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. AC/RF Superconductivity

    SciTech Connect (OSTI)

    Ciovati, Gianluigi

    2015-02-01

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

  3. Degreasing and cleaning superconducting RF Niobium cavities

    SciTech Connect (OSTI)

    Rauchmiller, Michael; Kellett, Ron; /Fermilab

    2011-09-01

    The purpose and scope of this report is to detail the steps necessary for degreasing and cleaning of superconducting RF Niobium cavities in the A0 clean room. It lists the required equipment and the cleaning procedure.

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

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect SciTech Connect Search Results Journal Article: Superfluid helium cryogenic systems for superconducting RF cavities at KEK Citation Details In-Document Search Title: Superfluid helium cryogenic systems for superconducting RF cavities at KEK Recent accelerator projects at KEK, such as the Superconducting RF Test Facility (STF) for R and D of the International Linear Collider (ILC) project and the compact Energy Recovery Linac (cERL), employ superconducting

  5. Superconducting RF systems for eRHIC

    SciTech Connect (OSTI)

    Belomestnykh S.; Ben-Zvi, I.; Brutus, J.C.; Hahn, H. et al

    2012-05-20

    The proposed electron-hadron collider eRHIC will consist of a six-pass 30-GeV electron Energy Recovery Linac (ERL) and one of RHIC storage rings operating with energy up to 250 GeV. The collider design extensively utilizes superconducting RF (SRF) technology in both electron and hadron parts. This paper describes various SRF systems, their requirements and parameters.

  6. R&D to Enhance the Performance of Superconducting RF Structures

    SciTech Connect (OSTI)

    Tajima, Tsuyoshi

    2015-10-30

    This report proposes techniques on how to increase the performance and efficiency of superconducting RF structures.

  7. Investigation of Microscopic Materials Limitations of Superconducting RF

    Office of Scientific and Technical Information (OSTI)

    Cavities (Technical Report) | SciTech Connect Technical Report: Investigation of Microscopic Materials Limitations of Superconducting RF Cavities Citation Details In-Document Search Title: Investigation of Microscopic Materials Limitations of Superconducting RF Cavities 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

  8. SUPERCONDUCTING RF-DIPOLE DEFLECTING AND CRABBING CAVITIES

    SciTech Connect (OSTI)

    Delayen, Jean; De Silva, Paygalage Subashini

    2013-09-01

    Recent interests in designing compact deflecting and crabbing structures for future accelerators and colliders have initiated the development of novel rf structures. The superconducting rf-dipole cavity is one of the first compact designs with attractive properties such as higher gradients, higher shunt impedance, the absence of lower order modes and widely separated higher order modes. Two rf-dipole designs of 400 MHz and 499 MHz have been designed, fabricated and tested as proof-of-principle designs of compact deflecting and crabbing cavities for the LHC high luminosity upgrade and Jefferson Lab 12 GeV upgrade. The first rf tests have been performed on the rf-dipole geometries at 4.2 K and 2.0 K in a vertical test assembly with excellent results. The cavities have achieved high gradients with high intrinsic quality factors, and multipacting levels were easily processed.

  9. 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.

  10. 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.

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

    Office of Science (SC) Website

    Superconducting laser photocathode RF gun at BNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear Science ...

  12. Superconducting Higher Harmonic RF Cavity for the APS Upgrade Electron

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

    Storage Rings | Argonne National Laboratory Superconducting Higher Harmonic RF Cavity for the APS Upgrade Electron Storage Rings March 14, 2016 3:30PM to 4:30PM Presenter Sanghoon Kim, Physics Division Location Building 203, Room R150 Type Seminar Series Physics Division Seminar Abstract: A new trend in electron storange rings is the use of a "nulti-bend achromat" (MBA) lattice to reduce the electron beam emittance. The Advanced Photon Source Upgrade (APS-U) MBA lattice improves

  13. 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.

  14. 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.

  15. Superconducting RF Linac Technology for ERL Light Sources

    SciTech Connect (OSTI)

    Chris Tennant

    2005-08-01

    Energy Recovering Linacs (ERLs) offer an attractive alternative as drivers for light sources as they combine the desirable characteristics of both storage rings (high efficiency) and linear accelerators (superior beam quality). Using superconducting RF technology allows ERLs to operate more efficiently because of the inherent characteristics of SRF linacs, namely that they are high gradient-low impedance structures and their ability to operate in the long pulse or CW regime. We present an overview of the physics challenges encountered in the design and operation of ERL based light sources with particular emphasis on those issues related to SRF technology. These challenges include maximizing a cavity???????¢????????????????s Qo to increase cryogenic efficiency, maintaining control of the cavity field in the presence of the highest feasible loaded Q and providing adequate damping of the higher-order modes (HOMs). If not sufficiently damped, dipole HOMs can drive the multipass beam breakup (BBU) instability which ERLs are particularly susceptible to. Another challenge involves efficiently extracting the potentially large amounts of HOM power that are generated when a bunch traverses the SRF cavities and which may extend over a high range of frequencies. We present experimental data from the Jefferson Lab FEL Upgrade, a 10 mA ERL light source presently in operation, aimed at addressing some of these issues. We conclude with an outlook towards the future of ERL based light sources.

  16. Compact superconducting rf-dipole cavity designs for deflecting and crabbing applications

    SciTech Connect (OSTI)

    De Silva, Subashini; Delayen, Jean R.; Castilla, Alejandro

    2013-06-01

    Over the years the superconducting parallel-bar design has evolved into an rf-dipole cavity with improved properties. The new rf-dipole design is considered for a number of deflecting and crabbing applications. Some of those applications are the 499 MHz rf separator system for the Jefferson Lab 12 GeV upgrade, the 400 MHz crabbing cavity system for the proposed LHC high luminosity upgrade, and the 750 MHz crabbing cavity for the medium energy electron-ion collider in Jefferson Lab. In this paper we present the optimized rf design in terms of rf performance including rf properties, higher order modes (HOM) properties, multipacting and multipole expansion for the above mentioned applications.

  17. Capture cavity cryomodule for quantum beam experiment at KEK superconducting RF test facility

    SciTech Connect (OSTI)

    Tsuchiya, K.; Hara, K.; Hayano, H.; Kako, E.; Kojima, Y.; Kondo, Y.; Nakai, H.; Noguchi, S.; Ohuchi, N.; Terashima, A.; Horikoshi, A.; Semba, T.

    2014-01-29

    A capture cavity cryomodule was fabricated and used in a beam line for quantum beam experiments at the Superconducting RF Test Facility (STF) of the High Energy Accelerator Research Organization in Japan. The cryomodule is about 4 m long and contains two nine-cell cavities. The cross section is almost the same as that of the STF cryomodules that were fabricated to develop superconducting RF cavities for the International Linear Collider. An attempt was made to reduce the large deflection of the helium gas return pipe (GRP) that was observed in the STF cryomodules during cool-down and warm-up. This paper briefly describes the structure and cryogenic performance of the captures cavity cryomodule, and also reports the measured displacement of the GRP and the cavity-containing helium vessels during regular operation.

  18. CAMD Nanofabrication Research

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

    local variations in reaction conditions and is amenable to scale-up through parallel processing or using continuous processes. Nanofabrication group is one of the very...

  19. 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.

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

    Office of Science (SC) Website

    Science (SC) Superconducting laser photocathode RF gun at BNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear Science Applications of Nuclear Science Archives Small Business Innovation / Technology Transfer Funding Opportunities Nuclear Science Advisory Committee (NSAC) Community Resources Contact Information Nuclear Physics U.S. Department of Energy SC-26/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P:

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

    SciTech Connect (OSTI)

    Chase, Brian; Pasquinelli, Ralph; Cullerton, Ed; Varghese, Philip

    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 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.

  2. 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, Brian; Pasquinelli, Ralph; Cullerton, Ed; Varghese, Philip

    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

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

    SciTech Connect (OSTI)

    Peterson, Thomas; Klebaner, Arkadiy; Nicol, Tom; Theilacker, Jay; Hayano, Hitoshi; Kako, Eiji; Nakai, Hirotaka; Yamamoto, Akira; Jensch, Kay; Matheisen, Axel; 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. 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.

  5. Progress on the high-current 704 MHz superconducting RF cavity at BNL

    SciTech Connect (OSTI)

    Xu W.; Astefanous, C.; Belomestnykh, S.; Ben-Zvi, I.; et al

    2012-05-20

    The 704 MHz high current superconducting cavity has been designed with consideration of both performance of fundamental mode and damping of higher order modes. A copper prototype cavity was fabricated by AES and delivered to BNL. RF measurements were carried out on this prototype cavity, including fundamental pass-band and HOM spectrum measurements, HOM studies using bead-pull setup, prototyping of antenna-type HOM couplers. The measurements show that the cavity has very good damping for the higher-order modes, which was one of the main goals for the high current cavity design. 3D cavity models were simulated with Omega3P code developed by SLAC to compare with the measurements. The paper describes the cavity design, RF measurement setups and results for the copper prototype. The progress with the niobium cavity fabrication will also be described.

  6. Development of fundamental power coupler for high-current superconducting RF cavity

    SciTech Connect (OSTI)

    Jain P.; Belomestnykh, S.; Ben-Zvi, I.; Xu, W.

    2012-05-20

    Brookhaven National Laboratory took a project of developing a 704 MHz five-cell superconducting RF cavity for high-current linacs, including Energy Recovery Linac (ERL) for planned electron-hadron collider eRHIC. The cavity will be fed by a high-power RF amplifier using a coaxial Fundamental Power Coupler (FPC), which delivers 20 kW of CW RF power to the cavity. The design of FPC is one of the important aspects as one has to take into account the heat losses dissipated on the surface of the conductor by RF fields along with that of the static heat load. Using a simple simulation model we show the temperature profile and the heat load dissipated along the coupler length. To minimize the heat load on FPC near the cavity end, a thermal intercept is required at an appropriate location on FPC. A 10 K intercept was chosen and its location optimized with our simulation code. The requirement on the helium gas flow rate for the effective heat removal from the thermal intercept is also discussed.

  7. Operation of the 56 MHz superconducting RF cavity in RHIC during run 14

    SciTech Connect (OSTI)

    Wu, Q.; Belomestnykh, S.; Ben-Zvi, I.; Blaskiewicz, M.; Hayes, T.; Mernick, K.; Severino, F.; Smith, K.; Zaltsman, A.

    2015-09-11

    A 56 MHz superconducting RF cavity was designed and installed in the Relativistic Heavy Ion Collider (RHIC). It is the first superconducting quarter wave resonator (QWR) operating in a high-energy storage ring. We discuss herein the cavity operation with Au+Au collisions, and with asymmetrical Au+He3 collisions. The cavity is a storage cavity, meaning that it becomes active only at the energy of experiment, after the acceleration cycle is completed. With the cavity at 300 kV, an improvement in luminosity was detected from direct measurements, and the bunch length has been reduced. The uniqueness of the QWR demands an innovative design of the higher order mode dampers with high-pass filters, and a distinctive fundamental mode damper that enables the cavity to be bypassed during the acceleration stage.

  8. Use of an Injection Locked Magnetron to Drive a Superconducting RF Cavity

    SciTech Connect (OSTI)

    Haipeng Wang, Robert Rimmer, G. Davis, Imran Tahir, Amos Dexter, Greame Burt, Richard Carter

    2010-05-01

    The use of an injection locked CW magnetron to drive a 2.45 GHz superconducting RF cavity has been successfully demonstrated. With a locking power less than -27 dB with respect to the output and with a phase control system acting on the locking signal, cavity phase was accurately controlled for hours at a time without loss of lock whilst suppressing microphonics. The phase control accuracy achieved was 0.8 deg. r.m.s. The main contributing disturbance limiting ultimate phase control was power supply ripple from the low specification switch mode power supply used for the experiment.

  9. 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.

  10. 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.

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

    SciTech Connect (OSTI)

    Castilla, Alejandro; Delayen, Jean R.; Park, HyeKyoung

    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.

  12. 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.

  13. 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.

  14. CAMD Nanofabrication Links

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

    Research :: Publications :: Infrastructure :: Links :: Nanofabrication Facility in News Nano 50TM Awards: The Nano 50TM Awards, presented by Nanotech Briefs magazine, recognize the top 50 technologies, products and innovators that have significantly impacted, or are expected to impact, the state of the art in nanotechnology. "The winners of the Nano 50 awards are the best of the best - the innovative people and technologies that will continue to move nanotechnology to key mainstream

  15. 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.

  16. 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.

  17. Towards a 100mA Superconducting RF Photoinjector for BERLinPro

    SciTech Connect (OSTI)

    Neumann, Axel; Anders, W.; Burrill, Andrew; Jankowiak, Andreas; Kamps, T.; Knobloch, Jens; Kugeler, Oliver; Lauinger, P.; Matveenko, A.N.; Schmeisser, M.; Volker, J.; Ciovati, Gianluigi; Kneisel, Peter; Nietubyc, R.; Schubert, S.G.; Smedley, John; Sekutowicz, Jacek; Volkov, V.; Will, I.; Zaplatin, Evgeny

    2013-09-01

    For BERLinPro, a 100 mA CW-driven SRF energy recovery linac demonstrator facility, HZB needs to develop a photo-injector superconducting cavity which delivers a at least 1mm*mr emittance beam at high average current. To address these challenges of producing a high peak brightness beam at high repetition rate, at first HZB tested a fully superconducting injector with a lead cathode*,followed now by the design of a SC cavity allowing operation up to 4 mA using CW-modified TTF-III couplers and inserting a normal conducting high quantum efficiency cathode using the HZDR-style insert scheme. This talk will present the latest results and an overview of the measurements with the lead cathode cavity and will describe the design and optimization process, the first production results of the current design and an outlook to the further development steps towards the full power version.

  18. New results of development on high efficiency high gradient superconducting rf cavities

    SciTech Connect (OSTI)

    Geng, Rongli; Li, Z.; Hao, K.; Liu, K.-X.; Zhao, H.-Y.; Adolphsen, C.

    2015-09-01

    We report on the latest results of development on high efficiency high gradient superconducting radio frequency (SRF) cavities. Several 1-cell cavities made of large-grain niobium (Nb) were built, processed and tested. Two of these cavities are of the Low Surface Field (LSF) shape. Series of tests were carried out following controlled thermal cycling. Experiments toward zero-field cooling were carried out. The best experimentally achieved results are Eacc = 41 MV/m at Q0 = 6.5×1010 at 1.4 K by a 1-cell 1.3 GHz large-grain Nb TTF shape cavity and Eacc = 49 MV/m at Q0 = 1.5×1010 at 1.8 K by a 1-cell 1.5 GHz large-grain Nb CEBAF upgrade low-loss shape cavity.

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

    SciTech Connect (OSTI)

    Li, Y. M.; Liu, Kexin; Geng, Rongli

    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.

  20. 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.

  1. Nanofabrication

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

    Facility The emerging fields of nanoscience and nanoengineering are leading to unprecedented understanding and control over the fundamental building blocks of all physical things. This is likely to change the way almost everything-from vaccines to computers to automobile tires to objects not yet imagined-is designed and made. It is anticipated that a new world of industrial products valued at $1trillion/yr and, at least, 2 million nanotech workers would emerge in 10-15yrs. In order to be part of

  2. 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.

  3. Five-cell superconducting RF module with a PBG coupler cell: design and cold testing of the copper prototype

    SciTech Connect (OSTI)

    Arsenyev, Sergey Andreyevich; Simakov, Evgenya Ivanovna; Shchegolkov, Dmitry; Boulware, Chase; Grimm, Terry; Rogacki, Adam

    2015-04-29

    We report the design and experimental data for a copper prototype of a superconducting radio-frequency (SRF) accelerator module. The five-cell module has an incorporated photonic band gap (PBG) cell with couplers. The purpose of the PBG cell is to achieve better higher order mode (HOM) damping, which is vital for preserving the quality of high-current electron beams. Better HOM damping raises the current threshold for beam instabilities in novel SRF accelerators. The PBG design also increases the real-estate gradient of the linac because both HOM damping and the fundamental power coupling can be done through the PBG cell instead of on the beam pipe via complicated end assemblies. First, we will discuss the design and accelerating properties of the structure. The five-cell module was optimized to provide good HOM damping while maintaining the same accelerating properties as conventional elliptical-cell modules. We will then discuss the process of tuning the structure to obtain the desired accelerating gradient profile. Finally, we will list measured quality factors for the accelerating mode and the most dangerous HOMs.

  4. 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

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

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Chip-Scale Nanofabrication of Single Spins and Spin Arrays in Diamond Citation Details In-Document Search Title: Chip-Scale Nanofabrication of Single Spins and Spin Arrays in Diamond 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

  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. A superconducting focusing solenoid for the neutrino factory linear accelerator

    SciTech Connect (OSTI)

    M.A. Green; V. Lebedev; B.R. Strauss

    2002-03-01

    The proposed superconducting linear accelerator that accelerates muons from 190 MeV to 2.45 GeV will use superconducting solenoids for focusing the muon beam. The accelerator will use superconducting RF cavities. These cavities are very sensitive to stay magnetic field from the focusing magnets. Superconducting solenoids can have large stray fields. This paper describes the 201.25-MHz acceleration system for the neutrino factory. This paper also describes a focusing solenoid that delivers almost no stray field to a neighboring superconducting RF cavity.

  9. 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.

  10. Femtosecond laser three-dimensional micro- and nanofabrication

    SciTech Connect (OSTI)

    Sugioka, Koji; Cheng, Ya

    2014-12-15

    The rapid development of the femtosecond laser has revolutionized materials processing due to its unique characteristics of ultrashort pulse width and extremely high peak intensity. The short pulse width suppresses the formation of a heat-affected zone, which is vital for ultrahigh precision fabrication, whereas the high peak intensity allows nonlinear interactions such as multiphoton absorption and tunneling ionization to be induced in transparent materials, which provides versatility in terms of the materials that can be processed. More interestingly, irradiation with tightly focused femtosecond laser pulses inside transparent materials makes three-dimensional (3D) micro- and nanofabrication available due to efficient confinement of the nonlinear interactions within the focal volume. Additive manufacturing (stereolithography) based on multiphoton absorption (two-photon polymerization) enables the fabrication of 3D polymer micro- and nanostructures for photonic devices, micro- and nanomachines, and microfluidic devices, and has applications for biomedical and tissue engineering. Subtractive manufacturing based on internal modification and fabrication can realize the direct fabrication of 3D microfluidics, micromechanics, microelectronics, and photonic microcomponents in glass. These microcomponents can be easily integrated in a single glass microchip by a simple procedure using a femtosecond laser to realize more functional microdevices, such as optofluidics and integrated photonic microdevices. The highly localized multiphoton absorption of a tightly focused femtosecond laser in glass can also induce strong absorption only at the interface of two closely stacked glass substrates. Consequently, glass bonding can be performed based on fusion welding with femtosecond laser irradiation, which provides the potential for applications in electronics, optics, microelectromechanical systems, medical devices, microfluidic devices, and small satellites. This review paper describes the concepts and principles of femtosecond laser 3D micro- and nanofabrication and presents a comprehensive review on the state-of-the-art, applications, and the future prospects of this technology.

  11. 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.

  12. 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.

  13. 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 1990s 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.

  14. NSLS-II RF Cryogenic System

    SciTech Connect (OSTI)

    Rose, J.; Dilgen, T.; Gash, B.; Gosman, J.; Mortazavi, P.; Papu, J.; Ravindranath, V.; Sikora, R.; Sitnikov, A.; Wilhelm, H.; Jia, Y.; Monroe, C.

    2015-05-03

    The National Synchrotron Light Source II is a 3 GeV X-ray user facility commissioned in 2014. A new helium refrigerator system has been installed and commissioned to support the superconducting RF cavities in the storage ring. Special care was taken to provide very stable helium and LN2 pressures and flow rates to minimize microphonics and thermal effects at the cavities. Details of the system design along with commissioning and early operations data will be presented.

  15. 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.

  16. Superconductive wire

    DOE Patents [OSTI]

    Korzekwa, David A. (Los Alamos, NM); Bingert, John F. (Jemez Springs, NM); Peterson, Dean E. (Los Alamos, NM); Sheinberg, Haskell (Santa Fe, NM)

    1995-01-01

    A superconductive article is made by inserting a rigid mandrel into an internal cavity of a first metallic tube, said tube having an interior surface and an exterior surface, said interior surface defining the interior cavity, forming a layer of a superconductive material or superconductive precursor upon the exterior surface of said first metallic tube, machining the layer of superconductive material or superconductive precursor to a predetermined diameter to form an intermediate article configured for insertion into a second metallic tube having an interior diameter corresponding to the predetermined diameter, inserting the machined intermediate article into a second metallic tube having an internal diameter corresponding to the predetermined diameter of the intermediate article to form a composite intermediate article, reducing or ironing the composite intermediate article to a predetermined cross-sectional diameter, and sintering the reduced or ironed composite intermediate article at temperatures and for time sufficient for the superconductive material or superconductive precursor to exhibit superconductivity.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  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. R&D ERL: High power RF systems

    SciTech Connect (OSTI)

    Zaltsman, A.

    2010-01-15

    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 2.5 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.

  3. 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.

  4. 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.

  5. 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.

  6. Rf System Requirements for JLabs MEIC Collider Ring

    SciTech Connect (OSTI)

    Wang, Shaoheng; Li, Rui; Rimmer, Robert A.; Wang, Haipeng; Zhang, Yuhong

    2013-06-01

    The Medium-energy Electron Ion Collider (MEIC), proposed by Jefferson Lab, consists of a series of accelerators. At the top energy are the electron and ion collider rings. For the ion ring, it accelerates five long ion bunches to colliding energy and rebunches ions into a train of very short bunches before colliding. A set of low frequency RF system is needed for the long ion bunch energy ramping. Another set of high frequency RF cavities is needed to rebunch ions. For the electron ring, superconducting RF (SRF) cavities are needed to compensate the synchrotron radiation energy loss. The impedance of the SRF cavities must be low enough to keep the high current electron beam stable. The preliminary design requirements of these RF cavities are presented.

  7. ANALYZING SURFACE ROUGHNESS DEPENDENCE OF LINEAR RF LOSSES

    SciTech Connect (OSTI)

    Reece, Charles E.; Kelley, Michael J.; Xu, Chen

    2012-09-01

    Topographic structure on Superconductivity Radio Frequency (SRF) surfaces can contribute additional cavity RF losses describable in terms of surface RF reflectivity and absorption indices of wave scattering theory. At isotropic homogeneous extent, Power Spectrum Density (PSD) of roughness is introduced and quantifies the random surface topographic structure. PSD obtained from different surface treatments of niobium, such Buffered Chemical Polishing (BCP), Electropolishing (EP), Nano-Mechanical Polishing (NMP) and Barrel Centrifugal Polishing (CBP) are compared. A perturbation model is utilized to calculate the additional rough surface RF losses based on PSD statistical analysis. This model will not consider that superconductor becomes normal conducting at fields higher than transition field. One can calculate the RF power dissipation ratio between rough surface and ideal smooth surface within this field range from linear loss mechanisms.

  8. Microbunching and RF Compression

    SciTech Connect (OSTI)

    Venturini, M.; Migliorati, M.; Ronsivalle, C.; Ferrario, M.; Vaccarezza, C.

    2010-05-23

    Velocity bunching (or RF compression) represents a promising technique complementary to magnetic compression to achieve the high peak current required in the linac drivers for FELs. Here we report on recent progress aimed at characterizing the RF compression from the point of view of the microbunching instability. We emphasize the development of a linear theory for the gain function of the instability and its validation against macroparticle simulations that represents a useful tool in the evaluation of the compression schemes for FEL sources.

  9. 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.

  10. Hydrogen in plasma-nanofabrication: Selective control of nanostructure heating and passivation

    SciTech Connect (OSTI)

    Wolter, Matthias; Levchenko, Igor; Ostrikov, Kostya; Kersten, Holger

    2010-03-29

    The possibility of independent control of the surface fluxes of energy and hydrogen-containing radicals, thus enabling selective control of the nanostructure heating and passivation, is demonstrated. In situ energy flux measurements reveal that even a small addition of H{sub 2} to low-pressure Ar plasmas leads to a dramatic increase in the energy deposition through H recombination on the surface. The heat release is quenched by a sequential addition of a hydrocarbon precursor while the surface passivation remains effective. Such selective control offers an effective mechanism for deterministic control of the growth shape, crystallinity, and density of nanostructures in plasma-aided nanofabrication.

  11. Barrier RF stacking

    SciTech Connect (OSTI)

    Weiren Chou and Akira Takagi

    2003-02-24

    This paper introduces a new method for stacking beams in the longitudinal phase space. It uses RF barriers to confine and compress beams in an accelerator, provided that the machine momentum acceptance is a few times larger than the momentum spread of the injected beam. This is the case for the Fermilab Main Injector. A barrier RF system employing Finemet cores and high-voltage solid-state switches is under construction. The goal is to double the number of protons per cycle on the production target for Run2 and NuMI experiments.

  12. 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.

  13. 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

    2012-02-14

    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

  14. 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.

  15. CAMD Nanofabrication

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

    Research :: Publications :: Infrastructure :: News :: Links :: The emerging fields of nanoscience and nanoengineering are leading to unprecedented understanding and control over the fundamental building blocks of all physical things. This is likely to change the way almost everything—from vaccines to computers to automobile tires to objects not yet imagined—is designed and made. It is anticipated that a new world of industrial products valued at $1trillion/yr and, at least, 2 million nanotech

  16. CAMD Nanofabrication

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

    Urbina, Josef Hormes, Challa S. S. R. Kumar, and W. Todd Monroe, Functionalization of Gold and Glass Surfaces with Magnetic Nanoparticles Using Biomolecular Interactions,...

  17. Critical Magnetic Field Determination of Superconducting Materials

    SciTech Connect (OSTI)

    Canabal, A.; Tajima, T.; Dolgashev, V.A.; Tantawi, S.G.; Yamamoto, T.; /Tsukuba, Natl. Res. Lab. Metrol.

    2011-11-04

    Superconducting RF technology is becoming more and more important. With some recent cavity test results showing close to or even higher than the critical magnetic field of 170-180 mT that had been considered a limit, it is very important to develop a way to correctly measure the critical magnetic field (H{sup RF}{sub c}) of superconductors in the RF regime. Using a 11.4 GHz, 50-MW, <1 {mu}s, pulsed power source and a TE013-like mode copper cavity, we have been measuring critical magnetic fields of superconductors for accelerator cavity applications. This device can eliminate both thermal and field emission effects due to a short pulse and no electric field at the sample surface. A model of the system is presented in this paper along with a discussion of preliminary experimental data.

  18. Commissioning and Early Operation Experience of the NSLS-II Storage Ring RF System

    SciTech Connect (OSTI)

    Gao, F.; Rose, J.; Cupolo, J.; Dilgen, T.; Rose, B.; Gash, W.; Ravindranath, V.; Yeddulla, M.; Papu, J.; Davila, P.; Holub, B.; Tagger, J.; Sikora, R.; Ramirez, G.; Kulpin, J.

    2015-05-03

    The National Synchrotron Light Source II (NSLS-II) is a 3 GeV electron X-ray user facility commissioned in 2014. The storage ring RF system, essential for replenishing energy loss per turn of the electrons, consists of digital low level RF controllers, 310 kW CW klystron transmitters, CESR-B type superconducting cavities, as well as a supporting cryogenic system. Here we will report on RF commissioning and early operation experience of the system for beam current up to 200mA.

  19. 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.

  20. 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.

  1. RF-Based Accelerators

    Office of Scientific and Technical Information (OSTI)

    RF-Based Accelerators for HEDP Research ∗ John W. Staples, Andrew Sessler, Roderich Keller, LBNL, Berkeley, California, Petr Ostroumov, ANL, Argonne, Illinois, Weiren Chou, Fermilab, Batavia, Illinois Abstract Accelerator-driven High-Energy Density Physics (HEDP) experiments require typically 1 nanosecond, 1 microcoulomb pulses of mass 20 ions accelerated to several MeV to produce eV-level excitations in thin targets, the "warm dense matter" regime. Traditionally the province of

  2. 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.

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

    Office of Scientific and Technical Information (OSTI)

    K refrigerator cold boxes, helium gas pumping systems and high-performance transfer lines. ... LINEAR COLLIDERS; NIOBIUM; PULSES; PUMPING; REFRIGERATORS; SUPERFLUIDITY; VAPOR ...

  4. 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.

  5. Fiber Optic Based Thermometry System for Superconducting RF Cavities

    SciTech Connect (OSTI)

    Dr. Kochergin, Vladimir

    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.

  6. Secrets of superconductivity revealed

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

    Secrets of superconductivity revealed Secrets of superconductivity revealed The superconducting material Cerium-Colbalt-Indium5 reveals new secrets about how superconductivity and magnetism can be related. January 3, 2014 Simon Gerber, first author of the publication on the superconducting properties of CeCoIn5 at the Morpheus instrument of the Spallation Neutron Source SINQ in Switzerland. (Photo: Paul Scherrer Institute/Markus Fischer) Simon Gerber, first author of the publication on the

  7. RF current sensor

    DOE Patents [OSTI]

    Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

    1998-11-10

    An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

  8. Tomcat-Projects_RF

    Energy Science and Technology Software Center (OSTI)

    2004-09-15

    Tomcat-Projects_RF is a software package for analyzing sensor data obtained from a database and displaying the results with Java Servlet Pages (JSP). SQL Views into the dataset are tailored for personnel having different roles in monitoring the items in a storage facility. For example, an inspector, a host treaty compliance officer, a system engineer and software developers were the users identified that would need to access data at different levels of detail, The analysis providesmore » a high level status of the storage facility and allows the user to go deeper into the data details if the user desires.« less

  9. 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.

  10. SRF and RF systems for LEReC Linac

    SciTech Connect (OSTI)

    Belomestnykh, S.; Ben-Zvi, I.; Brutus, J. C.; Fedotov, A.; McIntyre, G.; Polizzo, S.; Smith, K.; Than, R.; Tuozzolo, J.; Veshcherevich, V.; Wu, Q.; Xiao, B.; Xu, W.; Zaltsman, A.

    2015-05-03

    The Low Energy RHIC electron Cooling (LEReC) is under development at BNL to improve RHIC luminosity at low energies. It will consist of a short electron linac and two cooling sections, one for blue and one for yellow rings. For the first stage of the project, LEReC-I, we will install a 704 MHz superconducting RF cavity and three normal conducting cavities operating at 9 MHz, 704 MHz and 2.1 GHz. The SRF cavity will boost the electron beam energy up to 2 MeV. The warm cavities will be used to correct the energy spread introduced in the SRF cavity. The paper describes layouts of the SRF and RF systems, their parameters and status.

  11. Energetics of an rf SQUID Coupled to Two Thermal Reservoirs

    SciTech Connect (OSTI)

    Gardas, B.; Łuczka, J.; Ptok, A.; Dajka, J.

    2015-12-07

    We study energetics of a Josephson tunnel junction connecting a superconducting loop pierced by an external magnetic flux (an rf SQUID) and coupled to two independent thermal reservoirs of different temperature. In the framework of the theory of quantum dissipative systems, we analyze energy currents in stationary states. The stationary energy flow can be periodically modulated by the external magnetic flux exemplifying the rf SQUID as a quantum heat interferometer. Additionally, we consider the transient regime and identify three distinct regimes: monotonic decay, damped oscillations and pulse-type behavior of energy currents. Furthermore, the first two regimes can be controlled by the external magnetic flux while the last regime is robust against its variation.

  12. Energetics of an rf SQUID Coupled to Two Thermal Reservoirs

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

    Gardas, B.; Łuczka, J.; Ptok, A.; Dajka, J.

    2015-12-07

    We study energetics of a Josephson tunnel junction connecting a superconducting loop pierced by an external magnetic flux (an rf SQUID) and coupled to two independent thermal reservoirs of different temperature. In the framework of the theory of quantum dissipative systems, we analyze energy currents in stationary states. The stationary energy flow can be periodically modulated by the external magnetic flux exemplifying the rf SQUID as a quantum heat interferometer. Additionally, we consider the transient regime and identify three distinct regimes: monotonic decay, damped oscillations and pulse-type behavior of energy currents. Furthermore, the first two regimes can be controlled bymore » the external magnetic flux while the last regime is robust against its variation.« less

  13. NSLS-II RF SYSTEMS

    SciTech Connect (OSTI)

    Rose, J.; Gash, W.; Holub, B.; Kawashima, Y.; Ma, H.; Towne, N.; Yeddulla, M.

    2011-03-28

    The NSLS-II is a new third generation light source being constructed at Brookhaven Lab. The storage ring is optimized for low emittance by use of damping wigglers to reduce the emittance to below 1 nm-rad. The RF systems are designed to provide stable beam through tight RF phase and amplitude stability requirements.

  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. Measured performance of the GTA rf systems

    SciTech Connect (OSTI)

    Denney, P.M.; Jachim, S.P.

    1993-01-01

    This paper describes the performance of the RF systems on the Ground Test Accelerator (GTA). The RF system architecture is briefly described. Among the RF performance results presented are RF field flatness and stability, amplitude and phase control resolution, and control system bandwidth and stability. The rejection by the RF systems of beam-induced disturbances, such as transients and noise, are analyzed. The observed responses are also compared to computer-based simulations of the RF systems for validation.

  17. Measured performance of the GTA rf systems

    SciTech Connect (OSTI)

    Denney, P.M.; Jachim, S.P.

    1993-06-01

    This paper describes the performance of the RF systems on the Ground Test Accelerator (GTA). The RF system architecture is briefly described. Among the RF performance results presented are RF field flatness and stability, amplitude and phase control resolution, and control system bandwidth and stability. The rejection by the RF systems of beam-induced disturbances, such as transients and noise, are analyzed. The observed responses are also compared to computer-based simulations of the RF systems for validation.

  18. 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.

  19. 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.

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

    SciTech Connect (OSTI)

    Van Winkle, Daniel; Fox, John; Mastorides, Themis; Rivetta, Claudio; Baudrenghien, Philippe; Butterworth, Andrew; 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. 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.}

  2. 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.

  3. Fast Ferroelectric L-Band Tuner for Superconducting Cavities

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2012-07-03

    Design, analysis, and low-power tests are described on a ferroelectric tuner concept that could be used for controlling external coupling to RF cavities for the superconducting Energy Recovery Linac (ERL) in the electron cooler of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL). The tuner configuration utilizes several small donut-shaped ferroelectric assemblies, which allow the design to be simpler and more flexible, as compared to previous designs. Design parameters for 704 and 1300 MHz versions of the tuner are given. Simulation results point to efficient performance that could reduce by a factor-of-ten the RF power levels required for driving superconducting cavities in the BNL ERL.

  4. 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.

  5. 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.

  6. Status of the plasma generator of the superconducting proton linac

    SciTech Connect (OSTI)

    Kronberger, M.; Lettry, J.; Paoluzzi, M.; Pereira, H.; Arias, J. Sanchez; Schmitzer, C.; Scrivens, R.; Faircloth, D.

    2012-02-15

    In the framework of the superconducting proton linac (SPL) study at CERN, a new non-cesiated H{sup -} plasma generator driven by an external 2 MHz RF antenna has been developed and successfully operated at repetition rates of 50 Hz, pulse lengths of up to 3 ms, and average RF powers of up to 3 kW. The coupling efficiency of RF power into the plasma was determined by the cooling water temperatures and the analysis of the RF forward and reflected power and the antenna current and amounts to 50%-60%. The plasma resistance increases between 10 kW and 40 kW RF power from about 0.45 {Omega} to 0.65 {Omega}. Measurements of RF power dissipated in the ferrites and the magnets on a test bench show a 5-fold decrease of the power losses for the magnets when they are contained in a Cu box, thus validating the strategy of shielding the magnets with a high electrical conductivity material. An air cooling system was installed in the SPL plasma generator to control the temperatures of the ferrites despite hysteresis losses of several Watts.

  7. 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.

  8. 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.

  9. Superconducting radiofrequency window assembly

    DOE Patents [OSTI]

    Phillips, H.L.; Elliott, T.S.

    1997-03-11

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The srf window assembly has a superconducting metal-ceramic design. The srf window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. 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. 11 figs.

  10. Superconductive radiofrequency window assembly

    DOE Patents [OSTI]

    Phillips, H.L.; Elliott, T.S.

    1998-05-19

    The present invention is a superconducting radiofrequency window assembly for use in an electron beam accelerator. The SRF window assembly has a superconducting metal-ceramic design. The SRF window assembly comprises a superconducting frame, a ceramic plate having a superconducting metallized area, and a superconducting eyelet for sealing plate into frame. The plate is brazed to eyelet which is then electron beam welded to frame. 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. 11 figs.

  11. Superconducting Topological Insulators

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

    copper, it's possible to make the topologically ordered electrons superconducting, dropping electrical resistance in the surface states all the way to zero. A Major(ana) Quantum...

  12. Superconducting Topological Insulators

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

    Superconducting Topological Insulators Print Wednesday, 26 January 2011 00:00 Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a...

  13. Secrets of superconductivity revealed

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

    Los Alamos National Laboratory and a second at Los Alamos in collaboration with the Sungkyunkwan University in South Korea, the superconducting material Cerium-Colbalt-Indium5...

  14. Alexei Abrikosov and Superconductivity

    Office of Scientific and Technical Information (OSTI)

    Physics for his research in the area of superconductivity. ... Additional information about Alexei Abrikosov and his work ... New Developments in the Theory of HTSC High Temperature ...

  15. Superconducting Topological Insulators

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

    taken even further. Their studies showed that by doping the TI, bismuth selenide, with copper, it's possible to make the topologically ordered electrons superconducting, dropping...

  16. 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.

  17. Superconductive imaging surface magnetometer

    DOE Patents [OSTI]

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

    1991-01-01

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

  18. 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.

  19. 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.

  20. 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 ...

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. Superconductivity Program Overview High-Temperature Superconductivity

    Energy Savers [EERE]

    SuperconducTiviTy program haS Three FocuS areaS: SuperconducTiviTy applicaTionS Developing HTS-based electric power equipment such as transmission and distribution cables and fault current limiters Second-generaTion Wire developmenT Developing high-performance, low-cost, second- generation HTS wire at long lengths STraTegic reSearch Supporting fundamental research activities to better understand relationships between the microstructure of HTS materials and their ability to carry large electric

  7. Fast Superconducting Switch for Superconducting Power Devices - Energy

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

    Innovation Portal Fast Superconducting Switch for Superconducting Power Devices Brookhaven National Laboratory Contact BNL About This Technology Publications: PDF Document Publication Fast high-temperature superconductor switch for high current applications. (1,424 KB) Conceptual drawing of the fast superconducting switch.<br type="_moz" /> Conceptual drawing of the fast superconducting switch. Technology Marketing Summary Superconducting magnetic energy storage (SMES) offers

  8. 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.

  9. 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.

  10. DOE Superconductivity Program Stakeholders | Department of Energy

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

    Superconductivity Program Stakeholders DOE Superconductivity Program Stakeholders Map showing the stakeholders involved in High Temperature Superconductivity work with the DOE. PDF...

  11. Superconducting active impedance converter

    DOE Patents [OSTI]

    Ginley, D.S.; Hietala, V.M.; Martens, J.S.

    1993-11-16

    A transimpedance amplifier for use with high temperature superconducting, other superconducting, and conventional semiconductors 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. 12 figures.

  12. Superconducting active impedance converter

    DOE Patents [OSTI]

    Ginley, David S.; Hietala, Vincent M.; Martens, Jon S.

    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.

  13. 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.

  14. The Status of Normal Conducting RF (NCRF) Guns, a Summary of the ERL2005 Workshop

    SciTech Connect (OSTI)

    Dowell, D.H.; Lewellen, J.W.; Nguyen, D.; Rimmer, R.; /Jefferson Lab

    2006-03-13

    The 32nd Advanced ICFA Beam Dynamics Workshop on Energy Recovering Linacs (ERL2005) was held at Jefferson Laboratory, March 20 to 23, 2005. A wide range of ERL-related topics were presented and discussed in several working groups with Working Group 1 concentrated upon the physics and technology issues for DC, superconducting RF (SRF) and normal conducting RF (NCRF) guns. This paper summarizes the NCRF gun talks and reviews the status of NCRF gun technology. It begins with the presentations made on the subject of low-frequency, high-duty factor guns most appropriate for ERLs. One such gun at 433MHz was demonstrated at 25%DF in 1992, while the CW and much improved version is currently being constructed at 700MHz for LANL. In addition, the idea of combining the NCRF gun with a SRF linac booster was presented and is described in this paper. There was also a talk on high-field guns typically used for SASE free electron lasers. In particular, the DESY coaxial RF feed design provides rotationally symmetric RF fields and greater flexibility in the placement of the focusing magnetic field. While in the LCLS approach, the symmetric fields are obtained with a dual RF feed and racetrack cell shape. Although these guns cannot be operated at high-duty factor, they do produce the best quality beams. With these limitations in mind, a section with material not presented at the workshop has been included in the paper. This work describes a re-entrant approach which may allow NCRF guns to operate with simultaneously increased RF fields and duty factors. And finally, a novel proposal describing a high-duty factor, two-frequency RF gun using a field emission source instead of a laser driven photocathode was also presented.

  15. The status of normal conducting RF (NCRF) guns; a summary of the ERL2005 Workshop

    SciTech Connect (OSTI)

    D.H. Dowell; J.W. Lewellen; D. Nguyen; R.A. Rimmer

    2005-03-19

    The 32nd Advanced ICFA Beam Dynamics Workshop on Energy Recovering Linacs (ERL2005) was held at Jefferson Laboratory, March 20 to 23, 2005. A wide range of ERL-related topics were presented and discussed in several working groups with Working Group 1 concentrated upon the physics and technology issues for DC, superconducting RF (SRF) and normal conducting RF (NCRF) guns. This paper summarizes the NCRF gun talks and reviews the status of NCRF gun technology. It begins with the presentations made on the subject of low-frequency, high-duty factor guns most appropriate for ERLs. One such gun at 433MHz was demonstrated at 25%DF in 1992, while the CW and much improved version is currently being constructed at 700MHz for LANL. In addition, the idea of combining the NCRF gun with a SRF linac booster was presented and is described in this paper. There was also a talk on high-field guns typically used for SASE free electron lasers. In particular, the DESY coaxial RF feed design provides rotationally symmetric RF fields and greater flexibility in the placement of the focusing magnetic field. While in the LCLS approach, the symmetric fields are obtained with a dual RF feed and racetrack cell shape. Although these guns cannot be operated at high-duty factor, they do produce the best quality beams. With these limitations in mind, a section with material not presented at the workshop has been included in the paper. This work describes a re-entrant approach which may allow NCRF guns to operate with simultaneously increased RF fields and duty factors. And finally, a novel proposal describing a high-duty factor, two-frequency RF gun using a field emission source instead of a laser driven photocathode was also presented.

  16. 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.

  17. 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.

  18. 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.

  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. Superconducting Topological Insulators

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

    Superconducting Topological Insulators Superconducting Topological Insulators Print Wednesday, 26 January 2011 00:00 Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual

  1. Superconductive ceramic oxide combination

    SciTech Connect (OSTI)

    Chatterjee, D.K.; Mehrotra, A.K.; Mir, J.M.

    1991-03-05

    This patent describes the combination of a superconductive ceramic oxide which degrades in conductivity upon contact of ambient air with its surface and, interposed between the ceramic oxide surface and ambient air in the amount of at least 1 mg per square meter of surface area of the superconductive ceramic oxide, a passivant polymer selected from the group consisting of a polyester ionomer and an alkyl cellulose.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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].

  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. High Temperature Superconductivity Partners | Department of Energy

    Office of Environmental Management (EM)

    High Temperature Superconductivity Partners High Temperature Superconductivity Partners Map showing DOE's partners/stakeholders in the High Temperature Superconductivity Program PDF icon High Temperature Superconductivity Partners More Documents & Publications DOE Superconductivity Program Stakeholders DOE Provides up to $51.8 Million to Modernize the U.S. Electric Grid System. June 27, 2007 High-Temperature Superconductivity Cable Demonstration Projects

  11. High voltage RF feedthrough bushing

    DOE Patents [OSTI]

    Grotz, Glenn F. (Huntington Station, NY)

    1984-01-01

    Described is a multi-element, high voltage radio frequency bushing for trmitting RF energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

  12. Fast Ferroelectric L-Band Tuner for Superconducting Cavities

    SciTech Connect (OSTI)

    Jay L. Hirshfield

    2011-03-01

    Analysis and modeling is presented for a fast microwave tuner to operate at 700 MHz which incorporates ferroelectric elements whose dielectric permittivity can be rapidly altered by application of an external voltage. This tuner could be used to correct unavoidable fluctuations in the resonant frequency of superconducting cavities in accelerator structures, thereby greatly reducing the RF power needed to drive the cavities. A planar test version of the tuner has been tested at low levels of RF power, but at 1300 MHz to minimize the physical size of the test structure. This test version comprises one-third of the final version. The tests show performance in good agreement with simulations, but with losses in the ferroelectric elements that are too large for practical use, and with issues in bonding of ferroelectric elements to the metal walls of the tuner structure.

  13. RF Micro Devices | Open Energy Information

    Open Energy Info (EERE)

    for Others) for this property. Partnering Center within NREL National Center for Photovoltaics Partnership Year 2009 RF Micro Devices is a company located in Greensboro, NC....

  14. 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.

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

    DOE Patents [OSTI]

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

    2015-03-24

    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.

  16. Radio Frequency Surface Impedance Characterization System for Superconducting Samples at 7.5 GHz

    SciTech Connect (OSTI)

    Binping Xiao, Charles Reece, Michael Kelley, Larry Phillips, Rongli Geng, Haipeng Wang, Frank Marhauser

    2011-05-01

    A radio frequency (RF) surface impedance characterization (SIC) system that uses a sapphire-loaded Nb cavity operating at 7.5 GHz has been fabricated to measure the RF surface impedance of flat superconducting samples. Currently, the SIC system can make direct calorimetric surface impedance measurements in the central 0.8 cm2 area of 5 cm diameter disk samples in a temperature range from 2 to 20 K, exposed to a magnetic flux density of up to 14 mT. As an application, we present the measurement results for a bulk Nb sample.

  17. Barrier RF stacking at Fermilab

    SciTech Connect (OSTI)

    Weiren Chou et al.

    2003-06-04

    A key issue to upgrade the luminosity of the Tevatron Run2 program and to meet the neutrino requirement of the NuMI experiment at Fermilab is to increase the proton intensity on the target. This paper introduces a new scheme to double the number of protons from the Main Injector (MI) to the pbar production target (Run2) and to the pion production target (NuMI). It is based on the fact that the MI momentum acceptance is about a factor of four larger than the momentum spread of the Booster beam. Two RF barriers--one fixed, another moving--are employed to confine the proton beam. The Booster beams are injected off-momentum into the MI and are continuously reflected and compressed by the two barriers. Calculations and simulations show that this scheme could work provided that the Booster beam momentum spread can be kept under control. Compared with slip stacking, a main advantage of this new method is small beam loading effect thanks to the low peak beam current. The RF barriers can be generated by an inductive device, which uses nanocrystal magnet alloy (Finemet) cores and fast high voltage MOSFET switches. This device has been designed and fabricated by a Fermilab-KEK-Caltech team. The first bench test was successful. Beam experiments are being planned.

  18. High temperature interfacial superconductivity (Patent) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Patent: High temperature interfacial superconductivity Citation Details In-Document Search Title: High temperature interfacial superconductivity High-temperature superconductivity ...

  19. 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.

  20. 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.

  1. 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.

  2. 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.

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

  4. 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.

  5. Engineering Division Superconducting

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

    & Engineering Division Superconducting Magnet Technology for Fusion and Large Scale Applications Joseph V. Minervini Massachusetts Institute of Technology Plasma Science and Fusion Center Princeton Plasma Physics Laboratory Colloquium Princeton, NJ October 15, 2014 Technology & Engineering Division Contents * Fusion Magnets - Present and Future - Vision - State-of-the-art - New developments in superconductors * Advanced fusion magnet technology * Other large scale applications of

  6. 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 ...

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

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

    Robust Diamond-Based RF Switch Yields Enhanced Communication Capabilities Technology available for licesning: A radio frequency (RF) microelectromechanical system (MEMS) switch...

  8. Matching network for RF plasma source

    DOE Patents [OSTI]

    Pickard, Daniel S.; Leung, Ka-Ngo

    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.

  9. 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.

  10. Micropower RF material proximity sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1998-11-10

    A level detector or proximity detector for materials capable of sensing through plastic container walls or encapsulating materials is disclosed. 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. 5 figs.

  11. 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.

  12. 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 CaC₆ and YbC₆ 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

  13. 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.

  14. 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.

  15. 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.

  16. Superconducting Topological Insulators

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

    Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly

  17. Superconducting Topological Insulators

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

    Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly

  18. Superconducting Topological Insulators

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

    Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly

  19. Superconducting Topological Insulators

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

    Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly

  20. Superconducting Topological Insulators

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

    Superconducting Topological Insulators Print Three-dimensional topological insulators (TIs), discovered experimentally in 2007-2009 by a Princeton-ALS collaboration, are a promising platform for developing the next generation of electronics. Electrons within one nanometer of a TI's surface move at high speeds in a "light-like" fashion. The quantum interactions that generate these electronic states cause individual electrons to be spin polarized even at room temperature and to strongly

  1. 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..

  2. 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.

  3. Normal Conducting RF Cavity for MICE

    SciTech Connect (OSTI)

    Li, D.; DeMello, A.; Virostek, S.; Zisman, M.; Summers, D.

    2010-05-23

    Normal conducting RF cavities must be used for the cooling section of the international Muon Ionization Cooling Experiment (MICE), currently under construction at Rutherford Appleton Laboratory (RAL) in the UK. Eight 201-MHz cavities are needed for the MICE cooling section; fabrication of the first five cavities is complete. We report the cavity fabrication status including cavity design, fabrication techniques and preliminary low power RF measurements.

  4. Overview of High Power Vacuum Dry RF Load Designs

    SciTech Connect (OSTI)

    Krasnykh, Anatoly

    2015-08-27

    A specific feature of RF linacs based on the pulsed traveling wave (TW) mode of operation is that only a portion of the RF energy is used for the beam acceleration. The residual RF energy has to be terminated into an RF load. Higher accelerating gradients require higher RF sources and RF loads, which can stably terminate the residual RF power. RF feeders (from the RF source though the accelerating section to the load) are vacuumed to transmit multi-megawatt high power RF. This overview will outline vacuumed RF loads only. A common method to terminate multi-MW RF power is to use circulated water (or other liquid) as an absorbing medium. A solid dielectric interface (a high quality ceramic) is required to separate vacuum and liquid RF absorber mediums. Using such RF load approaches in TW linacs is troubling because there is a fragile ceramic window barrier and a failure could become catastrophic for linac vacuum and RF systems. Traditional loads comprising of a ceramic disk have limited peak and average power handling capability and are therefore not suitable for high gradient TW linacs. This overview will focus on ''vacuum dry'' or ''all-metal'' loads that do not employ any dielectric interface between vacuum and absorber. The first prototype is an original design of RF loads for the Stanford Two-Mile Accelerator.

  5. 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.

  6. 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.

  7. High-Temperature Superconducting Composite Conductors

    DOE Patents [OSTI]

    Holesinger, Terry G.; Foltyn, Stephen R.; Arendt, Paul N.; Groves, James R.; Jia, Quanxi; Ayala, Alicia

    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.

  8. Superconductivity (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Superconductivity Citation Details In-Document Search Title: Superconductivity Authors: Maiorov, Boris A. 1 + Show Author Affiliations Los Alamos National ...

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Power superconducting power transmission cable

    DOE Patents [OSTI]

    Ashworth, Stephen P.

    2003-06-10

    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. 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.

  16. CAMD Nanofabrication Links

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

    Infrastructure :: News :: Related sites National Nanotechnology Initiative Nano Technology Industries Advanced Materials Research Institute Institute of Physics Max-Planck Institute for Kohlenforschung The institute of nanotechnology Nanotechnology Now Nanotechnology - Education Nanojournals Chancellor's Distinguished Lectureship Series

  17. CAMD Nanofabrication Infrastructure

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

    is being strengthened to explore bio-medical applications of nanoparticles. Glove box Wet-Chemical Laboratory XAS Beam Line IR Spectroscopy Beam Line Modular Micro Reactor...

  18. SECTION V: SUPERCONDUCTING CYCLOTRON AND INSTRUMENTATION

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

    ... V-4 K. Hagel and R. Burch Commissioning of the superconducting solenoid rare isotope beamline......

  19. High-Temperature Superconductivity Cable Demonstration Projects |

    Office of Environmental Management (EM)

    Department of Energy High-Temperature Superconductivity Cable Demonstration Projects High-Temperature Superconductivity Cable Demonstration Projects A National Effort to Introduce New Technology into the Power Delivery Infrastructure PDF icon High-Temperature Superconductivity Cable Demonstration Projects More Documents & Publications HTS Cable Projects Superconductivity Program Overview Columbus HTS Power Cable

  20. 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.

  1. Rf capacitively-coupled electrodeless light source

    DOE Patents [OSTI]

    Manos, Dennis M. (Williamsburg, VA); Diggs, Jessie (Norfolk, VA); Ametepe, Joseph D. (Roanoke, VA); Fugitt, Jock A. (Livingston, TX)

    2000-01-01

    An rf capacitively-coupled electrodeless light source is provided. The light source comprises a hollow, elongated chamber and at least one center conductor disposed within the hollow, elongated chamber. A portion of each center conductor extends beyond the hollow, elongated chamber. At least one gas capable of forming an electronically excited molecular state is contained within each center conductor. An electrical coupler is positioned concentric to the hollow, elongated chamber and the electrical coupler surrounds the portion of each center conductor that extends beyond the hollow, elongated chamber. A rf-power supply is positioned in an operable relationship to the electrical coupler and an impedance matching network is positioned in an operable relationship to the rf power supply and the electrical coupler.

  2. The RF Design of an HOM Polarized RF Gun for the ILC

    SciTech Connect (OSTI)

    Wang, J.W.; Clendenin, J.E.; Colby, E.R.; Miller, R.A.; Lewellen, J.W.; /Argonne

    2006-11-15

    The ILC requires a polarized electron beam. While a highly polarized beam can be produced by a GaAs-type cathode in a DC gun of the type currently in use at SLAC, JLAB and elsewhere, the ILC injector system can be simplified and made more efficient if a GaAs-type cathode can be combined with a low emittance RF gun. Since this type of cathode is known to be extremely sensitive to vacuum contamination including back bombardment by electrons and ions, any successful polarized RF gun must have a significantly improved operating vacuum compared to existing RF guns. We present a new RF design for an L-Band normal conducting (NC) RF gun for the ILC polarized electron source. This design incorporates a higher order mode (HOM) structure, whose chief virtue in this application is an improved conductance for vacuum pumping on the cathode. Computer simulation models have been used to optimize the RF parameters with two principal goals: first to minimize the required RF power; second to reduce the peak surface field relative to the field at the cathode in order to suppress field emitted electron bombardment. The beam properties have been simulated initially using PARMELA. Vacuum and other practical issues for implementing this design are discussed.

  3. Los Alamos scientists see new mechanism for superconductivity

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

    superconductivity Researchers have posited an explanation for superconductivity that may open the door to the discovery of new, unconventional forms of superconductivity. November...

  4. Nozzle for superconducting fiber production

    DOE Patents [OSTI]

    Righi, Jamal

    1992-11-17

    A nozzle apparatus for producing flexible fibers of superconducting material receives melted material from a crucible for containing a charge of the superconducting material. The material is melted in the crucible and falls in a stream through a bottom hole in the crucible. The stream falls through a protecting collar which maintains the stream at high temperatures. The stream is then supplied through the downwardly directed nozzle where it is subjected to a high velocity air flow which breaks the melted superconducting material into ligaments which solidify into the flexible fibers. The fibers are collected by blowing them against a porous cloth.

  5. 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.

  6. 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.

  7. 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.

  8. Superconducting magnetic coil

    DOE Patents [OSTI]

    Aized, Dawood (Marlboro, MA); Schwall, Robert E. (Northborough, MA)

    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.

  9. Superconducting magnetic coil

    DOE Patents [OSTI]

    Aized, Dawood (Marlboro, MA); Schwall, Robert E. (Northborough, MA)

    1996-06-11

    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.

  10. 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.

  11. NSLS-II RF BEAM POSITION MONITOR

    SciTech Connect (OSTI)

    Vetter, K.; Della Penna, A. J.; DeLong, J.; Kosciuk, B.; Mead, J.; Pinayev, I.; Singh, O.; Tian, Y.; Ha, K.; Portmann, G.; Sebek J.

    2011-03-28

    An internal R&D program has been undertaken at BNL to develop a sub-micron RF Beam Position Monitor (BPM) for the NSLS-II 3rd generation light source that is currently under construction. The BPM R&D program started in August 2009. Successful beam tests were conducted 15 months from the start of the program. The NSLS-II RF BPM has been designed to meet all requirements for the NSLS-II Injection system and Storage Ring. Housing of the RF BPM's in +-0.1 C thermally controlled racks provide sub-micron stabilization without active correction. An active pilot-tone has been incorporated to aid long-term (8hr min) stabilization to 200nm RMS. The development of a sub-micron BPM for the NSLS-II has successfully demonstrated performance and stability. Pilot Tone calibration combiner and RF synthesizer has been implemented and algorithm development is underway. The program is currently on schedule to start production development of 60 Injection BPM's starting in the Fall of 2011. The production of {approx}250 Storage Ring BPM's will overlap the Injection schedule.

  12. Common Sense Copper and RF Guns

    SciTech Connect (OSTI)

    Mulhollan, G.

    2005-01-18

    The purpose of this document is to gather together both fundamental information on copper and on the cleaning and operation of copper in RF gun structures. While incomplete, this is a living document and will be added to and updated as necessary.

  13. 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.

  14. 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.

  15. Mixed-mu superconducting bearings

    DOE Patents [OSTI]

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

    1998-01-01

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

  16. 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.

  17. 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.

  18. Hermetically sealed superconducting magnet motor

    DOE Patents [OSTI]

    DeVault, Robert C. (Knoxville, TN); McConnell, Benjamin W. (Knoxville, TN); Phillips, Benjamin A. (Benton Harbor, MI)

    1996-01-01

    A hermetically sealed superconducting magnet motor includes a rotor separated from a stator by either a radial gap, an axial gap, or a combined axial and radial gap. Dual conically shaped stators are used in one embodiment to levitate a disc-shaped rotor made of superconducting material within a conduit for moving cryogenic fluid. As the rotor is caused to rotate when the field stator is energized, the fluid is pumped through the conduit.

  19. Electronic structure of superconductivity refined

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

    Electronic structure of superconductivity refined Electronic structure of superconductivity refined A team of physicists propose a new model that expands on a little understood aspect of the electronic structure in high-temperature superconductors. July 10, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma

  20. Hermetically sealed superconducting magnet motor

    DOE Patents [OSTI]

    DeVault, R.C.; McConnell, B.W.; Phillips, B.A.

    1996-07-02

    A hermetically sealed superconducting magnet motor includes a rotor separated from a stator by either a radial gap, an axial gap, or a combined axial and radial gap. Dual conically shaped stators are used in one embodiment to levitate a disc-shaped rotor made of superconducting material within a conduit for moving cryogenic fluid. As the rotor is caused to rotate when the field stator is energized, the fluid is pumped through the conduit. 6 figs.

  1. Process for producing clad superconductive materials

    DOE Patents [OSTI]

    Cass, Richard B. (Ringoes, NJ); Ott, Kevin C. (Los Alamos, NM); Peterson, Dean E. (Los Alamos, NM)

    1992-01-01

    A process for fabricating superconducting composite wire by the steps of placing a superconductive precursor admixture capable of undergoing a self propagating combustion in stoichiometric amounts sufficient to form a superconductive product within a metal tube, sealing one end of said tube, igniting said superconductive precursor admixture whereby said superconductive precursor admixture endburns along the length of the admixture, and cross-section reducing said tube at a rate substantially equal to the rate of burning of said superconductive precursor admixture and at a point substantially planar with the burnfront of the superconductive precursor mixture, whereby a clad superconductive product is formed in situ, the product characterized as superconductive without a subsequent sintering stage, is disclosed.

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

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

    Oct. 22, 2010 The Impact of ATLAS on SRF Development and Applications -- R. Laxdal, ATLAS 25 th Anniversary -- 1 The Impact of ATLAS on SRF Development and Applications Bob Laxdal,...

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

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

    Advanced Manufacturing | Department of Energy Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced Manufacturing Microwave (MW) and Radio Frequency (RF) as Enabling Technologies for Advanced Manufacturing PDF icon mw_rf_workshop_background_july2012.pdf More Documents & Publications Microwave and Radio Frequency Workshop Advanced Manufacturing Office Overview Manufacturing Demonstration Facility Workshop

  4. Tubular Radio Frequency (RF) Cage Field Confinement Cavity (IN...

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

    and more. Applications and Industries Medical technology Industrial uses such as polymerization, sterilization and waste treatment Superconducting accelerator applications...

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

    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.

  10. 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.

  11. 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.

  12. Design of an accelerating cavity for the Superconducting Super Collider Low-Energy Booster

    SciTech Connect (OSTI)

    Friedrichs, C.C.; Walling, L. ); Campbell, B.M. )

    1991-01-01

    This paper presents the history and current status of the design of the accelerator cavity to be incorporated into the Low-Energy Booster (LEB) of the Superconducting Super Collider (SSC). The LEB is a proton synchrotron, 540 meters in circumference, and having 108 buckets around the ring. Acceleration programs, each 50 msec long, take place at a rate of 10 per second. The beta change of the particles from injection to extraction is from 0.8 to 0.997. Since the rf excitation frequency must track beta, the rf frequency must shift from 47.5 to 60 MHz over the 50-msec acceleration program. The cavity will use ferrite in a perpendicular control bias mode to effect the require tuning. 4 refs., 1 fig.

  13. 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.

  14. 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.

  15. Optical emission spectroscopy of the Linac4 and superconducting proton Linac plasma generators

    SciTech Connect (OSTI)

    Lettry, J.; Kronberger, M.; Mahner, E.; Schmitzer, C.; Sanchez, J.; Scrivens, R.; Midttun, O.; O'Neil, M.; Pereira, H.; Paoluzzi, M.; Fantz, U.; Wuenderlich, D.; Kalvas, T.; Koivisto, H.; Komppula, J.; Myllyperkioe, P.; Tarvainen, O.

    2012-02-15

    CERN's superconducting proton Linac (SPL) study investigates a 50 Hz high-energy, high-power Linac for H{sup -} ions. The SPL plasma generator is an evolution of the DESY ion source plasma generator currently operated at CERN's Linac4 test stand. The plasma generator is a step towards a particle source for the SPL, it is designed to handle 100 kW peak RF-power at a 6% duty factor. While the acquisition of an integrated hydrogen plasma optical spectrum is straightforward, the measurement of a time-resolved spectrum requires dedicated amplification schemes. The experimental setup for visible light based on photomultipliers and narrow bandwidth filters and the UV spectrometer setup are described. The H{sub {alpha}}, H{sub {beta}}, and H{sub {gamma}} Balmer line intensities, the Lyman band and alpha transition were measured. A parametric study of the optical emission from the Linac4 ion source and the SPL plasma generator as a function of RF-power and gas pressure is presented. The potential of optical emission spectrometry coupled to RF-power coupling measurements for on-line monitoring of short RF heated hydrogen plasma pulses is discussed.

  16. 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.

  17. 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.

  18. Proximity effects of superconducting multilayer film

    SciTech Connect (OSTI)

    Xueyu, C.; Daole, Y.

    1984-07-01

    The proximity effects of superconducting multilayer films composed of different metals are considered. The relationship between the critical temperature of a superconducting multilayer film with strong heterogeneity and its geometric structure is given.

  19. 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}=232nm. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Structural feature controlling superconductivity in compressed...

    Office of Scientific and Technical Information (OSTI)

    Subject: catalysis (heterogeneous), solar (photovoltaic), phonons, thermoelectric, energy storage (including batteries and capacitors), hydrogen and fuel cells, superconductivity, ...

  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. 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.

  8. 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.

  9. Strain tolerant microfilamentary superconducting wire

    DOE Patents [OSTI]

    Finnemore, Douglas K. (Ames, IA); Miller, Theodore A. (Tuscon, AZ); Ostenson, Jerome E. (Ames, IA); Schwartzkopf, Louis A. (Mankato, MN); Sanders, Steven C. (Ames, IA)

    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.

  10. Freely oriented portable superconducting magnet

    DOE Patents [OSTI]

    Schmierer, Eric N.; Prenger, F. Coyne; Hill, Dallas D.

    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.

  11. 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.

  12. 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.

  13. STUDIES ON THE RCMS RF SYSTEM.

    SciTech Connect (OSTI)

    ZHAO,Y.

    2003-01-22

    This note addresses the various options for the Rapid Cycling Medical Synchrotron (RCMS) RF. The study was divided into three cases, namely non-tuning, tuning and filter. Each case also includes a few options. The primary study was focused on the non-tuning options. However, it was found that it requires too much driver power to cover the wide band and thus causes the cost being too high to be competitive. The proposal of RCMS is not yet clear if it can be approved or not. The results of this study might be useful to other similar machines.

  14. Robust Diamond-Based RF Switch Yields Enhanced Communication Capabilities |

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

    Argonne National Laboratory Robust Diamond-Based RF Switch Yields Enhanced Communication Capabilities Technology available for licesning: A radio frequency (RF) microelectromechanical system (MEMS) switch based on ultrananocrystalline diamond (UNCD) as a dielectric. A specialized radio frequency (RF) micro-electromechanical system (MEMS) switch that promises enhanced capabilities for next-generation military and commercial communication systems Robust and reliable with extremely low power

  15. 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.

  16. 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.

  17. RF Micro Devices Inc RFMD | Open Energy Information

    Open Energy Info (EERE)

    Greensboro, North Carolina Zip: 27409-9421 Product: RF Micro Devices, Inc. is a global leader in the design and manufacture of high-performance semiconductor components....

  18. 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.

  19. MICROSTRUCTURE OF SUPERCONDUCTING MGB(2).

    SciTech Connect (OSTI)

    ZHU,Y.; LI,Q.; WU,L.; VOLKOV,V.; GU,G.; MOODENBAUGH,A.R.

    2001-07-12

    Recently, Akimitsu and co-workers [1] discovered superconductivity at 39 K in the intermetallic compound MgB{sub 2}. This discovery provides a new perspective on the mechanism for superconductivity. More specifically, it opens up possibilities for investigation of structure/properties in a new class of materials. With the exceptions of the cuprate and C{sub 60} families of compounds, MgB{sub 2} possesses the highest superconducting transition temperature T{sub c}. Its superconductivity appears to follow the BCS theory, apparently being mediated by electron-phonon coupling. The coherence length of MgB{sub 2} is reported to be longer than that of the cuprates [2]. In contrast to the cuprates, grain boundaries are strongly coupled and current density is determined by flux pinning [2,3]. Presently, samples of MgB{sub 2} commonly display inhomogeneity and porosity on the nanoscale, and are untextured. In spite of these obstacles, magnetization and transport measurements show that polycrystalline samples may carry large current densities circulating across many grains [3,4]. Very high values of critical current densities and critical fields have been recently observed in thin films [5,6]. These attributes suggest possible large scale and electronic applications. The underlying microstructure can be intriguing, both in terms of basic science and in applied areas. Subsequent to the discovery, many papers were published [1-13], most dealing with synthesis, physical properties, and theory. There have yet been few studies of microstructure and structural defects [11, 14]. A thorough understanding of practical superconducting properties can only be developed after an understanding of microstructure is gained. In this work we review transmission electron microscopy (TEM) studies of sintered MgB{sub 2} pellets [14]. Structural defects, including second phase particles, dislocations, stacking faults, and grain boundaries, are analyzed using electron diffraction, electron-energy loss spectroscopy (EELS), high resolution imaging, and structural modeling.

  20. 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.

  1. 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.

  2. Design parameters and commissioning of vertical inserts used for testing the XFEL superconducting cavities

    SciTech Connect (OSTI)

    Schaffran, J.; Bozhko, Y.; Petersen, B.; Meissner, D.; Chorowski, M.; Polinski, J.

    2014-01-29

    The European XFEL is a new research facility currently under construction at DESY in the Hamburg area in Germany. From 2015 on, it will generate extremely intense X-ray flashes that will be used by researchers from all over the world. The superconducting XFEL linear accelerator consists of 100 accelerator modules with more than 800 RF-cavities inside. The accelerator modules, superconducting magnets and cavities will be tested in the accelerator module test facility (AMTF). This paper gives an overview of the design parameters and the commissioning of the vertical insert, used in two cryostats (XATC) of the AMTF-hall. The Insert serves as a holder for 4 nine-cell cavities. This gives the possibility to cool down 4 cavities to 2K in parallel and, consequently, to reduce the testing time. The following RF measurement, selected as quality check, will be done separately for each cavity. Afterwards the cavities will be warmed up again and will be sent to the accelerator module assembly.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. Hydrogen-filled RF Cavities for Muon Beam Cooling

    SciTech Connect (OSTI)

    CHARLES, Ankenbrandt

    2009-04-17

    Ionization cooling requires low-Z energy absorbers immersed in a strong magnetic field and high-gradient, large-aperture RF cavities to be able to cool a muon beam as quickly as the short muon lifetime requires. RF cavities that operate in vacuum are vulnerable to dark-current- generated breakdown, which is exacerbated by strong magnetic fields, and they require extra safety windows that degrade cooling, to separate RF regions from hydrogen energy absorbers. RF cavities pressurized with dense hydrogen gas will be developed that use the same gas volume to provide the energy absorber and the RF acceleration needed for ionization cooling. The breakdown suppression by the dense gas will allow the cavities to operate in strong magnetic fields. Measurements of the operation of such a cavity will be made as functions of external magnetic field and charged particle beam intensity and compared with models to understand the characteristics of this technology and to develop mitigating strategies if necessary.

  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. 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.

  12. 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.

  13. Processing method for superconducting ceramics

    DOE Patents [OSTI]

    Bloom, Ira D.; Poeppel, Roger B.; Flandermeyer, Brian K.

    1993-02-02

    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.

  14. Superconducting thin films on potassium tantalate substrates

    DOE Patents [OSTI]

    Feenstra, Roeland; Boatner, Lynn A.

    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.

  15. Dual control active superconductive devices

    DOE Patents [OSTI]

    Martens, Jon S. (Albuquerque, NM); Beyer, James B. (Madison, WI); Nordman, James E. (Madison, WI); Hohenwarter, Gert K. G. (Madison, WI)

    1993-07-20

    A superconducting active device has dual control inputs and is constructed such that the output of the device is effectively a linear mix of the two input signals. The device is formed of a film of superconducting material on a substrate and has two main conduction channels, each of which includes a weak link region. A first control line extends adjacent to the weak link region in the first channel and a second control line extends adjacent to the weak link region in the second channel. The current flowing from the first channel flows through an internal control line which is also adjacent to the weak link region of the second channel. The weak link regions comprise small links of superconductor, separated by voids, through which the current flows in each channel. Current passed through the control lines causes magnetic flux vortices which propagate across the weak link regions and control the resistance of these regions. The output of the device taken across the input to the main channels and the output of the second main channel and the internal control line will constitute essentially a linear mix of the two input signals imposed on the two control lines. The device is especially suited to microwave applications since it has very low input capacitance, and is well suited to being formed of high temperature superconducting materials since all of the structures may be formed coplanar with one another on a substrate.

  16. 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.

  17. 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...  

  18. 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;...

  19. Superconductivity, Glue, and the Pseudogap (Technical Report...

    Office of Scientific and Technical Information (OSTI)

    Research Org: Los Alamos National Laboratory (LANL) Sponsoring Org: NSF Country of Publication: United States Language: English Subject: Condensed Matter Physics, Superconductivity ...

  20. Superconductivity Program Overview | Department of Energy

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

    Publications Fault Current Limiters (FCL) Fact Sheet High-Temperature Superconductivity Cable Demonstration Projects U.S. Department of Energy and SuperPower, Inc. Increase Energy...

  1. 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...

  2. Quasiparticle properties of the superconducting state of the...

    Office of Scientific and Technical Information (OSTI)

    Quasiparticle properties of the superconducting state of the two-dimensional Hubbard model Title: Quasiparticle properties of the superconducting state of the two-dimensional ...

  3. High temperature interfacial superconductivity (Patent) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Patent: High temperature interfacial superconductivity Citation Details In-Document Search Title: High temperature interfacial superconductivity You are accessing a document ...

  4. Alternative RF coupling configurations for H{sup ?} ion sources

    SciTech Connect (OSTI)

    Briefi, S.; Fantz, U.; Gutmann, P.

    2015-04-08

    RF heated sources for negative hydrogen ions both for fusion and accelerators require very high RF powers in order to achieve the required H{sup ?} current what poses high demands on the RF generators and the RF circuit. Therefore it is highly desirable to improve the RF efficiency of the sources. This could be achieved by applying different RF coupling concepts than the currently used inductive coupling via a helical antenna, namely Helicon coupling or coupling via a planar ICP antenna enhanced with ferrites. In order to investigate the feasibility of these concepts, two small laboratory experiments have been set up. The PlanICE experiment, where the enhanced inductive coupling is going to be investigated, is currently under assembly. At the CHARLIE experiment systematic measurements concerning Helicon coupling in hydrogen and deuterium are carried out. The investigations show that a prominent feature of Helicon discharges occurs: the so-called low-field peak. This is a local improvement of the coupling efficiency at a magnetic field strength of a few mT which results in an increased electron density and dissociation degree. The full Helicon mode has not been achieved yet due to the limited available RF power and magnetic field strength but it might be sufficient for the application of the coupling concept to ion sources to operate the discharge in the low-field-peak region.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. The Development of the Electrically Controlled High Power RF Switch and Its Application to Active RF Pulse Compression Systems

    SciTech Connect (OSTI)

    Guo, Jiquan; /SLAC

    2009-03-20

    In the past decades, there has been increasing interest in pulsed high power RF sources for building high-gradient high-energy particle accelerators. Passive RF pulse compression systems have been used in many applications to match the available RF sources to the loads requiring higher RF power but a shorter pulse. Theoretically, an active RF pulse compression system has the advantage of higher efficiency and compactness over the passive system. However, the key component for such a system an element capable of switching hundreds of megawatts of RF power in a short time compared to the compressed pulse width is still an open problem. In this dissertation, we present a switch module composed of an active window based on the bulk effects in semiconductor, a circular waveguide three-port network and a movable short plane, with the capability to adjust the S-parameters before and after switching. The RF properties of the switch module were analyzed. We give the scaling laws of the multiple-element switch systems, which allow the expansion of the system to a higher power level. We present a novel overmoded design for the circular waveguide three-port network and the associated circular-to-rectangular mode-converter. We also detail the design and synthesis process of this novel mode-converter. We demonstrate an electrically controlled ultra-fast high power X-band RF active window built with PIN diodes on high resistivity silicon. The window is capable of handling multi-megawatt RF power and can switch in 2-300ns with a 1000A current driver. A low power active pulse compression experiment was carried out with the switch module and a 375ns resonant delay line, obtaining 8 times compression gain with a compression ratio of 20.

  12. Molybdenum-rhenium superconducting suspended nanostructures

    SciTech Connect (OSTI)

    Aziz, Mohsin; Christopher Hudson, David; Russo, Saverio

    2014-06-09

    Suspended superconducting nanostructures of MoRe 50%/50% by weight are fabricated employing commonly used fabrication steps in micro- and nano-meter scale devices followed by wet-etching with Hydro-fluoric acid of a SiO{sub 2} sacrificial layer. Suspended superconducting channels as narrow as 50?nm and length 3??m have a critical temperature of ?6.5?K, which can increase by 0.5?K upon annealing at 400?C. A detailed study of the dependence of the superconducting critical current and critical temperature upon annealing and in devices with different channel widths reveals that desorption of contaminants is responsible for the improved superconducting properties. These findings pave the way for the development of superconducting electromechanical devices using standard fabrication techniques.

  13. 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

  14. 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).

  15. Microelectronic superconducting crossover and coil

    DOE Patents [OSTI]

    Wellstood, F.C.; Kingston, J.J.; Clarke, J.

    1994-03-01

    A microelectronic component comprising a crossover is provided comprising a substrate, a first high T[sub c] superconductor thin film, a second insulating thin film comprising SrTiO[sub 3]; and a third high T[sub c] superconducting film which has strips which crossover one or more areas of the first superconductor film. An in situ method for depositing all three films on a substrate is provided which does not require annealing steps and which can be opened to the atmosphere between depositions. 13 figures.

  16. 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.

  17. 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.

  18. Micropower RF transponder with superregenerative receiver and RF receiver with sampling mixer

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1997-01-01

    A micropower RF transdponder employs a novel adaptation of the superregenerative receiver wherein the quench oscillator is external to the regenerative transistor. The quench oscillator applies an exponentially decaying waveform rather than the usual sinewave to achieve high sensitivity at microampere current levels. Further improvements include circuit simplifications for antenna coupling, extraction of the detected signal, and a low-voltage bias configuration that allows operation with less than a 1-volt rail voltage. The inventive transponder is expected to operate as long as the battery shelf life.

  19. Micropower RF transponder with superregenerative receiver and RF receiver with sampling mixer

    DOE Patents [OSTI]

    McEwan, T.E.

    1997-05-13

    A micropower RF transponder employs a novel adaptation of the superregenerative receiver wherein the quench oscillator is external to the regenerative transistor. The quench oscillator applies an exponentially decaying waveform rather than the usual sinewave to achieve high sensitivity at microampere current levels. Further improvements include circuit simplifications for antenna coupling, extraction of the detected signal, and a low-voltage bias configuration that allows operation with less than a 1-volt rail voltage. The inventive transponder is expected to operate as long as the battery shelf life. 13 figs.

  20. RF Sputtering for preparing substantially pure amorphous silicon monohydride

    DOE Patents [OSTI]

    Jeffrey, Frank R. (Ames, IA); Shanks, Howard R. (Ames, IA)

    1982-10-12

    A process for controlling the dihydride and monohydride bond densities in hydrogenated amorphous silicon produced by reactive rf sputtering of an amorphous silicon target. There is provided a chamber with an amorphous silicon target and a substrate therein with the substrate and the target positioned such that when rf power is applied to the target the substrate is in contact with the sputtering plasma produced thereby. Hydrogen and argon are fed to the chamber and the pressure is reduced in the chamber to a value sufficient to maintain a sputtering plasma therein, and then rf power is applied to the silicon target to provide a power density in the range of from about 7 watts per square inch to about 22 watts per square inch to sputter an amorphous silicon hydride onto the substrate, the dihydride bond density decreasing with an increase in the rf power density. Substantially pure monohydride films may be produced.

  1. 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.}

  2. 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.

  3. Sunpentown: ENERGY STAR Referral (RF-330SS) | Department of Energy

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

    DOE referred the matter of Sunpentown-brand refrigerator, model RF-330SS, manufactured by Hefei Hualing Co., Ltd, to the U.S. Environmental Protection Agency, brand manager for the ...

  4. 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.

  5. 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).

  6. RF thermal and new cold part design studies on TTF-III input coupler for Project-X

    SciTech Connect (OSTI)

    Pei, Shilun; Adolphsen, Chris E.; Li, Zenghai; Solyak, Nikolay A.; Gonin, Ivan V.

    2015-05-15

    An RF power coupler is one of the key components in a superconducting (SC) linac. It provides RF power to the SC cavity and interconnects different temperature layers (1.8 K, 4.2 K, 70 K and 300 K). The TTF-III coupler is one of the most promising candidates for the High Energy (HE) linac of Project X, but it cannot meet the average power requirements because of the relatively high temperature rise on the warm inner conductor, so some design modifications will be required. In this paper, we describe our simulation studies on the copper coating thickness on the warm inner conductor with RRR values of 10 and 100. Our purpose is to rebalance the dynamic and static loads, and finally lower the temperature rise along the warm inner conductor. Additionally, to get stronger coupling, better power handling and less multipacting probability, one new cold part design was proposed using a 60 mm coaxial line; the corresponding multipacting simulation studies have also been investigated.

  7. Method for making mirrored surfaces comprising superconducting material

    DOE Patents [OSTI]

    Early, J.T.; Hargrove, R.S.

    1989-12-12

    Superconducting mirror surfaces are provided by forming a mirror surface from a material which is superconductive at a temperature above about 40 K and adjusting the temperature of the surface to that temperature at which the material is superconducting. The mirror surfaces are essentially perfect reflectors for electromagnetic radiation with photon energy less than the superconducting band gap.

  8. 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 δ–MoN and cubic γ–MoN through an ion–exchange reaction at 3.5 GPa. The final products are in the bulk form withmore » crystallite sizes of 50 – 80 μm. Based on indentation testing on single crystals, hexagonal δ–MoN exhibits excellent hardness of ~30 GPa, which is 30% higher than cubic γ–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 δ–MoN and cubic γ–MoN are 13.8 and 5.5 K, respectively, in good agreement with previous measurements.« less

  9. 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 worlds 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.

  10. 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

    Transitionmetal (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 rocksalt structure, a structure that is unfavorable to resist shear strain, and they exhibit relatively low indentation hardness, typically in the range of 1020 GPa. Here, we report highpressure synthesis of hexagonal ?MoN and cubic ?MoN through an ionexchange reaction at 3.5 GPa. The final products are in the bulk form withmorecrystallite 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 MoN 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

  11. 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.

  12. 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.

  13. Modes in RFPs by RF Ponderomotive Forces V. A. Svidzinski, S. C. Prager

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

    Possibility of Stabilization of Resistive Wall Modes in RFPs by RF Ponderomotive Forces V. A. Svidzinski, S. C. Prager Physics Department, University of Wisconsin-Madison, WI53706 Abstract. Ponderomotive forces from applied rf fields are generally too weak to stabilize MHD instabilities in toroidal plasmas for practical values of rf fields. We are investigating whether rf waves in a vacuum region between a plasma and wall can stabilize resistive wall instabilities. In our model the rf waves are

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

    SciTech Connect (OSTI)

    Green, Michael A.

    2003-07-01

    The need for cryogenic cooling has been critical issue that has kept superconducting electronic devices from reaching the market place. Even though the performance of the superconducting circuit is superior to silicon electronics, the requirement for cryogenic cooling has put the superconducting devices at a disadvantage. This report will talk about the various methods for refrigerating superconducting devices. Cryocooler types will be compared for vibration, efficiency, and cost. Some solutions to specific problems of integrating cryocoolers to superconducting devices are presented.

  15. Fluorinated Precursors of Superconducting Ceramics - Energy Innovation

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

    Portal <p> Structure of superconducting YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7</sub></p> Structure of superconducting YBa2Cu3O7 Technology Marketing Summary Fluorinated precursors for superconducting ceramics typically increase the critical current in the superconductors they produce. Here the fluorinated precursors are obtained by combining salts of a rare earth, an alkaline earth, and copper in solution, spraying the solution onto a substrate,

  16. Nanofabrication & Devices | Argonne National Laboratory

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

    of hybrid materials and nanostructures Manipulation of nanoscale interactions Studying nonlinear phenomena at the nanoscale The group is developing new processes capable of...

  17. Investigation of Microscopic Materials Limitations of Superconducting...

    Office of Scientific and Technical Information (OSTI)

    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 ...

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

    SciTech Connect (OSTI)

    Singh, M. J.; Bandyopadhyay, M.; Yadava, Ratnakar; Chakraborty, A. K.; Bansal, G.; Gahlaut, A.; Soni, J.; Kumar, Sunil; Pandya, K.; Parmar, K. G.; Sonara, J.; Kraus, W.; Heinemann, B.; Riedl, R.; Obermayer, S.; Martens, C.; Franzen, P.; Fantz, U.

    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.

  19. 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.

    2013-04-26

    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.

  20. 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.

  1. 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.

  2. 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.

  3. 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...

  4. 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.

  5. 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...

  6. Influence of optically quenched superconductivity on quasiparticle...

    Office of Scientific and Technical Information (OSTI)

    Influence of optically quenched superconductivity on quasiparticle relaxation rates in Bi 2 Sr 2 CaCu 2 O 8 + Citation Details In-Document Search This content will become...

  7. 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.

  8. 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

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

    SciTech Connect (OSTI)

    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, 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.

  10. Ion extraction from a saddle antenna RF surface plasma source

    SciTech Connect (OSTI)

    Dudnikov, V. Johnson, R. P.; Han, B.; Murray, S.; Pennisi, T.; Piller, C.; Santana, M.; Stockli, M.; Welton, R.; Breitschopf, J.; Dudnikova, G.

    2015-04-08

    Existing RF Surface Plasma Sources (SPS) for accelerators have specific efficiencies for H{sup +} and H{sup ?} ion generation around 3 to 5 mA/cm{sup 2} per kW, where about 50 kW of RF power is typically needed for 50 mA beam current production. The Saddle Antenna (SA) SPS described here was developed to improve H{sup ?} ion production efficiency and SPS reliability and availability. At low RF power, the efficiency of positive ion generation in the plasma has been improved to 200 mA/cm{sup 2} per kW of RF power at 13.56 MHz. Initial cesiation of the SPS was performed by heating cesium chromate cartridges by discharge as was done in the very first versions of the SPS. A small oven to decompose cesium compounds and alloys was developed and tested. After cesiation, the current of negative ions to the collector was increased from 1 mA to 10 mA with RF power ?1.5 kW in the plasma (6 mm diameter emission aperture) and up to 30 mA with ?4 kW RF power in the plasma and 250 Gauss longitudinal magnetic field. The ratio of electron current to negative ion current was improved from 30 to 2. Stable generation of H{sup ?} beam without intensity degradation was demonstrated in the AlN discharge chamber for a long time at high discharge power in an RF SPS with an external antenna. Continuous wave (CW) operation of the SA SPS has been tested on the small test stand. The general design of the CW SA SPS is based on the pulsed version. Some modifications were made to improve the cooling and cesiation stability. The extracted collector current can be increased significantly by optimizing the longitudinal magnetic field in the discharge chamber. CW operation with negative ion extraction was tested with RF power up to 1.8 kW from the generator (?1.2 kW in the plasma) with production up to Ic=7 mA. Long term operation was tested with 1.2 kW from the RF generator (?0.8 kW in the plasma) with production of Ic=5 mA, Iex ?15 mA (Uex=8 kV, Uc=14 kV)

  11. rf beam-current, -phase, and -position monitors

    SciTech Connect (OSTI)

    Young, L.

    1984-12-12

    A prototype rf beam monitor has been tested on the Racetrack Microtron's (RTM) 100 kV injector beam line at the National Bureau of Standards (NBS). This beam monitor is capable of measuring the current, the relative phase, and the position of the beam. The beam is bunched at 2380 MHz for acceleration by the linac in the injector beam line. This train of beam bunches passing through the beam monitor cavities excites the cavities at this resonance frequency of 2380 MHz. Probes in the cavities couple some of the beam-excited rf power out of the cavities. This rf power can be amplified if necessary and then analyzed by a double balanced mixer (DBM). The DBM can also be used as a phase detector. The effective shunt impedance of the cavities was measured with the CW beam. For the position monitor cavity, the shunt impedance is proportional to the displacement from the axis. The measured response of the prototype rf beam current monitor setup is a linear function of beam current. Response of the rf beam-position monitor is also shown. (LEW)

  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; Curt, Stephane; Dobert, Steffen; McMonagle, Gerard; Rossat, Ghislain; Syratchev, Igor; Timeo, Luca; Haase, Andrew Jensen, Aaron; Jongewaard, Erik; Nantista, Christopher; Sprehn, Daryl; Vlieks, Arnold; Hamdi, Abdallah; Peauger, Franck; Kuzikov, Sergey; 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. RF breakdown of 805 MHz cavities in strong magnetic fields

    SciTech Connect (OSTI)

    Bowring, D.; Stratakis, D.; Kochemirovskiy, A.; Leonova, M.; Moretti, A.; Palmer, M.; Peterson, D.; Yonehara, K.; Freemire, B.; Lane, P.; Torun, Y.; Haase, A.

    2015-05-03

    Ionization cooling of intense muon beams requires the operation of high-gradient, normal-conducting RF structures in the presence of strong magnetic fields. We have measured the breakdown rate in several RF cavities operating at several frequencies. Cavities operating within solenoidal magnetic fields B > 0.25 T show an increased RF breakdown rate at lower gradients compared with similar operation when B = 0 T. Ultimately, this breakdown behavior limits the maximum safe operating gradient of the cavity. Beyond ionization cooling, this issue affects the design of photoinjectors and klystrons, among other applications. We have built an 805 MHz pillbox-type RF cavity to serve as an experimental testbed for this phenomenon. This cavity is designed to study the problem of RF breakdown in strong magnetic fields using various cavity materials and surface treatments, and with precise control over sources of systematic error. We present results from tests in which the cavity was run with all copper surfaces in a variety of magnetic fields.

  15. Towards a next theory of superconductivity

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

    Understanding high-temperature superconductivity Using magnetic fields to understand high-temperature superconductivity The eventual goal of the research would be to create a superconductor that operates at room temperature and needs no cooling at all March 26, 2015 Los Alamos National Laboratory scientist Brad Ramshaw conducts an experiment at the Pulsed Field Facility of the National High Magnetic Field Lab, exposing high-temperature superconductors to very high magnetic fields, changing the

  16. 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.

  17. 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).

  18. Abrupt Onset of a Second Energy Gap at the Superconducting Transition...

    Office of Scientific and Technical Information (OSTI)

    at the superconducting transition temperature (Tc) in conventional BCS superconductors. ... QUASI PARTICLES; SUPERCONDUCTIVITY; SUPERCONDUCTORS; TEMPERATURE DEPENDENCE; TRANSITION ...

  19. Longitudinal Bunch Lengthening Compensation in High Charge RF Photoinjector

    SciTech Connect (OSTI)

    Pei, S.; Adolphsen, C.; /SLAC

    2008-10-03

    In high charge RF photoinjectors for wakefield two beam acceleration studies, due to the strong longitudinal space charge, bunch lengthening between the photocathode and photoinjector exit is a critical issue. We present beam dynamics studies of bunch lengthening in an RF photoinjector for a high charge electron beam and describe methods to compensate the bunch lengthening to various degrees. In particular, the beam dynamics for bunch charge from 1nC to 30nC are studied for an S-band 2856 MHz photoinjector.

  20. 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.

  1. Plasma characterization of the superconducting proton linear accelerator plasma generator using a 2 MHz compensated Langmuir probe

    SciTech Connect (OSTI)

    Schmitzer, C.; Kronberger, M.; Lettry, J.; Sanchez-Arias, J.; Stoeri, H.

    2012-02-15

    The CERN study for a superconducting proton Linac (SPL) investigates the design of a pulsed 5 GeV Linac operating at 50 Hz. As a first step towards a future SPL H{sup -} volume ion source, a plasma generator capable of operating at Linac4 or nominal SPL settings has been developed and operated at a dedicated test stand. The hydrogen plasma is heated by an inductively coupled RF discharge e{sup -} and ions are confined by a magnetic multipole cusp field similar to the currently commissioned Linac4 H{sup -} ion source. Time-resolved measurements of the plasma potential, temperature, and electron energy distribution function obtained by means of a RF compensated Langmuir probe along the axis of the plasma generator are presented. The influence of the main tuning parameters, such as RF power and frequency and the timing scheme is discussed with the aim to correlate them to optimum H{sup -} ion beam parameters measured on an ion source test stand. The effects of hydrogen injection settings which allow operation at 50 Hz repetition rate are discussed.

  2. 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.

  3. BNL Direct Wind Superconducting Magnets

    SciTech Connect (OSTI)

    Parker, B.; Anerella, M.; Escallier, J.; Ghosh, A.; Jain, A.; Marone, A.; Muratore, A.; Wanderer, P.

    2011-09-12

    BNL developed Direct Wind magnet technology is used to create a variety of complex multi-functional multi-layer superconducting coil structures without the need for creating custom production tooling and fixturing for each new project. Our Direct Wind process naturally integrates prestress into the coil structure so external coil collars and yokes are not needed; the final coil package transverse size can then be very compact. Direct Wind magnets are produced with very good field quality via corrections applied during the course of coil winding. The HERA-II and BEPC-II Interaction Region (IR) magnet, J-PARC corrector and Alpha antihydrogen magnetic trap magnets and our BTeV corrector magnet design are discussed here along with a full length ILC IR prototype magnet presently in production and the coils that were wound for an ATF2 upgrade at KEK. A new IR septum magnet design concept for a 6.2 T combined-function IR magnet for eRHIC, a future RHIC upgrade, is introduced here.

  4. The modeling of RF stacking of protons in the Accumulator (Technical...

    Office of Scientific and Technical Information (OSTI)

    The modeling of RF stacking of protons in the Accumulator Citation Details In-Document Search Title: The modeling of RF stacking of protons in the Accumulator When the Run2...

  5. 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.

  6. Evolution of superconducting correlations within magnetic-field...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: phonons, thermal conductivity, energy storage (including batteries and capacitors), superconductivity, defects,...

  7. Method and means for separating and classifying superconductive particles

    DOE Patents [OSTI]

    Park, Jin Y. (Moscow, ID); Kearney, Robert J. (Moscow, ID)

    1991-01-01

    The specification and drawings describe a series of devices and methods for classifying and separating superconductive particles. The superconductive particles may be separated from non-superconductive particles, and the superconductive particles may be separated by degrees of susceptibility to the Meissner effect force. The particles may also be simultaneously separated by size or volume and mass to obtain substantially homogeneous groups of particles. The separation techniques include levitation, preferential sedimentation and preferential concentration. Multiple separation vector forces are disclosed.

  8. 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 door to the discovery of new, unconventional forms of superconductivity. November 24, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to

  9. ORNL Publishes Study on Superconducting Wire Performance | Department of

    Energy Savers [EERE]

    Energy ORNL Publishes Study on Superconducting Wire Performance ORNL Publishes Study on Superconducting Wire Performance August 23, 2013 - 4:06pm Addthis The Department of Energy's Oak Ridge National Laboratory (ORNL) recently released a new study on advances in superconducting wire technology. A team led by ORNL's Amit Goyal demonstrated that the ability to control nanoscale imperfections in superconducting wires results in materials with excellent and customized performance. The team's

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Design of RF Feed System for Standing-Wave Accelerator Structures

    SciTech Connect (OSTI)

    Neilson, J.; Tantawi, S.; Dolgashev, V.; /SLAC

    2012-05-25

    We are investigating a standing wave accelerator structure that uses a rf feed to each individual cell. This approach minimizes rf power flow and electromagnetic energy absorbed by an rf breakdown. The objective of this work is a robust high-gradient (above 100 MV/m) X-band accelerator structure.

  17. Preferential orientation of metal oxide superconducting materials

    DOE Patents [OSTI]

    Capone, Donald W. (Bolingbrook, IL); Poeppel, Roger B. (Glen Ellyn, IL)

    1991-01-01

    A polycrystalline metal oxide such as YBa.sub.2 Cu.sub.3 O.sub.7-X (where 0superconducting properties and is capable of conducting very large current densities. By aligning the two-dimensional Cu-O layers which carry the current in the superconducting state in the a- and b-directions, i.e., within the basal plane, a high degree of crystalline axes alignment is provided between adjacent grains permitting the conduction of high current densities.

  18. Apparatus for characterizing conductivity of superconducting materials

    DOE Patents [OSTI]

    Doss, James D. (Los Alamos, NM)

    1993-01-01

    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.

  19. Magnetic and Superconducting Materials at High Pressures

    SciTech Connect (OSTI)

    Struzhkin, Viktor V.

    2015-03-24

    The work concentrates on few important tasks in enabling techniques for search of superconducting compressed hydrogen compounds and pure hydrogen, investigation of mechanisms of high-Tc superconductivity, and exploring new superconducting materials. Along that route we performed several challenging tasks, including discovery of new forms of polyhydrides of alkali metal Na at very high pressures. These experiments help us to establish the experimental environment that will provide important information on the high-pressure properties of hydrogen-rich compounds. Our recent progress in RIXS measurements opens a whole field of strongly correlated 3d materials. We have developed a systematic approach to measure major electronic parameters, like Hubbard energy U, and charge transfer energy Δ, as function of pressure. This technique will enable also RIXS studies of magnetic excitations in iridates and other 5d materials at the L edge, which attract a lot of interest recently. We have developed new magnetic sensing technique based on optically detected magnetic resonance from NV centers in diamond. The technique can be applied to study superconductivity in high-TC materials, to search for magnetic transitions in strongly correlated and itinerant magnetic materials under pressure. Summary of Project Activities; development of high-pressure experimentation platform for exploration of new potential superconductors, metal polyhydrides (including newly discovered alkali metal polyhydrides), and already known superconductors at the limit of static high-pressure techniques; investigation of special classes of superconducting compounds (high-Tc superconductors, new superconducting materials), that may provide new fundamental knowledge and may prove important for application as high-temperature/high-critical parameter superconductors; investigation of the pressure dependence of superconductivity and magnetic/phase transformations in 3d transition metal compounds, including transitions from magnetic to nonmagnetic phases in a broad pressure-temperature range; using X-ray methods including the newly developed RIXS high-pressure technique to explore pressure-tuned electronic excitations in strongly correlated 3d-materials; and advancing transport and magnetic techniques for measurements on small samples at very high pressures in a wide temperature range, with the application of focused ion beam technology and photolithography tailored to the design of microcircuits down to a nanoscale size, thus expanding the horizon in the search for novel physical phenomena at ultrahigh pressures. Apply new optical magnetic sensing techniques with NV- centers in diamond to detect superconductivity and magnetic transitions with unprecedented spatial resolution.

  20. 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.

  1. Influence of optically quenched superconductivity on quasiparticle

    Office of Scientific and Technical Information (OSTI)

    relaxation rates in Bi 2 Sr 2 CaCu 2 O 8 + δ (Journal Article) | SciTech Connect Influence of optically quenched superconductivity on quasiparticle relaxation rates in Bi 2 Sr 2 CaCu 2 O 8 + δ Citation Details In-Document Search This content will become publicly available on October 5, 2016 Title: Influence of optically quenched superconductivity on quasiparticle relaxation rates in Bi 2 Sr 2 CaCu 2 O 8 + δ Authors: Smallwood, Christopher L. ; Zhang, Wentao ; Miller, Tristan L. ; Affeldt,

  2. Superconducting fault current controller/current controller

    DOE Patents [OSTI]

    Cha, Yung S.

    2004-06-15

    A superconducting fault current controller/current controller employs a superconducting-shielded core reactor (SSCR) with a variable impedance in a secondary circuit to control current in a primary circuit such as an electrical distribution system. In a second embodiment, a variable current source is employed in a secondary circuit of an SSCR to control current in the primary circuit. In a third embodiment, both a variable impedance in one secondary circuit and a variable current source in a second circuit of an SSCR are employed for separate and independent control of current in the primary circuit.

  3. 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.

  4. An Analysis of the Temperature and Field Dependence of the RF Surface Resistance of Nitrogen-Doped Niobium SRF Cavities with Respect to Existing Theoretical Models

    SciTech Connect (OSTI)

    Reece, Charles E.; Palczewski, Ari D.; Xiao, Binping

    2015-09-01

    Recent progress with the reduction of rf surface resistance (Rs) of niobium SRF cavities via the use of high temperature surface doping by nitrogen has opened a new regime for energy efficient accelerator applications. For particular doping conditions one observes dramatic decreases in Rs with increasing surface magnetic fields. The observed variations as a function of temperature may be analyzed in the context of recent theoretical treatments in hopes of gaining insight into the underlying beneficial mechanism of the nitrogen treatment. Systematic data sets of Q0 vs. Eacc vs. temperature acquired during the high Q0 R&D work of the past year will be compared with theoretical model predictions.1, 2 1. B. P. Xiao, C. E. Reece and M. J. Kelley, Physica C: Superconductivity 490 (0), 26-31 (2013). 2. A. Gurevich, PRL 113 (8), 087001 (2014).

  5. The Development of the Linac Coherent Light Source RF Gun

    SciTech Connect (OSTI)

    Dowell, David H.; Jongewaard, Erik; Lewandowski, James; Limborg-Deprey, Cecile; Li, Zenghai; Schmerge, John; Vlieks, Arnold; Wang, Juwen; Xiao, Liling; /SLAC

    2008-09-24

    The Linac Coherent Light Source (LCLS) is the first x-ray laser user facility based upon a free electron laser (FEL) requiring extraordinary beam quality to saturate at 1.5 angstroms within a 100 meter undulator.[1] This new type of light source is using the last kilometer of the three kilometer linac at SLAC to accelerate the beam to an energy as high as 13.6 GeV and required a new electron gun and injector to produce a very bright beam for acceleration. At the outset of the project it was recognized that existing RF guns had the potential to produce the desired beam but none had demonstrated it. Therefore a new RF gun or at least the modification of an existing gun was necessary. The parameters listed in Table 1 illustrate the unique characteristics of LCLS which drive the requirements for the electron gun as given in Table 2. The gun beam quality needs to accommodate emittance growth as the beam is travels through approximately one kilometer of linac and two bunch compressors before reaching the undulator. These beam requirements were demonstrated during the recent commissioning runs of the LCLS injector and linac [2] due to the successful design, fabrication, testing and operation of the LCLS gun. The goal of this paper is to relate the technical background of how the gun was able to achieve and in some cases exceed these requirements by understanding and correcting the deficiencies of the prototype s-band RF photocathode gun, the BNL/SLAC/UCLA Gun III. This paper begins with a brief history and technical description of Gun III and the Gun Test Facility (GTF) at SLAC, and studies of the gun's RF and emittance compensation solenoid. The work at the GTF identified the gun and solenoid deficiencies, and helped to define the specifications for the LCLS gun. Section 1.1.5 describes the modeling used to compute and correct the gun RF fields and Section 1.1.6 describes the use of these fields in the electron beam simulations. The magnetic design and measurements of the emittance compensation solenoid are discussed in Section 1.1.7. The novel feature of the LCLS solenoid is the embedded quadrupole correctors. The thermo-mechanical engineering of the LCLS gun is discussed in Section 1.1.8, and the cold and hot RF tests are described in Section 1.1.9. The results of this work are summarized and concluding remarks are given in Section 1.1.10.

  6. Superconducting fault current-limiter with variable shunt impedance

    DOE Patents [OSTI]

    Llambes, Juan Carlos H; Xiong, Xuming

    2013-11-19

    A superconducting fault current-limiter is provided, including a superconducting element configured to resistively or inductively limit a fault current, and one or more variable-impedance shunts electrically coupled in parallel with the superconducting element. The variable-impedance shunt(s) is configured to present a first impedance during a superconducting state of the superconducting element and a second impedance during a normal resistive state of the superconducting element. The superconducting element transitions from the superconducting state to the normal resistive state responsive to the fault current, and responsive thereto, the variable-impedance shunt(s) transitions from the first to the second impedance. The second impedance of the variable-impedance shunt(s) is a lower impedance than the first impedance, which facilitates current flow through the variable-impedance shunt(s) during a recovery transition of the superconducting element from the normal resistive state to the superconducting state, and thus, facilitates recovery of the superconducting element under load.

  7. DOE, Texas settle super(conducting) differences

    SciTech Connect (OSTI)

    Crawford, M.

    1994-08-02

    The US DOE agreed to pay over $200 million in cash and transfer $510 million in property to Texas to settle the state`s claims against the federal government for cancellation of the Superconducting Super Collider. This article discusses the settlement and its history and what will be done with the facilities.

  8. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, John R.

    1997-01-01

    A fault current limiter (10) for an electrical circuit (14). The fault current limiter (10) includes a high temperature superconductor (12) in the electrical circuit (14). The high temperature superconductor (12) is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter (10).

  9. Active superconducting devices formed of thin films

    DOE Patents [OSTI]

    Martens, Jon S. (Madison, WI); Beyer, James B. (Madison, WI); Nordman, James E. (Madison, WI); Hohenwarter, Gert K. G. (Madison, WI)

    1991-05-28

    Active superconducting devices are formed of thin films of superconductor which include a main conduction channel which has an active weak link region. The weak link region is composed of an array of links of thin film superconductor spaced from one another by voids and selected in size and thickness such that magnetic flux can propagate across the weak link region when it is superconducting. Magnetic flux applied to the weak link region will propagate across the array of links causing localized loss of superconductivity in the links and changing the effective resistance across the links. The magnetic flux can be applied from a control line formed of a superconducting film deposited coplanar with the main conduction channel and weak link region on a substrate. The devices can be formed of any type to superconductor but are particularly well suited to the high temperature superconductors since the devices can be entirely formed from coplanar films with no overlying regions. The devices can be utilized for a variety of electrical components, including switching circuits, amplifiers, oscillators and modulators, and are well suited to microwave frequency applications.

  10. High temperature superconducting fault current limiter

    DOE Patents [OSTI]

    Hull, J.R.

    1997-02-04

    A fault current limiter for an electrical circuit is disclosed. The fault current limiter includes a high temperature superconductor in the electrical circuit. The high temperature superconductor is cooled below its critical temperature to maintain the superconducting electrical properties during operation as the fault current limiter. 15 figs.

  11. 119Sn-NMR investigations on superconducting Ca3Ir4Sn13: Evidence for multigap superconductivity

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

    Sarkar, R.; Petrovic, C.; Bruckner, F.; Gunther, M.; Wang, Kefeng; Biswas, P. K.; Luetkens, H.; Morenzoni, E.; Amato, A.; Klauss, H. -H.

    2015-09-25

    In this study, we report bulk superconductivity (SC) in Ca3Ir4Sn13 by means of 119Sn nuclear magnetic resonance (NMR) experiments. Two classical signatures of BCS superconductivity in spin-lattice relaxation rate (1/T1), namely the Hebel–Slichter coherence peak just below the Tc, and the exponential decay in the superconducting phase, are evident. The noticeable decrease of 119Sn Knight shift below Tc indicates spin-singlet superconductivity. The temperature dependence of the spin-lattice relaxation rate 119(1/T1) is convincingly described by the multigap isotropic superconducting gap. NMR experiments do not witness any sign of enhanced spin fluctuations.

  12. Free electron laser using Rf coupled accelerating and decelerating structures

    DOE Patents [OSTI]

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

    1984-01-01

    A free electron laser and free electron laser amplifier using beam transport devices for guiding an electron beam to a wiggler of a free electron laser and returning the electron beam to decelerating cavities disposed adjacent to the accelerating cavities of the free electron laser. Rf energy is generated from the energy depleted electron beam after it emerges from the wiggler by means of the decelerating cavities which are closely coupled to the accelerating cavities, or by means of a second bore within a single set of cavities. Rf energy generated from the decelerated electron beam is used to supplement energy provided by an external source, such as a klystron, to thereby enhance overall efficiency of the system.

  13. Multipacting optimization of a 750 MHz rf dipole

    SciTech Connect (OSTI)

    Delayen, Jean R.; Castillo, Alejandro

    2014-12-01

    Crab crossing schemes have been proposed to re-instate luminosity degradation due to crossing angles at the interaction points in next generation colliders to avoid the use of sharp bending magnets and their resulting large synchrotron radiation generation, highly undessirable in the detector region. The rf dipole has been considered for a different set of applications in several machines, both rings and linear colliders. We present in this paper a study of the effects on the multipacting levels and location depending on geometrical variations on the design for a crabbing/deflecting application in a high current (3/0.5 A), high repetition (750 MHz) electron/proton collider, as a matter to provide a comparison point for similar applications of rf dipoles.

  14. High gradient rf gun studies of CsBr photocathodes

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

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-03

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV/m fields without breaking down or emitting dark current. They can operate in 2×10⁻⁹ torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  15. High gradient rf gun studies of CsBr photocathodes

    SciTech Connect (OSTI)

    Vecchione, Theodore; Maldonado, Juan R.; Gierman, Stephen; Corbett, Jeff; Hartmann, Nick; Pianetta, Piero A.; Hesselink, Lambertus; Schmerge, John F.

    2015-04-03

    CsBr photocathodes have 10 times higher quantum efficiency with only 3 times larger intrinsic transverse emittance than copper. They are robust and can withstand 80 MV/m fields without breaking down or emitting dark current. They can operate in 210?? torr vacuum and survive exposure to air. They are well suited for generating high pulse charge in rf guns without a photocathode transfer system.

  16. Local nonlinear rf forces in inhomogeneous magnetized plasmas

    SciTech Connect (OSTI)

    Chen, Jiale; Gao, Zhe

    2014-06-15

    The local nonlinear forces induced by radio frequency (rf) waves are derived in inhomogeneous magnetized plasmas, where the inhomogeneity exists in the rf fields, in the static magnetic field as well as in the equilibrium density and temperature. The local parallel force is completely resonant, but a novel component dependent on those inhomogeneities is obtained as the result of the inhomogeneous transport of parallel resonant-absorbed momentum by the nonlinear perpendicular drift flux. In the local poloidal force, the component induced by the inhomogeneity of rf power absorption is also confirmed and it can be recognized as the residual effect from the incomplete cancellation between the rate of the diamagnetic poloidal momentum gain and the Lorentz force due to the radial diffusion-like flux. The compact expression for radial force is also obtained for the first time, whose nonresonant component is expressed as the sum of the ponderomotive force on particles and the gradients of the nonresonant perpendicular pressure and of the nonresonant momentum flux due to the finite temperature effect. Numerical calculations in a 1-D slab model show that the resonant component dependent on the inhomogeneities may be significant when the ion absorption dominates the resonant wave-particle interaction. A quantitative estimation shows that the novel component in the parallel force is important to understand the experiments of the ion-cyclotron-frequency mode-conversion flow drive.

  17. RF Input Power Couplers for High Current SRF Applications

    SciTech Connect (OSTI)

    Khan, V. F.; Anders, W.; Burrill, Andrew; Knobloch, Jens; Kugeler, Oliver; Neumann, Axel; Wang, Haipeng

    2014-12-01

    High current SRF technology is being explored in present day accelerator science. The bERLinPro project is presently being built at HZB to address the challenges involved in high current SRF machines with the goal of generating and accelerating a 100 mA electron beam to 50 MeV in continuous wave (cw) mode at 1.3 GHz. One of the main challenges in this project is that of handling the high input RF power required for the photo-injector as well as booster cavities where there is no energy recovery process. A high power co-axial input power coupler is being developed to be used for the photo-injector and booster cavities at the nominal beam current. The coupler is based on the KEK–cERL design and has been modified to minimise the penetration of the coupler tip in the beam pipe without compromising on beam-power coupling (Qext ~105). Herein we report on the RF design of the high power (115 kW per coupler, dual couplers per cavity) bERLinPro (BP) coupler along with initial results on thermal calculations. We summarise the RF conditioning of the TTF-III couplers (modified for cw operation) performed in the past at BESSY/HZB. A similar conditioning is envisaged in the near future for the low current SRF photo-injector and the bERLinPro main linac cryomodule.

  18. RF generation in the DARHT Axis-II beam dump

    SciTech Connect (OSTI)

    Ekdahl, Carl A. Jr.

    2012-05-03

    We have occasionally observed radio-frequency (RF) electromagnetic signals in the downstream transport (DST) of the second axis linear induction accelerator (LIA) at the dual-axis radiographic hydrodynamic testing (DARHT) facility. We have identified and eliminated some of the sources by eliminating the offending cavities. However, we still observe strong RF in the range 1 GHz t0 2 GHz occurring late in the {approx}2-{micro}s pulse that can be excited or prevented by varying the downstream tune. The narrow frequency width (<0.5%) and near exponential growth at the dominant frequency is indicative of a beam-cavity interaction, and electro-magnetic simulations of cavity structure show a spectrum rich in resonances in the observed frequency range. However, the source of beam produced RF in the cavity resonance frequency range has not been identified, and it has been the subject of much speculation, ranging from beam-plasma or beam-ion instabilities to unstable cavity coupling.

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

    SciTech Connect (OSTI)

    High Current Electronics Institute, Tomsk, Russia; Anders, Andre; Mendelsberg, Rueben J.; Lim, Sunnie; Mentink, Matthijs; Slack, Jonathan L.; Wallig, Joseph G.; Nollau, Alexander V.; Yushkov, Georgy Yu.

    2011-07-24

    Niobium coatings on copper cavities have been considered as a cost-efficient replacement of bulk niobium RF cavities, however, coatings made by magnetron sputtering have not quite lived up to high expectations due to Q-slope and other issues. High power impulse magnetron sputtering (HIPIMS) is a promising emerging coatings technology which combines magnetron sputtering with a pulsed power approach. The magnetron is turned into a metal plasma source by using very high peak power density of ~ 1 kW/cm{sup 2}. In this contribution, the cavity coatings concept with HIPIMS is explained. A system with two cylindrical, movable magnetrons was set up with custom magnetrons small enough to be inserted into 1.3 GHz cavities. Preliminary data on niobium HIPIMS plasma and the resulting coatings are presented. The HIPIMS approach has the potential to be extended to film systems beyond niobium, including other superconducting materials and/or multilayer systems.

  20. ILC @ SLAC R&D Program for a Polarized RF Gun

    SciTech Connect (OSTI)

    Clendenin, J.E.; Brachman, A.; Dowell, D.H.; Garwin, E.L.; Ioakemidi, K.; Kirby, R.E.; Maruyama, T.; Miller, R.A.; Prescott, C.Y.; Wang, J.W.; Lewellen, J.W.; Prepost, R.; /Wisconsin U., Madison

    2006-01-25

    Photocathode rf guns produce high-energy low-emittance electron beams. DC guns utilizing GaAs photocathodes have proven successful for generating polarized electron beams for accelerators, but they require rf bunching systems that significantly increase the transverse emittance of the beam. With higher extraction field and beam energy, rf guns can support higher current densities at the cathode. The source laser system can then be used to generate the high peak current, relatively low duty-factor micropulses required by the ILC without the need for post-extraction rf bunching. The net result is that the injection system for a polarized rf gun can be identical to that for an unpolarized rf gun. However, there is some uncertainty as to the survivability of an activated GaAs cathode in the environment of an operating rf gun. Consequently, before attempting to design a polarized rf gun for the ILC, SLAC plans to develop an rf test gun to demonstrate the rf operating conditions suitable for an activated GaAs cathode.

  1. Torsional texturing of superconducting oxide composite articles

    DOE Patents [OSTI]

    Christopherson, Craig John (Grafton, MA); Riley, Jr., Gilbert N. (Marlborough, MA); Scudiere, John (Bolton, MA)

    2002-01-01

    A method of texturing a multifilamentary article having filaments comprising a desired oxide superconductor or its precursors by torsionally deforming the article is provided. The texturing is induced by applying a torsional strain which is at least about 0.3 and preferably at least about 0.6 at the surface of the article, but less than the strain which would cause failure of the composite. High performance multifilamentary superconducting composite articles having a plurality of low aspect ratio, twisted filaments with substantially uniform twist pitches in the range of about 1.00 inch to 0.01 inch (25 to 0.25 mm), each comprising a textured desired superconducting oxide material, may be obtained using this texturing method. If tighter twist pitches are desired, the article may be heat treated or annealed and the strain repeated as many times as necessary to obtain the desired twist pitch. It is preferred that the total strain applied per step should be sufficient to provide a twist pitch tighter than 5 times the diameter of the article, and twist pitches in the range of 1 to 5 times the diameter of the article are most preferred. The process may be used to make a high performance multifilamentary superconducting article, having a plurality of twisted filaments, wherein the degree of texturing varies substantially in proportion to the radial distance from the center of the article cross-section, and is substantially radially homogeneous at any given cross-section of the article. Round wires and other low aspect ratio multifilamentary articles are preferred forms. The invention is not dependent on the melting characteristics of the desired superconducting oxide. Desired oxide superconductors or precursors with micaceous or semi-micaceous structures are preferred. When used in connection with desired superconducting oxides which melt irreversibly, it provides multifilamentary articles that exhibit high DC performance characteristics and AC performance markedly superior to any currently available for these materials. In a preferred embodiment, the desired superconducting oxide material is BSCCO 2223.

  2. Critical parameters of superconducting materials and structures

    SciTech Connect (OSTI)

    Fluss, M.J.; Howell, R.H.; Sterne, P.A.; Dykes, J.W.; Mosley, W.D.; Chaiken, A.; Ralls, K.; Radousky, H.

    1995-02-01

    We report here the completion of a one year project to investigate the synthesis, electronic structure, defect structure, and physical transport properties of high temperature superconducting oxide materials. During the course of this project we produced some of the finest samples of single crystal detwinned YBa{sub 2}Cu{sub 3}O{sub 7}, and stoichiometrically perfect (Ba,K)BiO{sub 3}. We deduced the Fermi surface of YBa{sub 2}Cu{sub 3}O{sub 7}, (La,Sr){sub 2}CuO{sub 4}, and (Ba,K)BiO{sub 3} through the recording of the electron momentum density in these materials as measured by positron annihilation spectroscopy and angle resolved photoemission. We also performed extensive studies on Pr substituted (Y,Pr)Ba{sub 2}Cu{sub 3}O{sub 7} so as to further understand the origin of the electron pairing leading to superconductivity.

  3. Superconductivity and magnetism in rapidly solidified perovskites

    SciTech Connect (OSTI)

    O'Handley, R.C.; Kalonji, G.

    1991-01-01

    The report is divided into six parts, reflecting major thrusts of our work since 1987. The six areas are: molecular orbital theory of high {Tc} superconductivity; rapid solidification processing of oxide superconductors; time dependent magnetic and superconducting properties of these inhomogeneous materials; excess Gd in Gd{sub 1+x}Ba{sub 2-x}Cu{sub 3}O{sub 7-{delta}} perovskites; rapid solidification and directional annealing to achieve high Jc; and Mossbauer studies of T = Fe, Co and Ni site selection in YBa{sub 2}(CuT){sub 3}O{sub 7-{delta}} and GdBa{sub 2}(CuT){sub 3}O{sub 7-{delta}}.

  4. Composite arrays of superconducting microstrip line resonators

    SciTech Connect (OSTI)

    Mohebbi, H. R. Miao, G. X.; Benningshof, O. W. B.; Taminiau, I. A. J.; Cory, D. G.

    2014-03-07

    A novel design of an array of half-wave superconductive microstrip resonators is described. The resonator is intended to be useful for electron spin resonance studies of thin film samples at cryogenic temperatures. It achieves a high quality factor, has a small mode-volume, and creates a uniform magnetic field in a plane above the resonator. The device is made of thin film Niobium on sapphire wafer and is tested with a static magnetic field. Variation of Q-factor versus the magnetic field's strength at different temperatures is reported and is in a good agreement with simulation when the loss due to the vortices is included. Also, the power-dependence response of the resonator is shown in experiments and is verified by capturing the nonlinearity associated with the surface impedance of the superconducting film into the circuit model of the device.

  5. HINS Superconducting Lens and Cryostat Performance

    SciTech Connect (OSTI)

    Page, T.M.; DiMarco, J.; Huang, Y.; Orris, D.F.; Tartaglia, M.A.; Terechkine, I.; Tompkins, J.C.; /Fermilab

    2008-08-01

    Fermi National Accelerator Laboratory is involved in the development of a 60 MeV superconducting linac. This linac is part of the High Intensity Neutrino Source (HINS) R&D Program. The initial beam acceleration in the front end section of the linac is achieved using room temperature spoke cavities, each of which is combined with a superconducting focusing solenoid. These solenoid magnets are cooled with liquid helium at 4.5K, operate at 250 A and have a maximum magnetic field strength of 7.5 T. A prototype solenoid cryostat was built and tested at the Fermilab Magnet Test Facility. This paper discusses the test results of the prototype and compares the measured and estimated performance of the cryostat. We also present the methods and results for measuring and fiducializing the axis of the solenoid lens.

  6. Superconducting cuprate heterostructures for hot electron bolometers

    SciTech Connect (OSTI)

    Wen, B.; Yakobov, R.; Vitkalov, S. A.; Sergeev, A.

    2013-11-25

    Transport properties of the resistive state of quasi-two dimensional superconducting heterostructures containing ultrathin La{sub 2?x}Sr{sub x}CuO{sub 4} layers synthesized using molecular beam epitaxy are studied. The electron transport exhibits strong deviation from Ohm's law, ?V??I{sup 3}, with a coefficient ?(T) that correlates with the temperature variation of the resistivity d?/dT. Close to the normal state, analysis of the nonlinear behavior in terms of electron heating yields an electron-phonon thermal conductance per unit area g{sub e?ph}?1 W/K cm{sup 2} at T = 20 K, one-two orders of magnitude smaller than in typical superconductors. This makes superconducting LaSrCuO heterostructures to be attractive candidate for the next generation of hot electron bolometers with greatly improved sensitivity.

  7. Self-triggering superconducting fault current limiter

    DOE Patents [OSTI]

    Yuan, Xing (Albany, NY); Tekletsadik, Kasegn (Rexford, NY)

    2008-10-21

    A modular and scaleable Matrix Fault Current Limiter (MFCL) that functions as a "variable impedance" device in an electric power network, using components made of superconducting and non-superconducting electrically conductive materials. The matrix fault current limiter comprises a fault current limiter module that includes a superconductor which is electrically coupled in parallel with a trigger coil, wherein the trigger coil is magnetically coupled to the superconductor. The current surge doing a fault within the electrical power network will cause the superconductor to transition to its resistive state and also generate a uniform magnetic field in the trigger coil and simultaneously limit the voltage developed across the superconductor. This results in fast and uniform quenching of the superconductors, significantly reduces the burnout risk associated with non-uniformity often existing within the volume of superconductor materials. The fault current limiter modules may be electrically coupled together to form various "n" (rows).times."m" (columns) matrix configurations.

  8. Fermilab | Science | Particle Accelerators | Advanced Superconducting Test

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

    Accelerator Fermilab Accelerator Science and Technology Facility photo The Fermilab Accelerator Science and Technology (FAST) Facility is America's only test bed for cutting-edge particle beams and for accelerator research aimed at intensity frontier proton accelerators. FAST will also be unique in the United States as a particle beam research facility based on superconducting radio-frequency technology, on which nearly all proposed future accelerators in the world are based. The science

  9. Rotor assembly including superconducting magnetic coil

    DOE Patents [OSTI]

    Snitchler, Gregory L. (Shrewsbury, MA); Gamble, Bruce B. (Wellesley, MA); Voccio, John P. (Somerville, MA)

    2003-01-01

    Superconducting coils and methods of manufacture include a superconductor tape wound concentrically about and disposed along an axis of the coil to define an opening having a dimension which gradually decreases, in the direction along the axis, from a first end to a second end of the coil. Each turn of the superconductor tape has a broad surface maintained substantially parallel to the axis of the coil.

  10. RF system models for the CERN Large Hadron Collider with application to longitudinal dynamics

    SciTech Connect (OSTI)

    Mastorides, T.; Rivetta, C.; Fox, J.D.; Winkle, D.Van; Baudrenghien, P.; /CERN

    2011-03-03

    The LHC RF station-beam interaction strongly influences the longitudinal beam dynamics, both single bunch and collective effects. Non-linearities and noise generated within the Radio Frequency (RF) accelerating system interact with the beam and contribute to beam motion and longitudinal emittance blowup. Thus, the noise power spectrum of the RF accelerating voltage strongly affects the longitudinal beam distribution. Furthermore, the coupled-bunch instabilities are also directly affected by the RF components and the configuration of the Low Level RF (LLRF) feedback loops. In this work we present a formalism relating the longitudinal beam dynamics with the RF system configurations, an estimation of collective effects stability margins, and an evaluation of longitudinal sensitivity to various LLRF parameters and configurations.

  11. Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity

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

    Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in these manganites is remarkably similar to that found in high-temperature superconducting copper

  12. Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity

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

    Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in these manganites is remarkably similar to that found in high-temperature superconducting copper

  13. Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity

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

    Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Wednesday, 26 April 2006 00:00 Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in

  14. Substrates suitable for deposition of superconducting thin films

    DOE Patents [OSTI]

    Feenstra, Roeland; Boatner, Lynn A.

    1993-01-01

    A superconducting 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.

  15. Ultrasonic signatures at the superconducting and the pseudogap phase

    Office of Scientific and Technical Information (OSTI)

    boundaries in YBCO cuprates. (Technical Report) | SciTech Connect Ultrasonic signatures at the superconducting and the pseudogap phase boundaries in YBCO cuprates. Citation Details In-Document Search Title: Ultrasonic signatures at the superconducting and the pseudogap phase boundaries in YBCO cuprates. A major issue in the understanding of cuprate superconductors is the nature of the metallic state from which high temperature superconductivity emerges. Central to this issue is the pseudogap

  16. Superconductivity for Electric Systems: 2008 Annual Peer Review Final

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

    Report | Department of Energy Superconductivity for Electric Systems: 2008 Annual Peer Review Final Report Superconductivity for Electric Systems: 2008 Annual Peer Review Final Report The Office of Electricity Delivery and Energy Reliability's High Temperature Superconductivity (HTS) for Electric Systems Program's specific mission is to work in partnership with industry to develop HTS wire and perform other research and development activities leading to the commercialization of HTS-based

  17. Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity

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

    Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in these manganites is remarkably similar to that found in high-temperature superconducting copper

  18. Magnetism and superconductivity observed to exist in harmony

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

    Magnetism and superconductivity exist in harmony Magnetism and superconductivity observed to exist in harmony Physicists have observed, for the first time in a single exotic phase, a situation where magnetism and superconductivity are necessary for each other's existence. August 28, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable

  19. Method for manufacturing a rotor having superconducting coils

    DOE Patents [OSTI]

    Driscoll, David I. (South Euclid, OH); Shoykhet, Boris A. (Beachwood, OH)

    2001-01-01

    A method and apparatus for manufacturing a rotor for use with a rotating machine is provided that employs a superconducting coil on the rotor. An adhesive is applied to an outer surface of the rotor body, which may include a groove disposed within an outer surface of the rotor body. A superconducting coil is then mounted onto the rotor body such that the adhesive bonds the superconducting coil to the rotor body.

  20. Rotatable superconducting cyclotron adapted for medical use

    DOE Patents [OSTI]

    Blosser, Henry G. (East Lansing, MI); Johnson, David A. (Williamston, MI); Riedel, Jack (East Lansing, MI); Burleigh, Richard J. (Berkeley, CA)

    1985-01-01

    A superconducting cyclotron (10) rotatable on a support structure (11) in an arc of about 180.degree. around a pivot axis (A--A) and particularly adapted for medical use is described. The rotatable support structure (13, 15) is balanced by being counterweighted (14) so as to allow rotation of the cyclotron and a beam (12), such as a subparticle (neutron) or atomic particle beam, from the cyclotron in the arc around a patient. Flexible hose (25) is moveably attached to the support structure for providing a liquified gas which is supercooled to near 0.degree. K. to an inlet means (122) to a chamber (105) around superconducting coils (101, 102). The liquid (34) level in the cyclotron is maintained approximately half full so that rotation of the support structure and cyclotron through the 180.degree. can be accomplished without spilling the liquid from the cyclotron. With the coils vertically oriented, each turn of the winding is approximately half immersed in liquid (34) and half exposed to cold gas and adequate cooling to maintain superconducting temperatures in the section of coil above the liquid level is provided by the combination of cold gas/vapor and by the conductive flow of heat along each turn of the winding from the half above the liquid to the half below.

  1. Design of the fundamental power coupler and photocathode inserts for the 112MHz superconducting electron gun

    SciTech Connect (OSTI)

    Xin, T.; Ben-Zvi, I.; Belomestnykh, S.; Chang, X.; Rao, T.; Skaritka, J.; Wu, Q.; Wang, E.; Liang, X.

    2011-07-25

    A 112 MHz superconducting quarter-wave resonator electron gun will be used as the injector of the Coherent Electron Cooling (CEC) proof-of-principle experiment at BNL. Furthermore, this electron gun can be the testing cavity for various photocathodes. In this paper, we present the design of the cathode stalks and a Fundamental Power Coupler (FPC) designated to the future experiments. Two types of cathode stalks are discussed. Special shape of the stalk is applied in order to minimize the RF power loss. The location of cathode plane is also optimized to enable the extraction of low emittance beam. The coaxial waveguide structure FPC has the properties of tunable coupling factor and small interference to the electron beam output. The optimization of the coupling factor and the location of the FPC are discussed in detail. Based on the transmission line theory, we designed a half wavelength cathode stalk which significantly brings down the voltage drop between the cavity and the stalk from more than 5.6 kV to 0.1 kV. The transverse field distribution on cathode has been optimized by carefully choosing the position of cathode stalk inside the cavity. Moreover, in order to decrease the RF power loss, a variable diameter design of cathode stalk has been applied. Compared to the uniform shape of stalk, this design gives us much smaller power losses in important locations. Besides that, we also proposed a fundamental power coupler based on the designed beam parameters for the future proof-of-principle CEC experiment. This FPC should give a strong enough coupling which has the Q external range from 1.5e7 to 2.6e8.

  2. Glass antenna for RF-ion source operation

    DOE Patents [OSTI]

    Leung, Ka Ngo (Hercules, CA); Lee, Yung-Hee Yvette (Berkeley, CA); Perkins, Luke T. (Plainsboro, NJ)

    2000-01-01

    An antenna comprises a plurality of small diameter conductive wires disposed in a dielectric tube. The number and dimensions of the conductive wires is selected to improve the RF resistance of the antenna while also facilitating a reduction in thermal gradients that may create thermal stresses on the dielectric tube. The antenna may be mounted in a vacuum system using a low-stress antenna assembly that cushions and protects the dielectric tube from shock and mechanical vibration while also permitting convenient electrical and coolant connections to the antenna.

  3. High-voltage R-F feedthrough bushing

    DOE Patents [OSTI]

    Grotz, G.F.

    1982-09-03

    Described is a multi-element, high voltage radio frequency bushing for transmitting rf energy to an antenna located in a vacuum container. The bushing includes a center conductor of complex geometrical shape, an outer coaxial shield conductor, and a thin-walled hollow truncated cone insulator disposed between central and outer conductors. The shape of the center conductor, which includes a reverse curvature portion formed of a radially inwardly directed shoulder and a convex portion, controls the uniformity of the axial surface gradient on the insulator cone. The outer shield has a first substantially cylindrical portion and a second radially inwardly extending truncated cone portion.

  4. Capacitively coupled RF voltage probe having optimized flux linkage

    DOE Patents [OSTI]

    Moore, James A. (Powell, TN); Sparks, Dennis O. (Maryville, TN)

    1999-02-02

    An RF sensor having a novel current sensing probe and a voltage sensing probe to measure voltage and current. The current sensor is disposed in a transmission line to link all of the flux generated by the flowing current in order to obtain an accurate measurement. The voltage sensor is a flat plate which operates as a capacitive plate to sense voltage on a center conductor of the transmission line, in which the measured voltage is obtained across a resistance leg of a R-C differentiator circuit formed by the characteristic impedance of a connecting transmission line and a capacitance of the plate, which is positioned proximal to the center conductor.

  5. Fabrication process for the PEP II RF cavities

    SciTech Connect (OSTI)

    Franks, R.M.; Rimmer, R.A.; Schwarz, H.

    1997-06-05

    This paper presents the major steps used in the fabrication of the 26 RF Cavities required for the PEP-II B-factory. Several unique applications of conventional processes have been developed and successfully implemented: electron beam welding (EBW), with minimal porosity, of .75 inch (19 mm) copper cross-sections; extensive 5-axis milling of water channels; electroplating of .37 inch (10 mm) thick OFE copper; tuning of the cavity by profiling beam noses prior to final joining with the cavity body; and machining of the cavity interior, are described here.

  6. Asymmetric Bimodal Accelerator Cavity for Raising rf Breakdown Thresholds

    SciTech Connect (OSTI)

    Kuzikov, S. V.; Kazakov, S. Yu.; Jiang, Y.; Hirshfield, J. L.

    2010-05-28

    We consider an axisymmetric microwave cavity for an accelerator structure whose eigenfrequency for its second lowest TM-like axisymmetric mode is twice that of the lowest such mode, and for which the fields are asymmetric along its axis. In this cavity, the peak amplitude of the rf electric field that points into either longitudinal face can be smaller than the peak field which points out. Computations show that a structure using such cavities might support an accelerating gradient about 47% greater than that for a structure using similar single-mode cavities, without an increase in breakdown probability.

  7. Surface Characterization of the LCLS RF Gun Cathode

    SciTech Connect (OSTI)

    Brachmann, Axel; Decker, Franz-Josef; Ding, Yuantao; Dowell, David; Emma, Paul; Frisch, Josef; Gilevich, Sasha; Hays, Gregory; Hering, Philippe; Huang, Zhirong; Iverson, Richard; Loos, Henrik; Miahnahri, Alan; Nordlund, Dennis; Nuhn, Heinz-Dieter; Pianetta, Piero; Turner, James; Welch, James; White, William; Wu, Juhao; Xiang, Dao; /SLAC

    2012-06-25

    The first copper cathode installed in the LCLS RF gun was used during LCLS commissioning for more than a year. However, after high charge operation (> 500 pC), the cathode showed a decline of quantum efficiency within the area of drive laser illumination. They report results of SEM, XPS and XAS studies that were carried out on this cathode after it was removed from the gun. X-ray absorption and X-ray photoelectron spectroscopy reveal surface contamination by various hydrocarbon compounds. In addition they report on the performance of the second installed cathode with emphasis on the spatial distribution of electron emission.

  8. Microsoft Word - 14th_rf_conf.doc

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

    Lower Hybrid Antenna for Current Drive Experiments on MST J.A. Goetz, M.A. Thomas, C.B. Forest, S.C. Prager, E. Uchimoto a) , F.W. Baity b) , and R.I. Pinsker c) Department of Physics, University of Wisconsin, Madison, WI 53706 a) Department of Physics and Astronomy, University of Montana, Missoula, MT 59812 b) Oak Ridge National Laboratory, Oak Ridge, TN 37831 c) General Atomics, San Diego, CA 92186 Abstract. RF current drive has been proposed as a mechanism for reducing the tearing

  9. RF-Based Accelerators for HEDP Research (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Conference: RF-Based Accelerators for HEDP Research Citation Details In-Document Search Title: RF-Based Accelerators for HEDP Research Accelerator-driven High-Energy Density Physics (HEDP) experiments require typically 1 nanosecond, 1 microcoulomb pulses of mass 20 ions accelerated to several MeV to produce eV-level excitations in thin targets, the warm dense matter regime. Traditionally the province of induction linacs, RF-based acceleration may be a viable alternative with recent breakthroughs

  10. Ultrananocrystalline diamond films with optimized dielectric properties for advanced RF MEMS capacitive switches

    DOE Patents [OSTI]

    Sumant, Anirudha V.; Auciello, Orlando H.; Mancini, Derrick C.

    2013-01-15

    An efficient deposition process is provided for fabricating reliable RF MEMS capacitive switches with multilayer ultrananocrystalline (UNCD) films for more rapid recovery, charging and discharging that is effective for more than a billion cycles of operation. Significantly, the deposition process is compatible for integration with CMOS electronics and thereby can provide monolithically integrated RF MEMS capacitive switches for use with CMOS electronic devices, such as for insertion into phase array antennas for radars and other RF communication systems.

  11. Ultrasonic signatures at the superconducting and the pseudogap...

    Office of Scientific and Technical Information (OSTI)

    A major issue in the understanding of cuprate superconductors is the nature of the metallic state from which high temperature superconductivity emerges. Central to this issue is ...

  12. A young person's view of the Superconducting Super Collider

    SciTech Connect (OSTI)

    Moya, A.

    1990-08-01

    This report gives a simple description of the Superconducting Super Collider, how it works, and what it is used for. (LSP)

  13. Friedel-Like Oscillations from Interstitial Iron in Superconducting...

    Office of Scientific and Technical Information (OSTI)

    The interstitial >2muB moment is surrounded by compensating ferromagnetic four ... Subject: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS ...

  14. Using magnetic fields to understand high-temperature superconductivity

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

    (high-Tc) superconductivity has been the issue as to whether a quantum critical point-a special doping value where quantum fluctuations lead to strong...

  15. Quasiparticle properties of the superconducting state of the...

    Office of Scientific and Technical Information (OSTI)

    Quasiparticle properties of the superconducting state of the two-dimensional Hubbard model Citation Details In-Document Search Title: Quasiparticle properties of the ...

  16. Ultrasonic signatures at the superconducting and the pseudogap...

    Office of Scientific and Technical Information (OSTI)

    that extends from room temperature to the superconducting transition. Although polarized neutron scattering studies hint at magnetic order associated with the pseudogap, there is...

  17. Ultrasonic signatures at the superconducting and the pseudogap...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Ultrasonic signatures at the superconducting and the pseudogap phase boundaries in YBCO cuprates. Citation Details In-Document Search Title: Ultrasonic signatures...

  18. Anomalous Zeeman response of the coexisting superconducting and...

    Office of Scientific and Technical Information (OSTI)

    Anomalous Zeeman response of the coexisting superconducting and spin-density-wave phases as a probe of extended s -wave pairing in ferropnictide superconductors Prev Next ...

  19. Systems Reiter, George 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY...

    Office of Scientific and Technical Information (OSTI)

    Compton Scattering as a Probe of Hydrogen Bonded (and other) Systems Reiter, George 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 77 NANOSCIENCE AND...

  20. History of the superconducting-magnet bubble chambers

    SciTech Connect (OSTI)

    Derrick, M.; Hyman, L.G.; Pewitt, E.G.

    1980-01-01

    This review covers the development of superconducting magnets, small bubble chambers, and the early history of the 12-foot bubble chamber. (MOW)

  1. J. Robert Schrieffer and the BCS Theory of Superconductivity

    Office of Scientific and Technical Information (OSTI)

    J. Robert Schrieffer and the BCS Theory of Superconductivity Resources with Additional Information J. Robert Schrieffer Courtesy of NHMFL Robert Schrieffer received his BS from ...

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

    DOE Patents [OSTI]

    Hull, John R. (Sammamish, WA); McIver, Carl R. (Everett, WA); Mittleider, John A. (Kent, WA)

    2009-12-15

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

  3. High temperature interfacial superconductivity (Patent) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    a novel, unconventional way to fabricate stable, quasi two-dimensional high T.sub.c phases and to significantly enhance superconducting properties in other superconductors. ...

  4. Magnetism and Superconductivity Compete in Iron-based Superconductors...

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

    and the more recently discovered iron-based superconductors (FeSC). They both have phase diagrams in which superconductivity emerges in proximity to other complex quantum...

  5. Next-gen RF MEMS Switch for a Smarter, Faster Internet of Things...

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

    RF MEMS Switch for a Smarter, Faster Internet of Things Karen Lightman 2014.03.28 Big Data. Internet of Things. Quantified Self. Connected Home. Connected City. These...

  6. Tuning the Superconducting Properties of Magnesium Diboride

    SciTech Connect (OSTI)

    Rudeger Heinrich Theoderich Wilke

    2005-12-17

    This work is presented in the following order: A review of the relevant physics and discussion of theoretical predictions for a two gap superconducting compound is given in chapter 2. Chapter 3 provides a review of the basic properties of MgB{sub 2}. Details of sample synthesis and characterization are given in chapter 4. Chapter 5 presents normal state and superconducting properties of Mg(B{sub 1-x}C{sub x}){sub 2} wires. Attempts to increase critical current densities in filaments via titanium additions are discussed in chapter 6. In chapters 7 and 8 alternative methods for synthesizing doped MgB{sub 2} powders are explored. In chapter 7 we synthesize Mg(B{sub 1-x}C{sub x}){sub 2} up to x=0.069 using a mixture of Mg, B, and the binary compound B{sub 4}C. Chapter 8 explores an alternative method, plasma spray synthesis, to produce nanometer sized doped boron powders for powder-in-tube applications. The effects of neutron irradiation on pure MgB{sub 2} wires is discussed in chapter 9. This is followed by a study of the effects of neutron irradiation on Mg(B{sub .962}C{sub .038}){sub 2} wires, presented in chapter 10. I will summarize the results of all of these studies in chapter 11 and discuss future directions for research in understanding the physics behind this novel material as well as its development for practical applications. In this thesis I have presented the results of investigations into the changes in the superconducting properties of MgB{sub 2} as a function of carbon doping and neutron irradiation. The goal has been to understand the physics underlying this unique two-gap superconductor as different types of perturbations are made to the system. Such knowledge not only contributes to our understanding of two-gap superconductivity, but could potentially lead to the development of superconducting MgB{sub 2} wires for the use in power applications near 20 K.

  7. Permanent magnet design for high-speed superconducting bearings

    DOE Patents [OSTI]

    Hull, J.R.; Uherka, K.L.; Abdoud, R.G.

    1996-09-10

    A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure is disclosed. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing. 9 figs.

  8. Permanent magnet design for high-speed superconducting bearings

    DOE Patents [OSTI]

    Hull, John R.; Uherka, Kenneth L.; Abdoud, Robert G.

    1996-01-01

    A high temperature superconducting bearing including a permanent magnet rotor levitated by a high temperature superconducting structure. The rotor preferably includes one or more concentric permanent magnet rings coupled to permanent magnet ring structures having substantially triangular and quadrangular cross-sections. Both alternating and single direction polarity magnet structures can be used in the bearing.

  9. Superconducting articles, and methods for forming and using same

    DOE Patents [OSTI]

    Knoll, Allan Robert; Lenseth, Kenneth Patrick

    2007-01-09

    A superconducting tape is disclosed, including a substrate having a first surface and a second surface opposite the first surface, the substrate including a plurality of indicia provided on the first surface spaced apart along a length of the substrate; and a superconductor layer overlying the second surface. Also disclosed are components incorporating superconducting tapes, methods for manufacturing same, and methods for using same.

  10. Superconducting magnetic energy storage for asynchronous electrical systems

    DOE Patents [OSTI]

    Boenig, Heinrich J. (Los Alamos, NM)

    1986-01-01

    A superconducting magnetic energy storage coil connected in parallel between converters of two or more ac power systems provides load leveling and stability improvement to any or all of the ac systems. Control is provided to direct the charging and independently the discharging of the superconducting coil to at least a selected one of the ac power systems.

  11. EIS-0138-S: Superconducting Super Collider, Supplemental, Waxahatchie, Texas

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy developed this supplementary statement to analyze the environmental impacts of design modifications to the Superconducting Super Collider that were made following the publication of the Record of Decision that selected Ellis County, Texas, as the location of the laboratory facility. This statement supplements DOE/EIS-0138, Superconducting Super Collider.

  12. Superconducting magnetic energy storage for asynchronous electrical systems

    DOE Patents [OSTI]

    Boenig, H.J.

    1984-05-16

    It is an object of the present invention to provide superconducting magnetic energy storage for a plurality of asynchronous electrical systems. It is a further object of the present invention to provide load leveling and stability improvement in a plurality of independent ac systems using a single superconducting magnetic energy storage coil.

  13. RF physics of ICWC discharge at high cyclotron harmonics

    SciTech Connect (OSTI)

    Lyssoivan, A.; Van Eester, D.; Wauters, T.; Vervier, M.; Van Schoor, M.; Bobkov, V.; Rohde, V.; Schneider, P.; Douai, D.; Kogut, D.; Kreter, A.; Möller, S.; Philipps, V.; Sergienko, G.; Moiseenko, V.; Noterdaeme, J.-M.; Collaboration: TEXTOR Team; ASDEX Upgrade Team

    2014-02-12

    Recent experiments on Ion Cyclotron Wall Conditioning (ICWC) performed in tokamaks TEXTOR and ASDEX Upgrade with standard ICRF antennas operated at fixed frequencies but variable toroidal magnetic field demonstrated rather contrasting parameters of ICWC discharge in scenarios with on-axis fundamental ion cyclotron resonance (ICR) for protons,ω=ω{sub H+}, and with its high cyclotron harmonics (HCH), ω=10ω{sub cH+}⋅ HCH scenario: very high antenna coupling to low density RF plasmas (P{sub pl}≈0.9P{sub RF-G}) and low energy Maxwellian distribution of CX hydrogen atoms with temperature T{sub H}≈350 eV. Fundamental ICR: lower antenna-plasma coupling efficiency (by factor of about 1.5 times) and generation of high energy non-Maxwellian CX hydrogen atoms (with local energy E{sub ⊥H} ≥1.0 keV). In the present paper, we analyze the obtained experimental results numerically using (i) newly developed 0-D transport code describing the process of plasma production with electron and ion collisional ionization in helium-hydrogen gas mixture and (ii) earlier developed 1-D Dispersion Relation Solver accounting for finite temperature effects and collision absorption mechanisms for all plasma species in addition to conventionally examined Landau/TTPM damping for electrons and cyclotron absorption for ions. The numerical study of plasma production in helium with minor hydrogen content in low and high toroidal magnetic fields is presented. The investigation of the excitation, conversion and absorption of plasma waves as function of B{sub T}-field suggests that only fast waves (FW) may give a crucial impact on antenna coupling and characteristics of the ICWC discharge using standard poloidally polarized ICRF antennas designed to couple RF power mainly to FW. The collisional (non-resonant) absorption by electrons and ions and IC absorption by resonant ions of minor concentration in low T{sub e} plasmas is studied at fundamental ICR and its high harmonics.

  14. RF low-level control for the Linac4 H{sup ?} source

    SciTech Connect (OSTI)

    Butterworth, A. Grudiev, A.; Lettry, J.; Paoluzzi, M.; Schmitzer, C.; Nishida, K.

    2015-04-08

    The H{sup ?} source for the Linac4 accelerator at CERN uses an RF driven plasma for the production of H{sup ?}. The RF is supplied by a 2?MHz RF tube amplifier with a maximum power output of 100 kW and a pulse duration of up to 2?ms. The low-level RF signal generation and measurement system has been developed using standard CERN controls electronics in the VME form factor. The RF frequency and amplitude reference signals are generated using separate arbitrary waveform generator channels. The frequency and amplitude are both freely programmable over the duration of the RF pulse, which allows fine-tuning of the excitation. Measurements of the forward and reverse RF power signals are performed via directional couplers using high-speed digitizers, and permit the estimation of the plasma impedance and deposited power via an equivalent circuit model. The low-level RF hardware and software implementations are described, and experimental results obtained with the Linac4 ion sources in the test stand are presented.

  15. Balanced optical-microwave phase detector for sub-femtosecond optical-RF synchronization

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

    Peng, Michael Y.; Kalaydzhyan, Aram; Krtner, Franz X.

    2014-10-23

    We demonstrate that balanced optical-microwave phase detectors (BOMPD) are capable of optical-RF synchronization with sub-femtosecond residual timing jitter for large-scale timing distribution systems. RF-to-optical synchronization is achieved with a long-term stability of moresuppression ratio with potential improvement via DC offset adjustment.less

  16. Proposal of an Arc Detection Technique Based on RF Measurements for the ITER ICRF Antenna

    SciTech Connect (OSTI)

    Huygen, S.; Dumortier, P.; Durodie, F.; Messiaen, A.; Vervier, M.; Vrancken, M.

    2011-12-23

    RF arc detection is a key operational and safety issue for the ICRF system on ITER. Indeed the high voltages inside the antenna put it at risk of arcing, which could cause substantial damage. This paper describes the various possibilities explored by circuit simulation and the strategy now considered to protect the ITER ICRF antenna from RF arcs.

  17. Superconducting shielded core reactor with reduced AC losses

    DOE Patents [OSTI]

    Cha, Yung S.; Hull, John R.

    2006-04-04

    A superconducting shielded core reactor (SSCR) operates as a passive device for limiting excessive AC current in a circuit operating at a high power level under a fault condition such as shorting. The SSCR includes a ferromagnetic core which may be either closed or open (with an air gap) and extends into and through a superconducting tube or superconducting rings arranged in a stacked array. First and second series connected copper coils each disposed about a portion of the iron core are connected to the circuit to be protected and are respectively wound inside and outside of the superconducting tube or rings. A large impedance is inserted into the circuit by the core when the shielding capability of the superconducting arrangement is exceeded by the applied magnetic field generated by the two coils under a fault condition to limit the AC current in the circuit. The proposed SSCR also affords reduced AC loss compared to conventional SSCRs under continuous normal operation.

  18. Damping in high-temperature superconducting levitation systems

    DOE Patents [OSTI]

    Hull, John R.

    2009-12-15

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

  19. Nanoscale constrictions in superconducting coplanar waveguide resonators

    SciTech Connect (OSTI)

    Jenkins, Mark David; Naether, Uta; Ciria, Miguel; Zueco, David; Luis, Fernando; Ses, Javier; Atkinson, James; Barco, Enrique del; Snchez-Azqueta, Carlos; Majer, Johannes

    2014-10-20

    We report on the design, fabrication, and characterization of superconducting coplanar waveguide resonators with nanoscopic constrictions. By reducing the size of the center line down to 50?nm, the radio frequency currents are concentrated and the magnetic field in its vicinity is increased. The device characteristics are only slightly modified by the constrictions, with changes in resonance frequency lower than 1% and internal quality factors of the same order of magnitude as the original ones. These devices could enable the achievement of higher couplings to small magnetic samples or even to single molecular spins and have applications in circuit quantum electrodynamics, quantum computing, and electron paramagnetic resonance.

  20. Aditya Wakhle National Superconducting Cyclotron Laboratory

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

    Wakhle, 4/15/15, Slide 1 Measuring Fusion with RIBs and Dependence of Quasifission on Neutron Richness Aditya Wakhle National Superconducting Cyclotron Laboratory Michigan State University, E. Lansing, MI A. Wakhle, 4/15/15, Slide 2 Fusion Measurements at ReA3 Multi-purpose Beam Line CFFD Chamber ReA3 experimental area EBIT Charge Breeder F r o m C y c l o t r o n , g a s c a t c h e r A. Wakhle, 4/15/15, Slide 3 Coincidence Fission Fragment Detector CFFD A. Wakhle, 4/15/15, Slide 4 Coincidence

  1. Clamshell microwave cavities having a superconductive coating

    DOE Patents [OSTI]

    Cooke, D. Wayne (Los Alamos, NM); Arendt, Paul N. (Los Alamos, NM); Piel, Helmut (Wuppertal, DE)

    1994-01-01

    A microwave cavity including a pair of opposing clamshell halves, such halves comprised of a metal selected from the group consisting of silver, copper, or a silver-based alloy, wherein the cavity is further characterized as exhibiting a dominant TE.sub.011 mode is provided together with an embodiment wherein the interior concave surfaces of the clamshell halves are coated with a superconductive material. In the case of copper clamshell halves, the microwave cavity has a Q-value of about 1.2.times.10.sup.5 as measured at a temperature of 10K and a frequency of 10 GHz.

  2. Vacuum coupling of rotating superconducting rotor

    DOE Patents [OSTI]

    Shoykhet, Boris A.; Zhang, Burt Xudong; Driscoll, David Infante

    2003-12-02

    A rotating coupling allows a vacuum chamber in the rotor of a superconducting electric motor to be continually pumped out. The coupling consists of at least two concentric portions, one of which is allowed to rotate and the other of which is stationary. The coupling is located on the non-drive end of the rotor and is connected to a coolant supply and a vacuum pump. The coupling is smaller in diameter than the shaft of the rotor so that the shaft can be increased in diameter without having to increase the size of the vacuum seal.

  3. Conceptual Design for Superconducting Planar Helical Undulator

    SciTech Connect (OSTI)

    Sasaki, Shigemi

    2004-05-12

    A preliminary consideration was made on a short-period superconducting planar helical undulator (SCHU) for circularly polarized radiation. The SCHU consists of coils and iron poles/yokes. There is no magnetic structure in the horizontal plane of the electron orbit. The SCHU would provide the large horizontal aperture needed to allow injection into the storage ring. The expected field strength is at least 30% larger than that by an APPLE-type permanent-magnet device with the same gap and the same period.

  4. Design and commissioning of vertical test cryostats for XFEL superconducting cavities measurements

    SciTech Connect (OSTI)

    Polinski, J.; Chorowski, M.; Duda, P.; Bozhko, Y.; Petersen, B.; Schaffran, J.

    2014-01-29

    The European X-ray Free Electron Laser (XFEL), now under construction at DESY in Hamburg, will make an extensive use of 1.3 GHz superconducting cavities aimed at accelerating the electrons to the energy of 17.5 GeV. The cavities will be operated at 2 K with the use of saturated HeII. Prior to their assembly in accelerator cryomodules, the RF performance of the cavities will be cold-tested in two dedicated vertical cryostats. Each cryostat allows a simultaneous testing of 4 cavities mounted on a dedicated insert. The cryostats are equipped with external lines allowing their supply with liquid helium and further conversion of the helium into superfluid He II. The paper describes the test stand flow scheme, the technical key elements, including a recuperative heat exchanger, and the cold commissioning. The thermodynamic analysis of the cryostat cool down and steady-state operation is given. A Second Law of Thermodynamics based theoretical model of the heat exchanger performance, and the model experimental validation, is presented.

  5. Design and performance of a new induction furnace for heat treatment of superconducting radiofrequency niobium cavities

    SciTech Connect (OSTI)

    Pashupati Dhakal, Gianluigi Ciovati, Wayne Rigby, John Wallace, Ganapati Rao Myneni

    2012-06-01

    Superconducting radio frequency (SRF) cavities made of high purity niobium (Nb) are the building blocks of many modern particle accelerators. The fabrication process includes several cycles of chemical and heat treatment at low ({approx}120 deg C) and high ({approx}800 deg C) temperatures. In this contribution, we describe the design and performance of an ultra-high-vacuum furnace which uses an induction heating system to heat treat SRF cavities. Cavities are heated by radiation from the Nb susceptor. By using an all-niobium hot zone, contamination of the Nb cavity by foreign elements during heat treatment is minimized and allows avoiding subsequent chemical etching. The furnace was operated up to 1400 deg C with a maximum pressure of {approx}1 x 10{sup -5} Torr and the maximum achievable temperature is estimated to be higher than 2000 deg C. Initial results on the performance of a single cell 1.5 GHz cavity made of ingot Nb heat treated at 1200 deg C using this new induction furnace and without subsequent chemical etching showed a reduction of the RF losses by a factor of {approx}2 compared to cavities made of fine-grain Nb which underwent standard chemical and heat treatments.

  6. Development of the conventional facilities of the Superconducting Super Collider. Revision 1

    SciTech Connect (OSTI)

    Toohig, T.E.

    1994-02-01

    This report discusses an overview of the construction of facilities at the Superconducting Super Collider.

  7. Midwest superconductivity consortium. 1993 Progress report

    SciTech Connect (OSTI)

    Not Available

    1994-01-01

    The Midwest Superconductivity Consortium, MISCON, in the fourth year of operations further strengthened its mission to advance the science and understanding of high T{sub c} superconductivity. The goals of the organization and the individual projects continue to reflect the current needs for new knowledge in the field and the unique capabilities of the institutions involved. Group efforts and cooperative laboratory interactions to achieve the greatest possible synergy under the Consortium continue to be emphasized. Industrial affiliations coupled with technology transfer initiatives were expanded. Activities of the participants during the past year achieved an interactive and high level of performance. The number of notable achievements in the field contributed by Consortium investigators increased. The programmatic research continues to focus upon key materials-related problems in two areas. The first area has a focus upon {open_quotes}Synthesis and Processing{close_quotes} while the second is centered around {open_quotes}Limiting Features in Transport Properties of High T{sub c} Materials{close_quotes}.

  8. Next Generation Fast RF Interlock Module and ATCA Adapter for ILC High Availability RF Test Station Demonstration

    SciTech Connect (OSTI)

    Larsen, R

    2009-10-17

    High availability interlocks and controls are required for the ILC (International Linear Collider) L-Band high power RF stations. A new F3 (Fast Fault Finder) VME module has been developed to process both fast and slow interlocks using FPGA logic to detect the interlock trip excursions. This combination eliminates the need for separate PLC (Programmable Logic Controller) control of slow interlocks. Modules are chained together to accommodate as many inputs as needed. In the next phase of development the F3's will be ported to the new industry standard ATCA (Advanced Telecom Computing Architecture) crate (shelf) via a specially designed VME adapter module with IPMI (Intelligent Platform Management Interface). The goal is to demonstrate auto-failover and hot-swap for future partially redundant systems.

  9. Method for forming bismuth-based superconducting ceramics

    DOE Patents [OSTI]

    Maroni, Victor A.; Merchant, Nazarali N.; Parrella, Ronald D.

    2005-05-17

    A method for reducing the concentration of non-superconducting phases during the heat treatment of Pb doped Ag/Bi-2223 composites having Bi-2223 and Bi-2212 superconducting phases is disclosed. A Pb doped Ag/Bi-2223 composite having Bi-2223 and Bi-2212 superconducting phases is heated in an atmosphere having an oxygen partial pressure not less than about 0.04 atmospheres and the temperature is maintained at the lower of a non-superconducting phase take-off temperature and the Bi-2223 superconducting phase grain growth take-off temperature. The oxygen partial pressure is varied and the temperature is varied between about 815.degree. C. and about 835.degree. C. to produce not less than 80 percent conversion to Pb doped Bi-2223 superconducting phase and not greater than about 20 volume percent non-superconducting phases. The oxygen partial pressure is preferably varied between about 0.04 and about 0.21 atmospheres. A product by the method is disclosed.

  10. Abrupt Onset of a Second Energy Gap at the Superconducting Transition of

    Office of Scientific and Technical Information (OSTI)

    Underdoped Bi2212 (Journal Article) | SciTech Connect Abrupt Onset of a Second Energy Gap at the Superconducting Transition of Underdoped Bi2212 Citation Details In-Document Search Title: Abrupt Onset of a Second Energy Gap at the Superconducting Transition of Underdoped Bi2212 The superconducting gap--an energy scale tied to the superconducting phenomena--opens on the Fermi surface at the superconducting transition temperature ({Tc}) in conventional BCS superconductors. In underdoped

  11. Pressurized H_{2} rf Cavities in Ionizing Beams and Magnetic Fields

    SciTech Connect (OSTI)

    Chung, M.; et al.

    2013-10-01

    A major technological challenge in building a muon cooling channel is operating RF cavities in multi-tesla external magnetic fields. We report the first experimental characterization of a high pressure gas-filled 805 MHz RF cavity for use with intense ionizing beams and strong external magnetic fields. RF power consumption by beam-induced plasma was investigated with hydrogen and deuterium gases with pressures between 20 and 100 atm and peak RF gradients between 5 and 50 MV/m. The energy absorption per ion pair-RF cycle ranges from 10−18 to 10−16 J. The low pressure case agrees well with an analytical model based on electron and ion mobilities. Varying concentrations of oxygen gas were investigated to remove free electrons from the cavity and reduce the RF power consumption. Measurements of the electron attachment time to oxygen and rate of ion-ion recombination were also made. Additionally, we demonstrate the operation of the gas-filled RF cavity in a solenoidal field of up to 3 T, finding no major magnetic field dependence. These results indicate that a high pressure gas-filled cavity is potentially a viable technology for muon ionization cooling.

  12. Waveguide Structures for RF Undulators with Applications to FELs and Storage Rings

    SciTech Connect (OSTI)

    Yeddulla, M.; Geng, H.G.; Huang, Z.; Ma, Z.; Tantawi, S.G.; /SLAC

    2011-11-02

    RF undulators, suggested a long time ago, have the advantage of fast dynamic control of polarization, undulator strength and wavelength. However, RF undulators require very strong RF fields in order to produce radiation of the same order as conventional static devices. Very high power RF energy confined inside a waveguide or a cavity can provide the necessary RF fields to undulate the electron beam. However, the wall losses in the waveguide should be low enough to make it practically feasible as a CW or quasi CW undulator and, hence, competitive with static devices for applications to storage rings and FELs. Here we present various waveguide structures such as smooth walled and corrugated walled waveguides and various RF modes. We will show that there are some advantages in operating with higher order modes and also with hybrid modes in the corrugated guide. We will show that the RF power requirement for some of these modes will permit a quasi CW operation of the undulator, thus permitting its operation in a storage ring.

  13. Discharging a superconducting store into an inverting converter

    SciTech Connect (OSTI)

    Andrianov, V.V.; Zenkevich, V.B.; Popkov, O.V.; Sergeyenkov, B.N.; Sukhorukov, A.G.

    1983-11-01

    It is possible to invert the energy stored in a superconducting solenoid with both a constant mean value of the inverted power, and a constant mean value of the voltage in the leads of the solenoid, which is equal to the mean value of the opposing voltage (counter emf) of the inverter. The operation of a superconducting inductive store together with a high speed semiconductor switch and a three phase inverter is considered. Graphs show changes in currents and voltages on the compacitor, the current flowing through the superconducting solenoid, the current flowing through the capacitor, and that flowing through the controlled rectified.

  14. System and method for cooling a super-conducting device

    DOE Patents [OSTI]

    Bray, James William (Niskayuna, NY); Steinbach, Albert Eugene (Schenectady, NY); Dawson, Richard Nils (Voorheesville, NY); Laskaris, Evangelos Trifon (Schenectady, NY); Huang, Xianrul (Clifton Park, NY)

    2008-01-08

    A system and method for cooling a superconductive rotor coil. The system comprises a rotatable shaft coupled to the superconductive rotor coil. The rotatable shaft may comprise an axial passageway extending through the rotatable shaft and a first passageway extending through a wall of the rotatable shaft to the axial passageway. The axial passageway and the first passageway are operable to convey a cryogenic fluid to the superconductive rotor coil through the wall of the rotatable shaft. A cryogenic transfer coupling may be provided to supply cryogenic fluid to the first passageway.

  15. Friedel-Like Oscillations from Interstitial Iron in Superconducting

    Office of Scientific and Technical Information (OSTI)

    Fe1+yTe0.62Se0.38 (Journal Article) | SciTech Connect Journal Article: Friedel-Like Oscillations from Interstitial Iron in Superconducting Fe1+yTe0.62Se0.38 Citation Details In-Document Search Title: Friedel-Like Oscillations from Interstitial Iron in Superconducting Fe1+yTe0.62Se0.38 Using polarized and unpolarized neutron scattering we show that interstitial Fe in superconducting Fe$$_{1+y}$$Te$$_{1-x}$$Se$_x$ induces a magnetic Friedel-like oscillation that diffracts at $${\bf

  16. System and method for cooling a superconducting rotary machine

    DOE Patents [OSTI]

    Ackermann, Robert Adolf (Schenectady, NY); Laskaris, Evangelos Trifon (Schenectady, NY); Huang, Xianrui (Clifton Park, NY); Bray, James William (Niskayuna, NY)

    2011-08-09

    A system for cooling a superconducting rotary machine includes a plurality of sealed siphon tubes disposed in balanced locations around a rotor adjacent to a superconducting coil. Each of the sealed siphon tubes includes a tubular body and a heat transfer medium disposed in the tubular body that undergoes a phase change during operation of the machine to extract heat from the superconducting coil. A siphon heat exchanger is thermally coupled to the siphon tubes for extracting heat from the siphon tubes during operation of the machine.

  17. Silver-bearing, high-temperature, superconducting (HTS) paint

    SciTech Connect (OSTI)

    Ferrando, W.A.

    1990-02-15

    A substantial set of device applications awaits development of a workable, durable, high-temperature superconducting (HTS) paint. Such a paint should be truly superconducting with its critical temperature T sub c>77K. For most of these applications, a high critical current (J sub c) is not required, although probably desirable. A process is described which can be used to produce silver-bearing HTS paint coatings on many engineering materials. Preliminary tests have shown good adherence to several ceramics and the ability to meet the superconducting criteria. Moreover, the coatings withstand multiple thermal cycling and stability under laboratory ambient storage conditions for periods of at least several months.

  18. Measured and theoretical characterization of the RF properties of stacked, high-gradient insulator material

    SciTech Connect (OSTI)

    Houck, T. L., LLNL

    1997-05-09

    Recent high-voltage breakdown experiments of periodic metallic-dielectric insulating structures have suggested several interesting high-gradient applications. One such area is the employment of high-gradient insulators in high-current, electron-beam, accelerating induction modules. For this application, the understanding of the rf characteristics of the insulator plays an important role in estimating beam-cavity interactions. In this paper, we examine the rf properties of the insulator comparing simulation results with experiment. Different insulator designs are examined to determine their rf transmission properties in gap geometries.

  19. RF-driven ion source with a back-streaming electron dump

    DOE Patents [OSTI]

    Kwan, Joe; Ji, Qing

    2014-05-20

    A novel ion source is described having an improved lifetime. The ion source, in one embodiment, is a proton source, including an external RF antenna mounted to an RF window. To prevent backstreaming electrons formed in the beam column from striking the RF window, a back streaming electron dump is provided, which in one embodiment is formed of a cylindrical tube, open at one end to the ion source chamber and capped at its other end by a metal plug. The plug, maintained at the same electrical potential as the source, captures these backstreaming electrons, and thus prevents localized heating of the window, which due to said heating, might otherwise cause window damage.

  20. Development of an L-Band RF Electron Gun for SASE in the Infrared Region

    SciTech Connect (OSTI)

    Kashiwagi, Shigeru; Kato, Ryukou; Isoyama, Goro; Hayano, Hitoshi; Urakawa, Junji

    2010-02-03

    We conduct research on Self-Amplified Spontaneous Emission (SASE) in the infrared region using the 40 MeV, 1.3 GHz L-band linac of Osaka University. The linac equipped with a thermionic electron gun can accelerate a high-intensity single-bunch beam though its normalized emittance is high. In order to advance the research on SASE, we have begun development of an RF gun for the L-band linac in collaboration with KEK. We will report conceptual design of the RF gun and present the status of development of another RF gun for STF at KEK.

  1. Method of preparing composite superconducting wire

    DOE Patents [OSTI]

    Verhoeven, John D. (Ames, IA); Gibson, Edwin D. (Ames, IA); Finnemore, Douglas K. (Ames, IA); Ostenson, Jerome E. (Ames, IA); Schmidt, Frederick A. (Ames, IA); Owen, Charles V. (Ames, IA)

    1985-08-06

    An improved method of preparing composite multifilament superconducting wire of Nb.sub.3 Sn in a copper matrix which eliminates the necessity of coating the drawn wire with tin. A generalized cylindrical billet of an alloy of copper containing at least 15 weight percent niobium, present in the copper as discrete, randomly distributed and oriented dendritic-shaped particles, is provided with at least one longitudinal opening which is filled with tin to form a composite drawing rod. The drawing rod is then drawn to form a ductile composite multifilament wire containing a filament of tin. The ductile wire containing the tin can then be wound into magnet coils or other devices before heating to diffuse the tin through the wire to react with the niobium forming Nb.sub.3 Sn. Also described is an improved method for making large billets of the copper-niobium alloy by consumable-arc casting.

  2. DARHT Delivers Cibola Takes Flight Plutonium Superconductivity

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

    663 DARHT Delivers Cibola Takes Flight Plutonium Superconductivity Not for the Birds l o S a l a m o S N a T i o N a l l a B o r a T o r y loS alamoS SCieNCe aND TeChNology magaziNe may 2007 1 663 From Terry Wallace About Our Name: During World War II, all that the outside world knew of Los Alamos and its top-secret laboratory was the mailing address-P . O. Box 1663, Santa Fe, New Mexico. That box number, still part of our address, symbolizes our historic role in the nation's service. Located on

  3. Self field triggered superconducting fault current limiter

    DOE Patents [OSTI]

    Tekletsadik, Kasegn D. (Rexford, NY)

    2008-02-19

    A superconducting fault current limiter array with a plurality of superconductor elements arranged in a meanding array having an even number of supconductors parallel to each other and arranged in a plane that is parallel to an odd number of the plurality of superconductors, where the odd number of supconductors are parallel to each other and arranged in a plane that is parallel to the even number of the plurality of superconductors, when viewed from a top view. The even number of superconductors are coupled at the upper end to the upper end of the odd number of superconductors. A plurality of lower shunt coils each coupled to the lower end of each of the even number of superconductors and a plurality of upper shunt coils each coupled to the upper end of each of the odd number of superconductors so as to generate a generally orthoganal uniform magnetic field during quenching using only the magenetic field generated by the superconductors.

  4. Transformer current sensor for superconducting magnetic coils

    DOE Patents [OSTI]

    Shen, Stewart S.; Wilson, C. Thomas

    1988-01-01

    A transformer current sensor having primary turns carrying a primary current for a superconducting coil and secondary turns only partially arranged within the primary turns. The secondary turns include an active winding disposed within the primary turns and a dummy winding which is not disposed in the primary turns and so does not experience a magnetic field due to a flow of current in the primary turns. The active and dummy windings are wound in opposite directions or connected in series-bucking relationship, and are exposed to the same ambient magnetic field. Voltages which might otherwise develop in the active and dummy windings due to ambient magnetic fields thus cancel out. The resultant voltage is purely indicative of the rate of change of current flowing in the primary turns.

  5. Levitation pressure and friction losses in superconducting bearings

    DOE Patents [OSTI]

    Hull, John R.

    2001-01-01

    A superconducting bearing having at least one permanent magnet magnetized with a vertical polarization. The lower or stator portion of the bearing includes an array of high-temperature superconducting elements which are comprised of a plurality of annular rings. An annular ring is located below each permanent magnet and an annular ring is offset horizontally from at least one of the permanent magnets. The rings are composed of individual high-temperature superconducting elements located circumferentially along the ring. By constructing the horizontally-offset high-temperature superconducting ring so that the c-axis is oriented in a radial direction, a higher levitation force can be achieved. Such an orientation will also provide substantially lower rotational drag losses in the bearing.

  6. Radiofrequency amplifier based on a dc superconducting quantum interference device

    DOE Patents [OSTI]

    Hilbert, C.; Martinis, J.M.; Clarke, J.

    1984-04-27

    A low noise radiofrequency amplifer, using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID and an input coil are maintained at superconductivity temperatures in a superconducting shield, with the input coil inductively coupled to the superconducting ring of the dc SQUID. A radiofrequency signal from outside the shield is applied to the input coil, and an amplified radiofrequency signal is developed across the dc SQUID ring and transmitted to exteriorly of the shield. A power gain of 19.5 +- 0.5 dB has been achieved with a noise temperature of 1.0 +- 0.4 K at a frequency of 100 MHz.

  7. Evidence for charge Kondo effect in superconducting Tl-doped...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Evidence for charge Kondo effect in superconducting Tl-doped PbTe We report results of low-temperature thermodynamic and transport ...

  8. J. Robert Schrieffer and the BCS Theory of Superconductivity

    Office of Scientific and Technical Information (OSTI)

    and his research is available in full-text and on the Web. Documents: Microscopic Theory of Superconductivity; Physical Review, Vol. 106, Issue 1: 162-164, April 1, 1957...

  9. Kondo Physics and Unconventional Superconductivity in the U Intermetal...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Kondo Physics and Unconventional Superconductivity in the U Intermetallic U2PtC2 Revealed by NMR Citation Details In-Document Search Title: Kondo Physics and ...

  10. Magnetism and superconductivity observed to exist in harmony

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

    and helium. "It's really a question of the chicken and the egg," said coauthor Eric Bauer of Los Alamos. "Does superconductivity need magnetism in this state, or does magnetism...

  11. Cryogenic deformation of high temperature superconductive composite structures

    DOE Patents [OSTI]

    Roberts, Peter R. (Groton, MA); Michels, William (Brookline, MA); Bingert, John F. (Jemez Springs, NM)

    2001-01-01

    An improvement in a process of preparing a composite high temperature oxide superconductive wire is provided and involves conducting at least one cross-sectional reduction step in the processing preparation of the wire at sub-ambient temperatures.

  12. Photoinduced changes of the chemical potential in superconducting...

    Office of Scientific and Technical Information (OSTI)

    Photoinduced changes of the chemical potential in superconducting Bi 2 Sr 2 CaCu 2 O 8 + Citation Details In-Document Search This content will become publicly available on...

  13. Radiofrequency amplifier based on a dc superconducting quantum interference device

    DOE Patents [OSTI]

    Hilbert, Claude (Berkeley, CA); Martinis, John M. (Berkeley, CA); Clarke, John (Berkeley, CA)

    1986-01-01

    A low noise radiofrequency amplifier (10), using a dc SQUID (superconducting quantum interference device) as the input amplifying element. The dc SQUID (11) and an input coil (12) are maintained at superconductivity temperatures in a superconducting shield (13), with the input coil (12) inductively coupled to the superconducting ring (17) of the dc SQUID (11). A radiofrequency signal from outside the shield (13) is applied to the input coil (12), and an amplified radiofrequency signal is developed across the dc SQUID ring (17) and transmitted to exteriorly of the shield (13). A power gain of 19.5.+-.0.5 dB has been achieved with a noise temperature of 1.0.+-.0.4 K. at a frequency of 100 MHz.

  14. A small-bore high-field superconducting quadrupole magnet

    SciTech Connect (OSTI)

    Barlow, D.B.; Kraus, R.H.; Lobb, C.T.; Menzel, M.T. ); Walstrom, P.L. )

    1990-01-01

    A prototype superconducting quadrupole magnet was designed and built for use in superconducting coupled-cavity linacs where the use of permanent magnets is ruled out by consideration of trapped flux losses. The magnet has a clear bore diameter of 1.8 cm and outside diameter of 11 cm and length of 11 cm. The magnet was operated at a temperature of 4.2 K and obtained a peak quadrupole field gradient of 320 T/m.

  15. Toroidal constant-tension superconducting magnetic energy storage units

    DOE Patents [OSTI]

    Herring, J. Stephen (Idaho Falls, ID)

    1992-01-01

    A superconducting magnetic energy storage unit is provided in which the magnet is wound in a toroidal fashion such that the magnetic field produced is contained only within the bore of the magnet, and thus producing a very low external field. The superconducting magnet includes a coolant channel disposed through the wire. The bore of the magnet comprises a storage volume in which cryogenic coolant is stored, and this volume supplies the coolant to be delivered to the coolant channel in the magnet.

  16. Quasiparticle properties of the superconducting state of the

    Office of Scientific and Technical Information (OSTI)

    two-dimensional Hubbard model (Journal Article) | DOE PAGES Quasiparticle properties of the superconducting state of the two-dimensional Hubbard model Title: Quasiparticle properties of the superconducting state of the two-dimensional Hubbard model Authors: Gull, E. ; Millis, A. J. Publication Date: 2015-02-20 OSTI Identifier: 1180695 Grant/Contract Number: AC02-05CH11231 Type: Publisher's Accepted Manuscript Journal Name: Physical Review B Additional Journal Information: Journal Volume: 91;

  17. Frequency dispersion of nonlinear response of thin superconducting films in

    Office of Scientific and Technical Information (OSTI)

    the Berezinskii-Kosterlitz-Thouless state (Journal Article) | SciTech Connect Journal Article: Frequency dispersion of nonlinear response of thin superconducting films in the Berezinskii-Kosterlitz-Thouless state Citation Details In-Document Search Title: Frequency dispersion of nonlinear response of thin superconducting films in the Berezinskii-Kosterlitz-Thouless state The effects of microwave radiation on transport properties of atomically thin La2-xSrxCuO₄ films were studied in the

  18. Electro-thermal simulation of superconducting nanowire avalanche photodetectors

    SciTech Connect (OSTI)

    Marsili, F.; Najafi, F.; Herder, C.; Berggren, K. K.

    2011-01-01

    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 nanowires. We extrapolated the physical constants of the model from experimental data and we simulated the time evolution of the device resistance, temperature and current by solving two coupled electrical and thermal differential equations describing the nanowires. The predictions of the model were in good quantitative agreement with the experimental results.

  19. Frequency dispersion of nonlinear response of thin superconducting films in

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

    the Berezinskii-Kosterlitz-Thouless state (Journal Article) | SciTech Connect Journal Article: Frequency dispersion of nonlinear response of thin superconducting films in the Berezinskii-Kosterlitz-Thouless state Citation Details In-Document Search Title: Frequency dispersion of nonlinear response of thin superconducting films in the Berezinskii-Kosterlitz-Thouless state The effects of microwave radiation on transport properties of atomically thin La2-xSrxCuO₄ films were studied in the

  20. Graphite and its Hidden Superconductivity | Stanford Synchrotron Radiation

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

    Lightsource powders. Special emphasis will be given to the possible ways to differentiate between ferromagnetic- from superconducting-like signals when the magnetic moments of interest remain small in comparison with the large diamagnetic backgrounds. Recently done transport and persistent currents experiments at room temperature on graphite flakes embedded in alkanes and their reproducibility. All the experimental evidence as a whole suggests the existence of superconductivity at very high

  1. Graphite and its Hidden Superconductivity | Stanford Synchrotron Radiation

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

    Lightsource powders [7]. Special emphasis will be given to the possible ways to differentiate between ferromagnetic- from superconducting-like signals when the magnetic moments of interest remain small in comparison with the large diamagnetic backgrounds. Recently done transport and persistent currents experiments at room temperature on graphite flakes embedded in alkanes and their reproducibility. All the experimental evidence as a whole suggests the existence of superconductivity at very

  2. Frequency dispersion of nonlinear response of thin superconducting films in

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

    the Berezinskii-Kosterlitz-Thouless state (Journal Article) | DOE PAGES Frequency dispersion of nonlinear response of thin superconducting films in the Berezinskii-Kosterlitz-Thouless state Title: Frequency dispersion of nonlinear response of thin superconducting films in the Berezinskii-Kosterlitz-Thouless state The effects of microwave radiation on transport properties of atomically thin La2-xSrxCuO₄ films were studied in the 0.1-20 GHz frequency range. Resistance changes induced by

  3. Wire rope superconducting cable for diurnal load leveling SMES

    SciTech Connect (OSTI)

    Costello, G.A.

    1980-01-01

    The design of a wire rope cable for a superconducting magnetic energy storage (SMES) unit is discussed. The superconducting wires in the rope permit the passage of large currents in the relatively small conductors of the windings and hence cause large electromagnetic forces to act on the rope. The diameter of the rope, from a strength point of view, can be considerably reduced by supporting the rope at various points along its length.

  4. 2D barrier in a superconducting niobium square

    SciTech Connect (OSTI)

    Joya, Miryam R. Barba-ortega, J.; Sardella, Edson

    2014-11-05

    The presence of barriers changes the vortex structure in superconducting Nb square in presence of a uniform applied magnetic field. The Cooper pair configurations in a mesoscopics superconducting square of Nb with a barrier are calculated within the nonlinear Ginzburg Landau equations. We predict the nucleation of multi-vortex states into the sample and a soft entry of the magnetic field inside and around into the barrier. A novel and non-conventional vortex configurations occurs at determined magnetic field.

  5. 7-forming, superconducting filaments through bicomponent dry spinning

    DOE Patents [OSTI]

    Tuominen, Olli P. (Ogden, UT); Morgan, Carol W. (Asheville, NC); Burlone, Dominick A. (Asheville, NC); Blankenship, Keith V. (Asheville, NC)

    2001-01-01

    Fibers which contain potentially superconducting material are dry spun by the steps of preparing a suspension of potentially superconducting powder in a thickened solvent; preparing a solution of fiber-forming polymer; supplying the suspension and the solution to a spinning apparatus; in the spinning apparatus, arranging the solution and the suspension in a bicomponent arrangement; extruding the arranged solution and suspension from a spinneret as a bicomponent filament; and removing the solvent from the filament.

  6. Cooling of superconducting devices by liquid storage and refrigeration unit

    SciTech Connect (OSTI)

    Laskaris, Evangelos Trifon; Urbahn, John Arthur; Steinbach, Albert Eugene

    2013-08-20

    A system is disclosed for cooling superconducting devices. The system includes a cryogen cooling system configured to be coupled to the superconducting device and to supply cryogen to the device. The system also includes a cryogen storage system configured to supply cryogen to the device. The system further includes flow control valving configured to selectively isolate the cryogen cooling system from the device, thereby directing a flow of cryogen to the device from the cryogen storage system.

  7. DOE Science Showcase - Superconductivity | OSTI, US Dept of Energy, Office

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

    of Scientific and Technical Information Superconductivity "Harnessing the power of superconductivity, or the ability of certain materials to conduct electricity with zero energy loss, is one of the most exciting possibilities for creating a more energy-efficient future. But because most superconductors only work at very low temperatures-just a few degrees above absolute zero, or -273 degrees Celsius-they are not yet useful for everyday life. The discovery in the 1980s of

  8. Magnetism and Superconductivity Compete in Iron-based Superconductors |

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

    Stanford Synchrotron Radiation Lightsource Magnetism and Superconductivity Compete in Iron-based Superconductors Wednesday, April 30, 2014 HTSC Figure 1 Fig. 1. Measured electronic structure of underdoped Ba1-xKxFe2As2 in the orthorhombic spin-density-wave (SDW) ordered state. The antiferromagnetic and ferromagnetic directions are indicated by arrows. High-temperature superconductivity (HTSC), one of the long-standing unsolved mysteries of condensed matter physics, is a beautiful example of

  9. Project Fact Sheet Columbus HTS Power Cable Superconductivity

    Energy Savers [EERE]

    Columbus HTS Power Cable Superconductivity Partnerships with Industry www.oe.energy.gov Phone: 202 \ 586-1411 Office of Electricity Delivery and Energy Reliability, OE-1 U.S. Department of Energy - 1000 Independence Avenue, SW - Washington, DC 20585 Plugging America Into the Future of Power This project involves field-testing of a long-length high-temperature superconducting (HTS) cable under real environmental stresses and real electrical loads. The cable system forms an important electrical

  10. RF sputtering for controlling dihydride and monohydride bond densities in amorphous silicon hydride

    DOE Patents [OSTI]

    Jeffery, F.R.; Shanks, H.R.

    1980-08-26

    A process is described for controlling the dihydride and monohydride bond densities in hydrogenated amorphous silicone produced by reactive rf sputtering of an amorphous silicon target. There is provided a chamber with an amorphous silicon target and a substrate therein with the substrate and the target positioned such that when rf power is applied to the target the substrate is in contact with the sputtering plasma produced thereby. Hydrogen and argon are fed to the chamber and the pressure is reduced in the chamber to a value sufficient to maintain a sputtering plasma therein, and then rf power is applied to the silicon target to provide a power density in the range of from about 7 watts per square inch to about 22 watts per square inch to sputter an amorphous solicone hydride onto the substrate, the dihydride bond density decreasing with an increase in the rf power density. Substantially pure monohydride films may be produced.

  11. Characteristics of Hydrogen Negative Ion Source with FET based RF System

    SciTech Connect (OSTI)

    Ando, A.; Matsuno, T.; Funaoi, T.; Tanaka, N.; Tsumori, K.; Takeiri, Y.

    2011-09-26

    Characteristics of radio frequency (RF) plasma production were investigated using a FET inverter power supply as a RF generator. High density hydrogen plasma was obtained using an external coil wound a cylindrical ceramic tube (driver region) with RF frequency of lower than 0.5 MHz. When an axial magnetic field around 10 mT was applied to the driver region, an electron density increased drastically and attained to over 10{sup 19} m{sup -3} in the driver region. Effect of the axial magnetic field in driver and expansion region was examined. Lower gas pressure operation below 0.5 Pa was possible with higher RF frequency. H{sup -} density in the expansion region was measured by using laser photo-detachment system. It decreased as the axial magnetic field applied, which was caused by the increase of energetic electron from the driver.

  12. A Superconducting transformer system for high current cable testing

    SciTech Connect (OSTI)

    Godeke, A.; Dietderich, D. R.; Joseph, J. M.; Lizarazo, J.; Prestemon, S. O.; Miller, G.; Weijers, H. W.

    2010-02-15

    This article describes the development of a direct-current (dc) superconducting transformer system for the high current test of superconducting cables. The transformer consists of a core-free 10 464 turn primary solenoid which is enclosed by a 6.5 turn secondary. The transformer is designed to deliver a 50 kA dc secondary current at a dc primary current of about 50 A. The secondary current is measured inductively using two toroidal-wound Rogowski coils. The Rogowski coil signal is digitally integrated, resulting in a voltage signal that is proportional to the secondary current. This voltage signal is used to control the secondary current using a feedback loop which automatically compensates for resistive losses in the splices to the superconducting cable samples that are connected to the secondary. The system has been commissioned up to 28 kA secondary current. The reproducibility in the secondary current measurement is better than 0.05% for the relevant current range up to 25 kA. The drift in the secondary current, which results from drift in the digital integrator, is estimated to be below 0.5 A/min. The system's performance is further demonstrated through a voltage-current measurement on a superconducting cable sample at 11 T background magnetic field. The superconducting transformer system enables fast, high resolution, economic, and safe tests of the critical current of superconducting cable samples.

  13. Commissioning and Early Operation for the NSLS-II Booster RF System

    SciTech Connect (OSTI)

    Marques, C.; Cupolo, J.; Davila, P.; Gao, F.; Goel, A.; Holub, B.; Kulpin, J.; McDonald, K.; Oliva, J.; Papu, J.; Ramirez, G.; Rose, J.; Sikora, R.; Sorrentino, C.; Towne, N.

    2015-05-03

    The National Synchrotron Light Source II (NSLS-II) at Brookhaven National Laboratory (BNL) is a third generation 3GeV, 500mA synchrotron light source. We discuss the booster synchrotron RF system responsible for providing power to accelerate an electron beam from 200MeV to 3GeV. The RF system design and construction are complete and is currently in the operational phase of the NSLS-II project. Preliminary operational data is also discussed.

  14. Ku-band 6-bit RF MEMS time delay network. (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Conference: Ku-band 6-bit RF MEMS time delay network. Citation Details In-Document Search Title: Ku-band 6-bit RF MEMS time delay network. No abstract prepared. Authors: Nordquist, Christopher Daniel ; Sullivan, Charles Thomas ; Kraus, Garth Merlin ; Austin, Franklin, IV [1] ; Finnegan, Patrick Sean [1] ; Ballance, Mark H. [1] ; Dyck, Christopher William + Show Author Affiliations (LMATA Government Services, LLC, Albuquerque, NM) Publication Date: 2008-10-01 OSTI Identifier: 966236 Report

  15. Nanofabrication with the Scanning Tunneling Microscope

    SciTech Connect (OSTI)

    Shedd, G.M.; Russell, P.E.

    1988-12-01

    The Precision Engineering Center has recently begun a research program into applications of STM to Nanotechnology. Few tools permit humans to control events and processes at the manometer level, and of those, the STM is the most well-suited to the task. A versatile new ultra-high-vacuum (UHV) STM is being built to study the use of STM for the manipulation of nanometer-scale particles. Part of the STM`s usefulness will be due to its being positioned directly beneath the focused ion beam (FIB). The interface of the STM with the FIB will allow the STM to take advantage of the FIB for long-range imaging and as a particle source; the FIB can in turn use the STM for in situ, high-resolution imaging of micromachined features.

  16. Nanofabrication and Devices Capabilities | Argonne National Laboratory

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

    system (Emitech K675X) ThermalPECVD System for CNT and Graphene Synthesis Dry Etching RIE Oxford PlasmaLab 100, Chlorine Chamber RIE Oxford PlasmaLab 100, Fluorine Chamber...

  17. Center for Nanophase Materials Sciences (CNMS) - Nanofabrication...

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

    clean room space for carrying out material modification using advanced lithographic, etching, thin-film deposition, and characterization tools. Process Design Assistance with...

  18. Nano-fabricated plasmonic optical transformer

    DOE Patents [OSTI]

    Choo, Hyuck; Cabrini, Stefano; Schuck, P. James; Liang, Xiaogan; Yablonovitch, Eli

    2015-06-09

    The present invention provides a plasmonic optical transformer to produce a highly focuses optical beam spot, where the transformer includes a first metal layer, a dielectric layer formed on the first metal layer, and a second metal layer formed on the dielectric layer, where the first metal layer, the dielectric layer, and the second layer are patterned to a shape including a first section having a first cross section, a second section following the first section having a cross-section tapering from the first section to a smaller cross-section, and a third section following the second section having a cross-section matching the tapered smaller cross-section of the second section.

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

    DOE Patents [OSTI]

    Golner, Thomas M.; Mehta, Shirish P.

    2005-07-26

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

  20. Interplay between superconductivity and magnetism in iron-based superconductors

    SciTech Connect (OSTI)

    Chubukov, Andrey V

    2015-06-10

    This proposal is for theoretical work on strongly correlated electron systems, which are at the center of experimental and theoretical activities in condensed-matter physics. The interest to this field is driven fascinating variety of observed effects, universality of underlying theoretical ideas, and practical applications. I propose to do research on Iron-based superconductors (FeSCs), which currently attract high attention in the physics community. My goal is to understand superconductivity and magnetism in these materials at various dopings, the interplay between the two, and the physics in the phase in which magnetism and superconductivity co-exist. A related goal is to understand the origin of the observed pseudogap-like behavior in the normal state. My research explores the idea that superconductivity is of electronic origin and is caused by the exchange of spin-fluctuations, enhanced due to close proximity to antiferromagnetism. The multi-orbital/multi-band nature of FeSCs opens routes for qualitatively new superconducting states, particularly the ones which break time-reversal symmetry. By all accounts, the coupling in pnictdes is below the threshold for Mott physics and I intend to analyze these systems within the itinerant approach. My plan is to do research in two stages. I first plan to address several problems within weak-coupling approach. Among them: (i) what sets stripe magnetic order at small doping, (ii) is there a preemptive instability into a spin-nematic state, and how stripe order affects fermions; (iii) is there a co-existence between magnetism and superconductivity and what are the system properties in the co-existence state; (iv) how superconductivity emerges despite strong Coulomb repulsion and can the gap be s-wave but with nodes along electron FSs, (v) are there complex superconducting states, like s+id, which break time reversal symmetry. My second goal is to go beyond weak coupling and derive spin-mediated, dynamic interaction between fermions, understand what sets the upper scale for attractive interaction, compute T_c, and then obtain and solve matrix non-linear gap equation for spin-mediated pairing and study various feedbacks from the pairing on fermions on ARPES spectra, optical and thermal conductivity, and other observables, The problems I have chosen are quite generic, and the understanding of magnetically-mediated superconductivity in the strong-coupling regime will not only advance the theory of superconductivity in FeSCs, but will contribute to a generic understanding of the pairing of fermions near quantum-critical points -- the problems ranging from s-wave pairing by soft optical phonons to to color superconductivity of quarks mediated by a gluon exchange.