and method for producing electricity from heat. The present invention is a thermoelectric generator that uses materials with substantially no electrical resistance, often called superconductors, to efficiently convert heat into electrical energy without resistive losses. Preferably, an array of superconducting elements is encased within a second material with a high thermal conductivity. The second material is preferably a semiconductor. Alternatively, the superconducting material can be doped on a base semiconducting material, or the superconducting material and the semiconducting material can exist as alternating, interleaved layers of waferlike materials. A temperature gradient imposed across the boundary of the two materials establishes an electrical potential related to the magnitude of the temperature gradient. The superconducting material carries the resulting electrical current at zero resistivity, thereby eliminating resistive losses. The elimination of resistive losses significantly increases the conversion efficiency of the thermoelectric device.

  13. Superconducting transmission line particle detector

    DOE Patents [OSTI]

    Gray, Kenneth E. (Naperville, IL)

    1989-01-01

    A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non-superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propogating in a superconducting transmission line are used to resolve N.sup.2 ambiguity of charged particle events.

  14. Superconducting transmission line particle detector

    DOE Patents [OSTI]

    Gray, K.E.

    1988-07-28

    A microvertex particle detector for use in a high energy physic collider including a plurality of parallel superconducting thin film strips separated from a superconducting ground plane by an insulating layer to form a plurality of superconducting waveguides. The microvertex particle detector indicates passage of a charged subatomic particle by measuring a voltage pulse measured across a superconducting waveguide caused by the transition of the superconducting thin film strip from a superconducting to a non- superconducting state in response to the passage of a charged particle. A plurality of superconducting thin film strips in two orthogonal planes plus the slow electromagnetic wave propagating in a superconducting transmission line are used to resolve N/sup 2/ ambiguity of charged particle events. 6 figs.

  15. RF Processing Experience with the GTF Prototype RF Gun

    SciTech Connect (OSTI)

    Schmerge, J.F.

    2010-11-24

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. A total of five different metal cathodes (4 Cu and 1 Mg) have been installed on the GTF gun. The rf processing history with the different cathodes will be presented including peak field achieved at the cathode. The LCLS gun is intended to operate at 120 MV/m and fields up to 140 MV/m have been achieved in the GTF gun. After installing a new cathode the number of rf pulses required to reach 120 MV/m is approximately 5-10 million. Total emitted dark current and Fowler Nordheim plots are also shown over the life of the cathode. The GTF photo-injector gun is an S-band standing-wave structure, with two resonant cavities and an intervening thick washer (Figure 1). The flat, back wall of the first cavity is a copper plate that serves as photocathode when illuminated with ultraviolet light from a pulsed, high-power laser. RF power enters the gun through an iris on the outer wall of the second cavity, and is coupled to the first through the axial opening of the washer. The first cavity is often referred to as a half cell, because its full-cell length has been truncated by the cathode plate and the second cavity is called the full cell. The gun is designed to operate in a {pi} mode, with the peak field on axis in each cell approximately equal. The maximum in the half cell occurs at the cathode, and in the full cell near the center of the cavity. The field profile and tuning procedures are discussed in a separate tech note [1].

  16. Superconducting radiofrequency window assembly

    DOE Patents [OSTI]

    Phillips, Harry L. (Seaford, VA); Elliott, Thomas S. (Yorktown, VA)

    1997-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  17. Superconductive radiofrequency window assembly

    DOE Patents [OSTI]

    Phillips, Harry Lawrence (Seaford, VA); Elliott, Thomas S. (Yorktown, VA)

    1998-01-01

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly (20) has a superconducting metal-ceramic design. The srf window assembly (20) comprises a superconducting frame (30), a ceramic plate (40) having a superconducting metallized area, and a superconducting eyelet (50) for sealing plate (40) into frame (30). The plate (40) is brazed to eyelet (50) which is then electron beam welded to frame (30). A method for providing a ceramic object mounted in a metal member to withstand cryogenic temperatures is also provided. The method involves a new metallization process for coating a selected area of a ceramic object with a thin film of a superconducting material. Finally, a method for assembling an electron beam accelerator cavity utilizing the srf window assembly is provided. The procedure is carried out within an ultra clean room to minimize exposure to particulates which adversely affect the performance of the cavity within the electron beam accelerator.

  18. High temperature interfacial superconductivity

    DOE Patents [OSTI]

    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.

  19. Status of the SUNY superconducting RFQ

    SciTech Connect (OSTI)

    Jain, A.; Ben-Zvi, I.; Paul, P.; Wang, H. (Brookhaven National Lab., Upton, NY (United States)); Lombardi, A. (Istituto Nazionale di Fisica Nucleare, Legnaro (Italy). Lab. Nazionale di Legnaro)

    1991-01-01

    A RFQ resonator is presently being developed at SUNY. This resonator is a prototype for a chain of six short ({approximately}0.5m long), superconducting (Pb plated Cu), 50 MHz resonators designed to accelerate beam from {beta} = 0.01 to 0.05. The chain accepts a prebunched beam to save on superconducting length. The resonators are of four-rods type with vane-like electrodes. The prototype resonator is designed to accelerate ions of q/A = 1/6 from {beta} = 0.030 to 0.036, operating at a peak surface electric field of 16 MV/m. The electrodes have a rather high modulation parameter of 4 and a wide aperture of 1.57 cm radius. These values are chosen to maximize the accelerating field (E{sub a}) for a given peak surface electric field (E{sub s}). At the design value of E{sub s} = 16 MV/m, the resonator is estimated to have E{sub a} = 2.0 MV/m, stored energy of 4 J, peak surface magnetic field of 360 Gauss, and inter-vane voltage of 0.42 MV. Results of RF tests on this prototype resonator will be presented. 7 refs., 3 figs.

  20. RF/optical shared aperture for high availability wideband communication RF/FSO links

    DOE Patents [OSTI]

    Ruggiero, Anthony J; Pao, Hsueh-yuan; Sargis, Paul

    2014-04-29

    An RF/Optical shared aperture is capable of transmitting and receiving optical signals and RF signals simultaneously. This technology enables compact wide bandwidth communications systems with 100% availability in clear air turbulence, rain and fog. The functions of an optical telescope and an RF reflector antenna are combined into a single compact package by installing an RF feed at either of the focal points of a modified Gregorian telescope.

  1. First high power pulsed tests of a dressed 325 MHz superconducting single spoke resonator at Fermilab

    SciTech Connect (OSTI)

    Madrak, R.; Branlard, J.; Chase, B.; Darve, C.; Joireman, P.; Khabiboulline, T.; Mukherjee, A.; Nicol, T.; Peoples-Evans, E.; Peterson, D.; Pischalnikov, Y.; /Fermilab

    2011-03-01

    In the recently commissioned superconducting RF cavity test facility at Fermilab (SCTF), a 325 MHz, {beta} = 0.22 superconducting single-spoke resonator (SSR1) has been tested for the first time with its input power coupler. Previously, this cavity had been tested CW with a low power, high Q{sub ext} test coupler; first as a bare cavity in the Fermilab Vertical Test Stand and then fully dressed in the SCTF. For the tests described here, the design input coupler with Q{sub ext} {approx} 10{sup 6} was used. Pulsed power was provided by a Toshiba E3740A 2.5 MW klystron.

  2. RF Surface Impedance Characterization of Potential New Materials for SRF-based Accelerators

    SciTech Connect (OSTI)

    Xiao, Binping [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States) and College of William and Mary, Williamsburg, VA (United States); Eremeev, Grigory V. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Reece, Charles E. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Phillips, H. Lawrence [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Kelley, Michael J. [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States)

    2012-09-01

    In the development of new superconducting materials for possible use in SRF-based accelerators, it is useful to work with small candidate samples rather than complete resonant cavities. The recently commissioned Jefferson Lab RF Surface Impedance Characterization (SIC) system can presently characterize the central region of 50 mm diameter disk samples of various materials from 2 to 40 K exposed to RF magnetic fields up to 14 mT at 7.4 GHz. We report the recent measurement results of bulk Nb, thin film Nb on Cu and sapphire substrates, Nb{sub 3}Sn sample, and thin film MgB{sub 2} on sapphire substrate provided by colleagues at JLab and Temple University.

  3. High Thermal Conductivity Cryogenic RF Feedthroughs for Higher Order Mode Couplers

    SciTech Connect (OSTI)

    Charles Reece; Edward Daly; Thomas Elliott; H. Phillips; Joseph Ozelis; Timothy Rothgeb; Katherine Wilson; Genfa Wu

    2005-05-01

    The use of higher-order-mode (HOM) pickup probes in the presence of significant fundamental RF fields can present a thermal challenge for CW or high average power SRF cavity applications. The electric field probes on the HOM-damping couplers on the JLab ''High Gradient'' (HG) and ''Low Loss'' (LL) seven-cell cavities for the CEBAF upgrade are exposed to approximately 10% of the peak magnetic field in the cavity. To avoid significant dissipative losses, these probes must remain superconducting during operation. Typical cryogenic rf feedthroughs provide a poor thermal conduction path for the probes and provide inadequate stabilization. We have developed solutions that meet the requirements, providing a direct thermal path from the niobium probe, thorough single-crystal sapphire, to bulk copper which can be thermally anchored. Designs, electromagnetic and thermal analyses, and performance data will be presented.

  4. Tests of an RF Dipole Crabbing Cavity for an Electron-Ion Collider

    SciTech Connect (OSTI)

    Castilla Loeza, Alejandro; Delayen, Jean R.

    2013-12-01

    On the scheme of developing a medium energy electron-ion collider (MEIC) at Jefferson Lab, we have designed a compact superconducting rf dipole cavity at 750 MHz to crab both electron and ion bunches and increase luminosities at the interaction points (IP) of the machine. Following the design optimization and characterization of the electromagnetic properties such as peak surface fields and shunt impedance, along with field nonuniformities, multipole components content, higher order modes (HOM) and multipacting, a prototype cavity was built by Niowave Inc. The 750 MHz prototype crab cavity has been tested at 4 K and is ready for re-testing at 4 K and 2 K at Jefferson Lab. In this paper we present the detailed results of the rf tests performed on the 750 MHz crab cavity prototype.

  5. Bent crystal extraction of the SSC beam with RF noise induced diffusion

    SciTech Connect (OSTI)

    Shih, H.J. ); Taratin, A.M. )

    1991-03-01

    Channeling of charged particles in bent crystals has been considered for use in parasitic extraction of the Superconducting Super Collider (SSC) beam. To make this feasible, a small fraction of the SSC proton beam must be brought onto a bent crystal. In this paper, the method of introducing filtered phase noise into the rf system to diffuse the tails of the beam was investigated using computer simulations. The channeling efficiency of an incident beam by a bent silicon crystal was then analyzed using a theory and simulations. In addition, the increase in channeling efficiency because of the possibility of multiple passage through the crystal was studied in the presence of the injected filtered rf noise. 14 refs., 17 figs.

  6. Superconducting Quantum Computing without Switches

    E-Print Network [OSTI]

    Marc J. Feldman; Xingxiang Zhou

    2002-11-25

    This paper presents a very simple architecture for a large-scale superconducting quantum computer. All of the SQUID qubits are fixed-coupled to a single large superconducting loop.

  7. Cryogenic RF Material Testing with a High-Q Copper Cavity

    SciTech Connect (OSTI)

    Guo Jiquan; Tantawi, Sami; Martin, David; Yoneda, Charles [SLAC National Accelerator Laboratory, Menlo Park, CA (United States)

    2010-11-04

    An X-band RF cryogenic material testing system has been developed in the past few years. This system employs a high-Q copper cavity with an interchangeable flat bottom working under a TE{sub 013} like mode. By measuring the cavity Qs with a network analyzer, the system can characterize the surface resistance of different samples at different temperatures. Using a 50 MW 2{mu}s pulsed klystron, the system can measure the quenching H field for superconducting samples, up to 300-400 mT. In this paper, we will present the most recent developments of the system and testing results.

  8. Relativistic mechanism of superconductivity

    E-Print Network [OSTI]

    H. Y. Cui

    2002-12-17

    According to the theory of relativity, the relativistic Coulomb's force between an electron pair is composed of two parts, the main part is repulsive, while the rest part can be attractive in certain situations. Thus the relativistic attraction of an electron pair provides an insight into the mechanism of superconductivity. In superconductor, there are, probably at least, two kinds of collective motions which can eliminate the repulsion between two electrons and let the attraction being dominant, the first is the combination of lattice and electron gas, accounting for traditional superconductivity; the second is the electron gas themselves, accounting for high $T_c$ superconductivity. In usual materials, there is a good balance between the repulsion and attraction of an electron pair, the electrons are regarded as free electrons so that Fermi gas theory plays very well. But in some materials, when the repulsion dominates electron pairs, the electron gas will has a behavior opposite to superconductivity. In the present paper the superconducting states are discussed in terms of relativistic quantum theory in details, some significant results are obtained including quantized magnetic flux, London equation, Meissner effect and Josephson effect.

  9. Interplay of superconductivity, magnetism, and density waves in rare-earth tritellurides and iron-based superconducting materials

    E-Print Network [OSTI]

    Zocco, Diego Andrés

    2011-01-01

    B. Superconductivity . . . . . . . . . . . . . . . . .IV Superconductivity and Magnetism in Iron-PnictideSearch for Pressure Induced Superconductivity in Undoped Ce-

  10. Superconductivity and Magnetism: Materials Properties

    E-Print Network [OSTI]

    .g. within high-Tc superconductivity, magnetic superconductors, MgB2, CMR materials, nanomagnetism and spin#12;#12;Superconductivity and Magnetism: Materials Properties and Developments #12;Copyright 2003 Risø National Laboratory Roskilde, Denmark ISBN 87-550-3244-3 ISSN 0907-0079 #12;Superconductivity

  11. Nonlinear terahertz superconducting plasmonics

    SciTech Connect (OSTI)

    Wu, Jingbo; Liang, Lanju; Jin, Biaobing E-mail: tonouchi@ile.osaka-u.ac.jp Kang, Lin; Xu, Weiwei; Chen, Jian; Wu, Peiheng E-mail: tonouchi@ile.osaka-u.ac.jp; Zhang, Caihong; Kawayama, Iwao; Murakami, Hironaru; Tonouchi, Masayoshi E-mail: tonouchi@ile.osaka-u.ac.jp; Wang, Huabing

    2014-10-20

    Nonlinear terahertz (THz) transmission through subwavelength hole array in superconducting niobium nitride (NbN) film is experimentally investigated using intense THz pulses. The good agreement between the measurement and numerical simulations indicates that the field strength dependent transmission mainly arises from the nonlinear properties of the superconducting film. Under weak THz pulses, the transmission peak can be tuned over a frequency range of 145 GHz which is attributed to the high kinetic inductance of 50?nm-thick NbN film. Utilizing the THz pump-THz probe spectroscopy, we study the dynamic process of transmission spectra and demonstrate that the transition time of such superconducting plasmonic device is within 5 ps.

  12. Orbit Spaces in Superconductivity

    E-Print Network [OSTI]

    Vittorino Talamini

    2006-07-30

    In the framework of Landau theory of phase transitions one is interested to describe all the possible low symmetry ``superconducting'' phases allowed for a given superconductor crystal and to determine the conditions under which this crystal undergoes a phase transition. These problems are best described and analyzed in the orbit space of the high symmetry group of the ``normal, non-superconducting'' phase of the crystal. In this article it is worked out a simple example concerning superconductivity, that shows the P-matrix method to determine the equations and inequalities defining the orbit space and its stratification. This approach is of general validity and can be used in all physical problems that make use of invariant functions, as long as the symmetry group is compact.

  13. Superconductivity at Any Temperature

    E-Print Network [OSTI]

    Anber, Mohamed M; Sabancilar, Eray; Shaposhnikov, Mikhail

    2015-01-01

    We construct a 2+1 dimensional model that sustains superconductivity at all temperatures. This is achieved by introducing a Chern Simons mixing term between two Abelian gauge fields A and Z. The superfluid is described by a complex scalar charged under Z, whereas a sufficiently strong magnetic field of A forces the superconducting condensate to form at all temperatures. In fact, at finite temperature, the theory exhibits Berezinsky-Kosterlitz-Thouless phase transition due to proliferation of topological vortices admitted by our construction. However, the critical temperature is proportional to the magnetic field of A, and thus, the phase transition can be postponed to high temperatures by increasing the strength of the magnetic field. This model can be a step towards realizing the long sought room temperature superconductivity.

  14. Microwave (MW) and Radio Frequency (RF) as Enabling Technologies...

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

    Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced Manufacturing Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced...

  15. Superconducting metamaterials and qubits

    E-Print Network [OSTI]

    B. L. T. Plourde; Haozhi Wang; Francisco Rouxinol; M. D. LaHaye

    2015-05-05

    Superconducting thin-film metamaterial resonators can provide a dense microwave mode spectrum with potential applications in quantum information science. We report on the fabrication and low-temperature measurement of metamaterial transmission-line resonators patterned from Al thin films. We also describe multiple approaches for numerical simulations of the microwave properties of these structures, along with comparisons with the measured transmission spectra. The ability to predict the mode spectrum based on the chip layout provides a path towards future designs integrating metamaterial resonators with superconducting qubits.

  16. Superconducting thermoelectric generator

    DOE Patents [OSTI]

    Metzger, J.D.; El-Genk, M.S.

    1994-01-01

    Thermoelectricity is produced by applying a temperature differential to dissimilar electrically conducting or semiconducting materials, thereby producing a voltage that is proportional to the temperature difference. Thermoelectric generators use this effect to directly convert heat into electricity; however, presently-known generators have low efficiencies due to the production of high currents which in turn cause large resistive heating losses. Some thermoelectric generators operate at efficiencies between 4% and 7% in the 800{degrees} to 1200{degrees}C range. According to its major aspects and bradly stated, the present invention is an apparatus and method for producing electricity from heat. In particular, the invention is a thermoelectric generator that juxtaposes a superconducting material and a semiconducting material - so that the superconducting and the semiconducting materials touch - to convert heat energy into electrical energy without resistive losses in the temperature range below the critical temperature of the superconducting material. Preferably, an array of superconducting material is encased in one of several possible configurations within a second material having a high thermal conductivity, preferably a semiconductor, to form a thermoelectric generator.

  17. Hybrid superconducting neutron detectors

    SciTech Connect (OSTI)

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

    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?????+?{sup 7}Li, with ? 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.

  18. Langmuir vacuum and superconductivity

    SciTech Connect (OSTI)

    Veklenko, B. A.

    2012-06-15

    It is shown that, in the 'jelly' model of cold electron-ion plasma, the interaction between electrons and the quantum electromagnetic vacuum of Langmuir waves involves plasma superconductivity with an energy gap proportional to the energy of the Langmuir quantum.

  19. Superconducting Magnet Division

    E-Print Network [OSTI]

    Ohta, Shigemi

    Superconducting Magnet Division MAGNETIC DESIGN OF E-LENS SOLENOID AND CORRECTOR SYSTEM FOR RHIC* R.6 A gun collectors gun Combined Horizontal and Vertical Corrector Design Both types of dipole correctors. Gupta, M. Anerella, W. Fischer, G. Ganetis, X. Gu, A. Ghosh, A. Jain, P. Kovach, A. Marone, S. Plate, A

  20. Multi-level RF identification system

    DOE Patents [OSTI]

    Steele, Kerry D.; Anderson, Gordon A.; Gilbert, Ronald W.

    2004-07-20

    A radio frequency identification system having a radio frequency transceiver for generating a continuous wave RF interrogation signal that impinges upon an RF identification tag. An oscillation circuit in the RF identification tag modulates the interrogation signal with a subcarrier of a predetermined frequency and modulates the frequency-modulated signal back to the transmitting interrogator. The interrogator recovers and analyzes the subcarrier signal and determines its frequency. The interrogator generates an output indicative of the frequency of the subcarrier frequency, thereby identifying the responding RFID tag as one of a "class" of RFID tags configured to respond with a subcarrier signal of a predetermined frequency.

  1. Matching network for RF plasma source

    DOE Patents [OSTI]

    Pickard, Daniel S. (Palo Alto, CA); Leung, Ka-Ngo (Hercules, CA)

    2007-11-20

    A compact matching network couples an RF power supply to an RF antenna in a plasma generator. The simple and compact impedance matching network matches the plasma load to the impedance of a coaxial transmission line and the output impedance of an RF amplifier at radio frequencies. The matching network is formed of a resonantly tuned circuit formed of a variable capacitor and an inductor in a series resonance configuration, and a ferrite core transformer coupled to the resonantly tuned circuit. This matching network is compact enough to fit in existing compact focused ion beam systems.

  2. Cryogenic Test of a Coaxial Coupling Scheme for Fundamental and Higher Order Modes in Superconducting Cavities

    SciTech Connect (OSTI)

    J.K. Sekutowicz, P. Kneisel

    2009-05-01

    A coaxial coupling device located in the beam pipe of the TESLA type superconducting cavities provides for better propagation of Higher Order Modes (HOMs) and their strong damping in appropriate HOM couplers. Additionally, it also provides efficient coupling for fundamental mode RF power into the superconducting cavity. The whole coupling device can be designed as a detachable system. If appropriately dimensioned, the magnetic field can be minimized to a negligible level at the flange position. This scheme, presented previously*, provides for several advantages: strong HOM damping, flangeable solution, exchangeability of the HOM damping device on a cavity, less complexity of the superconducting cavity, possible cost advantages. This contribution will describe the results of the first cryogenic test.

  3. Fabrication of Niobium sheet for RF cavities 

    E-Print Network [OSTI]

    Balachandran, Shreyas

    2009-05-15

    This thesis investigated the microstructure and mechanical property of RRR( high purity) and RG (low purity) niobium (Nb) sheet material. RRR Nb is used in the fabrication RF cavities. Our method involves processing bulk ...

  4. Conquering Noise for Accurate RF and

    E-Print Network [OSTI]

    Anlage, Steven

    Conquering Noise for Accurate RF and Microwave Signal © Agilent Technologies, Inc. 2009 Microwave Signal Measurements Presented by: Ernie Jackson #12;The Noise Presentation · Review of Basics, Some Advanced & Newer Approaches · Noise in Signal Measurements-Summary · Basic Noise Reduction Approaches

  5. Monolithic RF frontends for ubiquitous wireless connectivity

    E-Print Network [OSTI]

    Goswami, Sushmit

    2014-01-01

    The desire for ubiquitous connectivity is pushing radios towards highly-integrated, multi-standard and multi-band implementations. This thesis explores architectures for next-generation RF frontends, which form the interface ...

  6. Si-based RF MEMS components.

    SciTech Connect (OSTI)

    Stevens, James E.; Nordquist, Christopher Daniel; Baker, Michael Sean; Fleming, James Grant; Stewart, Harold D.; Dyck, Christopher William

    2005-01-01

    Radio frequency microelectromechanical systems (RF MEMS) are an enabling technology for next-generation communications and radar systems in both military and commercial sectors. RF MEMS-based reconfigurable circuits outperform solid-state circuits in terms of insertion loss, linearity, and static power consumption and are advantageous in applications where high signal power and nanosecond switching speeds are not required. We have demonstrated a number of RF MEMS switches on high-resistivity silicon (high-R Si) that were fabricated by leveraging the volume manufacturing processes available in the Microelectronics Development Laboratory (MDL), a Class-1, radiation-hardened CMOS manufacturing facility. We describe novel tungsten and aluminum-based processes, and present results of switches developed in each of these processes. Series and shunt ohmic switches and shunt capacitive switches were successfully demonstrated. The implications of fabricating on high-R Si and suggested future directions for developing low-loss RF MEMS-based circuits are also discussed.

  7. Samsung: ENERGY STAR Referral (RF26VAB)

    Broader source: Energy.gov [DOE]

    DOE referred the matter of Samsung refrigerator-freezer model RF26VAB to the EPA for appropriate action after DOE testing showed that the model does not meet the ENERGY STAR specification.

  8. Deeply scaled CMOS for RF power applications

    E-Print Network [OSTI]

    Scholvin, Jörg, 1976-

    2006-01-01

    The microelectronics industry is striving to reduce the cost, complexity, and form factor of wireless systems through single-chip integration of analog, RF and digital functions. Driven by the requirements of the digital ...

  9. Micropower RF material proximity sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1998-01-01

    A level detector or proximity detector for materials capable of sensing through plastic container walls or encapsulating materials is of the sensor. Thus, it can be used in corrosive environments, as well as in a wide variety of applications. An antenna has a characteristic impedance which depends on the materials in proximity to the antenna. An RF oscillator, which includes the antenna and is based on a single transistor in a Colpitt's configuration, produces an oscillating signal. A detector is coupled to the oscillator which signals changes in the oscillating signal caused by changes in the materials in proximity to the antenna. The oscillator is turned on and off at a pulse repetition frequency with a low duty cycle to conserve power. The antenna consists of a straight monopole about one-quarter wavelength long at the nominal frequency of the oscillator. The antenna may be horizontally disposed on a container and very accurately detects the fill level within the container as the material inside the container reaches the level of the antenna.

  10. Superconductivity: the Gift that Keeps on Giving

    E-Print Network [OSTI]

    Goldberg, Bennett

    Superconductivity: the Gift that Keeps on Giving Superconductivity, first discovered recently the discovery of high superconducting transition temperatures in the ceramic copper oxides has superconductors. In the underdoped or pseudogap phase of the cuprate superconductors, a significant portion

  11. The superconducting solenoid magnets for MICE

    E-Print Network [OSTI]

    Green, Michael A.

    2002-01-01

    IEEE Transactions on Applied Superconductivity 13, No. 2 M.M. A. Green and J. M. Rey, “Superconducting Solenoids for anHigh Current Density Superconducting Solenoid Magnets for

  12. Superconducting vortex pinning with artificially prepared nanostructures

    E-Print Network [OSTI]

    Rosen, Yaniv Jacob

    E. Dubin, Physica C: Superconductivity 369, 21 (2002). R. D.P. G. De Gennes, Superconductivity of Metals and Alloys (W.Schuller, Journal of Superconductivity and Novel Magnetism

  13. Superconductivity in graphite intercalation compounds

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

    Smith, Robert P. [Univ. of Cambridge (United Kingdom); Dean, Mark P. M. [Brookhaven National Lab. (BNL), Upton, NY (United States); Weller, Thomas E. [Univ. College of London (United Kingdom); Howard, Christopher A. [Univ. College of London (United Kingdom); Rahnejat, Kaveh C. [Univ. College of London (United Kingdom); Saxena, Siddharth S. [Univ. of Cambridge (United Kingdom); Ellerby, Mark [Univ. College of London (United Kingdom)

    2015-07-01

    The field of superconductivity in the class of materials known as graphite intercalation compounds has a history dating back to the 1960s This paper recontextualizes the field in light of the discovery of superconductivity in CaC? and YbC? 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 this relates 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.

  14. Superconductivity in graphite intercalation compounds

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

    Smith, Robert P.; Weller, Thomas E.; Howard, Christopher A.; Dean, Mark P. M.; Rahnejat, Kaveh C.; Saxena, Siddharth S.; Ellerby, Mark

    2015-02-26

    This study examines the field of superconductivity in the class of materials known as graphite intercalation compounds which has a history dating back to the 1960s. This paper recontextualizes the field in light of the discovery of superconductivity in CaC? and YbC? 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 this relates to theoretical studies. The bulk of the evidence strongly supports a BCS superconducting state. However, important questions remain regarding which electronic statesmore »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.« less

  15. Model of Antiferromagnetic Superconductivity

    E-Print Network [OSTI]

    Geoffrey L. Sewell

    2015-09-28

    We present a simple model that supports superconductive and antiferromagnetic ordering. The model consists of a system of electrons on a simple cubic lattice that move by tunnel effect and interact via antiferromagnetic Ising spin couplings and short range repulsions: these include infinitely strong Hubbard forces that prevent double occupancy of any lattice site. Hence, under the filling condition of one electron per site and at sufficiently low temperature, the system is an antiferromagnetic Mott insulator. However, when holes are created by suitable doping, they are mobile charge carriers. We show that, at low concentration, their interactions induced by the above interelectronic ones lead to Schafroth pairing. Hence, under certain plausible but unproved assumptions, the model exhibits the off-diagonal long range order that characterises superconductivity, while retaining the antiferromagnetic ordering.

  16. Automatic Pole and Q-Value Extraction for RF Structures

    SciTech Connect (OSTI)

    C. Potratz, H.-W. Glock, U. van Rienen, F. Marhauser

    2011-09-01

    The experimental characterization of RF structures like accelerating cavities often demands for measuring resonant frequencies of Eigenmodes and corresponding (loaded) Q-values over a wide spectral range. A common procedure to determine the Q-values is the -3dB method, which works well for isolated poles, but may not be applicable directly in case of multiple poles residing in close proximity (e.g. for adjacent transverse modes differing by polarization). Although alternative methods may be used in such cases, this often comes at the expense of inherent systematic errors. We have developed an automation algorithm, which not only speeds up the measurement time significantly, but is also able to extract Eigenfrequencies and Q-values both for well isolated and overlapping poles. At the same time the measurement accuracy may be improved as a major benefit. To utilize this procedure merely complex scattering parameters have to be recorded for the spectral range of interest. In this paper we present the proposed algorithm applied to experimental data recorded for superconducting higher-order-mode damped multi-cell cavities as an application of high importance.

  17. Competition between singlet and triplet superconductivity

    E-Print Network [OSTI]

    Tian De Cao; Tie Bang Wang

    2009-10-04

    The competition between singlet and triplet superconductivity is examined in consideration of correlations on an extended Hubbard model. It is shown that the triplet superconductivity may not be included in the common Hubbard model since the strong correlation favors the singlet superconductivity, and thus the triplet superconductivity should be induced by the electron-phonon interaction and the ferromagnetic exchange interaction. We also present a superconducting qualification with which magnetism is unbeneficial to superconductivity.

  18. Optimizing RF gun cavity geometry within an automated injector design system

    SciTech Connect (OSTI)

    Alicia Hofler ,Pavel Evtushenko

    2011-03-28

    RF guns play an integral role in the success of several light sources around the world, and properly designed and optimized cw superconducting RF (SRF) guns can provide a path to higher average brightness. As the need for these guns grows, it is important to have automated optimization software tools that vary the geometry of the gun cavity as part of the injector design process. This will allow designers to improve existing designs for present installations, extend the utility of these guns to other applications, and develop new designs. An evolutionary algorithm (EA) based system can provide this capability because EAs can search in parallel a large parameter space (often non-linear) and in a relatively short time identify promising regions of the space for more careful consideration. The injector designer can then evaluate more cavity design parameters during the injector optimization process against the beam performance requirements of the injector. This paper will describe an extension to the APISA software that allows the cavity geometry to be modified as part of the injector optimization and provide examples of its application to existing RF and SRF gun designs.

  19. Superconducting magnet wire

    DOE Patents [OSTI]

    Schuller, Ivan K. (Woodridge, IL); Ketterson, John B. (Evanston, IL); Banerjee, Indrajit (San Jose, CA)

    1986-01-01

    A superconducting tape or wire with an improved critical field is formed of alternating layers of a niobium-containing superconductor such as Nb, NbTi, Nb.sub.3 Sn or Nb.sub.3 Ge with a thickness in the range of about 0.5-1.5 times its coherence length, supported and separated by layers of copper with each copper layer having a thickness in the range of about 170-600 .ANG..

  20. Equilibrium Distributions and Superconductivity

    E-Print Network [OSTI]

    Ashot Vagharshakyan

    2011-06-07

    In this article two models for charges distributions are discussed. On the basis of our consideration we put different points of view for stationary state. We prove that only finite energy model for charges' distribution and well-known variation principle explain some well-known experimental results. A new model for superconductivity was suggested, too. In frame of that model some characteristic experimental results for superconductors is possible to explain.

  1. Topological confinement and superconductivity

    SciTech Connect (OSTI)

    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.

  2. Superconducting VAR control. [Patent application

    DOE Patents [OSTI]

    Boenig, H.J.; Hassenzahl, W.V.

    1980-12-05

    Static VAR control means are described employing an asymmetrically controlled Graetz bridge and a superconducting direct current coil having low losses and low cost characteristics.

  3. Superconducting magnet development in Japan

    SciTech Connect (OSTI)

    Yasukochi, K.

    1983-05-01

    The present state of R and D works on the superconducting magnet and its applications in Japan are presented. On electrical rotating machines, 30 MVA superconducting synchronous rotary condenser (Mitsubishi and Fuji) and 50 MVA generator are under construction. Two ways of ship propulsion by superconducting magnets are developing. A superconducting magnetically levitated and linear motor propelled train ''MAGLEV'' was developed by the Japan National Railways (JNR). The superconducting magnet development for fusion is the most active field in Japan. The Cluster Test program has been demonstrated on a 10 T Nb/sub 3/Sn coil and the first coil of Large Coil Task in IEA collaboration has been constructed and the domestic test was completed in JAERI. These works are for the development of toroidal coils of the next generation tokamak machine. R and D works on superconducting ohmic heating coil are in progress in JAERI and ETL. The latter group has constructed 3.8 MJ pulsed coil. A high ramp rate of changing field in pulsed magnet, 200 T/s, has been tested successfully. High Energy Physics Laboratory (KEK) are conducting active works. The superconducting ..mu.. meson channel and ..pi.. meson channel have been constructed and are operating successfully. KEK has also a project of big accelerator named ''TRISTAN'', which is similar to ISABELLE project of BNL. Superconducting synchrotron magnets are developed for this project. The development of superconducting three thin wall solenoid has been started. One of them, CDF, is progressing under USA-Japan collaboration.

  4. Superconductivity and Superfluidity

    E-Print Network [OSTI]

    B. V. Vasiliev

    2013-10-31

    Currently there is a common belief that the explanation of superconductivity phenomenon lies in understanding the mechanism of the formation of electron pairs. Paired electrons, however, cannot form a superconducting condensate spontaneously. These paired electrons perform disorderly zero-point oscillations and there are no force of attraction in their ensemble. In order to create a unified ensemble of particles, the pairs must order their zero-point fluctuations so that an attraction between the particles appears. As a result of this ordering of zero-point oscillations in the electron gas, superconductivity arises. This model of condensation of zero-point oscillations creates the possibility of being able to obtain estimates for the critical parameters of elementary superconductors, which are in satisfactory agreement with the measured data. On the another hand, the phenomenon of superfluidity in He-4 and He-3 can be similarly explained, due to the ordering of zero-point fluctuations. It is therefore established that both related phenomena are based on the same physical mechanism.

  5. Superconducting dark energy

    E-Print Network [OSTI]

    Shi-Dong Liang; Tiberiu Harko

    2015-04-10

    Based on the analogy with superconductor physics we consider a scalar-vector-tensor gravitational model, in which the dark energy action is described by a gauge invariant electromagnetic type functional. By assuming that the ground state of the dark energy is in a form of a condensate with the U(1) symmetry spontaneously broken, the gauge invariant electromagnetic dark energy can be described in terms of the combination of a vector and of a scalar field (corresponding to the Goldstone boson), respectively. The gravitational field equations are obtained by also assuming the possibility of a non-minimal coupling between the cosmological mass current and the superconducting dark energy. The cosmological implications of the dark energy model are investigated for a Friedmann-Robertson-Walker homogeneous and isotropic geometry for two particular choices of the electromagnetic type potential, corresponding to a pure electric type field, and to a pure magnetic field, respectively. The time evolution of the scale factor, matter energy density and deceleration parameter are obtained for both cases, and it is shown that in the presence of the superconducting dark energy the Universe ends its evolution in an exponentially accelerating vacuum de Sitter state. By using the formalism of the irreversible thermodynamic processes for open systems we interpret the generalized conservation equations in the superconducting dark energy model as describing matter creation. The particle production rates, the creation pressure and the entropy evolution are explicitly obtained.

  6. Flavor Superconductivity & Superfluidity

    E-Print Network [OSTI]

    Matthias Kaminski

    2010-02-25

    In these lecture notes we derive a generic holographic string theory realization of a p-wave superconductor and superfluid. For this purpose we also review basic D-brane physics, gauge/gravity methods at finite temperature, key concepts of superconductivity and recent progress in distinct realizations of holographic superconductors and superfluids. Then we focus on a D3/D7-brane construction yielding a superconducting or superfluid vector-condensate. The corresponding gauge theory is 3+1-dimensional N=2 supersymmetric Yang-Mills theory with SU(N) color and SU(2) flavor symmetry. It shows a second order phase transition to a phase in which a U(1) subgroup of the SU(2) symmetry is spontaneously broken and typical superconductivity signatures emerge, such as a conductivity (pseudo-)gap and the Meissner-Ochsenfeld effect. Condensates of this nature are comparable to those recently found experimentally in p-wave superconductors such as a ruthenate compound. A string picture of the pairing mechanism and condensation is given using the exact knowledge of the corresponding field theory degrees of freedom.

  7. Magnetically leviated superconducting bearing

    DOE Patents [OSTI]

    Weinberger, Bernard R. (Avon, CT); Lynds, Jr., Lahmer (Glastonbury, CT)

    1993-01-01

    A magnetically levitated superconducting bearing includes a magnet (2) mounted on a shaft (12) that is rotatable around an axis of rotation and a Type II superconductor (6) supported on a stator (14) in proximity to the magnet (2). The superconductor (6) is positioned so that when it is cooled to its superconducting state in the presence of a magnetic field, it interacts with the magnet (2) to produce an attractive force that levitates the magnet (2) and supports a load on the shaft (12). The interaction between the superconductor (6) and magnet(2) also produces surface screening currents (8) that generate a repulsive force perpendicular to the load. The bearing also has means for maintaining the superconductor at a temperature below its critical temperature (16, 18). The bearing could also be constructed so the magnet (2) is supported on the stator (14) and the superconductor (6) is mounted on the shaft (12). The bearing can be operated by cooling the superconductor (6) to its superconducting state in the presence of a magnetic field.

  8. Superconducting Magnets for a Muon Collider

    E-Print Network [OSTI]

    Green, M.A.

    1996-01-01

    IEEE Transactions on Applied Superconductivity 3, No. 1,pMAG-544 LBL-38398 UC-414 Superconducting Magnets for a Muonsections, the nominal superconductor plus matrix current

  9. THE TECHNOLOGY OF SUPERCONDUCTING ACCELERATOR DIPOLES

    E-Print Network [OSTI]

    Hassenzahl, W.V.

    2010-01-01

    properties of practical superconductors,2 2. their sta-winding from the superconductive to the resistive state. *I. II. III. IV. V. Superconducting Materials Conductor Matri

  10. High-Temperature Superconducting Composite Conductors

    DOE Patents [OSTI]

    Holesinger, Terry G. (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM); Arendt, Paul N. (Los Alamos, NM); Groves, James R. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Ayala, Alicia (Santa Fe, NM)

    2005-01-18

    Copper or excess copper is added to one or more layers of a superconducting composite structure to reduce migration of copper form a copper based superconducting layer.

  11. Optimization of superconducting tiling pattern for superconducting bearings

    DOE Patents [OSTI]

    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.

  12. Optimization of superconducting tiling pattern for superconducting bearings

    DOE Patents [OSTI]

    Hull, J.R.

    1996-09-17

    An apparatus and method for reducing magnetic field inhomogeneities which produce rotational loss mechanisms in high temperature superconducting magnetic bearings are disclosed. 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. 20 figs.

  13. RF BREAKDOWN STUDIES USING PRESSURIZED CAVITIES

    SciTech Connect (OSTI)

    Johnson, Rolland

    2014-09-21

    Many present and future particle accelerators are limited by the maximum electric gradient and peak surface fields that can be realized in RF cavities. Despite considerable effort, a comprehensive theory of RF breakdown has not been achieved and mitigation techniques to improve practical maximum accelerating gradients have had only limited success. Part of the problem is that RF breakdown in an evacuated cavity involves a complex mixture of effects, which include the geometry, metallurgy, and surface preparation of the accelerating structures and the make-up and pressure of the residual gas in which plasmas form. Studies showed that high gradients can be achieved quickly in 805 MHz RF cavities pressurized with dense hydrogen gas, as needed for muon cooling channels, without the need for long conditioning times, even in the presence of strong external magnetic fields. This positive result was expected because the dense gas can practically eliminate dark currents and multipacting. In this project we used this high pressure technique to suppress effects of residual vacuum and geometry that are found in evacuated cavities in order to isolate and study the role of the metallic surfaces in RF cavity breakdown as a function of magnetic field, frequency, and surface preparation. One of the interesting and useful outcomes of this project was the unanticipated collaborations with LANL and Fermilab that led to new insights as to the operation of evacuated normal-conducting RF cavities in high external magnetic fields. Other accomplishments included: (1) RF breakdown experiments to test the effects of SF6 dopant in H2 and He gases with Sn, Al, and Cu electrodes were carried out in an 805 MHz cavity and compared to calculations and computer simulations. The heavy corrosion caused by the SF6 components led to the suggestion that a small admixture of oxygen, instead of SF6, to the hydrogen would allow the same advantages without the corrosion in a practical muon beam line. (2) A 1.3 GHz RF test cell capable of operating both at high pressure and in vacuum with replaceable electrodes was designed, built, and power tested in preparation for testing the frequency and geometry effects of RF breakdown at Argonne National Lab. At the time of this report this cavity is still waiting for the 1.3 GHz klystron to be available at the Wakefield Test Facility. (3) Under a contract with Los Alamos National Lab, an 805 MHz RF test cavity, known as the All-Seasons Cavity (ASC), was designed and built by Muons, Inc. to operate either at high pressure or under vacuum. The LANL project to use the (ASC) was cancelled and the testing of the cavity has been continued under the grant reported on here using the Fermilab Mucool Test Area (MTA). The ASC is a true pillbox cavity that has performed under vacuum in high external magnetic field better than any other and has demonstrated that the high required accelerating gradients for many muon cooling beam line designs are possible. (4) Under ongoing support from the Muon Acceleration Program, microscopic surface analysis and computer simulations have been used to develop models of RF breakdown that apply to both pressurized and vacuum cavities. The understanding of RF breakdown will lead to better designs of RF cavities for many applications. An increase in the operating accelerating gradient, improved reliability and shorter conditioning times can generate very significant cost savings in many accelerator projects.

  14. Power superconducting power transmission cable

    DOE Patents [OSTI]

    Ashworth, Stephen P. (Cambridge, GB)

    2003-01-01

    The present invention is for a compact superconducting power transmission cable operating at distribution level voltages. The superconducting cable is a conductor with a number of tapes assembled into a subconductor. These conductors are then mounted co-planarly in an elongated dielectric to produce a 3-phase cable. The arrangement increases the magnetic field parallel to the tapes thereby reducing ac losses.

  15. High critical current superconducting tapes

    DOE Patents [OSTI]

    Holesinger, Terry G. (Los Alamos, NM); Jia, Quanxi (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM)

    2003-09-23

    Improvements in critical current capacity for superconducting film structures are disclosed and include the use of a superconducting RE-BCO layer including a mixture of rare earth metals, e.g., yttrium and europium, where the ratio of yttrium to europium in the RE-BCO layer ranges from about 3 to 1 to from about 1.5 to 1.

  16. Design and evaluation of a low-level RF control system analog/digital receiver for the ILC main Linacs

    SciTech Connect (OSTI)

    Mavric, Uros; Vidmar, Matjaz; Chase, Brian; /Fermilab

    2008-06-01

    The proposed RF distribution scheme for the two 15 km long ILC LINACs, uses one klystron to feed 26 superconducting RF cavities operating at 1.3 GHz. For a precise control of the vector sum of the signals coming from the SC cavities, the control system needs a high performance, low cost, reliable and modular multichannel receiver. At Fermilab we developed a 96 channel, 1.3 GHz analog/digital receiver for the ILC LINAC LLRF control system. In the paper we present a balanced design approach to the specifications of each receiver section, the design choices made to fulfill the goals and a description of the prototyped system. The design is tested by measuring standard performance parameters, such as noise figure, linearity and temperature sensitivity. Measurements show that the design meets the specifications and it is comparable to other similar systems developed at other laboratories, in terms of performance.

  17. Superconducting Topological Insulators

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With Livermore National Lab on Supercomputing Click toSuperconducting

  18. Superconducting Topological Insulators

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With Livermore National Lab on Supercomputing ClickSuperconducting

  19. Superconductivity Conference Held

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With Livermore National Lab on SupercomputingSuperconductivity

  20. RF-Photonic Frequency Stability Gear Box

    E-Print Network [OSTI]

    Matsko, Andrey B; Ilchenko, Vladimir S; Seidel, David; Maleki, Lute

    2011-01-01

    An optical technique based on stability transfer among modes of a monolithic optical microresonator is proposed for long therm frequency stabilization of a radiofrequency (RF) oscillator. We show that locking two resonator modes, characterized with dissimilar sensitivity in responding to an applied forcing function, to a master RF oscillator allows enhancing the long term stability of a slave RF oscillator locked to two resonator modes having nearly identical sensitivity. For instance, the stability of a 10 MHz master oscillator characterized with Allan deviation of 10^-7 at 10^4s can be increased and transferred to a slave oscillator with identical stability performance, so that the resultant Allan deviation of the slave oscillator becomes equal to 10-13 at 10^4s. The method does not require absolute frequency references to achieve such a performance.

  1. X-Band RF Gun Development

    SciTech Connect (OSTI)

    Vlieks, Arnold; Dolgashev, Valery; Tantawi, Sami; Anderson, Scott; Hartemann, Fred; Marsh, Roark; /LLNL, Livermore

    2012-06-22

    In support of the MEGa-ray program at LLNL and the High Gradient research program at SLAC, a new X-band multi-cell RF gun is being developed. This gun, similar to earlier guns developed at SLAC for Compton X-ray source program, will be a standing wave structure made of 5.5 cells operating in the pi mode with copper cathode. This gun was designed following criteria used to build SLAC X-band high gradient accelerating structures. It is anticipated that this gun will operate with surface electric fields on the cathode of 200 MeV/m with low breakdown rate. RF will be coupled into the structure through a final cell with symmetric duel feeds and with a shape optimized to minimize quadrupole field components. In addition, geometry changes to the original gun, operated with Compton X-ray source, will include a wider RF mode separation, reduced surface electric and magnetic fields.

  2. High RF Power Production for CLIC

    E-Print Network [OSTI]

    Syratchev, I; Adli, E; Taborelli, M

    2007-01-01

    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and excite preferentially the synchronous mode. The RF power produced (several hundred MW) is collected at the downstream end of the structure by means of the Power Extractor and delivered to the main linac structure. The PETS geometry is a result of multiple compromises between beam stability and main linac RF power needs. Another requirement is to provide local RF power termination in case of accelerating structure failure (ON/OFF capability). Surface electric and magnetic fields, power extraction method, HOM damping, ON/OFF capability and fabrication technology were all evaluated to provide a reliable design

  3. Design and Construction of a 500 KW CW, 400 MHZ Klystron To Be Used As RF Power Source For LHC/RF Component Tests

    SciTech Connect (OSTI)

    Pearson, Chris

    2003-05-05

    A 500 kW cw klystron operating at 400 MHz was developed and constructed jointly by CERN and SLAC for use as a high-power source at CERN for testing LHC/RF components such as circulators, RF absorbers and superconducting cavities with their input couplers. The design is a modification of the 353 MHz SLAC PEP-I klystron. More than 80% of the original PEP-I tube parts could thus be incorporated in the LHC test klystron which resulted in lower engineering costs as well as reduced development and construction time. The physical length between cathode plane and upper pole plate was kept unchanged so that a PEP-I tube focusing solenoid, available at CERN, could be re-used. With the aid of the klystron simulation codes JPNDISK and CONDOR, the design of the LHC tube was accomplished, which resulted in a tube with noticeably higher efficiency than its predecessor, the PEP-I klystron. The integrated cavities were redesigned using SUPERFISH and the output coupling circuit, which also required redesigning, was done with the aid of MAFIA. Details of the tube development and test results are presented.

  4. The integration of cryogenic cooling systems with superconducting electronic systems

    E-Print Network [OSTI]

    Green, Michael A.

    2011-01-01

    applications for superconductivity have low heat loads in aTransactions on Applied Superconductivity t I, P 2615, (Cooling Systems With Superconducting Electronic Systems M.

  5. RECENT ADVANCES IN THE TECHNOLOGY OF SUPERCONDUCTING ACCELERATOR MAGNETS

    E-Print Network [OSTI]

    Taylor, C.E.

    2010-01-01

    Current Multipoles in Superconducting Accelerator Magnets."Utilization of the Superconducting Super Collider, Snowmass,Field Harmonics in Superconducting Accelerator Magnets,·

  6. Cryogenic Tests of the g-2 Superconducting Solenoid Magnet System

    E-Print Network [OSTI]

    Jia, L.X.

    2011-01-01

    in IEEE Transactions on Applied Superconductivity 5. No.F. Krienen et al.. "The Superconducting Inflector Dipole forTransactions on Applied Superconductivity 5. No.2 (1995) G.

  7. A superconducting focusing solenoid for the neutrino factory linear accelerator

    E-Print Network [OSTI]

    Green, Michael A.; Lebedev, V.; Strauss, B.P.

    2001-01-01

    et al, “The Role of Superconductivity and Cryogenics in theA Superconducting Focusing Solenoid for the Neutrino FactoryAcceleration Cells for the Superconducting Linac. Shown in

  8. Compressed Sensing Quantum Process Tomography for Superconducting Quantum Gates

    E-Print Network [OSTI]

    Rodionov, Andrey

    2014-01-01

    2.2 Review of superconducting qubits . . . . . .State Tomography for superconducting qubits 3.1 The idea ofPossible new effects in superconductive tunnelling”, Physics

  9. Fabrication, Testing and Modeling of the MICE Superconducting Spectrometer Solenoids

    E-Print Network [OSTI]

    Virostek, S.P.

    2010-01-01

    IEEE Transactions on Applied Superconductivity 15, No. 2, p.IEEE Transactions on Applied Superconductivity 15, No. 2, p.AND MODELING OF THE MICE SUPERCONDUCTING SPECTROMETER

  10. Quantum State Protection and Transfer Using Superconducting Qubits

    E-Print Network [OSTI]

    Keane, Kyle Michael

    2012-01-01

    relaxation . . . . . . . . .1.5 Superconducting ? ux-biasedCorrection Algorithms for Superconducting Qubits,” APS Marchand correction for superconducting qubits,” Phys. Rev. A,

  11. Preliminary Test Results for the MICE Spectrometer Superconducting Solenoids

    E-Print Network [OSTI]

    Virostek, Steve P.

    2009-01-01

    Transactions on Applied Superconductivity 19, No. 3 MICETransactions on Applied Superconductivity 15, No. 2, p 1259,Transactions on Applied Superconductivity 18, No. 2, p 937,

  12. Los Alamos scientists see new mechanism for superconductivity

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

    New mechanism for superconductivity Los Alamos scientists see new mechanism for superconductivity Researchers have posited an explanation for superconductivity that may open the...

  13. Design and fabrication of an RF power LDMOSFET on SOI

    E-Print Network [OSTI]

    Fiorenza, James G. (James George), 1972-

    2002-01-01

    This thesis studied thin-film Silicon-on-Insulator (SOI) LDMOSFET technology for RF power amplifier applications. To conduct this study, two generations of SOI RF power devices for portable wireless systems were designed ...

  14. eZ430-RF2500 Development Tool User's Guide

    E-Print Network [OSTI]

    ............................................................................................................... 6 2 eZ430-RF2500 Battery Board....................................................... 10 5 9600 bps With No Flow Control

  15. Superconducting structure with layers of niobium nitride and aluminum nitride

    DOE Patents [OSTI]

    Murduck, J.M.; Lepetre, Y.J.; Schuller, I.K.; Ketterson, J.B.

    1989-07-04

    A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources. 8 figs.

  16. Superconducting structure with layers of niobium nitride and aluminum nitride

    DOE Patents [OSTI]

    Murduck, James M. (Lisle, IL); Lepetre, Yves J. (Lauris, FR); Schuller, Ivan K. (Woodridge, IL); Ketterson, John B. (Evanston, IL)

    1989-01-01

    A superconducting structure is formed by depositing alternate layers of aluminum nitride and niobium nitride on a substrate. Deposition methods include dc magnetron reactive sputtering, rf magnetron reactive sputtering, thin-film diffusion, chemical vapor deposition, and ion-beam deposition. Structures have been built with layers of niobium nitride and aluminum nitride having thicknesses in a range of 20 to 350 Angstroms. Best results have been achieved with films of niobium nitride deposited to a thickness of approximately 70 Angstroms and aluminum nitride deposited to a thickness of approximately 20 Angstroms. Such films of niobium nitride separated by a single layer of aluminum nitride are useful in forming Josephson junctions. Structures of 30 or more alternating layers of niobium nitride and aluminum nitride are useful when deposited on fixed substrates or flexible strips to form bulk superconductors for carrying electric current. They are also adaptable as voltage-controlled microwave energy sources.

  17. Radio Broadcasts from Superconducting Strings

    E-Print Network [OSTI]

    Yi-Fu Cai; Eray Sabancilar; Daniele A. Steer; Tanmay Vachaspati

    2012-05-14

    Superconducting cosmic strings can give transient electromagnetic signatures that we argue are most evident at radio frequencies. We investigate the three different kinds of radio bursts from cusps, kinks, and kink-kink collisions on superconducting strings. We find that the event rate is dominated by kink bursts in a range of parameters that are of observational interest, and can be quite high (several a day at 1 Jy flux) for a canonical set of parameters. In the absence of events, the search for radio transients can place stringent constraints on superconducting cosmic strings.

  18. RF Design of the LCLS Gun

    SciTech Connect (OSTI)

    Limborg-Deprey, C

    2010-12-13

    Final dimensions for the LCLS RF gun are described. This gun, referred to as the LCLS gun, is a modified version of the UCLA/BNL/SLAC 1.6 cell S-Band RF gun [1], referred to as the prototype gun. The changes include a larger mode separation (15 MHz for the LCLS gun vs. 3.5 MHz for the prototype gun), a larger radius at the iris between the 2 cells, a reduced surface field on the curvature of the iris between the two cells, Z power coupling, increased cooling channels for operation at 120 Hz, dual rf feed, deformation tuning of the full cell, and field probes in both cells. Temporal shaping of the klystron pulse, to reduce the average power dissipated in the gun, has also been adopted. By increasing the mode separation, the amplitude of the 0-mode electric field on the cathode decreases from 10% of the peak on axis field for the prototype gun to less than 3% for the LCLS gun for the steady state fields. Beam performance is improved as shown by the PARMELA simulations. The gun should be designed to accept a future load lock system. Modifications follow the recommendations of our RF review committee [2]. Files and reference documents are compiled in Section IV.

  19. RF MEMS DC CONTACT SWTCHES FOR RECONFIGURABLE Presented to the

    E-Print Network [OSTI]

    Kassegne, Samuel Kinde

    RF MEMS DC CONTACT SWTCHES FOR RECONFIGURABLE ANTENNAS _______________ A Thesis Presented STATE UNIVERSITY The Undersigned Faculty Committee Approves the Thesis of Lei Zhou: RF DC Contact MEMS rock and water, water, through persistence, eventually wins. #12;vi ABSTRACT OF THE THESIS RF MEMS DC

  20. Superconducting magnetic coil

    DOE Patents [OSTI]

    Aized, D.; Schwall, R.E.

    1999-06-22

    A superconducting magnetic coil includes a plurality of sections positioned axially along the longitudinal axis of the coil, each section being formed of an anisotropic high temperature superconductor material wound about a longitudinal axis of the coil and having an associated critical current value that is dependent on the orientation of the magnetic field of the coil. The cross section of the superconductor, or the type of superconductor material, at sections along the axial and radial axes of the coil are changed to provide an increased critical current at those regions where the magnetic field is oriented more perpendicularly to the conductor plane, to thereby increase the critical current at these regions and to maintain an overall higher critical current of the coil. 15 figs.

  1. Superconductivity, Superfluidity and Holography

    E-Print Network [OSTI]

    Alberto Salvio

    2013-01-16

    This is a concise review of holographic superconductors and superfluids. We highlight some predictions of the holographic models and the emphasis is given to physical aspects rather than to the technical details, although some references to understand the latter are systematically provided. We include gapped systems in the discussion, motivated by the physics of high-temperature superconductivity. In order to do so we consider a compactified extra dimension (with radius R), or, alternatively, a dilatonic field. The first setup can also be used to model cylindrical superconductors; when these are probed by an axial magnetic field a universal property of holography emerges: while for large R (compared to the other scales in the problem) non-local operators are suppressed, leading to the so called Little-Parks periodicity, the opposite limit shows non-local effects, e.g. the uplifting of the Little-Parks periodicity. This difference corresponds in the gravity side to a Hawking-Page phase transition.

  2. Superconducting magnetic energy storage

    SciTech Connect (OSTI)

    Hassenzahl, W.

    1988-08-01

    Recent programmatic developments in Superconducting Magnetic Energy Storage (SMES) have prompted renewed and widespread interest in this field. In mid 1987 the Defense Nuclear Agency, acting for the Strategic Defense Initiative Office, issued a request for proposals for the design and construction of SMES Engineering Test Model (ETM). Two teams, one led by Bechtel and the other by Ebasco, are now engaged in the first phase of the development of a 10 to 20 MWhr ETM. This report presents the rationale for energy storage on utility systems, describes the general technology of SMES, and explains the chronological development of the technology. The present ETM program is outlined; details of the two projects for ETM development are described in other papers in these proceedings. The impact of high T/sub c/ materials on SMES is discussed. 69 refs., 3 figs., 3 tabs.

  3. Superconducting energy storage

    SciTech Connect (OSTI)

    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.

  4. Superconductivity from correlated hopping

    SciTech Connect (OSTI)

    Batista, C.D.; Lema, F.; Aligia, A.A. [Comision Nacional de Energia Atomica, Centro Atomico Bariloche and Instituto Balseiro, 8400 Bariloche (Argentina)] [Comision Nacional de Energia Atomica, Centro Atomico Bariloche and Instituto Balseiro, 8400 Bariloche (Argentina)

    1995-09-01

    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{sub 2} planes to a generalized {ital t}-{ital J} model and for large O-O hopping favors resonance-valence-bond superconductivity of predominantly {ital 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 {ital K}{sub {rho}}=(2{minus}{ital n}){sup 2}/2, where {ital n} is the particle density.

  5. Fabrication of arrays of nano-superconducting quantum interfernce devices using a double-angle processing approach

    E-Print Network [OSTI]

    Roediger, Peter

    2014-01-01

    incommensurate area superconducting quantum interferencearray of incommensurate superconducting quantum interferencetransition-temperature superconducting quantum interference

  6. An RF Waveguide Distribution System for the ILC Test Accelerator at Fermilab's NML

    SciTech Connect (OSTI)

    Nantista, Christopher; Adolphsen, Chris; Bowden, Gordon; Swent, Richard; McKee, Bobby; /SLAC

    2007-06-27

    An ILC R&D facility is being constructed in the NML building at Fermilab which, in addition to an injector and beam dump with spectrometer, will contain up to three cryomodules of ILC-type superconducting 9-cell cavities. This linac will be powered by a single klystron. As part of SLAC's contribution to this project, we will provide a distribution network in WR650 waveguide to the various cavity couplers. In addition to commercial waveguide components and circulators and loads, this system will include adjustable tap-offs, and customized hybrids. In one configuration, the circulators will be removed to test pair-wise cancellation of cavity reflections through hybrids. The system will be pressurized with nitrogen to 3 bar absolute to avoid the need for SF{sub 6}. The full distribution system for the first cryomodule will be delivered and installed later this year. We describe the design of the system and completed RF testing.

  7. Mixed-mu superconducting bearings

    DOE Patents [OSTI]

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

    1998-03-03

    A mixed-mu superconducting bearing is disclosed 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. 9 figs.

  8. On the theory of superconductivity 

    E-Print Network [OSTI]

    Cheng, Kai-Chia

    The phenomenon of superconductivity has so for defied all attempts of explanation since it was first discovered in 1911. Although two phenomenological theories have been put forward and proved very successful, yet no atomic theories based on quantum...

  9. EIS-0138: Superconducting Super Collider

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy developed this EIS to analyze the potential environmental impacts of constructing the Superconducting Super Collider, a large proton accelerator, at each of seven alternative locations.

  10. Superconducting laser photocathode RF gun at BNL | U.S. DOE Office...

    Office of Science (SC) Website

    megawatt) into the gun. This device will push ahead the performance of high-current CW guns by orders of magnitude and open the way for various applications, such as electron...

  11. Some wakefield effects in the superconducting RF cavities of LCLS-II

    E-Print Network [OSTI]

    Bane, K; Yakovlev, V

    2014-01-01

    For LCLS-II we estimate the power of radiated wakefields generated in the SRF cavities (including the 3rd harmonic cavities) and in the end transitions. Much of this power will pass through and reflect in the strings of cryomodules that comprise linacs L1, L2, or L3. Presumably, some of it will be absorbed by the higher order mode (HOM) couplers, or by the absorbers at warmer temperatures situated between the cryomodules. We investigate where such power gets generated, but not where it ends up. As such the results can serve as a pessimistic calculation of the extra power that needs to be removed by the cryosystem. Finally, we also estimate---under the assumption that all the wake power ends up in the SRF walls---the wall heating and the extent of Cooper pair breaking in L3, where the bunch is most intense. Note that all calculations here are of single bunch effects; thus resonant interactions are not included.

  12. A Study of Magnetic Shielding Performance of a Fermilab International Linear Collider Superconducting RF Cavity Cryomodule

    E-Print Network [OSTI]

    Crawford, Anthony C

    2014-01-01

    This note presents measurements that support the conclusion that it is feasible to achieve magnetic field values at the level of 5 milliGauss for a cryomodule in a realistic and representative ambient magnetic field environment.

  13. Field-dependent surface resistance of a superconducting RF cavity caused by impurity of surface

    E-Print Network [OSTI]

    Ge, M; Liepe, M; Hoffstaetter, G

    2015-01-01

    Q-slope issue, which is caused by the field dependent surface resistance, puzzled people for a long time in SRF fields. In this paper, we related the Q-slope with surface treatments; and proposed a surface-impurity model to explain the field-dependent of surface resistance of SRF cavities. Eighteen cavity-test results have been analyzed to examine the model. These cavities were treated by different recipes: Nitrogen-doping; BCP and HF-rinsing; EP with 120{\\deg}C baking; and EP without 120{\\deg}C baking. The performance of these cavities, which is normally represented by cavity quality factor versus accelerating gradient or surface magnetic field curves (Q0 vs. Eacc or Q0 vs. B), has included all types of Q-slope, such as Low-field Q-slope, Medium-field Q-slope, and Anti-Q-slope. The data fittings are quite successful; the fitting results will be shown. The model can be used to evaluate the effectiveness of the surface treatments. At last, the paper discussed the way to build a high-Q high-gradient SRF cavity.

  14. Superconducting laser photocathode RF gun at BNL | U.S. DOE Office of

    Office of Science (SC) Website

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorkingLosThe23-24, 2011Science (SC) RedefiningSign Up| U.S. DOEScience

  15. RF CAVITY PERFORMANCE in the ISAC-II SUPERCONDUCTING HEAVY ION LINAC

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impacts on Global TechnologyProceeding Sign In About227REVIEWOct.

  16. Progress on Superconducting Magnets for the MICE Cooling Channel

    SciTech Connect (OSTI)

    Green, Michael A; Virostek, Steve P.; Li, Derun; Zisman, Michael S.; Wang, Li; Pan, Heng; Wu, Hong; Guo, XingLong; Xu, FengYu; Liu, X. K.; Zheng, S. X.; Bradshaw, Thomas; Baynham, Elwyn; Cobb, John; Lau, Wing; Lau, Peter; Yang, Stephanie Q.

    2009-09-09

    The muon ionization cooling experiment (MICE) consists of a target, a beam line, a pion decay channel, the MICE cooling channel. Superconducting magnets are used in the pion decay channel and the MICE cooling channel. This report describes the MICE cooling channel magnets and the progress in the design and fabrication of these magnets. The MICE cooling channel consists of three types of superconducting solenoids; the spectrometer solenoids, the coupling solenoids and the focusing solenoids. The three types of magnets are being fabricated in he United States, China, and the United Kingdom respectively. The spectrometer magnets are used to analyze the muon beam before and after muon cooling. The coupling magnets couple the focusing sections and keep the muon beam contained within the iris of the RF cavities that re used to recover the muon momentum lost during ionization cooling. The focusing magnets focus the muon beam in the center of a liquid hydrogen absorber. The first of the cooling channel magnets will be operational in MICE in the spring of 2010.

  17. Strong Meissner screening change in superconducting radio frequency cavities due to mild baking

    SciTech Connect (OSTI)

    Romanenko, A. Grassellino, A.; Barkov, F.; Suter, A.; Salman, Z.; Prokscha, T.

    2014-02-17

    We investigate “hot” regions with anomalous high field dissipation in bulk niobium superconducting radio frequency cavities for particle accelerators by using low energy muon spin rotation (LE-?SR) on corresponding cavity cutouts. We demonstrate that superconducting properties at the hot region are well described by the non-local Pippard/BCS model for niobium in the clean limit with a London penetration depth ?{sub L}=23±2 nm. In contrast, a cutout sample from the 120??C baked cavity shows a much larger ?>100?nm and a depth dependent mean free path, likely due to gradient in vacancy concentration. We suggest that these vacancies can efficiently trap hydrogen and hence prevent the formation of hydrides responsible for rf losses in hot regions.

  18. Engineering Design and Fabrication of an Ampere-Class Superconducting Photocathode Electron Gun

    SciTech Connect (OSTI)

    Ben-Zvi,I.

    2008-11-17

    Over the past three years, Advanced Energy Systems and Brookhaven National Laboratory (BNL) have been collaborating on the design of an Ampere- class superconducting photocathode electron gun. BNL performed the physics design of the overall system and RF cavity under prior programs. Advanced Energy Systems (AES) is currently responsible for the engineering design and fabrication of the electron gun under contract to BNL. We will report on the engineering design and fabrication status of the superconducting photocathode electron gun. The overall configuration of the cryomodule will be reviewed. The layout of the hermitic string, space frame, shielding package, and cold mass will be discussed. The engineering design of the gun cavity and removable cathode will be presented in detail and areas of technical risk will be highlighted. Finally, the fabrication sequence and fabrication status of the gun cavity will be discussed.

  19. Development of microwave superconducting microresonators for neutrino mass measurement in the HOLMES framework

    E-Print Network [OSTI]

    Giachero, A; Falferi, P; Faverzani, M; Ferri, E; Giordano, C; Maino, M; Margesin, B; Mezzena, R; Nizzolo, R; Nucciotti, A; Puiu, A; Zanetti, L

    2015-01-01

    The European Research Council has recently funded HOLMES, a project with the aim of performing a calorimetric measurement of the electron neutrino mass measuring the energy released in the electron capture decay of \\textsuperscript{163}Ho. The baseline for HOLMES are microcalorimeters coupled to Transition Edge Sensors (TESs) read out with rf-SQUIDs, for microwave multiplexing purposes. A promising alternative solution is based on superconducting microwave resonators, that have undergone rapid development in the last decade. These detectors, called MKIDs (Microwave Kinetic Inductance Detectors), are inherently multiplexed in the frequency domain and suitable for even larger-scale pixel arrays, with theoretical high energy resolution and fast response. The aim of our activity is to develop arrays of microresonator detectors for X-ray spectroscopy and suitable for the calorimetric measurement of the energy spectra of \\textsuperscript{163}Ho. Superconductive multilayer films composed by a sequence of pure Titani...

  20. Strong Meissner screening change in superconducting radio frequency cavities due to mild baking

    E-Print Network [OSTI]

    Romanenko, A; Barkov, F; Suter, A; Salman, Z; Prokscha, T

    2013-01-01

    We investigate "hot" regions with anomalous high field dissipation in bulk niobium superconducting radio frequency cavities for particle accelerators by using low energy muon spin rotation (LE-$\\mu$SR) on corresponding cavity cutouts. We demonstrate that superconducting properties at the hot region are well described by the non-local Pippard/BCS model for niobium in the clean limit with a London penetration depth $\\lambda_\\mathrm{L} = 23 \\pm 2$ nm. In contrast, a cutout sample from the 120$^\\circ$C baked cavity shows a much larger $\\lambda > 100$ nm and a depth dependent mean free path, likely due to gradient in vacancy concentration. We suggest that these vacancies can efficiently trap hydrogen and hence prevent the formation of hydrides responsible for rf losses in hot regions.

  1. Rugged Ceramic Window for RF Applications

    SciTech Connect (OSTI)

    Neubauer, Michael; Johnson, Rolland P.; Rimmer, Robert; Elliot, Tom; Stirbet, Mircea

    2009-05-04

    High-current RF cavities that are needed for many accelerator applications are often limited by the power transmission capability of the pressure barriers (windows) that separate the cavity from the power source. Most efforts to improve RF window design have focused on alumina ceramic, the most popular historical choice, and have not taken advantage of new materials. Alternative window materials have been investigated using a novel Merit Factor comparison and likely candidates have been tested for the material properties which will enable construction in the self-matched window configuration. Window assemblies have also been modeled and fabricated using compressed window techniques which have proven to increase the power handling capability of waveguide windows. Candidate materials have been chosen to be used in fabricating a window for high power testing at Thomas Jefferson National Accelerator Facility.

  2. An Efficient RF Source for Jlab

    SciTech Connect (OSTI)

    Neubauer, M.; Dudas, A.; Rimmer, Robert A.; Wang, Haipeng

    2013-12-01

    We propose the development of a highly reliable high efficiency RF source for JLAB with a lower lifetime cost operating at 80% efficiency with system operating costs of about 0.7M$/year for the 6 GeV machine. The design of the RF source will be based upon two injection locked magnetrons in a novel combining architecture for amplitude modulation and a cross field amplifier (CFA) as an output tube for the 12 GeV upgrade. A cost analysis including efficiency and reliability will be performed to determine the optimum system architecture. Several different system architectures will be designed and evaluated for a dual injection locked magnetron source using novel combining techniques and possibly a CFA as the output tube. A paper design for the 1497 MHz magnetron system will be completed. The optimum system architecture with all relevant specifications will be completed so that a prototype can be built.

  3. ILC RF System R and D

    SciTech Connect (OSTI)

    Adolphsen, Chris; /SLAC

    2012-07-03

    The Linac Group at SLAC is actively pursuing a broad range of R&D to improve the reliability and reduce the cost of the L-band (1.3 GHz) rf system proposed for the ILC linacs. Current activities include the long-term evaluation of a 120 kV Marx Modulator driving a 10 MW Multi-Beam Klystron, design of a second-generation Marx Modulator, testing of a sheet-beam gun and beam transport system for a klystron, construction of an rf distribution system with remotely-adjustable power tapoffs, and development of a system to combine the power from many klystrons in low-loss circular waveguide where it would be tapped-off periodically to power groups of cavities. This paper surveys progress during the past few years.

  4. The new RF sources for accelerators

    SciTech Connect (OSTI)

    Ives, Lawrence; Read, Michael; Ferguson, Patrick; Marsden, David; Collins, George; Jackson, R. H.; Bui, Thuc; Kimura, Takuji; Eisen, Edward [Calabazas Creek Research, Inc., 690 Port Drive, San Mateo, CA, 94404, (650) 312-9575 (United States); Communications and Power Industries, LLC., 811 Hansen Way, Palo Alto, CA94304 (United States)

    2012-12-21

    Several new RF sources are being developed for accelerator and collider applications. Assembly is nearing completion of a multiple beam inductive output tube at 352 MHz. An annular beam klystron is being developed to produce 10 MW pulses at 1.3 GHz. The annular beam approach provides significant cost reduction over similar multiple beam devices. Fabrication is underway on a 10 kW, periodic permanent magnet klystron at 2.815 GHz. Permanent magnets eliminate the solenoid and associated power supplies and cooling requirements to reduce operational cost. Investigations are beginning on a novel approach for driving accelerator cavities using pulse shaping to increase coupling efficiency and dramatically reduce RF power requirements.

  5. RUGGED CERAMIC WINDOW FOR RF APPLICATIONS

    SciTech Connect (OSTI)

    MIKE NEUBAUER

    2012-11-01

    High-current RF cavities that are needed for many accelerator applications are often limited by the power transmission capability of the pressure barriers (windows) that separate the cavity from the power source. Most efforts to improve RF window design have focused on alumina ceramic, the most popular historical choice, and have not taken advantage of new materials. Alternative window materials have been investigated using a novel Merit Factor comparison and likely candidates have been tested for the material properties which will enable construction in the self-matched window configuration. Window assemblies have also been modeled and fabricated using compressed window techniques which have proven to increase the power handling capability of waveguide windows. Candidate materials have been chosen to be used in fabricating a window for high power testing at Thomas Jefferson National Accelerator Facility.

  6. The LASS (Larger Aperture Superconducting Solenoid) spectrometer

    SciTech Connect (OSTI)

    Aston, D.; Awaji, N.; Barnett, B.; Bienz, T.; Bierce, R.; Bird, F.; Bird, L.; Blockus, D.; Carnegie, R.K.; Chien, C.Y.

    1986-04-01

    LASS is the acronym for the Large Aperture Superconducting Solenoid spectrometer which is located in an rf-separated hadron beam at the Stanford Linear Accelerator Center. This spectrometer was constructed in order to perform high statistics studies of multiparticle final states produced in hadron reactions. Such reactions are frequently characterized by events having complicated topologies and/or relatively high particle multiplicity. Their detailed study requires a spectrometer which can provide good resolution in momentum and position over almost the entire solid angle subtended by the production point. In addition, good final state particle identification must be available so that separation of the many kinematically-overlapping final states can be achieved. Precise analyses of the individual reaction channels require high statistics, so that the spectrometer must be capable of high data-taking rates in order that such samples can be acquired in a reasonable running time. Finally, the spectrometer must be complemented by a sophisticated off-line analysis package which efficiently finds tracks, recognizes and fits event topologies and correctly associates the available particle identification information. This, together with complicated programs which perform specific analysis tasks such as partial wave analysis, requires a great deal of software effort allied to a very large computing capacity. This paper describes the construction and performance of the LASS spectrometer, which is an attempt to realize the features just discussed. The configuration of the spectrometer corresponds to the data-taking on K and K interactions in hydrogen at 11 GeV/c which took place in 1981 and 1982. This constitutes a major upgrade of the configuration used to acquire lower statistics data on 11 GeV/c K p interactions during 1977 and 1978, which is also described briefly.

  7. Cathode Ion Bombardment in RF Photoguns

    SciTech Connect (OSTI)

    Pozdeyev,E.; Kayran, D.; Litvinenko, V.

    2008-09-01

    In this paper, we use the method of rapid oscillating field to solve the equation of ion motion in an RF gun. We apply the method to the BNL 1/2-cell SRF photogun and demonstrate that a significant portion of ions produced in the gun can reach the cathode if no special precautions are taken. Also, the paper proposes a simple mitigation recipe that can reduce the rate of ion bombardment.

  8. PHYSICAL REVIEW B 91, 214508 (2015) Superconducting spin-valve effect and triplet superconductivity

    E-Print Network [OSTI]

    Fominov, Yakov

    2015-01-01

    PHYSICAL REVIEW B 91, 214508 (2015) Superconducting spin-valve effect and triplet superconductivity 12 June 2015) We report magnetic and superconducting properties of the modified spin-valve system Co theoretical description of the superconducting spin-valve effect and of the manifestation of the long

  9. RF Gun Photocathode Research at SLAC

    SciTech Connect (OSTI)

    Jongewaard, E.; Akre, R.; Brachmann, A.; Corbett, J.; Gilevich, S.; Grouev, K.; Hering, P.; P.Krejcik,; Lewandowski, J.; Loos, H.; Montagne, T.; Sheppard, J.C.; Stefan, P.; Vlieks, A.; Weathersby, S.; Zhou, F.; /SLAC

    2012-05-16

    LCLS is presently operating with a third copper photocathode in the original rf gun, with a quantum efficiency (QE) of {approx}1 x 10{sup -4} and projected emittance {gamma}{var_epsilon}{sub x,y} = 0.45 {micro}m at 250 pC bunch charge. The spare LCLS gun is installed in the SLAC Accelerator Structure Test Area (ASTA), fully processed to high rf power. As part of a wider photocathode R and D program, a UV laser system and additional gun diagnostics are being installed at ASTA to measure QE, QE lifetime, and electron beam emittance under a variety of operating conditions. The near-term goals are to test and verify the spare photocathode production/installation sequence, including transfer from the final holding chamber to the rf gun. Mid- and longer-term goals include development of a rigorous understanding of plasma and laser-assisted surface conditioning and investigation of new, high-QE photocathode materials. In parallel, an x-ray photoemission spectroscopy station is nearing completion, to analyze Cu photocathode surface chemistry. In this paper we review the status and anticipated operating parameters of ASTA and the spectroscopy test chamber.

  10. The Murmansk Initiative - RF: Acceptance Testing

    SciTech Connect (OSTI)

    Czajkowski, C.; Wester, D. W.; Dyer, R. S.; Soerlie, A. A.; Moller, B.; Barnes, E.

    2002-02-26

    The Murmansk Initiative-RF (MI) was conceived to provide the Russian Federation (RF) with the capacity to manage low-level liquid radioactive waste (LLRW) and comply with the requirements of the London Convention that prohibit ocean dumping. The trilateral project among Norway, the RF, and the United States of America (U.S.) began in 1994 and was the first to utilize exclusively Russian subcontractors to upgrade and expand an existing LLRW treatment plant on the premises of RTP Atomflot in Murmansk, Russia. The project moved quickly through the design phase. Progress during the construction phase was somewhat slower because of difficulties with acquisition of hardware, inexperience with automated instrumentation and control equipment, and unexpected design changes in the cementation unit. The project advanced into the test-operation phase, which is currently underway, in June 2001. Initial runs with liquid waste have revealed that procedures for unloading spent ion-exchange sorbents could be improved and that sludges formed during removal of alkaline-earth metals should be compacted in order for the facility to operate at its full potential. Resolution of these issues is expected within the next few months.

  11. Reducing the Heat Load on the LCLS 120 Hz RF Gun with RF Pulse Shaping

    SciTech Connect (OSTI)

    Schmerge, J.

    2005-01-31

    The LCLS injector must operate at 120 Hz repetition frequency but to date the maximum operating frequency of an S-band rf gun has been 50 Hz. The high fields desired for the LCLS gun operation limit the repetition frequency due to thermal expansion causing rf detuning and field redistribution. One method of addressing the thermal loading problem is too reduce the power lost on the cavity walls by properly shaping the rf pulse incident on the gun. The idea is to reach the steady state field value in the gun faster than the time constant of the gun would allow when using a flat incident rf pulse. By increasing the incident power by about a factor of three and then decreasing the incident power when the field reaches the desired value in the gun, the field build up time can be decreased by more than a factor of three. Using this technique the heat load is also decreased by more than a factor of three. In addition the rf coupling coefficient can be increased from the typical critically coupled designs to an overcoupled design which also helps reduce the field build up time. Increasing the coupling coefficient from 1 to 2 reduces the heat load by another 25% and still limits the reflected power and coupling hole size to manageable levels.

  12. Electrothermal simulation of superconducting nanowire avalanche photodetectors

    E-Print Network [OSTI]

    Marsili, Francesco

    We developed an electrothermal model of NbN superconducting nanowire avalanche photodetectors (SNAPs) on sapphire substrates. SNAPs are single-photon detectors consisting of the parallel connection of N superconducting ...

  13. Recent Developments in High Temperature Superconductivity 

    E-Print Network [OSTI]

    Hor, P. H.

    1988-01-01

    New material systems and the experimental progress of high temperature superconductivity are briefly reviewed. We examine both oxides and non-oxides which exhibit stable and/or unstable superconductivity at high temperatures....

  14. HIGH-FIELD SUPERCONDUCTING ACCELERATOR MAGNETS

    E-Print Network [OSTI]

    Taylor, C.

    2011-01-01

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

  15. Superconducting Partnership with Readiness Review Update

    E-Print Network [OSTI]

    1 Superconducting Partnership with Industry: Readiness Review Update Mike Gouge, ORNL Steve Ashworth, LANL Paul Bakke, DOE-Golden DOE 2004 Superconductivity Peer Review July 27-29, 2004 #12;2 SPI

  16. ORNL/HTSPC-10 ORNL Superconducting

    E-Print Network [OSTI]

    ORNL/HTSPC-10 ORNL Superconducting Technology Program for Electric Power Systems Annual Report http://www.doe.gov/bridge #12;ORNL/HTSPC-10 ORNL SUPERCONDUCTING TECHNOLOGY PROGRAM FOR ELECTRIC POWER

  17. Design of a Superconducting Quantum Computer

    E-Print Network [OSTI]

    Vallette, Bruno

    Design of a Superconducting Quantum Computer John Martinis UC Santa Barbara Is it really possible theory i d hi *error-correction and architecture* 4) Xmon superconducting qubits) p g q integrated

  18. AMORPHOUS MOLYBDENUM SILICON SUPERCONDUCTING THIN FILMS

    E-Print Network [OSTI]

    Bosworth, D.; Sahonta, S.-L.; Hadfield, R. H.; Barber, Z. H.

    2015-01-01

    Amorphous superconductors have become attractive candidate materials for superconducting nanowire single-photon detectors due to their ease of growth, homogeneity and competitive superconducting properties. To date the majority of devices have been...

  19. A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER

    E-Print Network [OSTI]

    O'Donnell, Tom

    A SUPERCONDUCTING-SOLENOID ISOTOPE SPECTROMETER FOR PRODUCTION OF NEUTRON-RICH NUCLEI ( 136 Xe Superconducting Cyclotron Laboratory's weekly \\Green Sheet," 30 July 1999 #12; c Thomas W. O'Donnell 2000 All

  20. A Synergy of Novel Experiments, Materials Science, Fundamental Physics, and Superconducting Magnets

    E-Print Network [OSTI]

    Godeke, Arno

    2007-01-01

    Fundamental Physics Superconducting Magnets Yields: Accuraterecord setting superconducting magnet systems ITER, NMRScience, Fundamental Physics, and Superconducting Magnets

  1. Superconducting Cable Termination

    DOE Patents [OSTI]

    Sinha, Uday K. (Carrollton, GA); Tolbert, Jerry (Newnan, GA)

    2005-08-30

    Disclosed is a termination that connects high temperature superconducting (HTS) cable immersed in pressurized liquid nitrogen to high voltage and neutral (shield) external bushings at ambient temperature and pressure. The termination consists of a splice between the HTS power (inner) and shield (outer) conductors and concentric copper pipes which are the conductors in the termination. There is also a transition from the dielectric tape insulator used in the HTS cable to the insulators used between and around the copper pipe conductors in the termination. At the warm end of the termination the copper pipes are connected via copper braided straps to the conventional warm external bushings which have low thermal stresses. This termination allows for a natural temperature gradient in the copper pipe conductors inside the termination which enables the controlled flashing of the pressurized liquid coolant (nitrogen) to the gaseous state. Thus the entire termination is near the coolant supply pressure and the high voltage and shield cold bushings, a highly stressed component used in most HTS cables, are eliminated. A sliding seal allows for cable contraction as it is cooled from room temperature to ˜72-82 K. Seals, static vacuum, and multi-layer superinsulation minimize radial heat leak to the environment.

  2. Improved superconducting magnet wire

    DOE Patents [OSTI]

    Schuller, I.K.; Ketterson, J.B.

    1983-08-16

    This invention is directed to a superconducting tape or wire composed of alternating layers of copper and a niobium-containing superconductor such as niobium of NbTi, Nb/sub 3/Sn or Nb/sub 3/Ge. In general, each layer of the niobium-containing superconductor has a thickness in the range of about 0.05 to 1.5 times its coherence length (which for Nb/sub 3/Si is 41 A) with each copper layer having a thickness in the range of about 170 to 600 A. With the use of very thin layers of the niobium composition having a thickness within the desired range, the critical field (H/sub c/) may be increased by factors of 2 to 4. Also, the thin layers of the superconductor permit the resulting tape or wire to exhibit suitable ductility for winding on a magnet core. These compositions are also characterized by relatively high values of critical temperature and therefore will exhibit a combination of useful properties as superconductors.

  3. A unified theory of superconductivity

    E-Print Network [OSTI]

    Xiuqing Huang

    2008-09-22

    In this paper, we study the reliability of BCS theory as a scientific explanation of the mystery of superconductivity. It is shown clearly that the phonon-mediated BCS theory is fundamentally 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, charge stripe order, spin density wave (SDW), checkerboard-type charge-ordered phase, magic doping fractions and vortex structures in conventional and unconventional (the high-Tc cuprates and MgB2) superconductors. The theory agrees with the existence of a pseudogap in high-temperature superconductors, while no pseudogap feature could be observed in MgB2 and most of the conventional superconductors. Our results indicate that the superconducting phase can coexist with a inclined hexagonal vortex lattice in pure MgB2 single crystal with a charge carrier density ps=1.49*10^{22}/cm^{3}. Finally, the physical reasons why the good conductors (for example, Ag, Au, and Cu) and the overdoped high-Tc superconductors are non-superconducting are also explored.

  4. Fast superconducting magnetic field switch

    DOE Patents [OSTI]

    Goren, Y.; Mahale, N.K.

    1996-08-06

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles. 6 figs.

  5. Fast superconducting magnetic field switch

    DOE Patents [OSTI]

    Goren, Yehuda (Mountain View, CA); Mahale, Narayan K. (The Woodlands, TX)

    1996-01-01

    The superconducting magnetic switch or fast kicker magnet is employed with electron stream or a bunch of electrons to rapidly change the direction of flow of the electron stream or bunch of electrons. The apparatus employs a beam tube which is coated with a film of superconducting material. The tube is cooled to a temperature below the superconducting transition temperature and is subjected to a constant magnetic field which is produced by an external dc magnet. The magnetic field produced by the dc magnet is less than the critical field for the superconducting material, thus, creating a Meissner Effect condition. A controllable fast electromagnet is used to provide a magnetic field which supplements that of the dc magnet so that when the fast magnet is energized the combined magnetic field is now greater that the critical field and the superconducting material returns to its normal state allowing the magnetic field to penetrate the tube. This produces an internal field which effects the direction of motion and of the electron stream or electron bunch. The switch can also operate as a switching mechanism for charged particles.

  6. Superconductive articles including cerium oxide layer

    DOE Patents [OSTI]

    Wu, Xin D. (Greenbelt, MD); Muenchausen, Ross E. (Espanola, NM)

    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. CAMD Nanofabrication Infrastructure

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L OBransenBusiness networkingFleetPuget Dr.Home :: Research ::

  8. CAMD Nanofabrication Links

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L OBransenBusiness networkingFleetPuget Dr.Home :: Research

  9. CAMD Nanofabrication Links

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L OBransenBusiness networkingFleetPuget Dr.Home ::

  10. CAMD Nanofabrication Research

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D B L OBransenBusiness networkingFleetPuget Dr.Home ::Publications ::

  11. Superconducting PM undiffused machines with stationary superconducting coils

    DOE Patents [OSTI]

    Hsu, John S.; Schwenterly, S. William

    2004-03-02

    A superconducting PM machine has a stator, a rotor and a stationary excitation source without the need of a ferromagnetic frame which is cryogenically cooled for operation in the superconducting state. PM material is placed between poles on the rotor to prevent leakage or diffusion of secondary flux before reaching the main air gap, or to divert PM flux where it is desired to weaken flux in the main air gap. The PM material provides hop-along capability for the machine in the event of a fault condition.

  12. Topical Review Progress in superconducting metamaterials

    E-Print Network [OSTI]

    Anlage, Steven

    Topical Review Progress in superconducting metamaterials Philipp Jung1,2 , Alexey V Ustinov1 in the development and applications of superconducting metamaterials. The review is organized in terms of several distinct advantages and unique properties brought to the metamaterials field by superconductivity

  13. Comment on "d id0 Chiral Superconductivity

    E-Print Network [OSTI]

    Wu, Zhigang

    Comment on "d þ id0 Chiral Superconductivity in Bilayer Silicene" In Ref. [1], Liu et al, their random-phase-approximation analysis sug- gests that the system is superconducting with the Cooper pairs, they claim that a high superconducting critical temperature is possible due to the tunable Fermi pocket via

  14. Superconductivity in iron compounds G. R. Stewart

    E-Print Network [OSTI]

    Wu, Zhigang

    of the superconductivity in this new class of compounds. These iron pnictide and chalcogenide (FePn/Ch) superconductors-phonon coupled ``conventional'' superconductors. Clearly, superconductivity and magnetism or magnetic of magnetism and superconductivity in FePn/Ch superconductors 1606 D. Tc and TS=TSDW versus pressure 1607 1

  15. Superconducting wire with improved strain characteristics

    DOE Patents [OSTI]

    Luhman, Thomas (Westhampton Beach, NY); Klamut, Carl J. (E. Patchogue, NY); Suenaga, Masaki (Bellport, NY); Welch, David (Stony Brook, NY)

    1982-01-01

    A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improves the strain characteristics of the wire.

  16. Superconducting wire with improved strain characteristics

    DOE Patents [OSTI]

    Luhman, Thomas (Westhampton Beach, NY); Klamut, Carl J. (East Patchogue, NY); Suenaga, Masaki (Bellport, NY); Welch, David (Stony Brook, NY)

    1982-01-01

    A superconducting wire comprising a superconducting filament and a beryllium strengthened bronze matrix in which the addition of beryllium to the matrix permits a low volume matrix to exhibit reduced elastic deformation after heat treating which increases the compression of the superconducting filament on cooling and thereby improve the strain characteristics of the wire.

  17. Design and Manufacture of the RF Power Supply and RF Transmission Line for SANAEM Project Prometheus

    E-Print Network [OSTI]

    Turemen, G; Unel, G; Alacakir, A

    2015-01-01

    A 1-5 MeV proton beamline is being built by the Turkish Atomic Energy Authority in collaboration with a number of graduate students from different universities. The most important aspect of the project, is to acquire the design ability and manufacturing capability of all the components locally. SPP will be an accelerator and beam diagnostics test facility and it will also serve the detector development community with its low beam current. This paper discusses the design and construction of the RF power supply and the RF transmission line components such as its waveguide converters and its circulator.

  18. Strain tolerant microfilamentary superconducting wire

    DOE Patents [OSTI]

    Finnemore, D.K.; Miller, T.A.; Ostenson, J.E.; Schwartzkopf, L.A.; Sanders, S.C.

    1993-02-23

    A strain tolerant microfilamentary wire capable of carrying superconducting currents is provided comprising a plurality of discontinuous filaments formed from a high temperature superconducting material. The discontinuous filaments have a length at least several orders of magnitude greater than the filament diameter and are sufficiently strong while in an amorphous state to withstand compaction. A normal metal is interposed between and binds the discontinuous filaments to form a normal metal matrix capable of withstanding heat treatment for converting the filaments to a superconducting state. The geometry of the filaments within the normal metal matrix provides substantial filament-to-filament overlap, and the normal metal is sufficiently thin to allow supercurrent transfer between the overlapped discontinuous filaments but is also sufficiently thick to provide strain relief to the filaments.

  19. EM modeling of RF drive in DTL tank 4

    SciTech Connect (OSTI)

    Kurennoy, Sergey S.

    2012-06-19

    A 3-D MicroWave Studio model for the RF drive in the LANSCE DTL tank 4 has been built. Both eigensolver and time-domain modeling are used to evaluate maximal fields in the drive module and RF coupling. The LANSCE DTL tank 4 has recently been experiencing RF problems, which may or may not be related to its replaced RF coupler. This situation stimulated a request by Dan Rees to provide EM modeling of the RF drive in the DTL tank 4 (T4). Jim O'Hara provided a CAD model that was imported into the CST Microwave Studio (MWS) and after some modifications became a part of a simplified MWS model of the T4 RF drive. This technical note describes the model and presents simulation results.

  20. Freely oriented portable superconducting magnet

    DOE Patents [OSTI]

    Schmierer, Eric N. (Los Alamos, NM); Prenger, F. Coyne (Los Alamos, NM); Hill, Dallas D. (Los Alamos, NM)

    2010-01-12

    A freely oriented portable superconducting magnet is disclosed. Coolant is supplied to the superconducting magnet from a repository separate from the magnet, enabling portability of the magnet. A plurality of support assemblies structurally anchor and thermally isolate the magnet within a thermal shield. A plurality of support assemblies structurally anchor and thermally isolate the thermal shield within a vacuum vessel. The support assemblies restrain movement of the magnet resulting from energizing and cooldown, as well as from changes in orientation, enabling the magnet to be freely orientable.

  1. Free-standing oxide superconducting articles

    DOE Patents [OSTI]

    Wu, X.D.; Muenchausen, R.E.

    1993-12-14

    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 layer.

  2. Multi-Physics Analysis of the Fermilab Booster RF Cavity

    SciTech Connect (OSTI)

    Awida, M.; Reid, J.; Yakovlev, V.; Lebedev, V.; Khabiboulline, T.; Champion, M.; /Fermilab

    2012-05-14

    After about 40 years of operation the RF accelerating cavities in Fermilab Booster need an upgrade to improve their reliability and to increase the repetition rate in order to support a future experimental program. An increase in the repetition rate from 7 to 15 Hz entails increasing the power dissipation in the RF cavities, their ferrite loaded tuners, and HOM dampers. The increased duty factor requires careful modelling for the RF heating effects in the cavity. A multi-physic analysis investigating both the RF and thermal properties of Booster cavity under various operating conditions is presented in this paper.

  3. Robust Diamond-Based RF Switch Yields Enhanced Communication...

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

    diamond (UNCD) as a dielectric. A specialized radio frequency (RF) micro-electromechanical system (MEMS) switch that promises enhanced capabilities for next-generation...

  4. DEVELOPMENT AND TESTING OF HIGH POWER RF VECTOR MODULATORS*

    SciTech Connect (OSTI)

    Kang, Yoon W [ORNL; Wilson, Joshua L [ORNL; Champion, Mark [FNAL; Hardek, Thomas W [ORNL; Kim, Sang-Ho [ORNL; McCarthy, Mike [ORNL; Vassioutchenko, Alexandre V [ORNL

    2007-01-01

    A fan-out RF power distribution system can allow many accelerating cavities to be powered by a single high-power klystron amplifier. High-power vector modulators can perform independent control of amplitudes and phases of RF voltages at the cavities without changing the klystron signal. A prototype highpower RF vector modulator employing a quadrature hybrid and two ferrite phase shifters in coaxial TEM transmission lines has been built and tested for 402.5 MHz. RF properties of the design and results of high power testing are presented.

  5. Locking Lasers to RF in an Ultra Fast FEL

    E-Print Network [OSTI]

    Wilcox, R.

    2011-01-01

    Lasers to RF in an Ultrafast FEL R. B . Wilcox, G . Huang,the X-ray pulses from the FEL. The phase-locked loop on the

  6. Active high-power RF switch and pulse compression system

    DOE Patents [OSTI]

    Tantawi, Sami G. (San Mateo, CA); Ruth, Ronald D. (Woodside, CA); Zolotorev, Max (Mountain View, CA)

    1998-01-01

    A high-power RF switching device employs a semiconductor wafer positioned in the third port of a three-port RF device. A controllable source of directed energy, such as a suitable laser or electron beam, is aimed at the semiconductor material. When the source is turned on, the energy incident on the wafer induces an electron-hole plasma layer on the wafer, changing the wafer's dielectric constant, turning the third port into a termination for incident RF signals, and. causing all incident RF signals to be reflected from the surface of the wafer. The propagation constant of RF signals through port 3, therefore, can be changed by controlling the beam. By making the RF coupling to the third port as small as necessary, one can reduce the peak electric field on the unexcited silicon surface for any level of input power from port 1, thereby reducing risk of damaging the wafer by RF with high peak power. The switch is useful to the construction of an improved pulse compression system to boost the peak power of microwave tubes driving linear accelerators. In this application, the high-power RF switch is placed at the coupling iris between the charging waveguide and the resonant storage line of a pulse compression system. This optically controlled high power RF pulse compression system can handle hundreds of Megawatts of power at X-band.

  7. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 16, NO. 5, OCTOBER 2007 1185 RF MEMS Sequentially Reconfigurable Sierpinski

    E-Print Network [OSTI]

    Tentzeris, Manos

    JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 16, NO. 5, OCTOBER 2007 1185 RF MEMS Sequentially, RF microelectromechanical systems (RF MEMS), Sierpinski fractal antenna. I. INTRODUCTION THE RF microelectromechanical systems (RF MEMS) switches are quickly becoming a popular switching ele- ment among microwave

  8. CLIC RF High Power Production Testing Program

    E-Print Network [OSTI]

    Syratchev, I; Tantawi, S

    2008-01-01

    The CLIC Power Extraction and Transfer Structure (PETS) is a passive microwave device in which bunches of the drive beam interact with the impedance of the periodically loaded waveguide and generate RF power for the main linac accelerating structure. The demands on the high power production (~ 150 MW) and the needs to transport the 100 A drive beam for about 1 km without losses, makes the PETS design rather unique and the operation very challenging. In the coming year, an intense PETS testing program will be implemented. The target is to demonstrate the full performance of the PETS operation. The testing program overview and test results available to date are presented.

  9. Sandia National Laboratories: RF & Photonics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust, High-ThroughputUpcoming Release of thePrograms:Mode Stirred ChamberReuseQuantum SystemsRF

  10. Design and first cold test of BNL superconducting 112 MHz QWR for electron gun applications

    SciTech Connect (OSTI)

    Belomestnykh, S.; Ben-Zvi, I.; Boulware, C.H.; Chang, X.; Grimm, T.L.; Siegel, B.; Than, R.; Winowski, M.

    2011-03-28

    Brookhaven National Laboratory and Niowave, Inc. have designed, fabricated, and performed the first cold test of a superconducting 112 MHz quarter-wave resonator (QWR) for electron gun experiments. The first cold test of the QWR cryomodule has been completed at Niowave. The paper discusses the cryomodule design, presents the cold test results, and outline plans to upgrade the cryomodule for future experiments. A quarter-wave resonator concept of superconducting RF (SRF) electron gun was proposed at BNL for electron cooling ion/proton beams at RHIC. QWRs can be made sufficiently compact even at low RF frequencies (long wavelengths). The long wavelength allows to produce long electron bunches, thus minimizing space charge effects and enabling high bunch charge. Also, such guns should be suitable for experiments requiring high average current electron beams. A 112 MHz QWR gun was designed, fabricated, and cold-tested in collaboration between BNL and Niowave. This is the lowest frequency SRF gun ever tested successfully. In this paper we describe the gun design and fabrication, present the cold test results, and outline plans for the cryomodule upgrade for future experiments.

  11. Superconducting flux flow digital circuits

    DOE Patents [OSTI]

    Hietala, V.M.; Martens, J.S.; Zipperian, T.E.

    1995-02-14

    A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs) are disclosed. Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics. 8 figs.

  12. Superconducting flux flow digital circuits

    DOE Patents [OSTI]

    Hietala, Vincent M. (Placitas, NM); Martens, Jon S. (Sunnyvale, CA); Zipperian, Thomas E. (Albuquerque, NM)

    1995-01-01

    A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs). Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics.

  13. Extremely high frequency RF effects on electronics.

    SciTech Connect (OSTI)

    Loubriel, Guillermo Manuel; Vigliano, David; Coleman, Phillip Dale; Williams, Jeffery Thomas; Wouters, Gregg A.; Bacon, Larry Donald; Mar, Alan

    2012-01-01

    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings.

  14. Recent advances in RF power generation

    SciTech Connect (OSTI)

    Tallerico, P.J.

    1990-01-01

    This paper is a review of the progress and methods used in RF generation for particle accelerators. The frequencies of interest are from a few megahertz to 100 GHz, and the powers are for super linear collider applications, but in this case the pulses are short, generally below 1 {mu}s. The very high-power, short-pulse generators are only lightly reviewed here, and for more details the reader should follow the specialized references. Different RF generators excel over various parts of the frequency spectrum. Below 100 MHz solid-state devices and gridded tubes prevail, while the region between 400 MHz and 3 GHz, the cyclotron-resonant devices predominate, and above 250 GHz, Free-Electron Lasers and ubitrons are the most powerful generators. The emphasis for this review is on microwave generation at frequencies below 20 GHz, so the cyclotron-resonant devices are only partially reviewed, while the progress on free-electron laser and ubitrons is not reviewed in this paper. 39 refs., 4 figs.

  15. High performance RF MEMS metal-contact switches and switching networks

    E-Print Network [OSTI]

    Patel, Chirag D.; Patel, Chirag D.

    2012-01-01

    A Compact Cantilever-Based RF MEMS Switch andA High-Performance RF MEMS Metal-Contact Switch and Switch-B High-Q 3-/4-Bit RF MEMS Digitally Tunable Capacitors for

  16. Quasi-optical network analyzers and high-reliability RF MEMS switched capacitors

    E-Print Network [OSTI]

    Grichener, Alexander

    2011-01-01

    Chapter 3 High-Reliability RF MEMS Switched Capacitors 3.1Technology 1.2 RF MEMS Technology . . . . . . . . . . . . .Reliability High-Q Switched RF MEMS Capacitors” IEEE Int.

  17. Cooling at the quantum limit and RF refrigeration

    E-Print Network [OSTI]

    Fominov, Yakov

    Cooling at the quantum limit and RF refrigeration Jukka Pekola Low Temperature Laboratory, Helsinki (electromagnetic) heat transport Cooling at the quantum limit: experiments RF refrigeration in a single as a refrigerator Optimum cooling power is reached at V 2/e: Cooling power of a NIS junction: Temperature TN

  18. RF Power Potential of 45 nm CMOS Technology Usha Gogineni

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    RF Power Potential of 45 nm CMOS Technology Usha Gogineni 1 , Jesús A. del Alamo 1 devices in recent years has motivated their use in millimeter-wave power applications. Specific, VT Abstract - This paper presents the first measurements of the RF power performance of 45 nm CMOS

  19. DEVELOPMENT OF BROADBAND LOW-VOLTAGE RF MEM SWITCHES

    E-Print Network [OSTI]

    Shen, Shyh-Chiang

    DEVELOPMENT OF BROADBAND LOW-VOLTAGE RF MEM SWITCHES S.C. Shen, D. T. Becher, D. C. Caruth, and M)333-4054 Fax: (217) 244-6375 Abstract We present novel RF switches using micro-electro- mechanical (MEM) technology. These MEM switches are built on GaAs substrates using GaAs MESFET MMIC- compatible processes

  20. RF cavity using liquid dielectric for tuning and cooling

    DOE Patents [OSTI]

    Popovic, Milorad (Warrenville, IL); Johnson, Rolland P. (Newport News, VA)

    2012-04-17

    A system for accelerating particles includes an RF cavity that contains a ferrite core and a liquid dielectric. Characteristics of the ferrite core and the liquid dielectric, among other factors, determine the resonant frequency of the RF cavity. The liquid dielectric is circulated to cool the ferrite core during the operation of the system.

  1. Booster Synchrotron RF System Upgrade for SPEAR3

    SciTech Connect (OSTI)

    Park, Sanghyun; Corbett, Jeff; /SLAC

    2012-07-06

    Recent progress at the SPEAR3 includes the increase in stored current from 100 mA to 200 mA and top-off injection to allow beamlines to stay open during injection. Presently the booster injects 3.0 GeV beam to SPEAR3 three times a day. The stored beam decays to about 150 mA between the injections. The growing user demands are to increase the stored current to the design value of 500 mA, and to maintain it at a constant value within a percent or so. To achieve this goal the booster must inject once every few minutes. For improved injection efficiency, all RF systems at the linac, booster and SPEAR3 need to be phase-locked. The present booster RF system is basically a copy of the SPEAR2 RF system with 358.5 MHz and 40 kW peak RF power driving a 5-cell RF cavity for 1.0 MV gap voltage. These requirements entail a booster RF system upgrade to a scaled down version of the SPEAR3 RF system of 476.3 MHz with 1.2 MW cw klystron output power capabilities. We will analyze each subsystem option for their merits within budgetary and geometric space constraints. A substantial portion of the system will come from the decommissioned PEP-II RF stations.

  2. Dial It In: Rotating RF Sensors to Enhance Radio Tomography

    E-Print Network [OSTI]

    Patwari, Neal

    --A radio tomographic imaging (RTI) system uses the received signal strength (RSS) measured by RF sensors of the antenna of each RF sensor can dramatically affect imaging and localization performance of an RTI system in a deployed RTI system requires the deployer to iteratively "guess-and-retest", i.e., pick a sensor to move

  3. Beyond ITER: RF Heating and Current Drive Issues for DEMO

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    Current devices Need flexible RF systems for heating, CD, start-up, instability suppression, and profileBeyond ITER: RF Heating and Current Drive Issues for DEMO C. K. Phillips, J. C. Hosea, G. Taylor under development ­ May need Lower Hybrid for r/a > 0.6 (not currently on ITER) ­ Need feedback control

  4. Model Reduction for RF MEMS Simulation David S. Bindel1

    E-Print Network [OSTI]

    California at Davis, University of

    Model Reduction for RF MEMS Simulation David S. Bindel1 , Zhaojun Bai2 , and James W. Demmel3 1@eecs.berkeley.edu Abstract. Radio-frequency (RF) MEMS resonators, integrated into CMOS chips, are of great interest-preserving model-reduction techniques and apply them to the frequency-domain analysis of two proposed MEMS

  5. RF-MEMS capacitive switches with high reliability

    DOE Patents [OSTI]

    Goldsmith, Charles L.; Auciello, Orlando H.; Carlisle, John A.; Sampath, Suresh; Sumant, Anirudha V.; Carpick, Robert W.; Hwang, James; Mancini, Derrick C.; Gudeman, Chris

    2013-09-03

    A reliable long life RF-MEMS capacitive switch is provided with a dielectric layer comprising a "fast discharge diamond dielectric layer" and enabling rapid switch recovery, dielectric layer charging and discharging that is efficient and effective to enable RF-MEMS switch operation to greater than or equal to 100 billion cycles.

  6. Shielded RF Lattice for the Muon Front End Chris Rogers,

    E-Print Network [OSTI]

    McDonald, Kirk

    Shielded RF Lattice for the Muon Front End Chris Rogers, Accelerator Science and Technology Centre (ASTeC), Rutherford Appleton Laboratory #12; Shielded RF Lattice I wanted to remind folks a lot of slides apologies I've tried to break it up a bit #12; Part 1 Shielded Lattice Baseline

  7. Tunnel MOS Heterostructure Field Effect Transistor for RF Switching Applications 

    E-Print Network [OSTI]

    Rezanezhad Gatabi, Iman

    2013-06-06

    GaN RF switches are widely used in today’s communication systems. With digital communications getting more and more popular nowadays, the need for improving the performance of involved RF switches is inevitable. Designing low ON-state resistance Ga...

  8. Proposal for high pressure RF cavity test in the MTA

    SciTech Connect (OSTI)

    Yonehara, K.; /Fermilab

    2010-09-01

    In order to demonstrate the feasibility of high pressure hydrogen gas filled RF (HPRF) cavities for muon ionization cooling, an HPRF cavity must be tested with a high intensity charged beam. When an HPRF cavity is irradiated with an intense beam each incident particle generates about 1000 electrons and ions per cubic centimeter in a high pressure cavity via ionization. These ionization electrons are influenced by the RF field and the RF quality factor goes down. This Q factor reduction will be a problem with a multi bunch beam, e.g., a muon beam for a muon collider consists of a 12 to 20 bunch train beam with 5 ns timing gap. Thus, the RF field must recover in few nano seconds. We propose to use a 400 MeV proton beam in the MTA and measure a beam loading effect in the HPRF cavity and study the recovery mechanism of the RF field.

  9. Cold Test Measurements on the GTF Prototype RF Gun

    SciTech Connect (OSTI)

    Gierman, S.M.

    2010-12-03

    The SSRL Gun Test Facility (GTF) was built to develop a high brightness electron injector for the LCLS and has been operational since 1996. Based on longitudinal phase space measurements showing a correlated energy spread the gun was removed and re-characterized in 2002. The low power RF measurements performed on the gun are described below. Perturbative bead measurements were performed to determine the field ratio in the two-cell gun, and network analyzer measurements were made to characterize the mode structure. A second probe was installed to monitor the RF field in the first cell, and a diagnostic was developed to monitor the high-power field ratio. Calibration of the RF probes, a model for analyzing RF measurements, and Superfish simulations of bead and RF measurements are described.

  10. Progress on a cryogenically cooled RF gun polarized electron source

    SciTech Connect (OSTI)

    Fliller, R.P., III; Edwards, H.; /Fermilab

    2006-08-01

    RF guns have proven useful in multiple accelerator applications. An RF gun capable of producing polarized electrons is an attractive electron source for the ILC or an electron-ion collider. Producing such a gun has proven elusive. The NEA GaAs photocathode needed for polarized electron production is damaged by the vacuum environment in an RF gun. Electron and ion back bombardment can also damage the cathode. These problems must be mitigated before producing an RF gun polarized electron source. In this paper we report continuing efforts to improve the vacuum environment in a normal conducting RF gun by cooling it with liquid nitrogen after a high temperature vacuum bake out. We also report on a design of a cathode preparation chamber to produce bulk GaAs photocathodes for testing in such a gun. Future directions are also discussed.

  11. RF-driven Proton Source with a Back-streaming Electron Dump

    E-Print Network [OSTI]

    Ji, Q.

    2010-01-01

    RESULTS A. Atomic ion fraction for RF power above 500 W. AtI, the atomic ion fraction increases with the RF power, and

  12. Superconducting Cable Having A Felexible Former

    DOE Patents [OSTI]

    Hughey, Raburn L. (Franklin, GA); Sinha, Uday K. (Carrollton, GA); Reece, David S. (Carrollton, GA); Muller, Albert C. (Eidson, TN)

    2005-03-15

    In order to provide a flexible oxide superconducting cable which is reduced in AC loss, tape-shaped superconducting wires covered with a stabilizing metal are wound on a flexible former. The superconducting wires are preferably laid on the former at a bending strain of not more than 0.2%. In laying on the former, a number of tape-shaped superconducting wires are laid on a core member in a side-by-side manner, to form a first layer. A prescribed number of tape-shaped superconducting wires are laid on top of the first layer in a side-by-side manner, to form a second layer. The former may be made of a metal, plastic, reinforced plastic, polymer, or a composite and provides flexibility to the superconducting wires and the cable formed therewith.

  13. Superconducting Cable Having A Flexible Former

    DOE Patents [OSTI]

    Hughey, Raburn L. (Franklin, GA); Sinha, Uday K. (Carrollton, GA); Reece, David S. (Carrollton, GA); Muller, Albert C. (Eidson, TN)

    2005-08-30

    In order to provide a flexible oxide superconducting cable which is reduced in AC loss, tape-shaped superconducting wires covered with a stabilizing metal are wound on a flexible former. The superconducting wires are preferably laid on the former at a bending strain of not more than 0.2%. In laying on the former, a number of tape-shaped superconducting wires are laid on a core member in a side-by-side manner, to form a first layer. A prescribed number of tape-shaped superconducting wires are laid on top of the first layer in a side-by-side manner, to form a second layer. The former may be made of a metal, plastic, reinforced plastic, polymer, or a composite and provides flexibility to the superconducting wires and the cable formed therewith.

  14. LHC RF System Time-Domain Simulation

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.

    2010-09-14

    Non-linear time-domain simulations have been developed for the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC). These simulations capture the dynamic behavior of the RF station-beam interaction and are structured to reproduce the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They are also a valuable tool for the study of diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Results from these studies and related measurements from PEP-II and LHC have been presented in multiple places. This report presents an example of the time-domain simulation implementation for the LHC.

  15. RF Power Generation in LINAC4

    E-Print Network [OSTI]

    Brunner, O; Schwerg, J N

    2010-01-01

    Linac4 is a lin­ear ac­cel­er­a­tor for neg­a­tive Hy­dro­gen ions (H-) which will re­place the old Linac2 as lin­ear in­jec­tor for the CERN ac­cel­er­a­tors. Its high­er en­er­gy of 160 MeV will give in­creased beam in­ten­si­ty in the down­stream ma­chines. Linac4 is about 100 m long, nor­mal-con­duct­ing, and will be housed in a tun­nel about 12 m below ground. The Linac4 tun­nel will be con­nect­ed to the ex­ist­ing chain of ac­cel­er­a­tors and can be ex­tend­ed to the new in­jec­tion chain. The high RF power for the Linac4 ac­cel­er­at­ing struc­tures will be gen­er­at­ed by thir­teen 1.3 MW klystrons, pre­vi­ous­ly used for the CERN LEP ac­cel­er­a­tor, and six new 2.8 MW klystrons of all op­er­at­ing at a fre­quen­cy of 352.2 MHz. The in­te­gra­tion of the RF power sys­tem in the build­ing is pre­sent­ed. The tech­ni­cal spec­i­fi­ca­tions and the per­for­mance of the var­i­ous high-pow­er el­e­ments are dis­cussed, ...

  16. Quadratic superconducting cosmic strings revisited

    E-Print Network [OSTI]

    Mustapha Azreg-Aïnou

    2008-02-22

    It has been shown that 5-dimensional general relativity action extended by appropriate quadratic terms admits a singular superconducting cosmic string solution. We search for cosmic strings endowed with similar and extended physical properties by directly integrating the non-linear matrix field equations thus avoiding the perturbative approach by which we constructed the above-mentioned \\textsl{exact} solution. The most general superconducting cosmic string, subject to some constraints, will be derived and shown to be mathematically \\textsl{unique} up to linear coordinate transformations mixing its Killing vectors. The most general solution, however, is not globally equivalent to the old one due to the existence of Killing vectors with closed orbits.

  17. Ten questions and answers about superconductivity

    E-Print Network [OSTI]

    Tian De Cao

    2012-11-13

    This work answers the basic questions of superconductivity in a question-and-answer format. We extend a basic hypothesis to various superconductors. This hypothesis is that superconductivity requires that the pairing gap locates around the Fermi level. On the basis of this hypothesis our calculations give the so-called three factor theory with which some key problems of the high temperature superconductivity are explained.

  18. Superconducting thin films on potassium tantalate substrates

    DOE Patents [OSTI]

    Feenstra, Roeland (Oak Ridge, TN); Boatner, Lynn A. (Oak Ridge, TN)

    1992-01-01

    A superconductive system for the lossless transmission of electrical current comprising a thin film of superconducting material Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7-x epitaxially deposited upon a KTaO.sub.3 substrate. The KTaO.sub.3 is an improved substrate over those of the prior art since the it exhibits small lattice constant mismatch and does not chemically react with the superconducting film.

  19. Effective theory of color superconductivity

    E-Print Network [OSTI]

    Deog Ki Hong

    2007-07-17

    We briefly review an effective theory of QCD at high baryon density, describing the relevant modes near the Fermi surface. The high density effective theory has properties of reparametrization invariance and gauge invariance, maintained in a subtle way. It also has a positive measure, allowing lattice simulations at high baryon density. We then apply it to gapless superconductors and discuss recent proposals to resolve the magnetic instability of gapless superconductivity.

  20. Processing method for superconducting ceramics

    DOE Patents [OSTI]

    Bloom, Ira D. (Bolingbrook, IL); Poeppel, Roger B. (Glen Ellyn, IL); Flandermeyer, Brian K. (Cincinnati, OH)

    1993-01-01

    A process for preparing a superconducting ceramic and particularly YBa.sub.2 Cu.sub.3 O.sub.7-.delta., where .delta. is in the order of about 0.1-0.4, is carried out using a polymeric binder which decomposes below its ignition point to reduce carbon residue between the grains of the sintered ceramic and a nonhydroxylic organic solvent to limit the problems with water or certain alcohols on the ceramic composition.

  1. Reverse circling supercurrents along a superconducting ring

    E-Print Network [OSTI]

    Tian De Cao

    2012-01-21

    The reason why high temperature superconductivity has been being debated is that many basic ideas in literatures are wrong. This work shows that the magnetic flux quantum in a superconducting ring have been inaccurately explained in fact, thus we suggest a reinterpretation of the magnetic flux quantum in a superconducting ring on the basis of the translations of pairs. We also predict that the internal and external surface of a superconducting tube have the reverse circling supercurrents. This means that a more thick tube could trap a larger amount of flux. Both the magnetic flux quantum and the reverse circling supercurrents could not be found with the London equation.

  2. MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; SOLID STATE...

    Office of Scientific and Technical Information (OSTI)

    Open problems in condensed matter physics, 1987 Falicov, L.M. 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; SOLID STATE PHYSICS; RESEARCH PROGRAMS;...

  3. Superconducting Magnet Technology for Future Hadron Colliders

    E-Print Network [OSTI]

    Scanlan, R.M.

    2011-01-01

    Trans. on Applied Superconductivity, 5 (1995), J.R. Millersummer study on superconductingdevices and acceleratorsGeneral. Advanced Superconductors (IGC). Waterbury.

  4. Superconductive articles including cerium oxide layer

    DOE Patents [OSTI]

    Wu, X.D.; Muenchausen, R.E.

    1993-11-16

    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 figures.

  5. New Advance in SuperConducting Materials

    ScienceCinema (OSTI)

    None

    2010-01-08

    Superconducting materials will transform the world's electrical infrastructure, saving billions of dollars once the technical details and installation are in place. At Los Alamos National Laborator...  

  6. Light Induced Superconductivity | Stanford Synchrotron Radiation...

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

    Light Induced Superconductivity Wednesday, August 5, 2015 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: Daniele Nicoletti, Max Planck Institute for the Structure and...

  7. Superconducting inductive displacement detection of a microcantilever

    SciTech Connect (OSTI)

    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??T, 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.

  8. Testing gravitational physics with superconducting gravimeters

    E-Print Network [OSTI]

    Sachie Shiomi

    2009-02-24

    Superconducting gravimeters are the most sensitive instruments to measure surface gravity changes at low frequencies. Currently, about twenty five superconducting gravimeters are operating in the world and their global network has been developed. We investigate possible applications of the superconducting gravimeters to tests of gravitational physics. Previous experimental searches for spatial anisotropies in the gravitational constant G and for gravitational waves, performed with gravimeters in 1960's to 1970's, can be improved by applications of the current superconducting gravimeters. Also, we describe other proposed applications of testing the universality of free-fall and searching for composition-dependent dilatonic waves, and discuss future works necessary for these geophysical tests.

  9. High-power magnetron transmitter as an RF source for the electron collider ring of the MEIC facility

    E-Print Network [OSTI]

    Kazakevich, G

    2014-01-01

    A novel concept of high-power transmitters utilizing the Continuous Wave (CW) magnetrons, frequency-locked by phase-modulated signals has been proposed to compensate energy losses caused by Synchrotron Radiation (SR) in the electron ring of the MEIC facility. At operating frequency of about 750 MHz the SR losses are ~2 MW. They can be compensated by some number of Superconducting RF (SRF) cavities at the feeding power of about 100-200 kW per cavity. A high-power CW transmitters, based on magnetrons, frequency-locked by phase-modulated signal, allowing a wide-band control in phase and power, and associated with a wide-band closed feedback loop are proposed to feed the SRF cavities to compensate the SR losses of the electron beam in the MEIC collider electron ring.

  10. Film Deposition, Cryogenic RF Testing and Materials Analysis of a Nb/Cu Single Cell SRF Cavity

    SciTech Connect (OSTI)

    Zhao, Xin; Geng, Rongli; Palczerski, Ari; Li, Yongming

    2013-09-01

    In this study, we present preliminary results on using a cathodic-arc-discharge Nb plasma ion source to establish a Nb film-coated single-cell Cu cavity for SRF research. The polycrystalline Cu cavity was fabricated and mirror-surface-finished by a centrifugal barrel polishing (CBP) process at Jefferson Lab. Special pre-coating processes were conducted, in order to create a template-layer for follow-on Nb grain thickening. A sequence of cryogenic RF testing demonstrated that the Nb film does show superconductivity. But the quality factor of this Nb/Cu cavity is low as a result of high residual surface resistance. We are conducting a thorough materials characterization to explore if some microstructural defects or hydrogen impurities, led to such a low quality factor.

  11. A potential Rosetta Stone of high temperature superconductivity...

    Office of Science (SC) Website

    for the high temperature superconductivity. Summary Superconductivity enables the flow of electricity without any loss of energy, but this extremely-low temperature...

  12. Distinct superconducting states in the pressure-induced metallic...

    Office of Scientific and Technical Information (OSTI)

    Distinct superconducting states in the pressure-induced metallic structures of the nominal semimetal Bi4Te3 Citation Details In-Document Search Title: Distinct superconducting...

  13. Spin Torques in Magnetic and Superconducting Tunnel Junctions

    E-Print Network [OSTI]

    Hoffman, Silas Eli

    2012-01-01

    Proximity Effects at Superconducting Interfaces . . . . . .of spin-triplet superconductivity in Co-based JosephsonExchange Field in Superconductor- Ferromagnet Structures. ”

  14. Estimating the Cost of Large Superconducting Thin Solenoid Magnets

    E-Print Network [OSTI]

    Green, M.A.

    2011-01-01

    W. C. T. Stoddart, Superconductivity Conference Proceedings,Powell, Applied Superconductivity p 346, (1972). Appliedpure aluminum stabilized superconductor. The cost of this

  15. FORCED TWO PHASE HELIUM COOLING OF LARGE SUPERCONDUCTING MAGNETS

    E-Print Network [OSTI]

    Green, M.A.

    2010-01-01

    DIAMETER TPC THIN SUPERCONDUCTING SOLENOID . 'i.A. Green,an Aluminum Stabilized Superconductor", Cryogenics 17, Vol.and Construction of a Superconducting Stabilized Aluminum

  16. Planar superconducting resonators with internal quality factors above one million

    E-Print Network [OSTI]

    Martinis, John M.

    Planar superconducting resonators with internal quality factors above one million A. Megrant,1,2 C criti- cal elements for superconducting electromagnetic radiation detectors,1 quantum memories,2

  17. GROUND PLANE INSULATION FAILURE IN THE FIRST TPC SUPERCONDUCTING COIL

    E-Print Network [OSTI]

    Green, M.A.

    2010-01-01

    FAILURE IN THE FIRST TPC SUPERCONDUCTING COIL M. A. Green,Time Projection Cnamber) thin superconducting solenoid. Theand breakage of the superconductor. The UPA circuit melted

  18. Progress on Superconducting Magnets for the MICE Cooling Channel

    E-Print Network [OSTI]

    Green, Michael A

    2010-01-01

    IEEE Transactions on Applied Superconductivty 15, No. 2, p274 Progress on the Superconducting Magnets for the MICETransactions on Applied Superconductivity 13, No. 2 p 1373 (

  19. A Superconducting transformer system for high current cable testing

    E-Print Network [OSTI]

    Godeke, A.

    2010-01-01

    A Superconducting Transformer System for High Current CableDC) superconducting transformer system for the high currentsuperconducting cables. The transformer consists of a core-

  20. LHC Beam Diffusion Dependence on RF Noise: Models And Measurements

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Van Winkle, D.; Baudrenghien, P.; Butterworth, A.; Molendijk, J.; ,

    2010-09-14

    Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work. During a long store, the relation between the energy lost to synchrotron radiation and the noise injected to the beam by the RF accelerating voltage determines the growth of the bunch energy spread and longitudinal emittance. Since the proton synchrotron radiation in the LHC is very low, the beam diffusion is extremely sensitive to RF perturbations. The theoretical formalism presented in [1], suggests that the noise experienced by the beam depends on the cavity phase noise power spectrum, filtered by the beam transfer function, and aliased due to the periodic sampling of the accelerating voltage signal V{sub c}. Additionally, the dependence of the RF accelerating cavity noise spectrum on the Low Level RF (LLRF) configurations has been predicted using time-domain simulations and models [2]. In this work, initial measurements at the LHC supporting the above theoretical formalism and simulation predictions are presented.

  1. Upgrading EMMA to Use Low-frequency RF Cavities

    SciTech Connect (OSTI)

    Ohmori, C.; Berg, J.

    2011-04-30

    EMMA is an experiment to study beam dynamics in fixed field alternating gradient accelerators (FFAGs). It accelerates the beam in about 10 turns using 1.3 GHz cavities in a mode like that used for muon accelerators. Many applications of FFAGs prefer to have slower acceleration, typically thousands of turns. To do so in EMMA would require the RF system to be replaced with a low-frequency, high-gradient system. This paper describes the motivation for studying slow acceleration in EMMA and the required parameters for an RF system to do that. It then describes the technology needed for the RF system.

  2. An RF dosimeter for independent SAR measurement in MRI scanners

    SciTech Connect (OSTI)

    Qian, Di; Bottomley, Paul A.; El-Sharkawy, AbdEl-Monem M.; Edelstein, William A.

    2013-12-15

    Purpose: The monitoring and management of radio frequency (RF) exposure is critical for ensuring magnetic resonance imaging (MRI) safety. Commercial MRI scanners can overestimate specific absorption rates (SAR) and improperly restrict clinical MRI scans or the application of new MRI sequences, while underestimation of SAR can lead to tissue heating and thermal injury. Accurate scanner-independent RF dosimetry is essential for measuring actual exposure when SAR is critical for ensuring regulatory compliance and MRI safety, for establishing RF exposure while evaluating interventional leads and devices, and for routine MRI quality assessment by medical physicists. However, at present there are no scanner-independent SAR dosimeters. Methods: An SAR dosimeter with an RF transducer comprises two orthogonal, rectangular copper loops and a spherical MRI phantom. The transducer is placed in the magnet bore and calibrated to approximate the resistive loading of the scanner's whole-body birdcage RF coil for human subjects in Philips, GE and Siemens 3 tesla (3T) MRI scanners. The transducer loop reactances are adjusted to minimize interference with the transmit RF field (B{sub 1}) at the MRI frequency. Power from the RF transducer is sampled with a high dynamic range power monitor and recorded on a computer. The deposited power is calibrated and tested on eight different MRI scanners. Whole-body absorbed power vs weight and body mass index (BMI) is measured directly on 26 subjects. Results: A single linear calibration curve sufficed for RF dosimetry at 127.8 MHz on three different Philips and three GE 3T MRI scanners. An RF dosimeter operating at 123.2 MHz on two Siemens 3T scanners required a separate transducer and a slightly different calibration curve. Measurement accuracy was ?3%. With the torso landmarked at the xiphoid, human adult whole?body absorbed power varied approximately linearly with patient weight and BMI. This indicates that whole-body torso SAR is on average independent of the imaging subject, albeit with fluctuations. Conclusions: Our 3T RF dosimeter and transducers accurately measure RF exposure in body-equivalent loads and provide scanner-independent assessments of whole-body RF power deposition for establishing safety compliance useful for MRI sequence and device testing.

  3. Characterization of an RF plasma ion source for ion implantation

    SciTech Connect (OSTI)

    Kopalidis, Peter M.; Wan Zhimin

    2012-11-06

    A novel inductively coupled RF plasma ion source has been developed for use in a beamline ion implanter. Ion density data have been taken with an array of four Langmuir probes spaced equally at the source extraction arc slit. These provide ion density uniformity information as a function of source pressure, RF power and gas mixture composition. In addition, total extracted ion beam current data are presented for the same conditions. The comparative advantages of the RF source in terms of higher beam current, reduced maintenance and overall productivity improvement compared to a hot cathode source are discussed.

  4. Communication methods, systems, apparatus, and devices involving RF tag registration

    DOE Patents [OSTI]

    Burghard, Brion J. (W. Richland, WA); Skorpik, James R. (Kennewick, WA)

    2008-04-22

    One technique of the present invention includes a number of Radio Frequency (RF) tags that each have a different identifier. Information is broadcast to the tags from an RF tag interrogator. This information corresponds to a maximum quantity of tag response time slots that are available. This maximum quantity may be less than the total number of tags. The tags each select one of the time slots as a function of the information and a random number provided by each respective tag. The different identifiers are transmitted to the interrogator from at least a subset of the RF tags.

  5. RF-MEMS load sensors with enhanced Q-factor and sensitivity in a suspended architecture

    E-Print Network [OSTI]

    Demir, Hilmi Volkan

    RF-MEMS load sensors with enhanced Q-factor and sensitivity in a suspended architecture Rohat Melik-implant RF-MEMS a b s t r a c t In this paper, we present and demonstrate RF-MEMS load sensors designed the strain change in real-time. For this purpose, we present RF- MEMS resonator sensors that shift

  6. Microwave Laminate PCB Compatible RF MEMS Technology for Wireless Communication Systems

    E-Print Network [OSTI]

    De Flaviis, Franco

    Microwave Laminate PCB Compatible RF MEMS Technology for Wireless Communication Systems * Bedri A microwave laminate printed circuit board (PCB) compatible RF MEMS technology for wireless communication systems. This technology is novel in that RF MEMS components, particularly RF MEM switches, can

  7. Superconducting Accelerating Cavity Pressure Sensitivity Analysis and Stiffening

    SciTech Connect (OSTI)

    Rodnizki, J [Soreq NRC, Yavne, Israel; Ben Aliz, Y [Soreq NRC, Yavne, Israel; Grin, A [Soreq NRC, Yavne, Israel; Horvitz, Z [Soreq NRC, Yavne, Israel; Perry, A [Soreq NRC, Yavne, Israel; Weissman, L [Soreq NRC, Yavne, Israel; Davis, G Kirk [JLAB; Delayen, Jean R. [Old Dominion Universtiy

    2014-12-01

    The Soreq Applied Research Accelerator Facility (SARAF) design is based on a 40 MeV 5 mA light ions superconducting RF linac. Phase-I of SARAF delivers up to 2 mA CW proton beams in an energy range of 1.5 - 4.0 MeV. The maximum beam power that we have reached is 5.7 kW. Today, the main limiting factor to reach higher ion energy and beam power is related to the HWR sensitivity to the liquid helium coolant pressure fluctuations. The HWR sensitivity to helium pressure is about 60 Hz/mbar. The cavities had been designed, a decade ago, to be soft in order to enable tuning of their novel shape. However, the cavities turned out to be too soft. In this work we found that increasing the rigidity of the cavities in the vicinity of the external drift tubes may reduce the cavity sensitivity by a factor of three. A preliminary design to increase the cavity rigidity is presented.

  8. Three-cell traveling wave superconducting test structure

    SciTech Connect (OSTI)

    Avrakhov, Pavel; Kanareykin, Alexei; /Euclid Techlabs, Solon; Kazakov, Sergey; Solyak, Nikolay; Wu, Genfa; Yakovlev, Vyacheslav P.; /Fermilab

    2011-03-01

    Use of a superconducting traveling wave accelerating (STWA) structure with a small phase advance per cell rather than a standing wave structure may provide a significant increase of the accelerating gradient in the ILC linac. For the same surface electric and magnetic fields the STWA achieves an accelerating gradient 1.2 larger than TESLA-like standing wave cavities. The STWA allows also longer acceleration cavities, reducing the number of gaps between them. However, the STWA structure requires a SC feedback waveguide to return the few hundreds of MW of circulating RF power from the structure output to the structure input. A test single-cell cavity with feedback was designed, manufactured and successfully tested demonstrating the possibility of a proper processing to achieve a high accelerating gradient. These results open way to take the next step of the TW SC cavity development: to build and test a travelingwave three-cell cavity with a feedback waveguide. The latest results of the single-cell cavity tests are discussed as well as the design of the test 3-cell TW cavity.

  9. RF Thermal Plasma Synthesis of Ferrite Nanopowders from Metallurgical Wastes

    E-Print Network [OSTI]

    Gubicza, Jenõ

    that of ferrites synthesized by the conventional ceramic route. Introduction Radiofrequency (RF) thermal plasmas by X-ray diffraction (XRD) using a Philips Xpert diffractometer and CuK radiation (=0.15418 nm

  10. Electrical degradation mechanisms of RF power GaAs PHEMTs

    E-Print Network [OSTI]

    Villanueva, Anita A. (Anita Ariel), 1978-

    2007-01-01

    GaAs Pseudomorphic High-Electron Mobility Transistors (PHEMTs) are widely used in RF power applications. Since these devices typically operate at high power levels and under high voltage biasing, their electrical reliability ...

  11. Possible high power limitations from RF pulsed heating

    SciTech Connect (OSTI)

    Pritzkau, D.P.; Bowden, G.B.; Menegat, A.; Siemann, R.H. [Stanford Linear Accelerator Center, Stanford University, California 94309 (United States)

    1999-05-01

    One of the possible limitations to achieving high power in RF structures is damage to metal surfaces due to RF pulsed heating. Such damage may lead to degradation of RF performance. An experiment to study RF pulsed heating on copper has been developed at SLAC. The experiment consists of operating two pillbox cavities in the TE{sub 011} mode using a 50 MW X-Band klystron. The estimated temperature rise of the surface of copper is 350&hthinsp;{degree}C for a power input of 20 MW to each cavity with a pulse length of 1.5 {mu}s. Preliminary results from an experiment performed earlier are presented. A revised design for continued experiments is also presented along with relevant theory and calculations. {copyright} {ital 1999 American Institute of Physics.}

  12. Efficiency enhancement techniques for RF and millimeter wave power amplifiers

    E-Print Network [OSTI]

    Ogunnika, Olumuyiwa Temitope, 1978-

    2012-01-01

    Power amplifiers are the circuit blocks in wireless transceivers that require the largest power budget because of their relatively low efficiencies. RF designers cannot depend solely on the development better semiconductor ...

  13. Klystron "efficiency loop" for the ALS storage ring RF system

    E-Print Network [OSTI]

    Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

    2002-01-01

    to Mod, Feb. 7, 2002] SRRF Klystron Beam Current (A) [AfterTime (hrs) Figure 2: SRRF Klystron Efficiency Comparison forKLYSTRON “EFFICIENCY LOOP” FOR THE ALS STORAGE RING RF

  14. Recent Progress of RF Cavity Study at Mucool Test Area

    SciTech Connect (OSTI)

    Yonehara, Katsuya; /Fermilab

    2011-12-02

    Summar of presentation is: (1) MTA is a multi task working space to investigate RF cavities for R&D of muon beam cooling channel - (a) Intense 400 MeV H{sup -} beam, (b) Handle hydrogen (flammable) gas, (c) 5 Tesla SC solenoid magnet, (d) He cryogenic/recycling system; (2) Pillbox cavity has been refurbished to search better RF material - Beryllium button test will be happened soon; (3) E x B effect has been tested in a box cavity - Under study (result seems not to be desirable); (4) 201 MHz RF cavity with SRF cavity treatment has been tested at low magnetic field - (a) Observed some B field effect on maximum field gradient and (b) Further study is needed (large bore SC magnet will be delivered end of 2011); and (5) HPRF cavity beam test has started - (a) No RF breakdown observed and (b) Design a new HPRF cavity to investigate more plasma loading effect.

  15. RADIATION SOLID STATE PHYSICS R.F. Konopleva

    E-Print Network [OSTI]

    Titov, Anatoly

    233 RADIATION SOLID STATE PHYSICS R.F. Konopleva The development of the nuclear and nuclear fusion, and the thermonuclear devices. In this connection the "Laboratory of the non-equilibrium electronic processes

  16. BN/Graphene/BN Transistors for RF Applications

    E-Print Network [OSTI]

    Taychatanapat, Thiti

    In this letter, we demonstrate the first BN/graphene/BN field-effect transistor for RF applications. This device structure can preserve the high mobility and the high carrier velocity of graphene, even when it is sandwiched ...

  17. Exotic Superconductivity in Correlated Electron Systems

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

    Mu, Gang; Sandu, Viorel; Li, Wei; Shen, Bing

    2015-05-25

    Over the past decades, the search for high-Tc superconductivity (SC) and its novel superconducting mechanisms is one of the most challenging tasks of condensed matter physicists and material scientists, wherein the most striking achievement is the discovery of high-c and unconventional superconductivity in strongly correlated 3d-electron systems, such as cuprates and iron pnictides/chalcogenides. Those exotic superconductors display the behaviors beyond the scope of the BCS theory (in the SC states) and the Landau-Fermi liquid theory (in the normal states). In general, such exotic superconductivity can be seen as correlated electron systems, where there are strong interplays among charge, spin, orbital,more »and lattice degrees of freedom. Thus, we focus on the exotic superconductivity in materials with correlated electrons in the present special issue.« less

  18. STRIPES AND SUPERCONDUCTIVITY IN CUPRATE SUPERCONDUCTORS

    SciTech Connect (OSTI)

    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.

  19. Free-standing oxide superconducting articles

    DOE Patents [OSTI]

    Wu, Xin D. (Greenbelt, MD); Muenchausen, Ross E. (Espanola, NM)

    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).

  20. Frequency and amplitude control for an experimental linac rf drive 

    E-Print Network [OSTI]

    Atre, Mahesh Purushottam

    1992-01-01

    FREQUENCY AND AMPLITUDE CONTROL FOR AN EXPERIMENTAL LINAC RF DRIVE A Thesis by MAHESH PURUSHOTTAM ATRE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1992 Major Subject: Electrical Engineering FREQUENCY AND AMPLITUDE CONTROL FOR AN EXPERIMENTAL LINAC RF DRIVE A Thesis by MAHESH PURUSHOTTAM ATRE Approved as to style and content by: S. P. Bhattachary (Chair of Committee) arng Huang...

  1. Measurement of current distribution on RF coils using MR imaging 

    E-Print Network [OSTI]

    Wu, Yu

    1993-01-01

    MEASUREMENT OF CURRENT DISTRIBUTION ON RF COILS USING MR IMAGING A Thesis by YU WU Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December... 1993 Major Subject' Electrical Engineering MEASUREMENT OF CURRENT DISTRIBUTION ON RF COILS USING MR IMAGING A Thesis by YU WU Submitted to Texas ASM University in partial fulfillment of the requirments for the degree of MASTER OF SCIENCE...

  2. DOE planning workshop on rf theory and computations

    SciTech Connect (OSTI)

    Not Available

    1984-01-01

    The purpose of the two-day workshop-meeting was to review the status of rf heating in magnetic fusion plasmas and to determine the outstanding problems in this area. The term rf heating was understood to encompass not only bulk plasma heating by externally applied electromagnetic power but also current generation in toroidal plasmas and generation of thermal barriers in tandem mirror plasmas.

  3. Handbook for Gas Filled RF Cavity Aficionados'

    SciTech Connect (OSTI)

    Tollestrup, A.V.; Chung, Moses; Yonehara, Katsuya; /Fermilab

    2009-05-01

    The use of hydrogen gas filled RF cavities in muon cooling channels has been proposed by Rolland Johnson. Impressive results have been obtained toward attaining high voltage gradients and rapid training in preliminary tests done at the FNAL MTA facility. However, so far it has not been possible to test them under conditions where they were subject to the transversal of a high intensity particle beam. This note is an attempt to bring together a description of some of the pertinent physical processes that take place in the dilute plasma that is generated in the hydrogen gas by the beam. Two effects dominate. The first is that the free electrons generated can load down the cavity and transfer its energy to heating the gas. The second is a question of what happens to the plasma in the longer term. There is an enormous literature on the subject of the subject of dilute hydrogen plasmas and we can tap into this information in order to understand and predict the behavior of the cavity.

  4. Fermionic Models with Superconducting Circuits

    E-Print Network [OSTI]

    U. Las Heras; L. García-Álvarez; A. Mezzacapo; E. Solano; L. Lamata

    2015-03-31

    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.

  5. Quantum trajectories of superconducting qubits

    E-Print Network [OSTI]

    S. J. Weber; K. W. Murch; M. E. Schwartz; N. Roch; I. Siddiqi

    2015-06-26

    In this review, we discuss recent experiments that investigate how the quantum sate of a superconducting qubit evolves during measurement. We provide a pedagogical overview of the measurement process, when the qubit is dispersively coupled to a microwave frequency cavity, and the qubit state is encoded in the phase of a microwave tone that probes the cavity. A continuous measurement record is used to reconstruct the individual quantum trajectories of the qubit state, and quantum state tomography is performed to verify that the state has been tracked accurately. Furthermore, we discuss ensembles of trajectories, time-symmetric evolution, two-qubit trajectories, and potential applications in measurement-based quantum error correction.

  6. Radio bursts from superconducting strings

    E-Print Network [OSTI]

    Yi-Fu Cai; Eray Sabancilar; Tanmay Vachaspati

    2012-01-30

    We show that radio bursts from cusps on superconducting strings are linearly polarized, thus, providing a signature that can be used to distinguish them from astrophysical sources. We write the event rate of string-generated radio transients in terms of observational variables, namely, the event duration and flux. Assuming a canonical set of observational parameters, we find that the burst event rate can be quite reasonable, e.g., order ten a year for Grand Unified strings with 100 TeV currents, and a lack of observed radio bursts can potentially place strong constraints on particle physics models.

  7. HIGH POWER RF DISTRIBUTION AND CONTROL FOR MULTI-CAVITY CRYOMODULE TESTING

    SciTech Connect (OSTI)

    Kang, Yoon W [ORNL; Broyles, Michael R [ORNL; Crofford, Mark T [ORNL; Geng, Xiaosong [ORNL; Kim, Sang-Ho [ORNL; Lee, Sung-Woo [ORNL; Phibbs, Curtis L [ORNL; Shin, Ki [ORNL; Strong, William Herb [ORNL

    2011-01-01

    Qualification of the superconducting radio-frequency (SRF) cavities in the cryomodules for the accelerating performance needs to be done through high power processing. A four-way waveguide power distribution system with independent control of power outputs has been being developed for testing the multi-cavity cryomodules for the SNS linac. SNS is employing two types of cryomodules: one type with three medium beta six-cell cavities and the other with four high beta six-cell cavities. The cryomodule that is being manufactured as a spare and the new crymodules for the future power upgrade project (PUP) of SNS will be high beta types. The four-way power distribution with independently controlled power outputs was considered useful for powering all cavities at the same time with a klystron amplifier since the SNS test facility was configured for a single klystron operation. Since certain interaction between the cavities under severe field emission was suspected in existing cryomodules, this type of high power test can be valuable for characterization of SRF cavities. By implementing a vector modulator at each arm of the splitting system, the amplitudes and the phases of RF outputs can be controlled independently. This paper discusses the present status of the development.

  8. Wakefield and RF Kicks Due to Coupler Asymmetry in TESLA-Type Accelerating Cavities

    SciTech Connect (OSTI)

    Bane, K.L.F.; Adolphsen, C.; Li, Z.; /SLAC; Dohlus, M.; Zagorodnov, I.; /DESY; Gonin, I.; Lunin, A.; Solyak, N.; Yakovlev, V.; /Fermilab; Gjonaj, E.; Weiland, T.; /Darmstadt, Tech. Hochsch.

    2008-07-07

    In a future linear collider, such as the International Linear Collider (ILC), trains of high current, low emittance bunches will be accelerated in a linac before colliding at the interaction point. Asymmetries in the accelerating cavities of the linac will generate fields that will kick the beam transversely and degrade the beam emittance and thus the collider performance. In the main linac of the ILC, which is filled with TESLA-type superconducting cavities, it is the fundamental (FM) and higher mode (HM) couplers that are asymmetric and thus the source of such kicks. The kicks are of two types: one, due to (the asymmetry in) the fundamental RF fields and the other, due to transverse wakefields that are generated by the beam even when it is on axis. In this report we calculate the strength of these kicks and estimate their effect on the ILC beam. The TESLA cavity comprises nine cells, one HM coupler in the upstream end, and one (identical, though rotated) HM coupler and one FM coupler in the downstream end (for their shapes and location see Figs. 1, 2) [1]. The cavity is 1.1 m long, the iris radius 35 mm, and the coupler beam pipe radius 39 mm. Note that the couplers reach closer to the axis than the irises, down to a distance of 30 mm.

  9. The Theory of Super-conductivity in the

    E-Print Network [OSTI]

    Landweber, Laura

    of high-Tc superconductivity in the cuprates. (Cuprates are ceramic materials that superconduct at temperatures much higher than should be possible according to conventional the- ory.) Superconductivity the development of a theory of high-temperature superconductivity. Since there is as yet no complete theory

  10. Superconductivity and Quantum Oscillations in Crystalline Bi Nanowire

    E-Print Network [OSTI]

    inner core and the surface oxide layer. Under a perpendicular H, the resistance in the superconducting

  11. Superconducting coil and method of stress management in a superconducting coil

    DOE Patents [OSTI]

    McIntyre, Peter M. (College Station, TX); Shen, Weijun (Oak Ridge, TN); Diaczenko, Nick (College Station, TX); Gross, Dan A. (College Station, TX)

    1999-01-01

    A superconducting coil (12) having a plurality of superconducting layers (18) is provided. Each superconducting layer (18) may have at least one superconducting element (20) which produces an operational load. An outer support structure (24) may be disposed outwardly from the plurality of layers (18). A load transfer system (22) may be coupled between at least one of the superconducting elements (20) and the outer support structure (24). The load transfer system (22) may include a support matrix structure (30) operable to transfer the operational load from the superconducting element (20) directly to the outer support structure (24). A shear release layer (40) may be disposed, in part, between the superconducting element (20) and the support matrix structure (30) for relieving a shear stress between the superconducting element (20) and the support matrix structure (30). A compliant layer (42) may also be disposed, in part, between the superconducting element (20) and the support matrix structure (30) for relieving a compressive stress on the superconducting element (20).

  12. High Temperature Superconducting Underground Cable

    SciTech Connect (OSTI)

    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.

  13. The Hardest Superconducting Metal Nitride

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

    Wang, Shanmin; Antonio, Daniel; Yu, Xiaohui; Zhang, Jianzhong; Cornelius, Andrew L.; He, Duanwei; Zhao, Yusheng

    2015-09-03

    Transition–metal (TM) nitrides are a class of compounds with a wide range of properties and applications. Hard superconducting nitrides are of particular interest for electronic applications under working conditions such as coating and high stress (e.g., electromechanical systems). However, most of the known TM nitrides crystallize in the rock–salt structure, a structure that is unfavorable to resist shear strain, and they exhibit relatively low indentation hardness, typically in the range of 10–20?GPa. Here, we report high–pressure synthesis of hexagonal ?–MoN and cubic ?–MoN through an ion–exchange reaction at 3.5?GPa. The final products are in the bulk form with crystallite sizesmore »of 50 – 80??m. Based on indentation testing on single crystals, hexagonal ?–MoN exhibits excellent hardness of ~30?GPa, which is 30% higher than cubic ?–MoN (~23?GPa) and is so far the hardest among the known metal nitrides. The hardness enhancement in hexagonal phase is attributed to extended covalently bonded Mo–N network than that in cubic phase. The measured superconducting transition temperatures for ?–MoN and cubic ?–MoN are 13.8 and 5.5?K, respectively, in good agreement with previous measurements.« less

  14. The Hardest Superconducting Metal Nitride

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

    Wang, Shanmin; Antonio, Daniel; Yu, Xiaohui; Zhang, Jianzhong; Cornelius, Andrew L.; He, Duanwei; Zhao, Yusheng

    2015-09-03

    Transition–metal (TM) nitrides are a class of compounds with a wide range of properties and applications. Hard superconducting nitrides are of particular interest for electronic applications under working conditions such as coating and high stress (e.g., electromechanical systems). However, most of the known TM nitrides crystallize in the rock–salt structure, a structure that is unfavorable to resist shear strain, and they exhibit relatively low indentation hardness, typically in the range of 10–20 GPa. Here, we report high–pressure synthesis of hexagonal ?–MoN and cubic ?–MoN through an ion–exchange reaction at 3.5 GPa. The final products are in the bulk form withmore »crystallite sizes of 50 – 80 ?m. Based on indentation testing on single crystals, hexagonal ?–MoN exhibits excellent hardness of ~30 GPa, which is 30% higher than cubic ?–MoN (~23 GPa) and is so far the hardest among the known metal nitrides. The hardness enhancement in hexagonal phase is attributed to extended covalently bonded Mo–N network than that in cubic phase. The measured superconducting transition temperatures for ?–MoN and cubic ?–MoN are 13.8 and 5.5 K, respectively, in good agreement with previous measurements.« less

  15. Progress on the Modeling and Modification of the MICE Superconducting Spectrometer Solenoids

    E-Print Network [OSTI]

    Virostek, S.P.

    2013-01-01

    IEEE Transactions on Applied Superconductivity 15, No. 2, p.E E Transactions on Applied Superconductivity 15, No. 2, p.and Modeling of the MICE Superconducting Spectrometer

  16. Superconducting magnets for induction linac phase-rotation in a neutrino factory

    E-Print Network [OSTI]

    Green, M.A.; Yu, S.

    2001-01-01

    et al, "The Role of Superconductivity and Cryogenics in theTransactions on Applied Superconductivity 11, p 2180, (2001)hydrogen absorbers. The superconducting solenoid quench

  17. Frequency-Domain Multiplexed Readout for Superconducting Gamma-Ray Detectors

    E-Print Network [OSTI]

    Dreyer, Jonathan G.

    2008-01-01

    sensor arrays with a superconducting quantum interferenceMultiplexed Readout for Superconducting Gamma-Ray Detectorsdetectors based on superconducting transition edge sensors (

  18. Update on the Modification and Testing of the MICE Superconducting Spectrometer Solenoids

    E-Print Network [OSTI]

    Virostek, S.P.

    2013-01-01

    IEEE Transactions on Applied Superconductivity 15, No. 2, p.IEEE Transactions on Applied Superconductivity 15, No. 2, p.TESTING OF THE MICE SUPERCONDUCTING SPECTROMETER SOLENOIDS*

  19. QUENCH PROTECTION AND DESIGN OF LARGE HIGH CURRENT DENSITY SUPERCONDUCTING MAGNETS

    E-Print Network [OSTI]

    Green, M.A.

    2010-01-01

    failure in the TPC superconducting magnet," Proceedings ofstrain on epoxy-impregnated superconducting composties," inQuench protection for superconduct­ ing magnets with a

  20. Fabrication of a Short-Period Nb3Sn Superconducting Undulator

    E-Print Network [OSTI]

    Dietderich, Daniel

    2008-01-01

    Trans. on Applied Superconductivity, Vol. 13, No. 2, pp.Trans. on Applied Superconductivity, MT-19, June 2005. [7]Trans. on Applied Superconductivity, vol. 15, no. 2, 2005,

  1. A LARGE HIGH CURRENT DENSITY SUPERCONDUCTING SOLENOID FOR THE TIME PROJECTION CHAMBER EXPERIMENT

    E-Print Network [OSTI]

    Green, M.A.

    2011-01-01

    TPC magnet integrates the superconduct- ing coil, the quenchto 1978 Applied Superconductivity Conference in Pittsburgh,HIGH CURRENT DENSITY SUPERCONDUCTING SOLENOID FOR THE TIME

  2. A Superconducting Bending Magnet System for a Compact Synchrotron Light Source

    E-Print Network [OSTI]

    Green, M.A.

    2011-01-01

    Garren, "Optimization of Superconducting Bending Magnets foral, "Development of a Superconducting Compact Storage Ringsdesigns M. A Green, "Superconducting Dipole Magnets for

  3. Antenna-coupled Superconducting Bolometers for Observations of the Cosmic Microwave Background Polarization

    E-Print Network [OSTI]

    Myers, Michael James

    2010-01-01

    4.3.2 Superconducting microstrip simulations 4.4 Impedance4.3 Superconducting microstrip . . . . . . . . . . 4.3.1Principles of superconductive devices and circuits, (second

  4. Optimization of superconducting flux qubit readout using near-quantum-limited amplifiers

    E-Print Network [OSTI]

    Johnson, Jedediah Edward Jensen

    2012-01-01

    junctions . . . . . . . 1.4 Superconducting QuantumInterference 1.5 Superconducting qubits . . . . . . . . .2 Superconducting flux qubits 2.1 The one-junction flux

  5. A SUPERCONDUCTING MAGNET SYSTEM FOR THE SPIRIT COSMIC RAY SPACE TELESCOPE

    E-Print Network [OSTI]

    Green, M.A.

    2010-01-01

    secondary circuit*® NbVSh superconducting coils ElectricalAugust 21-24, 1979 A SUPERCONDUCTING MAGNET SYSTEM FOR THETELESCOPE MASTER A SUPERCONDUCTING MAGNET SYSTEM FOR THE

  6. Fabrication of superconducting nanowire single proton detectors

    E-Print Network [OSTI]

    Yang, Joel K. (Joel Kwang wei)

    2005-01-01

    The future NASA Mars project will need an ultra-fast, highly sensitive photodetector to increase the bandwidth of free-space long-range communication, which is now done primarily using RF signals. Our original motivation ...

  7. RF-Plasma Source Commissioning in Indian Negative Ion Facility

    SciTech Connect (OSTI)

    Singh, M. J.; Bandyopadhyay, M.; Yadava, Ratnakar; Chakraborty, A. K. [ITER- India, Institute for Plasma Research, A-29, Sector 25, GIDC, Gandhinagar, Gujrat (India); Bansal, G.; Gahlaut, A.; Soni, J.; Kumar, Sunil; Pandya, K.; Parmar, K. G.; Sonara, J. [Institute for Plasma Research, Bhat Gandhinagar, Gujrat (India); Kraus, W.; Heinemann, B.; Riedl, R.; Obermayer, S.; Martens, C.; Franzen, P.; Fantz, U. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching (Germany)

    2011-09-26

    The Indian program of the RF based negative ion source has started off with the commissioning of ROBIN, the inductively coupled RF based negative ion source facility under establishment at Institute for Plasma research (IPR), India. The facility is being developed under a technology transfer agreement with IPP Garching. It consists of a single RF driver based beam source (BATMAN replica) coupled to a 100 kW, 1 MHz RF generator with a self excited oscillator, through a matching network, for plasma production and ion extraction and acceleration. The delivery of the RF generator and the RF plasma source without the accelerator, has enabled initiation of plasma production experiments. The recent experimental campaign has established the matching circuit parameters that result in plasma production with density in the range of 0.5-1x10{sup 18}/m{sup 3}, at operational gas pressures ranging between 0.4-1 Pa. Various configurations of the matching network have been experimented upon to obtain a stable operation of the set up for RF powers ranging between 25-85 kW and pulse lengths ranging between 4-20 s. It has been observed that the range of the parameters of the matching circuit, over which the frequency of the power supply is stable, is narrow and further experiments with increased number of turns in the coil are in the pipeline to see if the range can be widened. In this paper, the description of the experimental system and the commissioning data related to the optimisation of the various parameters of the matching network, to obtain stable plasma of required density, are presented and discussed.

  8. Superconducting surface impedance under radiofrequency field

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

    Xiao, Binping P; Reece, Charles E; Kelley, Michael J

    2013-07-01

    Based on BCS theory with moving Cooper pairs, the electron states distribution at 0K and the probability of electron occupation with finite temperature have been derived and applied to anomalous skin effect theory to obtain the surface impedance of a superconductor under radiofrequency (RF) field. We present the numerical results for Nb and compare these with representative RF field-dependent effective surface resistance measurements from a 1.5 GHz resonant structure.

  9. Note: Electronic damping of microphonics in superconducting resonators of a continuous wave linac

    SciTech Connect (OSTI)

    Joshi, Gopal; Sahu, Bhuban Kumar; Agarwal, Vivek; Kumar, Girish

    2014-02-15

    The paper presents an implementation technique to damp the microphonics in superconducting resonators utilizing the coupling between the electromagnetic and the mechanical modes of a resonator. In the technique used the resonant frequency variations are fed back to modulate the field amplitude through a suitable transfer function. Of the two transfer functions used in the experiments, one emulates a derivative action and is placed in a negative feedback configuration. The other transfer function is essentially a parallel combination of second order low pass filters and is used in a positive feedback configuration. Experiments with the Quarter Wave resonators of IUAC, New Delhi linac demonstrate that the damping of some of the modes increases significantly with the introduction of this feedback leading to a reduction in power required for field stabilization and quieter operation of the RF control system.

  10. Enabling cost-effective high-current burst-mode operation in superconducting accelerators

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

    Sheffield, Richard L.

    2015-06-01

    Superconducting (SC) accelerators are very efficient for CW or long-pulse operation, and normal conducting (NC) accelerators are cost effective for short-pulse operation. The addition of a short NC linac section to a SC linac can correct for the energy droop that occurs when pulsed high-current operation is required that exceeds the capability of the klystrons to replenish the cavity RF fields due to the long field fill-times of SC structures, or a requirement to support a broad range of beam currents results in variable beam loading. This paper describes the implementation of this technique to enable microseconds of high beam-current,more »90 mA or more, in a 12 GeV SC long-pulse accelerator designed for the MaRIE 42-keV XFEL proposed for Los Alamos National Laboratory.« less

  11. Status of superconducting magnets for the Superconducting Super Collider

    SciTech Connect (OSTI)

    Schermer, R.I.

    1993-09-01

    The arc sections of the High Energy Booster and the two Collider Rings will need more than 10,000, very large, superconducting dipole and quadrupole magnets. Development work on these magnets was carried out at US/DOE laboratories in a program that began in the mid 1980`s. In 1991-1992, the technology was transferred to industry and twenty, full-length, Collider dipoles were successfully fabricated and tested. This program, along with HERA and Tevatron experience, has provided industry a data base to use in formulating detailed designs for the prototypes of the accelerator magnets, with an eye to reducing cost and enhancing producibility. Several model magnets from this latest phase of the industrial program have already been tested. The excessive ramp-rate sensitivity of the magnets is understood and solutions are under investigation.

  12. RF Power Upgrade for CEBAF at Jefferson Laboratory

    SciTech Connect (OSTI)

    Andrew Kimber,Richard Nelson

    2011-03-01

    Jefferson Laboratory (JLab) is currently upgrading the 6GeV Continuous Electron Beam Accelerator Facility (CEBAF) to 12GeV. As part of the upgrade, RF systems will be added, bringing the total from 340 to 420. Existing RF systems can provide up to 6.5 kW of CW RF at 1497 MHZ. The 80 new systems will provide increased RF power of up to 13 kW CW each. Built around a newly designed and higher efficiency 13 kW klystron developed for JLab by L-3 Communications, each new RF chain is a completely revamped system using hardware different than our present installations. This paper will discuss the main components of the new systems including the 13 kW klystron, waveguide isolator, and HV power supply using switch-mode technology. Methodology for selection of the various components and results of initial testing will also be addressed. Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.

  13. A 12 GHz RF Power Source for the CLIC Study

    SciTech Connect (OSTI)

    Schirm, Karl; /CERN; Curt, Stephane; /CERN; Dobert, Steffen; /CERN; McMonagle, Gerard; /CERN; Rossat, Ghislain; /CERN; Syratchev, Igor; /CERN; Timeo, Luca; /CERN; Haase, Andrew /SLAC; Jensen, Aaron; /SLAC; Jongewaard, Erik; /SLAC; Nantista, Christopher; /SLAC; Sprehn, Daryl; /SLAC; Vlieks, Arnold; /SLAC; Hamdi, Abdallah; /Saclay; Peauger, Franck; /Saclay; Kuzikov, Sergey; /Nizhnii Novgorod, IAP; Vikharev, Alexandr; /Nizhnii Novgorod, IAP

    2012-07-03

    The CLIC RF frequency has been changed in 2008 from the initial 30 GHz to the European X-band 11.9942 GHz permitting beam independent power production using klystrons for CLIC accelerating structure testing. A design and fabrication contract for five klystrons at that frequency has been signed by different parties with SLAC. France (IRFU, CEA Saclay) is contributing a solid state modulator purchased in industry and specific 12 GHz RF network components to the CLIC study. RF pulses over 120 MW peak at 230 ns length will be obtained by using a novel SLED-I type pulse compression scheme designed and fabricated by IAP, Nizhny Novgorod, Russia. The X-band power test stand is being installed in the CLIC Test Facility CTF3 for independent structure and component testing in a bunker, but allowing, in a later stage, for powering RF components in the CTF3 beam lines. The design of the facility, results from commissioning of the RF power source and the expected performance of the Test Facility are reported.

  14. Gapless superconductivity and string theory

    E-Print Network [OSTI]

    Sergei Khlebnikov

    2014-11-06

    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. For clean samples, 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.

  15. Subranging technique using superconducting technology

    DOE Patents [OSTI]

    Gupta, Deepnarayan (Hawthorne, NY)

    2003-01-01

    Subranging techniques using "digital SQUIDs" are used to design systems with large dynamic range, high resolution and large bandwidth. Analog-to-digital converters (ADCs) embodying the invention include a first SQUID based "coarse" resolution circuit and a second SQUID based "fine" resolution circuit to convert an analog input signal into "coarse" and "fine" digital signals for subsequent processing. In one embodiment, an ADC includes circuitry for supplying an analog input signal to an input coil having at least a first inductive section and a second inductive section. A first superconducting quantum interference device (SQUID) is coupled to the first inductive section and a second SQUID is coupled to the second inductive section. The first SQUID is designed to produce "coarse" (large amplitude, low resolution) output signals and the second SQUID is designed to produce "fine" (low amplitude, high resolution) output signals in response to the analog input signals.

  16. Magnetic fluctuations and heavy electron superconductivity

    SciTech Connect (OSTI)

    Norman, M.R.

    1988-01-01

    A magnetic fluctuation self-energy based on neutron scattering data is used to calculate mass renormalizations, and superconducting critical temperatures and order parameters, for various heavy electron metals.

  17. Nonlinear high-temperature superconducting terahertz metamaterials

    E-Print Network [OSTI]

    Grady, Nathaniel K.

    We report the observation of a nonlinear terahertz response of split-ring resonator arrays made of high-temperature superconducting films. Intensity-dependent transmission measurements indicate that the resonance strength ...

  18. Bipolaron Model of Superconductivity in Chalcogenide Glasses

    E-Print Network [OSTI]

    Liang-You Zheng; Bo-Cheng Wang; Shan T. Lai

    2010-10-25

    In this paper we propose a small bipolaron model for the superconductivity in the Chalcogenide glasses (c-As2Te3 and c-GeTe). The results are agree with the experiments.

  19. Cooling arrangement for a superconducting coil

    DOE Patents [OSTI]

    Herd, K.G.; Laskaris, E.T.

    1998-06-30

    A superconducting device is disclosed, such as a superconducting rotor for a generator or motor. A vacuum enclosure has an interior wall surrounding a cavity containing a vacuum. A superconductive coil is placed in the cavity. A generally-annularly-arranged, thermally-conductive sheet has an inward-facing surface contacting generally the entire outward-facing surface of the superconductive coil. A generally-annularly-arranged coolant tube contains a cryogenic fluid and contacts a generally-circumferential portion of the outward-facing surface of the sheet. A generally-annularly-arranged, thermally-insulative coil overwrap generally circumferentially surrounds the sheet. The coolant tube and the inward-facing surface of the coil overwrap together contact generally the entire outward-facing surface of the sheet. 3 figs.

  20. Energy Programs | Center for Emergent Superconductivity

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

    Jin, R., Sales, B.C., Mandrus, D., Gillett, J., Sebastian, S.E., and Greene, L.H., Superconduct. Sci. Technol. 23, 054009-1-7 (2010). C-axis critical current density of...

  1. Towards a next theory of superconductivity

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

    Communications Office (505) 667-0471 Email "High magnetic-field measurements of doped copper-oxide superconductors are paving the way to a new theory of superconductivity," said...

  2. Cellulose-Bound Magnesium Diboride Superconductivity

    E-Print Network [OSTI]

    Ryan, Dominic

    Cellulose-Bound Magnesium Diboride Superconductivity Y.L. Lin and M.O. Pekguleryuz Department a cellulose based polymer. Cellulose tends to react only very weekly and is very robust, hence constitutes

  3. New Advances in SuperConducting Materials

    ScienceCinema (OSTI)

    None

    2014-08-12

    Superconducting materials will transform the world's electrical infrastructure, saving billions of dollars once the technical details and installation are in place. At Los Alamos National Laboratory, new materials science concepts are bringing this essential technology closer to widespread industrial use.

  4. Superconductivity with Stripes | Advanced Photon Source

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

    structure in high-Tc superconductors was manipulated in high-pressure experiments at the APS. The physics of low-temperature superconductivity is fairly well understood, but the...

  5. Operational experience with superconducting synchrotron magnets

    SciTech Connect (OSTI)

    Martin, P.S.

    1987-03-01

    The operational experience with the Fermilab Tevatron is presented, with emphasis on reliability and failure modes. Comprisons are made between the operating efficiencies for the superconducting machine and for he conventional Main Ring.

  6. Strongly correlated electron behavior : superconductivity and non-Fermi liquid behavior in Ce?-xRxColn?

    E-Print Network [OSTI]

    Gonzales, Eileen

    2009-01-01

    C. Superconductivity . . . . . . . . . . . . . . . . . . .1. Heavy Fermion Superconductivity . . . . . . .of a type I and type II superconductor showing magnetization

  7. Armored spring-core superconducting cable and method of construction

    DOE Patents [OSTI]

    McIntyre, Peter M. (611 Montclair, College Station, TX 77840); Soika, Rainer H. (1 Hensel, #X4C, College Station, TX 77840)

    2002-01-01

    An armored spring-core superconducting cable (12) is provided. The armored spring-core superconducting cable (12) may include a spring-core (20), at least one superconducting strand (24) wound onto the spring-core (20), and an armored shell (22) that encases the superconducting strands (24). The spring-core (20) is generally a perforated tube that allows purge gases and cryogenic liquids to be circulated through the armored superconducting cable (12), as well as managing the internal stresses within the armored spring-core superconducting cable (12). The armored shell (22) manages the external stresses of the armored spring-core superconducting cable (12) to protect the fragile superconducting strands (24). The armored spring-core superconducting cable (12) may also include a conductive jacket (34) formed outwardly of the armored shell (22).

  8. Architecture for high critical current superconducting tapes

    DOE Patents [OSTI]

    Jia, Quanxi (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM)

    2002-01-01

    Improvements in critical current capacity for superconducting film structures are disclosed and include the use of, e.g., multilayer YBCO structures where individual YBCO layers are separated by a layer of an insulating material such as CeO.sub.2 and the like, a layer of a conducting material such as strontium ruthenium oxide and the like or by a second superconducting material such as SmBCO and the like.

  9. Casimir energy and the superconducting phase transition

    E-Print Network [OSTI]

    Giuseppe Bimonte; Enrico Calloni; Giampiero Esposito; Luigi Rosa

    2006-01-24

    We study the influence of Casimir energy on the critical field of a superconducting film, and we show that by this means it might be possible to directly measure, for the first time, the variation of Casimir energy that accompanies the superconducting transition. It is shown that this novel approach may also help clarifying the long-standing controversy on the contribution of TE zero modes to the Casimir energy in real materials.

  10. Klystron 'efficiency loop' for the ALS storage ring RF system

    SciTech Connect (OSTI)

    Kwiatkowski, Slawomir; Julian, Jim; Baptiste, Kenneth

    2002-05-20

    The recent energy crisis in California has led us to investigate the high power RF systems at the Advanced Light Source (ALS) in order to decrease the energy consumption and power costs. We found the Storage Ring Klystron Power Amplifier system operating as designed but with significant power waste. A simple proportional-integrator (PI) analog loop, which controls the klystron collector beam current, as a function of the output RF power, has been designed and installed. The design considerations, besides efficiency improvement, were to interface to the existing system without major expense. They were to also avoid the klystron cathode power supply filter's resonance in the loop's dynamics, and prevent a conflict with the existing Cavity RF Amplitude Loop dynamics. This efficiency loop will allow us to save up to 700 MW-hours of electrical energy per year and increase the lifetime of the klystron.

  11. Adaptive RF Transient Reduction for HIGH Intensity Beams with Gaps

    E-Print Network [OSTI]

    Tückmantel, Joachim

    2006-01-01

    When a high-intensity beam with bunch-trains and gaps passes a cavity with a high-gain vector feedback enforcing a constant voltage, large transients appear, stressing the RF high power hardware and increasing the trip rate. By modulating the cavity voltage with a varying periodic waveform (set-function), the RF power can be made constant while still preserving the high feedback gain. The average cavity voltage is conserved but bunches have to settle at slightly shifted positions. A method is derived to obtain this set-function in practice while making no assumptions or measurements of the beam or RF parameters. Adiabatic iterations are made including the whole machine as an analog computing device, using all parameters as they are. A computer simulation shows the success of the method.

  12. In situ RF/microwave remediation of soil experiment overview

    SciTech Connect (OSTI)

    Regan, A.H.; Palomares, M.E.; Polston, C.; Rees, D.E.; Roybal, W.T. [Los Alamos National Lab., NM (United States); Ross, T.J. [Univ. of New Mexico, Albuquerque, NM (United States)

    1995-09-01

    Contaminant plumes are significant waste problems that require remediation in both the government and private sectors. The authors are developing an in situ process that uses RF/microwave stimulation to remove pollutants from contaminated soils. This process is more efficient than existing technologies, creates less secondary pollution, and is applicable to situations that are not amenable to treatment by existing technologies. Currently, the most commonly used process is soil vapor extraction. However, even when it is successful, this technology is energy inefficient. The authors objective is to combine RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove the soil contaminants, specifically demonstrating the viability of RF/microwave induced, in situ, soil remediation of light and dense non-aqueous phase liquids (LNAPL, DNAPL) contaminants.

  13. Recent development of RIKEN 28 GHz superconducting electron cyclotron resonance ion source

    SciTech Connect (OSTI)

    Higurashi, Y. Ohnishi, J.; Ozeki, K.; Kidera, M.; Nakagawa, T.

    2014-02-15

    Over the past two years, we have tried to improve the performance of the RIKEN superconducting electron cyclotron resonance ion source using several methods. For the production of U vapor, we chose the sputtering method because it is possible to install a large amount of material inside the plasma chamber and thus achieve long-term operation without a break, although it is assumed that the beam intensity is weaker than in the oven technique. We also used an aluminum chamber instead of a stainless steel one. Using these methods, we successfully produced ?180 e?A of U{sup 35+} and ?230 e?A of U{sup 33+} at the injected radio frequency (RF) power of ?4 kW (28 GHz). Very recently, to further increase the beam intensity of U{sup 35+}, we have started to develop a high temperature oven and have successfully produced a highly charged U ion beam. In this contribution, we report on the beam intensity of highly charged U ions as a function of various parameters (RF power and sputtering voltage) and discuss the effects of these parameters on the beam stability in detail.

  14. Coating power RF components with TiN

    SciTech Connect (OSTI)

    Kuchnir, M.; Hahn, E.

    1995-03-01

    A facility for coating RF power components with thin films of Ti and/or TiN has been in operation for some time at Fermilab supporting the Accelerator Division RF development work and the TESLA program. It has been experimentally verified that such coatings improve the performance of these components as far as withstanding higher electric fields. This is attributed to a reduction in the secondary electron emission coefficient of the surfaces when coated with a thin film containing titanium. The purpose of this Technical Memorandum is to describe the facility and the procedure used.

  15. CONCEPTUAL DESIGN OF A BRIGHT ELECTRON INJECTOR BASED ON A LASER-DRIVEN PHOTOCATHODE RF ELECTRON GUN

    E-Print Network [OSTI]

    Chattopadhyay, S.

    2010-01-01

    Photocathode RF Electron Gun S. Chattopadhyay, Y.J. Chen, D.PHOTOCATHODE RF ELECTRON GUN' S. Chnttopndhyny. Y.J. Chen (Photocathode RF Electron Gun S. Chattopadhyay, Y.I. Chen, D.

  16. High linearity 1.5-2.5 GHz RF-MEMS and varactor diodes based tunable filters for wireless applications

    E-Print Network [OSTI]

    El-Tanani, Mohammed Ahmed

    2009-01-01

    5.2.3 RF-MEMS Tunable Capacitive Network . . . . . . . .5.3Wide-Bandwidth Miniaturized RF-MEMS Tun- ableApplications104 Appendix B RF MEMS Cantilever Fabrication

  17. R & D on Very-High-Current Superconducting Proton Linac, Final Report

    SciTech Connect (OSTI)

    Ben-Zvi, Ilan

    2013-03-31

    The aim of this R&D project was to develop a superconducting cavity for a very-­? high-­?current proton accelerator. The particular application motivating the proposal was a LHC upgrade called the Superconducting Proton Linac, or SPL. Under the grant awarded to Stony Brook University the cavity was designed, a prototype copper cavity, followed by the niobium cavity, were built. A new set of HOM dampers was developed. The cavity has outstanding RF performance parameters – low surface fields, low power loss and all HOMs are fully damped. In fact, it is a “universal cavity” in the sense that it is suited for the acceleration of high-­?current protons and well as high current electrons. Its damping of HOM modes is so good that it can see service in a multi-­?pass linac or an Energy Recovery Linac in addition to the easier service in a single-­?pass linac. Extensive measurements were made on the cavities and couplers, with the exception of the cold test of the niobium cavity. At the time of this report the cavity has been chemically processed and is ready for vertical testing which will be carried out shortly.

  18. Entangling two superconducting LC coherent modes via a superconducting flux qubit

    E-Print Network [OSTI]

    Mei-Yu Chen; Matisse W. Y. Tu; Wei-Min Zhang

    2009-11-10

    Based on a pure solid-state device consisting of two superconducting LC circuits coupled to a superconducting flux qubit, we propose in this paper that the maximally entangled coherent states of the two LC modes can be generated for arbitrary coherent states through flux qubit controls.

  19. 2003 Annual Superconductivity2003 Annual Superconductivity Peer ReviewPeer Review

    E-Print Network [OSTI]

    ;Superconductivity Program at NREL for Electric SystemsSuperconductivity Program at NREL for Electric Systems Non NREL Team Members:NREL Team Members: RaghuRaghu BhattacharyaBhattacharya (Team Leader) Jun ChenJun Chen Cooperative Programs are funded by NREL. 03458202 #12;Program Objectives/Relevance (FY 2003)Program Objectives

  20. Fluctuations in systemsFluctuations in systems with superconducting islandswith superconducting islands

    E-Print Network [OSTI]

    Fominov, Yakov

    Fluctuations in systemsFluctuations in systems with superconducting islandswith superconducting islands Mikhail A. Skvortsov Mikhail V. Feigel'man Anatoly I. Larkin Landau Institute, Moscow #12;OutlineOutline #12;Uniform materials, grains, islandsUniform materials, grains, islands #12;Two mechanism of

  1. Hybrid Rings of Fixed 8T Superconducting Magnets and Iron Magnets Rapidly Cycling between -2T and +2T for a Muon Collider

    E-Print Network [OSTI]

    D. J. Summers

    2001-08-01

    Two 2200m radius hybrid rings of fixed superconducting magnets and iron magnets ramping at 200 Hz and 330 Hz are used to accelerate muons. Muons are given 25 GeV of RF energy per orbit. Acceleration is from 250 GeV/c to 2400 GeV/c and requires a total of 86 orbits in both rings; 82% of the muons survive. The total power consumption of the iron dipoles is 4 megawatts. Stranded copper conductors and thin Metglas laminations are used to reduce power losses.

  2. Hybrid Rings of Fixed 8T Superconducting Magnets and Iron Magnets Rapidly Cycling between -2T and +2T for a Muon Collider

    E-Print Network [OSTI]

    Summers, D J

    2001-01-01

    Two 2200m radius hybrid rings of fixed superconducting magnets and iron magnets ramping at 200 Hz and 330 Hz are used to accelerate muons. Muons are given 25 GeV of RF energy per orbit. Acceleration is from 250 GeV/c to 2400 GeV/c and requires a total of 86 orbits in both rings; 82% of the muons survive. The total power consumption of the iron dipoles is 4 megawatts. Stranded copper conductors and thin Metglas laminations are used to reduce power losses.

  3. Comparing the performance of plasma impedance probes and Langmuir probes for RF plasma diagnostics

    E-Print Network [OSTI]

    Walker, Mitchell

    conducted in a 14-ft diameter, 22-ft long diffusion-pumped vacuum chamber. Plasma was produced waves via RF heating. Results Conclusions For the discharge plasma condition, there was a significant hybrid frequency. RF Ca

  4. 1 Filter_Supplemental-Info_090913.doc Supplemental Information Regarding RF/Microwave Filter Design

    E-Print Network [OSTI]

    Weller/USF 1 Filter_Supplemental-Info_090913.doc Supplemental Information Regarding RF/Microwave Filter Design The video module on RF/microwave filter design, Filter Demonstration in Microwave Office

  5. Investigation of RF-enhanced plasma potentials on Alcator C-Mod

    E-Print Network [OSTI]

    Cziegler, I.

    Radio frequency (RF) sheath rectification is a leading mechanism suspected of causing anomalously high erosion of plasma facing materials in RF-heated plasmas on Alcator C-Mod. An extensive experimental survey of the plasma ...

  6. Inkjet-Printed Ferromagnetic Nanoparticles for Miniaturization of Flexible Printed RF Inductors

    E-Print Network [OSTI]

    Tentzeris, Manos

    the inductor for flexible printed electronics. This flexible, miniaturized inductor can be coupledInkjet-Printed Ferromagnetic Nanoparticles for Miniaturization of Flexible Printed RF Inductors to apply ferromagnetic nanomaterial is investigated to produce a truly flexible, printed RF inductor

  7. Advances in Filter Miniaturization and Design/Analysis of RF MEMS Tunable Filters 

    E-Print Network [OSTI]

    Sekar, Vikram

    2012-10-19

    The main purpose of this dissertation was to address key issues in the design and analysis of RF/microwave filters for wireless applications. Since RF/microwave filters are one of the bulkiest parts of communication systems, their miniaturization...

  8. Timing and RF Synchrotronization for Filling PEP/SPEAR with the SLC Damping Rings

    E-Print Network [OSTI]

    Ronan, M.T.

    2011-01-01

    respect to the beam and the Klystron 2.856 GHz RF over theto 2.856 GHz by the Klystron subboosters. A fiducialop- erating at lhe IlDac Klystron RF frequency (2.856 GHz)

  9. High performance RF MEMS metal-contact switches and switching networks

    E-Print Network [OSTI]

    Patel, Chirag D.; Patel, Chirag D.

    2012-01-01

    applications,” in Microelectromechanical Systems Conference,force microscopy,” Microelectromechanical Systems, JournalRF applications,” Microelectromechanical Systems, Journal

  10. RF power potential of 45 nm CMOS technology

    E-Print Network [OSTI]

    Putnam, Christopher

    This paper presents the first measurements of the RF power performance of 45 nm CMOS devices with varying device widths and layouts. We find that 45 nm CMOS can deliver a peak output power density of around 140 mW/mm with ...

  11. Development of RF CMOS receiver front-ends for ultrawideband 

    E-Print Network [OSTI]

    Guan, Xin

    2009-05-15

    .5dB and a noise figure of 3.3-4.5dB from 3-9.5GHz, while only consuming 9mW power. Based on the distributed amplifier and resistive shunt-feedback amplifier designs, two UWB RF front-ends are developed. One is a distributed LNA-Mixer. Unlike...

  12. rf testbed for thermoacoustic tomography D. Fallon,1

    E-Print Network [OSTI]

    Hanson, George

    rf testbed for thermoacoustic tomography D. Fallon,1 L. Yan,2 G. W. Hanson,3 and S. K. Patch4,a 1 Received 28 October 2008; accepted 22 April 2009; published online 9 June 2009 Thermoacoustic signal is a preferred acoustic coupling medium for thermoacoustics because acoustic and electromagnetic waves propagate

  13. Sifting Through the Airwaves: Efficient and Scalable Multiband RF Harvesting

    E-Print Network [OSTI]

    Washington at Seattle, University of

    option. Compared to solar power, ambient RF has the advantage of being available at night starved of its energy source the device must cease to operate, limiting the application space mostly wideband harvesting can capture energy across a large swath of spectrum, it typically results in very low

  14. RF sputtered piezoelectric zinc oxide thin film for transducer applications

    E-Print Network [OSTI]

    Tang, William C

    parameters that could influence the quality of the resulting films include RF power, the ratio of argon depen- dency of the c-axis zinc oxide growth in radio-frequency sputtering system. Different deposition on the piezoelectric and crystalline qualities of the ZnO thin films. Experimental results showed that the multilayer

  15. EE 402 Microwave and RF Circuits Aqeel Ahmad Qureshi

    E-Print Network [OSTI]

    Saskatchewan, University of

    EE 402 Microwave and RF Circuits Aqeel Ahmad Qureshi aqeel.ahmad@usask.ca Objective: There is currently an explosion in wireless communications at microwave and millimeter-wave frequencies, for both-effective and highly integrated devices and circuits are required. An understanding of modern microwave theory

  16. LWA Equipment RF Emissions: Spectrum Analyzers and Ylva Pihlstrm, UNM

    E-Print Network [OSTI]

    Ellingson, Steven W.

    1 LWA Equipment RF Emissions: Spectrum Analyzers and Laptops Ylva Pihlström, UNM 8/27/06 Summary I be used at the LWDA site during standard VLA operations. Two brands of spectrum analyzers and laptop are therefore considered typical of spectrum analyzers and laptops. The results of the measurements suggest

  17. Klystron based high power rf system for proton accelerator

    SciTech Connect (OSTI)

    Pande, Manjiri; Shrotriya, Sandip; Sharma, Sonal; Patel, Niranjan; Handu, Verander, E-mail: manjiri@barc.gov.in, E-mail: manjiri08@gmail.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai (India)

    2011-07-01

    As a part of ADS program a proton accelerator (20 MeV, 30 mA) and its high power RF systems (HPRF) are being developed in BARC. This paper explains design details of this klystron based HPRF system. (author)

  18. Supply Chain Planning Analyst 4 Optical Components /RF Products

    E-Print Network [OSTI]

    Heller, Barbara

    Supply Chain Planning Analyst 4 Optical Components /RF Products Job Number: 82686511 Company Name to apply internal investment to improve their position in meeting current and future NGES sourcing needs, executing the plans put forth by the domain team. Minimum US citizen with ability to obtain DoD Secret

  19. In situ RF/microwave remediation of soil experiment overview

    SciTech Connect (OSTI)

    Regan, A.H.; Roybal, W.T.; Ortega, R.; Palomares, M.; Rees, D.E.; Tischler, D.

    1996-06-01

    Contaminant plumes are significant waste problems that require remediation in both the government and private sectors. The authors have developed an in situ process that uses RF/microwave stimulation to remove pollutants from contaminated soils. This process is more efficient than existing technologies, creates less secondary pollution, and is applicable to situations that are not amenable to treatment by existing technologies. Currently the most commonly used process is soil vapor extraction. However, even when it is successful, this technology is energy inefficient. The objective is to combine RF/microwave energy application with soil vapor extraction to help mobilize and efficiently remove the soil contaminants, specifically demonstrating the viability of RF/microwave induced, in situ, soil remediation of light and dense non-aqueous phase liquids (LNAPL, DNAPL) contaminants. The authors have conducted a number of benchtop experiments involving RF/microwave energy deposition and vapor extraction on controlled contaminated soil samples with successful removal of the contaminants. This paper will describe the experimental hardware utilized, the experiments performed, the chemical analysis performed pre- and post-energy application, and results. In the experiments, two different halogenated liquids were used to contaminate the soil: carbon tetrachloride and 1,1,1-trichloroethane.

  20. Wafer-Level Packaging Technology for RF Applications Based on a Rigid Low-Loss Spacer

    E-Print Network [OSTI]

    Technische Universiteit Delft

    Wafer-Level Packaging Technology for RF Applications Based on a Rigid Low-Loss Spacer Substrate Alexander Polyakov #12;#12;Wafer-Level Packaging Technology for RF Applications Based on a Rigid Low ICs...............................................13 1.4. Wafer-level packaging for RF applications

  1. Evidence that global processing does not limit thresholds for RF shape discrimination

    E-Print Network [OSTI]

    Mullen, Kathy T.

    Evidence that global processing does not limit thresholds for RF shape discrimination McGill Vision whether shape discrimination thresholds for radial frequency (RF) patterns are limited at this global.75­6 cpd). First, we show using sections of an RF4 that shape discrimination thresholds are invariant

  2. Performance Analysis of Simultaneous Wireless Information and Power Transfer with Ambient RF

    E-Print Network [OSTI]

    Privault, Nicolas

    isotropic wireless power, and reception of the power by converting the harvested RF waves into electricity. INTRODUCTION RF energy harvesting techniques have evolved as a promis- ing and cost-effective solutionPerformance Analysis of Simultaneous Wireless Information and Power Transfer with Ambient RF Energy

  3. Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control

    E-Print Network [OSTI]

    Tentzeris, Manos

    Ambient-RF-Energy-Harvesting Sensor Node with Capacitor-Leakage-Aware Duty Cycle Control Ryo (WSN) that are solely powered by ambient RF power. Different from all other energy harvesting WSN systems, RF powered systems present a new challenge for the energy management. A WSN node repeatedly

  4. RF-MEMS Capacitive Series Switches of CPW & MSL Configurations for Reconfigurable Antenna Application

    E-Print Network [OSTI]

    De Flaviis, Franco

    RF-MEMS Capacitive Series Switches of CPW & MSL Configurations for Reconfigurable Antenna, University of California Irvine, Irvine, CA, 92697 Abstract: The air-bridged RF-MEMS switches in single pole) and coplanar waveguide (CPW) structures. RF-MEMS series switches are monolithic fabricated in both transmission

  5. Modeling and Optimization of RF-MEMS Reconfigurable Tuners with Computationally Efficient Time-Domain Techniques

    E-Print Network [OSTI]

    Tentzeris, Manos

    Modeling and Optimization of RF-MEMS Reconfigurable Tuners with Computationally Efficient Time of Technology, Atlanta, GA 30332 2 Raytheon Company, Tucson AZ, 85734 Abstract -- Modern RF-MEMS device design methods in which the FDTD technique can be used to model a reconfigurable RF-MEMS tuner. A new method

  6. Low Cost RF MEMS Switches Fabricated on Microwave Laminate Printed Circuit Boards

    E-Print Network [OSTI]

    De Flaviis, Franco

    1 Low Cost RF MEMS Switches Fabricated on Microwave Laminate Printed Circuit Boards Hung-Pin Chang process for directly constructing RF MEMS capacitive switches has been developed on microwave laminate among components. Index Terms--RF MEMS switches, compressive molding planarization, high density

  7. Anisotropic transport properties of ferromagnetic-superconducting bilayers 

    E-Print Network [OSTI]

    Kayali, MA; Pokrovsky, Valery L.

    2004-01-01

    We study the transport properties of vortex matter in a superconducting thin film separated by a thin insulator layer from a ferromagnetic layer. We assume an alternating stripe structure for both FM and superconducting (SC) layers as found in S...

  8. Supplementary Information for Simulating weak localization in superconducting quantum circuit

    E-Print Network [OSTI]

    Martinis, John M.

    Supplementary Information for Simulating weak localization in superconducting quantum circuit Yu-type entangled state in superconducting quantum circuits.[2, 3] We rst generated a photon in the readout qubit

  9. Superconducting magnets for muon capture and phase rotation

    E-Print Network [OSTI]

    Green, M.A.

    2011-01-01

    of Various Cases for Superconducti ng Magnets Inside andTransactions on Applied Superconductivity 7, No 2. P 642 (LBNL-43998 SC-MAG-683 SUPERCONDUCTING MAGNETS FOR MUON

  10. Control of Superconductivity in Cuprate/Manganite Heterostructures

    E-Print Network [OSTI]

    Pang, Brian SiewHan

    deposited, which exhibited superconducting and magnetic properties to minimum thicknesses of 3nm for both YBCO and LSMO. Using spin injection, via a ferromagnet, to create a spin imbalance in the superconductor, a suppression of superconducting critical...

  11. Friedel-Like Oscillations from Interstitial Iron in Superconducting...

    Office of Scientific and Technical Information (OSTI)

    Interstitial Iron in Superconducting Fe1+yTe0.62Se0.38 Using polarized and unpolarized neutron scattering we show that interstitial Fe in superconducting Fe1+yTe1-xSex...

  12. Optimization of superconducting magnetic bearings using finite element modeling

    E-Print Network [OSTI]

    Bryslawskyj, Jason (Jason Bogdan)

    2009-01-01

    This project investigated the possibility of using superconducting bearings in large (3 - 100 MW) electric drives. Superconducting bearings are used to levitate the rotors inside electric drives via the Meiissner effect, ...

  13. Comparative Analysis of Carbon Plasma in Arc and RF Reactors

    SciTech Connect (OSTI)

    Todorovic-Markovic, B.; Markovic, Z.; Mohai, I.; Szepvolgyi, J.

    2004-12-01

    Results on studies of molecular spectra emitted in the initial stages of fullerene formation during the processing of graphite powder in induction RF reactor and evaporation of graphite electrodes in arc reactor are presented in this paper. It was found that C2 radicals were dominant molecular species in both plasmas. C2 radicals have an important role in the process of fullerene synthesis. The rotational-vibrational temperatures of C2 and CN species were calculated by fitting the experimental spectra to the simulated ones. The results of optical emission study of C2 radicals generated in carbon arc plasma have shown that rotational temperature of C2 species depends on carbon concentration and current intensity significantly. The optical emission study of induction RF plasma and SEM analysis of graphite powder before and after plasma treatment have shown that evaporation of the processed graphite powder depends on feed rate and composition of gas phase significantly. Based on the obtained results, it was concluded that in the plasma region CN radicals could be formed by the reaction of C2 species with atomic nitrogen at smaller loads. At larger feed rate of graphite powder, CN species were produced by surface reaction of the hot carbon particles with nitrogen atoms. The presence of nitrogen in induction RF plasma reduces the fullerene yield significantly. The fullerene yield obtained in two different reactors was: 13% in arc reactor and 4.1% in induction RF reactor. However, the fullerene production rate was higher in induction RF reactor-6.4 g/h versus 1.7 g/h in arc reactor.

  14. The RF power system for the SNS linac

    SciTech Connect (OSTI)

    Tallerico, P.J.; Reass, W.A.

    1998-12-31

    The initial goal of the SNS project is to produce a 1 MW average beam of protons with short pulse lengths onto a neutron-producing target. The objective of the SNS RF system is to generate 117 MW peak of pulsed 805 MHz microwave power with an accelerated beam pulse length of 1.04 ms at a 60 Hz repetition rate. The power system must be upgradeable in peak power to deliver 2 MW average power to the neutron target. The RF system also requires about 3 MW peak of RF power at 402.5 MHz, but that system is not discussed here. The design challenge is to produce an RF system at minimum cost, that is very reliable and economical to operate. The combination of long pulses and high repetition rates make conventional solutions, such as the pulse transformer and transmission line method, very expensive. The klystron, with a modulating anode, and 1.5 MW of peak output power is the baseline RF amplifier, an 56 are required in the baseline design. The authors discuss four power system configurations that are the candidates for the design. The baseline design is a floating-deck modulating anode system. A second power system being investigated is the fast-pulsed power supply, that can be turned on and off with a rise time of under 0.1 ms. This could eliminate the need for a modulator, and drastically reduce the energy storage requirements. A third idea is to use a pulse transformer with a series IGBT switch and a bouncer circuit on the primary side, as was done for the TESLA modulator. A fourth method is to use a series IGBT switch at high voltage, and not use a pulse transformer. The authors discuss the advantages and problems of these four types of power systems, but they emphasize the first two.

  15. High Temperature Superconductivity in Cuprates: a model

    E-Print Network [OSTI]

    P. R. Silva

    2010-07-16

    A model is proposed such that quasi-particles (electrons or holes) residing in the CuO2 planes of cuprates may interact leading to metallic or superconducting behaviors. The metallic phase is obtained when the quasi-particles are treated as having classical kinetic energies and the superconducting phase occurs when the quasi-particles are taken as extremely relativistic objects. The interaction between both kinds of particles is provided by a force dependent-on-velocity. In the case of the superconducting behavior, the motion of apical oxygen ions provides the glue to establish the Cooper pair. The model furnishes explicit relations for the Fermi velocity, the perpendicular and the in-plane coherence lengths, the zero-temperature energy gap, the critical current density, the critical parallel and perpendicular magnetic fields. All these mentioned quantities are expressed in terms of fundamental physical constants as: charge and mass of the electron, light velocity in vacuum, Planck constant, electric permittivity of the vacuum. Numerical evaluation of these quantities show that their values are close those found for the superconducting YBaCuO, leading to think the model as being a possible scenario to explain superconductivity in cuprates.

  16. Superconductivity at Dawn of the Iron Age

    ScienceCinema (OSTI)

    Tesanovic, Zlatko [Johns Hopkins University, Baltimore, Maryland, United States

    2010-09-01

    Superconductivity is a stunning quantum phenomenon and among the deepest paradigms in all of physics. From fundamental theories of the universe to strange goings-on in exotic materials to medical imaging and cell phones, its conceptual and practical dimensions span a reach as wide as anything in science. Twenty-odd years ago, the discovery of copper oxides ushered in a new era of high-temperature superconductivity, and the joyous exuberance that followed - with physicists throwing everything from fancy gauge theories to synchrotron radiation into its kitchen sink - only recently began to show any signs of waning. In the spring of 2008, as if on cue, a new family of iron pnictide high-temperature superconductors burst on the scene, hinting at an alternative route to room-temperature superconductivity and all of its momentous consequences. Fueled by genuine excitement - and a bit of hype - the iron-based superconductivity turned into a science blockbuster of 2009. I will present a pedagogical review of this new field, contrast the physics of iron- and copper-based systems, and speculate on the microscopic origins of the two types of high-temperature superconductivity.

  17. Color superconductivity and dense quark matter

    E-Print Network [OSTI]

    Massimo Mannarelli

    2008-12-26

    The properties of cold and dense quark matter have been the subject of extensive investigation, especially in the last decade. Unfortunately, we still lack of a complete understanding of the properties of matter in these conditions. One possibility is that quark matter is in a color superconducting phase which is characterized by the formation of a diquark condensate. We review some of the basic concepts of color superconductivity and some of the aspects of this phase of matter which are relevant for compact stars. Since quarks have color, flavor as well as spin degrees of freedom many different color superconducting phases can be realized. At asymptotic densities QCD predicts that the color flavor locked phase is favored. At lower densities where the QCD coupling constant is large, perturbative methods cannot be applied and one has to rely on some effective model, eventually trying to constrain such a model with experimental observations. The picture is complicated by the requirement that matter in the interior of compact stars is in weak equilibrium and neutral. These conditions and the (possible) large value of the strange quark mass conspire to separate the Fermi momenta of quarks with different flavors, rendering homogenous superconducting phases unstable. One of the aims of this presentation is to introduce non-experts in the field to some of the basic ideas of color superconductivity and to some of its open problems.

  18. Superconducting Circuitry for Quantum Electromechanical Systems

    E-Print Network [OSTI]

    Matthew D. LaHaye; Francisco Rouxinol; Yu Hao; Seung-Bo Shim; Elinor K. Irish

    2015-04-11

    Superconducting systems have a long history of use in experiments that push the frontiers of mechanical sensing. This includes both applied and fundamental research, which at present day ranges from quantum computing research and efforts to explore Planck-scale physics to fundamental studies on the nature of motion and the quantum limits on our ability to measure it. In this paper, we first provide a short history of the role of superconducting circuitry and devices in mechanical sensing, focusing primarily on efforts in the last decade to push the study of quantum mechanics to include motion on the scale of human-made structures. This background sets the stage for the remainder of the paper, which focuses on the development of quantum electromechanical systems (QEMS) that incorporate superconducting quantum bits (qubits), superconducting transmission line resonators and flexural nanomechanical elements. In addition to providing the motivation and relevant background on the physical behavior of these systems, we discuss our recent efforts to develop a particular type of QEMS that is based upon the Cooper-pair box (CPB) and superconducting coplanar waveguide (CPW) cavities, a system which has the potential to serve as a testbed for studying the quantum properties of motion in engineered systems.

  19. PERCOLATION AND SUPERCONDUCTIVITY IN ION-IMPLANTED ALUMINIUM FILMS (*)

    E-Print Network [OSTI]

    Boyer, Edmond

    L-435 PERCOLATION AND SUPERCONDUCTIVITY IN ION-IMPLANTED ALUMINIUM FILMS (*) F. MEUNIER and P of Si and Ge in Al thin films at 8 K produces alloys exhibiting enhanced superconducting transition in the superconducting transition temperature Tc of several such alloys [2], [5], [6] : Josephson tunnelling

  20. Superconducting Wires Enabled by Nanodots wins Nano50TM Award

    E-Print Network [OSTI]

    includes nanoscale columns of non-superconducting material embedded within the superconductorSuperconducting Wires Enabled by Nanodots wins Nano50TM Award HTS Wires Enabled via 3D Self-Assembly of Insulating Nanodots Background · For most large-scale applications of high-temperature superconducting (HTS

  1. Fluctuations from edge defects in superconducting resonators A. Megrant,1

    E-Print Network [OSTI]

    Martinis, John M.

    Fluctuations from edge defects in superconducting resonators C. Neill,1 A. Megrant,1 R. Barends,1 August 2013) Superconducting resonators, used in astronomy and quantum computation, couple strongly to microscopic two-level defects. We monitor the microwave response of superconducting resonators and observe

  2. Field Test of the Superconducting Gravimeter as a Hydrologic Sensor

    E-Print Network [OSTI]

    Scanlon, Bridget R.

    Field Test of the Superconducting Gravimeter as a Hydrologic Sensor by Clark R. Wilson1 , Bridget of a transportable version of a superconducting gravimeter (SG) intended for groundwater storage monitoring. The test of a transportable superconducting gravimeter (SG) designed to monitor sur- face gravity and provide a direct measure

  3. Strong Coupling of a Spin Ensemble to a Superconducting Resonator

    E-Print Network [OSTI]

    Vallette, Bruno

    Strong Coupling of a Spin Ensemble to a Superconducting Resonator: Towards Superconducting Hybrid Quantum Circuits Yui KUBO, Cecile Greze, Florian R. Ong, Patrice Bertet). Superconducting qubit #12;Yui KUBO GDR-IQFA, Nice, 24 Mar 2011 Y. Nakamura et al., Nature

  4. Emulation of a Quantum Spin with a Superconducting Phase Qudit

    E-Print Network [OSTI]

    Martinis, John M.

    Emulation of a Quantum Spin with a Superconducting Phase Qudit Matthew Neeley,1 M. Ansmann,1 computing tasks. We demonstrate the operation of a superconducting phase qudit with d = 5, showing how, making a qudit emulator potentially more efficient. We demonstrate the operation of a superconducting

  5. Quantum Logic Gates in Superconducting Qubits John M. Martinis

    E-Print Network [OSTI]

    Martinis, John M.

    Quantum Logic Gates in Superconducting Qubits John M. Martinis Department of Physics University on surface codes may allow errors in the 10-2 range [2]. Much research in superconducting qubits has been di for superconducting qubits, since they typically use fixed coupling elements set by fabrication. TRANSITION LOGIC

  6. Singlet oxygen luminescence detection with a fibre-coupled superconducting

    E-Print Network [OSTI]

    Greenaway, Alan

    Singlet oxygen luminescence detection with a fibre-coupled superconducting nanowire single luminescence detection Fibre-based singlet oxygen luminescence detection References Superconducting Detector, is an intermediate in many biological processes. We employ a superconducting nanowire single-photon detector (SNSPD

  7. Sr2IrO4: Gateway to cuprate superconductivity?

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

    Mitchell, J. F.

    2015-06-05

    High temperature superconductivity in cuprates remains a defining challenge in condensed matter physics. Recently, a new set of related compounds based on Ir rather than Cu has been discovered that may be on the verge of superconductivity themselves or be able to shed new light on the underlying interactions responsible for superconductivity in the cuprates.

  8. Study on the energy criterion of cuprate superconductivity

    E-Print Network [OSTI]

    Gu Jiapu

    2010-02-09

    In this paper, we use the variation of spontaneous magnetization to describe the influence of electron holes in cuprate superconductors, and use competitive energy relations to explore the superconductivity rule and energy criterion, on this basis, we can deduce a clear physical image of superconducting phase diagram and superconducting mechanism.

  9. Impurity effects in superconducting UPt sub 3

    SciTech Connect (OSTI)

    Aronson, M.C. (The Harrison M. Randall Laboratory of Physics, The University of Michigan, Ann Arbor, Michigan 48109 (USA)); Vorenkamp, T.; Koziol, Z.; de Visser, A.; Bakker, K.; Franse, J.J.M. (Natuurkundig Laboratorium der Universiteit van Amsterdam, Valckenierstraat 65, 1018 XE Amsterdam, The Netherlands (USA)); Smith, J.L. (Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (USA))

    1991-04-15

    Superconducting UPt{sub 3} is characterized by a novel and complex magnetic field-temperature phase diagram, with two superconducting transitions at {ital T}{sub {ital c}1} and {ital T}{sub {ital c}2} in zero field. We have studied the effects of Pd and Y impurities on the zero field superconducting properties of UPt{sub 3}. Resistance measurements show that both dopants increase the residual resistivity and decrease the spin fluctuation temperature in the normal state. {ital T}{sub {ital c}1} is depressed by both dopants, but more effectively by Pd. {vert bar}{ital T}{sub {ital c}1} {minus} {ital T}{sub {ital c}2}{vert bar} is essentially unaffected by Y doping, but increases dramatically with Pd doping.

  10. Superconducting magnetic shielding apparatus and method

    DOE Patents [OSTI]

    Clem, John R. (Ames, IA); Clem, John R. (Ames, IA)

    1983-01-01

    Disclosed is a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped.

  11. Superconducting magnetic shielding apparatus and method

    DOE Patents [OSTI]

    Clem, J.R.

    1982-07-09

    Disclosed is a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped.

  12. Superconducting magnetic shielding apparatus and method

    DOE Patents [OSTI]

    Clem, J.R.; Clem, J.R.

    1983-10-11

    Disclosed are a method and apparatus for providing magnetic shielding around a working volume. The apparatus includes a hollow elongated superconducting shell or cylinder having an elongated low magnetic pinning central portion, and two high magnetic pinning end regions. Transition portions of varying magnetic pinning properties are interposed between the central and end portions. The apparatus further includes a solenoid substantially coextensive with and overlying the superconducting cylinder, so as to be magnetically coupled therewith. The method includes the steps passing a longitudinally directed current through the superconducting cylinder so as to depin magnetic reservoirs trapped in the cylinder. Next, a circumferentially directed current is passed through the cylinder, while a longitudinally directed current is maintained. Depinned magnetic reservoirs are moved to the end portions of the cylinder, where they are trapped. 5 figs.

  13. Discovery of plutonium-based superconductivity

    SciTech Connect (OSTI)

    Sarrao, John L.,; Thompson, J. D. (Joe David); Moreno, N. O.; Morales, L. A. (Luis A.); Wastin, F. (Franck); Rebizant, J.; Boulet, P.; Colineau, E.; Lander, G. H.

    2002-01-01

    The discovery of superconductivity in single crystals of PuCoGa{sub 5} with transition temperature T{sub c}=18.5 K is discussed. The existing data lead to the speculation that the superconductivity in PuCoGa{sub 5} may be unconventional. In such a scenario the properties of PuCoGa{sub 5} would be intermediate between those of isostructural UCoGa{sub 5} and CeCoIn{sub 5}, more heavily studied f-electron materials.

  14. Criterion of stability of the superconducting state

    E-Print Network [OSTI]

    Iogann Tolbatov

    2009-10-23

    In this paper, we propose to draw attention to the stability criterion of the superconductor current state. We use for this purpose the rough systems mathematical apparatus allowing us to relate the desired criterion with the dielectric permittivity of the matter and to identify the type of all possible phonons trajectories in its superconducting state. The state of superconductivity in the matter can be explained only by the phonons behavior peculiarity. And on the basis of the above-mentioned assumption, the corresponding mathematical model is constructed.

  15. Apparatus for characterizing conductivity of superconducting materials

    DOE Patents [OSTI]

    Doss, J.D.

    1993-12-07

    Apparatus and method for noncontact, radio-frequency shielding current characterization of materials. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples. 10 figures.

  16. On Testing Entropic Inequalities for Superconducting Qudit

    E-Print Network [OSTI]

    Evgenii Glushkov; Anastasiia Glushkova; V. I. Man'ko

    2015-05-20

    The aim of this work is to verify the new entropic and information inequalities for non-composite systems using experimental $5 \\times 5$ density matrix of the qudit state, measured by the tomographic method in a multi-level superconducting circuit. These inequalities are well-known for bipartite and tripartite systems, but have never been tested for superconducting qudits. Entropic inequalities can also be used to evaluate the accuracy of experimental data and the value of mutual information, deduced from them, may charachterize correlations between different degrees of freedom in a noncomposite system.

  17. Superconducting Detectors for Super Light Dark Matter

    E-Print Network [OSTI]

    Yonit Hochberg; Yue Zhao; Kathryn M. Zurek

    2015-04-27

    We propose and study a new class of of superconducting detectors which are sensitive to O(meV) electron recoils from dark matter-electron scattering. Such devices could detect dark matter as light as the warm dark matter limit, mX > keV. We compute the rate of dark matter scattering off free electrons in a (superconducting) metal, including the relevant Pauli blocking factors. We demonstrate that classes of dark matter consistent with all astrophysical and terrestrial constraints could be detected by such detectors with a moderate size exposure.

  18. Induced Magnetism in Color-Superconducting Media

    E-Print Network [OSTI]

    Efrain J. Ferrer

    2010-01-22

    The dense core of compact stars is the natural medium for the realization of color superconductivity. A common characteristic of such astrophysical objects is their strong magnetic fields, especially those of the so called magnetars. In this talk, I discuss how a color superconducting core can generate or/and enhance the stellar magnetic field independently of a magnetohydrodynamic dynamo mechanism. The magnetic field generator is in this case a gluonic current which circulates to stabilize the color superconductor in the presence of a strong magnetic field or under the pairing stress produced in the medium by the neutrality and $\\beta$-equilibrium constraints.

  19. Superconducting nanowire single photon detector on diamond

    SciTech Connect (OSTI)

    Atikian, Haig A.; Burek, Michael J.; Choy, Jennifer T.; Lon?ar, Marko; Eftekharian, Amin; Jafari Salim, A.; Hamed Majedi, A.

    2014-03-24

    Superconducting nanowire single photon detectors are fabricated directly on diamond substrates and their optical and electrical properties are characterized. Dark count performance and photon count rates are measured at varying temperatures for 1310?nm and 632?nm photons. A multi-step diamond surface polishing procedure is reported, involving iterative reactive ion etching and mechanical polishing to create a suitable diamond surface for the deposition and patterning of thin film superconducting layers. Using this approach, diamond substrates with less than 300?pm Root Mean Square surface roughness are obtained.

  20. Superconductivity observed in platinum-silicon interface

    SciTech Connect (OSTI)

    Kuo, Pai-Chia, E-mail: paichia@phys.sinica.edu.tw [Research Program on Nanoscience and Nanotechnology, Academia Sinica, Taipei 11529, Taiwan (China); Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China); Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Chen, Chun-Wei [Department of Materials Science and Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Lee, Ku-Pin; Shiue, Jessie, E-mail: yshiue@phys.sinica.edu.tw [Research Program on Nanoscience and Nanotechnology, Academia Sinica, Taipei 11529, Taiwan (China); Institute of Physics, Academia Sinica, Taipei 11529, Taiwan (China)

    2014-05-26

    We report the discovery of superconductivity with an onset temperature of ?0.6?K in a platinum-silicon interface. The interface was formed by using a unique focused ion beam sputtering micro-deposition method in which the energies of most sputtered Pt atoms are ?2.5?eV. Structural and elemental analysis by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy reveal a???7?nm interface layer with abundant Pt, which is the layer likely responsible for the superconducting transport behavior. Similar transport behavior was also observed in a gold-silicon interface prepared by the same technique, indicating the possible generality of this phenomenon.